CN110631286B

CN110631286B - Heat exchange system and control method

Info

Publication number: CN110631286B
Application number: CN201910996266.9A
Authority: CN
Inventors: 郑波; 吕如兵; 梁祥飞; 黄健贵
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2023-10-10
Anticipated expiration: 2039-10-18
Also published as: CN110631286A

Abstract

The application provides a heat exchange system and a control method, wherein the heat exchange system comprises a first four-way reversing valve, a second four-way reversing valve, a first indoor heat exchanger, a second indoor heat exchanger, an outdoor heat exchanger and a compressor with a first cylinder and a second cylinder. And the indoor return air is subjected to step cooling and dehumidifying treatment, so that the system operation energy efficiency is improved under the condition of ensuring the refrigerating capacity and dehumidifying capacity of the system.

Description

Heat exchange system and control method

Technical Field

The application relates to the technical field of air conditioners, in particular to a heat exchange system and a control method.

Background

In order to meet the dehumidification requirement when air conditioning is performed using an air conditioner, it is generally necessary to lower the evaporator temperature to a greater extent than the return air dew point temperature. From the angle of energy efficiency of the refrigeration system, the lower the evaporation temperature is, namely the larger the suction-discharge pressure ratio of the compressor is, the lower the energy efficiency of the system is under the condition that the condensation temperature of the system is certain.

In order to solve the problem of low system energy efficiency caused by large temperature difference between the return air temperature and the evaporating temperature when the air conditioning system operates, a heat exchange system is provided in the prior art, namely, two evaporators are respectively arranged in a single or same heat exchange channel, and indoor return air is subjected to heat exchange through the two evaporators successively, so that the evaporating temperature of one evaporator is higher than the evaporating temperature of a conventional system, and the system energy efficiency is improved. However, the system uses two mutually independent four-way reversing valves, and when the refrigerating mode and the heating mode are switched, the two four-way reversing valves are required to synchronously act to successfully switch. However, when the four-way reversing valve is used, synchronous operation is not easy to ensure, if the operation is not synchronous, one four-way reversing valve can normally reverse, and the other four-way reversing valve does not normally reverse, so that the operation mode is finally failed to switch.

Disclosure of Invention

The application provides a heat exchange system and a control method, which are used for solving the problem that the heat exchange system in the prior art can fail in switching when switching operation modes.

In order to solve the above problems, according to one aspect of the present application, there is provided a heat exchange system including a first four-way reversing valve, a second four-way reversing valve, a first indoor heat exchanger, a second indoor heat exchanger, an outdoor heat exchanger, and a compressor having a first cylinder and a second cylinder, wherein a first D pipe of the first four-way reversing valve communicates with an exhaust port of the compressor, a first E pipe of the first four-way reversing valve communicates with one end of the first indoor heat exchanger, a first S pipe of the first four-way reversing valve communicates with an intake port of the first cylinder, and a first C pipe of the first four-way reversing valve communicates with one end of the outdoor heat exchanger; the second D pipe of the second four-way reversing valve is communicated with the first E pipe, the second E pipe of the second four-way reversing valve is communicated with one end of the second indoor heat exchanger, the second S pipe of the second four-way reversing valve is communicated with the air suction port of the second air cylinder, and the second C pipe of the second four-way reversing valve is communicated with the first S pipe in an on-off manner; the other end of the first indoor heat exchanger and the other end of the second indoor heat exchanger are communicated with the other end of the outdoor heat exchanger.

Further, the heat exchange system is provided with a refrigeration mode, the first D pipe is communicated with the first C pipe, the first E pipe is communicated with the first S pipe, the second D pipe is communicated with the second C pipe, the second E pipe is communicated with the second S pipe, and the second C pipe is communicated with the first S pipe under the condition that the heat exchange system is in the refrigeration mode.

Further, the heat exchange system is further provided with a heating mode and a cooling-to-heating mode, and under the condition that the heat exchange system is in the cooling-to-heating mode, the first D pipe is communicated with the first E pipe, the first C pipe is communicated with the first S pipe, the second D pipe is communicated with the second C pipe, the second E pipe is communicated with the second S pipe, and the second C pipe is disconnected with the first S pipe.

Further, the heat exchange system is provided with a heating mode, the heat exchange system is in the heating mode, the first D pipe is communicated with the first E pipe, the first C pipe is communicated with the first S pipe, the second D pipe is communicated with the second E pipe, the second C pipe is communicated with the second S pipe, and the second C pipe is communicated with the first S pipe.

Further, the heat exchange system is further provided with a refrigerating mode and a heating-to-refrigerating mode, and under the condition that the heat exchange system is in the heating-to-refrigerating mode, the first D pipe is communicated with the first C pipe, the first E pipe is communicated with the first S pipe, the second D pipe is communicated with the second E pipe, the second C pipe is communicated with the second S pipe, and the second C pipe is disconnected with the first S pipe.

Further, in the case that the heat exchange system is in the cooling mode, the evaporation temperature of the first indoor heat exchanger is higher than the evaporation temperature of the second indoor heat exchanger.

Further, the displacement of the first air cylinder is V1, the displacement of the second air cylinder is V2, and the ratio of V1 to V2 is A, wherein A is more than or equal to 0.3 and less than or equal to 3.

Further, the heat exchange system further comprises: the fan is used for blowing air towards the first indoor heat exchanger and the second indoor heat exchanger, and the first indoor heat exchanger is located between the fan and the second indoor heat exchanger.

