A stepped flow guide structure and a battery composite cooling device

Abstract

This invention discloses a stepped flow guiding structure and a battery composite cooling device. The stepped flow guiding structure includes multiple sets of flow guiding components, each set having multiple flow guiding plates. These are all disposed within the battery box between multiple battery cells arranged in a matrix. The multiple flow guiding plates form the stepped flow guiding structure as follows: the multiple battery cells are divided into rows along the liquid flow direction; the multiple sets of flow guiding components are arranged sequentially along the liquid flow direction within the gaps between the rows of the battery cell matrix; two flow guiding plates are symmetrically arranged in the gaps between adjacent rows of battery cells; the horizontal distance between the two flow guiding plates in the same gap gradually decreases along the liquid flow direction. The flow guiding plates in a single set of flow guiding components have a uniform height, and the multiple sets of flow guiding plates are arranged in a stepped, progressively increasing height arrangement along the liquid flow direction. This invention, through its stepped flow guiding structure, can extend the coolant flow path, increase the effective heat transfer area, and suppress the development of the flow boundary layer and delay flow separation, significantly enhancing the convective heat transfer effect on the battery side.

Description

Technical Field

[0001] This invention relates to the field of battery thermal management technology in energy storage systems, specifically a stepped flow guiding structure and a battery composite cooling device. Background Technology

[0002] With the development and advancement of new energy technologies, electrochemical energy storage technology, which is essential for addressing the challenges of integrating renewable energy, has been widely adopted. Energy storage battery technology is trending towards higher energy density; however, high energy density also introduces safety issues, such as the potential for thermal runaway under abnormal conditions.

[0003] An efficient and reliable battery thermal management system is crucial for the safe and effective operation of electrochemical energy storage systems. Currently, commonly used battery thermal management systems include air cooling, liquid cooling, and phase change material cooling systems. Traditional air cooling technology often struggles to meet heat dissipation requirements under high-load conditions. When the ambient temperature exceeds 35°C, even forced convection air cooling cannot guarantee that the temperature difference between the system and the battery remains within a safe range. Immersion liquid cooling technology has gained widespread application in the market due to its superior cooling effect. By directly immersing the battery in the cooling liquid, it eliminates thermal resistance caused by air gaps and thermally conductive materials, thereby improving heat dissipation efficiency. Furthermore, the coolant can rapidly remove heat from the battery during thermal runaway, inhibiting the propagation of thermal runaway and thus reducing the risk of power plant fires.

[0004] When using immersion liquid cooling to cool batteries, the coolant needs to be filled into the gaps between the cells in the battery box in a flowing form to improve the heat dissipation effect. However, immersion liquid cooling has certain requirements for the performance of the coolant, which needs to be a coolant with a high flash point and high thermal conductivity. However, due to the limitations of molecular structure, the viscosity of such coolant is generally high. The conventional liquid flow path between cells is relatively short, and coolant stagnation occurs in some areas, while the flow velocity is too fast in some areas. This makes it easy for the coolant flow boundary layer to develop and for flow separation to occur. The effective heat transfer area is insufficient, the convective heat transfer effect is poor, and it is difficult to achieve uniform heat dissipation between cells. Summary of the Invention

[0005] The purpose of this invention is to provide a stepped flow guiding structure and a battery composite cooling device to solve the problem of uneven heat dissipation in current immersion liquid cooling technology when cooling batteries.

[0006] The technical solution of this invention is: A stepped flow guiding structure includes multiple sets of flow guiding components, each set having multiple flow guiding plates, all disposed inside the battery box between multiple battery cells arranged in a matrix. The multiple flow guiding plates are arranged in the following manner to form a stepped flow guiding structure: The number of rows of multiple battery cells is determined along the direction of liquid flow; Multiple sets of flow guiding components are arranged sequentially in the gaps between rows of the cell matrix along the direction of liquid flow. In each set of flow guiding components, two flow guiding plates are arranged in the gap between two adjacent rows of cells. The two flow guiding plates are symmetrically arranged with the central axis of the cell matrix parallel to the direction of liquid flow as the axis of symmetry. The horizontal distance between the two flow guiding plates in each gap gradually decreases along the direction of liquid flow. The guide plates in each flow guiding assembly have the same height, and the height of the guide plates in multiple flow guiding assemblies increases in a stepped manner along the direction of liquid flow.

