Yilin Zhu's research while affiliated with Chongqing Jiaotong University and other places

Since the computational fluid dynamics (CFD) method is cumbersome and computationally intensive in optimizing the battery thermal management system (BTMS), a comprehensive computational method of total thermal resistance and pressure loss of liquid-cooled battery thermal management system with coupled flow resistance model (FRM) and thermal resistance model (TRM) was proposed, so that the total thermal resistance (TTR) and pressure drop (ΔP) of liquid-cooled battery thermal management system under various operating conditions can be calculated concisely and quickly, and then the optimization of the structural parameters of liquid-cooled plates can be achieved quickly. First, the reliability of the CFD simulation was verified by liquid-cooled plate (LCP) experiments, and the reliability of the flow resistance-thermal resistance model was further verified by CFD simulation results. Then, the sensitivity of different mass flow rate and liquid cooling channel structure parameters were analyzed. The results showed that the thermal performance and system energy consumption of the cold plate were mainly influenced by the coolant mass flow rate (m) and the channel structure factors such as the bifurcation channel angle (α), channel width (b), channel height (h), and distance between bifurcation channels (d1, d4) of the cold plate. Finally, the Neighborhood Cultivation Genetic Algorithm (NCGA) was used to optimize the total thermal resistance (TTR) and pressure drop (ΔP) of the liquid-cooled plate with the above six parameters as design variables and the total thermal resistance (TTR) and pressure drop (ΔP) as objective functions. Compared to the model before optimization, the total thermal resistance (TTR) and pressure drop (ΔP) of the optimized cold plate were reduced by 0.2409 K/W and 8.7371 Pa, respectively.

In order to enhance the heat transfer performance of the battery thermal management system, to obtain a more uniform temperature distribution and to achieve the lightweight design requirements, a new liquid cooling plate design approach with primary and secondary combined fins synergistic phase change materials and nanofluid is proposed in this paper. Based on the traditional square fins, 10 new improved fin design options are proposed in this paper. Firstly, the thermal and flow characteristics of the 10 new improved fins are compared and analyzed, and the optimization is carried out. Next, the optimal model is obtained by considering the primary fin size and introducing the secondary fins of the partitioned combination for optimization. Compared to the traditional square fins, the average temperature is reduced by 0.288 °C and the pressure drop is reduced by 1.287 Pa (17.42%). Then, based on the optimal model, the thermal performance of the combined filling method and thickness of PCM is discussed and analyzed for different Reynolds number conditions. The results indicated that the smaller the Reynolds number, the more significant the heat dissipation effect of the filled PCM. The optimal model with PCM filling reduces the mass by 41.4 g (68.86%) compared to the model without PCM, with significant lightweighting effect. Finally, to further improve the thermal performance of the system, different types of nanoparticles with different volume fractions are introduced into the system. Compared to pure water liquid cooling, the Nusselt number can be increased by 9% to 78%, and the heat dissipation effect is significantly improved.

In order to improve the cooling performance of the reverse layered air‐cooled cylindrical lithium‐ion battery pack, a structure optimization design scheme integrated with a staggered battery arrangement and longitudinal spoiler was proposed. Based on the computational fluid dynamics (CFD) method, the cooling performance of an air‐cooled battery thermal management system (BTMS) was studied, and the reliability of CFD calculation results was verified by the forced air cooling experiment of the battery pack. Firstly, the effect of a staggered arrangement of batteries on the cooling performance of the battery pack was explored. The results revealed that the hybrid staggered arrangement of the batteries greatly improved the heat dissipation performance of the cooling system. Compared with the initial condition, the maximum temperature (Tmax) and maximum temperature difference (ΔTmax) were reduced by 12.73 °C (24.96%) and 7.7 °C (87.8%), respectively. However, the problems of high temperature of batteries and poor temperature uniformity of the battery pack still existed. Secondly, the cooling performance of BTMS was further improved by constructing the structure integrated with hybrid staggered arrangement and longitudinal spoilers. The results respectively revealed that Tmax and ΔTmax were decreased by 13.06 °C (25.6%) and 8.45 °C (96.35%). Finally, the influences of the length, thickness, and number of spoilers were discussed.

Aiming at the problems of large temperature gradient of traditional parallel channel and high pressure loss of tree fractal channel, a novel stepped liquid cooling plate combining the above two structures was proposed in this paper. Firstly, based on the liquid cooling plate experimental platform, the reliability of computational fluid dynamics method was verified by experiments. Secondly, based on computational fluid dynamics and orthogonal test methods, the effects of the arrangement form of cooling channels, the number of inlets and outlets and structural parameters (number of channels, longitudinal length, width, thickness and width of inlets and outlets) were analyzed. In comparison with the original model, the average temperature and pressure drop were reduced by 1.12 °C and 22.09 Pa, respectively. Finally, in order to further improve the heat dissipation effect of the system, a new hybrid liquid cooling plates formed by filling the liquid cooling plate with composite phase change material were proposed. The results indicated that the cooling performance of the hybrid liquid cooling plate filling with more phase change material was better, meanwhile, the average temperature and pressure drop were reduced by 2.46 °C and 22.09 Pa, respectively, compared with the original model. In addition, the effect of inlet mass flow was discussed. The results revealed that the cooling performance of hybrid liquid cooling plate was better at lower mass flow rate, while the cooling performance of the liquid cooling plate was better at higher mass flow rate.