Further, the heat exchange system further comprises: and the electromagnetic valve is arranged on a pipeline connecting the second C pipe and the first S pipe so as to control the connection or disconnection of the second C pipe and the first S pipe.

Further, the heat exchange system further comprises: the first throttling structure is arranged on a pipeline connecting the first indoor heat exchanger and the outdoor heat exchanger; and the second throttling structure is arranged on a pipeline for connecting the second indoor heat exchanger and the outdoor heat exchanger.

Further, the heat exchange system further comprises: one end of the third throttling structure is communicated with the other end of the outdoor heat exchanger, and the other end of the first indoor heat exchanger and the other end of the second indoor heat exchanger are both communicated with the other end of the third throttling structure; and the fourth throttling structure is arranged on a pipeline for connecting the second indoor heat exchanger and the third throttling structure.

Further, the heat exchange area of the first indoor heat exchanger is A1, the heat exchange area of the second indoor heat exchanger is A2, and the ratio of A1 to A2 is B, wherein B is more than or equal to 0.3 and less than or equal to 3.

According to another aspect of the present application, there is provided a control method for controlling the above heat exchange system, the control method comprising: and switching the heat exchange system from a refrigerating mode to a heating mode, and controlling the reversing of a first four-way reversing valve of the heat exchange system and then controlling the reversing of a second four-way reversing valve of the heat exchange system in the switching process.

Further, in the process of switching from the refrigeration mode to the heating mode, controlling the reversing of the first four-way reversing valve of the heat exchange system first includes: pushing a sliding block in the first four-way reversing valve to move by utilizing the pressure difference between a first D pipe and a first S pipe of the first four-way reversing valve, so that the communication between the first S pipe and a first E pipe of the first four-way reversing valve is switched to the communication between the first S pipe and a first C pipe of the first four-way reversing valve, and the communication between the first D pipe and the first C pipe is switched to the communication between the first D pipe and the first E pipe; then controlling the reversing of a second four-way reversing valve of the heat exchange system comprises the following steps: and pushing a sliding block in the second four-way reversing valve to move by utilizing the pressure difference between a second D pipe and a second S pipe of the second four-way reversing valve, so that the communication between the second S pipe and a second E pipe of the second four-way reversing valve is switched to the communication between the second S pipe and a second C pipe of the second four-way reversing valve, and the communication between the second D pipe and the second C pipe is switched to the communication between the second D pipe and the second E pipe.

Further, the control method further includes: and switching the heat exchange system from the heating mode to the refrigerating mode, and controlling the reversing of a first four-way reversing valve of the heat exchange system and then controlling the reversing of a second four-way reversing valve of the heat exchange system in the switching process.

Further, in the process of switching from the heating mode to the cooling mode, controlling the reversing of the first four-way reversing valve of the heat exchange system first includes: pushing a sliding block in the first four-way reversing valve to move by utilizing the pressure difference between a first D pipe and a first S pipe of the first four-way reversing valve, so that the communication between the first S pipe and a first C pipe of the first four-way reversing valve is switched to the communication between the first S pipe and a first E pipe of the first four-way reversing valve, and the communication between the first D pipe and the first E pipe is switched to the communication between the first D pipe and the first C pipe; then controlling the reversing of a second four-way reversing valve of the heat exchange system comprises the following steps: and pushing a sliding block in the second four-way reversing valve to move by utilizing the pressure difference between a second D pipe and a second S pipe of the second four-way reversing valve, so that the communication between the second S pipe and a second C pipe of the second four-way reversing valve is switched to the communication between the second S pipe and a second E pipe of the second four-way reversing valve, and the communication between the second D pipe and the second E pipe is switched to the communication between the second D pipe and the second C pipe.

By applying the technical scheme of the application, in the heat exchange system, a first D pipe of a first four-way reversing valve is communicated with an exhaust port of a compressor, a first E pipe of the first four-way reversing valve is communicated with one end of a first indoor heat exchanger, a first S pipe of the first four-way reversing valve is communicated with an air suction port of a first air cylinder, and a first C pipe of the first four-way reversing valve is communicated with one end of an outdoor heat exchanger; the second D pipe of the second four-way reversing valve is communicated with the first E pipe, the second E pipe of the second four-way reversing valve is communicated with one end of the second indoor heat exchanger, the second S pipe of the second four-way reversing valve is communicated with the air suction port of the second air cylinder, and the second C pipe of the second four-way reversing valve can be communicated with the first S pipe in an on-off mode. According to the scheme, the interfaces of the first four-way reversing valve and the second four-way reversing valve are associated, refrigerant discharged from the compressor firstly enters the first four-way reversing valve, then enters the second four-way reversing valve through a pipeline or other parts, so that when the refrigerating and heating operation modes of the heat exchange system are switched, the first four-way reversing valve can be switched to the interface communication state firstly, then the second four-way reversing valve is switched to the interface communication state later, the operation modes of the heat exchange system can be smoothly and reliably switched, and the problem of switching failure is avoided.

