Liquid pump-enabled hydrogen refueling system for medium and heavy duty fuel cell vehicles: Station design and technoeconomic assessment

Recent progress in submerged liquid hydrogen (LH₂) cryopump technology development offers improved hydrogen fueling performance at a reduced cost in medium- and heavy-duty (MDV and HDV) fuel cell vehicle refueling applications at 35 MPa pressure, compared to fueling via gas compression. In this paper, we evaluate the fueling cost associated with cryopump-based refueling stations for different MDV and HDV hydrogen demand profiles. We adapt the Heavy Duty Refueling Station Analysis Model (HDRSAM) tool to analyze the submerged cryopump case, and compare the estimated fuel dispensing costs of stations supplied with LH₂ for fueling Class 4 delivery van (MDV), public transit bus (HDV), and Class 8 truck (HDV) fleets using cryopumps relative to station designs. A sensitivity analysis around upstream costs illustrates the trade-offs associated with H₂ production from onsite electrolysis versus central LH₂ production and delivery. Our results indicate that LH₂ cryopump-based stations become more economically attractive as the total station capacity (kg dispensed per day) and hourly demand (vehicles per hour) increase. Depending on the use case, savings relative to next best options range from about 5% up to 44% in dispensed costs, with more favorable economics at larger stations with high utilization.     

Gas species, their evolution and segregation through the ITER vacuum systems

This paper takes the ITER fueling requirements and current knowledge of gas balance and exhaust from operating tokamaks to predict all likely gas inputs into the ITER Vacuum systems. Areas where gas dynamics modeling is relevant to the ITER design are highlighted. The design and operation of the ITER vacuum system gives an element of segregation of different gas flows and species. This paper analyses the time dependent gas segregation in the vacuum system resulting from different temperature dependences of cryogenic sorption and condensation processes of different gas species. As a specific example, the optimal transfer of ⁴¹Ar through the vacuum system is studied with respect to its decay and the resulting effects on the design of system components.     

12位清洁开关管真空排气系统

这个系统是真空开关管的真空排气系统。由机架、主真空室、１２支预抽管路、超高真空插板阀和ＺＤＢ－２５０型低温泵组成。经过半年的运转系统工作正常。     

中性束注入器漂移管道用低温泵的设计

随着中性束注入器研究的深入开展,我们在成功地设计了一台真空室用的400 000 L/s低温泵的基础上又对漂移管道用的20 000 L/s的低温泵进行研制.本文在详细分析漂移管道特点及其对低温泵结构的特殊要求的基础上,对低温泵的结构及冷凝板的温度分布进行具体的分析.设计了一台符合中性束注入器漂移管道特殊要求的液氦低温泵.     

Neutronic analysis of iter cryopump system

The ITER Vacuum Vessel has upper, equatorial and lower port structures. The bottom ports are dedicated to the divertor replacement (five ports) and to vacuum pumping by means of cryopumps (four ports). The latest cryopump port design is more complex as it has a pump with a direct view of the vessel (upper cryopump) and a second pump at the end of a branch port (lower cryopump).3D neutronic analyses have been performed in order to study the radiation conditions in and around the port system. In detail, nuclear heating on the cryopump has been calculated updating previous analysis performed in 2003 [L. Petrizzi, ITER CTA Detailed Neutronic Analyses, Final Report on contract EFDA/01-633 ENEA ref NE-VV-R-001 April 2003. Also included in Nuclear Analyis Report NAR ITER ref document G 73 DDD 2W 0.2 (v2.0) March 2006]. Calculations have been performed by means of MCNP 5 Monte Carlo code supplied with FENDL 2.1 library. In this work a new 40° model of ITER has been used in which full details of the cryopump system and remote handling ports have been included as well as the updated divertor components.The paper will present the neutronics results. They consist of nuclear heating on cryopump components; a map of dpa and helium production is provided as well.Gamma doses after shutdown have been calculated around the port flange to have an idea of the possible dose to which the eventual operator will be subject and to plan adequately manual operations.The cryopump is located at a distance of almost 5 m from the mouth of the divertor port and it is 3 m long. Calculations of such deep penetration problem are very challenging require special variance reduction techniques with Monte Carlo codes in order to use in an efficient way the computer resources. These will be described.     

R&D and design for the cryogenic and mechanical vacuum pumping systems of ITER

The next generation thermonuclear fusion machine ITER comprises large cryogenic pumping systems to process very high gas throughputs. The paper starts from a summary of the requirements for the torus exhaust pumping system and the neutral beam injection system for plasma heating and discusses the design solutions derived to match them. All ITER force-cooled cryopumps are based on a modular set-up and incorporate similar design of charcoal-coated cryopanels cooled to 4.5 K with supercritical helium. A systematic approach for how to design a tailor-made cryopump is presented. It is based on Monte Carlo simulation to calculate the overall capture coefficient being the primary design parameter. Experimental results measured with a model pump of representative scale are used to validate the design procedure. In the last part, the paper addresses the design issues to be solved for tritium-compatible forepumps with high pumping speeds.     

6000m~3/h空分设备氮水预冷系统管路改造

分析6000m3/h空分设备氮水预冷系统工艺设计存在的问题,通过改变低温水泵启动时的上水流路,彻底消除了低温水泵汽蚀现象,缩短空分设备的启动时间。     

索尔文制冷机低温泵

介绍自己研制的索尔文制冷机低温泵的压缩净化机组、改进型索尔文两级膨胀机以及低温泵体的设计及特点。目前已完成低温泵的中试生产，开始批量生产。     

制冷机工况变化对低温泵抽气特性的影响

低温泵的冷源是小型气体制冷机。制冷系统在长期运行中可能发生种种故障，使制冷工况发生变化。制冷机制冷工况的变化，对制冷机一，二级冷头的制冷量和制冷温度有明显影响，从而对低温泵抽气特性产生重大影响。     

用于中性束注入器的4.2 K液氦低温冷凝泵的设计

在中性束注入器的研制中 ,大抽速低温泵的设计是其中非常重要的一部分。本文结合中性束注入器对真空系统的要求 ,介绍了中性束注入器真空系统的构成 ,并以布置于中性化室部位的低温泵为例 ,详细阐述了用于中性束注入系统的低温泵的结构设计以及抽速确定、冷凝面积确定等关键问题 ,成功设计了一套完全满足中性束注入系统对动态真空度要求的低温泵。