Since January, 1970, LNG (Liquefied Natural Gas) has been used in Minami Yokohama Power Station of the Tokyo Electric Power Co. as the fuel of steam power generation. It is the first trial in the world that electric power is generated by use of LNG. This essay deals with technical features in using LNG for power generation, as well as those of marine transportation and regasification of LNG.
In order to facilitate the design of heat exchangers used at cryogenic temperature, a numerical method was tried to heat exchangers of a 4°K helium refrigerator. Experiment of the helium refrigerator showed that this calculation satisfied prediction of heat transfer area above 10°K. For J-T heat exchanger below 10°K, this calculation was helpful for approaching near to the suitable value, although some correction of heat transfer area was necessary. With reference to literatures of Collins, Starr, Nagano and others, several numerical methods are also reviewed and compared with the method of this report.
Leak rate of helium was measumed in labyrinthine clearance 11 or 13μ of an Collinstype expansion engine in 36mm diameter, under the pressure difference of 20kg/cm2. Temperature coefficient of leak rate by theoretical calculation was in good coincidence with the observed value. Therefore the affect of the leak rate to refrigeration capacity of engine can be evaluated at 20-280°K. A comment on Doll's report is also presented. Leak rate of helium at a valve sheet made of leather or TEFLON was measured at 30-280°K under the pressure difference of 15kg/cm2 and a theoretical equation was derived.
The effect of the addition of Si to Nb-60at.%Ti alloy on the critical current density in the transverse magnetic field was investigated. The critical current density of Nb-60at.%Ti alloy aged at temperatures ranging from 350 to 550°C increases markedly with the addition of 0.5-2at.%Si. The α-precipitates as pinning points of flux lines become finer and dispersed more uniformly with the addition of Si, thus leading to the increase in the critical current density. By means of the aging at 500°C for 3hr after the cold-drawing of 98.4% reduction, the critical current density of Nb-58at.%Ti-2at.%Si alloy reached the maximum value of 6.0×104A/cm2 at