Heat exchange system and air conditioner having the same

Abstract

The present application provides a heat exchange system and an air conditioner having the same, comprising a compressor unit; the compressor unit comprises at least two compressors; a first operating mode in which one compressor is in operation and the other compressors are in operation; a second operating mode in which all or some of the compressors are in operation and the operating compressors are connected in parallel; a third operating mode in which all or some of the compressors are in operation and the operating compressors are connected in series; the compressor unit is capable of switching between the first operating mode, the third operating mode, and the third operating mode. The heat exchange system and the air conditioner having the same according to the present application have a wide range of applications and can meet the needs of different regions.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioners, and specifically to a heat exchange system and an air conditioner having the same. Background Art

[0002] Currently, heat pumps on the market are primarily categorized into several types: standard single-stage heat pumps and low-temperature heat pumps, as well as two-stage compression heat pumps, cascade heat pumps, or CO2 heat pumps. Standard single-stage heat pumps are suitable for use in southern China; low-temperature heat pumps (low-temperature liquid injection, low-temperature enthalpy increase) are suitable for use in parts of the north of the Yangtze River; and two-stage compression heat pumps, cascade heat pumps, or CO2 heat pumps are suitable for use in areas with temperatures below -35°C. Cascade heat exchange systems, which require an additional compressor and intermediate heat exchanger compared to conventional systems, are more expensive and suffer from low efficiency at low pressure ratios, hindering technology adoption. CO2 heat pumps, on the other hand, have high system pressures and demanding material requirements, resulting in higher overall costs. Furthermore, due to the refrigerant's characteristics, CO2 production requires a significant temperature differential (above 50°C) to be effective, limiting their application scenarios. Two-stage compression heat pumps are also inefficient at low pressure ratios. Consequently, existing heat pumps cannot meet the needs of diverse regions and have a limited scope of application.

[0003] Therefore, how to provide a heat exchange system with a wide range of applications and capable of meeting the needs of use in different regions and an air conditioner having the same has become an urgent problem that technicians in this field need to solve. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present application is to provide a heat exchange system and an air conditioner having the same, which has a wide range of applications and can meet the needs of use in different regions.

[0005] In order to solve the above problems, the present application provides a heat exchange system, including a compressor unit; the compressor unit includes at least two compressors; one of the compressors is running and the other compressors are turned off as a first working mode; all or part of the compressors are running, and the running compressors are connected in parallel with each other as a second working mode; all or part of the compressors are running, and the running compressors are connected in series in sequence as a third working mode; the compressor unit can switch between the first working mode, the third working mode and the third working mode.

[0006] Furthermore, the two adjacent compressors include a first compressor and a second compressor; the heat exchange system also includes an exhaust pipeline, which is used to discharge the gas compressed by all compressors; the exhaust port of the first compressor can be switchably connected to the intake port and exhaust pipeline of the second compressor, so that the first compressor and the second compressor can be switched between series and parallel.

[0007] Furthermore, the heat exchange system also includes a first heat exchanger, a second heat exchanger, a third heat exchanger, an intake pipe and a four-way valve; the intake pipe is connected to the intake ports of each compressor in the compressor unit; the exhaust pipe, the first port of the first heat exchanger, the first port of the second heat exchanger and the intake pipe are connected to the four ports of the four-way valve in a one-to-one correspondence; the second port of the first heat exchanger and the second port of the second heat exchanger are connected through a connecting pipe; the third heat exchanger is arranged on the connecting pipe, and the third heat exchanger is used to replenish air to at least one compressor in the compressor unit.

[0008] Furthermore, the heat exchange system further includes a first temperature detection device, which is used to detect the temperature of the first heat exchanger; so that T1+d1 can refer to the refrigerant physical parameter table to obtain the exhaust pressure of the compressor unit; wherein the temperature of the first heat exchanger is T1; the first preset temperature is d1;

[0009] Furthermore, the heat exchange system also includes a second temperature detection device, which is used to detect the temperature of the second heat exchanger; so that T2+d2 can refer to the refrigerant physical property parameter table to obtain the suction pressure of the compressor unit; wherein the temperature of the second heat exchanger is T2; the second preset temperature is d2.

