Data center air conditioning system and control method thereof

Abstract

The invention discloses a data center air conditioning system and a control method thereof.The air conditioning system comprises a compressor, a condenser, a throttling element, an evaporation coil and a natural cooling coil, the condenser is provided with a refrigerant pipeline and a water pipeline which are arranged in parallel, and the compressor, the refrigerant pipeline, the throttling element and the evaporation coil are sequentially connected to form a refrigerant circulation loop; the cooling water inlet, the water pipeline and the cooling water outlet are sequentially connected to form a first cooling water loop, the cooling water inlet, the natural cooling coil and the cooling water outlet are sequentially connected to form a second cooling water loop, and the cooling water inlet, the natural cooling coil, the water pipeline and the cooling water outlet are sequentially connected to form a third cooling water loop. At least one of the first cooling water loop, the second cooling water loop and the third cooling water loop is conducted for refrigeration, and when the first cooling water loop and the third cooling water loop are conducted, the refrigerant circulation loop is conducted at the same time. Refrigeration modes can be flexibly selected according to indoor and outdoor temperatures, so that the effects of efficient refrigeration and energy conservation are achieved.

Description

Technical Field

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

[0002] The rapid development of the information industry and digital construction has promoted the rapid growth of the number and construction scale of data center computer rooms. According to statistics, the energy consumption of air conditioning in data center computer rooms accounts for about 40%-50% of its total energy consumption. The sensible heat load of data center computer rooms is relatively large, and continuous cooling operation is required all year round. Therefore, how to improve the annual energy efficiency ratio of air conditioners and reduce air conditioning energy consumption is a technical problem that needs to be solved urgently.

[0003] At present, the air conditioning system of the computer room of the data center includes a compressor, a condenser, a throttling element, an evaporating coil, a natural cooling coil, etc. According to the path of the cooling water circulation flow, the natural cooling coil and the condenser can be set in parallel or in series. For the natural cooling coil and condenser set in series, the cooling water first passes through the natural cooling coil to evaporate and exchange heat with the indoor air, and then flows to the condenser to exchange heat with the refrigerant. In this way, the indoor return air is first pre-cooled by the natural cooling coil, and then cooled through the refrigerant circulation loop, so that the cooling capacity of the refrigerant circulation loop is minimized, which can greatly reduce the energy consumption of the compressor and maximize the natural cooling effect of the natural cooling coil. However, the cooling water needs to flow through the natural cooling coil and the condenser in sequence, which has a large resistance and a high demand for the water pump. In addition, the temperature of the cooling water will rise after heat exchange at the natural cooling coil, resulting in a smaller heat exchange amount of the cooling water at the condenser and lower compressor energy efficiency. At the same time, the data center computer room has the characteristics of low load and low indoor return air temperature in the initial stage of construction. Once the indoor return air temperature is lower than the cooling water temperature, the heat exchange when the cooling water flows through the natural cooling coil will cause the return air temperature to rise, which not only fails to achieve the purpose of pre-cooling, but also increases the cooling capacity of the subsequent refrigerant circulation loop, greatly increasing the energy consumption of the compressor.

[0004] For the natural cooling coil and condenser arranged in parallel, the cooling water can be directly supplied to the condenser or the natural cooling coil for heat exchange, or the cooling water can be diverted to the natural cooling coil for evaporative heat exchange with the indoor air while being supplied to the condenser for heat exchange, so as to realize the cooling mode of mechanical cooling or natural cooling alone, or the cooling mode of mechanical cooling and natural cooling at the same time. In this way, the flow resistance of the cooling water is small, and the corresponding demand for the water pump is also low; and the cooling water flows directly to the condenser for efficient heat exchange, so that the compressor has high energy efficiency; at the same time, in the case of low load and low indoor return air temperature in the early stage of the construction of the data center computer room, mechanical cooling can be directly carried out, and there will be no reverse heating of the indoor return air, thereby avoiding excessive energy consumption of the compressor. However, the natural cooling coil and condenser arranged in parallel have a more complex control logic to select the cooling mode, which is inconvenient to operate; and the cooling mode is mainly mechanical cooling, and the compressor basically runs all year round, and the natural cooling mode cannot be fully utilized to the maximum.

[0005] Therefore, the existing data center air-conditioning system is unable to select the appropriate cooling mode according to the actual environment to maximize the advantages of mechanical refrigeration, natural cooling, pre-cooling and other modes, resulting in the air-conditioning system having the disadvantages of complex operation, high energy consumption, low energy efficiency and high equipment requirements. Summary of the invention

[0006] In order to solve the above-mentioned defects in the prior art, an object of the present invention is to provide a data center air conditioning system and a control method thereof, so as to flexibly select a cooling mode according to indoor and outdoor temperatures, thereby achieving efficient cooling and energy saving effects.

