Heat recovery air conditioning system and control method thereof

Abstract

The present invention provides a heat recovery air-conditioning system and a control method thereof, wherein the system comprises a computer room air-conditioning system, a heat source recovery system connected to the computer room air-conditioning system via a first heat exchanger, and a heat source application system connected to the heat source recovery system via a second heat exchanger; heat exchange is performed by connecting the heat exchangers between the various systems to achieve the purpose of recovering heat energy, and the first compressor in the heat source recovery system can perform secondary compression on the recovered heat energy, thereby improving the heat energy recovery efficiency and heat energy recovery quality, and expanding the spatial application range of the recovered heat energy, and the heat source application system comprises a heat storage device, thereby expanding the temporal application range of the recovered heat energy.

Description

Technical Field

[0001] The present invention relates to the technical field of heat recovery, and in particular to a heat recovery air-conditioning system and a control method thereof. Background Art

[0002] Because data center computer rooms require a constant cooling source, the air conditioners used in these rooms constantly need to dissipate large amounts of heat. This heat can be discharged in three ways: directly into the atmosphere, which is extremely wasteful; through heat exchangers connected to hot water pipes for heat recovery, the recovered heat is of low quality and has a limited scope of application; and through refrigerant heat exchange in secondary-side heat exchangers connected to household or commercial air conditioners, which can only be used when heat is needed in winter, resulting in low heat utilization. All three methods suffer from low heat recovery rates and a limited scope of application for the recovered heat. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a heat recovery air conditioning system and a control method thereof in view of at least one defect in the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a heat recovery air conditioning system, including a computer room air conditioning system, a heat source recovery system connected to the computer room air conditioning system through a first heat exchanger, and a heat source application system connected to the heat source recovery system through a second heat exchanger;

[0005] The heat source recovery system includes a first compressor and a first expansion valve; the inlet of the first compressor is connected to the second refrigerant outlet of the first heat exchanger on the heat source recovery side, the outlet of the first compressor is connected to the third refrigerant inlet of the second heat exchanger on the heat source recovery side, the third refrigerant outlet of the second heat exchanger on the heat source recovery side is connected to the inlet of the first expansion valve, and the outlet of the first expansion valve is connected to the second refrigerant inlet of the first heat exchanger on the heat source recovery side;

[0006] The heat source application system includes a heat storage device and a third transmission device; the inlet of the heat storage device is connected to the fourth refrigerant outlet of the second heat exchanger on the heat source application side, the outlet of the heat storage device is connected to the inlet of the third transmission device, and the outlet of the third transmission device is connected to the fourth refrigerant inlet of the second heat exchanger on the heat source application side.

[0007] Preferably, in the heat recovery air-conditioning system described in the present invention, the heat source recovery system also includes a first transmission device connected between the third refrigerant outlet of the second heat exchanger on the heat source recovery side and the second refrigerant inlet of the first heat exchanger on the heat source recovery side, and a fourth valve connected to both ends of the first compressor.

[0008] Preferably, in the heat recovery air conditioning system of the present invention, the computer room air conditioning system includes an evaporator, a second compressor, a first valve, a second valve, a third valve, a condenser and a second expansion valve;

[0009] Among them, the inlet of the second compressor is connected to the outlet of the evaporator; the first refrigerant inlet of the first heat exchanger on the computer room air conditioner side and the inlet of the first valve are commonly connected to the outlet of the second compressor; the inlet of the second valve and the inlet of the third valve are commonly connected to the first refrigerant outlet of the first heat exchanger on the computer room air conditioner side; the outlet of the first valve and the outlet of the second valve are commonly connected to the inlet of the condenser; the outlet of the condenser and the outlet of the third valve are commonly connected to the inlet of the second expansion valve; and the outlet of the second expansion valve is connected to the inlet of the evaporator.

[0010] Preferably, in the heat recovery air-conditioning system described in the present invention, the computer room air-conditioning system also includes a second transmission device and a fifth valve, wherein the inlet of the second transmission device is connected to the outlet of the third valve and the outlet of the condenser, and the outlet of the second transmission device is connected to the inlet of the evaporator; the fifth valve is connected to both ends of the second compressor.

[0011] Preferably, in the heat recovery air conditioning system of the present invention, the computer room air conditioning system and the heat source recovery system use Freon as the heat exchange refrigerant.

[0012] Preferably, in the heat recovery air-conditioning system described in the present invention, the heat storage device further includes a water replenishment port and a water outlet.

