Low-energy cooling system for data centers

Abstract

This invention discloses a low-energy cooling system for data centers, comprising an air conditioning unit, a natural cooling plate heat exchanger assembly, an electric chiller unit, and a cooling tower. The air conditioning unit, the natural cooling plate heat exchanger assembly, and the electric chiller unit are connected in series via chilled water piping to form a chilled water system. The cooling tower, the natural cooling plate heat exchanger assembly, and the electric chiller unit are connected in series via cooling water piping to form a cooling water system. The electric chillers within the electric chiller unit are connected in series. While ensuring the chilled water system has the same safety as the air-cooled system in the data center, the low-energy cooling system for data centers operates only in transition mode and natural cooling mode. This invention features low energy consumption, safety, stability, high efficiency, simplified control, and minimal maintenance.

Description

Technical Field

[0001] This invention relates to the field of energy-saving technology, and in particular to a low-energy cooling system for data centers. Background Technology

[0002] With the accelerating pace of digitalization and intelligentization in society, the demand for data communication, computing, and storage is increasing daily, leading to rapid growth in the scale and electricity consumption of data centers. All electricity consumed by data centers is ultimately converted into heat, and its heat dissipation is primarily affected by server energy consumption, with less influence from outdoor temperature (i.e., ambient temperature). Servers operate at high temperatures and do not generate moisture. Existing data center air conditioning solutions mainly include water-cooled systems, DX direct expansion systems, direct evaporative cooling systems, and indirect evaporative cooling systems, which can be broadly categorized into water-cooled and air-cooled systems.

[0003] Air-cooled systems use air as the primary distribution medium. While individual distribution stages have high energy consumption, low air-side heat transfer coefficients, and short natural cooling times, they offer advantages such as fewer distribution stages, modular design, factory prefabrication and integration, and shorter construction cycles. Water-cooled systems, compared to air-cooled systems, involve an additional distribution process. Individual distribution stages have lower energy consumption, but natural cooling times are longer. However, their construction cycles are longer, and initial costs are higher. Theoretically, water-cooled systems have significantly lower operating energy consumption than air-cooled systems. Current data center air conditioning solutions primarily use water-cooled systems, but in actual operation, their CLF (Coefficient of Cooling Load) and PUE (Power Usage Effectiveness) are actually higher than those of air-cooled systems.

[0004] The vast majority of newly built and planned cooling systems are air-cooled, not only because air-cooled systems have shorter construction cycles and lower costs, but also because water-cooled systems have higher energy consumption. Air-cooled systems typically operate at high supply air temperatures, high return air temperatures, and large distribution temperature differences (e.g., 25 / 38℃); while water-cooled systems operate at low supply water temperatures, low return water temperatures, and small distribution temperature differences (e.g., 12 / 18℃). The design and operation of these water-cooled data centers have failed to fully utilize the advantages of long natural cooling times and low energy consumption per stage of distribution, resulting in persistently high energy consumption for water-cooled systems.

[0005] The main changes in the operating conditions of data center water cooling systems include: changes in heat dissipation due to changes in data center traffic; and changes in cooling tower exhaust temperature due to changes in outdoor temperature. Conventional water cooling systems used in the industry (where the electric chillers are usually connected in parallel) generally have three operating modes: mechanical cooling mode, transition mode, and natural cooling mode. When the outdoor temperature is high, the cooling tower outlet water cannot provide natural cooling capacity, and all cooling capacity relies on the electric chillers; this is mechanical cooling mode. When the cooling tower outlet water can provide some natural cooling capacity, it is transition mode. When the outdoor temperature drops further, and all cooling capacity can be achieved through natural cooling, it is natural cooling mode. In mechanical cooling mode, the cooling tower fans run at full frequency, and the electric chillers also run at full frequency. In transition mode, the cooling tower fans run at full frequency, and the frequency of the electric chillers is adjusted to maintain a constant chilled water supply temperature when the outdoor temperature changes. In natural cooling mode, the electric chillers do not run; the frequency of the cooling tower fans is adjusted to maintain a constant chilled water supply temperature. Switching from transition mode to mechanical cooling mode requires switching valves to bypass the natural cooling plate. Therefore, when temperatures fluctuate frequently, with some time in transitional mode and some in mechanical refrigeration mode, frequent valve switching is required, or the entire system can be in mechanical refrigeration mode with only one valve switch, but electric chillers consume more electricity. In transitional season mode, when outdoor temperatures are low, mechanical refrigeration capacity is reduced, and chillers have minimum frequency limitations, increasing power consumption. When the heat dissipation of the data center changes, it is controlled by frequency conversion of water pumps and the number of variable-voltage chillers and cooling towers. The existing water-cooling system control methods described above require frequent valve switching, resulting in increased power consumption and complexity. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide a low-energy cooling system for data centers that is energy-efficient, safe, stable, and highly efficient, with simplified control and reduced maintenance workload.

