车载高压氢气分级充注系统的设计与模拟

研究单级氢气充注时,氢气充注速率、初始温度和压力对氢气终了温度的影响。通过调用NIST REFPROP 中标准氢状态方程,模拟氢气在充注过程温度、压力、充注率等参数的变化。设计和模拟两级和三级氢气充注系统。结果表明：多级充注时,存在最佳的中间压力,使得充灌终了氢气温度最低,且增加级数可降低终了氢气温度。最后,对多级充注系统的能耗进行分析,结果表明随着级数的增加,系统的总能耗降低。     

金属氢化物储氢器吸氢过程的数值分析

基于金属氢化物吸氢基本特性,建立圆柱形金属氢化物储氢器吸氢过程的-维数学物理模型.采用有限差分法对金属氢化物床体的传热传质进行计算.分别研究金属氢化物床体各处温度和氢含量在吸氢过程中的变化以及氢气压力、对流传热系数和金属氢化物床体径向厚度对金属氢化物吸氢过程的影响.计算结果表明:初始阶段金属氢化物床均匀吸氢,但随着氢化过程的进行,其中心区域的吸氢速率逐渐低于边缘区域;增加吸氢压力、提高对流传热系数均可促进储氢器的吸氢;金属氢化物床的径向厚度对吸氢速率影响很大,金属氢化物床越薄,氢化反应的速度越快.     

车用高压储氢气瓶局部火烧试验方法研究

高压储氢气瓶作为氢燃料电池汽车的关键部件,其在火烧情况下的安全性能备受关注。《氢燃料电池汽车全球技术法规》首次提出的车用高压储氢气瓶局部火烧试验方法,将对我国氢燃料电池汽车的发展产生重大影响。该文在分析车用高压储氢气瓶整体火烧试验方法局限性的基础上,系统研究局部火烧试验方法提出的技术理由、主要内容和特点,指出我国车用高压储氢气瓶和压缩氢气储存系统发展面临的挑战,并针对我国正在制定的相关标准,提出若干建议。     

IV型瓶聚乙烯内胆材料氢渗透行为研究

对IV型高压储氢气瓶内胆材料高密度聚乙烯（HDPE）的氢气气体渗透性进行了研究,主要分析了结晶度及温度对HDPE氢渗透的影响。通过对试样熔融后降温过程的控制,制备了不同结晶度的HDPE试样,试验结果表明,随着结晶度的增加,试样的氢气气体渗透系数降低。当温度从15℃升高到80℃时,氢渗透系数升高了近一个数量级,但渗透系数的温度依赖性低于二氧化碳及甲烷。     

AB5型固态金属储氢系统吸/放氢特性实验研究

为研究AB₅型固态金属储氢系统在不同温度和压力条件下的吸/放氢性能,搭建小型固态金属储氢罐实验平台,设计不同温度及压力条件下的吸/放氢循环实验,利用循环水浴系统构造换热环境对固态金属储氢罐进行循环换热,测试吸/放氢压力和温度等关键操作参数对AB₅型固态金属储氢系统吸/放氢性能的影响。结果表明：在达到相应吸氢反应平衡压力的条件下,较高的吸氢压力和温度对吸氢效率均具有促进作用,同时,较高的吸氢压力会加剧系统主要吸氢阶段的化合反应,伴有强烈的热交换行为,且维持不同放氢压力条件下的持续放氢需达到相应的放氢温度;同一压力条件下,较高的放氢温度可提高系统的放氢效率,使系统内部氢气压差达到相应放氢条件以维持系统持续稳定放氢的需求。上述结论可为AB₅型固态金属储氢系统的研究提供参考。     

基于扩散点火理论的高压氢气泄漏自燃研究

运用扩散点火理论对高压氢气泄漏到下游管道内的自燃点火情况进行了分析。利用激波管流动理论讨论了氢气射流前端激波加热区域的参数变化情况,分析了前沿激波强度、均匀区压力和温度与初始压力的关系,给出了高压氢气泄漏到下游管道后,预测前沿激波强度、均匀区压力和温度的数学方程,建立了判断高压氢气泄漏到下游管道内是否发生自燃点火的函数表达式。提出了理论点火临界压力的概念,计算发现氢气的理论点火临界压力明显低于其他几种常见的气体燃料。讨论了影响泄漏自燃发生的可能因素,结果可为预防高压储氢泄漏自燃提供科学依据。     

金属氢化物复合式高压储氢器的研究

为提高高压储氢容器的体积储氢密度,采用具有高体积储氢密度的储氢合金与轻质高压容器复合组成高压金属氢化物复合式储氢器.为获得高压氢源,研究了Mm-Ml-Ni-Al(Mm为富铈混合稀土,Ml为富镧混合稀土)的储氢特性,并试制了化学热压缩器.采用研制的高压氢源,对具有高吸放氢平台压力的Ce-Ni系合金的高压储氢特性进行了研究.实验结果表明:以Ml或Ca部分取代Mm以及Al对Ni的部分置换后合金活化性能和吸放氢压力滞后明显改善,(Mm-Ml)0.8Ca0.2(Ni-Al)多元合金具有较好的储氢性能,适合于作为化学热压缩合金.CeNi5基多元合金在40MPa氢压条件下,合金具有较好的活化性能和吸放氢动力学性能,合金最大储氢容量分别达到1.6wt%.将优化的储氢合金与自制的轻质高压储氢容器复合组成的金属氢化物复合式高压储氢器,当储氢合金的填充量达到0.2(体积分数)时,其体积储氢密度提高50%.     

