Server liquid cooling cabinet group heat dissipation system with phase change energy storage

Abstract

The invention discloses a server liquid cooling cabinet group heat dissipation system with phase change energy storage, which comprises two linear array type server liquid cooling cabinet groups, two cooling capacity distribution units, two heat pipe air conditioner all-in-one machines, a multi-channel cold liquid distributor, a multi-channel hot liquid backflow device and the like, the all-in-one machine comprises a heat pipe natural cold source refrigerating loop and a compressor mechanical refrigerating loop, the two refrigerating loops independently or jointly provide an outdoor cold source, heat of all the liquid cooling cabinets is transmitted to the all-in-one machine in the cold capacity distribution unit, and therefore the heat is transmitted out of the machine room. A phase change energy storage flow channel is preferably arranged on the primary side of the intermediate heat exchanger in parallel, cold storage and buffering are achieved by switching a channel, a cold storage and cold release intelligent control strategy based on a lag temperature difference threshold value is constructed, a main cold source linkage and cold source switching smooth transition mechanism is achieved, the thermal stability, operation continuity and response capacity of the system are improved, and the system reliability is improved. The liquid cooling heat dissipation device is suitable for data center liquid cooling heat dissipation scenes with high heat density, high energy efficiency and high reliability requirements.

Description

Technical Field

[0001] The present invention belongs to the field of heat exhaust in server computer rooms, relates to the heat dissipation of a server liquid-cooled cabinet group, and particularly relates to a server liquid-cooled cabinet group heat dissipation system with phase change energy storage, which is used to achieve stable, efficient and energy-saving heat dissipation of servers under high heat density conditions in different seasonal environments. Background Art

[0002] For ultra-high density data centers, due to limitations such as low specific heat capacity of air and uneven air flow organization, the traditional air-cooled heat dissipation method is difficult to meet the heat dissipation requirements of high heat density cabinets. In this context, the liquid-cooled solution has a high heat exchange efficiency and is increasingly being adopted.

[0003] Currently, liquid-cooling technology is mainly applied to high heat density servers or entire rows of liquid-cooled cabinets. Common liquid-cooling solutions include forms such as immersion liquid-cooling, cold plate liquid-cooling, and back plate liquid-cooling. Among them, cold plate liquid-cooling has become one of the mainstream cooling methods for liquid-cooled servers due to its clear structure, flexible deployment, and convenient maintenance. In a cold plate liquid-cooling heat dissipation system, a cold quantity distribution unit is usually set up as a heat exchange hub connecting the liquid-cooled server and the upstream cold source system.

[0004] The cooling distribution unit generally adopts a dual-circuit structure, that is, the secondary side cools the server through circulating liquid, and the heat is transferred to the primary side through the intermediate heat exchanger, and then the primary side exchanges heat with the outdoor cold source to achieve the final heat dissipation. However, the primary and secondary sides of the cooling distribution unit CDU of the liquid cooling solution usually use water or ethylene glycol solution, propylene glycol solution, etc. as the heat exchange medium. In the cold season in the north, when the primary side pipeline is exposed to the low temperature environment for a long time, the water-based heat exchange medium is very easy to freeze and expand, causing pipeline cracking, equipment damage or system shutdown, which seriously affects the system stability and data center operation safety. Special attention should be paid to the anti-freezing problem of the heat exchange medium in the system where the primary side is connected to the outdoor cold source. In addition, the heat dissipation efficiency of most current liquid cooling systems depends on a specific single cooling method (such as mechanical compression cooling). When the outdoor environment temperature difference resources are rich, it is impossible to fully utilize the natural cold source, resulting in limited overall energy efficiency and high operating costs, which is not in line with the development trend of green energy-saving data centers. For example, Chinese invention patent CN116033712A discloses a liquid cooling system and server cabinet for server cabinets, which adopts a two-stage water cooling design on the primary side and the secondary side, and adjusts the cooling intensity by linking the external water cooler and the CDU heat exchanger through a three-way regulating valve. However, the scheme relies on water-based working fluid and external water cooler on the primary side, and does not solve the risk of pipeline freezing and cracking in cold areas; the cold source only uses mechanical refrigeration, and does not operate in conjunction with the natural cold source, which limits energy efficiency optimization; there is a lack of redundant configuration of the cold distribution unit and cold source equipment, and the system reliability is insufficient. Therefore, it is difficult to meet the antifreeze needs of high-latitude areas and the high-efficiency heat dissipation requirements of ultra-high-density data centers throughout the year. At the same time, data centers have extremely high requirements for the reliability of the heat dissipation system, but traditional liquid cooling systems mostly adopt a single cold source design. Once key components (such as coolant pumps and outdoor condensers) fail, the entire heat dissipation system may fail. Although some schemes use dual pump backup, there is a lack of overall redundant design for the cold distribution unit and outdoor cold source equipment, and there is still a single point failure risk.

