CN115183492B

CN115183492B - Air conditioner and control method thereof

Info

Publication number: CN115183492B
Application number: CN202210668311.XA
Authority: CN
Inventors: 陈日帅; 蒋贤国; 徐春峰
Original assignee: Hisense Air Conditioning Co Ltd
Current assignee: Hisense Air Conditioning Co Ltd
Priority date: 2022-06-14
Filing date: 2022-06-14
Publication date: 2023-09-22
Anticipated expiration: 2042-06-14
Also published as: CN115183492A

Abstract

The invention discloses an air conditioner and a control method thereof, wherein the air conditioner is integrated with a coil pipe indoor unit and a capillary pipe indoor unit, and partial refrigerant is remained in the room when the air conditioner is operated at the end of normal operation due to circulation of the refrigerant when the air conditioner is operated, so that the quantity of the refrigerant added by a system is difficult to control in a proper range when the air conditioner is operated next time, and the indoor temperature control effect is poor.

Description

Air conditioner and control method thereof

Technical Field

The invention relates to the technical field of air conditioners, in particular to an air conditioner and a control method thereof.

Background

Along with the improvement of living standard, people's requirement to living environment is also higher and higher, and indoor temperature is the important factor that influences living environment suitability, therefore, for can adjusting indoor temperature, provide the air conditioner that has integrated coil pipe indoor set and capillary indoor set on the market, this kind of hybrid air conditioner is in the temperature regulation in-process refrigerant control degree of difficulty great, and indoor temperature control effect is relatively poor.

Disclosure of Invention

The embodiment of the invention aims to provide an air conditioner and a control method thereof, which can recover the refrigerant in an indoor unit when a system starts to operate, reduce the control difficulty of the refrigerant when the air conditioner normally operates, improve the control effect of indoor temperature and improve user experience.

To achieve the above object, an embodiment of the present invention provides an air conditioner, including:

the coil pipe indoor unit is used for adjusting indoor temperature and comprises a coil pipe air valve, a coil pipe heat exchanger and a coil pipe expansion valve which are connected in sequence;

the capillary tube indoor unit is used for adjusting indoor temperature and comprises a capillary tube air valve, a capillary tube heat exchanger and a capillary tube expansion valve which are connected in sequence;

the outdoor unit is used for providing temperature-regulating circulating power for the coil pipe indoor unit and the capillary tube indoor unit and comprises a compressor, an outdoor heat exchanger and a four-way valve;

and the controller is used for responding to the starting operation instruction, closing the coil expansion valve and the capillary expansion valve, opening the coil air valve and the capillary air valve, controlling the starting of the compressor until the preset refrigerant recovery ending condition is met, closing the air valve of the indoor unit which does not operate and opening the expansion valve of the indoor unit which operates, so that the air conditioner enters a normal operation stage.

As an improvement of the above solution, the controller is configured to close an air valve of an indoor unit that does not operate and open an expansion valve of the indoor unit that operates, and specifically includes:

when the starting operation instruction is a capillary tube heating operation instruction, closing the coil air valve and opening the capillary tube expansion valve so that the air conditioner enters a capillary tube heating stage;

when the starting operation instruction is a coil refrigerating operation instruction, closing the capillary air valve and opening the coil expansion valve so that the air conditioner enters a coil refrigerating stage;

and when the starting operation instruction is a coil heating operation instruction, closing the capillary air valve and opening the coil expansion valve so that the air conditioner enters a coil heating stage.

As an improvement of the above scheme, a first end of the four-way valve is connected with the outdoor heat exchanger, a second end of the four-way valve is connected with an exhaust port of the compressor, a third end of the four-way valve is respectively connected with the coil pipe air valve and the capillary air valve, and a fourth end of the four-way valve is connected with an air suction port of the compressor; the controller is further configured to:

after responding to a starting operation instruction, controlling the four-way valve to be in a non-energized state so as to conduct a first end and a second end in the four-way valve, wherein a third end and a fourth end of the four-way valve are conducted;

When the air conditioner is in a refrigeration mode, the four-way valve is controlled to be in a non-energized state so that a first end and a second end in the four-way valve are conducted, and a third end and a fourth end of the four-way valve are conducted;

when the air conditioner is in a heating mode, the four-way valve is controlled to be in an electrified state, so that a first end and a fourth end in the four-way valve are conducted, and a second end and a third end of the four-way valve are conducted.

As an improvement of the above-mentioned scheme, the air conditioner further includes:

the first pressure sensor is arranged between the fourth end of the four-way valve and the air suction port of the compressor and is used for detecting a first pressure value of a pipeline between the fourth end of the four-way valve and the air suction port of the compressor;

the refrigerant recovery end condition is: and detecting that the first pressure value is smaller than a preset low pressure threshold value.

the injection valve is arranged between the outdoor heat exchanger and the air suction port of the compressor and used for balancing the internal pressure of the air conditioner;

the unloading valve is arranged between the exhaust port of the compressor and the air suction port of the compressor and used for balancing the internal pressure of the air conditioner;

The controller is further configured to:

after the preset refrigerant recovery end condition is met and before the normal refrigerating operation or the normal heating operation is carried out, the injection valve and the unloading valve are opened.

the exhaust temperature sensor is arranged at the exhaust port of the compressor and used for detecting the exhaust temperature of the compressor;

the second pressure sensor is arranged at the second end of the four-way valve and is used for detecting a second pressure value of gas passing through the second end of the four-way valve;

the controller is further configured to:

after the air conditioner enters normal refrigeration operation or normal heating operation, acquiring the exhaust temperature and the second pressure value;

when the exhaust temperature is greater than a preset high temperature threshold, reducing the operation frequency of the compressor, and after reducing the operation frequency, if the exhaust temperature is detected to be increased, opening the injection valve;

and when the second pressure value is larger than a preset high-pressure threshold value, reducing the operation frequency of the compressor, and after the operation frequency is reduced, if the second pressure value is detected to be increased, opening the unloading valve.

In order to achieve the above objective, the embodiment of the present invention further provides a control method for an air conditioner, where the air conditioner includes a coil indoor unit, a capillary indoor unit, and an outdoor unit, the coil indoor unit includes a coil air valve, a coil heat exchanger, and a coil expansion valve that are sequentially connected, the capillary indoor unit includes a capillary air valve, a capillary heat exchanger, and a capillary expansion valve that are sequentially connected, and the outdoor unit includes a compressor, an outdoor heat exchanger, and a four-way valve; the air conditioner control method includes:

Closing the coil expansion valve and the capillary expansion valve in response to the start-up operation command;

opening a coil pipe air valve and a capillary air valve, controlling the starting of a compressor until a preset refrigerant recovery end condition is met, closing the air valve of the indoor unit which does not operate and opening the expansion valve of the indoor unit which operates, so that the air conditioner enters a normal operation stage.

As an improvement of the above solution, the closing the air valve of the non-operating indoor unit and opening the expansion valve of the operating indoor unit to make the air conditioner enter the normal operation phase specifically includes:

As an improvement of the above scheme, a first end of the four-way valve is connected with the outdoor heat exchanger, a second end of the four-way valve is connected with an exhaust port of the compressor, a third end of the four-way valve is respectively connected with the coil pipe air valve and the capillary air valve, and a fourth end of the four-way valve is connected with an air suction port of the compressor; the air conditioner control method further comprises the following steps:

As an improvement of the above solution, the air conditioner further includes a first pressure sensor disposed between the fourth end of the four-way valve and the air suction port of the compressor;

Compared with the prior art, the air conditioner and the control method thereof disclosed by the embodiment of the invention integrate the coil indoor unit and the capillary indoor unit, and the air conditioner has the advantages that partial refrigerant is remained in the indoor heat exchanger when the air conditioner is in operation due to the circulation of the refrigerant during heating or refrigerating of the air conditioner, so that the air conditioner is difficult to control the quantity of the refrigerant added by a system in a proper range during the next operation, the indoor temperature control effect is poor, and the user experience is influenced.

