水-溴化锂-硝酸锂与水-溴化锂吸收式制冷循环的比较

比较了水-溴化锂-硝酸锂三元工质与传统的水-溴化锂工质的单、双效吸收式制冷循环，分析了发生温度、冷凝温度和蒸发温度对系统性能的影响；同时也分析了直燃型双效制冷系统。结果表明：采用新工质后，系统的热力系数COP有了明显的提高，其它表征系统热力性能的经济指标也均有不同程度的改善，尤其在直燃型双效冷热水机组中有明显的优势，热力系数COP提高约30％，溶液循环倍率f降低12％。因此，该新工质与传统的水-溴化锂工质相比，具有较好的热力性能。     

小型直燃型溴化锂吸收式制冷机制冷性能的测试研究

本文针对小型直燃型溴化锂吸收式制冷机设计了一套简单实用的制冷性能测试设备。该测试设备不仅在理论上可以保证测试过程中误差达到要求，而且在实际应用时简便和经济，采用该设备成功地完成了最新研制的１１６ｋＷ直燃型溴化锂吸收式制冷机的制冷性能测试。     

溴化锂吸收式制冷的耗能分析

<正> 一、引言传统的制冷是消耗电能,但为了大面积空间的空调,因电力紧张,迫使人们寻找不耗电的制冷技术,因而溴化锂吸收式制冷,得到迅速推广。国内不少杂志都发表文章,认为溴化锂制冷节电节能,并提出在热电联产机组上配置相     

三效溴化锂吸收制冷循环的参数优化

三效吸收循环是提高现有单效和双效吸收循环性能的一个发展方向。本文建立了使用溴化锂水溶液在做工质的三效吸收制冷循环模型,并进行了性能比较计算。结果表明：并联流程涵环的性能系数（ＣＯＰ）最高。同时对并联流程和串联流程的三效吸收循环分别进行了系统发生压力和溶液分配率的性能系数以及经济性能指标的优化计算,为三效吸收循环的最优设计提供理论依据。     

烟气热水型溴化锂吸收式制冷机组的仿真及性能分析

基于某烟气热水型溴化锂吸收式制冷机组的工作原理及内部系统流程,建立相应的仿真模型,通过系统热力过程计算,分析热水负荷、溴化锂溶液放气范围、机组负荷率及冷却水温度等因素对机组性能的影响。研究表明:烟气热水型溴化锂机组处于低负荷工况下,优先利用烟气余热,制冷系数可提高16.7%,冷却水流量可减少22.5%;增大溴化锂溶液放气范围,可提高制冷系数,其中放气范围在0.05～0.08之间,COP增长较快,溴化锂溶液浓度差每增长0.01,可增加约3%的制冷量,增大放气范围时,稀溶液浓度的降低受限于冷却水温度;冷却水温度降低,可提高制冷系数,当冷却水进口温度降低,可降低吸收温度,吸收压力降低,蒸发温度降低;发生器满负荷工况下,制冷系数最高;发生器负荷率降低,制冷系数明显降低,发生器负荷率为50%时,制冷量负荷只有30%左右。     

太阳能驱动溴化锂吸收式制冷装置的优化设计

本文介绍了用于夏季室内空调的太阳能驱动溴化锂吸收式制冷装置的优化设计。分别就高、低两种驱动热水设计温度进行了优化计算，得出了装置的结构参数和各自的运行参数，编制的优化设计程序不仅可用于装置结构参数和运行参数的优化，还可用于预示不同驱动热水温度下装置的性能。     

太阳能溴化锂吸收式制冷技术的发展趋势及研究进展

在能源紧张、环境污染日益严重的今天,太阳能的开发利用符合环境保护的可持续发展要求。在太阳能的应用中,太阳能空调技术具有良好的发展前景,既满足了人们追求高品质生活的要求,又节能环保,是空调制冷的理想形式。文中介绍太阳能溴化锂吸收式制冷系统的工作原理,阐述吸收式制冷循环系统的几种典型结构及相关的研究进展,对影响溴化锂吸收式制冷机组性能的因素进行分析,最后探讨太阳能溴化锂吸收式制冷机的发展前景。     

