چكيده به لاتين
The pressure of gas extracted from gas wells and inside transmission pipelines is high so it should be reduced to distribution system. The pressure reduction is generally accomplished by throttle valves near cities. Recently, for recovering the wasted energy by throttle valves, turbo expanders are used to produce electricity. However, as the pressure reduces, the natural gas temperature drops down significantly which results in hydrate forming in the NG stream. For this reason, the NG stream should be preheated before the pressure reduction in the CGS to prevent gas hydrate forming. In this research, the required energy for preheating is provided by line heater and solar energy with and without thermal energy storage. Parabolic trough collector is used to collect solar arrays. Solar irradiation for Mashhadd city is calculated by using clearness index. In order to determine the optical and thermal performance of the parabolic trough solar collector, a computer program based on one dimensional implicit finite difference method with energy balance approach has been developed. In this research, the cost saving and reduction of CO2 pollutant is calculated for pressure reduction station with two different configuration of with and without storage tank. The results revealed that by utilizing the solar collector, the fuel consumption and pollutant emitted by preheater is reduced by 45% without storage and 90% with storage.
Keywords: pressure reduction station, turbo expander, solar irradiation, parabolic trough collector, storage tank.