[0013] The present invention also constructs a control method for the heat recovery air conditioning system as described in any of the above items, including a full heat recovery mode, a partial heat recovery mode and a no heat recovery mode;

[0014] When it is detected that the heat load of the heat source application system is greater than or equal to the heat discharge capacity of the computer room air conditioning system, the heat recovery air conditioning system enters the full heat recovery mode; wherein, the first valve and the second valve are closed, and the third valve is opened; in the computer room air conditioning system, the refrigerant enters the first refrigerant inlet of the first heat exchanger on the computer room air conditioning side for heat exchange, and the heat energy to be recovered is transferred to the heat source recovery system in the first heat exchanger; after the refrigerant completes the heat exchange in the first heat exchanger, it flows from the first refrigerant outlet of the first heat exchanger on the computer room air conditioning side to the inlet of the third valve, waiting for the next heat exchange;

[0015] When it is detected that the heat load of the heat source application system is less than the heat discharge capacity of the computer room air conditioning system, the heat recovery air conditioning system enters the partial heat recovery mode; wherein, the first valve and the third valve are closed, and the second valve is opened; in the computer room air conditioning system, the refrigerant enters the first refrigerant inlet of the first heat exchanger on the computer room air conditioning side for heat exchange, and transfers part of the heat energy to be recovered to the heat source recovery system in the first heat exchanger; after the refrigerant completes the heat exchange in the first heat exchanger, it flows out from the first refrigerant outlet of the first heat exchanger on the computer room air conditioning side, flows to the inlet of the condenser through the second valve, and transfers the remaining heat energy to be recovered to the atmosphere around the condenser in the condenser; the refrigerant flows out from the outlet of the condenser and waits for the next heat exchange;

[0016] When it is detected that the heat load of the heat source application system is lower than the starting value for a long time, the heat recovery air-conditioning system enters the no-heat recovery mode; wherein, the first valve is opened, and the second valve and the third valve are closed; the refrigerant to be heat released flows to the inlet of the condenser through the first valve, and the heat energy to be released is transferred to the atmosphere around the condenser in the condenser; the refrigerant flows out from the outlet of the condenser, waiting for the next heat exchange.

[0017] The present invention also provides a control method for the heat recovery air conditioning system described in any one of the above items, comprising:

[0018] Heat storage mode: When receiving a heat storage instruction from the user, the heat recovery air conditioning system will disable the no heat recovery mode at a preset time, determine the relationship between the heat load of the heat storage instruction and the heat discharge capacity of the computer room air conditioning system, and enter the full heat recovery mode or the partial heat recovery mode;

[0019] Non-heat storage mode: When no heat storage instruction is received from the user, the heat recovery air-conditioning system determines whether to enter the non-heat recovery mode based on the relationship between the heat load of the heat source application system and the startup value; if it is determined not to enter the non-heat recovery mode, the heat recovery air-conditioning system determines whether to enter the full heat recovery mode or the partial heat recovery mode based on the relationship between the heat load of the heat source application system and the heat discharge capacity of the computer room air-conditioning system.

[0020] The present invention also provides a control method for the heat recovery air conditioning system described in any one of the above items, comprising:

[0021] First compressor mode: when it is detected that the difference between the evaporation temperature of the refrigerant in the heat source recovery system and the temperature of the refrigerant in the heat source application system is less than or equal to the heat exchange temperature difference of the second heat exchanger, the first transmission device stops running, the fourth valve is closed, and the first compressor starts;

[0022] First transmission device mode: when it is detected that the difference between the refrigerant evaporation temperature in the heat source recovery system and the refrigerant temperature in the heat source application system is greater than the heat exchange temperature difference of the second heat exchanger, the first compressor stops running, the fourth valve opens, and the first transmission device operates.

[0023] The present invention also provides a control method for the heat recovery air conditioning system described in any one of the above items, comprising:

[0024] Second compressor mode: when it is detected that the larger of the ambient temperature and the refrigerant evaporation temperature in the heat source recovery system is greater than or equal to the preset heat exchange temperature, the second transmission device stops running, the fifth valve is closed, and the second compressor starts running;

[0025] Second transmission device mode: when it is detected that the larger of the ambient temperature and the refrigerant evaporation temperature in the heat source recovery system is lower than the preset heat exchange temperature, the second compressor stops running, the fifth valve opens, and the second transmission device operates.

[0026] By implementing the present invention, the following beneficial effects are achieved:

[0027] The heat recovery air-conditioning system provided by the present invention includes a computer room air-conditioning system, a heat source recovery system connected to the computer room air-conditioning system through a first heat exchanger, and a heat source application system connected to the heat source recovery system through a second heat exchanger. Through heat exchange between the first heat exchanger and the second heat exchanger, and the heat source recovery system includes a first compressor, which can perform secondary compression on the recovered heat energy. The heat recovery air-conditioning system can improve the heat energy recovery efficiency and heat energy recovery quality, expand the spatial application range of the recovered heat energy, and the heat source application system includes a heat storage device, which expands the temporal application range of the recovered heat energy.

