Analysis of a Combined Cycle Recovering Pressure Energy of Natural Gas

With the development of economy and the pressure of environment pollution, natural gas industry have been developing as fast as well in recent years in China. Because of the unbalance distribution of natural gas resources in China, transportation pipelines have been developing quickly. There is huge pressure energy stored in the pipeline networks. A gas-steam combined cycle recovering pressure energy of transportation pipelines is presented. The high pressure natural gas expands in the expander and drive the air compressor. Then the natural gas out of the expander of lower temperature and pressure goes to cool the air going into the compressor and the exhaust gas of the boiler successively. Then the lower pressure natural gas recovers the heat of the smoke which is exhausting to atmosphere. At last the lower pressure natural gas is heated by a certain temperature and supplied to the consumer. This paper makes a analysis of the benefits brought by the new flow to the combined cycle. Generally speaking, the new cycle will increase the efficiency of the combined cycle and the utilization rate of energy.