Machine room air conditioner, operation control method and device thereof

Abstract

The application discloses a machine room air conditioner, a running control method and device thereof. The machine room air conditioner comprises a first refrigerating system, a second refrigerating system, a ventilation channel, an indoor fan and a controller. The first refrigerating system comprises a first evaporator, a first compressor, a first condenser and a first electronic expansion valve which are connected in sequence and constitute a loop. The second refrigerating system comprises a second evaporator, a second compressor, a second condenser and a second electronic expansion valve which are connected in sequence and constitute a loop. The ventilation channel has an air return inlet and an air outlet. The first evaporator and the second evaporator are arranged in sequence in the ventilation channel along the direction from the air return inlet to the air outlet. The indoor fan is located in the ventilation channel and is used for sending the cooled return air from the air outlet into the machine room. The controller is signal connected with the first electronic expansion valve and the second electronic expansion valve. The machine room air conditioner can adapt to different humidity and refrigeration demand occasions by controlling the running mode of the first refrigerating system and the second refrigerating system, and the applicability is improved.

Description

TECHNICAL FIELD

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

[0002] Machine room equipment includes servers, memories, switches and the like, in order to ensure normal operation of the machine room equipment, the temperature and humidity of the machine room have strict requirements. The influence of temperature on the machine room equipment is well known, and the influence of humidity on the machine room equipment is actually not inferior to temperature, and even more so. Air humidity is easy to cause rust on the metal parts and plug parts of the equipment, and cause the insulation of the circuit board, plug and wiring to be reduced, and in severe cases, it can also cause a short circuit. When the air humidity increases, the water film formed on the surface of the medium material is easy to form a "conductive path" and an arc phenomenon, thereby causing equipment failure; when the humidity is too low, the static voltage will be higher, and the devices sensitive to static electricity will be irreversibly damaged, thereby affecting the normal work of electronic computers and the like. In addition, static electricity also affects the normal work and physical and mental health of the operating personnel and maintenance personnel.

[0003] The dehumidification means of the traditional machine room air conditioner mainly includes the following: 1. Reduce the air volume to make the evaporation temperature of the air conditioner lower than the dew point temperature of the return air. Although this method can achieve the purpose of dehumidification, it cannot maintain the refrigerating capacity of the air conditioner, resulting in large temperature fluctuations in the machine room. 2. Control the opening degree of the throttling element to make the evaporation temperature of the air conditioner lower than the dew point temperature of the return air. This method can achieve the purpose of dehumidification, but it cannot be applied to low-load high-humidity environments. 3. Close part of the evaporator coil through the electromagnetic valve to make the evaporation temperature lower than the dew point temperature of the return air, which increases the cost of the air conditioning unit. SUMMARY

[0004] The present application provides a machine room air conditioner, a running control method and device thereof, which can adapt to different humidity and refrigeration demand occasions by controlling the running mode of the first refrigeration system and the second refrigeration system, thereby improving the applicability.

[0005] To achieve the above purpose, the present application provides the following technical scheme:

[0006] A machine room air conditioner, comprising a first refrigeration system, a second refrigeration system, a ventilation channel, an indoor fan and a controller;

[0007] The first refrigeration system comprises a first evaporator, a first compressor, a first condenser and a first electronic expansion valve connected in sequence and constituting a loop, and further comprises a first condensing fan corresponding to the first condenser;

[0008] The second refrigeration system comprises a second evaporator, a second compressor, a second condenser and a second electronic expansion valve connected in sequence and constituting a loop, and further comprises a second condensing fan corresponding to the second condenser;

[0009] The ventilation channel has a return air outlet and a supply air outlet at two ends, and the first evaporator and the second evaporator are arranged in sequence in the ventilation channel in a direction from the return air outlet to the supply air outlet;

[0010] The indoor fan is located in the ventilation channel and is used to send return air in the ventilation channel from the supply air outlet into the machine room;

[0011] The controller is signal connected with the indoor fan, the first compressor, the second compressor, the first condensing fan, the second condensing fan, the first electronic expansion valve and the second electronic expansion valve, and the controller is used to:

[0012] Obtain the dehumidification demand of the machine room;

[0013] If the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, and until the dehumidification demand is re-acquired and is again less than or equal to 0%, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system keep the original refrigeration state.

[0014] Optionally, the controller is specifically further used to:

[0015] If the dehumidification demand is greater than or equal to the preset dehumidification demand value, a first dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled and adjusted so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, and until the dehumidification demand is re-acquired and is again greater than 0% and less than the preset dehumidification demand value, a second dehumidification mode is entered.

[0016] Optionally, the preset dehumidification demand value is 50%.

[0017] Optionally, the system further comprises a first temperature and humidity sensor, a second temperature and humidity sensor, a first temperature sensor, a second temperature sensor, a first pressure sensor and a second pressure sensor;

[0018] The first temperature and humidity sensor is used to detect the return air temperature and the return air humidity of the return air at the return air outlet, and the second temperature and humidity sensor is used to detect the supply air temperature and the supply air humidity of the supply air at the supply air outlet.

[0019] The first temperature sensor is used to detect the temperature of the first compressor suction gas, and the second temperature sensor is used to detect the temperature of the second compressor suction gas;

[0020] The first pressure sensor is used to detect the suction pressure of the first compressor, and the second pressure sensor is used to detect the suction pressure of the second compressor;

[0021] The controller is in signal connection with the first and second temperature sensors, the first and second temperature sensors, the first and second pressure sensors.

[0022] Optionally, when the opening of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller is specifically used for:

[0023] According to the real-time return air temperature and return air humidity, the return air dew point temperature of the first refrigeration system is calculated;

[0024] According to the real-time suction pressure of the first compressor, the evaporation temperature of the first refrigeration system is calculated;

[0025] The opening of the first electronic expansion valve is adjusted in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature, and the first target evaporation temperature is the difference between the return air dew point temperature of the first refrigeration system and the first preset temperature difference, so that the first refrigeration system is in a dehumidification state.

[0026] Optionally, when the opening of the second electronic expansion valve is adjusted to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, and enters the second dehumidification mode, the controller is specifically used for:

[0027] According to the real-time supply air temperature and supply air humidity, the supply air dew point temperature of the second refrigeration system is calculated;

[0028] According to the real-time suction pressure of the second compressor, the evaporation temperature of the second refrigeration system is calculated;

[0029] The opening of the second electronic expansion valve is adjusted until the evaporation temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system;

[0030] According to the real-time return air humidity and supply air humidity, the dehumidification amount in each preset period is calculated in real time;

[0031] acquire the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand;

[0032] control and adjust the opening degree of the second electronic expansion valve according to the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, and the second dehumidification mode is entered.

[0033] Optionally, when the opening degree of the second electronic expansion valve is controlled and adjusted according to the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand of the machine room is acquired again greater than 0% and less than the preset dehumidification demand value, and the second dehumidification mode is entered, the controller is specifically configured to:

[0034] acquire the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, and determine whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period; if the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, and the opening degree of the second electronic expansion valve is controlled and adjusted in real time, so that the evaporation temperature of the next preset period of the second refrigeration system is kept unchanged at the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state;

[0035] acquire the dehumidification time length when the second refrigeration system enters the dehumidification state, and determine whether the dehumidification time length when the second refrigeration system enters the dehumidification state is greater than the first preset time length; if the dehumidification time length when the second refrigeration system enters the dehumidification state is not greater than the first preset time length, the dehumidification demand of the machine room is acquired again;

[0036] if the dehumidification demand of the machine room acquired again is greater than 0% and less than the preset dehumidification demand value, the air conditioning system enters the second dehumidification mode, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system is not dehumidified.

[0037] Optionally, the controller is further configured to:

[0038] acquire the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, determine whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, if the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period, control the opening degree of the second electronic expansion valve to make the evaporation temperature of the next preset period of the second refrigeration system equal to the evaporation temperature of the current preset period of the second refrigeration system minus the second preset temperature difference;

[0039] calculate the superheat degree of the second refrigeration system according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature;

[0040] if the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, control the opening degree of the second electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature;

[0041] again acquire the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, and continue to determine whether the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period.

[0042] Optionally, the dehumidification amount of the current preset period and the dehumidification amount of the last preset period are acquired, and it is determined whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period. If the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, and the opening degree of the second electronic expansion valve is controlled in real time to make the evaporation temperature of the next preset period of the second refrigeration system remain equal to the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state. After that, the controller is further specifically used for:

[0043] calculate the superheat degree of the second refrigeration system according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature;

[0044] if the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, control the opening degree of the second electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature;

[0045] again control the opening degree of the second electronic expansion valve in real time to make the evaporation temperature of the second refrigeration system continue to remain equal to the second target evaporation temperature.

[0046] Optionally, the controller is further specific for:

[0047] judging whether the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than a first preset duration, if the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than the first preset duration, the air conditioning system re-enters the first dehumidification mode, the opening degree of the first electronic expansion valve is controlled to adjust so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled to adjust so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, entering the second dehumidification mode.

[0048] Optionally, if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, entering the second dehumidification mode, the opening degree of the first electronic expansion valve is controlled to adjust so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled to adjust so that the second refrigeration system does not dehumidify, until the dehumidification demand is less than or equal to 0% again, entering the third dehumidification mode, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0049] wherein when the opening degree of the first electronic expansion valve is controlled to adjust so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system until the dehumidification demand is less than or equal to 0%, entering the third dehumidification mode, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state, the controller is specific for:

[0050] controlling the opening degree of the first electronic expansion valve to adjust so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system;

[0051] judging whether the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than a second preset duration, if the dehumidification duration of the first refrigeration system entering the dehumidification state is less than or equal to the second preset duration, the dehumidification demand of the machine room is re-acquired;

[0052] if the dehumidification demand is less than or equal to 0%, entering the third dehumidification mode, the first refrigeration system and the second refrigeration system do not dehumidify, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0053] Optionally, after the opening degree of the first electronic expansion valve is controlled to adjust so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the controller is further for:

[0054] calculating a superheat degree of the first refrigeration system according to the real-time suction pressure of the first compressor and the first compressor suction gas temperature;

[0055] if the superheat degree of the first refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the first refrigeration system is less than or equal to a preset minimum evaporation temperature, controlling the opening degree of the first electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the first refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is greater than the preset minimum evaporation temperature;

[0056] controlling the opening degree of the first electronic expansion valve in real time again to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

[0057] Optionally, after controlling the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the dew point temperature of the return air of the first refrigeration system, the controller is further configured to:

[0058] judging whether a dehumidification duration of the first refrigeration system in the dehumidification state is greater than a second preset duration;

[0059] if the dehumidification duration of the first refrigeration system in the dehumidification state is greater than the second preset duration, the air conditioning system reenters the second dehumidification mode, and the opening degree of the first electronic expansion valve is controlled to keep the evaporation temperature of the first refrigeration system lower than the dew point temperature of the return air of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled to keep the second refrigeration system from dehumidifying, until the dehumidification demand is less than or equal to 0% again, and the third dehumidification mode is entered.

