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1.
应用有限时间热力学理论,基于仅考虑传热损失的内可逆往复式Maisotsenko-Brayton循环模型,推导出了循环熵产率和生态学函数等重要参数表达式。通过数值计算,分析与研究了空气饱和器出口温度、循环最高温度和注水流率对循环性能的影响。将内可逆往复式Maisotsenko-Brayton循环与传统往复式Brayton循环进行比较,结果表明内可逆往复式Maisotsenko-Brayton循环性能优于传统往复式Brayton循环性能。  相似文献   

2.
不可逆吸收式制冷机的(火用)经济和生态学优化准则   总被引:9,自引:2,他引:7  
研究不可逆吸收式制冷机的Yong经济化性能,得到一些新的性能参数,并揭示了它与生态学优化性能的内在联系,所得结论可为三热源制冷机的优化设计和最佳工况选择等提供些新理论依据。  相似文献   

3.
研究不可逆吸收式制冷机的经济化性能 ,得到一些新的性能参数 ,并揭示了它与生态学优化性能的内在联系。所得结论可为三热源制冷机的优化设计和最佳工况选择等提供些新理论依据。  相似文献   

4.
普适内可逆热机循环模型及其生态学优化   总被引:1,自引:1,他引:0  
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。  相似文献   

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6.
考虑内可逆正反向两热源循环中工质与热源之间的传热服从复杂规律q∝(△Tn)m(包括了牛顿传热规律、线性唯象传热规律、辐射传热规律、Dulong-Petit传热规律、广义对流传热规律和广义辐射传热规律),导出内可逆卡诺热机功率与效率、内可逆卡诺制冷机制冷率与制冷系数和内可逆卡诺热泵供热率与供热系数间的基本优化关系特性.该文结果具有一定普适性和包容性,对实际热机、制冷机和热泵的设计工作有一定理论指导作用.  相似文献   

7.
基于前人建立的恒温热源内可逆Braysson循环模型,以换热器热导率分配和工质对数温比为优化变量,引入功率、效率、生态学函数和功率密度,应用NSGA-Ⅱ算法对不同目标函数组合完成了多目标优化。分析了最佳热导率分配和最佳工质对数温比与四目标优化时各个目标的关系。通过比较不同优化目标组合时LINMAP、TOPSIS和香农熵3种决策方式的偏差指数,从而得到最佳方案。结果表明,四目标优化时,TOPSIS决策方式所得偏差指数为0.204 0,且为最小,故相比于单、二和三目标优化,四目标优化方案最佳。  相似文献   

8.
基于有限时间热力学理论,对恒温热源内可逆Lenoir循环进行功率效率特性分析与优化,得到换热器总热导给定的条件下循环的最大功率和最大效率。结果表明:在给定高、低温侧换热器热导的条件下,循环的功率、效率特性呈现"点"的特征;在高、低温侧换热器热导可优化的条件下,存在最佳的热导分配,使得循环的功率或效率取得最大值。高、低温热源温比增大或换热器总热导增大时,循环的功率、效率都将增大。  相似文献   

9.
杨惠山 《太阳能学报》2004,25(3):325-329
研究存在热阻和回热损失的埃里克森热机的炯经济优化性能和生态学优化性能,得到一些新的性能参数,并揭示了炯经济优化性能与生态学优化性能问的联系,所得结果具有普遍意义,可为埃里克森热机的研制和优化设计提供些新理论指导。  相似文献   

10.
广义不可逆卡诺热机的生态学最优性能   总被引:7,自引:0,他引:7  
以反映热机功率与熵产率之间最佳折衷的“生态学”准则为目标,综合考虑热阻、热漏及其它不可逆性对卡诺热机性能的影响,导出牛顿传热规律下循环的生态学最优性能,由数值计算分析比较了热漏、内不可逆性的影响特点。生态学优化以牺牲小部分输出功率为代价,较大地降低了循环的熵产率,而且在一定程度上提高了热机效率。因此,生态学目标函数不仅反映了输出功率和熵产率之间的最佳折衷,而且反映了输出功率和热效率之间的最佳折衷。  相似文献   