[0028] The present invention also provides a control method for a heat recovery air-conditioning system. After measuring the heat load required by the heat source application system and the heat discharge capacity that the computer room air-conditioning system can provide, different operating modes can be selected according to the situation to avoid the waste of resources caused by heat recovery when the heat source application system has no heat load demand for a long time, and also expand the time application range of the recovered heat energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0030] Figure 1 It is a structural schematic diagram of the heat recovery air conditioning system of the present invention;

[0031] Figure 2 is a first flow chart of the heat recovery air conditioning system of the present invention;

[0032] Figure 3is a second flow chart of the heat recovery air conditioning system of the present invention;

[0033] Figure 4 This is the second flow chart of the heat recovery air conditioning system of the present invention. DETAILED DESCRIPTION

[0034] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0035] It should be noted that the flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all content and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0036] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0037] like Figure 1 As shown, this embodiment discloses a heat recovery air conditioning system, comprising a computer room air conditioning system 10, a heat source recovery system 20 connected to the computer room air conditioning system 10 via a first heat exchanger 40, and a heat source application system 30 connected to the heat source recovery system 20 via a second heat exchanger 50. Preferably, the computer room air conditioning system 10 is a computer room air conditioning system for a data center, used to provide a cooling source for the data center's computer rooms; the heat source application system 30 is a system for supplying hot water for industrial and domestic use.

[0038] The heat source recovery system 20 includes a first compressor 21 and a first expansion valve 23; the inlet of the first compressor 21 is connected to the second refrigerant outlet of the first heat exchanger 40 on the heat source recovery side, the outlet of the first compressor 21 is connected to the third refrigerant inlet of the second heat exchanger 50 on the heat source recovery side, the third refrigerant outlet of the second heat exchanger 50 on the heat source recovery side is connected to the inlet of the first expansion valve 23, and the outlet of the first expansion valve 23 is connected to the second refrigerant inlet of the first heat exchanger 40 on the heat source recovery side.

[0039] Furthermore, the first compressor 21 compresses the refrigerant from the first heat exchanger 40 in the heat source recovery system 20, converting the refrigerant from its original relatively low pressure state to a relatively high pressure state. This relatively high-pressure refrigerant passes through the second heat exchanger 50, exchanging heat energy with the refrigerant in the heat source application system 30, which also passes through the second heat exchanger 50. It then passes through the first expansion valve 23, returning to a relatively low pressure state, and enters the first heat exchanger 40, where it exchanges heat energy with the refrigerant in the computer room air conditioning system 10.

[0040] It can be understood that after the above heat exchange, under the secondary compression of the heat source recovery system 20, the quality of the heat energy recovered by the heat recovery air-conditioning system becomes higher.

[0041] The heat source application system 30 includes a heat storage device 32 and a third transmission device 31. The inlet of the heat storage device 32 is connected to the fourth refrigerant outlet of the second heat exchanger 50 on the heat source application side, the outlet of the heat storage device 32 is connected to the inlet of the third transmission device 31, and the outlet of the third transmission device 31 is connected to the fourth refrigerant inlet of the second heat exchanger 50 on the heat source application side. Furthermore, the heat storage device 32 is a water tank, and the third transmission device 31 is a water pump; in other preferred embodiments, the heat storage device 32 is a refrigerant storage chamber, and the third transmission device 31 is a refrigerant pump. It can be understood that the heat storage device 32 can store heat energy that has undergone heat recovery, and also has the function of preventing the loss of stored heat energy and / or the function of heating the refrigerant inside the heat storage device 32, so as to avoid the problem of insufficient heating in other emergency situations.

[0042] In some embodiments, the pipes used to connect the various devices in the above system are insulated pipes, which can effectively reduce the heat energy dissipated outside the system during transmission and better maintain the working efficiency and heat recovery quality of the heat recovery air conditioning system.

[0043] In some embodiments, the heat recovery system 20 further includes a first conveying device 22 connected between the third refrigerant outlet of the second heat exchanger 50 on the heat recovery side and the second refrigerant inlet of the first heat exchanger 40 on the heat recovery side, and a fourth valve 24 connected to both ends of the first compressor 21. It is understood that the first conveying device 22 and the fourth valve 24, together with the first heat exchanger 40, the second heat exchanger 50, and the first expansion valve 23, form a second refrigerant circuit in the heat recovery system 20. When the refrigerant is liquid in the heat recovery system 20, it circulates solely through the first conveying device 22. The refrigerant circulates through the system, starting with the first conveying device 22 and progressing sequentially through the first conveying device 22, the first expansion valve 23, the first heat exchanger 40, the fourth valve 24, and the second heat exchanger 50. After passing through the second heat exchanger 50, the refrigerant re-enters the first conveying device 22 for the next cycle.

[0044] In some embodiments, the computer room air conditioning system 10 includes an evaporator 11 , a second compressor 12 , a first valve 13 , a second valve 14 , a third valve 15 , a condenser 16 , and a second expansion valve 18 .

[0045] Among them, the inlet of the second compressor 12 is connected to the outlet of the evaporator 11; the first refrigerant inlet of the first heat exchanger 40 on the computer room air-conditioning side and the inlet of the first valve 13 are commonly connected to the outlet of the second compressor 12; the inlet of the second valve 14 and the inlet of the third valve 15 are commonly connected to the first refrigerant outlet of the first heat exchanger 40 on the computer room air-conditioning side; the outlet of the first valve 13 and the outlet of the second valve 14 are commonly connected to the inlet of the condenser 16; the outlet of the condenser 16 and the outlet of the third valve 15 are commonly connected to the inlet of the second expansion valve 18; the outlet of the second expansion valve 18 is connected to the inlet of the evaporator 11.

