A direct-cooling energy storage cabinet cooling system and direct-cooling energy storage cabinet

Abstract

This utility model belongs to the field of energy storage cabinet technology, specifically relating to an improved direct-cooling energy storage cabinet cooling system and a corresponding energy storage cabinet. The direct-cooling energy storage cabinet cooling system includes a battery pack, an evaporator module adjacent to the battery pack, a direct-cooling unit, and a refrigerant circulation pipeline connected to the direct-cooling unit. The refrigerant circulation pipeline includes a primary liquid delivery pipeline, a liquid distribution assembly, a secondary liquid delivery pipeline, and a primary return pipeline. Multiple sets of the secondary liquid delivery pipelines are connected to the primary liquid delivery pipeline through the same liquid distribution assembly. The refrigerant has at least one flow path that sequentially flows through the primary liquid delivery pipeline, the liquid distribution assembly, the secondary liquid delivery pipeline, the evaporator interface, the evaporator module, and the primary return pipeline. The main improvement is achieved by designing the direction and connection of the pipelines to accommodate phase changes in the refrigerant within the pipeline, thereby improving the uniformity of refrigerant distribution at the phase level.

Description

Technical Field

[0001] This utility model belongs to the field of energy storage cabinet technology, specifically relating to an improved direct-cooling energy storage cabinet cooling system and a corresponding energy storage cabinet. Background Technology

[0002] Direct-cooled energy storage system is a concept relative to air-cooled energy storage system and liquid-cooled energy storage system. In direct-cooled energy storage system, the refrigerant flows in the circulation pipeline and absorbs the heat generated by the battery pack when it passes through the surface area of ​​the battery pack, thereby achieving the effect of cooling the battery pack area.

[0003] In the prior art, patent CN222507754U proposes a direct-cooling energy storage cabinet. The energy storage cabinet includes a compressor, a heat exchanger, a regenerator, and direct-cooling plates connected in sequence by pipelines to form a refrigerant circulation loop. The pipelines include internal pipelines located inside the shell and external pipelines located outside the shell but inside the cabinet. The external pipelines include two main pipelines and multiple parallel branches connected between the two main pipelines. One end of each of the two main pipelines is connected to the two ports of the heat exchanger via a three-way shut-off valve. One end of each parallel branch is connected to one of the main pipelines via a two-way shut-off valve, and the other end is connected to the other main pipeline via a two-way shut-off valve. Each direct-cooling plate is connected to each of the parallel branches. A cylindrical pipe support is provided on the left and right sides of the front opening of the cabinet. Each pipe support is arranged along the height direction of the cabinet and has a pipe channel extending along the height direction of the cabinet. The two main pipelines extend within the two pipe channels. Pipe holes are provided on the pipe supports corresponding to each direct-cooling plate for the parallel branches to pass through. In this scheme, the access points of the parallel branches are distributed at different locations on the main pipeline flow path. This means that the refrigerant will be continuously diverted by the parallel branches during its flow in the main pipeline, resulting in unstable flow and pressure in the branches located at the later part of the flow path, which affects the cooling effect. Utility Model Content

[0004] In view of this, this utility model aims to propose an improved cooling system for direct-cooling energy storage cabinets, which can solve the problem of uneven refrigerant distribution in the prior art.

[0005] This utility model is achieved through the following technical solution:

[0006] A direct-cooling energy storage cabinet cooling system includes a battery pack, an evaporator module adjacent to the battery pack, a direct-cooling unit, and a refrigerant circulation pipeline connected to the direct-cooling unit. The refrigerant circulation pipeline includes a primary liquid delivery pipeline, a liquid distribution assembly, a secondary liquid delivery pipeline, and a primary return pipeline. Multiple sets of the secondary liquid delivery pipelines are connected to the primary liquid delivery pipeline through the same liquid distribution assembly. The refrigerant has at least one flow path that sequentially flows through the primary liquid delivery pipeline, the liquid distribution assembly, the secondary liquid delivery pipeline, the evaporator interface, the evaporator module, and the primary return pipeline.

