Machine room air conditioning system and control method

Abstract

The embodiment of the invention discloses a machine room air conditioning system and a control method, and belongs to the technical field of air conditioning refrigeration. In the machine room air conditioning system, the water inlet end of the machine room air conditioning system is connected with the input end of a surface air cooler coil and the first end of a first valve, the second end of the first valve is connected with the output end of the surface air cooler coil, and the third end of the first valve is connected with a water inlet of a plate heat exchanger and one end of a second valve; a water outlet of the plate heat exchanger is connected with one end of a third valve; the other end of the third valve is connected with the other end of the second valve and a water outlet end of the machine room air-conditioning system; the output end of the evaporation coil is connected with the input end of the compressor; the output end of the compressor is connected with the input port of the plate heat exchanger; an output port of the plate heat exchanger is connected with one end of the electronic expansion valve, and the other end of the electronic expansion valve is connected with the input end of the evaporation coil. Power consumption of a compressor in the compressor refrigerating unit can be effectively reduced, and energy conservation of a machine room air conditioner is facilitated.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of air conditioning and refrigeration technology, and in particular, to a computer room air conditioning system and a control method. Background Art

[0002] Existing computer rooms are equipped with loads (such as transformers and substations in distribution rooms, switches and routers in communication rooms, etc.). When the loads are running, a large amount of heat will be generated. At this time, the operating temperature of the loads is too high, which is not conducive to the normal operation of the loads. Air conditioners are often installed in computer rooms to cool the loads.

[0003] In the existing computer room air conditioner, the load is cooled by the compressor. In order to maintain the operating temperature of the load at a low temperature, the computer room air conditioner needs to operate continuously for cooling. At this time, the power consumption of the compressor will be greatly increased, which is not conducive to the energy saving of the computer room air conditioner. Summary of the invention

[0004] The embodiment of the present application provides a computer room air conditioning system and a control method, which can effectively reduce the power consumption of the compressor and is beneficial to energy saving of the computer room air conditioning.

[0005] The embodiment of the present application provides a computer room air conditioning system, including: a compressor refrigeration unit and a natural cooling unit;

[0006] The natural cooling unit includes: a surface cooler coil, a first valve and a second valve, and the compressor refrigeration unit includes: a compressor, an evaporating coil, a plate heat exchanger, an electronic expansion valve and a third valve;

[0007] The water inlet of the computer room air conditioning system is connected to the input end of the condenser coil and the first end of the first valve, the second end of the first valve is connected to the output end of the condenser coil, and the third end of the first valve is connected to the water inlet of the plate heat exchanger and one end of the second valve;

[0008] The water outlet of the plate heat exchanger is connected to one end of the third valve, and the other end of the third valve is connected to the other end of the second valve and the water outlet of the computer room air conditioning system;

[0009] The output end of the evaporation coil is connected to the input end of the compressor, and the output end of the compressor is connected to the input port of the plate heat exchanger;

[0010] The output port of the plate heat exchanger is connected to one end of the electronic expansion valve, and the other end of the electronic expansion valve is connected to the input end of the evaporating coil.

[0011] Furthermore, the natural cooling unit further comprises: an inlet water temperature detector, an outlet water temperature detector and a flow meter;

[0012] The water inlet temperature detector and the flow meter are arranged at the water inlet end of the computer room air conditioning system;

[0013] The outlet water temperature detector is arranged at the outlet water end of the computer room air conditioning system.

[0014] Furthermore, the compressor refrigeration unit further comprises: a suction pressure detector, a suction temperature detector, a condensing pressure detector and a condensing temperature detector;

[0015] The suction pressure detector and the suction temperature detector are arranged between the output end of the evaporator coil and the input end of the compressor;

[0016] The condensing pressure detector and the condensing temperature detector are arranged between the output port of the plate heat exchanger and the electronic expansion valve.

[0017] The embodiment of the present application also provides a control method for a computer room air conditioning system, the computer room air conditioning system comprising: a natural cooling unit and a compressor refrigeration unit, the natural cooling unit comprising: a surface cooler coil, a first valve and a second valve, the compressor refrigeration unit comprising: a compressor, an evaporating coil, a plate heat exchanger, an electronic expansion valve and a third valve;

[0018] The control method comprises:

[0019] In the cooling mode currently operated by the computer room air conditioning system, the heat exchange amount of the surface cooler coil and the heat exchange amount of the evaporator coil are obtained; wherein the cooling mode operated by the computer room air conditioning system includes: any one of a compressor cooling mode, a natural cooling mode and a mixed pre-cooling mode;

[0020] Compare the heat exchange of the surface cooler coil and the heat exchange of the evaporator coil with the heat exchange required by the load in the computer room air conditioning system, and determine a target cooling mode that meets the heat exchange required by the load;

[0021] The computer room air conditioning system is controlled to switch the currently running cooling mode to the target cooling mode.