Drawings

Fig. 1 is a schematic structural diagram of an air conditioner according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an internal device connection structure of an air conditioner according to an embodiment of the present invention;

FIG. 3 is a first workflow diagram of a controller provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a refrigerant recovery flow direction according to an embodiment of the present invention;

FIG. 5 is a second workflow diagram of a controller provided by an embodiment of the present invention;

fig. 6 is a schematic diagram of a refrigerant flow direction in a cooling mode according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a refrigerant flow direction in a heating mode according to an embodiment of the present invention;

FIG. 8 is a third workflow diagram of a controller provided by an embodiment of the present invention;

FIG. 9 is a schematic diagram illustrating a refrigerant flow according to an embodiment of the present invention;

FIG. 10 is a fourth operational flow diagram of a controller provided by an embodiment of the present invention;

FIG. 11 is a flowchart of a fifth workflow diagram of a controller provided by an embodiment of the present invention;

fig. 12 is a schematic view of an internal device connection structure of an air conditioner according to an embodiment of the present invention;

fig. 13 is a flowchart of an air conditioner control method according to an embodiment of the present invention;

100, a coil pipe indoor unit; 200. a capillary tube indoor unit; 300. an outdoor unit; PMV1, coiled tubing expansion valve; PMV2, capillary expansion valve; t1, a coil pipe air valve; t2, capillary air valve; COM, compressor; e1, a coil heat exchanger; e2, a capillary tube heat exchanger; e3, an outdoor heat exchanger; FWV, four-way valve; GV1, tracheal stop valve; GV2, liquid pipe stop valve; PMV3, electronic expansion valve; PS, first pressure sensor; PD, second pressure sensor; a TD, exhaust gas temperature sensor; SV1, injection valve; SV2, unloading valve; OS, oil separator; GLS, gas-liquid separator; and E4, a water tank heat exchanger.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

In the description of the present application, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Referring to fig. 1, the air conditioner according to the embodiment of the present application includes a coil indoor unit 100, a capillary indoor unit 200, and an outdoor unit 300, wherein the coil indoor unit 100 is used for reducing or increasing the temperature of indoor air, the capillary indoor unit 200 is used for increasing the temperature of indoor air, the outdoor unit 300 is used for providing refrigeration cycle power or heating cycle power to the coil indoor unit 100 and heating cycle power to the capillary indoor unit 200, the outdoor unit 300 is installed outdoors, and the coil indoor unit 100 and the capillary indoor unit 200 are installed indoors. Referring to fig. 2, fig. 2 is a schematic diagram of an internal device connection structure of an air conditioner according to an embodiment of the present application, where a coil indoor unit 100 includes a coil air valve T1, a coil heat exchanger E1, and a coil expansion valve PMV1, which are sequentially connected, and a capillary indoor unit 200 includes a capillary air valve T2, a capillary heat exchanger E2, and a capillary expansion valve PMV2, which are sequentially connected; the outdoor unit 300 includes a compressor COM, an outdoor heat exchanger E3, and a four-way valve FWV.

Specifically, a first end c of the four-way valve FWV is connected to the outdoor heat exchanger E3, a second end d of the four-way valve FWV is connected to an exhaust port of the compressor COM, a third end E of the four-way valve FWV is connected to the coil air valve T1 and the capillary air valve T2, respectively, and a fourth end s of the four-way valve FWV is connected to an air suction port of the compressor COM. The flow direction of the refrigerant is controlled by controlling the state of the four-way valve FWV, and then the mode of the air conditioner is controlled.

The operation modes of the air conditioner comprise a refrigeration mode, a heating mode and a refrigerant recovery mode. When the air conditioner receives the start operation command, it will first enter a refrigerant recovery mode, and the capillary tube indoor unit 200 and the coil indoor unit 100 will not operate at this time, and the outdoor unit 300 will operate to recover the refrigerant.

Specifically, in the embodiment of the present invention, the controller of the air conditioner is configured to close the coil expansion valve PMV1 and the capillary expansion valve PMV2 in response to a start operation command, open the coil air valve T1 and the capillary air valve T2, and control the compressor COM to start, until a preset refrigerant recovery end condition is satisfied and the start operation command is a refrigeration operation command, close the capillary air valve T2 and open the coil expansion valve PMV1, so that the air conditioner enters a normal refrigeration stage (coil refrigeration stage).

Referring to fig. 3, for an example, fig. 3 is a first workflow diagram of a controller provided by an embodiment of the present invention; the controller is configured to execute steps S11 to S14:

s11, responding to the starting operation command, closing the coil expansion valve PMV1 and the capillary expansion valve PMV2, and then proceeding to step S12.

The start operation instruction may be an instruction input by a user in real time, or may be a preset instruction, for example, a timing trigger start operation instruction; the user can input control signals to the air conditioner in a pulse modulation signal mode through the air conditioner remote controller, wherein the control signals can be instant trigger start operation instructions, timing trigger start operation instructions and the like, and the start operation instructions can be coil refrigerating operation instructions, capillary heating operation instructions, coil heating operation instructions and operation instructions of other operation modes of the air conditioner.

S12, opening the coil air valve T1 and the capillary air valve T2, controlling the starting of the compressor COM, and then proceeding to step S13.

For example, since the air conditioner integrates the capillary indoor unit and the coil indoor unit, the circulation of the refrigerant during heating or heating of the air conditioner may cause that part of the refrigerant remains in the room when the operation of the air conditioner is finished, in order to avoid the problems of large difficulty in controlling the refrigerant and poor temperature adjustment effect during the subsequent operation caused by the residual refrigerant in the capillary heat exchanger E2, the air conditioner responds to the starting operation command to enter the refrigerant recovery mode to recover the indoor refrigerant, specifically, the coil expansion valve PMV1 on one side of the coil heat exchanger E1 and the capillary expansion valve PMV2 on one side of the capillary heat exchanger E2 are respectively closed, the coil air valve T1 on the other side of the coil heat exchanger E1 and the capillary air valve T2 on the other side of the capillary heat exchanger E2 are respectively opened, and after the valve control is performed, the external fans (not shown in the drawing) in the compressor COM and the outdoor unit 300 can be started, so that the refrigerant in the coil heat exchanger E1 and the capillary heat exchanger E2 can be respectively recovered from the coil air valve T1 and the capillary air valve T2 to the outdoor unit 300, and the external fans can be operated at the maximum speed allowed by the external fans to accelerate the refrigerant recovery efficiency. In the specific refrigerant recovery process, as shown in fig. 4, after the compressor COM and the external fan are operated, the refrigerant in the compressor COM is transferred to the outdoor heat exchanger E3 (shown by a dotted line in the drawing) through the second end d and the first end c of the four-way valve FWV by the exhaust port of the compressor COM, and the refrigerant in the coil heat exchanger E1 and the capillary heat exchanger E2 flows out from the coil air valve T1 and the capillary air valve T2 respectively and flows into the compressor COM (shown by a solid line in the drawing) through the third end E and the fourth end s of the four-way valve FWV by the suction port of the compressor COM.

Note that the execution sequence of the closing/opening of the coil expansion valve PMV1 and the capillary expansion valve PMV2 in step S11 and the coil air valve T1 and the capillary air valve T2 in step S12 is not limited to the specific execution sequence described above, and may be controlled in any execution sequence. Preferably, in order to complete refrigerant recovery as soon as possible, the closing of the coil expansion valve PMV1 and the capillary expansion valve PMV2 and the opening of the coil air valve T1 and the capillary air valve T2 are performed before the start of the compressor COM, for example, if the coil expansion valve PMV1 (capillary expansion valve PMV 2) is closed after the start of the compressor COM, the coil expansion valve PMV1 (capillary expansion valve PMV 2) is closed, which causes additional refrigerant to enter the coil heat exchanger E1 (capillary heat exchanger E2), increasing the amount of refrigerant to be recovered; if the coil air valve T1 (capillary air valve T2) is opened after the compressor COM is started, the refrigerant in the coil heat exchanger E1 (capillary heat exchanger E2) can be recycled to the compressor COM without a channel after the compressor COM is started before the coil air valve T1 (capillary air valve T2) is opened, and the compressor COM does idle work at this time, so that in order to improve the recycling efficiency, the closing of the coil expansion valve PMV1 and the capillary expansion valve PMV2 and the opening of the coil air valve T1 and the capillary air valve T2 are performed before the compressor COM is started.

