Showing papers in "Cryogenics in 2014"

TL;DR: In this paper, the status of magnetic refrigeration system for hydrogen liquefaction was reviewed and a high efficient system with >80% efficiency was developed by using the heat pipe.

TL;DR: In this paper, the authors evaluated the improvements in the grinding force and surface roughness by the application of LN2 (liquid nitrogen) as a coolant in the cryogenic grinding process.

TL;DR: In this paper, the energy optimization of the PRICO natural gas liquefaction (LNG) process was performed with the genetic algorithm (GA) and the process simulation software Aspen Plus.

TL;DR: Adiabatic demagnetization refrigerators (ADR) as mentioned in this paper are solid-state coolers that were the first to achieve cooling well into the sub-kelvin regime.

TL;DR: In this article, two different precooling cycles including propane pre-cleaning cycle and R410a pre-cooling cycle are proposed to the nitrogen expansion liquefaction process to improve the process performance.

TL;DR: In this paper, a thermal-electrical analogy is used to solve the heat transfer equations inside SCFCL sub-components, which enables one to handle with relative easy the strong and nonlinear coupling between thermal and electrical phenomena.

TL;DR: In this article, a heat exchanger model that includes axial conduction and flow maldistribution effect is developed in consideration of the micro-channel heat exchangers geometry.

TL;DR: In this article, the magnetocaloric effect is defined as the thermal response of a material to an external magnetic field, and the physics and properties of materials commonly used for magnetic refrigeration at cryogenic temperatures are discussed.

TL;DR: In this article, the authors report the research progress that has been made on developing rational MgB2 superconducting conductors toward practical applications and report the most effective dopants have been identified to be silicon carbide, carbon, and malic acid.

TL;DR: In this paper, a theoretical investigation to optimize thermoelectric cooling modules is performed using a novel one-dimensional analytic model, in which the optimum current, which maximizes the COP of a thermoccluded cooling module, is determined by the cooling capacity of the thermoelement, the hot and cold side temperatures, the thermal and electrical contact resistances and the properties of the material.

TL;DR: Several types of heat switches have been used for Adiabatic Demagnetization Refrigerators (ADRs) and some of the trade-off are detailed in this paper.

TL;DR: In this paper, an improved simulation model for the static characteristics of MOSFETs operating at cryogenic temperatures is presented, where the critical parameters of the BSIM model are extracted from 77 k to 300 k, and the temperature-dependent parameter functions are built to improve fitting precision at different low temperatures.

TL;DR: Active Magnetic Regenerative (AMR) refrigeration as discussed by the authors is a novel cooling method to expand the temperature span of a magneto-caloric effect for low temperature applications that allows a heat transfer medium (typically helium gas) to flow through it.

TL;DR: In this paper, a model based on finite volume analysis is presented for multistream plate fin heat exchangers for cryogenic applications, where the heat exchanger core is discretised in both the axial and transverse directions.

TL;DR: In this paper, a distributed parameter model was built to simulate the LNG (Liquefied Natural Gas) evaporating process in a SuperORV heat transfer tube, where the heat transfer region was divided into the single-phase liquid convection zone, the subcooled boiling zone, saturated boiling zone and liquid deficient zone along the vaporizing section, and the single phase vapor convection zones along the heating section.

TL;DR: In this article, the Soft X-ray Spectrometer (SXS) on board Astro-H is evaluated with a continuous running test to verify lifetime using the engineering model (EM) of the 4K-JT cooler.

TL;DR: In this article, the structure and morphology of superconducting Nb3Sn layers in multifilamentary Nb-Ti/Cu-Sn and Nb/Cu−Sn-Ti composite wires have been studied by transmission and scanning electron microscopy.

TL;DR: In this article, the authors analyzed the thermodynamic phenomena of the initial active pressurization process of a cryogenic propellant tank and found that the main mode of heat transfer appears from pressurant gas to the tank wall, through which the heat is then partly conducted into the uppermost liquid layers.

TL;DR: In this paper, the effect of aggregate type on the damage potential of concrete subjected to cryogenic freezing was investigated, and the impact of the microstructural evolution obtained from acoustic emission (AE) sensors were placed on the concrete cubes during freezing.

TL;DR: In this article, a coaxial Stirling-type pulse tube cryocooler was designed to meet the need of high-temperature superconductivity power-grid technologies.

TL;DR: In this paper, a non-interlayer-contact spacer MLI (NICS MLI) is proposed to exclude uncertain interlayer contact between films, which is made of polyetheretherketone.

TL;DR: In this article, a set of semi-analytic relationships were proposed to determine cooling power and magnetic work as a function of temperature span, regenerator characteristics, operating conditions, and magnetic field waveform.

TL;DR: It is demonstrated that the stiffness of the container wall can affect the location of maximum stress, with implications on the development of cryopreservation protocols, and the dependency of the various stress components on the storage temperature is discussed.

TL;DR: In this paper, the thermal conductivity and expansion measurements of the structural materials used for the production of the Rutherford cables in the temperature range from 4 k to 300 k were discussed.

TL;DR: In this article, the dimensions of the pulse tube and regenerator were optimized by using Response Surface Methodology (RSM) and Non-Sorted Genetic Algorithm II (NSGA II).

TL;DR: In this article, a thermodynamic study is carried out for natural gas liquefaction cycles applicable to offshore floating plants, as partial efforts of an ongoing governmental project in Korea, and the optimal condition for NG Claude cycle is determined with a process simulator (Aspen HYSYS), and the results are compared with fully developed C3-MR (propane pre-cooled mixed refrigerant) JT cycles and various N2 (nitrogen) Brayton cycles in terms of efficiency and compactness.

TL;DR: In this article, the authors present experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325x2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2).

TL;DR: In this article, the authors measured the emissivities of a thermal shield made from SS304L stainless steel coated with silver and showed that it can have an emissivity as low as 0.0035 at 80 K.

TL;DR: In this article, Coupling-Loss Induced Quench (CLIQ) is proposed to detect quench in a large fraction of the solenoid coils in high-voltage superconducting magnets.