EP2679933A1

EP2679933A1 - Air conditioning and hot-water supplying system

Info

Publication number: EP2679933A1
Application number: EP11859253.4A
Authority: EP
Inventors: Masanao Kotani; Yoko Kokugan; Mari Uchida
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2011-02-22
Filing date: 2011-02-22
Publication date: 2014-01-01
Also published as: JPWO2012114450A1; CN103348200A; JP5492346B2; EP2679933A4; WO2012114450A1; CN103348200B

Abstract

An air-conditioning and hot-water supply system that enables enhancing the efficiency of the whole air-conditioning and hot-water supply system is provided.

A refrigerant circuit for air conditioning (10) is provided with a compressor for air conditioning (11), an operation switching means for air conditioning (12), a heat exchanger on the heat source side for air conditioning (13), decompression devices (14, 16), a heat exchanger on the heat utilization side for air conditioning (15) and an intermediate heat exchanger (21) that exchanges heat between a first refrigerant and a second refrigerant, a first branched part (22) that branches between the compressor for air conditioning (11) and the heat exchanger on the heat source side for air conditioning (13) and adjusts a flow rate of the first refrigerant which flows in each branched direction and a second branched part (32) that branches between the compressor for air conditioning (11) and the heat exchanger on the heat utilization side for air conditioning (15) and adjusts a flow rate of the first refrigerant which flows in each branched direction are formed, one end of the intermediate heat exchanger (21) is connected to the first branched part (22) and the second branched part (32), the other end is connected to a junction (24) between the heat exchanger on the heat source side for air conditioning (13) and the heat exchanger on the heat utilization side for air conditioning (15), and the intermediate heat exchanger functions as a condenser of the first refrigerant.

Description

Technical Field

The present invention relates to an air-conditioning and hot-water supply system that performs air conditioning and the supply of hot water.

Background Art

For an air-conditioning and hot-water supply system that performs air conditioning and hot-water supply, technique described in a patent literature 1 for example is disclosed.
The patent literature 1 discloses an air conditioner (an air-conditioning and hot-water supply system) having a characteristic that a main cycle is formed by connecting a first compressor, a first four-way valve, an outdoor heat exchanger, a first electromagnetic expansion valve and an indoor heat exchanger, a subcycle is formed by connecting a second compressor, a second four-way valve, a third four-way valve, a heat exchanger for hot-water supply, an auxiliary heat exchanger, a second electromagnetic expansion valve and a third electromagnetic expansion valve and a refrigerant circuit is configured by coupling the main cycle and the subcycle by a cascade capacitor so that heat exchange is possible.

Citation List

Patent Literature

Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2005-299935

Summary of Invention

Technical Problem

In the air conditioner (the air-conditioning and hot-water supply system) disclosed in the patent literature 1, exhaust heat of the main cycle can be utilized for the subcycle in cooling and hot-water supply operation by making the primary side (the side of the main cycle) of the cascade capacity function as a condenser and making the secondary side (the side of the subcycle) function as an evaporator (see Figs. 5 and 8 in the patent literature 1).
However, the air conditioner (the air-conditioning and hot-water supply system) disclosed in the patent literature 1 cannot make the primary side of the cascade capacity (the intermediate heat exchanger) function as the condenser in heating operation of the main cycle (the air-conditioning cycle).
Therefore, in the heating and hot-water supply operation, as shown in Fig. 9 in the patent literature 1, no refrigerant flows in the cascade capacity (the intermediate heat exchanger) and the main cycle (the air-conditioning cycle) and the subcycle (the hot-water supply cycle) are made to independently function.
Then, an object of the present invention is to provide an air-conditioning and hot-water supply system that enables enhancing the efficiency of the whole air-conditioning and hot-water supply system.

Solution to Problem

To settle the above-mentioned problem, the present invention according to Claim 1 is based upon an air-conditioning and hot-water supply system provided with a refrigerant circuit for air conditioning in which a first refrigerant is circulated and a refrigerant circuit for hot-water supply in which a second refrigerant is circulated, and has a characteristic that the refrigerant circuit for air conditioning is provided with a compressor for air conditioning that compresses the first refrigerant, an operation switching means for air conditioning that switches directions in which the first refrigerant flows between cooling operation and heating operation, a heat exchanger on the heat source side for air conditioning that functions as a condenser in cooling operation and functions as an evaporator in heating operation, a decompression device that decompresses the first refrigerant, a heat exchanger on the heat utilization side by air conditioning that functions as an evaporator in cooling operation and functions as s condenser in heating operation and an intermediate heat exchanger that exchanges heat between the first refrigerant and the second refrigerant, the refrigerant circuit for air conditioning is branched between the compressor for air conditioning and the heat exchanger on the heat source side for air conditioning, a first branched part that adjusts a flow rate of the first refrigerant flowing in a branching direction and a second branched part which is branched between the compressor for air conditioning and the heat exchanger on the heat utilization side for air conditioning and which adjusts the flow rate of the first refrigerant flowing in a branching direction are formed, one end of the intermediate heat exchanger is connected to the first branched part and the second branched part, the other end of the intermediate heat exchanger is connected to a confluence between the heat exchanger on the heat source side for air conditioning and the heat exchanger on the heat utilization side for air conditioning and the intermediate heat exchanger functions as a condenser in cooling operation and heating operation.

Advantageous Effects of Invention

According to the present invention, the air-conditioning and hot-water supply system that enables enhancing the efficiency of the whole air-conditioning and hot-water supply system can be provided.

Brief Description of Drawings

[Fig. 1] Fig. 1 is a system diagram showing an air-conditioning and hot-water supply system in this embodiment;
[Fig. 2] Fig. 2 is a flowchart showing a procedure of a process for determining an operation mode of the air-conditioning and hot-water supply system in this embodiment;
[Fig. 3] Fig. 3 is a flowchart showing the procedure of the process for determining the operation mode of the air-conditioning and hot-water supply system in this embodiment;
[Fig. 4] Fig. 4 is a flowchart showing a procedure of a process for estimating the quantity of exhaust heat by air conditioning and endothermic quantity in hot-water supply;
[Fig. 5] Fig. 5 is a flowchart showing a procedure of a process for estimating independent total power consumption and surplus heat operation power consumption;
[Fig. 6] Fig. 6 is a system diagram showing flows of a refrigerant and heated liquid in a heat pump unit in a hot-water supply operation mode;
[Fig. 7] Fig. 7 is a system diagram showing flows of the refrigerant and a heat transfer medium in the heat pump unit in a cooling operation mode;
[Fig. 8] Fig. 8 is a system diagram showing flows of the refrigerant and the heat transfer medium in the heat pump unit in a heating operation mode;
[Fig. 9] Fig. 9 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit in a cooling and hot-water supply operation (exhaust heat recovery A) mode;
[Fig. 10] Fig. 10 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit in a cooling and hot-water supply operation (exhaust heat recovery B) mode;
[Fig. 11] Fig. 11 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit in a cooling and hot-water supply operation (exhaust heat recovery C) mode;
[Fig. 12] Fig. 12 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit in a heating and hot-water supply operation (self-supporting) mode;
[Fig. 13] Fig. 13 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit in a heating and hot-water supply operation (air conditioning surplus heating) mode; and
[Fig. 14] Fig. 14 is a graph showing the variation of a heating load on days before and after the coldest day in Tokyo. Description of Embodiments

An embodiment of the present invention will be described in detail below, suitably referring to the drawings. In each drawing, the same reference numeral is allocated to a common part and the duplicate description is omitted.

<<Air-conditioning and hot-water supply system>>

Fig. 1 is a system diagram showing an air-conditioning and hot-water supply system S in this embodiment.
The air-conditioning and hot-water supply system S is provided with a heat pump unit 1 installed outdoor (outside air-conditioned space), an indoor unit 2 installed indoors (in air-conditioned space), a hot water tank unit 3 and a controller 4.
The air-conditioning and hot-water supply system S is provided with a function that performs "cooling operation" to cool air in a room where the indoor unit 2 is arranged, a function that performs "heating operation" to heat air in the room where the indoor unit 2 is arranged, a function that performs "operation for hot-water supply" to heat heated liquid and store the high-temperature heated liquid in the hot water tank unit 3 (a tank 62 described later), a function that performs "cooling and hot-water supply operation" in which the cooling operation and the operation for hot-water supply are performed and a function that performs "heating and hot-water supply operation" in which the heating operation and the operation for hot-water supply are performed.
The air-conditioning and hot-water supply system S is provided with a refrigerant circuit for air conditioning 10 in which a first refrigerant is circulated, a refrigerant circuit for hot-water supply 40 in which a second refrigerant is circulated, a heat transfer medium circulation circuit for air conditioning 50 in which a heat transfer medium is circulated and a hot-water supply circuit 60 in which heated liquid flows.

