Developing a Model for Predicting the Outlet Gas Temperature of Natural Gas Pressure Reduction Stations to reduce Energy loss

Natural gas stream must be preheated before pressure reduction takes place at natural gas pressure reduction station (PRS). It ensures that the natural gas stream remains above hydrateformation zone. Heaters are used to prevent this problem. There is no precise method for determining the adjustment points of heaters; and the gas is usually heated to a temperature higher than the required temperature leading to the energy loss in heaters. In the present paper, the outlet gas temperature of regulator was predicted to prevent the energy dissipation by an applied analysis through thermodynamics equations and considering the deviation of natural gas from the ideal gas state using MATLAB software. The prediction of outlet temperature and application of control mechanisms made the temperature close to the standard temperature, so that avoiding the formation of destructive hydrate phenomenon, prevented the dissipation of 7983.7 standard cubic meter of natural gas and reduced 15.29 tone greenhouse gas emissions in a year at the PRS under study. The economic analysis of the proposed system has been carried out using Payback ratio method. The payback period of implementation of this control system is only less than one year. Results of comparison between the measured output temperature and calculated temperature through the software indicated an average difference of 9%.