CN-121983715-A - Thermal management method of power battery temperature equalization plate and temperature equalization plate

CN121983715ACN 121983715 ACN121983715 ACN 121983715ACN-121983715-A

Abstract

The invention relates to the technical field of power battery thermal management, in particular to a thermal management method of a power battery temperature equalization plate and the temperature equalization plate, wherein the temperature equalization plate comprises a first substrate and a second substrate, and a plurality of liquid absorption cores and a plurality of channels are positioned in a sealed vacuum cavity; the method comprises the steps of calculating a heat flow density vector of a power battery interface, which is in contact with an electric core, of a temperature equalization plate and a temperature gradient vector inside the temperature equalization plate based on a transient temperature field to determine whether the power battery interface is in a heat flow accumulation deviation state, determining a target temperature equalization plate to be subjected to heat dispersion based on a heat resistance deviation integral value of a single temperature equalization plate, determining a local enhanced cooling strategy based on a distribution state of the target temperature equalization plate or adjusting a global cooling strategy based on temperature gradient characteristics of the target temperature equalization plate, and executing a heat exchange process based on the determined cooling strategy to complete dynamic heat balance between all the electric cores and the temperature equalization plate. The invention improves the long-term operation stability of the power battery module.

Inventors

ZHANG LONGBIAO
FU BO
ZHOU JUXIANG
TONG XIAOFEI

Assignees

重庆莹帆科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A method for thermally managing a power cell temperature equalization plate, comprising: A plurality of temperature equalizing plates are arranged in the power battery module and used for conducting heat between the battery cells; In the process of charging and discharging, monitoring a plurality of original instantaneous temperatures on a power battery interface where the temperature equalizing plate is in contact with the battery core in real time to form a plurality of space discrete temperature point sets at the same moment, generating a continuous temperature field at the same moment based on the space discrete temperature point sets through a space difference algorithm, and connecting the continuous temperature fields in series according to a time axis to form a transient temperature field; Determining a heat flux density vector of the power battery interface based on the transient temperature field, and differentiating the heat flux density vector of the single power battery interface with a standard heat flux vector to obtain a temperature difference driving force vector, so as to determine whether the power battery interface is in a heat flux accumulation deviation state or not according to the comparison result of the amplitude of the heat flux accumulation deviation vector obtained by superposition of the space heat fields of all the temperature difference driving force vectors and a preset amplitude; Determining at least one target temperature equalizing plate to be thermally dispersed based on a thermal resistance deviation integral value of a single temperature equalizing plate in an interface thermal resistance distribution diagram of the temperature equalizing plate in response to the thermal flow accumulation deviation state, wherein the target temperature equalizing plate is the temperature equalizing plate with the thermal resistance deviation integral value exceeding a preset integral value; determining to adjust a local enhanced cooling strategy based on the judgment result that the spatial distribution state of the target temperature equalizing plate in the power battery module is aggregation distribution, Or determining a regulation and control mode of a global cooling strategy based on a comparison result of a vector isotropy index of a temperature gradient vector of the target temperature-uniformizing plate and a preset index; And performing a heat exchange process based on the determined cooling strategy to complete dynamic heat balance between all the cells and the temperature equalization plates.
2. The method of claim 1, wherein determining whether the power cell interface is in a heat flow accumulated bias state based on a comparison of the magnitude of the heat flow accumulated bias vector and a preset magnitude comprises: comparing the amplitude of the heat flow accumulated deviation vector with a preset amplitude; And determining that the power battery interface is in a heat flow accumulation deviation state based on a comparison result that the amplitude is larger than the preset amplitude.
3. The method of thermal management of a power cell temperature plate according to claim 2, wherein the process of determining at least one target temperature plate to be thermally dispersed based on the thermal resistance deviation integrated value of the individual temperature plates includes: Comparing the thermal resistance deviation integral value with a preset integral value; And determining the temperature equalization plate with the thermal resistance deviation integral value larger than the preset integral value as a target temperature equalization plate to be subjected to heat dispersion.
4. The method of thermal management of a power cell temperature plate of claim 3, wherein adjusting a locally enhanced cooling strategy based on a distribution state of the target temperature plate comprises: Determining the space distribution state of a plurality of target temperature equalizing plates in the power battery module; and determining the preset temperature for adjusting and starting local intensive cooling based on the judgment result that the spatial distribution state of the target temperature-equalizing plates in the power battery module is the aggregation distribution.
5. The method of thermal management of a power cell temperature plate of claim 4, wherein adjusting the preset temperature to initiate localized enhanced cooling comprises: Determining the aggregation density of the target temperature-uniforming plate with aggregation distribution; comparing the aggregate density with a preset density; Based on the result of comparing the aggregate density with a preset density, a plurality of temperature adjustment coefficients are set to reduce the preset temperature at which localized enhanced cooling is initiated.
6. The method of thermal management of a power cell temperature plate of claim 3, wherein determining a process of adjusting a global cooling strategy based on a distribution state of the target temperature plate comprises: Determining the space distribution state of a plurality of target temperature equalizing plates in the power battery module; and determining to adjust the global cooling strategy based on the judgment result that the spatial distribution state of the target temperature-equalizing plates in the power battery module is distributed in a scattered way.
7. The method of thermal management of a power cell cold plate of claim 6, wherein adjusting a global cooling strategy comprises: comparing the vector isotropic indexes of the temperature gradient vectors of the target temperature equalizing plates with preset indexes; Based on the judgment result that the vector isotropy index is smaller than or equal to a preset index, determining a global cooling strategy for enhancing the overall convective heat transfer; and determining a global cooling strategy adopting partition flow regulation based on a judging result that the vector isotropy index is larger than the preset index.
8. The method for thermal management of a power cell temperature-uniformity plate according to claim 7, wherein said vector anisotropy index is a standard deviation of cosine values of angles between a temperature gradient vector direction of a single target temperature-uniformity plate and an average temperature gradient vector direction of all target temperature-uniformity plates.
9. The method of thermal management of a power cell temperature plate of claim 8, wherein the global cooling strategy employing zoned flow regulation comprises: Determining a flow regulation coefficient based on the thermal resistance deviation integral value of the target temperature-equalizing plate, regulating the liquid cooling flow of the grid partition of the liquid cooling plate corresponding to the target temperature-equalizing plate with the corresponding flow regulation coefficient, The flow adjustment coefficient is determined based on a thermal resistance deviation integral value of a target temperature equalization plate of the grid partition of the liquid cooling plate.
10. A power cell temperature equalization plate, a thermal management method for use in a power cell temperature equalization plate according to any of claims 1-9, comprising: the liquid sucking device comprises a first substrate and a second substrate which are arranged vertically symmetrically, and a plurality of liquid sucking cores and a plurality of channels which are fixed on the inner surface of the first substrate and positioned in a sealed vacuum cavity formed by the first substrate and the second substrate.

