Flow channel design method of liquid cooling plate

Abstract

The invention discloses a flow channel design method of a liquid cooling plate. The method comprises the following steps: constructing a first average temperature formula after heat exchange of a first heat exchange channel according to a first convection heat exchange coefficient, a first flow and the width of the first heat exchange channel, and constructing a second average temperature formula after exchange of the second heat exchange channel according to the second convection heat exchange coefficient, the first flow and the width of the second heat exchange channel, constructing a flow channel design formula when the first average temperature formula is equal to the second average temperature formula, and determining the width of the bypass channel according to the flow channel design formula. In the first cavity, the cooling liquid of the bypass channel does not participate in heat exchange, the cooling liquid of the first heat exchange channel participates in heat exchange, and after being converged, the cooling liquid enters the second cavity to jointly participate in heat exchange of the second heat exchange channel, so that flow distribution is adjusted by setting the width of the bypass channel; the average temperature of the first sequence battery after heat exchange is consistent with the average temperature of the second sequence battery after heat exchange.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of battery thermal management of a liquid cooling system, and in particular to a flow channel design method of a liquid cooling plate. Background Art

[0002] As the requirements for electric vehicle range and safety performance continue to increase, the energy density and power requirements for battery cells are also getting higher and higher. Batteries will experience high-power charging and discharging conditions, which requires improving the thermal management capabilities of batteries. At present, the most widely used cooling method in the battery industry is liquid cooling. With the development of batteries, MTB, CTB and other structural forms have emerged, and liquid cooling plates of different designs need to be adapted to meet the heat dissipation of high-energy-density batteries. However, there will be many requirements in the layout of the whole vehicle, resulting in uneven heat dissipation of the battery and the problem of temperature gradient distribution. For example, after heat exchange, the heat dissipation of batteries in different sequences is uneven. Summary of the invention

[0003] The present invention provides a flow channel design method for a liquid cooling plate, which adjusts the flow distribution by setting the width of a bypass channel so that the average temperature of a first sequence battery after heat exchange is consistent with the average temperature of a second sequence battery after heat exchange.

[0004] In a first aspect, an embodiment of the present invention provides a flow channel design method for a liquid cooling plate, wherein the liquid cooling plate comprises a first chamber and a second chamber; a first water inlet is provided in the first chamber, and a first water outlet is provided in the second chamber;

[0005] A bypass channel and a first heat exchange channel are provided in the first chamber, and a second heat exchange channel is provided in the second chamber; a battery assembly is provided on the liquid cooling plate, and a coolant flows in the liquid cooling plate, and the battery assembly includes a first sequence battery and a second sequence battery, the first sequence battery and the first heat exchange channel are overlapped, and the second sequence battery and the second heat exchange channel are overlapped;

[0006] The bypass channel, the first heat exchange channel and the second heat exchange channel each include a plurality of flow channels, and partitions are provided between different flow channels;

[0007] The flow channel design method comprises:

[0008] Acquire a first heat generation power of the first sequence battery and a second heat generation power of the second sequence battery, and determine a first flow rate of the first water inlet according to the first heat generation power and the second heat generation power;

[0009] Determining a first convective heat exchange coefficient between the first sequence battery and the first heat exchange channel, and a second convective heat exchange coefficient between the second sequence battery and the second heat exchange channel;

[0010] A first average temperature formula after heat exchange in the first heat exchange channel is constructed according to the first convection heat exchange coefficient, the first flow rate, and the width of the first heat exchange channel; and a second average temperature formula after heat exchange in the second heat exchange channel is constructed according to the second convection heat exchange coefficient, the first flow rate, and the width of the second heat exchange channel;

[0011] A flow channel design formula is constructed when the first average temperature formula and the second average temperature formula are equal, and the width of the bypass channel is determined according to the flow channel design formula.

[0012] Optionally, determining the first flow rate of the first water inlet according to the first heat generation power and the second heat generation power includes:

[0013] Setting a first temperature of the coolant when it enters from the first water inlet, and a second temperature of the coolant when it flows out from the first water outlet;

[0014] A first flow rate of the first water inlet is determined according to the first heat generating power, the second heat generating power, the first temperature, the second temperature, a first calculation formula, and the mass and specific heat of the coolant.

[0015] Optionally, the first calculation formula includes:

[0016]

[0017] Wherein, Q is the first flow rate of the first water inlet, P 1 is the first heat generation power, P 2 is the second heat generation power, T in1 is the first temperature, T out1 is the second temperature, m is the mass of the coolant, c p is the specific heat of the coolant.

