Air conditioning system capable of recovering heat energy in compression mode

Abstract

The invention relates to the technical field of heat recovery, in particular to an air conditioning system for recovering heat energy in a compression mode, which comprises a first system, a second system and a recovery system, each of the first system and the second system comprises a compressor, a compression one-way valve, a fluorine pump, a fluorine cooling one-way valve, a condenser, a first two-way valve, a second two-way valve and an evaporator; the recovery system comprises a heat exchanger and a proportional two-way valve; the first system and the second system each comprise a fluorine cooling mode, a compression mode and a recovery mode. By arranging the first system and the second system, the whole air conditioning system has multiple refrigeration modes; the other two systems are each provided with a recovery mode, the condenser is bypassed through the two two-way valves, the refrigerant enters the heat exchange channel of the heat exchanger after absorbing heat through the evaporator, and therefore heat can be conducted into the water supply channel of the heat exchanger, and heat generated by the air conditioning system can be recovered.

Description

Technical Field

[0001] The invention relates to the technical field of heat recovery, and in particular to an air conditioning system that recovers heat energy in a compression mode. Background Art

[0002] Energy efficiency optimization of air conditioning systems is an important topic in data centers and other high-energy consumption facilities. Existing air conditioning systems have some deficiencies in heat recovery and waste heat treatment, which affect the overall energy efficiency and operational stability of the system.

[0003] For air-to-air heat exchangers, they cannot completely recover all heat during heat exchange, resulting in partial energy loss. In addition, in low temperature environments, air-to-air heat exchangers are prone to ice formation, resulting in reduced heat exchange efficiency and even blocking the heat exchange channel, affecting the normal operation of the system.

[0004] For air-cooled heat exchangers, the air-cooled heat exchangers fail to effectively utilize waste heat, resulting in energy waste. The impact of waste heat emissions on the surrounding environment cannot be ignored. It may cause local temperature increases and affect the operation of other equipment.

[0005] In order to overcome the shortcomings of existing technologies and improve the energy efficiency of air-conditioning systems throughout the year, a preheating and recovery air-conditioning system is needed. It makes full use of natural cold sources and intelligently selects the machine operation mode according to different ambient temperatures, thereby achieving the best operation plan and reducing the energy consumption of the entire system. Summary of the invention

[0006] The purpose of the present invention is to provide an air conditioning system for heat recovery in compression mode in view of the above-mentioned deficiencies in the prior art.

[0007] The object of the present invention is achieved through the following technical solutions: an air conditioning system for heat recovery in compression mode, comprising a first system, a second system and a recovery system; the first system and the second system both comprise a compressor, a compression check valve, a fluorine pump, a fluorine cooling check valve, a condenser, a first two-way valve, a second two-way valve and an evaporator; a blower is provided at the evaporator; an exhaust fan is provided at the condenser;

[0008] The recovery system includes a heat exchanger and a proportional two-way valve; the heat exchanger includes a water supply channel and two heat exchange channels; the proportional two-way valve is connected to the water supply channel; a pressure difference switch is provided between the water inlet and the water outlet of the water supply channel; the two heat exchange channels are respectively connected to the first system and the second system;

[0009] The first system and the second system both include a fluorine cooling mode, a compression mode and a recovery mode.

[0010] The present invention is further configured such that, in compression mode, the flow paths of the refrigeration systems of the first system and the second system are: compressor-first two-way valve-condenser-fluorine cooling one-way valve-evaporator-compressor;

[0011] In the fluorine cooling mode, the flow paths of the refrigeration system of the first system and the second system are: fluorine pump-evaporator-compression check valve-first two-way valve-condenser-fluorine pump;

[0012] In the recovery mode, the flow paths of the refrigeration systems of the first system and the second system are: compressor-second two-way valve-heat exchange channel-fluorine cooling one-way valve-evaporator-compressor.