[0022] Further, the heat exchange of the surface cooler coil and the heat exchange of the evaporator coil are compared with the heat exchange required by the load in the computer room air conditioning system to determine a target cooling mode that meets the heat exchange required by the load, including:

[0023] If the sum of the heat exchange of the surface cooler coil and the heat exchange of the evaporator coil matches the heat exchange required by the load and lasts for a first preset time, the target cooling mode is determined to be: mixed precooling mode;

[0024] If the heat exchange amount of the surface cooler coil matches the heat exchange amount required by the load and lasts for a second preset time, determining that the target cooling mode is: natural cooling mode;

[0025] If the heat exchange amount of the evaporating coil matches the heat exchange amount required by the load and lasts for a third preset time period, the target cooling mode is determined to be: compressor cooling mode.

[0026] Furthermore, the method further comprises:

[0027] When the refrigeration mode of the computer room air conditioning system is: compressor refrigeration mode, the compressor is controlled to adjust the operating frequency based on the refrigeration demand of the load to adjust the air supply temperature of the evaporator coil to the load; the second end of the first valve and the second valve are controlled to be closed, and the third valve is controlled to adjust the valve opening based on the inlet and outlet water temperature difference; wherein the inlet and outlet water temperature difference is: the difference between the inlet water temperature of the water inlet end of the computer room air conditioning system and the outlet water temperature of the water outlet end of the computer room air conditioning system;

[0028] When the cooling mode of the computer room air conditioning system is a natural cooling mode, the compressor is controlled to be turned off, the second end of the first valve is controlled to be opened, the second valve is controlled to adjust the valve opening based on the air supply temperature of the condenser coil to the load, and the third valve is controlled to be closed;

[0029] When the refrigeration mode operated by the computer room air conditioning system is a mixed pre-cooling mode, the compressor is controlled to adjust the operating frequency based on the refrigeration demand of the load, the second end of the first valve is controlled to open, the second valve is controlled to close, and the third valve is controlled to adjust the valve opening based on the inlet and outlet water temperature difference.

[0030] Furthermore, the currently running refrigeration mode is: compressor refrigeration mode, and the target refrigeration mode is: mixed precooling mode;

[0031] The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes:

[0032] The second end of the first valve is controlled to open to switch the computer room air conditioning system from a compressor cooling mode to a mixed pre-cooling mode.

[0033] Furthermore, the currently running refrigeration mode is: natural cooling mode, and the target refrigeration mode is: mixed precooling mode;

[0034] The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes:

[0035] The valve opening of the second valve is controlled to be gradually closed to be fully closed, the valve opening of the third valve is controlled to be adjusted based on the valve opening of the second valve and the inlet and outlet water temperature difference, and after the third valve is opened, the compressor is started with a delayed start to switch the computer room air conditioning system from the natural cooling mode to the mixed pre-cooling mode.

[0036] Furthermore, the currently running refrigeration mode is: mixed pre-cooling mode, and the target refrigeration mode is: natural cooling mode;

[0037] The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes:

[0038] Control the compressor to shut down, control the second valve to open after the compressor is shut down and delayed for a preset time, and adjust the valve opening based on the inlet and outlet water temperature difference, and control the third valve to close step by step after the compressor is shut down and delayed for a preset time, so as to switch the computer room air conditioning system from the mixed pre-cooling mode to the natural cooling mode.

[0039] Furthermore, the currently running refrigeration mode is: mixed pre-cooling mode, and the target refrigeration mode is: compressor refrigeration mode;

[0040] The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes:

[0041] The second end of the first valve is controlled to be closed to switch the computer room air conditioning system from the mixed pre-cooling mode to the compressor cooling mode.

[0042] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0043] In an embodiment of the present application, the computer room air conditioning system includes: a compressor refrigeration unit and a natural cooling unit, two cold sources; the surface cooler coil of the natural cooling unit and the evaporator coil of the compressor refrigeration unit are used to cool the load of the computer room air conditioning system. When cooling the load of the computer room air conditioning system, not only can it be cooled by the compressor refrigeration unit, but it can also be cooled by the natural cooling unit, which can effectively reduce the power consumption of the compressor in the compressor refrigeration unit, which is beneficial to energy saving of the computer room air conditioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of a computer room air conditioning system disclosed in an embodiment of the present application;

[0046] Figure 2 A schematic diagram of another computer room air conditioning system disclosed in an embodiment of the present application;

[0047] Figure 3 A control flow chart of a computer room air conditioning system disclosed in an embodiment of the present application;

[0048] Figure 4 This is a control flow chart of another computer room air conditioning system disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] In the description of the embodiments of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present application.

[0051] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0052] In the existing computer room air conditioner, the load is cooled by the compressor. In order to maintain the operating temperature of the load at a low temperature, the computer room air conditioner needs to operate continuously. At this time, the power consumption of the compressor will increase greatly, which is not conducive to the energy saving of the computer room air conditioner. Therefore, the embodiment of the present application provides a computer room air conditioner system, which can effectively reduce the power consumption of the compressor in the compressor refrigeration unit, which is conducive to the energy saving of the computer room air conditioner. Figure 1 As shown, the details are as follows:

[0053] In the embodiment of the present application, the computer room air conditioning system includes: a compressor refrigeration unit and a natural cooling unit; the compressor refrigeration unit and the natural cooling unit are arranged indoors; wherein the natural cooling unit includes: a surface cooler coil 101, a first valve 102 and a second valve 103, and the compressor refrigeration unit includes: a compressor 201, an evaporating coil 202, a plate heat exchanger 203, an electronic expansion valve 204 and a third valve 205. The surface cooler coil 101 and the evaporating coil 202 are arranged at positions corresponding to the load of the computer room air conditioning system. It can be understood that the surface cooler coil 101 and the evaporating coil 202 can both receive the high-temperature return air output by the load, perform heat exchange on the high-temperature return air, and then output low-temperature supply air to the load to cool the load.

