Efficiency Criteria and Comparative Analysis of Combined Energy Plants Utilizing LNG Cold Energy

A decent grow in cold energy use is detected during recent years. Authors suggest different schemes and energy plants using the LNG cold energy, which raise a question of the correct comparison of their efficiency. Traditional ways of thermodynamic analysis allow to estimate a degree of every plant thermodynamic perfection but do not answer the main question – which plant utilize a LNG cold energy in a most effective way. This article deals with a universal criterion of reduced specific work which is based on the concept of nominal separation of generated useful work on parts which are related to heat sources of different temperature level. An analysis of four different schemes realizing different ways of LNG cold energy utilization is presented.