Cooling system of data center

Abstract

The invention provides a cold supply system of a data center, which comprises a cooling tower, a terminal air conditioner of a data center machine room, at least one refrigeration unit, a cold storage unit and a control system, and is characterized in that the at least one refrigeration unit is connected with the cooling tower, the terminal air conditioner and the control system; the cold storage unit is connected with the at least one refrigeration unit in parallel and connected with the cooling tower, the tail end air conditioner and the control system, and the cold storage unit is connected with the cooling tower, the tail end air conditioner and the control system under the control of the control system. The at least one refrigeration unit operates independently, or the cold storage unit operates independently, or the at least one refrigeration unit and the cold storage unit operate together.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of data center cooling technology, in particular to a cooling system of a data center. BACKGROUND

[0002] In recent years, with the rapid development of information industry and social economy, the construction scale and quantity of data centers are increasing rapidly, and the heat dissipation of data centers is also rising rapidly. In order to ensure the normal operation of data centers, the precision air conditioning system needs to be turned on all year round to discharge the heat generated by data centers in the machine room. Therefore, with the increasing pressure of data center operation cost, how to realize the energy saving of the cooling system of the machine room is imminent. In addition, when unexpected accidents such as power failure occur or the system equipment needs to be maintained or repaired, the cooling system still needs to continuously meet the requirements of the normal operation of the data center.

[0003] On the other hand, the cooling system of the data center machine room usually includes a cooling tower, a refrigeration unit, an end air conditioner of the data center machine room, and a control system. In the pre-cooling mode and the natural cooling mode, the heat of the machine room is taken away by the chilled water of the precision air conditioner, and then the low-temperature cooling water returned from the cooling tower is exchanged by the plate heat exchanger. After the heat exchange, the cooling water dissipates the heat of the machine room to the atmosphere through the cooling tower.

[0004] In the pre-cooling mode and the natural cooling mode, due to the instability of the outdoor wet-bulb temperature, the cold water unit in the refrigeration unit is repeatedly started and stopped, which is easy to cause the failure of the cold water unit, thereby affecting the heat dissipation of the whole data center machine room, and leading to the instability of the heat dissipation effect of the data center machine room. SUMMARY

[0005] The present application is completed in view of the above problems, and aims to provide a cooling system of a data center with a reasonable structure design, which improves the utilization efficiency of the natural cooling source of the data center, improves the stability and reliability of the system operation, and effectively reduces the PUE (Power Usage Effectiveness) of the data center.

[0006] One aspect of the present application relates to a cooling system of a data center, which comprises a cooling tower, an end air conditioner of a data center machine room, at least one refrigeration unit, a cold storage unit, and a control system. The at least one refrigeration unit is connected with the cooling tower, the end air conditioner, and the control system. The cold storage unit is connected with the at least one refrigeration unit in parallel, and is connected with the cooling tower, the end air conditioner, and the control system. Under the control of the control system, the at least one refrigeration unit operates alone, or the cold storage unit operates alone, or the at least one refrigeration unit and the cold storage unit operate together.

[0007] According to the application, a cooling system for a data center can be provided, which has a reasonable structure design, improves the utilization efficiency of natural cooling sources of the data center, improves the stability and reliability of the system, and effectively reduces the PUE of the data center. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a structural principle schematic diagram of the cooling system of the application. DETAILED DESCRIPTION

[0009] The technical solutions of the application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0010] In the description of the embodiments of the application, it should be noted that unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection or can communicate with each other; it can be direct connection, or indirect connection through intermediate equipment, or internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the term in the application can be immediately understood according to the specific circumstances.

[0011] In addition, the terms "first", "second" and "third" and the like in the specification of the application are used to distinguish different objects, rather than to describe a specific order. In addition, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

[0012] The cooling system 100 of the application is a cooling system for a data center, which can improve the utilization efficiency of natural cooling sources of the data center, and can safely and stably supply the cooling system, while effectively reducing the PUE (Power Usage Effectiveness, power usage efficiency) of the data center.

[0013] Figure 1 is a structural principle schematic diagram of the cooling system of the application. As shown in Figure 1 The cooling system 100 includes a cooling tower 1, an end air conditioner 12 of a data center machine room, a refrigeration unit 14, a cold storage unit 15, and a control system (not shown).

[0014] The control system is connected to the cooling tower 1, the terminal air conditioner 12, the refrigeration unit 14, and the cold storage unit 15 to control their operation. It can be understood that under the control of the control system, the refrigeration unit 14 operates independently, the cold storage unit 15 operates independently, or the refrigeration unit 14 and the cold storage unit 15 operate together.

[0015] The cooling system 100 also includes a cooling water supply loop R1 and a cooling water return loop R2 connected to the cooling tower 1, the refrigeration unit 14 and the cold storage unit 15. The cooling system 100 also includes a chilled water supply loop R3 and a chilled water return loop R4 connected to the cold storage tank 11, the terminal air conditioner 12, the refrigeration unit 14 and the cold storage unit 15.

[0016] The outlet of cooling tower 1 is connected to the inlet of refrigeration unit 14 via cooling water supply loop R1. The outlet of refrigeration unit 14 is connected to the inlet pipe of terminal air conditioner 12 via chilled water supply loop R3, so that the cooling water of cooling tower 1 reaches terminal air conditioner 12 via refrigeration unit 14. The water flowing out of the outlet of terminal air conditioner 12 reaches the inlet of cooling tower 1 via chilled water return loop R4, refrigeration unit 13, and cooling water return loop R2, so as to continuously circulate and cool the terminal air conditioner 12 of the data center computer room.

[0017] Since the cold storage unit 15 and the refrigeration unit 14 are connected in parallel between the cooling tower 1 and the terminal air conditioner 12, even if the refrigeration unit 14 fails, the cold storage unit 15 can replace the refrigeration unit 14 to operate, thereby improving the reliability of the cooling system 100 and further enhancing the reliability of the data center cold source system.

[0018] Furthermore, the control system involved in this invention consists of a central computer, terminal equipment, and various substations. Typically, a computer and LCD screen are configured in the control center to display and automatically record the operating status, fault alarms, and start / stop control of each cooling source device, water pump, etc., in the cooling system 100. All equipment can be operated automatically or manually, as well as locally. In other words, all equipment can be started and stopped locally and has manual and automatic control switch options. Using the control system, the control center can display the operating status and main operating parameters of the equipment, and perform centralized remote control and program control.

[0019] The following is a detailed description of the refrigeration unit 14 and the cold storage unit 15 in the cooling system 100.

