Optimized Analysis of Cold Energy Utilization for Cold Storage Project of Xingtan LNG Satellite Station

Abstract

The project of cold energy utilization for cold storage of Xingtan LNG satellite station is the first cold energy utilization demonstration project of LNG satellite station in China with (2–4) × 104 m3/day gasification rate of LNG and 10–15 tons/day supply of liquid ammonia in a temperature range of −25 to −38 °C. Its innovation lies in the point of adopting two ammonia refrigeration circulation systems to recover LNG cold energy for cold storage at the same time. Although this project had operated smoothly for more than 2 years after commissioning, there still existed some problems. Such as refrigerant frozen blocking problem and undersupply of cold energy which are caused by underperformed coordination between the two ammonia refrigeration circulation systems. According to the equipment running state and automatic control system data, this article presented optimized analyses of the whole process, including using a redesigned ammonia refrigerant flow channel and achieving dynamic balance of ammonia refrigeration to relieve the refrigerant frozen blocking phenomenon, improving production process and optimizing process parameters to ameliorate the condition of the cold supply shortage problem. Combined with the above research, many new methods were proposed which can effectively solve the above problems in the utilization of LNG cold energy so as to increase the LNG cold energy utilization ratio and enhance the safety and stability of project operation. In addition, it provides a valuable reference for design, development and construction of other analogous LNG cold energy utilization projects in China.