[0018] Optionally, determining a first convective heat exchange coefficient between the first sequence battery and the first heat exchange channel, and a second convective heat exchange coefficient between the second sequence battery and the second heat exchange channel includes:

[0019] Determine a first flow rate of the coolant in the first chamber according to the width of the first chamber, the thickness of the first chamber, and the first flow rate, and determine a first fluid Reynolds number of the first chamber according to the first flow rate, the density of the coolant, the characteristic length of the flow channel, the viscosity coefficient of the coolant, and a fluid Reynolds number calculation formula;

[0020] Determine a first Nusselt number according to the Reynolds number of the first fluid, and determine the first convective heat transfer coefficient according to the first Nusselt number, the thermal conductivity of the coolant, the characteristic length of the flow channel, and a convective heat transfer coefficient calculation formula;

[0021] Determine a second flow rate of the coolant in the second chamber according to the width of the second chamber, the thickness of the second chamber, and the first flow rate, and determine a second fluid Reynolds number of the second chamber according to the second flow rate, the density of the coolant, the characteristic length of the flow channel, the viscosity coefficient of the coolant, and a fluid Reynolds number calculation formula;

[0022] The second Nusselt number is determined according to the Reynolds number of the second fluid, and the second convective heat transfer coefficient is determined according to the second Nusselt number, the thermal conductivity of the coolant, the characteristic length of the flow channel and a convective heat transfer coefficient calculation formula.

[0023] Optionally, the fluid Reynolds number calculation formula includes:

[0024]

[0025] Wherein, Re includes the Reynolds number of the first fluid or the Reynolds number of the second fluid, ρ is the density of the coolant, d e is the characteristic length of the flow channel, μ is the viscosity coefficient of the coolant, and v includes the first flow velocity or the second flow velocity;

[0026] The calculation formula of the convective heat transfer coefficient includes:

[0027]

[0028] Among them, α f Including the first convective heat transfer coefficient or the second convective heat transfer coefficient, N u Including the first Nusselt number or the second Nusselt number, λ is the thermal conductivity of the coolant.

[0029] Optionally, the first chamber is further provided with a second water outlet, and the second chamber is further provided with a second water inlet, the coolant flows into the first chamber through the first water inlet, flows out of the first chamber through the second water outlet, and flows into the second chamber through the second water inlet, and flows out of the second chamber through the first water outlet;

[0030] The formula for constructing the first average temperature of the first heat exchange channel after heat exchange according to the first convection heat exchange coefficient, the first flow rate and the width of the first heat exchange channel includes:

[0031] Constructing a second flow formula for the first heat exchange channel according to the first flow rate, the number of the flow channels in the first heat exchange channel, and the number of the flow channels in the bypass channel;

[0032] The first average temperature formula is constructed based on the second flow formula, the contact thermal resistance during the heat exchange process, the first convection heat transfer coefficient, the width of the first heat exchange channel, the characteristic scale of the flow channel, the first temperature of the coolant when it enters from the first water inlet, and the third temperature of the coolant when it flows out from the second water outlet.

[0033] Optionally, the second flow formula includes:

[0034]

[0035] Among them, Q 1 is the second flow rate of the coolant flowing through the first heat exchange channel, n 1 is the number of the flow channels in the first heat exchange channel, n 0 is the number of the flow channels in the bypass channel, and Q is the first flow rate;

[0036] The first average temperature formula includes:

[0037]

[0038] Among them, Q 1 is the second flow rate of the coolant flowing through the first heat exchange channel, d 1 is the width of the first heat exchange channel, αf 1 is the first convection heat transfer coefficient, is the thermal contact resistance during heat exchange, T in1 is the first temperature of the coolant when it enters from the first water inlet, T out2 is the third temperature of the coolant when it flows out from the second water outlet, and l is the characteristic dimension of the flow channel.

[0039] Optionally, the first chamber is further provided with a second water outlet, and the second chamber is further provided with a second water inlet, the coolant flows into the first chamber through the first water inlet, flows out of the first chamber through the second water outlet, and flows into the second chamber through the second water inlet, and flows out of the second chamber through the first water outlet;

[0040] The second average temperature formula after heat exchange in the second heat exchange channel is constructed according to the second convection heat exchange coefficient, the first flow rate and the width of the second heat exchange channel includes:

[0041] determining a third flow rate of the coolant flowing into the second chamber according to the first flow rate;

[0042] The second average temperature formula is constructed based on the third flow rate, the contact thermal resistance during the heat exchange process, the second convection heat transfer coefficient, the width of the second heat exchange channel, the characteristic scale of the flow channel, the fourth temperature of the coolant when it enters from the second water inlet, and the second temperature of the coolant when it flows out from the first water outlet.

[0043] Optionally, the second average temperature formula includes:

[0044]

[0045] Among them, Q 2 is the third flow rate of the coolant flowing into the second chamber, d 2 is the width of the second heat exchange channel, αf 2 is the second convective heat transfer coefficient, is the thermal contact resistance during heat exchange, T in2 is the fourth temperature of the coolant when it enters from the second water inlet, T out1 is the second temperature of the coolant when it flows out of the first water outlet, and l is the characteristic dimension of the flow channel.