[0007] A first aspect of the present invention provides a data center air conditioning system, comprising: a compressor, a condenser, a throttling element, an evaporating coil and a natural cooling coil, the condenser having a refrigerant pipeline and a water pipeline arranged in parallel, the compressor, the refrigerant pipeline, the throttling element and the evaporating coil are sequentially connected to form a refrigerant circulation loop;

[0008] The cooling water inlet, water pipeline and cooling water outlet are connected in sequence to form a first cooling water circuit, the cooling water inlet, natural cooling coil and cooling water outlet are connected in sequence to form a second cooling water circuit, the cooling water inlet, natural cooling coil, water pipeline and cooling water outlet are connected in sequence to form a third cooling water circuit, at least one of the first cooling water circuit, the second cooling water circuit and the third cooling water circuit is connected for refrigeration, and when the first cooling water circuit and the third cooling water circuit are connected, the refrigerant circulation circuit is also connected at the same time.

[0009] As a preferred embodiment, in the first aspect of the present invention, a water pump is provided on the cooling water inlet pipeline, and the cooling water inlet is powered by the water pump to flow to the first cooling water circuit, the second cooling water circuit and the third cooling water circuit.

[0010] As a preferred embodiment, in the first aspect of the present invention, fans are provided on the sides of the evaporating coil and the natural cooling coil, and the air outlet of the fans is directed toward the evaporating coil and the natural cooling coil.

[0011] As a preferred embodiment, in the first aspect of the present invention, in the first cooling water circuit, a first valve body is provided on the pipeline between the cooling water inlet and the water pipeline, and a second valve body is provided on the pipeline between the water pipeline and the cooling water outlet.

[0012] As a preferred embodiment, in the first aspect of the present invention, in the second cooling water circuit, a third valve body is provided on the pipeline between the cooling water inlet and the natural cooling coil, and a fourth valve body is provided on the pipeline between the natural cooling coil and the cooling water outlet.

[0013] As a preferred embodiment, in the first aspect of the present invention, in the third cooling water circuit, a fifth valve body is provided on the pipeline between the natural cooling coil and the water pipeline.

[0014] A second aspect of the present invention provides a control method for a data center air conditioning system, comprising the following steps:

[0015] Obtain the cooling water inlet temperature and indoor return air temperature and compare them;

[0016] If the indoor return air temperature is lower than the cooling water inlet temperature, the refrigerant circulation loop formed by the compressor, the refrigerant pipeline, the throttling element and the evaporating coil are controlled to be turned on, and the first cooling water loop formed by the cooling water inlet, the water pipeline and the cooling water outlet are controlled to be turned on to start the mechanical refrigeration mode;

[0017] If the indoor return air temperature is higher than the cooling water inlet temperature and the temperature difference between the two is small, the refrigerant circulation loop formed by the compressor, refrigerant pipeline, throttling element and evaporation coil connected in sequence is controlled to be turned on, and the third cooling water loop formed by the cooling water inlet, natural cooling coil, water pipeline and cooling water outlet connected in sequence is controlled to be turned on to start the precooling mode;

[0018] If the indoor return air temperature is higher than the cooling water inlet temperature and the temperature difference between the two is large, the second cooling water circuit formed by connecting the cooling water inlet, the natural cooling coil and the cooling water outlet in sequence is controlled to be turned on to start the natural cooling mode.

[0019] As a preferred embodiment, in the second aspect of the present invention, when the mechanical refrigeration mode is turned on, the compressor and the throttling element are controlled to open to make the refrigerant circulation circuit conductive, and the first valve body on the pipeline between the cooling water inlet and the water pipeline, and the second valve body on the pipeline between the water pipeline and the cooling water outlet are controlled to open to make the first cooling water circuit conductive.

[0020] As a preferred embodiment, in the second aspect of the present invention, when the pre-cooling mode is turned on, the compressor and the throttling element are controlled to open to make the refrigerant circulation circuit conductive, and the third valve body on the pipeline between the cooling water inlet and the natural cooling coil, the fifth valve body on the pipeline between the natural cooling coil and the water pipeline, and the second valve body on the pipeline between the water pipeline and the cooling water outlet are controlled to open to make the third cooling water circuit conductive.

[0021] As a preferred embodiment, in the second aspect of the present invention, when the natural cooling mode is turned on, the third valve body on the pipeline between the cooling water inlet and the natural cooling coil, and the fourth valve body on the pipeline between the natural cooling coil and the cooling water outlet are controlled to open so that the second cooling water circuit is conductive.

[0022] As a preferred embodiment, in the second aspect of the present invention, the mechanical refrigeration mode, pre-cooling mode and natural cooling mode are controlled by a controller. If the indoor return air temperature is higher than the cooling water inlet temperature, the controller can control at least one of the mechanical refrigeration mode, pre-cooling mode and natural cooling mode to start according to the minimum refrigeration energy consumption.