[0054] Among them, the water inlet end of the computer room air conditioning system is connected to the input end of the surface cooler coil 101 and the first end of the first valve 102, the second end of the first valve 102 is connected to the output end of the surface cooler coil 101, and the third end of the first valve 102 is connected to the water inlet of the plate heat exchanger 203 and one end of the second valve 103. It can be understood that the first valve 102 has at least three ports and can be a three-way valve or a four-way valve, which is not specifically limited here; it can be understood that the first end and the third end of the first valve 102 remain in an open state regardless of whether the computer room air conditioning system is operating in the cooling mode or in the switching cooling mode, and the control process of the first valve 102 is mainly to control the opening and closing of the first valve 102. The water inlet end of the computer room air conditioning system is used to flow cooling water into the computer room air conditioning system.

[0055] The water outlet of the plate heat exchanger 203 is connected to one end of the third valve 205, and the other end of the third valve 205 is connected to the other end of the second valve 103 and the water outlet of the computer room air conditioning system; the output end of the evaporating coil 202 is connected to the input end of the compressor 201, and the output end of the compressor 202 is connected to the input port of the plate heat exchanger 203; the output port of the plate heat exchanger 203 is connected to one end of the electronic expansion valve 204, and the other end of the electronic expansion valve 204 is connected to the input end of the evaporating coil 202.

[0056] When the computer room air conditioning system operates in the compressor cooling mode, the compressor refrigeration unit is operated to cool the load, that is, the compressor 201 starts to run, the first end and the third end of the first valve 102 are opened, the second end of the first valve 102 is closed (that is, the output end of the surface cooler coil 101 is closed), the second valve 103 is closed, and the third valve 205 is opened. At this time, the high-temperature and high-pressure refrigerant gas from the compressor 20 is input to the input port of the plate heat exchanger 203, and the cooling water flowing into the water inlet end of the computer room air conditioning system flows to the water inlet of the plate heat exchanger 203 through the first valve 102. After the cooling water in the plate heat exchanger 203 absorbs heat and condenses the high-temperature and high-pressure refrigerant gas (that is, after the plate heat exchanger 203 exchanges heat with the high-temperature and high-pressure refrigerant gas), the water outlet of the plate heat exchanger 203 outputs the heat-absorbed cooling water to the water outlet end of the computer room air conditioning system, and the output port of the plate heat exchanger 203 outputs low-temperature and low-pressure refrigerant, which can be a liquid or a gas-liquid mixture, which is not limited here; the refrigerant is throttled to a two-phase refrigerant by the electronic expansion valve 204, enters the evaporator coil 202 for heat absorption and evaporation, and becomes a low-temperature and low-pressure refrigerant gas, and then enters the compressor 201 for compression to form a cycle.

[0057] It is understandable that when the plate heat exchanger 203 does not exchange heat with the high-temperature and high-pressure refrigerant gas, the refrigerant input to the input port of the plate heat exchanger 203 and the refrigerant output from the output port of the plate heat exchanger 203 are both refrigerant gas. When the load is low (i.e., less heat is generated), the refrigerant entering the evaporator coil 202 fails to completely absorb heat and evaporate into refrigerant gas. At this time, the refrigerant in the compressor refrigeration unit is in a gas-liquid mixed state, i.e., the refrigerant input to the input port of the plate heat exchanger 203 and the refrigerant output from the output port of the plate heat exchanger 203 are both gas-liquid mixtures. That is, the refrigerant input to the input port of the plate heat exchanger 203 and the refrigerant output from the output port of the plate heat exchanger 203 can be gas, liquid, or a gas-liquid mixture, which is not specifically limited here.

[0058] When the computer room air conditioning system operates in the natural cooling mode, the natural cooling unit operates to cool the load, that is, the compressor 201 is closed, the second end of the first valve is opened (that is, the output end of the condenser coil 101 is opened), the second valve 103 is opened, and the third valve 205 is closed. At this time, the cooling water flowing into the water inlet of the computer room air conditioning system flows through the condenser coil 101, and after the cooling water absorbs heat from the high-temperature return air of the load, the output end of the condenser coil 101 outputs the absorbed cooling water, which flows to the water outlet of the computer room air conditioning system through the first valve 102 and the second valve 103.

[0059] Preferably, the evaporator coil is a threaded tube, which can increase the heat exchange area and improve the heat exchange effect of the evaporator coil; the condenser coil is a smooth tube (smooth water pipe), which can effectively prevent dirt from clogging the cooling water pipe and affecting the heat exchange effect of the condenser coil.

