EP4224093A1

EP4224093A1 - Refrigeration device

Info

Publication number: EP4224093A1
Application number: EP22155366.2A
Authority: EP
Inventors: Hideo Chikami
Original assignee: Daikin Europe NV
Current assignee: Daikin Europe NV
Priority date: 2022-02-07
Filing date: 2022-02-07
Publication date: 2023-08-09
Also published as: WO2023148396A1

Abstract

A refrigeration device comprises a compressor (1), a plurality of utilization side heat exchangers, an expansion mechanism (4) and a heat source side heat exchanger (5), which are fluidly connected in series to constitute a refrigeration circuit. The refrigeration device further comprises a first refrigerant pipe (6), which extends from the compressor (1) to a first utilization side heat exchanger (2) of the plurality of utilization side heat exchangers. The first refrigerant pipe (6) comprises a first valve (7) configured to at least fully open and fully close the first refrigerant pipe (6). The refrigeration device also comprises a second refrigerant pipe (8), which extends from the compressor (1) to a second utilization side heat exchanger (3.1, 3.2, 3.3) of the plurality of utilization side heat exchangers. The second refrigerant pipe (8) comprises a second valve (9) configured to at least fully open and fully close the second refrigerant pipe (8). The refrigeration device also comprises a controller, which is configured to fully close the first valve (7) when the operation of the first utilization side heat exchanger (2) is stopped and/or which is configured to fully close the second valve (9) when the operation of the second utilization side heat exchanger (3.1, 3.2, 3.3) is stopped. In addition, the refrigeration device comprises a first bypass pipe (10) extending from a downstream side (6.2) of the first valve (7) when the refrigeration device is used in a heating mode to a suction side of the compressor (1) and a second bypass pipe (11) extending from a downstream side (8.2) of the second valve (9) when the refrigeration device is used in a heating mode to a suction side of the compressor (1). The first and second bypass pipes (10, 11) each comprise pressure-reducing means (12) that are configured to reduce the pressure of a refrigerant in the first and second bypass pipes (10, 11) .

Description

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates to a refrigeration device, preferably a heat pump type air conditioning and hot water supplying device, that is capable of simultaneously providing an air conditioning load and a hot water load.

Background of the Present Invention

In general, refrigeration devices that comprise a compressor, a plurality of utilization side heat exchangers, an expansion mechanism and a heat source side heat exchanger, which are fluidly connected in series to constitute a refrigeration circuit, are known in the prior art. Such refrigeration circuits enable to provide cooling or heating depending on the direction in which a refrigerant is flown through such a refrigerant circuit.
Nowadays, refrigeration devices have been developed that are configured to provide air conditioning and hot water at the same time. That is, such refrigeration devices comprise a plurality of utilization side heat exchangers, wherein at least one of said utilization side heat exchangers is configured to generate, for example, hot water when the refrigerant circuit is used in a heating mode. In addition, at least one further utilization side heat exchanger of the plurality of utilization side heat exchangers is configured to provide air conditioning. Such air conditioning can be heating when the refrigerant circuit is used in a heating mode or cooling when the refrigerant circuit is used in a cooling mode.
Such refrigeration devices that are capable of providing domestic hot water and/or domestic heating, when the refrigerant circuit is used in a heating mode, are also known as heat pump type air conditioning and hot water supplying devices and are oftentimes abbreviated as DHW-DX combined systems.
In other words, such combined systems can be understood as combined air conditioning and hot water supply systems that are capable of simultaneously providing an air conditioning load and a hot water load.
An example for such a previously known refrigeration device is derivable from EP 2 653 805 A1 . Therein, a known DHW-DX combined system is described, which is capable of providing domestic hot water and air conditioning with warm air at the same time, but also enables to use the refrigerant in the refrigerant circuit, for example, only for air conditioning or for producing hot water when the refrigeration device of EP 2 653 805 A1 is used in a heating mode.
Nonetheless, in such DHW-DX combined systems also a plurality of utilization side heat exchangers, for example, in the form of a plurality of air conditioning indoor units in several rooms to be airconditioned, can be provided. In such a configuration, situations may arise, wherein not all of the air conditioning indoor units are operated.
If this is the case, branches of the refrigerant circuit that are not in operation constrain unused refrigerant in it and it may occur that a large amount of refrigerant is "stuck" in non-operated branches of the refrigerant circuit. In other words, when, for example, several air conditioning indoor units are not used and the branches are correspondingly closed, such that no refrigerant is flowing therethrough, a large amount of refrigerant is unavailable and bound in the non-operated branches of the refrigerant circuit.
This is particularly disadvantageous because situations, in which the remaining system is operated under full load, i.e. under full capacity and performance, may occur. Consequently, the rest of the system that is operated will not have enough refrigerant. The refrigerant "stuck" in the non-operated branches of the refrigerant circuit may provoke that the rest of the operated system will not have enough refrigerant for an operation under full load. This leads to an efficiency drop, as the remaining utilization side heat exchangers are expected to have less refrigerant for the operation and an undesired operational behavior for a user of such a refrigeration device may occur.
Further issues may occur when refrigerant is stuck in a branch that is not connected to an air conditioning indoor unit, but is stuck in a branch of the refrigerant circuit that is connected to a utilization side heat exchanger configured to produce domestic hot water.
If such a branch of the refrigerant circuit directed to producing domestic hot water is closed and the refrigerant is stuck therein, the constrained and pressurized refrigerant may be heated up by an electrical heater that is usually additionally provided in such a hot water supply unit.
The heated constrained and pressurized refrigerant will cause unnecessary stress on the piping and may cause damage of said piping from time to time.

