包含6种热机模型的普适内可逆热机循环(火用)经济性能优化

用有限时间热力学方法分析了工作在恒温热源TH、TL之间的普适定常流内可逆热机循环模型的炯经济性能,导出了循环利润率与工质温比、热效率与工质温比的关系式,以及利润率和效率的特性关系,并由数值计算分析了循环过程对循环性能的影响特点。所得结果包含了内可逆Carnot、Diesel、Otto、Atkinson、Brayton和Dual循环的有限时间炯经济性能。     

闭式中冷回热燃气轮机循环经济性能优化

建立了考虑变温热源的闭式中冷回热(ICR)燃气轮机循环有限时间热力学(FTT)模型,导出了循环利润率和效率解析式,优化各换热器热导率分配和中冷压比,得到了最大利润率;进一步优化总压比,得到双重最大利润率;并分析了总热导率等重要设计参数对循环最优性能的影响。结果表明,随着高低温侧热源进口温比、低压压气机效率、高压压气机效率、涡轮效率、各换热器有效度以及压力恢复系数的增大,循环最大利润率和对应的功率和效率增大。随着价格比的增大,循环利润率增大,但对应的效率却有所减小。存在一个最佳的工质与热源热容率匹配值使变温热源闭式不可逆中冷回热燃气轮机循环的利润率取得三重最大值。     

高炉余能余热驱动的内可逆闭式布雷顿热电冷联产装置火用经济性能分析

用有限时间热力学理论研究恒温热源条件下由一个内可逆闭式布雷顿热机循环和一个内可逆四热源吸收式制冷循环组成的高炉余能余热驱动的热电冷联产装置的火用经济性能,导出热电冷联产装置的利润率和火用效率与压气机压比的关系。利用数值计算,分析热电比和吸收式制冷循环总放热量在吸收器和冷凝器之间的分配率对利润率与火用效率关系的影响,并研究联产装置各种参数对最大利润率及相应火用效率特性的影响。     

等温加热修正Diesel循环及其内可逆特性

提出一种新的Diesel循环，即等温加热修正的Diesel循环，并运用有限时间热力学理论建立内可逆修正Diesel循环模型，导出循环功率与效率、功率与压缩比和效率与压缩比的特性关系，研究循环温比、预胀比和传热损失对循环性能的影响，将修正后的循环性能与传统的Diesel循环性能进行比较。结果显示：循环功率与效率的关系曲线呈扭叶型，而功率与压缩比和效率与压缩比的关系曲线均呈类抛物线型；随着预胀比和循环温比的变大，循环性能明显提升；与传统的Diesel循环相比，修正后的循环性能更优。     

传热规律对卡诺热泵最大利润率特性的影响

用有限时间用经济分析法导出了在Qa（T~n）和Qa（△T）~n下内可逆卡诺热泵的最佳利润率与供热系数间的关系，并藉此讨论了四种传热规律时内可逆卡诺热泵的有限时间经济最优性能的特点，得到了一些新的普适结果。     

广义不可逆联合热泵循环有限时间炯经济性分析与优化

研究了存在热阻、热漏和内不可逆性的广义不可逆联合热泵循环有限时间火用经济性能,导出了在线性传热定律下循环最佳利润率和最佳供热系数的解析式以及二者的优化关系,并用数值算例对比分析了热漏、内不可逆性和价格比对利润率和火用经济性能界限的影响。广义不可逆联合热泵循环的有限时间火用经济学性能界限通过价格比与有限时间热力学性能界限和经典热力学限建立联系。结果对于实际联合热泵确定设计参数,判定工况是否处于最优经济状态有一定的指导作用。     

广义不可逆联合热泵循环有限时间火用经济性分析与优化

研究了存在热阻、热漏和内不可逆性的广义不可逆联合热泵循环有限时间火 用经济性能,导出了在线性传热定律下循环最佳利润率和最佳供热系数的解析式以及二者的优化关系,并用数值算例对比分析了热漏、内不可逆性和价格比对利润率和火 用经济性能界限的影响.广义不可逆联合热泵循环的有限时间火 用经济学性能界限通过价格比与有限时间热力学性能界限和经典热力学限建立联系.结果对于实际联合热泵确定设计参数,判定工况是否处于最优经济状态有一定的指导作用.     

空气标准等温加热修正Brayton循环：(1)功率效率特性分析

在已有文献建立的闭式等温加热修正定常流式Brayton循环模型基础上,提出了一种新的五分支Brayton循环,即空气标准等温加热修正Brayton循环,并运用有限时间热力学理论建立了内可逆空气标准等温加热修正Brayton循环模型,导出了其功率效率表达式,分析了最大温比和预胀比对功率与效率、功率与压缩比和效率与压缩比特性关系的影响,以及传热损失对功率与效率特性关系的影响,并将修正后的Brayton循环性能与传统的Brayton循环性能进行了对比。结果表明：循环功率与效率的关系曲线呈扭叶形,而功率与压缩比和效率与压缩比的关系曲线均呈类抛物线形;随着预胀比和循环温比的增加,循环性能明显提升;与传统的Brayton循环相比,修正后的循环性能更优。     

恒温热源内可逆Brayton热电联产循环的利润率密度分析

根据能量系统有限时间综合经济分析的思路,引入新的循环性能指标:利润率密度(定义为利润率与循环最大比容之比),对恒温热源内可逆Brayton热电联产循环的利润率密度特性进行了分析,并将最大利润率密度及最大利润率时的循环参数进行了对比.研究表明,与最大利润率工况相比,尽管最大利润率密度工况下循环的利润率有所减小,但循环的火用效率有较大幅度的提高,设备体积也大为减小,实现了循环利润率与设备体积的最佳折衷.本文的研究表明,利润率密度可以作为热电联产系统设计的一种备选方案.     