[0013] The present invention is further configured as follows: the compressor is arranged in parallel with the compression check valve; the fluorine pump is arranged in parallel with the fluorine cooling check valve; one end of the compressor is respectively connected with one end of the first two-way valve and one end of the second two-way valve; the other end of the first two-way valve is connected with one end of the condenser; the other end of the condenser is connected with one end of the fluorine pump; the other end of the second two-way valve is connected with the other end of the condenser after passing through the heat exchange channel; the other end of the fluorine pump is connected with one end of the evaporator; the other end of the evaporator is connected with the other end of the compressor.

[0014] The present invention is further configured such that a liquid storage tank is provided between the other end of the condenser and one end of the fluorine pump; an electronic expansion valve is provided between the other end of the fluorine pump and one end of the evaporator; a gas-liquid separator is provided between the other end of the evaporator and the other end of the compressor; a branch connecting the compressor and the gas-liquid separator is provided in parallel at both ends of the compression check valve;

[0015] The evaporator of the first system and the evaporator of the second system are arranged overlappingly; the evaporator of the second system is arranged between the evaporator of the first system and the blower.

[0016] The present invention is further configured to include the following steps:

[0017] Step S1, detect whether the proportional two-way valve is opened to the first opening, if yes, proceed to step S2; if no, the first system and the second system maintain the current mode;

[0018] Step S2, detect whether the pressure difference switch is turned on, if so, proceed to step S3; if not, the first system and the second system maintain the current mode;

[0019] Step S3, detecting whether the return water temperature of the water inlet of the water supply channel is less than the first return water temperature value, if so, proceed to step A; if not, proceed to step S4;

[0020] Step A: both the first system and the second system enter the recovery mode; then enter step B1;

[0021] Step S4, detecting whether the return water temperature of the water inlet of the water supply channel is less than the second return water temperature value, and the second return water temperature value is greater than the first return water temperature value, if so, proceed to step C; if not, the first system and the second system maintain the current mode;

[0022] Step C: The first system maintains the current mode, and the second system enters the recovery mode; then proceeds to step D.

[0023] The present invention is further configured to include the following steps:

[0024] Step D, detect the water supply temperature of the water outlet of the water supply channel, the air supply temperature of the blower and the opening of the proportional two-way valve; if the water supply temperature of the water outlet of the water supply channel is less than the water supply temperature setting value within the first time, the air supply temperature of the blower is less than the first air supply temperature value within the second time, and the opening of the proportional two-way valve is less than the second opening, then enter step A; the second opening is less than the first opening.

[0025] The present invention is further configured that the step D further includes: if the proportional two-way valve is opened to a third opening and the air supply temperature of the blower is greater than the second air supply temperature value within a third time, then entering step D1; the third opening is less than the first opening and greater than the second opening;

[0026] Step D1, detect whether the outdoor temperature is less than the outdoor temperature setting value, if so, proceed to step D11; if not, proceed to step D12;

[0027] Step D11, the first system maintains the current mode, the second system enters the fluorine cooling mode, and then enters step S1;

[0028] Step D12: The first system maintains the current mode, the second system enters the compression mode, and then enters step S1.

[0029] The present invention is further configured to include the following steps:

[0030] Step B1, detect whether the proportional two-way valve is opened to the third opening, if yes, proceed to step B2; if no, the first system and the second system maintain the recovery mode;

[0031] Step B2, detecting whether the air supply temperature of the blower is greater than the second air supply temperature value within the third time, if so, proceeding to step B3; if not, the first system and the second system maintain the recovery mode;

[0032] Step B3, check whether the outdoor temperature is less than the outdoor temperature setting value, if so, proceed to step B31; if not, proceed to step B32;

[0033] Step B31, the first system maintains the recovery mode, the second system enters the fluorine cooling mode, and then enters step B4;

[0034] Step B32: the first system maintains the recovery mode, the second system enters the compression mode, and then enters step B4;

[0035] Step B4, detecting whether the air supply temperature of the blower is greater than the third air supply temperature value within the fourth time, and the third air supply temperature value is less than the second air supply temperature value; if so, proceed to step B5; if not, proceed to step D;

[0036] Step B5: The first system enters the compression mode or the fluorine cooling mode, and then enters step S1.