[0010] Furthermore, the third heat exchanger has a first heat exchange channel and a second heat exchange channel; the first heat exchange channel and the second heat exchange channel are capable of heat exchange; the first end of the first heat exchange channel is connected to the first heat exchanger, and the second end of the first heat exchange channel is connected to the second heat exchanger; the first end of the second heat exchange channel is connected to the second heat exchanger and the first heat exchange channel through a connecting pipe; a second throttling device is provided on the connecting pipe; the second end of the second heat exchange channel can be switchably connected to the air supply port of at least one compressor and the exhaust port of at least one compressor.

[0011] Furthermore, when the compressor unit operates in the third working mode, the compressor includes a low-stage compressor and a high-stage compressor, the exhaust port of the low-stage compressor is connected to the intake port of the high-stage compressor, and the exhaust port of the high-stage compressor is connected to the exhaust pipeline; the number of low-stage compressors is set to at least one, and when the number of low-stage compressors is more than two, more than two low-stage compressors are connected in series in sequence; the second end of the second heat exchange channel can be switchably connected to the air supply port of at least one compressor and the exhaust port of at least one low-stage compressor.

[0012] Furthermore, when the heat exchange system further includes a first heat exchanger, a second heat exchanger, and an air intake pipeline, and the second port of the first heat exchanger and the second port of the second heat exchanger are connected via a connecting pipe, a first throttling device is further provided on the connecting pipe; and / or, the heat exchange system further includes a gas-liquid separator, and the gas-liquid separator is provided on the air intake pipeline;

[0013] Further, the heat exchange system further includes a pressure detection component for detecting the discharge pressure and suction pressure of each compressor;

[0014] Further, the heat exchange system further includes a temperature detection component for detecting the discharge temperature and suction temperature of each compressor.

[0015] Further, the suction pressure of the compressor unit is p1; the discharge pressure of the compressor unit is p2; the preset pressure ratio is P; when p2 / p1 ≥ P, the compressor unit operates in the third working mode;

[0016] Further, when the output load of the compressor unit is greater than the required load and p2 / p1 < P, the compressor unit operates in the first working mode or the second working mode.

[0017] Further, the heat exchange system further includes an oil-gas separator having an inlet and an oil outlet. The inlet is connected to the discharge end of the compressor unit; the oil outlet is connected to the suction end of at least one compressor.

[0018] According to another aspect of the present application, an air conditioner is provided, including a heat exchange system, and the heat exchange system is the above-mentioned heat exchange system.

[0019] The heat exchange system provided by the present application and the air conditioner having the same. The present application has a wide range of applications and can meet the use in different regions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the working principle diagram of the heat exchange system in the embodiment of the present application.

[0021] 11. First compressor; 12. Second compressor; 21. First heat exchanger; 22. Second heat exchanger; 23. Third heat exchanger; 31. First throttling device; 32. Second throttling device; 4. Four-way valve; 51. First three-way valve; 52. Second three-way valve; 61. Oil-gas separator; 62. Gas-liquid separator; 71. First control valve; 72. Second control valve; 73. Check valve; 81. First pressure detection device; 82. Second pressure detection device; 83. Third pressure detection device; 91. First temperature sensing element; 92. Second temperature sensing element; 93. Third temperature sensing element; 94. Fourth temperature sensing element. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Refer to in combination Figure 1As shown, a heat exchange system includes a compressor unit; the compressor unit includes at least two compressors; one of the compressors is running and the other compressors are turned off as the first working mode; all or part of the compressors are running, and the running compressors are connected in parallel as the second working mode; all or part of the compressors are running, and the running compressors are connected in series in sequence as the third working mode; the compressor unit can switch between the first working mode, the third working mode and the third working mode. The present application can effectively realize the free switching between single-stage compression and two-stage or multi-stage compression, and the present application can select any one of the compressors to operate during single-stage compression, so that when some of the compressors fail or for other reasons, a normal compressor or a better compressor can be selected to operate; the present application can operate in a single-stage compression mode under low compression ratio conditions to improve operating efficiency; operate in a two-stage or multi-stage compression mode under high compression ratio conditions to decompose the compression ratio, reduce the exhaust temperature, and improve operating reliability and efficiency. The present application has a wide range of applications and can meet the needs of different regions; it provides a more economical and applicable solution for severely cold areas.

