回热型S-CO2布雷顿循环热电联产装置有限时间热力学性能分析与优化

Finite time thermodynamic performance analysis and optimization of regenerative S-CO2 Brayton cycle cogeneration plant

中文关键词: 有限时间热力学  回热型S-CO2布雷顿循环  热电联产装置  可用能率  第一定律效率

英文关键词: Finite time thermodynamics  Regenerative S-CO2 Brayton cycle  Cogeneration plant  Available energy rate  First law efficiency

中文摘要:

      针对燃气轮机余热回收，提出了一种新型的回热型超临界二氧化碳(Supercritical CO2, 简称S-CO2)布雷顿循环热电联产装置，对经过加热器的烟气进行深度利用，具有广阔的应用前景。本文首先建立了回热型S-CO2布雷顿循环热电联产装置模型，利用有限时间热力学理论，考虑有限温差传热、不可逆压缩、不可逆膨胀等不可逆性损失，以可用能率和第一定律效率为目标，分析了工质质量流率、压比、压缩机效率、透平效率和热水换热器热导率分配比等参数对可用能率和第一定律效率的影响。在总热导率一定的条件下，分别以可用能率和第一定律效率最大为优化目标进行优化，结果表明：相比于初始设计点，可用能率提高了29.63%，第一定律效率提高了25.55%，研究结果对S-CO2布雷顿循环热电联产装置的最优设计具有一定的指导意义。

英文摘要:

      For gas turbine waste heat recovery, a novel regenerative Supercritical CO2 (S-CO2) Brayton cycle cogen-eration plant is proposed, which can deeply utilize flue gas through the heater and has broad application prospect. In this paper, the model of regenerative S-CO2 Brayton cycle cogeneration plant is first estab-lished. Based on the theory of finite time thermodynamics, the irreversibility losses of finite temperature difference heat transfer, irreversible compression and irreversible expansion are considered, and the availa-ble energy rate and the first law efficiency are taken as the objective. The effects of mass flow rate, pressure ratio, compressor efficiency, turbine efficiency and thermal conductivity distribution ratio of hot water heat exchanger on available energy rate and first law efficiency are analyzed. Under the condition of the fixed total thermal conductivity, optimizations for the maximum optimization target of available energy rate and first law efficiency are performed, respectively. The results show that: compared with the initial design point, the available energy rate is increased by 29.63%, and the first law efficiency is increased by 25.55%. The research results have certain guiding significance for the optimal design of S-CO2 Brayton cycle cogeneration plant.