Base-type natural cooling air conditioning system and control method

Abstract

The present invention discloses a base-type natural cooling air-conditioning system, in which a first coil and a second coil connected to each other are arranged in an indoor unit of the base-type natural cooling air-conditioning system, the first coil is connected to a first electronic expansion valve, and the second coil is connected to a second electronic expansion valve. The base-type natural cooling air-conditioning system of the present invention has two cooling modes, namely, mechanical cooling and natural cooling. In the mechanical cooling mode, the controller switches the first electronic expansion valve and the second electronic expansion valve on and off according to the size of the IT load power of the computer room, so as to achieve a basic match between the output of the indoor machine cooling capacity and the IT load, ensure a relatively balanced temperature and humidity field in the data center, reduce the operating power consumption of the base-type natural cooling air-conditioning system, and achieve energy saving. At the same time, it can be determined whether to turn on the natural cooling function according to the temperature difference between the indoor and outdoor environments, and in the natural cooling mode, the utilization efficiency of the outdoor natural cold source can be maximized by adjusting the frequency of the refrigerant pump of the base-type natural cooling air-conditioning system.

Description

Technical Field

[0001] The present invention relates to the field of data center air conditioning, and in particular to a base-type natural cooling air conditioning system and a control method thereof. Background Art

[0002] With the rapid development of the data center industry, the power consumption of air-conditioning and refrigeration systems has received more and more attention from air-conditioning manufacturers. Building a green data center is also an inevitable trend of future development. How to design a data center that meets the green, environmentally friendly and energy-saving index requirements proposed by national policies is an issue that all air-conditioning manufacturers urgently need to focus on.

[0003] The current base-type natural cooling air-conditioning system, especially the cooling capacity of the air-conditioning indoor unit, cannot match the IT load power in the computer room well, resulting in excessive power consumption of the air-conditioning system and energy waste.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a base-mounted natural cooling air-conditioning system and a control method, aiming to reduce the operating power consumption of the base-mounted natural cooling air-conditioning system of a data center.

[0006] The technical solution of the present invention is as follows:

[0007] A base-type natural cooling air conditioning system, comprising: an indoor unit and a controller; the indoor unit comprises: a chassis and a refrigeration component arranged in the chassis, the refrigeration component comprising:

[0008] First coil;

[0009] a second coil, a first end of the second coil connected to the first end of the first coil;

[0010] a first electronic expansion valve connected to the second end of the first coil and connected to the controller;

[0011] a second electronic expansion valve connected to the second end of the second coil and connected to the controller;

[0012] Wherein, when the base-type natural cooling air-conditioning system is in a mechanical cooling mode, the controller is used to control the opening or closing of the first electronic expansion valve and the second electronic expansion valve.

[0013] In the base-type natural cooling air-conditioning system, the first coil and the second coil are arranged in a "V" shape.

[0014] The base-type natural cooling air-conditioning system, wherein the indoor unit further includes a return air filter, and the return air filter is connected to the chassis via a first magnetic attraction component.

[0015] The base-type natural cooling air-conditioning system, wherein the base-type natural cooling air-conditioning system further includes an outdoor unit, and the outdoor unit includes:

[0016] A compressor, wherein the connecting end of the first coil and the second coil is connected to the compressor; and the controller is also connected to the compressor;

[0017] A refrigerant pump, wherein the first electronic expansion valve, the second electronic expansion valve and the compressor are respectively connected to the refrigerant pump; and the controller is also connected to the refrigerant pump;

[0018] Among them, when the compressor is turned on and the refrigerant pump is turned off, the base-type natural cooling air-conditioning system is in a mechanical refrigeration mode, and the controller is also used to control the operating frequency of the compressor; when the refrigerant pump is turned on and the compressor is turned off, the base-type natural cooling air-conditioning system is in a natural cooling mode, the first electronic expansion valve and the second electronic expansion valve are both turned on, and the controller is used to control the operating frequency of the refrigerant pump.

[0019] A control method for a base-type natural cooling air conditioning system, wherein the base-type natural cooling air conditioning system comprises an indoor unit and an outdoor unit, the outdoor unit comprises a compressor and a refrigerant pump connected to the compressor; the indoor unit comprises: a chassis and a refrigeration component arranged in the chassis, the refrigeration component comprises:

[0020] First coil;

[0021] a second coil, a first end of the second coil connected to the first end of the first coil;

[0022] a first electronic expansion valve connected to the second end of the first coil;

[0023] a second electronic expansion valve connected to the second end of the second coil;

[0024] The refrigeration mode of the base-type natural cooling air-conditioning system includes a mechanical refrigeration mode and a natural cooling mode. When the compressor is turned on and the refrigerant pump is turned off, the base-type natural cooling air-conditioning system is in the mechanical refrigeration mode. When the refrigerant pump is turned on and the compressor is turned off, the base-type natural cooling air-conditioning system is in the natural cooling mode.

[0025] The control method comprises:

[0026] After the base-type natural cooling air conditioning system is turned on, a first temperature difference is obtained, and a cooling mode is determined according to the first temperature difference, wherein the first temperature difference is the temperature difference between the return air temperature and the outdoor temperature;

[0027] During the operation of the mechanical refrigeration mode, the first electronic expansion valve and the second electronic expansion valve are controlled to be opened or closed according to the operating frequency of the compressor. If the operating frequency of the compressor does not exceed the first frequency threshold, the first electronic expansion valve is opened and the second electronic expansion valve is closed; if the operating frequency of the compressor exceeds the first frequency threshold, the first electronic expansion valve and the second electronic expansion valve are opened at the same time;

[0028] When the base-type natural cooling air conditioning system meets a first preset condition, the mechanical cooling mode is switched to the natural cooling mode;

[0029] The control method further comprises: during the operation of the natural cooling mode, when the base-type natural cooling air-conditioning system meets a second preset condition, switching the natural cooling mode to a mechanical cooling mode.