[0007] Preferably, as a further improvement of the present invention, the guide plates in the first group of guide components are arranged starting from the gap between the second and third rows of cells in the cell matrix, and the subsequent groups of guide components are arranged adjacent to each other.

[0008] Preferably, as a further improvement of the present invention, when the number of columns m in the cell matrix is ​​even, the specific arrangement of the multiple guide plates in the first group of the current guiding components is as follows: starting from the gap between the second row of cells and the third row of cells, a guide plate is first arranged between the first column of cells and the second column of cells, and between the (m-1)th column of cells and the mth column of cells. In the gap between two adjacent rows of cells, the position of the guide plate is symmetrically shifted one column towards the center of the matrix until a guide plate is arranged between the m / 2-1th column of cells and the m / 2th column of cells, and between the m / 2+1th column of cells and the m / 2+2th column of cells in the corresponding gap. Then, a guide plate is arranged between the m / 2th column of cells and the m / 2+1th column of cells in the gap between two adjacent rows of cells.

[0009] Preferably, as a further improvement of the present invention, when the number of columns m in the cell matrix is ​​odd, the specific arrangement of the multiple guide plates in the first group of the current guiding components is as follows: starting from the gap between the second row of cells and the third row of cells, a guide plate is first arranged between the first column of cells and the second column of cells, and between the (m-1)th column of cells and the mth column of cells. In the gap between two adjacent rows of cells, the position of the guide plate is symmetrically shifted one column towards the center of the matrix until a guide plate is arranged between the (m-1) / 2th column of cells and the (m+1) / 2th column of cells, and between the (m+1) / 2th column of cells and the (m+3) / 2nd column of cells in the corresponding gap, thus completing one cycle of arrangement.

[0010] The present invention also discloses a battery composite cooling device, including a battery box and multiple battery cells. The battery box has liquid inlet and liquid outlet on its two side walls, respectively. The battery box contains a first coolant. The multiple battery cells are arranged in a matrix inside the battery box and are immersed in the first coolant. The device also includes the aforementioned stepped flow guiding structure and cold plate. The multiple flow guiding plates are arranged in a preset manner in the gaps between the rows of the battery cell matrix. The cold plate is located at the bottom of the battery box and is used to absorb the heat generated by the battery. The cold plate is filled with a second coolant.

[0011] Preferably, as a further improvement of the present invention, a heat-conducting sheet is provided between the surface of the cold plate and the bottom of the battery box.

[0012] Preferably, as a further improvement of the present invention, the first coolant is at least one of silicone oil coolant, hydrocarbon coolant and ester coolant.

[0013] Preferably, as a further improvement of the present invention, the second coolant is a mixture of water and ethylene glycol or a mixture of water and propylene glycol.

[0014] Preferably, as a further improvement of the present invention, the cold plate and the guide plate are both made of aluminum or aluminum alloy.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The staggered flow guide structure significantly enhances the convective heat transfer effect on the battery side by extending the coolant flow path, increasing the effective heat transfer area, and suppressing the development of the flow boundary layer and delaying flow separation. Even when using a high-viscosity coolant, the system can still achieve uniform and efficient heat dissipation.

[0016] 2. The battery composite cooling device, compared to traditional single cooling methods, exhibits superior thermal management performance and operational stability under complex operating conditions with high heat generation, such as high-rate discharge and high-temperature environments. By employing two different coolant formulations working synergistically, this system combines the active suppression of thermal runaway by immersion liquid cooling with the efficient temperature control capabilities of forced heat dissipation via cold plate circulation. Immersion cooling can...