The refrigerant circuit for air conditioning 10 provided to the heat pump unit 1 is configured by annularly connecting a compressor for air conditioning 11 that compresses the first refrigerant to be a high-pressure refrigerant, a four-way valve for air conditioning 12 that switches a direction in which the first refrigerant flows between cooling operation and heating operation, a heat exchanger on the heat source side for air conditioning 13 that performs heat exchange with air (outside air) blown by a fan for air conditioning 13a, a main expansion valve for air conditioning 14 as a first decompression device for decompressing the first refrigerant and a heat exchanger tube for the secondary side 15b of a heat exchanger on the heat utilization side for air conditioning 15 that performs heat exchange with a heat transfer medium respectively via piping.
For the first refrigerant, HFC, HFO-1234yf, HFO-1234ze, a natural refrigerant (for example, a CO₂ refrigerant) and others can be used.
Besides, in the refrigerant circuit for air conditioning 10, an auxiliary expansion valve for air conditioning 16 as a second decompression device that decompresses the first refrigerant is connected on a circuit that connects the heat exchanger on the heat source side for air conditioning 13 and the main expansion valve for air conditioning 14.
Moreover, in the refrigerant circuit for air conditioning 10, a heat exchanger tube on the primary side 21a of an intermediate heat exchanger 21 that performs heat exchange with the second refrigerant is connected in parallel with the heat exchanger on the heat source side for air conditioning 13. One end of the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 is connected to a first air conditioning control three-way valve 22 connected on a circuit for connecting the four-way valve for air conditioning 12 and the heat exchanger on the heat source side for air conditioning 13. The other end of the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 is connected to the circuit that connects the auxiliary expansion valve for air conditioning 16 and the main expansion valve for air conditioning 14 via a first air conditioning control valve 23. In the following description, a part in which piping extended from the auxiliary expansion valve for air conditioning 16, piping extended from the main expansion valve for air conditioning 14 and piping extended from the other end of the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 are connected is also called a junction 24.
The first air conditioning control three-way valve 22 is a three-way valve configured so that the ratio in a flow rate of the flowing first refrigerant can be adjusted. The first air conditioning control valve 23 is a closing valve configured so that a closing motion can be controlled.
In addition, in the refrigerant circuit for air conditioning 10, a bypass circuit 31 in which the first refrigerant can flow is connected. One end of the bypass circuit 31 is connected to a second air conditioning control three-way valve 32 connected on a circuit that connects the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 and the four-way valve for air conditioning 12. The other end of the bypass circuit 31 is connected to a circuit that connects the first air conditioning control three-way valve 22 and the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 via a second air conditioning control valve 33.
The second air conditioning control three-way valve 32 is a three-way valve configured so that the ratio in a flow rate of the flowing first refrigerant can be adjusted. The second air conditioning control valve 33 is a closing valve configured so that a closing motion can be controlled.

The refrigerant circuit for hot-water supply 40 provided to the heat pump unit 1 is configured by annularly connecting a compressor for hot-water supply 41 that compresses the second refrigerant to be a high-pressure refrigerant, a heat exchanger tube on the primary side 42a of a heat exchanger on the heat utilization side for hot-water supply 42 that performs heat exchange with the heated liquid, a main expansion valve for hot-water supply 43 as a decompression device that decompresses the second refrigerant and a heat exchanger on the hot-water supply heat source side 44 that performs heat exchange with air blown by a fan for hot-water supply 44a (outside air) via piping.
For the second refrigerant, HFC, HFO-1234yf, HFO-1234ze, a natural refrigerant (for example, a CO₂ refrigerant) and others can be used.
Besides, in the refrigerant circuit for hot-water supply 40, a heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 that performs heat exchange with the first refrigerant is connected in parallel with the heat exchanger on the hot-water supply heat source side 44. One end of the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 is connected to a first hot-water supply control three-way valve 45 connected on a circuit that connects the main expansion valve for hot-water supply 43 and the heat exchanger on the hot-water supply heat source side 44. The other end of the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 is connected to a second hot-water supply control three-way valve 46 connected on a circuit that connects the heat exchanger on the hot-water supply heat source side 44 and the compressor for hot-water supply 41.
The first hot-water supply control three-way valve 45 and the second hot-water supply control three-way valve 46 are three-way valves configured so that the ratio in a flow rate of the flowing second refrigerant can be adjusted.

The heat transfer medium circulation circuit for air conditioning 50 provided across the heat pump unit 1 and the indoor unit 2 is configured by annularly connecting a first pump 51 that pumps out a heat transfer medium, a heat transfer medium four-way valve 52 that switches a direction in which a heat transfer medium flows between cooling operation and heating operation, a heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 that performs heat exchange with the first refrigerant and an indoor heat exchanger 53 that performs heat exchange with air (indoor air) blown by an indoor fan 53a via piping.
For the heat transfer medium, brine (non-freezing solution) of water, ethylene glycol and others can be used.

<Hot-water supply circuit>

The hot-water supply circuit 60 provided across the heat pump unit 1 and the hot water tank unit 3 is configured by annularly connecting a second pump 61 that pumps out the heated liquid, a heat exchanger tube on the secondary side 42b of the heat exchanger on the heat utilization side for hot-water supply 42 that performs heat exchange with the second refrigerant and a tank 62 which is arranged in the hot water tank unit 3 and which stores the heated liquid via piping.
In the following description, water shall be used for the heated liquid.
The hot water tank unit 3 is provided with a water supply fitting 63 connected to the bottom of the tank 62 and connected to an external water supply source (for example, a water supply) and a hot-water supply fitting 64 connected to an upper part of the tank 62 and connected to an external water supply terminal (not shown).
When a user operates the water supply terminal (not shown), the heated liquid (water) flows into a lower part of the tank 62 from the water supply source via the water supply fitting 63. The high-temperature heated liquid (hot water) stored in the upper part of the tank 62 is supplied to the water supply terminal (not shown) via the hot-water supply fitting 64.

Besides, the air-conditioning and hot-water supply system S is provided with the controller 4.
The controller 4 is provided with a function that determines an operation mode of the air-conditioning and hot-water supply system S, a function that controls a state (an angle) of each valve (the first air conditioning control valve 23, the second air conditioning control valve 33, the first air conditioning control three-way valve 22, the second air conditioning control three-way valve 32, the first hot-water supply control three-way valve 45, the second hot-water supply control three-way valve 46, the four-way valve for air conditioning 12, the heat transfer medium four-way valve 52, the main expansion valve for air conditioning 14, the auxiliary expansion valve for air conditioning 16 and the main expansion valve for hot-water supply 43), the rotational speed of the pump (the first pump 51 and the second pump 61), the rotational speed of the compressor (the compressor for air conditioning 11 and the compressor for hot-water supply 41) and the rotational speed of the fan for each heat exchanger (the fan for air conditioning 13a, the fan for hot-water supply 44a and the indoor fan 53a) according to the determined operation mode and a function that controls each operation of the air-conditioning and hot-water supply system S.

(Process for determining operation mode)

