Machine room air conditioner system, control method of machine room air conditioner system and storage medium

Abstract

The invention provides a machine room air conditioner system, a control method of the machine room air conditioner system and a storage medium, the system comprises an indoor unit which comprises an evaporator, a compressor, an oil separator, an electromagnetic valve and an electronic expansion valve, and the electromagnetic valve is arranged on a pipeline for connecting an exhaust port of the compressor and the oil separator; the electronic expansion valve is arranged on a pipeline through which a refrigerant flows from the outdoor unit to the evaporator; the outdoor unit comprises a liquid storage device, a booster pump and a condenser, the booster pump is arranged on a pipeline through which a refrigerant flows to the indoor unit from the liquid storage device, the liquid storage device is connected with the condenser through a pipeline, and the condenser is used for cooling the refrigerant; the refrigerant can normally circulate between the indoor unit and the outdoor unit by adjusting the frequency of the booster pump and the opening degree of the electronic expansion valve. According to the system, by controlling the frequency of the booster pump and the opening degree of the electronic expansion valve, circulation of refrigerants and refrigerant oil under the whole system is guaranteed, circulation of the refrigerants and the refrigerant oil of the whole system is guaranteed, and reliable and stable operation of the compressor is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to a machine room air conditioner system, a control method of the machine room air conditioner system and a computer readable storage medium. BACKGROUND

[0002] With the development of building floors being higher and higher, the actual installation of machine room air conditioners is more and more complex, and the installation position is limited by building design and site, etc. In some actual engineering installation, a form of long connecting pipe with negative high drop must be used for installation, wherein the negative high drop refers to that when the compressor is in the indoor, the installation height of the outdoor unit is lower than that of the indoor unit, which belongs to a negative drop scene.

[0003] Generally, the existing technology adopts a positive drop installation mode in which the outdoor unit is higher than the indoor unit. However, in the case of high drop long connecting pipe, this installation mode is easy to cause unstable system operation, reduce the service life of the compressor, and the pressure loss of the pipe is too large, the pressure loss is serious, and even the refrigerant in the pipe is difficult to maintain circulation, and the high drop of the indoor and outdoor units will cause the liquid refrigerant to flash before throttling, and the refrigeration performance is reduced. SUMMARY

[0004] The main purpose of the present application is to provide a machine room air conditioner system, a control method of the machine room air conditioner system and a computer readable storage medium, so as to at least solve the problem that the installation mode of the indoor unit and the outdoor unit of the machine room air conditioner in the prior art is easy to cause unstable system operation, reduce the service life of the compressor and has low refrigeration performance.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a machine room air conditioner system is provided, comprising: an indoor unit comprising an evaporator, a compressor, an oil separator, an electromagnetic valve and an electronic expansion valve, the electromagnetic valve is arranged on a pipe connected between the exhaust port of the compressor and the oil separator, the electronic expansion valve is arranged on a pipe through which refrigerant flows from an outdoor unit to the evaporator, and the evaporator and the compressor are connected through a pipe; the outdoor unit comprises a liquid accumulator, a booster pump and a condenser, the booster pump is arranged on a pipe through which the refrigerant flows from the liquid accumulator to the indoor unit, the liquid accumulator and the condenser are connected through a pipe, and the condenser is used for cooling the refrigerant, wherein the normal circulation of the refrigerant between the indoor unit and the outdoor unit is realized by adjusting the frequency of the booster pump and the opening degree of the electronic expansion valve.

[0006] Optionally, the indoor unit further comprises an oil return capillary tube and a first one-way valve, the oil return capillary tube is installed on a pipeline between an air inlet of the compressor and the oil separator, and the first one-way valve is installed on a pipeline between the electronic expansion valve and the outdoor unit; the outdoor unit further comprises a second one-way valve, the second one-way valve is installed on a pipeline in parallel with the booster pump, and the second one-way valve is connected to the reservoir through a pipeline.

[0007] Optionally, an oil storage bend is arranged at a vertical distance of a preset length from each phase on a pipeline connecting the outdoor unit and the indoor unit.

[0008] According to another aspect of the present application, a control method of a machine room air conditioner system is provided, which is used for controlling any one of the machine room air conditioner systems, and the method comprises the following steps: acquiring an outdoor unit height, an indoor unit height, an air suction superheat degree, and a pump-in pressure and a pump-out pressure of a booster pump of the machine room air conditioner; determining a difference between the outdoor unit height and the indoor unit height as an indoor-outdoor unit height difference, and determining a difference between the pump-in pressure and the pump-out pressure as a pump pressure difference; determining a frequency of the booster pump of the machine room air conditioner according to at least a size of the pump pressure difference and a size of the indoor-outdoor unit height difference in a case where the indoor-outdoor unit height difference is less than or equal to a preset height difference, and / or determining an opening degree of an electronic expansion valve of the machine room air conditioner according to at least the air suction superheat degree.

[0009] Optionally, the compressor of the machine room air conditioner is in a shutdown state, and before the outdoor unit height, the indoor unit height, the air suction superheat degree, and the pump-in pressure and the pump-out pressure of the booster pump of the machine room air conditioner are acquired, the method further comprises the following steps: acquiring an indoor environment temperature and an outdoor environment temperature of the machine room air conditioner, and determining a difference between the indoor environment temperature and the outdoor environment temperature as an environment temperature difference; closing a solenoid valve of the machine room air conditioner in a case where the environment temperature difference is greater than a first preset temperature or less than a second preset temperature, the first preset temperature being greater than the second preset temperature; and opening the solenoid valve of the machine room air conditioner in a case where the environment temperature difference is greater than or equal to the second preset temperature and less than or equal to the first preset temperature.

[0010] Optionally, the compressor of the machine room air conditioner is in a running state, and the electromagnetic valve of the machine room air conditioner is in an open state. In the case that the height difference between the indoor unit and the outdoor unit is less than or equal to a preset height difference, the frequency of the booster pump of the machine room air conditioner is determined according to at least the size of the pump pressure difference and the size of the height difference between the indoor unit and the outdoor unit, including: determining a preset pressure difference according to the height difference between the indoor unit and the outdoor unit; in the case that the pump pressure difference is less than the preset pressure difference, and the liquid level of the liquid accumulator of the machine room air conditioner is greater than a first liquid level, increasing the frequency of the booster pump until the booster pump reaches a maximum frequency threshold or the liquid level of the liquid accumulator is less than or equal to the first liquid level; in the case that the pump pressure difference is less than the preset pressure difference, and the liquid level of the liquid accumulator of the machine room air conditioner is less than or equal to the first liquid level, reducing the frequency of the booster pump until the booster pump is turned off or the liquid level of the liquid accumulator is greater than the first liquid level; in the case that the pump pressure difference is greater than or equal to the preset pressure difference, and the liquid level of the liquid accumulator of the machine room air conditioner is greater than the first liquid level and less than a second liquid level, the frequency of the booster pump is controlled to be unchanged, the first liquid level being less than the second liquid level; in the case that the pump pressure difference is greater than or equal to the preset pressure difference, and the liquid level of the liquid accumulator of the machine room air conditioner is greater than or equal to the second liquid level, increasing the frequency of the booster pump until the booster pump reaches a maximum frequency threshold or the liquid level of the liquid accumulator is less than or equal to the second liquid level.

[0011] Optionally, the preset pressure difference is determined according to the height difference between the indoor unit and the outdoor unit, including: obtaining a first parameter table and an outdoor environment temperature of the machine room air conditioner at a current time, the first parameter table representing a mapping relationship between the outdoor environment temperature of the machine room air conditioner and the liquid phase density of the refrigerant; determining the liquid phase density of the refrigerant of the machine room air conditioner according to the outdoor environment temperature of the machine room air conditioner at the current time and the first parameter table; determining the preset pressure difference according to a first formula ΔP=aρ1gH, wherein ΔP is the preset pressure difference, a is a coefficient, ρ1 is the liquid phase density of the refrigerant of the machine room air conditioner, g is the acceleration of gravity, and H is the height difference between the indoor unit and the outdoor unit.

[0012] Optionally, the method further comprises: in a case that the suction superheat is greater than a first preset superheat, gradually increasing the opening degree of the electronic expansion valve according to each step length in a first step length sequence, each step length in the first step length sequence being less than or equal to a first preset step length; in a case that the suction superheat is greater than a second preset superheat and less than or equal to the first preset superheat, gradually increasing the opening degree of the electronic expansion valve according to each step length in a second step length sequence, each step length in the second step length sequence being less than or equal to a second preset step length, the first preset step length being greater than the second preset step length; in a case that the suction superheat is greater than a third preset superheat and less than or equal to the second preset superheat, controlling the opening degree of the electronic expansion valve to be unchanged; in a case that the suction superheat is less than or equal to the third preset superheat, gradually decreasing the opening degree of the electronic expansion valve according to each step length in a third step length sequence, an absolute value of each step length in the third step length sequence being less than or equal to the first preset step length.

