The so-called organic Rankine cycle(ORC)is an effective technology allowing heat recovery from lower temperature sources.In the present study,to improve its thermal efficiency,a preheated ejector using exhaust steam c...The so-called organic Rankine cycle(ORC)is an effective technology allowing heat recovery from lower temperature sources.In the present study,to improve its thermal efficiency,a preheated ejector using exhaust steam coming from the expander is integrated in the cycle(EPORC).Considering net power output,pump power,and thermal efficiency,the proposed system is compared with the basic ORC.The influence of the ejector ratio(ER)of the preheated ejector on the system performances is also investigated.Results show that the net power output of the EPORC is higher than that of the basic ORC due to the decreasing pump power.Under given working conditions,the average thermal efficiency of EPORC is 29%higher than that of ORC.The ER has a great impact on the performance of EPORC by adjusting the working fluid fed to the pump,leading to significant variations of the pump work Moreover,the ER has a remarkable effect on the working fluid temperature lift(TL)at the evaporator inlet,thus reducing the evaporator heat load.According to the results,the thermal efficiency of EPORC increases by 30%,when the ER increases from 0.05 to 0.4.展开更多
In this paper,the operation perfonnance of three novel kinds of cogeneration systems under design and off-design condition was investigated.The systems are MGT(micro gas turbine)+ORC(organic Rankine cycle)for electric...In this paper,the operation perfonnance of three novel kinds of cogeneration systems under design and off-design condition was investigated.The systems are MGT(micro gas turbine)+ORC(organic Rankine cycle)for electricity demand,MGT+ERC(ejector refrigeration cycle)for electricity and cooling demand,and MGT+ORC+ERC for electricity and cooling demand.The effect of 5 different working fluids on cogeneration systems was studied.The results show that under the design condition,when using R600 in the bottoming cycle,the MGT+ORC system has the lowest total output of 117.1 kW with a thermal efficiency of 0.334,and the MGT+ERC system has the largest total output of 142.6 kW with a thermal efficiency of 0.408.For the MGT+ORC+ERC system,the total output is between the other two systems,which is 129.3 kW with a thermal efficiency of 0.370.For the effect of different working fluids,R123 is the most suitable working fluid for MGT+ORC with the maximum electricity output power and R600 is the most suitable working fluid for MGT+ERC with the maximum cooling capacity,while both R600 and R123 can make MGT+ORC+ERC achieve a good comprehensive performance of refrigeration and electricity.The thermal efficiency of three cogeneration systems can be effectively improved under oredesign condition because the bottoming cycle can compensate for the power decrease of MGT.The results obtained in this paper can provide a reference for the design and operation of the cogeneration system for distributed energy systems(DES).展开更多
为回收利用丙烯腈生产投料段液态原料的冷能及吸收塔尾气焚烧炉排放的低温烟气余热,设计了一种喷射式制冷循环与低温有机朗肯循环复合的低品位能量回收系统。结合某年产200 kt丙烯腈项目,利用Matlab建模对所设计的系统进行仿真。试验结...为回收利用丙烯腈生产投料段液态原料的冷能及吸收塔尾气焚烧炉排放的低温烟气余热,设计了一种喷射式制冷循环与低温有机朗肯循环复合的低品位能量回收系统。结合某年产200 kt丙烯腈项目,利用Matlab建模对所设计的系统进行仿真。试验结果表明,在满足工艺冷量需求的前提下,喷射式制冷机组较原工艺中的螺杆制冷机组可节电110.65 k W;由于利用了液态原料蒸发过程的冷能,该系统中有机朗肯循环在较低的冷凝温度下运行,较常规有机朗肯循环系统热效率提高52.4%;该系统的热效率和?效率分别为19.1%和49.8%;提高热源发生压力和循环工质过热度及降低循环工质冷凝温度,均有利于提高系统的性能。展开更多
基金This work was supported by the National Risk Assessment Laboratory of Agroproducts Processing Quality and Safety,Ministry of Agriculture and Rural Affairs(S2020KFKT-06).
文摘The so-called organic Rankine cycle(ORC)is an effective technology allowing heat recovery from lower temperature sources.In the present study,to improve its thermal efficiency,a preheated ejector using exhaust steam coming from the expander is integrated in the cycle(EPORC).Considering net power output,pump power,and thermal efficiency,the proposed system is compared with the basic ORC.The influence of the ejector ratio(ER)of the preheated ejector on the system performances is also investigated.Results show that the net power output of the EPORC is higher than that of the basic ORC due to the decreasing pump power.Under given working conditions,the average thermal efficiency of EPORC is 29%higher than that of ORC.The ER has a great impact on the performance of EPORC by adjusting the working fluid fed to the pump,leading to significant variations of the pump work Moreover,the ER has a remarkable effect on the working fluid temperature lift(TL)at the evaporator inlet,thus reducing the evaporator heat load.According to the results,the thermal efficiency of EPORC increases by 30%,when the ER increases from 0.05 to 0.4.
文摘In this paper,the operation perfonnance of three novel kinds of cogeneration systems under design and off-design condition was investigated.The systems are MGT(micro gas turbine)+ORC(organic Rankine cycle)for electricity demand,MGT+ERC(ejector refrigeration cycle)for electricity and cooling demand,and MGT+ORC+ERC for electricity and cooling demand.The effect of 5 different working fluids on cogeneration systems was studied.The results show that under the design condition,when using R600 in the bottoming cycle,the MGT+ORC system has the lowest total output of 117.1 kW with a thermal efficiency of 0.334,and the MGT+ERC system has the largest total output of 142.6 kW with a thermal efficiency of 0.408.For the MGT+ORC+ERC system,the total output is between the other two systems,which is 129.3 kW with a thermal efficiency of 0.370.For the effect of different working fluids,R123 is the most suitable working fluid for MGT+ORC with the maximum electricity output power and R600 is the most suitable working fluid for MGT+ERC with the maximum cooling capacity,while both R600 and R123 can make MGT+ORC+ERC achieve a good comprehensive performance of refrigeration and electricity.The thermal efficiency of three cogeneration systems can be effectively improved under oredesign condition because the bottoming cycle can compensate for the power decrease of MGT.The results obtained in this paper can provide a reference for the design and operation of the cogeneration system for distributed energy systems(DES).
文摘为回收利用丙烯腈生产投料段液态原料的冷能及吸收塔尾气焚烧炉排放的低温烟气余热,设计了一种喷射式制冷循环与低温有机朗肯循环复合的低品位能量回收系统。结合某年产200 kt丙烯腈项目,利用Matlab建模对所设计的系统进行仿真。试验结果表明,在满足工艺冷量需求的前提下,喷射式制冷机组较原工艺中的螺杆制冷机组可节电110.65 k W;由于利用了液态原料蒸发过程的冷能,该系统中有机朗肯循环在较低的冷凝温度下运行,较常规有机朗肯循环系统热效率提高52.4%;该系统的热效率和?效率分别为19.1%和49.8%;提高热源发生压力和循环工质过热度及降低循环工质冷凝温度,均有利于提高系统的性能。
