复式朗肯循环的输出和效率分析

本文对复式朗肯循环进行了分析研究 ,其目的在于优化低温热源的功率输出。根据有限时间热力学并应用最大功率概念 ,确定最大动力循环曲线形状和功率输出 ,同时也为动力循环研究提供方法 ,从而为改进工程设计奠定了基础     

HAT循环关键部件饱和器研究概况

HAT循环是一种先进的热力循环,具有高效率、高比功、低花费、低污染的良好性能,被誉为21世纪最有竞争力的动力循环。本文综述了HAT循环的关键部件饱和器的研究概况,指出了目前饱和器研究的一些成果和今后研究的重点。     

SCO2布雷顿循环发电系统与性能的综合分析比较

基于布雷顿循环的原理与特点,对典型循环结构的动力部件与换热部件布局的效率和功率性能进行了比较,分析了运行参数对循环效率的影响规律,同时进一步阐述了关键循环动力部件（叶轮机械包括压缩机与透平）与换热部件（热交换器）的综合技术性能及部件选择的差异性。研究表明:实验中循环操作参数取最低温度为32 ℃、最高温度为342 ℃、压比为1.65时,循环效率可达31.5%;最低循环温度下降和最高循环温度升高有利于改善循环效率,并且对于复杂循环一般存在最佳压比;根据循环输出功率大小,叶轮机械一般采用径流（<10 MW时）或轴流结构（≥10 MW时）;与常规换热器相比,印刷电路板式换热器具有更为紧凑的结构和高效的换热性能。     

对用燃气轮机改造燃煤引电站的若干方案性能的理论分析

本文从理论上详细推导了以：（１）常规的不补燃的燃气－蒸汽联合循环方案（２）前置动力布置方式的燃气－蒸汽联合循环方案；（３）并列动力布置方式的燃气－蒸汽联合循环方案；（４）增加动力布置方式的燃气－蒸汽联合循环方案来改造燃煤旧电站时，电站供电效率等一些性能指标的计算关系式；它能帮助我们更本质地理解这些改造方案之间的差异及其工作特性，并能预估旧电站改造后可能达到的性能指标。     

循环流化床锅炉内流动和燃烧特性的理论模型

在对１台１２ＭＷ循环流化床锅炉进行试验研究的基础上,建立了能描述宽筛分循环流化床锅炉的炉内流动体动力特性和燃烧过程的数学模型。循环流化床锅炉总体数学模型以所建流体动力特性模型为子模型,模拟了１２ＭＷ循环流化床锅炉的运行,模拟计算结果合理正确,与试验研究结果吻合良好。     

对用燃气轮机改造燃煤旧电站的若干方案性能的理论分析

本文从理论上洋细推导了以：①常规的不补燃的燃气-蒸汽联合循环方案；②前置动力布置方式的燃气-蒸汽联合循环方案；③并列动力布置方式的燃气-蒸汽联合循环方案；④增加动力布置方式的燃气-蒸汽联合循环方案来改造燃煤旧电站时．电站供电效率等一些性能指标的计算关系式．它能帮助我们更本质地理解这些改造方案之间的差异及其工作特性，并能预估旧电站改造后可能达到的性能指标。     

角管式蒸汽锅炉再循环管的实验研究

通过对角管式蒸汽锅炉侧墙水冷壁的循环原理进行分析,找到了影响再循环管水动力特性的主要因素,并建立了水动力特性实验台,对热负荷和预分离集箱影响再循环管作用的规律了实验研究。     

太阳能驱动有机朗肯循环的工质比较

针对太阳能热水和其它低品位热能的动力利用,研究了工作在100℃供热温度和30℃冷凝温度之间的有机朗肯循环工质的优化选择,以满足较高的循环效率、较大的机械能输出、较小的排气量需求等要求。工质模型采用RKS状态方程,针对R22在-30～95℃温度区间内,计算结果与ASHRAE20-2005数据比较,除液相密度外,其它的热力学参数计算绝对误差小于5%,满足工程模拟要求。利用RKS模型,文中分析了19种有机工质的动力循环参数,发现工质R11的热力学性能系数最高。结合GWP和ODP环境指标,发现R142b、Rc318与R600适合于低温朗肯循环。     