[0023] The data center air conditioning system and control method thereof provided by the present invention have the following technical effects:

[0024] The refrigerant circulation circuit, the first cooling water circuit, the second cooling water circuit and the third cooling water circuit can be flexibly selected to be connected according to the indoor and outdoor temperatures.

[0025] When the indoor temperature is lower than the outdoor temperature, the mechanical refrigeration mode is turned on, the refrigerant circulation circuit formed by the compressor, refrigerant pipeline, throttling element and evaporating coil are connected in sequence, and the first cooling water circuit formed by the cooling water inlet, water pipeline and cooling water outlet are connected in sequence, and the compressor drives the refrigerant to flow in the refrigerant circulation circuit, the refrigerant condenses and exchanges heat with the cooling water in the water pipeline in the refrigerant pipeline of the condenser, and evaporates and exchanges heat in the evaporating coil to cool the room.

[0026] If the indoor temperature is higher than the outdoor temperature and the temperature difference between the two is small, the pre-cooling mode is turned on, the refrigerant circulation circuit formed by the compressor, refrigerant pipeline, throttling element and evaporating coil connected in sequence is turned on, and the third cooling water circuit formed by the cooling water inlet, natural cooling coil, water pipeline and cooling water outlet connected in sequence is turned on, the cooling water flows into the natural cooling coil to exchange heat with the indoor air to initially cool the indoor air, and then when the compressor drives the refrigerant to flow in the refrigerant circulation circuit, the refrigerant condenses and exchanges heat with the cooling water in the water pipeline in the refrigerant pipeline of the condenser, and evaporates and exchanges heat in the evaporating coil to cool the room.

[0027] If the indoor temperature is higher than the outdoor temperature and the temperature difference between the two is large, the natural cooling mode is turned on. The second cooling water circuit formed by connecting the cooling water inlet, the natural cooling coil and the cooling water outlet in sequence is turned on, and the cooling water flows into the natural cooling coil to exchange heat with the indoor air to cool the room.

[0028] In this way, the present invention can flexibly select the refrigeration mode of the air-conditioning system according to the indoor and outdoor temperature information, and make full use of the natural cooling mode, thereby reducing the output and energy consumption of the compressor, thereby improving the annual energy efficiency ratio of the air-conditioning system, reducing the energy consumption of the air-conditioning system, and achieving the purpose of efficient refrigeration and energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The structural diagram of the invented data center air conditioning system;

[0030] Figure 2 It is a schematic diagram of the data center air conditioning control method of the present invention.

[0031] Reference numerals:

[0032] 1. Compressor; 2. Condenser; 21. Refrigerant pipeline; 22. Water pipeline; 3. Throttling element; 4. Evaporator coil; 5. Natural cooling coil; 6. Water pump; 7. Fan; 8. First valve body; 9. Second valve body; 10. Third valve body; 11. Fourth valve body; 12. Fifth valve body. DETAILED DESCRIPTION

[0033] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0036] Example 1

[0037] See also Figure 1This embodiment provides a data center air conditioning system, including: a compressor 1, a condenser 2, a throttling element 3, an evaporating coil 4 and a natural cooling coil 5, the condenser 2 has a refrigerant pipeline 21 and a water pipeline 22 arranged in parallel, the compressor 1, the refrigerant pipeline 21, the throttling element 3 and the evaporating coil 4 are sequentially connected to form a refrigerant circulation loop. The cooling water inlet, the water pipeline 22 and the cooling water outlet are sequentially connected to form a first cooling water loop, the cooling water inlet, the natural cooling coil 5, and the cooling water outlet are sequentially connected to form a second cooling water loop, the cooling water inlet, the natural cooling coil 5, the water pipeline 22 and the cooling water outlet are sequentially connected to form a third cooling water loop, at least one of the first cooling water loop, the second cooling water loop and the third cooling water loop is connected for cooling, and when the first cooling water loop and the third cooling water loop are connected, the refrigerant circulation loop is simultaneously connected.