[0020] In this embodiment, the cooling system 100 includes two sets of cooling units 14. It is understood that the number of cooling units 14 can be one or more, as long as the maximum number of cooling units 14 can meet the maximum cooling capacity requirement of the data center terminal air conditioner 12 under normal cooling mode (hereinafter referred to as mechanical cooling mode). Preferably, the cooling system 100 includes N (a natural number greater than 1) sets of conventional cooling units 14 and 1 set of standby cooling units 14.

[0021] Each refrigeration unit 14 includes a cooling water pump 2, a chiller unit 4, a plate heat exchanger for natural cooling 6, a primary chilled water pump 8 on the refrigeration side, multiple valves, and multiple pipes.

[0022] like Figure 1 As shown, the multiple pipes include a first cooling water supply pipe 21, a first branch pipe 22, a second branch pipe 23, a third branch pipe 24, a fourth branch pipe 25, a fifth branch pipe 26, a sixth branch pipe 27, a first chilled water supply pipe 28, a second chilled water return pipe 33, and a first cooling water return pipe 35. Additionally, the cooling system 100 also includes a second chilled water supply pipe 29 and a first chilled water return pipe 31.

[0023] In addition, multiple valves include four on / off valves respectively configured on the cooling side and the chiller side of the chiller unit 4 and the natural cooling plate heat exchanger 6. Specifically, on the cooling side, there are the natural cooling plate heat exchanger cooling bypass valve A2, the natural cooling plate heat exchanger cooling outlet valve B2, the chiller unit cooling bypass valve C2, and the chiller unit cooling inlet valve D2; and on the chiller side, there are the natural cooling plate heat exchanger chiller bypass valve A1, the natural cooling plate heat exchanger chiller outlet valve B1, the chiller unit chiller bypass valve C1, and the chiller unit chiller inlet valve D1. Hereinafter, they are simply referred to as valves A1 to D1 and A2 to D2.

[0024] The control system can switch the operating mode by controlling the opening and closing of the valves mentioned above to switch the connection mode in the refrigeration unit 14.

[0025] also, Figure 1 The arrows in the diagram indicate the direction of water flow in the pipes. Chiller unit 4 includes an evaporator and a condenser (not shown).

[0026] In each refrigeration unit 14, the outlet of the cooling tower 1 is connected to one end of the first cooling water supply pipe 21 via the cooling water supply loop R1, and the other end of the first cooling water supply pipe 21 is connected to the inlet of the cooling water side of the natural cooling plate heat exchanger 6. On the other hand, the outlet of the evaporator side of the chiller unit 4 is connected to the first chilled water supply pipe 28, and is connected to the inlet pipe of the terminal air conditioner 12 via the second chilled water supply pipe 29 through the chilled water supply loop R3.

[0027] Furthermore, the outlet pipe of the terminal air conditioner 12, namely the first chilled water return pipe 31, is connected to one end of the second chilled water return pipe 33 via the chilled water return loop R4, and the other end of the second chilled water return pipe 33 is connected to the inlet of the chilled water side of the plate heat exchanger 6 for natural cooling. On the other hand, the outlet of the condenser side of the chiller unit 4 is connected to the first cooling water return pipe 35, and is connected to the inlet of the cooling tower 1 via the cooling water return loop R2.

[0028] Furthermore, in the refrigeration unit 14, the first branch pipe 22 is connected to the first cooling water supply pipe 21 and the first cooling water return pipe 35; the second branch pipe 23 is connected to the first branch pipe 22 and the outlet on the cooling water side of the natural cooling plate heat exchanger 6; the third branch pipe 24 is connected to the first branch pipe 22 and the inlet on the condenser side of the chiller unit 4; the fourth branch pipe 25 is connected to the first chilled water supply pipe 28 and the second chilled water return pipe 33; the fifth branch pipe 26 is connected to the fourth branch pipe 25 and the outlet on the chilled water side of the natural cooling plate heat exchanger 6; and the sixth branch pipe 27 is connected to the fourth branch pipe 25 and the inlet on the evaporator side of the chiller unit 4.

[0029] In addition, the cooling water pump 2 is installed on the first cooling water supply pipe 21, specifically, between the connection points of the first cooling water supply pipe 21 and the cooling water supply loop R1 and the first branch pipe 22.

[0030] The chilled water primary pump 8 is installed on the second chilled water return pipe 33, specifically between the connection points of the second chilled water return pipe 33 and the chilled water return loop R4 and the fourth branch pipe 25. The chilled water secondary pump 10 is installed on the second chilled water supply pipe 29.

[0031] In addition, valves A1 and C1 are located on the fourth branch pipe 25. Specifically, valve A1 is located on the fourth branch pipe 25 between the connection of the second chilled water return pipe 33 and the fifth branch pipe 26; valve C1 is located on the fourth branch pipe 25 between the connection of the first chilled water supply pipe 28 and the sixth branch pipe 27.

[0032] On the other hand, valves A2 and C2 are located on the first branch pipe 22. Specifically, valve A2 is located on the first branch pipe 22 between the connection of the first cooling water supply pipe 21 and the second branch pipe 23; valve C2 is located on the first branch pipe 22 between the connection of the first cooling water return pipe 35 and the third branch pipe 24.

[0033] In addition, valve B1 is located on the fifth branch pipe 26, valve B2 is located on the second branch pipe 23, valve D1 is located on the sixth branch pipe 27, and valve D2 is located on the third branch pipe 24.

[0034] In addition, the chiller unit 4 is a water-cooled variable frequency centrifugal chiller unit, mainly used to supply cooling to the terminal air conditioner 12. Preferably, the cooling capacity of a single chiller unit 4 is 1750RT (6153kW). Each chiller unit 4 is equipped with one plate heat exchanger 6 for natural cooling (hereinafter, sometimes simply referred to as plate heat exchanger) to cool the chilled water during natural cooling and partial natural cooling.

[0035] Furthermore, in the cooling system 100 of the present invention, one cooling tower 1 can be configured for each group of refrigeration units 14 to provide cooling water to the chiller unit 4 in mechanical refrigeration mode. In the natural cooling and pre-cooling modes described below, the cooling water can be used to directly cool the chilled water through the plate heat exchanger 6 for natural cooling. In the refrigeration unit 14, the cooling tower 1 and the chiller unit 4 / plate heat exchanger 6 for natural cooling are connected in parallel and can serve as backups for each other. Each cooling tower 1 is controlled in a one-to-one correspondence with the chiller unit 4 in the same refrigeration unit 14. In addition, each cooling tower 1 is equipped with a regulating inlet valve (not shown) to automatically control the opening degree of the inlet valve according to the cooling tower inlet water flow rate when the cooling tower 1 needs to be opened.