[0060] Optionally, after controlling the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the dew point temperature of the return air of the first refrigeration system, the controller is further configured to:

[0061] if the dehumidification demand is greater than 0%, the opening degree of the first electronic expansion valve is controlled in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

[0062] Based on the same inventive concept, the present application also provides a running control method of a computer room air conditioner, applied to any one of the computer room air conditioners provided in the above technical solutions, comprising:

[0063] obtaining a dehumidification demand of the computer room;

[0064] If the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, until the re-acquired dehumidification demand is less than or equal to 0% again, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0065] Based on the same inventive concept, the application also provides an operation control device of a machine room air conditioner, comprising:

[0066] An acquisition unit is configured to acquire a dehumidification demand of a machine room.

[0067] A control unit is configured to:

[0068] If the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, until the re-acquired dehumidification demand is less than or equal to 0% again, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0069] The machine room air conditioner provided by the embodiment of the present application, the operation control method and device thereof comprise a first refrigeration system and a second refrigeration system, the first evaporator in the first refrigeration system and the second evaporator in the second refrigeration system are arranged in sequence along the direction from the return air outlet to the air supply outlet in the ventilation channel, and the first refrigeration system and the second refrigeration system can complement each other in the process of dehumidification and refrigeration of the machine room air conditioner; when the machine room air conditioner has refrigeration demand, the rotation speed of the first compressor, the first condensing fan, the second compressor and the second condensing fan can be controlled and adjusted to realize the refrigeration of the first refrigeration system and the second refrigeration system, so that the machine room air conditioner can adapt to different refrigeration demands; meanwhile, when the machine room air conditioner has dehumidification demand, the opening degree of the first electronic expansion valve and the second electronic expansion valve can be controlled to make the machine room adapt to different dehumidification demands. Specifically, if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, the second dehumidification mode is entered, the opening degree of the first electronic expansion valve 14 is controlled and adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is controlled and adjusted to make the second refrigeration system not dehumidify, until the dehumidification demand is less than or equal to 0% again, the third dehumidification mode is entered, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system keep the original refrigeration state, that is, when the machine room is in a low humidity state, the opening degree of the first electronic expansion valve can be controlled and adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve can be controlled and adjusted to make the second refrigeration system not dehumidify, at this time, the machine room air conditioner enters the second dehumidification mode, and in the process of dehumidification, if the dehumidification demand is less than or equal to 0%, the first refrigeration system can be controlled to stop dehumidification, and the first refrigeration system and the second refrigeration system keep the original refrigeration state, at this time, the machine room air conditioner enters the third dehumidification mode. The machine room air conditioner can make the machine room air conditioner be in different operation modes, can adapt to occasions with different humidity demands and different refrigeration demands, and can improve the applicability of the air conditioner by controlling the operation state of the first refrigeration system and the second refrigeration system. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 A structural schematic diagram of a machine room air conditioner provided by the embodiment of the present application;

[0071] Figure 2 A variation curve diagram of the dehumidification amount of a machine room air conditioner provided by the embodiment of the present application;

[0072] Figure 3 A flow control diagram of a machine room air conditioner provided by the embodiment of the present application;

[0073] Figure 4 A flow chart of an operation control method of a machine room air conditioner provided by the embodiment of the present application;

[0074] Figure 5 Fig. 1 is a structural schematic diagram of an operation control device of a computer room air conditioner according to an embodiment of the present application.

[0075] Fig. 1 is a structural schematic diagram of an operation control device of a computer room air conditioner according to an embodiment of the present application.

[0076] 11-First evaporator; 12-First compressor; 13-First condenser; 14-First electronic expansion valve; 15-First condensing fan; 16-First temperature and humidity sensor; 21-Second evaporator; 22-Second compressor; 23-Second condenser; 24-Second electronic expansion valve; 25-Second condensing fan; 26-Second temperature and humidity sensor; 3-Indoor fan; 4-Ventilation channel. DETAILED DESCRIPTION

[0077] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0078] Please refer to Figure 1 The present application provides a computer room air conditioner, which comprises a first refrigeration system, a second refrigeration system, a ventilation channel 4, an indoor fan 3 and a controller.

[0079] The first refrigeration system comprises a first evaporator 11, a first compressor 12, a first condenser 13 and a first electronic expansion valve 14 connected in sequence and constituting a loop, and further comprises a first condensing fan 15 corresponding to the first condenser 13.

[0080] The second refrigeration system comprises a second evaporator 21, a second compressor 22, a second condenser 23 and a second electronic expansion valve 24 connected in sequence and constituting a loop, and further comprises a second condensing fan 25 corresponding to the second condenser 23.

[0081] The ventilation channel 4 has return air inlets and supply air outlets at two ends, and the first evaporator 11 and the second evaporator 21 are arranged in sequence in the ventilation channel 4 along a direction from the return air inlets to the supply air outlets.

[0082] The indoor fan 3 is located in the ventilation channel 4 and is used to send the return air in the ventilation channel 4 from the supply air outlets into the computer room.

[0083] The controller is signal-connected with the indoor fan 3, the first compressor 12, the second compressor 22, the first condensing fan 15, the second condensing fan 25, the first electronic expansion valve 14 and the second electronic expansion valve 24, and the controller is used to:

[0084] Obtain the dehumidification demand of the computer room;

[0085] If the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, the second dehumidification mode is entered, the opening degree of the first electronic expansion valve 14 is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is controlled and adjusted so that the second refrigeration system does not dehumidify, until the dehumidification demand is less than or equal to 0% again, the third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system keep the original refrigeration state.

[0086] In the above-mentioned machine room air conditioner, the first refrigeration system and the second refrigeration system are included, the first evaporator 11 in the first refrigeration system and the second evaporator 21 in the second refrigeration system are arranged in sequence along the direction from the return air outlet to the air outlet in the ventilation channel 4, and the first refrigeration system and the second refrigeration system can complement each other in the process of dehumidification and refrigeration of the machine room air conditioner. When the machine room air conditioner has a refrigeration demand, the speed of the first compressor 12, the first condensing fan 15, the second compressor 22 and the second condensing fan 25 can be controlled and adjusted to realize the cooperation of the first refrigeration system and the second refrigeration system for refrigeration, so that the machine room air conditioner can adapt to different refrigeration demands. At the same time, when the machine room air conditioner has a dehumidification demand, the opening degrees of the first electronic expansion valve 14 and the second electronic expansion valve 24 can be controlled to make the machine room adapt to different dehumidification demands. Specifically, if the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, the second dehumidification mode is entered, the opening degree of the first electronic expansion valve 14 is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is controlled and adjusted so that the second refrigeration system does not dehumidify, until the dehumidification demand is less than or equal to 0% again, the third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system keep the original refrigeration state. That is, when the machine room has a low humidity, the opening degree of the first electronic expansion valve 14 can be controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is controlled and adjusted so that the second refrigeration system does not dehumidify, at this time the machine room air conditioner enters the second dehumidification mode. During the dehumidification process, if the dehumidification demand is less than or equal to 0%, the first refrigeration system can stop dehumidifying, and the first refrigeration system and the second refrigeration system keep the original refrigeration state, at this time the machine room air conditioner enters the third dehumidification mode. The above-mentioned machine room air conditioner can make the machine room air conditioner be in different operation modes by controlling the operation state of the first refrigeration system and the second refrigeration system, can adapt to occasions with different humidity demands and different refrigeration demands, and can improve the applicability of the air conditioner.

[0087] Specifically, the controller is further configured to: if the dehumidification demand is greater than or equal to a preset dehumidification demand value, enter a first dehumidification mode, control the opening degree of the first electronic expansion valve 14 to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and control the opening degree of the second electronic expansion valve 24 to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, and then enter a second dehumidification mode. That is, when the dehumidification demand is greater than the preset dehumidification demand, the humidity in the machine room is high, the opening degrees of the first electronic expansion valve 14 and the second electronic expansion valve 24 can be controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system and the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, so that the first refrigeration system and the second refrigeration system are both in a dehumidification state, and the air conditioner in the machine room enters the first dehumidification mode. When the dehumidification demand changes to be greater than 0% and less than the preset dehumidification demand value during the dehumidification process, the air conditioner in the machine room can be adjusted to enter the second dehumidification mode, the first refrigeration system is dehumidified, and the second refrigeration system is not dehumidified.

[0088] The specific value of the dehumidification demand can be calculated according to the collected return air relative humidity at the air supply outlet, the preset target relative humidity, the humidity dead zone and the humidity control precision. The collected relative humidity can be collected by a sensor. Specifically, the dehumidification demand calculation formula can be: when the collected relative humidity is greater than or equal to (the preset target relative humidity + the humidity dead zone), the dehumidification demand = (the collected relative humidity - the preset target relative humidity - the humidity dead zone) / the humidity control precision; and when the collected relative humidity is less than (the preset target relative humidity - the humidity dead zone), the dehumidification demand = the collected relative humidity - the preset target relative humidity + the humidity dead zone) / the temperature control precision.

[0089] The specific value of the dehumidification demand can be calculated according to the collected return air relative humidity at the air supply outlet, the preset target relative humidity, the humidity dead zone and the humidity control precision. The collected relative humidity can be collected by a sensor. Specifically, the dehumidification demand calculation formula can be: when the collected relative humidity is greater than or equal to (the preset target relative humidity + the humidity dead zone), the dehumidification demand = (the collected relative humidity - the preset target relative humidity - the humidity dead zone) / the humidity control precision; and when the collected relative humidity is less than (the preset target relative humidity - the humidity dead zone), the dehumidification demand = the collected relative humidity - the preset target relative humidity + the humidity dead zone) / the temperature control precision.

