Comparisons of Different Power Generation Processes by LNG Cold Energy

Power generation is one of the effective utilization ways of LNG cold energy. To use LNG cold energy to generate electricity, three kinds of generation processes are designed, which are the processes of single-stage direct expansion, single-stage recycling direct expansion and multi-stage recycling direct expansion. The generation rate of each process at the same initial and final states are calculated, they are separately 19.1%, 20.1% and 28.7%. The LNG cold energy of multi-stage recycling process is used more efficient, but the number of equipments and the cost of investment of it are also much more. The investment of equipments, the operation difficulties and the percentage of LNG cold energy utilization are needed to be taken into account in selecting of process program. Single-stage direct expansion process is more suitable to be used in small power generation stations; multi-stage recycling process is suitable to middle or large scales ones.