[0037] The present invention is further configured to convert from the compression mode to the recovery mode, comprising the following steps:

[0038] E1, gradually open the second two-way valve at T1, and keep the second two-way valve fully open at T3;

[0039] E2, gradually close the first two-way valve at T2, and keep the first two-way valve completely closed at T3;

[0040] E3. Keep the exhaust fan completely closed at T4.

[0041] The present invention is further configured to convert from the fluorine cooling mode to the recovery mode, comprising the following steps:

[0042] E1, gradually opening the second two-way valve at T5, and keeping the second two-way valve fully open at T7;

[0043] E2, gradually close the first two-way valve at T6, and keep the first two-way valve completely closed at T7;

[0044] E3. Keep the exhaust fan completely closed at T8;

[0045] E4, gradually turn on the compressor at T5, and automatically adjust the compressor after it is fully turned on at T7;

[0046] E5. Gradually turn off the fluorine pump at T7 and keep it completely closed at T8.

[0047] Beneficial effects of the present invention: The present invention provides a first system and a second system so that the entire air-conditioning system has a variety of refrigeration modes; the other two systems are both provided with a recovery mode, and the condenser is bypassed through two two-way valves, so that the refrigerant enters the heat exchange channel of the heat exchanger after absorbing heat in the evaporator, thereby being able to conduct heat to the water supply channel of the heat exchanger, thereby being able to recover the heat generated by the air-conditioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0049] Figure 1 It is a module block diagram of the present invention;

[0050] Figure 2 is a system flow chart of the present invention;

[0051] Figure 3 is a timing diagram of the conversion of the compression mode to the recovery mode of the present invention;

[0052] Figure 4 It is a timing diagram of the conversion of the fluorine cooling mode into the recovery mode of the present invention;

[0053] Among them: 1. Compressor; 11. Compression check valve; 2. Fluorine pump; 21. Fluorine cooling check valve; 3. Condenser; 31. Exhaust fan; 41. First two-way valve; 42. Second two-way valve; 5. Evaporator; 51. Blower; 6. Heat exchanger; 61. Water supply channel; 62. Heat exchange channel; 63. Proportional two-way valve; 64. Pressure difference switch; 7. Liquid storage tank; 8. Electronic expansion valve; 9. Gas-liquid separator. DETAILED DESCRIPTION

[0054] The present invention is further described in conjunction with the following examples.

[0055] Depend on Figures 1 to 4 It can be seen that the air conditioning system for heat recovery in compression mode described in this embodiment includes a first system, a second system and a recovery system; the first system and the second system both include a compressor 1, a compression check valve 11, a fluorine pump 2, a fluorine cooling check valve 21, a condenser 3, a first two-way valve 41, a second two-way valve 42 and an evaporator 5; the evaporator 5 is provided with a blower 51; the condenser 3 is provided with an exhaust fan 31;

[0056] The recovery system includes a heat exchanger 6 and a proportional two-way valve 63; the heat exchanger 6 includes a water supply channel 61 and two heat exchange channels 62; the proportional two-way valve 63 is connected to the water supply channel 61; a pressure difference switch 64 is provided between the water inlet and the water outlet of the water supply channel 61; the two heat exchange channels 62 are respectively connected to the first system and the second system;

[0057] The first system and the second system both include a fluorine cooling mode, a compression mode and a recovery mode.

[0058] Specifically, the air-conditioning system for heat recovery in compression mode described in this embodiment can start the compression mode of the two systems at the same time and the fluorine cooling mode of the two systems at the same time by setting the first system and the second system, or one system can start the compression mode and the other system can start the fluorine cooling mode, so that the entire air-conditioning system has multiple refrigeration modes.

[0059] The other two systems are both provided with a recovery mode. In the recovery mode, the condenser 3 is bypassed through the first two-way valve 41 and the second two-way valve 42, so that the refrigerant enters the heat exchange channel 62 of the heat exchanger 6 after absorbing heat in the evaporator 5, thereby conducting the heat to the water supply channel 61 of the heat exchanger 6 to heat the water in the water supply channel 61, thereby recovering the heat generated by the air-conditioning system.

