摘 要

高压气态储氢技术的储氢密度受压力影响较大，压力又受储罐材质限制。因此，研究的难点在于储罐材质的改进。目前，高压储氢罐区分为Ⅲ型和Ⅳ型，其中Ⅲ型储氢罐的内衬材料为铝合金，外壁材料为高强度复合材料；Ⅳ型储氢罐内衬材料为高密度聚乙烯，外壁材料为高密度复合材料。复合材料的外壳使得储氢罐有更高耐压强度的同时，还减少了近一半的质量，在汽车市场上有着很大的竞争优势。

高压氢气在加注过程中，储氢罐内的温度和压力都会急剧增加，一旦加氢过程中出现泄漏或者爆炸，后果将不堪设想。因此由于存在安全隐患，在美国汽车工程师协会中，专门制定了有关加氢站与车载储氢罐的充气协议，即SAE J2601轻型气态氢汽车的燃料协议，是目前国际通行的氢气加注标准，也在不断完善当中，标准定义了加注协议和操作中的加注变量。从该协议中我们可以了解到，储氢罐的最高工作温度不得超过85℃，而最低工作稳定不得低于-45℃，压力不超过额定压力的125%，保证加氢站和车辆在进行加注过程时能满足安全要求。

根据协议中的规定，一般加氢时间控制在 3～5min，同时加氢速率不能超过 10g/s，这给加氢策略的制定带来了挑战。因此，在保证加氢安全的同时，需要探索最佳的充气方式。在车载储氢罐的实际充气过程中，加氢站内的多级加压设备会将加氢站储存的氢气加压，然后由预冷设备将氢气降温，最后才能将氢气充入储氢罐内。在实际研究中要进行如此高压、高密封性的操作需要耗费很大的财力物力，理论模拟在加氢的研究中就显得尤为重要了。本研究将利用CFD建立氢气加注过程的模拟，研究储氢罐内压力和温度的变化曲线，希望能够在氢气加注的优化提供一些指导意义。

关键词：高压储氢，传热，快充，模拟，氢安全

Abstract

The utilization of hydrogen energy includes the preparation, purification, storage, transportation and use of hydrogen. Although the key technology of fuel cell engine has been basically broken through, it needs to further improve and upgrade the fuel cell industrialization technology to make the industrialization technology mature. The development of fuel cell vehicles will further promote the widespread use of hydrogen energy, but the efficient storage of hydrogen is one of the bottlenecks restricting the promotion of hydrogen powered fuel cell vehicles. Hydrogen is a flammable and explosive gas. When the concentration of hydrogen reaches 4.1% ~ 74.2%, it will explode in case of fire. Therefore，to improve the utilization technology of hydrogen energy, its safety must be considered. The storage of hydrogen is an important link, which is closely related to other links. It is of great significance for the safety, university and durable use of automobile hydrogen energy system. Hydrogen storage, as a bridge between the generation and utilization of hydrogen, is a technology to ensure that hydrogen is stored in a stable energy form for use. At present, the commonly used hydrogen storage technologies mainly include physical hydrogen storage, chemical hydrogen storage and other hydrogen storage. Among them, the high-pressure gas hydrogen storage technology in physical hydrogen storage refers to the most mature and commonly used hydrogen storage technology at present. This technology refers to compressing hydrogen under high pressure and storing it in the form of high-density gas. It has the characteristics of low cost, low energy consumption, easy dehydrogenation and wide working conditions. Generally, it is the preferred hydrogen storage scheme for fuel cell vehicles. The fuel cell vehicles on the market also use compressed hydrogen as the fuel source.

The hydrogen storage density of high-pressure gas hydrogen storage technology is greatly affected by pressure, and the pressure is limited by the tank material. Therefore, the difficulty of research lies in the improvement of tank material. At present, the high-pressure hydrogen storage tank is divided into type III and type IV, among which the inner lining material of type III hydrogen storage tank is aluminum alloy and the outer wall material is high-strength composite material; the inner lining material of type IV hydrogen storage tank is high-density polyethylene and the outer wall material is high-density composite material. The composite shell is the hydrogen storage tank with higher compressive strength, but also reduces the quality by nearly half, which has a great competitive advantage in the automobile market.

In the process of high-pressure hydrogen filling, the temperature and pressure in the hydrogen storage tank will increase sharply. Once there is leakage or explosion in the process of hydrogenation, the consequences are unimaginable. Therefore, due to potential safety hazards, the American Society of Automotive Engineers has formulated the charging protocol between the hydrogenation station and the on-board hydrogen storage tank, that is, the fuel protocol of SAE j2601 light gas hydrogen vehicle, which is currently the internationally accepted hydrogen charging standard and is constantly improving. The standard defines the charging protocol and the charging variables in operation. The agreement states that the maximum working temperature of the hydrogen storage tank shall not exceed 85 ℃, the minimum working stability shall not be lower than - 45 ℃, and the pressure shall not exceed 125% of the rated pressure, so as to ensure that the hydrogenation station and vehicle can meet the safety requirements during the filling process.

According to the agreement, the general hydrogenation time is controlled within 3-5min, and the hydrogenation rate cannot exceed 10g /s, which brings challenges to the formulation of hydrogenation strategy. Therefore, to ensure the safety of hydrogenation, it is necessary to explore the best way of charging. During the actual charging process of the vehicle mounted hydrogen storage tank, the multi-level pressurization equipment in the hydrogenation station will pressurize the hydrogen stored in the hydrogenation station, then the precooling equipment will cool the hydrogen, and finally the hydrogen can be charged into the hydrogen storage tank. In practical research, such high pressure and high sealing operation requires a lot of financial and material resources, so theoretical simulation is particularly important in the research of hydrogenation. In this study, CFD will be used to establish the simulation of hydrogen filling process and study the change curve of pressure and temperature in the hydrogen storage tank, hoping to provide some guidance in the optimization of hydrogen filling.

Key Words: High Pressure Hydrogen Storage；Heat Transfer；Fast Filling；Simulation； Hydrogen Safety

目录

第 1 章 绪论 1

1.1 研究背景与意义 1