[0030] The control method, wherein after the base-type natural cooling air-conditioning system is turned on, the cooling mode is determined according to the first temperature difference, including: after the base-type natural cooling air-conditioning system is turned on, when the first temperature difference does not exceed the first temperature deviation, only the compressor is turned on to run the mechanical cooling mode; when the first temperature difference is greater than the first temperature deviation, only the refrigerant pump is turned on to run the natural cooling mode; and / or,

[0031] When the base-type natural cooling air conditioning system meets a first preset condition, switching the mechanical cooling mode to the natural cooling mode comprises:

[0032] During the operation of the mechanical refrigeration mode, when the first temperature difference exceeds the first temperature deviation and when the operating frequency of the compressor is less than the second frequency threshold, or when the first temperature difference exceeds the second temperature deviation and the second temperature difference is less than the third temperature deviation, the mechanical refrigeration mode is switched to the natural cooling mode; and / or,

[0033] When the base-type natural cooling air conditioning system meets the second preset condition, switching the natural cooling mode to the mechanical cooling mode includes:

[0034] During operation in the natural cooling mode, when the second temperature difference is greater than the third temperature deviation, or when the first temperature difference does not exceed the first temperature deviation and the second temperature difference is greater than the fourth temperature deviation, the natural cooling mode is switched to the mechanical cooling mode;

[0035] Wherein, the second temperature difference is the temperature difference between the return air temperature and the set temperature.

[0036] The control method, wherein the operating frequency of the compressor is a calibrated compressor frequency, and the calibration method of the calibrated compressor frequency includes:

[0037] Set the calibration factor, the calibration factor is Where T1 is the return air temperature corresponding to the compressor operating frequency being the upper limit frequency of the compressor, and T2 is the actual return air temperature;

[0038] When T2>T1, the calibrated compressor frequency Hcp=Hc×(1+&), where Hc is the operating frequency of the compressor corresponding to when the cooling capacity of the base-type natural cooling air-conditioning system is half of the upper limit of the cooling capacity;

[0039] When T2≤T1, the calibrated compressor frequency Hcp=Hc×(1-&), wherein Hc is the operating frequency of the compressor corresponding to when the cooling capacity of the base-type natural cooling air-conditioning system is half of the upper limit of the cooling capacity.

[0040] The control method, wherein the control method further comprises:

[0041] During the operation of the natural cooling mode, when the supply air temperature is less than or equal to the first temperature threshold, adjusting the operating frequency of the refrigerant pump to the upper limit frequency of the refrigerant pump at a first adjustment rate;

[0042] When the supply air temperature is greater than a second temperature threshold, adjusting the operating frequency of the refrigerant pump to a lower limit frequency of the refrigerant pump at a first adjustment rate;

[0043] When the supply air temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold, determining the adjustment rate of the operating frequency of the refrigerant pump according to the third temperature difference, the operating frequency of the refrigerant pump being between the upper frequency limit and the lower frequency limit;

[0044] The third temperature difference is the absolute value of the temperature difference between the supply air temperature and the preset supply air temperature.

[0045] The control method, wherein when the supply air temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold, determining the adjustment rate of the operating frequency of the refrigerant pump according to the third temperature difference, comprises:

[0046] When the third temperature difference exceeds the sixth temperature deviation and does not exceed the fifth temperature deviation, adjusting the operating frequency of the refrigerant pump at a second adjustment rate;

[0047] When the third temperature difference does not exceed the sixth temperature deviation, adjusting the operating frequency of the refrigerant pump at a third adjustment rate until the supply air temperature reaches a preset supply air temperature;

[0048] The first adjustment rate is greater than the second adjustment rate, and the second adjustment rate is greater than the third adjustment rate.

[0049] Beneficial effect: The present invention provides a base-type natural cooling air-conditioning system, in which a first coil and a second coil connected to each other are arranged in an indoor unit of the base-type natural cooling air-conditioning system, the first coil is connected to a first electronic expansion valve, and the second coil is connected to a second electronic expansion valve. In the mechanical refrigeration mode, the controller switches the first electronic expansion valve and the second electronic expansion valve on and off according to the size of the IT load power of the computer room, so as to achieve a basic match between the output of the indoor machine cooling capacity and the IT load, ensure a relatively balanced temperature and humidity field in the data center, reduce the operating power consumption of the base-type natural cooling air-conditioning system, and achieve energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a first structural diagram of an indoor unit of a base-type natural cooling air-conditioning system of the present invention.

[0051] Figure 2 This is a second structural diagram of an indoor unit of a base-type natural cooling air-conditioning system of the present invention.

[0052] Figure 3 It is a structural schematic diagram of a base-type natural cooling air conditioning system of the present invention.

[0053] 10. Indoor unit, 11. First coil, 12. Second coil, 13. First electronic expansion valve, 14. Second electronic expansion valve, 15. First magnetic element, 16. Card slot, 17. Fan module, 171. Fan housing, 172. Air supply assembly, 173. Air guide grille, 174. Air supply grid, 18. Chassis, 19. Water tray, 20. Outdoor unit, 21. Compressor, 22. Refrigerant pump, 23. Condenser. DETAILED DESCRIPTION

[0054] The present invention provides a base-type natural cooling air conditioning system and control method. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] See also Figures 1 to 3The present invention provides a base-type natural cooling air-conditioning system, comprising: an indoor unit 10 and a controller; the indoor unit 10 comprises: a chassis 18 and a refrigeration component arranged in the chassis 18, the refrigeration component comprises: a first coil 11, a second coil 12, a first electronic expansion valve 13 and a second electronic expansion valve 14, the first end of the second coil 12 is connected to the first end of the first coil 11, the first electronic expansion valve 13 is connected to the second end of the first coil 11 and is connected to the controller, the second electronic expansion valve 14 is connected to the second end of the second coil 12 and is connected to the controller; wherein, when the base-type natural cooling air-conditioning system is in a mechanical cooling mode, the controller is used to control the opening or closing of the first electronic expansion valve 13 and the second electronic expansion valve 14.