SUMMARY OF THE INVENTION

In view of the above, it is an object of the present invention to provide a refrigeration device with a simple configuration that can prevent refrigerant from being stuck in non-operated branches of a refrigerant circuit.
This object is solved by means of an apparatus according to claim 1. Distinct embodiments are derivable from the dependent claims.
According to a first aspect, a refrigeration device comprises a compressor, a plurality of utilization side heat exchangers, an expansion mechanism and a heat source side heat exchanger fluidly connected in series to constitute a refrigerant circuit.
Further, the refrigeration device comprises a first refrigerant pipe, which extends from the compressor to a first utilization side heat exchanger of the plurality of utilization side heat exchangers, and which comprises a first valve configured to at least fully open and fully close the first refrigerant pipe.
The refrigeration device furthermore comprises a second refrigerant pipe, which extends from the compressor to a second utilization side heat exchanger of the plurality of utilization side heat exchangers, and which comprises a second valve configured to at least fully open and fully close the second refrigeration pipe.
Additionally, the refrigeration device comprises a controller, which is configured to fully close the first valve when the operation of the first utilization side heat exchanger is stopped and/or which is configured to fully close the second valve when the operation of the second utilization side heat exchanger is stopped.
The refrigeration device also comprises a first bypass pipe extending from a downstream side of the first valve when the refrigeration device is used in a heating mode to a suction side of the compressor and a second bypass pipe extending from a downstream side of the second valve when the refrigeration device is used in a heating mode to a suction side of the compressor.
Here, the first bypass pipe and the second bypass pipe each, i.e. respectively, comprise pressure-reducing means configured to reduce the pressure of a refrigerant in the first bypass pipe and the second bypass pipe.
In this context, the first refrigerant pipe and the second refrigerant pipe as well as the first bypass pipe and the second bypass pipe are also to be understood as pipings that form part of the refrigerant circuit.
Additionally, the "first valve" and the "second valve" are to be understood as valves that are able to block and open the first refrigerant pipe and the second refrigerant pipe.
That is, when the first valve and/or the second valve are/is closed, the first refrigerant pipe and/or the second refrigerant pipe are blocked and no refrigerant can flow through said pipes.
Here, the provision of the first bypass pipe and the second bypass pipe each comprising pressure-reducing means enables that a connection between a low pressure side and a high pressure side after the first and second valve can be established through the pressure-reducing means.
Accordingly, it is possible to achieve a suction effect through said first bypass pipe or said second bypass pipe by the operation of the compressor when the corresponding first refrigerant pipe or second refrigerant pipe are shut off, i.e. when the first valve or second valve are closed.
Thus, when, for example, the system is used in a heating mode and only domestic hot water should be produced, it is possible to suck the refrigerant out of the shut-off branches of the refrigerant circuit, such that no unused refrigerant is constrained in non-operated branches of the refrigerant circuit.
The respective bypass pipes and pressure reducing means provided therein enable that constrained and unused refrigerant can be sucked back to the compressor, where it can be reused for ongoing operations, for example, a heating operation of water.
Put differently, unused refrigerant sucked out of the shut-off branches of the refrigerant circuit can contribute to a heating (or a cooling) effect and ensure that the largest amount of refrigerant possible is used to provide efficient heating (or cooling). Even further, it is possible to ensure a lower electricity consumption due to a better availability of the refrigerant. This increases the overall efficiency of the refrigeration device
It is therefore a key idea of the present invention to provide a more efficient and long-lasting refrigeration device that enables to recover and reuse refrigerant that is taken from non-operated branches of a refrigerant circuit. That is, the present invention enables to achieve a mediated recovery and reuse of refrigerant due to the provision of the first bypass pipe and the second bypass pipe each comprising pressure-reducing means. In addition to that, the presence of the pressure-reducing means in the refrigeration device does not only enable refrigerant recovery and reuse but is also particularly beneficial for security reasons because the safety issue caused by pressurized piping damage can be resolved.
Preferably, the first and second valves are solenoid valves.
This enables that the valves can switch from a fully closed to a fully open state. Also, the first and second valves may be motor operated valves. This enables to allow and establish a vast variety of valve settings and a more flexible control of refrigerant flows through the refrigerant circuit.
Preferably, the first and second refrigerant pipes extend in parallel from the compressor via a branching pipe arranged on the downstream side of the compressor.
Due to said configuration, there is one single piping leaving the compressor and the branching pipe enables to have the first and second refrigerant pipes to extend in parallel from said branching pipe.
Additionally, the opened/closed states of the first refrigerant pipe and second refrigerant pipe can be controlled separately by the first valve and the second valve.