[0036] In addition, two regulating bypass valves (not shown) are installed on the main cooling water supply and return loop, which includes cooling water supply loop R1 and cooling water return loop R2. These valves automatically adjust according to the temperature on cooling water supply loop R1. For example, when the outlet water temperature of cooling tower 1 is lower than the minimum allowable inlet water temperature of the corresponding refrigeration unit 14, the bypass valve is automatically opened, allowing a portion of the high-temperature cooling water to be directly mixed with the low-temperature cooling water before being supplied to chiller unit 4.

[0037] In addition, each refrigeration unit 14 is equipped with one chilled water primary pump 8 and one cooling water pump 2. In each refrigeration unit 14, the cooling water pump 2 and the chilled water primary pump 8 are designed in a one-to-one series connection with the chiller unit 4 / natural cooling plate heat exchanger 6; that is, the number of chilled water primary pumps 8 required to be in operation equals the required number of refrigeration units. When any chilled water primary pump 8 fails, the corresponding refrigeration unit 14 automatically stops, an alarm signal is issued, and other standby refrigeration units 14 are put into operation. Under other circumstances, the chilled water primary pumps 8 follow their respective refrigeration units 14, switching as needed.

[0038] In addition, the cooling system 100 also includes at least one chilled water secondary pump 10. Figure 1This embodiment illustrates an example with two chilled water secondary pumps 10. However, the number of chilled water secondary pumps 10 is not limited to this, as long as the maximum cooling capacity supply to the terminal air conditioner 12 is ensured. Each chilled water secondary pump 10 serves as a backup for the others; if one fails during operation, it can automatically switch to the other. Furthermore, both the chilled water primary pump 8 and the chilled water secondary pump 10 on the cooling side are variable frequency pumps. After the cooling system 100 is started, the frequency and number of chilled water secondary pumps 10 are automatically adjusted according to the terminal pressure difference setpoint (e.g., 100 kPa) to ensure the supply of cooling capacity to the terminal. For example, when the pressure difference is lower than the setpoint, the frequency of the chilled water secondary pump 10 is automatically increased; when the pressure difference is higher than the setpoint, the frequency of the chilled water secondary pump 10 is automatically decreased. Furthermore, both the chilled water primary pump 8 and the chilled water secondary pump 10 on the cooling side are variable frequency pumps.

[0039] In the cooling system 100 of this invention, a group control controller (not shown) is also provided, and a unit controller (not shown) is provided for each group of refrigeration units 14. The group control controller adopts a hard-wired configuration to monitor: outdoor wet-bulb temperature; temperature, flow rate, and pressure on the chilled water supply main and return water lines; flow rate and direction on the cold storage tank and loop bypass lines; and the status of the electrically operated valves on the main line and the status of the unit controllers. The group control controller analyzes the above monitoring data and determines the system's operating mode based on outdoor wet-bulb temperature, terminal load, availability of natural cooling mode, and equipment malfunctions.

[0040] The group controller can start and stop its corresponding refrigeration unit 14 through the unit controller. For example, if the group controller sends a refrigeration unit start command to the unit controller and does not receive feedback on the refrigeration unit's operating status 5 minutes later, the group controller will trigger a refrigeration unit failure alarm and start the next group of refrigeration units until they start successfully. The command signal sent by the group controller to the unit controller that failed to start must be canceled after the refrigeration unit failure alarm is triggered, and the refrigeration unit will be locked and not put into operation. When the refrigeration unit that failed to start can operate normally after maintenance and the alarm is cleared, the refrigeration unit that replaced it will continue to operate without switching.

[0041] In addition, each unit controller needs to monitor the status of the group controller. When a unit controller cannot detect a signal from the group controller, it issues an alarm. At this time, the unit controller maintains its previous operating state, while the corresponding chilled water primary pump 8 on the cooling side ignores the control signal from the group controller and switches to mains frequency operation.

[0042] Furthermore, if the secondary chilled water load detected by the group control controller exceeds, for example, 80% of the rated cooling capacity of the chiller unit operating on the primary chilled water side for a period of, for example, 10 minutes, another set of refrigeration units 14 should be started according to the operating time and startup strategy; conversely, if the detected secondary chilled water load is lower than, for example, 40% of the rated cooling capacity of the chiller unit operating on the primary chilled water side for a period of, for example, 10 minutes, one set of refrigeration units 14 should be shut down. The above ratios and times can be adjusted and set according to the actual operating environment.

[0043] In this embodiment, the cooling system 100 is equipped with a set of cold storage units 15, which includes a cold storage host 5, a cold storage plate heat exchanger 7, a cold storage side cooling water pump 3, a cold storage side chilled water primary pump 9, multiple pipes, and multiple valves. The cooling system 100 also includes a cold storage tank 11.

[0044] like Figure 1 As shown, the multiple pipes include a second cooling water supply pipe 41, a seventh branch pipe 42, an eighth branch pipe 43, a ninth branch pipe 44, a tenth branch pipe 45, an eleventh branch pipe 46, a twelfth branch pipe 47, a third chilled water supply pipe 48, a second cooling water drain pipe 53, and a second cooling water return pipe 55. In addition, the cooling system 100 also includes a fourth chilled water supply pipe 49 and a first cooling water drain pipe 51.

[0045] In addition, the multiple valves include four on / off valves respectively configured on the cooling side and the freezing side of the cold storage unit 5 and the cold storage plate heat exchanger 7. Specifically, these are the cold storage plate heat exchanger cooling bypass valve A4, the cold storage plate heat exchanger cooling outlet valve B4, the cold storage unit cooling bypass valve C4, and the cold storage unit cooling inlet valve D4 located on the cooling side; and the cold storage plate heat exchanger freezing bypass valve A3, the cold storage plate heat exchanger freezing outlet valve B3, the cold storage unit freezing bypass valve C3, and the cold storage unit freezing inlet valve D3 located on the freezing side. Hereinafter, these are simply referred to as valves A3 to D3 and A4 to D4. The multiple valves also include valves V1 and DV1 to DV3.

[0046] The control system can switch the connection mode of the cold storage unit 15 and thus switch its operating mode by controlling the opening and closing of the valves mentioned above.

[0047] The cold storage unit 15 and the refrigeration unit 14 are connected in parallel. The outlet of the cooling tower 1 is connected to the inlet of the cold storage unit 15 via the cooling water supply loop R1. The outlet of the cold storage unit 15 is connected to the cold storage tank 11 and can be connected to the inlet pipe of the terminal air conditioner 12 via the chilled water supply loop R3. This allows the cooling water from the cooling tower 1 to be cooled by the cold storage unit 15 and then directly reach the terminal air conditioner 12. The water flowing out of the outlet of the terminal air conditioner 12 reaches the cooling tower 1 via the chilled water return loop R4, the cold storage unit 15, and the cooling water return loop R2.