[0038] The refrigerant circulation loop, the first cooling water loop, the second cooling water loop and the third cooling water loop can be flexibly selected to be turned on or off according to the indoor and outdoor temperatures. In this embodiment, the indoor temperature is the indoor return air temperature, and the outdoor temperature is the dry bulb temperature or the wet bulb temperature, which is reflected in the cooling water inlet temperature. Based on this, the cooling mode selection of this embodiment is specifically:

[0039] When the outdoor dry bulb temperature or wet bulb temperature is high, causing the cooling water temperature to be higher than the indoor return air temperature, the mechanical refrigeration mode is turned on. The compressor 1 and the throttling element 3 are turned on, so that the refrigerant circulation loop formed by the compressor 1, the refrigerant pipeline 21, the throttling element 3 and the evaporation coil 4 are connected in sequence, and at the same time, the first cooling water loop formed by the cooling water inlet, the water pipeline 22 and the cooling water outlet are controlled to be connected. In this mode, the cooling water flows completely through the water pipeline 22, and the compressor 1 drives the refrigerant to flow in the refrigerant circulation loop. The refrigerant condenses and exchanges heat with the cooling water in the water pipeline 22 in the refrigerant pipeline 21 of the condenser 2, and evaporates and exchanges heat with the indoor return air in the evaporation coil 4 to cool the room. This mode is often used in the early stage of the construction of the data center computer room. It has the characteristics of low load and low indoor return air temperature. In this case, the cooling water flows directly through the water pipeline 22 to use the refrigerant circulation loop to cool the indoor return air, avoiding the occurrence of reverse heating of the indoor return air, thereby avoiding excessive energy consumption of the compressor.

[0040] When the outdoor dry bulb temperature or wet bulb temperature decreases, making the cooling water temperature lower than the indoor return air temperature, but the temperature difference between the cooling water temperature and the indoor return air temperature is small, the pre-cooling mode is turned on. The compressor 1 and the throttling element 3 are turned on, so that the refrigerant circulation loop formed by the compressor 1, the refrigerant pipeline 21, the throttling element 3 and the evaporating coil 4 are connected in sequence, and at the same time, the third cooling water loop formed by the cooling water inlet, the natural cooling coil 5, the water pipeline 22 and the cooling water outlet are controlled to be connected. In this mode, the cooling water first flows into the natural cooling coil 5 to exchange heat with the indoor return air to initially cool the indoor return air, and then flows through the water pipeline 22, and then the compressor 1 is used to drive the refrigerant to flow in the refrigerant circulation loop, and the refrigerant condenses and exchanges heat with the cooling water in the water pipeline 22 in the refrigerant pipeline 21 of the condenser 2, and evaporates and exchanges heat with the indoor return air in the evaporating coil 4 to cool the room. Therefore, the pre-cooling mode can be realized by combining the natural cooling mode with the mechanical refrigeration mode. Since the temperature difference between the cooling water temperature and the indoor return air temperature is small, complete natural cooling is not enough to provide all the cooling capacity. Combining natural cooling with mechanical refrigeration can pre-cool the indoor return air in advance, and then perform mechanical refrigeration, which is beneficial to reduce the energy consumption of the compressor 1 and achieve the purpose of energy saving. In this mode, the natural cooling coil 5 and the condenser 2 are in series mode. The indoor return air is first evaporated and heat-exchanged by the natural cooling coil 5 and the indoor air, and then refrigerated through the refrigerant circulation loop, so that the cooling capacity of the refrigerant circulation loop is minimized, which can not only greatly reduce the energy consumption of the compressor 1, but also maximize the natural cooling effect of the natural cooling coil 5, and has the characteristics of high efficiency and energy saving.

[0041] When the outdoor dry-bulb temperature or wet-bulb temperature decreases, making the cooling water temperature lower than the indoor return air temperature, and the temperature difference between the cooling water temperature and the indoor return air temperature is large, the natural cooling mode is turned on. The large temperature difference makes natural cooling sufficient to provide all the cooling capacity. The second cooling water circuit formed by controlling the cooling water inlet, the natural cooling coil 5 and the cooling water outlet to be connected in sequence, and the cooling water flows into the natural cooling coil 5 to exchange heat with the indoor return air to cool the room. This mode relies entirely on natural cooling, and the natural cooling effect of the natural cooling coil 5 is fully utilized, without the need for the compressor 1 to work, and the energy saving effect is optimized.

[0042] Among them, the natural cooling coil 5 is connected in parallel with the condenser 2 in the mechanical refrigeration mode and the natural cooling mode, and the natural cooling coil 5 is connected in series with the condenser 2 in the pre-cooling mode. Generally, the data center room has the characteristics of low load and low indoor return air temperature in the initial stage of construction, and the indoor return air temperature is generally lower than the cooling water temperature. In this case, the mechanical refrigeration mode is generally adopted, and the cooling water flows directly through the water pipe 22 to use the refrigerant circulation loop to cool the indoor return air, avoiding the reverse heating of the indoor return air, thereby avoiding excessive energy consumption of the compressor. When the indoor return air temperature is higher than the cooling water temperature, the above only lists the commonly used pre-cooling mode and natural cooling mode. In actual application, any one of the mechanical refrigeration mode, pre-cooling mode, and natural cooling mode, or a combination of two or even a combination of three can be selected. The selection needs to comprehensively consider the demand of the cooling water inlet resistance on the water pump 6, the influence of the cooling water temperature rise in the series mode on the energy efficiency of the compressor 1, the energy consumption of the compressor 1 and other factors, and select the appropriate refrigeration mode with the goal of the most energy saving.

