Pump driven two-phase loop apparatus with gas-liquid separator and its use in data center cooling

Abstract

This invention discloses a pump-driven two-phase loop device with a gas-liquid separator and its application in data center cooling. The heat exchange cooling end is composed of one or more parallel evaporation branches. The outlet of the heat exchange cooling end is connected to the gas-liquid separator via a pipeline. The liquid phase outlet of the gas-liquid separator is connected sequentially via a pipeline to a liquid reservoir, a magnetic gear pump, a second heat exchanger, and the inlet of the heat exchange cooling end. Under the action of the magnetic gear pump, the working fluid is directionally transported along the flow channel. The gas phase outlet of the gas-liquid separator is connected to the first heat exchanger and the liquid reservoir via a pipeline. The first heat exchanger cools the gaseous working fluid into a liquid working fluid, which enters the liquid reservoir for the next working cycle. The liquid reservoir is connected to the working fluid charging port. The heat exchange cooling end is connected to the vacuum port. This invention, through the combined regulation of two-stage subcooling and gas-liquid separation, significantly suppresses the boiling oscillation and drying phenomenon of traditional two-phase loops under high heat flux density, improves the flow boiling stability and energy efficiency ratio, and can be used in heat dissipation scenarios such as data center chip cooling.

Description

Technical Field

[0001] This invention belongs to the field of two-phase flow heat dissipation technology, and in particular relates to a pump-driven two-phase circuit device with a gas-liquid separator and its application in data center cooling. Background Technology

[0002] With the rapid development of artificial intelligence, cloud computing, and big data processing technologies, the integration of computing nodes in data centers is constantly increasing, leading to a surge in the computing power demand for AI chips. This has resulted in a significant increase in the power density and heat generation of chips within data centers. Traditional air cooling technologies, due to air's low specific heat capacity and low heat transfer coefficient, are no longer sufficient to meet the heat dissipation requirements of high-power-density servers. Therefore, developing efficient and low-energy-consumption liquid cooling solutions has become a crucial development trend in the field of data center thermal management technology.

[0003] In liquid cooling technology, pumped two-phase (P2P) heat transfer utilizes the latent heat of phase change of the working fluid for heat exchange, achieving a significantly higher heat exchange efficiency than traditional single-phase water cooling. However, in practical applications, two-phase loop systems face complex flow instability issues. As the heat exchange increases, the proportion of vapor generated in the loop rapidly increases, leading to a dramatic increase in internal pressure drop and a tendency for desiccation, severely limiting the system's operational stability and reliability under high-power conditions.

[0004] In existing pump-driven two-phase circuits, the fluid at the condenser outlet or after the evaporator is often in a gas-liquid two-phase mixed state. If unseparated gas enters the circulating pump in a high proportion, it will reduce the pump's service life and reliability. At the same time, if the unseparated gas and liquid phases enter the condenser simultaneously, the liquid phase will cover the heat exchange wall, significantly weakening the condensation effect of the working fluid vapor and increasing the subcooling of the condensate, thus reducing the overall energy efficiency ratio of the system.

[0005] Therefore, developing a high-efficiency gas-liquid separation structure adapted to pump-driven two-phase circuit devices to solve the instability caused by gas-liquid two-phase flow coupling and the problem of reduced heat exchange capacity on the condensation side has become an important breakthrough for improving the overall performance of data center chip heat dissipation systems. Summary of the Invention

[0006] The present invention relates to the design of a pump-driven two-phase flow device with a gas-liquid separator and its application in data center cooling. The aim is to solve the problems of instability caused by gas-liquid two-phase flow coupling and reduced heat exchange capacity on the condenser side in existing pump-driven two-phase flow systems, so as to meet the heat dissipation requirements of high power density AI chips or other related objects in data centers.

[0007] The technical solution adopted in this invention is as follows:

[0008] A pump-driven two-phase circuit device with a gas-liquid separator includes:

[0009] The heat exchange and cooling end is composed of one or more evaporation branches connected in parallel;

[0010] The outlet of the heat exchange cooling end is connected to the gas-liquid separator through a pipeline. The liquid phase outlet of the gas-liquid separator is connected in sequence through a pipeline to a liquid storage tank, a magnetic gear pump, a second heat exchanger, and the inlet of the heat exchange cooling end. Under the action of the magnetic gear pump, the working fluid is transported directionally along the flow channel.