Preferably, the expansion mechanism comprises a first expansion valve arranged downstream of the first utilization side heat exchanger, when the refrigeration device is used in a heating mode. Further, the expansion mechanism comprises a second expansion valve arranged downstream of the second utilization side heat exchanger, when the refrigeration device is used in a heating mode.
Such an expansion mechanism comprising a first and a second expansion valve respectively arranged downstream of the respective utilization side heat exchangers enables that the refrigerant pipes of the utilization side heat exchangers cannot only be shut off on an upstream side of the utilization side heat exchangers, but also on a downstream side thereof.
In other words, both sides of the piping directed to and away from the respective utilization side heat exchangers can be opened and closed. Accordingly, branches of the refrigerant circuit containing an utilization side heat exchanger arranged thereon can be fully closed and opened.
When a current operation situation does temporarily not require the operation of one of the utilization side heat exchangers and is therefore provoking a closing of the, for example, first valve and the first expansion valve, the whole branch containing, for example, the first utilization side heat exchanger is shut off from the remaining refrigerant circuit. Then, due to the provided pressure-reducing means in the first bypass pipe, the refrigerant that is constrained in said shut-off part of the refrigerant circuit stemming from the first valve via the first utilization side heat exchanger to the first expansion valve, can be sucked back through the first bypass pipe and can accordingly be recovered and reused in the remaining operated refrigerant circuit. Accoringly, the shut-off section can be emptied, and no pressured refrigerant is constrained therein.
Preferably, the controller is configured to fully close the first valve and the first expansion valve when the operation of the first utilization side heat exchanger is stopped and/or is configured to fully close the second valve and the second expansion valve when the operation of the second utilization side heat exchanger is stopped.
Due to such a configuration, one control step enables to simultaneously close the relevant valves downstream and upstream of the respective utilization side heat exchangers and, therefore, enables to efficiently shut-off or re-open the respective refrigerant pipings.
As mentioned earlier, such a configuration furthermore enables that refrigerant constrained and stuck in shut off parts of the refrigerant circuit can be automatically sucked through the pressure-reducing means by the operation of the compressor and be reused in the remaining operated refrigerant circuit.
Preferably, downstream of the second valve in the second refrigerant pipe, a plurality second utilization side heat exchangers is arranged in parallel.
More preferably, downstream of the second valve in the second refrigerant pipe, three second utilization side heat exchangers are arranged in parallel.
For example, such second utilization side heat exchangers can be provided for air conditioning a space, in which said second utilization side heat exchangers are provided. Such a configuration enables that, for example, several rooms of a house, in which the refrigeration device is provided, can respectively be provided with a utilization side heat exchanger.
In this context, the second utilization heat exchangers do not require that all the second utilization side heat exchangers are of the same model or type of utilization side heat exchangers. As explained in more detail below, such utilization side heat exchangers can be air conditioners or radiators that can be arranged in parallel in the refrigerant circuit, for example, in different rooms or positions of a room.
Preferably, when the refrigeration device is used in the heating mode, the expansion mechanism comprises the first expansion valve arranged downstream of the first utilization side heat exchanger. Further, when the refrigeration device is used in the heating mode, the expansion mechanism comprises a single second expansion valve arranged downstream of and connected to the second utilization side heat exchangers, or the expansion mechanism comprises a plurality of second expansion valves arranged downstream of and respectively connected to the second utilization side heat exchangers.
Here, the first expansion valve enables to completely close the stream directed to the first utilization side heat exchanger. Accordingly, when the first expansion valve and the first valve are closed, constrained refrigerant that is stuck in said refrigerant piping that is not an operation can be recovered via the pressure-reducing means in the first bypass pipe and efficiently used in other operated parts of the refrigerant circuit.
A configuration of having one single second expansion valve arranged downstream of and connected to the second utilization heat exchangers enables to achieve a simple configuration of a refrigerant circuit in which all pipings downstream of the second utilization side heat exchangers can be shut off by one single expansion valve.
Vice versa, the provision of a plurality of second expansion valves arranged downstream of and respectively connected to the second utilization side heat exchangers enables an individual opening and closing of a refrigerant piping downstream of the respective utilization side heat exchangers. Hence, such a configuration enables that individual second utilization side heat exchangers can be operated, whereas other second utilization side heat exchangers are not operated, and the refrigerant stuck in said parts of the refrigerant circuit is easily recovered.
Preferably, the controller is configured to fully close the second valve and the second expansion valve or the second expansion valves when the operation of the second utilization side heat exchangers is stopped.