By the technical scheme of the application, the following technical effects can be realized: two evaporators are arranged at the evaporator side, and the indoor return air is subjected to step cooling and dehumidification treatment, so that the running energy efficiency of the system is improved under the condition that the refrigerating capacity and the dehumidification capacity of the system are ensured; two four-way reversing valves are arranged between the compressor and the two indoor heat exchangers and are connected in a certain connection mode, and when the system operation mode is switched, the two four-way reversing valves are switched successively to realize the reliable switching of the operation mode, so that the reliability of the system operation is improved; through a reasonable control method, the stable switching requirement of the heat exchange system operation mode is met.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

FIG. 1 is a schematic diagram of a heat exchange system according to a first embodiment of the present application in a cooling mode;

FIG. 2 shows a schematic diagram of the heat exchange system of FIG. 1 in a cooling to heating mode;

FIG. 3 shows a schematic view of the heat exchange system of FIG. 1 in a heating mode;

FIG. 4 shows a schematic diagram of the heat exchange system of FIG. 1 in a heating-to-cooling mode;

fig. 5 shows a schematic diagram of a heat exchange system according to a second embodiment of the present application in a cooling mode;

fig. 6 shows a schematic view of the heat exchange system of fig. 5 in a heating mode.

Wherein the above figures include the following reference numerals:

10. a first four-way reversing valve; 20. a second four-way reversing valve; 30. a first indoor heat exchanger; 40. a second indoor heat exchanger; 50. an outdoor heat exchanger; 60. a compressor; 61. a first cylinder; 62. a second cylinder; 74. an electromagnetic valve; 81. a first throttle structure; 82. a second throttle structure; 83. a third throttle structure; 84. and a fourth throttle structure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses. 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.

As shown in the drawings, the embodiment of the present application provides a heat exchange system, which comprises a first four-way reversing valve 10, a second four-way reversing valve 20, a first indoor heat exchanger 30, a second indoor heat exchanger 40, an outdoor heat exchanger 50 and a compressor 60 having a first cylinder 61 and a second cylinder 62, wherein a first D pipe of the first four-way reversing valve 10 is communicated with an exhaust port of the compressor 60, a first E pipe of the first four-way reversing valve 10 is communicated with one end of the first indoor heat exchanger 30, a first S pipe of the first four-way reversing valve 10 is communicated with an air suction port of the first cylinder 61, and a first C pipe of the first four-way reversing valve 10 is communicated with one end of the outdoor heat exchanger 50; the second D pipe of the second four-way reversing valve 20 is communicated with the first E pipe, the second E pipe of the second four-way reversing valve 20 is communicated with one end of the second indoor heat exchanger 40, the second S pipe of the second four-way reversing valve 20 is communicated with the air suction port of the second cylinder 62, and the second C pipe of the second four-way reversing valve 20 is communicated with the first S pipe in an on-off manner; the other end of the first indoor heat exchanger 30 and the other end of the second indoor heat exchanger 40 are both in communication with the other end of the outdoor heat exchanger 50.

By applying the technical scheme of the application, in the heat exchange system, a first D pipe of a first four-way reversing valve 10 is communicated with an exhaust port of a compressor 60, a first E pipe of the first four-way reversing valve 10 is communicated with one end of a first indoor heat exchanger 30, a first S pipe of the first four-way reversing valve 10 is communicated with an air suction port of a first air cylinder, and a first C pipe of the first four-way reversing valve 10 is communicated with one end of an outdoor heat exchanger 50; the second D pipe of the second four-way reversing valve 20 is communicated with the first E pipe, the second E pipe of the second four-way reversing valve 20 is communicated with one end of the second indoor heat exchanger 40, the second S pipe of the second four-way reversing valve 20 is communicated with the air suction port of the second cylinder, and the second C pipe of the second four-way reversing valve 20 is communicated with the first S pipe in an on-off manner. According to the scheme, the interfaces of the first four-way reversing valve 10 and the second four-way reversing valve 20 are associated, the refrigerant discharged from the compressor 60 firstly enters the first four-way reversing valve 10 and then enters the second four-way reversing valve 20 through a pipeline or other parts, so that when the refrigerating and heating operation modes of the heat exchange system are switched, the first four-way reversing valve 10 can be switched to the interface communication state firstly, then the second four-way reversing valve 20 is switched to the interface communication state later, the operation modes of the heat exchange system can be smoothly and reliably switched, and the problem of switching failure is avoided.

As shown in fig. 1, in the drawing, the position marked D of the first four-way reversing valve 10 is a first D pipe, the position marked C is a first C pipe, the position marked E is a first E pipe, the position marked S is a first S pipe, and the first D pipe, the first C pipe, the first E pipe, and the first S pipe can be understood as four interfaces of the first four-way reversing valve 10. In the figure, the position marked D, E, C, S of the second four-way reversing valve 20 is the second D pipe, the second E pipe, the second C pipe, the second S pipe, the second E pipe, the second C pipe, and the second S pipe can be understood as four interfaces of the second four-way reversing valve 20.

In this embodiment, the evaporating temperature of the first indoor heat exchanger 30 and the evaporating temperature of the second indoor heat exchanger 40 may be set to different temperatures, that is, the evaporating temperature of one of the evaporators is higher than the evaporating temperature of the conventional system, so that the system energy efficiency may be improved.

In this embodiment, the heat exchange system has a refrigeration mode, and under the condition that the heat exchange system is in the refrigeration mode, the first D pipe is communicated with the first C pipe, the first E pipe is communicated with the first S pipe, the second D pipe is communicated with the second C pipe, the second E pipe is communicated with the second S pipe, and the second C pipe is communicated with the first S pipe.

