基于(火用)分析的内可逆简单空气制冷循环性能优化

基于(火用)分析的观点,运用有限时间热力学方法分析恒温热源内可逆简单空气制冷循环的特性,导出制冷率、生态学目标函数和(火用)效率与压缩机压比等主要影响参数的解析式,以相应的数值计算分析压缩机压比、高低温侧换热器热导率分配对循环性能优化的影响特点,并把生态学优化目标、(火用)效率优化目标和传统的制冷率优化目标进行综合比较.所得结果对工程制冷系统设计具有一定的指导意义.     

变温热源不可逆布雷顿制冷循环制冷率和制冷系数优化

用有限时间热力学方法分析变温热源不可逆简单布雷顿制冷循环的特性,分别以制冷率和制冷系数为优化目标,优化了循环中换热器的热导分配以及工质和热源间的热容率匹配,并采用数值计算分析了压比、换热器总热导、压缩机和膨胀机效率、工质热容率等参数对最优制冷率和制冷系数的影响特点.所得结果对工程制冷系统设计有一定的指导意义.     

回热式空气制冷循环性能新析

采用制冷率密度这一新的性能参数作为热力学优化目标,用有限时间热力学的方法,分析了回热式空气制冷循环的性能,得到了普适的解析关系式,并由数值计算分析了压比、热导率分配、压缩机和膨胀机的效率等参数对制冷率密度的影响特点。     

吸附式制冷循环的yong分析

以吸附式制冷循环的热力过程为依据，使用yong分析的方法对连续回热循环做了分析，对循环中各部分yong损进行了比较，指出了连续回热循环中yong损的主要部位，并探讨了回热率及吸附床的传热性能对循环yong效率的影响。     

不可逆恒温热源空气制冷机的炯经济性能优化

文章用有限时间热力学理论和方法,研究了恒温热源条件下不可逆空气制冷机的有限时间炯经济性能,导出了利润率解析式。用数值计算分析了压比、热源温比、热导率分配、压缩机和膨胀机的效率等参数对利润率的影响,并优化了循环压比和换热器的热导率分配。通过价格比,将有限时间炯经济性能目标与制冷率、熵产率及生态学目标建立了联系。所得结果对实际空气制冷设备的设计有一定指导意义。     

变温热源内可逆空气制冷循环制冷率密度优化

以制冷率密度为热力学优化目标,分析了变温热源条件下内可逆空气制冷循环的性能,导出了解析关系式,并由数值计算分析了压比、热导率分配以及工质和热源间热容率匹配对制冷率密度的影响特点。     

变温热源不可逆布雷顿制冷循环制冷率密度优化

用有限时间热力学分析方法,制冷率密度为热力学优化目标,分析了变温热源条件下不可逆布雷顿制冷循环的性能,得到了普适的解析关系式,并由数值计算分析了压比、热导率分配以及工质和热源间热容率匹配等参数对制冷率密率的影响特点.     

一种新型的自动复叠制冷循环

研究了一种新型的具有精馏装置的自动复叠制冷循环，采用了环保多元混合物R50／R23／R600a为制冷工质，对新循环进行了数值模拟，深入分析了循环工质配比、循环压比和精馏柱回流液的抽取率对系统COP的影响。在压缩机效率、冷凝温度和蒸发温度相同的前提条件下，进一步将新循环与未改进前的精馏循环进行了性能上的比较，发现新循环能够获得更高的COP。     

考虑热漏损失的实际空气制冷机制冷率密度优化

以制冷率密度作为热力性能目标,综合考虑热漏、热阻和循环内不可逆性,对不可逆简单空气制冷机进行分析,导出了制冷率密度和制冷系数解析关系式,对制冷率密度进行了优化,并由数值计算分析了热漏、压比、热导率分配等参数对制冷率密度的影响特点.     

内可逆空气制冷机制冷率密度分析与优化

以制冷率密度作为热力性能目标,对内逆空气制冷机进行分析与优化,得到了不同于以制冷率为目标的优化结果,并由数值计算分析了压比和热导率分配对制冷率密度的影响特点。     

包含五种循环的普适定常流内可逆制冷循环最优性能

用有限时间热力学方法分析了一类普适定常流内可逆制冷机循环,导出了存在传热损失时,由一个吸热过程、一个放热过程和两个绝热过程组成的一类普适的定常流内可逆制冷机循环的制冷率、制冷系数、(火用)损失率、(火用)输出率和生态学性能,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Carnot、Diesel、Otto、Atkinson和Brayton制冷循环的特性.     