[0046] Optionally, constructing a flow channel design formula when the first average temperature formula and the second average temperature formula are equal, and determining the bypass channel width according to the flow channel design formula includes:

[0047] Let the first average temperature formula and the second average temperature formula be equal to obtain a transition formula;

[0048] Simplifying the transition formula to obtain the flow channel design formula, and determining the bypass channel width according to the flow channel design formula;

[0049] The flow channel design formula includes:

[0050]

[0051] Among them, n 1 is the number of the flow channels in the first heat exchange channel, n 0 is the number of the flow channels in the bypass channel, Q is the first flow rate, d 1 is the width of the first heat exchange channel, αf 1 is the first convection heat transfer coefficient, is the thermal contact resistance during heat exchange, T in1 is the first temperature of the coolant when it enters from the first water inlet, d 2is the width of the second heat exchange channel, αf 2 is the second convective heat transfer coefficient, T out1 is the second temperature of the coolant when it flows out of the first water outlet, and l is the characteristic dimension of the flow channel.

[0052] In the embodiment of the present invention, the first heat generation power of the first sequence battery and the second heat generation power of the second sequence battery are obtained, and the first flow rate of the first water inlet is determined according to the first heat generation power and the second heat generation power, and the first convection heat exchange coefficient between the first sequence battery and the first heat exchange channel and the second convection heat exchange coefficient between the second sequence battery and the second heat exchange channel are determined. The first average temperature formula after heat exchange in the first heat exchange channel is constructed according to the first convection heat exchange coefficient, the first flow rate and the width of the first heat exchange channel, and the second average temperature formula after heat exchange in the second heat exchange channel is constructed according to the second convection heat exchange coefficient, the first flow rate and the width of the second heat exchange channel. Finally, the flow channel design formula is constructed when the first average temperature formula and the second average temperature formula are equal, and the width of the bypass channel is determined according to the flow channel design formula. In this way, the first chamber is separated from the second chamber. In the first chamber, the coolant in the bypass channel does not flow through the first heat exchange channel, that is, the coolant in the bypass channel does not participate in the heat exchange. The first heat exchange channel overlaps with the first sequence battery, that is, the coolant in the first heat exchange channel participates in the heat exchange. After the two merge, they enter the second chamber and jointly participate in the heat exchange in the second heat exchange channel. In this way, by setting the coolant in the bypass channel not to participate in the heat exchange, the overall heat dissipation efficiency of the coolant entering the second chamber is guaranteed, and it is avoided that the coolant flows through the first sequence battery and the temperature of all the coolant increases, and then when exchanging heat with the second sequence battery, there is a large temperature difference between the two after the heat exchange. On this basis, the flow distribution is adjusted by setting the width of the bypass channel, so that the average temperature of the first sequence battery after the heat exchange is consistent with that of the second sequence battery after the heat exchange, and the life of the battery assembly is improved at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a structural schematic diagram of a liquid cooling plate provided by an embodiment of the present invention;

[0054] Figure 2 is a flow chart of a flow channel design method of a liquid cooling plate provided by an embodiment of the present invention;

[0055] Figure 3 It is a flow chart of another flow channel design method of a liquid cooling plate provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0058] Figure 1 Schematic diagram of the structure of a liquid cooling plate provided by an embodiment of the present invention. Figure 1 , the liquid cooling plate includes a first chamber 10 and a second chamber 20. Among them, the first chamber 10 and the second chamber are isolated, a first water inlet 110 and a second water outlet 120 are arranged in the first chamber 10, and a second water inlet 210 and a first water outlet 220 are arranged in the second chamber. Specifically, there is cooling liquid in the liquid cooling plate, and the cooling liquid enters the first chamber 10 from the first water inlet 110, flows out of the first chamber 10 from the second water outlet 120, flows into the second chamber 20 from the second water inlet 210, and flows out of the second chamber 20 from the first water outlet 220, completing the entire heat exchange process. It should be noted that the second water outlet 120 and the second water inlet 210 can share an outlet. In addition, when the total amount of cooling liquid remains unchanged, the flow rates of the first water inlet 110, the second water outlet 120, the second water inlet 210 and the first water outlet 220 are all the same.

[0059] The first chamber 10 is provided with a bypass channel 101 and a first heat exchange channel 102, and the second chamber 20 is provided with a second heat exchange channel 202. A battery assembly 30 is provided on the liquid cooling plate, and the battery assembly 30 includes a first sequence battery 310 and a second sequence battery 320, the first sequence battery 310 and the first heat exchange channel 102 are overlapped, and the second sequence battery 320 and the second heat exchange channel 202 are overlapped, and the bypass channel 101, the first heat exchange channel 102 and the second heat exchange channel 202 each include a plurality of flow channels 40, and a partition 50 is provided between different flow channels 40.