[0043] In this way, this embodiment can flexibly select the cooling mode of the air-conditioning system according to the indoor and outdoor temperature information, so that the natural cooling mode can be fully utilized to the maximum extent, thereby reducing the output and energy consumption of the compressor 1, thereby improving the annual energy efficiency ratio of the air-conditioning system, reducing the energy consumption of the air-conditioning system, and achieving the purpose of efficient cooling and energy saving.

[0044] In addition, the mechanical refrigeration mode, pre-cooling mode and natural cooling mode can be considered to be turned on in pairs or at the same time according to the actual indoor and outdoor temperature information and theoretical energy consumption information, so as to minimize energy consumption while cooling. Of course, in actual application, generally only one of the refrigeration modes will be selected to achieve the purpose of energy saving, and it has a simpler control logic, but the possibility of turning on two or three at the same time is not ruled out.

[0045] Among them, the condenser 2 is a plate condenser or a shell and tube condenser, etc., which are common condensers on the market. The throttling element 3 can be an electronic expansion valve or a thermal expansion valve, etc. The evaporating coil 4 can be a fluorine coil. Accordingly, the refrigerant can be selected as Freon.

[0046] The air conditioning system of this embodiment is controlled by a controller to achieve automatic refrigeration.

[0047] A water pump 6 is provided on the cooling water inlet pipeline, and the cooling water inlet is powered by the water pump 6 to flow to the first cooling water circuit, the second cooling water circuit and the third cooling water circuit. When any of the first cooling water circuit, the second cooling water circuit and the third cooling water circuit needs to introduce cooling water, the cooling water is introduced into the air conditioning system by turning on the water pump 6 to pump water. The water pump 6 can have the function of adjusting the cooling water flow rate and flow velocity to achieve the optimal cooling and heat exchange effect.

[0048] A fan 7 is provided on the side of the evaporating coil 4 and the natural cooling coil 5, and the air outlet of the fan 7 is directed toward the evaporating coil 4 and the natural cooling coil 5. When the evaporating coil 4 and the natural cooling coil 5 are used for evaporative heat exchange, the fan 7 blows the indoor return air toward the evaporating coil 4 and the natural cooling coil 5, so that the indoor return air exchanges heat with the refrigerant in the evaporating coil 4 and the cooling water in the natural cooling coil 5. The evaporating coil 4 and the natural cooling coil 5 can be equipped with the same fan 7, or each can be equipped with a fan 7.

[0049] In the first cooling water circuit, a first valve body 8 is provided on the pipeline between the cooling water inlet and the water pipeline 22, and a second valve body 9 is provided on the pipeline between the water pipeline 22 and the cooling water outlet. When the mechanical refrigeration mode is turned on, the first valve body 8 and the second valve body 9 are opened, so that the cooling water enters the water pipeline 22 and exchanges heat with the refrigerant in the refrigerant pipeline 21 before flowing out of the air conditioning system.

[0050] In the second cooling water loop, a third valve body 10 is provided on the pipeline between the cooling water inlet and the natural cooling coil 5, and a fourth valve body 11 is provided on the pipeline between the natural cooling coil 5 and the cooling water outlet. When the natural cooling mode is turned on, the third valve body 10 and the fourth valve body 11 are opened, so that the cooling water enters the natural cooling coil 5 and exchanges heat with the indoor return air before flowing out of the air conditioning system.

[0051] In the third cooling water loop, a fifth valve body 12 is provided on the pipeline between the natural cooling coil 5 and the water pipeline 22. When the pre-cooling mode is turned on, the third valve body 10, the fifth valve body 12 and the second valve body 9 are opened, so that the cooling water first enters the natural cooling coil 5 to exchange heat with the indoor return air, and then enters the water pipeline 22 to exchange heat with the refrigerant in the refrigerant pipeline 21 before flowing out of the air conditioning system.

[0052] Of course, when the mechanical refrigeration mode, precooling mode, and natural cooling mode are turned on, the valve body adapted to the cooling water circuit can be opened accordingly. The first valve body 8, the second valve body 9, the third valve body 10, the fourth valve body 11, and the fifth valve body 12 of this embodiment can all be electric valves and electrically connected to the controller to realize automatic control of the opening and closing of the valve body.