[0046] Furthermore, the refrigerant absorbs heat energy from the outside air in the evaporator 11, causing the outside air temperature to drop and the refrigerant temperature to rise. When the refrigerant temperature rises to the evaporation temperature, the refrigerant changes phase to a gaseous state and is compressed into a high-temperature, high-pressure gas by the second compressor 12. In the first heat exchanger 40, the refrigerant transfers heat to the refrigerant in the heat recovery system 20 before re-entering the next refrigerant cycle in the computer room air conditioning system 10.

[0047] In some embodiments, the computer room air conditioning system 10 also includes a second transmission device 17 and a fifth valve 19; the inlet of the second transmission device 17 is connected to the outlet of the third valve 15 and the outlet of the condenser 16, and the outlet of the second transmission device 17 is connected to the inlet of the evaporator 11; the fifth valve 19 is connected to both ends of the second compressor 12.

[0048] It can be understood that the second transmission device 17 and the fifth valve 19 constitute a second refrigerant circuit in the computer room air conditioning system 10. When the refrigerant in the computer room air conditioning system 10 is in liquid state, the second transmission device 17 can be used as a driving device for the refrigerant circulation. At this time, the refrigerant in the computer room air conditioning system 10 does not pass through the second compressor 12, but takes the second transmission device 17 as the starting point of the path, and passes through the second transmission device 17, the second expansion valve 18, the evaporator 11, the second compressor 12 and the first heat exchanger 40 in sequence. After passing through the first heat exchanger 40, the refrigerant enters the first transmission device 22 again for the next cycle.

[0049] In some embodiments, the computer room air conditioning system 10 and the heat recovery system 20 use Freon as a heat exchange refrigerant. Freon continuously circulates in the system, absorbing and releasing heat in a phase change manner, completing each stage of heat exchange.

[0050] In some embodiments, the heat storage device 32 further includes a water inlet 321 and a water outlet 322. Furthermore, the water inlet 321 and the water outlet 322 are used to provide users with direct production and domestic hot water, such as hot water for bathing in school bathrooms, via water supply pipes. In some embodiments, the heat energy in the heat source application system 30 can also be used as hot water for heating in factories and homes, circulating directly within the hot water heating system without requiring extraction for use.

[0051] In some embodiments, the first heat exchanger 40 and the second heat exchanger 50 are plate heat exchangers. Plate heat exchangers are high-efficiency heat exchangers made of a series of corrugated metal sheets stacked together, which can improve the heat recovery efficiency of heat recovery air conditioning systems.

[0052] In some embodiments, the heat recovery system 20 further includes a first three-way valve 61, the inlet of which is connected to the second outlet of the first heat exchanger 40 on the heat recovery side. The first outlet of the first three-way valve 61 is connected to the inlet of the first compressor 21, and the second outlet of the first three-way valve 61 is connected to the inlet of the fourth valve 24. When the first compressor 21 is required to operate, the first outlet of the first three-way valve 61 is opened and the second outlet of the first three-way valve 61 is closed. At this time, the refrigerant of the heat recovery system 20 flows from the inlet of the first three-way valve 61, passes through the first outlet of the first three-way valve 61, and flows into the inlet of the first compressor 21. When only the first transmission device 22 is required to operate, the first outlet of the first three-way valve 61 is closed and the second outlet of the first three-way valve 61 is opened. At this time, the refrigerant of the heat recovery system 20 flows from the inlet of the first three-way valve 61, passes through the second outlet of the first three-way valve 61, and flows into the inlet of the fourth valve 24. Through the above method, the function of a gate circuit can be achieved.

[0053] In some embodiments, the computer room air conditioning system 10 further includes a second three-way valve 62, the inlet of which is connected to the outlet of the second compressor 12, the first outlet of which is connected to the first inlet of the first heat exchanger 40 on the computer room air conditioning side, and the second outlet of which is connected to the inlet of the first valve 13. When refrigerant is required to flow through the first heat exchanger 40, the first outlet of the second three-way valve 62 is opened and the second outlet of the second three-way valve 62 is closed. At this time, refrigerant in the computer room air conditioning system 10 flows from the inlet of the second three-way valve 62, passes through the first outlet of the second three-way valve 62, and flows into the first inlet of the first heat exchanger 40 on the computer room air conditioning side. When refrigerant is required to flow through the first valve 13, the first outlet of the second three-way valve 62 is closed and the second outlet of the second three-way valve 62 is opened. At this time, refrigerant in the computer room air conditioning system 10 flows from the inlet of the second three-way valve 62, passes through the second outlet of the second three-way valve 62, and flows into the inlet of the first valve 13. This method can achieve the function of a gate circuit.