[0060] In an embodiment of the present application, the computer room air conditioning system includes: a compressor refrigeration unit and a natural cooling unit, two cold sources; the surface cooler coil of the natural cooling unit and the evaporator coil of the compressor refrigeration unit are arranged at a position corresponding to the load of the computer room air conditioning system. When cooling the load of the computer room air conditioning system, not only can it be cooled by the compressor refrigeration unit, but it can also be cooled by the natural cooling unit, which can effectively reduce the power consumption of the compressor in the compressor refrigeration unit, which is beneficial to energy saving of the computer room air conditioning.

[0061] Furthermore, in an embodiment of the present application, the high-temperature return air of the load is exchanged with low-temperature supply air through the condenser coil and the evaporator coil to cool the load; at this time, the heat exchange rate of the condenser coil and the heat exchange rate of the evaporator coil directly affect the cooling effect of the load, the higher the heat exchange rate, the better the cooling effect, and the lower the heat exchange rate, the worse the cooling effect; the cooling effect of the load can be determined by measuring the heat exchange rate of the condenser coil and the heat exchange rate of the evaporator coil.

[0062] Specific as Figure 2 As shown, the natural cooling unit also includes: an inlet water temperature detector 104, an outlet water temperature detector 105 and a flow meter 106; wherein, the inlet water temperature detector 104 and the flow meter 106 are arranged at the inlet end of the computer room air conditioning system; and the outlet water temperature detector 105 is arranged at the outlet end of the computer room air conditioning system. It can be understood that when the computer room air conditioning system operates in the natural cooling mode, the second valve 103 is opened and the third valve 205 is closed. At this time, the inlet water temperature detector 104 detects the inlet water temperature at the input end of the condenser coil 101, the outlet water temperature detector 105 detects the outlet water temperature at the output end of the condenser coil 101, and the flow meter 106 detects the flow rate of cooling water flowing through the condenser coil 101; at this time, it can be obtained that: the heat exchange of the condenser coil = the inlet and outlet water temperature difference (the temperature difference between the inlet water temperature and the outlet water temperature) * flow rate * specific heat capacity.

[0063] The compressor refrigeration unit also includes: an intake pressure detector 206, an intake temperature detector 207, a condensing pressure detector 208 and a condensing temperature detector 209; the intake pressure detector 206 and the intake temperature detector 207 are arranged between the output end of the evaporating coil 202 and the input end of the compressor 201; the intake pressure detector 206 is used to detect the first pressure of the refrigerant gas output from the output end of the evaporating coil 202 (i.e., the pressure before compression by the compressor 201), and the intake temperature detector 207 is used to detect the first temperature of the refrigerant gas output from the output end of the evaporating coil 202 (i.e., the temperature before compression by the compressor 201). The condensing pressure detector 208 and the condensing temperature detector 209 are arranged between the output port of the plate heat exchanger 203 and the electronic expansion valve 204; the condensing pressure detector 208 is used to detect the second pressure (i.e., the pressure after the compressor 201 compresses) of the refrigerant gas output from the input end of the evaporating coil 202, and the condensing temperature detector 209 is used to detect the second temperature (i.e., the temperature after the compressor 201 compresses) of the refrigerant gas output from the input end of the evaporating coil 202. At this time, the heat exchange amount of the evaporating coil can be obtained = the pressure difference between the first pressure and the second pressure * the temperature difference between the first temperature and the second temperature * the frequency of the compressor.

[0064] It can be understood that there can be two groups of compressor refrigeration units, each of which is similar and has a corresponding compressor and an evaporating coil; heat exchange through two evaporating coils can improve the heat exchange effect.

[0065] Furthermore, when the existing computer room air conditioning system switches the cooling mode, it often uses the temperature difference between the water inlet temperature at the water inlet end and the return air temperature of the load to compare with the preset temperature threshold, and then determines the cooling mode after switching. Among them, the preset temperature threshold is generally fixed based on the load state. If the preset temperature threshold is set based on the full load state, and the load in the computer room air conditioning system is in a low load state, the preset temperature threshold will not be able to meet the heat exchange demand of the load, that is, the switched cooling mode will be difficult to meet the heat exchange demand (cooling demand) of the load; at the same time, if the preset temperature threshold is set unreasonably, it will switch to the wrong cooling mode, resulting in the need for repeated switching, which is not conducive to the stability of the computer room air conditioning system.

[0066] Therefore, the embodiment of the present application also provides a control method for a computer room air conditioning system, which can ensure that the switched cooling mode meets the heat exchange requirements of the load, and the switched cooling mode does not need to be switched repeatedly, so that the computer room air conditioning system can quickly stabilize after switching, thereby improving the stability of the computer room air conditioning system. It can be understood that the control method is used to control the above-mentioned computer room air conditioning system, and the computer room air conditioning system is not described in detail here. The control method is as follows Figure 3 As shown, the specific steps are as follows:

[0067] 301. In the cooling mode currently operated by the computer room air conditioning system, obtain the heat exchange capacity of the condenser coil and the heat exchange capacity of the evaporator coil.