[0056] Specifically, the base-type natural cooling air conditioning system of the present invention is mainly used for temperature regulation of the computer room of the data center, and the indoor unit 10 is a base-type indoor unit 10, which is usually arranged on the cabinet of the computer room of the data center. The indoor unit 10 includes a chassis 18 and a first coil 11, a second coil 12, a first electronic expansion valve 13 and a second electronic expansion valve 14 arranged in the chassis 18. The first electronic expansion valve 13 is used to control whether the refrigerant flowing into the first coil 11 has refrigeration capacity, and the second electronic expansion valve 14 is used to control whether the refrigerant flowing into the second coil 12 has refrigeration capacity. The mechanical refrigeration mode refers to the mechanical refrigeration mode. At this time, the base-type natural cooling air conditioning system drives the refrigerant to flow in the pipeline through the compressor 21. The controller controls the opening or closing of the first electronic expansion valve 13 and the second electronic expansion valve 14 according to the IT load size of the computer room of the data center, thereby controlling the cooling capacity output of the indoor unit 10. When the IT load does not exceed 50% of the full load configuration, only one electronic expansion valve needs to be opened, that is, the first electronic expansion valve 13 is opened and the second electronic expansion valve 14 is closed, or the second electronic expansion valve 14 is opened and the first electronic expansion valve 13 is closed. When the IT load exceeds 50% of the full load configuration, the first electronic expansion valve 13 and the second electronic expansion valve 14 are both opened. The basic matching of the cooling capacity output of the base-type indoor unit 10 and the IT load is achieved, ensuring that the temperature and humidity field of the data center is relatively balanced. In addition, under low-load operating conditions, that is, when the IT load does not exceed 50% of the full load configuration, closing one coil is beneficial to the compressor 21 of the base-type natural cooling air-conditioning system when it is running at a low frequency, increasing the circulation flow rate of the pipeline refrigerant, and having a significant effect on the oil return of the base-type natural cooling air-conditioning system. Through calculation and comparison, when the compressor 21 is running at a low frequency (the calculation is based on the compressor 2140Hz operation as the calculation data), when two evaporation coils are opened, the gas side pipeline flow rate of the indoor unit 10 is about 3.5m / s. When one coil is closed, the indoor unit 1 0 The flow rate of the gas side pipeline is increased to 5.3m / s, and the flow rate in the refrigerant gas side pipe is increased by more than 50%. It has very meaningful application value for many long piping and high drop applications on site; in addition, since the air flow temperature of the closed coil is basically unchanged, it is mixed with the air flow passing through another refrigeration coil at the end away from the expansion valve, thereby increasing the air supply temperature of the air conditioner, that is, effectively extending the single refrigeration operation time of the base-type natural cooling air-conditioning system under low-load application conditions, reducing the frequent start and stop of the compressor 21, and helping to increase the operating life of the base-type natural cooling air-conditioning system.

[0057] In one embodiment, in order to increase the heat exchange area of ​​the coil, the first coil 11 and the second coil 12 are arranged in a "V" shape, the first end of the first coil 11 is connected to the first end of the second coil 12, the second end of the first coil 11 is inclined in a direction away from the second coil 12, and the second end of the second coil 12 is inclined in a direction away from the first coil 11, so that the first coil 11 and the second coil 12 are arranged in a "V" shape, and at the same time, it is convenient to realize the distribution of the pipes of the electronic expansion valve and the coil. Further, a water receiving pan 19 is provided at the lower ends of the first coil 11 and the second coil 12, and the water receiving pan 19 is used to receive the condensed water condensed from the first coil 11 and the second coil 12.

[0058] In one embodiment, the indoor unit 10 further includes a return air filter, and the return air filter is connected to the chassis 18 via a first magnetic component 15. The return air filter is disposed at the rear end of the chassis 18, and is used to filter and remove dust from the hot air in the air conditioner. The return air filter is connected to the chassis 18 via a first magnetic component 15, and the first magnetic component 15 can specifically be a permanent magnet, which can permanently maintain its magnetism and can be used for a long time without failure. A sheet metal frame is provided on the frame at the rear end of the chassis 18, and the first magnetic component 15 is fixed to the sheet metal frame by screws.

[0059] Furthermore, a card slot 16 can be provided on the sheet metal frame, and the card slot 16 can fix the return air filter more stably and improve the stability of its installation. Furthermore, a card slot 16 is provided on the lower frame portion of the sheet metal frame, and a first magnetic suction member 15 is provided on the left frame portion and the right frame portion of the sheet metal frame. When the return air filter needs to be repaired, the return air filter can be easily removed by simply pulling the upper end of the metal frame with your hand and pulling back with a little force. There is no need to remove the screws on site, which effectively improves the on-site operation and maintenance efficiency of the project. When reinstalling the return air filter, first align the frame of the return air filter and insert it into the card slot 16, and then adsorb the metal frame to the strong magnet.

[0060] In one embodiment, a fan module 17 is provided at the front end of the chassis 18, and an air supply grid 174 is provided on the fan module 17. The fan module 17 is used for air conditioning and air supply, and the fan module 17 includes a fan housing 171 and an air supply component 172 provided in the fan housing 171, and an air supply grid 174 is provided on the top of the fan housing 171. The air supply component 172 sends the cold air flow into the cold channel of the cabinet through the air supply grid 174 to cool the server, and the hot air flow exhausted by the server is filtered and dusted by the return air filter of the indoor unit 10, and then exchanges heat with the evaporator for continuous circulation.

[0061] Furthermore, an adjustable air guide grille 173 is provided at the front end of the fan module 17. The louver air guide angle of the air guide grille 173 is adjusted through the actual installation position of the air-conditioning indoor unit 10 to form air outlet channels with different air outlet directions. The cold air flow output by the indoor fan of the air-conditioning can be quickly diffused to areas with heat dissipation requirements such as the upper end and the front end, thereby forming a more reasonable air flow organization circulation.