11.
用有限时间热力学方法分析工作在恒温热源TH、TL之间内可逆普适热机循环模型的经济性能,导出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。所得结果包含了内可逆D iese、lO tto、A tk inson和B rayton循环的有限时间经济性能。  相似文献   

12.
An endoreversible closed modified simple Brayton cycle model with isothermal heat addition coupled to variable-temperature heat reservoirs is established using finite-time thermodynamics. Analytical expressions of dimensionless power output, thermal efficiency, dimensionless entropy generation rate and dimensionless ecological function are derived. Influences of cycle thermodynamic parameters on ecological performance and optimal compressor pressure ratio, optimal power output, optimal cycle thermal efficiency and optimal entropy generation rate corresponding to maximum ecological function are obtained and compared with those corresponding to maximum power output. The results show that cycle thermal efficiency improvement and entropy generation rate reduction are obtained at the expense of higher compressor pressure ratio and a little sacrifice of power output at maximum ecological function. The compromises between power output and entropy generation rate and between power output and cycle thermal efficiency, respectively, are achieved.  相似文献   

13.
The performance optimization of an endoreversible air refrigerator with variable‐temperature heat reservoirs is carried out by taking the cooling load density, i.e. the ratio of cooling load density to the maximum specific volume in the cycle, as the optimization objective in this paper. The analytical relations of cooling load, cooling load density and coefficient of performance are derived with the heat resistance losses in the hot‐ and cold‐side heat exchangers. The maximum cooling load density optimization is performed by searching the optimum pressure ratio of the compressor, the optimum distribution of heat conductance of the hot‐ and cold‐side heat exchangers for the fixed total heat exchanger inventory, and the heat capacity rate matching between the working fluid and the heat reservoirs. The influences of some design parameters, including the heat capacitance rate of the working fluid, the inlet temperature ratio of heat reservoirs and the total heat exchanger inventory on the maximum cooling load density, the optimum heat conductance distribution, the optimum pressure ratio and the heat capacity rate matching between the working fluid and the heat reservoirs are provided by numerical examples. The refrigeration plant design with optimization leads to a smaller size including the compressor, expander and the hot‐ and cold‐side heat exchangers. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

14.
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.  相似文献   

15.
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。  相似文献   

16.
在恒温热源内可逆四热源吸收式制冷循环的基础上,建立不可逆吸收式制冷循环的模型,考虑环境热源到制冷空间的热漏以及工质与外部热源间的热阻损失,导出牛顿定律下循环的制冷率和制冷系数的基本优化关系、最大制冷系数及相应的制冷率和最大制冷率及相应的制冷系数;并通过数值计算分析了循环参数对循环的制冷率、制冷系数的影响。  相似文献   

17.
The ecological optimization and parametric study of an irreversible Ericsson cryogenic refrigerator cycle with finite heat capacities of external reservoirs is studied. The ecological function is defined as the cooling load minus the loss of the cooling load (the irreversibility) due to the entropy generation rate. The ecological function is optimized with respect to working fluid temperatures and the values of the cooling load, power input, the loss rate of the cooling load and COP are calculated for a typical set of operating parameters. The effects of different operating parameters on the ecological function, cooling load, the loss rate of the cooling load and COP are studied. The loss rate of the cooling load and the power input are found to be increasing functions of the cycle temperature ratio and decreasing functions of COP while the COP is found to be a decreasing function of the cycle temperature ratio. On the other hand, there exist the optimal values of the cycle temperature ratio and COP at which the ecological function and cooling load attain their maximum values. Also the ecological function and the cooling load are found to be increasing functions of the sink‐side heat capacitance rate and the effectiveness on the source‐, sink‐, and regenerative‐side heat exchangers while the decreasing functions of the source‐side heat capacitance rate. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

18.
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。  相似文献   

19.
考虑热阻损失、压缩机与膨胀机的内损失及管路系统的压力损失,研究一个比较接近实际装置的回热式交温热源空气制冷循环,得出了循环容积制冷率制冷系数的解析关系式。由数值计算分析了压比、热导率分配以及工质与热源间的热容率匹配等参数对容积制冷率的影响。  相似文献   

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