Machine room air conditioner, operation control method thereof, and operation control device thereof

Abstract

The application discloses a machine room air conditioner, a running control method thereof and a running control device thereof. The machine room air conditioner comprises a first refrigeration system, a second refrigeration system and a ventilation air duct. The first refrigeration system comprises a first evaporator, a first compressor, a first condenser, a first one-way valve and a first throttling valve which are sequentially connected and form a refrigerant circulation loop, and further comprises a second one-way valve connected in parallel with the first compressor and a first refrigerant pump connected in parallel with the first one-way valve. The second refrigeration system comprises a second evaporator, a second compressor, a second condenser, a third one-way valve and a second throttling valve which are sequentially connected and form a refrigerant circulation loop, and further comprises a fourth one-way valve connected in parallel with the second compressor and a second refrigerant pump connected in parallel with the third one-way valve. The first evaporator and the second evaporator are sequentially arranged in the ventilation air duct along a direction from a return air outlet to a supply air outlet. The machine room air conditioner can ensure that the refrigerating capacity of the air conditioner remains stable during the switching process of the operation mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioning, in particular to a machine room air conditioner, a running control method thereof and a running control device thereof. BACKGROUND

[0002] In 2019, the power usage efficiency (PUE) index of newly built data centers was released by the state and major cities, which has been greatly improved compared with the past. The air conditioning energy consumption of existing data centers accounts for more than 50% of the total energy consumption, and the PUE of the machine room is more than 1.5, and some even close to 2.0. In order to meet or exceed the specified PUE index, the air conditioning products used in newly built data centers need to be innovative in energy saving, and the air conditioning PUE needs to be less than 1.2. In some regions, the outdoor temperature is relatively low in autumn and winter, and by utilizing the natural cold source outdoors, the cooling demand of the machine room can be met while reducing the power consumption, thereby achieving the goal of reducing the PUE of the machine room.

[0003] The traditional compressor / refrigerant pump air conditioner adds a set of refrigerant pump system on the basis of the compressor refrigeration system structure. When the outdoor temperature is low, the refrigerant pump of the air conditioner runs, and the natural cold source on the outdoor side is moved to the indoor side through the heat exchanger; when the outdoor temperature rises and the pump system cannot meet the operating conditions, the refrigerant pump stops running, and the compressor system provides the cooling capacity. This scheme cannot provide sufficient cooling capacity and cannot accurately control the supply air temperature in the transition season because the indoor and outdoor temperature difference is too low. If only one air conditioning unit is running in the machine room, the air conditioning cooling capacity cannot be kept constant during the switching process between the compressor mode and the refrigerant pump mode, which will cause large fluctuations in the temperature of the machine room. SUMMARY

[0004] The present application provides a machine room air conditioner, a running control method thereof and a running control device thereof, which can ensure that the cooling capacity of the air conditioner remains stable during the switching process of the operating mode of the air conditioning body, and reduce the fluctuations in the temperature of the machine room.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A machine room air conditioner, comprising a first refrigeration system, a second refrigeration system, a ventilation air duct, a first temperature sensor, a second temperature sensor, a third temperature sensor and a controller;

[0007] The first refrigeration system comprises a first evaporator, a first compressor, a first condenser, a first check valve and a first throttling valve connected in sequence and forming a refrigerant circulation loop, further comprising a second check valve connected in parallel with the first compressor and a first refrigerant pump connected in parallel with the first check valve;

[0008] The second refrigeration system comprises a second evaporator, a second compressor, a second condenser, a third one-way valve and a second throttling valve connected in sequence and forming a refrigerant circulation loop, and further comprises a fourth one-way valve connected in parallel with the second compressor and a second refrigerant pump connected in parallel with the third one-way valve;

[0009] The ventilation duct has a return air inlet and a supply air outlet, and the first evaporator and the second evaporator are arranged in sequence in the ventilation duct along a direction from the return air inlet to the supply air outlet;

[0010] The first temperature sensor is configured to detect an outdoor ambient temperature, the second temperature sensor is configured to detect a return air temperature at the return air inlet, and the third temperature sensor is configured to detect a supply air temperature at the supply air outlet;

[0011] The controller is signal-connected with the first compressor, the first refrigerant pump, the second compressor, the second refrigerant pump, the first temperature sensor, the second temperature sensor and the third temperature sensor, and is configured to:

[0012] According to a difference between the return air temperature and the outdoor ambient temperature, the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump are controlled, so that the supply air temperature is kept close to or equal to a target temperature.

[0013] In the machine room air conditioner provided by the embodiment of the present application, the first refrigeration system has the first compressor and the first refrigerant pump, and can switch refrigeration between the compressor mode and the refrigerant pump mode, and the second refrigeration system has the second compressor and the second refrigerant pump, and can also switch refrigeration between the compressor mode and the refrigerant pump mode. Since the first evaporator in the first refrigeration system and the second evaporator in the second refrigeration system are arranged in sequence in the ventilation duct along a direction from the return air inlet to the supply air outlet, when the return air in the room enters the ventilation duct from the return air inlet, the first refrigeration system can pre-cool the return air, and the second refrigeration system can re-cool the return air. The controller can control the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to a difference between the return air temperature and the outdoor ambient temperature, and can make the supply air temperature close to or equal to the target temperature by switching the refrigeration mode of the first refrigeration system in cooperation with the switching of the refrigeration mode of the second refrigeration system, so as to keep the refrigerating capacity of the air conditioner stable during the switching of the operation mode of the air conditioning unit and reduce the fluctuation of the temperature in the machine room.

[0014] Optionally, when the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump are controlled according to the difference between the return air temperature and the outdoor ambient temperature, the controller is specifically configured to:

[0015] if the difference between the return air temperature and the outdoor ambient temperature is less than or equal to a first preset threshold, controlling the first compressor and the second compressor to operate, and controlling the first refrigerant pump and the second refrigerant pump to be closed, so that the air conditioner operates in a cooling mode;

[0016] if the difference between the return air temperature and the outdoor ambient temperature is greater than the first preset threshold and less than a second preset threshold, controlling the second compressor and the first refrigerant pump to operate, and controlling the first compressor and the second refrigerant pump to be closed, so that the air conditioner operates in a partial economy mode;

[0017] if the difference between the return air temperature and the outdoor ambient temperature is greater than or equal to the second preset threshold, controlling the first refrigerant pump and the second refrigerant pump to operate, and controlling the first compressor and the second compressor to be closed, so that the air conditioner operates in a full economy mode;

[0018] wherein the second preset threshold is greater than the first preset threshold.

[0019] Optionally, when controlling the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor ambient temperature, the controller is further configured to:

[0020] adjusting the values of the first preset threshold and the second preset threshold according to the air conditioner load.

[0021] Optionally, the controller is configured to:

[0022] when the air conditioner operates in the cooling mode, controlling the first compressor to operate at a first operating frequency, and controlling the second compressor to operate at a second operating frequency;

[0023] when the air conditioner operates in the partial economy mode, controlling the second compressor to operate at a third operating frequency, and controlling the first refrigerant pump to operate at a fourth operating frequency;

[0024] when the air conditioner operates in the full economy mode, controlling the first refrigerant pump to operate at a fifth operating frequency, and controlling the second refrigerant pump to operate at a sixth operating frequency.

[0025] Optionally, when the air conditioner operating mode switches between the cooling mode and the partial economy mode, the controller is configured to:

[0026] adjusting the working states of the first compressor, the first refrigerant pump, and the second compressor, so that the supply air temperature remains close to or equal to a target temperature.

[0027] Optionally, when the air conditioner operating mode switches from the cooling mode to the partial economy mode, the controller is configured to:

[0028] controlling the first compressor to be turned off after gradually decreasing from the first operating frequency to a seventh operating frequency at a first preset frequency decreasing speed, and synchronously controlling the second compressor to gradually increase from the second operating frequency to an eighth operating frequency at a first preset frequency increasing speed;

[0029] controlling the first refrigerant pump to be turned on and gradually increase from the second operating frequency to the fourth operating frequency at a second preset frequency increasing speed, and synchronously controlling the second compressor to gradually decrease from the eighth operating frequency to the third operating frequency at a second preset frequency decreasing speed, so that the air conditioner runs in a partial economy mode.