[0013] Optionally, the booster pump is a variable frequency booster pump, and the method further comprises: in a case that the frequency of the booster pump changes and the frequency change value of the booster pump is negative, determining the opening degree of the electronic expansion valve according to a second formula A = B + C × D, wherein A is the opening degree of the electronic expansion valve at a current time, B is the suction superheat, C is the frequency change value of the booster pump, and D is an opening degree-frequency coefficient.

[0014] According to another aspect of the present application, a computer readable storage medium is provided, which comprises a stored program, wherein the computer readable storage medium controls a device where the computer readable storage medium is located to perform any one of the control methods of the machine room air conditioner system when the program is executed.

[0015] According to the technical scheme, the machine room air conditioner system comprises an indoor unit and an outdoor unit, the indoor unit comprises an evaporator, a compressor, an oil separator, an electromagnetic valve and an electronic expansion valve, the electromagnetic valve is arranged on a pipeline connected between an exhaust port of the compressor and the oil separator, the electronic expansion valve is arranged on a pipeline through which refrigerant flows from the outdoor unit to the evaporator, and the evaporator is connected to the compressor through the pipeline; the outdoor unit comprises a liquid accumulator, a booster pump and a condenser, the booster pump is arranged on a pipeline through which refrigerant flows from the liquid accumulator to the indoor unit, the liquid accumulator is connected to the condenser through the pipeline, and the condenser is used for cooling the refrigerant; and the refrigerant is normally circulated between the indoor unit and the outdoor unit by adjusting the frequency of the booster pump and the opening degree of the electronic expansion valve. The system is controlled by the frequency of the booster pump and the opening degree of the electronic expansion valve under negative high drop and low outdoor temperature, so as to ensure the circulation of the refrigerant and the refrigeration oil under the entire negative high drop system. The refrigerant of the entire system can be normally circulated by adjusting and controlling the frequency of the booster pump and the electronic expansion valve, the frequency of the booster pump is controlled by pressure difference and the liquid level of the liquid accumulator, so as to ensure that the outdoor unit is balanced under the shutdown state and the device is not damaged. The electronic expansion valve is adjusted by suction superheat control and the frequency of the booster pump, so as to ensure that the system normally operates under the negative high drop condition and the compressor is prevented from being liquid struck. The problems that the installation mode of the indoor unit and the outdoor unit of the machine room air conditioner in the prior art easily causes unstable system operation, reduces the service life of the compressor and has low refrigeration performance are solved. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein in their entirety. The embodiments illustrated in the drawings are provided to explain the present application and are not intended to limit the present application. In the drawings:

[0017] Figure 1 A hardware structure schematic diagram of a machine room air conditioner system is shown according to an embodiment of the present application;

[0018] Figure 2 A hardware structure schematic diagram of a liquid accumulator of a machine room air conditioner system is shown according to an embodiment of the present application;

[0019] Figure 3 A hardware structure block diagram of a mobile terminal of a control method of a machine room air conditioner system is shown according to an embodiment of the present application;

[0020] Figure 4 A flowchart of a control method of a machine room air conditioner system is shown according to an embodiment of the present application;

[0021] Figure 5 A flowchart of a control method of a machine room air conditioner system is shown according to an embodiment of the present application;

[0022] Figure 6 A structural block diagram of a control device of a machine room air conditioner system according to an embodiment of the present application is shown.

[0023] In the above drawings, reference numerals:

[0024] 10, indoor unit; 11, evaporator; 12, compressor; 13, oil separator; 14, solenoid valve; 15, electronic expansion valve; 16, oil return capillary; 17, first check valve; 18, discharge temperature bulb; 19, suction temperature bulb; 20, outdoor unit; 21, accumulator; 211, first liquid level meter; 212, second liquid level meter; 22, booster pump; 23, condenser; 24, second check valve; 25, three-way valve; 26, first pump-out pressure gauge; 27, second pump-out pressure gauge; 30, oil storage bend; 102, processor; 104, memory; 106, transmission device; 108, input and output device. DETAILED DESCRIPTION

[0025] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0026] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and their any variations, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0028] As introduced in the background, the installation mode of the outdoor unit and the indoor unit of the existing machine room air conditioner generally does not allow the form of negative drop, that is, the indoor unit is installed higher than the outdoor unit, and most of them are installed in the form of positive drop, that is, the outdoor unit is installed higher than the indoor unit. Under the condition of positive drop installation, the connecting pipeline of the general machine room air conditioner can be about 30m. The installation of the machine room air conditioner with such positive drop and long connecting pipeline will cause the problems of low refrigerant flow rate due to too long pipeline, oil return difficulty, and oil shortage of the compressor, which will cause wear and tear or motor burnout.

[0029] The positive drop installation can cause the liquid refrigerant to flow back to the compressor exhaust pipe or even into the compressor exhaust port, which can easily damage the compressor or cause high pressure protection during the next start; the liquid refrigerant can accumulate in the outdoor unit or the indoor unit, which can cause unstable system operation and reduce the service life of the compressor during the next start; the pipeline loss resistance is too large, the pressure loss is serious, and even the refrigerant in the pipeline can be difficult to maintain circulation. When the valve is suddenly closed, the impact force of the liquid refrigerant on the system can reduce the service life of the entire system, and the setting can affect the operation of the refrigeration system; the longer the pipe length, the greater the suction pipe resistance, which can cause the suction pressure to decrease and the refrigeration performance to decrease; the high drop of the indoor and outdoor units can cause the liquid refrigerant to flash before throttling, which can reduce the refrigeration performance.

[0030] To solve the problems of unstable system operation, reduced service life of the compressor, and low refrigeration performance caused by the installation mode of the indoor unit and the outdoor unit of the existing machine room air conditioner, embodiments of the present application provide a machine room air conditioner system, a control method of the machine room air conditioner system, and a computer readable storage medium.

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application.

[0032] The present embodiment provides a machine room air conditioner system, which is installed in a negative drop mode, that is, the installation position of the indoor unit is higher than that of the outdoor unit, as shown in Figure 1 The machine room air conditioner system comprises:

[0033] The indoor unit 10 comprises an evaporator 11, a compressor 12, an oil separator 13, an electromagnetic valve 14, and an electronic expansion valve 15. The electromagnetic valve 14 is arranged on the pipeline connected between the exhaust port of the compressor 12 and the oil separator 13. The electronic expansion valve 15 is arranged on the pipeline through which the refrigerant flows from the outdoor unit 20 to the evaporator 11. The evaporator 11 is connected to the compressor 12 through a pipeline.

[0034] Wherein, in the exhaust port set electromagnetic valve 14, compressor 12 stop state, when the indoor and outdoor temperature difference is large, close the electromagnetic valve 14 valve. When the compressor stops running, if the indoor and outdoor temperature difference is large, especially when the outdoor temperature is much lower than the indoor temperature, liquid refrigerant may flow back to the compressor exhaust pipe along the pipeline. This liquid backflow can cause liquid hammer when the compressor is started again, that is, the liquid refrigerant directly enters the compressor, causing damage to the mechanical structure of the compressor, and may cause the compressor to stop or the motor to burn out. The closing of the electromagnetic valve can prevent the refrigerant from flowing from high to low due to gravity during shutdown, thereby helping to maintain the pressure balance inside the system, reducing the system pressure changes caused by refrigerant migration, ensuring smooth operation of the system when restarting, and avoiding high or low pressure protection misoperation.

[0035] The oil separator 13 separates the lubricating oil and refrigerant in the refrigeration system. After the exhaust, the lubricating oil passes through the oil return capillary tube 16 and returns to the compressor 12 through suction.

[0036] The above outdoor unit 20 includes a liquid reservoir 21, a booster pump 22 and a condenser 23, the above-mentioned booster pump 22 is arranged on the pipeline through which the refrigerant flows from the above-mentioned liquid reservoir 21 to the above-mentioned indoor unit 10, the above-mentioned liquid reservoir 21 is connected to the above-mentioned condenser 23 through a pipeline, and the above-mentioned condenser 23 is used to cool the above-mentioned refrigerant, wherein the above-mentioned refrigerant is normally circulated between the above-mentioned indoor unit 10 and the above-mentioned outdoor unit 20 by adjusting the frequency of the above-mentioned booster pump 22 and the opening of the above-mentioned electronic expansion valve 15.

[0037] Wherein, after heat exchange through the condenser, the liquid refrigerant becomes medium-temperature high-pressure liquid, which is stored in the liquid reservoir 21. Due to the large resistance of the liquid refrigerant to the height difference, the liquid refrigerant is pumped to the electronic expansion valve 15 for throttling and pressure reduction by the booster pump 22.

[0038] In the form of high-drop long connecting pipe, the system pressure loss is relatively serious, and the booster pump 22 is arranged behind the liquid reservoir 21, which can lift the liquid refrigerant to the electronic expansion valve 15 in the room for throttling and pressure reduction. The booster pump 22 is a gas pump, and the gas pump is selected to be a variable frequency pump, which can adjust the operating frequency of the gas pump according to the system pressure.