At this time, the high-pressure gas compressed by the compressor 60 passes through the first D pipe of the first four-way reversing valve 10, then passes through the first C pipe of the first four-way reversing valve 10, enters the inlet of the outdoor heat exchanger 50, is discharged and condensed into high-pressure refrigerant liquid in the outdoor heat exchanger 50, and the high-pressure refrigerant liquid enters the first indoor heat exchanger 30 and the second indoor heat exchanger 40 respectively, is gasified by absorbing heat in the two evaporators respectively, and the gasified refrigerant gas is communicated with the first E pipe of the first four-way reversing valve 10 and the second E pipe of the second four-way reversing valve 20 respectively, and then is conveyed to the first cylinder 61 and the second cylinder 62 of the compressor 60 respectively through the first S pipe and the second S pipe for compression, thereby completing the whole refrigeration cycle.

In this embodiment, the heat exchange system further has a heating mode and a cooling-to-heating mode, and under the condition that the heat exchange system is in the cooling-to-heating mode, the first D pipe is communicated with the first E pipe, the first C pipe is communicated with the first S pipe, the second D pipe is communicated with the second C pipe, the second E pipe is communicated with the second S pipe, and the second C pipe is disconnected from the first S pipe.

That is, when the cooling mode is switched to the heating mode, the first four-way reversing valve 10 finishes reversing first, the internal sliding block is pushed to finish reversing by utilizing the pressure difference between the first D pipe and the first S pipe of the first four-way reversing valve 10, and the system schematic diagram of the first four-way reversing valve 10 which finishes reversing and the second four-way reversing valve 20 which does not finish reversing is shown in fig. 2. At this time, the second D pipe of the second four-way selector valve 20 is connected to the first E pipe of the first four-way selector valve 10, and is on the high-pressure side of the discharge pressure, while the second S pipe of the second four-way selector valve 20 is connected to the second E pipe, and is on the low-pressure side of the suction of the compressor 60. Therefore, the second four-way reversing valve 20 can utilize the pressure difference between the second D pipe and the second S pipe to push the sliding block to reverse, namely, the sliding block can be converted into a heating operation mode. And when the cold mode is switched to the heating mode, the second C pipe and the first S pipe are switched from the connection state to the disconnection state and then are switched to the connection state.

Through the arrangement, when the refrigerating and heating operation modes of the heat exchange system are switched, the first four-way reversing valve 10 can be switched to the interface communication state firstly, and then the second four-way reversing valve 20 is switched to the interface communication state later, so that the operation modes of the heat exchange system can be switched smoothly and reliably, and the problem of switching failure is avoided.

As shown in fig. 3, the heat exchange system has a heating mode, and in the case that the heat exchange system is in the heating mode, the first D pipe is communicated with the first E pipe, the first C pipe is communicated with the first S pipe, the second D pipe is communicated with the second E pipe, the second C pipe is communicated with the second S pipe, and the second C pipe is communicated with the first S pipe.

In this mode, the exhaust gas of the compressor 60 is connected to the first indoor heat exchanger 30 and the second D pipe of the second four-way reversing valve 20 through the first D pipe and the first E pipe of the first four-way reversing valve 10, the exhaust gas of the compressor 60 is sent to the second indoor heat exchanger 40 through the second E pipe of the second four-way reversing valve 20, so that the high-pressure refrigerant gas is exothermically condensed into high-pressure liquid inside the first indoor heat exchanger 30 and the second indoor heat exchanger 40 and then sent to the outdoor heat exchanger 50 respectively, and the high-pressure refrigerant gas absorbs heat and gasifies in the outdoor heat exchanger 50 and then is sent to the first cylinder 61 and the second cylinder 62 of the compressor 60 through the first C pipe and the first S pipe of the first four-way reversing valve 10, and the second C pipe and the second S pipe of the second four-way reversing valve 20 to be compressed, thereby completing the whole heating cycle.

As shown in fig. 4, the heat system further has a cooling mode and a heating-to-cooling mode, and when the heat exchange system is in the heating-to-cooling mode, the first D pipe is communicated with the first C pipe, the first E pipe is communicated with the first S pipe, the second D pipe is communicated with the second E pipe, the second C pipe is communicated with the second S pipe, and the second C pipe is disconnected from the first S pipe.

Namely, in the heating mode, when the refrigerating mode is switched, the first four-way reversing valve 10 finishes reversing by utilizing the pressure difference between the first D pipe and the second S pipe, at this time, the first C pipe and the second E pipe are switched from being connected to being disconnected, the second D pipe of the second four-way reversing valve 20 is connected with the first E pipe of the first four-way reversing valve 10, the pressure is the suction pressure of the first indoor heat exchanger 30, at this time, the second S pipe of the second four-way reversing valve 20 is in a vacuum state after being sucked by the compressor 60, and the second four-way reversing valve 20 can finish reversing by utilizing the pressure difference between the second D pipe and the second S pipe at this time, so that the refrigerating mode operation is switched. In the heat exchange system, various refrigerants such as R32, R410a, R134a, R1234yf and the like can be used as the refrigerant.

In the present embodiment, in the case where the heat exchange system is in the cooling mode, the evaporation temperature of the first indoor heat exchanger 30 is higher than the evaporation temperature of the second indoor heat exchanger 40. Thus, the evaporating temperature of the first indoor heat exchanger 30 is high, the energy efficiency is high, the evaporating temperature of the second indoor heat exchanger 40 is low, and the dehumidifying effect is good, so that the energy efficiency of the heat exchange system can be improved under the condition of ensuring the refrigerating and dehumidifying effects.