Preferably, the coil air valve T1 and the capillary air valve T2 are solenoid valves, and the coil expansion valve PMV1 and the capillary expansion valve PMV2 are electronic expansion valves.

And S13, judging whether the refrigerant recovery ending condition is met, if so, proceeding to the step S14, and if not, repeating the step S13 until the refrigerant recovery ending condition is met, and proceeding to the step S14.

For example, in view of practical engineering application, when the number of refrigerants in the coil heat exchanger E1 and the capillary heat exchanger E2 is small, the refrigerant recovery can be finished, and at this time, the air conditioner is switched from the refrigerant recovery mode to the normal operation mode (such as a cooling mode and a heating mode), and when the number of refrigerants in the specific coil heat exchanger E1 and the capillary heat exchanger E2 is small, the refrigerant recovery is finished, which needs to be set according to practical application.

S14, closing an air valve in a non-operating room and opening an expansion valve of an operating indoor unit so that the air conditioner enters a normal operation stage.

The method includes the steps of firstly recovering residual refrigerant from an indoor heat exchanger in response to a starting operation instruction, closing an air valve of an indoor unit which does not operate when a refrigerant recovery end condition is met, opening an expansion valve of the indoor unit which operates to switch the air conditioner back to a normal operation mode from a refrigerant recovery mode, for example, assuming that a coil indoor unit is used for refrigerating, and a capillary indoor unit is not operated, valves at two ends of the capillary heat exchanger E2 are in a closed state at the moment, so that refrigerant and lubricating oil cannot enter the capillary heat exchanger E2 in a normal refrigerating stage, and comprehensively, the refrigerant is recovered before the air conditioner is normally operated, and the valves at two ends of the indoor heat exchanger which does not operate are closed after the refrigerant recovery is finished, so that the air conditioner is subjected to refrigerant addition according to the requirements of the indoor heat exchanger which is actually operated when the air conditioner is normally operated, the control difficulty of the refrigerant is reduced, the temperature adjusting effect is improved, and the user experience is improved.

It should be noted that, the normal operation stage indicates that the air conditioner enters a conventional cooling/heating link, and performs cooling/heating according to the existing cooling/heating mode.

In the embodiment of the invention, the air conditioner is provided with the coil expansion valve PMV1 and the capillary expansion valve PMV2 closed and the coil air valve T1 and the capillary air valve T2 opened by responding to the starting operation instruction, so that a communication channel exists between the coil heat exchanger E1 and the capillary heat exchanger E2 and the compressor COM respectively, refrigerants in the coil heat exchanger E1 and the capillary heat exchanger E2 are recovered to the compressor COM respectively through the communication channel after the compressor COM is started, when the refrigerant is recovered, and when the starting operation instruction is a refrigerating operation instruction, the air valve of the indoor unit which is not operated is closed and the expansion valve of the indoor unit which is operated is opened, and the air conditioner enters a normal operation stage, thereby reducing the refrigerant control difficulty, improving the temperature control effect and ensuring the user experience.

Specifically, the start operation instruction may be a coil refrigeration operation instruction, a capillary heating operation instruction, or a coil heating operation instruction, whether the start operation instruction is a coil refrigeration operation instruction, a capillary heating operation instruction, or a coil heating operation instruction, the air conditioner first enters a refrigerant recovery mode, and the corresponding operation mode is performed according to the type of the start operation instruction after the refrigerant recovery mode is finished, which is specifically described in the following three specific embodiments.

In a first embodiment, referring to fig. 5, fig. 5 shows a second workflow diagram of a controller under capillary tube heating run instructions, the controller executing steps S11-S13 in response to the capillary tube heating run instructions, and further for executing step S15:

and S15, when a preset refrigerant recovery ending condition is met and the starting operation instruction is a heating operation instruction, closing the coil pipe air valve T1 and opening the capillary tube expansion valve PMV2 so that the air conditioner enters a capillary tube heating stage.

When the starting operation instruction is a capillary heating operation instruction, the refrigerant recovery is performed on the indoor heat exchanger, and the main purpose is to recover the refrigerant in the indoor heat exchanger which does not participate in operation. When the refrigerant recovery end condition is met and the starting operation instruction is the capillary tube heating operation instruction, the coil pipe air valve T1 is closed, and the capillary tube expansion valve PMV2 is opened, so that the air conditioner is switched back to the capillary tube heating mode from the refrigerant recovery mode.

In a second embodiment, the controller responds to a coil refrigeration operation command, and after steps S11 to S13 are performed, closes the capillary valve T2 and opens the coil expansion valve PMV1 when a preset refrigerant recovery end condition is satisfied, so that the air conditioner enters a coil refrigeration mode.

In a third embodiment, the controller responds to a coil heating operation command, and after steps S11 to S13 are performed, closes the capillary valve T2 and opens the coil expansion valve PMV1 when a preset refrigerant recovery end condition is satisfied, so that the air conditioner enters a coil heating mode.

In the embodiment of the invention, after the refrigerant recovery of the coil heat exchanger E1 and the capillary heat exchanger is finished, the valves at the two ends of the non-operating heat exchanger are in a normally closed state, so that the refrigerant and lubricating oil cannot enter the non-operating heat exchanger in a normal operation stage, the refrigerant is added according to the requirements of the actually operating heat exchanger when the air conditioner heats/refrigerates, and the control difficulty of the refrigerant is reduced. In addition, in the air conditioner, the effect of heating is better through laying the capillary on the floor, when the capillary is used for refrigerating, the capillary pipeline laid on the ground is too long, the pressure drop loss is larger, the whole pipeline from the capillary to the air suction side of the compressor is easily frosted seriously, the low pressure is too low, the operation frequency of the compressor is low, the refrigerating effect is poor, and the condensation on the ground of a room is caused, so that the capillary is not used for refrigerating in the embodiment. In general, the coil indoor unit is used for cooling and the capillary indoor unit is used for heating (when the capillary indoor unit fails, the coil indoor unit is used for heating).

The outdoor unit 300 is configured to provide refrigeration cycle power/heating cycle power to the coil indoor unit 100 and provide heating cycle power to the capillary tube indoor unit 200, and includes a compressor COM, an outdoor heat exchanger E3, and a four-way valve FWV, where the four-way valve FWV is a control valve having four ports, and is an indispensable device in an air conditioner having a refrigeration function and a heating function, and is configured to change a flow direction of a refrigerant in a system pipeline, thereby changing a refrigeration condition and a heating condition of the air conditioner.

The controller is further configured to perform steps S110 to S130:

and S110, after responding to a starting operation instruction, controlling the four-way valve FWV to be in a non-energized state so as to conduct a first end and a second end in the four-way valve FWV, wherein a third end and a fourth end of the four-way valve FWV are conducted.

In response to the start-up operation command, the controller controls the four-way valve FWV to be in a non-energized state, wherein the first end c and the second end d of the four-way valve FWV are communicated, and the third end e and the fourth end s of the four-way valve FWV are communicated. At this time, the flow direction of the refrigerant in the air conditioner may be seen in fig. 4, specifically, the coil expansion valve PMV1 and the capillary expansion valve PMV2 are closed, the coil air valve T1 and the capillary air valve T2 are opened, the compressor COM and the outdoor fan are operated, the refrigerant in the coil heat exchanger E1 and the capillary heat exchanger E2 respectively flows out of the coil air valve T1 and the capillary air valve T2, then flows in from the third end E of the four-way valve FWV through the air pipe stop valve, flows out of the fourth end s of the four-way valve FWV, finally flows in the compressor COM through the air suction port of the compressor COM, and the refrigerant in the compressor COM is discharged through the air discharge port, flows out of the second end d of the four-way valve FWV, flows out of the first end c of the four-way valve FWV, finally flows in the outdoor heat exchanger E3, and the refrigerant can only stay in the outdoor heat exchanger E3, and the pipes between the outdoor heat exchanger E3 and the capillary expansion valve PMV2 and the coil expansion valve PMV 1; the air pipe stop valve GV1 and the liquid pipe stop valve GV2 in fig. 4 only function before the indoor unit and the outdoor unit 300 of the air conditioner are not assembled, so as to avoid leakage of refrigerant and the like in the outdoor unit 300 before being assembled, and the air pipe stop valve and the liquid pipe stop valve are normally opened during operation of the subsequent air conditioner.

