A combined power cycle utilizing low-temperature waste heat and LNG cold energy

This paper has proposed a combined power system, in which low-temperature waste heat can be efficiently recovered and cold energy of liquefied natural gas (LNG) can be fully utilized as well. This system consists of an ammonia–water mixture Rankine cycle and an LNG power generation cycle, and it is modelled by considering mass, energy and species balances for every component and thermodynamic analyses are conducted. The results show that the proposed combined cycle has good performance, with net electrical efficiency and exergy efficiency of 33% and 48%, respectively, for a typical operating condition. The power output is equal to 1.25 MWh per kg of ammonia–water mixture. About 0.2 MW of electrical power for operating sea water pumps can be saved. Parametric analyses are performed for the proposed combined cycle to evaluate the effects of key factors on the performance of the proposed combined cycle through simulation calculations. Results show that a maximum net electrical efficiency can be obtained as the inlet pressure of ammonia turbine increases and the peak value increases as the ammonia mass fraction increases. Exergy efficiency goes up with the increased ammonia turbine inlet pressure. With the ammonia mass fraction increases, the net electrical efficiency increases, whereas exergy efficiency decreases. For increasing LNG turbine inlet pressure or heat source temperature, there is also a peak of net electrical efficiency and exergy efficiency. With the increase of LNG gas turbine outlet pressure, exergy efficiency increases while net electrical efficiency drops.

[1]  Yiping Dai,et al.  Exergy analysis, parametric analysis and optimization for a novel combined power and ejector refrigeration cycle , 2009 .

[2]  Gao Lin.  A NOVEL BINARY CYCLE WITH INTEGRATION OF LOW-LEVEL WASTE HEAT RECOVERY & LNG COLD ENERGY UTILIZATION , 2002 .

[3]  L. Tagliafico,et al.  On the recovery of LNG physical exergy by means of a simple cycle or a complex system , 2002 .

[4]  Noam Lior,et al.  A Novel Ammonia-Water Cycle for Power and Refrigeration Cogeneration , 2004 .

[5]  Beno Sternlicht,et al.  Waste energy recovery: An excellent investment opportunity , 1982 .

[6]  B. Reddy,et al.  Second law analysis of a waste heat recovery based power generation system , 2007 .

[7]  Y Yamasaki,et al.  Proposal for a high efficiency LNG power-generation system utilizing waste heat from the combined cycle , 1998 .

[8]  D. Y. Goswami,et al.  A combined power and cooling cycle modified to improve resource utilization efficiency using a distillation stage , 2006 .

[9]  Yiping Dai,et al.  Parametric analysis for a new combined power and ejector–absorption refrigeration cycle , 2009 .

[10]  D. Y. Goswami,et al.  On Evaluating Efficiency of a Combined Power and Cooling Cycle , 2003 .

[11]  P. N. Suganthan,et al.  Differential Evolution Algorithm With Strategy Adaptation for Global Numerical Optimization , 2009, IEEE Transactions on Evolutionary Computation.

[12]  D. Y. Goswami,et al.  Effectiveness of cooling production with a combined power and cooling thermodynamic cycle , 2006 .

[13]  D. Y. Goswami,et al.  Optimum operating conditions for a combined power and cooling thermodynamic cycle , 2007 .

[14]  Chi-Chuan Wang,et al.  Effect of working fluids on organic Rankine cycle for waste heat recovery , 2004 .

[15]  Yiping Dai,et al.  Parametric analysis and optimization for a combined power and refrigeration cycle , 2008 .

[16]  Noam Lior,et al.  Energy, exergy, and Second Law performance criteria , 2007 .

[17]  A. I. Kalina,et al.  Combined-Cycle System With Novel Bottoming Cycle , 1984 .

[18]  Na Zhang,et al.  Proposal and analysis of a novel ammonia–water cycle for power and refrigeration cogeneration , 2007 .

[19]  Hongtan Liu,et al.  Characteristics and applications of the cold heat exergy of liquefied natural gas , 1999 .

[20]  Noam Lior,et al.  Methodology for thermal design of novel combined refrigeration/power binary fluid systems , 2007 .

[21]  B. Babu,et al.  Differential evolution for multi-objective optimization , 2003, The 2003 Congress on Evolutionary Computation, 2003. CEC '03..

[22]  Gunnar Tamm,et al.  Novel Combined Power and Cooling Thermodynamic Cycle for Low Temperature Heat Sources, Part I: Theoretical Investigation , 2002 .

[23]  Charles H. Marston,et al.  Parametric Analysis of the Kalina Cycle , 1989 .

[24]  Xiaojun Shi,et al.  Thermodynamic analysis of an LNG fuelled combined cycle power plant with waste heat recovery and utilization system , 2007 .

[25]  Mehmet Fatih Tasgetiren,et al.  Differential evolution algorithm with ensemble of parameters and mutation strategies , 2011, Appl. Soft Comput..

[26]  A. Hasan,et al.  First and second law analysis of a new power and refrigeration thermodynamic cycle using a solar heat source , 2002 .

[27]  Yong Tae Kang,et al.  A combined power cycle using refuse incineration and LNG cold energy , 2000 .

[28]  S. K. Wang,et al.  A Review of Organic Rankine Cycles (ORCs) for the Recovery of Low-grade Waste Heat , 1997 .

[29]  D. Yogi Goswami,et al.  Analysis of a New Thermodynamic Cycle for Combined Power and Cooling Using Low and Mid Temperature Solar Collectors , 1999 .

[30]  T. Hung.  Waste heat recovery of organic Rankine cycle using dry fluids , 2001 .

[31]  Rainer Storn,et al.  Differential Evolution – A Simple and Efficient Heuristic for global Optimization over Continuous Spaces , 1997, J. Glob. Optim..

[32]  A. Belegundu,et al.  Optimization Concepts and Applications in Engineering , 2011 .

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

[34]  Shaoguang Lu,et al.  Optimization of a novel combined power/refrigeration thermodynamic cycle , 2002 .

[35]  Gunnar Tamm,et al.  Theoretical and experimental investigation of an ammonia–water power and refrigeration thermodynamic cycle , 2004 .

[36]  Wang Qiang,et al.  Analysis of power cycle based on cold energy of liquefied natural gas and low-grade heat source , 2004 .

[37]  P. Nag,et al.  Exergy analysis of the Kalina cycle , 1998 .

[38]  Zhen Lu,et al.  Performance analysis and optimization of organic Rankine cycle (ORC) for waste heat recovery , 2007 .

[39]  Hongguang Jin,et al.  Thermodynamic analysis of a novel absorption power/cooling combined-cycle , 2006 .