[0007] According to an embodiment of the present invention, a low-energy cooling system for data centers includes an air conditioning unit, a natural cooling plate heat exchanger assembly, an electric chiller unit, and a cooling tower. The air conditioning unit, the natural cooling plate heat exchanger assembly, and the electric chiller unit are connected in series via chilled water pipes to form a chilled water system. The cooling tower, the natural cooling plate heat exchanger assembly, and the electric chiller unit are connected in series via cooling water pipes to form a cooling water system. The electric chillers within the electric chiller unit are connected in series. While ensuring the chilled water system has the same safety as the air-cooled system in the data center, the low-energy cooling system for data centers operates only in transition mode and natural cooling mode.

[0008] The low-energy cooling system for data centers according to embodiments of the present invention has the following advantages: First, it increases the supply and return temperatures of chilled water and achieves large temperature difference distribution of chilled water, ensuring the safety of the data center computer room with a suitable chilled water supply temperature; at the same time, it increases the proportion of natural cooling and reduces system energy consumption; Second, through the series arrangement design of natural cooling plate heat exchangers and electric chiller units, it realizes stepped heat exchange on the chilled water side and the cooling water side, improving the efficiency of the electric chillers in the electric chiller units; Third, it does not require valve switching throughout the year, only the frequency of chilled water pumps in the chilled water system, the frequency and number of cooling water pumps in the cooling water system, the frequency and number of electric chillers, and the frequency and number of cooling towers need to be controlled, thus reducing the workload of regulation and maintenance, lowering the failure rate, and ensuring stable operation of the low-energy cooling system for data centers according to embodiments of the present invention; Fourth, it decouples the regulation of data center traffic changes from the regulation of external temperature changes, simplifying the regulation process; Fifth, it can also achieve waste heat utilization with minimal modifications.

[0009] In some embodiments, the natural cooling plate heat exchangers in the natural cooling plate heat exchanger group are connected in series or in parallel.

[0010] In some embodiments, the chilled water pipeline has a first annular network between the electric chiller unit and the air conditioning unit, the chilled water pipeline has a second annular network between the air conditioning unit and the natural cooling plate heat exchanger, the cooling water pipeline has a third annular network between the electric chiller unit and the cooling tower, and the cooling water pipeline has a fourth annular network between the cooling tower and the natural cooling plate heat exchanger.

[0011] In some embodiments, there are multiple air conditioning units, which are arranged in parallel on the chilled water pipeline; there are multiple cooling towers, which are arranged in parallel on the cooling water pipeline.

[0012] In some embodiments, the chilled water pipeline has a first annular network between the electric chiller unit and the air conditioning unit, and a second annular network between the air conditioning unit and the natural cooling plate heat exchanger assembly; multiple air conditioning units are connected in parallel between the first annular network and the second annular network; the cooling water pipeline has a third annular network between the electric chiller unit and the cooling tower, and a fourth annular network between the cooling tower and the natural cooling plate heat exchanger assembly; multiple cooling towers are connected in parallel between the third annular network and the fourth annular network.

[0013] In some embodiments, the chilled water supply temperature of the chilled water system is designed to take into account the temperature of the data center computer room, and the chilled water return temperature of the chilled water system is designed to achieve partial natural cooling under the most unfavorable operating conditions in the local summer.

[0014] In some embodiments, the chilled water supply temperature and chilled water return temperature of the chilled water system are designed according to the following method:

[0015] (1)

[0016] (2)

[0017] in, The chilled water supply temperature of the chilled water system. For data center server room temperature, The temperature difference between the surface cooler and the heat exchanger of the air conditioning unit. The chilled water return temperature of the chilled water system. The cooling water supply temperature for the cooling tower, The difference in heat exchange end of the natural cooling plate group.

[0018] In some embodiments, when the data center traffic changes, the frequency of the chilled water pumps in the chilled water system, the frequency of the cooling water pumps in the cooling water system, and the number of cooling towers are changed to ensure that the chilled water supply temperature, chilled water return temperature, and chilled water supply-return temperature difference of the chilled water system remain unchanged, and that the cooling water supply temperature, cooling water return temperature, and cooling water supply-return temperature difference of the cooling water system remain unchanged.

[0019] When the external temperature changes, the valves in the low-energy cooling system applied to the data center are not adjusted throughout the year, and the cooling water supply temperature of the cooling tower can completely cool the chilled water return water of the chilled water system naturally. In this case, the low-energy cooling system applied to the data center operates in the natural cooling mode. When the cooling water supply temperature of the cooling tower cannot completely cool the chilled water return water of the chilled water system naturally, the low-energy cooling system applied to the data center operates in the transition mode.

