车载深冷高压储供氢过程预测和影响因素研究

Study on Prediction and Influencing Factors of Cryogenic Compressed Hydrogen Storage and Supply Process

针对应用深冷高压储氢技术的车载系统,为补充现有研究中缺乏的描述系统实时运行状态的方法,提出利用储氢密度确定工况的预测模型。基于丰田Mirai氢燃料电池车型建立动力学部分的模型。电堆功率和氢气流量的相对误差分别不超过7%和1.3%。基于Refprop物性软件建立热力学部分的模型。储氢密度的相对误差不超过1%,从而验证储供氢过程预测模型的精度。此外,还研究储氢容器的初始温度和压力工况对汽车续驶里程和容器休眠期的影响。结果表明,35 MPa下,容器初温由40 K变为70 K,车辆的续航里程减少约18%。同时,增加容器初压可以延长续航里程,但在35 MPa左右的高压时,增压的效果很不明显。而初温70 K、初压5~35 MPa的常见工况范围内,行驶过程中容器压力变化很大,易发生疲劳破坏。为达到固定的休眠期,对漏热量更大的储罐,加注后需实现更低的初温来满足使用需求。

For on-board system using cryogenic compressed hydrogen storage technology,a prediction model using hydrogen storage density to determine working conditions is proposed to supplement the lack of existing research methods to describe the consecutive operating status of the system.Establish the kinetics section of the model based on the parameter of Toyota Mirai hydrogen fuel cell vehicle. In this part,the relative error of stack power and hydrogen flow rate are less than 7% and 1.3%,respectively. Establish the thermodynamic section of the model based on the Refprop physical property software.In this part,the relative error of the hydrogen density of the model is less than 1%,thus verifying the accuracy of the prediction model for the hydrogen storage and supply process In addition,explore the effects of the initial temperature and pressure conditions of the hydrogen storage vessel on the driving mileage of the vehicle and the dormancy of the vessel. The results show that under 35 MPa,the initial temperature of the vessel changes from 40 K to 70 K,and the driving mileage of the vehicle is reduced by about 18%. Meanwhile,increasing the initial pressure of the vessel can extend the driving mileage,but at a high pressure of about 35 MPa,the effect of pressurization is not obvious.In the common working condition range of initial temperature of 70 K and initial pressure of 5-35 MPa,the pressure of the vessel changes greatly during driving and fatigue damage is likely to occur.Finally,in order to achieve a fixed dormancy,for storage vessel with greater heat leakage,a lower initial temperature must be achieved after filling to meet the use requirements.