Cost-based design optimization of the heat exchangers in a parabolic trough power plant Articles uri icon

published in

publication date

  • March 2017

start page

  • 314

end page

  • 325

volume

  • 123

international standard serial number (ISSN)

  • 0360-5442

electronic international standard serial number (EISSN)

  • 1873-6785

abstract

  • This paper addresses two important concerns of the design of steam generators of parabolic trough power plants: cost minimization and component reliability. A thorough economic analysis of the heat exchangers of the steam generator and oil-to-salt heat exchangers of a 50 MWe parabolic trough power plant is presented. The heat exchanger design is realized following TEMA standards and optimized using a genetic algorithm. Two design strategies are compared: the minimization of the total heat transfer area and the minimization of the total annualized cost. It is seen that the second approach provides substantial savings over the lifetime of the plant. The economic analysis reveals a global optimum with an outlet temperature of the heat transfer fluid of 293 degrees C and an evaporator pinch point of 4.85 degrees C. The best design of the steam generator consists of a TEMA-H shell superheater and preheater and a TEMA-F shell reheater. The best design of the oil-to-salt heat exchangers includes six TEMA-F shell heat exchangers in series, with a log mean temperature difference of 7 degrees C and the molten salt on the shell-side. Lastly, a TEMA-X recirculation evaporator is proposed with a considerably reduced wall thickness when compared to a kettle evaporator. (C) 2017 Elsevier Ltd. All rights reserved.

keywords

  • solar thermal power plant; parabolic trough; thermal energy storage; steam generator; heat exchanger design; design optimization; thermal-energy storage; solar power