[0007] This invention proposes a direct-cooling energy storage cabinet cooling system. The refrigerant from the primary liquid delivery pipeline is centrally distributed to multiple secondary liquid delivery pipelines through the same liquid distribution component, ensuring uniform distribution of refrigerant flow and dryness among multiple evaporator modules. Furthermore, the refrigerant that has completed one heat exchange is finally centrally recovered through the primary return pipeline, avoiding the complex pipeline layout and cumulative pressure drop loss caused by multiple separate return pipelines.

[0008] Preferably, the direct cooling unit is located at the bottom of the battery pack, and the primary liquid delivery pipeline includes at least a refrigerant flow channel from bottom to top.

[0009] Preferably, the primary liquid delivery pipeline includes a liquid delivery ascending section and a liquid delivery descending section sequentially arranged on the refrigerant flow path; the refrigerant has an upward flow path in the ascending section and a downward flow path in the descending section; the liquid distribution assembly is arranged on the descending section.

[0010] Ideally, the refrigerant entering the pipeline from the direct-cooling unit should be entirely liquid. However, in actual operation, it is difficult to achieve a 100% liquid phase ratio. The primary liquid delivery pipeline has a sharp 180° bend, causing a sudden change in the refrigerant flow direction. Since the flow direction before and after this change is along a straight line aligned with gravity, it forces the liquid refrigerant and a small amount of gaseous refrigerant to fully remix, ensuring that the refrigerant state (dryness) entering each branch is essentially consistent.

[0011] Preferably, the secondary liquid delivery pipeline includes a vertical liquid delivery section that starts at the liquid distribution component and ends at the battery pack installation location.

[0012] Preferably, the secondary liquid delivery pipeline further includes a horizontal liquid delivery section connecting the vertical liquid delivery section and the evaporator interface.

[0013] In the vertically downward flowing section, the high-density liquid refrigerant is driven by gravity and flows rapidly downward, while low-density bubbles are carried downward by the high-speed liquid flow, effectively suppressing airlock. The vertical liquid delivery section is connected to the evaporator interface in a horizontal manner, making the length of the horizontal liquid delivery section the shortest possible. This minimizes the time window during which the refrigerant stratifies and stagnates due to the density difference between gas and liquid in the horizontal flow, allowing the mixed fluid to enter the evaporator module quickly and relatively uniformly to begin absorbing heat and evaporating.

[0014] Preferably, the primary return pipe and the primary liquid delivery pipe are arranged opposite each other on both sides of the direct-cooling energy storage cabinet.

[0015] In actual operation, the liquid delivery pipe contains a two-phase flow dominated by low temperature and liquid, while the return pipe contains a two-phase flow dominated by gas after absorbing heat and increasing in temperature. The two are arranged on opposite sides and physically isolated to block the direct heat conduction path from the high-temperature return gas pipe to the low-temperature liquid supply pipe, thus avoiding the loss of cold energy and the premature local vaporization of the heated liquid.

[0016] Preferably, the primary return pipe includes a return rising section and a return falling section sequentially arranged on the refrigerant flow path; the refrigerant has an upward flow path in the return rising section and a downward flow path in the return falling section.

[0017] In the rising section, the gaseous refrigerant carrying a small amount of incompletely evaporated droplets will slow down, settle, and flow back down along the pipe wall due to its high density and significant gravity. When the gas enters the falling section from the top of the rising section, the remaining tiny droplets continue to move towards the pipe wall and slide down under the influence of gravity, instead of continuing to enter the compressor with the gas phase. This achieves coarse separation between the liquid and gas phases, improves the compressor's suction dryness, prevents the risk of liquid slugging, and ensures stable compressor operation.

[0018] Preferably, a secondary reflux pipe is also included; the refrigerant flows between the evaporator interface and the primary reflux pipe through the secondary reflux pipe.