[0060] Specifically, Figure 1 As shown, the first chamber 10 includes a bypass channel 101, a first heat exchange channel 102 and a first water inlet 110. After the coolant flows in from the first water inlet 110, it enters the multiple flow channels 40 in the bypass channel 101 and the multiple flow channels in the first heat exchange channel 102 respectively. Since a partition 50 is provided between different flow channels 40, and the first sequence battery 310 only overlaps with the first heat exchange channel 102, the coolant flowing into the first chamber 10 is divided into two parts, one part flows through the bypass channel 101 without heat exchange with the first sequence battery 310, and the other part passes through the first heat exchange channel 102 to heat exchange with the first sequence battery 310. After the two parts merge, they enter the second chamber 20 through the second water outlet 120 (second water inlet 210) to participate in the second heat exchange channel 202 and the second sequence battery The heat exchange of the first sequence battery 310 and the second sequence battery 320 is performed by setting the coolant in the bypass channel 101 not to participate in the heat exchange, so as to ensure the overall heat dissipation efficiency of the coolant entering the second chamber, and avoid the coolant flowing through the first sequence battery 310 and causing the temperature of all the coolants to rise (low heat dissipation efficiency), and then after the heat exchange with the second sequence battery 320, there is a large temperature difference between the first sequence battery 310 and the second sequence battery 320 after the heat exchange (usually the temperature of the second sequence battery 320 after the heat exchange is higher). On this basis, the flow distribution is adjusted by setting the width of the bypass channel 101, so that the average temperature of the first sequence battery 310 after the heat exchange is consistent with that of the second sequence battery 320 after the heat exchange, and the life of the battery assembly is improved at the same time.

[0061] See also Figure 1 and Figure 2 , the flow channel design method includes:

[0062] S110, obtaining a first heat generation power of a first sequence battery and a second heat generation power of a second sequence battery, and determining a first flow rate of a first water inlet according to the first heat generation power and the second heat generation power.

[0063] Specifically, since the liquid cooling plate is used to match the battery assembly 30 for heat dissipation, the size of the first sequence battery 310 and the first heat generation power are determined during the design, and the size of the second sequence battery and the second heat generation power are also determined. In addition, the first temperature of the coolant when it enters the first chamber 10 from the first water inlet, and the second temperature of the coolant when it finally flows out of the second chamber 20 from the first water outlet 220, can also be predetermined, and then according to the first heat generation power, the second heat generation power, and the heat to be taken away by the coolant after completing the heat exchange process, the total amount of coolant required, that is, the first flow rate flowing into the first water inlet 110, can be determined.

[0064] S120, determining a first convective heat exchange coefficient between the first sequence of batteries and the first heat exchange channel, and a second convective heat exchange coefficient between the second sequence of batteries and the second heat exchange channel.

[0065] Since the overall flow rate of the coolant in the first chamber 10 is the same, and the overall flow rate in the second chamber 20 is the same, therefore, according to the volume of the first chamber 10 and the first flow rate, the first flow rate of the coolant when flowing through the first heat exchange channel 102 can be determined, and similarly, the second flow rate of the coolant when flowing through the second heat exchange channel 202 can also be determined. The first flow rate can be used to determine the first convective heat exchange coefficient between the first sequence battery 310 and the first heat exchange channel 102 when the coolant flows through the first heat exchange channel 102, and the second flow rate can be used to determine the second convective heat exchange coefficient between the second sequence battery 320 and the second heat exchange channel 202 when the coolant flows through the second heat exchange channel 202.

[0066] 130. A first average temperature formula after heat exchange in the first heat exchange channel is constructed based on the first convective heat transfer coefficient, the first flow rate, and the width of the first heat exchange channel. A second average temperature formula after heat exchange in the second heat exchange channel is constructed based on the second convective heat transfer coefficient, the first flow rate, and the width of the second heat exchange channel.

[0067] Specifically, after determining the first convective heat exchange coefficient, a first average temperature formula after the first sequence battery 310 performs heat exchange with the coolant in the first heat exchange channel 102 can be constructed according to the first flow rate and the width of the first heat exchange channel 102. The first average temperature formula can be used to calculate the average temperature of the first sequence battery 310 after being cooled by the coolant in the first heat exchange channel 102. Similarly, after determining the second convective heat exchange coefficient, a second average temperature formula after the second sequence battery 320 performs heat exchange with the coolant in the second heat exchange channel 202 can be constructed according to the first flow rate and the width of the second heat exchange channel 202. The second average temperature formula can be used to calculate the average temperature of the second sequence battery 310 after being cooled by the coolant in the second heat exchange channel 202.

[0068] S140, constructing a flow channel design formula when the first average temperature formula and the second average temperature formula are equal, and determining the width of the bypass channel according to the flow channel design formula.

[0069] Specifically, the average temperature of the first sequence battery 310 after being cooled by the coolant in the first heat exchange channel 102 is set to be the same as the average temperature of the second sequence battery 310 after being cooled by the coolant in the second heat exchange channel 202, so as to construct a formula when the first average temperature formula and the second average temperature formula are equal, and simplify the formula to obtain the flow channel design formula. It should be noted that the unknown quantity in the flow channel design formula only includes the width of the bypass channel, and the others are all determined values. Therefore, the flow channel design formula can be used to determine the required width of the bypass channel 101 when the average temperature of the first sequence battery 310 after cooling is the same as the average temperature of the second sequence battery 320 after cooling.

