Experimental investigation of cold energy recovery from cryogenic liquid gasification processes

This paper investigated a frozen-free and high efficiency cold energy recovery system for cryogenic liquid gasification process. This system comprises three heat exchangers: evaporator, superheater and recuperator. In the evaporator, the cryogenic liquid is heated and vaporized by its own multiple cyclic vapor stream and then the vapor flows into the superheater, where it is further heated by a heat medium. The superheated vapor flows back to the evaporator acting as the first high temperature cyclic stream. In the recuperator, the low temperature cyclic streams from the evaporator are reheated by the heat medium. The last cyclic stream is gas product while the rest cyclic streams return back to evaporator as heating source for the incoming cryogenic liquid. Through cyclic operation by flow arrangement, heat exchanger structure and appropriate flow rate controls, the system prevents the heat medium from freezing and improves the cold energy recovery efficiency. Moreover, the system can achieve different temperature outputs of heat medium for various applications by regulating its flow rate.