[0030] Optionally, when the air conditioner runs in the partial economy mode and enters a cooling mode, the controller is specifically configured to:

[0031] controlling the first refrigerant pump to be turned off after gradually decreasing from the fourth operating frequency to a ninth operating frequency at a third preset frequency decreasing speed, and synchronously controlling the second compressor to gradually increase from the third operating frequency to a tenth operating frequency at a third preset frequency increasing speed;

[0032] controlling the first compressor to be turned on and gradually increase from the fourth operating frequency to the first operating frequency at the fourth preset frequency increasing speed, and synchronously controlling the second compressor to gradually decrease from the tenth operating frequency to the second operating frequency at a fourth preset frequency decreasing speed, so that the air conditioner runs in a cooling mode.

[0033] Optionally, when the air conditioner runs in the partial economy mode and switches between the partial economy mode and a full economy mode, the controller is specifically configured to:

[0034] adjusting the working states of the second compressor, the first refrigerant pump, and the second refrigerant pump, so that the supply air temperature is kept close to or equal to the target temperature.

[0035] Optionally, when the air conditioner runs in the partial economy mode and enters the full economy mode, the controller is specifically configured to:

[0036] controlling the second compressor to be turned off after gradually decreasing from the third operating frequency to an eleventh operating frequency at a fifth preset frequency decreasing speed, and synchronously controlling the first refrigerant pump to gradually increase from the fourth operating frequency to a twelfth operating frequency at a fifth preset frequency increasing speed;

[0037] controlling the second refrigerant pump to be turned on and gradually increase from the second operating frequency to the sixth operating frequency at a sixth preset frequency increasing speed, and synchronously controlling the first refrigerant pump to gradually decrease from the twelfth operating frequency to the fifth operating frequency at a sixth preset frequency decreasing speed, so that the air conditioner runs in a full economy mode.

[0038] Optionally, when entering the partial economic mode from the full economic mode, the controller is specifically configured to:

[0039] controlling the second refrigerant pump to gradually reduce the frequency from the sixth operating frequency to a thirteenth operating frequency at a seventh preset frequency reduction speed, and synchronously controlling the first refrigerant pump to gradually increase the frequency from the fifth operating frequency to a fourteenth operating frequency at a seventh preset frequency increase speed;

[0040] controlling the second compressor to start and gradually increase the frequency to the third operating frequency at an eighth preset frequency increase speed, and synchronously controlling the first refrigerant pump to gradually reduce the frequency from the fourteenth operating frequency to the fourth operating frequency at an eighth preset frequency reduction speed, so that the air conditioner operates in the partial economic mode.

[0041] Optionally, the first refrigeration system further comprises a first liquid storage tank and a fifth one-way valve, the first liquid storage tank is located on the pipeline connected between the first condenser and the first one-way valve, and the fifth one-way valve is located on the pipeline connected between the first compressor and the first condenser and is connected in parallel with the second one-way valve.

[0042] The second refrigeration system further comprises a second liquid storage tank and a sixth one-way valve, the second liquid storage tank is located on the pipeline connected between the second condenser and the second one-way valve, and the sixth one-way valve is located on the pipeline connected between the second compressor and the second condenser and is connected in parallel with the fourth one-way valve.

[0043] The application also provides a running control method of a computer room air conditioner, which applies any one of the computer room air conditioners provided in the above technical solutions, and the running control method comprises the following steps:

[0044] obtaining an outdoor environment temperature, a return air temperature and a target temperature;

[0045] controlling the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature, so that the supply air temperature is kept close to or equal to the target temperature.

[0046] The application also provides a running control device of a computer room air conditioner, which comprises the following:

[0047] an obtaining unit configured to obtain an outdoor environment temperature, a return air temperature and a target temperature;

[0048] a control unit configured to control the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature, so that the supply air temperature is kept close to or equal to the target temperature. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 A structural schematic diagram of a computer room air conditioner provided by an embodiment of the present application is provided;

[0050] Figure 2a A device output diagram of a computer room air conditioner provided by an embodiment of the present application is provided;

[0051] Figure 2b A device output diagram of a computer room air conditioner provided by an embodiment of the present application is provided;

[0052] Figure 3 A flow chart of a running control method of a computer room air conditioner provided by an embodiment of the present application is provided;

[0053] Figure 4 A structural schematic diagram of a running control device of a computer room air conditioner provided by an embodiment of the present application is provided.

[0054] Icon:

[0055] 1-First refrigeration system; 11-First evaporator; 12-First compressor; 13-First condenser; 14-First check valve; 15-First throttling valve; 16-Second check valve; 17-First refrigerant pump; 18-First liquid storage tank; 19-Fifth check valve; 2-Second refrigeration system; 21-Second evaporator; 22-Second compressor; 23-Second condenser; 24-Third check valve; 25-Second throttling valve; 26-Fourth check valve; 27-Second refrigerant pump; 28-Second liquid storage tank; 29-Sixth check valve. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be described clearly and completely 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, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0057] Please refer to Figure 1 The embodiment of the present application provides a computer room air conditioner, which comprises a first refrigeration system 1, a second refrigeration system, a ventilation air duct, a first temperature sensor, a second temperature sensor, a third temperature sensor and a controller.

[0058] The first refrigeration system 1 comprises a first evaporator 11, a first compressor 12, a first condenser 13, a first check valve 14 and a first throttling valve 15 connected in sequence and forming a refrigerant circulation loop, and further comprises a second check valve 16 connected in parallel with the first compressor 12 and a first refrigerant pump 17 connected in parallel with the first check valve 14.

[0059] The second refrigeration system comprises a second evaporator 21, a second compressor 22, a second condenser 23, a third one-way valve 24 and a second throttling valve 25 connected in sequence and forming a refrigerant circulation loop, and further comprises a fourth one-way valve 26 connected in parallel with the second compressor 22 and a second refrigerant pump 27 connected in parallel with the third one-way valve 24;

[0060] The ventilation duct has a return air inlet and a supply air outlet, and the first evaporator 11 and the second evaporator 21 are arranged in sequence in the ventilation duct along the direction from the return air inlet to the supply air outlet;

[0061] The first temperature sensor is used for detecting the outdoor ambient temperature, the second temperature sensor is used for detecting the return air temperature at the return air inlet, and the third temperature sensor is used for detecting the supply air temperature at the supply air outlet;

[0062] The controller is signal-connected with the first compressor 12, the first refrigerant pump 17, the second compressor 22, the second refrigerant pump 27, the first temperature sensor, the second temperature sensor and the third temperature sensor; and the controller is used for:

[0063] According to the difference between the return air temperature and the outdoor ambient temperature, the working states of the first compressor 12, the first refrigerant pump 17, the second compressor 22 and the second refrigerant pump 27 are controlled, so that the supply air temperature is kept close to or equal to the target temperature.

[0064] In the machine room air conditioner provided by the embodiment of the application, the first refrigeration system 1, the second refrigeration system and the controller are included, the first refrigeration system 1 has the first compressor 12 and the first refrigerant pump 17, and the first refrigeration system 1 can switch between the compressor mode and the refrigerant pump mode for refrigeration, and the second refrigeration system has the second compressor 22 and the second refrigerant pump 27, and the second refrigeration system can also switch between the compressor mode and the refrigerant pump mode for refrigeration, the first evaporator 11 in the first refrigeration system 1 and the second evaporator 21 in the second refrigeration system are arranged in sequence in the ventilation duct along the direction from the return air inlet to the supply air outlet, when the return air in the room enters the ventilation duct from the return air inlet, the first refrigeration system 1 can pre-cool the return air, and the second refrigeration system can re-cool the return air, the controller can control the working states of the first compressor 12, the first refrigerant pump 17, the second compressor 22 and the second refrigerant pump 27 according to the difference between the return air temperature and the outdoor ambient temperature, the refrigeration mode of the first refrigeration system 1 can be switched in cooperation with the refrigeration mode of the second refrigeration system, so that the supply air temperature is close to or equal to the target temperature, the refrigeration capacity of the air conditioner is kept stable during the switching process of the operation mode of the air conditioning body, and the fluctuation of the temperature in the machine room is reduced.