[0039] Through the addition of the above components and accessories, the entire high-drop system can run safely, stably and reliably. In addition, through the pressure detection control of the booster pump, the height difference between the indoor and outdoor units of the air conditioner is not limited by the actual engineering installation position.

[0040] The above machine room air conditioner system of the present application controls the frequency of the booster pump and the opening degree of the electronic expansion valve under negative high drop and low outdoor temperature to ensure the circulation of refrigerant and refrigeration oil under the whole negative high drop system. The oil return bend and the one-way valve are arranged in the indoor unit under the negative drop height to ensure normal oil return and prevent the refrigerant from migrating to the outdoor unit, thereby prolonging the service life of the compressor. The refrigerant in the whole system can be normally circulated through the adjustment and control of the frequency of the booster pump and the electronic expansion valve. The frequency of the booster pump is controlled by the pressure difference and the liquid level of the accumulator to ensure that the outdoor unit pressure is balanced under the shutdown state, and the device is not damaged. The electronic expansion valve is adjusted by the suction superheat degree control and the frequency of the booster pump to ensure the normal operation of the system under the negative high drop condition and prevent the compressor from being liquid struck. The problems of unstable system operation, reduced service life of the compressor and low refrigeration performance caused by the installation mode of the indoor unit and the outdoor unit of the machine room air conditioner in the prior art are solved.

[0041] As shown in FIG. 1, the indoor unit 10 further comprises an oil return capillary tube 16 and a first one-way valve 17. The oil return capillary tube 16 is installed on the pipeline between the suction port of the compressor 12 and the oil separator 13. The first one-way valve 17 is installed on the pipeline between the electronic expansion valve 15 and the outdoor unit 20. Figure 1 As shown in FIG. 1, the indoor unit 10 further comprises an oil return capillary tube 16 and a first one-way valve 17. The oil return capillary tube 16 is installed on the pipeline between the suction port of the compressor 12 and the oil separator 13. The first one-way valve 17 is installed on the pipeline between the electronic expansion valve 15 and the outdoor unit 20.

[0042] Specifically, the oil separator 13 is essential for the machine room air conditioner under negative drop, which can ensure that the lubricating oil in the system exhaust is reabsorbed into the compressor 12 through the oil return capillary tube 16, plays a lubricating and sealing role for the compressor 12, and prolongs the service life of the compressor 12. When the unit is in the shutdown state, the first one-way valve 17 in the indoor unit and the electromagnetic valve 14 at the exhaust port can prevent the migration of refrigerant caused by the temperature difference and the height difference between the indoor side and the outdoor side.

[0043] As shown in FIG. 1, the indoor unit 10 further comprises an oil return capillary tube 16 and a first one-way valve 17. The oil return capillary tube 16 is installed on the pipeline between the suction port of the compressor 12 and the oil separator 13. The first one-way valve 17 is installed on the pipeline between the electronic expansion valve 15 and the outdoor unit 20. Figure 1 As shown in FIG. 1, the indoor unit 10 further comprises an oil return capillary tube 16 and a first one-way valve 17. The oil return capillary tube 16 is installed on the pipeline between the suction port of the compressor 12 and the oil separator 13. The first one-way valve 17 is installed on the pipeline between the electronic expansion valve 15 and the outdoor unit 20.

[0044] Specifically, the oil retention bend can create an oil pool in the gas and liquid pipes, preventing the lubricating oil (compressor oil) from directly sliding down the pipe and failing to return to the compressor. In the case of high drop installation, if there is no proper oil return mechanism, the lubricating oil may accumulate in the lower components, causing the compressor to run out of oil, which in turn affects the lubrication and cooling of the compressor, accelerating its wear and failure. The oil retention bend can prevent the liquid refrigerant from flowing directly under gravity, especially after the system is shut down or when running at low load. This helps to avoid the phenomenon of liquid hammer, i.e. the liquid refrigerant directly enters the interior of the compressor, causing damage to the compressor.

[0045] wherein, as shown in Figure 1 The indoor unit further comprises an exhaust temperature bulb 18 and a suction temperature bulb 19, and the outdoor unit further comprises a first pump-out pressure gauge 26 and a second pump-out pressure gauge 27.

[0046] The exhaust temperature bulb 18 is directly installed on the exhaust pipe of the compressor and can monitor the temperature of the gas discharged by the compressor in real time. The suction temperature bulb 19 is installed on the suction pipe of the compressor and is used to detect the temperature of the gas entering the compressor. The exhaust temperature bulb 18 and the suction temperature bulb 19 provide critical real-time data for the system by monitoring the exhaust and suction temperatures of the compressor, helping to achieve precise control of the system and ensure the normal operation of the compressor, while optimizing the overall performance and efficiency of the refrigeration system.

[0047] The first pump-out pressure gauge 26 is directly connected to the outlet pipe of the booster pump and is used to monitor the pressure of the refrigerant output by the booster pump in real time. By monitoring the pressure of the second pump-out pressure gauge 27, it can ensure that the circulation of refrigerant in the system is more uniform, avoiding system instability caused by pressure imbalance. By monitoring and controlling the pressure at the outlet of the booster pump in real time, these two pressure gauges help to ensure that the refrigeration system can operate safely and efficiently under various installation conditions, including negative high drop and long connecting pipes, while extending the service life of the equipment and reducing maintenance requirements.

[0048] As shown in Figure 1 , Figure 1The arrows in the middle are the flow direction of the refrigerant. The compressor 12 first discharges high-temperature and high-pressure refrigerant gas, which is cooled by the outdoor condenser 23. To prevent the lubricating oil of the air conditioner compressor 12 from accumulating at the low position of the condenser due to the drop, an oil separator 13 is provided at the exhaust port of the compressor 12, and an oil storage bend 30 is provided every 5m of the drop height of the indoor unit 10 and the outdoor unit 20 to ensure normal oil return of the entire system. After heat exchange in the condenser 23, the liquid refrigerant becomes medium-temperature and high-pressure, and is stored in the liquid accumulator 21. Due to the large resistance of the drop height to the liquid refrigerant, the liquid refrigerant is pumped to the electronic expansion valve 15 for throttling and pressure reduction by the booster pump 22. After heat exchange in the evaporator 11, low-temperature and low-pressure refrigerant gas is formed, which enters from the suction side of the compressor 12 to circulate refrigeration.

[0049] The oil separator 13 is essential for the negative drop room air conditioner, which can ensure that the lubricating oil in the system exhaust is reabsorbed into the compressor 12 through the oil return capillary tube 16, plays a lubricating and sealing role for the compressor 12, and prolongs the service life of the compressor 12. When the unit is in a shutdown state, the first one-way valve 17 in the indoor and the electromagnetic valve 14 at the exhaust port are turned on and off, which can prevent the refrigerant from migrating due to the temperature difference and height difference between the indoor and outdoor sides.

[0050] As shown in Figure 1 and Figure 2 , the outdoor negative high-drop assembly is provided with a liquid accumulator 21, and the liquid accumulator 21 has two liquid level gauges, namely a first liquid level gauge 211 and a second liquid level gauge 212, which can indirectly control the opening and operating frequency of the booster pump 22. In addition, to avoid the liquid level of the liquid accumulator 21 being too low, a second one-way valve 24 is provided on the parallel branch, and when the booster pump 22 is closed, the refrigerant passes through this branch.

[0051] A three-way valve 25 is provided above the booster pump 22, which is connected with the liquid accumulator 21. On the one hand, it can balance the pressure between the liquid accumulator 21 and the booster pump 22; on the other hand, when the unit is in a shutdown state, the refrigerant liquid in the liquid pipe can flow back into the liquid accumulator 21 through the three-way valve 25, thereby avoiding the refrigerant flowing back to the outlet of the booster pump 22 and the damage of the unit caused by pressure imbalance in a long shutdown state.

[0052] The method embodiments provided in the embodiments of the application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking the case of running on a mobile terminal, Figure 3 is a hardware structure block diagram of a mobile terminal of a control method of a machine room air conditioner system according to an embodiment of the application. As shown in Figure 3 , the mobile terminal can include one or more Figure 3The mobile terminal can further include a transmission device 106 for communication function and an input / output device 108. Those skilled in the art can understand that, Figure 3 The structure shown is only schematic and does not limit the structure of the mobile terminal. For example, the mobile terminal can include more or less components than those shown, or have a different configuration or arrangement of the components. Figure 3 The mobile terminal can include more or less components than those shown, or have a different configuration or arrangement of the components. Figure 3 The mobile terminal can include more or less components than those shown, or have a different configuration or arrangement of the components.