[0005] In summary, the existing server liquid cooling cabinet groups still have defects and deficiencies in heat dissipation, energy efficiency optimization, and redundant design, and are difficult to meet the stringent requirements of high-latitude areas, ultra-high-density data centers, and year-round uninterrupted operation. Therefore, how to design a system that can efficiently solve the heat dissipation problem of server liquid cooling cabinet groups while taking into account the antifreeze of outdoor units in the cold season in the north is a technical problem that needs to be solved urgently. Summary of the invention

[0006] 1. Purpose of the invention To address at least one of the above-mentioned drawbacks and deficiencies of the existing technologies, the present invention aims to provide a server liquid cooling cabinet group heat dissipation system with phase change energy storage. The outdoor cold source adopts a heat pipe air conditioner integrated machine that combines natural cold source and mechanical refrigeration, providing Freon-based refrigerant for the primary side of the cold quantity distribution unit. The system is energy-saving and there is no risk of winter freezing and cracking in the outdoor pipeline. The secondary side of the cold quantity distribution unit directly uses the coolant to take out the heat of the liquid-cooled servers in the server liquid cooling cabinets and transfer the heat to the Freon-based refrigerant on the primary side. It has a large heat exchange capacity and high heat exchange efficiency, can significantly reduce the PUE of the data center, and ensure the safe and stable operation of the data center. In addition, the present invention realizes the partitioned liquid supply and shunt liquid return control of the liquid-cooled server cabinet group by setting up a multi-channel cold liquid distributor and a multi-channel hot liquid refluxer, improving the uniformity of coolant flow distribution and the adjustability of the cooling path, and adapting to the cooling requirements under non-uniform heat load conditions. Further, it is preferably to parallelly arrange a phase change energy storage flow channel on the primary side of the intermediate heat exchanger and combine an intelligent control strategy for cold storage and cold release based on the hysteresis temperature threshold, enabling the phase change energy storage module to store cold energy when the cold source is surplus and buffer and output cold energy when the cold load suddenly increases or the main cold source switching is delayed, effectively improving the system's cold and heat balance adjustment ability and temperature continuity during the main cold source switching process, thereby enhancing the system's thermal stability, operation flexibility, and energy efficiency performance.

[0007] (II) Technical Solution The technical solution adopted by the present invention to solve its technical problems is as follows: A server liquid cooling cabinet group heat dissipation system with phase change energy storage, used for efficient heat exchange and safe heat dissipation under the high heat density operation conditions of servers in different environmental conditions, including: A linear array type server liquid cooling cabinet group, arranged in two relatively arranged columns, with multiple server liquid cooling cabinets arranged adjacent to each other in each column, and at least one liquid-cooled server is provided in each cabinet; Cold quantity distribution units, provided in two sets, one for standby and one for use, respectively arranged at the head, middle or tail positions of the two linear array type server liquid cooling cabinet groups. Each cold quantity distribution unit includes an intermediate heat exchanger, and each intermediate heat exchanger includes a primary side and a secondary side. The primary side is filled with refrigerant, and the secondary side is filled with coolant, used to realize the heat exchange between the refrigerant and the coolant; A multi-channel cold liquid distributor, including two cold liquid inlets and multiple cold liquid distribution channels. The two cold liquid inlets are respectively and correspondingly connected to the secondary side outlets of the two intermediate heat exchangers, and each cold liquid distribution channel is respectively and correspondingly connected to the cold plate inlets of each liquid-cooled server, used to distribute the coolant to each liquid-cooled server for heat exchange; Multi-channel hydrothermal refluxer, including multiple hydrothermal reflux channels and two hydrothermal outlets. Each hydrothermal reflux channel is correspondingly connected to the cold plate outlet of each liquid-cooled server, and the two hydrothermal outlets are correspondingly connected to the secondary side inlets of two intermediate heat exchangers, which is used to collect the high-temperature coolant discharged from each liquid-cooled server and reflux it to the cold quantity distribution unit; Two sets of integrated heat pipe air conditioners are provided, one for standby and one for use, each corresponding to an intermediate heat exchanger. Each set includes a heat pipe natural cold source refrigeration circuit and a compressor mechanical refrigeration circuit. The two circuits are arranged in parallel on the primary side of the corresponding intermediate heat exchanger, and a valve assembly is used to select to operate alone or cooperatively based on a preset control logic to provide a cold source for the corresponding secondary side, realizing efficient heat dissipation under different environmental conditions.

[0008] (3) Technical effects Compared with the prior art, the technical effects of the server liquid cooling cabinet group heat dissipation system with phase change energy storage provided by the present invention are as follows: (1) In the server liquid cooling cabinet group heat dissipation system with phase change energy storage of the present invention, the outdoor cold source adopts an integrated heat pipe air conditioner that combines natural cold source and mechanical refrigeration to provide Freon refrigerant for the primary side of the cold quantity distribution unit. The system is energy-saving and there is no risk of freezing and cracking of outdoor pipelines in winter. And its dual refrigeration circuit setting can dynamically select the operation mode according to the external environmental temperature, realizing energy-saving and efficient heat dissipation under all-year working conditions. The secondary side of the cold quantity distribution unit directly uses the coolant to take out the heat of the liquid-cooled servers in the server liquid cooling cabinet and transfer the heat to the Freon refrigerant on the primary side, with large heat exchange capacity and high heat exchange efficiency. These characteristics make the present invention have good engineering deployment flexibility and adaptability, and can be widely applied to liquid cooling deployment scenarios in different climate regions and different scales of data centers.

[0009] (2) By setting a multi-channel cold liquid distributor and a multi-channel hydrothermal refluxer, the present invention realizes refined liquid supply and shunt-type return liquid management for each cooling path of the liquid-cooled server group, not only improving the flow distribution uniformity of the coolant among each server node, avoiding local cooling insufficiency or overcurrent, but also enhancing the system's adaptability to uneven heat loads. Cooperating with the main and standby pump groups and the pressure balance control mechanism can effectively improve the cooling efficiency and flow control accuracy, and enhance the redundancy and stability of the system.