The operation mode executed by the controller 4 of the air-conditioning and hot-water supply system S will be described below. Figs. 2 and 3 are flowcharts showing a procedure of a process for determining the operation mode of the air-conditioning and hot-water supply system S in this embodiment.
First, referring to Fig. 2, the procedure will be described.
In a step S101, the controller 4 determines whether an air-conditioning cycle operation request is issued or not. In this case, the air-conditioning cycle operation request is an operation request that air in a room (air-conditioned space) in which the indoor unit 2 is installed should be air-conditioned (cooled/heated). The air-conditioning cycle operation request may be also input to the controller 4 by a user's operating a remote control (not shown) installed in the room for example and may be also determined based upon temperature (indoor temperature) detected by an indoor temperature detector (not shown) that detects the temperature of the room and indoor set temperature.
When the air-conditioning cycle operation request is issued (Yes in S101), the processing of the controller 4 proceeds to a step S105. When no air-conditioning cycle operation request is issued (No in S101), the processing of the controller 4 proceeds to a step S102.
In the step S102, the controller 4 determines whether a hot-water supply cycle operation request is issued or not. In this case, the hot-water supply cycle operation request is a request for executing the operation for hot-water supply of the air-conditioning and hot-water supply system S. The hot-water supply cycle operation request may be also input to the controller 4 by a user's operating the remote control (not shown) installed in the room for example, may be also issued when the quantity of the high-temperature heated liquid stored in the tank 62 in the hot water tank unit 3 is equal to or less than predetermined quantity, and may be also issued in a predetermined time zone.
When the hot-water supply cycle operation request is issued (Yes in S102), the processing of the controller 4 proceeds to a step S104. When no hot-water supply cycle operation request is issued (No in S102), the processing of the controller 4 proceeds to a step S103.
In the step S103, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as a standby mode. The standby mode means a mode in which the air-conditioning operation (cooling operation/heating operation) and the hot-water supply operation of the air-conditioning and hot-water supply system S are stopped and the input of an operation instruction is awaited.
In the step S104, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as a hot-water supply operation mode. The hot-water supply operation mode means a mode for executing the hot-water supply operation of the air-conditioning and hot-water supply system S. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 6.
In the step S105, the controller 4 determines whether the hot-water supply cycle operation request is issued or not. The hot-water supply cycle operation request in the step S105 is similar to the hot-water supply cycle operation request in the step S102 and the description is omitted.
When the hot-water supply cycle operation request is issued (Yes in S105), the processing of the controller 4 proceeds to a step S109. When no hot-water supply cycle operation request is issued (No in S105), the processing of the controller 4 proceeds to a step S106.
In the step S106, the controller 4 determines whether the hot-water supply cycle operation request is cooling operation or not.
When the hot-water supply cycle operation request is cooling operation (Yes in S106), the processing of the controller 4 proceeds to a step S107. When the hot-water supply cycle operation request is not cooling operation (No in S106), the processing of the controller 4 proceeds to a step S108.
In the step S107, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as a cooling operation mode. The cooling operation mode means a mode for executing the cooling operation of the air-conditioning and hot-water supply system S. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 7.
In the step S108, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as a heating operation mode. The heating operation mode means a mode for executing the heating operation of the air-conditioning and hot-water supply system S. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 8.
In the step S109, the controller 4 determines whether the hot-water supply cycle operation request is cooling operation or not.
When the hot-water supply cycle operation request is cooling operation (Yes in S109), the processing of the controller 4 proceeds to a step S110. When the hot-water supply cycle operation request is not cooling operation (No in S109), the processing of the controller 4 proceeds to a step S201 shown in Fig. 3.
In the step S110, the controller 4 estimates the quantity of exhaust heat by air conditioning Qac_ex and endothermic quantity in hot-water supply Qec_ex. In this case, the quantity of exhaust heat by air conditioning Qac_ex means the quantity of exhaust heat to a heat source required for cooling operation when the refrigerant circuit for air conditioning 10 and the refrigerant circuit for hot-water supply 40 are independently operated. Besides, the endothermic quantity in hot-water supply Qec_ex means endothermic quantity from a heat source required for hot-water supply operation when the refrigerant circuit for air conditioning 10 and the refrigerant circuit for hot-water supply 40 are independently operated.
A process for estimating the quantity of exhaust heat by air conditioning Qac_ex and endothermic quantity in hot-water supply Qec_ex will be described later using Fig. 4.
In a step S111, the controller 4 determines whether the quantity of exhaust heat by air conditioning Qac_ex is larger than endothermic quantity in hot-water supply Qec_ex or not.
When the quantity of exhaust heat by air conditioning Qac_ex is larger than the endothermic quantity in hot-water supply Qec_ex (Yes in S111), the processing of the controller 4 proceeds to a step S112. When the quantity of exhaust heat by air conditioning Qac_ex is not larger than the endothermic quantity in hot-water supply Qec_ex (No in S111), the processing of the controller 4 proceeds to a step S113.
In the step S112, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as a cooling and hot-water supply operation (exhaust heat recovery A) mode. The cooling and hot-water supply operation (exhaust heat recovery A) mode is one type of a mode for executing the cooling operation and the hot-water supply operation of the air-conditioning and hot-water supply system S, exhaust heat in the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40, and the refrigerant circuit for hot-water supply is operated. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 9.
In the step S113, the controller 4 determines whether the quantity of exhaust heat by air conditioning Qac_ex is equal to the endothermic quantity in hot-water supply Qec_ex or not.
When the quantity of exhaust heat by air conditioning Qac_ex is equal to the endothermic quantity in hot-water supply Qec_ex (Yes in S113), the processing of the controller 4 proceeds to a step S114. When the quantity of exhaust heat by air conditioning Qac_ex is not equal to the endothermic quantity in hot-water supply Qec_ex (No in S113), the processing of the controller 4 proceeds to a step S115.
In the step S114, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as a cooling and hot-water supply operation (exhaust heat recovery B) mode. The cooling and hot-water supply operation (exhaust heat recovery B) mode is one type of the mode for executing the cooling operation and the hot-water supply operation of the air-conditioning and hot-water supply system S, exhaust heat of the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40, and the refrigerant circuit for hot-water supply is operated. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 10.
In the step S115, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as a cooling and hot-water supply operation (exhaust heat recovery C) mode. The cooling and hot-water supply operation (exhaust heat recovery C) mode is one type of the mode for executing the cooling operation and the hot-water supply operation of the air-conditioning and hot-water supply system S, exhaust heat of the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40, and the refrigerant circuit for hot-water supply is operated. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 11.
Next, in the step S109, a case that the air-conditioning cycle operation request is not cooling operation (No in S109) will be described using Fig. 3. That is, a case that the hot-water supply cycle operation request is issued (Yes in S105) and the air-conditioning cycle operation request is heating operation will be described below.
In the step S201, the controller 4 estimates independent total power consumption Wsys1 and surplus heat operation power consumption Wsys2. In this case, the independent total power consumption Wsys1 means estimated power consumption when the air-conditioning and hot-water supply system S is operated in a heating and hot-water supply operation (self-supporting) mode (see Fig. 12 described later). Besides, the surplus heat operation power consumption Wsys2 means estimated power consumption when the air-conditioning and hot-water supply system S is operated in a heating and hot-water supply operation (air conditioning surplus heating) mode (see Fig. 13 described later).
A process for estimating the independent total power consumption Wsys1 and the surplus heat operation power consumption Wsys2 will be described later using Fig. 5.
In a step S202, the controller 4 determines whether the independent total power consumption Wsys1 is equal to ore less than the surplus heat operation power consumption Wsys2 or not.
When the independent total power consumption Wsys1 is equal to or less than the surplus heat operation power consumption Wsys2 (Yes in S202), the processing of the controller 4 proceeds to a step S203. When the independent total power consumption Wsys1 is not equal to or not less than the surplus heat operation power consumption Wsys2 (No in S202), the processing of the controller 4 proceeds to a step S204.
In the step S203, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as the heating and hot-water supply operation (self-supporting) mode. The heating and hot-water supply operation (self-supporting) mode means one type of the mode for executing the heating operation and the hot-water supply operation of the air-conditioning and hot-water supply system S, the refrigerant circuit for hot-water supply 40 and the refrigerant circuit for air conditioning 10 are independently operated, and the intermediate heat exchanger 21 is not used. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 12.
In the step S204, the controller 4 determines the operation mode of the air-conditioning and hot-water supply system S as the heating and hot-water supply operation (air conditioning surplus heating) mode. The heating and hot-water supply operation (air conditioning surplus heating) mode means a mode in which the heating operation of the air-conditioning and hot-water supply system S is executed, the surplus heat of the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40 and hot-water supply operation is performed. The operation of the air-conditioning and hot-water supply system S (the heat pump unit 1) in this operation mode will be described later using Fig. 13.
(Process for estimating quantity of exhaust heat by air conditioning Qac_ex and endothermic quantity in hot-water supply Qec_ex)
Fig. 4 is a flowchart showing a procedure of the process for estimating the quantity of exhaust heat by air conditioning Qac_ex and endothermic quantity in hot-water supply Qec_ex in the step S110 shown in Fig. 2.
In a step S301, the controller 4 estimates an air-conditioning load Qac. The air-conditioning load Qac is estimated based upon outdoor temperature Tao, indoor temperature Tai, indoor set temperature Tac_set and indoor gas volume Vac_set.
The outdoor temperature Tao is detected by a temperature sensor (not shown) provided to a fresh-air inlet of the fan for air conditioning 13a or the fan for hot-water supply 44a of the heat pump unit 1 for example. The indoor temperature Tai is detected by a temperature sensor (not shown) provided to an indoor air intake of the indoor fan 53a of the indoor unit 2 for example. The indoor gas volume Vac_set is calculated as gas volume (a flow rate of air) by detecting the rotational speed of the indoor fan 53a for example. Or the indoor gas volume is calculated based upon set gas volume set by a user using a remote control (not shown) installed indoors. The indoor set temperature Tac_set is input to the controller 4 by the user's operating the remote control (not shown) installed indoors for example.
In a step S302, the controller 4 estimates air conditioning power consumption Wac. The air conditioning power consumption Was is estimated based upon the air-conditioning load Qac, the outdoor temperature Tao and the indoor set temperature Tac_set respectively estimated in the step S301.
In a step S303, the controller 4 estimates the quantity of exhaust heat by air conditioning Qac_ex. The quantity of exhaust heat by air conditioning Qac_ex is estimated based upon the air-conditioning load Qac estimated in the step S301 and the air conditioning power consumption Wac estimated in the step S302.
In a step S304, the controller 4 estimates a load of hot-water supply Qec. The load of hot-water supply Qec is estimated based upon outdoor temperature Tao, feed water temperature Twi, feed hot-water temperature Two and a feed water flow rate Vw.
The feed water temperature Twi is detected by a temperature sensor (not shown) provided on the inlet side of the heat exchanger tube on the secondary side 42b of the heat exchanger on heat utilization side for hot-water supply 42 of the heat pump unit 1 for example. The feed hot-water temperature Two means set temperature of hot water (the heated liquid) boiled in the heat pump unit 1 and is input to the controller 4 by the user's operating the remote control (not shown) installed indoors for example. The feed water flow rate Vw is calculated by detecting the rotational speed of the second pump 61 of the heat pump unit 1 for example.
In a step S305, the controller 4 estimates power consumption for hot-water supply Wec. The power consumption for hot-water supply Wec is estimated based upon the load of hot-water supply Qec, the outdoor temperature Tao and the feed hot-water temperature Two respectively estimated in the step S304.
In a step S306, the controller 4 estimates the endothermic quantity in hot-water supply Qec_ex. The endothermic quantity in hot-water supply Qec_ex is estimated based upon the load of hot-water supply Qec estimated in the step S304 and the power consumption by hot-water supply Wec estimated in the step S305.
As described above, the controller 4 estimates the quantity of exhaust heat by air conditioning Qac_ex (refer to S303), estimates the endothermic quantity in hot-water supply Qec_ex (refer to S306), the processing of the controller 4 finishes the step S110 shown in Fig. 2, and proceeds to the step S111.
(Process for estimating independent total power consumption Wsys1 and surplus heat operation power consumption Wsys2)
Fig. 5 is a flowchart showing a procedure of the process for estimating the independent total power consumption Wsys1 and the surplus heat operation power consumption Wsys2 in the step S201 shown in Fig. 3.
In a step S401, the controller 4 estimates the air-conditioning load Qac. The air-conditioning load Qac is estimated based upon outdoor temperature Tao, indoor temperature Tai, indoor set temperature Tac_set and indoor gas volume Vac_set.
In a step S402, the controller 4 estimates target rotational speed of the compressor for air conditioning Ncp_ac. The target rotational speed of the compressor for air conditioning Ncp_ac is estimated based upon the air-conditioning load Qac, the outdoor temperature Tao, the indoor set temperature Tac_set and the indoor gas volume Vac_set respectively estimated in the step S401.
In a step S403, the controller 4 determines whether the target rotational speed of the compressor for air conditioning Ncp_ac estimated in the step S402 is equal to or higher than the minimum rotational speed of the compressor for air conditioning Ncp_acmin or not.
In this case, the minimum rotational speed of the compressor for air conditioning Ncp_acmin means a lower limit of rotational speed at which the operation of the compressor for air conditioning 11 of the refrigerant circuit for air conditioning 10 can be controlled.
When the target rotational speed of the compressor for air conditioning Ncp_ac is equal to or higher than the minimum rotational speed of the compressor for air conditioning Ncp_acmin (Yes in S403), the processing of the controller 4 proceeds to a step S404. When the target rotational speed of the compressor for air conditioning Ncp_ac is not equal to or not higher than the minimum rotational speed of the compressor for air conditioning Ncp_acmin (No in S403), the processing of the controller 4 proceeds to a step S409.
In the step S404, the controller 4 estimates the air conditioning power consumption Wac. The air conditioning power consumption Wac is estimated based upon the air-conditioning load Qac, the outdoor temperature Tao and the indoor set temperature Tac_set respectively estimated in the step S401.
In a step S405, the controller 4 estimates the load of hot-water supply Qec. The load of hot-water supply Qec is estimated based upon the outdoor temperature Tao, the feed water temperature Twi, the feed hot-water temperature Two and the feed water flow rate Vw.
In a step S406, the controller 4 estimates the power consumption for hot-water supply Wec. The power consumption for hot-water supply Wec is estimated based upon the load of hot-water supply Qec, the outdoor temperature Tao and the feed hot-water temperature Two respectively estimated in the step S405.
In a step S407, the controller 4 estimates the independent total power consumption Wsys1. The independent total power consumption Wsys1 is estimated by adding the air conditioning power consumption Wac estimated in the step S404 and the power consumption for hot-water supply Wec estimated in the step S406 (that is, Wsys1=Wac+Wec).
In a step S408, the controller 4 estimates the surplus heat operation power consumption Wsys2. In this embodiment, the surplus heat operation power consumption is estimated by calculating Wsys2 (=Wsys1).
As described above, the controller 4 estimates the independent total power consumption Wsys1 (refer to S407), estimates the surplus heat operation power consumption Wsys2 (refer to S408), the processing of the controller 4 finishes the S201 shown in Fig. 3, and proceeds to the step S202.
Next, in the step S403, a case that the rotational speed of the compressor for air conditioning Ncp_ac is not equal to or not higher than the minimum rotational speed of the compressor for air conditioning Ncp_acmin (No in S403) will be described.
As the compressor for air conditioning 11 cannot be operated at rotational speed below the minimum rotational speed of the compressor for air conditioning Ncp_acmin, the compressor is rotated at Ncp_acmin when the target rotational speed of the compressor for air conditioning Ncp_ac estimated based upon the air-conditioning load Qac is below the minimum rotational speed of the compressor for air conditioning Ncp_acmin. Therefore, as actually output air-conditioning power is larger than the air-conditioning load Qac by Ncp_acmin/Ncp_ac, the controller 4 instructs the controller 4 instructs the compressor for air conditioning 11 to repeat operation and a halt (intermittent operation). Therefore, the efficiency of the air-conditioning and hot-water supply system S is deteriorated.
In the step S409, the controller 4 estimates a rate of the deterioration of power consumption by air conditioning ε in the intermittent operation. Besides, the controller estimates air conditioning power consumption Wac1 acquired by considering intermittent operation. The rate of the deterioration of air conditioning power consumption ε is estimated based upon the target rotational speed of the compressor for air conditioning Ncp_ac and the minimum rotational speed of the compressor for air conditioning Ncp_acmin. Moreover, the air conditioning power consumption Wac1 acquired by considering the intermittent operation is estimated based upon the air-conditioning load Qac, the outdoor temperature Tao, the indoor set temperature Tac_set and the rate of the deterioration of air conditioning power consumption ε respectively estimated in the step S401.
In a step S410, the controller 4 estimates the load of hot-water supply Qec. The load of hot-water supply Qec is estimated based upon the outdoor temperature Tao, the feed water temperature Twi, the feed hot-water temperature Two and the feed water flow rate Vw.
In a step S411, the controller 4 estimates power consumption for hot-water supply Wec. The power consumption for hot-water supply Wec is estimated based upon the load of hot-water supply Qec, the outdoor temperature Tao and the feed hot-water temperature Two respectively estimated in the step S304.
In a step S412, the controller 4 estimates the independent total power consumption Wsys1. The independent total power consumption Wsys1 is estimated by adding the air conditioning power consumption Wac1 estimated in the step S409 and acquired by considering the intermittent operation and the power consumption for hot-water supply Wec estimated in the step S411 (that is, Wsys=Wac1+Wec).
In a step S413, the controller 4 estimates an air-conditioning pseudo load Qac_ec. The air-conditioning pseudo load Qac_ec is estimated based upon the outdoor temperature Tao, the feed water temperature Twi, the feed hot-water temperature Two and the feed water flow rate Vw.
In a case that the operation in the heating and hot-water supply operation (air conditioning surplus heating) mode of the air-conditioning and hot-water supply system S is controlled, the heat exchanger on the heat utilization side for air conditioning 15 in the refrigerant circuit for air conditioning 10 is made to function as a condenser and the intermediate heat exchanger 21 in the refrigerant circuit for air conditioning 10 is also made to function as a condenser.
Therefore, the air-conditioning pseudo load Qac_ec is estimated with endothermic quantity in hot-water supply in the intermediate heat exchanger 21 in the refrigerant circuit for hot-water supply 40 regarded as the air-conditioning pseudo load Qac_ec in the intermediate heat exchanger 21 in the refrigerant circuit for air conditioning 10.
In a step S414, the controller 4 estimates an air-conditioning pseudo load Qac2 acquired by considering the air-conditioning pseudo load Qac_ec. The air-conditioning load Qac2 acquired by considering the pseudo load is estimated by adding the air-conditioning load Qac estimated in the step S401 and the air-conditioning pseudo load Qac_ec estimated in the step S413 (that is, Qac2=Qac+Qac_ec).
In a step S415, the controller 4 estimates air conditioning power consumption Wac2 acquired by considering the pseudo load. The air conditioning power consumption Wac2 is estimated based upon the air-conditioning load Qac2 acquired by considering the pseudo load and estimated in the step S414, the outdoor temperature Tao and the indoor set temperature Tac_set.
In a step S416, the controller 4 estimates power consumption for hot-water supply Wec2 acquired by considering the pseudo load. The power consumption for hot-water supply Wec2 is estimated based upon the air-conditioning load Qac2 acquired by considering the pseudo load and estimated in the step S414, the load of hot-water supply Qec estimated in the step S410, the outdoor temperature Tao, the feed hot-water temperature Two and the indoor set temperature Tac_set.
In a step S417, the controller 4 estimates surplus heat operation power consumption Wsys2. The surplus heat operation power consumption Wsys2 is estimated by adding the air conditioning system power consumption Wac2 acquired by considering the pseudo load and estimated in the step S415 and the power consumption for hot-water supply system Wec2 acquired by considering the pseudo load and estimated in the step S416 (that is, Wsys2=Wac2+Wec2).
As described above, the controller 4 estimates the independent total power consumption Wsys1 (refer to S407, S412), estimates the surplus heat operation power consumption Wsys2 (refer to S408, S417), the processing of the controller 4 finishes the step S201 shown in Fig. 3, and proceeds to the step S202.