[0053] Example 2

[0054] See also Figure 2 This embodiment provides a control method for a data center air conditioning system, which is used to control the data center air conditioning system of embodiment 1. The control method includes the following steps:

[0055] Obtain the cooling water inlet temperature and indoor return air temperature and compare them;

[0056] If the indoor return air temperature is lower than the cooling water inlet temperature, the refrigerant circulation loop formed by the compressor 1, the refrigerant pipeline 21, the throttling element 3 and the evaporating coil 4 connected in sequence is controlled to be turned on, and the first cooling water loop formed by the cooling water inlet, the water pipeline 22 and the cooling water outlet connected in sequence is controlled to be turned on to start the mechanical refrigeration mode;

[0057] If the indoor return air temperature is higher than the cooling water inlet temperature and the temperature difference between the two is small, the refrigerant circulation loop formed by the compressor 1, the refrigerant pipe 21, the throttling element 3 and the evaporating coil 4 connected in sequence is controlled to be turned on, and the third cooling water loop formed by the cooling water inlet, the natural cooling coil 5, the water pipe 22 and the cooling water outlet connected in sequence is controlled to be turned on to start the precooling mode;

[0058] If the indoor return air temperature is higher than the cooling water inlet temperature and the temperature difference between the two is large, the second cooling water circuit formed by connecting the cooling water inlet, the natural cooling coil 5 and the cooling water outlet in sequence is controlled to be turned on to start the natural cooling mode.

[0059] Specifically, when the outdoor dry-bulb temperature or wet-bulb temperature is high, causing the cooling water inlet temperature to be higher than the indoor return air temperature, the mechanical refrigeration mode is turned on. The compressor 1 and the throttling element 3 are turned on, so that the refrigerant circulation loop formed by the compressor 1, the refrigerant pipeline 21, the throttling element 3 and the evaporating coil 4 are connected in sequence, and at the same time, the first cooling water loop formed by the cooling water inlet, the water pipeline 22 and the cooling water outlet are controlled to be connected. In this mode, the cooling water flows completely through the water pipeline 22, and the compressor 1 drives the refrigerant to flow in the refrigerant circulation loop. The refrigerant condenses and exchanges heat with the cooling water in the water pipeline 22 in the refrigerant pipeline 21 of the condenser 2, and evaporates and exchanges heat with the indoor return air in the evaporating coil 4 to cool the room.

[0060] When the outdoor dry-bulb temperature or wet-bulb temperature decreases, making the cooling water inlet temperature lower than the indoor return air temperature, but the temperature difference between the cooling water inlet temperature and the indoor return air temperature is small, the pre-cooling mode is turned on. The compressor 1 and the throttling element 3 are turned on, so that the refrigerant circulation loop formed by the compressor 1, the refrigerant pipeline 21, the throttling element 3 and the evaporating coil 4 are connected in sequence, and at the same time, the third cooling water loop formed by the cooling water inlet, the natural cooling coil 5, the water pipeline 22 and the cooling water outlet are controlled to be connected. In this mode, the cooling water first flows into the natural cooling coil 5 to exchange heat with the indoor return air to initially cool the indoor return air, and then flows through the water pipeline 22, and then the compressor 1 is used to drive the refrigerant to flow in the refrigerant circulation loop, and the refrigerant condenses and exchanges heat with the cooling water in the water pipeline 22 in the refrigerant pipeline 21 of the condenser 2, and evaporates and exchanges heat with the indoor return air in the evaporating coil 4 to cool the room. Therefore, the pre-cooling mode can be realized by combining the natural cooling mode with the mechanical refrigeration mode. Since the temperature difference between the cooling water temperature and the indoor return air temperature is small, complete natural cooling is not enough to provide all the cooling capacity. Combining natural cooling with mechanical refrigeration can pre-cool the indoor return air in advance, and then perform mechanical refrigeration, which is beneficial to reduce the energy consumption of compressor 1 and achieve the purpose of energy saving.

[0061] When the outdoor dry-bulb temperature or wet-bulb temperature decreases, making the cooling water inlet temperature lower than the indoor return air temperature, and the temperature difference between the cooling water inlet temperature and the indoor return air temperature is large, the natural cooling mode is turned on. The large temperature difference makes natural cooling sufficient to provide all the cooling capacity. The second cooling water circuit formed by the cooling water inlet, the natural cooling coil 5 and the cooling water outlet are controlled to be connected, and the cooling water flows into the natural cooling coil 5 to exchange heat with the indoor return air to cool the room.