[0011] The gas phase outlet of the gas-liquid separator is connected to the first heat exchanger and the liquid storage tank through a pipeline. The first heat exchanger cools the gaseous working fluid into a liquid working fluid, which then enters the liquid storage tank for the next working cycle.

[0012] The reservoir is connected to the working fluid filling port;

[0013] The heat exchange cooling end is connected to the vacuum port.

[0014] Furthermore, a single heat exchange cooling end or multiple heat exchange cooling ends are connected after the second heat exchanger to simultaneously dissipate heat and cool down a single heat source or multiple heat sources.

[0015] Furthermore, each evaporation branch has at least one evaporator connected in series, and a flow regulator is provided at the inlet of the evaporator.

[0016] Furthermore, the evaporator is a plate evaporator of the parallel microchannel type.

[0017] Furthermore, both the second heat exchanger and the first heat exchanger are plate heat exchangers.

[0018] Furthermore, the pipeline is also equipped with flow meters, pressure gauges, and valves.

[0019] Furthermore, the plate evaporator is placed parallel to the pipeline, with its outlet end connected to the inlet end of the gas-liquid separator, and its bottom in contact with the heat source. To ensure that the inlet and outlet fluids enter and exit the evaporator uniformly and stably, the internal liquid cavity is arranged with turbulence columns and parallel flow channels. The turbulence columns are staggered cylindrical turbulence columns, and the parallel flow channels are straight microchannels of equal width. The array of turbulence columns is located at the front and rear ends of the parallel microchannels. The plate evaporators are arranged vertically in parallel in the server rack.

[0020] Furthermore, the inner diameter of the gas phase outlet at the top of the gas-liquid separator is larger than the inner diameter of the liquid phase outlet at the bottom, so that the gas phase is discharged first, maintaining the internal pressure of the separator and ensuring that the liquid phase can flow smoothly into the liquid storage tank.

[0021] Furthermore, the pump body of the magnetic gear pump adopts a non-dynamic seal structure to adjust the flow state of the inflowing working fluid.

[0022] An application of a pump-driven two-phase circuit device with a gas-liquid separator is described, in which the aforementioned pump-driven two-phase circuit device with a gas-liquid separator is used to cool a data center, and the heat exchange cooling end contacts the chips in the server rack of the data center for heat exchange.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention proposes a novel pump-driven two-phase flow structure. A gas-liquid separator and a liquid receiver are simultaneously introduced into the pump-driven two-phase flow system. The gas-liquid separator first efficiently separates the gas and liquid working fluid at the evaporator outlet, preventing the gas phase working fluid from entering the subsequent liquid phase loop. The liquid receiver stores and stabilizes the separated liquid working fluid before delivering it to the magnetic gear pump. This fundamentally avoids problems such as pump idling and accelerated wear caused by gas phase mixing. When the system's heat load fluctuates, the liquid working fluid can be replenished in a timely manner, regulating the flow rate and buffering pressure fluctuations. The pressure stabilizing effect of the liquid receiver significantly reduces fluctuations in the flowing working fluid, ensuring the pump operates under stable, pure liquid phase conditions. Simultaneously, the liquid receiver can replenish the system's working fluid in real time, preventing evaporator liquid shortages and heat exchange interruptions due to insufficient working fluid, ensuring continuous and reliable heat dissipation for data center chips. Through a reasonable structural arrangement, the heat dissipation efficiency of the pump-driven two-phase flow system is improved, and energy loss is reduced.

[0025] 2. The present invention introduces a second heat exchanger into the pump-driven two-phase flow system, which can further adjust the subcooling of the liquid working fluid in the pipeline system before entering the evaporator, and make the working fluid flow into the flow regulator at a constant temperature, thus creating conditions for uniform phase change heat absorption of the subsequent chip heat exchange surface.

[0026] 3. The single-rack working mode, dual-rack working mode or multi-rack working mode proposed in this invention can be adjusted according to the actual heat dissipation requirements of the data center chip, and the number of plate evaporators can be increased or decreased in a single rack cooling loop.

[0027] 4. The flow regulator can adjust and control the flow rate of the working fluid entering the plate evaporator, maintain a stable flow input, and complete the circulation of the working fluid within the system.