Accordingly, it is possible to individually and completely close and open the respective pipings of the second utilization side heat exchangers.
Preferably, the pressure-reducing means is a capillary.
Having a capillary as a pressure-reducing means enables that the refrigerant flow must not be regulated by an active element, such that a simple configuration of a refrigerant circuit can be achieved that efficiently uses the refrigerant in the refrigerant circuit.
The provision of a capillary as a pressure-reducing means also enables to regulate the pressure reduction by the natural restriction of a small cross section area and the corresponding length of the capillary.
In other words, the refrigerant flow and the pressure reduction can be moderated by the physical parameters of a piping cross section of the capillary in the bypass pipe and the corresponding length of the capillary.
This also allows to achieve not only an efficient but also a cost-efficient system, as these two physical parameters can already be set during the manufacturing process.
With regard to the safety requirements, such a configuration enables a simple, reliable, and cost-efficient solution without any moving parts or active elements that could be damaged or malfunctioning from time to time. Furthermore, no additional control device or the like is required.
Preferably, the pressure-reducing means is a motor operated valve.
In this context, it is also possible to combine a capillary with a motor operated valve.
Due to such configurations, it is possible to achieve a system that does not only adjust the amount of pressure reduction due to the manufacturing constraints and the settings given during the manufacturing, but can also change the amount of pressure reduction during the use of the refrigeration device.
Additionally, this enables to achieve a more flexible system which can also react to changes in the refrigerant circuit, particularly if new utilization side heat exchangers or the like are brought into the refrigerant circuit, or if some elements of the refrigeration device, particularly utilization side heat exchangers, are taken out of the system.
Preferably, the first utilization side heat exchanger is a hot water supply unit. More preferably, the hot water supply unit can be a coil in a water tank.
Said hot water supply unit is for producing domestic hot water when the refrigeration device is used in a heating mode.
Here, the more preferred embodiment of the coil in the water tank enables that refrigerant can flow through the coil of the first utilization side heat exchanger and exchange heat with water inside the tank such that the water, when the refrigeration device is used in a heating mode, gets heated up by the refrigerant flowing through said coil. Hence domestic hot water can be efficiently produced.
Nonetheless, and as already known from the prior art, it is possible that an electrical heater is additionally provided in such a hot water supply unit.
Preferably, the second utilization side heat exchanger is an air conditioning indoor unit or a radiator for heating a space in which the second utilization side heat exchanger is positioned when the refrigeration device is used in a heating mode and/or for cooling the space in which the second utilization side heat exchanger is positioned when the refrigeration device is used in a cooling mode.
Hence, providing, for example, a plurality of such air conditioning indoor units enables that several rooms can be provided with several air conditioning indoor units and the heating or cooling in said rooms can be adjusted individually. Hence, such a system enables to achieve a system which has different temperatures in different spaces.
Preferably, the refrigeration device further comprises an accumulator arranged upstream of the compressor in the refrigerant circuit. Here, the first bypass pipe extends from the downstream side of the first valve, when the refrigeration device is used in the heating mode, to a suction side of the accumulator, and the second bypass pipe extends from the downstream side of the second valve, when the refrigeration device is used in the heating mode, to a suction side of the accumulator.
Such a configuration enables that, when refrigerant is sucked out of branches of the refrigerant circuit that are not operated, said refrigerant can first be accumulated before it enters the compressor. Accoringly, the operational reliability of the compressor can be increased, as no liquid refrigerant or the like is sucked into the compressor.
Preferably, the first and second refrigerant pipes are gas pipes containing the refrigerant in at least partial gaseous state, when the refrigeration device is used in the heating mode.
More preferably, the first and second refrigerant pipes are gas pipes containing the refrigerant in a fully gaseous state, when the refrigeration device is used in a heating mode.
Such configurations enable that, since the refrigerant is used in a at least partial (or fully) gaseous state, the efficiency of the system can be as high as possible, and a large amount of heat exchange can be achieved.
Preferably, the refrigeration device further comprises a switching valve, preferably a four-way switching valve. The switching valve is configured to switch the refrigerant circuit from the heating mode to the cooling mode.
Such a switching device may be provided, for example, on a downstream side of a compressor, such that the flow direction of a refrigerant leaving the compressor and having a high pressure can be controlled by said switching device. In other words, the switching device decides on the direction in which the refrigerant flows through the refrigerant circuit.
In view of the above, the present invention relates to a refrigeration device, which enables to reuse refrigerant from parts of the refrigerant circuit that are not in operation in order to efficiently use the recycled refrigerant in ongoing operations in operated parts of the refrigerant circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