不可逆回热式变温热源空气制冷机的利润率优化

用有限时间经济分析法,考虑换热器、压缩机和膨胀机的不可逆性,研究变温热源条件下回热式不可逆空气制冷机的最优性能,导出利润率解析式。用数值算例分析利润率与压比的关系,优化循环中换热器和回热器的热导率分配及工质与热源间的热容率匹配,分析总热导率、压缩机和膨胀机的效率等参数对利润率与热导率分配、热容率匹配关系的影响。通过价格比,将利润率目标与制冷率、熵产率及生态学目标建立联系。     

普适内可逆热机循环模型及其生态学优化

用有限时间热力学的方法分析了空气标准内可逆热机循环,导出了存在传热损失时,由两个加热过程、一个放热过程和两个绝热过程组成的普适的空气标准内可逆热机循环的功率、效率和生态学性能,并由数值计算分析了循环过程对循环性能的影响特点。所得结果包含了内可逆D iese l循环、O tto循环、B rayton循环、A tk inson循环和Dua l循环的特性。     

Power optimization of an endoreversible Brayton gas heat engine

The power output of a simple endoreversible Brayton gas heat engine is analyzed and optimized. The endoreversible engine is defined as a power cycle in which the two processes of heat transfer from and to the surrounding heat reservoirs are the only irreversible processes in the Brayton cycle. A mathematical expression is derived for the power output of the irreversible heat engine. The power optimization provides the basis for designing a real gas heat engine and for a performance comparison with existing Brayton power plants.     

Exergoeconomic performance of an endoreversible Carnot heat pump with complex heat transfer law

The finite-time exergoeconomic performance of an endoreversible Carnot heat pump with a complex heat transfer law, including generalized convective heat transfer law and generalized radiative heat transfer law q∝ (Δ T ⁿ ) ^m , is investigated in this paper. The focus of this paper is to obtain the compromised optimization between economics (profit) and the energy utilization factor (coefficient of performance, COP) for the endoreversible Carnot heat pump, by searching the optimum COP at maximum profit, which is termed as the finite-time exergoeconomic performance bound. The obtained results include those obtained in much of the literature and can provide some theoretical guidance for the design of practical heat pumps.     

Optimum performance of a heat engine‐driven combined vapour compression–absorption–ejector heat pump

Optimum performance of an endoreversible heat engine‐driven heat pump cycle, based on a combination of an absorption cycle with a vapour and ejector compression cycles is investigated. This combination increases the performance of the conventional ejector and absorption cycles and provides high performance for heating. The analysis show that the combined heat pump cycle has a significant increase in system performance over the heat engine‐driven vapour compression or absorption heat pump cycle and heat engine‐driven combined vapour compression and absorption heat pump cycle. Copyright © 2000 John Wiley & Sons, Ltd.     

Thermodynamic analysis of the performance of a solar absorption heat transformer at maximum coefficient of performance

It is proven that a solar absorption heat transformer affected by the irreversibility of finite-rate heat transfer may be modelled as an equivalent combined system consisting of a solar collector and an endoreversible absorption heat transformer, the latter being further treated as a combined cycle having an endoreversible heat pump driven by an endoreversible heat engine. The maximum coefficient of performance of the system is determined, based on the linear heat loss model for solar collectors and the general optimum relation for endoreversible absorption heat transformers. The optimality problems concerning the primary performance parameters of the system are discussed. The results obtained here may serve as a good guide for the evaluation of existing real solar absorption heat transformers or provide some theoretical bases for the optimal design of future solar absorption heat transformers. © 1997 by John Wiley & Sons, Ltd.     

Effect of the heat transfer law on the finite-time, exergoeconomic performance of heat engines

The efficiency bounds at maximum profit are obtained from finite-time exergoeconomic analysis for three common heat transfer laws: Newton's law (n = 1), a linear pheomenological law in irreversible thermodynamics (n = 1), and the radiative heat law (n = 4). The relation between optimal profit and efficiency of an endoreversible Carnot engine is derived on the basis of the general heat-transfer law q∝Δ(Tⁿ).     

具有热阻和热漏的再热布雷顿循环性能分析

用有限时间热力学方法建立了一个工作在恒温热源TH、TL之间,存在热阻、热漏和再热的定常流空气标准闭式布雷顿循环模型。导出了其功率、效率的一般关系并对其进行优化,得到循环的基本优化关系;分析了在傅立叶导热定律下再热对循环最优性能的影响。     

Optimization of the endoreversible otto cycle with respect to both power and mean effective pressure

The output response of an endoreversible Otto cycle with combustion is optimized with respect to both power and mean effective pressure. The endoreversible cycle is one in which the heating process by combustion and the heat removing process to the surroundings are the only irreversible processes in the cycle. Expressions for these two responses are derived and optimized and a comparative analysis of results conducted. This paper provides an additional criterion for use in the evaluation of the performance and the suitability of an Otto engine.