[0053] The memory 104 can be used to store computer programs, such as software programs and modules of application software, and a computer program corresponding to the control method of the computer room air conditioner system in the embodiments of the present application. The processor 102 can execute various functional applications and data processing by running the computer program stored in the memory 104, i.e., implement the method described above. The memory 104 can include a high-speed random access memory, and can further include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory 104 can further include a memory remotely arranged with respect to the processor 102, and the remote memory can be connected to the mobile terminal through a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The transmission device 106 is used to receive or send data via a network. The specific example of the network can include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet in a wireless manner.

[0054] In the embodiments, a control method of a computer room air conditioner system running on a mobile terminal, a computer terminal or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0055] Figure 4 is a flowchart of the control method of the computer room air conditioner system according to the embodiments of the present application. The control method is used to control any one of the computer room air conditioner systems described above, such as Figure 4As shown, the method comprises the following steps:

[0056] In step S201, the height of the outdoor unit, the height of the indoor unit, the suction superheat degree, and the pump-in pressure and the pump-out pressure of the booster pump of the machine room air conditioner are acquired.

[0057] Specifically, the two parameters of the height of the outdoor unit and the height of the indoor unit are used to determine the vertical distance between the indoor and outdoor units in the system, i.e., the height difference. The size of the height difference directly affects the circulation process of the refrigerant in the system, especially the backflow of the lubricating oil and the flow characteristics of the refrigerant. The suction superheat degree is the degree to which the temperature of the refrigerant vapor entering the compressor is higher than its saturation temperature, which is an important indicator for measuring the efficiency and operating state of the refrigeration system. The booster pump plays a role in lifting the pressure of the refrigerant in the high-fall system, enabling the refrigerant to overcome gravity and pipeline resistance and smoothly flow from the outdoor unit to the indoor unit. The monitoring of the pump-in pressure and the pump-out pressure is the basis for the control strategy of the booster pump. By comparing the two pressure values, the working efficiency of the booster pump and the pressure loss in the system can be evaluated.

[0058] In step S202, the difference between the height of the outdoor unit and the height of the indoor unit is determined as the indoor-outdoor unit height difference, and the difference between the pump-in pressure and the pump-out pressure is determined as the pump pressure difference.

[0059] Specifically, the indoor-outdoor unit height difference refers to the vertical distance difference between the outdoor unit and the indoor unit, and the indoor-outdoor unit height difference can also be manually input by the user on the display screen. In the air conditioning system, especially in the case of negative height difference and long connecting pipe, this difference has an important influence on the circulation of the refrigerant and the backflow of the lubricating oil. The pump pressure difference refers to the difference between the pump-out pressure and the pump-in pressure of the booster pump. This parameter reflects the ability of the booster pump to lift the pressure of the refrigerant and the pressure change of the refrigerant after passing through the booster pump. The larger the pump pressure difference, the higher the working intensity of the booster pump, and it may also mean that the resistance of the refrigerant circulation in the system is larger.

[0060] In step S203, in the case where the indoor-outdoor unit height difference is less than or equal to a preset height difference, the frequency of the booster pump of the machine room air conditioner is determined according to at least the size of the pump pressure difference and the size of the indoor-outdoor unit height difference, and / or the opening degree of the electronic expansion valve of the machine room air conditioner is determined according to at least the suction superheat degree.

[0061] Specifically, the preset height difference is a negative number, and is generally set to -5 m. Since the preset height difference is a negative number, and the installation position of the indoor unit is higher than the installation position of the outdoor unit in the present embodiment, the height difference between the indoor unit and the outdoor unit is also negative, and the smaller the height difference between the indoor unit and the outdoor unit, the farther the distance between the indoor unit and the outdoor unit. In a negative height difference environment, the refrigerant returning from the indoor unit to the outdoor unit encounters the hindrance of gravity, and this hindrance is more significant when the height difference between the indoor unit and the outdoor unit is large (i.e., the height difference between the indoor unit and the outdoor unit is large here), which affects the efficiency and stability of the refrigerant circulation. When the height difference between the indoor unit and the outdoor unit is less than or equal to the preset height difference, it is proved that the height difference between the indoor unit and the outdoor unit is high, and the booster pump needs to be turned on to pump the refrigerant from the outdoor unit to the indoor unit.

[0062] The control method of the above-mentioned machine room air conditioner system of the present application controls the frequency of the booster pump and the opening degree of the electronic expansion valve in a negative height difference and low outdoor temperature to ensure the circulation of the refrigerant and the refrigeration oil in the entire negative height difference system. The adjustment mode of the frequency of the booster pump and the electronic expansion valve is adjusted to ensure the normal circulation of the refrigerant in the entire system. The frequency of the booster pump is controlled by the pressure difference and the liquid level of the accumulator to ensure the pressure balance of the outdoor unit in the shutdown state and prevent damage to the device. The electronic expansion valve is adjusted by the suction superheat control and the frequency of the booster pump to ensure the normal operation of the system in a negative height difference and prevent liquid knock of the compressor. The above-mentioned method solves the problem of unstable system operation, reduced service life of the compressor, and low refrigeration performance caused by the installation mode of the indoor unit and the outdoor unit of the machine room air conditioner in the prior art.

[0063] In some embodiments, the compressor of the above-mentioned machine room air conditioner is in a shutdown state, and before obtaining the height of the outdoor unit, the height of the indoor unit, the suction superheat, and the pump-in pressure and the pump-out pressure of the booster pump of the machine room air conditioner, the above-mentioned method further includes the following steps: obtaining the indoor environment temperature and the outdoor environment temperature of the machine room air conditioner, and determining the difference between the indoor environment temperature and the outdoor environment temperature as an environment temperature difference; in the case that the environment temperature difference is greater than a first preset temperature or less than a second preset temperature, closing the electromagnetic valve of the machine room air conditioner, the first preset temperature being greater than the second preset temperature; in the case that the environment temperature difference is greater than or equal to the second preset temperature and less than or equal to the first preset temperature, opening the electromagnetic valve of the machine room air conditioner.

[0064] In the case of uninterrupted power supply of the machine room air conditioner, the indoor and outdoor environment temperatures of the machine room air conditioner can be detected every 30 seconds. The first preset temperature can be set to 0℃, and the second preset temperature can be set to -5℃. When the environment temperature difference AT satisfies AT > 0℃ or AT < -5℃ in the compressor shutdown state, the electromagnetic valve is closed, and at this time, the indoor and outdoor temperature difference is large, so as to prevent the refrigerant from migrating to the outdoor side, thereby causing the compressor to be difficult to start. When -5℃ ≤ AT ≤ 0℃, the electromagnetic valve is not closed and is always in an open state, and at this time, the outdoor environment temperature is high and the indoor temperature is high, so that part of the refrigerant can be ensured to return to the inside of the compressor smoothly.

[0065] Specifically, by monitoring the environment temperature difference and controlling the opening and closing of the electromagnetic valve, the stability of the air conditioning system in the shutdown state is significantly enhanced, and the starting difficulty and equipment damage caused by improper movement of the refrigerant are avoided.

[0066] In the case of the compressor of the machine room air conditioner being in the start operation state and the electromagnetic valve of the machine room air conditioner being in the open state, the frequency of the booster pump of the machine room air conditioner is determined according to at least the size of the pump pressure difference and the size of the indoor and outdoor unit height difference when the indoor and outdoor unit height difference is less than or equal to the preset height difference, including the following steps:

[0067] Step S301, determining a preset pressure difference according to the indoor and outdoor unit height difference;

[0068] Step S302, in the case that the pump pressure difference is less than the preset pressure difference and the liquid level of the liquid accumulator of the machine room air conditioner is greater than a first liquid level, increasing the frequency of the booster pump until the booster pump reaches a maximum frequency threshold or the liquid level of the liquid accumulator is less than or equal to the first liquid level;

[0069] At this time, the frequency of the booster pump is only increased and not decreased. When the actual pump pressure difference is lower than the preset pressure difference and the liquid level in the liquid accumulator is higher than the first liquid level, it indicates that the pressure in the system is not enough to drive the circulation of the refrigerant and the lubricating oil, especially to overcome the gravity influence of the negative height difference. At this time, by increasing the frequency of the booster pump, the pump-out pressure can be improved, and the circulating power of the system can be increased. This process will continue until the booster pump reaches its maximum operating frequency or the liquid level of the liquid accumulator drops below the first liquid level, so as to ensure that the system realizes effective circulation of the refrigerant under the minimum energy consumption.

[0070] Step S303, in the case that the pump pressure difference is less than the preset pressure difference and the liquid level of the liquid accumulator of the machine room air conditioner is less than or equal to the first liquid level, reducing the frequency of the booster pump until the booster pump is closed or the liquid level of the liquid accumulator is greater than the first liquid level;

[0071] This prevents cavitation in the booster pump. If the pump pressure difference remains below the preset pressure difference, but the reservoir level has dropped below the first level, it may indicate that the circulation of refrigerant and lubricating oil in the system is sufficient, and further increasing the pump frequency is unnecessary, and may even lead to excessive depletion of the reservoir. In this case, the frequency of the booster pump should be reduced until the pump is turned off or the reservoir level returns to above the first level to avoid unnecessary energy waste and potential damage to system stability.

