Discuss on refrigeration methods of gas liquefying facilities

Some mature refrigeration methods (such as the cascade refrigeration cycle. the mixture refrigeration cycle, the expansion refrigeration cycle etc.) used in gas liquefying facilities and the latest development of study in the field at home and abroad are reviewed, The methods are analyzed and compared. Based on the results, a new refrigeration method of gas liquefying facilities (the absorption refrigeration cycle) is introduced. The method utilizes the variation of the solution concentration to obtain refrigeration, i. e. the cryogen absorbs heat by vaporization under a certain pressure and the absorber is utilized to absorb the vapor from the cryogen. The cycle system is adaptable not only for offshore gas liquefying facilities but also for the areas where there are rich solar energy and geothermal energy. It not only decreases the cost of products but also realizes the utilization of wastages. Aiming at the vapor producing in the transportation and storage process of LNG, some auxiliary refrigeration methods are introduced for the transportation and storage facilities of LNG. They are G-M refrigerating machine, Stirling refrigerating machine, refrigerating by phase change, and pulse refrigerating machine.