[0010] (3)In a preferred embodiment of the present invention, the primary side of the intermediate heat exchanger is structurally designed as a main flow channel and a phase change energy storage flow channel that are connected in parallel and spatially isolated from each other. Combining with the hysteresis temperature difference judgment strategy, the dynamic linkage control of cold storage and cold release is realized, which has the bidirectional cold buffer capacity and can effectively cope with problems such as sudden changes in cold load and delay in cold source switching. The system sets the temperature difference threshold range for starting and stopping cold storage / cold release, and combines with the detection of the state of the phase change material to realize the precise activation of the energy storage module in the states of surplus and shortage of the cold source, avoiding frequent start and stop caused by fluctuations, and improving the operation stability of the system. Description of the Drawings

[0011] Figure 1 It is a schematic structural diagram of a server liquid cooling cabinet group heat dissipation system with phase change energy storage.

[0012] Figure 2 It is a schematic structural diagram when only the heat pipe natural cold source refrigeration circuit is operating.

[0013] Figure 3 It is a schematic structural diagram when the two refrigeration circuits are operating simultaneously.

[0014] Figure 4 It is a schematic structural diagram when only the compressor mechanical refrigeration circuit is operating; Figure 5 It is a schematic structural diagram of the main flow channel + phase change energy storage flow channel on the primary side of the intermediate heat exchanger; Figure 6 It is a schematic diagram of the linkage control strategy based on the hysteresis temperature difference judgment by the distribution unit controller.

[0015] Description of the Reference Numerals: 1 - Server liquid cooling cabinet, 1 - 1 Cabinet main body, 1 - 2 Liquid cooling server, 1 - 3 Coolant distribution inlet pipe, 1 - 3 - 1 Coolant distribution inlet pipe, 1 - 4 Coolant distribution outlet pipe, 1 - 4 - 1 Coolant quick - connection inlet, 2 - Heat pipe air conditioner integrated machine, 2 - 1 Sheet metal housing, 2 - 2 Heat pipe condenser, 2 - 3 Air - cooled condenser, 2 - 4 Expansion valve, 2 - 5 Refrigerant evaporator, 2 - 6 Compressor, 2 - 7 Outdoor fan, 2 - 8 Outdoor unit controller, 2 - 9 Inlet refrigerant three - way valve, 2 - 10 Outlet refrigerant three - way valve, 2 - 11 Liquid receiver, 2 - 12 Refrigerant pump, 3 - Cold quantity distribution unit, 3 - 1 Intermediate heat exchanger, 3 - 2 Secondary side inlet liquid pipeline, 3 - 3 Secondary side outlet liquid pipeline, 3 - 4 Coolant pump, 3 - 5 Distribution unit controller, 4 - Multi - channel cold liquid distributor, 4 - 1 Cold liquid distribution channel, 5 - Multi - channel hot liquid refluxer, 5 - 1 Hot liquid reflux channel, 6 - Refrigerant gas pipe, 7 - Refrigerant liquid pipe, 311 - Main flow channel, 312 - Phase change energy storage flow channel, 313 - Input - end three - way valve, 314 - Output - end three - way valve, 315 - Temperature sensor array. Detailed implementation mode

[0016] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the following is only a preferred embodiment of the present invention, but the content of the present invention is not limited to the following embodiments.

[0017] Embodiment 1: Basic structure Figure 1 It is a schematic structural diagram of a server liquid cooling cabinet group heat dissipation system with phase change energy storage of the present invention. As shown in the figure, the server liquid cooling cabinet group heat dissipation system with phase change energy storage of the present invention includes two linear array type server liquid cooling cabinet groups 1, two cold quantity distribution units 3, two heat pipe air conditioner integrated machines 2, a multi-channel cold liquid distributor 4, and a multi-channel hot liquid refluxer 5.

[0018] Each server liquid cooling cabinet 1 includes a cabinet main body 1-1, a liquid cooling server 1-2, a coolant distribution inlet pipe 1-3, and a coolant distribution outlet pipe 1-4. The coolant distribution inlet pipe 1-3 includes a coolant inlet and a plurality of coolant quick-connect outlets 1-3-1 leading to each liquid cooling server 1-2. The coolant distribution outlet pipe 1-4 includes a plurality of coolant quick-connect inlets 1-4-1 connected to each liquid cooling server 1-2 and a coolant outlet. Each of the two cold quantity distribution units 3 includes an intermediate heat exchanger 3-1, a primary side refrigerant inlet, a primary side refrigerant outlet, a secondary side liquid inlet pipeline 3-2, and a secondary side liquid outlet pipeline 3-3. On the secondary side liquid inlet pipeline 3-2, a main and a standby coolant pump 3-4 are installed in parallel.

