Development and Engineering Design of Technology for Utilization of Liquefied Natural Gas (LNG) Cold Energy in Ice-making

摘要

A process of using LNG cold energy for ice-making was proposed, the process consisted of three parts: LNG vaporization system, the refrigerant circulation system and ice-making system. And LNG cold energy was delivered to ice-maker by refrigerant. Through design and optimization, the optimum temperature was confirmed in the ice-making process, the benefit of power saving was calculated, and the efficiency of energy utilization was analyzed by exergy analysis method. The research results showed that the average ice quantity was 1.59t/h with vaporization amount of 1000kg/h LNG. Taking ethylene glycol aqueous solution as refrigerant, when its temperature changed from -15°C to -6°C, the energy efficiency was higher with 18°C temperature difference. And the benefit of electricity saving was 112 kW and the efficiency of cold exergy was 5.52%. The process can be designed into skid-mounted, which can flexibly operate between different LNG vaporization stations.