Subsequently, an illustration of an exemplary embodiment of a refrigeration device according to the present invention will be given. It shows:
Fig. 1: A schematic illustration of a refrigeration device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Fig. 1 shows a refrigeration device according to an embodiment of the present invention.
Here, a refrigerant circuit is constituted by a compressor 1, a plurality of utilization side heat exchangers, which will be described in more detail below, an expansion mechanism 4 and a heat source side heat exchanger 5. The compressor 1, the utilization side heat exchangers, the expansion mechanism 4 and the heat source side heat exchanger 5 are fluidly connected in series to constitute a refrigerant circuit.
As can be taken from Fig. 1, also a switching device 16, which is configured to switch the refrigerant circuit from a heating mode to a cooling mode is provided.
The exemplary embodiment of Fig. 1 shows a switching device 16 in the form of a four-way switching valve. Fig. 1 also shows a configuration in which said switching device 16 is switched in such a manner that the refrigeration device is used in a heating mode. That is, the switching position of the switching device 16 enables that a pressurized refrigerant that leaves the compressor 1 subsequently flows to the plurality of utilization side heat exchangers to exchange heat, before it continues to stream to the expansion mechanism 4 in the refrigerant circuit. When the refrigeration device is used in a heating mode, heat is dispensed from the refrigerant to the surrounding environment, such as air or water (to be described later) in the utilization side heat exchangers.
When the refrigerant has flown through the utilization side heat exchangers, the refrigerant continues to stream to the expansion mechanism 4, when the refrigeration device is used in a heating mode. Said expansion mechanism 4 enables to reduce the pressure of the refrigerant, such that it then can continued to stream to the heat source side heat exchanger 5. Here, heat can once again be exchanged. When the refrigeration device is operated in the heating mode, the heat source side heat exchanger 5 can, for example, be arranged in an outdoor unit. Vice versa, the utilization side heat exchangers can be considered as indoor units.
When the refrigeration device is being operated in the heating mode, the refrigerant then flows from the heat source side heat exchanger 5 back to the compressor 1.
Here, Fig. 1 illustrates the provision of an accumulator 15, which is arranged intermittent between the heat source side heat exchanger 5 and the compressor 1 in the refrigeration circuit. In other words, the accumulator 15 is arranged upstream of the compressor 1 in the refrigerant circuit. This accumulator 15 thus enables the refrigerant being streamed through the refrigerant circuit to be accumulated before it streams into the refrigeration circuit.
Due to the compression of the refrigerant in the compressor 1, the refrigerant leaving the compressor 1 is in a gaseous state when the refrigeration device is used in the heating mode.
When the refrigeration device according to the exemplary embodiment of Fig. 1 is to be switched from a heating mode (as illustrated) to a cooling mode, the switching device 16 changes the flow direction of the refrigerant through the refrigerant circuit. In particular, the flow direction of the refrigerant through the refrigerant circuit is opposed, such that the refrigerant leaving the compressor 1 first streams through the heat source side heat exchanger 5, then through the expansion mechanism 4, and then through the utilization side heat exchangers before it returns back to the compressor 1.
Nonetheless, it will subsequently be focused on the refrigeration device being operated in a heating mode.
As mentioned earlier, a plurality of utilization side heat exchangers is provided. Here, a first utilization side heat exchanger 2 is provided in the refrigerant circuit. In the exemplary embodiment of Fig. 1, said first utilization side heat exchanger 2 is a hot water supply unit in the form of a coil 13 in a water tank 14. Hence, said hot water supply unit is an exemplary embodiment of the first utilization side heat exchanger 2 configured to produce domestic hot water when the refrigeration device is used in a heating mode (as illustrated in Fig. 1).
Yet, it is also derivable from Fig. 1 that not only a first utilization side heat exchanger 2, but also a plurality of second utilization side heat exchangers 3.1, 3.2, 3.3 is provided in the refrigerant circuit. Here, three second utilization side heat exchangers 3.1, 3.2, 3.3 are exemplarily provided. These three second utilization side heat exchangers 3.1, 3.2, 3.3 are arranged in parallel (see Fig. 1).
In the exemplary embodiment, the three second utilization side heat exchangers 3.1, 3.2, 3.3 are illustrated as air conditioning indoor units for heating a space, in which the second utilization side heat exchangers 3.1, 3.2, 3.3 are positioned, when the refrigeration device is used in a heating mode.
As mentioned earlier, said air conditioning indoor units 3.1, 3.2, 3.3 may also be capable of cooling a space in which the second utilization side heat exchangers are respectively positioned, when the refrigeration device is used in a cooling mode.
Instead of being configured as being an air conditioning indoor unit, one, more or all of the second utilization side heat exchangers 3.1, 3.2, 3.3 provided in the refrigerant circuit may also be configured as radiators for heating the space and/or for cooling the space in which the respective second utilization side heat exchangers 3.1, 3.2, 3.3 are arranged.
It may in this context be well known that the second utilization side heat exchangers 3.1, 3.2, 3.3 do not have to be arranged in the same space to be heated and/or to be cooled, but they can also be arranged in different spaces, for example, in different rooms of a building in order to heat or cool different rooms of a building or to establish difference temperatures therein.
Accordingly, the configuration of the first utilization side heat exchanger 2 and the provision of at least one, here three, second utilization side heat exchangers 3.1, 3.2, 3.3 enables to achieve a so-called "combined system", which is commonly known as a domestic hot water and air conditioning combined system.
As it will be elaborated in more detail subsequently, the first utilization side heat exchanger 2 and the plurality of second utilization side heat exchangers 3.1, 3.2, 3.3 are arranged in parallel.