[0070] In summary, in the embodiment of the present invention, the first heat generation power of the first sequence battery and the second heat generation power of the second sequence battery are obtained, and the first flow rate of the first water inlet is determined according to the first heat generation power and the second heat generation power, and the first convection heat exchange coefficient between the first sequence battery and the first heat exchange channel and the second convection heat exchange coefficient between the second sequence battery and the second heat exchange channel are determined. The first average temperature formula after heat exchange in the first heat exchange channel is constructed according to the first convection heat exchange coefficient, the first flow rate and the width of the first heat exchange channel, and the second average temperature formula after heat exchange in the second heat exchange channel is constructed according to the second convection heat exchange coefficient, the first flow rate and the width of the second heat exchange channel. Finally, the flow channel design formula is constructed when the first average temperature formula and the second average temperature formula are equal, and the width of the bypass channel is determined according to the flow channel design formula. In this way, the first chamber and the second chamber are separated. In the first chamber, the coolant in the bypass channel does not flow through the first heat exchange channel, that is, the coolant in the bypass channel does not participate in the heat exchange. The first heat exchange channel overlaps with the first sequence battery, that is, the coolant in the first heat exchange channel participates in the heat exchange. After the two merge, they enter the second chamber and participate in the heat exchange of the second heat exchange channel. In this way, by setting the coolant in the bypass channel not to participate in the heat exchange, the overall heat dissipation efficiency of the coolant entering the second chamber is guaranteed, and the coolant is prevented from flowing through the first sequence battery and causing the temperature of all coolants to rise. After the heat exchange with the second sequence battery, the temperature difference between the first sequence battery and the second sequence battery is large. On this basis, the flow distribution is adjusted by setting the width of the bypass channel, so that the average temperature of the first sequence battery after the heat exchange is consistent with that of the second sequence battery after the heat exchange, and the life of the battery assembly is improved. In addition, the flow channel design method ensures that the temperature of the battery assembly meets the design indicators through theoretical calculation, saves the time of simulation iteration optimization, and minimizes the power of the battery assembly thermal management system.

[0071] Figure 3 is a flow chart of another flow channel design method of a liquid cooling plate provided by an embodiment of the present invention, see Figure 1 and Figure 3 , the flow channel design method includes:

[0072] S210. Set the first temperature of the coolant when it enters from the first water inlet and the second temperature of the coolant when it flows out from the first water outlet, and determine the first flow rate of the first water inlet according to the first heat generation power, the second heat generation power, the first temperature, the second temperature, the first calculation formula, the mass and specific heat of the coolant.

[0073] Specifically, the first calculation formula includes:

[0074]

[0075] Wherein, Q is the first flow rate of the first water inlet 110, P1 is the first heat generation power, P 2 is the second heat generation power, T in1 is the first temperature, T out1 is the second temperature, m is the mass of the coolant, c p The first heat generation power P of the first sequence battery 310 is 1 The second heat generation power of the second sequence battery 320 is a determined value. The first temperature of the coolant when it enters the first chamber 10 from the first water inlet, and the second temperature of the coolant when it finally flows out of the second chamber 20 from the first water outlet 220 are pre-set, and the difference between the second temperature and the first temperature is the heat to be taken away by the coolant after completing the heat exchange process. The quality of the coolant and the specific heat of the coolant are determined after the coolant is selected, and then the total amount of coolant required when the cooling setting difference (the difference between the second temperature and the first temperature) is obtained through the above-determined values, that is, the first flow rate flowing into the first water inlet 110.

[0076] S220, determining a first convective heat exchange coefficient between the first sequence of batteries and the first heat exchange channel, and a second convective heat exchange coefficient between the second sequence of batteries and the second heat exchange channel.

[0077] Specifically, the formula for calculating the fluid Reynolds number includes:

[0078]

[0079] Where Re is the Reynolds number of the first fluid or the Reynolds number of the second fluid, ρ is the density of the coolant, and d e is the characteristic length of the flow channel, μ is the viscosity coefficient of the coolant, and v includes the first flow rate or the second flow rate. The calculation formula for the convective heat transfer coefficient includes:

[0080]

[0081] Among them, α f Including the first convective heat transfer coefficient or the second convective heat transfer coefficient, N u It includes the first Nusselt number or the second Nusselt number, and λ is the thermal conductivity of the coolant.

[0082] Exemplarily, the volume of the first chamber 10 can be determined according to the width of the first chamber 10 and the thickness of the first chamber 10 (the thickness of the flow channel 40). The first flow rate of the coolant in the first chamber 10 can be determined according to the volume of the first chamber 10 and the first flow rate. Since the flow rates in the same chamber are the same, the first flow rate of the coolant in the first chamber 10 is the flow rate of the coolant in the first heat exchange channel 102. The first flow rate, the density of the coolant, the characteristic length of the flow channel 40, and the viscosity coefficient of the coolant are substituted into the above-mentioned fluid Reynolds number calculation formula to determine the first fluid Reynolds number of the first chamber 10 (the first heat exchange channel 102). If the first convective heat transfer coefficient between the first sequence battery 310 and the first heat exchange channel 102 is to be calculated, the first Nusselt number also needs to be obtained, and the first Nusselt number is related to the first fluid Reynolds number. Specifically, when R e <2300N u =6.49, when R e ≥2300N u =0.023R e 0.8 Pr 0.33 , where Pr is the Prandtl number. In this way, the first Nusselt number is determined according to the Reynolds number of the first fluid, and the first Nusselt number, the thermal conductivity of the coolant, and the characteristic length of the flow channel 40 are substituted into the above convective heat transfer coefficient calculation formula to determine the first convective heat transfer coefficient of the first heat exchange channel 102.