[0023] The series connection mentioned in this application refers to the connection between the exhaust port of one compressor and the intake port of another compressor; when there are multiple compressors, the exhaust port of each compressor is connected to the intake port of the adjacent compressor, the intake port of the first compressor is connected to the intake pipe of the entire compressor unit (i.e., the main intake pipe), and the exhaust port of the last compressor is connected to the exhaust pipe of the entire compressor unit (i.e., the main exhaust pipe). The "adjacent compressors" mentioned in this application do not refer to spatial proximity, but to connection. For example, the first, second, and third compressors are arranged in sequence in space, but the exhaust port of the first compressor is connected to the intake port of the third compressor. In this application, the first compressor 11 is adjacent to the third compressor.

[0024] The present application also discloses some embodiments, wherein two adjacent compressors include a first compressor 11 and a second compressor 12; the heat exchange system also includes an exhaust pipeline for discharging the gas compressed by all compressors; the exhaust port of the first compressor 11 can be switchably connected to the intake port and exhaust pipeline of the second compressor 12, so that the first compressor 11 and the second compressor 12 can be switched between series and parallel connection. When the exhaust port of the first compressor 11 is connected to the intake port of the second compressor 12, the present application is a two-stage or multi-stage compressor. Here, the two adjacent compressors include the first compressor 11 and the second compressor 12, which does not mean that the compressor unit of the present application can only have two compressors. The present application can also have multiple compressors. When the present application has three or more compressors, each adjacent two compressors include the first compressor 11 and the second compressor 12; and the same compressor can be the first compressor 11 and the second compressor 12 in different adjacent relationships. For example, the first compressor, the second compressor, and the third compressor are connected in series, that is, the exhaust port of the first compressor is connected to the intake port of the second compressor, and the exhaust port of the second compressor is connected to the intake port of the third compressor. The first compressor and the second compressor are two adjacent compressors. Here, the first compressor is the first compressor 11, and the second compressor is the second compressor 12. The second compressor and the third compressor are also two adjacent compressors. In this adjacent relationship, the second compressor is the first compressor 11, and the third compressor is the second compressor 12. The exhaust port of the first compressor 11 is switchably connected to the intake port and exhaust pipeline of the second compressor 12 through a first three-way valve 51. The first three-way valve 51 has an A1 port, a B1 port, and a C1 port. The A1 port is connected to the exhaust port of the first compressor 11; the B1 port is connected to the exhaust pipeline; the C1 port is connected to the intake port of the second compressor 12; the exhaust port of the second compressor 12 is connected to the exhaust pipeline; the exhaust pipeline is used to discharge the gas compressed by the compressor unit; the connection between the A1 port and the B1 port is the first connection state; the connection between the A1 port and the C1 port is the second connection state. The first three-way valve 51 can switch between the first connection state and the second connection state, so that the first compressor 11 and the second compressor 12 are switched between series connection and parallel connection.

[0025] The present application also discloses some embodiments, wherein the heat exchange system further includes a first heat exchanger 21, a second heat exchanger 22, a third heat exchanger 23, an intake pipe, and a four-way valve 4; the intake pipe connects to the intake ports of each compressor in the compressor unit; the exhaust pipe, the first port of the first heat exchanger 21, the first port of the second heat exchanger 22, and the intake pipe are connected to the four ports of the four-way valve 4 in a one-to-one correspondence; the second port of the first heat exchanger 21 and the second port of the second heat exchanger 22 are connected by a connecting pipe; the third heat exchanger 23 is arranged on the connecting pipe and is used to replenish air to at least one compressor in the compressor unit. The third heat exchanger 23 is a plate heat exchanger; in the first working mode or the second working mode, the third heat exchanger 23 replenishes air to the corresponding compressor through the intake port of at least one compressor. In the third working mode, the intake port of the third heat exchanger 23 is connected to the exhaust port of the lower-stage compressor to replenish air and cool the exhaust of the lower-stage compressor. This can further improve the energy efficiency of the compressor.

[0026] This application also discloses certain embodiments, in which the heat exchange system further includes a first temperature detection device for detecting the temperature of the first heat exchanger 21, so that T1 + d1 can be used to obtain the exhaust pressure of the compressor unit by referring to the refrigerant physical parameter table. The temperature of the first heat exchanger 21 is T1, and the first preset temperature is d1. This method uses the temperature of the first heat exchanger 21 (i.e., the temperature of the refrigerant in the first heat exchanger 21) combined with the refrigerant physical parameter table to obtain an estimated value of the exhaust pressure. When the compressor exhaust pressure or compression ratio cannot be determined, this method can be used to obtain an estimated value of the exhaust pressure to determine the operating mode of the compressor unit. d1 is a positive number and can be an empirical value.

