Research On Performance Of Power-cooling Co-generation System Based On Non-azeotropic Mixed Working Fluid For Internal Combustion Engine Waste Heat Utilization

There is a large amount of waste heat resource waste in the exhaust gas of internal combustion engine and cylinder liner cooling water.If suitable technology can efficiently convert and utilize the waste heat resources,enormous economic and ecological benefits will be produced.To improve the utilization level of the exhaust heat of the internal combustion engine and the waste heat of cylinder liner cooling water,this paper uses the exhaust heat of the internal combustion engine and the waste heat of cylinder liner water as the driving heat source.Based on the Rankine cycle(ORC)and the ejector refrigeration cycle(ERC),a new type is constructed.The dual heat source power and cooling cogeneration system adopt non-azeotropic mixed working fluid as the circulating working fluid.Based on MATLAB R2020 b and REFPROP 9.0 to model the proposed dual heat source power and cooling cogeneration system,including the establishment of thermodynamic model and economic model,then 9 key parameters were selected for analysis through sensitivity analysis,and the genetic algorithm was used to loop optimization of working fluid and optimization of system performance.The non-azeotropic mixed working medium R245fa/R1234 yf is selected as the circulating working medium of the system.Under the primary working conditions,the generation temperature of the ORC steam generator,the steam generator's generation temperature with low boiling point components,the high-temperature heat source,the inlet temperature of the internal combustion's exhaust gas engine are investigated.Low-temperature heat source-cylinder jacket cooling water inlet temperature,low boiling point component steam generator outlet dryness,low boiling point component steam generator inlet high boiling point working fluid component concentration,refrigeration evaporation temperature,condenser condensation temperature,and refrigeration evaporator The impact of critical parameters such as condensation temperature on system performance.Multi-objective genetic algorithm optimization toolbox based on MATLAB optimizes the efficiency of the system and the total cost of the unit product as the objective function and obtains the thermodynamic energy and economic performance of the system under the optimized conditions: R245fa/R1234 yf is used as the circulating working medium,the system Obtaining a net output power of 27.35 k W and a cooling capacity of 1.49 k W,the system thermal efficiency,exergy efficiency,and total unit product cost are 14.07%,21.94% and 94.75 $/MWh,respectively.Compared with the basic operating conditions,the net output power of the optimized operating conditions has increased by 11.47 k W,the thermal efficiency and exergy efficiency of the system have increased by 2.47% and 7.53 %,respectively,and the total unit product cost has been reduced by 23.32 $/MWh.When the low boiling point component steam generator inlet high boiling point working fluid component concentration is 0.1-0.5,the optimized conditions of R245fa/R1234 yf,R245fa/R1234 ze,R245fa/R134 a,R600/R1234 yf,R600/R1234 ze,and R600/R134 a of the thermodynamic and economic performance.The results show that when R600/R1234 ze is a circulating working fluid,the system exhibits better thermodynamic and economic performance.The maximum net output power and cooling capacity obtained are 28.51 k W and 1.52 k W,respectively,and the thermal efficiency and exergy efficiency of the system are 17.69 % and 33.31 %,respectively.The total cost per unit product consumed is 89.59 $/MWh.