[0083] Similarly, the volume of the second chamber 20 can be determined according to the width of the second chamber 20 and the thickness of the second chamber 20, and the second flow rate of the coolant in the second chamber 20 can be determined according to the volume of the second chamber 20 and the first flow rate (which can be understood as the flow rate entering the second chamber 20 from the second water inlet 210), and the second flow rate, the density of the coolant, the characteristic length of the flow channel 40, and the viscosity coefficient of the coolant are substituted into the above fluid Reynolds number calculation formula to determine the second fluid Reynolds number of the second chamber 20 (the second heat exchange channel 202). The second Nusselt number is determined according to the second fluid Reynolds number, and the second Nusselt number, the thermal conductivity of the coolant, and the characteristic length of the flow channel 40 are substituted into the convective heat exchange coefficient calculation formula to determine the second convective heat exchange coefficient of the second heat exchange channel 202.

[0084] 230. Construct a first average temperature formula of the first heat exchange channel after heat exchange according to the first convection heat exchange coefficient, the first flow rate, and the width of the first heat exchange channel.

[0085] Specifically, a second flow formula of the first heat exchange channel is constructed according to the first flow rate, the number of channels 40 in the first heat exchange channel 102, and the number of channels 40 in the bypass channel 101. The second flow formula includes:

[0086]

[0087] Among them, Q 1 is the second flow rate of the coolant flowing through the first heat exchange channel 102, n 1 is the number of flow channels 40 in the first heat exchange channel 102, n 0 is the number of flow channels 40 in the bypass channel 101, and Q is the first flow rate. Since the width of the bypass channel 101 is unknown, the second flow formula constructed is an equation rather than a specific value. The flow rate (second flow rate) of the coolant in the first heat exchange channel 102 can be calculated by the second flow formula. Then, according to the second flow formula, the contact thermal resistance during the heat exchange process, the first convection heat transfer coefficient, the width of the first heat exchange channel 102, the characteristic scale of the flow channel 40, the first temperature of the coolant when it enters from the first water inlet 110, and the third temperature of the coolant when it flows out from the second water outlet 120, the first average temperature formula is constructed. The first average temperature formula includes:

[0088]

[0089] Among them, Q 1 is the second flow rate of the coolant flowing through the first heat exchange channel 102, d 1 is the width of the first heat exchange channel 120, αf 1 is the first convection heat transfer coefficient, is the thermal contact resistance during heat exchange, T in1 is the first temperature of the coolant when it enters from the first water inlet 110, T out2 is the third temperature of the coolant when it flows out from the second water outlet 220 , and l is the characteristic dimension of the flow channel 40 .

[0090] S240. Construct a second average temperature formula after heat exchange in the second heat exchange channel according to the second convection heat exchange coefficient, the first flow rate, and the width of the second heat exchange channel.

[0091] Specifically, since the flow rate of the coolant in the first chamber 10 is the same as the flow rate in the second chamber 20, the third flow rate of the coolant flowing into the second chamber 20 can be determined based on the first flow rate. In addition, since the second chamber 20 only includes the second heat exchange channel 202, the second average temperature formula can be constructed based on the third flow rate, the contact thermal resistance during the heat exchange process, the second convection heat transfer coefficient, the width of the second heat exchange channel 202, the characteristic scale of the flow channel 40, the fourth temperature of the coolant when it enters from the second water inlet 210, and the second temperature of the coolant when it flows out from the first water outlet 220. The second average temperature formula includes:

[0092]

[0093] Among them, Q 2 is the third flow rate of the coolant flowing into the second chamber 20, d 2 is the width of the second heat exchange channel 202, αf 2 is the second convective heat transfer coefficient, is the thermal contact resistance during heat exchange, T in2 is the fourth temperature of the coolant when it enters from the second water inlet 210, T out1 is the second temperature of the coolant when it flows out from the first water outlet 220 , and l is the characteristic dimension of the flow channel 40 .

[0094] S250, making the first average temperature formula equal to the second average temperature formula to obtain a transition formula, simplifying the transition formula to obtain a flow channel design formula, and determining the bypass channel width according to the flow channel design formula.