[0065] It should be noted that the above supply air temperature close to the target temperature means that the temperature difference between the supply air temperature and the target temperature is within the preset temperature difference range, for example, the preset temperature difference range between the supply air temperature and the target temperature is greater than -0.5° and less than 0.5°, or other preset temperature difference range, which is not limited here and can be set according to actual needs.

[0066] The first evaporator 11 and the second evaporator 21 are located on the indoor side and can realize heat exchange between indoor return air and refrigerant. The first evaporator 11 and the second evaporator 21 are arranged in the ventilation air duct in sequence, and can be realized by the laminated design of the coil of the first evaporator 11 and the coil of the second evaporator 21, that is, the first evaporator 11 and the second evaporator 21 are arranged in parallel along the path of the ventilation air duct. The first evaporator 11 and the second evaporator 21 can be two separate evaporators, or two systems of one evaporator, which is not limited here. The first condenser 13 and the second condenser 23 are located on the outdoor side and can realize heat exchange between external air and refrigerant. The first throttling valve and the second throttling valve can be electronic expansion valves.

[0067] Specifically, the first temperature sensor, the second temperature sensor and the third temperature sensor can be temperature sensors with single temperature detection function, or composite multifunctional sensors capable of detecting temperature and other parameters, which is not limited here.

[0068] Specifically, the first refrigeration system 1 of the machine room air conditioner can further include a first liquid storage tank 18 and a fifth one-way valve 19, and the second refrigeration system can further include a second liquid storage tank 28 and a sixth one-way valve 29; the first liquid storage tank 18 is located on the pipeline connected between the first condenser 13 and the first one-way valve 14, and the second liquid storage tank 28 is located on the pipeline connected between the second condenser 23 and the third one-way valve 24, which can ensure stable transmission of refrigerant in the refrigeration system; the fifth one-way valve 19 is located on the pipeline between the first compressor 12 and the first condenser 13 and is connected in parallel with the second one-way valve 16, and the sixth one-way valve 29 is located on the pipeline between the second compressor 22 and the second condenser 23 and is connected in parallel with the fourth one-way valve 26, which can prevent the refrigerant from flowing back to the compressor.

[0069] In the above machine room air conditioner, the first refrigeration system 1 can pre-cool the return air, the second refrigeration system can re-cool the return air, the first refrigeration system 1 has a compressor refrigeration mode and a refrigerant pump refrigeration mode, the second refrigeration system has a compressor refrigeration mode and a refrigerant pump refrigeration mode, the first refrigeration system 1 and the second refrigeration system cooperate, and the air conditioning body can also have multiple refrigeration modes. In order to save energy and fully utilize natural cold sources, the operation mode of the air conditioning body can be divided into a refrigeration mode, a partial economy mode and a full economy mode. When the air conditioner is in the refrigeration mode, the first compressor 12 and the second compressor 22 operate, when the air conditioner is in the partial economy mode, the first refrigerant pump 17 and the second compressor 22 operate, and when the air conditioner is in the full economy mode, the first refrigerant pump 17 and the second refrigerant pump 27 operate.

[0070] In the above first refrigeration system, when the first compressor 12 operates, the first check valve 14 is turned on, the second check valve 16 is turned off, and the first refrigerant pump 17 is bypassed. The air conditioner is refrigerated by the first compressor 12 to provide cold energy. When the first refrigerant pump 17 operates, the second check valve 16 is turned on, the first check valve 14 is turned off, and the first compressor 12 is bypassed. The air conditioner is refrigerated by the first refrigerant pump 17 to provide cold energy.

[0071] In the above second refrigeration system, when the second compressor 22 operates, the third check valve 24 is turned on, the fourth check valve 26 is turned off, and the second refrigerant pump 27 is bypassed. The air conditioner is refrigerated by the second compressor 22 to provide cold energy. When the second refrigerant pump 27 operates, the fourth check valve 26 is turned on, the third check valve 24 is turned off, and the second compressor 22 is bypassed. The air conditioner is refrigerated by the second refrigerant pump 27 to provide cold energy.

[0072] In a specific embodiment, in order to save energy and fully utilize natural cold sources, the controller can be specifically used for:

[0073] If the difference between the return air temperature and the outdoor environment temperature is less than or equal to a first preset threshold A, the first compressor 12 and the second compressor 22 are controlled to operate, and the first refrigerant pump 17 and the second refrigerant pump 27 are controlled to be closed, so that the air conditioner operates in a refrigeration mode. For example, when the outdoor environment temperature is high and the difference between the return air temperature and the outdoor environment temperature is negative, in the case that natural cold sources cannot be utilized to achieve refrigeration capacity, the compressor refrigeration in the two refrigeration systems is used to provide the refrigeration capacity required by the air conditioner.

[0074] If the difference between the return air temperature and the outdoor environment temperature is greater than the first preset threshold A and less than the second preset threshold B, the second compressor 22 and the first refrigerant pump 17 are controlled to operate, the first compressor 12 and the second refrigerant pump 27 are controlled to be closed, so that the air conditioner runs in the partial economic mode, and the second preset threshold is greater than the first preset threshold; for example, in the transition season, when the indoor and outdoor temperature difference is too low, the first refrigerant pump 17 in the first refrigeration system 1 can be used for refrigeration, the return air in the room is pre-cooled by using the natural cold source, the energy consumption of the unit is saved, the second compressor 22 in the second refrigeration system is used for refrigeration, and the return air in the room is re-cooled to ensure the air supply temperature of the air conditioner, thereby ensuring the refrigerating capacity of the air conditioning unit.

[0075] If the difference between the return air temperature and the outdoor environment temperature is greater than or equal to the second preset threshold B, the first refrigerant pump 17 and the second refrigerant pump 27 are controlled to operate, and the first compressor 12 and the second compressor 22 are controlled to be closed, so that the air conditioner runs in the full economic mode; for example, when the outdoor environment temperature is low, the refrigerant pumps in the two refrigeration systems can be used for refrigeration, the natural cold source on the outdoor side is moved to the indoor side through the evaporator heat exchange, the natural cold source is fully used to meet the refrigerating capacity demand of the air conditioning unit, and the energy consumption can be saved.

[0076] The air conditioning unit provided by the embodiment of the application can control the switching of the operation mode of the air conditioner according to the difference between the return air temperature and the outdoor environment temperature, can save energy consumption, and can reduce the fluctuation of the air conditioning refrigerating capacity and the fluctuation of the temperature in the machine room during the switching process of the operation mode of the air conditioner compared with the prior art.

[0077] The controller can also be configured to adjust the values of the first preset threshold A and the second preset threshold B according to the air conditioning load. That is, the switching points of the air conditioning operation mode, the first preset threshold and the second preset threshold, can be adjusted according to the air conditioning load, the first preset threshold and the second preset threshold can be increased when the air conditioning load decreases, and the first preset threshold and the second preset threshold can be decreased when the air conditioning load increases. The corresponding operation mode is switched at the corresponding first preset threshold and second preset threshold, so that the system can have the highest energy efficiency and the system energy consumption can be reduced.

[0078] Specifically, in order to better meet the air conditioning refrigerating capacity adjustment, the first compressor 12, the second compressor 22, the first refrigerant pump 17 and the second refrigerant pump 27 can be designed as variable frequency. The first compressor 12 and the second compressor 22 can be variable frequency compressors, or can be multi-stage compressors or multiple compressors connected in parallel, so as to realize variable frequency, which is not limited here and can be selected according to actual needs. The first refrigerant pump 17 and the second refrigerant pump 27 can be variable frequency refrigerant pumps, or can be refrigerant pumps controlled by a frequency converter, which is not limited here and can be selected according to actual needs.