To achieve a parallel production of hot water by the first utilization side heat exchanger 2 and heating of a space by the plurality of air conditioning indoor units 3.1, 3.2, 3.3, a first refrigerant pipe 6, which extends from the compressor 1 to the first utilization side heat exchanger 2, here subsequently in the form of the hot water supply units, is provided. Said first refrigerant pipe 6 comprises a first valve 7. Said first valve 7 divides said first refrigerant pipe 6 in a section on a upstream side 6.1 of the first valve 7, when the refrigeration device is used in a heating mode, and in a section on a downstream side 6.2 of the first valve 7, when the refrigeration device is used in a heating mode.
Said first valve 7 is configured to at least fully open and fully close the first refrigerant pipe 6.
Additionally, a second refrigerant pipe 8 is provided, which extends from the compressor 1 to the second utilization side heat exchangers 3.1, 3.2, 3.3. Said second refrigerant pipe 8 comprises a second valve 9.
Similar to the first refrigerant pipe 6, the second refrigerant pipe 8 is divided in an upstream side 8.1 of the second valve 9 and a downstream side 8.2 of the second valve 9. Similar to the first valve 7, also the second valve 9 is configured to at least fully open and fully close the second refrigerant pipe 8.
In the exemplary embodiment illustrated in Fig. 1, the first valve 7 and second valve 9 are configured as solenoid valves, which are configured to at least fully open and fully close the first refrigerant pipe 6 and the second refrigerant pipe 8. Also, the first valve 7 and second valve 9 may be configured as motor operated valves. In this case, they are configured to adjust the amount of refrigerant flowing in the first refrigerant pipe 6 and the second refrigerant pipe 8.
As mentioned earlier, the refrigeration device as illustrated in Fig. 1 enables a parallel production of domestic hot water and warm air for heating up a space.
To do so, the first utilization side heat exchanger 2 and the second utilization side heat exchangers 3.1, 3.2, 3.3 are arranged in parallel.
Specifically, the first refrigerant pipe 6 and the second refrigerant pipe 8 extend in parallel from the compressor 1 via a branching pipe 17 arranged on a downstream side of the compressor 1. That is, the branching pipe 17 enables to stream refrigerant leaving the compressor 1 to both of the first refrigerant pipe 6 and the second refrigerant pipe 8 in order to deliver refrigerant to the first utilization side heat exchanger 2 and the three second utilization side heat exchangers 3.1, 3.2, 3.3 in the exemplary form of air conditioning indoor units.
In this context, it can be taken from Fig. 1 that the three air conditioning indoor units, as an exemplary form of the second utilization side heat exchangers 3.1, 3.2, 3.3, are arranged on a downstream side 8.2 of the second valve 9 in the second refrigerant pipe 8. Hence, when the refrigeration device is used in the heating mode, the first refrigerant pipe 6 and the second refrigerant pipe 8 are gas pipes containing the refrigerant in at least partial gaseous state.
The embodiment of the refrigeration device as illustrated in Fig. 1 further comprises a first bypass pipe 10, which extends from a downstream side 6.2 of the first valve 7 when the refrigeration device is used in a heating mode to a suction side of the compressor 1. Here, since an accumulator 15 is additionally provided, the first bypass pipe 10 does not extend directly to the compressor 1, but rather extends from the downstream side 6.2 of the first valve 7 to a suction side of the accumulator 15.
In addition to that, also a second bypass pipe 11 extending from a downstream side 8.2 of the second valve 9, when the refrigeration device is used in a heating mode, to a suction side of the compressor 1 is provided.
Like the configuration of the first bypass pipe 10 described above, also the second bypass pipe 11 does not directly extend to a suction side of the compressor 1, as the accumulator 15 is intermittent thereto. In particular, the second bypass pipe 11 extends in the illustrated exemplary embodiment of Fig. 1 from the downstream side 8.2 of the second valve 9 to a suction side of the accumulator 15.
In addition, Fig. 1 illustrates that the first bypass pipe 10 and the second bypass pipe 11 each comprise pressure-reducing means 12, which are configured to reduce the pressure of a refrigerant in the first bypass pipe 10 and the second bypass pipe 11.
As illustrated in Fig 1, the pressure-reducing means 12 can, for example, be a capillary.
Accordingly, the pressure of the refrigerant flowing through the first bypass pipe 10 and the second bypass pipe 11 can be gradually reduced by said capillary without the need of further actuated means.
Alternatively, or in addition to that, the pressure-reducing means 12 may also be provided with a motor operated valve (not illustrated) to adapt the level of pressure reduction in the respective bypass pipes.
The expansion mechanism 4 of the refrigeration device as illustrated in Fig. 1 comprises a first expansion valve 4.1 arranged downstream of the first utilization side heat exchanger 2.
Additionally, the expansion mechanism 4 also comprises a plurality of second expansion valves 4.2, 4.3, 4.4 arranged downstream of and respectively connected to the second utilization side heat exchangers 3.1, 3.2, 3.3.
In other words, not only the first utilization side heat exchanger 2 is provided with a first expansion valve 4.1 arranged on a downstream side thereof, but also each of the three illustrated air conditioning indoor units 3.1, 3.2, 3.3 is respectively provided with an own expansion valve 4.2, 4.3, 4.4.
Accordingly, a section between the first valve 7 and the first expansion valve 4.1 comprises the first utilization side heat exchanger 2 therebetween. Thus, the first valve 7 and the first expansion valve 4.1 can control whether refrigerant is streaming through said branch of the refrigerant circuit or not - depending on whether the valves are open or not.
The parallel branch, i.e. the second refrigerant pipe 8 is also configured with the second valve 9 on an upstream side of the second utilization side heat exchangers 3.1, 3.2, 3.3 and also comprises respective second expansion valves 4.2, 4.3, 4.4 on the respective sub-branches (see Fig. 1).
Put differently, the first refrigerant pipe 6 and the second refrigerant pipe 8 extend in parallel from the compressor 1 via the branching pipe 17 and can be open and closed via the first valve 7 and the first expansion valve 4.1 as well as via the second valve 9 and the second expansion valves 4.2, 4.3, 4.4.
As illustrated in Fig. 1, the three air conditioning indoor units 3.1, 3.2, 3.3 also extend in parallel in said second refrigerant pipe 8.