[0072] Step S304, in the case where the pump pressure difference is greater than or equal to the preset pressure difference, and the reservoir level of the machine room air conditioner is greater than the first level and less than the second level, the frequency of the booster pump is not changed, and the first level is less than the second level.

[0073] When the pump pressure difference reaches or exceeds the preset pressure difference, and the reservoir level is between the first level and the second level, it indicates that the current booster pump frequency of the system is sufficient to maintain stable refrigerant circulation, and the reservoir level is also within a safe range. At this time, the frequency of the booster pump should be kept unchanged to ensure that the system operates efficiently and stably under the current conditions, avoiding energy fluctuations and stability problems caused by frequent adjustments of the frequency.

[0074] Step S305, in the case where the pump pressure difference is greater than or equal to the preset pressure difference, and the reservoir level of the machine room air conditioner is greater than or equal to the second level, the frequency of the booster pump is increased until the booster pump reaches the maximum frequency threshold or the reservoir level is less than or equal to the second level.

[0075] If the pump pressure difference is greater than or equal to the preset pressure difference, but the reservoir level has risen to the second level or higher, it may indicate the accumulation of liquid refrigerant in the system, which requires additional power to circulate and distribute. Therefore, the system will further increase the frequency of the booster pump until the pump reaches the maximum frequency threshold or the reservoir level drops below the second level. This step can prevent the improper accumulation of liquid refrigerant, avoid compressor liquid knock and reduce the efficiency of system operation.

[0076] Specifically, through the above control strategy, the frequency adjustment of the booster pump can accurately reflect the current operating state and demand of the system, ensure the effective circulation of refrigerant and lubricating oil in negative high-drop environments, improve the overall efficiency and stability of system operation, and ensure that the refrigerant in the reservoir can be fully circulated in the entire system. Timely adjustment of the booster pump frequency can prevent excessive pump pressure difference and abnormal reservoir level, thereby avoiding potential problems such as compressor liquid knock, refrigerant leakage, or excessive wear of equipment, protecting critical equipment and prolonging the life of the system.

[0077] wherein the preset pressure difference is determined according to the height difference between the indoor unit and the outdoor unit, and the method comprises the following steps:

[0078] In step S3011, a first parameter table and an outdoor environment temperature of the computer room air conditioner at the current time are obtained, and the first parameter table represents a mapping relationship between the outdoor environment temperature of the computer room air conditioner and the liquid-phase density of the refrigerant.

[0079] The first parameter table is a pre-established database or function mapping, which associates the outdoor environment temperature of the computer room air conditioner with the liquid-phase density of the refrigerant. The change of the outdoor environment temperature directly affects the physical state of the refrigerant, including its density. By querying the first parameter table, the system can quickly obtain the liquid-phase density of the refrigerant at the current outdoor temperature, which provides a key density parameter for subsequent preset pressure difference calculation.

[0080] In step S3012, the liquid-phase density of the refrigerant of the computer room air conditioner is determined according to the outdoor environment temperature of the computer room air conditioner at the current time and the first parameter table.

[0081] In step S3013, the preset pressure difference is determined according to the first formula ΔP=aρ1gH, where ΔP is the preset pressure difference, a is a coefficient, ρ1 is the liquid-phase density of the refrigerant of the computer room air conditioner, g is the acceleration of gravity, and H is the height difference between the indoor and outdoor units.

[0082] Specifically, by combining the current outdoor environment temperature and the height difference between the indoor and outdoor units, the system can calculate a preset pressure difference that adapts to the current operating conditions, ensuring that the operating frequency of the booster pump matches the system pressure demand, avoiding the decrease of circulation efficiency and equipment damage caused by excessive or insufficient pressure. This control strategy takes into account the influence of outdoor temperature changes on the density of the refrigerant, enabling the system to adapt to changes in outdoor environment temperature in different seasons and different regions, enhancing the system's operating stability and adaptability in various environmental conditions. Adjusting the preset pressure difference according to the actual outdoor temperature and the height difference between the indoor and outdoor units, and then adjusting the operating state of the booster pump, can avoid unnecessary energy consumption and achieve energy-saving operation of the system. Especially when the temperature is high, the density of the refrigerant decreases, and the required pressure difference of the booster pump also decreases accordingly, thereby reducing energy waste.

[0083] where g is the acceleration of gravity, with a value of 9.81 m / s 2, a is a safety factor, the value range is generally 1.1~1.2, multiplied by the coefficient a is to consider the characteristics of the system and the actual operating conditions, such as pipe resistance, refrigerant type. The calculation of the preset pressure difference ensures that the booster pump can provide enough power to overcome gravity and pipe resistance under different height difference and external temperature conditions, and maintain the normal circulation of the refrigerant. After detecting the outdoor environment temperature, the corresponding first parameter table R410A liquid phase density ρ1 is converted by program. The first parameter table is obtained by the parameter table of R410A refrigerant, and the first parameter table is shown in Table 1:

[0084] Table 1, R410A corresponding to the property parameter table of saturated temperature

[0085]

[0086]

[0087]

[0088]

[0089] For the electronic expansion valve opening control under high drop and low outdoor temperature, the focus is to prevent the compressor from being liquid struck and damaged. On the one hand, in order to reduce the working pressure of the booster pump and the migration of the refrigerant under the negative drop; on the other hand, in order to protect the compressor. By controlling the suction superheat and the booster pump to control the electronic expansion valve opening, the refrigerant can be more easily circulated to the indoor unit, and the whole system circulation is more smooth.

[0090] First, the suction superheat is obtained. First, the suction pressure of the compressor is detected, and the corresponding property parameter under the saturated temperature of the suction pressure of the compressor (equivalent to the pressure in Table 2) is determined according to the second parameter table, and the second parameter table is also for R410A refrigerant. According to the saturated temperature, the suction temperature T 吸气 and the evaporation temperature T 蒸发 of the compressor are determined, and the suction superheat SH=T 吸气 -T 蒸发 . The second parameter table is shown in Table 2:

[0091] Table 2, second parameter table

[0092]

[0093]

[0094]

[0095] The opening degree of the electronic expansion valve of the machine room air conditioner is determined according to the suction superheat, and the method comprises the following steps:

[0096] In step S401, when the suction superheat is greater than a first preset superheat, the opening degree of the electronic expansion valve is gradually increased according to each step length in a first step length sequence, and each step length in the first step length sequence is less than or equal to a first preset step length.

[0097] The first preset superheat is generally set to 15 DEG C, and the first preset step length is generally 20 steps. The first step length sequence can be a step length sequence with step lengths increasing in turn, such as 5 steps, 10 steps, and 15 steps, or a step length sequence with all step lengths being equal, such as 5 steps. It should be noted that the size of each step length in the first step length sequence can be set at will according to requirements, as long as it is less than the first preset step length.

[0098] The suction superheat refers to the degree to which the temperature of refrigerant before entering the compressor is higher than the saturated vapor temperature of the refrigerant. When the suction superheat is too high, it indicates that the system can be overheated or the circulation amount of refrigerant is insufficient, which will affect the refrigeration effect of the system and the efficiency of the compressor. In this case, the system gradually increases the opening degree of the electronic expansion valve according to the preset first step length sequence, so as to increase the flow of refrigerant and reduce the suction superheat, so as to achieve an ideal refrigeration state.

[0099] In step S402, when the suction superheat is greater than a second preset superheat and less than or equal to the first preset superheat, the opening degree of the electronic expansion valve is gradually increased according to each step length in a second step length sequence, each step length in the second step length sequence is less than or equal to a second preset step length, and the first preset step length is greater than the second preset step length.

[0100] The second preset superheat is generally set to 5 DEG C, and the second preset step length is generally 10 steps. The second step length sequence can be a step length sequence with step lengths increasing in turn, such as 5 steps, 6 steps, and 7 steps, or a step length sequence with all step lengths being equal, such as 5 steps. It should be noted that the size of each step length in the second step length sequence can be set at will according to requirements, as long as it is less than the second preset step length.

[0101] When the suction superheat is between the two preset superheats, it indicates that the system is close to an ideal operating state but still has adjustment space. At this time, the system gradually increases the opening degree of the electronic expansion valve according to the second step length sequence with smaller step lengths, so as to fine-tune the flow of refrigerant and further approach the optimal refrigeration condition.

[0102] In step S403, when the suction superheat is greater than a third preset superheat and less than or equal to the second preset superheat, the opening degree of the electronic expansion valve is not changed.

[0103] The third preset superheat degree is generally set to 2℃. When the suction superheat degree is at a low but still acceptable level, the opening degree of the electronic expansion valve remains unchanged. This is because the system determines that the current refrigerant flow is sufficient to maintain stable refrigeration operation, and further adjustment is not needed. This step helps the system avoid unnecessary opening degree adjustment, reduces energy consumption, while maintaining the consistency and stability of the system operation.

