Liquid Hydrogen Technology Present State and Future Fuel Application

Peschka, W.

doi:10.1007/978-94-015-9054-9_69

Cited by 3 publications

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previously, it was shown that a metamagnetic transition in an AFM compound can lead to a large positive MCE [17,18]. The magnetic transition temperature of about 27 K makes it possible to use YbCoC 2 , for example, to liquefy hydrogen, which is now actively used for various engines [19,20].…”

Section: Introductionmentioning

confidence: 99%

Some Magnetic Properties and Magnetocaloric Effects in the High-Temperature Antiferromagnet YbCoC2

et al. 2023

View full text Add to dashboard Cite

The YbCoC2 compound, which crystallizes in a base-centered orthorhombic unit cell in the Amm2 space group CeNiC2 structure, is unique among Yb-based compounds due to the highest magnetic ordering temperature of TN=27 K. Magnetization measurements have made it possible to plot the H-T magnetic phase diagram and determine the magnetocaloric effect of this recently discovered high-temperature heavy-fermion compound, YbCoC2. YbCoC2 undergoes spin transformation to the spin-polarized state through a metamagnetic transition in an external magnetic field. The transition is found to be of the first order. The dependencies of magnetic entropy change ΔSm(T)—have segments with positive and negative magnetocaloric effects for ΔH≤6 T. For ΔH=9 T, the magnetocaloric effect becomes positive, with a maximum ΔSm(T) value of 4.1 J (kg K)−1 at TN and a refrigerant capacity value of 56.6 J kg−1.

show abstract

Section: Introductionmentioning

confidence: 99%

Some Magnetic Properties and Magnetocaloric Effects in the High-Temperature Antiferromagnet YbCoC2

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Liquid hydrogen is an important solution for convenient utilization and low cost of hydrogen energy, processing high safety and reduced transportation expense, especially for long-distance transportation (Yang and Ogden, 2007). Liquid hydrogen also acts as oxy-hydrogen engine propellant and high-energy fuel, which has an increasing demand in the aerospace and military industry (Peschka, 1998). The core refrigeration machinery in the large-scale hydrogen liquefaction process is the cryogenic turboexpander (Yan et al , 2021).…”

Section: Introductionmentioning

confidence: 99%

Clearance compatibility and design principle of the single-structured hybrid gas-magnetic bearing

Liu,

Wang,

Feng

2023

ILT

View full text Add to dashboard Cite

Purpose This paper aims to study the clearance compatibility of active magnetic bearing (AMB) and gas bearing (GB) to achieve a single-structured hybrid gas-magnetic bearing (HGMB), which uses a single bearing structure to realize both the functions of gas bearing and magnetic bearing. Design/methodology/approach Because the radial clearance size of the AMB is typically ten times larger than that of the GB, radial clearance compatibility of GB and AMB needs to maximize the radial clearance of GB by adjusting structural parameters. Parametric analysis of structural parameters of GB is explored. Furthermore, a general structural design principle based on static analysis, rotordynamic performance and system stability is established for the single-structured HGMB. Findings Load capacity is vastly reduced due to the enlarged radial clearance of the GB. A minimum clearance needs to be ensured by increasing the bearing diameter or width to compensate for the reduced load capacity, yet indirectly raising the bearing load. Increased bearing load is conducive to stability, yet it raises the risk of rotor abrasion. In addition, excessively large bearing diameter leads to system instability, and inappropriate bearing width affects critical speeds. A general structural design principle is established and the designed HGMB–rotor processes optimal performances. Originality/value A single-structured HGMB is proposed to address the urgent demand for high-speed, cryogenic turboexpanders with frequent starts/stops. This design applies a single-bearing structure to realize the characteristics of both GB and AMB, greatly simplifying the implementation, reducing air friction loss and raising critical speeds. This paper provides a fresh perspective on the development of cryogenic turboexpanders for hydrogen liquefaction. It theoretically validates the feasibility and provides a design guide for a single-structured HGMB system.

show abstract