[0027] This application also discloses certain embodiments, in which the heat exchange system further includes a second temperature detection device for detecting the temperature of the second heat exchanger 22, so that the suction pressure of the compressor unit can be obtained by referring to a refrigerant physical parameter table based on T2 + d2. The temperature of the second heat exchanger 22 is T2, and the second preset temperature is d2. This method uses the temperature of the second heat exchanger 22 (i.e., the temperature of the refrigerant in the second heat exchanger 22) combined with the refrigerant physical parameter table to obtain an estimated value for the suction pressure. When the compressor suction pressure or compression ratio is uncertain, this method can be used to obtain an estimated value for the suction pressure to determine the operating mode of the compressor unit. d2 is a negative number and can be an empirical value. For example, the first heat exchanger 21 is the condenser, and the second heat exchanger 22 is the evaporator; the temperature of the first heat exchanger 21 is the temperature inside the condenser; d1 is an empirical value. Since the refrigerant in the condenser is a heat release process, it can be inferred that the condensation temperature of the refrigerant after the compressor is started must be greater than the temperature before starting, d1≤7°C; the temperature of the second heat exchanger 22 is the refrigerant temperature inside the evaporator; d2 is also an empirical value. The refrigerant in the evaporator is a heat absorption process, so the refrigerant temperature will drop after the compressor is started, d1≤5°C.

[0028] For example, d1=7; d2=-5; if the compressor cannot be determined before startup, the estimated discharge pressure can be obtained by looking up the refrigerant physical parameter table at a condenser temperature of +7°C, and the estimated suction pressure can be obtained by looking up the table at an evaporator temperature of -5°C, and the estimated compression ratio can be used instead of the compression ratio.

[0029] The present application also discloses some embodiments, in which the third heat exchanger 23 has a first heat exchange channel and a second heat exchange channel; the first heat exchange channel and the second heat exchange channel are capable of heat exchange; the first end of the first heat exchange channel is connected to the first heat exchanger 21, and the second end of the first heat exchange channel is connected to the second heat exchanger 22; a second throttling device 32 is provided on the connecting pipeline at the first end of the second heat exchange channel, which is connected to the second heat exchanger 22 and the first heat exchange channel; a second throttling device 32 is provided on the connecting pipeline; the second end of the second heat exchange channel can be switchably connected to the air supply port of at least one compressor and the exhaust port of at least one compressor. The second end of the second heat exchange channel is switchably connected to the air supply port of at least one compressor and the exhaust port of at least one compressor through a second three-way valve 52; the second three-way valve 52 has an A2 port, a B2 port, and a C2 port; the A2 port is connected to the second end of the second heat exchange channel; the B2 port is connected to the air supply port of at least one compressor; the C2 port is connected to the exhaust port of at least one compressor; with the A2 port and the B2 port connected as the first state; with the A2 port and the C2 port connected as the second state, the second three-way valve 52 can switch between the first state and the second state so that the second end of the second heat exchange channel is switchably connected to the air supply port of at least one compressor and the exhaust port of at least one compressor. The second throttling device 32 is a second electronic expansion valve. In the present application, the fluid temperature in the first heat exchange channel is higher, while the fluid in the second heat exchange channel is lower due to the throttling and pressure reduction by the second throttling device 32. After the two exchange heat with each other, they can reach the air supply temperature to supply air to the compressor.

[0030] The present application also discloses some embodiments, when the compressor unit operates in the third working mode, the compressor includes a low-stage compressor and a high-stage compressor, the exhaust port of the low-stage compressor is connected to the intake port of the high-stage compressor, and the exhaust port of the high-stage compressor is connected to the exhaust pipeline; the number of low-stage compressors is set to at least one, when the number of low-stage compressors is more than two, the more than two low-stage compressors are connected in series in sequence; the second end of the second heat exchange channel can be switchably connected to the air supply port of at least one compressor and the exhaust port of at least one low-stage compressor.