[0090] In the embodiment of the application, the preset dehumidification demand value can be 50%. The setting of the preset dehumidification demand value can make the switching of the dehumidification modes of the first refrigeration system and the second refrigeration system more adaptive to the changes in the dehumidification demand. Alternatively, the preset dehumidification demand can also be other values, which are not limited here and can be set according to actual conditions.

[0091] Specifically, the above-mentioned machine room air conditioner can adapt to occasions such as high-load high-humidity, high-load low-humidity, low-load high-humidity, and low-load low-humidity, wherein the high-load condition can be that the refrigeration demand is greater than or equal to a preset refrigeration demand value, and the low-load condition is that the refrigeration demand is less than the preset refrigeration demand value. The preset refrigeration demand value is not limited here and can be determined according to the actual design experience of the designer. The machine room air conditioner can achieve the demand for high load and low load by controlling and adjusting the rotational speed of the first compressor 12, the first condensing fan 15, the second compressor 22, and the second condensing fan 25, and can achieve the demand for high humidity and low humidity by controlling and adjusting the opening degree of the first electronic expansion valve 14 and the second electronic expansion valve 24 at the same time.

[0092] The first evaporator 11 and the second evaporator 21 can be a stacked coil structure in the ventilation channel 4, that is, the first evaporator 11 and the second evaporator 21 are arranged in parallel in the ventilation channel 4. The first evaporator 11 and the second evaporator 21 can be two separate evaporators or two systems of one evaporator. When the first evaporator 11 and the second evaporator 21 are a stacked coil structure, the temperature and humidity sensor cannot be added between the coil of the first evaporator 11 and the coil of the second evaporator 21 due to the limitation of the structure. Therefore, when the return air dew point temperature of the second refrigeration system is unknown and the second refrigeration system needs to dehumidify, the second refrigeration system cannot directly calculate the evaporation temperature of the second refrigeration system according to the return air dew point temperature of the second refrigeration system, which is a problem to be solved.

[0093] To solve the above-mentioned problem, the embodiment of the present application can further include a first temperature and humidity sensor 16, a second temperature and humidity sensor 26, a first temperature sensor, a second temperature sensor, a first pressure sensor, and a second pressure sensor. The first temperature and humidity sensor 16 is used to detect the return air temperature and return air humidity of the return air at the return air outlet, and the second temperature and humidity sensor 26 is used to detect the supply air temperature and supply air humidity of the supply air at the supply air outlet. The first temperature sensor is used to detect the temperature of the gas sucked by the first compressor 12, and the second temperature sensor is used to detect the temperature of the gas sucked by the second compressor 22. The first pressure sensor is used to detect the suction pressure of the first compressor 12, and the second pressure sensor is used to detect the suction pressure of the second compressor 22. Specifically, the controller can be signal-connected with the first temperature and humidity sensor 16, the second temperature and humidity sensor 26, the first temperature sensor, the second temperature sensor, the first pressure sensor, and the second pressure sensor.

[0094] In the embodiment of the present application, the controller obtains the return air temperature and return air humidity of the return air at the return air outlet and the supply air temperature and supply air humidity of the supply air at the supply air outlet, and the evaporation temperature of the first refrigeration system can be obtained through the return air dew point temperature of the first refrigeration system.

[0095] Specifically, if the dehumidification demand is greater than or equal to the preset dehumidification demand value, the first refrigeration system and the second refrigeration system are both in the dehumidification state, and the machine room air conditioner is in the process of the first dehumidification mode, when the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, i.e. when the first refrigeration system needs to dehumidify, the controller can be specifically used for: first, calculating the return air dew point temperature of the first refrigeration system according to the real-time return air temperature and return air humidity; then, calculating the evaporation temperature of the first refrigeration system according to the real-time suction pressure of the first compressor 12; then, controlling the real-time adjustment of the opening degree of the first electronic expansion valve 14 to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature, and the first target evaporation temperature is the difference between the return air dew point temperature of the first refrigeration system and the first preset temperature difference, so that the first refrigeration system is in the dehumidification state.

[0096] Wherein, the first preset temperature difference is not limited here, and can be set according to the design experience of the designer. By optimizing the setting of the first preset temperature difference, accurate dehumidification of the first refrigeration system can be achieved.

[0097] In order to make the second refrigeration system cooperate with the first refrigeration system to dehumidify, in the case of the first evaporator 11 and the second evaporator 21 in the stacked structure, although the machine room air conditioner in this embodiment cannot detect the return air temperature and return air humidity of the second refrigeration system, resulting in that the return air dew point temperature of the second refrigeration system cannot be directly calculated, but the return air temperature and return air humidity of the first refrigeration system and the supply air temperature and supply air humidity of the second refrigeration system can be detected, and the supply air dew point temperature of the second refrigeration system and the dehumidification amount of the entire system of the machine room air conditioner can be directly calculated. It can be known from the air characteristics that in the case where the second refrigeration system does not dehumidify, the return air dew point temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system, so in the case where the return air dew point temperature of the second refrigeration system cannot be calculated, the opening degree of the second electronic expansion valve 24 can also be controlled and adjusted according to the supply air dew point temperature of the second refrigeration system and the dehumidification amount of the entire system of the machine room air conditioner, so that the evaporation temperature of the second refrigeration system can be kept lower than the return air dew point temperature of the second refrigeration system.

[0098] Specifically, in the control of adjusting the opening degree of the second electronic expansion valve 24 to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, the second dehumidification mode is entered, that is, the second refrigeration system is required to cooperate with dehumidification, the controller can be specifically used for: first, calculating the supply air dew point temperature of the second refrigeration system according to the real-time supply air temperature and supply air humidity, and calculating the evaporation temperature of the second refrigeration system according to the real-time suction pressure of the second compressor 22; then, controlling the adjustment of the opening degree of the second electronic expansion valve 24 until the evaporation temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system; then, calculating the dehumidification amount in each preset period in real time according to the real-time return air humidity and supply air humidity; obtaining the dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period; and controlling the adjustment of the opening degree of the second electronic expansion valve 24 according to the dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, and the second dehumidification mode is entered.

[0099] Specifically, in the control of adjusting the opening degree of the second electronic expansion valve 24 to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, the second dehumidification mode is entered, that is, the second refrigeration system is required to cooperate with dehumidification, the controller can be specifically used for: first, calculating the supply air dew point temperature of the second refrigeration system according to the real-time supply air temperature and supply air humidity, and calculating the evaporation temperature of the second refrigeration system according to the real-time suction pressure of the second compressor 22; then, controlling the adjustment of the opening degree of the second electronic expansion valve 24 until the evaporation temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system; then, calculating the dehumidification amount in each preset period in real time according to the real-time return air humidity and supply air humidity; obtaining the dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period; and controlling the adjustment of the opening degree of the second electronic expansion valve 24 according to the dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, and the second dehumidification mode is entered.

[0100] Obtaining the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, and judging whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, if the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period, controlling the adjustment of the opening degree of the second electronic expansion valve 24 so that the evaporation temperature of the next preset period of the second refrigeration system is equal to the evaporation temperature of the current preset period of the second refrigeration system minus the second preset temperature difference.

[0101] Calculating the superheat degree of the second refrigeration system according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature.

[0102] If the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, controlling the adjustment of the opening degree of the second electronic expansion valve 24 to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature.

[0103] Again, the dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is continuously determined whether the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period.

[0104] Specifically, the opening degree of the second electronic expansion valve 24 is adjusted according to the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, the dehumidification time, and the dehumidification demand control, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand of the machine room is reacquired to be greater than 0% and less than the preset dehumidification demand value, and the second dehumidification mode is entered, and the controller can be specifically used for:

[0105] The dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is continuously determined whether the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period. If the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, and the opening degree of the second electronic expansion valve 24 is adjusted in real time to keep the evaporation temperature of the next preset period of the second refrigeration system unchanged at the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state.

[0106] The dehumidification time length when the second refrigeration system enters the dehumidification state is obtained, and it is determined whether the dehumidification time length when the second refrigeration system enters the dehumidification state is greater than the first preset time length. If the dehumidification time length when the second refrigeration system enters the dehumidification state is not greater than the first preset time length, the dehumidification demand of the machine room is reacquired.

[0107] If the reacquired dehumidification demand of the machine room is greater than 0% and less than the preset dehumidification demand value, the air conditioning system enters the second dehumidification mode, the opening degree of the first electronic expansion valve 14 is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is adjusted to keep the second refrigeration system from dehumidifying.

[0108] The above one preset period can be one unit time, for example, 1 min or 1 s; the second preset temperature difference can be a value set by the designer according to design experience, for example, the second preset temperature difference is 1℃.

[0109] The specific value of the above preset step is not limited here and can be selected according to the design experience of the designer, for example, the preset step can be 1 step / s.

[0110] In the above embodiment, the process of adjusting the second refrigeration system to enter the dehumidification state makes the second refrigeration system cooperate with the first refrigeration system to dehumidify, and the specific operation process can be as shown in Figure 2 When the machine room air conditioner is running, the return air dew point temperature D h2In the case that the second refrigeration system evaporating temperature T e2 equals the second refrigeration system supply air dew point temperature D S2 , the first refrigeration system return air humidity (return air humidity) M h1 and the second refrigeration system supply air humidity (supply air humidity) M s1 are detected and recorded at t1 moment, the machine room air conditioning system runs to t2 moment, the first refrigeration system return air humidity M h2 and the second refrigeration system supply air humidity M s2 are detected and recorded at t2 moment. Wherein, the dehumidification amount of the machine room air conditioning unit time △M = the first refrigeration system return air humidity M h - the second refrigeration system supply air humidity M s , then the dehumidification amount of the machine room air conditioning t1 moment △M t1 = M h1 - M s1 , the dehumidification amount of the machine room air conditioning t2 moment △M t2 = M h2 - M s2 . Comparing the dehumidification amount △M t1 and △M t1 of the previous moment t1 moment and the current moment t2 moment, since the evaporating temperature of the first refrigeration system is determined, the dehumidification amount of the first refrigeration system can be assumed to be constant, if △M t1 > △M t2 , it indicates that the dehumidification amount of the machine room air conditioning has not increased, only the first refrigeration system dehumidification exists, and the second refrigeration system does not cooperate with dehumidification, at this time the evaporating temperature of the second refrigeration system is higher than the return air dew point temperature of the second refrigeration system, then the opening of the second expansion valve is adjusted to make the evaporating temperature T e2 of the second refrigeration system at the next unit time equal to the supply air dew point temperature D S2 of the second refrigeration system at t1 moment minus 1℃. Then continue to repeat the above process until tn moment exists △M t（n-1） < △M tn at t(n-1)moment, which indicates that the dehumidification amount of the machine room air conditioning increases, and the second refrigeration system cooperates with the first refrigeration system to dehumidify, at this time the evaporating temperature of the second refrigeration system is lower than the return air dew point temperature, then the second target evaporating temperature of the second refrigeration system is T e2 = D S2 -(n-2)℃ at tn moment, the opening of the second expansion valve is adjusted to make the evaporating temperature of the second refrigeration system at the next moment equal to the second target evaporating temperature, the second refrigeration system is in dehumidification state, and cooperates with the first refrigeration system to dehumidify the machine room.