[0019] Preferably, each secondary reflux pipeline and / or the secondary liquid delivery pipeline is equipped with an independent shut-off valve.

[0020] Each secondary return pipe and / or the secondary liquid delivery pipe is equipped with an independent shut-off valve, providing flexible control over the cooling system's operation. By opening and closing these shut-off valves, the refrigerant flow in each branch pipe can be controlled individually, facilitating precise adjustment of the cooling intensity in different areas within the energy storage cabinet. For example, when a battery pack module experiences a light workload or malfunction, the corresponding shut-off valve can be closed to suspend refrigerant supply to that area, achieving energy-saving operation or fault isolation. Simultaneously, the shut-off valves also facilitate the isolation of specific branch pipes during system maintenance or repair, improving the system's maintainability and reliability.

[0021] A direct-cooling energy storage cabinet is equipped with the direct-cooling energy storage cabinet cooling system described in any of the preceding claims.

[0022] This invention proposes a direct-cooling energy storage cabinet cooling system, which mainly adapts to the phase changes of the refrigerant in the pipeline by designing the direction and connection of the pipeline, thereby improving the uniformity of refrigerant distribution at the phase level. Specifically, this invention first sets a large 180° bend in the primary liquid delivery pipeline, placing the liquid distribution component at the outlet of the descending section of the bend structure, using the change in flow direction to suppress gas-liquid phase separation; the extension direction of the secondary liquid delivery pipeline is mainly vertical, minimizing the horizontal length to reduce the risk of gas-liquid separation in the horizontal section and ensure that the refrigerant enters each evaporator quickly and homogeneously; an inverted U-shaped bend is set again in the primary return pipeline to perform coarse separation of the gas and liquid phases, preventing liquid slugging after the liquid phase enters the compressor. This invention also proposes an energy storage cabinet equipped with this direct-cooling energy storage cabinet cooling system, which has the effect of stable operation of the refrigerant circulation system. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a direct-cooling energy storage cabinet cooling system;

[0024] Figure 2 This is a schematic diagram of a direct-cooling cabinet.

[0025] Legend

[0026] 1 first-level liquid delivery pipeline, 101 liquid delivery ascending section, 102 liquid delivery descending section;

[0027] 2. Secondary liquid delivery pipeline, 201. Vertical liquid delivery section, 202. Horizontal liquid delivery section;

[0028] 3-stage liquid separator;

[0029] 4. Evaporator interface;

[0030] 5. Primary reflux conduit; 501 reflux rising section; 502 reflux falling section;

[0031] 6. Secondary reflux pipeline;

[0032] 7. Direct cooling unit; 8. Shut-off valve. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a part of the embodiments of the present invention, and not all of the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Example

[0034] This embodiment proposes a direct-cooling energy storage cabinet equipped with a direct-cooling energy storage cabinet cooling system.

[0035] Please see Figure 2 This device is a cabinet-type unit. The lower part of the cabinet houses the battery management system, control system, and direct-cooling unit 7, among other equipment. The upper part of the cabinet contains multiple battery modules, each with a plate evaporator at its bottom; the evaporator contains a refrigerant flow channel. The cabinet also contains refrigerant circulation pipes running through the lower and upper parts of the cabinet; the refrigerant, in liquid form, flows from the direct-cooling unit 7 into the plate evaporator, where it absorbs heat generated by the battery modules and evaporates into gas, then flows back to the direct-cooling unit 7 in gaseous form, completing one refrigerant cycle.

[0036] Please see Figure 1 The refrigerant circulation pipeline includes, in sequence according to the refrigerant flow direction, a primary liquid delivery pipeline 1, a liquid distribution assembly 3, a secondary liquid delivery pipeline 2, an evaporator interface 4, a secondary return pipeline 6, and a primary return pipeline 5.