[0068] In the embodiment of the present application, the refrigeration mode operated by the computer room air conditioning system includes: any one of a compressor refrigeration mode, a natural cooling mode and a mixed pre-cooling mode. Among them, the compressor refrigeration mode is to refrigerate the load by the action of the compressor refrigeration unit, the natural cooling mode is to refrigerate the load by the action of the natural cooling unit, and the mixed pre-cooling mode is to refrigerate the load by the action of the compressor refrigeration unit and the natural cooling unit. In the refrigeration mode currently running in the computer room air conditioning system, the heat exchange of the surface cooler coil and the heat exchange of the evaporator coil are obtained. Specifically, it can be done by Figure 2 The inlet water temperature detector 104, the outlet water temperature detector 105 and the flow meter 106 in the natural cooling unit shown are used to detect the heat exchange capacity of the condenser coil, and the suction pressure detector 206, the suction temperature detector 207, the condensing pressure detector 208 and the condensing temperature detector 209 in the compressor refrigeration unit are used to detect the heat exchange capacity of the evaporating coil.

[0069] 302. Compare the heat exchange of the condenser coil and the evaporator coil with the heat exchange required by the load in the computer room air conditioning system, and determine a target cooling mode that meets the heat exchange required by the load.

[0070] After obtaining the heat exchange of the condenser coil and the evaporator coil, the heat exchange of the condenser coil and the evaporator coil can be compared with the heat exchange required by the load in the computer room air conditioning system to determine the target cooling mode that meets the heat exchange required by the load. The heat exchange required by the load is the heat exchange demand of the load (the cooling demand of the load). Under different load conditions, the heat exchange required by the load is different. For example, under full load, the heat generated by the load is large, and the heat exchange required by the load is high; under low load, the heat generated by the load is low, and the heat exchange required by the load is also low. The heat exchange required by the load can be adjusted based on the load state.

[0071] Determine the target cooling mode that meets the heat exchange required by the load. Specifically, if the sum of the heat exchange of the cooler coil and the heat exchange of the evaporator coil matches the heat exchange required by the load and lasts for a first preset time, then determine the target cooling mode as: mixed pre-cooling mode. Among them, matching the heat exchange required by the load can be greater than or equal to the heat exchange required by the load, and the first preset time can be any time from 60 seconds to 600 seconds, which is not limited here. That is, the sum of the heat exchange of the cooler coil and the heat exchange of the evaporator coil is required to meet the heat exchange required by the load. At this time, the target cooling mode can be determined as: mixed pre-cooling mode, that is, the compressor refrigeration unit and the natural cooling unit are in operation, and the load is cooled by heat exchange through the cooler coil and the evaporator coil.

[0072] If the heat exchange of the surface cooler coil matches the heat exchange required by the load and lasts for the second preset time, the target cooling mode is determined to be: natural cooling mode. The second preset time can be any time from 60 seconds to 600 seconds, and is not limited here. That is, only the heat exchange of the surface cooler coil is needed to meet the heat exchange required by the load. At this time, the target cooling mode can be determined to be: natural cooling mode, that is, only the natural cooling unit is activated, and the load is cooled by heat exchange through the surface cooler coil.

[0073] If the heat exchange rate of the evaporating coil matches the heat exchange rate required by the load and lasts for a third preset time, the target cooling mode is determined to be: compressor cooling mode. The third preset time can be any time from 60 seconds to 600 seconds, which is not limited here; it can be understood that the above-mentioned first preset time, second preset time and third preset time can be the same time or different time, which is not limited here. That is, only the heat exchange rate of the evaporating coil is needed to meet the heat exchange rate required by the load. At this time, the target cooling mode can be determined to be: compressor cooling mode, that is, only the compressor refrigeration unit performs heat exchange and cooling on the load through the evaporating coil.

[0074] It is understandable that if the heat exchange rate of the condenser coil matches the heat exchange rate required by the load, and the heat exchange rate of the evaporator coil matches the heat exchange rate required by the load, preferably, the target refrigeration mode is determined to be: natural cooling mode, so as to save compressor power consumption and effectively save energy.

[0075] 303. Control the air conditioning system in the computer room to switch the currently running cooling mode to the target cooling mode.

[0076] After determining the target cooling mode, the computer room air conditioning system can be controlled to automatically switch the currently running cooling mode to the target cooling mode. It is understandable that the currently running cooling mode can be automatically switched to the target cooling mode by controlling the compressor, the first valve, the second valve and the third valve in the computer room air conditioning system. Based on the difference in the cooling mode before switching, even if the target cooling mode after switching is the same, there are differences in the switching control process. The cooling modes operated by the computer room air conditioning system include: compressor cooling mode, natural cooling mode and mixed pre-cooling mode, and these three cooling modes can be switched arbitrarily between each other. For example, directly switching from the compressor cooling mode to the natural cooling mode, that is, controlling the compressor to close, controlling the second end of the first valve to open, controlling the second valve to open after the compressor is closed, and controlling the third valve to close after the compressor is closed. Alternatively, switching from the natural cooling mode to the compressor cooling mode, that is, controlling the compressor to start running, controlling the second end of the first valve to close, controlling the second valve to open, and controlling the third valve to open.