[0020] In some embodiments, when the data center traffic increases, the frequency of the chilled water pump in the chilled water system and the frequency of the cooling water pump in the cooling water system both increase, and the number of cooling towers increases; when the data center traffic decreases, the frequency of the chilled water pump in the chilled water system and the frequency of the cooling water pump in the cooling water system both decrease, the number of cooling towers decreases, and the design temperature difference of the chilled water in each electric chiller in the electric chiller unit remains unchanged.

[0021] When the external temperature changes, if The low-energy cooling system applied to the data center then operates in the natural cooling mode, making... ;like In this case, the low-energy cooling system applied to the data center operates in the transition mode, whereby an appropriate number of electric chillers are preferentially activated in the order from the Xth level electric chiller to the 1st level electric chiller. X represents the water temperature after the natural cooling plate is replaced, and X represents the total number of electric chillers in the electric chiller unit. The first-stage electric chillers to the Xth-stage electric chillers are arranged sequentially in the chilled water pipeline according to the chilled water flow direction.

[0022] In some embodiments, when the external temperature changes, if The number of electric chillers operating in the electric chiller unit is i, namely, the Xth stage electric chiller, the (X-1)th stage electric chiller, ..., the (X-i+1)th stage electric chiller, wherein the design value of the chilled water side temperature drop of the Xth stage electric chiller, the (X-1)th stage electric chiller, ..., the (X-i+1)th stage electric chiller is... ,but:

[0023] (3);

[0024] (4);

[0025] in, This is the design temperature drop value for the X-i+1 stage electric chiller.

[0026] In some embodiments, the evaporator outlet water temperature of each electric chiller is set, and the evaporator outlet water temperature of the i-th stage electric chiller is set to... ,

[0027] (5);

[0028] When the actual outlet water temperature of the evaporator of the i-th stage electric chiller is lower than or equal to If so, the i-th stage electric chiller will not start.

[0029] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0031] Figure 1 This is a schematic diagram of a low-energy cooling system applied to a data center according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a low-energy cooling system applied to a data center according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of a low-energy cooling system applied to a data center, according to another embodiment of the present invention.

[0034] Figure 4 This is a schematic diagram of a low-energy cooling system applied to a data center, according to another embodiment of the present invention.

[0035] Figure Labels

[0036] Low-energy cooling system 1000 for data centers; Air conditioning unit 1; Natural cooling plate heat exchanger 2; Natural cooling plate heat exchanger 201; Electric chiller unit 3; Electric chiller 301; Cooling tower 4; Chilled water piping 5; Chilled water return piping 501; Second ring network 5011; Chilled water supply piping 502; First ring network 5021; Chilled water normally open valve 503; Fifth ring network 504; Cooling water piping 6; Cooling water return piping 601; Third ring network 6011; Cooling water supply piping 602; Fourth ring network 6021; Cooling water normally open valve 603; Sixth ring network 604; Fault bypass piping 7; Chilled water main bypass 701; Chilled water normally closed valve 7011; Chilled water branch bypass 702; Cooling water main bypass 703; Cooling water normally closed valve 7031; Cooling water branch bypass 704. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] The following is combined Figures 1 to 4 This invention describes a low-energy cooling system 1000 applied to a data center, according to an embodiment of the present invention.

[0039] like Figures 1 to 4 As shown, a low-energy cooling system 1000 for data centers according to an embodiment of the present invention includes an air conditioning unit 1, a natural cooling plate heat exchanger 2, an electric chiller unit 3, and a cooling tower 4.

[0040] The chilled water system is formed by connecting the air conditioning unit 1, the natural cooling plate heat exchanger 2, and the electric chiller unit 3 in series via the chilled water pipeline 5. Specifically, the chilled water pipeline 5 has a chilled water return pipeline 501 and a chilled water supply pipeline 502. The air conditioning unit 1 is used to provide cooling capacity for the data center computer room. The air conditioning unit 1 is installed on the chilled water pipeline 5 and is located between the inlet end of the chilled water return pipeline 501 and the outlet end of the chilled water supply pipeline 502. The natural cooling plate heat exchanger 2 and the electric chiller unit 3 are connected in series in the chilled water pipeline 5 according to the chilled water flow direction and are located between the outlet end of the chilled water return pipeline 501 and the inlet end of the chilled water supply pipeline 502, thus forming the chilled water system.

[0041] The cooling tower 4, the natural cooling plate heat exchanger 2, and the electric chiller unit 3 are connected in series through the cooling water pipeline 6 to form a cooling water system. Specifically, the cooling water pipeline 6 has a cooling water return pipeline 601 and a cooling water supply pipeline 602. The natural cooling plate heat exchanger 2 and the electric chiller unit 3 are connected in series in the cooling water pipeline 6 according to the cooling water flow direction and are located between the outlet end of the cooling water supply pipeline 602 and the inlet end of the cooling water return pipeline 601. The cooling tower 4 is installed on the cooling water pipeline 6 and between the inlet end of the cooling water supply pipeline 602 and the outlet end of the cooling water return pipeline 601. Thus, the cooling water system is formed.