Preferably, referring to fig. 4, an electronic expansion valve PMV3 is provided at one side of the outdoor heat exchanger E3 to which the coil expansion valve PMV1 and the capillary expansion valve PMV2 are connected, and the refrigerant is confined in the outdoor heat exchanger E3.

Specifically, the embodiment of the present invention performs a refrigerating cycle and a heating cycle of an air conditioner by using a compressor, a condenser, an expansion valve, and an evaporator, the refrigerating cycle and the heating cycle including a series of processes involving compression, condensation, expansion, and evaporation, and supplying a refrigerant to air that has been conditioned and heat-exchanged, the compressor compressing a refrigerant gas in a high-temperature and high-pressure state and discharging the compressed refrigerant gas, the discharged refrigerant gas flowing into the condenser, the condenser condensing the compressed refrigerant into a liquid phase, and heat being released through the condensation process. The expansion valve expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve to take heat away, and returns the refrigerant gas in a low temperature and low pressure state to the compressor. In the refrigeration cycle, the outdoor heat exchanger E3 of the air conditioner serves as a condenser, the coil heat exchanger E1 serves as an evaporator, and in the heating cycle, the outdoor heat exchanger E3 of the air conditioner serves as an evaporator, and the capillary heat exchanger E2/coil heat exchanger E1 serves as a condenser, thereby achieving the purpose of adjusting the temperature of the indoor space.

And S120, when the air conditioner is in a refrigeration mode, controlling the four-way valve FWV to be in a non-energized state so as to conduct a first end and a second end in the four-way valve FWV, and conducting a third end and a fourth end of the four-way valve FWV.

The air conditioner in the refrigeration mode is in a normal refrigeration stage, and when the start operation command is a coil refrigeration operation command, the air conditioner is switched from a refrigerant recovery mode to a refrigeration mode after refrigerant recovery, the four-way valve FWV is in a non-energized state, a first end c and a second end d of the four-way valve FWV are communicated, and a third end e and a fourth end s of the four-way valve FWV are communicated. At this time, the flow direction of the refrigerant in the air conditioner may be referred to as fig. 6, in which fig. 6 shows a schematic flow direction of the refrigerant in the cooling mode, in which the capillary valve T2 and the capillary valve PMV2 are normally closed, the coil valve PMV1 and the coil valve T1 are normally opened, the refrigerant gas with high temperature and high pressure is discharged from the discharge port of the compressor COM, flows into the four-way valve FWV, flows into the second end d of the four-way valve FWV, flows out from the first end c of the four-way valve FWV, flows into the outdoor heat exchanger E3, the outdoor heat exchanger E3 at this time acts as a condenser, the refrigerant gas releases heat at the outdoor heat exchanger E3, flows into the coil valve PMV1 in the room through the electronic expansion valve at the condenser side, then absorbs heat at the coil heat exchanger E1 acting as an evaporator, flows out of the coil valve T1, flows into the four-way valve FWV, flows into the third end E of the four-way valve FWV, flows out of the fourth end s, finally flows into the suction port of the compressor COM, and one cycle is completed.

And S130, when the air conditioner is in a heating mode, controlling the four-way valve FWV to be in an electrified state so as to conduct a first end and a fourth end in the four-way valve FWV, and conducting a second end and a third end of the four-way valve FWV.

The air conditioner in the heating mode is in a normal heating stage, for example, when the start operation command is a capillary heating operation command, the air conditioner is switched from the refrigerant recovery mode to the capillary heating mode (the heating mode includes a capillary heating mode and a coil heating mode) after the refrigerant is recovered, the four-way valve FWV is controlled to be electrified, so that the second end d and the third end e of the four-way valve FWV are communicated, and the first end c and the fourth end s of the four-way valve FWV are communicated. At this time, the flow direction of the refrigerant in the air conditioner may be referred to as fig. 7, in which fig. 7 shows a schematic flow direction of the refrigerant in the heating mode, in which the coil air valve T1 and the coil air valve PMV1 are normally closed, the capillary air valve PMV2 and the capillary air valve T2 are normally open, the refrigerant gas with high temperature and high pressure is discharged from the exhaust port of the compressor COM, flows into the four-way valve FWV, flows into the second end d of the four-way valve FWV, flows out from the third end E of the four-way valve FWV, flows into the capillary heat exchanger E2 through the capillary air valve T2, at this time, the capillary heat exchanger E2 acts as a condenser, the refrigerant releases heat at the capillary heat exchanger E2, then flows out through the capillary air valve PMV2, flows into the outdoor heat exchanger E3, at this time, the outdoor heat exchanger E3 acts as an evaporator, the refrigerant absorbs heat at the outdoor heat exchanger E3, flows into the four-way valve FWV, flows out from the first end c of the four-way valve FWV, flows out from the fourth end s of the four-way valve FWV, and finally flows into the air intake port of the compressor COM, thereby completing the heating cycle once.

In the embodiment of the invention, the operation mode of the air conditioner can be adjusted by the working state of the four-way valve FWV, the four-way valve FWV in the cooling mode and the refrigerant recovery mode is in the non-energized state, the four-way valve FWV in the heating mode is in the energized state, in addition, the specific function of the outdoor heat exchanger E3 is also related to the working state of the four-way valve FWV, the outdoor heat exchanger E3 in the cooling mode acts as a condenser, and the outdoor heat exchanger E3 in the heating mode acts as an evaporator.

Specifically, when the air conditioner is in the refrigerant recovery mode, a certain pressure is formed when the refrigerant flows in the pipeline, so that the refrigerant recovery degree can be determined through pressure detection, and whether the refrigerant recovery is finished or not is determined.

Specifically, the air conditioner further includes a first pressure sensor PS, disposed between the fourth end of the four-way valve FWV and the air intake port of the compressor COM, for detecting a first pressure value of a pipeline between the fourth end of the four-way valve FWV and the air intake port of the compressor COM; the refrigerant recovery end condition is: and detecting that the first pressure value is smaller than a preset low pressure threshold value.

Referring to fig. 8, fig. 8 shows a third operation flowchart of the controller according to the embodiment of the present invention, where the controller is configured to perform the determination in step S13 as to whether the refrigerant recovery end condition is satisfied, and specifically includes steps S131 to S132:

S131, acquiring a first pressure value detected by the first pressure sensor PS, and then entering step S132;

s132, judging whether the first pressure value is smaller than a preset low pressure threshold value, if yes, entering a step S133, and if not, returning to the step S131;

s133, meeting the refrigerant recovery ending condition.

As an example, in connection with the refrigerant recovery process shown in fig. 4, the first pressure sensor PS is disposed between the fourth end s of the four-way valve FWV and the suction port of the compressor COM, the indoor refrigerant flows from the third end e of the four-way valve FWV to the fourth end of the four-way valve FWV, and finally the compressor COM is recovered from the suction port of the compressor COM, so that it is known that the refrigerant passing therethrough is less when the first pressure value detected by the first pressure sensor PS is smaller, and the refrigerant recovery end condition is satisfied when the obtained first pressure value is smaller than 0.05Mpa, assuming that the low pressure threshold is 0.05 Mpa. The first pressure value may be obtained and judged by a real-time calculation method or a timing obtaining/judging method, and the first pressure value is specifically set according to practical application and is not limited herein.