In the present embodiment, the exhaust port of the first cylinder 61 and the exhaust port of the second cylinder 62 are both in communication with the exhaust port of the compressor 60. The refrigerant independently compressed by the first cylinder 61 and the refrigerant independently compressed by the second cylinder 62 can be mixed and discharged in a unified manner for circulation.

In the present embodiment, the displacement of the first cylinder 61 is V1, the displacement of the second cylinder 62 is V2, and the ratio of V1 to V2 is A, 0.3.ltoreq.A.ltoreq.3. By this arrangement, the cooling, heating and dehumidifying effects of the first and second indoor heat exchangers 30 and 40 can be ensured, and the energy efficiency can be improved.

In the present embodiment, the heat exchange area of the first indoor heat exchanger 30 is A1, the heat exchange area of the second indoor heat exchanger 40 is A2, and the ratio of A1 to A2 is B, and B is 0.3 and 3. By the above arrangement, the cooling, heating and dehumidifying effects of the first and second indoor heat exchangers 30 and 40 can be further ensured, and the energy efficiency can be improved.

For a heat exchange system having two heat exchangers (a high temperature evaporator and a low temperature evaporator, i.e., a first indoor heat exchanger 30 and a second indoor heat exchanger 40), the displacement ratio of the compressor is related to the load distribution of the high and low temperature evaporators. That is, in order to ensure the same heat exchange amount as that of the single evaporator system under the refrigeration condition, the evaporation temperature of the high-temperature evaporator is higher than that of the low-temperature evaporator, and the high-temperature evaporator and the low-temperature evaporator have a preferable temperature combination so as to optimize the energy efficiency value of the heat exchange system with two heat exchangers, and the temperature difference between the two evaporation temperatures is about 0.5 times of the temperature difference of the inlet air and the outlet air of the whole evaporator. If the load borne by the high-temperature evaporator is too high, the evaporation temperature of the high-temperature evaporator is reduced, if the load borne by the high-temperature evaporator is too low, the evaporation temperature of the low-temperature evaporator is too low, and a preferable combination of the high-temperature evaporator and the low-temperature evaporator enables the energy efficiency of the heat exchange system to be better than that of a system with one evaporator.

Therefore, in order to secure the cooling, heating and dehumidifying effects and to improve the energy efficiency, in the present application, the range of the ratio of the displacement of the first cylinder 61 to the displacement of the second cylinder 62 is set to 0.3.ltoreq.A.ltoreq.3, and the range of the ratio of the heat exchanging area of the first indoor heat exchanger 30 to the heat exchanging area of the second indoor heat exchanger 40 is set to 0.3.ltoreq.B.ltoreq.3. Preferably, a may be set to 1.25 and b may be set to 2. The energy efficiency improvement of the heat exchange system is the combined effect of the effects of the first indoor heat exchanger 30 and the second indoor heat exchanger 40, so that the displacement ratio of the two air cylinders and the heat exchange area ratio of the two indoor heat exchangers of the heat exchange system are key factors for improving the energy efficiency of the system. The scheme pointedly carries out parameter definition, thereby improving the energy efficiency of the system.

In the present embodiment, the first indoor heat exchanger 30 or the second indoor heat exchanger 40 may be a fin tube heat exchanger, a micro-channel heat exchanger, or other forms of heat exchangers. The first indoor heat exchanger 30 and the second indoor heat exchanger 40 may be disposed in the same air duct, or may be disposed in different air ducts, respectively. The first indoor heat exchanger 30 may take the form of a radiant panel heat exchanger. In the dehumidifying operation, the first indoor heat exchanger 30 mainly bears a sensible heat load, and the second indoor heat exchanger 40 mainly bears an indoor latent heat load.

In this embodiment, the heat exchange system further includes: the fan is used for blowing air towards the first indoor heat exchanger 30 and the second indoor heat exchanger 40, and the first indoor heat exchanger 30 is located between the fan and the second indoor heat exchanger 40. Through the above arrangement, the gas to be subjected to heat exchange can be subjected to heat exchange through the first indoor heat exchanger 30 and then subjected to heat exchange through the second indoor heat exchanger 40, so that the evaporating temperature of the first indoor heat exchanger 30 can be conveniently higher than that of the second indoor heat exchanger 40.

In this embodiment, the heat exchange system further includes: and a solenoid valve 74, wherein the solenoid valve 74 is arranged on a pipeline connecting the second C pipe and the first S pipe so as to control the connection or disconnection of the second C pipe and the first S pipe. By arranging the electromagnetic valve 74, the connection or disconnection of the second C pipe and the first S pipe is convenient to control, and the working mode of the heat exchange system is convenient to control.

As shown in fig. 1 to 4, the heat exchange system further includes: the heat exchange system further comprises: a first throttling structure 81 provided on a pipe line connecting the first indoor heat exchanger 30 and the outdoor heat exchanger 50; the second throttling structure 82 is provided on a pipe connecting the second indoor heat exchanger 40 and the outdoor heat exchanger 50. The first throttling structure 81 and the second throttling structure 82 can play a role in throttling and depressurization, so that the heat exchange system can stably and reliably operate. The first throttle structure 81 and the second throttle structure 82 may each employ an electronic expansion valve.