[0042] The electric chillers 301 within the electric chiller unit 3 are connected in series, meaning they are connected together on both the chilled water and cooling water sides. The total number of individual electric chillers 301 within the electric chiller unit 3 is X, where X is greater than or equal to 1.

[0043] The working principle of the chilled water system and cooling water system is as follows: The chilled water return from the air conditioning unit 1 first exchanges heat with the cooling water supply from the cooling tower 4 through the natural cooling plate heat exchanger 2 to obtain natural cooling capacity, and then passes through the electric chiller unit 3 to cool down to the required chilled water supply temperature. In the cooling water system, the cooling water supply from the cooling tower 4 first passes through the natural cooling plate heat exchanger 2 to provide natural cooling capacity, then passes through the electric chiller unit 3 to remove heat, and finally all the heat is discharged into the environment through the cooling tower 4. Thus, through the series arrangement of the natural cooling plate heat exchanger 2 and the electric chiller unit 3, stepped heat exchange is achieved on both the chilled water side and the cooling water side, improving the efficiency of the electric chiller 301 within the electric chiller unit 3.

[0044] Under the condition of ensuring the same safety as the chilled water system and the air-cooled system of the data center, the low-energy cooling system 1000 used in the data center only adopts the transition mode and natural cooling mode. It can be understood that the supply and return air temperature of the air-cooled system of the data center can generally be 25 / 38℃. Under the same conditions, the temperature of the chilled water system in the data center can also be set to 25 / 38℃. At the same time, considering that the air conditioning unit 1 is a wind-water heat exchanger, the chilled water flow rate can be adjusted so that the inlet and outlet water temperatures of the chilled water can be 20 / 33℃ or even higher. Therefore, while ensuring the same safety as the air-cooled system in the data center, the chilled water system can increase the supply and return temperatures of the chilled water and widen the temperature difference between the supply and distribution of the chilled water. This allows for an increase in the proportion of natural cooling, enabling the low-energy cooling system 1000 used in the data center to operate in only transition and natural cooling modes, without requiring mechanical refrigeration. For example, when changes in data center workload lead to changes in heat dissipation, the chilled water pump frequency converter, the cooling water pump frequency converter, the frequency of the electric chiller 301 in the electric chiller unit 3, and the number of cooling towers 4 can be used to change the chilled water flow rate and the cooling water flow rate, ensuring that the chilled water supply temperature, chilled water return temperature, and chilled water supply and return temperature difference of the chilled water system remain constant, and ensuring the cooling water system's cooling capacity remains constant. The supply water temperature, return water temperature, and supply-return water temperature difference remain constant. When the external temperature changes, the valves in the low-energy cooling system 1000 used in the data center are not adjusted throughout the year. When the supply water temperature of cooling tower 4 is sufficient to naturally cool the return water of the chilled water system, the low-energy cooling system 1000 operates in natural cooling mode, i.e., the frequency of the cooling tower 4 fan is varied, and the electric chillers 301 in the electric chiller unit 3 are not turned on. When the supply water temperature of cooling tower 4 is insufficient to naturally cool the return water of the chilled water system, the low-energy cooling system 1000 operates in transition mode, i.e., the cooling tower 4 fan runs at full frequency, the number of electric chillers is varied, and the supply water temperature and flow rate remain constant. Therefore, by increasing the proportion of natural cooling and avoiding mechanical refrigeration, system energy consumption is reduced.

[0045] It should be noted that air conditioning unit 1 provides cooling capacity to the data center server room. To accommodate the large temperature difference in chilled water heat exchange, a closed hot aisle configuration is recommended for the data center server room. The heat exchange tubes of air conditioning unit 1 should be arranged in a quasi-counterflow pattern to increase the return air temperature and widen the temperature difference between the chilled water supply and return. Cooling tower 4 requires an increased air-to-water ratio and NTU. The selection of cooling tower 4 needs to consider the meteorological conditions of the data center's location. In dry areas, parallel indirect evaporative chillers are recommended, while in humid areas, direct evaporative cooling tower 4 is recommended.