[0079] The machine room air conditioner provided by the embodiment of the application has the advantages that Figure 2a and Figure 2b The controller can be specifically configured to: when the air conditioner is running in the cooling mode, control the first compressor 12 to run at the first running frequency H1 and control the second compressor 22 to run at the second running frequency H2; when the air conditioner is running in the partial economy mode, control the second compressor 22 to run at the third running frequency H3 and control the first refrigerant pump 17 to run at the fourth running frequency H4; and when the air conditioner is running in the full economy mode, control the first refrigerant pump 17 to run at the fifth running frequency H5 and control the second refrigerant pump 27 to run at the sixth running frequency H6. The first running frequency H1, the second running frequency H2, the third running frequency H3, the fourth running frequency H4, the fifth running frequency H5 and the sixth running frequency H6 can be calculated by the controller according to PID comparison of the supply air temperature and the target temperature, so that the supply air temperature is close to or equal to the target temperature, which is not specifically limited herein.

[0080] The machine room air conditioner provided by the embodiment of the application has the advantages that, in order to ensure the stability of the supply air temperature during the switching process of the operation mode of the air conditioner, when the operation mode of the air conditioner is switched between the cooling mode and the partial economy mode, the controller can be specifically configured to: adjust the working states of the first compressor 12, the first refrigerant pump 17 and the second compressor 22, so that the supply air temperature is kept close to or equal to the target temperature.

[0081] Specifically, during the process of switching from the cooling mode to the partial economy mode, that is, during the running process of the cooling mode, if the difference between the return air temperature and the outdoor environment temperature is greater than the first preset threshold A and less than the second preset threshold B, the air conditioner enters the partial economy mode, as shown in Figure 2a The controller can be specifically configured to:

[0082] First, the first compressor 12 is controlled to be gradually reduced in frequency from the first running frequency H1 to the seventh running frequency H7 at a first preset frequency reduction speed and then be turned off, and the second compressor 22 is controlled to be gradually increased in frequency from the second running frequency H2 to the eighth running frequency H8 at a first preset frequency increase speed, so that the supply air temperature is kept close to or equal to the target temperature during the process of turning off the first compressor 12, the supply air temperature is kept constant and fluctuation is avoided.

[0083] Then, the first refrigerant pump 17 is controlled to be turned on and gradually increased in frequency to the fourth running frequency H4 at a second preset frequency increase speed, and the second compressor 22 is controlled to be gradually reduced in frequency from the eighth running frequency H8 to the third running frequency H3 at a second preset frequency reduction speed, so that the air conditioner runs in the partial economy mode, the supply air temperature is kept close to or equal to the target temperature during the process of switching to the running of the first refrigerant pump 17, the supply air temperature is kept constant and fluctuation is avoided.

[0084] Specifically, when the air conditioner enters the cooling mode from the partial economy mode, i.e. during the operation of the partial economy mode, if the difference between the return air temperature and the outdoor environment temperature is less than or equal to a first preset threshold A, the air conditioner enters the cooling mode, as shown in the following table. Figure 2b As shown, the controller can be specifically used for:

[0085] First, the first refrigerant pump 17 is controlled to be turned off after being gradually reduced from the fourth operating frequency H4 to the ninth operating frequency H9 at a third preset frequency reduction speed, and the second compressor 22 is controlled to be gradually increased from the third operating frequency H3 to the tenth operating frequency H10 at a third preset frequency increase speed, so that the supply air temperature is kept close to or equal to the target temperature during the process of turning off the first refrigerant pump 17, and the supply air temperature is kept constant to avoid fluctuation.

[0086] Then, the first compressor 12 is controlled to be turned on and gradually increased to the first operating frequency H1 at a fourth preset frequency increase speed, and the second compressor 22 is controlled to be gradually reduced from the tenth operating frequency H10 to the second operating frequency H2 at a fourth preset frequency reduction speed, so that the air conditioner operates in the cooling mode, and the supply air temperature is kept close to or equal to the target temperature during the process of switching to the operation of the first compressor 12, and the supply air temperature is kept constant to avoid fluctuation.

[0087] Specifically, the eighth operating frequency H8 and the tenth operating frequency H10 can be calculated by the controller according to the PID comparison of the supply air temperature and the target temperature to achieve that the supply air temperature is close to or equal to the target temperature, which is not limited here. The eighth operating frequency H8 can be equal to the tenth operating frequency H10.

[0088] The seventh operating frequency H7 and the ninth operating frequency H9 can be the recommended closing speed of the compressor specification book and the recommended closing speed of the refrigerant pump specification book, or other set values that meet the conditions, which are not limited here and are determined according to the actual situation. Specifically, the opening speed of the compressor can be the same as the closing speed of the compressor, the opening speed of the refrigerant pump can be the same as the closing speed of the refrigerant pump, and the seventh operating frequency H7 can be equal to the ninth operating frequency H9.

[0089] The first preset frequency increase speed, the third preset frequency increase speed, and the fourth preset frequency increase speed can be the recommended frequency increase speed in the compressor specification book, and the first preset frequency reduction speed, the second preset frequency reduction speed, and the fourth preset frequency reduction speed can be the recommended frequency reduction speed in the compressor specification book. The second preset frequency increase speed can be the recommended frequency increase speed in the refrigerant pump specification book, and the second preset frequency reduction speed can be the recommended frequency reduction speed in the refrigerant pump specification book. The specific values of the frequency increase and frequency reduction speeds are not limited here and are determined according to the actual situation.

[0090] The machine room air conditioner provided by the embodiment of the application can seamlessly switch between the refrigeration mode and the partial economy mode by adjusting the working states of the first compressor 12, the first refrigerant pump 17, the first one-way valve 14, the second one-way valve 16, and the second compressor 22, can accurately control the air supply temperature of the air conditioner, and can ensure seamless switching of the cooling capacity of the air conditioner, thereby preventing fluctuations in the temperature of the machine room.

[0091] To ensure the stability of the air supply temperature during the switching process of the operation mode of the air conditioner, when the air conditioner switches between the partial economy mode and the full economy mode, the controller can be specifically configured to adjust the working states of the second compressor 22, the first refrigerant pump 17, and the second refrigerant pump 27, so that the air supply temperature is close to or equal to the target temperature.

[0092] Specifically, when switching from the partial economy mode to the full economy mode, that is, during the operation of the partial economy mode, if the difference between the return air temperature and the outdoor environment temperature is greater than or equal to the second preset threshold B, the air conditioner enters the full economy mode, as shown in FIG. 6. Figure 2a The controller can be specifically configured to:

[0093] First, the second compressor 22 is gradually reduced in frequency from the third operating frequency H3 to the eleventh operating frequency H11 at a fifth preset frequency reduction speed and then is turned off, and the first refrigerant pump 17 is gradually increased in frequency from the fourth operating frequency H4 to the twelfth operating frequency H12 at a fifth preset frequency increase speed, which can ensure that the air supply temperature is close to or equal to the target temperature during the process of turning off the first refrigerant pump 17, so that the air supply temperature remains constant and fluctuations are avoided.

[0094] Then, the second refrigerant pump 27 is turned on and gradually increased in frequency to the sixth operating frequency H6 at a sixth preset frequency increase speed, and the first refrigerant pump 17 is gradually reduced in frequency from the twelfth operating frequency H12 to the fifth operating frequency at a sixth preset frequency reduction speed, so that the air conditioner operates in the full economy mode, which can ensure that the air supply temperature is close to or equal to the target temperature during the switching process to the operation of the second refrigerant pump 27, so that the air supply temperature remains constant and fluctuations are avoided.

[0095] Specifically, when switching from the full economy mode to the partial economy mode, that is, during the operation of the full economy mode, if the difference between the return air temperature and the outdoor environment temperature is greater than the first preset threshold A and less than the second preset threshold B, the air conditioner enters the partial economy mode, as shown in FIG. 7. Figure 2b The controller can be specifically configured to:

[0096] Firstly, the second refrigerant pump 27 is gradually reduced from the sixth operating frequency H6 to the thirteenth operating frequency H13 at a seventh preset frequency reduction speed, and the first refrigerant pump 17 is gradually increased from the fifth operating frequency H5 to the fourteenth operating frequency H14 at a seventh preset frequency increase speed, so that the air supply temperature is kept close to or equal to the target temperature during the process of turning off the second refrigerant pump, and the air supply temperature is kept constant and fluctuation is avoided.