[0054] In some embodiments, the computer room air conditioning system 10 further includes a third three-way valve 63, the inlet of which is connected to the outlet of the evaporator 11, the first outlet of which is connected to the inlet of the second compressor 12, and the second outlet of which is connected to the inlet of the fifth valve 19. When the second compressor is required to operate, the first outlet of the third three-way valve 63 is opened and the second outlet of the third three-way valve 63 is closed. In this case, the refrigerant of the computer room air conditioning system 10 flows from the inlet of the third three-way valve 63, passes through the first outlet of the third three-way valve 63, and flows into the inlet of the second compressor 12. When only the second transmission device 17 is required to operate, the first outlet of the third three-way valve 63 is closed and the second outlet of the third three-way valve 63 is opened. In this case, the refrigerant of the computer room air conditioning system 10 flows from the inlet of the third three-way valve 63, passes through the second outlet of the third three-way valve 63, and flows into the inlet of the fifth valve 19. This method can achieve the function of a gate circuit.

[0055] like Figure 2 As shown, this embodiment also constructs a control method for the heat recovery air conditioning system of any of the above items, including a full heat recovery mode, a partial heat recovery mode and a no heat recovery mode.

[0056] When it is detected that the heat load of the heat source application system 30 is greater than or equal to the heat exhaust capacity of the computer room air conditioning system 10, the heat recovery air conditioning system enters the full heat recovery mode; wherein, the first valve 13 and the second valve 14 are closed, and the third valve 15 is opened; in the computer room air conditioning system 10, the refrigerant enters the first refrigerant inlet of the first heat exchanger 40 on the computer room air conditioning side for heat exchange, and the heat energy to be recovered is transferred to the heat source recovery system 20 in the first heat exchanger 40; after completing the heat exchange in the first heat exchanger 40, the refrigerant flows from the first refrigerant outlet of the first heat exchanger 40 on the computer room air conditioning side to the inlet of the third valve 15, waiting for the next heat exchange;

[0057] When it is detected that the heat load of the heat source application system 30 is less than the heat discharge capacity of the computer room air conditioning system 10, the heat recovery air conditioning system enters the partial heat recovery mode; wherein, the first valve 13 and the third valve 15 are closed, and the second valve 14 is opened; in the computer room air conditioning system 10, the refrigerant enters the first refrigerant inlet of the first heat exchanger 40 on the computer room air conditioning side for heat exchange, and transfers part of the heat energy to be recovered to the heat source recovery system 20 in the first heat exchanger 40; after the refrigerant completes the heat exchange in the first heat exchanger 40, it flows out from the first refrigerant outlet of the first heat exchanger 40 on the computer room air conditioning side, passes through the second valve 14 and flows to the inlet of the condenser 16, and transfers the remaining heat energy to be recovered in the condenser 16 to the atmosphere around the condenser 16; the refrigerant flows out from the outlet of the condenser 16 and waits for the next heat exchange;

[0058] When it is detected that the heat load of the heat source application system 30 is lower than the starting value for a long time, the heat recovery air-conditioning system enters the no-heat recovery mode; wherein, the first valve 13 is opened, and the second valve 14 and the third valve 15 are closed; the refrigerant to be heat released flows through the first valve 13 to the inlet of the condenser 16, and the heat energy to be released is transferred to the atmosphere around the condenser 16 in the condenser 16; the refrigerant flows out from the outlet of the condenser 16, waiting for the next heat exchange.

[0059] It can be understood that in the full heat recovery mode, the refrigerant in the computer room air conditioning system 10 is compressed by the second compressor 12 and then directly passed into the first heat exchanger 40, exchanging the heat energy absorbed from the data center to the heat source recovery system 20. The refrigerant then flows out of the first heat exchanger 40, passes through the third valve 15, and flows into the evaporator 11 through the second expansion valve 18. The refrigerant absorbs the heat energy of the data center, providing a cold source for the data center, and then flows into the second compressor 12 for the next cycle. In this full heat recovery mode, the refrigerant in the computer room air conditioning system 10 only enters the first heat exchanger 40 for heat exchange. Therefore, except for some inevitable transportation losses, the rest of the heat energy absorbed from the evaporator 11 can be exchanged to the heat source recovery system 20. After secondary compression by the heat source recovery system 20, the heat energy quality is improved and transferred to the heat source application system 30.

[0060] As can be understood, in partial heat recovery mode, after being compressed by the second compressor 12, the refrigerant in the computer room air conditioning system 10 is directly passed into the first heat exchanger 40, exchanging heat energy absorbed from the data center with the heat source recovery system 20. The refrigerant then flows out of the first heat exchanger 40. At this point, the refrigerant first passes through the second valve 14 and enters the condenser 16, where it transfers some of the heat energy absorbed from the data center to the outside air, thereby improving the cooling effect of the data center computer room. After completing the heat exchange with the outside air in the condenser 16, the refrigerant passes through the second expansion valve 18 and enters the evaporator 11.

[0061] As can be understood, in non-heat recovery mode, the refrigerant in the computer room air conditioning system 10, after being compressed by the second compressor 12, flows through the first valve 13 into the condenser 16, transferring all the heat energy absorbed from the data center to the outside air. After completing the heat exchange with the outside air in the condenser 16, the refrigerant passes through the second expansion valve 18 and enters the evaporator 11. In this mode, both the heat source recovery system 20 and the heat source utilization system 30 are deactivated, the first heat exchanger 40 and the second heat exchanger 50 do not perform heat exchange, and the computer room air conditioning system 10 does not recover any heat energy.