[0060] In this embodiment, an air conditioning system for heat recovery in compression mode is described. In compression mode, the flow paths of the refrigeration system of the first system and the second system are: compressor 1-first two-way valve 41-condenser 3-fluorine cooling check valve 21-evaporator 5-compressor 1;

[0061] In the fluorine cooling mode, the flow paths of the refrigeration system of the first system and the second system are: fluorine pump 2-evaporator 5-compression check valve 11-first two-way valve 41-condenser 3-fluorine pump 2;

[0062] In the recovery mode, the flow paths of the refrigeration systems of the first system and the second system are: compressor 1 - second two-way valve 42 - heat exchange channel 62 - fluorine cooling one-way valve 21 - evaporator 5 - compressor 1.

[0063] Specifically, the air-conditioning system that recovers heat in the compression mode described in this embodiment only needs to start the compressor 1 in the recovery mode, and there is no need to start the fluorine pump 2. The compressor 1 can provide a large amount of heat in the circulation mode to heat the water in the water supply channel 61. It is suitable for scenarios with higher requirements on the water temperature in the water supply channel 61, such as meeting winter heating or domestic hot water needs.

[0064] The present embodiment describes an air-conditioning system for heat recovery in compression mode, wherein the compressor 1 is arranged in parallel with the compression check valve 11; the fluorine pump 2 is arranged in parallel with the fluorine cooling check valve 21; one end of the compressor 1 is connected to one end of the first two-way valve 41 and one end of the second two-way valve 42 respectively; the other end of the first two-way valve 41 is connected to one end of the condenser 3; the other end of the condenser 3 is connected to one end of the fluorine pump 2; the other end of the second two-way valve 42 is connected to the other end of the condenser 3 through the heat exchange channel 62; the other end of the fluorine pump 2 is connected to one end of the evaporator 5; the other end of the evaporator 5 is connected to the other end of the compressor 1.

[0065] In the present embodiment, an air conditioning system for heat recovery in compression mode is provided, wherein a liquid storage tank 7 is provided between the other end of the condenser 3 and one end of the fluorine pump 2; an electronic expansion valve 8 is provided between the other end of the fluorine pump 2 and one end of the evaporator 5; a gas-liquid separator 9 is provided between the other end of the evaporator 5 and the other end of the compressor 1; a branch connecting the compressor 1 and the gas-liquid separator 9 is provided in parallel at both ends of the compression check valve 11; the above arrangement makes the entire air conditioning system more stable and reliable;

[0066] The evaporator 5 of the first system is arranged overlapping with the evaporator 5 of the second system; the above arrangement makes the whole air conditioning system more stable and reliable, and can reduce the number of exhaust fans 31 and air blowers 51, which can effectively save costs. The evaporator 5 of the second system is arranged between the evaporator 5 and the air blower 51 of the first system; specifically, after the evaporator 5 of the second system overlaps with the evaporator 5 of the first system, the evaporator 5 of the second system is located on the leeward side relative to the evaporator 5 of the first system, and the airflow first passes through the evaporator 5 of the first system and then passes through the evaporator 5 of the second system. Therefore, when the air blower 51 is shared, the heat exchange efficiency of the second system at the evaporator 5 is lower than that of the first system, so it is preferred to let the second system enter the recovery mode first.

[0067] The air conditioning system for heat recovery in compression mode described in this embodiment includes the following steps:

[0068] Step S1, detect whether the proportional two-way valve 63 is opened to the first opening degree, if yes, proceed to step S2; if no, the first system and the second system maintain the current mode; wherein the first opening degree can be 100%;

[0069] Step S2, detect whether the pressure difference switch 64 is turned on, if so, proceed to step S3; if not, the first system and the second system maintain the current mode;

[0070] Step S3, detect whether the return water temperature of the water inlet of the water supply channel 61 is less than the first return water temperature value, if so, proceed to step A; if not, proceed to step S4; wherein the first return water temperature value may be 40 degrees;

[0071] Step A: both the first system and the second system enter the recovery mode; then enter step B1;

[0072] Step S4, detect whether the return water temperature of the water inlet of the water supply channel 61 is less than the second return water temperature value, and the second return water temperature value is greater than the first return water temperature value. If so, proceed to step C; if not, the first system and the second system maintain the current mode; wherein the second return water temperature value can be 45 degrees;

[0073] Step C: The first system maintains the current mode, and the second system enters the recovery mode; then proceeds to step D.