氢能燃气轮机循环低温能有效利用及热力学分析

为了充分利用液氢的低温Ｙｏｎｇ,在气能燃气轮机循环中附加了一个空气预冷器和氢气透平。该循环的比功,热效率,Ｙｏｎｇ效率均较简单循环燃气轮机有很大提高。本文对液氢－燃气动力循环进行了热力学分析,指出它的优越的动力性能。     

热水锅炉水循环计算方法的探讨

文章以现行的《热水锅炉水动力计算方法》为基础,探讨用公式法和图解法的结合,对热水锅炉的自然循环、引射循环的合力循环进行计算的计算方法。并对用这些方法产生的偏差和采用这些方法的条件进行分析。     

布雷顿与斯特林联合循环性能分析

本文构建了一个由布雷顿循环与斯特林循环组成的新型联合循环,用有限时间热力学的方法分析具有热阻、热漏的布雷顿与斯特林联合循环性能。导出了在牛顿传热律下联合循环无因次功率、效率的解析式,并通过数值算例得到它们之间的关系。分析并研究了各种参数对联合循环的性能影响。     

Performance optimisation for two classes of combined regenerative Brayton and inverse Brayton cycles

This paper proposes a new cyclic model of combined regenerative Brayton and inverse Brayton cycles. The new combined regenerative Brayton and inverse Brayton cycles recover heat energy after the working fluid leaves the turbine of the inverse Brayton cycle while the original combined regenerative Brayton and inverse Brayton cycles recover heat energy before the working fluid enters the turbine of the inverse Brayton cycle. Performance analysis and optimisation of the two classes combined cycles are carried out. Furthermore, the effect of the regenerator on the performance of the two combined cycles is analysed. It is found that the new combined cycle can obtain higher thermal efficiency and larger specific work than those of the original combined cycle at low compressor pressure ratio of the top cycle, and the regenerator can improve the performance of both the combined cycles. By theoretical analysis of this paper, it reveals that the new combined cycle will be well applied in the prospect, and the original combined cycle will be suited to low power output equipments. This paper aims at enriching the gas turbine theory and providing a possible way to save energy.     

Application of modified Kalina cycle in biomass chp plants

This paper presents alternatives to Kalina cycles typically used in place of the organic Rankine cycle in biomass power plants. Overviews of both Rankine and Kalina cycles are given alongside the possibilities of using biomass as a viable energy source and recommended guidelines from the engineering practice for selection and management of these cycles. Benefits of Kalina novel bottoming cycle (and the alternative cycles presented herewith) over the Rankine cycle are the higher thermodynamic cycle efficiency and lower capital expenditures combined with the possibility of using low-grade heat sources, such as biomass or waste heat from exhaust gases. Analysis of ammonia-water binary system under various operating conditions has been performed for all the proposed cycles based on the published references and it has been shown that the proposed alternative models prove to be simpler and to have similar or even greater thermodynamic efficiency compared with the Kalina novel bottoming cycle.     

SRC-LeCV工况循环与AMA工况循环比对研究

欧盟2013年发布的法规对L类车辆V型试验测试工况循环做出了新的规定,包括AMA循环和SRC-LeCV循环。详细地介绍了SRC-LeCV循环,并对车辆在AMA和SRC-LeCV两种不同循环下的实际行驶状态进行对比研究,对开展摩托车排放耐久检测与试验研究具有重要参考意义。     

Thermodynamic Analysis and Comparison of Performances of Air Standard Atkinson,Otto, and Diesel Cycles with Heat Transfer Considerations