[0062] like Figure 2 As shown, in some embodiments, the control method of the heat recovery air conditioning system further includes:

[0063] Heat storage mode: When receiving a heat storage instruction from the user, the heat recovery air conditioning system will disable the no heat recovery mode at a preset time, determine the relationship between the heat load of the heat storage instruction and the heat discharge capacity of the computer room air conditioning system 10, and enter the full heat recovery mode or the partial heat recovery mode;

[0064] Non-heat storage mode: When no heat storage instruction is received from the user, the heat recovery air-conditioning system determines whether to enter the non-heat recovery mode based on the relationship between the heat load of the heat source application system 30 and the startup value; if it is determined not to enter the non-heat recovery mode, the heat recovery air-conditioning system determines whether to enter the full heat recovery mode or the partial heat recovery mode based on the relationship between the heat load of the heat source application system 30 and the heat discharge capacity of the computer room air-conditioning system 10.

[0065] Furthermore, the heat storage instruction may be an instruction that takes effect during a certain time period, during which the system disables the no-heat recovery mode; the content of the heat storage instruction includes the heat load of the heat energy that the user needs to store during the time period when the no-heat recovery mode is disabled. The heat storage instruction requires that the stored heat energy be stored in the heat storage device 32 of the heat source application system 30. In some embodiments, the content of the heat storage instruction includes the heating temperature required by the user. After the heat storage instruction is issued, the system detects whether the refrigerant temperature in the heat storage device 32 is greater than or equal to the heating temperature required by the user. If not, the system keeps disabling the no-heat recovery mode until the system detects that the refrigerant temperature in the heat storage device 32 is greater than or equal to the heating temperature required by the user.

[0066] It can be understood that when no heat storage instruction is received from the user, the heat recovery air conditioning system performs tasks according to the aforementioned judgment logic of the full heat recovery mode, partial heat recovery mode and no heat recovery mode.

[0067] like Figure 3 As shown, in some embodiments, the control method of the heat recovery air conditioning system further includes:

[0068] First compressor mode: When it is detected that the difference between the evaporation temperature of the refrigerant in the heat source recovery system 20 and the temperature of the refrigerant in the heat source application system 30 is less than or equal to the heat exchange temperature difference of the second heat exchanger 50, the first transmission device 22 stops operating, the fourth valve 24 is closed, and the first compressor 21 operates;

[0069] First transmission device mode: When it is detected that the difference between the refrigerant evaporation temperature in the heat source recovery system 20 and the refrigerant temperature in the heat source application system 30 is greater than the heat exchange temperature difference of the second heat exchanger 50, the first compressor 21 stops running, the fourth valve 24 opens, and the first transmission device 22 operates.

[0070] In the first transmission device mode, when the relationship between the evaporation temperature of the refrigerant in the heat source recovery system 20 and the refrigerant temperature in the heat source application system 30 is greater than a certain set temperature difference (i.e., the heat exchange temperature difference), due to the principle that the greater the temperature difference, the faster the heat exchange, at this time, the first transmission device 22 is used to transport the refrigerant in the heat source recovery system 20, which can be coordinated with the heating rate of the refrigerant in the heat source application system 30 to save the overall heat recovery operating cost of the heat recovery air-conditioning system.

[0071] In the first compressor mode, when the relationship between the evaporation temperature of the refrigerant in the heat source recovery system 20 and the refrigerant temperature in the heat source application system 30 is less than a certain set temperature difference (i.e., the heat exchange temperature difference), due to the principle that the greater the temperature difference, the faster the heat exchange, at this time, the first compressor 21 is used to compress the refrigerant flowing out of the first heat exchanger 40, which can cooperate with the heating rate of the refrigerant in the heat source application system 30 to improve the overall heat recovery efficiency of the recovery air-conditioning system.

[0072] Furthermore, the first compressor mode and the first transmission device mode can be combined into a first composite operating mode. In this first composite operating mode, the fourth valve 24 is closed, the first transmission device 22 and the first compressor 21 operate simultaneously, and the refrigerant in the heat source recovery system 20 is driven by the first transmission device 22 and the first compressor 21 at the same time, and circulates in the heat source recovery system 20. This first composite mode can play a role in compensating for pipe losses.

[0073] like Figure 4 As shown, in some embodiments, the control method of the heat recovery air conditioning system further includes:

[0074] Second compressor mode: When the larger of the ambient temperature and the refrigerant evaporation temperature in the heat source recovery system 20 is detected to be greater than or equal to the preset heat exchange temperature, the second transmission device 17 stops operating, the fifth valve 19 closes, and the second compressor 12 operates. In this mode, the refrigerant in the computer room air conditioning system 10 circulates through the system, driven by the compression of the second compressor 12.