[0104] In step S404, in the case where the suction superheat degree is less than or equal to the third preset superheat degree, the opening degree of the electronic expansion valve is gradually reduced according to each step length in the third step length sequence, and the absolute value of each step length in the third step length sequence is less than or equal to the first preset step length.

[0105] The third step length sequence can be a step length sequence that decreases by 5 steps, 10 steps, 15 steps, or a step length sequence in which all step lengths are equal to 5 steps. It should be noted that the size of each step length in the third step length sequence can be arbitrarily set according to requirements, as long as the absolute value is a negative number less than the first preset step length.

[0106] A suction superheat degree that is too low can mean that there is too much liquid refrigerant in the system, which can negatively affect the operation of the compressor and the efficiency of the system. Therefore, the system gradually reduces the opening degree of the electronic expansion valve according to the third step length sequence to reduce the refrigerant flow, increase the suction superheat degree, ensure that the compressor is not damaged by liquid hammer, and maintain the system in the best refrigeration performance state.

[0107] Specifically, by setting multiple preset superheat degrees and corresponding step length sequences, the system can dynamically adjust the opening degree of the electronic expansion valve according to the real-time changes of the suction superheat degree, improving the response speed and control accuracy of the control, ensuring that the system quickly adapts to environmental changes and maintains stable operation. Different opening degree adjustment strategies correspond to different ranges of suction superheat degree, which can help the system optimize the refrigerant flow under various conditions, avoiding both the low efficiency caused by insufficient refrigerant circulation and the increased energy consumption and equipment risks caused by excessive refrigerant, and overall optimizing the refrigeration performance and energy utilization efficiency. The control strategy prevents the suction superheat degree from being abnormal, avoiding the occurrence of compressor liquid hammer, refrigerant leakage and other faults, reducing the demand for equipment maintenance, reducing maintenance costs, while protecting key equipment and prolonging the service life of the system.

[0108] In some other embodiments, when the suction pressure is detected to be ≥200kpa, if the condensing pressure ÷ suction pressure ≤1.7, the electronic expansion valve is not allowed to open large; if the condensing pressure ÷ suction pressure ≤1.6 is detected for 3 consecutive minutes, the electronic expansion valve is forced to close at least 4 steps (the larger value is taken compared with the superheat calculation result) per adjustment cycle until the condensing pressure ÷ suction pressure >1.7.

[0109] The above booster pump is a variable frequency booster pump, and the method further comprises: in the case that the frequency of the booster pump changes and the frequency change value of the booster pump is negative, determining the opening degree of the electronic expansion valve according to a second formula A = B + C x D, wherein A is the opening degree of the electronic expansion valve at the current time, B is the suction superheat degree, C is the frequency change value of the booster pump, and D is an opening degree frequency coefficient.

[0110] Specifically, the opening degree frequency coefficient is initially valued as 2, there is no compensation for the fixed frequency booster pump, and for the variable frequency booster pump, when the frequency of the booster pump changes, the electronic expansion valve opening degree calculation increases the booster pump frequency change compensation value on the basis of the superheat degree calculation value, and the compensation is negative when the frequency change value of the booster pump is negative, and the compensation is positive when the frequency change value of the booster pump is positive.

[0111] By synchronously adjusting the booster pump frequency and the electronic expansion valve opening degree, the system can more effectively coordinate the pressure and flow of the refrigerant, ensure that the system can still maintain normal refrigerant circulation and pressure balance when the frequency of the variable frequency booster pump is reduced, and avoid system instability caused by frequency changes. The application of the second formula makes the opening degree adjustment of the electronic expansion valve more refined, can dynamically adjust the opening degree according to the real-time situation of the booster pump frequency change and the specific value of the suction superheat degree, realize fine control of the refrigerant circulation, and enhance the energy efficiency and operation stability of the system.

[0112] In summary, when the frequency change value of the variable frequency booster pump is negative, the strategy of dynamically adjusting the opening degree of the electronic expansion valve according to the second formula can realize efficient coordination of refrigerant pressure and flow control in the air conditioning system, enhance the operation stability, energy efficiency and equipment protection capability of the system, and reflect the intelligent and fine control characteristics of the system design.

[0113] In order for those skilled in the art to more clearly understand the technical solutions of the present application, the implementation process of the control method of the machine room air conditioner system of the present application will be described in detail below in conjunction with specific embodiments.

[0114] The present embodiment relates to a specific control method of a machine room air conditioner system, as shown in Figure 5 First, the height of the actual running negative difference is input on the display screen, then the indoor and outdoor environment temperature difference is detected, then the liquid level height of the accumulator is detected, and the compressor suction superheat degree is detected, and according to the parameters obtained by the above detection, the frequency of the booster pump and the opening degree of the electronic expansion valve are controlled.

[0115] The embodiment of the present application further provides a control device of a machine room air conditioner system. It should be noted that the control device of the machine room air conditioner system of the embodiment of the present application can be used to execute the control method for the machine room air conditioner system provided by the embodiment of the present application. The device is used to realize the above-mentioned embodiment and preferred embodiment, and the description has been made and will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the device described in the following embodiment is preferably realized in software, the realization of hardware or a combination of software and hardware is also possible and conceived.

[0116] The control device of the machine room air conditioner system provided by the embodiment of the present application is introduced below.

[0117] Figure 6 is a schematic diagram of the control device of the machine room air conditioner system according to the embodiment of the present application. As shown in Figure 6 , the device comprises an acquisition unit 100, a first determination unit 200 and a second determination unit 300. The acquisition unit 100 is used to acquire the height of the outdoor unit, the height of the indoor unit, the suction superheat degree of the machine room air conditioner, and the pump-in pressure and the pump-out pressure of the booster pump. The first determination unit 200 is used to determine the difference between the height of the outdoor unit and the height of the indoor unit as the height difference between the indoor unit and the outdoor unit, and determine the difference between the pump-in pressure and the pump-out pressure as the pump pressure difference. The second determination unit 300 is used to determine the frequency of the booster pump of the machine room air conditioner according to at least the size of the pump pressure difference and the size of the height difference between the indoor unit and the outdoor unit, and / or determine the opening degree of the electronic expansion valve of the machine room air conditioner according to at least the suction superheat degree, in the case that the height difference between the indoor unit and the outdoor unit is less than or equal to a preset height difference.

[0118] The control device of the machine room air conditioner system of the present application, through the control of the frequency of the booster pump and the opening degree of the electronic expansion valve under the negative height difference and the low outdoor temperature, ensures the circulation of the refrigerant and the refrigeration oil under the entire negative height difference system. Through the adjustment control of the frequency of the booster pump and the electronic expansion valve, it is ensured that the refrigerant of the entire system can circulate normally. The frequency of the booster pump is controlled through the pressure difference and the liquid level of the accumulator, so as to ensure that the pressure of the outdoor unit is balanced in the shutdown state, and the device is not damaged. The electronic expansion valve is adjusted through the control of the suction superheat degree and the frequency of the booster pump, so as to ensure that the system operates normally under the negative height difference, and prevent the liquid strike of the compressor. The problems that the installation mode of the indoor unit and the outdoor unit of the machine room air conditioner in the prior art easily causes the unstable operation of the system, reduces the service life of the compressor, and has low refrigeration performance are solved.

[0119] In some embodiments, the compressor of the machine room air conditioner is in a shutdown state, and the device further comprises a first acquisition module, a first control module and a second control module. The first acquisition module is configured to acquire an indoor environment temperature and an outdoor environment temperature of the machine room air conditioner, and determine a difference between the indoor environment temperature and the outdoor environment temperature as an environment temperature difference. The first control module is configured to close a solenoid valve of the machine room air conditioner when the environment temperature difference is greater than a first preset temperature or less than a second preset temperature, the first preset temperature being greater than the second preset temperature. The second control module is configured to open the solenoid valve of the machine room air conditioner when the environment temperature difference is greater than or equal to the second preset temperature and less than or equal to the first preset temperature. By monitoring the environment temperature difference and controlling the opening and closing of the solenoid valve accordingly, the stability of the air conditioning system in the shutdown state is significantly enhanced, and the starting difficulty and equipment damage caused by improper movement of the refrigerant are avoided.