[0095] Specifically, the average temperature of the first sequence of batteries 310 after being cooled by the coolant in the first heat exchange channel 102 is set to be the same as the average temperature of the second sequence of batteries 310 after being cooled by the coolant in the second heat exchange channel 202, so as to construct a transition formula when the first average temperature formula and the second average temperature formula are equal, and the transition formula includes:

[0096]

[0097] Since the first water outlet 120 and the second water inlet 210 are the same outlet, T in2 is the fourth temperature of the coolant when it enters from the second water inlet 210, T out2 is the third temperature of the coolant when it flows out from the second water outlet 220. Therefore, T out2 =T in2 ;

[0098] Further simplification gives:

[0099]

[0100] Since the first flow rate is the sum of the flow rate flowing through the first heat exchange channel 102 and the flow rate flowing through the bypass channel 101, that is, And Q 2 =Q, therefore, the above formula is further simplified to obtain the flow channel design formula, which includes:

[0101]

[0102] Among them, n 1 is the number of flow channels 40 in the first heat exchange channel 102, n 0 is the number of flow channels 40 in the bypass channel 101, Q is the first flow rate, d1 is the width of the first heat exchange channel 102, αf 1 is the first convection heat transfer coefficient, is the thermal contact resistance during heat exchange, T in1 is the first temperature of the coolant when it enters from the first water inlet 110, d 2 is the width of the second heat exchange channel 202, αf 2 is the second convection heat transfer coefficient, T out1 is the second temperature of the coolant when it flows out of the first water outlet 220, and l is the characteristic dimension of the flow channel 40. In the above formula, the width d of the first heat exchange channel 201 is 1 The width d of the second heat exchange channel 202 is determined by the width of the first series battery 310. 2 The number n of the flow channels 40 in the first heat exchange channel 102 is determined by the width of the second series battery 320. 1 According to the width d of the first heat exchange channel 201 1 and the width of the flow channel 40 is determined, except for the number n of the flow channels 40 in the bypass channel 101 0 , other parameters have been determined through the above embodiments. Thus, the required width of the bypass channel 101 can be determined according to the flow channel design formula when the average temperature of the first sequence battery 310 after cooling is the same as the average temperature of the second sequence battery 320 after cooling. The flow channel design method ensures that the battery assembly temperature meets the design index through theoretical calculation, saves the time of simulation iteration optimization, and minimizes the power of the battery assembly thermal management system.

[0103] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A flow channel design method for a liquid cooling plate, characterized in that: The liquid cooling plate comprises a first chamber and a second chamber; a first water inlet is provided in the first chamber, and a first water outlet is provided in the second chamber; A bypass channel and a first heat exchange channel are provided in the first chamber, and a second heat exchange channel is provided in the second chamber; a battery assembly is provided on the liquid cooling plate, and a coolant flows in the liquid cooling plate, and the battery assembly includes a first sequence battery and a second sequence battery, the first sequence battery and the first heat exchange channel are overlapped, and the second sequence battery and the second heat exchange channel are overlapped; The bypass channel, the first heat exchange channel and the second heat exchange channel each include a plurality of flow channels, and partitions are provided between different flow channels; The flow channel design method comprises: Acquire a first heat generation power of the first sequence battery and a second heat generation power of the second sequence battery, and determine a first flow rate of the first water inlet according to the first heat generation power and the second heat generation power; Determining a first convective heat exchange coefficient between the first sequence battery and the first heat exchange channel, and a second convective heat exchange coefficient between the second sequence battery and the second heat exchange channel; A first average temperature formula after heat exchange in the first heat exchange channel is constructed according to the first convection heat exchange coefficient, the first flow rate, and the width of the first heat exchange channel; and a second average temperature formula after heat exchange in the second heat exchange channel is constructed according to the second convection heat exchange coefficient, the first flow rate, and the width of the second heat exchange channel; A flow channel design formula is constructed when the first average temperature formula and the second average temperature formula are equal, and the width of the bypass channel is determined according to the flow channel design formula.

2. The flow channel design method according to claim 1, characterized in that: The determining the first flow rate of the first water inlet according to the first heat generating power and the second heat generating power comprises: Setting a first temperature of the coolant when it enters from the first water inlet, and a second temperature of the coolant when it flows out from the first water outlet; A first flow rate of the first water inlet is determined according to the first heat generating power, the second heat generating power, the first temperature, the second temperature, a first calculation formula, and the mass and specific heat of the coolant.

3. The flow channel design method according to claim 2, characterized in that: The first calculation formula includes: Wherein, Q is the first flow rate of the first water inlet, P1 is the first heat generation power, P2 is the second heat generation power, T in1 is the first temperature, T out1 is the second temperature, m is the mass of the coolant, c p is the specific heat of the coolant.

4. The flow channel design method according to claim 1, characterized in that: The determining of a first convective heat exchange coefficient between the first sequence battery and the first heat exchange channel, and a second convective heat exchange coefficient between the second sequence battery and the second heat exchange channel comprises: Determine a first flow rate of the coolant in the first chamber according to the width of the first chamber, the thickness of the first chamber, and the first flow rate, and determine a first fluid Reynolds number of the first chamber according to the first flow rate, the density of the coolant, the characteristic length of the flow channel, the viscosity coefficient of the coolant, and a fluid Reynolds number calculation formula; Determine a first Nusselt number according to the Reynolds number of the first fluid, and determine the first convective heat transfer coefficient according to the first Nusselt number, the thermal conductivity of the coolant, the characteristic length of the flow channel, and a convective heat transfer coefficient calculation formula; Determine a second flow rate of the coolant in the second chamber according to the width of the second chamber, the thickness of the second chamber, and the first flow rate, and determine a second fluid Reynolds number of the second chamber according to the second flow rate, the density of the coolant, the characteristic length of the flow channel, the viscosity coefficient of the coolant, and a fluid Reynolds number calculation formula; The second Nusselt number is determined according to the Reynolds number of the second fluid, and the second convective heat transfer coefficient is determined according to the second Nusselt number, the thermal conductivity of the coolant, the characteristic length of the flow channel and a convective heat transfer coefficient calculation formula.