[0075] Second conveyor mode: When the larger of the ambient temperature of computer room air conditioning system 10 and the evaporation temperature of the refrigerant in computer room air conditioning system 10 is detected to be less than the preset heat exchange temperature, second compressor 12 stops, fifth valve 19 opens, and second conveyor 17 operates. In this mode, the refrigerant in computer room air conditioning system 10 circulates within the system, driven by the extraction and discharge of second conveyor 17. The refrigerant does not flow through second compressor 12. Instead, it flows from the outlet of second conveyor 17 through evaporator 11 and to the inlet of fifth valve 19.

[0076] It can be understood that the ambient temperature refers to the temperature of the atmospheric environment outside the heat recovery air-conditioning system; the preset heat exchange temperature is set based on the principle that heat exchange between heat exchangers requires a certain heat exchange temperature difference to be achieved. The management personnel can preset the heat exchange temperature before the system is put into operation based on the various properties of the refrigerant used in the system.

[0077] Furthermore, the second compressor mode and the second transmission device mode can be combined into a second composite operation mode. In the second composite operation mode, the fifth valve 19 is closed, and the second transmission device 17 and the second compressor 12 operate simultaneously, which can compensate for pipe loss.

[0078] By implementing the present invention, the following beneficial effects are achieved:

[0079] The heat recovery air-conditioning system provided by the present invention includes a computer room air-conditioning system, a heat source recovery system connected to the computer room air-conditioning system through a first heat exchanger, and a heat source application system connected to the heat source recovery system through a second heat exchanger. Through heat exchange between the first heat exchanger and the second heat exchanger, and the heat source recovery system includes a first compressor, which can perform secondary compression on the recovered heat energy. The heat recovery air-conditioning system can improve the heat energy recovery efficiency and heat energy recovery quality, expand the spatial application range of the recovered heat energy, and the heat source application system includes a heat storage device, which expands the temporal application range of the recovered heat energy.

[0080] The present invention also provides a control method for a heat recovery air-conditioning system. After measuring the heat load required by the heat source application system and the heat discharge capacity that the computer room air-conditioning system can provide, different operating modes can be selected according to the situation to avoid the waste of resources caused by heat recovery when the heat source application system has no heat load demand for a long time, and also expand the time application range of the recovered heat energy.

[0081] It is understandable that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A heat recovery air conditioning system, characterized in that: It comprises a computer room air conditioning system (10), a heat source recovery system (20) connected to the computer room air conditioning system (10) via a first heat exchanger (40), and a heat source application system (30) connected to the heat source recovery system (20) via a second heat exchanger (50); The heat source recovery system (20) includes a first compressor (21) and a first expansion valve (23); the inlet of the first compressor (21) is connected to the second refrigerant outlet of the first heat exchanger (40) on the heat source recovery side, the outlet of the first compressor (21) is connected to the third refrigerant inlet of the second heat exchanger (50) on the heat source recovery side, the third refrigerant outlet of the second heat exchanger (50) on the heat source recovery side is connected to the inlet of the first expansion valve (23), and the outlet of the first expansion valve (23) is connected to the second refrigerant inlet of the first heat exchanger (40) on the heat source recovery side; The heat source application system (30) includes a heat storage device (32) and a third transmission device (31); the inlet of the heat storage device (32) is connected to the fourth refrigerant outlet of the second heat exchanger (50) on the heat source application side, the outlet of the heat storage device (32) is connected to the inlet of the third transmission device (31), and the outlet of the third transmission device (31) is connected to the fourth refrigerant inlet of the second heat exchanger (50) on the heat source application side; The computer room air conditioning system (10) includes an evaporator (11), a second compressor (12), a first valve (13), a second valve (14), a third valve (15), a condenser (16), and a second expansion valve (18); wherein the inlet of the second compressor (12) is connected to the outlet of the evaporator (11); the first refrigerant inlet of the first heat exchanger (40) on the machine room air conditioning side and the inlet of the first valve (13) are commonly connected to the outlet of the second compressor (12); the inlet of the second valve (14) and the inlet of the third valve (15) are commonly connected to the first refrigerant outlet of the first heat exchanger (40) on the machine room air conditioning side; the outlet of the first valve (13) and the outlet of the second valve (14) are commonly connected to the inlet of the condenser (16); the outlet of the condenser (16) and the outlet of the third valve (15) are commonly connected to the inlet of the second expansion valve (18); the outlet of the second expansion valve (18) is connected to the inlet of the evaporator (11); The pipes used to connect various devices in the heat recovery air-conditioning system are heat-insulating pipes.

2. The heat recovery air conditioning system according to claim 1, characterized in that: The heat source recovery system (20) further includes a first transmission device (22) connected between a third refrigerant outlet of the second heat exchanger (50) on the heat source recovery side and a second refrigerant inlet of the first heat exchanger (40) on the heat source recovery side, and a fourth valve (24) connected to both ends of the first compressor (21).

3. The heat recovery air conditioning system according to claim 2, characterized in that: The computer room air conditioning system (10) further includes a second transmission device (17) and a fifth valve (19); the inlet of the second transmission device (17) is connected to the outlet of the third valve (15) and the outlet of the condenser (16), and the outlet of the second transmission device (17) is connected to the inlet of the evaporator (11); and the fifth valve (19) is connected to both ends of the second compressor (12).