Thermoeconomic optimization of a two stage combined refrigeration system: a finite-time approach

A finite-time thermoeconomic performance analysis based on a new kind of optimization criterion has been carried out for a two-stage endoreversible combined refrigeration cycle model. The optimal performances and design parameters that maximize the objective function (cooling load per total cost) are investigated. In this context, the optimal temperatures of the working fluids, the optimum performance coefficient, the optimum specific cooling load and the optimal distribution of the heat exchanger areas are determined in terms of technical and economical parameters. The effects of the economical parameter that characterizes the investment and energy consumption costs on the general and the optimal performances have been discussed.     

Potential energy benefits of integrated refrigeration system with microturbine and absorption chiller

This paper presents and analyzes the performance potential of a refrigeration system that is integrated with a microturbine and an absorption chiller (RMA). The waste heat from the microturbine operates the absorption chiller, which provides additional cooling. This additional cooling capacity can be utilized either to subcool the liquid exiting the condenser of the refrigeration system or to precool the air entering the condenser in the refrigeration system. Moreover, any surplus cooling capacity not utilized in the subcooler can be utilized to precool the microturbine intake air. The additional assistance to the refrigeration system enhances the efficiency of the refrigeration cycle, which in turn reduces the required microturbine size. The smaller size of the microturbine enhances the part load efficiency, especially in lower ambient temperatures. With increased microturbine efficiency, RMA with subcooler, RMA with subcooler and microturbine intake air precooler, and RMA with condenser air precooler can reduce the annual energy consumption by 12, 19, and 3%, respectively, as compared to a refrigeration system operating without any waste heat utilization from the microturbine. Therefore, RMA with subcooler and microturbine intake air precooler has the best potential of energy savings. The payback period of RMA with subcooler and microturbine intake air precooler is estimated in 3 years, which facilitates it as an economically feasible solution among the options investigated.     

不可逆空气制冷循环的制冷率和制冷系数优化

用有限时间热力学方法分析恒温热源不可逆空气制冷循环特性 ,在总热导率一定的条件下 ,研究最优制冷率、制冷系数时热导率的最优分配 ,并分析了各种参数对循环特性的影响 ,所得结果对工程制冷系统设计有一定的指导意义。     

Thermodynamic analysis of a novel ejector-cascade refrigeration cycles for freezing process applications and air-conditioning

Waste heat from the gas cooler is a form of free energy, which can be utilized to drive an ejector cooling cycle. This paper presents a new CO₂ ejector-cascade refrigeration cycle. The effects of important parameters on the thermodynamic performance of the new cycle are theoretically investigated based on energetic and exergetic analyses. Furthermore, the performance comparison of the proposed cycle and conventional cycle is carried out. The theoretical study shows that the new cycle exhibits a reasonable value of COP (coefficient of performance) and system second law efficiency. For the same cooling capacity, the improvements of the maximum COP and second law efficiency could reach 37% and 12%, respectively, over those of the conventional cascade cycle under the given operating conditions and at the optimum gas cooler pressure.     

R404A直接接触凝结制冷循环的性能分析

提出R404A直接接触凝结换热的制冷循环,分析R404A直接接触凝结制冷循环的热力性能,并与常规双级压缩制冷循环的性能进行对比。得出结论:在一定的冷凝温度、蒸发温度和过冷液体的过冷度下,直接接触凝结制冷循环存在最佳的饱和液体温度,并在此最佳的饱和液体温度下,获得最优的性能和最小的冷凝热负荷,随着过冷液体的过冷度增大和蒸发温度升高,直接接触凝结制冷循环的性能系数增加、冷凝热负荷减少,获得最优性能的最佳饱和液体温度值提高。过冷液体的过冷度为25℃时,直接接触凝结制冷循环的最佳性能系数较双级压缩制冷循环的最佳性能系数提高6.2%。直接接触凝结制冷循环的最小冷凝热负荷较双级压缩制冷循环的最小冷凝热负荷减小1.8%。