[0046] The low-energy cooling system 1000 for data centers according to embodiments of the present invention has the following advantages: First, it increases the supply and return temperatures of chilled water and achieves large temperature difference distribution of chilled water, ensuring the safety of the data center computer room with a suitable chilled water supply temperature; at the same time, it increases the proportion of natural cooling and reduces system energy consumption; Second, through the series arrangement design of the natural cooling plate heat exchanger group 2 and the electric chiller unit 3, it realizes stepped heat exchange on the chilled water side and the cooling water side, improving the efficiency of the electric chiller 301 in the electric chiller unit 3; Third, it does not require valve switching throughout the year, only the frequency of the chilled water pump in the chilled water system, the frequency of the cooling water pump in the cooling water system, the frequency and number of electric chillers 301, and the frequency and number of cooling towers 4 need to be controlled, which reduces the workload of regulation and maintenance, lowers the failure rate, and ensures stable operation of the low-energy cooling system 1000 for data centers according to embodiments of the present invention; Fourth, it decouples the regulation of data center business volume changes from the regulation of external temperature changes, simplifying the regulation process; Fifth, it can also realize waste heat utilization with minimal modifications.

[0047] In some embodiments, the natural cooling plate heat exchangers 201 within the natural cooling plate heat exchanger group 2 may be selected to be connected in series as needed (e.g., ...). Figure 2 and Figure 3 (as shown) or in parallel (e.g.) Figure 4 (As shown).

[0048] In some embodiments, such as Figures 2 to 4 As shown, there are multiple air conditioning units 1, which are connected in parallel on the chilled water pipeline 5; there are multiple cooling towers 4, which are connected in parallel on the cooling water pipeline 6. This ensures the safety of the low-energy cooling system 1000 used in the data center.

[0049] In some embodiments, such as Figure 3 and Figure 4 As shown, chilled water pipe 5 has a first ring network 5021 between the electric chiller unit 3 and the air conditioning unit 1, and a second ring network 5011 between the air conditioning unit 1 and the natural cooling plate heat exchanger group 2. Multiple air conditioning units 1 are connected in parallel between the first ring network 5021 and the second ring network 5011. Cooling water pipe 6 has a third ring network 6011 between the electric chiller unit 3 and the cooling tower 4, and a fourth ring network 6021 between the cooling tower 4 and the natural cooling plate heat exchanger group 2. Multiple cooling towers 4 are connected in parallel between the third ring network 6011 and the fourth ring network 6021. This ensures the safety of the low-energy cooling system 1000 used in the data center.

[0050] In some embodiments, such as Figure 3 and Figure 4As shown, it also includes a fault bypass pipe 7; when the natural cooling plate heat exchangers 201 in the natural cooling plate heat exchanger group 2 are connected in series, the fault bypass pipe 7 is used to bypass any faulty natural plate heat exchanger in the natural cooling plate heat exchanger group 2 and / or bypass any faulty electric chiller 301 in the power-off chiller group 3; when the natural cooling plate heat exchangers 201 in the natural cooling plate heat exchanger group 2 are connected in parallel, the fault bypass pipe 7 is used to bypass any faulty electric chiller 301 in the power-off chiller group 3. By setting the fault bypass pipe 7, the safe operation of the low-energy cooling system 1000 applied to the data center can be ensured.

[0051] like Figure 3 and Figure 4 As shown, the fault bypass pipeline 7 includes a chilled water main bypass 701, multiple chilled water branch bypasses 702, a cooling water main bypass 703, and multiple cooling water branch bypasses 704.

[0052] Among them, such as Figure 3As shown, when the natural cooling plate heat exchangers 201 in the natural cooling plate heat exchanger group 2 are connected in series, the two ends of the chilled water main bypass 701 are respectively connected to the first annular pipe network 5021 and the second annular pipe network 5011. Multiple chilled water branch bypasses 702 are connected in parallel between the chilled water main bypass 701 and the chilled water pipeline 5 at intervals. One end of the multiple chilled water branch bypasses 702 is arranged sequentially between two adjacent natural cooling plate heat exchangers 201, between adjacent natural cooling plate heat exchangers 201 and electric chillers 301, and between two adjacent electric chillers 301. A normally closed chilled water valve 7011 is provided on the chilled water main bypass 701, corresponding to the position of each natural cooling plate heat exchanger 201 and each electric chiller 301. On the chilled water pipeline 5, there are chilled water valves located upstream and downstream of each natural cooling plate heat exchanger 201 and upstream and downstream of each electric chiller 301. A chilled water normally open valve 503 is provided on the side; the two ends of the cooling water main bypass 703 are respectively connected to the third ring network 6011 and the fourth ring network 6021. Multiple cooling water branch bypasses 704 are connected in parallel between the cooling water main bypass 703 and the cooling water pipeline 6 at intervals. Among them, one end of the multiple cooling water branch bypasses 704 is arranged sequentially between two adjacent natural cooling plate heat exchangers 201, between adjacent natural cooling plate heat exchangers 201 and electric chillers 301, and between two adjacent electric chillers 301. A cooling water normally closed valve 7031 corresponding to each natural cooling plate heat exchanger 201 and each electric chiller 301 is provided on the cooling water main bypass 703. A cooling water normally open valve 603 is provided on the cooling water pipeline 6 on the upstream and downstream sides of each natural cooling plate heat exchanger 201 and the upstream and downstream sides of each electric chiller 301. When the low-energy cooling system 1000 applied to the data center is operating normally, all normally open valves 503 of chilled water on chilled water line 5 are open, all normally open valves 603 of cooling water on cooling water line 6 are open, while all normally closed valves 7011 of chilled water on chilled water main bypass 701 are closed, and all normally closed valves 7031 of cooling water on cooling water main bypass 703 are closed. When a natural cooling plate heat exchanger 201 fails, the normally closed chilled water valve 7011 and normally closed cooling water valve 7031 corresponding to the failed natural cooling plate heat exchanger 201 open. At the same time, the normally open chilled water valve 503 and normally open cooling water valve 603 on the upstream and downstream sides of the failed natural cooling plate heat exchanger 201 close, thus bypassing the failed natural cooling plate heat exchanger 201. Similarly, when an electric chiller 301 fails, the normally closed chilled water valve 7011 and normally closed cooling water valve 7031 corresponding to the failed electric chiller 301 open. At the same time, the normally open chilled water valve 503 and normally open cooling water valve 603 on the upstream and downstream sides of the failed electric chiller 301 close, thus bypassing the failed electric chiller 301. This ensures the safe operation of the low-energy cooling system 1000 used in the data center.