As shown in fig. 5 and 6, in the second embodiment of the present application, unlike the above-described embodiment, the heat exchange system further includes: a third throttling structure 83, one end of the third throttling structure 83 is communicated with the other end of the outdoor heat exchanger 50, and the other end of the first indoor heat exchanger 30 and the other end of the second indoor heat exchanger 40 are communicated with the other end of the third throttling structure 83; a fourth throttling structure 84 is provided on a pipe connecting the second indoor heat exchanger 40 and the third throttling structure 83. The third throttle structure 83 and the fourth throttle structure 84 perform throttle depressurization instead of the first throttle structure 81 and the second throttle structure 82 in the above-described embodiment. The third throttling structure 83 may employ an electronic expansion valve. The original two parallel electronic expansion valves are replaced by an electronic expansion valve with a caliber larger than that of the original electronic expansion valve in the loop of the first indoor heat exchanger 30, and a fourth throttling structure 84 is arranged in the loop of the second indoor heat exchanger 40. Specifically, the fourth throttling structure 84 may employ a throttling capillary.

In this embodiment, in the cooling mode, after the liquid high-pressure refrigerant at the outlet of the outdoor heat exchanger 50 passes through the throttling of the third throttling structure 83, a part of the liquid high-pressure refrigerant directly enters the first indoor heat exchanger 30 (i.e. the indoor windward side high-temperature evaporator), and at the same time, another part of the liquid high-pressure refrigerant passes through the fourth throttling structure 84 and enters the second indoor heat exchanger 40 (i.e. the leeward side low-temperature evaporator); in the heating mode, after the high-pressure refrigerant gas is condensed into high-pressure supercooled liquid in the two indoor heat exchangers, the refrigerant in the first indoor heat exchanger 30 (i.e. the indoor windward side condenser) directly throttles by the third throttling structure 83 and enters the outdoor heat exchanger 50, and the refrigerant in the second indoor heat exchanger 40 (i.e. the leeward side condenser) throttles by the fourth throttling structure 84 and then throttles by the third throttling structure 83 and enters the outdoor heat exchanger 50, so that the system circulation is completed.

The application also provides a control method for controlling the heat exchange system, the control method comprises the following steps: the heat exchange system is switched from a refrigeration mode to a heating mode, and in the switching process, the first four-way reversing valve 10 of the heat exchange system is controlled to reverse, and then the second four-way reversing valve 20 of the heat exchange system is controlled to reverse. By the mode, when the refrigerating and heating operation modes of the heat exchange system are switched, the first four-way reversing valve 10 can be switched to the interface communication state firstly, and then the second four-way reversing valve 20 is switched to the interface communication state later, so that the operation modes of the heat exchange system can be switched smoothly and reliably, and the problem of switching failure is avoided.

Specifically, in the process of switching from the cooling mode to the heating mode, controlling the first four-way reversing valve 10 of the heat exchange system to reverse includes: pushing a sliding block in the first four-way reversing valve 10 to move by utilizing the pressure difference between the first D pipe and the first S pipe of the first four-way reversing valve 10, so that the communication between the first S pipe and the first E pipe of the first four-way reversing valve 10 is switched to the communication between the first S pipe and the first C pipe of the first four-way reversing valve 10, and the communication between the first D pipe and the first C pipe is switched to the communication between the first D pipe and the first E pipe; then controlling the reversing of the second four-way reversing valve 20 of the heat exchange system includes: the sliding block in the second four-way reversing valve 20 is pushed to move by utilizing the pressure difference between the second D pipe and the second S pipe of the second four-way reversing valve 20, so that the communication between the second S pipe and the second E pipe of the second four-way reversing valve 20 is switched to the communication between the second S pipe and the second C pipe of the second four-way reversing valve 20, and the communication between the second D pipe and the second C pipe is switched to the communication between the second D pipe and the second E pipe.

Further, the control method for switching the system from the cooling mode to the heating mode comprises the following steps: the electromagnetic valve 74 is closed firstly, the first four-way reversing valve 10 is electrified, the second four-way reversing valve 20 is electrified after about t seconds, the electromagnetic valve 74 is opened after the reversing is completed, the system operates in a heating mode, and a sliding block in the first four-way reversing valve 10 is pushed to move by utilizing the pressure difference between a D pipe of the first four-way reversing valve 10 and an S pipe of the first four-way reversing valve 10, so that the communication between the S pipe of the first four-way reversing valve 10 and an E pipe of the first four-way reversing valve 10 is switched to the communication between the S pipe of the first four-way reversing valve 10 and a C pipe of the first four-way reversing valve 10, and the communication between the D pipe of the first four-way reversing valve 10 and the C pipe of the first four-way reversing valve 10 is switched to the communication between the D pipe of the first four-way reversing valve 10 and the E pipe of the first four-way reversing valve 10; the sliding block in the second four-way reversing valve 20 is pushed to move by utilizing the pressure difference between the D pipe of the second four-way reversing valve 20 and the S pipe of the second four-way reversing valve 20, so that the communication between the E pipe of the second four-way reversing valve 20 and the S pipe of the second four-way reversing valve 20 is switched to the communication between the S pipe of the second four-way reversing valve 20 and the C pipe of the second four-way reversing valve 20, and the communication between the D pipe of the second four-way reversing valve 20 and the C pipe of the second four-way reversing valve 20 is switched to the communication between the D pipe of the second four-way reversing valve 20 and the E pipe of the second four-way reversing valve 20; after the first four-way reversing valve 10 and the second four-way reversing valve 20 are successfully reversed, the electromagnetic valve 74 is opened.

