Multi-objective optimization of a bottoming Organic Rankine Cycle (ORC) of gasoline engine using swash-plate expander

Abstract

This paper presents a mathematical model of a bottoming Organic Rankine Cycle coupled to a 2l turbocharged gasoline engine to optimize the cycle from a thermoeconomic and sizing point of view. These criteria were optimized with different cycle values. Therefore, a methodology to optimize the ORC coupled to Waste Heat Recovery systems in vehicle applications is presented using a multiobjective optimization algorithm. Multi-objective optimization results show that the optimum solution depend on the importance of each objective to the final solution. Considering thermo-economic criteria as the main objective, greater sizes will be required. Considering sizing criteria as the main objective, higher thermoeconomic parameters will be obtained. Therefore, in order to select a singlesolution from the Pareto frontier, a multiple attribute decision-making method (TOPSIS) was implemented in order to take into account the preferences of the Decision Maker. Considering the weight factors 0.5 for Specific Investment Cost (SIC), 0.3 for the area of the heat exchangers (Atot) and 0.2 for Volume Coefficient (VC) and the boundaries of this particular application, the result is optimized with

Energy, Exergy and Economic Evaluation Comparison of Small-Scale Single and Dual Pressure Organic Rankine Cycles Integrated with Low-Grade Heat Sources

“…As the heat source delivers energy at a higher temperature, SIC becomes as low as 1600 USD/kW. This result is promising as compared with a study of Galindo et al [47], who carried out a multi-objective optimization of an ORC as a bottoming cycle of a gasoline engine using swash-plate expander to reduce SIC. The heat source considered was the exhaust gases of the engine (678°C at a mass flow rate of 48 g/s) and the working fluid was ethanol.…”

Optimum composition ratios of multicomponent mixtures of organic Rankine cycle for engine waste heat recovery

“…To effectively recover the waste heat of a marine engine, Song et al 12 proposed an optimized system utilizing the jacket cooling water for preheating and the engine exhaust as the heat source for evaporation. Galindo et al 15 presented a methodology to optimize the ORC coupled to a turbocharged gasoline engine using a multiobjective optimization algorithm. Employing genetic algorithm to retrieve exhaust waste heat from a diesel engine, Yang et al 14 presented the parametric optimization and performance analysis of an organic Rankine cycle.…”

“…At maximum rated power of engine, the ORC system achieved the maximum net power output per unit heat transfer area of 0.74 kW/m 2 , and the ratio of maximum effective heat transfer area to actual area of the evaporator was 69.19%. Galindo et al 15 presented a methodology to optimize the ORC coupled to a turbocharged gasoline engine using a multiobjective optimization algorithm. Considering sizing of the expander as the main objective, higher specific investment cost and heat exchanger areas were obtained.…”

Energy Analysis of Cascade Heating with High Back-Pressure Large-Scale Steam Turbine

“…On the other hand, the exhaust steam from the low pressure cylinder of turbine condenses into water by releasing large amount latent heat, which results in great cold source loss [12]. Therefore, making full use of the steam turbine's exhaust heat and reducing the throttling loss from the extracting steam is the key to further improving the efficiency of the CHP unit.Several improvements have been made to the traditional steam extraction heating method, including that of the steam turbine using dual-axis rotors and can be operated under all condensation, extraction, and back pressure conditions [13,14]. When the heat load during the heating period is high, the low pressure cylinder is removed, and the steam turbine operates on the high back pressure, which can increase the heating capacity by using all of the exhaust heat.…”

“…Several improvements have been made to the traditional steam extraction heating method, including that of the steam turbine using dual-axis rotors and can be operated under all condensation, extraction, and back pressure conditions [13,14]. When the heat load during the heating period is high, the low pressure cylinder is removed, and the steam turbine operates on the high back pressure, which can increase the heating capacity by using all of the exhaust heat.…”