[0077] It can be seen that in the embodiment of the present application, the heat exchange rate of the condenser coil and the heat exchange rate of the evaporator coil are compared with the heat exchange rate required by the load in the computer room air-conditioning system, and a target cooling mode that meets the heat exchange rate required by the load is determined. This ensures that the switched cooling mode meets the heat exchange requirements of the load, and the switched cooling mode does not need to be repeatedly switched, so that the computer room air-conditioning system can quickly stabilize after the switch, thereby improving the stability of the computer room air-conditioning system.

[0078] Furthermore, the following will combine Figure 4 The control process of the computer room air conditioning system in the embodiment of the present application is described in detail, and the specific steps are as follows:

[0079] 401. Control the computer room air conditioning system to operate in cooling mode.

[0080] In an embodiment of the present application, when the load requires cooling, the computer room air conditioning system can be controlled to operate in a cooling mode, wherein the cooling modes operated by the computer room air conditioning system include: compressor cooling mode, natural cooling mode and mixed pre-cooling mode. Controlling the computer room air conditioning system to operate in the cooling mode is specifically performed in the following steps 4011 to 4013.

[0081] 4011. Control the computer room air conditioning system to operate in compressor cooling mode.

[0082] When the cooling mode of the computer room air conditioning system is: compressor cooling mode, the compressor is controlled to adjust the operating frequency based on the cooling demand of the load to adjust the air supply temperature of the evaporator coil to the load; that is, if the cooling temperature required by the load is lower, the compressor frequency is increased, and the high-frequency compressor can compress more refrigerant gas to reduce the air supply temperature of the evaporator coil to the load; if the cooling temperature required by the load is higher, the compressor frequency is reduced, and the low-frequency compressor can compress less refrigerant gas to increase the air supply temperature of the evaporator coil to the load.

[0083] At the same time, the second end of the first valve (the first end and the third end of the first valve remain in an open state) and the second valve can be controlled to close, and the third valve can be controlled to adjust the valve opening based on the inlet and outlet water temperature difference; wherein, the inlet and outlet water temperature difference is: the difference between the inlet water temperature at the water inlet end of the computer room air conditioning system and the outlet water temperature at the water outlet end of the computer room air conditioning system; it can be understood that when the computer room air conditioning system operates in the compressor cooling mode, the inlet and outlet water temperature difference can be understood as the inlet and outlet water temperature difference of the plate heat exchanger, and the flow rate detected by the flowmeter is the flow rate flowing through the plate heat exchanger, and the heat exchange capacity of the plate heat exchanger = inlet and outlet water temperature difference*flow rate*specific heat capacity can be obtained. In order to maintain the heat exchange rate of the plate heat exchanger, the third valve can perform PID adjustment according to the inlet and outlet water temperature difference; if the inlet and outlet water temperature difference is large, it is necessary to increase the valve opening of the third valve to reduce the flow rate through the plate heat exchanger and maintain the heat exchange rate of the plate heat exchanger; if the inlet and outlet water temperature difference is small, it is necessary to reduce the valve opening of the third valve to increase the flow rate through the plate heat exchanger and maintain the heat exchange rate of the plate heat exchanger.

[0084] 4012. Control the computer room air conditioning system to operate in natural cooling mode.

[0085] When the cooling mode of the computer room air conditioning system is natural cooling mode, the compressor is controlled to be closed, the second end of the first valve is controlled to be opened (the second end of the first valve can be controlled to be fully opened), the second valve is controlled to adjust the valve opening based on the air supply temperature of the condenser coil to the load, and the third valve is controlled to be closed. That is, the air supply temperature of the condenser coil to the load can be maintained by adjusting the valve opening of the second valve. If the air supply temperature is too high, the valve opening of the second valve needs to be increased to increase the flow rate through the condenser coil to reduce the air supply temperature. If the air supply temperature is too low, the valve opening of the second valve needs to be reduced to reduce the flow rate through the condenser coil to increase the air supply temperature.

[0086] 4013. Control the computer room air conditioning system to operate in mixed pre-cooling mode.

[0087] When the refrigeration mode of the computer room air conditioning system is: mixed pre-cooling mode, the compressor is controlled to adjust the operating frequency based on the refrigeration demand of the load, the second end of the first valve is controlled to open (the second end of the first valve can be controlled to be fully open), the second valve is controlled to close, and the third valve is controlled to adjust the valve opening based on the inlet and outlet water temperature difference. That is, when the mixed pre-cooling mode is running, the compressor refrigeration unit and the natural cooling unit are operated at the same time, and the surface cooler coil and the steam coil cool the load at the same time.

[0088] 402. In the cooling mode currently operated by the computer room air conditioning system, obtain the heat exchange capacity of the condenser coil and the heat exchange capacity of the evaporator coil.

[0089] 403. Compare the heat exchange of the condenser coil and the evaporator coil with the heat exchange required by the load in the computer room air conditioning system, and determine a target cooling mode that meets the heat exchange required by the load.

[0090] It can be understood that step 402 and step 403 are similar to the above-mentioned step 301 and step 302, and the details are not repeated here.

[0091] 404. Control the air conditioning system of the computer room to switch the currently running cooling mode to the target cooling mode.

[0092] After the target cooling mode is determined, the computer room air conditioning system can be controlled to switch the currently running cooling mode to the target cooling mode; the details are as follows:

[0093] 4041. Switch from compressor cooling mode to mixed precooling mode.