[0074] Specifically, the air-conditioning system for heat recovery in compression mode described in this embodiment first fully opens the proportional two-way valve 63, determines through the pressure difference switch 64 whether the water flow in the water supply channel 61 is sufficient, and then determines whether the heat supply is sufficient, thereby determining the number of dual systems entering the recovery mode; when the water flow temperature of the water supply channel 61 is lower than 40 degrees, two systems are required to supply heat to the water supply channel 61, and when the water flow temperature of the water supply channel 61 is greater than 40 degrees and less than 45 degrees, only one system is required to supply heat to the water supply channel 61; the above-mentioned setting can ensure that the return water temperature meets the standard, thereby ensuring sufficient heat supply.

[0075] The air conditioning system for heat recovery in compression mode described in this embodiment further includes the following steps:

[0076] Step D, detect the water supply temperature of the water outlet of the water supply channel 61, the air supply temperature of the blower 51 and the opening of the proportional two-way valve 63; if the water supply temperature of the water outlet of the water supply channel 61 is lower than the water supply temperature setting value within the first time, the air supply temperature of the blower 51 is lower than the first air supply temperature value within the second time, and the opening of the proportional two-way valve 63 is lower than the second opening, then enter step A; the second opening is lower than the first opening.

[0077] Specifically, assuming that the water supply temperature at the outlet of the water supply channel 61 is lower than the water supply temperature setting value within the first time, the air supply temperature of the blower 51 is lower than the first air supply temperature value within the second time, and the opening of the proportional two-way valve 63 is lower than the second opening, it means that the entire system has insufficient heating for a long time and sufficient cooling. At this time, both systems enter the recovery mode to increase the heating to the water supply channel 61.

[0078] In the air conditioning system for heat recovery in compression mode described in this embodiment, step D further includes: if the proportional two-way valve 63 is opened to a third opening and the air supply temperature of the blower 51 is greater than the second air supply temperature value within a third time, then entering step D1; the third opening is less than the first opening and greater than the second opening;

[0079] Step D1, detect whether the outdoor temperature is less than the outdoor temperature setting value, if so, proceed to step D11; if not, proceed to step D12;

[0080] Step D11, the first system maintains the current mode, the second system enters the fluorine cooling mode, and then enters step S1;

[0081] Step D12: The first system maintains the current mode, the second system enters the compression mode, and then enters step S1.

[0082] Specifically, since the air supply temperature of the blower 51 is greater than the second air supply temperature value within the third time, it means that the cooling effect is poor. Therefore, in order to ensure the overall cooling effect, it is necessary to reduce the load of the second system in the recovery mode, and determine whether the second system enters the compression mode or the fluorine cooling mode after the load reduction according to the outdoor temperature.

[0083] The air conditioning system for heat recovery in compression mode described in this embodiment further includes the following steps:

[0084] Step B1, detect whether the proportional two-way valve 63 is opened to the third opening degree, if yes, proceed to step B2; if no, the first system and the second system maintain the recovery mode;

[0085] Step B2, detecting whether the air supply temperature of the blower 51 is greater than the second air supply temperature value within the third time, if so, proceeding to step B3; if not, the first system and the second system maintain the recovery mode;

[0086] Step B3, check whether the outdoor temperature is less than the outdoor temperature setting value, if so, proceed to step B31; if not, proceed to step B32;

[0087] Step B31, the first system maintains the recovery mode, the second system enters the fluorine cooling mode, and then enters step B4;

[0088] Step B32: the first system maintains the recovery mode, the second system enters the compression mode, and then enters step B4;

[0089] Step B4, detecting whether the air supply temperature of the blower 51 is greater than the third air supply temperature value within the fourth time, and the third air supply temperature value is less than the second air supply temperature value; if so, proceed to step B5; if not, proceed to step D;

[0090] Step B5: The first system enters the compression mode or the fluorine cooling mode, and then enters step S1.