[0037] This plan first plans the flow pattern of the refrigerant before it enters the evaporator during the refrigerant circulation process, that is, it designs the pipeline between the direct cooling unit 7 and the evaporator interface 4.

[0038] Please see Figure 1 The initial position of the primary liquid delivery pipe 1 is connected to the direct cooling unit 7. Since the direct cooling unit 7 is located at the bottom of this device, the primary liquid delivery pipe 1 extends from bottom to top, and the refrigerant in the pipe flows from bottom to top. This section is the liquid delivery rising section 101. When the liquid delivery rising section 101 extends to the top of the cabinet, the extension direction changes 180°, and the refrigerant in the pipe reverses its flow and flows from top to bottom, forming the liquid delivery falling section 102. The end of the liquid delivery falling section 102 is connected to the liquid distribution component 3. The lower end of the liquid distribution component 3 is connected to multiple sets of secondary liquid delivery pipes 2. The refrigerant in the falling section is evenly distributed by the liquid distribution component 3 into the multiple sets of secondary liquid delivery pipes 2. Ideally, the refrigerant entering the pipe from the direct cooling unit 7 should be completely liquid, but in actual operation, the liquid phase ratio is difficult to reach 100%. The primary liquid delivery pipeline 1 has a sharp 180° bend, causing a sudden change in the flow direction of the refrigerant inside the pipeline. The flow direction before and after this change is along a straight line aligned with the direction of gravity, forcing the liquid refrigerant and a small amount of gaseous refrigerant to remix thoroughly, ensuring that the refrigerant state (dryness) entering each branch is basically consistent. The liquid separator 3 can be a commonly available liquid separator.

[0039] Please see Figure 1The secondary liquid delivery pipe 2 includes a vertical liquid delivery section 201 that transfers refrigerant from the liquid distribution assembly 3 to the height of the battery pack module, and a horizontal liquid delivery section 202 that connects the vertical liquid delivery section 201 to the evaporator interface 4. It extends downwards to the height corresponding to the evaporator, and then horizontally into the evaporator's flow channel. In the vertically downward flowing section, the high-density liquid refrigerant flows rapidly downwards under gravity, while low-density bubbles are carried downwards by the high-speed liquid flow, effectively suppressing airlock. Connecting the vertical liquid delivery section 201 to the evaporator interface 4 horizontally minimizes the length of the horizontal liquid delivery section 202, reducing the time window for refrigerant stratification and retention due to gas-liquid density differences during horizontal flow. This allows the mixed fluid to quickly and relatively uniformly enter the evaporator module to begin heat absorption and evaporation.

[0040] After entering the evaporator, the refrigerant absorbs the heat generated by the battery module, and its physical state changes from liquid to gas. This solution further plans the flow pattern of the refrigerant after leaving the evaporator, that is, designs the piping between evaporator interface 4 and direct cooling unit 7.

[0041] Please see Figure 1 The primary return pipe 5 is located on the left side of the direct-cooling energy storage cabinet, opposite the primary liquid supply pipe 1, forming a pair on both sides of the cabinet. During actual operation, the liquid supply pipe contains a low-temperature, predominantly liquid two-phase flow, while the return pipe contains a heat-absorbing, temperature-increasing, predominantly gaseous two-phase flow. This opposite arrangement and physical isolation prevents direct heat transfer from the high-temperature return pipe to the low-temperature supply pipe, avoiding cold loss and premature partial vaporization of the heated liquid. The primary return pipe 5 includes a return rising section 501 and a return falling section 502 sequentially arranged along the refrigerant flow path; the refrigerant has an upward flow path in the return rising section 501 and a downward flow path in the return falling section 502. In the rising section, the gaseous refrigerant carrying a small amount of incompletely evaporated droplets will slow down, settle, and flow back down along the pipe wall due to its high density and significant gravity. When the gas enters the falling section from the top of the rising section, the remaining tiny droplets continue to move towards the pipe wall and slide down under the influence of gravity, instead of continuing to enter the compressor with the gas phase. This achieves coarse separation between the liquid and gas phases, improves the compressor's suction dryness, prevents the risk of liquid slugging, and ensures stable compressor operation.