[0031] The present application also discloses some embodiments, when the heat exchange system also includes a first heat exchanger 21, a second heat exchanger 22 and an intake pipeline, and the second port of the first heat exchanger 21 and the second port of the second heat exchanger 22 are connected through a connecting pipe, a first throttling device 31 is also provided on the connecting pipe; and / or, the heat exchange system also includes a gas-liquid separator 62, and the gas-liquid separator 62 is provided on the intake pipeline; the first throttling device 31 is a first electronic expansion valve.

[0032] The present application also discloses some embodiments. The heat exchange system further includes a pressure detection component for detecting the discharge pressure and suction pressure of each compressor. The pressure detection component includes a first pressure detection device 81, a second pressure detection device 82, and a third pressure detection device 83. The first pressure detection device 81 is used to detect the discharge temperature of the first compressor 11, the second pressure detection device 82 is used to detect the suction temperature of the first compressor 11, and the third pressure detection device 83 is used to detect the discharge temperature of the second compressor 12. Each pressure detection device is a pressure detection sensor.

[0033] The present application also discloses some embodiments. The heat exchange system further includes a temperature detection component for detecting the discharge temperature and suction temperature of each compressor. The pressure detection component includes a first temperature sensing bulb 91, a second temperature sensing bulb 92, a third temperature sensing bulb 93, and a fourth temperature sensing bulb 94. The first temperature sensing bulb 91 is used to detect the discharge temperature of the second compressor 12, the second temperature sensing bulb 92 is used to detect the discharge temperature of the first compressor 11, the third temperature sensing bulb 93 is used to detect the suction temperature of the first compressor 11, and the fourth temperature sensing bulb 94 is used to detect the suction temperature of the second compressor 12.

[0034] The present application also discloses some embodiments. The suction pressure of the compressor unit is p1; the discharge pressure of the compressor unit is p2; the preset pressure ratio is P; when p2 / p1 ≥ P, the compressor unit operates in the third working mode; the preset pressure ratio P is the dividing line where the energy efficiency of single-stage compression is higher than that of two-stage compression, which is an empirical value related to the design of the heat pump system; for example, in some of the compressors, the preset pressure ratio P = 3.8.

[0035] The present application also discloses some embodiments. When the output load of the compressor unit is greater than the demand load and p2 / p1 < P, the compressor unit operates in the first working mode or the second working mode.

[0036] 1. First working mode: The first working mode is adopted in any of the following situations:

[0037] When one or several compressors fail, but there is still one or several compressors operating normally;

[0038] Or, when a two-stage or multi-stage compressor operates, the output load is greater than the demand load, and the compression ratio < the preset pressure ratio. For example, when the heat pump is heating, the heat required by the room is the demand load, and the heat output by the heat pump is the output load. As the pressure ratio increases, the working efficiency of the compressor decreases, the discharge temperature rises, and the requirement for mechanical strength also increases. Therefore, staged compression is required at high pressure ratios.

[0039] When the first compressor 11 is operated alone, at this time, in the first three-way valve 51, the A1 port is connected to the B1 port; in the second three-way valve 52, the A2 port is connected to the B2 port; the refrigerant compressed by the first compressor 11 flows from the A1 port to the B1 port, enters the exhaust pipe, and then enters the oil-gas separator 61 for oil and gas separation. The oil after oil and gas separation can enter the oil outlet pipe to supply oil to the first compressor 11; the gas after oil and gas separation enters the four-way valve 4, flows through the first heat exchanger 21 and the second heat exchanger 22 for heat exchange, and then flows back to the intake port through the gas-liquid separator 62; and after the first heat exchange channel and the second heat exchange channel in the third heat exchanger 23 exchange heat, the air supply fluid in the second heat exchange channel flows from the A2 port to the B2 port, and flows into the air supply port of the first compressor 11 after passing through the one-way valve 73.

[0040] When the second compressor 12 is operated alone, at this time, in the first three-way valve 51, the A1 port is connected to the C1 port; in the second three-way valve 52, the A2 port is connected to the B2 port; the refrigerant compressed by the second compressor 12 enters the exhaust pipe, and then enters the oil-gas separator 61 for oil and gas separation. The oil after oil and gas separation can enter the oil outlet pipe to supply oil to the first compressor 11; the gas after oil and gas separation enters the four-way valve 4, flows through the first heat exchanger 21 and the second heat exchanger 22 for heat exchange, and then flows back to the intake port through the gas-liquid separator 62; and after the first heat exchange channel and the second heat exchange channel in the third heat exchanger 23 exchange heat, the air supply fluid in the second heat exchange channel flows from the A2 port to the B2 port, and flows into the air supply port of the second compressor 12 after passing through the one-way valve 73.