[0048] More specifically, the cold storage unit 5 also includes an evaporator and a condenser (not shown). In the cold storage unit 15, the outlet of the cooling tower 1 is connected to one end of the second cooling water supply pipe 41 via the cooling water supply loop R1, and the other end of the second cooling water supply pipe 41 is connected to the inlet of the cooling water side of the cold storage plate heat exchanger 7. On the other hand, the outlet of the evaporator side of the cold storage unit 5 is connected to a third chilled water supply pipe 48 and a fourth chilled water supply pipe 49. One end of the fourth chilled water supply pipe 49 is connected to the inlet of the cold storage tank 11, and the other end is connected to the inlet pipe of the terminal air conditioner 12 via the second chilled water supply pipe 29 through the chilled water supply loop R3.

[0049] Furthermore, the outlet pipe of the cold storage tank 11, namely the first cold water discharge pipe 51, is connected to the second cold water discharge pipe 53. One end of the second cold water discharge pipe 53 is connected to the inlet of the chilled water side of the cold storage plate heat exchanger 7, and the other end is connected to the chilled water return loop R4. In other words, the outlet pipe of the terminal air conditioner 12 can be connected to the inlet of the chilled water side of the cold storage plate heat exchanger 7 via the chilled water return loop R4 and the second cold water discharge pipe 53. On the other hand, the outlet of the condenser side of the cold storage unit 5 is connected to the second cooling water return pipe 55, and is connected to the inlet of the cooling tower 1 via the cooling water return loop R2.

[0050] In addition, in the cold storage unit 15, the seventh branch pipe 42 is connected to the second cooling water supply pipe 41 and the second cooling water return pipe 55; the eighth branch pipe 43 is connected to the seventh branch pipe 42 and the outlet of the cooling water side of the cold storage plate heat exchanger 7; the ninth branch pipe 44 is connected to the seventh branch pipe 42 and the inlet of the condenser side of the cold storage host 5; the tenth branch pipe 45 is connected to the third chilled water supply pipe 48 and the second cooling water pipe 53; the eleventh branch pipe 46 is connected to the tenth branch pipe 45 and the outlet of the chilled water side of the cold storage plate heat exchanger 7; and the twelfth branch pipe 47 is connected to the tenth branch pipe 45 and the inlet of the evaporator side of the cold storage host 5.

[0051] Additionally, the cold storage side cooling water pump 3 is mounted on the second cooling water supply pipe 41, specifically between the connection points of the second cooling water supply pipe 41 and the cooling water supply loop R1 and the seventh branch pipe 42. The cold storage side chilled water primary pump 9 is mounted on the second cooling water discharge pipe 53, specifically between the connection points of the second cooling water discharge pipe 53 and the first cooling water discharge pipe 51 and the tenth branch pipe 45.

[0052] In addition, valves A3 and C3 are configured on the tenth branch pipe 45. Specifically, valve A3 is located on the tenth branch pipe 45 between the connection of the second cold water pipe 53 and the eleventh branch pipe 46; valve C3 is located on the tenth branch pipe 45 between the connection of the third chilled water supply pipe 48 and the twelfth branch pipe 47.

[0053] On the other hand, valves A4 and C4 are configured on the seventh branch pipe 42. Specifically, valve A4 is located on the seventh branch pipe 42 between the connection of the second cooling water supply pipe 41 and the eighth branch pipe 43; valve C4 is located on the seventh branch pipe 42 between the connection of the second cooling water return pipe 55 and the ninth branch pipe 44.

[0054] Additionally, valve B3 is configured on the eleventh branch pipe 46, valve B4 on the eighth branch pipe 43, valve D3 on the twelfth branch pipe 47, and valve D4 on the ninth branch pipe 44. Furthermore, a parallel-connected valve group (V1, DV1, DV2) is configured on the second chilled water discharge pipe 53, specifically between the connections of the second chilled water discharge pipe 53 to the first chilled water discharge pipe 51 and the chilled water return loop R4. Valve DV3 is configured on the fourth chilled water supply pipe 49, specifically between the connections of the fourth chilled water supply pipe 49 to the third chilled water supply pipe 48 and the chilled water supply loop R3.

[0055] Furthermore, in this embodiment, the cold storage tank 11 in the cooling system 100 is a large cold storage tank, and the highest water level is the highest point of the entire cooling system 100. By setting up such a cold storage tank 11, it is possible to: (1) ensure sufficient cooling capacity to meet the needs of the terminal air conditioner 12 when the refrigeration unit 14 is not working; (2) achieve cost savings by storing cold at off-peak electricity prices and releasing cold at peak electricity prices when the cold storage capacity allows; and (3) improve the energy efficiency ratio of the entire system by storing cold at low temperatures and using a mixed plate heat exchanger cooling method during transitional seasons. In addition, the cold storage tank 11 and the refrigeration unit 14 are connected in parallel, and the chilled water secondary pump 10 can freely draw chilled water from the cold storage tank 11 or the refrigeration unit 14. Furthermore, the above-mentioned cold storage host 5 is a fixed-frequency centrifugal chiller unit, preferably with a cooling capacity of 1750RT (6153kW), mainly for low-temperature cold storage in the cold storage tank 11. In addition, a flow meter (not shown) is installed on the main pipeline (loop bypass pipeline) of the cold storage tank 11 to control the speed or frequency of the chilled water primary pump 8 on the refrigeration side.

[0056] In addition, two sets of bypass valves (not shown) are installed on the chilled water supply and return loop, which includes chilled water supply loop R3 and chilled water return loop R4. Each set of valves includes one on / off valve and one regulating valve. When the chilled water storage tank 11 needs to be isolated for maintenance, the four valves are automatically adjusted according to the pressure difference between R3 and R4 to balance the flow of primary and secondary chilled water. When the cooling system 100 is in the following cooling mode, the opening of the two regulating valves is controlled to mix the low-temperature water inside the chilled water storage tank 11 with a portion of the return water so that the temperature reaches the set value of the chilled water supply temperature before it is supplied to the terminal air conditioner 12.

[0057] Furthermore, the chilled water secondary pump 10 is powered by dual power sources: one from the mains and the other from a UPS battery, with the UPS battery providing power for at least 15 minutes. The effective volume of the cold storage tank 11 is designed to allow the cooling system 100 to operate continuously at full load for more than 15 minutes, and it is an open-type cold storage tank placed outdoors. In this invention, the effective volume of the cold storage tank 11 is 3200 cubic meters or more.

