Research on Performance Test and Evaluation of Thermal Management System of Power Battery Module under Harsh Conditions

Under harsh conditions, the battery module (BM) used for Ev’s power system has issues of local overheating, continuous high temperature, and spontaneous combustion causing thermal accidents. This problem is directly related to the safety of life and property of drivers and passengers. What’s more, it also seriously restricts the high-quality development and promotion of Evs. To solve the limitations and drawbacks of the BM. this paper designs the thermal management structure with TiO2 nanofluids closed loop pulsating heat pipe (TiO2-CLPHP) as the key component and constructs the thermal management system with TiO2-CLPHP (TiO2-CLPHP TMS). On the basis, the temperature optimal thermal management strategy (TOS) and energy consumption optimal thermal management strategy (ECOS) is proposed. To investigate the performance response of TiO2-CLPHP TMS, the performance test of TiO2-CLPHP TMS is carried out. The results show that in terms of thermal management performance, the TiO2-CLPHP TMS with TOS and ECOS (TOS-TiO2-CLPHP TMS, ECOS-TiO2-CLPHP TMS) can effectively suppress the highest temperature, temperature rise and improve temperature uniformity of the PM. Of these, the minimum improvement rates of TOS-TiO2-CLPHP TMS can reach 29.41%, 78.37%, 65.88%, 58.82%, and 64.95%. The minimum improvement rates of ECOS-TiO2-CLPHP TMS can reach 27.24%, 72.65%, 64.71%, 55.88%, and 68.04%, respectively. In terms of the thermal management economy, compared with TOS-TiO2-CLPHP TMS, ECOS-TiO2-CLPHP TMS has lower energy consumption. The efficiency values of the ECOS-TiO2-CLPHP TMS are not less than 87.72%. It can be concluded that the proposed TiO2-CLPHP TMS has excellent thermal management performance. The ECOS-TiO2-CLPHP TMS can maximize the dual requirements of the thermal management performance and thermal management economy. This study innovatively proposed a thermal management method for nanofluids PHP used in BM. Compared with previous studies, the proposed TiO2-CLPHP TMS reduced the temperature difference from the traditional 5.00 ℃ to less than 3.40 ℃, greatly improving the temperature uniformity of the BM. The completion of this research provides a new idea of battery thermal management based on metal oxide nanofluids PHP, and the constructed performance evaluation method provides a referral scheme for the performance test and evaluation of thermal management technology.