摘要:

For the St. Louis World Fair of 1904, James Dewar exhibited a hydrogen liquefier of his own design as part of the British exhibit. This was the first hydrogen liquefier in the USA and was subsequently purchased by the National Bureau of Standards. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774660

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

This is a review of hydrogen liquefiers and refrigerators over the last half century. Attention is given to the unusual shape of the hydrogen cooling curve at higher pressures and to the problem of ortho‐para conversion. High and low pressure liquefaction cycles are reviewed including the innovative discussion by Quack [9] in Volume 47A of “Advances.” Heat exchangers are discussed in detail. Requirements for other components are identified and safety considerations are listed. Future trends are projected. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774661

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In 1952 D. Glaser demonstrated that a radioactive source’s radiation could boil 135°C superheated‐diethyl ether in a 3‐mm Ø glass vessel and recorded bubble track growth on high‐speed film in a 2‐cm3chamber. This Bubble Chamber (BC) promised improved particle track time and spatial resolution and cycling rate. Hildebrand and Nagle, U of Chicago, reported Liquid Hydrogen minimum ionizing particle boiling in August 1953. John Wood created the 3.7‐cm Ø Liquid Hydrogen BC at LBL in January 1954. By 1959 the Lawrence Berkley Laboratory (LBL) Alvarez group’s “72‐inch” BC had tracks in liquid hydrogen. Within 10 years bubble chamber volumes increased by a factor of a million and spread to every laboratory with a substantial high‐energy physics program. The BC, particle accelerators and special separated particle beams created a new era of High Energy Physics (HEP) experimentation. The BC became the largest most complex cryogenic installation at the world’s HEP laboratories for decades. The invention and worldwide development, deployment and characteristics of these cryogenic dynamic target/detectors and related hydrogen targets are described. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774662

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The overall objective of the WE‐NET (World Energy Network System) project is to construct clean energy systems using hydrogen as a medium, focusing on the development of technologies for hydrogen production, transport, storage and utilization. The project is promoted by NEDO under the auspices of the Japan’s Ministry of Economy, Trade and Industry. The research and development of Phase I (1993–1998) mainly involved ascertaining long‐term goals. Based on the results of Phase I, Phase II (1999–2002) entailed promoting the steady introduction of hydrogen energy into society and proceeded with technical development leading to practical applications in the short and medium term such as the demonstration of hydrogen refueling stations for hydrogen fuel cell vehicles. The WE‐NET project was successfully completed in 2002 and a new five‐year hydrogen project was initiated from 2003. This report summarizes the major results achieved during the Phase I and II in the area of liquid hydrogen and cryogenic technologies, as well as describing related hydrogen projects. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774663

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Liquid hydrogen (LH2) takes up less storage volume than gas but requires cryogenic vessels. State‐of‐the‐art applications for passenger vehicles consist of double‐wall cylindrical tanks that hold a hydrogen storage mass of up to 10 kg. The preferred shell material of the tanks is stainless steel, since it is very resistant against hydrogen brittleness and shows negligible hydrogen permeation. Therefore, the weight of the whole tank system including valves and heat exchanger is more than 100 kg. The space between the inner and outer vessel is mainly used for thermal super‐insulation purposes. Several layers of insulation foils and high vacuums of 10−3Pa reduce the heat entry. The support structures, which keep the inner tank in position to the outer tank, are made of materials with low thermal conductivity, e.g. glass or carbon fiber reinforced plastics. The remaining heat in‐leak leads to a boil‐off rate of 1 to 3 percent per day. Active cooling systems to increase the stand‐by time before evaporation losses occur are being studied. Currently, the production of several liquid hydrogen tanks that fulfill the draft of regulations of the European Integrated Hydrogen Project (EIHP) is being prepared. New concepts of lightweight liquid hydrogen storage tanks will be investigated. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774664