[0028] 5. The pump body of the magnetic gear pump adopts a non-dynamic seal structure, which adjusts the flow state of the inflowing working medium, eliminates the "overcooling" and "overheating" of the working medium, and effectively suppresses the phenomenon of unstable flow of the working medium. Attached Figure Description

[0029] The accompanying drawings used in the description of specific embodiments or prior art will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the single-cabinet operating mode system structure of the pump-driven two-phase circuit device with gas-liquid separator of the present invention.

[0031] Figure 2 This is a schematic diagram of the dual-cabinet operating mode system structure of the pump-driven two-phase circuit device with gas-liquid separator of the present invention.

[0032] Figure 3 This is a structural diagram of the liquid chamber of a plate evaporator with a pump-driven two-phase circuit device and a gas-liquid separator according to the present invention.

[0033] In the diagram: 1. Plate evaporator; 1A. Turbulence column; 1B. Flow channel; 2. Flow regulator; 3. Gas-liquid separator; 4. Liquid receiver; 5. Magnetic gear pump; 61. First heat exchanger; 62. Second heat exchanger; 71, 72, 73, and 74 are all flow meters; 81, 82, 83, 84, 85, and 86 are all pressure gauges; 9. Valve; 101. Working fluid charging port; 102. Vacuum port; 11. Heat exchange cooling end. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0035] Embodiments of the present invention are described in detail below, examples of which are given in the accompanying drawings, wherein the same or similar reference numerals are used to denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0036] In the description of this invention, it should be understood that the terms "front end," "rear end," "length," "width," "height," "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "arrangement," "connection," and "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] Example 1:

[0039] like Figure 1 This is a schematic diagram of the system structure of a single-rack operating mode of a pump-driven two-phase circuit device with a gas-liquid separator according to the present invention. It includes: a heat exchange cooling end 11, a gas-liquid separator 3, a liquid receiver 4, a magnetic gear pump 5, a heat exchanger 6, a server rack 11, and a piping system. The heat exchange cooling end 11 is composed of one or more parallel evaporation branches, each evaporation branch having at least one evaporator 1; the outlet ends of all evaporation branches are connected to the inlet end of the gas-liquid separator 3, and the outlet ends of all evaporation branches are also connected to a vacuum port 122. The gas phase outlet of the gas-liquid separator 3 is connected to the inlet of the first heat exchanger 61, the liquid phase outlet of the gas-liquid separator 3 is connected to the inlet of the liquid storage tank 4, the inlet of the liquid storage tank 4 is also connected to the outlet of the first heat exchanger 61 and the charging port 101, the outlet of the liquid storage tank 4 is connected to the inlet of the magnetic gear pump 5, the outlet of the magnetic gear pump 5 is connected to the inlet of the second plate heat exchanger 62, the outlet of the second heat exchanger 62 is connected to the inlet of each evaporation branch, and a flow regulator 2 is provided at the inlet of each evaporation branch.

[0040] More specifically, the second heat exchanger 62 and the first heat exchanger 61 are both plate heat exchangers or other types of heat exchangers.

[0041] More specifically, the evaporator 1 in the heat exchange cooling end 11 is a plate evaporator of the parallel microchannel type, which is arranged in parallel along the vertical direction.

[0042] More specifically, the piping system also includes working fluid channels, flow meters, pressure gauges, and valves.

[0043] More specifically, the gas-liquid separator 3 has inlet ends on both sides that connect to the outlet ends of the plate evaporator, a gas phase outlet end at the top that connects to the inlet end of the first plate heat exchanger, and a liquid phase outlet end at the bottom that connects to the inlet end of the liquid storage tank. The inner diameter of the top gas phase outlet of the gas-liquid separator is larger than the inner diameter of the bottom liquid phase outlet, so the gas phase is discharged first, maintaining the internal pressure of the separator is stable and ensuring that the liquid phase can flow smoothly into the liquid storage tank.

[0044] More specifically, such as Figure 3 This is an internal structural diagram of the plate evaporator 1. The internal liquid chamber is arranged with turbulence columns 1A and flow channels 1B. The heating section consists of 18 parallel channels, each 68mm long, 1mm wide, and 3mm high. The baffles between the channels are 1mm thick. The inlet end has 19 staggered turbulence columns 111 with a diameter of 2mm, and the outlet end has 7 turbulence columns 111 with a diameter of 3mm. The cooled chip is in contact with the back of the plate evaporator, and the heat from the chip is carried away by the boiling evaporation of the refrigerant.

