Maryam Karami - Faculty of Engineering, Kharazmi University, Tehran, Iran
Ali Noroozi - Faculty of Engineering. Kharazmi University, Tehran, Iran.

A waste heat recovery unit is a heat exchanger that transfers the high temperature waste heat of a process to another part of that usually increases efficiency. In this paper, the effect of using waste heat recovery unit for preheating of water/glycol mixture of city gate station bath heater is thermodynamically investigated. Water bath heaters are common heating systems used in city gate stations which heats high pressure gas before passing regulators. Governing equations (mass and energy conservation equations) on the heater performance is solved using EES software and the results are compared with/without using waste heat recovery unit. As a case study, a city gate station located in cold climate of Iran (Shahrekord) with nominal capacity of ۱۲۰۰۰۰ SCMH has been considered. Comparison of the results show that the energy consumption of heaters is decreased by about ۵۰% using heat recovery unit during a year which results in approximately ۸۲۲۰۰ cost saving. The heater efficiency is also increased by about ۲۰%.

Gas City gate station (CGS), Water Bath Heater, Heat recovery, Cold Climate