[0111] That is, the first refrigeration system can realize precise dehumidification by adjusting the difference between the evaporation temperature and the return air dew point temperature, and the second refrigeration system can realize dehumidification by adjusting the supply air dew point temperature, so that the air conditioner can adapt to various humidity occasions.

[0112] In the process of adjusting the second refrigeration system into the dehumidification state, the second refrigeration system may have an evaporation temperature less than or equal to a preset minimum evaporation temperature or a superheat degree of the refrigeration system less than a preset minimum superheat degree, at which time the action of closing the electronic expansion valve needs to be limited and the opening degree of the electronic expansion valve needs to be increased to eliminate the above-mentioned adverse conditions, so that the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature, the safe operation of the second refrigeration system is maintained, and then the adjustment of the state of the second refrigeration system is continued. The above-mentioned preset minimum evaporation temperature is an anti-freezing temperature to prevent the evaporator from freezing, and the value of the preset minimum evaporation temperature is not limited here and can be set according to the design experience of the designer. For example, the preset minimum evaporation temperature (anti-freezing temperature) can be 1℃. The above-mentioned superheat degree of the refrigeration system is the suction superheat degree of the compressor in the refrigeration system, and the preset minimum superheat degree is the minimum limit value of the suction superheat degree of the compressor. During the operation of the computer room air conditioner, the compressor lift frequency takes into account the refrigeration demand to maintain the stability of the supply air temperature. Considering that the condenser fan speed reduction and the compressor frequency increase process will cause the suction superheat degree of the compressor to decrease, if the superheat degree of the refrigeration system is less than or equal to the preset minimum superheat degree, it may be not conducive to the operation of the refrigeration system. The value of the preset minimum superheat degree is not limited here and can be set according to the design experience of the designer. For example, the preset minimum superheat degree can be 6k.

[0113] In addition, after the second refrigeration system enters the dehumidification state and cooperates with the first refrigeration system to dehumidify, the return air humidity content of the first refrigeration system and the supply air humidity content of the second refrigeration system will both change, which will cause the return air dew point temperature of the second refrigeration system to change. Therefore, after the second refrigeration system enters the dehumidification state, the controller can specifically determine whether the dehumidification time length of the second refrigeration system entering the dehumidification mode is greater than a first preset time length, as shown in FIG. 6. Figure 2 If the dehumidification time length of the second refrigeration system entering the dehumidification mode is not greater than the first preset time length, the dehumidification demand of the computer room is reacquired. If the reacquired dehumidification demand of the computer room is greater than 0% and less than a preset dehumidification demand value, the computer room air conditioner enters the second dehumidification mode, so that the first refrigeration system continues to dehumidify and the second refrigeration system does not dehumidify. This way can detect the humidity content of the air in the computer room in real time, and through the change of the dehumidification demand of the computer room air conditioner, the operating states of the first refrigeration system and the second refrigeration system are switched, the operating mode of the computer room air conditioner changes with the change of the dehumidification demand, and the adaptability of the computer room air conditioner under different computer room environments can be improved.

[0114] Specifically, the dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, it is judged whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, if the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, the opening of the second electronic expansion valve 24 is adjusted in real time to keep the evaporation temperature of the next preset period of the second refrigeration system equal to the second target evaporation temperature unchanged, so that the second refrigeration system is in the dehumidification state, and the controller can be specifically used for:

[0115] According to the real-time suction pressure of the second compressor and the second compressor suction gas temperature, the superheat degree of the second refrigeration system is calculated;

[0116] If the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, the opening of the second electronic expansion valve 24 is adjusted to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature;

[0117] The opening of the second electronic expansion valve 24 is adjusted in real time again to keep the evaporation temperature of the second refrigeration system equal to the second target evaporation temperature.

[0118] That is, after the second refrigeration system enters the dehumidification state, the second refrigeration system may also exist the case that the evaporation temperature is less than or equal to the preset minimum evaporation temperature or the superheat degree of the refrigeration system is less than the preset minimum superheat degree, at this time, the action of closing the electronic expansion valve is limited, and the opening of the electronic expansion valve is increased to eliminate the above-mentioned adverse state, so that the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature, and then the second refrigeration system is eliminated from the low suction superheat degree of the second compressor 22 or the anti-freezing state of the second evaporator 21, and the safe operation of the second refrigeration system is kept; then, after the speed of the second condensing fan 25 is reduced or the frequency of the second compressor 22 is increased, the opening of the second electronic expansion valve 24 can be adjusted in real time again to keep the evaporation temperature of the second refrigeration system equal to the second target evaporation temperature, that is, the evaporation temperature T e2 = D S2 -(n-2)℃, continue dehumidification.

[0119] Specifically, when the first refrigeration system and the second refrigeration system cooperate to dehumidify, if the superheat degree of the first refrigeration system is less than or equal to the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is less than or equal to the preset minimum evaporation temperature during the dehumidification state of the first refrigeration system, the opening degree of the first electronic expansion valve 14 is controlled to stop decreasing and gradually increase by a preset step size until the superheat degree of the first refrigeration system is greater than the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is greater than the preset minimum evaporation temperature, and the abnormal operating condition is removed; the opening degree of the first electronic expansion valve 14 is controlled again to adjust in real time so that the evaporation temperature of the first refrigeration system continues to be equal to the first target evaporation temperature, and the dehumidification continues.

[0120] In the above embodiment, specifically, when the second refrigeration system cooperates with the first refrigeration system to dehumidify, the controller can be further configured to: determine whether the dehumidification duration of the second refrigeration system in the dehumidification state is greater than a first preset duration, and if the dehumidification duration of the second refrigeration system in the dehumidification state is greater than the first preset duration, the air conditioning system reenters the first dehumidification mode, the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is controlled to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, and the second dehumidification mode is entered.

[0121] In the above embodiment, when the first refrigeration demand and the second refrigeration demand cooperate to dehumidify, if the dehumidification duration of the second refrigeration system in the dehumidification state is greater than the first preset duration, the air conditioning system reenters the first dehumidification mode, a new second target evaporation temperature is determined again, the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is controlled to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, so that the second refrigeration system can dehumidify better; and if the dehumidification demand is less than the preset dehumidification demand and greater than 0%, that is, the air humidity in the machine room is reduced to a low humidity state under the action of the first refrigeration system and the second refrigeration system dehumidifying together for a period of time, the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve 24 is controlled to keep the second refrigeration system from dehumidifying, so that the first refrigeration system continues to dehumidify and the second refrigeration system stops dehumidifying, thereby enabling the air conditioning system in the machine room to operate in the second dehumidification mode to dehumidify the machine room with low humidity.

[0122] The first preset duration can be determined according to the design experience of designers, for example, the first preset duration can be 15 minutes, which is not limited herein.

[0123] In the above embodiment, after the machine room air conditioner enters the second dehumidification mode, the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system until the dehumidification demand is less than or equal to 0%, and the machine room air conditioner enters the third dehumidification mode, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state. The controller can be specifically used for:

[0124] controlling the opening degree of the first electronic expansion valve 14 to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system;

[0125] judging whether the dehumidification duration of the first refrigeration system in the dehumidification state is greater than a second preset duration, and if the dehumidification duration of the first refrigeration system in the dehumidification state is less than or equal to the second preset duration, reacquiring the dehumidification demand of the machine room;

[0126] if the dehumidification demand is less than or equal to 0%, the machine room air conditioner enters the third dehumidification mode, and the first refrigeration system and the second refrigeration system do not dehumidify, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0127] Specifically, after the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller can also be used for:

[0128] if the dehumidification demand is greater than 0%, the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

[0129] After the machine room air conditioner enters the second dehumidification mode, the opening degree of the first electronic expansion valve 14 is first controlled to make the first refrigeration system dehumidify; then the duration of the first refrigeration system in the dehumidification state is judged, and if the dehumidification duration of the first refrigeration system in the dehumidification state is less than or equal to the second preset duration, the dehumidification demand of the machine room is reacquired, and if the dehumidification demand is less than or equal to 0%, the humidity of the air in the machine room reaches the target humidity, and the machine room air conditioner does not need to dehumidify the air in the machine room. If the machine room has a refrigeration demand at this time, the machine room air conditioner only needs to meet the refrigeration demand of the machine room, and then the machine room air conditioner enters the third dehumidification mode, so that the first refrigeration system and the second refrigeration system do not dehumidify, and if the dehumidification demand is greater than 0%, the humidity of the air in the machine room has not reached the target humidity at this time, and then the machine room air conditioner continues to be in the second dehumidification mode, the first refrigeration system dehumidifies and the second refrigeration system does not dehumidify. The dehumidification demand of the machine room can be changed to switch the running state of the first refrigeration system, change the operation mode of the machine room air conditioner, and improve the adaptability of the machine room air conditioner in different machine room environments.