(Process for controlling each operation mode)

The controller 4 determines the operation mode of the air-conditioning and hot-water supply system S (see Figs. 2 and 3), controls the air-conditioning and hot-water supply system S according to the determined operation mode, and instructs the system to execute each operation. Each operation mode executed by the controller 4 of the air-conditioning and hot-water supply system S will be described using Figs. 6 to 13 below.
In Figs. 6 to 13 described below, piping in which the first refrigerant, the second refrigerant, the heat transfer medium and the heated liquid flow is shown by a thick line and a direction of the flow is shown by an arrow. Besides, the side on which the flow is closed of each control valve (the first air conditioning control valve 23, the second air conditioning control valve 33, the first air conditioning control three-way valve 22, the second air conditioning control three-way valve 32, the first hot-water supply control three-way valve 45, the second hot-water supply control three-way valve 46, the auxiliary expansion valve for air conditioning 16) is shown in black.

(Operation mode 0. Standby mode: step S103)

In this mode, the refrigerant circuit for air conditioning 10, the refrigerant circuit for hot-water supply 40, the heat transfer medium circulation circuit for air conditioning 50 and the hot-water supply circuit 60 are stopped. The controller 4 waits for the input of an operation instruction. When the operation instruction is input, the operation mode of the air-conditioning and hot-water supply system S is determined (see Figs. 2 and 3).

(Operation mode 1. Hot-water supply operation mode: step S104)

Fig. 6 is a system diagram showing flows of the refrigerant and the heated liquid in the heat pump unit 1 in the hot-water supply operation mode.
In this mode, the refrigerant circuit for air conditioning 10 and the heat transfer medium circulation circuit for air conditioning 50 are stopped. Besides, flows of the refrigerants into the intermediate heat exchanger 21 are stopped in both refrigerant circuit for air conditioning 10 and the refrigerant circuit for hot-water supply 40.
The refrigerant circuit for hot-water supply 40 will be described below. The controller 4 controls the first hot-water supply control three-way valve 45 so that the side connected to the intermediate heat exchanger 21 is closed so as to enable the second refrigerant to flow between the main expansion valve for hot-water supply 43 and the heat exchanger on the heat source side for hot-water supply 44. Besides, the controller 4 controls the second hot-water supply control three-way valve 46 so that the side connected to the intermediate heat exchanger 21 is closed so as to enable the second refrigerant to flow between the heat exchanger on the heat source side for hot-water supply 44 and the compressor for hot-water supply 41. Further, the controller 4 controls an aperture of the main expansion valve for hot-water supply 43. Furthermore, the controller 4 controls each rotational speed of the compressor for hot-water supply 41 and the fan for hot-water supply 44a.
The high-temperature high-pressure second refrigerant discharged from the compressor for hot-water supply 41 flows into the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 that functions as a condenser. The second refrigerant that flows in the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 radiates heat by exchanging heat with the heated liquid that flows in the heat exchanger tube on the secondary side 42b of the heat exchanger on the heat utilization side for hot-water supply 42 to be the medium-temperature high-pressure second refrigerant. The medium-temperature high-pressure second refrigerant that flows out of the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 is decompressed in the main expansion valve for hot-water supply 43 to be the low-temperature low-pressure second refrigerant.
The low-temperature low-pressure second refrigerant flows into the heat exchanger on the heat source side for hot-water supply 44 that functions as an evaporator. The second refrigerant that flows in the heat exchanger on the heat source side for hot-water supply 44 absorbs heat from air (outside air) by exchanging heat with the air (the outside air) blown from the fan for hot-water supply 44a. The second refrigerant that absorbs the heat is delivered from the heat exchanger on the heat source side for hot-water supply 44 to the compressor for hot-water supply 41 and is circulated in the refrigerant circuit for hot-water supply 40.
Next, the hot-water supply circuit 60 will be described. The controller 4 controls the rotational speed of the second pump 61.
The heated liquid that flows out from a lower part of the tank 62 by driving the second pump 61 flows into the heat exchanger tube on the secondary side 42b of the heat exchanger on the heat utilization side for hot-water supply 42. The heated liquid that flows in the heat exchanger tube on the secondary side 42b of the heat exchanger on the heat utilization side for hot-water supply 42 absorbs heat by exchanging heat with the second refrigerant that flows in the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 to be high-temperature heated liquid. The high-temperature heated liquid is returned to an upper part of the tank 62 from the heat exchanger tube on the secondary side 42b of the heat exchanger on the heat utilization side for hot-water supply 42 and is stored there.

