Application of waste heat recovery unit for CGS heater

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 120000 SCMH has been considered. Comparison of the results show that the energy consumption of heaters is decreased by about 50% using heat recovery unit during a year which results in approximately 82200$ cost saving. The heater efficiency is also increased by about 20%.