[0019] The two-in-one heat pipe air conditioner 2 includes a heat pipe natural cold source refrigeration circuit and a compressor mechanical refrigeration circuit, and also includes a sheet metal housing 2-1, an outdoor fan 2-7, an outdoor unit controller 2-8, an inlet refrigerant three-way valve 2-9, and an outlet refrigerant three-way valve 2-10. The heat pipe natural cold source refrigeration circuit includes a heat pipe condenser 2-2, whose inlet is connected to the first outlet of the inlet refrigerant three-way valve 2-9, and the outlet is connected to the first inlet of the outlet refrigerant three-way valve 2-10; the compressor mechanical refrigeration circuit includes an air-cooled condenser 2-3, an expansion valve 2-4, a refrigerant evaporator 2-5, a compressor 2-6 and the connecting pipelines therebetween. The hot side inlet of the refrigerant evaporator 2-5 is connected to the second outlet of the inlet refrigerant three-way valve 2-9, and the hot side outlet is connected to the second inlet of the outlet refrigerant three-way valve 2-10; the heat pipe natural cold source refrigeration circuit, the compressor mechanical refrigeration circuit, the outdoor fan 2-7, the controller 2-8, the inlet refrigerant three-way valve 2-9, and the outlet refrigerant three-way valve 2-10 are all installed in the sheet metal housing 2-1; the inlet of the inlet refrigerant three-way valve 2-9 is connected to the primary side refrigerant outlet of the cold quantity distribution unit 3 through a refrigerant gas pipe 6. The outlet of the outlet refrigerant three-way valve 2-10 is connected to the primary side refrigerant inlet of the cold quantity distribution unit 3 through a refrigerant liquid pipe 7. Preferably, on the pipeline at the outlet of the outlet refrigerant three-way valve 2-10 of the two-in-one heat pipe air conditioner 2, a liquid receiver 2-11 and a refrigerant pump 2-12 are selected and equipped through a parallel pipeline. The liquid receiver is used to store and stabilize the refrigerant flow, and the refrigerant pump is used to provide the refrigerant circulation power when there is a power-driven demand or when the adjustment force needs to be increased.

[0020] The multi-channel cold liquid distributor 4 includes a two cold liquid inlets and multiple cold liquid distribution channels 4-1. The cold liquid inlet is connected to the secondary side liquid outlet pipeline 3-3 of the cold quantity distribution unit 3, and each cold liquid distribution channel 4-1 leads to each server liquid cooling cabinet 1 and is connected to a cooling medium inlet of a coolant distribution inlet pipe 1-3 thereof; the multi-channel hot liquid refluxer 5 includes multiple hot liquid reflux channels 5-1 and two hot liquid outlets. Each hot liquid reflux channel 5-1 is connected to a coolant outlet of a coolant distribution outlet pipe 1-4 of each server liquid cooling cabinet 1, and the hot liquid outlet is connected to the secondary side liquid inlet pipeline 3-2 of the cold quantity distribution unit 3.

[0021] One main and one standby of the two coolant pumps 3-4 in the two cold quantity distribution units 3. When the main coolant pump 3-4 fails, the standby coolant pump 3-4 automatically starts to run; the two cold quantity distribution units 3 are in a one-for-one standby mode and are respectively arranged at the head, middle or end of the columns of the two linear array type server liquid cooling cabinet groups 1. The two cold quantity distribution units 3 are both connected to the multi-channel cold liquid distributor 4 and the multi-channel hot liquid refluxer 5 through pipelines; the two two-in-one heat pipe air conditioners 2 are in a one-for-one standby mode and are respectively connected to the two one-for-one standby cold quantity distribution units 3 through a refrigerant gas pipe 6 and a refrigerant liquid pipe 7.

[0022] The integrated heat pipe air conditioner 2 further includes monitoring components such as temperature sensors and pressure sensors. The outdoor unit controller 2-8 can adjust the operation mode, operation status of the integrated heat pipe air conditioner 2 and the operation status of the outdoor fan 2-7 according to the monitoring data and upload them to the upper monitoring system. Each of the two cooling capacity distribution units 3 includes a distribution unit controller 3-5, multiple temperature and humidity sensors, multiple pressure sensors, multiple liquid leakage sensors, and an automatic pressure relief device. The distribution unit controller 3-5 can monitor the temperature of the refrigerant entering / leaving the primary side, the temperature of the liquid supply / return on the secondary side, the pressure of the liquid supply / return on the secondary side, whether there is liquid leakage in the unit, the temperature and humidity of the machine room environment, etc., and can adjust the speed, start and stop of the coolant pump 3-4 according to the load and actual operation requirements, and open the automatic pressure relief device when the coolant pressure on the secondary side is high. When there is a liquid leakage situation in the unit or the monitored temperature and pressure exceed the limit values, an alarm is issued and uploaded to the upper monitoring system. In addition, preferably, the intermediate heat exchanger is a plate heat exchanger or a shell and tube heat exchanger. The working medium in the primary side system composed of the two integrated heat pipe air conditioners 2 and the two cooling capacity distribution units 3 is a Freon refrigerant; the working medium in the secondary side system composed of the two cooling capacity distribution units 3 and the two linear array type server liquid cooling cabinet groups 1 can be deionized pure water, ethylene glycol solution, propylene glycol solution, etc.

[0023] In the server liquid cooling cabinet group heat dissipation system with phase change energy storage of the present invention, the heat pipe natural cold source refrigeration circuit and the compressor mechanical refrigeration circuit alone or jointly provide outdoor cold source for the corresponding cooling capacity distribution unit. The heat from each liquid cooling server of the linear array type server liquid cooling cabinet group is collected in the secondary side coolant of the multi-channel hot liquid refluxer and returns to the cooling capacity distribution unit for cooling. The cooled secondary side coolant enters the multi-channel cold liquid distributor and then is split to each liquid cooling server of each server liquid cooling cabinet to absorb heat again, so as to discharge the heat out of the machine room.