(Operation mode 2. Cooling operation mode: step S107)

Fig. 7 is a system diagram showing flows of the refrigerant and the heat transfer medium in the heat pump unit 1 in the cooling operation mode.
In this mode, the refrigerant circuit for hot-water supply 40 and the hot-water supply circuit 60 are stopped. Besides, flows of the refrigerants into the intermediate heat exchanger 21 are closed in both the refrigerant circuit for air conditioning 10 and the refrigerant circuit for hot-water supply 40.
The refrigerant circuit for air conditioning 10 will be describedbelow. The controller 4 controls so that the four-way valve for air conditioning 12 is located in a position of cooling operation. Besides, the controller 4 controls the first air conditioning control three-way valve 22 so that the side connected to the intermediate heat exchanger 21 is closed so as to enable the first refrigerant to flow between the compressor for air conditioning 11 and the heat exchanger on the heat source side for air conditioning 13. Moreover, the controller 4 controls the second air conditioning control three-way valve 32 so that the side connected to the bypass circuit 31 is closed so as to enable the first refrigerant to flow between the heat exchanger on the heat utilization side for air conditioning 15 and the compressor for air conditioning 11. In addition, the controller 4 controls so that the first air conditioning control valve 23 and the second air conditioning control valve 33 are closed and an aperture of the auxiliary expansion valve for air conditioning 16 is fully opened. Further, the controller 4 controls the aperture of the main expansion valve for air conditioning 14. Furthermore, the controller 4 controls each rotational speed of the compressor for air conditioning 11 and the fan for air conditioning 13a.
The high-temperature high-pressure first refrigerant discharged from the compressor for air conditioning 11 flows into the heat exchanger on the heat source side for air conditioning 13 that functions as a condenser. The first refrigerant that flows in the heat exchanger on the heat source side for air conditioning 13 radiates heat (exhausts heat) by exchanging heat with air (outside air) blown by the fan for air conditioning 13a to be the medium-temperature high-pressure first refrigerant. The medium-temperature high-pressure first refrigerant that flows out of the heat exchanger on the heat source side for air conditioning 13 is decompressed by the main expansion valve for air conditioning 14 to be the low-temperature low-pressure first refrigerant.
The low-temperature low-pressure first refrigerant flows into the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 that functions as an evaporator. The first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 absorbs heat from the heat transfer medium by exchanging heat with the heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15. The first refrigerant that absorbs the heat is delivered from the heat exchanger on the heat utilization side for air conditioning 15 to the compressor for air conditioning 11 and is circulated in the refrigerant circuit for air conditioning 10.
Next, the heat transfer medium circulation circuit for air conditioning 50 will be described. The controller 4 controls each rotational speed of the first pump 51 and the indoor fan 53a. Besides, the controller 4 controls the heat transfer medium four-way valve 52 so that the heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 and the first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 are counter flows.
The heat transfer medium flows into the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 by driving the first pump 51. The heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 radiates heat by exchanging heat with the first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 to be the cool-temperature heat transfer medium.
The low-temperature heat transfer medium flows into the indoor heat exchanger 53 of the indoor unit 2. The heat transfer medium that flows in the indoor heat exchanger 53 absorbs heat by exchanging heat with air (indoor air) blown by the indoor fan 53a. The heat transfer medium that absorbs the heat is delivered from the indoor heat exchanger 53 to the first pump 51 and is circulated in the heat transfer medium circulation circuit for air conditioning 50.
As described above, air (indoor air) is cooled when the heat transfer medium absorbs the heat in the indoor heat exchanger 53 of the indoor unit 2 and the indoor air (air in the air-conditioned space) is cooled.

(Operation mode 3. Heating operation mode: step S108)

Fig. 8 is a system diagram showing flows of the refrigerant and the heat transfer medium in the heat pump unit 1 in the heating operation mode.
In this mode, the refrigerant circuit for hot-water supply 40 and the hot-water supply circuit 60 are stopped. Flows of the refrigerant into the intermediate heat exchanger 21 are closed in both the refrigerant circuit for air conditioning 10 and the refrigerant circuit for hot-water supply 40.
The refrigerant circuit for air conditioning 10 will be described below. The controller 4 controls so that the four-way valve for air conditioning 12 is located in a position of heating operation. Besides, the controller 4 controls the first air conditioning control three-way valve 22 so that the side connected to the intermediate heat exchanger 21 is closed so as to enable the first refrigerant to flow between the compressor for air conditioning 11 and the heat exchanger on the heat source side for air conditioning 13. Moreover, the controller 4 controls the second air conditioning control three-way valve 32 so that the side connected to the bypass circuit 31 is closed so as to enable the first refrigerant to flow between the heat exchanger on the heat utilization side for air conditioning 15 and the compressor for air conditioning 11. In addition, the controller 4 controls so that the first air conditioning control valve 23 and the second air conditioning control valve 33 are closed and controls so that the aperture of the main expansion valve for air conditioning 14 is fully opened. Further, the controller 4 controls the aperture of the auxiliary expansion valve for air conditioning 16. Furthermore, the controller 4 controls each rotational speed of the compressor for air conditioning 11 and the fan for air conditioning 13a.
The high-temperature high-pressure first refrigerant discharged from the compressor for air conditioning 11 flows into the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 that functions as a condenser. The first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 radiates heat by exchanging heat with the heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 to be the medium-temperature high-pressure first refrigerant. The medium-temperature high-pressure first refrigerant that flows out of the heat exchanger on the heat utilization side for air conditioning 15 is decompressed in the auxiliary expansion valve for air conditioning 16 to be the low-temperature low-pressure first refrigerant.
The low-temperature low-pressure first refrigerant flows into the heat exchanger on the heat source side for air conditioning 13 that functions as an evaporator. The first refrigerant that flows in the heat exchanger on the heat source side for air conditioning 13 absorbs heat from air (outside air) by exchanging heat with the air (the outside air) blown by the fan for air conditioning 13a. The first refrigerant that absorbs the heat is delivered from the heat exchanger on the heat source side for air conditioning 13 to the compressor for air conditioning 11 and is circulated in the refrigerant circuit for air conditioning 10.
Next, the heat transfer medium circulation circuit for air conditioning 50 will be described. The controller 4 controls each rotational speed of the first pump 51 and the indoor fan 53a. Besides, the controller 4 controls the heat transfer medium four-way valve 52 so that the heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 and the first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 are counter flows.
The heat transfer medium flows into the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 by driving the first pump 51. The heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 absorbs heat by exchanging heat with the first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 to be the high-temperature heat transfer medium.
The high-temperature heat transfer medium flows into the indoor heat exchanger 53 of the indoor unit 2. The heat transfer medium that flows in the indoor heat exchanger 53 radiates heat by exchanging heat with air (indoor air) blown by the indoor fan 53a. The heat transfer medium that radiates the heat is delivered from the indoor heat exchanger 53 to the first pump 51 and is circulated in the heat transfer medium circulation circuit for air conditioning 50.
As described above, when the heat transfer medium radiates heat in the indoor heat exchanger 53 of the indoor unit 2, air (indoor air) is heated and the room (the air-conditioned space) is heated.