[0091] Specifically, since the air supply temperature of the air supply fan 51 is greater than the second air supply temperature value within the third time, it means that the cooling effect is poor. Therefore, in order to ensure the overall cooling effect, it is necessary to reduce the load of the second system in the recovery mode, and determine whether the second system enters the compression mode or the fluorine cooling mode after the load reduction according to the outdoor temperature; since the cooling capacity provided by the water-cooled plate heat exchanger 6 to the evaporator 5 is less than the cooling capacity provided to the evaporator 5 after the air-cooled condenser 3 exchanges heat. Although there is a heat recovery function, the air conditioner in the computer room has a higher priority for cooling capacity. Therefore, when the cooling capacity is insufficient, it is necessary to reduce the load of water cooling and convert it to air cooling after heat recovery; conversely, when the cooling capacity is sufficient, the air-cooled condenser 3 can be switched to a water-cooled plate heat exchanger 6. Turning off the air supply fan 51 on the premise of satisfying the cooling priority can reduce energy consumption, and the heat recovered can also be used for further energy saving.

[0092] If the supply air temperature of the blower 51 is detected to be greater than the third supply air temperature value within the fourth time, it means that the overall refrigeration effect is still insufficient. At this time, the first system needs to exit the recovery mode at the same time. This control method ensures that the water flow is sufficient in the load-reducing system recovery mode. Because the supply air temperature of the refrigeration is high, the refrigeration capacity is insufficient, so it is necessary to reduce the load and exit the recovery mode. The outdoor temperature is used to determine whether the system after the load-reducing recovery mode enters the compressor cycle or the fluorine pump cycle; if both systems are in the recovery mode, it is necessary to decide whether to exit the recovery mode of the other system based on the supply air temperature.

[0093] The air conditioning system for heat recovery in compression mode described in this embodiment converts from compression mode to recovery mode, including the following steps:

[0094] E1, gradually opening the second two-way valve 42 at T1, and keeping the second two-way valve 42 fully open at T3;

[0095] E2, gradually closing the first two-way valve 41 at T2, and keeping the first two-way valve 41 completely closed at T3;

[0096] E3. Keep the exhaust fan 31 completely closed at T4.

[0097] Specifically, through the above-mentioned arrangement, when the compression mode is converted to the recovery mode, the proportional two-way valve 63 is first gradually opened. When the proportional two-way valve 63 is opened to 100% opening, the refrigerant begins to switch between the condenser 3 and the heat exchange channel 62 through the first two-way valve 41 and the second two-way valve 42. When the switching is complete, the exhaust fan 31 is turned off. In this embodiment, the second two-way valve 42 is opened for a period of time, and then the first two-way valve 41 is closed after the second two-way valve 42 is opened to a certain ratio, for example, 80% opening. This can make the overall system more stable and reliable during the switching process.

[0098] The air conditioning system for heat recovery in compression mode described in this embodiment is converted from fluorine cooling mode to recovery mode, including the following steps:

[0099] E1, gradually opening the second two-way valve 42 at T5, and keeping the second two-way valve 42 fully open at T7;

[0100] E2, gradually closing the first two-way valve 41 at T6, and keeping the first two-way valve 41 completely closed at T7;

[0101] E3, at T8, the exhaust fan 31 is kept completely closed;

[0102] E4, gradually turning on compressor 1 at T5, and automatically adjusting after compressor 1 is fully turned on at T7;

[0103] E5. At T7, fluorine pump 2 is gradually turned off, and at T8, fluorine pump 2 remains completely turned off.