[0053] like Figure 4 As shown, when the natural cooling plate heat exchangers 201 in the natural cooling plate heat exchanger group 2 are connected in parallel, the chilled water pipeline 5 has a fifth ring network 504 between the natural cooling plate heat exchanger group 2 and the electric chiller unit 3, and the cooling water pipeline 6 has a sixth ring network 604 between the natural cooling plate heat exchanger group 2 and the electric chiller unit 3. The two ends of the chilled water main bypass 701 are connected to the first ring network 5021 and the fifth ring network 504 respectively. Multiple chilled water branch bypasses 702 are connected in parallel between the chilled water main bypass 701 and the chilled water pipeline 5 at intervals. One end of each of the multiple chilled water branch bypasses 702 is sequentially arranged between two adjacent electric chillers 301. A normally closed chilled water valve 7011 corresponding to the position of each electric chiller 301 is installed on the chilled water main bypass 701, and a normally open chilled water valve 503 is installed on the chilled water pipeline 5 on the upstream and downstream sides of each electric chiller 301. The two ends of the main cooling water bypass 703 are connected to the third ring network 6011 and the sixth ring network 604 respectively. Multiple cooling water branch bypasses 704 are connected in parallel between the main cooling water bypass 703 and the cooling water pipeline 6 at intervals. One end of each of the multiple cooling water branch bypasses 704 is arranged between two adjacent electric chillers 301. A normally closed cooling water valve 7031 corresponding to the position of each electric chiller 301 is provided on the main cooling water bypass 703. A normally open cooling water valve 603 is provided on the upstream and downstream sides of each electric chiller 301 on the cooling water pipeline 6. When the low-energy cooling system 1000 used in the data center is operating normally, all normally open chilled water valves 503 on chilled water line 5 are open, and all normally open cooling water valves 603 on cooling water line 6 are open. Meanwhile, all normally closed chilled water valves 7011 on the main chilled water bypass 701 are closed, and all normally closed cooling water valves 7031 on the main cooling water bypass 703 are closed. When a chiller 301 malfunctions, the normally closed chilled water valves 7011 and 7031 corresponding to the malfunctioning chiller 301 open. Simultaneously, the normally open chilled water valves 503 and 603 on the upstream and downstream sides of the malfunctioning chiller 301 close, thus bypassing the malfunctioning chiller 301. This ensures the safe operation of the low-energy cooling system 1000 used in the data center.

[0054] In some embodiments, the chilled water supply temperature of the chilled water system is designed with the temperature of the data center computer room in mind to meet the cooling needs of the data center computer room. The chilled water return temperature of the chilled water system is designed to achieve partial natural cooling under the most unfavorable operating conditions in the local summer, in order to increase the proportion of natural cooling and simplify system control.

[0055] In some embodiments, the chilled water supply temperature and chilled water return temperature of the chilled water system are designed according to the following method:

[0056] (1)

[0057] (2)

[0058] in, The chilled water supply temperature for the chilled water system. For data center server room temperature, The difference in heat exchange between the surface cooler and the heat exchanger of air conditioning unit 1. The chilled water return temperature of the chilled water system. The cooling water supply temperature for cooling tower 4, The heat exchange end difference of the natural cooling plate group 2 is used. It is understood that the chilled water supply temperature can be designed through formula (1) to meet the cooling needs of the data center computer room, and the cooling water return temperature can be designed through formula (2) to ensure that the chilled water system and the air cooling system of the data center computer room have the same safety, increase the chilled water supply and return temperature and widen the chilled water distribution temperature difference to increase the natural cooling ratio, reduce energy consumption and simplify system control.