(Operation mode 4-1. Cooling and hot-water supply operation (exhaust heat recovery A) mode: step S112)

Fig. 9 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit 1 in the cooling and hot-water supply operation (exhaust heat recovery A) mode.
In this case, the exhaust heat recovery A means a case that exhaust heat by air conditioning > absorbed heat in hot-water supply, exhaust heat of the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40 via the intermediate heat exchanger 21, and surplus exhaust heat by air conditioning is exhausted in outside air.
The operation of the hot-water supply circuit 60 is similar to that in the hot-water supply operation mode shown in Fig. 6 and the description is omitted.
The operation of the heat transfer medium circulation circuit for air conditioning 50 is similar to that in the cooling operation mode shown in Fig. 7 and the description is omitted.
The refrigerant circuit for air conditioning 10 will be described below. The refrigerant circuit for air conditioning 10 in the cooling operation mode (see Fig. 7) and the refrigerant circuit for air conditioning 10 in the cooling and hot-water supply operation (exhaust heat recovery A) mode (see Fig. 9) are different in that in the cooling operation mode (see Fig. 7), the first refrigerant flows in the heat exchanger on the heat source side for air conditioning 13 and in the meantime, in the cooling and hot-water supply operation (exhaust heat recovery A) mode (see Fig. 9), the first refrigerant flows in the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 and in the heat exchanger on the heat source side for air conditioning 13.
That is, the controller 4 controls to open the valve so that the first refrigerant can flow between the compressor for air conditioning 11 and the intermediate heat exchanger 21 and so that the first refrigerant can flow between the compressor for air conditioning 11 and the heat exchanger on the heat source side for air conditioning 13, and controls an aperture (the ratio of a flow rate of the flowing first refrigerant) from the compressor for air conditioning 11 to the intermediate heat exchanger 21 or to the heat exchanger on the heat source side for air conditioning 13. Besides, the controller 4 controls so that the first air conditioning control valve 23 is opened. The other control is similar to that in the refrigerant circuit for air conditioning 10 in the cooling operation mode (see Fig. 7) and the description is omitted.
The high-temperature high-pressure first refrigerant discharged from the compressor for air conditioning 11 is branched in the first air conditioning control three-way valve 22 and a part flows into the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 that functions as a condenser. The first refrigerant that flows in the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 radiates heat by exchanging heat with the second refrigerant that flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 to be the medium-temperature high-pressure first refrigerant. Besides, the residual high-temperature high-pressure first refrigerant branched in the first air conditioning control three-way valve 22 flows into the heat exchanger on the heat source side for air conditioning 13 that functions as a condenser. The first refrigerant that flows in the heat exchanger on the heat source side for air conditioning 13 radiates heat (exhausts heat) by exchanging heat with air (outside air) blown by the fan for air conditioning 13a to be the medium-temperature high-pressure first refrigerant. The medium-temperature high-pressure first refrigerant that flows out of the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 and the medium-temperature high-pressure first refrigerant that flows out of the heat exchanger on the heat source side for air conditioning 13 are decompressed in the main expansion valve for air conditioning 14 to be the low-temperature low-pressure first refrigerant.
The low-temperature low-pressure first refrigerant flows into the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 that functions as an evaporator. The first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 absorbs heat from the heat transfer medium by exchanging heat with the heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15. The first refrigerant that absorbs the heat is delivered from the heat exchanger on the heat utilization side for air conditioning 15 to the compressor for air conditioning 11 and is circulated in the refrigerant circuit for air conditioning 10.
Next, the refrigerant circuit for hot-water supply 40 will be described. The refrigerant circuit for hot-water supply 40 in the hot-water supply operation mode (see Fig. 6) and the refrigerant circuit for hot-water supply 40 in the cooling and hot-water supply operation (exhaust heat recovery A) mode (see Fig. 9) are different in that in the hot-water supply operation mode (see Fig. 6), the second refrigerant flows in the heat exchanger on the heat source side for hot-water supply 44 and in the meantime, in the cooling and hot-water supply operation (exhaust heat recovery A) mode (see Fig. 9), the second refrigerant flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21.
That is, the controller 4 controls the first hot-water supply control three-way valve 45 so that the side connected to the heat exchanger on the heat source side for hot-water supply 44 is closed so as to enable the second refrigerant to flow between the main expansion valve for hot-water supply 43 and the intermediate heat exchanger 21. Besides, the controller 4 controls the second hot-water supply control three-way valve 46 so that the side connected to the heat exchanger on the heat source side for hot-water supply 44 is closed so as to enable the second refrigerant to flow between the intermediate heat exchanger 21 and the compressor for hot-water supply 41. Moreover, the controller 4 instructs the fan for hot-water supply 44a to stop. The other control is similar to that in the refrigerant circuit for hot-water supply 40 in the hot-water supply operation mode (see Fig. 6) and the description is omitted.
The high-temperature high-pressure second refrigerant discharged from the compressor for hot-water supply 41 flows into the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 that function s as a condenser. The second refrigerant that flows in the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 radiates heat by exchanging heat with the heated liquid that flows in the heat exchanger tube on the secondary side 42b of the heat exchanger on the heat utilization side for hot-water supply 42 to be the medium-temperature high-pressure second refrigerant. The medium-temperature high-pressure second refrigerant discharged from the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 is decompressed in the main expansion valve for hot-water supply 43 to be the low-temperature low pressure second refrigerant.
The low-temperature low-pressure second refrigerant flows into the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 that functions as an evaporator. The second refrigerant that flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 absorbs heat from the first refrigerant by exchanging heat with the first refrigerant that flows in the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21. The second refrigerant that absorbs the heat is delivered from the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 to the compressor for hot-water supply 41 and is circulated in the refrigerant circuit for hot-water supply 40.

(Operation mode 4-2. Cooling and hot-water supply operation (exhaust heat recovery B) mode: step S114)

Fig. 10 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit 1 in the cooling and hot-water supply operation (exhaust heat recovery B) mode.
In this case, the exhaust heat recovery B means a case that exhaust heat by air conditioning = absorbed heat in hot-water supply and exhaust heat and exhaust heat of the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40 via the intermediate heat exchanger 21.
The operation of the hot-water supply circuit 60 is similar to that in the hot-water supply operation mode shown in Fig. 6 and the description is omitted.
The operation of the heat transfer medium circulation circuit for air conditioning 50 is similar to that in the cooling operation mode shown in Fig. 7 and the description is omitted.
The operation of the refrigerant circuit for hot-water supply 40 is similar to that in the cooling and hot-water supply operation (exhaust heat recovery A) mode shown in Fig. 9 and the description is omitted.
The refrigerant circuit for air conditioning 10 will be described below. The refrigerant circuit for air conditioning 10 in the cooling operation mode (see Fig. 7) and the refrigerant circuit for air conditioning 10 in the cooling and hot-water supply operation (exhaust heat recovery B) mode (see Fig. 10) are different in that in the cooling operation mode (see Fig. 7), the first refrigerant flows in the heat exchanger on the heat source side for air conditioning 13 and in the meantime, in the cooling and hot-water supply operation (exhaust heat recovery B) mode (see Fig. 10), the first refrigerant flows in the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21.
That is, the controller 4 controls the first air conditioning control three-way valve 22 so that the side connected to the heat exchanger on the heat source side for air conditioning 13 is closed so as to enable the first refrigerant to flow between the compressor for air conditioning 11 and the intermediate heat exchanger 21. Besides, the controller 4 controls so that the first air conditioning control valve 23 is opened and so that an aperture of the auxiliary expansion valve for air conditioning 16 is fully closed. Moreover, the controller 4 instructs the fan for air conditioning 13a to stop. The other control is similar to that of the refrigerant circuit for air conditioning 10 in the cooling operation mode (see Fig. 7) and the description is omitted.
The high-temperature high-pressure first refrigerant discharged from the compressor for air conditioning 11 flows into the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 that functions as a condenser. The first refrigerant that flows in the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 radiates heat by exchanging heat with the second refrigerant that flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 to be the medium-temperature high-pressure first refrigerant. The medium-temperature high-pressure first refrigerant discharged from the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 is decompressed in the main expansion valve for air conditioning 14 to be the low-temperature low-pressure first refrigerant.
The low-temperature low-pressure first refrigerant flows into the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 that functions as an evaporator. The first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 absorbs heat from the heat transfer medium by exchanging heat with the heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the sides utilized for air conditioning 15. The first refrigerant that absorbs the heat is delivered from the heat exchanger on the heat utilization side for air conditioning 15 to the compressor for air conditioning 11 and is circulated in the refrigerant circuit for air conditioning 10.

(Operation mode 4-3. Cooling and hot-water supply operation (exhaust heat recovery C) mode: step S115)

Fig. 11 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit 1 in the cooling and hot-water supply operation (exhaust heat recovery C) mode.
In this case, the exhaust heat recovery C means a case that exhaust heat by air conditioning < absorbed heat in hot-water supply, exhaust heat of the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40 via the intermediate heat exchanger 21, and the shortage of absorbed heat in hot-water supply is absorbed from outside air.
The operation of the hot-water supply circuit 60 is similar to that in the hot-water supply operation mode shown in Fig. 6 and the description is omitted.
The operation of the heat transfer medium circulation circuit for air conditioning 50 is similar to that in the cooling operation mode shown in Fig. 7 and the description is omitted.
The operation of the refrigerant circuit for air conditioning 10 is similar to that in the cooling and hot-water supply operation (exhaust heat recovery B) mode shown in Fig. 10 and the description is omitted.
Next, the refrigerant circuit for hot-water supply 40 will be described. The refrigerant circuit for hot-water supply 40 in the hot-water supply operation mode (see Fig. 6) and the refrigerant circuit for hot-water supply 40 in the cooling and hot-water supply operation (exhaust heat recovery C) mode (see Fig. 11) are different in that in the hot-water supply operation mode (see Fig. 6), the second refrigerant flows in the heat exchanger on the heat source side for hot-water supply 44 and in the meantime, in the cooling and hot-water supply operation (exhaust heat recovery C) mode (see Fig. 11), the second refrigerant flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 and in the heat exchanger on the heat source side for hot-water supply 44.
That is, the controller 4 controls to open the valve so that the second refrigerant can flow between the main expansion valve for hot-water supply 43 and the heat exchanger on the heat source side for hot-water supply 44 so as to enable the second refrigerant to flow between the main expansion valve for hot-water supply 43 and the intermediate heat exchanger 21 and controls an aperture (the ratio of a flow rate of the flowing second refrigerant) from the main expansion valve for hot-water supply 43 to the intermediate heat exchanger 21 or to the heat exchanger on the heat source side for hot-water supply 44. Besides, the controller 4 controls to open the valve so that the second refrigerant can flow between the heat exchanger on the heat source side for hot-water supply 44 and the compressor for hot-water supply 41 so as to enable the second refrigerant to flow between the intermediate heat exchanger 21 and the compressor for hot-water supply 41 and controls an aperture (a flow rate of the flowing second refrigerant) from the intermediate heat exchanger 21 or the heat exchanger on the heat source side for hot-water supply 44 to the compressor for hot-water supply 41. The other control is similar to that of the refrigerant circuit for hot-water supply 40 in the hot-water supply operation mode (see Fig. 6) and the description is omitted.
The high-temperature high-pressure second refrigerant discharged from the compressor for hot-water supply 41 flows into the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 that functions as a condenser. The second refrigerant that flows in the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 radiates heat by exchanging heat with the heated liquid that flows in the heat exchanger tube on the secondary side 42b of the heat exchanger on the heat utilization side for hot-water supply 42 to be the medium-temperature high-pressure second refrigerant. The medium-temperature high-pressure second refrigerant that flows out of the heat exchanger tube on the primary side 42a of the heat exchanger on the heat utilization side for hot-water supply 42 is decompressed in the main expansion valve for hot-water supply 43 to be the low-temperature low-pressure second refrigerant.
The low-temperature low-pressure second refrigerant is branched in the first hot-water supply control three-way valve 45 and a part flows into the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 that functions as an evaporator. The second refrigerant that flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 absorbs heat from the first refrigerant by exchanging heat with the first refrigerant that flows in the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21. Besides, the residual low-temperature low-pressure second refrigerant branched in the first hot-water supply control three-way valve 45 flows into the heat exchanger on the heat source side for hot-water supply 44 that functions as an evaporator. The second refrigerant that flows in the heat exchanger on the heat source side for hot-water supply 44 absorbs heat from air (outside air) by exchanging heat with the air (the outside air) blown by the fan for hot-water supply 44a. The second refrigerant that flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 and absorbs the heat and the second refrigerant that flows in the heat exchanger on the heat source side for hot-water supply 44 and absorbs the heat meet in the second hot-water supply control three-way valve 46, the joined second refrigerant is delivered to the compressor for hot-water supply 41, and is circulated in the refrigerant circuit for hot-water supply 40.