[0062] Furthermore, two handles are provided on the top of the chassis 18 to facilitate transportation during on-site installation and maintenance; at the same time, a handle is pre-set at the rear end of the base-type air-conditioning indoor unit 10 to facilitate moving the indoor unit 10 into or out of the cabinet.

[0063] In one embodiment, the base-type natural cooling air-conditioning system also includes an outdoor unit 20, and the outdoor unit 20 includes: a compressor 21, the connecting end of the first coil 11 and the second coil 12 is connected to the compressor 21; the controller is also connected to the compressor 21; a refrigerant pump 22, the first electronic expansion valve 13, the second electronic expansion valve 14 and the compressor 21 are respectively connected to the refrigerant pump 22; the controller is also connected to the refrigerant pump 22; wherein, when the compressor 21 is turned on and the refrigerant pump 22 is turned off, the base-type natural cooling air-conditioning system is in a mechanical cooling mode, and the controller is also used to control the operating frequency of the compressor 21; when the refrigerant pump 22 is turned on and the compressor 21 is turned off, the base-type natural cooling air-conditioning system is in a natural cooling mode, the first electronic expansion valve 13 and the second electronic expansion valve 14 are both turned on, and the controller is used to control the operating frequency of the refrigerant pump 22.

[0064] Specifically, the refrigerant circulation direction is as follows: Figure 3In the direction of the arrow in the figure, the base-type natural cooling air-conditioning system can be placed in different cooling modes by controlling the compressor 21 and the refrigerant pump 22 to run separately. When the compressor 21 is turned on and the refrigerant pump 22 is turned off, the base-type natural cooling air-conditioning system is in mechanical cooling mode. At this time, the compressor 21 works alone, and the controller controls the opening or closing of the first electronic expansion valve 13 and the second electronic expansion valve 14 according to the IT load size of the data center computer room, thereby controlling the cooling capacity output of the indoor unit 10. At the same time, the controller also needs to control the operating frequency of the compressor 21 according to the actual return air temperature, so as to more accurately match the cooling capacity output. When the refrigerant pump 22 is turned on and the compressor 21 is turned off, the base-type natural cooling air-conditioning system is in natural cooling mode. At this time, in order to make full use of the natural cold source of the outdoor environment, the first expansion valve and the second expansion valve are both opened synchronously, that is, the first coil 11 and the second coil 12 are both cooling output at the same time, and the controller controls the operating frequency of the refrigerant pump 22 according to the actual supply air temperature, and outputs the cooling capacity matching the IT load in real time, reducing the operating power consumption of the base-type natural cooling air-conditioning system, maximizing the utilization efficiency of the outdoor natural cold source, and further achieving energy-saving effects. Furthermore, the outdoor unit 20 further includes a condenser 23 , and the compressor 21 and the refrigerant pump 22 are respectively connected to the condenser 23 .

[0065] In one embodiment, the present invention further provides a control method for a base-type natural cooling air-conditioning system, wherein the cooling mode of the base-type natural cooling air-conditioning system includes a mechanical cooling mode and a natural cooling mode, and when the compressor is turned on and the refrigerant pump is turned off, the base-type natural cooling air-conditioning system is in the mechanical cooling mode, and when the refrigerant pump is turned on and the compressor is turned off, the base-type natural cooling air-conditioning system is in the natural cooling mode, and the control method includes:

[0066] S10, after the base-type natural cooling air conditioning system is turned on, a first temperature difference is obtained, and a cooling mode is determined according to the first temperature difference, wherein the first temperature difference is a temperature difference between a return air temperature and an outdoor temperature;

[0067] S20, during the operation of the mechanical refrigeration mode, controlling the opening or closing of the first electronic expansion valve and the second electronic expansion valve according to the operating frequency of the compressor, if the operating frequency of the compressor does not exceed the first frequency threshold, opening the first electronic expansion valve and closing the second electronic expansion valve; if the operating frequency of the compressor exceeds the first frequency threshold, opening the first electronic expansion valve and the second electronic expansion valve at the same time;

[0068] S30: During the operation of the mechanical refrigeration mode, when the base-type natural cooling air-conditioning system meets a first preset condition, the mechanical refrigeration mode is switched to the natural cooling mode.

[0069] Specifically, the base-type natural cooling air-conditioning system of the present invention automatically starts when there is a cooling demand, and the base-type natural cooling air-conditioning system is provided with temperature sensors for detecting the return air temperature and the outdoor ambient temperature respectively. When the return air temperature satisfies: return air temperature - set temperature > set temperature deviation (specifically can be set to 2°C), the base-type natural cooling air-conditioning system automatically starts. When the air conditioner meets the startup conditions and starts, the refrigeration mode to be turned on first is determined by the indoor and outdoor temperature difference (that is, the first temperature difference) when the base-type natural cooling air-conditioning system is just started, thereby reducing power consumption. The temperature difference between the return air temperature and the outdoor temperature is specifically the temperature difference obtained by subtracting the outdoor ambient temperature from the average return air temperature. Since the base-type natural cooling air-conditioning system of the present invention is operated all year round, the outdoor temperature will change due to changes in the morning and evening or the seasons. Therefore, during the operation of different cooling modes, it is necessary to adjust the cooling mode of the base-type natural cooling air-conditioning system according to the changes in the outdoor temperature to make full use of the natural cold source. It should be noted that the first temperature difference = return air temperature - outdoor temperature.