[0059] In some embodiments, when the data center traffic changes, the frequency of the chilled water pumps in the chilled water system, the frequency of the cooling water pumps in the cooling water system, and the number of cooling towers are changed to ensure that the chilled water supply temperature, chilled water return temperature, and chilled water supply-return temperature difference of the chilled water system remain constant, as do the cooling water supply temperature, cooling water return temperature, and cooling water supply-return temperature difference of the cooling water system. When the external temperature changes, the valves in the low-energy cooling system 1000 used in the data center are not adjusted throughout the year. These valves may include normally open chilled water valve 503, normally closed chilled water valve 7011, normally open cooling water valve 603, and normally closed cooling water valve 7031, etc. When the cooling water supply temperature of the cooling tower 4 can completely cool the chilled water return of the chilled water system naturally, the low-energy cooling system 1000 used in the data center operates in natural cooling mode. When the cooling water supply temperature of the cooling tower 4 cannot completely cool the chilled water return of the chilled water system naturally, the low-energy cooling system 1000 used in the data center operates in transition mode. Therefore, by increasing the proportion of natural cooling and eliminating the use of mechanical refrigeration, system energy consumption is reduced; valves do not need to be switched throughout the year, only the frequency of chilled water pumps in the chilled water system, the frequency of cooling water pumps in the cooling water system, the frequency and number of electric chillers 301, and the frequency and number of cooling towers 4 need to be controlled. This reduces the workload of regulation and maintenance, lowers the failure rate, and ensures stable operation of the low-energy cooling system 1000 applied to data centers in this embodiment of the invention; the regulation of data center traffic changes is decoupled from the regulation of external temperature changes, simplifying the regulation process.

[0060] In some embodiments, when data center traffic increases, the frequency of the chilled water pumps in the chilled water system and the frequency of the cooling water pumps in the cooling water system both increase, and the number of cooling towers (4 units) increases; when data center traffic decreases, the frequency of the chilled water pumps in the chilled water system and the frequency of the cooling water pumps in the cooling water system both decrease, the number of cooling towers (4 units) decreases, and the design temperature difference of the chilled water (i.e., the chilled water supply and return temperature difference) for each electric chiller 301 in the electric chiller unit 3 remains unchanged; when the external temperature changes, if The low-energy cooling system 1000 used in data centers operates in natural cooling mode, making... ;like In this case, the low-energy cooling system 1000 used in the data center operates in transition mode. Within the electric chiller unit 3, an appropriate number of electric chillers 301 are activated in the order of X-level electric chillers 301 to 1-level electric chillers 301. X represents the water temperature after the natural cooling plate is replaced with group 2, and X represents the total number of all electric chillers 301 in electric chiller unit 3. The first-stage electric chillers 301 to the Xth-stage electric chillers 301 are arranged sequentially in the chilled water pipeline 5 according to the chilled water flow direction. Therefore, there is no need to switch valves throughout the year; only the frequency and number of chilled water pumps in the chilled water system, the frequency and number of cooling water pumps in the cooling water system, the frequency of electric chillers 301, and the frequency and number of cooling towers 4 need to be controlled. This results in low energy consumption, reduced control and maintenance workload, lower failure rate, and stable operation of the low-energy cooling system 1000 applied to data centers according to this embodiment of the invention. The adjustment of data center traffic changes and external temperature changes are decoupled, simplifying the adjustment process.

[0061] In some embodiments, when the external temperature changes, if The number of electric chillers 301 operating within electric chiller unit 3 is i, namely, stage X electric chiller 301, stage X-1 electric chiller 301...stage X-i+1 electric chiller 301, where the design value for the chilled water side temperature drop of stage X electric chiller 301, stage X-1 electric chiller 301...stage X-i+1 electric chiller 301 is... ,but:

[0062] (3);

[0063] (4);

[0064] in, This is the design value for the temperature drop of the X-i+1th stage electric chiller 301.