[0042] Please see Figure 1After heat exchange with the battery pack, the refrigerant vapor does not directly enter the primary return pipe 5. Instead, it connects to the primary return pipe 5 via the secondary return pipe 6, which connects the evaporator interface 4. Each secondary return pipe 6 and the secondary liquid delivery pipe 2 is equipped with an independent shut-off valve 8. By opening and closing the shut-off valve 8, the refrigerant flow in each branch pipe can be controlled individually, facilitating precise adjustment of the cooling intensity in different areas within the energy storage cabinet. For example, when a battery pack module experiences a light workload or malfunction, the corresponding shut-off valve 8 can be closed to suspend the refrigerant supply to that area, achieving energy-saving operation or fault isolation. Simultaneously, the shut-off valve 8 also facilitates the isolation of specific branch pipes during system maintenance or repair, improving the system's maintainability and reliability.

Claims

1. A direct-cooling energy storage cabinet cooling system, comprising a battery pack, an evaporator module arranged adjacent to the battery pack, a direct-cooling unit (7), and a refrigerant circulation pipeline connected to the direct-cooling unit (7); characterized in that, The refrigerant circulation pipeline includes a primary liquid delivery pipeline (1), a liquid distribution assembly (3), a secondary liquid delivery pipeline (2), and a primary return pipeline (5). Multiple sets of the secondary liquid delivery pipelines (2) are connected to the primary liquid delivery pipeline (1) through the same liquid distribution assembly (3). The refrigerant has at least one flow path that flows sequentially through the primary liquid delivery pipeline (1), the liquid distribution assembly (3), the secondary liquid delivery pipeline (2), the evaporator interface (4), the evaporator module, and the primary return pipeline (5).

2. The direct-expansion energy storage cabinet cooling system of claim 1, wherein, The direct cooling unit (7) is located at the bottom of the battery pack, and the primary liquid delivery pipe (1) includes at least a refrigerant flow channel from bottom to top.

3. The direct-expansion energy storage cabinet cooling system of claim 2, wherein, The primary liquid delivery pipeline (1) includes a liquid delivery ascending section (101) and a liquid delivery descending section (102) arranged sequentially on the refrigerant flow path; the refrigerant has an upward flow path in the ascending section and a downward flow path in the descending section; the liquid distribution assembly (3) is arranged on the descending section.

4. The direct-expansion energy storage cabinet cooling system of claim 1, wherein, The secondary liquid delivery pipeline (2) includes a vertical liquid delivery section (201) that starts at the liquid distribution component (3) and ends at the battery pack installation location.

5. The direct-expansion energy storage cabinet cooling system of claim 4, wherein, The secondary liquid delivery pipeline (2) also includes a horizontal liquid delivery section (202) connecting the vertical liquid delivery section (201) and the evaporator interface (4).

6. The direct-expansion energy storage cabinet cooling system of claim 1, wherein, The primary return pipe (5) includes a return rising section (501) and a return falling section (502) arranged sequentially on the refrigerant flow path; the refrigerant has a bottom-up flow path in the return rising section (501) and a top-down flow path in the return falling section (502).

7. The direct-expansion energy storage cabinet cooling system of claim 6, wherein, It also includes a secondary return pipe (6); the refrigerant flows between the evaporator interface (4) and the primary return pipe (5) through the secondary return pipe (6).

8. The direct-expansion energy storage cabinet cooling system of claim 7, wherein, Each secondary return pipe (6) and / or the secondary liquid delivery pipe (2) is equipped with an independent shut-off valve (8).

9. A direct-cooled energy storage cabinet characterized by, It is equipped with the direct-cooling energy storage cabinet cooling system as described in any one of claims 1 to 8.

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