[0130] In the above embodiment, after the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller can also be used to:

[0131] According to the real-time suction pressure of the first compressor and the first compressor suction gas temperature, the superheat degree of the first refrigeration system is calculated;

[0132] If the superheat degree of the first refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is less than or equal to the preset minimum evaporation temperature, the control of adjusting the opening degree of the first electronic expansion valve 14 is stopped to decrease and gradually increases by a preset step size until the superheat degree of the first refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is greater than the preset minimum evaporation temperature;

[0133] The opening degree of the first electronic expansion valve 14 is again controlled to be adjusted in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

[0134] In the above embodiment, during the dehumidification process of the machine room air conditioner, the superheat degree of the first refrigeration system may be less than the preset minimum superheat degree or the evaporation temperature of the first refrigeration system may be less than or equal to the preset minimum evaporation temperature. Therefore, when the first refrigeration system is in the above two adverse states, the control of adjusting the opening degree of the first electronic expansion valve 14 is stopped to decrease and gradually increases by a preset step size until the adverse state of the first refrigeration system is eliminated. Then, after the first evaporator 11 is out of the anti-freezing state or the first condensing fan 15 is reduced in speed or the first compressor 12 is increased in frequency, the opening degree of the first electronic expansion valve 14 is again controlled to be adjusted in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature, so that the first refrigeration system continues to dehumidify.

[0135] In the above embodiment, during the dehumidification process of the machine room air conditioner, the return air humidity of the first refrigeration system changes, which also causes the return air dew point temperature of the first refrigeration system to change. In order to better dehumidify the first refrigeration system, after the opening degree of the first electronic expansion valve 14 is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller can also be used to:

[0136] Judge whether the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than a second preset duration;

[0137] If the dehumidification time of the first refrigeration system in dehumidification mode is longer than the second preset time, the air conditioning system re-enters the second dehumidification mode, controls and adjusts the opening of the first electronic expansion valve 14 to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, controls and adjusts the opening of the second electronic expansion valve 24 to prevent the second refrigeration system from dehumidifying, until the dehumidification demand is less than or equal to 0% again, and enters the third dehumidification mode.

[0138] Because the humidity content of the return air of the first refrigeration system changes during the second dehumidification mode of the computer room air conditioner, this will also cause the return air dew point temperature of the first refrigeration system to change. In order to better dehumidify the first refrigeration system, if the dehumidification time of the first refrigeration system in the dehumidification state is longer than the second preset time, a new first target evaporation temperature can be determined so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system until the dehumidification demand is less than or equal to 0% again, and then the third dehumidification mode is entered. This can improve the adaptability of the computer room air conditioner in different computer room environments.

[0139] The second preset duration can be determined based on the designer's design experience. For example, the second preset duration can be 15 minutes, and there is no limit here.

[0140] Specifically, after the computer room air conditioner enters the second dehumidification mode, when controlling the opening of the second electronic expansion valve to prevent the second refrigeration system from dehumidifying, the controller can be used to:

[0141] The superheat of the second refrigeration system is calculated based on the real-time suction pressure of the second compressor 22 and the suction gas temperature of the second compressor 22.

[0142] The opening of the second electronic expansion valve 24 is controlled in real time to keep the superheat of the second refrigeration system equal to the first preset superheat.

[0143] When the dehumidification demand in the computer room is less than the preset dehumidification demand but greater than 0%, the first refrigeration system can be controlled to dehumidify, while the superheat of the second refrigeration system remains equal to the first preset superheat, so that the second refrigeration system is in a cooling state. The specific value of the first preset superheat is not limited here and can be selected according to the actual situation. For example, the first preset superheat can be 6K.

[0144] like Figure 3 The diagram shown is a control flowchart of the dehumidification process of a computer room air conditioner according to the above-described embodiment of the invention. The control flow of the dehumidification process of the computer room air conditioner can be as follows:

[0145] S301: Obtain the dehumidification requirements of the computer room (CFD);

[0146] S302: judge whether the dehumidification demand CFD is less than 50%, if not, execute S303, if yes, execute S309;

[0147] S303: control the opening degree of the first electronic expansion valve to make the evaporation temperature Te1 of the first refrigeration system = the dew point temperature Dh1 of the return air of the first refrigeration system - the first preset temperature difference AT1, that is, the first refrigeration system is in the dehumidification state, and control the opening degree of the second electronic expansion valve to make the evaporation temperature Te2 of the second refrigeration system = the dew point temperature DS2 of the supply air of the second refrigeration system;

[0148] S304: calculate the dehumidification amount at each unit time in real time, judge whether the dehumidification amount t(n-1) at the last unit time is greater than the dehumidification amount tn at the current unit time, if yes, execute S305, if not, execute S306;

[0149] S305: control the opening degree of the second electronic expansion valve to make the evaporation temperature Te2 of the second refrigeration system = DS2-(n-1); wherein, if the superheat degree of the second refrigeration system is less than 6K or the evaporation temperature is less than or equal to 1℃, control the opening degree of the second electronic expansion valve to stop decreasing and increase the opening degree by 1 step / s, until the above-mentioned adverse state is eliminated, and then continue to judge whether the dehumidification amount tn at the last unit time is greater than the dehumidification amount t(n+1) at the current unit time;

[0150] S306: control the opening degree of the second electronic expansion valve to make the evaporation temperature Te2 of the second refrigeration system = DS2-(n-2), so that the second refrigeration system enters the dehumidification state, and the machine room air conditioner enters the first dehumidification mode; wherein, if the superheat degree of the second refrigeration system is less than 6K or the evaporation temperature is less than or equal to 1℃, control the opening degree of the second electronic expansion valve to stop decreasing and increase the opening degree by 1 step / s, until the above-mentioned adverse state is eliminated, and then continue to control the opening degree of the second expansion valve to make the evaporation temperature of the second refrigeration system continue to keep Te2=DS2-(n-2) to continue dehumidification;

[0151] S307: judge whether the dehumidification time length of the second refrigeration system entering the dehumidification state exceeds the preset time length tlimit, if not, execute S308, if yes, execute S303;

[0152] S308: judge whether the dehumidification demand of the machine room is less than 50%, if yes, execute S309, if not, continue to execute S306;

[0153] S309: controlling to adjust the opening degree of the first electronic expansion valve to make the evaporation temperature Te1 of the first refrigeration system equal to the return air dew point temperature Dh1 of the first refrigeration system minus the first preset temperature difference AT1, that is, the first refrigeration system is in a dehumidification state, and controlling to adjust the opening degree of the second expansion valve to make the superheat degree of the second refrigeration system equal to 6K, that is, the second refrigeration system does not dehumidify, and the machine room air conditioner enters a second dehumidification mode; wherein, if the superheat degree of the first refrigeration system is less than 6K or the evaporation temperature is less than or equal to 1℃, controlling to adjust the opening degree of the first electronic expansion valve to stop decreasing and increase the opening degree by 1 step / s until the above-mentioned adverse state is eliminated, and then continue to control to adjust the opening degree of the first expansion valve to make the evaporation temperature of the first refrigeration system continue to keep Te1=Dh1-AT1, and continue to dehumidify;

[0154] S310: judging whether the dehumidification time length of the first refrigeration system entering the dehumidification state exceeds a preset time length tlimit, if not, executing S3011, and if yes, executing S309;

[0155] S3011: controlling to adjust the opening degree of the first expansion valve to make the evaporation temperature of the first refrigeration system continue to keep Te1=Dh1-AT1, and continue to dehumidify;

[0156] S3012: judging whether the dehumidification demand of the machine room is less than or equal to 0%, if yes, executing S3013, and if not, continuing to execute S309;

[0157] S3013: the first refrigeration system and the second refrigeration system of the machine room air conditioner both exit the dehumidification state, and the machine room air conditioner enters a third dehumidification mode, and the first refrigeration system and the second refrigeration system continue to keep the refrigeration state.

[0158] The control flow of the above-mentioned machine room air conditioner dehumidification process can control the first refrigeration system and the second refrigeration system to switch different dehumidification modes according to the change of the air humidity in the machine room, can better meet the dehumidification demand of the machine room, and improve the adaptability of the machine room air conditioner.

[0159] Based on the same inventive concept, the embodiments of the present application also provide a running control method of a machine room air conditioner, which is applied to any one of the machine room air conditioners provided in the above-mentioned technical solutions, as shown in the figure, and the running control method comprises: Figure 4 as shown in the figure, the running control method comprises:

[0160] S401: acquiring the dehumidification demand of the machine room;

[0161] S402: If the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, until the re-acquired dehumidification demand is less than or equal to 0%, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0162] The operation control method of the machine room air conditioner provided by the above-mentioned embodiments can realize the cooperation of the first refrigeration system and the second refrigeration system for refrigeration by controlling and adjusting the rotation speeds of the first compressor, the first condenser fan, the second compressor and the second condenser fan when the machine room air conditioner has a refrigeration demand, so that the machine room air conditioner can adapt to different refrigeration demands. Meanwhile, the machine room can adapt to different dehumidification demands by controlling the opening degrees of the first electronic expansion valve and the second electronic expansion valve when the machine room air conditioner has a dehumidification demand. Specifically, if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, until the re-acquired dehumidification demand is less than or equal to 0%, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state. That is, when the machine room has a low humidity, the opening degree of the first electronic expansion valve can be controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve can be controlled and adjusted so that the second refrigeration system does not dehumidify, at this time the machine room air conditioner enters the second dehumidification mode. During the dehumidification process, if the acquired dehumidification demand is less than or equal to 0%, the first refrigeration system can stop dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state, at this time the machine room air conditioner enters the third dehumidification mode. The operation control method of the machine room air conditioner can make the machine room air conditioner be in different operation modes by controlling the operation states of the first refrigeration system and the second refrigeration system, can adapt to occasions with different humidity demands and different refrigeration demands, and can improve the applicability of the air conditioner.

[0163] Optionally, the operation control method further comprises:

[0164] If the dehumidification demand is greater than or equal to the preset dehumidification demand value, a first dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled and adjusted so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, a second dehumidification mode is entered.

[0165] Optionally, the preset dehumidification demand value is 50%.

[0166] Optionally, the control and adjustment of the opening degree of the first electronic expansion valve so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system comprises:

[0167] According to the real-time return air temperature and return air humidity, the return air dew point temperature of the first refrigeration system is calculated;

[0168] According to the real-time suction pressure of the first compressor, the evaporation temperature of the first refrigeration system is calculated;

[0169] The opening degree of the first electronic expansion valve is controlled and adjusted in real time so that the evaporation temperature of the first refrigeration system is kept equal to the first target evaporation temperature, which is the difference between the return air dew point temperature of the first refrigeration system and the first preset temperature difference, so that the first refrigeration system is in a dehumidification state.