[0024] Embodiment 2: Only the heat pipe natural cold source refrigeration circuit is operated. Figure 2It is a schematic structural diagram when only the heat pipe natural cold source refrigeration circuit is operating. As shown in the figure, the heat pipe air conditioner integrated unit 2 selects the operating circuit according to the outdoor cold source supply situation. When it is the cold season in winter and the outdoor natural cold source is sufficient, only the heat pipe natural cold source refrigeration circuit operates. At this time, the heat pipe natural cold source refrigeration circuit alone provides the outdoor cold source for the cold quantity distribution unit 3. The flow direction of the primary side refrigerant in the heat pipe air conditioner integrated unit 2, refrigerant liquid pipe 7, cold quantity distribution unit 3, and refrigerant gas pipe 6 participating in the operation is shown by the arrow B direction in the figure; the heat of each liquid-cooled server 1-2 from the linear array type server liquid-cooled cabinet group 1 converges in the secondary side water of the multi-channel hot liquid refluxer 5 and returns to the cold quantity distribution unit 3 for cooling. The cooled secondary side water enters the multi-channel cold liquid distributor 4 and then is split to each liquid-cooled server 1-2 of each server liquid-cooled cabinet 1 to absorb heat again, so as to discharge the heat out of the computer room. The flow direction of the secondary side coolant is shown by the arrow A in the figure.

[0025] Embodiment 3: Simultaneous operation of the dual refrigeration circuits Figure 3 It is a schematic structural diagram when the heat pipe natural cold source refrigeration circuit and the compressor mechanical refrigeration circuit are operating simultaneously. As shown in the figure, the heat pipe air conditioner integrated unit 2 selects the operating circuit according to the outdoor cold source supply situation. When it is the transitional season between spring and autumn and the outdoor natural cold source can provide part of the cold quantity, the heat pipe natural cold source refrigeration circuit and the compressor mechanical refrigeration circuit operate simultaneously. At this time, the heat pipe natural cold source refrigeration circuit and the compressor mechanical refrigeration circuit jointly provide the outdoor cold source for the cold quantity distribution unit 3. The flow direction of the primary side refrigerant in the heat pipe air conditioner integrated unit 2, refrigerant liquid pipe 7, cold quantity distribution unit 3, and refrigerant gas pipe 6 participating in the operation is shown by the arrow C direction in the figure; the flow direction of the refrigerant in the air-cooled condenser 2-3, expansion valve 2-4, refrigerant evaporator 2-5, compressor 2-6 of the compressor mechanical refrigeration circuit and the connecting pipelines among them is shown by the arrow E in the figure. The heat of each liquid-cooled server 1-2 from the linear array type server liquid-cooled cabinet group 1 converges in the secondary side coolant of the multi-channel hot liquid refluxer 5 and returns to the cold quantity distribution unit 3 for cooling. The cooled secondary side coolant enters the multi-channel cold liquid distributor 4 and then is split to each liquid-cooled server 1-2 of each server liquid-cooled cabinet 1 to absorb heat again, so as to discharge the heat out of the computer room. The flow direction of the secondary side coolant is shown by the arrow A in the figure.

[0026] Embodiment 4: Only the compressor mechanical refrigeration circuit operates Figure 4It is a schematic structural diagram when only the compressor mechanical refrigeration circuit is running. As shown in the figure, the integrated heat pipe air conditioner 2 selects the operating circuit according to the outdoor cold source supply situation. When the outdoor natural cold source cannot provide cooling capacity in the hot summer season, only the compressor mechanical refrigeration circuit operates. At this time, the compressor mechanical refrigeration circuit alone provides the outdoor cold source for the cold quantity distribution unit 3. The flow direction of the refrigerant on the primary side in the integrated heat pipe air conditioner 2, refrigerant liquid pipe 7, cold quantity distribution unit 3, and refrigerant gas pipe 6 participating in the operation is shown by the arrow D in the figure; the flow direction of the refrigerant in the air-cooled condenser 2-3, expansion valve 2-4, refrigerant evaporator 2-5, compressor 2-6 of the compressor mechanical refrigeration circuit and the connecting pipes between them is shown by the arrow E in the figure; the heat of each liquid-cooled server 1-2 from the linear array type server liquid-cooled cabinet group 1 is collected in the secondary side coolant of the multi-channel hot liquid refluxer 5 and flows back to the cold quantity distribution unit 3 for cooling. The cooled secondary side coolant enters the multi-channel cold liquid distributor 4 and then is split to each liquid-cooled server 1-2 of each server liquid-cooled cabinet 1 to absorb heat again, so as to discharge the heat out of the computer room. The flow direction of the secondary side water is shown by the arrow A in the figure.

[0027] Embodiment 5: Optimized cold quantity distribution structure with phase change energy storage buffer This Embodiment 5 is optimized on the basis of Embodiment 1. To improve the thermal stability of the system during drastic fluctuations in heat and cold loads or during cold source switching, in the cold quantity distribution unit 3, a phase change energy storage module is introduced into the primary side refrigerant pipeline of the intermediate heat exchanger 3-1, which is used to improve the system response ability and cold quantity balance performance during heat and cold load fluctuations and refrigeration switching.