[0041] 2. Second working mode: dual compressors in single-stage compression operation, i.e. dual compressors in parallel:

[0042] When the compression ratio is less than the preset compression ratio, the second working mode is operated, the A1 port of the first three-way valve 51 is connected to the B1 port; the A2 port of the second three-way valve 52 is connected to the B2 port, and the dual compressors of the unit operate in parallel.

[0043] 2. The third working mode: dual compressor dual-stage compression operation, that is, dual compressors in series:

[0044] When the compression ratio is greater than or equal to the preset pressure ratio, the system operates in the third working mode. At this time, the A1 port of the first three-way valve 51 is connected to the C1 port; and the A2 port of the second three-way valve 52 is connected to the C2 port.

[0045] The exhaust gas of the first compressor 11 flows into the C1 port through the A1 port, and then enters the suction port of the second compressor 12. After secondary compression by the second compressor 12, it is discharged to the oil-gas separator 61 for oil-gas separation. The oil after oil-gas separation can enter the oil outlet pipeline to supply oil to the first compressor 11; the gas after oil-gas separation enters the four-way valve 4, flows through the first heat exchanger 21 and the second heat exchanger 22 for heat exchange, and then flows back to the suction port through the gas-liquid separator 62; and after heat exchange between the first heat exchange channel and the second heat exchange channel in the third heat exchanger 23, the refrigerant in the air supply pipeline is throttled by the second throttling device 32, and after heat exchange and temperature increase in the first heat exchange channel, the air supply fluid in the second heat exchange channel flows from the A2 port to the C2 port, and then enters the exhaust pipe of the first compressor 11 (that is, mixed with the exhaust gas of the first compressor 11, and then enters the suction port of the second compressor 12) to supply air and cool the refrigerant after the first stage of compression.

[0046] The present application also discloses some embodiments, in which the heat exchange system further includes an oil-gas separator 61, which has an inlet and an oil outlet. The inlet is connected to the exhaust end of the compressor unit; the oil outlet is connected to the intake end of at least one compressor. The oil-gas separator 61 also has an outlet. The inlet and the outlet are connected to the exhaust pipeline. The oil outlet is connected to the intake end of the compressor through the oil outlet pipeline. A control valve is provided on the oil outlet pipeline to control the on-off of the oil outlet pipeline. The oil outlet pipeline can be opened when the compressor is short of oil, and closed when there is too much or enough oil in the compressor. The number of oil outlet pipelines is set to multiple, and the multiple oil outlet pipelines are all connected to the oil outlet. Each oil outlet pipeline is set to correspond to a compressor one by one. Each oil outlet pipeline is provided with a control valve, which can be controlled separately, so that the present application can control the on-off of the oil outlet pipeline according to the conditions of different compressors; the control valve is a solenoid valve, which is more convenient to control. For example, when the present application has two compressors, two oil outlet pipelines are provided, and a first control valve 71 and a second control valve 72 are provided on the two oil outlet pipelines respectively to control the on-off of the two oil outlet pipelines.

[0047] According to another aspect of the present application, an air conditioner is provided, comprising a heat exchange system, which is the above-mentioned heat exchange system.

[0048] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0049] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application. The above are merely preferred embodiments of the present application. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present application, and such improvements and variations shall also be considered within the scope of protection of the present application.