[0062] Among them, the natural cooling coil 5 is connected in parallel with the condenser 2 in the mechanical refrigeration mode and the natural cooling mode, and the natural cooling coil 5 is connected in series with the condenser 2 in the pre-cooling mode. Generally, the data center room has the characteristics of low load and low indoor return air temperature in the initial stage of construction, and the indoor return air temperature is generally lower than the cooling water temperature. In this case, the mechanical refrigeration mode is generally adopted, and the cooling water flows directly through the water pipe 22 to use the refrigerant circulation loop to cool the indoor return air, avoiding the reverse heating of the indoor return air, thereby avoiding excessive energy consumption of the compressor. When the indoor return air temperature is higher than the cooling water temperature, the above only lists the commonly used pre-cooling mode and natural cooling mode. In actual application, any one of the mechanical refrigeration mode, pre-cooling mode, and natural cooling mode, or a combination of two or even a combination of three can be selected. The selection needs to comprehensively consider the demand of the cooling water inlet resistance on the water pump 6, the influence of the cooling water temperature rise in the series mode on the energy efficiency of the compressor 1, the energy consumption of the compressor 1 and other factors, and select the appropriate refrigeration mode with the goal of the most energy saving.

[0063] In this way, this embodiment can flexibly select the cooling mode of the air-conditioning system according to the indoor and outdoor temperature information, so that the natural cooling mode can be fully utilized to the maximum extent, thereby reducing the output and energy consumption of the compressor 1, thereby improving the annual energy efficiency ratio of the air-conditioning system, reducing the energy consumption of the air-conditioning system, and achieving the purpose of efficient cooling and energy saving.

[0064] Furthermore, when the mechanical refrigeration mode is turned on, the compressor 1 and the throttling element 3 are controlled to be turned on to open the refrigerant circulation circuit, and the first valve body 8 on the pipeline between the cooling water inlet and the water pipeline 22, and the second valve body 9 on the pipeline between the water pipeline 22 and the cooling water outlet are controlled to be turned on to open the first cooling water circuit. In this way, the refrigerant can circulate in the refrigerant circulation circuit, and when the refrigerant flows to the refrigerant pipeline 21 of the condenser 2, it exchanges heat with the cooling water entering the water pipeline 22.

[0065] When the pre-cooling mode is turned on, the compressor 1 and the throttling element 3 are controlled to be turned on to open the refrigerant circulation circuit, and the third valve body 10 on the pipeline between the cooling water inlet and the natural cooling coil 5, the fifth valve body 12 on the pipeline between the natural cooling coil 5 and the water pipeline 22, and the second valve body 9 on the pipeline between the water pipeline 22 and the cooling water outlet are controlled to be turned on to open the third cooling water circuit. In this way, the cooling water can first flow to the natural cooling coil 5 to exchange heat with the indoor return air, and then flow into the water pipeline 22. When the refrigerant circulates in the refrigerant circulation circuit and flows to the refrigerant pipeline 21 of the condenser 2, the refrigerant exchanges heat with the cooling water.

[0066] When the natural cooling mode is turned on, the third valve body 10 on the pipeline between the cooling water inlet and the natural cooling coil 5 and the fourth valve body 11 on the pipeline between the natural cooling coil 5 and the cooling water outlet are controlled to open, so that the second cooling water circuit is connected. In this way, the cooling water can flow into the natural cooling coil 5 to exchange heat with the indoor return air and then flow out of the air conditioning system.

[0067] Since the load is relatively small in the initial stage of construction of the data center computer room, and the indoor return air temperature is generally lower than the cooling water temperature, the mechanical refrigeration mode can be turned on by controlling the opening and closing of the first valve body 8, the second valve body 9, the third valve body 10, the fourth valve body 11 and the fifth valve body 12, that is, the first valve body 8 and the second valve body 9 are opened, and the third valve body 10, the fourth valve body 11 and the fifth valve body 12 are closed to open the first cooling water circuit, and the cooling water directly flows through the water pipe 22 to utilize the refrigerant circulation circuit to cool the indoor return air, thereby avoiding the occurrence of reverse heating of the indoor return air, thereby avoiding excessive energy consumption of the compressor.

[0068] When the data center room is fully loaded, the indoor return air temperature is higher than the cooling water temperature. By controlling the opening and closing of the first valve body 8, the second valve body 9, the third valve body 10, the fourth valve body 11 and the fifth valve body 12, and based on the maximum available cooling water inlet and the resistance of the air-conditioning system, a more energy-efficient mechanical refrigeration mode and / or natural cooling mode and / or pre-cooling mode can be comprehensively selected to enable the air-conditioning system to operate in the most efficient and energy-saving refrigeration mode.

[0069] Based on this, the mechanical refrigeration mode, pre-cooling mode and natural cooling mode are controlled by the controller. If the indoor return air temperature is higher than the cooling water inlet temperature, the controller can control at least one of the mechanical refrigeration mode, pre-cooling mode and natural cooling mode to start according to the minimum cooling energy consumption. That is, the mechanical refrigeration mode, pre-cooling mode and natural cooling mode can be combined in pairs or all three can be started at the same time, which needs to be jointly determined according to the indoor return air temperature, cooling water inlet temperature, energy consumption, etc.