[0104] Specifically, through the above-mentioned arrangement, when the fluorine cooling mode is converted to the recovery mode, the proportional two-way valve 63 is first gradually opened. When the proportional two-way valve 63 is opened to 100% opening, the compressor 1 is first started and the second two-way valve 42 is opened. After the second two-way valve 42 is opened for a period of time, wait until the second two-way valve 42 is opened to a certain ratio, such as 80% opening, and then start to close the first two-way valve 41. When the second two-way valve 42 is fully opened, the first two-way valve 41 is fully closed, and the compressor 1 is also fully opened; at this time, start to close the fluorine pump 2. When the fluorine pump 2 is fully closed, the exhaust fan 31 is turned off, so that the overall system is more stable and reliable during the switching process.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An air conditioning system for heat recovery in compression mode, characterized in that: The invention comprises a first system, a second system and a recovery system; the first system and the second system both comprise a compressor (1), a compression check valve (11), a fluorine pump (2), a fluorine cooling check valve (21), a condenser (3), a first two-way valve (41), a second two-way valve (42) and an evaporator (5); the evaporator (5) is provided with a blower (51); the condenser (3) is provided with an exhaust fan (31); The recovery system comprises a heat exchanger (6) and a proportional two-way valve (63); the heat exchanger (6) comprises a water supply channel (61) and two heat exchange channels (62); the proportional two-way valve (63) is in communication with the water supply channel (61); a pressure difference switch (64) is provided between the water inlet and the water outlet of the water supply channel (61); the two heat exchange channels (62) are respectively in communication with the first system and the second system; The first system and the second system both include a fluorine cooling mode, a compression mode and a recovery mode.

2. An air conditioning system for heat recovery in compression mode according to claim 1, characterized in that: In the compression mode, the flow paths of the refrigeration systems of the first system and the second system are: compressor (1) - first two-way valve (41) - condenser (3) - fluorine cooling check valve (21) - evaporator (5) - compressor (1); In the fluorine cooling mode, the flow paths of the refrigeration systems of the first system and the second system are: fluorine pump (2) - evaporator (5) - compression check valve (11) - first two-way valve (41) - condenser (3) - fluorine pump (2); In the recovery mode, the flow paths of the refrigeration systems of the first system and the second system are: compressor (1) - second two-way valve (42) - heat exchange channel (62) - fluorine cooling one-way valve (21) - evaporator (5) - compressor (1).

3. An air conditioning system for heat recovery in compression mode according to claim 2, characterized in that: The compressor (1) is arranged in parallel with the compression check valve (11); the fluorine pump (2) is arranged in parallel with the fluorine cooling check valve (21); one end of the compressor (1) is respectively connected to one end of a first two-way valve (41) and one end of a second two-way valve (42); the other end of the first two-way valve (41) is connected to one end of a condenser (3); the other end of the condenser (3) is connected to one end of the fluorine pump (2); the other end of the second two-way valve (42) is connected to the other end of the condenser (3) through a heat exchange channel (62); the other end of the fluorine pump (2) is connected to one end of an evaporator (5); and the other end of the evaporator (5) is connected to the other end of the compressor (1).

4. The air conditioning system for heat recovery in compression mode according to claim 3, characterized in that: A liquid storage tank (7) is provided between the other end of the condenser (3) and one end of the fluorine pump (2); an electronic expansion valve (8) is provided between the other end of the fluorine pump (2) and one end of the evaporator (5); a gas-liquid separator (9) is provided between the other end of the evaporator (5) and the other end of the compressor (1); a branch connecting the compressor (1) and the gas-liquid separator (9) is provided in parallel at both ends of the compression check valve (11); The evaporator (5) of the first system and the evaporator (5) of the second system are arranged overlappingly; the evaporator (5) of the second system is arranged between the evaporator (5) of the first system and the blower (51).