Claims

1. A heat exchange system, characterized in that: The compressor unit comprises at least two compressors; one of the compressors is in operation and the other compressors are shut down as a first working mode; All or part of the compressors are operated, and the operating compressors are connected in parallel to form a second working mode; All or part of the compressors are operated, and the operating compressors are connected in series in sequence to form a third working mode; the compressor unit can switch between the first working mode, the third working mode and the third working mode; The two adjacent compressors include a first compressor (11) and a second compressor (12); the heat exchange system further includes an exhaust pipeline, the exhaust pipeline being used to discharge gas compressed by all the compressors; the exhaust port of the first compressor (11) is switchably connected to the intake port of the second compressor (12) and the exhaust pipeline, so that the first compressor (11) and the second compressor (12) are switched between series connection and parallel connection; The heat exchange system further comprises a first heat exchanger (21), a second heat exchanger (22), a third heat exchanger (23), an air intake pipe and a four-way valve (4); the air intake pipe is connected to the air intake ports of each compressor in the compressor unit; the exhaust pipe, the first port of the first heat exchanger (21), the first port of the second heat exchanger (22) and the air intake pipe are connected to the four ports of the four-way valve (4) in a one-to-one correspondence; the second port of the first heat exchanger (21) and the second port of the second heat exchanger (22) are connected via a connecting pipe; the third heat exchanger (23) is arranged on the connecting pipe, and the third heat exchanger (23) is used to supply air to at least one of the compressors in the compressor unit; The third heat exchanger (23) has a first heat exchange channel and a second heat exchange channel; the first heat exchange channel and the second heat exchange channel are capable of exchanging heat; the first end of the first heat exchange channel is connected to the first heat exchanger (21), and the second end of the first heat exchange channel is connected to the second heat exchanger (22); the first end of the second heat exchange channel is connected to the second heat exchanger (22) and the first heat exchange channel through a connecting pipe; a second throttling device (32) is provided on the connecting pipe; the second end of the second heat exchange channel is switchably connected to the air supply port of at least one compressor and the exhaust port of at least one compressor.

2. The heat exchange system according to claim 1, characterized in that: The heat exchange system further comprises a first temperature detection device, the first temperature detection device being used to detect the temperature of the first heat exchanger (21); so that T1+d1 can refer to the refrigerant physical property parameter table to obtain the exhaust pressure of the compressor unit; wherein the temperature of the first heat exchanger (21) is T1; and the first preset temperature is d1; And / or, the heat exchange system further includes a second temperature detection device configured to detect the temperature of the second heat exchanger (22); so that T2 + d2 can refer to the refrigerant physical property parameter table to obtain the suction pressure of the compressor unit; wherein the temperature of the second heat exchanger (22) is T2; and the second preset temperature is d2.

3. The heat exchange system according to claim 1, characterized in that: When the compressor unit operates in the third operating mode, the compressor includes a low-stage compressor and a high-stage compressor. The discharge port of the low-stage compressor is connected to the suction port of the high-stage compressor, and the discharge port of the high-stage compressor is connected to the exhaust pipe. The number of the low-stage compressors is set to be at least one. When the number of the low-stage compressors is more than two, the two or more low-stage compressors are connected in series in sequence. The second end of the second heat exchange passage is switchably connected to the gas injection port of at least one compressor and the discharge port of at least one low-stage compressor.

4. The heat exchange system according to any one of claims 1 to 3, characterized in that: When the heat exchange system further includes a first heat exchanger (21), a second heat exchanger (22) and a suction pipe, and the second ports of the first heat exchanger (21) and the second heat exchanger (22) are connected by a connecting pipe, a first throttling device (31) is further provided on the connecting pipe; and / or, the heat exchange system further includes an oil-gas separator (62), and the oil-gas separator (62) is arranged on the suction pipe. And / or, the heat exchange system further includes a pressure detection component configured to detect the discharge pressure and suction pressure of each compressor. And / or, the heat exchange system further includes a temperature detection component configured to detect the discharge temperature and suction temperature of each compressor.

5. The heat exchange system according to claim 1, characterized in that: The suction pressure of the compressor unit is p1; the discharge pressure of the compressor unit is p2; the preset pressure ratio is P; when p2 / p1 ≥ P, the compressor unit operates in the third operating mode. And / or, when the output load of the compressor unit is greater than the required load and p2 / p1 < P, the compressor unit operates in the first operating mode or the second operating mode.

6. The heat exchange system according to claim 1, characterized in that: The heat exchange system further includes an oil-gas separator (61), the oil-gas separator (61) has an inlet and an oil outlet, the inlet is connected to the exhaust end of the compressor unit; and the oil outlet is connected to the suction end of at least one compressor.

7. An air conditioner, characterized in that: The air conditioner includes a heat exchange system, and the heat exchange system is the heat exchange system according to any one of claims 1-6.

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