4. The heat recovery air conditioning system according to any one of claims 1 to 3, characterized in that: The machine room air conditioning system (10) and the heat source recovery system (20) use Freon as a heat exchange refrigerant.

5. The heat recovery air conditioning system according to any one of claims 1 to 3, characterized in that: The heat storage device (32) further includes a water replenishment port (321) and a water outlet (322).

6. A control method for the heat recovery air conditioning system according to claim 3, characterized in that: Including full heat recovery mode, partial heat recovery mode and no heat recovery mode; When it is detected that the heat load of the heat source application system (30) is greater than or equal to the heat discharge capacity of the computer room air conditioning system (10), the heat recovery air conditioning system enters the full heat recovery mode; wherein, the first valve (13) and the second valve (14) are closed, and the third valve (15) is opened; in the computer room air conditioning system (10), the refrigerant enters the first refrigerant inlet of the first heat exchanger (40) on the computer room air conditioning side for heat exchange, and the heat energy to be recovered is transferred to the heat source recovery system (20) in the first heat exchanger (40); after the refrigerant completes the heat exchange in the first heat exchanger (40), it flows from the first refrigerant outlet of the first heat exchanger (40) on the computer room air conditioning side to the inlet of the third valve (15), waiting for the next heat exchange; When it is detected that the heat load of the heat source application system (30) is less than the heat discharge capacity of the computer room air conditioning system (10), the heat recovery air conditioning system enters the partial heat recovery mode; wherein the first valve (13) and the third valve (15) are closed, and the second valve (14) is opened; in the computer room air conditioning system (10), the refrigerant enters the first refrigerant inlet of the first heat exchanger (40) on the computer room air conditioning side for heat exchange, and transfers part of the heat energy to be recovered to the heat source recovery system (20) in the first heat exchanger (40); after the refrigerant completes the heat exchange in the first heat exchanger (40), it flows out from the first refrigerant outlet of the first heat exchanger (40) on the computer room air conditioning side, passes through the second valve (14) and flows to the inlet of the condenser (16), and transfers the remaining heat energy to be recovered in the condenser (16) to the atmosphere around the condenser (16); the refrigerant flows out from the outlet of the condenser (16) and waits for the next heat exchange; When it is detected that the heat load of the heat source application system (30) is lower than the starting value for a long time, the heat recovery air conditioning system enters the no-heat recovery mode; wherein the first valve (13) is opened, and the second valve (14) and the third valve (15) are closed; the refrigerant to be heat-released flows through the first valve (13) to the inlet of the condenser (16), and the heat energy to be released is transferred to the atmosphere around the condenser (16) in the condenser (16); the refrigerant flows out from the outlet of the condenser (16) and waits for the next heat exchange.

7. The control method of the heat recovery air conditioning system according to claim 6, characterized in that: Also includes: Heat storage mode: when receiving a heat storage instruction from the user, the heat recovery air conditioning system will disable the no heat recovery mode at a preset time, determine the relationship between the heat load of the heat storage instruction and the heat discharge capacity of the computer room air conditioning system (10), and enter the full heat recovery mode or the partial heat recovery mode; Non-heat storage mode: When no heat storage instruction is received from the user, the heat recovery air conditioning system determines whether to enter the non-heat recovery mode based on the relationship between the heat load of the heat source application system (30) and the start value; if it is determined not to enter the non-heat recovery mode, the heat recovery air conditioning system determines whether to enter the full heat recovery mode or the partial heat recovery mode based on the relationship between the heat load of the heat source application system (30) and the heat discharge capacity of the computer room air conditioning system (10).

8. The control method of the heat recovery air conditioning system according to claim 6, characterized in that: Also includes: First compressor (21) mode: when it is detected that the difference between the evaporation temperature of the refrigerant in the heat source recovery system (20) and the temperature of the refrigerant in the heat source application system (30) is less than or equal to the heat exchange temperature difference of the second heat exchanger (50), the first transmission device (22) stops running, the fourth valve (24) is closed, and the first compressor (21) runs; First transmission device mode: when it is detected that the difference between the evaporation temperature of the refrigerant in the heat source recovery system (20) and the temperature of the refrigerant in the heat source application system (30) is greater than the heat exchange temperature difference of the second heat exchanger (50), the first compressor (21) stops running, the fourth valve (24) opens, and the first transmission device (22) operates.

9. The control method of the heat recovery air conditioning system according to claim 6, characterized in that: Also includes: Second compressor mode: when it is detected that the larger of the ambient temperature and the refrigerant evaporation temperature in the heat source recovery system (20) is greater than or equal to the preset heat exchange temperature, the second transmission device (17) stops running, the fifth valve (19) is closed, and the second compressor (12) starts running; Second transmission device mode: when it is detected that the larger of the ambient temperature and the refrigerant evaporation temperature in the heat source recovery system (20) is less than the preset heat exchange temperature, the second compressor (12) stops running, the fifth valve (19) opens, and the second transmission device (17) operates.

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