Description

Thermal management method of power battery temperature equalization plate and temperature equalization plate Technical Field The invention relates to the technical field of power battery thermal management, in particular to a thermal management method of a power battery temperature equalization plate and the temperature equalization plate. Background Along with the rapid development of new energy automobiles and energy storage fields, the energy density and the charge and discharge power of the power battery module are continuously improved, a large amount of heat can be generated in the charge and discharge process, if the heat cannot be timely emitted and the temperature distribution among the battery cells is uneven, the consistency of the electrochemical performance of the battery cells is degraded, the cycle life is reduced, local overheating, lithium precipitation and even thermal runaway can be caused in severe cases, and the safety and the reliability of the power battery module are greatly influenced. In order to solve the problems, the temperature equalizing plate is widely applied to a power battery thermal management system as an efficient heat transfer element, and has the core functions of realizing quick heat transfer and temperature equalization among the electric cores and reducing the temperature difference among the electric cores through evaporation-condensation circulation of an internal phase change working medium. At present, in the existing thermal management method of the temperature equalization plate, the accurate identification of abnormal thermal resistance of the contact interface between the temperature equalization plate and the battery cell is lacking, the cause of heat flow accumulation deviation cannot be accurately positioned, the pertinence of thermal compensation measures is not strong, the problem of local heat accumulation caused by the attenuation of the soaking function of the temperature equalization plate is difficult to effectively solve, and further the long-term stable operation of the power battery module cannot be fully ensured. CN119603934a discloses a heat conduction control method and device for a heat sink module of a temperature equalizing plate, which relates to the technical field of intelligent heat conduction control, and comprises the steps of monitoring and obtaining real-time operation parameters of a heat source area, analyzing thermal load variation in a predetermined time window, and generating predicted temperature rise rate distribution; and setting an adaptive heat conduction strategy based on the high heat distribution discrete coefficient and the temperature rise distribution discrete coefficient, and executing heat dissipation control of the heat source region. According to the application, the technical problems that the existing method is difficult to realize rapid and accurate heat conduction adjustment under dynamic heat load, the heat management efficiency is low, and the overall performance and reliability of the server are affected can be solved, matched heat conduction control parameters can be set according to the actual heat load state, the heat dissipation efficiency is remarkably improved, and the stable and reliable operation of the server is ensured. The problem that the abnormal thermal resistance and the accumulated heat flow deviation of the contact interface of the temperature equalization plate and the battery core cannot be accurately identified, the pertinence of thermal compensation measures is lacking, the problem of local heat accumulation caused by the attenuation of the soaking function of the temperature equalization plate is difficult to solve, and the long-term stable operation of the power battery module cannot be fully ensured. Disclosure of Invention Therefore, the invention provides a thermal management method of a power battery temperature equalization plate and the temperature equalization plate, which are used for solving the problem that the long-term operation stability of a power battery module is poor because abnormal thermal resistance and accumulated heat flow deviation of a contact interface of the temperature equalization plate and a battery core cannot be accurately identified in the prior art. In order to achieve the above object, in one aspect, the present invention provides a thermal management method for a power battery temperature equalization plate, including: A plurality of temperature equalizing plates are arranged in the power battery module and used for conducting heat between the battery cells; monitoring a transient temperature field of the power battery module in a charging and discharging process in real time; based on the transient temperature field, determining a heat flow density vector of a power battery interface, which is in contact with an electric core, of the temperature equalization plate and a temperature gradient vector inside the temperature equalization plate so as t