[0017] The stepped flow-guiding structure guides the high-viscosity coolant to quickly absorb the heat released by the battery, blocking heat spread; the cold plate circulation can continuously remove the heat generated during normal battery operation and recover the heat of the working fluid inside the battery box, thereby significantly improving the overall heat dissipation efficiency and reducing the risk of thermal runaway. Attached Figure Description

[0018] Figure 1 This is a top view showing the arrangement of an interlaced flow guide structure according to an embodiment of the present invention.

[0019] Figure 2 For the present invention Figure 1 Side view.

[0020] Figure 3 This is a schematic diagram showing the arrangement of baffles in an alternating current guiding structure according to an embodiment of the present invention, where the number of columns in the cell matrix is ​​odd or even.

[0021] Figure 4 This is a schematic diagram of a battery composite cooling device according to an embodiment of the present invention.

[0022] Figure 5 This is a top view of the cold plate structure of a battery composite cooling device according to an embodiment of the present invention. Detailed Implementation

[0023] The following is combined Figures 1-5 The specific embodiments of the present invention will be described in detail below. In the description of the invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to 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 present invention.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0025] Example 1 like Figures 1-3 As shown, this embodiment of the invention provides an interlaced flow guiding structure, including multiple sets of flow guiding components. Each set of flow guiding components has multiple flow guiding plates, which are installed inside the battery box 1 between multiple battery cells 2. The multiple battery cells 2 are arranged in a matrix. Since the interlaced arrangement cannot be reflected when the number of columns is less than or equal to 3, and the stepped distribution of the baffle height cannot be reflected when the number of rows is less than or equal to 3, the number of rows n ≥ 4 and the number of columns m ≥ 4 in the matrix formed by the multiple battery cells 2 are required. Among them, multiple guide vanes 3 are arranged in the following manner to form a stepped guide structure: Divide the number of rows of multiple battery cells 2 along the direction of liquid flow; Multiple sets of flow guiding components are arranged sequentially in the gaps between rows of the cell matrix along the direction of liquid flow. In each set of flow guiding components, two flow guiding plates 3 are arranged in the gap between two adjacent rows of cells. The two flow guiding plates 3 are symmetrically arranged with the central axis of the cell matrix parallel to the direction of liquid flow as the axis of symmetry. The horizontal distance between the two flow guiding plates 3 in each gap gradually decreases along the direction of liquid flow. The guide plates 3 in each group of flow guiding components have the same height, and the height of the guide plates 3 in multiple groups of flow guiding components increases in a stepped manner along the direction of liquid flow.

[0026] The above configuration extends the coolant flow path, increases the effective heat transfer area, and suppresses the development of the flow boundary layer and delays flow separation, significantly enhancing the convective heat transfer effect on the battery side. Even with a high-viscosity coolant, the system can still achieve uniform and efficient heat dissipation.

[0027] In order to prevent the coolant from flowing into the inlet and immediately encountering the guide plate 3 and causing backflow, the guide plate 3 is not arranged in the gap between the first row of cells 2 and the second row of cells 2. The guide plate 3 in the first group of guide components is arranged starting from the gap between the second row of cells 2 and the third row of cells 3 in the cell matrix, and the subsequent groups of guide components are arranged adjacent to each other.

