Heat recovery from export gas compression: Analyzing power cycles with detailed heat exchanger models

Abstract Offshore oil and gas production platforms release substantial amounts of heat to the sea. A major source of waste heat is the cooling unit for the compressed export gas. In this paper, the potential for power production from this heat source is analyzed. The emphasis was not only put on net power output, but also on system size, which is a key parameter for offshore operation. To find a suitable trade-off between those two values, a cycle calculation tool was programmed which uses detailed heat exchanger models to ensure a fair comparison of the different working fluids. A subcritical propane cycle, a transcritical CO2 cycle and a transcritical cycle with a mixture of propane and ethane were analyzed. It was shown that more than 10% of the export gas compression work could be recovered. The hydrocarbon mixture shows very promising results, but a more comprehensive study is required to reach an economical decision between power output and system size.

[1]  G. Angelino,et al.  Multicomponent Working Fluids For Organic Rankine Cycles (ORCs) , 1998 .

[2]  Jiangfeng Wang,et al.  Parametric optimization and comparative study of organic Rankine cycle (ORC) for low grade waste heat recovery , 2009 .

[3]  Andreas Schuster,et al.  Efficiency optimization potential in supercritical Organic Rankine Cycles , 2010 .

[4]  H. Martin.  A theoretical approach to predict the performance of chevron-type plate heat exchangers , 1996 .

[5]  N. Galanis,et al.  Analysis of a carbon dioxide transcritical power cycle using a low temperature source , 2009 .

[6]  H. Kretzschmar,et al.  The IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam , 2000 .

[7]  W. Worek,et al.  Optimum design criteria for an Organic Rankine cycle using low-temperature geothermal heat sources , 2007 .

[8]  L. Friedel.  Improved Friction Pressure Drop Correlation for Horizontal and Vertical Two-Phase Pipe Flow , 1979 .

[9]  George Papadakis,et al.  Low­grade heat conversion into power using organic Rankine cycles - A review of various applications , 2011 .

[10]  Nicolas Galanis,et al.  Parametric study and optimization of a transcritical power cycle using a low temperature source , 2010 .

[11]  S. Kim,et al.  Power-based performance comparison between carbon dioxide and R125 transcritical cycles for a low-grade heat source , 2011 .

[12]  V. Gnielinski.  New equations for heat and mass transfer in turbulent pipe and channel flow , 1976 .

[13]  M. McLinden,et al.  NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP, Version 8.0 , 2007 .

[14]  W. Wagner,et al.  A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple‐Point Temperature to 1100 K at Pressures up to 800 MPa , 1996 .

[15]  M. M. Rahman,et al.  A supercritical Rankine cycle using zeotropic mixture working fluids for the conversion of low-grade , 2011 .

[16]  D. L. Bennett,et al.  Forced convective boiling in vertical tubes for saturated pure components and binary mixtures , 1980 .

[17]  K. S. Lee,et al.  The characteristics of condensation in brazed plate heat exchangers with different chevron angles , 2003 .

[18]  G. Soave.  Equilibrium constants from a modified Redlich-Kwong equation of state , 1972 .

[19]  G. Antolín,et al.  Low temperature heat source for power generation: Exhaustive analysis of a carbon dioxide transcritical power cycle , 2011 .