[0097] Then, the second compressor 22 is turned on and gradually increased to the third operating frequency H3 at an eighth preset frequency increase speed, and the first refrigerant pump 17 is gradually reduced from the fourteenth operating frequency H14 to the fourth operating frequency H4 at an eighth preset frequency reduction speed, so that the air conditioner runs in the partial economy mode, and the air supply temperature is kept close to or equal to the target temperature during the process of switching to the second compressor 22, and the air supply temperature is kept constant and fluctuation is avoided.

[0098] The above-mentioned embodiment of the application provides a machine room air conditioner, when the air conditioner running mode is switched between the partial economy mode and the full economy mode, the working state of the second compressor 22, the first refrigerant pump 17 and the second refrigerant pump 27 is adjusted, so that the second compressor 22 and the second refrigerant pump are seamlessly switched between refrigeration and refrigeration, the air supply temperature of the air conditioner is accurately controlled, the seamless switching of the air conditioner cooling capacity is ensured, and the fluctuation of the machine room temperature is avoided.

[0099] Specifically, the twelfth operating frequency H12 and the fourteenth operating frequency H14 can be calculated by the controller according to the PID comparison of the air supply temperature and the target temperature, so that the air supply temperature is close to or equal to the target temperature, which is not limited here. The twelfth operating frequency H12 can be equal to the fourteenth operating frequency H14.

[0100] Specifically, the eleventh operating frequency H11 and the thirteenth operating frequency H13 can be the recommended closing speed of the compressor specification book and the recommended closing speed of the refrigerant pump specification book, or other set values that meet the conditions, which are not limited here and are determined according to the actual situation. Specifically, the opening speed of the compressor can be the same as the closing speed of the compressor, the opening speed of the refrigerant pump can be the same as the closing speed of the refrigerant pump, and the eleventh operating frequency H11 can be equal to the thirteenth operating frequency H13.

[0101] The fifth preset frequency reduction speed can be a recommended frequency reduction speed in a compressor specification book, and the eighth preset frequency increase speed can be a recommended frequency increase speed in the compressor specification book. The fifth preset frequency increase speed, the sixth preset frequency increase speed, and the seventh preset frequency increase speed can be recommended frequency increase speeds in a refrigerant pump specification book, and the sixth preset frequency reduction speed, the seventh preset frequency reduction speed, and the eighth preset frequency reduction speed can be recommended frequency reduction speeds in the refrigerant pump specification book. The specific values of the frequency increase and frequency reduction speeds are not limited here and are determined according to actual conditions.

[0102] Based on the same inventive concept, the embodiments of the present application also provide a running control method of a computer room air conditioner, which applies any one of the computer room air conditioners provided in the above technical solutions, such as Figure 3 as shown, the running control method comprises:

[0103] S301: acquiring an outdoor environment temperature, a return air temperature, and a target temperature;

[0104] S302: controlling working states of the first compressor, the first refrigerant pump, the second compressor, and the second refrigerant pump according to a difference between the return air temperature and the outdoor environment temperature, so that the supply air temperature is kept close to or equal to the target temperature.

[0105] In the running control method of the computer room air conditioner provided by the embodiments of the present application, the first evaporator in the first refrigeration system and the second evaporator in the second refrigeration system of the computer room air conditioner are arranged in the ventilation air duct in the direction from the return air port to the supply air port in sequence, when the return air in the room enters the ventilation air duct from the return air port, the first refrigeration system can pre-cool the return air, and the second refrigeration system can re-cool the return air. The outdoor environment temperature, the return air temperature, and the target temperature are acquired, the working states of the first compressor, the first refrigerant pump, the second compressor, and the second refrigerant pump are controlled according to the difference between the return air temperature and the outdoor environment temperature, the supply air temperature can be kept close to or equal to the target temperature by cooperation of switching of the refrigeration mode of the first refrigeration system and switching of the refrigeration mode of the second refrigeration system, the refrigeration capacity of the air conditioner is kept stable in the switching process of the operation mode of the air conditioning body, and the fluctuation of the temperature in the computer room is reduced.

[0106] Optionally, the controlling of the working states of the first compressor, the first refrigerant pump, the second compressor, and the second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature comprises:

[0107] If the difference between the return air temperature and the outdoor environment temperature is less than or equal to a first preset threshold, the first compressor and the second compressor are controlled to run, and the first refrigerant pump and the second refrigerant pump are controlled to be closed, so that the air conditioner runs in a refrigeration mode.

[0108] if the difference between the return air temperature and the outdoor ambient temperature is greater than the first preset threshold value and less than a second preset threshold value, controlling the second compressor and the first refrigerant pump to run open, controlling the first compressor and the second refrigerant pump to close, so that the air conditioner runs in a partial economy mode;

[0109] if the difference between the return air temperature and the outdoor ambient temperature is greater than or equal to the second preset threshold value, controlling the first refrigerant pump and the second refrigerant pump to run open, and controlling the first compressor and the second compressor to close, so that the air conditioner runs in a full economy mode;

[0110] wherein the second preset threshold value is greater than the first preset threshold value;

[0111] Optionally, the method comprises:

[0112] adjusting the values of the first preset threshold value and the second preset threshold value according to the air conditioning load.

[0113] Optionally, the method comprises:

[0114] when the air conditioner runs in a refrigeration mode, controlling the first compressor to run at a first running frequency and controlling the second compressor to run at a second running frequency;

[0115] when the air conditioner runs in a partial economy mode, controlling the second compressor to run at a third running frequency and controlling the first refrigerant pump to run at a fourth running frequency;

[0116] when the air conditioner runs in a full economy mode, controlling the first refrigerant pump to run at a fifth running frequency and controlling the second refrigerant pump to run at a sixth running frequency.

[0117] Optionally, when the air conditioner running mode is switched between the refrigeration mode and the partial economy mode, the method comprises:

[0118] adjusting the working states of the first compressor, the first refrigerant pump, and the second compressor so that the supply air temperature remains close to or equal to a target temperature.

[0119] Optionally, when the air conditioner running mode is switched from the refrigeration mode to the partial economy mode, the method comprises:

[0120] controlling the first compressor to gradually reduce the first running frequency to a seventh running frequency at a first preset frequency reduction speed and then to be turned off, and synchronously controlling the second compressor to gradually increase the second running frequency to an eighth running frequency at a first preset frequency increase speed;

[0121] controlling the first refrigerant pump to be turned on and gradually increase the frequency to the fourth operating frequency at a second preset frequency increasing speed, and synchronously controlling the second compressor to gradually decrease the frequency from the eighth operating frequency to the third operating frequency at a second preset frequency decreasing speed, so that the air conditioner runs in the partial economy mode.

[0122] Optionally, when the air conditioner runs in the partial economy mode and enters the cooling mode, the method comprises:

[0123] controlling the first refrigerant pump to gradually decrease the frequency from the fourth operating frequency to a ninth operating frequency at a third preset frequency decreasing speed and then turn off, and synchronously controlling the second compressor to gradually increase the frequency from the third operating frequency to a tenth operating frequency at a third preset frequency increasing speed;

[0124] controlling the first compressor to be turned on and gradually increase the frequency to the first operating frequency at the fourth preset frequency increasing speed, and synchronously controlling the second compressor to gradually decrease the frequency from the tenth operating frequency to the second operating frequency at a fourth preset frequency decreasing speed, so that the air conditioner runs in the cooling mode.

[0125] Optionally, when the air conditioner runs in the partial economy mode and switches between the partial economy mode and the full economy mode, the method comprises:

[0126] adjusting the working states of the second compressor, the first refrigerant pump and the second refrigerant pump, so that the supply air temperature is kept close to or equal to the target temperature.