[0028] Considering that the number of columns m in the cell matrix has parity, the number of guide plates 3 in the last row of each cycle is adjusted according to the parity of the number of columns m. Specifically, such as Figure 3 As shown in (a), when the number of columns m in the cell matrix is ​​even: The following is described as Figure 3 (a) The arrangement of the guide plate 3 in the first group of guide components outlined by the dashed line is as follows: the guide plate 3 is arranged in the gap between the second row of cells 2 and the third row of cells 2, between the first column of cells 2 and the second column of cells 2, and between the (m-1)th column of cells 2 and the mth column of cells 2. A total of 2 guide plates 3 are arranged in this gap. The guide plates in the gap between the batteries in the third and fourth rows are arranged between the second column of cells 2 and the third column of cells 2, as well as between the (m-2)th column of cells 2 and the (m-1)th column of cells 2. A total of two guide plates 3 are arranged in this gap. And so on, until the guide plate 3 in the gap between cell 2 in row k and cell 2 in row k+1 is arranged between two cells 2 in column m / 2 and column m / 2-1 and between two cells 2 in column m / 2+1 and column m / 2+2, a total of 2 guide plates 3 are arranged in this gap; The guide plates in the gap between the batteries in the (k+1)th row (last row) and the (k+2)th row (second to last row) are arranged between the two cell columns in the (m / 2)th and (m / 2+1)th columns. A total of one guide plate 3 is arranged in this gap. The height of the guide plate 3 in the first group of guide components is h1.

[0029] The guide plates 3 in the second group of flow guiding components are arranged in the same way as the first group, adjacent to each other. The height of the guide plates 3 in the second group of flow guiding components is h2, and so on. If there is a preset f group of flow guiding components, then the height of the guide plates 3 in the f-th group of flow guiding components is hf. The height of the guide plates 3 is distributed in a stepped manner along the liquid flow direction, increasing sequentially from h1 to hf. If the number of battery rows is limited, the guide plates 3 in the last group of flow guiding components may not be fully arranged, but it can still be put into use.

[0030] Specifically, such as Figure 3 As shown in (b), when the number of columns m in the cell matrix is ​​odd: The following is described as Figure 3 (b) The arrangement of the guide plates 3 in the first group of guide components (highlighted by dashed lines) is similar to the even number of columns m in the cell matrix. The difference is that two guide plates 3 are arranged in the gap between the last row of cells 2 and the second-to-last row of cells 2 in the first group of guide components. Starting from the gap between the second row of cells 2 and the third row of cells 2, a flow guide plate 3 is first placed between the first column of cells 2 and the second column of cells 2, and between the (m-1)th column of cells 2 and the mth column of cells 2. In the gaps between two adjacent rows of cells 2, the position of the flow guide plate 3 is symmetrically shifted one column towards the center of the matrix until a flow guide plate 3 is placed between the (m-1) / 2th column of cells 2 and the (m+1) / 2th column of cells 2, and between the (m+1) / 2th column of cells 2 and the (m+3) / 2th column of cells 2, thus completing the arrangement of the first set of flow guide components.

[0031] Example 2 This embodiment is based on embodiment 1, such as... Figure 4 As shown, a battery composite cooling device is disclosed, including a battery box 1 and multiple battery cells 2. The battery box 1 has liquid inlet and liquid outlet on its two side walls, respectively. The battery box 1 is filled with a first coolant. The multiple battery cells 2 are arranged in a matrix inside the battery box 1 and are immersed in the first coolant. The device also includes the aforementioned staggered flow guiding structure and a cold plate 4. Multiple flow guiding plates 3 are arranged in a preset manner in the gaps between the rows of the battery cell matrix. The cold plate 4 is located at the bottom of the battery box 1 and is used to absorb the heat generated by the battery. The interior of the cold plate 4 is filled with a second coolant.

[0032] Each battery cell 2 is fixed inside the module housing using conventional battery module fixing methods (such as wire harness clamping, bonding, snap-fitting, etc.) to ensure relative stability with the housing during operation and prevent shaking or tipping due to the impact of the immersion coolant flow. Therefore, under normal operating conditions, structural damage to the battery cells is only possible due to long-term natural aging or improper external forces; all battery cells maintain a reliable relative fixation with the housing under normal operating conditions.

[0033] Any one of the battery cells 2 can be a cylindrical battery, a square battery, or a pouch battery, etc. The shapes of all the battery cells inside the module casing are completely or partially the same.