太阳能溴化锂吸收式制冷技术的研究进展

介绍了太阳能澳化锂吸收式制冷循环的工作原理和系统构成,具体阐述了该制冷循环的几种典型结构,包括单效、双效、两级以及三效涣化锂吸收式制冷循环,分析了各种制冷循环的优缺点以及目前研究进展;进一步讨论了太阳能澳化锂吸收式制冷机组的性能特点受冷媒水出口温度、冷却水进口温度、加热蒸汽温度、污垢系数及不凝性气体等诸多因素的影响;提出了太阳能溴化锂吸收式制冷技术现存问题,最后指出,随着科学技术的发展和绿色建筑的兴起,太阳能溴化锂吸收式制冷将会有非常大的发展前景。     

利用汽车发动机余热的溴化锂吸收式制冷研究

根据现有汽车空调的制冷系统和发动机冷却水及排气系统的结构特点,结合溴化锂吸收式制冷系统的工作原理,提出将汽车排气管和发动机冷却水箱进行结构改造作为溴化锂吸收式制冷系统的发生器,代替传统的汽车空调的制冷和采暖系统及发动机冷却系统。并对该溴化锂制冷系统进行了热力计算和传热面积的计算,计算结果表明,溴化锂制冷系统充分利用了废气余热和冷却水余热,减少了汽车油耗,并且改造后的排气热交换器和冷却水箱传热面积小,结构简单紧凑。     

Thermodynamic optimization of a solar system for cogeneration of water heating and absorption cooling

This paper presents a contribution to understanding the behavior of solar‐powered air conditioning and refrigeration systems with a view to determining the manner in which refrigeration rate, mass flows, heat transfer areas, and internal architecture are related. A cogeneration system consisting of a solar concentrator, a cavity‐type receiver, a gas burner, and a thermal storage reservoir is devised to simultaneously produce heat (hot water) and cooling (absorption refrigerator system). A simplified mathematical model, which combines fundamental and empirical correlations, and principles of classical thermodynamics, mass and heat transfer, is developed. The proposed model is then utilized to simulate numerically the system transient and steady‐state response under different operating and design conditions. A system global optimization for maximum performance (or minimum exergy destruction) in the search for minimum pull‐down and pull‐up times, and maximum system second law efficiency is performed with low computational time. Appropriate dimensionless groups are identified and the results are presented in normalized charts for general application. The numerical results show that the three‐way maximized system second law efficiency, η_{II,max,max,max}, occurs when three system characteristic mass flow rates are optimally selected in general terms as dimensionless heat capacity rates, i.e. (ψ_ss, ψ_wxwx, ψ_Hs)_opt=(0.335, 0.28, 0.2). The minimum pull‐down and pull‐up times, and maximum second law efficiencies found with respect to the optimized operating parameters are sharp and, therefore, important to be considered in actual design. As a result, the model is expected to be a useful tool for simulation, design, and optimization of solar energy systems in the context of distributed power generation. Copyright © 2008 John Wiley & Sons, Ltd.     

地源热泵空调系统可行性分析及设计软件开发

介绍自主开发的地源热泵空调系统可行性分析设计软件的理论基础、主要功能和操作过程,并应用实例验证软件的准确性和实用性。该软件的开发以实际可行性分析过程为参考,采用实际常用的分析模板,可以方便快捷地计算出结果,有效地提高了设计者的工作效率。     

煤矿井下供电系统管理软件设计模型

从煤矿井下供电管理现状、供电管理软件设计的目标、设计完成的功能,以及供电系统管理软件应用应注重的问题等几方面作浅析.     

Exergy analysis of a compression–absorption system for heating and cooling applications

An exergy analysis of a single‐stage compression–absorption system with R22‐E181 as the working fluid pair is carried out. Theoretical results obtained have been compared with those obtained from the experiment. Results show that the heat of mixing of the refrigerant vapour and solution at absorber and desorber contributes a significant amount to the internal entropy generation rates. A significant part of internal entropy generation rate is also due to non‐isentropic compression of refrigerant vapour at higher absorber pressure. The exergetic efficiency of the system increases with the increase in absorber pressure due to reduction in internal irreversibilities. Higher value of weak solution concentration along with the increase in solution concentration difference results in higher exergetic efficiency of the system. Thus, a compression–absorption system performs better when operated at higher absorber pressure, and an improved system performance can also be achieved with higher value of weak solution concentration with higher possible solution concentration difference. Copyright © 2008 John Wiley & Sons, Ltd.     