[0127] Optionally, when the air conditioner runs in the partial economy mode and enters the full economy mode, the method comprises:

[0128] controlling the second compressor to gradually decrease the frequency from the third operating frequency to an eleventh operating frequency at a fifth preset frequency decreasing speed and then turn off, and synchronously controlling the first refrigerant pump to gradually increase the frequency from the fourth operating frequency to a twelfth operating frequency at a fifth preset frequency increasing speed;

[0129] controlling the second refrigerant pump to be turned on and gradually increase the frequency to the sixth operating frequency at a sixth preset frequency increasing speed, and synchronously controlling the first refrigerant pump to gradually decrease the frequency from the twelfth operating frequency to the fifth operating frequency at a sixth preset frequency decreasing speed, so that the air conditioner runs in the full economy mode.

[0130] Optionally, when the air conditioner runs in the full economy mode and enters the partial economy mode, the method comprises:

[0131] controlling the second refrigerant pump to gradually decrease the frequency from the sixth operating frequency to a thirteenth operating frequency at a seventh preset frequency decreasing speed and then turn off, and synchronously controlling the first refrigerant pump to gradually increase the frequency from the fifth operating frequency to a fourteenth operating frequency at a seventh preset frequency increasing speed;

[0132] The second compressor is controlled to be turned on and gradually increase in frequency to the third operating frequency at an eighth preset frequency increasing speed, and the first refrigerant pump is synchronously controlled to gradually decrease in frequency from the fourteenth operating frequency to the fourth operating frequency at an eighth preset frequency decreasing speed, so that the air conditioner runs in a partial economy mode.

[0133] Based on the same inventive concept, the embodiment of the present application provides a running control device of a computer room air conditioner, as shown in the drawings, comprising: Figure 4

[0134] The acquisition unit 100 acquires an outdoor environment temperature, a return air temperature and a target temperature;

[0135] The control unit 200 controls the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature, so that the supply air temperature is kept close to or equal to the target temperature.

[0136] In the running control device of the computer room air conditioner provided by the embodiment of the present application, the first evaporator in the first refrigeration system and the second evaporator in the second refrigeration system are arranged in the ventilation air duct in sequence along the direction from the return air port to the supply air port, the first refrigeration system can pre-cool the return air after the return air enters the ventilation air duct from the return air port, and the second refrigeration system can re-cool the return air, the outdoor environment temperature, the return air temperature and the target temperature are acquired, the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump are controlled according to the difference between the return air temperature and the outdoor environment temperature, the supply air temperature can be kept close to or equal to the target temperature by matching the switching of the refrigeration mode of the first refrigeration system with the switching of the refrigeration mode of the second refrigeration system, the refrigeration capacity of the air conditioner is kept stable during the switching of the running mode of the air conditioning body, and the fluctuation of the temperature in the computer room is reduced.

[0137] Optionally, the control unit 200 is specifically used for:

[0138] If the difference between the return air temperature and the outdoor environment temperature is less than or equal to a first preset threshold value, the first compressor and the second compressor are controlled to run, and the first refrigerant pump and the second refrigerant pump are controlled, so that the air conditioner runs in a refrigeration mode;

[0139] If the difference between the return air temperature and the outdoor environment temperature is greater than the first preset threshold value and less than a second preset threshold value, the second compressor and the first refrigerant pump are controlled to run, and the first compressor and the second refrigerant pump are controlled to be turned off, so that the air conditioner runs in a partial economy mode; ​

[0140] if the difference between the return air temperature and the outdoor ambient temperature is greater than or equal to the second preset threshold, controlling the first refrigerant pump and the second refrigerant pump to operate, and controlling the first compressor and the second compressor to be closed, so that the air conditioner operates in a full economy mode;

[0141] wherein the second preset threshold is greater than the first preset threshold;

[0142] Optionally, when controlling the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor ambient temperature, the control unit 100 is further configured to:

[0143] adjusting the values of the first preset threshold and the second preset threshold according to the air conditioning load.

[0144] Optionally, the control unit 200 is configured to:

[0145] when the air conditioner operates in a cooling mode, controlling the first compressor to operate at a first operating frequency and controlling the second compressor to operate at a second operating frequency;

[0146] when the air conditioner operates in a partial economy mode, controlling the second compressor to operate at a third operating frequency and controlling the first refrigerant pump to operate at a fourth operating frequency;

[0147] when the air conditioner operates in a full economy mode, controlling the first refrigerant pump to operate at a fifth operating frequency and controlling the second refrigerant pump to operate at a sixth operating frequency.

[0148] Optionally, when the air conditioner operating mode is switched between the cooling mode and the partial economy mode, the control unit 200 is configured to:

[0149] adjusting the working states of the first compressor, the first refrigerant pump and the second compressor so that the supply air temperature remains close to or equal to a target temperature.

[0150] Optionally, when the air conditioner operating mode is switched from the cooling mode to the partial economy mode, the control unit 200 is configured to:

[0151] controlling the first compressor to gradually decrease in frequency from the first operating frequency to a seventh operating frequency at a first preset frequency decreasing speed and then to be closed, and simultaneously controlling the second compressor to gradually increase in frequency from the second operating frequency to an eighth operating frequency at a first preset frequency increasing speed;

[0152] control the first refrigerant pump to be turned on and gradually increase the frequency to the fourth operating frequency at a second preset frequency increasing speed, and synchronously control the second compressor to gradually decrease the frequency from the eighth operating frequency to the third operating frequency at a second preset frequency decreasing speed, so that the air conditioner runs in the partial economy mode.

[0153] Optionally, when the air conditioner runs in the partial economy mode and enters the cooling mode, the control unit 200 is specifically configured to:

[0154] control the first refrigerant pump to gradually decrease the frequency from the fourth operating frequency to the ninth operating frequency at a third preset frequency decreasing speed and then be turned off, and synchronously control the second compressor to gradually increase the frequency from the third operating frequency to the tenth operating frequency at a third preset frequency increasing speed;

[0155] control the first compressor to be turned on and gradually increase the frequency to the first operating frequency at the fourth preset frequency increasing speed, and synchronously control the second compressor to gradually decrease the frequency from the tenth operating frequency to the second operating frequency at a fourth preset frequency decreasing speed, so that the air conditioner runs in the cooling mode.

[0156] Optionally, when the air conditioner runs in the partial economy mode and switches between the partial economy mode and the full economy mode, the control unit 200 is specifically configured to:

[0157] adjust the working states of the second compressor, the first refrigerant pump, the second refrigerant pump, the third one-way valve and the fourth one-way valve, so that the supply air temperature is kept close to or equal to the target temperature.

[0158] Optionally, when the air conditioner runs in the partial economy mode and enters the full economy mode, the control unit 200 is specifically configured to:

[0159] control the second compressor to be turned off after gradually decreasing the frequency from the third operating frequency to the eleventh operating frequency at a fifth preset frequency decreasing speed, and synchronously control the first refrigerant pump to gradually increase the frequency from the fourth operating frequency to the twelfth operating frequency at a fifth preset frequency increasing speed;

[0160] control the second refrigerant pump to be turned on and gradually increase the frequency to the sixth operating frequency at a sixth preset frequency increasing speed, and synchronously control the first refrigerant pump to gradually decrease the frequency from the twelfth operating frequency to the fifth operating frequency at a sixth preset frequency decreasing speed, so that the air conditioner runs in the full economy mode.

[0161] Optionally, when the air conditioner runs in the full economy mode and enters the partial economy mode, the control unit 200 is specifically configured to:

[0162] controlling the second refrigerant pump to gradually reduce the frequency from the sixth operating frequency to a thirteenth operating frequency at a seventh preset frequency reduction rate, and then to be turned off, and simultaneously controlling the first refrigerant pump to gradually increase the frequency from the fifth operating frequency to a fourteenth operating frequency at a seventh preset frequency increase rate;

[0163] controlling the second compressor to be turned on and gradually increase the frequency to the third operating frequency at an eighth preset frequency increase rate, and simultaneously controlling the first refrigerant pump to gradually reduce the frequency from the fourteenth operating frequency to the fourth operating frequency at an eighth preset frequency reduction rate, so that the air conditioner operates in the partial economy mode.