[0170] Optionally, the control and adjustment of the opening degree of the second electronic expansion valve so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, a second dehumidification mode is entered, comprising:

[0171] According to the real-time supply air temperature and supply air humidity, the supply air dew point temperature of the second refrigeration system is calculated;

[0172] According to the real-time suction pressure of the second compressor, the evaporation temperature of the second refrigeration system is calculated;

[0173] The opening degree of the second electronic expansion valve is controlled and adjusted until the evaporation temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system;

[0174] According to the real-time return air humidity and supply air humidity, the dehumidification amount in each preset period is calculated in real time;

[0175] The dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period are obtained;

[0176] The opening degree of the second electronic expansion valve is adjusted according to the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand control, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand of the machine room is greater than 0% and less than the preset dehumidification demand value again, and the second dehumidification mode is entered.

[0177] Optionally, the second dehumidification mode includes:

[0178] The dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is determined whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period. If the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, and the opening degree of the second electronic expansion valve is adjusted in real time to keep the evaporation temperature of the next preset period of the second refrigeration system equal to the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state.

[0179] The dehumidification time length when the second refrigeration system enters the dehumidification state is obtained, and it is determined whether the dehumidification time length when the second refrigeration system enters the dehumidification state is greater than the first preset time length. If the dehumidification time length when the second refrigeration system enters the dehumidification state is not greater than the first preset time length, the dehumidification demand of the machine room is obtained again.

[0180] If the dehumidification demand of the machine room obtained again is greater than 0% and less than the preset dehumidification demand value, the air conditioning system enters the second dehumidification mode, the opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is adjusted to make the second refrigeration system not dehumidify.

[0181] Optionally, it further includes:

[0182] The dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is determined whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period. If the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period, the opening degree of the second electronic expansion valve is adjusted to make the evaporation temperature of the next preset period of the second refrigeration system equal to the evaporation temperature of the current preset period of the second refrigeration system minus the second preset temperature difference.

[0183] calculating a superheat degree of the second refrigeration system according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature;

[0184] if the superheat degree of the second refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to a preset minimum evaporation temperature, controlling the opening degree of the second electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature;

[0185] again acquiring the dehumidification amount of the current preset period and the dehumidification amount of the previous preset period, and continuing to determine whether the dehumidification amount of the previous preset period is greater than the dehumidification amount of the current preset period.

[0186] Optionally, the dehumidification amount of the current preset period and the dehumidification amount of the previous preset period are acquired, and it is determined whether the dehumidification amount of the previous preset period is less than or equal to the dehumidification amount of the current preset period. If the dehumidification amount of the previous preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as a second target evaporation temperature, and the opening degree of the second electronic expansion valve is controlled in real time to keep the evaporation temperature of the next preset period of the second refrigeration system equal to the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state, comprising:

[0187] calculating a superheat degree of the second refrigeration system according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature;

[0188] if the superheat degree of the second refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to a preset minimum evaporation temperature, controlling the opening degree of the second electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature;

[0189] again controlling the opening degree of the second electronic expansion valve in real time to keep the evaporation temperature of the second refrigeration system equal to the second target evaporation temperature.

[0190] Optionally, further comprising:

[0191] determining whether the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than a first preset duration, if the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than the first preset duration, the air conditioning system reenters the first dehumidification mode, the opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is adjusted to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, entering the second dehumidification mode.

[0192] Optionally, if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, entering the second dehumidification mode, the opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is adjusted to keep the second refrigeration system from dehumidifying, until the dehumidification demand is less than or equal to 0% again, entering the third dehumidification mode, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state;

[0193] The control of the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system until the dehumidification demand is less than or equal to 0%, entering the third dehumidification mode, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state, comprises:

[0194] The opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system;

[0195] Determining whether the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than a second preset duration; if the dehumidification duration of the first refrigeration system entering the dehumidification state is less than or equal to the second preset duration, the dehumidification demand of the machine room is reacquired;

[0196] If the dehumidification demand is less than or equal to 0%, entering the third dehumidification mode, the first refrigeration system and the second refrigeration system are both dehumidified, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0197] Optionally, after the control of the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, comprising:

[0198] According to the real-time suction pressure of the first compressor and the first compressor suction gas temperature, the superheat degree of the first refrigeration system is calculated;

[0199] if the superheat degree of the first refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the first refrigeration system is less than or equal to a preset minimum evaporation temperature, controlling the opening degree of the first electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the first refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is greater than the preset minimum evaporation temperature;

[0200] controlling the opening degree of the first electronic expansion valve to adjust in real time again so that the evaporation temperature of the first refrigeration system continues to be kept equal to the first target evaporation temperature.

[0201] Optionally, after the controlling the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system below the dew point temperature of the return air of the first refrigeration system, comprising:

[0202] judging whether the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than a second preset duration;

[0203] if the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than the second preset duration, the air conditioning system reenters the second dehumidification mode, and the opening degree of the first electronic expansion valve is controlled to keep the evaporation temperature of the first refrigeration system below the dew point temperature of the return air of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled to keep the second refrigeration system from dehumidifying, until the dehumidification demand is less than or equal to 0% again, entering the third dehumidification mode.

[0204] Optionally, after the controlling the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system below the dew point temperature of the return air of the first refrigeration system, comprising:

[0205] if the dehumidification demand is greater than 0%, the opening degree of the first electronic expansion valve is controlled to adjust in real time so that the evaporation temperature of the first refrigeration system continues to be kept equal to the first target evaporation temperature.

[0206] Based on the same inventive concept, the embodiments of the present application also provide a running control device of a computer room air conditioner, as shown in Figure 5 comprising:

[0207] an acquisition unit 100, configured to acquire a dehumidification demand of a computer room;

[0208] a control unit 200, configured to:

[0209] If the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, until the re-acquired dehumidification demand is less than or equal to 0%, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0210] The operation control device of the machine room air conditioner provided by the embodiment of the application can realize the cooperation of the first refrigeration system and the second refrigeration system for refrigeration by controlling and adjusting the rotation speeds of the first compressor, the first condenser fan, the second compressor and the second condenser fan when the machine room air conditioner has a refrigeration demand, so that the machine room air conditioner can adapt to different refrigeration demands. Meanwhile, the machine room air conditioner can adapt to different dehumidification demands by controlling the opening degrees of the first electronic expansion valve and the second electronic expansion valve when the machine room air conditioner has a dehumidification demand. Specifically, if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, until the re-acquired dehumidification demand is less than or equal to 0%, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state. That is, when the machine room has a low humidity, the opening degree of the first electronic expansion valve can be controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve can be controlled and adjusted so that the second refrigeration system does not dehumidify, at this time, the machine room air conditioner enters the second dehumidification mode. During the dehumidification process, if the acquired dehumidification demand is less than or equal to 0%, the first refrigeration system can stop dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state, at this time, the machine room air conditioner enters the third dehumidification mode. The operation control device of the machine room air conditioner can make the machine room air conditioner be in different operation modes by controlling the operation states of the first refrigeration system and the second refrigeration system, can adapt to occasions with different humidity demands and different refrigeration demands, and can improve the applicability of the air conditioner.

[0211] Optionally, the control unit 200 is further configured to:

[0212] If the dehumidification demand is greater than or equal to the preset dehumidification demand value, a first dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, a second dehumidification mode is entered.

[0213] Optionally, the preset dehumidification demand value is 50%.

[0214] Optionally, the control unit 200 is further configured to:

[0215] calculate the return air dew point temperature of the first refrigeration system according to the real-time return air temperature and the real-time return air humidity;

[0216] calculate the evaporation temperature of the first refrigeration system according to the real-time suction pressure of the first compressor;

[0217] control the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature, and the first target evaporation temperature is the difference between the return air dew point temperature of the first refrigeration system and the first preset temperature difference, so that the first refrigeration system is in a dehumidification state.

[0218] Optionally, the control unit 200 is further configured to:

[0219] calculate the supply air dew point temperature of the second refrigeration system according to the real-time supply air temperature and the real-time supply air humidity;

[0220] calculate the evaporation temperature of the second refrigeration system according to the real-time suction pressure of the second compressor;

[0221] control the opening degree of the second electronic expansion valve until the evaporation temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system;

[0222] calculate the dehumidification amount in each preset period in real time according to the real-time return air humidity and the real-time supply air humidity;

[0223] obtain the dehumidification amount of the current preset period, the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand;

[0224] controlling the opening degree of the second electronic expansion valve according to the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand of the machine room is greater than 0% and less than the preset dehumidification demand value again, entering the second dehumidification mode.

[0225] Optionally, the second electronic expansion valve is controlled according to the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand of the machine room is greater than 0% and less than the preset dehumidification demand value again, entering the second dehumidification mode, and the control unit 200 is further configured to:

[0226] obtaining the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, and determining whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, if the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, taking the evaporation temperature of the current preset period as the second target evaporation temperature, and controlling the opening degree of the second electronic expansion valve to be adjusted in real time, so that the evaporation temperature of the next preset period of the second refrigeration system is kept unchanged at the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state;

[0227] obtaining the dehumidification duration of the second refrigeration system entering the dehumidification state, and determining whether the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than the first preset duration, if the dehumidification duration of the second refrigeration system entering the dehumidification state is not greater than the first preset duration, re-obtaining the dehumidification demand of the machine room;

[0228] if the re-obtained dehumidification demand of the machine room is greater than 0% and less than the preset dehumidification demand value, the air conditioning system enters the second dehumidification mode, the opening degree of the first electronic expansion valve is controlled to be adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled to be adjusted so that the second refrigeration system is not dehumidified.

[0229] Optionally, the control unit 200 is further configured to:

[0230] obtaining the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, and determining whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, if the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period, controlling the opening degree of the second electronic expansion valve to be adjusted, so that the evaporation temperature of the next preset period of the second refrigeration system is equal to the evaporation temperature of the current preset period of the second refrigeration system minus the second preset temperature difference;

[0231] calculate the superheat degree of the second refrigeration system according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature;

[0232] If the superheat degree of the second refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to a preset minimum evaporation temperature, control the adjustment of the opening degree of the second electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature;

[0233] Again, obtain the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, and continue to determine whether the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period.