[0058] In addition, the chilled water storage tank 11 and the chilled water secondary pump 10 are connected in parallel on the chilled water supply and return main loop. The chilled water storage tank 11 is normally in a slightly charged state to meet the conditions for emergency cooling release during cooling supply interruptions. When the mains power fails, before the cooling unit 14 resumes normal operation, the chilled water secondary pump 10 continues to operate, and the chilled water storage tank 11 is in a cooling release state to provide chilled water to the terminal air conditioners 12, ensuring continuous cooling for the data center.

[0059] [About Operating Mode]

[0060] Based on the above-designed cooling system 100, there are three operating modes according to the outdoor temperature. Furthermore, the switching between operating modes is divided into manual and automatic switching. In manual switching, maintenance personnel set the operating mode according to the system's operating status. In automatic switching, the system automatically switches based on the outdoor wet-bulb temperature, cooling tower outlet water temperature, and chilled water outlet temperature of each plate heat exchanger. Specifically, in automatic switching mode, the cooling system 100 automatically switches based on the outdoor wet-bulb temperature, cooling tower outlet water temperature, and chilled water outlet temperature of the plate heat exchangers.

[0061] (1) Mechanical refrigeration mode

[0062] When the outdoor wet-bulb temperature is ≥19.5℃, the cooling system 100 operates in mechanical refrigeration mode, using the chiller unit to supply cooling to the terminal air conditioner 12. This mechanical refrigeration mode is also called the main unit refrigeration mode. In this mechanical refrigeration mode, only the chiller unit 4 is used to supply cooling to the terminal air conditioner 12. At this time, valves A2, D2 and valves A1, D1 are open, valves B2 and valves B1, C1 are closed, valve C2 is closed or used to regulate and control the water temperature, valves DV1, DV2, DV3 are open, and valve V1 is closed.

[0063] At this time, the outlet of cooling tower 1 is connected to the inlet of the condenser side of chiller unit 4 via cooling water supply loop R1, first cooling water supply pipe 21, first branch pipe 22, and third branch pipe 24 through cooling water pump 2. The outlet of evaporator side of chiller unit 4 is connected to the inlet of terminal air conditioner 12 via first chilled water supply pipe 28, chilled water supply loop R3, and second chilled water supply pipe 29 through chilled water secondary pump 10. The outlet of terminal air conditioner 12 is connected to the inlet of evaporator side of chiller unit 4 via chilled water return loop R4, second chilled water return pipe 33, fourth branch pipe 25, and sixth branch pipe 27 through chilled water primary pump 8 on the cooling side. The outlet of condenser side of chiller unit 4 is connected to the inlet of cooling tower 1 via cooling water return loop R2.

[0064] This mode relies entirely on chiller unit 4 to produce chilled water, and it typically operates when the outdoor temperature is high, in other words, when the outdoor wet-bulb temperature is above 19.5°C.

[0065] At this time, the cooling tower outlet water temperature / the cooling water inlet water temperature of the refrigeration unit (generally between 22 and 33 degrees Celsius) is higher than the return water temperature - the plate heat exchanger heat exchange temperature difference set value (the preset value is 2 degrees Celsius, which can be adjusted according to the actual heat exchange capacity of the plate heat exchanger). Therefore, the cooling tower 1 cannot be used to cool the chilled water through the natural cooling plate heat exchanger 6. So the valve is switched so that the cooling water does not pass through the natural cooling plate heat exchanger 6, but is all cooled by the chiller unit 4 and then supplied to the terminal air conditioner 12.

[0066] (2) Precooling mode

[0067] When the outdoor temperature is low (e.g., the outdoor wet-bulb temperature is above 12.5°C and below 19.5°C), the cooling system 100 operates in pre-cooling mode. In this pre-cooling mode, the cooling tower 1 is used to cool the plate heat exchanger 6 for natural cooling, and then the chiller unit 4 supplies cooling to the terminal air conditioner 12. Thus, the plate heat exchanger 6 for natural cooling, i.e., the natural cold source, can be used for pre-cooling, making full use of the natural cold source, improving the cooling efficiency of the chiller unit 4, and reducing the energy consumption of the chiller unit 4. At this time, valves B2, D2 and B1, D1 are open, valves A2, A1, C1 are closed, valve C2 is closed or used to regulate and control the water temperature, valves DV1, DV2, DV3 are open, and valve V1 is closed.

[0068] At this time, the outlet of cooling tower 1 is connected to the inlet pipe on the cooling water side of the plate heat exchanger 6 for natural cooling via cooling water supply loop R1 and first cooling water supply pipe 21, through cooling water pump 2. The outlet pipe on the cooling water side of the plate heat exchanger 6 for natural cooling is connected to the inlet pipe on the condenser side of chiller unit 4. The outlet pipe on the evaporator side of chiller unit 4 is connected to the inlet pipe on the terminal air conditioner 12 via chilled water supply loop R3 and second chilled water supply pipe 29, through chilled water secondary pump 10. Water pipes are connected; the outlet pipe of the terminal air conditioner 12 is connected to the chilled water inlet of the natural cooling plate heat exchanger 6 via the chilled water return loop R4 and the second chilled water return pipe 33, through the chilled water primary pump 8 on the cooling side. The outlet pipe of the chilled water side of the natural cooling plate heat exchanger 6 is connected to the inlet of the evaporator side of the chiller unit 4. The outlet of the condenser side of the chiller unit 4 is connected to the inlet of the cooling tower 1 via the first cooling water return pipe 35 and the cooling water return loop R2. In this mode, the chiller unit 4 and the natural cooling plate heat exchanger 6 are connected in series.

[0069] This mode typically operates when outdoor temperatures are low, such as during transitional seasons like spring and autumn (e.g., outdoor wet-bulb temperature above 12.5°C and below 19.5°C). In this mode, the chilled water supply temperature setpoint minus the plate heat exchanger temperature difference setpoint is less than the cooling tower outlet temperature / cooling unit cooling water inlet temperature, which is less than the return water temperature minus the plate heat exchanger temperature difference setpoint. Cooling tower 1 can be used to cool the chilled water, but it cannot fully meet the requirements of the terminal air conditioner 12. The chilled water outlet temperature from the plate heat exchanger is higher than the chilled water supply temperature setpoint (e.g., preset to 18°C). Therefore, the chilled water can first be cooled by the natural cooling plate heat exchanger 6 before entering the chiller unit 4 for further cooling. Simultaneously, cooling tower 1 and chiller unit 4 provide cooling. In this mode, chiller unit 4 and the natural cooling plate heat exchanger 6 operate in series.