[0028] Specifically, as Figure 5 shown, the primary side of the intermediate heat exchanger 3-1 is designed as a double-flow channel structure that is parallel to each other in structure and spatially isolated from each other, including a main flow channel 311 and a phase change energy storage flow channel 312. The phase change energy storage flow channel 312 is internally encapsulated with a phase change energy storage material (preferably a paraffin-graphene composite material with a melting point of 25±0.5°C and a graphene content of ≥15wt%) and a heat exchange coil passing through it, which is used to exchange heat with the flowing refrigerant. An input end three-way valve 313 is provided on the primary side refrigerant inlet pipeline, its first outlet is communicated with the inlet of the main flow channel 311, and its second outlet is communicated with the inlet of the heat exchange coil of the phase change energy storage flow channel 312; an output end three-way valve 314 is provided on the primary side refrigerant outlet pipeline, its first inlet is communicated with the outlet of the main flow channel 311, and its second inlet is communicated with the outlet of the heat exchange coil of the phase change energy storage flow channel 312. The phase change energy storage flow channel 312 has the ability to buffer cold quantity bidirectionally, absorbs cold quantity to complete "cold storage" during the refrigeration surplus period, and releases cold quantity to compensate for the temperature difference of the primary side refrigerant in scenarios such as high heat load or temporary unavailability of the main cold source, realizing the cold quantity adjustment and buffering function.

[0029] During the operation of the system, when it is detected that the external temperature is relatively low and the natural cold source or mechanical cold source is in a surplus state, the distribution unit controller 3-5 judges based on relevant sensor signals (such as the secondary side return water temperature, PCM temperature / status, primary side refrigerant temperature, etc.), and controls the passages and opening degrees of the input three-way valve 313 and the output three-way valve 314, so that part of the low-temperature refrigerant flows through the phase change energy storage flow channel 312, completing the solidification process of the phase change material and storing cold energy, and the rest of the refrigerant is introduced into the main flow channel 311 to maintain the conventional heat exchange operation. Conversely, when the system enters the cold load peak, the refrigeration mode is switched (such as switching from natural cooling to mechanical refrigeration, and the compressor needs time to start), or the main cold source is temporarily insufficient, etc., the distribution unit controller 3-5 controls the input three-way valve 313 and the output three-way valve 314, so that all the refrigerant is preferentially introduced into the phase change energy storage flow channel 312, and the cold energy released by the phase change material is used for precooling or buffering heat exchange, so as to achieve the balance of heat and cold loads, reduce the start-stop frequency of the system, and improve the operation continuity and the sensitivity of cold source regulation.

[0030] Furthermore, to achieve the efficient cooperation and smooth transition between the phase change energy storage and the main cold source (natural cold source or mechanical refrigeration), the distribution unit controller 3-5 incorporates a linkage control strategy based on the judgment of the hysteresis temperature difference. Specifically, as Figure 6 shown, this linkage control strategy includes: One is the cold storage start and stop strategy S100 based on the hysteresis threshold, which includes the following when implemented: S101. Cold storage start judgment. The controller 3-5 continuously monitors the difference between the secondary side return liquid temperature T sec_return and the set target temperature T setpoint , as well as the primary side refrigerant supply temperature T pri_supply or the operation status of the main cold source. When it is detected that the system is in a stable operation state, and T sec_return continually drops below T setpoint −ΔT charge_start for a period of time (such as several consecutive minutes), indicating that the cold energy provided by the main cold source is significantly surplus, and the phase change material state sensor indicates that it is not full (a temperature sensor array 315 is arranged inside the phase change energy storage flow channel 312, including at least three groups of temperature sensors evenly distributed along the thickness direction of the phase change material, used to accurately monitor the temperature gradient and phase change state of the phase change material), the controller starts the cold storage mode. ΔT charge_start is the preset cold storage start temperature difference threshold (such as 1.5 °C), to avoid frequent start of cold storage due to minor fluctuations.

[0031] S102. Cold storage process regulation and stop. In the cold storage mode, the controller 3-5 dynamically regulates the refrigerant ratio flowing through the heat exchange coil 312 according to the degree of surplus cooling capacity. The cold storage process will continue until the phase change material state sensor indicates that it has completely solidified or the secondary side return water temperature T sec_return rises back to near the set point (e.g., higher than T setpoint −ΔT charge_stop , where ΔT charge_stop is the cold storage stop temperature difference threshold less than ΔT charge_start , forming a hysteresis interval), indicating a reduction in surplus cooling capacity. This hysteresis design (ΔT charge_start >ΔT charge_stop ) prevents the repeated start and stop of the cold storage process near the critical point.

[0032] Second, it is the cold release start and coordination strategy S200 based on the hysteresis threshold, which includes when implemented: S201. Cold release start judgment. When the controller 3-5 detects that the secondary side return liquid temperature T sec_return continues to be higher than (T setpoint +ΔT discharge_start ), indicating that the cooling capacity provided by the current main cold source is insufficient to meet the load demand, and the phase change material state sensor indicates that it is in the cold storage (solid or partially solid) state, the cold release mode is immediately started. ΔT discharge_start is the preset cold release start temperature difference threshold.

[0033] S202. Immediate buffering and linkage with the main cold source. Once the cold release is started, the controller 3-5 quickly guides most or all of the primary side refrigerant into the heat exchange coil 312, uses the latent heat absorbed by the melting of the phase change material to deeply cool the refrigerant, and immediately buffers the rise of the secondary side temperature. At the same time or with a slight delay, the controller 3-5 sends a command to the heat pipe air conditioner integrated unit 2 to require an increase in the output capacity of the main cold source (such as further opening the natural cooling bypass valve, increasing the compressor operation frequency). The presence of the phase change material buys precious time for the slower responding main cold source (especially the start of mechanical refrigeration).