[0164] Obviously, various modifications and changes can be made to the embodiments of the present application without departing from the spirit and scope of the present application. It is intended that the present application encompass such modifications and changes as fall within the scope of the claims and their equivalents.

Claims

1. A machine room air conditioner characterized by, The air conditioner comprises a first refrigeration system, a second refrigeration system, a ventilation air duct, a first temperature sensor, a second temperature sensor, a third temperature sensor and a controller. The first refrigeration system comprises a first evaporator, a first compressor, a first condenser, a first check valve and a first throttling valve connected in sequence and forming a refrigerant circulation loop, and further comprises a second check valve connected in parallel with the first compressor and a first refrigerant pump connected in parallel with the first check valve. The second refrigeration system comprises a second evaporator, a second compressor, a second condenser, a third check valve and a second throttling valve connected in sequence and forming a refrigerant circulation loop, and further comprises a fourth check valve connected in parallel with the second compressor and a second refrigerant pump connected in parallel with the third check valve. The ventilation air duct has an air return port and an air supply port, and the first evaporator and the second evaporator are arranged in sequence along a direction from the air return port to the air supply port in the ventilation air duct. The first temperature sensor is configured to detect an outdoor ambient temperature, the second temperature sensor is configured to detect an air return temperature at the air return port, and the third temperature sensor is configured to detect an air supply temperature at the air supply port. The controller is in signal connection with the first compressor, the first refrigerant pump, the second compressor, the second refrigerant pump, the first temperature sensor, the second temperature sensor and the third temperature sensor. The controller is configured to: control working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to a difference between the air return temperature and the outdoor ambient temperature, so that the air supply temperature is kept close to or equal to a target temperature, and the air supply temperature close to the target temperature means that a temperature difference between the air supply temperature and the target temperature is within a preset temperature difference range. In the control of the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the air return temperature and the outdoor ambient temperature, the controller is specifically configured to: if the difference between the air return temperature and the outdoor ambient temperature is less than or equal to a first preset threshold, control the first compressor and the second compressor to run and control the first refrigerant pump and the second refrigerant pump to be closed, so that the air conditioner runs in a refrigeration mode; if the difference between the air return temperature and the outdoor ambient temperature is greater than the first preset threshold and less than a second preset threshold, control the second compressor and the first refrigerant pump to run and control the first compressor and the second refrigerant pump to be closed, so that the air conditioner runs in a partial economy mode; if the difference between the air return temperature and the outdoor ambient temperature is greater than or equal to the second preset threshold, control the first refrigerant pump and the second refrigerant pump to run and control the first compressor and the second compressor to be closed, so that the air conditioner runs in a full economy mode; wherein the second preset threshold is greater than the first preset threshold. In the process of entering the partial economy mode from the refrigeration mode, the controller is specifically configured to: control the first compressor to gradually reduce the frequency and then be closed, and synchronously control the second compressor to gradually increase the frequency to an eighth running frequency. control the first refrigerant pump to be turned on and gradually increase to a fourth operating frequency, and synchronously control the second compressor to gradually decrease from the eighth operating frequency to a third operating frequency, so that the air conditioner runs in a partial economy mode; when entering a full economy mode from a partial economy mode, the controller is specifically configured to: control the second compressor to gradually decrease and then be turned off, and synchronously control the first refrigerant pump to gradually increase to a twelfth operating frequency; control the second refrigerant pump to be turned on and gradually increase to a sixth operating frequency, and synchronously control the first refrigerant pump to gradually decrease to a fifth operating frequency, so that the air conditioner runs in a full economy mode.

2. The machine room air conditioner according to claim 1, wherein when controlling the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature, the controller is further specifically configured to: adjust the values of the first preset threshold and the second preset threshold according to the air conditioner load.

3. The machine room air conditioner according to claim 1, wherein the controller is specifically configured to: when the air conditioner runs in a cooling mode, control the first compressor to run at a first operating frequency, and control the second compressor to run at a second operating frequency; when the air conditioner runs in a partial economy mode, control the second compressor to run at a third operating frequency, and control the first refrigerant pump to run at a fourth operating frequency; when the air conditioner runs in a full economy mode, control the first refrigerant pump to run at a fifth operating frequency, and control the second refrigerant pump to run at a sixth operating frequency.

4. The machine room air conditioner according to claim 3, wherein when the air conditioner running mode is switched between the cooling mode and the partial economy mode, the controller is specifically configured to: adjust the working states of the first compressor, the first refrigerant pump and the second compressor, so that the supply air temperature remains close to or equal to the target temperature.

5. The machine room air conditioner according to claim 4, wherein when entering the partial economy mode from the cooling mode, the controller is specifically configured to: control the first compressor to gradually decrease from the first operating frequency to a seventh operating frequency at a first preset decrease frequency, and then be turned off, and synchronously control the second compressor to gradually increase from the second operating frequency to an eighth operating frequency at a first preset increase frequency; control the first refrigerant pump to be turned on and gradually increase to the fourth operating frequency at a second preset increase frequency, and synchronously control the second compressor to gradually decrease from the eighth operating frequency to the third operating frequency at a second preset decrease frequency, so that the air conditioner runs in a partial economy mode.

6. The machine room air conditioner according to claim 4, wherein when entering the cooling mode from the partial economy mode, the controller is specifically configured to: control the first refrigerant pump to gradually decrease from the fourth operating frequency to a ninth operating frequency at a third preset decrease frequency, and then be turned off, and synchronously control the second compressor to gradually increase from the third operating frequency to a tenth operating frequency at a third preset increase frequency; control the first compressor to be turned on and gradually increase to the first operating frequency at a fourth preset increase frequency, and synchronously control the second compressor to gradually decrease from the tenth operating frequency to the second operating frequency at a fourth preset decrease frequency, so that the air conditioner runs in a cooling mode.

7. The machine room air conditioner, as claimed in claim 3, wherein when the air conditioner running mode is switched between the partial economy mode and the full economy mode, the controller is specifically configured to: Adjusting the working states of the second compressor, the first refrigerant pump and the second refrigerant pump so that the supply air temperature is kept close to or equal to the target temperature.

8. The machine room air conditioner according to claim 7, wherein When entering the full economy mode from the partial economy mode, the controller is specifically configured to: control the second refrigerant pump to be turned on and gradually increase the frequency to the sixth operating frequency at a sixth preset frequency increasing speed, and synchronously control the first refrigerant pump to gradually decrease the frequency to the fifth operating frequency at a sixth preset frequency decreasing speed, so that the air conditioner runs in the full economy mode. When entering the full economy mode from the partial economy mode, the controller is specifically configured to:

9. The machine room air conditioner, as claimed in claim 7, wherein control the second refrigerant pump to be turned on and gradually increase the frequency to the sixth operating frequency at a sixth preset frequency increasing speed, and synchronously control the first refrigerant pump to gradually decrease the frequency to the fifth operating frequency at a sixth preset frequency decreasing speed, so that the air conditioner runs in the full economy mode. The first refrigeration system further comprises a first liquid storage tank and a fifth one-way valve, the first liquid storage tank being located on a pipeline connected between the first condenser and the first one-way valve, and the fifth one-way valve being located on a pipeline connected between the first compressor and the first condenser and being connected in parallel with the second one-way valve. The second refrigeration system further comprises a second liquid storage tank and a sixth one-way valve, the second liquid storage tank being located on a pipeline connected between the second condenser and the second one-way valve, and the sixth one-way valve being located on a pipeline connected between the second compressor and the second condenser and being connected in parallel with the fourth one-way valve.

