Optimization and Comparison of Two Combined Cycles Consisting of CO2 and Organic Trans-Critical Cycle for Waste Heat Recovery

Energies

Liya Ren¹  Huaixin Wang¹ 

[1] MOE Key Laboratory of Efficient Utilization of Low and Medium Grade Energy, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China;

关键词: co₂ trans-critical cycle;    organic trans-critical cycle;    combined cycle;    waste heat recovery;    thermodynamic optimization;   

DOI  :  10.3390/en13030724

来源: DOAJ

【 摘 要 】

CO₂-based trans-critical and supercritical cycles have received more and more attention for power generation in many applications such as solar and nuclear energy due to the desirable thermal stability and properties of CO₂ and the high efficiency and compact size of the plant. In this study, two combined cycles driven by the flue gas exhausted from the LM2500+ gas turbine, CO₂-TC+OTC (organic trans-critical cycle) and CO₂-TC/OTC, which can achieve a good trade-off between thermal efficiency and utilization of the waste heat, are investigated. Parameters optimization is carried out by means of genetic algorithm to maximize the net power output of the combined cycle and the effects of the key parameters on the cycle performance are examined. Results show that the exergy efficiency of CO₂-TC+OTC is about 2% higher than that of CO₂-TC/OTC. In CO₂-TC+OTC, the recuperation process of CO₂ causes the largest exergy loss; in CO₂-TC/OTC, the largest exergy loss occurs in the heat recovery vapor generator, followed by the intermediate heat exchanger due to the larger variation of the specific heat capacity of CO₂ and organic fluid in the heat addition process.

【 授权许可】

Unknown