5. The flow channel design method according to claim 4, characterized in that: The fluid Reynolds number calculation formula includes: Wherein, Re includes the Reynolds number of the first fluid or the Reynolds number of the second fluid, ρ is the density of the coolant, d e is the characteristic length of the flow channel, μ is the viscosity coefficient of the coolant, and v includes the first flow velocity or the second flow velocity; The calculation formula of the convective heat transfer coefficient includes: Among them, α f Including the first convective heat transfer coefficient or the second convective heat transfer coefficient, N u Including the first Nusselt number or the second Nusselt number, λ is the thermal conductivity of the coolant.

6. The flow channel design method according to claim 1, characterized in that: The first chamber is further provided with a second water outlet, and the second chamber is further provided with a second water inlet, the coolant flows into the first chamber through the first water inlet, flows out of the first chamber through the second water outlet, and flows into the second chamber through the second water inlet, and flows out of the second chamber through the first water outlet; The formula for constructing the first average temperature of the first heat exchange channel after heat exchange according to the first convection heat exchange coefficient, the first flow rate and the width of the first heat exchange channel includes: Constructing a second flow formula for the first heat exchange channel according to the first flow rate, the number of the flow channels in the first heat exchange channel, and the number of the flow channels in the bypass channel; The first average temperature formula is constructed based on the second flow formula, the contact thermal resistance during the heat exchange process, the first convection heat transfer coefficient, the width of the first heat exchange channel, the characteristic scale of the flow channel, the first temperature of the coolant when it enters from the first water inlet, and the third temperature of the coolant when it flows out from the second water outlet.

7. The flow channel design method according to claim 6, characterized in that: The second flow formula includes: Wherein, Q1 is the second flow rate of the coolant flowing through the first heat exchange channel, n1 is the number of the flow channels in the first heat exchange channel, n0 is the number of the flow channels in the bypass channel, and Q is the first flow rate; The first average temperature formula includes: Wherein, Q1 is the second flow rate of the coolant flowing through the first heat exchange channel, d1 is the width of the first heat exchange channel, αf1 is the first convection heat transfer coefficient, is the thermal contact resistance during heat exchange, T in1 is the first temperature of the coolant when it enters from the first water inlet, T out2 is the third temperature of the coolant when it flows out from the second water outlet, and l is the characteristic dimension of the flow channel.

8. The flow channel design method according to claim 1, characterized in that: The first chamber is further provided with a second water outlet, and the second chamber is further provided with a second water inlet, the coolant flows into the first chamber through the first water inlet, flows out of the first chamber through the second water outlet, and flows into the second chamber through the second water inlet, and flows out of the second chamber through the first water outlet; The second average temperature formula after heat exchange in the second heat exchange channel is constructed according to the second convection heat exchange coefficient, the first flow rate and the width of the second heat exchange channel includes: determining a third flow rate of the coolant flowing into the second chamber according to the first flow rate; The second average temperature formula is constructed based on the third flow rate, the contact thermal resistance during the heat exchange process, the second convection heat transfer coefficient, the width of the second heat exchange channel, the characteristic scale of the flow channel, the fourth temperature of the coolant when it enters from the second water inlet, and the second temperature of the coolant when it flows out from the first water outlet.

9. The flow channel design method according to claim 8, characterized in that: The second average temperature formula includes: Wherein, Q2 is the third flow rate of the coolant flowing into the second chamber, d2 is the width of the second heat exchange channel, αf2 is the second convection heat exchange coefficient, is the thermal contact resistance during heat exchange, T in2 is the fourth temperature of the coolant when it enters from the second water inlet, T out1 is the second temperature of the coolant when it flows out of the first water outlet, and l is the characteristic dimension of the flow channel.

10. The flow channel design method according to claim 1, characterized in that: The constructing of the flow channel design formula when the first average temperature formula and the second average temperature formula are equal, and determining the bypass channel width according to the flow channel design formula comprises: Let the first average temperature formula and the second average temperature formula be equal to obtain a transition formula; Simplifying the transition formula to obtain the flow channel design formula, and determining the bypass channel width according to the flow channel design formula; The flow channel design formula includes: Wherein, n1 is the number of the flow channels in the first heat exchange channel, n0 is the number of the flow channels in the bypass channel, Q is the first flow rate, d1 is the width of the first heat exchange channel, αf1 is the first convective heat transfer coefficient, is the thermal contact resistance during heat exchange, T in1 is the first temperature of the coolant when it enters from the first water inlet, d2 is the width of the second heat exchange channel, αf2 is the second convection heat exchange coefficient, T out1 is the second temperature of the coolant when it flows out of the first water outlet, and l is the characteristic dimension of the flow channel.

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