[0070] During the operation of the mechanical cooling mode, the opening and closing of the first electronic expansion valve 13 and the second electronic expansion valve 14 are intelligently adjusted according to the size of the IT load power of the computer room. The size of the IT load power can be read from the front-end power distribution cabinet by the upper computer monitoring host. When the front-end power distribution cabinet does not support the reading of the value of the IT load power, that is, the air conditioner cannot determine the load ratio by this value, it can also be determined by the operating frequency of the compressor 21, that is, the size of the IT load power of the computer room is determined by the operating frequency of the compressor. Under the condition of the return air temperature being T1, when the operating frequency of the compressor 21 is preset to Ha (the upper limit of the operating frequency of the compressor 21), the corresponding maximum cooling capacity is Qa; when the operating frequency of the compressor 21 is Hc, the corresponding cooling capacity is 0.5Qa (the output cooling capacity is approximately equal to 50% of the maximum cooling capacity Qa output). The operating frequency Hc of the compressor 21 corresponding to the cooling capacity of 0.5Qa is used as the first frequency threshold. When the actual operating frequency of the compressor 21 does not exceed the first frequency threshold within a certain period of time (specifically, it can be set to 5min), it is defined that the IT load power at this time does not exceed 50% of the full load configuration. When the actual operating frequency of the compressor 21 exceeds the first frequency threshold within a certain period of time (specifically, it can be set to 5min), it is defined that the IT load power at this time exceeds 50% of the full load configuration. When the IT load power of the computer room does not exceed 50% of the full load configuration, that is, the operating frequency of the compressor does not exceed the first frequency threshold, at this time, the first electronic expansion valve 13 is closed and the second electronic expansion valve 14 is closed, then the first coil 11 starts cooling, and the second coil 12 has no cooling; when the IT load power of the computer room exceeds 50% of the full load configuration, that is, the operating frequency of the compressor exceeds the first frequency threshold, at this time, the first electronic expansion valve 13 and the second electronic expansion valve 14 are opened at the same time, then the first coil 11 and the second coil 12 both start cooling.

[0071] Furthermore, since the return air temperature has a great influence on the cooling capacity output, the operating frequency of the compressor 21 is calibrated. The present invention calibrates the frequency of the compressor 21 by the return air calibration coefficient. When the actual return air temperature is T2, the return air temperature calibration coefficient at this time is If T2>T1, the actual operating frequency of the compressor Hcp=Hc×(1+&); if T2≤T1, the actual operating frequency of the compressor Hcp=Hc×(1-&).

[0072] During the operation of the mechanical refrigeration mode, it is also necessary to switch to the natural cooling mode according to the first preset condition, so that the base-type natural cooling air-conditioning system can make full use of the natural cold source and reduce energy loss.

[0073] In one implementation, the step S30 specifically includes:

[0074] During the operation of the mechanical refrigeration mode, when the first temperature difference exceeds the first temperature deviation and when the operating frequency of the compressor is less than the first frequency threshold, or when the first temperature difference exceeds the second temperature deviation and when the second temperature difference is less than the third temperature deviation, the mechanical refrigeration mode is switched to the natural cooling mode, wherein the second temperature difference is the temperature difference between the return air temperature and the set temperature.

[0075] Specifically, during the mechanical refrigeration mode, the first frequency threshold refers to the maximum frequency of the return oil detection of the compressor 21, the second temperature deviation refers to the sum of the first temperature deviation and the refrigeration mode switching temperature difference, and the second temperature difference refers to the temperature difference between the return air temperature and the air conditioning setting temperature, that is, the second temperature difference = return air temperature - air conditioning setting temperature. The third temperature deviation refers to 1.5 times the set temperature deviation, and the fourth temperature deviation refers to the set temperature deviation. When the first temperature deviation exceeds the first temperature deviation and lasts for a period of time (specifically, it can be set to 5 minutes) and the operating frequency of the compressor is less than the first frequency threshold and lasts for a period of time (specifically, it can be set to 10 minutes), it means that the IT load in the computer room is not large at this time, and the natural cooling mode can be turned on. At this time, the compressor 21 is turned off and the refrigerant pump 22 is turned on at the lower limit of the frequency of the refrigerant pump 22. At the same time, the first electronic expansion valve 13 and the second electronic expansion valve 14 of the indoor unit 10 are both opened synchronously. Alternatively, when the first temperature difference exceeds the second temperature deviation and when the second temperature difference is less than the third temperature deviation and lasts for a period of time (specifically, it can be set to 3 minutes), it means that the indoor and outdoor temperature difference is large enough (the full cooling capacity of the pump is equal to the full-frequency output cooling capacity of the compressor 21), and the natural cooling mode can also be turned on.

[0076] Further, when the base-type natural cooling air conditioning system has no cooling demand, it automatically shuts down to save energy. Specifically, during the operation of the mechanical cooling mode, when the return air temperature satisfies: return air temperature-set temperature ≤ set temperature deviation and lasts for a period of time (specifically, it can be set to 3 minutes), the compressor 21 stops running and shuts down the system; in one embodiment, the control method further includes:

[0077] S40: During the operation of the natural cooling mode, when the base-type natural cooling air-conditioning system meets a second preset condition, the natural cooling mode is switched to a mechanical cooling mode.

[0078] Further, the step S40 specifically includes:

[0079] During operation in the natural cooling mode, when the second temperature difference is greater than the third temperature deviation, or when the first temperature difference does not exceed the first temperature deviation and the second temperature difference is greater than the fourth temperature deviation, the natural cooling mode is switched to the mechanical cooling mode.

[0080] Specifically, during the natural cooling mode, if the outdoor temperature gradually rises, it means that the indoor and outdoor temperature difference is getting smaller and smaller, and the cooling capacity output of the pump will also be smaller. When the return air temperature rises, when the second temperature difference is greater than the third temperature deviation and lasts for a period of time (specifically, it can be set to 3 minutes), it means that the natural cooling capacity of the refrigerant pump 22 is insufficient, and it is necessary to use the mechanical cooling mode for cooling. Then, the refrigerant pump 22 is turned off and the compressor 21 is turned on at the lower limit of the frequency of the compressor 21. At this time, the indoor unit 10 preferentially turns on any one of the first electronic expansion valve 13 and the second electronic expansion valve 14 and keeps the other closed. After that, after the frequency of the compressor 21 rises to the start-up frequency and lasts for the start-up time, the compressor 21 adjusts the frequency according to demand and operates normally. During the operation of the natural cooling mode, when the return air temperature meets: the average return air temperature < the temperature setting value - the temperature setting deviation × 1.5 and lasts for a period of time (specifically, it can be set to 3 minutes), the refrigerant pump 22 stops running and shuts down the system.