[0120] In some embodiments, the compressor of the machine room air conditioner is in a startup state, and the solenoid valve of the machine room air conditioner is in an open state. The second determination unit comprises a first determination module, a third control module, a fourth control module, a fifth control module and a sixth control module. The first determination module is configured to determine a preset pressure difference according to the height difference between the indoor unit and the outdoor unit. The third control module is configured to increase the frequency of the booster pump until the booster pump reaches a maximum frequency threshold or the liquid level of the reservoir of the machine room air conditioner is less than or equal to a first liquid level, when the pump pressure difference is less than the preset pressure difference and the liquid level of the reservoir of the machine room air conditioner is greater than the first liquid level. The fourth control module is configured to decrease the frequency of the booster pump until the booster pump is closed or the liquid level of the reservoir of the machine room air conditioner is greater than the first liquid level, when the pump pressure difference is less than the preset pressure difference and the liquid level of the reservoir of the machine room air conditioner is less than or equal to the first liquid level. The fifth control module is configured to keep the frequency of the booster pump unchanged when the pump pressure difference is greater than or equal to the preset pressure difference and the liquid level of the reservoir of the machine room air conditioner is greater than the first liquid level and less than a second liquid level, the first liquid level being less than the second liquid level. The sixth control module is configured to increase the frequency of the booster pump until the booster pump reaches a maximum frequency threshold or the liquid level of the reservoir of the machine room air conditioner is less than or equal to the second liquid level, when the pump pressure difference is greater than or equal to the preset pressure difference and the liquid level of the reservoir of the machine room air conditioner is greater than or equal to the second liquid level. Through the above control strategy, the frequency adjustment of the booster pump can accurately reflect the current operating state and demand of the system, ensure the effective circulation of the refrigerant and lubricating oil in the negative height difference environment, improve the overall efficiency and stability of the system operation, and ensure that the refrigerant in the reservoir can be fully circulated in the entire system.

[0121] In some embodiments, the first determining module comprises a first obtaining sub-module, a first determining sub-module and a second determining sub-module. The first obtaining sub-module is configured to obtain the first parameter table and the outdoor environment temperature of the computer room air conditioner at the current time. The first parameter table represents the mapping relationship between the outdoor environment temperature of the computer room air conditioner and the liquid phase density of the refrigerant. The first determining sub-module is configured to determine the liquid phase density of the refrigerant of the computer room air conditioner according to the outdoor environment temperature of the computer room air conditioner at the current time and the first parameter table. The second determining sub-module is configured to determine the preset pressure difference according to the first formula ΔP = aρ1gH, wherein ΔP is the preset pressure difference, a is a coefficient, ρ1 is the liquid phase density of the refrigerant of the computer room air conditioner, g is the acceleration of gravity, and H is the height difference between the indoor unit and the outdoor unit. By combining the current outdoor environment temperature and the height difference between the indoor unit and the outdoor unit, the system can calculate the preset pressure difference that adapts to the current operating condition, ensure that the operating frequency of the booster pump matches the system pressure demand, and avoid the decrease in cycle efficiency and equipment damage caused by excessive or insufficient pressure.

[0122] In some embodiments, the second determining unit comprises a first control sub-unit, a second control sub-unit, a third control sub-unit and a fourth control sub-unit. The first control sub-unit is configured to gradually increase the opening degree of the electronic expansion valve according to each step length in a first step length sequence when the suction superheat degree is greater than a first preset superheat degree. Each step length in the first step length sequence is less than or equal to a first preset step length. The second control sub-unit is configured to gradually increase the opening degree of the electronic expansion valve according to each step length in a second step length sequence when the suction superheat degree is greater than a second preset superheat degree and less than or equal to the first preset superheat degree. Each step length in the second step length sequence is less than or equal to a second preset step length. The first preset step length is greater than the second preset step length. The third control sub-unit is configured to keep the opening degree of the electronic expansion valve unchanged when the suction superheat degree is greater than a third preset superheat degree and less than or equal to the second preset superheat degree. The fourth control sub-unit is configured to gradually decrease the opening degree of the electronic expansion valve according to each step length in a third step length sequence when the suction superheat degree is less than or equal to the third preset superheat degree. The absolute value of each step length in the third step length sequence is less than or equal to the first preset step length. By setting multiple preset superheat degrees and corresponding step length sequences, the system can dynamically adjust the opening degree of the electronic expansion valve according to the real-time change of the suction superheat degree, improve the response speed and control accuracy of the control, and ensure that the system quickly adapts to environmental changes and maintains stable operation.

[0123] In some embodiments, the above-mentioned booster pump is a variable frequency booster pump, and the device further comprises a third determination unit configured to determine the opening degree of the electronic expansion valve according to a second formula A=B+C×D when the frequency of the booster pump changes and the frequency change value of the booster pump is negative, wherein A is the opening degree of the electronic expansion valve at the current time, B is the suction superheat, C is the frequency change value of the booster pump, and D is an opening degree-frequency coefficient. By synchronously adjusting the frequency of the booster pump and the opening degree of the electronic expansion valve, the system can more effectively coordinate the pressure and flow of the refrigerant, ensuring that the system can still maintain normal refrigerant circulation and pressure balance when the frequency of the variable frequency booster pump decreases, thereby avoiding system instability caused by frequency changes.

[0124] The control device of the machine room air conditioner system comprises a processor and a memory, and the above-mentioned acquisition unit and the like are stored in the memory as program units, and the corresponding functions are realized by the processor executing the above-mentioned program units stored in the memory. The above-mentioned modules are located in the same processor; or, the above-mentioned modules are located in different processors in any combination.

[0125] The processor comprises a core, and the core retrieves the corresponding program unit from the memory. The core can be one or more, and the problem that the installation mode of the indoor unit and the outdoor unit of the machine room air conditioner in the prior art easily causes unstable system operation, reduces the service life of the compressor and has low refrigeration performance can be solved by adjusting the core parameters.

[0126] The memory can include a non-permanent memory in a computer readable medium, a random access memory (RAM) and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory (flash RAM), and the memory comprises at least one memory chip.

[0127] The embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium comprises a stored program, wherein the computer readable storage medium controls a device to execute the control method of the machine room air conditioner system when the program runs.

[0128] The embodiment of the present application provides a processor, and the processor is used for running a program, wherein the control method of the machine room air conditioner system is executed when the program runs.

[0129] The embodiment of the present application provides a device, and the device comprises a processor, a memory and a program stored in the memory and capable of running on the processor, and the processor executes the program to realize at least the following steps:

[0130] In step S201, the height of the outdoor unit of the machine room air conditioner, the height of the indoor unit, the suction superheat and the pump-in pressure and the pump-out pressure of the booster pump are acquired.

[0131] Step S202, determining the difference between the outdoor unit height and the indoor unit height as the indoor-outdoor unit height difference, and determining the difference between the pump-in pressure and the pump-out pressure as the pump pressure difference;

[0132] Step S203, determining the frequency of the booster pump of the machine room air conditioner according to at least the size of the pump pressure difference and the size of the indoor-outdoor unit height difference, and / or determining the opening degree of the electronic expansion valve of the machine room air conditioner according to at least the suction superheat, in the case that the indoor-outdoor unit height difference is less than or equal to a preset height difference.

[0133] The device herein can be a server, a PC, a PAD, a mobile phone, etc.

[0134] The present application also provides a computer program product, which, when executed on a data processing device, is adapted to execute a program that has at least the following method steps:

[0135] Step S201, obtaining the outdoor unit height, the indoor unit height, the suction superheat, the pump-in pressure and the pump-out pressure of the machine room air conditioner;

[0136] Step S202, determining the difference between the outdoor unit height and the indoor unit height as the indoor-outdoor unit height difference, and determining the difference between the pump-in pressure and the pump-out pressure as the pump pressure difference;

[0137] Step S203, determining the frequency of the booster pump of the machine room air conditioner according to at least the size of the pump pressure difference and the size of the indoor-outdoor unit height difference, and / or determining the opening degree of the electronic expansion valve of the machine room air conditioner according to at least the suction superheat, in the case that the indoor-outdoor unit height difference is less than or equal to a preset height difference.

[0138] Obviously, those skilled in the art should understand that the modules or steps of the present application described above can be realized by general computing devices, which can be concentrated on a single computing device or distributed on a network composed of multiple computing devices, and they can be realized by program codes executable by the computing devices, so that they can be stored in storage devices and executed by the computing devices, and in some cases, the steps shown or described herein can be executed in different orders, or they can be respectively manufactured into individual integrated circuit modules, or multiple modules or steps among them can be manufactured into a single integrated circuit module. Thus, the present application is not limited to any specific combination of hardware and software.

[0139] Those skilled in the art will appreciate that embodiments of the application can be readily used as software, hardware, or a combination of software and hardware. In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0140] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks. Figure 1 means for performing each of the functions specified in the flowchart block or blocks.

[0141] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks. Figure 1 means for performing each of the functions specified in the flowchart block or blocks.

[0142] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more functions specified in the flowchart block or blocks. Figure 1 means for performing each of the functions specified in the flowchart block or blocks.

[0143] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0144] The memory can include non-persistent memory and / or volatile memory, such as a random access memory (RAM) including a cache area for the temporary storage of data. The memory can also include non-volatile memory, such as a read only memory (ROM) device, a floppy disk, a flexible disk, hard disk, or a tape, cloud storage, flash memory card, or another suitable data storage device. The memory stores a data processing application, in accordance with an embodiment of the application.

[0145] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology for storing information. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0146] It should also be noted that the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device that includes the element.