Hence, a stream through the respective sub-branches of the second refrigerant pipe 8 of each of the second utilization side heat exchangers, here in the form of air conditioning indoor units 3.1, 3.2, 3.3, can be controlled via the opening/closing state of the second expansion valves 4.2, 4.3, 4.4.
In addition, the refrigeration device according to an exemplary embodiment also comprises a (non-illustrated) controller, which is configured to fully close the first valve 7 when the operation of the first utilization side heat exchanger 2, i.e. the hot water supply unit, is or shall be stopped and/or which is configured to fully close the second valve 9, when the operation of the second utilization side heat exchangers 3.1, 3.2, 3.3 is or shall be stopped. In addition to that, the controller is also configured to fully close the first expansion valve 4.1 at the same time when the operation of the first utilization side heat exchanger 2 is or shall be stopped, and is additionally also configured to close the second expansion valves 4.2, 4.3, 4.4, when the operation of one, two or all of the three illustrated second utilization side heat exchangers 3.1, 3.2, 3.3 is or shall be stopped.
That is, the controller can control the refrigerant flow to one of the air conditioning indoor units, to more than one of the air conditioning indoor units or all of the air conditioning indoor units and to the hot water supply device (as an exemplary embodiment of the first utilization side heat exchanger 2) depending on a switching status of the first valve 7, the second valve 9 and each of the first to fourth expansion valve 4.1, 4.2, 4.3, 4.4.
For easier orientation, a function of the refrigeration device, which is illustrated in Fig. 1, shall now be described.
As briefly mentioned above, the controller enables to achieve different opening and closing states of each of the provided valves, such as the first valve 7, the second valve 9, the first expansion valve 4.1 and the three second expansion valves 4.2, 4.3, 4.4 arranged on a downstream side of the three second utilization side heat exchangers 3.1, 3.2, 3.3.
In this context, when, for example, no production of hot water via the hot water supply unit (as the first utilization side heat exchanger 2) is required, the controller is configured to close the first valve 7 as well as the first expansion valve 4.1 of the expansion mechanism 4. Accordingly, the branch extending from the first valve 7 to the first expansion valve 4.1 can be fully shut off from the remaining refrigerant circuit via the controller.
Additionally, when, for example, no operation of one, more or all of the air conditioning indoor units (as the second utilization side heat exchangers 3.1, 3.2, 3.3) is required, the controller is also configured to shut off the refrigerant flow through said second utilization side heat exchangers 3.1, 3.2, 3.3.
To do so, the controller can close the second valve 9 and all of the three illustrated second expansion valves 4.2, 4.3, 4.4 when no air conditioning indoor unit is needed at all.
When at least one of the air conditioning indoor units 3.1, 3.2, 3.3 shall be operated, the controller is configured to open the second valve 9 and is furthermore configured to close only the amount of second expansion valves 4.2, 4.3, 4.4 that are arranged downstream of air conditioning indoor units 3.1, 3.2, 3.3 that shall not be operated.
For example, when only domestic hot water shall be produced, i.e. when none of the air conditioning indoor units is required to be operated, the controller is configured to close the second valve 9 and all of the three second expansion valves 4.2, 4.3, 4.4. Consequently, no refrigerant is passing through the second refrigerant pipe 8 after the second valve 9. Accordingly, solely the first refrigerant pipe 6 is operated in such a heating mode for producing domestic hot water only.
Subsequently, it will, for easier orientation, be focused on states in which none of the second utilization side heat exchangers 3.1, 3.2, 3.3, or no domestic hot water production is required.
In such an exemplary case, in which a user wishes the system to produce domestic hot water only, the controller closes the second valve 9 and the second expansion valves 4.2, 4.3, 4.4, such that no refrigerant is circulating through the second utilization side heat exchangers 3.1, 3.2, 3.3.
The refrigerant accordingly flows from the compressor 1 through the switching valve 16, through the branching pipe 17 to the first refrigerant pipe 6, passes the first valve 7 and then flows through the first utilization side heat exchanger 2, such that hot water is produced. After heat has been exchanged with the refrigerant in the first utilization side heat exchanger 2 to heat up the water, the refrigerant then continues to flow through the first expansion valve 4.1 and to the heat source side heat exchanger 5 before it continues to flow through the accumulator 15 and back to the compressor 1.
The closed second valve 9 in conjunction with the provided second bypass pipe 11 thereby enables that a suction force through said second bypass pipe 11 is produced.
Accordingly, when the second utilization side heat exchangers 3.1, 3.2, 3.3 are not operated, said suction force enables that the refrigerant constrained in said blocked pipes of the refrigerant circuit (downstream of the second valve 9 and upstream of the first expansion valves 4.2, 4.3, 4.4), can be recovered and be flown through the capillary.
That is, the refrigerant can be recovered from unused piping and additionally be used for a stream through the first utilization side heat exchanger 2 to efficiently produce domestic hot water.
Vice versa, when no domestic hot water is to be produced, but, for example, air conditioning of a space in which the second utilization side heat exchangers 3.1, 3.2, 3.3 are arranged shall be performed, the first valve 7 can be closed together with the first expansion valve 4.1.
Accordingly, refrigerant is then merely circulating through (at least one of) the second utilization side heat exchangers 3.1, 3.2, 3.3 and the second refrigerant pipe 8.
Due to the beneficial provision of the first bypass pipe 10, which extends from the downstream side 6.2 of first valve 7, when the refrigeration device is used in a heating mode, to a suction side of the compressor 1, here the accumulator 15, the constrained refrigerant that does not take part in any heat exchange in such a control state can be recovered.
Consequently, the refrigerant that is stuck in non-operated branches of the refrigerant circuit can easily be reused for heat exchange in operated branches of the refrigerant circuit of the refrigeration device to achieve efficient heat exchange.