5. The air conditioning system for heat recovery in compression mode according to claim 1, characterized in that: The following steps are involved: Step S1, detecting whether the proportional two-way valve (63) is opened to a first opening degree, if so, proceeding to step S2; if not, the first system and the second system maintain the current mode; Step S2, detecting whether the pressure difference switch (64) is turned on, if so, proceeding to step S3; if not, the first system and the second system maintain the current mode; Step S3, detecting whether the return water temperature of the water inlet of the water supply channel (61) is less than the first return water temperature value, if so, proceed to step A; if not, proceed to step S4; Step A: both the first system and the second system enter the recovery mode; then enter step B1; Step S4, detecting whether the return water temperature of the water inlet of the water supply channel (61) is less than the second return water temperature value, and the second return water temperature value is greater than the first return water temperature value. If so, proceed to step C; if not, the first system and the second system maintain the current mode; Step C: The first system maintains the current mode, and the second system enters the recovery mode; then proceeds to step D.

6. An air conditioning system for heat recovery in compression mode according to claim 5, characterized in that: The following steps are also included: Step D, detecting the water supply temperature of the water outlet of the water supply channel (61), the air supply temperature of the blower (51), and the opening of the proportional two-way valve (63); if the water supply temperature of the water outlet of the water supply channel (61) is less than the water supply temperature setting value within the first time, the air supply temperature of the blower (51) is less than the first air supply temperature value within the second time, and the opening of the proportional two-way valve (63) is less than the second opening, then proceed to step A; the second opening is less than the first opening.

7. An air conditioning system for heat recovery in compression mode according to claim 6, characterized in that: The step D further comprises: if the proportional two-way valve (63) is opened to a third opening and the air supply temperature of the air supply fan (51) is greater than the second air supply temperature value within a third time, then entering step D1; the third opening is less than the first opening and greater than the second opening; Step D1, detect whether the outdoor temperature is less than the outdoor temperature setting value, if so, proceed to step D11; if not, proceed to step D12; Step D11, the first system maintains the current mode, the second system enters the fluorine cooling mode, and then enters step S1; Step D12: The first system maintains the current mode, the second system enters the compression mode, and then enters step S1.

8. An air conditioning system for heat recovery in compression mode according to claim 7, characterized in that: The following steps are also included: Step B1, detecting whether the proportional two-way valve (63) is opened to the third opening degree, if so, proceeding to step B2; if not, the first system and the second system maintain the recovery mode; Step B2, detecting whether the air supply temperature of the air supply fan (51) is greater than the second air supply temperature value within the third time, if so, proceeding to step B3; if not, the first system and the second system maintain the recovery mode; Step B3, check whether the outdoor temperature is less than the outdoor temperature setting value, if so, proceed to step B31; if not, proceed to step B32; Step B31, the first system maintains the recovery mode, the second system enters the fluorine cooling mode, and then enters step B4; Step B32: the first system maintains the recovery mode, the second system enters the compression mode, and then enters step B4; Step B4, detecting whether the air supply temperature of the air supply fan (51) is greater than a third air supply temperature value within a fourth time, and whether the third air supply temperature value is less than the second air supply temperature value; If yes, proceed to step B5; if no, proceed to step D; Step B5: The first system enters the compression mode or the fluorine cooling mode, and then enters step S1.

9. The air conditioning system for heat recovery in compression mode according to claim 3, characterized in that: Switching from compression mode to recycling mode involves the following steps: E1, gradually opening the second two-way valve (42) at T1, and keeping the second two-way valve (42) fully open at T3; E2, gradually closing the first two-way valve (41) at T2, and keeping the first two-way valve (41) completely closed at T3; E3. At T4, the exhaust fan (31) is kept completely closed.

10. The air conditioning system for heat recovery in compression mode according to claim 3, characterized in that: Converting from fluorine cooling mode to recovery mode includes the following steps: E1, gradually opening the second two-way valve (42) at T5, and keeping the second two-way valve (42) fully open at T7; E2, gradually closing the first two-way valve (41) at T6, and keeping the first two-way valve (41) completely closed at T7; E3. At T8, the exhaust fan (31) is kept completely closed; E4, gradually turning on the compressor (1) at T5, and automatically adjusting the compressor (1) after it remains fully turned on at T7; E5. At T7, the fluorine pump (2) is gradually turned off, and at T8, the fluorine pump (2) remains completely turned off.

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