Specifically, after the refrigerant is recovered, more refrigerant is accumulated at the outdoor heat exchanger E3 of the air conditioner, and in order to balance the internal pressure of the air conditioner, the refrigerant is split in a manner of arranging a pipeline and a valve, so that the system runs stably.

Specifically, in connection with fig. 9, the air conditioner further includes:

an injection valve SV1 provided between the outdoor heat exchanger E3 and the intake port of the compressor COM for balancing the internal pressure of the air conditioner;

an unloading valve SV2, which is arranged between the exhaust port of the compressor COM and the air suction port of the compressor COM, and is used for balancing the internal pressure of the air conditioner;

the controller is further configured to: after the preset refrigerant recovery end condition is met and before the normal refrigerating operation or the normal heating operation is performed, the injection valve SV1 and the unloading valve SV2 are opened.

For example, taking the refrigerant flow direction after the start operation command is the cooling operation command (coil cooling operation command) and the end of the refrigerant recovery condition as an example, referring to the refrigerant flow direction schematic shown in fig. 9, the capillary valve T2 and the capillary expansion valve PMV2 are closed, the coil valve T1 and the coil expansion valve PMV1 are opened, the injection valve SV1 and the unloading valve SV2 are opened, two other refrigerant flows are included in addition to the refrigerant circulation necessary for cooling, the first being the refrigerant part discharged from the discharge port of the compressor COM flows to the unloading valve SV2 and returns from the unloading valve SV2 to the suction port of the compressor COM, and the second being the refrigerant part flowing to the injection valve SV1 from the injection valve SV1 back to the suction port of the compressor COM. It will be appreciated that, in the refrigeration start stage, since the outdoor heat exchanger E3 has more refrigerant after the refrigerant is recovered, in order to balance the internal pressure of the air conditioner, the opening of the unloading valve SV2 reduces the refrigerant flowing to the outdoor heat exchanger E3, and the opening of the injection valve SV1 avoids a large amount of refrigerant flowing to the indoor space, so that the unloading valve SV2 and the injection valve SV1 play a role in maintaining stability, and the unloading valve SV2 and the injection valve SV1 are not closed until the number of refrigerant in the outdoor heat exchanger E3 is reduced to a preset degree or the opening time of the unloading valve SV2 and the injection valve SV1 reaches a preset time. Preferably, the unloader valve SV2 and the injector valve SV1 are opened before opening the coil expansion valve PMV1 and closing the capillary valve T2.

It can be understood that, in the case where the start-up operation instruction is the capillary heating operation instruction, when the refrigerant recovery end condition is satisfied, the unloading valve SV2 and the injection valve SV1 are also opened to balance the internal pressure of the air conditioner. Preferably, the unloader valve SV2 and the injector valve SV1 are opened before opening the capillary expansion valve PMV2 and closing the coil valve T1.

Specifically, in connection with fig. 9, the air conditioner further includes:

the exhaust temperature sensor TD is arranged at an exhaust port of the compressor COM and is used for detecting the exhaust temperature of the compressor COM;

and a second pressure sensor PD provided at a second end of the four-way valve FWV for detecting a second pressure value of the gas passing through the second end of the four-way valve FWV.

Referring to fig. 10, a fourth operational flow diagram of a controller is provided according to an embodiment of the present invention. The controller is further configured to perform steps S16 to S20:

s16, after the air conditioner enters normal refrigeration operation or normal heating operation, acquiring the exhaust temperature, and then entering a step S17;

s17, judging whether the exhaust temperature is greater than a preset high temperature threshold, if so, entering a step S18, and if not, returning to the step S16;

s18, reducing the running frequency of the compressor COM, and then entering step S19;

S19, monitoring the change trend of the exhaust temperature, and then entering step S20;

s20, when the exhaust temperature increases, the injection valve SV1 is opened.

Referring to fig. 11, a fifth workflow diagram of a controller is provided for an embodiment of the present invention. The controller is further configured to perform steps S21 to S25:

s21, after the air conditioner enters normal refrigeration operation (coil refrigeration stage) or normal heating operation (capillary tube heating stage/coil heating stage), acquiring the second pressure value, and then entering step S22;

s22, judging whether the second pressure value is larger than a preset high pressure threshold value, if so, entering a step S23, and if not, returning to the step S21;

s23, reducing the running frequency of the compressor COM, and then entering step S24;

s24, monitoring the change trend of the second pressure value, and then entering step S25;

s25, when the second pressure value increases, opening the unloading valve SV2.

In the present embodiment, after the step of closing the injection valve SV1 and the unloading valve SV2, which is "until the amount of refrigerant in the outdoor heat exchanger E3 decreases to a preset level or the opening time periods of the unloading valve SV2 and the injection valve SV1 reach a preset time period, the unloading valve SV2 and the injection valve SV1 are closed", steps S16 to S20 and steps S21 to S25 are performed to determine whether the injection valve SV1 and the unloading valve SV2 need to be re-opened. When the temperature of the air discharged from the compressor COM is too high or the discharged air is too much, the operating frequency of the compressor COM is first reduced to limit the temperature and quantity of the air discharged from the compressor COM, if the temperature continues to rise after the compressor COM is down-converted, the injection valve SV1 is opened to introduce part of the air discharged from the air outlet of the compressor COM back to the air inlet of the compressor COM, so as to reduce the supply of the refrigerant to the room, and if the second pressure value continues to rise after the compressor COM is down-converted, the unloading valve SV2 is opened to reflux part of the refrigerant from the unloading valve SV2 to the compressor COM.

Specifically, referring to fig. 9, the air conditioner further includes an oil separator OS, a gas-liquid separator GLS; the first end of the oil separator OS is connected with the exhaust port of the compressor COM, the second end of the oil separator OS is connected with the second end of the four-way valve FWV, the third end of the oil separator OS is connected with the air suction port of the compressor COM, and the oil separator OS is used for separating lubricating oil in high-pressure steam exhausted by the compressor COM so as to ensure that the air conditioner runs safely and efficiently; the gas-liquid separator GLS is disposed at the air suction port side of the compressor COM, and the main function of the gas-liquid separator GLS is to accommodate part of refrigerant in the liquid return system, prevent the compressor COM from being impacted by liquid, and avoid the dilution of the compressor COM oil by excessive refrigerant.

Specifically, referring to fig. 12, the air conditioner further includes a tank heat exchanger E4 for supplying domestic hot water, and the four-way valve FWV of the tank heat exchanger E4 is in an energized state when operated.

Specifically, the coil indoor unit 100 and the capillary indoor unit 200 of the air conditioner are not limited to one, and can be expanded according to practical applications, when the air conditioner cools, all the coil indoor units 100 are not required to work simultaneously, and can be controlled according to practical requirements, when the air conditioner heats, all the capillary indoor units 200 are not required to work simultaneously, and can be controlled according to practical requirements, and in a cooling mode/heating mode, valves on two sides of an indoor heat exchanger which does not participate in cooling/heating are closed. Referring to the schematic structure of the air conditioner shown in fig. 12, it is assumed that the air conditioner includes 4 rooms, each of the room 1 and the room 2 includes a coil indoor unit and a capillary indoor unit, the room 3 includes a coil indoor unit, the room 4 includes a tank heat exchanger E4, two ends of the tank heat exchanger E4 are respectively provided with an expansion valve PMV4 and a solenoid valve T3, the solenoid valve of the tank heat exchanger E4 is connected with a third end of the four-way valve FWV, the expansion valve of the tank heat exchanger E4 is connected with the outdoor heat exchanger E3, and similarly, in the refrigerant recovery mode, the expansion valve of the tank heat exchanger E4 is closed, the solenoid valve of the tank heat exchanger E4 is opened so that refrigerant in the tank heat exchanger E4 is recovered, and in the cooling mode, the valves on both sides of the tank heat exchanger E4 are closed when the tank heat is required to supply hot water to the tank.

