Analysis of Gas-Steam Combined Cycle Based on Pressure Energy Recovery of Gas Transportation Pipelines

Abstract

As the economy developing rapidly, the quota of natural gas in Chinese energy consumption is increasing rapidly. Meanwhile, the natural gas transportation pipelines have been developing quickly and the pressure of the pipelines is also becoming higher and higher. So the pressure energy stored in the pipelines is tremendous. This paper analyzed the gas-steam combined cycle based on the recovery of pressure energy in the gas transportation pipelines. The high pressure natural gas expands in the expander to recover some work to drive the air compressor, and then the lower temperature and lower pressure natural gas from the expander goes to cool the air which is going into the compressor and the exhaust of the turbine successively. Then the lower pressure natural gas recovers the heat of the smoke which is going to exhaust to air. At last the lower pressure natural gas is heated by a certain temperature and supplied to the consumer. This paper makes a qualitative 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.