[0094] If the currently running cooling mode is: compressor cooling mode, and the target cooling mode is: mixed pre-cooling mode; the second end of the first valve can be controlled to switch from closed to open, and the other valves maintain their original actions, so as to switch the computer room air conditioning system from compressor cooling mode to mixed pre-cooling mode.

[0095] 4042. Switch from natural cooling mode to mixed precooling mode.

[0096] If the currently running cooling mode is natural cooling mode, and the target cooling mode is mixed precooling mode, the second end of the first valve can be controlled to remain open, the valve opening of the second valve can be controlled to gradually close to fully closed, and the third valve can be controlled to adjust the valve opening based on the valve opening of the second valve and the inlet and outlet water temperature difference. Among them, the valve opening of the third valve can be controlled to be = the valve opening of the second valve + the set opening value, and the set opening value is determined based on the inlet and outlet water temperature difference; the valve opening can be adjusted based on the valve opening of the second valve and the inlet and outlet water temperature difference, so as to adjust the cooling water flow into the plate heat exchanger and maintain the heat exchange of the plate heat exchanger. After the third valve is opened, the compressor is started with a delay to switch the computer room air conditioning system from the natural cooling mode to the mixed precooling mode.

[0097] It can be understood that when the third valve corresponding to the water outlet on the plate heat exchanger is opened, the compressor is started with a delay, and the delay time can be 0 to 120 seconds, which is not limited here. The high-temperature and high-pressure gaseous refrigerant compressed by the compressor can be condensed into low-temperature and low-pressure refrigerant gas through heat exchange through the water inlet and outlet of the plate heat exchanger through cooling water, thereby preventing the high-temperature and high-pressure refrigerant gas from flowing into the evaporator coil and ensuring the safety of the compressor refrigeration unit.

[0098] 4043. Switch from mixed precooling mode to natural cooling mode.

[0099] If the currently running refrigeration mode is: mixed pre-cooling mode, and the target refrigeration mode is: natural cooling mode, then the compressor can be controlled to be turned off, the second valve can be controlled to open after the compressor is turned off and delayed for a preset time, and the third valve can be controlled to be closed step by step after the compressor is turned off and delayed for a preset time, so as to switch the computer room air conditioning system from the mixed pre-cooling mode to the natural cooling mode. Among them, the preset time length can be 0 to 300 seconds, which is not limited here. After the compressor is turned off and delayed for a preset time, the second valve is controlled to open and the third valve is controlled to close, that is, after the compressor is turned off, switch to the natural cooling mode to avoid the compressor not being turned off affecting the operation of the natural cooling mode.

[0100] At the same time, the valve opening of the second valve is adjusted based on the inlet and outlet water temperature difference, and the inlet and outlet water temperature difference is the inlet and outlet water temperature difference of the condenser coil. By adjusting the valve opening of the second valve, the heat exchange capacity of the condenser coil can be adjusted during the switching process; that is, if the inlet and outlet water temperature difference is too small, the valve opening of the second valve is increased to increase the flow rate through the condenser coil; if the inlet and outlet water temperature difference is too large, the valve opening of the second valve is reduced to reduce the flow rate through the condenser coil, so as to maintain the heat exchange capacity of the condenser coil consistent with the heat exchange capacity required by the load.

[0101] 4044. Switch from mixed precooling mode to compressor cooling mode.

[0102] If the currently running cooling mode is: mixed pre-cooling mode, and the target cooling mode is: compressor cooling mode, the second end of the first valve can be controlled to close, and the other valves maintain their original actions to switch the computer room air conditioning system from the mixed pre-cooling mode to the compressor cooling mode.

[0103] An embodiment of the present application also provides a computer-readable storage medium, comprising instructions, which, when executed on a computer, enable the computer to execute the control method described above.

[0104] In the present invention, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0105] The above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application are described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and description of the embodiments of the present application.

Claims

1. A computer room air conditioning system, characterized in that: include: Compressor refrigeration units and free cooling units; The natural cooling unit includes: a surface cooler coil, a first valve and a second valve, and the compressor refrigeration unit includes: a compressor, an evaporating coil, a plate heat exchanger, an electronic expansion valve and a third valve; The water inlet of the computer room air conditioning system is connected to the input end of the condenser coil and the first end of the first valve, the second end of the first valve is connected to the output end of the condenser coil, and the third end of the first valve is connected to the water inlet of the plate heat exchanger and one end of the second valve; The water outlet of the plate heat exchanger is connected to one end of the third valve, and the other end of the third valve is connected to the other end of the second valve and the water outlet of the computer room air conditioning system; The output end of the evaporation coil is connected to the input end of the compressor, and the output end of the compressor is connected to the input port of the plate heat exchanger; The output port of the plate heat exchanger is connected to one end of the electronic expansion valve, and the other end of the electronic expansion valve is connected to the input end of the evaporating coil.

2. The computer room air conditioning system according to claim 1, characterized in that: The natural cooling unit further comprises: an inlet water temperature detector, an outlet water temperature detector and a flow meter; The water inlet temperature detector and the flow meter are arranged at the water inlet end of the computer room air conditioning system; The outlet water temperature detector is arranged at the outlet water end of the computer room air conditioning system.