[0234] Optionally, the dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is determined whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period. If the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, and the opening degree of the second electronic expansion valve is adjusted in real time to keep the evaporation temperature of the next preset period of the second refrigeration system equal to the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state. The control unit 200 is further configured to:

[0235] calculate the superheat degree of the second refrigeration system according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature;

[0236] If the superheat degree of the second refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to a preset minimum evaporation temperature, control the adjustment of the opening degree of the second electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature;

[0237] Again, control the opening degree of the second electronic expansion valve in real time to keep the evaporation temperature of the second refrigeration system equal to the second target evaporation temperature.

[0238] Optionally, the control unit 200 is further configured to:

[0239] determining whether the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than a first preset duration, if the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than the first preset duration, the air conditioning system reenters the first dehumidification mode, the opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is adjusted to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, the second dehumidification mode is entered.

[0240] Optionally, if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, the second dehumidification mode is entered, the opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is adjusted to keep the second refrigeration system from dehumidifying, until the dehumidification demand is less than or equal to 0% again, the third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state;

[0241] The control unit 200 is further configured to:

[0242] adjust the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system;

[0243] determining whether the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than a second preset duration; if the dehumidification duration of the first refrigeration system entering the dehumidification state is less than or equal to the second preset duration, the dehumidification demand of the machine room is reacquired;

[0244] if the dehumidification demand is less than or equal to 0%, the third dehumidification mode is entered, the first refrigeration system and the second refrigeration system are controlled to not dehumidify, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

[0245] Optionally, after the opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the control unit 200 is further configured to:

[0246] calculate a superheat degree of the first refrigeration system according to the real-time suction pressure of the first compressor and the first compressor suction gas temperature;

[0247] if the superheat degree of the first refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the first refrigeration system is less than or equal to a preset minimum evaporation temperature, control the opening degree of the first electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the first refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is greater than the preset minimum evaporation temperature;

[0248] control the opening degree of the first electronic expansion valve in real time again to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

[0249] Optionally, after the control unit 200 controls the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the control unit 200 is further configured to:

[0250] determine whether a dehumidification duration of the first refrigeration system in the dehumidification state is greater than a second preset duration;

[0251] if the dehumidification duration of the first refrigeration system in the dehumidification state is greater than the second preset duration, the air conditioning system reenters the second dehumidification mode, the opening degree of the first electronic expansion valve is controlled to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled to keep the second refrigeration system from dehumidifying, until the dehumidification demand is less than or equal to 0% again, and the third dehumidification mode is entered.

[0252] Optionally, after the control unit 200 controls the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the control unit 200 is further configured to:

[0253] if the dehumidification demand is greater than 0%, the opening degree of the first electronic expansion valve is controlled in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

[0254] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A machine room air conditioner characterized by, The first refrigeration system, the second refrigeration system, the ventilation channel, the indoor fan and the controller are included. The first refrigeration system includes a first evaporator, a first compressor, a first condenser and a first electronic expansion valve connected in sequence and constituting a loop, and further includes a first condensing fan corresponding to the first condenser. The second refrigeration system includes a second evaporator, a second compressor, a second condenser and a second electronic expansion valve connected in sequence and constituting a loop, and further includes a second condensing fan corresponding to the second condenser. The ventilation channel has return air inlets and supply air outlets at two ends, and the first evaporator and the second evaporator are arranged in sequence in the ventilation channel along a direction from the return air inlets to the supply air outlets. The indoor fan is located in the ventilation channel and is used to send return air in the ventilation channel from the supply air outlets into the machine room. The controller is signal connected with the indoor fan, the first compressor, the second compressor, the first condensing fan, the second condensing fan, the first electronic expansion valve and the second electronic expansion valve, and is used to: obtain the dehumidification demand of the machine room; if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, enter a second dehumidification mode, control and adjust the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, control and adjust the opening degree of the second electronic expansion valve to keep the second refrigeration system from dehumidifying, until the dehumidification demand is obtained again and is less than or equal to 0%, enter a third dehumidification mode, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system keep the original refrigeration state; The controller is specifically further used for: if the dehumidification demand is greater than or equal to the preset dehumidification demand value, enter a first dehumidification mode, control and adjust the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, control and adjust the opening degree of the second electronic expansion valve to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is obtained again and is greater than 0% and less than the preset dehumidification demand value, enter the second dehumidification mode; when the first evaporator and the second evaporator are a stacked coil structure, the controller is further used for: obtain the dehumidification amount of a current preset period and the dehumidification amount of a previous preset period, judge whether the dehumidification amount of the previous preset period is less than or equal to the dehumidification amount of the current preset period, if the dehumidification amount of the previous preset period is less than or equal to the dehumidification amount of the current preset period, take the evaporation temperature of the current preset period as a second target evaporation temperature, control and adjust the opening degree of the second electronic expansion valve in real time, so that the evaporation temperature of the next preset period of the second refrigeration system keeps unchanged at the second target evaporation temperature, so that the second refrigeration system is in a dehumidifying state; obtain the dehumidification time length of the second refrigeration system in the dehumidifying state, judge whether the dehumidification time length of the second refrigeration system in the dehumidifying state is greater than a first preset time length, if the dehumidification time length of the second refrigeration system in the dehumidifying state is not greater than the first preset time length, obtain the dehumidification demand of the machine room again. If the re-acquired dehumidification demand of the machine room is greater than 0% and less than the preset dehumidification demand value, the air conditioning system enters the second dehumidification mode, controls and adjusts the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and controls and adjusts the opening degree of the second electronic expansion valve to keep the second refrigeration system from dehumidifying.

2. The machine room air conditioner according to claim 1, wherein The preset dehumidification demand value is 50%.

3. The machine room air conditioner according to claim 1, wherein The first temperature sensor, the second temperature sensor, the first pressure sensor, and the second pressure sensor are further included. The first temperature sensor is used to detect the return air temperature and the return air humidity of the return air at the return air outlet, and the second temperature sensor is used to detect the supply air temperature and the supply air humidity of the supply air at the supply air outlet. The first temperature sensor is used to detect the temperature of the suction gas of the first compressor, and the second temperature sensor is used to detect the temperature of the suction gas of the second compressor. The first pressure sensor is used to detect the suction pressure of the first compressor, and the second pressure sensor is used to detect the suction pressure of the second compressor. The controller is in signal connection with the first temperature sensor, the second temperature sensor, the first pressure sensor, and the second pressure sensor.

4. The machine room air conditioner according to claim 3, wherein In the control and adjustment of the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller is specifically used for: calculating the return air dew point temperature of the first refrigeration system according to the real-time return air temperature and the real-time return air humidity; calculating the evaporation temperature of the first refrigeration system according to the real-time suction pressure of the first compressor; controlling and adjusting the opening degree of the first electronic expansion valve in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature, and the first target evaporation temperature is the difference between the return air dew point temperature of the first refrigeration system and the first preset temperature difference, so that the first refrigeration system is in a dehumidification state.

5. The machine room air conditioner according to claim 4, wherein In the control and adjustment of the opening degree of the second electronic expansion valve to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value to enter the second dehumidification mode, the controller is specifically used for: calculating the supply air dew point temperature of the second refrigeration system according to the real-time supply air temperature and the real-time supply air humidity; calculating the evaporation temperature of the second refrigeration system according to the real-time suction pressure of the second compressor; controlling and adjusting the opening degree of the second electronic expansion valve until the evaporation temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system; calculating the dehumidification amount in each preset period in real time according to the real-time return air humidity and the real-time supply air humidity; acquiring the dehumidification amount of the current preset period, the dehumidification amount of the last preset period, the dehumidification time, and the dehumidification demand; The opening degree of the second electronic expansion valve is adjusted according to the dehumidification amount of the current preset period, the dehumidification amount of the last preset period, the dehumidification time and the dehumidification demand control, so that the evaporation temperature of the second refrigeration system is kept lower than the return air dew point temperature of the second refrigeration system until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, and the second dehumidification mode is entered.

6. The machine room air conditioner according to claim 5, wherein The controller is also specifically used for: The dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is determined whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period. If the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period, the opening degree of the second electronic expansion valve is controlled and adjusted, so that the evaporation temperature of the next preset period of the second refrigeration system is equal to the evaporation temperature of the current preset period of the second refrigeration system minus the second preset temperature difference. The superheat degree of the second refrigeration system is calculated according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature. If the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, the opening degree of the second electronic expansion valve is controlled and adjusted to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature. The dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained again, and it is continuously determined whether the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period.

7. The machine room air conditioner according to claim 5, wherein The dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is determined whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period. If the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, and the opening degree of the second electronic expansion valve is controlled and adjusted in real time, so that the evaporation temperature of the next preset period of the second refrigeration system remains equal to the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state. After that, the controller is also specifically used for: The superheat degree of the second refrigeration system is calculated according to the real-time suction pressure of the second compressor and the second compressor suction gas temperature. If the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, the opening degree of the second electronic expansion valve is controlled and adjusted to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature. The opening degree of the second electronic expansion valve is controlled and adjusted in real time again, so that the evaporation temperature of the second refrigeration system continues to remain equal to the second target evaporation temperature.

8. The machine room air conditioner according to claim 5, wherein The controller is also specifically used for: determining whether the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than a first preset duration, if the dehumidification duration of the second refrigeration system entering the dehumidification state is greater than the first preset duration, the air conditioning system reenters the first dehumidification mode, controls the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, controls the opening degree of the second electronic expansion valve to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, entering the second dehumidification mode.

9. The machine room air conditioner, as claimed in claim 1, wherein If the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, enter the second dehumidification mode, control the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, control the opening degree of the second electronic expansion valve to keep the second refrigeration system from dehumidification, until the dehumidification demand is less than or equal to 0% again, enter the third dehumidification mode, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state; Wherein in the control of adjusting the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, until the dehumidification demand is less than or equal to 0%, enter the third dehumidification mode, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state, the controller is specifically used for: controlling the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system; determining whether the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than a second preset duration, if the dehumidification duration of the first refrigeration system entering the dehumidification state is less than or equal to the second preset duration, reacquire the dehumidification demand of the machine room; If the dehumidification demand is less than or equal to 0%, enter the third dehumidification mode, control the first refrigeration system and the second refrigeration system to not dehumidify, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

10. The machine room air conditioner according to claim 9, wherein After controlling the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller is further used for: calculating the superheat degree of the first refrigeration system according to the real-time suction pressure of the first compressor and the first compressor suction gas temperature; if the superheat degree of the first refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the first refrigeration system is less than or equal to a preset minimum evaporation temperature, control the opening degree of the first electronic expansion valve to stop decreasing and gradually increase by a preset step size until the superheat degree of the first refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is greater than the preset minimum evaporation temperature; control the opening degree of the first electronic expansion valve in real time again to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

11. The machine room air conditioner according to claim 9, wherein After the control adjusts the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller is further configured to: determine whether the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than a second preset duration, if the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than the second preset duration, the air conditioning system reenters the second dehumidification mode, the control adjusts the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the control adjusts the opening degree of the second electronic expansion valve to keep the second refrigeration system from dehumidification until the dehumidification demand is less than or equal to 0% again, and enters the third dehumidification mode.