[0070] (3) Natural cooling mode

[0071] When the outdoor temperature continues to decrease (e.g., the outdoor wet-bulb temperature is below 12.5°C), the cooling system 100 operates in natural cooling mode. In this natural cooling mode, the chiller unit 4 is shut down, and the cooling tower 1 is used to cool the plate heat exchanger 6 for natural cooling, supplying cooling to the terminal air conditioners 12. At this time, valves B2, C2 and valves B1, C1 are open, valves A2, D2 and valves A1, D1 are closed, valves DV1, DV2, DV3 are open, and valve V1 is closed.

[0072] At this time, the outlet of cooling tower 1 is connected to the inlet of the cooling water side of the plate heat exchanger 6 for natural cooling via cooling water supply loop R1, first cooling water supply pipe 21, and cooling water pump 2. The outlet of the chilled water side of the plate heat exchanger 6 for natural cooling is connected to the inlet of the terminal air conditioner 12 via the fifth branch pipe 26, fourth branch pipe 25, first chilled water supply pipe 28, chilled water supply loop R1, and chilled water secondary pump 10. The outlet of the terminal air conditioner 12 is connected to the inlet of the chilled water side of the plate heat exchanger 6 for natural cooling via chilled water return loop R4, second chilled water return pipe 33, and chilled water primary pump 8 on the cooling side. The outlet of the cooling water side of the plate heat exchanger 6 for natural cooling is connected to the inlet of cooling tower 1 via the second branch pipe 23, first branch pipe 22, first cooling water return pipe 35, and cooling water return loop R2.

[0073] This mode typically operates when outdoor temperatures drop further, such as during winter (e.g., when outdoor wet-bulb temperature is below 12.5°C). In this case, the cooling tower outlet water temperature is less than the chilled water supply temperature setpoint minus the plate heat exchanger temperature difference setpoint, and all non-started refrigeration units switch to natural cooling mode. For example, if, 10 minutes after cooling water pump 2 starts, the plate heat exchanger chilled water outlet temperature remains below the chilled water supply temperature setpoint for 5 minutes, and cooling from cooling tower 1 alone is sufficient to meet the cooling requirements of terminal air conditioner 12, then chiller unit 4 is directly shut down, valves are switched, and cooling from cooling tower 1 is fully utilized to supply cooling to terminal air conditioner 12.

[0074] Furthermore, when switching between the above modes, there should be an adjustable time delay and a setpoint pause zone to avoid frequent switching between modes. All setpoints and time delays should be adjustable in the control system. Additionally, the operating status of the cold storage tank 11 can be disregarded in the above three operating modes.

[0075] In addition, the cooling system 100 of the present invention can also be divided into the following two operating modes according to the working status of the cold storage tank.

[0076] (1) Cold storage mode

[0077] The cold storage mode is divided into cold storage host cold storage mode and cooling tower cold storage mode.

[0078] (a) Cold storage host cold storage mode

[0079] In this mode, the cold storage unit 5 is used to store cold for the cold storage tank 11. At this time, valves A4 and D4 are open, valves A3 and D3 are open, valves B4 and C4 are closed, valves B3 and C3 are closed, valve DV3 is open, and valves DV1, DV2, and V1 are closed.

[0080] This mode typically operates during periods of low electricity prices, utilizing the off-peak hours at night to store cold water in the cold storage tank 11, thereby reducing operating costs. For example, a timed cold storage schedule can be set, activating the cold storage unit 15 every evening for cold storage, but automatically stopping when the cold storage capacity of the cold storage tank 11 reaches 100%. Alternatively, a minimum emergency cold storage capacity of 30% can be set. When the cooling system 100 is started, if the cold storage capacity of the cold storage tank 11 is below 30%, the cold storage unit 15 will automatically activate to store cold water in the cold storage tank 11. Once the cold storage capacity of the cold storage tank 11 reaches 80%, the operation of the cold storage unit 15 will automatically stop.

[0081] (b) Cooling tower cold storage mode

[0082] In this mode, cooling tower 1 is used to store cold for cold storage tank 11 through plate heat exchanger 7. At this time, valves B4 and C4 are open, valves B3 and C3 are open, valves A4 and D4 are closed, valves A3 and D3 are closed, valve DV3 is open, and valves DV1, DV2, and V1 are closed.

[0083] This mode, which operates when the outdoor temperature is low enough, shuts down the cold storage unit 5, further reducing operating costs.

[0084] (2) Cooling mode

[0085] The cooling modes are divided into cold storage tank cooling mode and mixed cooling mode.

[0086] (a) Cold storage tank cooling mode

[0087] In this mode, only the cooling capacity stored in the cold storage tank 11 is used to provide cooling capacity to the terminal air conditioner 12. At this time, valve DV3 of the cold storage side circulation loop is open, valve V1 is closed, and valves DV1 and DV2 are regulated. Other valves remain in their original or closed states until the required cooling is completed, at which point the control system switches to the corresponding operating mode.

[0088] This mode is typically used as an emergency mode in case of problems with cooling unit 14 or power outages. Alternatively, it can be used, for example, when the initial demand at the data center terminals is small and the capacity of the cold storage tank 11 is sufficient to supply cooling to the terminals for a longer period of time. During off-peak electricity prices (e.g., at night), the cold storage tank 11 is charged with cold water, and during peak electricity prices (e.g., during the day), the cooling mode is activated. In this case, all chiller units 4 and the chilled water primary pump 8 and cooling water pump 2 on the cooling side are shut down to save operating costs.

[0089] (b) Hybrid cooling mode

[0090] This mode is typically used during transitional seasons when outdoor temperatures are low but not high enough to fully rely on the aforementioned natural cooling mode to reach the chilled water supply temperature setpoint. For example, during the aforementioned pre-cooling mode, if the cooling water inlet temperature of chiller unit 4 is low, and refrigeration unit 14 starts chiller unit 4 at a (chilled) water supply temperature of 18°C, the energy efficiency ratio of chiller unit 4 will typically be very low and prone to abnormalities such as surge. In this case, if the internal cold storage capacity of cold storage tank 11 is higher than 30% or cold storage unit 15 has been started, refrigeration unit 14 does not need to consider the chilled water outlet temperature of the plate heat exchanger and can automatically switch to natural cooling mode.

[0091] Specifically, the chilled water outlet flow rate of the corresponding refrigeration unit 14 is controlled by adjusting the frequency of the chilled water primary pump 8 on the refrigeration side, ensuring that the temperature of the chilled water supplied to the terminal air conditioner 12 after mixing with the low-temperature chilled water from the cold storage tank 11 is constant at the set chilled water supply temperature (e.g., 18°C). Furthermore, if the actual chilled water supply temperature is higher than the set value, the chilled water outlet flow rate of the refrigeration unit 14 is reduced, and the chilled water secondary pump 10 draws more low-temperature chilled water from the cold storage tank 11 for use; if the actual chilled water supply temperature is lower than the set value, the chilled water outlet flow rate of the refrigeration unit 14 is increased, reducing the amount of chilled water drawn from the cold storage tank 11 and extending the service life of the cold storage tank 11.