Further, the control method further includes: the heat exchange system is switched from a heating mode to a refrigerating mode, and in the switching process, the first four-way reversing valve 10 of the heat exchange system is controlled to reverse, and then the second four-way reversing valve 20 of the heat exchange system is controlled to reverse. By the mode, when the refrigerating and heating operation modes of the heat exchange system are switched, the first four-way reversing valve 10 can be switched to the interface communication state firstly, and then the second four-way reversing valve 20 is switched to the interface communication state later, so that the operation modes of the heat exchange system can be switched smoothly and reliably, and the problem of switching failure is avoided.

Specifically, in the process of switching from the heating mode to the cooling mode, controlling the reversing of the first four-way reversing valve 10 of the heat exchange system includes: pushing a sliding block in the first four-way reversing valve 10 to move by utilizing the pressure difference between the first D pipe and the first S pipe of the first four-way reversing valve 10, so that the communication between the first S pipe and the first C pipe of the first four-way reversing valve 10 is switched to the communication between the first S pipe and the first E pipe of the first four-way reversing valve 10, and the communication between the first D pipe and the first E pipe is switched to the communication between the first D pipe and the first C pipe; then controlling the reversing of the second four-way reversing valve 20 of the heat exchange system includes: the sliding block in the second four-way reversing valve 20 is pushed to move by utilizing the pressure difference between the second D pipe and the second S pipe of the second four-way reversing valve 20, so that the communication between the second S pipe and the second C pipe of the second four-way reversing valve 20 is switched to the communication between the second S pipe and the second E pipe of the second four-way reversing valve 20, and the communication between the second D pipe and the second E pipe is switched to the communication between the second D pipe and the second C pipe.

Further, the control method for switching the system from the heating mode to the cooling mode comprises the following steps: the solenoid valve 74 is closed firstly, the first four-way reversing valve 10 is electrified, the second four-way reversing valve 20 is electrified after about t seconds, the solenoid valve 74 is opened after the reversing is completed, the system operates in a refrigerating mode, the sliding block in the first four-way reversing valve 10 is pushed to move by utilizing the pressure difference between the D pipe of the first four-way reversing valve 10 and the S pipe of the first four-way reversing valve 10, so that the communication between the D pipe of the first four-way reversing valve 10 and the E pipe of the first four-way reversing valve 10 is switched to the communication between the D pipe of the first four-way reversing valve 10 and the C pipe of the first four-way reversing valve 10, and the communication between the S pipe of the first four-way reversing valve 10 and the E pipe of the first four-way reversing valve 10 is switched to; the sliding block in the second four-way reversing valve 20 is pushed to move by utilizing the pressure difference between the D pipe and the S pipe of the second four-way reversing valve 20, so that the communication between the S pipe of the second four-way reversing valve 20 and the C pipe of the second four-way reversing valve 20 is switched to the communication between the E pipe of the second four-way reversing valve 20 and the S pipe of the second four-way reversing valve 20, the communication state between the D pipe of the second four-way reversing valve 20 and the E pipe of the second four-way reversing valve 20 is switched to the communication state between the D pipe of the second four-way reversing valve 20 and the C pipe of the second four-way reversing valve 20, and the electromagnetic valve 74 is opened after the reversing of the first four-way reversing valve 10 and the second four-way reversing valve 20 is successful.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A heat exchange system is characterized by comprising a first four-way reversing valve (10), a second four-way reversing valve (20), a first indoor heat exchanger (30), a second indoor heat exchanger (40), an outdoor heat exchanger (50) and a compressor (60) with a first cylinder (61) and a second cylinder (62), wherein,

a first D pipe of the first four-way reversing valve (10) is communicated with an exhaust port of the compressor (60), a first E pipe of the first four-way reversing valve (10) is communicated with one end of the first indoor heat exchanger (30), a first S pipe of the first four-way reversing valve (10) is communicated with an air suction port of the first cylinder (61), and a first C pipe of the first four-way reversing valve (10) is communicated with one end of the outdoor heat exchanger (50);

a second D pipe of the second four-way reversing valve (20) is communicated with the first E pipe, a second E pipe of the second four-way reversing valve (20) is communicated with one end of the second indoor heat exchanger (40), a second S pipe of the second four-way reversing valve (20) is communicated with an air suction port of the second air cylinder (62), and a second C pipe of the second four-way reversing valve (20) is communicated with the first S pipe in an on-off manner;

the other end of the first indoor heat exchanger (30) and the other end of the second indoor heat exchanger (40) are communicated with the other end of the outdoor heat exchanger (50);

the heat exchange system is provided with a refrigeration mode, the first D pipe is communicated with the first C pipe, the first E pipe is communicated with the first S pipe, the second D pipe is communicated with the second C pipe, the second E pipe is communicated with the second S pipe, and the second C pipe is communicated with the first S pipe; the heat exchange system is further provided with a heating mode and a cooling-to-heating mode, the first D pipe is communicated with the first E pipe, the first C pipe is communicated with the first S pipe, the second D pipe is communicated with the second C pipe, the second E pipe is communicated with the second S pipe, the second C pipe is disconnected with the first S pipe, and the second C pipe is switched from the communication to the disconnection;

the heat exchange system is in the heating mode, the first D pipe is communicated with the first E pipe, the first C pipe is communicated with the first S pipe, the second D pipe is communicated with the second E pipe, the second C pipe is communicated with the second S pipe, and the second C pipe is communicated with the first S pipe; the heat exchange system is also provided with a heating-to-cooling mode, the first D pipe is communicated with the first C pipe, the first E pipe is communicated with the first S pipe, the second D pipe is communicated with the second E pipe, the second C pipe is communicated with the second S pipe, the second C pipe is disconnected with the first S pipe, and the second S pipe is sucked by the compressor (60) and is in a vacuum state;

the heat exchange system further comprises an electromagnetic valve (74), wherein the electromagnetic valve (74) is arranged on a pipeline connecting the second C pipe and the first S pipe so as to control the connection or disconnection of the second C pipe and the first S pipe.