[0081] In one embodiment, after the base-type natural cooling air-conditioning system is turned on, the cooling mode is determined according to the first temperature difference, including: after the base-type natural cooling air-conditioning system is turned on, when the first temperature difference does not exceed the first temperature deviation, only the compressor 21 is turned on to run the mechanical refrigeration mode; when the first temperature difference is greater than the first temperature deviation, only the refrigerant pump 22 is turned on to run the natural cooling mode.

[0082] Specifically, the first temperature deviation is the opening deviation of the natural cooling mode. When the first temperature difference does not exceed the first temperature deviation, the condition for opening the natural cooling mode is not met, and the base-type natural cooling air-conditioning system opens the mechanical cooling mode, that is, the compressor 21 is turned on and the refrigerant pump 22 is turned off. When the first temperature difference exceeds the first temperature deviation, it means that the indoor and outdoor temperature difference when the base-type natural cooling air-conditioning system is turned on is large enough, and the air conditioner opens the natural cooling mode, that is, the refrigerant pump 22 is turned on and the compressor 21 is turned off. The first temperature deviation can be set according to actual conditions. Preferably, the first temperature deviation is 10°C.

[0083] In one embodiment, during operation in natural cooling mode, when the supply air temperature is less than or equal to a first temperature threshold, the operating frequency of the refrigerant pump 22 is adjusted to the upper limit frequency of the refrigerant pump 22 at a first adjustment rate; when the supply air temperature is greater than the second temperature threshold, the operating frequency of the refrigerant pump 22 is adjusted to the lower limit frequency of the refrigerant pump 22 at the first adjustment rate; when the supply air temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold, the adjustment rate of the operating frequency of the refrigerant pump 22 is determined according to a third temperature difference, and the operating frequency of the refrigerant pump 22 is between the upper limit frequency and the lower limit frequency, wherein the third temperature difference is the absolute value of the temperature difference between the supply air temperature and the preset supply air temperature.

[0084] Specifically, the base-type natural cooling air conditioning system is also provided with a temperature sensor for detecting the supply air temperature. In the natural cooling mode, the operating frequency of the refrigerant pump 22 is adjusted according to the supply air temperature, and the upper limit frequency (which can be set to 20-120Hz), lower limit frequency (which can be set to 20-120Hz) and supply air temperature of the refrigerant pump 22 are preset, wherein the preset supply air temperature is also the set temperature (the temperature that needs to be maintained in the machine room). The first temperature threshold = preset supply air temperature - set temperature deviation, the second temperature threshold = preset supply air temperature + set temperature deviation, the base-type natural cooling air conditioning system compares the different supply air temperatures with the first temperature threshold and the second temperature threshold, and adjusts the operating frequency of the refrigerant pump 22 to the operating frequency of the refrigerant pump 22 corresponding to each supply air temperature range at different adjustment rates, thereby minimizing energy consumption. When the supply air temperature is less than or equal to the first temperature threshold, or when the supply air temperature is greater than the second temperature threshold, it means that the supply air temperature deviates from the pump steady-state temperature. At this time, the frequency adjustment rate of the refrigerant pump 22 is faster, and the first adjustment rate of the refrigerant pump can be set according to the preset adjustment time. The preset adjustment time refers to the frequency adjustment time of the refrigerant pump 22 when the supply air temperature reaches the pump steady-state temperature. The preset adjustment time can be 1 to 3600s according to the actual setting. For example, assuming that the preset adjustment time is ΔT, the first adjustment rate is 1Hz / (ΔT×0.2). When the supply air temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold, it means that the supply air temperature is close to the preset supply air temperature. At this time, it is also necessary to adjust the operating frequency of the refrigerant pump 22 according to different supply air temperature ranges, so that the operating frequency of the refrigerant pump 22 is adjusted between the upper limit frequency and the lower limit frequency until the supply air temperature reaches the preset supply air temperature.

[0085] Further, when the supply air temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold, if the third temperature difference exceeds the sixth temperature deviation and does not exceed the fifth temperature deviation, the operating frequency of the refrigerant pump 22 is adjusted at the second adjustment rate; if the third temperature difference does not exceed the sixth temperature deviation, the operating frequency of the refrigerant pump 22 is adjusted at the third adjustment rate until the supply air temperature reaches the preset supply air temperature, wherein the first adjustment rate is greater than the second adjustment rate, and the second adjustment rate is greater than the third adjustment rate.

[0086] Specifically, the fifth temperature deviation refers to the set temperature deviation, and the sixth temperature deviation refers to half of the set temperature deviation. When the third temperature difference exceeds the sixth temperature deviation but does not exceed the fifth temperature deviation, the frequency regulation rate of the refrigerant pump 22 is the second regulation rate, which is slightly lower than the first regulation rate. For example, the second regulation rate is 1Hz / (ΔT×0.5). When the absolute value of the third temperature difference does not exceed the sixth temperature deviation, it means that the supply air temperature is closest to the preset supply air temperature. At this time, the frequency regulation rate of the refrigerant pump 22 is the third regulation rate, which is slightly lower than the second regulation rate. For example, the third regulation rate is 1Hz / (ΔT).