[0092] At this time, the internal temperature of the cold storage tank continues to rise. If the cold storage capacity inside the cold storage tank 11 is less than 30% and cannot meet the emergency cooling demand, the cold storage unit 5 of the cold storage unit 15 will be automatically turned on to ensure the supply of low-temperature chilled water while storing cold. After the cold storage capacity inside the cold storage tank 11 is higher than 80%, the cold storage unit 15 will be turned off and the cold storage tank 11 will be used again for mixed cooling.

[0093] Furthermore, to fully utilize low-temperature cold storage, for example during peak electricity consumption periods, chiller unit 4 can be started while simultaneously using the low-temperature chilled water in cold storage tank 11 for mixed cooling. In this case, the control system controls the frequency of the primary chilled water pump 8 on the refrigeration side based on the difference between the total flow rate of secondary chilled water and the total flow rate of primary chilled water, to ensure that the total flow rate of primary chilled water is not lower than the total flow rate of secondary chilled water.

[0094] [other]

[0095] When the refrigeration unit 14 is operating normally and the temperature inside the cold storage tank 11 is normal, the cooling system 100 controls the charging flow rate of the cold storage tank 11 to maintain the total primary chilled water flow rate being, for example, 50 m³ / s greater than the total secondary chilled water flow rate. 3 / h, where the flow rate setpoint can be adjusted based on the following: considering that the temperature inside the cold storage tank 11 can be maintained at the design requirement temperature of 18°C ​​at this flow rate; and considering the accuracy of the flow meter, the lower the setpoint, the more energy-efficient it is. At this time, most of the chilled water is transported from the chiller unit 4 or the plate heat exchanger 6 for natural cooling to the chilled water supply loop R3, and then transported to the terminal by the chilled water secondary pump 10 to supply cooling to the terminal air conditioner 12. In addition, a small portion of the chilled water enters the cold storage tank 11 from the chilled water supply loop R3 and then returns directly to the chilled water return loop R4.

[0096] [Summarize]

[0097] According to the design of the cooling system 100 involved in this invention, the cold storage unit can operate independently of the refrigeration unit. In other words, the cold storage unit is designed to be connected in parallel with the refrigeration unit. Therefore, the reliability of the entire cooling system will not be affected by the failure of the cold storage unit (reducing redundancy). Furthermore, since the cold storage unit is connected in parallel with the refrigeration unit, it can also serve as a backup chiller. When the chiller fails, the cold storage unit can replace it, effectively adding a backup refrigeration unit to the cooling system and further improving the reliability of the entire system. Simultaneously, the control system replenishes and updates the cooling capacity in the cold storage tank according to actual needs, ensuring that the cold storage tank always maintains a good operating condition.

[0098] Furthermore, by introducing a secondary pump cooling system through the installation of a primary chilled water pump and a secondary chilled water pump, the primary chilled water pump is primarily responsible for ensuring the stable operation of the chiller unit, while the secondary chilled water pump adjusts the flow rate according to changes in the terminal load, enabling the entire system to output cooling and heating capacity according to actual needs. In addition, this secondary pump cooling system effectively reduces transmission energy consumption by changing the chilled water flow rate within the delivery loop to meet load requirements. Moreover, by separating chilled water production and transmission, the numerical control capability and energy efficiency of the cooling system are further improved. Furthermore, according to the design of the cooling system based on the present invention, compared to the prior art, the number of mixing valves can be reduced, thereby reducing the resistance of the piping system.

[0099] In addition, in this cooling system 100, the control system can automatically monitor the temperature of cooling water and chilled water, changes in outdoor weather, and power grid load, so that in automatic mode, the cooling system can automatically adjust its operating status based on the monitoring results.

[0100] Furthermore, by applying the technical solution of this invention, the operation modes and control strategies of the cooling system can be effectively enriched, energy utilization efficiency can be improved, and energy conservation and environmental protection can be achieved.

[0101] For example, during transitional seasons, i.e., in pre-cooling mode, large-capacity cold storage tanks can be used to store and mix cold air, replacing water chillers. This avoids water chillers operating under low load conditions, extends the service life of water chillers, and reduces operating and maintenance costs.

[0102] In natural cooling mode, large-capacity cold storage tanks can be used to store and mix cold water, replacing water chillers to reduce the frequent start-up and shutdown of water chillers, improve the utilization efficiency of natural cold sources, and the cooling system can store chilled water below the design temperature of chilled water according to natural conditions and mix it for cooling.

[0103] Furthermore, this invention utilizes a peak-shaving and valley-filling model. During nighttime periods when grid load is low and electricity prices are cheap, chillers and cold storage units are activated for cooling and cold storage. Conversely, during daytime periods of peak grid load and higher electricity prices, the operating load of the chillers is reduced or shut down, and a hybrid cooling mode combining natural cooling and cold release is used for cold release. This alleviates pressure on the grid during peak hours, improves grid stability and reliability, increases cold release redundancy time, and enhances the energy efficiency ratio of the chillers. Therefore, by optimizing system operation and reducing energy consumption, this invention further reduces environmental pollution and damage.

[0104] All aspects of the embodiments disclosed in this invention are illustrative and should not be construed as limiting. Therefore, the technical scope of this invention is not limited to the above embodiments, but is defined based on the claims. Furthermore, all modifications within the meaning and scope equivalent to the claims are included.

Claims

1. A cooling system for a data center, characterized by, comprises: a cooling tower, a terminal air conditioning unit of a data center room, at least one refrigeration unit, a cold storage unit, a control system, the at least one refrigeration unit is connected with the cooling tower, the terminal air conditioning unit and the control system, the cold storage unit is connected in parallel with the at least one refrigeration unit, and is connected with the cooling tower, the terminal air conditioning unit and the control system, under the control of the control system, the at least one refrigeration unit is operated alone, or the cold storage unit is operated alone, or the at least one refrigeration unit and the cold storage unit are operated together.

2. The cooling system of a data center according to claim 1, wherein the cooling system further comprises a chilled water secondary pump, the refrigeration unit comprises a refrigeration-side chilled water primary pump, and the cold storage unit comprises a cold storage-side chilled water primary pump, the refrigeration-side chilled water primary pump is connected with the chilled water secondary pump, and the cold storage-side chilled water primary pump is connected with the chilled water secondary pump.