[0147] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0148] 1) The above-mentioned machine room air conditioner system of the present application controls the frequency of the booster pump and the opening degree of the electronic expansion valve under negative high drop and outdoor low temperature to ensure the circulation of refrigerant and refrigeration oil under the whole negative high drop system. The oil return bend and one-way valve are arranged in the indoor unit under negative drop height to ensure normal oil return and prevent the refrigerant from migrating to the outdoor unit, thereby prolonging the service life of the compressor. The adjustment mode is adjusted and controlled by the frequency of the booster pump and the electronic expansion valve to ensure that the refrigerant of the whole system can circulate normally. The frequency of the booster pump is controlled by the pressure difference and the liquid level of the accumulator to ensure that the outdoor unit pressure is balanced in the shutdown state, without damaging the device. The electronic expansion valve is adjusted by the suction superheat degree control and the frequency of the booster pump to ensure that the system operates normally under negative high drop, preventing liquid knock of the compressor. The installation mode of the indoor unit and the outdoor unit of the machine room air conditioner in the prior art easily causes unstable system operation, reduces the service life of the compressor, and has low refrigeration performance.

[0149] 2) The control method of the above-mentioned machine room air conditioner system of the present application, through the negative high drop and the boost pump frequency and the electronic expansion valve opening degree control under the low outdoor temperature, to ensure the circulation of the refrigerant and the refrigeration oil under the whole negative high drop system. Through the frequency and the electronic expansion valve adjustment control adjustment mode, to ensure the refrigerant of the whole system can be normally circulated, the boost pump frequency is controlled through the pressure difference and the liquid level of the accumulator, to ensure the outdoor unit pressure balance under the shutdown state, without damaging the device. The electronic expansion valve is adjusted through the suction superheat control and the boost pump frequency, to ensure the system normal operation under the negative high drop condition, to prevent the compressor liquid knock. The problems of the existing technology that the installation mode of the indoor unit and the outdoor unit of the machine room air conditioner is easy to cause the system operation unstable, to reduce the service life of the compressor and the refrigeration performance is low are solved.

[0150] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A computer room air conditioner system, characterized in that: include: The indoor unit includes an evaporator, a compressor, an oil separator, a solenoid valve, and an electronic expansion valve. The solenoid valve is provided on a pipeline connecting the exhaust port of the compressor and the oil separator. The electronic expansion valve is provided on a pipeline where the refrigerant flows from the outdoor unit to the evaporator. The evaporator is connected to the compressor via a pipeline. The outdoor unit includes a liquid reservoir, a booster pump and a condenser. The booster pump is arranged on the pipeline where the refrigerant flows from the liquid reservoir to the indoor unit. The liquid reservoir is connected to the condenser through a pipeline. The condenser is used to cool the refrigerant. The refrigerant is allowed to circulate normally between the indoor unit and the outdoor unit by adjusting the frequency of the booster pump and the opening of the electronic expansion valve.

2. The computer room air conditioner system according to claim 1, characterized in that: The indoor unit further includes an oil return capillary tube and a first one-way valve, wherein the oil return capillary tube is installed on the pipeline between the air inlet of the compressor and the oil separator, and the first one-way valve is installed on the pipeline between the electronic expansion valve and the outdoor unit; The outdoor unit further includes a second one-way valve, which is installed on a pipeline connected in parallel with the booster pump, and the second one-way valve is connected to the liquid reservoir through a pipeline.

3. The computer room air conditioner system according to claim 1, wherein: include: On the pipeline connecting the outdoor unit and the indoor unit, an oil trap is provided for each vertical distance with a preset length difference.

4. A control method for a computer room air conditioner system, characterized in that: For controlling the computer room air conditioner system according to any one of claims 1 to 3, the method comprising: Obtain the outdoor unit height, indoor unit height, suction superheat, and booster pump inlet and outlet pressures of the computer room air conditioner; Determine the difference between the height of the outdoor unit and the height of the indoor unit as the height difference between the indoor and outdoor units, and determine the difference between the pump inlet pressure and the pump outlet pressure as the pump pressure difference; When the height difference between the indoor and outdoor units is less than or equal to a preset height difference, the frequency of the booster pump of the computer room air conditioner is determined at least based on the magnitude of the pump pressure difference and the magnitude of the height difference between the indoor and outdoor units, and / or the opening degree of the electronic expansion valve of the computer room air conditioner is determined at least based on the suction air superheat.

5. The method according to claim 4, characterized in that The compressor of the computer room air conditioner is in a stopped state. Before obtaining the height of the outdoor unit, the height of the indoor unit, the suction superheat, and the pumping pressure and the pumping pressure of the booster pump of the computer room air conditioner, the method further includes: Acquiring the indoor ambient temperature and the outdoor ambient temperature of the computer room air conditioner, and determining the difference between the indoor ambient temperature and the outdoor ambient temperature as the ambient temperature difference; closing the solenoid valve of the computer room air conditioner when the ambient temperature difference is greater than a first preset temperature or less than a second preset temperature, the first preset temperature being greater than the second preset temperature; When the ambient temperature difference is greater than or equal to the second preset temperature and less than or equal to the first preset temperature, the solenoid valve of the computer room air conditioner is opened.

6. The method according to claim 4, characterized in that The compressor of the computer room air conditioner is in an on-state, the solenoid valve of the computer room air conditioner is in an open state, and when the height difference between the internal and external units is less than or equal to a preset height difference, the frequency of the booster pump of the computer room air conditioner is determined based on at least the magnitude of the pump pressure difference and the magnitude of the height difference between the internal and external units, including: Determining a preset pressure difference based on the height difference between the internal and external units; When the pump pressure difference is less than a preset pressure difference and the liquid level of the liquid reservoir of the computer room air conditioner is greater than a first liquid level, increasing the frequency of the booster pump until the booster pump reaches a maximum frequency threshold or the liquid level of the liquid reservoir is less than or equal to the first liquid level; When the pump pressure difference is less than the preset pressure difference and the liquid level of the liquid reservoir of the computer room air conditioner is less than or equal to the first liquid level, reducing the frequency of the booster pump until the booster pump is shut down or the liquid level of the liquid reservoir is greater than the first liquid level; When the pump pressure difference is greater than or equal to the preset pressure difference and the liquid level in the liquid reservoir of the computer room air conditioner is greater than the first liquid level and less than the second liquid level, controlling the frequency of the booster pump to remain unchanged and the first liquid level to be less than the second liquid level; When the pump pressure difference is greater than or equal to the preset pressure difference and the liquid level of the liquid reservoir of the computer room air conditioner is greater than or equal to the second liquid level, the frequency of the booster pump is increased until the booster pump reaches a maximum frequency threshold or the liquid level of the liquid reservoir is less than or equal to the second liquid level.

7. The method according to claim 6, characterized in that Determining a preset pressure difference according to the height difference between the inner and outer units includes: Obtaining a first parameter table and the outdoor ambient temperature of the computer room air conditioner at a current moment, wherein the first parameter table represents a mapping relationship between the outdoor ambient temperature of the computer room air conditioner and the liquid phase density of the refrigerant; determining a liquid phase density of a refrigerant in the computer room air conditioner based on the current outdoor ambient temperature of the computer room air conditioner and the first parameter table; The preset pressure difference is determined according to the first formula ΔP=aρ1gH, where ΔP is the preset pressure difference, a is a coefficient, ρ1 is the liquid phase density of the refrigerant in the computer room air conditioner, g is the acceleration of gravity, and H is the height difference between the indoor and outdoor units.

8. The method according to claim 4, characterized in that Determining the opening of the electronic expansion valve of the computer room air conditioner at least according to the suction air superheat comprises: When the suction superheat is greater than a first preset superheat, gradually increasing the opening of the electronic expansion valve according to each step in the first step sequence, wherein each step in the first step sequence is less than or equal to the first preset step; When the suction superheat is greater than a second preset superheat and less than or equal to the first preset superheat, gradually increasing the opening of the electronic expansion valve according to each step in a second step sequence, each step in the second step sequence is less than or equal to a second preset step, and the first preset step is greater than the second preset step; When the suction air superheat is greater than a third preset superheat and less than or equal to the second preset superheat, controlling the opening of the electronic expansion valve to remain unchanged; When the suction superheat is less than or equal to the third preset superheat, the opening of the electronic expansion valve is gradually reduced according to each step in a third step sequence, and the absolute value of each step in the third step sequence is less than or equal to the first preset step.

9. The method according to claim 4, characterized in that The booster pump is a variable frequency booster pump, and the method further comprises: When the frequency of the booster pump changes and the frequency change value of the booster pump is negative, the opening of the electronic expansion valve is determined according to the second formula A=B+C×D, where A is the opening of the electronic expansion valve at the current moment, B is the suction superheat, C is the frequency change value of the booster pump, and D is the opening frequency coefficient.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the control method for the computer room air conditioner system according to any one of claims 4 to 9.

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