(Operation mode 5-1. Heating and hot-water supply operation (self-supporting) mode: step S203)

Fig. 12 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit 1 in the heating and hot-water supply operation (self-supporting) mode.
In this mode, flows into the intermediate heat exchanger 21 of the refrigerants are closed in both the refrigerant circuit for air conditioning 10 and the refrigerant circuit for hot-water supply 40.
Each operation of the refrigerant circuit for hot-water supply 40 and the hot-water supply circuit 60 is similar to each operation in the hot-water supply operation mode shown in Fig. 6 and the description is omitted.
Each operation of the refrigerant circuit for air conditioning 10 and the heat transfer medium circulation circuit for air conditioning 50 is similar to each operation in the heating operation mode shown in Fig. 8 and the description is omitted.

(Operation mode 5-2. Heating and hot-water supply operation (air conditioning surplus heating) mode: step S204)

Fig. 13 is a system diagram showing flows of the refrigerant, the heat transfer medium and the heated liquid in the heat pump unit 1 in the heating and hot-water supply operation (air conditioning surplus heating) mode.
This mode is executed when an air-conditioning load (a heating load) is small and surplus heat of the refrigerant circuit for air conditioning 10 is recovered in the refrigerant circuit for hot-water supply 40 via the intermediate heat exchanger 21.
The operation of the hot-water supply circuit 60 is similar to that in the hot-water supply operation mode shown in Fig. 6 and the description is omitted.
The operation of the heat transfer medium circulation circuit for air conditioning 50 is similar to that in the cooling operation mode shown in Fig. 7 and the description is omitted.
The operation of the refrigerant circuit for hot-water supply 40 is similar to that in the cooling and hot-water supply operation (exhaust heat recovery B) mode shown in Fig. 10 and the description is omitted.
The refrigerant circuit for air conditioning 10 will be described below. The refrigerant circuit for air conditioning 10 in the heating operation mode (see Fig. 8) and the refrigerant circuit for air conditioning 10 in the heating and hot-water supply operation (air conditioning surplus heating) mode (see Fig. 13) are different in that in the heating operation mode (see Fig. 8), the first refrigerant flows in the heat exchanger on the heat utilization side for air conditioning 15 and in the meantime, in the cooling and hot-water supply operation (exhaust heat recovery B) mode (see Fig. 10), the first refrigerant flows in the heat exchanger on the heat utilization side for air conditioning 15 and the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21.
That is, the controller 4 controls to open the valves so that the first refrigerant can flow between the compressor for air conditioning 11 and the intermediate heat exchanger 21 so as to enable the first refrigerant to flow between the compressor for air conditioning 11 and the heat exchanger on the heat utilization side for air conditioning 15, and controls apertures (the ratio of a flow rate of the flowing first refrigerant) from the compressor for air conditioning 11 to the heat exchanger on the heat utilization side for air conditioning 15 or the intermediate heat exchanger 21. Besides, the controller 4 controls so that the first air conditioning control valve 23 and the second air conditioning control valve 33 are opened. The other control is similar to that of the refrigerant circuit for air conditioning 10 in the heating operation mode (see Fig. 8) and the description is omitted.
The high-temperature high-pressure first refrigerant discharged from the compressor for air conditioning 11 is branched in the second air conditioning control three-way valve 32 and a part flows into the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 that functions as a condenser. The first refrigerant that flows in the heat exchanger tube on the secondary side 15b of the heat exchanger on the heat utilization side for air conditioning 15 radiates heat by exchanging heat with the heat transfer medium that flows in the heat exchanger tube on the primary side 15a of the heat exchanger on the heat utilization side for air conditioning 15 to be the medium-temperature high-pressure first refrigerant. Besides, the residual high-temperature high-pressure first refrigerant branched in the second air conditioning control three-way valve 32 flows in the bypass circuit 31 and flows into the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 that functions as a condenser. The first refrigerant that flows in the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 radiates heat by exchanging heat with the second refrigerant that flows in the heat exchanger tube on the secondary side 21b of the intermediate heat exchanger 21 to be the medium-temperature high-pressure first refrigerant. The medium-temperature high-pressure first refrigerant discharged from the heat exchanger on the heat utilization side for air conditioning 15 and the medium-temperature high-pressure first refrigerant discharged from the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 are decompressed in the auxiliary expansion valve for air conditioning 16 to be the low-temperature low-pressure first refrigerant.
The low-temperature low-pressure first refrigerant flows into the heat exchanger on the heat source side for air conditioning 13 that functions as an evaporator. The first refrigerant that flows in the heat exchanger on the heat source side for air conditioning 13 absorbs heat from air (outside air) by exchanging heat with the air (the outside air) blown by the fan for air conditioning 13a. The first refrigerant that absorbs the heat is delivered from the heat exchanger on the heat source side for air conditioning 13 to the compressor for air conditioning 11 and is circulated in the refrigerant circuit for air conditioning 10.

<<Action and effect of air-conditioning and hot-water supply system in this embodiment>>

According to the air-conditioning and hot-water supply system S in this embodiment that has been described, the air-conditioning and hot-water supply system S where "hot-water supply operation", "cooling operation", "cooling and hot-water supply operation", "heating operation" and "heating and hot-water supply operation" can be realized according to a request of a user can be acquired.
Besides, in the "cooling and hot-water supply operation", the cooling and hot-water supply operation (exhaust heat recovery A) mode (see Fig. 9) in which the exhaust heat of the refrigerant circuit for air conditioning 10 can be used for heating for hot-water supply, the cooling and hot-water supply operation (exhaust heat recovery B) mode (see Fig. 10) and the cooling and hot-water supply operation (exhaust heat recovery C) mode (see Fig. 11) can be executed.
Hereby, the efficiency of the whole air-conditioning and hot-water supply system S can be enhanced.
Next, the air-conditioning and hot-water supply system S in this embodiment will be compared with the air conditioner (the air-conditioning and hot-water supply system) disclosed in the patent literature 1.
In the air conditioner (the air-conditioning and hot-water supply system) disclosed in the patent literature 1, as the first compressor (equivalent to the compressor for air conditioning 11 of the air-conditioning and hot-water supply system S in this embodiment) in an air-conditioning cycle (of the refrigerant circuit for air conditioning 10) is intermittently operated (intermittent operation in which a working condition and a stopped condition are repeated) when a heating load is low in heating operation (heating and hot-water supply operation), the operational efficiency of the air conditioner (the air-conditioning and hot-water supply system) is deteriorated.
in the meantime, as the air-conditioning and hot-water supply system S in this embodiment is provided with the bypass circuit 31 in the refrigerant circuit for air conditioning 10, the heat exchanger tube on the primary side 21a (on the side of the refrigerant circuit for air conditioning 10) of the intermediate heat exchanger 21 can be also made to function as a condenser in heating and hot-water supply operation (see Fig. 13).
Hereby, the air-conditioning and hot-water supply system S in this embodiment supplies desired quantity of heat (a part of the high-temperature high-pressure first refrigerant discharged from the compressor for air conditioning 11) to the heat exchanger on the heat utilization side for air conditioning 15 with the compressor for air conditioning 11 continuously operated even if a heating load is low in heating and hot-water supply operation, surplus quantity of heat (the rest of the high-temperature high-pressure first refrigerant discharged from the compressor for air conditioning 11) is delivered to the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 via the bypass circuit 31, and the surplus quantity of heat is used for heating for hot-water supply via the refrigerant circuit for hot-water supply 40.
Hereby, as the intermittent operation of the compressor for air conditioning 11 is prevented and the surplus heat can be also reserved as high-temperature heated liquid, operational efficiency as the whole air-conditioning and hot-water supply system S can be enhanced.
That is, as in the air-conditioning and hot-water supply system S in this embodiment, heat (exhaust heat, surplus heat) can be delivered from the refrigerant circuit for air conditioning 10 into the refrigerant circuit for hot-water supply 40 in both cooling operation and heating operation, the air-conditioning and hot-water supply system that enables enhancing operational efficiency throughout a year can be configured.
The effects of the air-conditioning and hot-water supply system S in this embodiment will be further described below. Fig. 14 is a graph showing the variation of a heating load before and after the coldest day in Tokyo.
Fig. 14 shows a heating load [kW](shown by a full line in the graph shown in Fig. 14), outside air temperature [°C] (shown by a broken line in the graph shown in Fig. 14) and an amount of solar radiation [MJ](shown by an alternate long and short dash line in the graph shown in Fig. 14) on an axis of ordinates, shows time [day] on an axis of abscissas, and shows since a day (time 0.0 to 1.0 [day]) before the coldest day (time 1.0 to 2.0 [day]) till the next day (2.0 to 3.0 [day]). The heating load is acquired based upon highly thermally insulated housing where a quality (Q) factor (a heat loss coefficient) showing adiabatic performance is 1.6 [W/m²·K].
Housing (air-conditioned space) is highly thermally insulated corresponding to a recent request for energy saving and the reduction of a heating load in winter is tried. It is considered that as a heating load is small in highly thermally insulated housing, energy saving effect is acquired in indoor air conditioning.
However, as the heating load is reduced, the compressor for air conditioning 11 in the refrigerant circuit for air conditioning 10 may be intermittently operated. As shown in Fig. 14, even on the coldest day, the heating load rapidly decreases in the day time (in Fig. 14, the heating load decreases from approximately 4.0 kW to approximately 0.6 kW). In this case, when the heating load is equal to or below a predetermined value (for example, 1.0 kW), the compressor for air conditioning 11 in the refrigerant circuit for air conditioning 10 is intermittently operated. Such intermittent operation is undesirable in terms of operational efficiency.
As described above, as the compressor for air conditioning 11 is intermittently operated, energy saving effect acquired when the air-conditioning system (the air-conditioning and hot-water supply system) is actually operated is smaller, compared with expected energy saving effect by highly insulating the housing from heat and reducing the heating load.
In the meantime, the air-conditioning and hot-water supply system S in this embodiment can prevent the intermittent operation of the compressor for air conditioning 11 in the refrigerant circuit for air conditioning 10 even if a heating load is low in heating operation. Besides, in the air-conditioning and hot-water supply system S in this embodiment, as the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21 can be also made to function as a condenser in heating operation, the surplus heat of the refrigerant circuit for air conditioning 10 can be used for hot-water supply and the efficiency of the whole air-conditioning and hot-water supply system S can be enhanced.

