An experimental investigation on using heat pipe heat exchanger to improve energy performance in gas city gate station

Abstract

Natural gas pressure drops in city gate stations, in the natural gas distribution network, and bypassing through throttle valves. On the other hand, sudden gas pressure drop causes extreme temperature drop. To prevent natural gas from being hydrated in city gate stations, a water bath heater is used, leading to heating natural gas before the pressure reduction stage.The main consequence of this research is the consideration of the challenge of low thermal efficiency in water bath heaters and the high potential of flue gases, which leads to the preheating of the gas by heat loss recovery and consequently improving the energy performance of the whole system.In this study, a heat pipe heat exchanger was laboratory designed and constructed by using the ε-NTU method. The heat exchanger performs to recover partly the waste energy of flue gas emitted to the environment through heat pipes. This has been investigated in several experiments, based on conducted studies, measured data from a city gate station during a year, and also corresponding the experimental results with real conditions. In addition, to determine energy saving in fuel consumption, the city gate stations process was simulated in HYSYS software and evaluated according to gas temperature in new conditions.As major findings applying heat pipes reduces natural gas consumption by 510,132 SCM a year; it also annually prevents 756 tons of CO2 from being emitted off a city gate station.