Alternative Methods for Conventional City Gate Station

In this paper the preheating system of the conventional city gate station, CGS, and four alternatives have been studied. These alternatives are based on the turbo-expander, vortex tube and cooled weather technologies, CWT, heaters. The conventional CGS as well as these alternatives have been simulated based on the actual operational conditions of the CGS of five cities of tropical regions of Fars province. Based on the results, using the turbo-expander require more heat duty than that the conventional method. The vortex tube as the third alternative needs minimum required heat duty between proposed alternatives. High efficiency of CWT heater, as the fourth alternative reduces the heat duty of this method considerably. Using turbo-expander increases capital and operating cost compared with the conventional and other methods. Difference between the 1st and 2nd alternatives is related to the type of pre-heater heat exchanger used in turboexpander method.