2. Heat exchange system according to claim 1, wherein the evaporation temperature of the first indoor heat exchanger (30) is higher than the evaporation temperature of the second indoor heat exchanger (40) in case the heat exchange system is in the cooling mode.

3. The heat exchange system according to claim 1, wherein the displacement of the first cylinder (61) is V1, the displacement of the second cylinder (62) is V2, and the ratio of V1 to V2 is a, 0.3.ltoreq.a.ltoreq.3.

4. The heat exchange system of claim 1, further comprising:

the fan is used for blowing air towards the first indoor heat exchanger (30) and the second indoor heat exchanger (40), and the first indoor heat exchanger (30) is located between the fan and the second indoor heat exchanger (40).

5. The heat exchange system of claim 1, further comprising:

a first throttle structure (81) provided on a pipe connecting the first indoor heat exchanger (30) and the outdoor heat exchanger (50);

and a second throttling structure (82) arranged on a pipeline connecting the second indoor heat exchanger (40) and the outdoor heat exchanger (50).

6. The heat exchange system of claim 1, further comprising:

a third throttling structure (83), wherein one end of the third throttling structure (83) is communicated with the other end of the outdoor heat exchanger (50), and the other end of the first indoor heat exchanger (30) and the other end of the second indoor heat exchanger (40) are both communicated with the other end of the third throttling structure (83);

and a fourth throttling structure (84) arranged on a pipeline connecting the second indoor heat exchanger (40) and the third throttling structure (83).

7. The heat exchange system according to claim 1, wherein the heat exchange area of the first indoor heat exchanger (30) is A1, the heat exchange area of the second indoor heat exchanger (40) is A2, and the ratio of A1 to A2 is B, and B is 0.3.ltoreq.3.

8. A control method for controlling the heat exchange system according to any one of claims 1 to 7, characterized by comprising:

and switching the heat exchange system from a refrigerating mode to a heating mode, and controlling the reversing of a first four-way reversing valve (10) of the heat exchange system and then controlling the reversing of a second four-way reversing valve (20) of the heat exchange system in the switching process.

9. A control method according to claim 8, wherein, during switching from the cooling mode to the heating mode,

the first four-way reversing valve (10) of the heat exchange system is controlled to be reversed firstly, and the reversing comprises the following steps: pushing a sliding block in the first four-way reversing valve (10) to move by utilizing the pressure difference between a first D pipe and a first S pipe of the first four-way reversing valve (10), so that the communication between the first S pipe and a first E pipe of the first four-way reversing valve (10) is switched to the communication between the first S pipe and a first C pipe of the first four-way reversing valve (10), and the communication between the first D pipe and the first C pipe is switched to the communication between the first D pipe and the first E pipe;

then controlling the reversing of a second four-way reversing valve (20) of the heat exchange system comprises: and pushing a sliding block in the second four-way reversing valve (20) to move by utilizing the pressure difference between a second D pipe and a second S pipe of the second four-way reversing valve (20), so that the communication between the second S pipe and a second E pipe of the second four-way reversing valve (20) is switched to the communication between the second S pipe and a second C pipe of the second four-way reversing valve (20), and the communication between the second D pipe and the second C pipe is switched to the communication between the second D pipe and the second E pipe.

10. The control method according to claim 8, characterized in that the control method further comprises:

and switching the heat exchange system from the heating mode to the refrigerating mode, and controlling the reversing of a first four-way reversing valve (10) of the heat exchange system and then controlling the reversing of a second four-way reversing valve (20) of the heat exchange system in the switching process.

11. A control method according to claim 10, wherein, during switching from the heating mode to the cooling mode,

the first four-way reversing valve (10) of the heat exchange system is controlled to be reversed firstly, and the reversing comprises the following steps: pushing a sliding block in the first four-way reversing valve (10) to move by utilizing the pressure difference between a first D pipe and a first S pipe of the first four-way reversing valve (10), so that the communication between the first S pipe and a first C pipe of the first four-way reversing valve (10) is switched to the communication between the first S pipe and a first E pipe of the first four-way reversing valve (10), and the communication between the first D pipe and the first E pipe is switched to the communication between the first D pipe and the first C pipe;

then controlling the reversing of a second four-way reversing valve (20) of the heat exchange system comprises: and pushing a sliding block in the second four-way reversing valve (20) to move by utilizing the pressure difference between a second D pipe and a second S pipe of the second four-way reversing valve (20), so that the communication between the second S pipe and a second C pipe of the second four-way reversing valve (20) is switched to the communication between the second S pipe and a second E pipe of the second four-way reversing valve (20), and the communication between the second D pipe and the second E pipe is switched to the communication between the second D pipe and the second C pipe.