[0087] For example, the upper limit frequency of the refrigerant pump 22 is preset to 100 Hz, the lower limit frequency is 30 Hz, the preset air supply temperature is 22°C, and the set temperature deviation is 2°C. Then the first temperature threshold = 22-2 = 20°C, the second temperature threshold = 22+2 = 24°C, and the third temperature difference = |T 送 -22℃|, the fifth temperature deviation is 2℃, the sixth temperature deviation is 1℃, the preset adjustment time is 10s, and the air supply temperature is T 送 , the first adjustment rate = 1 / (10×0.2) = 0.5Hz, the first adjustment rate = 1 / (10×0.5) = 0.2Hz, the third adjustment rate = 1 / 10 = 0.1Hz, when T 送 When the temperature is ≤20℃, the operating frequency of the refrigerant pump 22 is adjusted to 30Hz at a rate of 0.5Hz. 送 >24℃, adjust the operating frequency of the refrigerant pump 22 to 100Hz at a rate of 0.5Hz. <T 送 ≤24℃, the operating frequency of the refrigerant pump 22 is adjusted within the range of 30-100Hz. At this time, when 1℃<|T 送 -22℃|≤2℃, i.e. 20℃≤T 送 <21℃ and 23℃ <T 送 ≤24℃, the operating frequency of the refrigerant pump 22 is adjusted at a rate of 0.2Hz. 送 -22℃|≤1℃, i.e. 21℃≤T 送≤23℃, adjust the operating frequency of the refrigerant pump 22 at a regulation rate of 0.1Hz. After the refrigerant pump 22 is started and running, in order to ensure the safety and stability of the pump, the pressure difference between the start-up and the start-up is detected 60s after the start-up. If the pressure difference ΔP ≤ the pump pressure low threshold (specifically, it can be preset to 0-3bar) and lasts for more than 3min, the pump pressure difference alarm will be triggered and the refrigerant pump 22 will stop running. 180s after the start-up, detect the pressure difference between the start-up and the start-up. If the pressure difference ΔP ≥ the pump frequency reduction deviation (specifically, it can be preset to 1-10bar), the operating frequency of the refrigerant pump 22 will decrease at a regulation rate of 1Hz / s. When the pressure difference drops to the pump frequency reduction reset deviation (specifically, it can be set to 0-7bar), the frequency reduction will stop, and the pump will automatically perform frequency adjustment according to the average air supply temperature of the air conditioner.

[0088] In summary, the present invention provides a base-type natural cooling air-conditioning system, in which a first coil and a second coil connected to each other are arranged in the indoor unit of the base-type natural cooling air-conditioning system, the first coil is connected to the first electronic expansion valve, and the second coil is connected to the second electronic expansion valve. The base-type natural cooling air-conditioning system of the present invention has two cooling modes, namely mechanical cooling and natural cooling. In the mechanical cooling mode, the controller switches the first electronic expansion valve and the second electronic expansion valve on and off according to the size of the IT load power of the computer room, so as to achieve a basic match between the output of the indoor machine cooling capacity and the IT load, ensure the relative balance of the temperature and humidity field in the data center, reduce the operating power consumption of the base-type natural cooling air-conditioning system, and achieve energy saving. At the same time, it can be determined whether to turn on the natural cooling function according to the temperature difference between the indoor and outdoor environments, and in the natural cooling mode, by adjusting the frequency of the refrigerant pump of the base-type natural cooling air-conditioning system, the utilization efficiency of the outdoor natural cold source can be maximized, and the energy-saving effect is further achieved.

[0089] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A base-type natural cooling air conditioning system, characterized in that: include: Indoor unit and controller; The indoor unit comprises: a chassis and a refrigeration component arranged in the chassis, and the refrigeration component comprises: First coil; a second coil, a first end of the second coil connected to the first end of the first coil; a first electronic expansion valve connected to the second end of the first coil and connected to the controller; a second electronic expansion valve connected to the second end of the second coil and connected to the controller; The base-type natural cooling air conditioning system is provided with temperature sensors for detecting the return air temperature and the outdoor ambient temperature respectively; Wherein, when the base-type natural cooling air conditioning system is in a mechanical cooling mode, the controller is used to control the opening or closing of the first electronic expansion valve and the second electronic expansion valve; The base-type natural cooling air conditioning system further includes an outdoor unit, which includes: A compressor, wherein the connecting end of the first coil and the second coil is connected to the compressor; and the controller is also connected to the compressor; A refrigerant pump, wherein the first electronic expansion valve, the second electronic expansion valve and the compressor are respectively connected to the refrigerant pump; and the controller is also connected to the refrigerant pump; Wherein, when the compressor is turned on and the refrigerant pump is turned off, the base-type natural cooling air-conditioning system is in a mechanical cooling mode, and the controller is also used to control the operating frequency of the compressor; when the refrigerant pump is turned on and the compressor is turned off, the base-type natural cooling air-conditioning system is in a natural cooling mode, the first electronic expansion valve and the second electronic expansion valve are both turned on, and the controller is used to control the operating frequency of the refrigerant pump; After the base-type natural cooling air-conditioning system is turned on, when the first temperature difference does not exceed the first temperature deviation, only the compressor is turned on to run the mechanical cooling mode; when the first temperature difference is greater than the first temperature deviation, only the refrigerant pump is turned on to run the natural cooling mode; wherein the first temperature difference is the indoor and outdoor temperature difference when the base-type natural cooling air-conditioning system is just turned on; and / or, during operation in the mechanical refrigeration mode, when the first temperature difference exceeds a first temperature deviation and when the operating frequency of the compressor is less than a second frequency threshold, or when the first temperature difference exceeds a second temperature deviation and the second temperature difference is less than a third temperature deviation, the mechanical refrigeration mode is switched to the natural cooling mode; and / or, During operation in the natural cooling mode, when the second temperature difference is greater than the third temperature deviation, or when the first temperature difference does not exceed the first temperature deviation and the second temperature difference is greater than the fourth temperature deviation, the natural cooling mode is switched to the mechanical cooling mode; Wherein, the second temperature difference is the temperature difference between the return air temperature and the set temperature.