Further, a water temperature sensor is arranged at the water tank and used for monitoring the real-time water temperature, and the controller is also used for comparing the real-time water temperature with the preset water temperature and controlling the opening of the expansion valve of the water tank heat exchanger E4 according to the comparison result. For example, the opening degree of the expansion valve of the water tank heat exchanger is increased when the difference between the real-time water temperature and the preset water temperature is greater than the preset temperature difference and the real-time water temperature is less than the preset water temperature, and the opening degree of the expansion valve of the water tank heat exchanger is decreased when the difference between the real-time water temperature and the preset water temperature is greater than the preset temperature difference and the real-time water temperature is greater than the preset water temperature.

Compared with the prior art, the air conditioner disclosed by the embodiment of the invention integrates the coil pipe indoor unit and the capillary pipe indoor unit, the refrigerant in the indoor heat exchanger is recovered, the valves at the two ends of the non-operating heat exchanger are closed after the refrigerant is recovered, the residual refrigerant in the non-operating indoor heat exchanger is avoided, the addition of the refrigerant is accurately controlled according to the actually operating indoor unit, the insufficient refrigerant and liquid return caused by excessive refrigerant addition are avoided, a liquid storage device is not required to be specially added, the refrigerant control difficulty and cost are reduced, and the control effect and the user experience of the indoor temperature during refrigeration are improved.

Referring to fig. 13, fig. 13 is a flowchart of an air conditioner control method according to an embodiment of the present invention, wherein the air conditioner control method according to an embodiment of the present invention is implemented by a controller in the air conditioner, and the air conditioner includes a coil indoor unit 100, a capillary indoor unit 200, and an outdoor unit 300, the coil indoor unit 100 includes a coil air valve T1, a coil heat exchanger E1, and a coil expansion valve PMV1 that are sequentially connected, the capillary indoor unit 200 includes a capillary air valve T2, a capillary heat exchanger E2, and a capillary expansion valve PMV2 that are sequentially connected, and the outdoor unit 300 includes a compressor COM, an outdoor heat exchanger E3, and a four-way valve FWV; the air conditioner control method includes:

s1, responding to a starting operation command, and closing a coil expansion valve PMV1 and a capillary expansion valve PMV2;

s2, opening a coil pipe air valve T1 and a capillary pipe air valve T2, controlling a compressor COM to start until a preset refrigerant recovery end condition is met, closing an air valve of an indoor unit which does not operate and opening an expansion valve of the indoor unit which operates, so that the air conditioner enters a normal operation stage.

It should be noted that, the air conditioner according to the embodiment of the present invention includes a coil indoor unit 100, a heating outdoor unit 300 and an outdoor unit 300, wherein the coil indoor unit 100 is used for reducing the temperature of indoor air, the capillary indoor unit 200 is used for increasing the temperature of indoor air, the outdoor unit 300 is used for providing cooling/heating cycle power to the coil indoor unit 100 and heating cycle power to the capillary indoor unit 200, the outdoor unit 300 is installed outdoors, and the coil indoor unit 100 and the capillary indoor unit 200 are installed indoors. The coil indoor unit 100 comprises a coil air valve T1, a coil heat exchanger E1 and a coil expansion valve PMV1 which are sequentially connected, and the capillary indoor unit 200 comprises a capillary air valve T2, a capillary heat exchanger E2 and a capillary expansion valve PMV2 which are sequentially connected; the outdoor unit 300 includes a compressor COM, an outdoor heat exchanger E3, and a four-way valve FWV. Specifically, a first end c of the four-way valve FWV is connected to the outdoor heat exchanger E3, a second end d of the four-way valve FWV is connected to an exhaust port of the compressor COM, a third end E of the four-way valve FWV is connected to the coil air valve T1 and the capillary air valve T2, respectively, and a fourth end s of the four-way valve FWV is connected to an air suction port of the compressor COM. The flow direction of the refrigerant is controlled by controlling the state of the four-way valve FWV, and then the mode of the air conditioner is controlled. The operation modes of the air conditioner comprise a refrigeration mode, a heating mode and a refrigerant recovery mode, wherein the heating mode comprises disk heating and capillary heating.

When the air conditioner receives the start operation command, it will first enter a refrigerant recovery mode, and the capillary tube indoor unit 200 and the coil indoor unit 100 will not operate at this time, and the outdoor unit 300 will operate to recover the refrigerant.

Specifically, in step S1, in response to a start-up operation instruction, the coil expansion valve PMV1 and the capillary expansion valve PMV2 are closed, where the start-up operation instruction may be an instruction input in real time by a user, or may be a preset instruction, such as a timing trigger start-up operation instruction; the user can input a control signal to the air conditioner in a pulse modulation signal mode through the air conditioner remote controller, wherein the control signal can be a prompt trigger start operation instruction, a timing trigger start operation instruction and the like, and the start operation instruction can be a refrigeration operation instruction, a heating operation instruction or an operation instruction of other operation modes of the air conditioner, and is not limited herein.

Specifically, in step S2, the coil air valve T1 and the capillary air valve T2 are opened, and the compressor COM is controlled to be started. Because the air conditioner integrates the coil indoor unit and the capillary indoor unit, the circulation of the refrigerant during heating or heating of the air conditioner can cause the situation that part of the refrigerant remains indoors when the operation of the air conditioner is finished, in order to avoid the problems of large control difficulty and poor temperature regulation effect of the refrigerant in the subsequent operation caused by the residual refrigerant in the capillary tube heat exchanger E2, the air conditioner responds to the starting operation instruction and enters a refrigerant recovery mode to recover the indoor refrigerant, specifically, the coil expansion valve PMV1 at one side of the coil heat exchanger E1 and the capillary tube expansion valve PMV2 at one side of the capillary tube heat exchanger E2 are respectively closed, the coil air valve T1 at the other side of the coil heat exchanger E1 and the capillary air valve T2 at the other side of the capillary tube heat exchanger E2 are respectively opened, after the valve control is finished, the external fans in the compressor COM and the outdoor unit 300 can be started, so that the refrigerant in the coil heat exchanger E1 and the capillary tube heat exchanger E2 can be respectively recovered to the outdoor unit 300 from the coil air valve T1 and the capillary air valve T2, and the external fans can be operated at the highest speed allowed. In the specific refrigerant recovery process, as shown in fig. 4, after the compressor COM and the external fan are operated, the exhaust port of the compressor COM transmits the refrigerant in the compressor COM to the outdoor heat exchanger E3 through the second end d and the first end c of the four-way valve FWV, and the refrigerant in the coil heat exchanger E1 and the capillary heat exchanger E2 flows out from the coil air valve T1 and the capillary air valve T2 respectively, and flows into the compressor COM through the third end E and the fourth end s of the four-way valve FWV from the air suction port of the compressor COM.

Note that the execution sequence of the closing/opening of the coil expansion valve PMV1 and the capillary expansion valve PMV2 in step S1 and the coil air valve T1 and the capillary air valve T2 in step S2 is not limited to the specific execution sequence described above, and may be controlled in any execution sequence. Preferably, in order to complete refrigerant recovery as soon as possible, the closing of the coil expansion valve PMV1 and the capillary expansion valve PMV2 and the opening of the coil air valve T1 and the capillary air valve T2 are performed before the start of the compressor COM, for example, if the coil expansion valve PMV1 (capillary expansion valve PMV 2) is closed after the start of the compressor COM, the coil expansion valve PMV1 (capillary expansion valve PMV 2) is closed, which causes additional refrigerant to enter the coil heat exchanger E1 (capillary heat exchanger E2), increasing the amount of refrigerant to be recovered; if the coil air valve T1 (capillary air valve T2) is opened after the compressor COM is started, the refrigerant in the coil heat exchanger E1 (capillary heat exchanger E2) can be recycled to the compressor COM without a channel after the compressor COM is started before the coil air valve T1 (capillary air valve T2) is opened, and the compressor COM does idle work at this time, so that in order to improve the recycling efficiency, the closing of the coil expansion valve PMV1 and the capillary expansion valve PMV2 and the opening of the coil air valve T1 and the capillary air valve T2 are performed before the compressor COM is started.