This paper focuses on the overall performances of Otto, Atkinson, and Diesel air standard cycles. This study compares performance of these cycles with regard to parameters such as variable specific heat ratio, heat transfer loss, frictional loss, and internal irreversibility based on finite‐time thermodynamics. The relationship between thermal efficiency and compression ratio, and between power output and compression ratio of these cycles are obtained by numerical examples. In this study, it is assumed that during the combustion process, the heat transfer occurs only through the cylinder wall. The heat transfer is affected by the average temperature of both the cylinder wall and the working fluid. The results show that for each cycle, with the increase of the compression ratio in the specific mean piston speed, power output and thermal efficiency first increase and after reaching their maximum value, start to decrease. The results also indicate that maximum power output and maximum thermal efficiency of an Atkinson cycle could be higher than the values of these parameters in Diesel cycle and Otto cycle in the same operating conditions. The maximum power output and the maximum thermal efficiency of the Otto cycle have the lowest value among studied cycles. By increasing the mean piston speed, power output and thermal efficiency of Atkinson, Diesel, and Otto cycles start to decrease. The results of this study provide guidance for the performance analysis and show the improvement areas of practical Otto, Atkinson, and Diesel engines.     

A review of cryogenic power generation cycles with liquefied natural gas cold energy utilization

Liquefied natural gas (LNG), an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG cold energy are introduced and summarized. The direction of cycle improvement can be divided into the key factors affecting basic power generation cycles and the structural enhancement of cycles utilizing LNG cold energy. The former includes the effects of LNG-side parameters, working fluids, and inlet and outlet thermodynamic parameters of equipment, while the latter is based on Rankine cycle, Brayton cycle, Kalina cycle and their compound cycles. In the present paper, the diversities of cryogenic power generation cycles utilizing LNG cold energy are discussed and analyzed. It is pointed out that further researches should focus on the selection and component matching of organic mixed working fluids and the combination of process simulation and experimental investigation, etc.     

燃气轮机循环有限时间热力学研究新进展

在概述有限时间热力学理论产生和发展的基础上,着重介绍了运用该理论对闭、开式燃气轮机简单和复杂循环以及燃气轮机热电和热电冷联产循环性能进行热力学分析和优化的最新研究进展。指出了由于有限时间热力学理论进一步充分考虑了实际装置中的不可逆性,因此得到的循环最优性能是综合最佳的,同时也发现了一些与经典热力学理论研究不同的新结果。     

A critical assessment of thermo‐economic analyses of different air bottoming cycles for waste heat recovery

Steam turbine cycle's low operating temperature makes it suitable for waste heat recovery applications. Even though conventional combined cycles, ie, topping gas turbine and bottoming steam turbine cycles, are thermodynamically efficient, they are not the most economical alternatives for power generation with capacities less than 50 MWe. A recently proposed alternative is to utilize a bottoming gas turbine cycle in form of an air bottoming cycle. In this study, an overview of air bottoming cycle is presented. Based on the discussed studies, it is decided to further evaluate the merits of water injection in the bottoming cycle air stream by using either a humidifier or an air saturator. Thermo‐economic analysis and optimization are performed to evaluate simple and water injected air bottoming cycles against steam bottoming cycles. Results indicate that conventional combined cycles can achieve the highest thermal efficiency of about 48%. While water injected air bottoming cycle with air saturator is the most cost effective combined cycle configuration and most efficient air bottoming cycle with levelized cost of electricity and energy efficiency of 64.41 US$/MWh and 39%–40%, respectively, followed by the water injected air bottoming cycle with humidifier and simple air bottoming cycle with reported levelized cost of electricity of 65.75 US$/MWh, 66.36 US$/MWh, respectively. Steam bottoming cycle has the highest levelized cost of electricity of 68.88 US$/MWh.     

正反向布雷顿循环有限时间热力学分析与优化研究进展

在概述正反向布雷顿循环发展现状和有限时间热力学理论产生及发展的基础上,综述了利用有限时间热力学方法对闭式、开式正反向布雷顿循环进行的热力学分析与优化的最新研究进展。     

燃气蒸汽联合循环技术的发展

讨论燃气蒸汽联合循环的发展历程,并介绍了若干种先进的联合循环,有助于人们把握联合循环技术发展的趋势。