[0045] Before operating the device, open valve 92 at the connection of vacuum port 102 to evacuate the entire pipeline system to a negative pressure state and fully remove non-condensable gases. Then close valve 92 and charge refrigerant R-1234yf into the liquid receiver 4 through charging port 101. When the refrigerant level reaches two-thirds of the liquid receiver 4, stop charging and close valve 91 at the connection of charging port 101.

[0046] After completing the above work, when the object being cooled (such as the data center chip generating heat) in contact with the heat exchange cooling end 11 comes into contact with the heat exchanger, adjust the pump speed of the magnetic gear pump 5. At this time, the system is in single-rack working mode.

[0047] The refrigerant is heated and boils in the plate evaporator 1, which is horizontally arranged with the connecting pipeline. The pure liquid refrigerant becomes a gas-liquid two-phase mixture, which is then transported to the gas-liquid separator 3 through the pipeline system. In the gas-liquid separator 3, the gas-liquid two-phase mixture is separated by gravity. The gaseous refrigerant enters the first heat exchanger 61 from the upper gas phase outlet of the gas-liquid separator 3 for primary cooling, while the liquid refrigerant enters the liquid storage tank 4 from the bottom liquid phase outlet of the gas-liquid separator 3. The gaseous refrigerant that has passed through the first heat exchanger 61 is cooled into liquid and enters the liquid storage tank 4 through the pipeline. The liquid storage tank 4 stores and stabilizes the refrigerant transported through the pipeline system, and then transports the refrigerant to the magnetic gear pump 5 through the bottom outlet. Under the action of the magnetic gear pump 5, the flow state of the inflowing refrigerant is adjusted, and the gas-liquid two-phase mixture is transported directionally along the flow channel without backflow, effectively suppressing the phenomenon of unstable flow of the refrigerant in the pipeline system.

[0048] The working fluid flowing through the magnetic gear pump 5 then enters the second heat exchanger 62 via the pipeline system, further adjusting the subcooling of the liquid working fluid before entering the evaporator. The liquid working fluid after passing through the second heat exchanger 62 enters the flow regulator 2 via the pipeline system. After the flow regulator 2 adjusts and stabilizes the working fluid flow rate, it is then transported to the plate evaporator 1 for heating, boiling, and evaporation, completing one working fluid cycle.

[0049] The flow meters 71 and 72 and the pressure gauges 81, 82 and 83 in the pipeline system can monitor the pressure and working fluid flow in the system in real time. When the pressure or flow fluctuates significantly, the pump speed can be adjusted to regulate the flow of the working fluid.

[0050] Example 2:

[0051] like Figure 2 This invention relates to a dual-cabinet operating mode of a pump-driven two-phase circuit device with a gas-liquid separator. Structurally, based on Embodiment 1, a heat exchange cooling end 11 is connected in series after the second heat exchanger 62, and the two heat exchange cooling ends 11 are connected in parallel. This system structure allows for simultaneous heat dissipation and cooling of multiple objects.

[0052] In terms of the working process, before the device is put into operation, valve 93 on the second heat exchange cooling end 11 in series is opened, the entire pipeline system is evacuated to a negative pressure state through vacuum port 102, and non-condensable gases are fully discharged. Valve 92 is then closed, and refrigerant R-1234yf is charged through charging port 101. When the refrigerant level reaches two-thirds of the liquid level in the reservoir, charging is stopped and valve 91 is closed.

[0053] After completing the above tasks, adjust the pump speed of the magnetic gear pump 5. At this time, the system is in dual-cabinet working mode.

[0054] The refrigerant boils and evaporates in a plate evaporator 1, which is horizontally connected to the piping. The pure liquid refrigerant becomes a gas-liquid two-phase mixture, which is then transported to a gas-liquid separator 3 via a piping system. Under the action of a magnetic gear pump 5, the gas-liquid two-phase mixture is directionally transported along the flow channel without backflow. In the gas-liquid separator 3, the gas-liquid two-phase mixture separates under the influence of gravity. The gaseous refrigerant enters the first heat exchanger 61 from the upper gas phase outlet of the gas-liquid separator 3 for primary cooling, while the liquid refrigerant enters the liquid reservoir 4 from the bottom liquid phase outlet of the gas-liquid separator 3. The gaseous refrigerant, after passing through the first heat exchanger 61, is cooled back to liquid and enters the liquid reservoir 4 through a pipe. The liquid reservoir 4 stores and stabilizes the refrigerant transported through the piping system before transporting it to the magnetic gear pump 5 through its bottom outlet. The magnetic gear pump 5 adjusts the flow state of the incoming refrigerant, suppressing unstable flow of the refrigerant in the piping system. The working fluid flowing through the magnetic gear pump 4 then enters the second heat exchanger 62 via the piping system, further adjusting the subcooling of the liquid working fluid before entering the evaporator. The liquid working fluid passing through the second heat exchanger 62 then enters the flow regulator 2 in the dual-cabinet loop via the piping system. After the flow regulator 2 adjusts and stabilizes the working fluid flow rate, the working fluid enters the plate evaporator 1, completing one working fluid cycle.