In step S2, when a preset refrigerant recovery end condition is satisfied, and the start operation instruction is a refrigeration operation instruction, the air valve of the indoor unit that is not in operation is closed, and the expansion valve of the indoor unit that is in operation is opened, so as to switch the air conditioner from the refrigerant recovery mode to the normal operation mode. Considering practical engineering application, when the number of refrigerants in the coil heat exchanger E1 and the capillary heat exchanger E2 is small, the refrigerant recovery can be finished, and at this time, the air conditioner is switched from the refrigerant recovery mode to the normal operation mode (such as a refrigeration mode and a heating mode), and when the number of refrigerants in the specific coil heat exchanger E1 and the capillary heat exchanger E2 is small, the refrigerant recovery is finished, and the air conditioner needs to be set according to practical application. For example, the coil indoor unit is assumed to refrigerate, and the capillary indoor unit is not operated, then the valves at the two ends of the capillary heat exchanger E2 are all in a closed state, so that in the normal refrigeration stage, the refrigerant and the lubricating oil cannot enter the capillary heat exchanger E2, and in a comprehensive way, the refrigerant is recovered before the air conditioner is normally operated, and the valves at the two ends of the indoor heat exchanger which is not operated are closed after the refrigerant is recovered, so that the refrigerant is added according to the requirements of the indoor heat exchanger which is actually operated when the air conditioner is normally operated, the control difficulty of the refrigerant is reduced, the temperature adjusting effect is improved, and the user experience is improved.

And step S2, closing an air valve of the indoor unit which does not operate and opening an expansion valve of the indoor unit which operates so that the air conditioner enters a normal operation stage, and specifically comprises the following steps:

For example, taking a starting operation instruction as a capillary heating operation instruction as an example, firstly, refrigerant recovery is performed on an indoor heat exchanger, and the main purpose is to recover the refrigerant in the indoor heat exchanger which does not participate in operation. When the refrigerant recovery end condition is met and the starting operation instruction is the capillary tube heating operation instruction, the coil pipe air valve T1 is closed, and the capillary tube expansion valve PMV2 is opened, so that the air conditioner is switched back to the capillary tube heating mode from the refrigerant recovery mode.

Specifically, a first end of the four-way valve FWV is connected to the outdoor heat exchanger E3, a second end of the four-way valve FWV is connected to an exhaust port of the compressor COM, a third end of the four-way valve FWV is connected to the coil air valve T1 and the capillary air valve T2, respectively, and a fourth end of the four-way valve FWV is connected to an air suction port of the compressor COM. The flow direction of the refrigerant is controlled by controlling the state of the four-way valve FWV, and then the mode of the air conditioner is controlled.

It should be noted that the four-way valve FWV is a control valve having four ports, and is an indispensable device in an air conditioner having a refrigeration function and a heating function, and is used for changing the flow direction of a refrigerant in a system pipeline, so as to change the refrigeration working condition and the heating working condition of the air conditioner.

In a first embodiment, the air conditioner control method further includes:

after responding to a starting operation command, the four-way valve FWV is controlled to be in a non-energized state so as to enable a first end and a second end in the four-way valve FWV to be conducted, and a third end and a fourth end of the four-way valve FWV are conducted.

Illustratively, in response to a start-up operation command, the air conditioner first enters a refrigerant recovery mode, controls the four-way valve FWV to be in a non-energized state, and in the non-energized state, the first end c and the second end d of the four-way valve FWV are in communication, and the third end e and the fourth end s of the four-way valve FWV are in communication. At this time, the flow direction of the refrigerant in the air conditioner may be seen in fig. 4, specifically, the coil expansion valve PMV1 and the capillary expansion valve PMV2 are closed, the coil air valve T1 and the capillary air valve T2 are opened, the compressor COM and the outdoor fan are operated, the refrigerant in the coil heat exchanger E1 and the capillary heat exchanger E2 respectively flows out of the coil air valve T1 and the capillary air valve T2, then flows in from the third end E of the four-way valve FWV through the air pipe stop valve, flows out of the fourth end s of the four-way valve FWV, finally flows in the compressor COM through the air suction port of the compressor COM, and the refrigerant in the compressor COM is discharged through the air discharge port, flows out of the second end d of the four-way valve FWV, flows out of the first end c of the four-way valve FWV, finally flows in the outdoor heat exchanger E3, and the refrigerant can only stay in the outdoor heat exchanger E3, and the pipes between the outdoor heat exchanger E3 and the capillary expansion valve PMV2 and the coil expansion valve PMV 1; the air pipe stop valve and the liquid pipe stop valve in fig. 4 only act before the indoor unit and the outdoor unit 300 of the air conditioner are not assembled, so that leakage of refrigerant and the like in the outdoor unit 300 before the air conditioner is not assembled is avoided, and the air pipe stop valve and the liquid pipe stop valve are normally open in the operation process of the subsequent air conditioner.

Preferably, referring to fig. 4, an electronic expansion valve is provided at one side of the outdoor heat exchanger E3 to which the coil expansion valve PMV1 and the capillary expansion valve PMV2 are connected, to restrict the refrigerant in the outdoor heat exchanger E3.

In a second embodiment, the air conditioner control method further includes:

when the air conditioner is in a refrigeration mode, the four-way valve FWV is controlled to be in a non-energized state so that a first end and a second end in the four-way valve FWV are conducted, and a third end and a fourth end of the four-way valve FWV are conducted.

In a third embodiment, the air conditioner control method further includes:

when the air conditioner is in a heating mode, the four-way valve FWV is controlled to be in an electrified state, so that a first end and a fourth end in the four-way valve FWV are conducted, and a second end and a third end of the four-way valve FWV are conducted.

As an example, in connection with the refrigerant recovery process shown in fig. 4, the first pressure sensor PS is disposed between the fourth end s of the four-way valve FWV and the suction port of the compressor COM, the indoor refrigerant flows from the third end e of the four-way valve FWV to the fourth end s of the four-way valve FWV, and finally the compressor COM is recovered from the suction port of the compressor COM, so that it is known that the refrigerant passing therethrough is less when the first pressure value detected by the first pressure sensor PS is smaller, and the refrigerant recovery end condition is satisfied when the obtained first pressure value is smaller than 0.05Mpa, assuming that the low pressure threshold is 0.05 Mpa. The first pressure value may be obtained and judged by a real-time calculation method or a timing obtaining/judging method, and the first pressure value is specifically set according to practical application and is not limited herein.

Specifically, the air conditioner further includes:

the air conditioner control method further includes: after the preset refrigerant recovery end condition is met and before the normal refrigerating operation or the normal heating operation is performed, the injection valve SV1 and the unloading valve SV2 are opened.

Specifically, the air conditioner further includes:

the exhaust temperature sensor is arranged at an exhaust port of the compressor COM and used for detecting the exhaust temperature of the compressor COM;

and a second pressure sensor provided at the second end of the four-way valve FWV for detecting a second pressure value of the gas passing through the second end of the four-way valve FWV.

The air conditioner control method further comprises the following steps:

after the air conditioner enters normal refrigeration operation or normal heating operation, acquiring the exhaust temperature;

and when the exhaust temperature is greater than a preset high temperature threshold value, reducing the operating frequency of the compressor COM, and opening the injection valve SV1 if the exhaust temperature is detected to be increased after the operating frequency is reduced.

The air conditioner control method further comprises the following steps:

after the air conditioner enters normal refrigeration operation or normal heating operation, acquiring the second pressure value;

And when the second pressure value is larger than a preset high pressure threshold value, reducing the running frequency of the compressor COM, and if the second pressure value is detected to be increased after the running frequency is reduced, opening the unloading valve SV2.

