中冷回热布雷顿热电联产装置的经济性能——不可逆恒温热源循环性能分析

Exergoeconomic Performance of Intercooled Regenerated Brayton Heat and Power Cogeneration Plant:Performance Analysis for an Irreversible Constant-Temperature Heat Reservoir Cycle

用有限时间热力学理论和方法研究了恒温热源不可逆中冷回热布雷顿热电联产装置的经济性能,导出了无量纲利润率和效率的解析式。讨论了总压比给定和总压比变化两种情形,优化了中间压比,通过数值计算详细分析了各设计参数对循环一般性能和最优性能的影响,发现回热和中冷能够较大地提高装置的利润率和效率,并且随压比的变化对利润率和效率具有不同的影响。讨论了利润率和效率之间的关系,其特性关系为扭叶型。最后发现分别存在最佳用户侧温度使得利润率和效率取得双重最大值。

The exergoeconomic performance of an irreversible intercooled regenerative Brayton cogeneration plant coupled to constant-temperature heat sources is investigated using finite time thermodynamics.Analytical formulae about dimensionless profit rate and exergy efficiency are deduced.The two cases with fixed and variable total pressure ratios are discussed and the intercooling pressure ratios are optimized.The effects of the design parameters on the general and optimal performance of the cycle are analyzed by detailed numerical examples.It is found that regeneration and intercooling can increase profit rate and exergy efficiency of the cogeneration plant largely and have different effects for profit rate and exergy efficiency with the change of pressure ratios.The relation between profit rate and exergy efficiency is discussed and the characteristic of profit rate versus exergy efficiency is loop-shaped.At last,it is found that there exist optimal consumer temperatures,which can achieve double-maximum profit rate and double-maximum exergy efficiency.