成型前后活性炭储氢性能的初步研究

初步分析成型措施对活性炭储氢特性的影响.首先,在温度区间113～293 K、压力范围0～12.5 MPa测定氢平衡吸附数据,比较氢在未成型和经丙烯酸甲脂乳胶粘合剂成型的YK-1活性炭上的吸附量和等量吸附热;其次,通过储罐在室温、10.5MPa压力下的快速充/放气试验,分析成型措施对储罐吸附床吸附热效应的影响.结果表明,成型措施改变活性炭的密度和比表面积,使吸附量和吸附床中心在充放气过程的温度曲线以及吸附床的脱氢流率发生变化;在活性炭成型后,必须强化吸附床传热或引入吸附热管理措施以抑制吸附过程热效应.     

初始压力对天然气-氢气-空气混合气火焰传播特性的影响

使用定容燃烧弹研究了不同初始压力下天然气-氢气-空气混合气的火焰传播规律,得到了初始压力、掺氢比和燃空当量比对无拉伸层流燃烧速率、质量燃烧流量的影响,结合高速纹影图片分析了影响火焰稳定性的因素(马克斯坦长度、火焰面两侧密度比和火焰厚度).结果表明,掺氢天然气无拉伸层流燃烧速率以及火焰的不稳定性受掺氢比、初始压力和燃空当量比的综合影响.结合高速纹影图片,得出火焰的稳定性会随初始压力的增加而减小;在相同的燃空当量比和掺氢比下,初始压力对密度比的影响不大,但是对火焰厚度的影响比较明显.     

激波管内高压氢气泄漏自燃现象的模拟研究

利用开源程序包Open FOAM对激波管内的高压氢气泄漏自燃现象进行数值模拟,通过与实验数据的比较证明模拟结果的正确性,并对比分析H2在不同工况、结构条件下的泄漏自燃特性。研究结果表明:H2的初始压力和初始温度,下游管道的直径和长度等条件均会影响管内激波的产生与传播,从而对高压氢气泄漏自燃现象产生重要的影响。     

Hydrogen refueling process from the buffer and the cascade storage banks to HV cylinder

The focus of this research is on refueling process from a buffer and a cascade storage bank. A thermodynamic analysis is developed to investigate the filling process of fuel transmission from a storage bank to hydrogen cylinder. Refueling Process from Buffer and Cascade Storage Banks is the subject of this research. Filling the hydrogen cylinder to the required final condition is influenced by the volume and pressure of storage bank. For both buffer and cascade storage banks, ambient temperature is also an important parameter that affects the initial condition, the final condition and the refueling process. Comparison of buffer and cascade storage banks showed that refueling time using buffer storage bank is 200 s less than the cascade storage bank. However, the energy required for gas storage is higher in buffer storage system. As shown by the study, reduction in the final temperature of the filling process can be achieved by controlling the ambient temperature, the initial pressure and the fuel charging rate.     

潜艇燃料电池AIP氢燃料活性炭低温吸附储存

设计利用潜艇液氧冷量的燃料电池(FC)-AIP活性炭低温吸附储氢系统,在模拟潜艇航行中晃动和振动的平台上,测试氢在活性炭上的吸附等温线和储氢系统在为质子交换膜燃料电池(PEMFC)供气时的特性。结果表明,吸附等温线受平台晃振的影响小;温度为113K、压力为6MPa时,比表面积为1450m2.g-1的SAC-02活性炭储氢系统的质量储氢密度可超过当前艇用储氢合金的质量储氢密度;在2kW PEMFC电堆典型工况所需的氢气量(质量流率21.44L.min-1)下,通过充气过程的液氧预冷和放气过程的循环介质加热,可使储罐中心和壁面在整个过程中的最大温差小于5℃。活性炭低温吸附储氢系统的质量密度和储放氢特性能满足艇用FC-AIP系统的要求。     

考虑氢燃料电池响应延迟特性的电网日内优化调度

在以往调度模型中忽略了氢储能系统中氢-电环节氢燃料电池（HFC）作为一种电源其自身的响应延迟特性,这将造成电网切负荷并影响其稳定运行;由于HFC在不同负载其最优运行温度不同,当HFC在常温下启动时,工作温度的变化是造成其响应延迟的主要因素,因此该文从HFC的工作温度出发,分析HFC的响应延迟特性,建立其响应延迟特性模型,并分析负荷对其响应时间的影响,得到其在不同载荷率下的响应时间,最后结合电网日内调度周期的特点,提出根据HFC的载荷率不同,制定其能够响应不同调度周期的日内调度策略。     

Thermodynamic parametric analysis of refueling heavy-duty hydrogen fuel-cell electric vehicles