[0065] In some embodiments, the evaporator outlet water temperature of each electric chiller 301 is set, and the evaporator outlet water temperature of the i-th stage electric chiller 301 is set to... ,

[0066] (5);

[0067] When the actual outlet water temperature of the evaporator of the i-th stage electric chiller 301 is lower than or equal to If the i-th stage electric chiller 301 is not turned on, then the low-energy cooling system 1000 applied to the data center according to the embodiment of the present invention has low energy consumption, reduced control and maintenance workload, lower failure rate, and stable operation; the adjustment of data center traffic changes and external temperature changes are decoupled, simplifying the adjustment process.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0069] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A low-energy cooling system for data centers, characterized in that, The system includes an air conditioning unit, a natural cooling plate heat exchanger assembly, an electric chiller unit, and a cooling tower. The air conditioning unit, the natural cooling plate heat exchanger assembly, and the electric chiller unit are connected in series via chilled water piping to form a chilled water system. The cooling tower, the natural cooling plate heat exchanger assembly, and the electric chiller unit are connected in series via cooling water piping to form a cooling water system. The electric chillers within the electric chiller unit are connected in series. While ensuring the chilled water system has the same safety as the air-cooled system in the data center, the low-energy cooling system used in the data center operates only in transition mode and natural cooling mode. The chilled water supply temperature of the chilled water system is designed with the temperature of the data center computer room in mind, and the chilled water return temperature of the chilled water system is designed to achieve partial natural cooling under the most unfavorable conditions in the local summer. The chilled water supply temperature and chilled water return temperature of the chilled water system are designed according to the following method: （1） （2） in, The chilled water supply temperature of the chilled water system. For data center server room temperature, The temperature difference between the surface cooler and the heat exchanger of the air conditioning unit. The chilled water return temperature of the chilled water system. The cooling water supply temperature for the cooling tower, The difference in heat exchange end of the natural cooling plate heat exchanger group; When the data center's workload increases, the frequency of the chilled water pumps in the chilled water system and the frequency of the cooling water pumps in the cooling water system both increase, and the number of cooling towers increases; when the data center's workload decreases, the frequency of the chilled water pumps in the chilled water system and the frequency of the cooling water pumps in the cooling water system both decrease, the number of cooling towers decreases, and the design temperature difference of the chilled water in each electric chiller unit in the electric chiller unit remains unchanged. When the external temperature changes, if The low-energy cooling system applied to the data center then operates in the natural cooling mode, making... ;like In this case, the low-energy cooling system applied to the data center operates in the transition mode, whereby an appropriate number of electric chillers are preferentially activated in the order from the Xth level electric chiller to the 1st level electric chiller. X represents the water temperature after the natural cooling plate is replaced, and X represents the total number of electric chillers in the electric chiller unit. The first-stage electric chillers to the Xth-stage electric chillers are arranged sequentially in the chilled water pipeline according to the chilled water flow direction.

2. The low-energy cooling system for data centers according to claim 1, characterized in that, The natural cooling plate heat exchangers in the natural cooling plate heat exchanger group are connected in series or in parallel.

3. The low-energy cooling system for data centers according to claim 1, characterized in that, There are multiple air conditioning units, which are arranged in parallel on the chilled water pipeline; there are multiple cooling towers, which are arranged in parallel on the cooling water pipeline.

4. The low-energy cooling system for data centers according to claim 3, characterized in that, The chilled water pipeline has a first ring network between the electric chiller unit and the air conditioning unit, and a second ring network between the air conditioning unit and the natural cooling plate heat exchanger. Multiple air conditioning units are connected in parallel between the first and second ring networks. The cooling water pipeline has a third ring network between the electric chiller unit and the cooling tower, and a fourth ring network between the cooling tower and the natural cooling plate heat exchanger. Multiple cooling towers are connected in parallel between the third and fourth ring networks.

5. The low-energy cooling system for data centers according to claim 2, characterized in that, It also includes a fault bypass pipeline; when the natural cooling plate heat exchangers in the natural cooling plate heat exchanger group are connected in series, the fault bypass pipeline is used to bypass any natural plate heat exchanger that fails in the natural cooling plate heat exchanger group or / and bypass any electric chiller that fails in the electric chiller unit; when the natural cooling plate heat exchangers in the natural cooling plate heat exchanger group are connected in parallel, the fault bypass pipeline is used to bypass any electric chiller that fails in the electric chiller unit.

6. The low-energy cooling system for data centers according to claim 1, characterized in that, When the external temperature changes, if The number of electric chillers operating in the electric chiller unit is i, namely, the Xth stage electric chiller, the (X-1)th stage electric chiller, ..., the (X-i+1)th stage electric chiller, wherein the design value of the chilled water side temperature drop of the Xth stage electric chiller, the (X-1)th stage electric chiller, ..., the (X-i+1)th stage electric chiller is... ,but: （3）； （4）； in, This is the design temperature drop value for the X-i+1 stage electric chiller.

7. The low-energy cooling system for data centers according to claim 6, characterized in that, Set the evaporator outlet water temperature for each electric chiller. The evaporator outlet water temperature for the i-th stage electric chiller is set as follows: , （5） ； When the actual outlet water temperature of the evaporator of the i-th stage electric chiller is lower than or equal to If so, the i-th stage electric chiller will not start.

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