3. The computer room air conditioning system according to claim 1, characterized in that: The compressor refrigeration unit further comprises: a suction pressure detector, a suction temperature detector, a condensing pressure detector and a condensing temperature detector; The suction pressure detector and the suction temperature detector are arranged between the output end of the evaporator coil and the input end of the compressor; The condensing pressure detector and the condensing temperature detector are arranged between the output port of the plate heat exchanger and the electronic expansion valve.

4. A control method for a computer room air conditioning system, characterized in that: The computer room air conditioning system includes: a natural cooling unit and a compressor refrigeration unit, the natural cooling unit includes: a surface cooler coil, a first valve and a second valve, and the compressor refrigeration unit includes: a compressor, an evaporating coil, a plate heat exchanger, an electronic expansion valve and a third valve; The control method comprises: In the cooling mode currently operated by the computer room air conditioning system, the heat exchange amount of the surface cooler coil and the heat exchange amount of the evaporator coil are obtained; wherein the cooling mode operated by the computer room air conditioning system includes: any one of a compressor cooling mode, a natural cooling mode and a mixed pre-cooling mode; Compare the heat exchange of the surface cooler coil and the heat exchange of the evaporator coil with the heat exchange required by the load in the computer room air conditioning system, and determine a target cooling mode that meets the heat exchange required by the load; The computer room air conditioning system is controlled to switch the currently running cooling mode to the target cooling mode.

5. The control method according to claim 4, characterized in that: The step of comparing the heat exchange amount of the surface cooler coil and the heat exchange amount of the evaporator coil with the heat exchange amount required by the load in the computer room air conditioning system to determine a target cooling mode that satisfies the heat exchange amount required by the load includes: If the sum of the heat exchange of the surface cooler coil and the heat exchange of the evaporator coil matches the heat exchange required by the load and lasts for a first preset time, the target cooling mode is determined to be: mixed precooling mode; If the heat exchange amount of the surface cooler coil matches the heat exchange amount required by the load and lasts for a second preset time, determining that the target cooling mode is: natural cooling mode; If the heat exchange amount of the evaporating coil matches the heat exchange amount required by the load and lasts for a third preset time period, the target cooling mode is determined to be: compressor cooling mode.

6. The control method according to claim 4, characterized in that: The method further comprises: When the refrigeration mode of the computer room air conditioning system is: compressor refrigeration mode, the compressor is controlled to adjust the operating frequency based on the refrigeration demand of the load to adjust the air supply temperature of the evaporator coil to the load; the second end of the first valve and the second valve are controlled to be closed, and the third valve is controlled to adjust the valve opening based on the inlet and outlet water temperature difference; wherein the inlet and outlet water temperature difference is: the difference between the inlet water temperature of the water inlet end of the computer room air conditioning system and the outlet water temperature of the water outlet end of the computer room air conditioning system; When the cooling mode of the computer room air conditioning system is a natural cooling mode, the compressor is controlled to be turned off, the second end of the first valve is controlled to be opened, the second valve is controlled to adjust the valve opening based on the air supply temperature of the condenser coil to the load, and the third valve is controlled to be closed; When the refrigeration mode operated by the computer room air conditioning system is a mixed pre-cooling mode, the compressor is controlled to adjust the operating frequency based on the refrigeration demand of the load, the second end of the first valve is controlled to open, the second valve is controlled to close, and the third valve is controlled to adjust the valve opening based on the inlet and outlet water temperature difference.

7. The control method according to claim 6, characterized in that: The currently running refrigeration mode is: compressor refrigeration mode, and the target refrigeration mode is: mixed precooling mode; The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes: The second end of the first valve is controlled to open to switch the computer room air conditioning system from a compressor cooling mode to a mixed pre-cooling mode.

8. The control method according to claim 6, characterized in that: The currently running cooling mode is: natural cooling mode, and the target cooling mode is: mixed precooling mode; The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes: The valve opening of the second valve is controlled to be gradually closed to be fully closed, the valve opening of the third valve is controlled to be adjusted based on the valve opening of the second valve and the inlet and outlet water temperature difference, and after the third valve is opened, the compressor is started with a delayed start to switch the computer room air conditioning system from the natural cooling mode to the mixed pre-cooling mode.

9. The control method according to claim 6, characterized in that: The currently running cooling mode is: mixed pre-cooling mode, and the target cooling mode is: natural cooling mode; The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes: Control the compressor to shut down, control the second valve to open after the compressor is shut down and delayed for a preset time, and adjust the valve opening based on the inlet and outlet water temperature difference, and control the third valve to close step by step after the compressor is shut down and delayed for a preset time, so as to switch the computer room air conditioning system from the mixed pre-cooling mode to the natural cooling mode.

10. The control method according to claim 6, characterized in that: The currently running refrigeration mode is: mixed precooling mode, and the target refrigeration mode is: compressor refrigeration mode; The controlling the computer room air conditioning system to switch the currently running cooling mode to the target cooling mode includes: The second end of the first valve is controlled to be closed to switch the computer room air conditioning system from the mixed pre-cooling mode to the compressor cooling mode.

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