2. The base-type natural cooling air conditioning system according to claim 1, characterized in that: The first coil and the second coil are arranged in a "V" shape.

3. The base-type natural cooling air conditioning system according to claim 1, characterized in that: The indoor unit further includes a return air filter, and the return air filter is connected to the chassis via a first magnetic attraction component.

4. A control method for a base-type natural cooling air conditioning system, characterized in that: The base-type natural cooling air conditioning system comprises an indoor unit and an outdoor unit, wherein the outdoor unit comprises a compressor and a refrigerant pump connected to the compressor; The indoor unit comprises: a chassis and a refrigeration component arranged in the chassis, and the refrigeration component comprises: First coil; a second coil, a first end of the second coil connected to the first end of the first coil; a first electronic expansion valve connected to the second end of the first coil; a second electronic expansion valve connected to the second end of the second coil; The refrigeration mode of the base-type natural cooling air-conditioning system includes a mechanical refrigeration mode and a natural cooling mode. When the compressor is turned on and the refrigerant pump is turned off, the base-type natural cooling air-conditioning system is in the mechanical refrigeration mode. When the refrigerant pump is turned on and the compressor is turned off, the base-type natural cooling air-conditioning system is in the natural cooling mode. The control method comprises: After the base-type natural cooling air conditioning system is turned on, a first temperature difference is obtained, and a cooling mode is determined according to the first temperature difference, wherein the first temperature difference is the temperature difference between the return air temperature and the outdoor temperature; wherein the first temperature difference is the indoor and outdoor temperature difference when the base-type natural cooling air conditioning system is just turned on; During the operation of the mechanical refrigeration mode, the first electronic expansion valve and the second electronic expansion valve are controlled to be opened or closed according to the operating frequency of the compressor. If the operating frequency of the compressor does not exceed the first frequency threshold, the first electronic expansion valve is opened and the second electronic expansion valve is closed; if the operating frequency of the compressor exceeds the first frequency threshold, the first electronic expansion valve and the second electronic expansion valve are opened at the same time; When the base-type natural cooling air conditioning system meets a first preset condition, the mechanical cooling mode is switched to the natural cooling mode; The control method further comprises: during the operation of the natural cooling mode, when the base-type natural cooling air conditioning system meets a second preset condition, switching the natural cooling mode to a mechanical cooling mode; After the base-type natural cooling air-conditioning system is turned on, the cooling mode is determined according to the first temperature difference, including: after the base-type natural cooling air-conditioning system is turned on, when the first temperature difference does not exceed the first temperature deviation, only the compressor is turned on to run the mechanical cooling mode; when the first temperature difference is greater than the first temperature deviation, only the refrigerant pump is turned on to run the natural cooling mode; and / or, When the base-type natural cooling air conditioning system meets a first preset condition, switching the mechanical cooling mode to the natural cooling mode comprises: During the operation of the mechanical refrigeration mode, when the first temperature difference exceeds the first temperature deviation and when the operating frequency of the compressor is less than the second frequency threshold, or when the first temperature difference exceeds the second temperature deviation and the second temperature difference is less than the third temperature deviation, the mechanical refrigeration mode is switched to the natural cooling mode; and / or, When the base-type natural cooling air conditioning system meets the second preset condition, switching the natural cooling mode to the mechanical cooling mode includes: During operation in the natural cooling mode, when the second temperature difference is greater than the third temperature deviation, or when the first temperature difference does not exceed the first temperature deviation and the second temperature difference is greater than the fourth temperature deviation, the natural cooling mode is switched to the mechanical cooling mode; Wherein, the second temperature difference is the temperature difference between the return air temperature and the set temperature.

5. The control method according to claim 4, characterized in that: The operating frequency of the compressor is a calibrated compressor frequency, and the calibration method of the calibrated compressor frequency includes: Set the calibration factor, the calibration factor is , where T1 is the return air temperature corresponding to the compressor operating frequency being the upper limit frequency of the compressor, and T2 is the actual return air temperature; When T2>T1, the calibrated compressor frequency Hcp=Hc×(1+&), where Hc is the operating frequency of the compressor corresponding to when the cooling capacity of the base-type natural cooling air-conditioning system is half of the upper limit of the cooling capacity; When T2≤T1, the calibrated compressor frequency Hcp=Hc×(1-&), wherein Hc is the operating frequency of the compressor corresponding to when the cooling capacity of the base-type natural cooling air-conditioning system is half of the upper limit of the cooling capacity.

6. The control method according to claim 5, characterized in that: The control method further comprises: During the operation of the natural cooling mode, when the supply air temperature is less than or equal to the first temperature threshold, adjusting the operating frequency of the refrigerant pump to the upper limit frequency of the refrigerant pump at a first adjustment rate; When the supply air temperature is greater than a second temperature threshold, adjusting the operating frequency of the refrigerant pump to a lower limit frequency of the refrigerant pump at a first adjustment rate; When the supply air temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold, determining the adjustment rate of the operating frequency of the refrigerant pump according to the third temperature difference, the operating frequency of the refrigerant pump being between the upper frequency limit and the lower frequency limit; The third temperature difference is the absolute value of the temperature difference between the supply air temperature and the preset supply air temperature.

7. The control method according to claim 6, characterized in that: When the supply air temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold, determining the adjustment rate of the operating frequency of the refrigerant pump according to the third temperature difference includes: When the third temperature difference exceeds the sixth temperature deviation and does not exceed the fifth temperature deviation, adjusting the operating frequency of the refrigerant pump at a second adjustment rate; When the third temperature difference does not exceed the sixth temperature deviation, adjusting the operating frequency of the refrigerant pump at a third adjustment rate until the supply air temperature reaches a preset supply air temperature; The first adjustment rate is greater than the second adjustment rate, and the second adjustment rate is greater than the third adjustment rate.

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