12. The machine room air conditioner according to claim 9, wherein After the control adjusts the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, the controller is further configured to: if the dehumidification demand is greater than 0%, the control adjusts the opening degree of the first electronic expansion valve in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature.

13. An operation control method of a machine room air conditioner, characterized by, The application is applied to the machine room air conditioner of any one of claims 1-12, comprising: obtaining the dehumidification demand of the machine room; if the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, entering the second dehumidification mode, the control adjusts the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the control adjusts the opening degree of the second electronic expansion valve to keep the second refrigeration system from dehumidification until the dehumidification demand is less than or equal to 0% again, and enters the third dehumidification mode, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system keep the original refrigeration state.

14. The operation control method according to claim 13, characterized by, Further comprising: if the dehumidification demand is greater than or equal to the preset dehumidification demand value, entering the first dehumidification mode, the control adjusts the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the control adjusts the opening degree of the second electronic expansion valve to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value again, and enters the second dehumidification mode.

15. The operation control method according to claim 14, characterized by, The preset dehumidification demand value is 50%.

16. The operation control method according to claim 14, characterized by The control adjusts the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, comprising: calculating the return air dew point temperature of the first refrigeration system according to the real-time return air temperature and the return air humidity; calculating the evaporation temperature of the first refrigeration system according to the real-time suction pressure of the first compressor; the control adjusts the opening degree of the first electronic expansion valve in real time to keep the evaporation temperature of the first refrigeration system equal to the first target evaporation temperature, and the first target evaporation temperature is the difference between the return air dew point temperature of the first refrigeration system and the first preset temperature difference, so that the first refrigeration system is in the dehumidification state.

17. The operation control method according to claim 16, characterized by, The control adjusts the opening degree of the second electronic expansion valve to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, and enters the second dehumidification mode, comprising: According to the real-time supply air temperature and supply air humidity, the supply air dew point temperature of the second refrigeration system is calculated; According to the real-time suction pressure of the second compressor, the evaporation temperature of the second refrigeration system is calculated; The opening degree of the second electronic expansion valve is controlled and adjusted until the evaporation temperature of the second refrigeration system is equal to the supply air dew point temperature of the second refrigeration system; According to the real-time return air humidity and supply air humidity, the dehumidification amount in each preset period is calculated in real time; The dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period are obtained; According to the dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period, the opening degree of the second electronic expansion valve is controlled and adjusted to keep the evaporation temperature of the second refrigeration system lower than the return air dew point temperature of the second refrigeration system until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, and enters the second dehumidification mode.

18. The operation control method according to claim 17, characterized by, The second target evaporation temperature is obtained according to the dehumidification amount of the current preset period and the dehumidification amount, dehumidification time and dehumidification demand of the last preset period, and the opening degree of the second electronic expansion valve is controlled and adjusted in real time to keep the evaporation temperature of the next preset period of the second refrigeration system equal to the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state. The dehumidification time length of the second refrigeration system entering the dehumidification state is obtained, and it is judged whether the dehumidification time length of the second refrigeration system entering the dehumidification state is greater than the first preset time length. If the dehumidification time length of the second refrigeration system entering the dehumidification state is not greater than the first preset time length, the dehumidification demand of the machine room is reacquired. If the reacquired dehumidification demand of the machine room is greater than 0% and less than the preset dehumidification demand value, the air conditioning system enters the second dehumidification mode, the opening degree of the first electronic expansion valve is adjusted to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is adjusted to keep the second refrigeration system from dehumidifying. Further comprising:

19. The operation control method according to claim 18, characterized by, ​ Obtaining the dehumidification amount of the current preset period and the dehumidification amount of the last preset period, determining whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, if the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period, controlling the opening degree of the second electronic expansion valve to make the evaporation temperature of the next preset period of the second refrigeration system equal to the evaporation temperature of the current preset period of the second refrigeration system minus the second preset temperature difference; According to the real-time suction pressure of the second compressor and the second compressor suction gas temperature, the superheat degree of the second refrigeration system is calculated; If the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, the opening degree of the second electronic expansion valve is controlled to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature; Again, the dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, and it is determined whether the dehumidification amount of the last preset period is greater than the dehumidification amount of the current preset period.

20. The operation control method according to claim 18, characterized by, The dehumidification amount of the current preset period and the dehumidification amount of the last preset period are obtained, it is determined whether the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, and if the dehumidification amount of the last preset period is less than or equal to the dehumidification amount of the current preset period, the evaporation temperature of the current preset period is taken as the second target evaporation temperature, and the opening degree of the second electronic expansion valve is controlled in real time to make the evaporation temperature of the next preset period of the second refrigeration system remain equal to the second target evaporation temperature, so that the second refrigeration system is in a dehumidification state, which includes: According to the real-time suction pressure of the second compressor and the second compressor suction gas temperature, the superheat degree of the second refrigeration system is calculated; If the superheat degree of the second refrigeration system is less than the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is less than or equal to the preset minimum evaporation temperature, the opening degree of the second electronic expansion valve is controlled to stop decreasing and gradually increase by a preset step size until the superheat degree of the second refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the second refrigeration system is greater than the preset minimum evaporation temperature; The opening degree of the second electronic expansion valve is controlled in real time again to make the evaporation temperature of the second refrigeration system continue to remain equal to the second target evaporation temperature.

21. The operation control method according to claim 18, characterized by, It also includes: It is determined whether the dehumidification time length of the second refrigeration system entering the dehumidification state is greater than the first preset time length, if the dehumidification time length of the second refrigeration system entering the dehumidification state is greater than the first preset time length, the air conditioning system reenters the first dehumidification mode, the opening degree of the first electronic expansion valve is controlled to make the evaporation temperature of the first refrigeration system remain lower than the return air dew point temperature of the first refrigeration system, and the opening degree of the second electronic expansion valve is controlled to make the evaporation temperature of the second refrigeration system remain lower than the return air dew point temperature of the second refrigeration system, until the dehumidification demand is greater than 0% and less than the preset dehumidification demand value, entering the second dehumidification mode.

22. The operation control method according to claim 13, characterized by If the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, a second dehumidification mode is entered, the opening degree of the first electronic expansion valve is controlled and adjusted so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, the opening degree of the second electronic expansion valve is controlled and adjusted so that the second refrigeration system does not dehumidify, until the dehumidification demand is less than or equal to 0% again, a third dehumidification mode is entered, the first refrigeration system stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state; The control and adjustment of the opening degree of the first electronic expansion valve so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system until the dehumidification demand is less than or equal to 0%, the first refrigeration system enters a third dehumidification mode and stops dehumidifying, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state, characterized in that it comprises: controlling and adjusting the opening degree of the first electronic expansion valve so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system; determining whether the dehumidification time length of the first refrigeration system entering the dehumidification state is greater than a second preset time length, if the dehumidification time length of the first refrigeration system entering the dehumidification state is less than or equal to the second preset time length, the dehumidification demand of the machine room is reacquired; If the dehumidification demand is less than or equal to 0%, a third dehumidification mode is entered, the first refrigeration system and the second refrigeration system are controlled and adjusted not to dehumidify, and the first refrigeration system and the second refrigeration system remain in the original refrigeration state.

23. The operation control method according to claim 22, characterized by, After the control and adjustment of the opening degree of the first electronic expansion valve so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, comprising: calculating the superheat degree of the first refrigeration system according to the real-time suction pressure of the first compressor and the first compressor suction gas temperature; If the superheat degree of the first refrigeration system is less than a preset minimum superheat degree or the evaporation temperature of the first refrigeration system is less than or equal to a preset minimum evaporation temperature, the opening degree of the first electronic expansion valve is controlled and adjusted to stop decreasing and gradually increase by a preset step size until the superheat degree of the first refrigeration system is greater than or equal to the preset minimum superheat degree or the evaporation temperature of the first refrigeration system is greater than the preset minimum evaporation temperature; The opening degree of the first electronic expansion valve is again controlled and adjusted in real time so that the evaporation temperature of the first refrigeration system continues to be kept equal to the first target evaporation temperature.

24. The operation control method according to claim 22, characterized by, After the control and adjustment of the opening degree of the first electronic expansion valve so that the evaporation temperature of the first refrigeration system is kept lower than the return air dew point temperature of the first refrigeration system, comprising: determining whether the dehumidification time length of the first refrigeration system entering the dehumidification state is greater than a second preset time length, If the dehumidification duration of the first refrigeration system entering the dehumidification state is greater than the second preset duration, the air conditioning system reenters the second dehumidification mode, controls adjustment of the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, controls adjustment of the opening degree of the second electronic expansion valve to make the second refrigeration system not dehumidify, and until the dehumidification demand is less than or equal to 0% again, enters the third dehumidification mode.

25. The operation control method according to claim 22, characterized by, After the control adjustment of the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, comprising: If the dehumidification demand is greater than 0%, control real-time adjustment of the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system continue to be equal to the first target evaporation temperature.

26. An operation control device of a machine room air conditioner, characterized by comprising: Applied to the machine room air conditioner as claimed in any one of claims 1-12, comprising: An acquisition unit is configured to acquire a dehumidification demand of the machine room; A control unit is configured to: If the dehumidification demand is greater than 0% and less than a preset dehumidification demand value, enter the second dehumidification mode, control adjustment of the opening degree of the first electronic expansion valve to keep the evaporation temperature of the first refrigeration system lower than the return air dew point temperature of the first refrigeration system, control adjustment of the opening degree of the second electronic expansion valve to make the second refrigeration system not dehumidify, until the dehumidification demand is less than or equal to 0% again, enter the third dehumidification mode, the first refrigeration system stops dehumidification, and the first refrigeration system and the second refrigeration system keep the original refrigeration state.

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