[0070] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above-mentioned technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims

1. A data center air conditioning system, characterized in that: include: A compressor, a condenser, a throttling element, an evaporating coil and a natural cooling coil, wherein the condenser has a refrigerant pipeline and a water pipeline arranged in parallel, and the compressor, the refrigerant pipeline, the throttling element and the evaporating coil are sequentially connected to form a refrigerant circulation loop; The cooling water inlet, the water pipeline and the cooling water outlet are connected in sequence to form a first cooling water circuit, the cooling water inlet, the natural cooling coil and the cooling water outlet are connected in sequence to form a second cooling water circuit, the cooling water inlet, the natural cooling coil, the water pipeline and the cooling water outlet are connected in sequence to form a third cooling water circuit, at least one of the first cooling water circuit, the second cooling water circuit and the third cooling water circuit is connected for refrigeration, and when the first cooling water circuit and the third cooling water circuit are connected, the refrigerant circulation circuit is connected at the same time.

2. The data center air conditioning system according to claim 1, characterized in that: A water pump is provided on the cooling water inlet pipeline, and the cooling water inlet is powered by the water pump to flow to the first cooling water circuit, the second cooling water circuit and the third cooling water circuit.

3. The data center air conditioning system according to claim 1, characterized in that: Fans are provided on the sides of the evaporating coil and the natural cooling coil, and the air outlet of the fans is directed toward the evaporating coil and the natural cooling coil.

4. The data center air conditioning system according to claim 1, characterized in that: In the first cooling water circuit, a first valve body is provided on the pipeline between the cooling water inlet and the water pipeline, and a second valve body is provided on the pipeline between the water pipeline and the cooling water outlet.

5. The data center air conditioning system according to claim 1, characterized in that: In the second cooling water circuit, a third valve body is provided on the pipeline between the cooling water inlet and the natural cooling coil, and a fourth valve body is provided on the pipeline between the natural cooling coil and the cooling water outlet.

6. The data center air conditioning system according to claim 1, characterized in that: In the third cooling water circuit, a fifth valve body is provided on the pipeline between the natural cooling coil and the water pipeline.

7. A control method for a data center air conditioning system, characterized in that: The following steps are involved: Obtain the cooling water inlet temperature and indoor return air temperature and compare them; If the indoor return air temperature is lower than the cooling water inlet temperature, the refrigerant circulation loop formed by the compressor, the refrigerant pipeline, the throttling element and the evaporating coil are controlled to be turned on, and the first cooling water loop formed by the cooling water inlet, the water pipeline and the cooling water outlet are controlled to be turned on to start the mechanical refrigeration mode; If the indoor return air temperature is higher than the cooling water inlet temperature and the temperature difference between the two is small, the refrigerant circulation loop formed by the compressor, refrigerant pipeline, throttling element and evaporation coil connected in sequence is controlled to be turned on, and the third cooling water loop formed by the cooling water inlet, natural cooling coil, water pipeline and cooling water outlet connected in sequence is controlled to be turned on to start the precooling mode; If the indoor return air temperature is higher than the cooling water inlet temperature and the temperature difference between the two is large, the second cooling water circuit formed by connecting the cooling water inlet, the natural cooling coil and the cooling water outlet in sequence is controlled to be turned on to start the natural cooling mode.

8. The control method of the data center air conditioning system according to claim 7, characterized in that: When the mechanical refrigeration mode is turned on, the compressor and the throttling element are controlled to open to make the refrigerant circulation circuit conductive, and the first valve body on the pipeline between the cooling water inlet and the water pipeline, and the second valve body on the pipeline between the water pipeline and the cooling water outlet are controlled to open to make the first cooling water circuit conductive.

9. The control method of the data center air conditioning system according to claim 7, characterized in that: When the pre-cooling mode is turned on, the compressor and the throttling element are controlled to open to make the refrigerant circulation circuit conductive, and the third valve body on the pipeline between the cooling water inlet and the natural cooling coil, the fifth valve body on the pipeline between the natural cooling coil and the water pipeline, and the second valve body on the pipeline between the water pipeline and the cooling water outlet are controlled to open to make the third cooling water circuit conductive.

10. The control method of the data center air conditioning system according to claim 7, characterized in that: When the natural cooling mode is turned on, the third valve body on the pipeline between the cooling water inlet and the natural cooling coil and the fourth valve body on the pipeline between the natural cooling coil and the cooling water outlet are controlled to open so that the second cooling water circuit is conductive.

11. The control method of the data center air conditioning system according to claim 7, characterized in that: The mechanical refrigeration mode, the pre-cooling mode and the natural cooling mode are controlled by a controller. If the indoor return air temperature is higher than the cooling water inlet temperature, the controller can control at least one of the mechanical refrigeration mode, the pre-cooling mode and the natural cooling mode to be turned on according to the minimum refrigeration energy consumption.

Images