[0055] The flow meters 71, 72, 73, 74 and the pressure gauges 81, 82, 83, 84, 85 in the pipeline system can monitor the pressure and working fluid flow in the system in real time. When the pressure or flow fluctuates significantly, the pump speed can be adjusted to regulate the flow of the working fluid.

[0056] Depending on the actual situation of the heat source (such as a data center), a single-rack, dual-rack, or multi-rack working mode can be adopted. The number of plate evaporators can also be increased or decreased in a single-rack cooling loop.

[0057] Example 3:

[0058] The design disclosed in Embodiment 1 or 2 above is used for heat dissipation and cooling of data centers. Cooling can be achieved simply by cooling the bottom of the evaporator in the chip heat exchange cooling end 11 in the server rack.

[0059] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A pump-driven two-phase circuit device with a gas-liquid separator, characterized in that, include: The heat exchange cooling end (11) is composed of one or more evaporation branches connected in parallel. The outlet of the heat exchange cooling end (11) is connected to the gas-liquid separator (3) through a pipeline. The liquid phase outlet of the gas-liquid separator (3) is connected in sequence to the liquid storage tank (4), the magnetic gear pump (5), the second heat exchanger (62) and the inlet of the heat exchange cooling end 11 through a pipeline. Under the action of the magnetic gear pump (5), the working fluid is transported directionally along the flow channel. The gas phase outlet of the gas-liquid separator (3) is connected to the first heat exchanger (61) and the liquid storage tank (4) through a pipeline. The first heat exchanger (61) cools the gaseous working fluid into a liquid working fluid, which then enters the liquid storage tank (4) and enters the next working cycle. The reservoir (4) is connected to the working fluid inlet (101). The heat exchange cooling end (11) is connected to the vacuum port (102).

2. The pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, A single heat exchange cooling end (11) or multiple heat exchange cooling ends (11) are connected after the second heat exchanger (62) to dissipate heat and cool down a single heat source or multiple heat sources simultaneously.

3. The pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, Each evaporation branch has at least one evaporator connected in series, and a flow regulator (2) is provided at the inlet end of the evaporator.

4. A pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, The evaporator is a plate evaporator of the parallel microchannel type.

5. A pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, Both the second heat exchanger (62) and the first heat exchanger (61) are plate heat exchangers.

6. A pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, The pipeline is also equipped with flow meters, pressure gauges, and valves.

7. A pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, The plate evaporator is placed parallel to the pipeline, with its outlet end connected to the inlet end of the gas-liquid separator and its bottom in contact with the heat source. To ensure that the inlet and outlet fluids enter and exit the evaporator uniformly and stably, the internal liquid cavity is arranged with turbulence columns and parallel flow channels. The turbulence columns are staggered cylindrical turbulence columns, and the parallel flow channels are straight microchannels of equal width. The array of turbulence columns is located at the front and rear ends of the parallel microchannels. The plate evaporators are arranged vertically in parallel in the server rack.

8. A pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, The gas-liquid separator (3) has a gas phase outlet diameter at the top that is larger than the liquid phase outlet diameter at the bottom. It prioritizes the discharge of the gas phase, maintains stable internal pressure within the separator, and ensures that the liquid phase can flow smoothly into the storage tank.

9. A pump-driven two-phase circuit device with a gas-liquid separator according to claim 1, characterized in that, The pump body of the magnetic gear pump adopts a non-dynamic seal structure to adjust the flow state of the inflowing working fluid.

10. An application of a pump-driven two-phase circuit device with a gas-liquid separator, characterized in that, The pump-driven two-phase circuit device with gas-liquid separator described in claim 1 is used to cool the data center, so that the chips in the server rack in the data center come into contact with the bottom of the evaporator in the heat exchange cooling end (11) for heat exchange.

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