3. The cooling system of a data center according to claim 2, wherein the cooling system further comprises: a cooling supply and return water total loop comprising a cooling water supply loop and a cooling water return loop connected with the cooling tower, the at least one refrigeration unit and the cold storage unit; and a chilled supply and return water total loop comprising a chilled water supply loop and a chilled water return loop connected with the terminal air conditioning unit, the at least one refrigeration unit and the cold storage unit, an outlet of the cooling tower is connected to an inlet of the cold storage unit via the cooling supply and return water total loop, and an outlet of the cold storage unit is connected to an inlet of the terminal air conditioning unit via the chilled supply and return water total loop, so that, under the control of the control system, water flowing out of the outlet of the cooling tower can reach the terminal air conditioning unit via the cooling water supply loop, the cold storage unit and the chilled water supply loop, and water flowing out of an outlet of the terminal air conditioning unit can reach the cooling tower via the chilled water return loop, the cold storage unit and the cooling water return loop.

4. The cooling system of a data center according to claim 1, wherein the cooling system further comprises a cold storage tank, and the outlet of the cold storage unit is connected to the cold storage tank and the terminal air conditioning unit.

5. The cooling system of a data center according to claim 2, wherein the cooling system further comprises: a cooling supply and return water total loop comprising a cooling water supply loop and a cooling water return loop connected with the cooling tower, the at least one refrigeration unit and the cold storage unit; and a chilled supply and return water total loop comprising a chilled water supply loop and a chilled water return loop connected with the terminal air conditioning unit, the at least one refrigeration unit and the cold storage unit, each of the refrigeration units comprises a cooling water pump, a water chiller, a natural cooling plate heat exchanger, a plurality of valves and a plurality of pipes, and the water chiller comprises a condenser and an evaporator, The cooling water pump, the water chiller, the natural cooling plate heat exchanger, the refrigeration side chilled water primary pump are connected through the plurality of valves and the plurality of pipes, and the cooling water pump, the water chiller, the natural cooling plate heat exchanger, the refrigeration side chilled water primary pump, the plurality of valves are connected with the control system respectively, The outlet of the cooling tower is connected to the inlet of the cooling water side of the natural cooling plate heat exchanger through the cooling water supply loop, the outlet of the evaporator side of the water chiller is connected to the inlet of the water chiller through the chilled water secondary pump and the chilled water supply loop, and the outlet of the water chiller is connected to the inlet of the cooling tower through the chilled water return loop.

6. The cooling system of the data center according to claim 5, wherein The outlet of the water chiller is connected to the inlet of the evaporator side of the water chiller through the chilled water primary pump and the chilled water return loop, the outlet of the cooling water side of the natural cooling plate heat exchanger is connected to the inlet of the condenser side of the water chiller through the cooling water return loop, and the outlet of the condenser side of the water chiller is connected to the inlet of the cooling tower through the cooling water supply loop.

7. The cooling system of the data center according to claim 1, wherein The cooling system further comprises: a cooling water supply loop and a cooling water return loop connected with the cooling tower, the at least one refrigeration unit and the cold storage unit; a chilled water supply loop and a chilled water return loop connected with the terminal air conditioner, the at least one refrigeration unit and the cold storage unit, and a cold storage tank, The cold storage unit comprises a cold storage main machine, a cold storage plate heat exchanger, a cold storage side cooling water pump, a cold storage side chilled water primary pump, a plurality of pipes and a plurality of valves, The cold storage main machine, the cold storage plate heat exchanger, the cold storage side cooling water pump, the cold storage side chilled water primary pump are connected through the plurality of valves and the plurality of pipes, and the cold storage main machine, the cold storage plate heat exchanger, the cold storage side cooling water pump, the cold storage side chilled water primary pump, the plurality of valves are connected with the control system respectively, The outlet of the cooling tower is connected to the inlet of the cooling water side of the natural cooling plate heat exchanger through the cooling water supply loop, the outlet of the evaporator side of the water chiller is connected to the inlet of the condenser side of the water chiller through the chilled water secondary pump and the chilled water supply loop, and the outlet of the condenser side of the water chiller is connected to the inlet of the cooling tower through the chilled water return loop. The outlet of the water chiller is connected to the inlet of the evaporator side of the water chiller through the chilled water primary pump and the chilled water return loop, the outlet of the cooling water side of the natural cooling plate heat exchanger is connected to the inlet of the condenser side of the water chiller through the cooling water return loop, and the outlet of the condenser side of the water chiller is connected to the inlet of the cooling tower through the cooling water supply loop.

8. The cooling system of the data center according to claim 5, wherein The cooling system has a plurality of operation modes for at least one refrigeration unit, The cooling system can switch one mode of the plurality of operation modes, The plurality of operation modes comprise: a mechanical refrigeration mode, in which only the water chiller is used to supply cooling to the terminal air conditioner, a natural cooling mode, in which only the natural cooling plate heat exchanger is used to supply cooling to the terminal air conditioner, a cold storage mode, in which only the cold storage tank is used to supply cooling to the terminal air conditioner, a mechanical refrigeration and natural cooling mode, in which the water chiller and the natural cooling plate heat exchanger are used to supply cooling to the terminal air conditioner, a mechanical refrigeration and cold storage mode, in which the water chiller and the cold storage tank are used to supply cooling to the terminal air conditioner, a natural cooling and cold storage mode, in which the natural cooling plate heat exchanger and the cold storage tank are used to supply cooling to the terminal air conditioner, and a mechanical refrigeration, natural cooling and cold storage mode, in which the water chiller, the natural cooling plate heat exchanger and the cold storage tank are used to supply cooling to the terminal air conditioner. a pre-cooling mode, in which the cooling tower is used to cool the natural cooling plate heat exchanger, and then the water chiller is used to cool the terminal air conditioner; a natural cooling mode, in which the water chiller is turned off, the cooling tower is used to cool the natural cooling plate heat exchanger, and the terminal air conditioner is cooled.

9. The cooling system of the data center of claim 7, wherein the cooling system further comprises a cold storage mode. The cooling system further comprises a cold storage mode. The cold storage mode comprises a cold storage host cold storage mode and a cooling tower cold storage mode. In the cold storage host cold storage mode, the cold storage host is used to store cold energy in the cold storage tank. In the cooling tower cold storage mode, the cooling tower is used to store cold energy in the cold storage tank through the cold storage plate heat exchanger.

10. The cooling system of the data center of claim 9, wherein the cooling system further comprises a cold release mode. The cold release mode comprises a cold storage tank cold release mode and a mixed cooling mode. In the cold storage tank cold release mode, only the cold energy stored in the cold storage tank is used to cool the terminal air conditioner. In the mixed cooling mode, the water chiller is started and the chilled water in the cold storage tank is extracted for mixed cooling, and the chilled water of the water chiller mixed with the chilled water of the cold storage tank is supplied to the terminal air conditioner. ​

Images