[0034] The battery box 1 of the battery module has a rectangular parallelepiped shape, such as... Figure 4As shown, its length direction is parallel to the column direction of multiple battery cells 2 arranged in a matrix, and its width direction is parallel to the row direction. The outer shell consists of two parts: a bottom shell and a top cover. The bottom shell is designed as a rectangular open type, which houses the battery cell matrix inside, and the height of the shell is not lower than the total height of the battery cells to achieve full bearing and enclosure of the battery. The top cover can adopt two forms: one is a flat rectangular cover plate, which is sealed by fitting into the sunken step provided along the upper edge of the bottom shell; the other is a rectangular cover shell with a certain depth, which is sleeved outside the bottom shell in an outer cover structure to also achieve reliable sealing of the top opening.

[0035] Among them, a heat conduction sheet is provided between the surface of the cold plate 4 and the bottom of the battery box 1. The shape and size of the heat conduction sheet match the shape and size of the bottom of the battery box 1. By setting a heat conduction sheet with the same size as the bottom of the battery box 1 on the surface of the cold plate 4 and making it completely contact the bottom surface of the battery box to absorb the heat generated by the battery, the cold plate is used to recover the heat of the working fluid in the battery box 1. The flow channels inside the cold plate 4 can be optimized in shape or layout according to the heat dissipation requirements of the battery pack.

[0036] Among them, the liquid inlet and the liquid outlet are arranged in pairs and symmetrically opened on both sides of the battery box 1. A pair of liquid inlets and liquid outlets are provided between adjacent two columns of battery cells 2, and a total of m - 1 pairs of liquid inlets and liquid outlets are set.

[0037] As Figure 1 and Figure 4 shown, taking a 4-column and 13-row battery module as an example, the positional relationship between the flow guide plate and the battery module is drawn, and a total of 3 liquid inlets 5a, 5b and 5c and 3 liquid outlets 6a, 6b and 6c are arranged.

[0038] As an optimized improvement scheme, the materials of the cold plate 4 and the flow guide plate 3 are both aluminum or aluminum alloy to reduce the overall weight.

[0039] Preferably, the cold plate 4 and the flow guide plate 3 are made of aluminum to reduce the overall weight.

[0040] Among them, the first coolant in the battery box 1 is at least one of high flash point silicone oil coolant, hydrocarbon coolant and ester coolant. The coolant in the cold plate 4 can be selected as a mixture of water and ethylene glycol or a mixture of water and propylene glycol aqueous solution with low viscosity and high thermal conductivity.

[0041] When the battery composite cooling device is implemented, its control principle is as follows: First, use a temperature sensor to obtain the maximum value T of the temperatures of all battery cells 2 in the battery box 1, and transmit the temperature value signal to the controller. Through processing and judgment by the controller, control is carried out; When T < T1, close the fluid drive of the immersion cooling and the fluid drive of the cold plate cooling; When T1 ≤ T < T2, the driving of the first coolant fluid for cooling inside the battery box is turned off, the driving of the second coolant fluid for cold plate cooling is turned on and controlled at the first gear; When T2 ≤ T < T3, the driving of the first coolant fluid for cooling inside the battery box is turned off, the driving of the second coolant fluid for cold plate cooling is turned on and controlled at the second gear; When T3 ≤ T < T4, the driving of the first coolant fluid for cooling inside the battery box is turned on, the driving of the second coolant fluid for cold plate cooling is turned on and controlled at the second gear; When T ≥ T4, the driving of the first coolant fluid for cooling inside the battery box is turned on, the driving of the second coolant fluid for cold plate cooling is turned on and controlled at the third gear; Among them, T1, T2, T3, and T4 are preset temperature thresholds.

[0042] In specific implementation, T1 is 28 °C, T2 is 35 °C, T3 is 45 °C, and T4 is 55 °C. The above work adjusts the working state of the fluid driving based on the highest temperature value T of the battery module. When the battery temperature is relatively low, the system can pause the fluid driving to reduce energy consumption; when the temperature rises to the heat dissipation range, the cooling cycle is started in a timely manner, and the driving gear is dynamically adjusted according to the temperature. This strategy effectively optimizes the overall energy consumption of the system while ensuring the heat dissipation requirements.