Thermodynamic analysis of a lithium bromide/water absorption system for cooling and heating applications

Absorption systems have the potential of employing thermal energy such as waste heat to produce both chilled water and hot water for building cooling and heating applications. In the present study, a lithium bromide/water (LiBr/H₂O) absorption system for cooling and heating applications was analysed on the basis of the first and second laws of thermodynamics. Simulation was employed to determine the coefficient of performance (COP) and the exergetic efficiency of the absorption system under different operating conditions such as the heat source, cooling water, chilled water, and supply hot water temperatures. Copyright © 2001 John Wiley & Sons, Ltd.     

Experience with fully operational solar-driven 10-ton LiBr/H2O single-effect absorption cooling system in Thailand

A solar-driven 10-ton LiBr/H₂O single-effect absorption cooling system has been designed and installed at the School of Renewable Energy Technology (SERT), Phitsanulok, Thailand. Construction took place in 2005, after which this system became fully operational and has been supplying cooling for our main testing building's air-conditioning. Data on the system's operation were collected during 2006 and analyzed to find the extent to which solar energy replaced conventional energy sources. Here, we present these data and show that the 72 m² evacuated tube solar collector delivered a yearly average solar fraction of 81%, while the remaining 19% of thermal energy required by the chiller was supplied by a LPG-fired backup heating unit. We also show that the economics of this cooling system are dominated by the initial cost of the solar collector array and the absorption chiller, which are significantly higher than that of a similar-size conventional VCC system.     

内燃机车冷却系统技术经济模型的建立及优化设计

指出经济性指标全面地反映了内燃机车冷却系统的性能指标和结构指标 ,是比较理想的评价指标。采用非线性规划中的惩罚函数法 ,运用最优化理论来确定内燃机车冷却系统的最优方案。还以干线内燃机车为例进行优化设计分析     

新能源汽车动力电池冷却系统热仿真及优化

动力电池的温度控制是新能源汽车发展中的一个难题,而电池冷却系统在动力电池的温度控制过程中起着相当重要的作用。利用Solidworks软件对电池包进行建模,利用ICEM CFD软件对电池包模型进行网格划分等前处理。利用Fluent软件并采用控制变量法分别对冷却管道截面宽度、冷却液质量流量和冷却液进口温度等3个对电池包散热性能影响较大的参数进行仿真计算和对比分析。根据仿真结果选择可优化电池包散热性能的参数,并在原方案基础上提出了一种新的冷却管道分布方案。经过仿真计算发现,该方案可有效降低电池在使用过程中的最高温度和温差,提高了电池冷却系统的散热性能。     

Numerical investigation of a two-stage air-cooled absorption refrigeration system for solar cooling: Cycle analysis and absorption cooling performances

Two-stage air-cooled ammonia–water absorption refrigeration system could make good use of low-grade solar thermal energy to produce cooling effect. The system simulation results show that thermal COP is 0.34 and electrical COP is 26 under a typical summer condition with 85 °C hot water supplied from solar collector. System performances under variable working conditions are also analyzed. Circular finned tube bundles are selected to build the air-cooled equipment. The condenser should be arranged in the front to get an optimum system performance. The mathematical model of the two-stage air-cooled absorber considering simultaneous heat and mass transfer processes is developed. Low pressure absorber should be arranged in front of middle pressure absorber to minimize the absorption length. Configuration of the air-cooled equipment is suggested for a 5 kW cooling capacity system. Temperature and concentration profiles along the finned tube length show that mass transfer resistance mainly exists in liquid phase while heat transfer resistance mainly exists in cooling air side. The impacts on system refrigeration capacities related to absorption behaviors under variable working conditions are also investigated. Both cycle analysis and absorption performances show that two-stage air-cooled ammonia–water absorption chiller is technically feasible in practical solar cooling applications.     

Theoretical analysis and optimization of a double-effect series-flow-type absorption chiller

A thermodynamic analysis was carried out to study the effect of design parameters, including heat recovery ratio and solution circulation ratio, on the performance of a double-effect absorption chiller of the series-flow-type using water-lithium bromide as the working fluid. Increases in the heat recovery ratios of the high-temperature heat exchanger and the low-temperature heat exchanger and/or decreases in the solution circulation ratio improved the coefficient of performance. An increase in the heat recovery ratio of the high-temperature heat exchanger increased the total heat transfer area of the absorption chiller. The optimum design and operating conditions of a double-effect absorption chiller are suggested based on this cycle simulation analysis.