[0034] S203. Cold release process regulation and stop. The cold release process continues until the secondary side return liquid temperature T sec_return falls back to the safe range (e.g., lower than T setpoint +ΔT discharge_stop , where ΔT discharge_stop is the cold release stop temperature difference threshold less than ΔT discharge_start , forming a hysteresis interval), and the main cold source has successfully increased the output and stably taken over the load, or the phase change material state sensor indicates that the cooling capacity has been exhausted. The hysteresis design (ΔT discharge_start >ΔT discharge_stop ) avoids frequent oscillations near the demand critical point.

[0035] Thirdly, it is the smooth transition strategy S300 for mode switching, which includes the following when implemented: S301. Anticipate the switching scenario: When the controller 3-5 detects a decrease in natural cooling capacity and the system is about to switch from the natural cooling mode to the mechanical refrigeration mode, evaluate the switching lag risk in advance.

[0036] S302. Start phase change buffering: While issuing the mechanical refrigeration start command, the controller 3-5 controls the input three-way valve 313 and the output three-way valve 314, so that the refrigerant preferentially flows through the phase change energy storage flow channel 312, and the cooling capacity released by the phase change material is used to maintain the heat exchange capacity at the cold end of the primary side, realizing the smooth transition of the cooling capacity between the natural cold source and the mechanical cold source.

[0037] S303. Recovery after switching is completed: When the compression refrigeration system starts and outputs stably, the controller adjusts the passage according to the secondary side return liquid temperature T sec_return , the main cold source state and the energy storage state, ends the cold release state and re-enters the normal operation mode.

[0038] Through the above-mentioned linkage control strategy based on the lag temperature difference threshold, this embodiment not only provides effective cooling capacity buffering by using the phase change energy storage module, but also realizes the intelligent cooperation between the energy storage module and the main cold source, ensuring the efficient, stable and smooth operation of the entire cooling system under various working conditions, and significantly improving the reliability and energy efficiency performance of the data center thermal management.

[0039] Through the above embodiments, the object of the present invention is completely and effectively achieved. Any equivalent or simple changes made according to the structure, features and principles described in the inventive concept of this invention patent are included in the protection scope of this invention patent. Those skilled in the technical field to which the present invention belongs can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, as long as they do not deviate from the structure of the present invention or exceed the scope defined by this claim book, they should all belong to the protection scope of the present invention.

Claims

1. A server liquid cooling cabinet group heat dissipation system with phase change energy storage, characterized in that: include: A linear array server liquid cooling cabinet group is arranged in two opposite rows, each row is provided with a plurality of server liquid cooling cabinets arranged closely together, and each cabinet is provided with at least one liquid cooling server; The cooling capacity distribution unit is provided in two sets, one for backup and one for use, and is respectively arranged at the head, middle or tail of the two linear array server liquid cooling cabinet groups. Each cooling capacity distribution unit includes an intermediate heat exchanger, and each intermediate heat exchanger includes a primary side and a secondary side. The refrigerant is introduced into the primary side, and the cooling liquid is introduced into the secondary side. A multi-channel cooling liquid distributor, comprising two cooling liquid inlets and a plurality of cooling liquid distribution channels, wherein the two cooling liquid inlets are respectively connected to the secondary side outlets of the two intermediate heat exchangers, and each outlet is respectively connected to the cooling liquid inlet of each liquid-cooled server in a one-to-one correspondence; A multi-channel hot liquid recirculator, comprising a plurality of hot liquid recirculation channels and two hot liquid outlets, each of which is connected to a cooling liquid outlet of each liquid-cooled server in a one-to-one correspondence, and the two hot liquid outlets are connected to the secondary side inlets of the two intermediate heat exchangers in a corresponding manner; The heat pipe air conditioning integrated unit is provided with two sets, one for backup and one for use, respectively corresponding to an intermediate heat exchanger. Each set includes a heat pipe natural cold source refrigeration circuit and a compressor mechanical refrigeration circuit. The two circuits are arranged in parallel on the primary side of the corresponding intermediate heat exchanger, and the valve assembly is used to select one of the two refrigeration circuits to operate or to operate both refrigeration circuits to provide a cold source for the secondary side.

2. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 1 is characterized in that: Each heat pipe air-conditioning integrated unit also includes a refrigerant inlet three-way valve and a refrigerant outlet three-way valve. The inlet of the refrigerant inlet three-way valve is connected to the primary side outlet of the corresponding intermediate heat exchanger, and the outlet of the refrigerant outlet three-way valve is connected to the primary side inlet of the corresponding intermediate heat exchanger; the heat pipe natural cold source refrigeration circuit includes a heat pipe condenser, the inlet of the heat pipe condenser is connected to the first outlet of the refrigerant inlet three-way valve, and the outlet of the heat pipe condenser is connected to the first inlet of the refrigerant outlet three-way valve; the compressor mechanical refrigeration circuit includes an air-cooled condenser, an expansion valve, a refrigerant evaporator, a compressor and connecting pipelines therebetween, and the hot side inlet of the refrigerant evaporator is connected to the second outlet of the refrigerant inlet three-way valve, and the hot side outlet is connected to the second inlet of the refrigerant outlet three-way valve.

3. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 2 is characterized in that: Each cooling distribution unit is equipped with a distribution unit controller, a temperature sensor and a pressure sensor, which are used to monitor the primary side refrigerant supply temperature, the secondary side coolant return temperature, the primary side refrigerant supply pressure and the secondary side coolant return pressure respectively.

4. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 3 is characterized in that: The heat pipe air conditioner also includes an outdoor unit controller, a temperature sensor and a pressure sensor. The outdoor unit controller dynamically adjusts the operating mode of the heat pipe air conditioner and the operating status of the outdoor fan according to the preset logic based on the monitored outdoor temperature and refrigerant pipeline pressure data.

5. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 4 is characterized in that: The heat pipe air-conditioning integrated unit selects the operating circuit in different scenarios according to the outdoor cold source provision by switching the refrigerant inlet three-way valve and the refrigerant outlet three-way valve: when the outdoor natural cold source is sufficient, only the heat pipe natural cold source refrigeration circuit is operated; when the outdoor natural cold source can provide part of the cooling capacity, the heat pipe natural cold source refrigeration circuit and the compressor mechanical refrigeration circuit are operated at the same time; when the outdoor natural cold source cannot provide cooling capacity, only the compressor mechanical refrigeration circuit is operated.

6. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to any one of claims 3 to 5, characterized in that: The primary side of the intermediate heat exchanger is structurally designed as a dual-channel structure that is connected in parallel and spatially isolated from each other, including a main channel and a phase change energy storage channel, wherein the phase change energy storage channel is encapsulated with phase change energy storage material and a heat exchange coil running through it, and a state sensor is arranged inside the phase change energy storage channel, including at least three groups of temperature sensors evenly distributed along the thickness direction of the phase change energy storage material, which are used to monitor the temperature gradient and phase change state of the phase change energy storage material.

7. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 6, characterized in that: An input three-way valve is provided on the primary side inlet pipeline of the intermediate heat exchanger, and its first outlet is connected to the inlet of the main flow channel, and the second outlet is connected to the inlet of the heat exchange coil of the phase change energy storage channel; an output three-way valve is provided on the primary side outlet pipeline, and its first inlet is connected to the outlet of the main flow channel, and the second inlet is connected to the outlet of the heat exchange coil of the phase change energy storage channel.

8. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 7, characterized in that: The distribution unit controller is based on the secondary side return liquid temperature T sec_return , primary side refrigerant supply temperature T pri_supply As well as the state of the phase-change energy storage material, combined with the built-in preset control strategy, it is determined whether the cold storage mode and the cold release mode need to be activated, and the opening and passage of the three-way valve at the input end and the three-way valve at the output end are controlled accordingly, and the ratio of the refrigerant flowing through the main flow channel and the phase-change energy storage flow channel is adjusted to achieve the absorption of cold energy to complete cold storage during the period of surplus cooling, and release cold energy in scenarios with high heat load or when the main cold source is temporarily unavailable.

9. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 8, characterized in that: The built-in preset control strategy includes a cold storage start and stop strategy based on a hysteresis threshold, including: S101. Cold storage start judgment: Continuously monitor the secondary side return liquid temperature T sec_return With the set target temperature T setpoint The difference between the primary side refrigerant supply temperature T pri_supply Or the main cooling source is in operation state. When the system is detected to be in a stable cooling source operation state, T sec_return Continue to be lower than T setpoint Subtract the preset cold storage start temperature difference threshold ΔT charge_start , and when the phase change energy storage material is not fully charged, the cold storage mode is started; S102. Cold storage process adjustment and stop: In the cold storage mode, dynamically adjust the refrigerant ratio entering the phase change energy storage channel and sec_return Rebound above T setpoint Subtract the preset cold storage stop temperature difference threshold ΔT charge_stop Stop cold storage when ΔT charge_start >ΔT charge_stop .

10. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 8 or 9, characterized in that: Built-in preset control strategies also include cold start and coordination strategies based on hysteresis thresholds, including: S201. Release cold start judgment: When T is detected sec_return Continue to be higher than T setpoint Add and release cold start temperature difference threshold ΔT discharge_start , and when the phase change energy storage material is in a cold storage state, the cold release mode is started; S202. Instant buffering and main cold source linkage: After the cold release is started, the primary side refrigerant is preferentially introduced into the phase change energy storage channel for immediate buffering, and at the same time or with a slight delay, an instruction to increase the output capacity of the main cold source is sent to the outdoor heat pipe air conditioner, so as to realize the coordinated linkage between the cold release and the main cold source; S203. Cooling process adjustment and stop: When the secondary side return liquid temperature T sec_return Falling back below T setpoint Temperature difference threshold ΔT for cooling stop discharge_stop , and when the main cooling source stably takes over the load or the cooling capacity of the phase change energy storage material is exhausted, the cooling process is terminated and the normal cooling path is restored, where ΔT discharge_start >ΔT discharge_stop .

11. The server liquid cooling cabinet group heat dissipation system with phase change energy storage according to claim 10, characterized in that: The built-in preset control strategy also includes a mode switching smooth transition strategy, including: S301. Predicting the switching scenario: When it is detected that the natural cooling capacity is reduced and the system is about to switch to the mechanical cooling mode, assessing the risk of switching delay; S302. Start phase change buffer: When issuing a mechanical refrigeration start command, control the valve so that the refrigerant flows preferentially through the phase change energy storage channel for buffering; S303. Recovery after switching is completed: After the compressor refrigeration system runs stably, adjust the valve passage according to the system status to end the cooling release state.

Images