10. The machine room air conditioner, as claimed in claim 1, wherein The operation control method comprises: obtaining an outdoor environment temperature, a return air temperature and a target temperature; 11. An operation control method of a machine room air conditioner, characterized by, controlling the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature, so that the supply air temperature is kept close to or equal to the target temperature; The operation control method comprises: if the difference between the return air temperature and the outdoor environment temperature is less than or equal to a first preset threshold, controlling the first compressor and the second compressor to run, and controlling the first refrigerant pump and the second refrigerant pump to be turned off, so that the air conditioner runs in a cooling mode. ​ ​ if the difference between the return air temperature and the outdoor ambient temperature is greater than the first preset threshold value and less than a second preset threshold value, the second compressor and the first refrigerant pump are controlled to run open, the first compressor and the second refrigerant pump are controlled to run closed, so that the air conditioner runs in a partial economy mode; if the difference between the return air temperature and the outdoor ambient temperature is greater than or equal to the second preset threshold value, the first refrigerant pump and the second refrigerant pump are controlled to run, and the first compressor and the second compressor are controlled to run closed, so that the air conditioner runs in a full economy mode; wherein the second preset threshold value is greater than the first preset threshold value; when entering the partial economy mode from the refrigeration mode, the operation control method comprises: controlling the first compressor to gradually reduce the frequency and then close, and synchronously controlling the second compressor to gradually increase the frequency to the eighth operating frequency; controlling the first refrigerant pump to open and gradually increase the frequency to the fourth operating frequency, and synchronously controlling the second compressor to gradually reduce the frequency from the eighth operating frequency to the third operating frequency, so that the air conditioner runs in a partial economy mode; when entering the full economy mode from the partial economy mode, the operation control method comprises: controlling the second compressor to gradually reduce the frequency and then close, and synchronously controlling the first refrigerant pump to gradually increase the frequency to the twelfth operating frequency; controlling the second refrigerant pump to open and gradually increase the frequency to the sixth operating frequency, and synchronously controlling the first refrigerant pump to gradually reduce the frequency to the fifth operating frequency, so that the air conditioner runs in a full economy mode.

12. The operation control method according to claim 11, characterized by, The operation state of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump is controlled according to the difference between the return air temperature and the outdoor ambient temperature, comprising: adjusting the values of the first preset threshold value and the second preset threshold value according to the air conditioner load.

13. The operation control method according to claim 11, characterized by, comprising: when the air conditioner runs in a refrigeration mode, the first compressor is controlled to run at a first operating frequency, and the second compressor is controlled to run at a second operating frequency; when the air conditioner runs in a partial economy mode, the second compressor is controlled to run at a third operating frequency, and the first refrigerant pump is controlled to run at a fourth operating frequency; when the air conditioner runs in a full economy mode, the first refrigerant pump is controlled to run at a fifth operating frequency, and the second refrigerant pump is controlled to run at a sixth operating frequency.

14. The operation control method according to claim 13, characterized by, when the air conditioner operating mode is switched between the refrigeration mode and the partial economy mode, comprising: adjusting the operation state of the first compressor, the first refrigerant pump and the second compressor, so that the supply air temperature remains close to or equal to the target temperature.

15. The operation control method according to claim 14, characterized by, when entering the partial economy mode from the refrigeration mode, comprising: controlling the first compressor to gradually reduce the frequency from the first operating frequency to the seventh operating frequency at a first preset frequency reduction rate, and then closing, and synchronously controlling the second compressor to gradually increase the frequency from the second operating frequency to the eighth operating frequency at a first preset frequency increase rate; Controlling the first refrigerant pump to start and gradually increase to the fourth operating frequency at a second preset frequency increasing speed, and synchronously controlling the second compressor to gradually decrease from the eighth operating frequency to the third operating frequency at a second preset frequency decreasing speed, so that the air conditioner runs in the partial economy mode.

16. The operation control method according to claim 14, characterized by When the air conditioner runs in the partial economy mode and enters the cooling mode, the method comprises the following steps: controlling the first refrigerant pump to gradually decrease from the fourth operating frequency to the ninth operating frequency at a third preset frequency decreasing speed and then to stop, and synchronously controlling the second compressor to gradually increase from the third operating frequency to the tenth operating frequency at a third preset frequency increasing speed; controlling the first compressor to start and gradually increase to the first operating frequency at the fourth preset frequency increasing speed, and synchronously controlling the second compressor to gradually decrease from the tenth operating frequency to the second operating frequency at a fourth preset frequency decreasing speed, so that the air conditioner runs in the cooling mode.

17. The operation control method according to claim 13, characterized by, When the air conditioner runs in the partial economy mode and switches between the partial economy mode and the full economy mode, the method comprises the following steps: adjusting the working states of the second compressor, the first refrigerant pump and the second refrigerant pump, so that the supply air temperature is kept close to or equal to the target temperature.

18. The operation control method according to claim 17, characterized by, When the air conditioner runs in the partial economy mode and enters the full economy mode, the method comprises the following steps: controlling the second compressor to gradually decrease from the third operating frequency to the eleventh operating frequency at a fifth preset frequency decreasing speed and then to stop, and synchronously controlling the first refrigerant pump to gradually increase from the fourth operating frequency to the twelfth operating frequency at a fifth preset frequency increasing speed; controlling the second refrigerant pump to start and gradually increase to the sixth operating frequency at a sixth preset frequency increasing speed, and synchronously controlling the first refrigerant pump to gradually decrease from the twelfth operating frequency to the fifth operating frequency at a sixth preset frequency decreasing speed, so that the air conditioner runs in the full economy mode.

19. The operation control method according to claim 17, characterized by, When the air conditioner runs in the full economy mode and enters the partial economy mode, the method comprises the following steps: controlling the second refrigerant pump to gradually decrease from the sixth operating frequency to the thirteenth operating frequency at a seventh preset frequency decreasing speed and then to stop, and synchronously controlling the first refrigerant pump to gradually increase from the fifth operating frequency to the fourteenth operating frequency at a seventh preset frequency increasing speed; controlling the second compressor to start and gradually increase to the third operating frequency at an eighth preset frequency increasing speed, and synchronously controlling the first refrigerant pump to gradually decrease from the fourteenth operating frequency to the fourth operating frequency at an eighth preset frequency decreasing speed, so that the air conditioner runs in the partial economy mode.

20. An operation control device of a machine room air conditioner, characterized by comprising: The method comprises the following steps: an acquisition unit acquires an outdoor environment temperature, a return air temperature and a target temperature; a control unit controls the working states of a first compressor, a first refrigerant pump, a second compressor and a second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature, so that the supply air temperature is kept close to or equal to the target temperature, and the supply air temperature close to the target temperature means that the temperature difference between the supply air temperature and the target temperature is within a preset temperature difference range; the control unit is specifically used for: controlling the working states of the first compressor, the first refrigerant pump, the second compressor and the second refrigerant pump according to the difference between the return air temperature and the outdoor environment temperature, the control unit is specifically used for: if the difference between the return air temperature and the outdoor environment temperature is less than or equal to a first preset threshold, the first compressor and the second compressor are controlled to operate, the first refrigerant pump and the second refrigerant pump are controlled, so that the air conditioner operates in a cooling mode; if the difference between the return air temperature and the outdoor environment temperature is greater than the first preset threshold and less than a second preset threshold, the second compressor and the first refrigerant pump are controlled to operate, the first compressor and the second refrigerant pump are controlled to be closed, so that the air conditioner operates in a partial economy mode; if the difference between the return air temperature and the outdoor environment temperature is greater than or equal to the second preset threshold, the first refrigerant pump and the second refrigerant pump are controlled to operate, the first compressor and the second compressor are controlled to be closed, so that the air conditioner operates in a full economy mode; wherein the second preset threshold is greater than the first preset threshold; when entering the partial economy mode from the cooling mode, the control unit is configured to: control the first compressor to gradually reduce the frequency and then be closed, and synchronously control the second compressor to gradually increase the frequency to an eighth operating frequency; control the first refrigerant pump to be opened and gradually increase the frequency to a fourth operating frequency, and synchronously control the second compressor to gradually reduce the frequency from the eighth operating frequency to a third operating frequency, so that the air conditioner operates in the partial economy mode; when entering the full economy mode from the partial economy mode, the control unit is configured to: control the second compressor to gradually reduce the frequency and then be closed, and synchronously control the first refrigerant pump to gradually increase the frequency to a twelfth operating frequency; control the second refrigerant pump to be opened and gradually increase the frequency to a sixth operating frequency, and synchronously control the first refrigerant pump to gradually reduce the frequency to a fifth operating frequency, so that the air conditioner operates in the full economy mode.

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