Reference List

1: compressor
2: first utilization side heat exchanger
3.1, 3.2, 3.3: second utilization side heat exchangers (air conditioning indoor units)
4: expansion mechanism
4.1: first expansion valve
4.2, 4.3, 4.4: second expansion valves
5: heat source side heat exchanger
6: first refrigerant pipe
6.1: upstream side of the first valve
6.2: downstream side of the first valve
7: first valve
8: second refrigerant pipe
8.1: upstream side of the second valve
8.2: downstream side of the second valve
9: second valve
10: first bypass pipe
11: second bypass pipe
12: pressure-reducing means
13: coil
14: water tank
15: accumulator
16: switching device
17: branching pipe

Claims

A refrigeration device comprising:
a compressor (1), a plurality of utilization side heat exchangers, an expansion mechanism (4) and a heat source side heat exchanger (5) fluidly connected in series to constitute a refrigeration circuit;

a first refrigerant pipe (6), which extends from the compressor (1) to a first utilization side heat exchanger (2) of the plurality of utilization side heat exchangers and comprises a first valve (7) configured to at least fully open and fully close the first refrigerant pipe (6),

a second refrigerant pipe (8), which extends from the compressor (1) to a second utilization side heat exchanger (3.1, 3.2, 3.3) of the plurality of utilization side heat exchangers and comprises a second valve (9) configured to at least fully open and fully close the second refrigerant pipe (8),

a controller, which is configured to fully close the first valve (7) when the operation of the first utilization side heat exchanger (2) is stopped and/or which is configured to fully close the second valve (9) when the operation of the second utilization side heat exchanger (3.1, 3.2, 3.3) is stopped,

characterised by

a first bypass pipe (10) extending from a downstream side (6.2) of the first valve (7) when the refrigeration device is used in a heating mode to a suction side of the compressor (1),

a second bypass pipe (11) extending from a downstream side (8.2) of the second valve (9) when the refrigeration device is used in a heating mode to a suction side of the compressor (1),

wherein the first and second bypass pipes (10, 11) each comprise pressure-reducing means (12) configured to reduce the pressure of a refrigerant in the first and second bypass pipes (10, 11) .
The refrigeration device according to claim 1, wherein the first and second valves (7, 9) are solenoid valves.
The refrigeration device according to any of the preceding claims, wherein the first and second refrigerant pipes (6, 8) extend in parallel from the compressor (1), preferably via a branching pipe (17) arranged on a downstream side of the compressor (1).
The refrigeration device according to any of the preceding claims, wherein the expansion mechanism (4) comprises a first expansion valve (4.1) arranged downstream of the first utilization side heat exchanger (2), when the refrigeration device is used in the heating mode, and
wherein the expansion mechanism (4) comprises a second expansion valve (4.2, 4.3, 4.4) arranged downstream of the second utilization side heat exchanger (3.1, 3.2, 3.3), when the refrigeration device is used in the heating mode.
The refrigeration device according to claim 4, wherein the controller is configured to fully close the first valve (7) and the first expansion valve (4.1) when the operation of the first utilization side heat exchanger (2) is stopped and/or which is configured to fully close the second valve (9) and the second expansion valve (4.2, 4.3, 4.4) when the operation of the second utilization side heat exchanger (3.1, 3.2, 3.3) is stopped.
The refrigeration device according to any of the preceding claims, wherein, on the downstream side (8.2) of the second valve (9) in the second refrigerant pipe (8), a plurality, preferably three, second utilization side heat exchangers (3.1, 3.2, 3.3) are arranged in parallel.
The refrigeration device according to claim 6, wherein,
when the refrigeration device is used in the heating mode, the expansion mechanism (4) comprises the first expansion valve (4.1) arranged downstream of the first utilization side heat exchanger (2),

the expansion mechanism (4) comprises a single second expansion valve arranged downstream of and connected to the second utilization side heat exchangers (3.1, 3.2, 3.3), or

the expansion mechanism (4) comprises a plurality of second expansion valves (4.2, 4.3, 4.4) arranged downstream of and respectively connected to the second utilization side heat exchangers (3.1, 3.2, 3.3).
The refrigeration device according to claims 7, wherein the controller is configured to fully close the second valve (9) and the second expansion valve or the second expansion valves (4.2, 4.3, 4.4) when the operation of the second utilization side heat exchangers (3.1, 3.2, 3.3) is stopped.
The refrigeration device according to any of the preceding claims, wherein the pressure-reducing means (12) is a capillary.
The refrigeration device according to any of the preceding claims, wherein the pressure-reducing means (12) is a motor-operated valve.
The refrigeration device according to any of the preceding claims, wherein the first utilization side heat exchanger (2) is a hot water supply unit, preferably a coil (13) in a water tank (14), for producing domestic hot water when the refrigeration device is used in a heating mode.
The refrigeration device according to any of the preceding claims, wherein the second utilization side heat exchanger (3.1, 3.2, 3.3) is an air conditioning indoor unit or a radiator for heating a space in which the second utilization side heat exchanger (3.1, 3.2, 3.3) is positioned when the refrigeration device is used in a heating mode and/or for cooling the space in which the second utilization side heat exchanger (3.1, 3.2, 3.3) is positioned when the refrigeration device is used in a cooling mode.
The refrigeration device according to any of the preceding claims, wherein the refrigeration device further comprises an accumulator (15) arranged upstream of the compressor (1) in the refrigeration circuit,
wherein the first bypass pipe (10) extends from the downstream side (6.1) of the first valves (7), when the refrigeration device is used in the heating mode, to a suction side of the accumulator (15), and

wherein the second bypass pipe (11) extends from the downstream side (8.2) of the second valves (9), when the refrigeration device is used in the heating mode, to a suction side of the accumulator (15).
The refrigeration device according to any of the preceding claims, wherein the first and second refrigerant pipes (6, 8) are gas pipes containing the refrigerant in at least partial gaseous state when the refrigeration device is used in the heating mode.
The refrigeration device according to any of the preceding claims, wherein the refrigeration device further comprises a switching device (16), preferably a four-way switching valve,
wherein the switching device (16) is configured to switch the refrigeration circuit from the heating mode to the cooling mode.