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The use of LNG and LH2as fuels in heavy duty vehicles is increasing steadily because cryogenic liquids provides superior volumetric and gravimetric energy densities compared to other means of on‐board storage. Although several sizes and types of tanks exist, a typical vehicular storage tank has a volume of ∼400 liters (∼100 gallons). The pressure in the ullage space of a tank freshly filled is usually ∼0.25 MPa but may vary during use from ∼0.25 MPa (∼20 psig) to ∼0.92 MPa (∼120 psig). Cryogenic vehicular tanks are typically dual‐walled, stainless steel vessels with vacuum and superinsulation isolation between the inner and outer vessel walls. The heat leaks into such tanks are measured as a percentage boil‐off per day. For a storage tank of vehicular size range, the boil‐off may be ∼ 1 &percent; day, depending upon the cryogen and the quality of the tank. The corresponding heat leak into the cryogenic liquid vaporizes a certain amount of liquid that in turn increases the pressure in the tank which in turn significantly influences the properties of the cryogens. We have used a novel approach to calculate the increase in pressure of LNG and LH2in a closed cryogenic vessel with a fixed heat leak as a function of time using real equations of state for the properties of the cryogens. The method and results for the time it takes for a freshly filled tank to increase in pressure from the filling pressure of ∼0.25 MPa to a venting pressure of ∼1.73 MPa are presented. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774665

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

A new MuCool test area (MTA) is under construction at Fermi National Accelerator Laboratory. This facility will house a cryo‐system composed of a liquid hydrogen absorber enclosed in a 5 Tesla magnet. The total volume of liquid hydrogen in the system is 25 liters. Helium gas at 14 K is provided by an in‐house refrigerator and will sub‐cool the hydrogen system to 17 K. Liquid hydrogen temperature in the absorber is chosen to satisfy the requirement of a density change smaller than +/− 2.5 &percent;. To accommodate this goal and to remove the heat deposited by a beam, a pump will circulate liquid hydrogen at a rate of 450 g/s. The cooling loop was optimized with respect to the heat transport in liquid hydrogen and the pressure drop across the pump. Specific instrumentation will permit an intrinsically safe monitoring and control of the cryo‐system. Safety issues are the main driver of the cryo‐design.This paper describes the implementation of the liquid hydrogen system at MTA and the preliminary results of a finite element analysis used to size the LH2absorber force‐flow. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774666

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Slush hydrogen is a two‐phase solid‐liquid cryogenic fluid consisting of solid hydrogen particles in liquid hydrogen. Various applications are anticipated, including fuel for reusable space shuttles, coolant for cold neutron generation and for superconducting equipment, as well as the transport and storage of hydrogen as a clean energy source. This paper reports on the results of laboratory scale experiments involving three slush hydrogen production methods: the spray method, the freeze‐thaw method, and the auger method. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774667

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Propellant densification has many beneficial properties when space launch systems are considered. Among these are reduced tank volumes, decreased vapor pressures, and increased enthalpy gain before boil off. Previous NASA investigations have focused on advanced methods of producing densified propellants, but not much work has been accomplished in the area of storing and handling densified propellants. NASA KSC has 50+ years experience in handling cryogenic propellants, but all that experience is with saturated liquids. This work is focused on using existing cryogenic refrigeration technology to subcool hydrogen, and to develop a testbed where propellant handling techniques are researched. Among these topics include continuous operation, zero boil off storage, densification, pressurization techniques, handling of stratification layers, liquefaction, and recovery of boil off losses from chill down procedures. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774668

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Natural gas liquefaction plants with cooling capacities of approximately 100 kW are facilitating the development of a distributed LNG infrastructure. To be economically viable, liquefiers of this scale must be able to operate on a variety of feed gases while offering relatively low capital costs, short delivery time, and good performance. This paper opens with a discussion of a natural gas liquefier design focusing on the refrigeration system. Linde, cascade, mixed refrigerant, and modified‐Brayton cycle refrigeration systems are then discussed in context of the overall plant design. Next, a detailed comparison of the modified‐Brayton and mixed refrigerant cycles is made including cycle selection’s impact on main system components like the recuperative heat exchanger and compressors. In most cases, a reverse‐Brayton or a mixed refrigerant cycle refrigerator is the best‐suited available technology for local liquefaction. The mixed refrigerant cycle liquefier offers the potential of better real performance at lower capital costs but requires more know‐how in the areas of two‐phase flow and refrigerant composition management, heat exchanger design, and process control. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1774669

出版商:AIP    

年代:1904

数据来源: AIP