<<Modification>>

The air-conditioning and hot-water supply system S in this embodiment is not limited to the above-mentioned configuration in the embodiment and various modifications are allowed within the object of the present invention.
For example, in the above-mentioned embodiment, it has been described that air in the room is heated (cooled) by heating (or cooling) the heat transfer medium in the heat exchanger on the heat utilization side for air conditioning 15 in the heat pump unit 1, supplying the heated (or cooled) heat transfer medium to the indoor unit 2 and exchanging heat between the heat transfer medium heated (or cooled) in the indoor heat exchanger 53 of the indoor unit 2 and indoor air, however, the present invention is not limited to this, and the present invention may be also provided with configuration that heating (cooling) is made by omitting the heat transfer medium circulation circuit for air conditioning 50, installing the heat exchanger on the heat utilization side for air conditioning 15 in the indoor unit 2 and exchanging heat between the first refrigerant that flows in the heat exchanger on the heat utilization side for air conditioning 15 and the indoor air.
Besides, in the above-mentioned embodiment, it has been described that the heated liquid is water, the high-temperature heated liquid (hot water) is stored in the tank 62 and the high-temperature heated liquid (hot water) stored in the tank 62 is supplied to a hot-water supply terminal (not shown), however, the present invention is not limited to this, and the present invention may be also provided with configuration that a heat exchanger (not shown) that can exchange heat between the high-temperature heated liquid stored in the tank 62 and feed water to be supplied to the hot-water supply terminal (not shown) is further provided, the feed water is heated with the high-temperature heated liquid stored in the tank 62 and the heated feed water is supplied to the hot-water supply terminal (not shown). As described above, the heated liquid is not limited to water.
Moreover, it has been described that the first air conditioning control three-way valve 22 is a tree-way valve that branches the first refrigerant that flows in from the compressor for air conditioning 11 (the four-way valve for air conditioning 12) and can control the ratio of the flow rate of the first refrigerant that flows into the heat exchanger on the heat source side for air conditioning 13 and the flow rate of the first refrigerant that flows into the heat exchanger tube on the primary side 21a of the intermediate heat exchanger 21, however, the present invention is not limited to this and may be also provided with configuration that two flow control valves are provided so as to control the ratio of flow rates.
Similarly, the second air conditioning control three-way valve 32, the first hot-water supply control three-way valve 45 and the second hot-water supply control three-way valve 46 may also have configuration that two flow control valves are provided.
In addition, the first air conditioning control valve 23 is not necessarily required to be provided. However, as the intermediate heat exchanger 21 can be detached from the circulation circuit of the first refrigerant by closing the first air conditioning control valve 23 when the intermediate heat exchanger 21 is not used, it is desirable that the first air conditioning control valve 23 is provided.
Further, the second air conditioning control valve 33 is not necessarily required to be provided. However, as the bypass circuit 31 can be detached from the circulation circuit of the first refrigerant by closing the second air conditioning control valve 33 when the bypass circuit 31 is not used, it is desirable that the second air conditioning control valve 33 is provided.

List of Reference Signs

S: Air-conditioning and hot-water supply system
1: Heat pump unit
2: Indoor unit
3: Hot water tank unit
4: Controller
10: Refrigerant circuit for air conditioning
11: Compressor for air conditioning
12: Four-way valve for air conditioning (Operation switching means for air conditioning)
13: Heat exchanger on heat source side for air conditioning
13a: Fan for air conditioning
14: Main expansion valve for air conditioning (Decompression device, First decompression device)
15: Heat exchanger on heat utilization side for air conditioning
15a: Heat exchanger tube on primary side of heat exchanger on heat utilization side for air conditioning
15b: Heat exchanger tube on secondary side of heat exchanger on heat utilization side for air conditioning
16: Auxiliary expansion valve for air conditioning (Decompression device, Second decompression device)
21: Intermediate heat exchanger
21a: Heat exchanger tube on primary side of intermediate heat exchanger
21b: Heat exchanger tube on secondary side of intermediate heat exchanger
22: First air conditioning control three-way valve (First branched part)
23: First air conditioning control valve
24: Junction
31: Bypass circuit
32: Second air conditioning control three-way valve (Second branched part)
33: Second air conditioning control valve
40: Refrigerant circuit for hot-water supply
41: Compressor for hot-water supply
42: Heat exchanger on heat utilization side for hot-water supply
42a: Heat exchanger tube on primary side of heat exchanger on heat utilization side for hot-water supply
42b: Heat exchanger tube on secondary side of heat exchanger on heat utilization side for hot-water supply
43: Main expansion valve for hot-water supply (Third decompression device)
44: Heat exchanger on heat source side for hot-water supply
44a: Fan for hot-water supply
45: First hot-water supply control three-way valve
46: Second hot-water supply control three-way valve
50: Heat transfer medium circulation circuit for air conditioning
51: First pump
52: Heat transfer medium four-way valve
53: Indoor heat exchanger
53a: Indoor fan
60: Hot-water supply circuit
61: Second pump
62: Tank
63: Water supply fitting
64: Hot-water supply fitting

Claims

An air-conditioning and hot-water supply system provided with a refrigerant circuit for air conditioning in which a first refrigerant is circulated and a refrigerant circuit for hot-water supply in which a second refrigerant is circulated, wherein:
the refrigerant circuit for air conditioning comprises:
a compressor for air conditioning that compresses the first refrigerant;

an operation switching means for air conditioning that switches directions in which the first refrigerant flows between cooling operation and heating operation;

a heat exchanger on the heat source side for air conditioning that functions as a condenser in the cooling operation and functions as an evaporator in the heating operation;

a decompression device that decompresses the first refrigerant;

a heat exchanger on the heat utilization side for air conditioning that functions as an evaporator in the cooling operation and functions as a condenser in the heating operation; and

an intermediate heat exchanger that exchanges heat between the first refrigerant and the second refrigerant;

a first branched part that branches between the compressor for air conditioning and the heat exchanger on the heat source side for air conditioning and that adjusts a flow rate of the first refrigerant which flows in a branched direction and a second branched part that branches between the compressor for air conditioning and the heat exchanger on the heat utilization side for air conditioning and that adjusts a flow rate of the first refrigerant which flows in a branched direction are formed; and

the intermediate heat exchanger one end of which is connected to the first branched part and the second branched part and the other end of which is connected to a junction between the heat exchanger on the heat source side for air conditioning and the heat exchanger on the heat utilization side for air conditioning functions as a condenser of the first refrigerant.
The air-conditioning and hot-water supply system according to Claim 1, wherein:
the decompression device comprises:
a first decompression device arranged on the side of the heat exchanger on the heat utilization side for air conditioning with the junction as a starting point; and

a second decompression device arranged on the side of the heat exchanger on the heat source side for air conditioning with the junction as the starting point.
The air-conditioning and hot-water supply system according to Claim 2, wherein:
the decompression device decompresses the first refrigerant in the first decompression device in the cooling operation; and

the decompression device decompresses the first refrigerant in the second decompression device in the heating operation.
The air-conditioning and hot-water supply system according to Claim 1, wherein:
the refrigerant circuit for hot-water supply comprises:
a compressor for hot-water supply that compresses the second refrigerant;

a heat exchanger on the heat utilization side for hot-water supply that functions as a condenser in hot-water supply operation;

a third decompression device that decompresses the second refrigerant; and

the intermediate heat exchanger that functions as a condenser of the first refrigerant and functions as an evaporator of the second refrigerant.