[0043] The above-disclosed are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be thought of by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A stepped flow guiding structure, characterized in that, It includes multiple sets of flow guiding components, each set having multiple flow guiding plates, all of which are arranged in a matrix between multiple battery cells inside the battery box. The multiple flow guiding plates are arranged in the following way to form a stepped flow guiding structure: The number of rows of multiple battery cells is determined along the direction of liquid flow; Multiple sets of flow guiding components are arranged sequentially in the gaps between rows of the cell matrix along the direction of liquid flow. In each set of flow guiding components, two flow guiding plates are arranged in the gap between two adjacent rows of cells. The two flow guiding plates are symmetrically arranged with the central axis of the cell matrix parallel to the direction of liquid flow as the axis of symmetry. The horizontal distance between the two flow guiding plates in each gap gradually decreases along the direction of liquid flow. The guide plates in each flow guiding assembly have the same height, and the height of the guide plates in multiple flow guiding assemblies increases in a stepped manner along the direction of liquid flow.

2. The stepped flow guiding structure according to claim 1, characterized in that, The flow guide plates in the first group of flow guide components are arranged starting from the gap between the second and third rows of cells in the cell matrix, and the subsequent groups of flow guide components are arranged adjacent to each other.

3. The stepped flow guiding structure according to claim 2, characterized in that, When the number of columns m in the cell matrix is ​​even, the specific arrangement of the multiple guide plates in the first group of the current guiding components is as follows: starting from the gap between the second row of cells and the third row of cells, a guide plate is first arranged between the first column of cells and the second column of cells, and between the (m-1)th column of cells and the mth column of cells. In the gap between two adjacent rows of cells, the position of the guide plate is symmetrically shifted one column towards the center of the matrix until a guide plate is arranged between the m / 2-1th column of cells and the m / 2th column of cells, and between the m / 2+1th column of cells and the m / 2+2th column of cells in the corresponding gap. Then, a guide plate is arranged between the m / 2th column of cells and the m / 2+1th column of cells in the gap between two adjacent rows of cells.

4. The stepped flow guiding structure according to claim 2, characterized in that, When the number of columns m in the cell matrix is ​​odd, the specific arrangement of the multiple guide plates in the first group of current guiding components is as follows: starting from the gap between the second row of cells and the third row of cells, a guide plate is first arranged between the first column of cells and the second column of cells, and between the (m-1)th column of cells and the mth column of cells. In the gap between two adjacent rows of cells, the position of the guide plate is symmetrically shifted one column towards the center of the matrix until a guide plate is arranged between the (m-1) / 2th column of cells and the (m+1) / 2th column of cells, and between the (m+1) / 2th column of cells and the (m+3) / 2nd column of cells in the corresponding gap, thus completing one cycle of arrangement.

5. A battery composite cooling device, comprising a battery box and multiple battery cells, wherein inlet and outlet are respectively provided on the two side walls of the battery box, a first coolant is provided inside the battery box, and the multiple battery cells are arranged in a matrix inside the battery box and immersed in the first coolant, characterized in that, It also includes the stepped flow guiding structure and cold plate as described in any one of claims 1 to 4, wherein a plurality of the flow guiding plates are arranged in a preset manner in the row gaps of the cell matrix, the cold plate is arranged at the bottom of the battery box for absorbing the heat generated by the battery, and the interior of the cold plate is filled with a second coolant.

6. The battery composite cooling device according to claim 5, characterized in that, A heat-conducting sheet is provided between the surface of the cold plate and the bottom of the battery box.

7. The battery composite cooling device according to claim 5, characterized in that, The first coolant is at least one of silicone oil coolant, hydrocarbon coolant and ester coolant.

8. The battery composite cooling device according to claim 5, characterized in that, The second coolant is a mixture of water and ethylene glycol or a mixture of water and propylene glycol.

9. The battery composite cooling device according to claim 5, characterized in that, Both the cold plate and the guide plate are made of aluminum or aluminum alloy.

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