Thermodynamic assessment and proposal of new configurations of an indirect water bath heater for a City Gate Station (a case study)

Document Type : Research Paper


Department of Mechanical Engineering, Faculty of Energy Engineering, Kermanshah University of Technology, Kermanshah, Iran



This paper deals with thermodynamic modeling and proposal new configurations of an indirect water bath heater used in a city gate station (CGS) to preheat the natural gas (NG). In the transmission pipeline of natural gas before reducing NG pressure, it is necessary preheating to prevent hydrate formation. In the traditional systems, an indirect water bath heater is used for this purpose. Thermodynamic modeling of the proposed systems has been done in EES software, and an effective analysis based on proposed new configurations is conducted. The results indicate that using exhaust combustion products to preheat the combustion air can increase the thermal efficiency of the system from 46.36% (for base case) to 73.84%. In addition, with the use of an ORC to utilize the exhaust waste thermal energy, the system efficiency of 55.27% with an electrical output of 79 kW can be achieved. A comparison between configurations indicates that the second configuration (preheating combustion air) with 78.97 kg/h has the lowest emission rate.


[1] Arabkoohsar, A., L. Machado, and R. Koury, Operation analysis of a photovoltaic plant integrated with a compressed air energy storage system and a city gate station. Energy, 2016. 98: 78-91.
[2] Farzaneh-Gord, M., S., Hashemi, and M. Sadi, Energy destruction in Iran's natural gas pipe line network. Energy Exploration & Exploitation, 2007. 25: 393-406.
[3] Sanaye, S. and A. Mohammadi Nasab, Modeling and optimizing a CHP system for natural gas pressure reduction plant. Energy, 2012. 40: 358-369.
[4] Neseli, M.A., O. Ozgener, L. Ozgener, Energy and exergy analysis of electricity generation from natural gas pressure reducing stations. Energy Conversion and Management, 2015. 93: 109-120.
[5] Arabkoohsar, A., M. Farzaneh-Gord, M. Deymi-Dashtebayaz, L. Machado, R.N.N. Koury, A new design for natural gas pressure reduction points by employing a turbo expander and a solar heating set, Renewable Energy, 2015. 81: 239-250.
[6] Tan, H., Q. Zhao, N. Sun, and Y. Li, Proposal and design of a natural gas liquefaction process recovering the energy obtained from the pressure reducing stations of high-pressure pipelines. Cryogenics, 2016. 80: 82-90.
[7] Farzaneh-Gord, M., A. Arabkoohsar, M. Rezaei, M.D. Dasht-bayaz, and H.R. Rahbari, Feasibility of employing solar energy in natural gas pressure drop stations. Journal of the Energy Institute, 2011. 84: 165-173.
[8] Ashouri, E., et al., The minimum gas temperature at the inlet of regulators in natural gas pressure reduction stations (CGS) for energy saving in water bath heaters. Journal of Natural Gas Science and Engineering, 2014. 21: 230-240.
[9] Zabihi, A. and M. Taghizadeh, New energy-saving temperature controller for heater at natural gas gate station. Journal of Natural Gas Science and Engineering, 2015. 27: 1043-1049.
[10] Ghezelbash, R., M. Farzaneh-Gord, and M. Sadi, Performance assessment of vortex tube and vertical ground heat exchanger in reducing fuel consumption of conventional pressure drop stations. Applied Thermal Engineering, 2016. 102: 213-226.
[11] Farzaneh-Gord, M., R. Ghezelbash, M. Sadi, and A. Jabari Moghadam, Integration of vertical ground-coupled heat pump into a conventional natural gas pressure drop station: Energy, economic and CO2 emission assessment. Energy, 2016. 112: 998-1014.
[12] Khalili, E., S.M. Hosseinalipour, and E. Hybatian. Efficiency and heat losses of indirect water bath heater installed in natural gas pressure reduction station; evaluating a case study in Iran. In 8th International Energy Conference. 2011. Tehran.
[13] Incropera, F. P. and D. P. De Witt, Fundamentals of heat and mass transfer, 1985.
[14] Khanmohammadi, S., P. Heidarnejad, N. Javani and H. Ganjehsarabi, Exergoeconomic analysis and multi objective optimization of a solar based integrated energy system for hydrogen production." International Journal of Hydrogen Energy, 2017, in press.
[15] Farzaneh-Kord, V., A. Khoshnevis, A. Arabkoohsar, M. Deymi-Dashtebayaz, M. Aghili, M. Khatib, M. Kargaran and M. Farzaneh-Gord, Defining a technical criterion for economic justification of employing CHP technology in city gate stations. Energy 2016. 111: 389-401.
[16] Khanmohammadi, S., P. Ahmadi, K. Atashkari and R. K. Kamali (2015). Design and Optimization of an Integrated System to Recover Energy from a Gas Pressure Reduction Station. Progress in Clean Energy 2015. 1: 89-107.
[17] Iran meteorological organization website:
[18] Iranian ministry of petroleum, website:
[19] Bao, J. and L. Zhao, A review of working fluid and expander selections for organic Rankine cycle. Renewable and Sustainable Energy Reviews 2013. 24: 325-342.
[20] Tchanche, B. F., G. Papadakis, G. Lambrinos and A. Frangoudakis, Fluid selection for a low-temperature solar organic Rankine cycle. Applied Thermal Engineering 2009. 29: 2468-2476.
[21] Sprouse, C., and C. Depcik, Review of organic Rankine cycles for internal combustion engine exhaust waste heat recovery. Applied thermal engineering 2013. 51: 711-722.
[22] Khanmohammadi, S., Saadat-Targhi M., Thermodynamic modeling and analysis of a novel heat recovery system in a natural gas city gate station, Journal of Cleaner Production , 2019, 224: 346-360
[23] M Saadat-Targhi, S Khanmohammadi, Energy and exergy analysis and multi-criteria optimization of an integrated city gate station with organic Rankine flash cycle and thermoelectric generator, Applied Thermal Engineering, 2019, 149, 312-324.