Reliable design and safe operation of heavy-duty hydrogen refueling stations are essential for the successful deployment of heavy-duty fuel cell electric vehicles (FCEVs). Fueling heavy-duty FCEVs is different from light-duty vehicles in terms of the dispensed hydrogen quantities and fueling rates, requiring tailored fueling station design for each vehicle class. In particular, the selection and design of the onboard hydrogen storage tank system and the fueling performance requirements influence the safe design of hydrogen fueling stations. A thermodynamic modeling and analysis are performed to evaluate the impact of various fueling parameters and boundary conditions on the fueling performance of heavy-duty FCEVs. We studied the effect of dispenser pressure ramp rate and precooling temperature, initial tank temperature and pressure, ambient temperature, and onboard storage design parameters, such as onboard storage pipe diameter and length, on the fueling rate and final vehicle state-of-charge, while observing prescribed tank pressure and temperature safety limits. An important finding was the sensitivity of the temporal fueling rate profile and the final tank state of charge to the design factors impacting pressure drop between the dispenser and vehicle tank, including onboard storage pipe diameter selection, and flow coefficients of nozzle, valves, and fittings. The fueling rate profile impacts the design and cost of the hydrogen precooling unit upstream of the dispenser.     

高压氢气储运移动式压力容器发展趋势与挑战

高压储运是主要氢气储运方式,高压氢气移动式压力容器是主要氢气储运装备.高压氢气储运容器充放频繁,氢气储量大,介质易燃易爆,具有潜在的泄漏和爆炸危险.此外,作为移动式压力容器,对运输效率要求较高,运输环境复杂多变.中国已把氢能列为未来产业,高压氢气储运容器类型和数量也将快速发展.该文总结了高压氢气储运容器主要类型、应用特...     

The design and optimization of a cryogenic compressed hydrogen refueling process

Cryo-compressed hydrogen storage has excellent volume and mass hydrogen storage density, which is the most likely way to meet the storage requirements proposed by United States Department of Energy（DOE）. This paper contributes to propose and analyze a new cryogenic compressed hydrogen refueling station. The new type of low temperature and high-pressure hydrogenation station system can effectively reduce the problems such as too high liquefaction work when using liquid hydrogen as the gas source, the need to heat and regenerate to release hydrogen, and the damage of thermal stress on the storage tank during the filling process, so as to reduce the release of hydrogen and ensure the non-destructive filling of hydrogen. This paper focuses on the study of precooling process in filling. By establishing a heat transfer model, the dynamic trend of tank temperature with time in the precooling process of low-temperature and high-pressure hydrogen storage tank under constant pressure is studied. Two analysis methods are used to provide theoretical basis for the selection of inlet diameter of hydrogen storage tank. Through comparative analysis of the advantages and disadvantages of the two analysis methods, it is concluded that the analysis method of constant mass flow is more suitable for the selection in practical applications. According to it, the recommended diameter of the storage tank at the initial temperature of 300 K, 200 K and 100 K is selected, which are all 15 mm. It is further proved that the calculation method can meet the different storage tank states of hydrogen fuel cell vehicles when selecting the pipe diameter.     

加氢站高压储氢瓶分级方法

应用真实气体状态方程,拟合了常用温度压力范围内的氢气压缩因子,建立了加氢站高压氢气多级加注的计算方法。以取气率作为指标,研究比较了二级加注和三级加注方式,讨论了等质量加注和变质量加注两种模式及储气压力和储气容积对取气率的影响。通过计算,发现三级变质量加注是最佳模式,可获得较高的取气率。研究表明:三级加注加氢站储氢瓶组的通用最佳容积比是4:3:2和2:2:1,研究结果对加氢站的设计和操作具有重要参考价值。     

固态储氢技术的研究进展

综述固态储氢技术的研究进展,包括储氢材料、储氢装置及其应用现状。部分储氢合金已成功用于固态储氢装置中,开发温和吸放氢条件下新型高容量可逆储氢材料是当前研发重点;储氢装置的优化设计可有效改善装置的快速传热特性,安全性能也得以保证,储氢装置已在分布式供能、机动车等领域得到示范应用,但还需进一步实现储氢系统快速响应、安全可靠和高储氢密度的协调统一。     

Experimental studies on temperature rise within a hydrogen cylinder during refueling

In this research, experiments were performed to investigate the thermal behaviors such as temperature rise and distributions inside 35 MPa, 150 L hydrogen storage cylinders during its refueling. The main factors affecting the temperature rise in the fast fill process such as the mass filling rate and initial pressure in the cylinder were considered. The experimental results show that the mass filling rate is a constant when the ratio of the pressure in the tank to the cylinder is higher than 1.7, and the mass filling rate decreases when the ratio is lower than 1.7; the temperature inside the cylinder increases nonlinearly in the filling process and the maximum value of temperature rise at the interface of the cylinder exists in the caudal region; the temperature rise reaches a larger value with a lower initial pressure in the cylinder or a higher mass filling rate. Furthermore, the limit of mass filling rate in the case of different ambient temperature was obtained.