In the present embodiment, after the step of closing the injection valve SV1 and the unloading valve SV2, which is described above until the amount of refrigerant in the outdoor heat exchanger E3 decreases to a preset degree or the opening time periods of the unloading valve SV2 and the injection valve SV1 reach a preset time period, the unloading valve SV2 and the injection valve SV1 are closed, a subsequent cooling/heating process needs to be status-monitored to determine whether the injection valve SV1 and the unloading valve SV2 need to be re-opened. When the temperature of the air discharged from the compressor COM is too high or the discharged air is too much, the operating frequency of the compressor COM is first reduced to limit the temperature and quantity of the air discharged from the compressor COM, if the temperature continues to rise after the compressor COM is down-converted, the injection valve SV1 is opened to introduce part of the air discharged from the air outlet of the compressor COM back to the air inlet of the compressor COM, so as to reduce the supply of the refrigerant to the room, and if the second pressure value continues to rise after the compressor COM is down-converted, the unloading valve SV2 is opened to reflux part of the refrigerant from the unloading valve SV2 to the compressor COM.

Specifically, the air conditioner further comprises an oil separator OS and a gas-liquid separator GLS; the first end of the oil separator OS is connected with the exhaust port of the compressor COM, the second end of the oil separator OS is connected with the second end of the four-way valve FWV, the third end of the oil separator OS is connected with the air suction port of the compressor COM, and the oil separator OS is used for separating lubricating oil in high-pressure steam exhausted by the compressor COM so as to ensure that the air conditioner runs safely and efficiently; the gas-liquid separator GLS is disposed at the air suction port side of the compressor COM, and the main function of the gas-liquid separator GLS is to accommodate part of refrigerant in the liquid return system, prevent the compressor COM from being impacted by liquid, and avoid the dilution of the compressor COM oil by excessive refrigerant.

Specifically, the air conditioner further comprises a water tank heat exchanger E4, the water tank heat exchanger E4 is used for providing domestic hot water, and the four-way valve FWV of the water tank heat exchanger E4 is in an electrified state when working.

Specifically, the coil indoor unit 100 and the capillary indoor unit 200 of the air conditioner are not limited to one, and can be expanded according to practical applications, when the air conditioner cools, all the coil indoor units are not required to work simultaneously, and can be controlled according to practical requirements, when the air conditioner heats, all the capillary indoor units are not required to work simultaneously, and can be controlled according to practical requirements, and in a cooling mode/heating mode, valves on two sides of an indoor heat exchanger which does not participate in cooling/heating are closed. Referring to the schematic structure of the air conditioner shown in fig. 12, it is assumed that the air conditioner includes three rooms, each of the room 1 and the room 2 includes a coil indoor unit and a capillary indoor unit, the room 3 includes a coil indoor unit, the room 4 includes a tank heat exchanger E4, both ends of the tank heat exchanger E4 are respectively provided with an expansion valve and an electromagnetic valve, the electromagnetic valve of the tank heat exchanger E4 is connected with a third end of the four-way valve FWV, the expansion valve of the tank heat exchanger E4 is connected with the outdoor heat exchanger E3, and similarly, in the refrigerant recovery mode, the expansion valve of the tank heat exchanger E4 is closed, the electromagnetic valve of the tank heat exchanger E4 is opened so that refrigerant in the tank heat exchanger E4 is recovered, in the cooling mode, valves on both sides of the tank heat exchanger E4 are closed, and when the tank heat exchanger E4 is required to supply heat to the tank so that the tank provides hot water, the valves on both sides of the tank heat exchanger E4 are opened.

Compared with the prior art, the air conditioner control method disclosed by the embodiment of the invention integrates the coil pipe indoor unit and the capillary pipe indoor unit, the refrigerant in the indoor heat exchanger is recovered, the valves at the two ends of the non-operating heat exchanger are closed after the refrigerant is recovered, the residual refrigerant in the non-operating indoor heat exchanger is avoided, the addition of the refrigerant is accurately controlled according to the actually operating indoor unit, the occurrence of insufficient refrigerant and liquid return caused by excessive refrigerant addition is avoided, a liquid storage device is not required to be specially added, the refrigerant control difficulty and cost are reduced, and the control effect and the user experience of the indoor temperature during refrigeration are improved.

While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that changes and modifications may be made without departing from the principles of the invention, such changes and modifications are also intended to be within the scope of the invention.

Claims

1. An air conditioner, comprising:

the controller is used for responding to a starting operation instruction, closing the coil expansion valve and the capillary expansion valve, opening the coil air valve and the capillary air valve, controlling the starting of the compressor until a preset refrigerant recovery ending condition is met, closing the air valve of the indoor unit which does not operate and opening the expansion valve of the indoor unit which operates, so that the air conditioner enters a normal operation stage;

the air conditioner further includes:

the controller is further configured to:

after the preset refrigerant recovery end condition is met and before the normal refrigeration operation or the normal heating operation is carried out, the injection valve and the unloading valve are opened;

the air conditioner further includes:

the controller is further configured to:

2. The air conditioner of claim 1, wherein the controller is configured to close an air valve of the non-operating indoor unit and open an expansion valve of the operating indoor unit to bring the air conditioner into a normal operation phase, and specifically comprises:

3. The air conditioner as set forth in claim 1 or 2, wherein a first end of the four-way valve is connected to the outdoor heat exchanger, a second end of the four-way valve is connected to an exhaust port of the compressor, a third end of the four-way valve is connected to the coil air valve and the capillary air valve, respectively, and a fourth end of the four-way valve is connected to an air suction port of the compressor; the controller is further configured to:

4. The air conditioner according to claim 1 or 2, further comprising:

5. The control method of the air conditioner is characterized in that the air conditioner comprises a coil pipe indoor unit, a capillary pipe indoor unit and an outdoor unit, wherein the coil pipe indoor unit comprises a coil pipe air valve, a coil pipe heat exchanger and a coil pipe expansion valve which are sequentially connected, the capillary pipe indoor unit comprises a capillary pipe air valve, a capillary pipe heat exchanger and a capillary pipe expansion valve which are sequentially connected, and the outdoor unit comprises a compressor, an outdoor heat exchanger and a four-way valve; the air conditioner control method includes:

opening a coil pipe air valve and a capillary air valve, controlling the starting of a compressor until a preset refrigerant recovery end condition is met, closing the air valve of the indoor unit which does not operate and opening an expansion valve of the indoor unit which operates, so that the air conditioner enters a normal operation stage;

after the preset refrigerant recovery end condition is met and before the normal refrigeration operation or the normal heating operation is carried out, an injection valve and an unloading valve are opened; the injection valve is arranged between the outdoor heat exchanger and the air suction port of the compressor and used for balancing the internal pressure of the air conditioner; the injection valve is arranged between the outdoor heat exchanger and the air suction port of the compressor and used for balancing the internal pressure of the air conditioner; the unloading valve is arranged between the exhaust port of the compressor and the air suction port of the compressor and used for balancing the internal pressure of the air conditioner;

after the air conditioner enters normal refrigeration operation or normal heating operation, acquiring an exhaust temperature and a second pressure value; wherein the discharge temperature is detected by a discharge temperature sensor provided at a discharge port of the compressor; the second pressure value is detected by a second pressure sensor arranged at the second end of the four-way valve;

6. The method of controlling an air conditioner according to claim 5, wherein the closing of the air valve of the non-operating indoor unit and the opening of the expansion valve of the operating indoor unit to bring the air conditioner into a normal operation phase, specifically comprise:

7. The air conditioner control method as set forth in claim 5 or 6, wherein a first end of the four-way valve is connected to the outdoor heat exchanger, a second end of the four-way valve is connected to an exhaust port of the compressor, a third end of the four-way valve is connected to the coil air valve and the capillary air valve, respectively, and a fourth end of the four-way valve is connected to an air suction port of the compressor; the air conditioner control method further comprises the following steps:

8. The air conditioner control method as set forth in claim 5 or 6, wherein the air conditioner further comprises a first pressure sensor provided between a fourth end of the four-way valve and an intake port of the compressor;

The refrigerant recovery end condition is: it is detected that the first pressure value is less than a preset low pressure threshold.