新型太阳能吸收式制冷系统发生器的研究

设计了一种新型太阳能吸收式制冷系统的发生器,利用喷嘴把澳化锂溶液切向喷射到发生器中,通过溴化锂溶液在发生器内的旋转流动,有效降低发生器内部压力,达到降低溴化锂溶液的蒸发温度、充分利用太阳能等低品位热源的目的.     

新型太阳能吸收式制冷循环的性能分析

在两级溴化锂吸收式制冷循环的基础上,提出了一种由太阳能驱动的新型吸收式制冷循环,并对其进行性能分析。通过大量计算,分析结果表明,在现有太阳能集热器所能提供的热水温度范围内,新型太阳能吸收式制冷循环有较高的热力系数。该循环系统的中间压力、中间浓度对系统的热力系数和热源可利用温差有较大影响。     

朗肯循环耦合双效溴化锂吸收式制冷系统建模及性能分析

为提高船用柴油机余热回收效率,利用MATLAB对朗肯循环及双效溴化锂吸收式制冷系统进行建模及热力学分析,确定朗肯循环热效率的影响因素及双效溴化锂吸收式制冷阶段中废气温度、高压发生器温度、低压发生器温度对制冷量和性能系数的影响。结果表明：朗肯循环最佳工质为水;升高初温、初压和降低背压可提高朗肯循环热效率;随着废气温度增加,双效溴化锂吸收式制冷系统的制冷量增加,制冷性能因数降低;随着高压发生器温度升高,制冷量降低,制冷性能因数降低;随着低压发生器温度降低,制冷量增加,制冷性能因数降低;应根据不同环境及场合要求,调整双效溴化锂吸收式制冷系统相关参数。     

小型太阳能驱动单效溴化锂吸收式制冷机组的模拟研究

对太阳能驱动的单效溴化锂吸收式制冷机组的性能进行数值模拟研究,通过TRNSYS建立太阳集热器仿真系统,分析太阳能辐射强度及太阳能驱动温度对机组制冷性能的影响;利用EES(engineering equation solver)编程建立小型单效溴化锂吸收式制冷机组(12 kW)模型,采用动态数值模拟的方法,研究小型制冷机在设计工况以及变工况下的热力性能和机组运行状态。并采用耦合研究的方式,系统分析驱动热源温度、热源流量、冷媒水进出口温度、冷却水进口温度等因素对机组制冷性能的影响。研究结果表明:低温集热器的工作温度区间和单效溴化锂制冷机匹配性较好,既可避免能源品位的浪费,又不会使热源驱动温度过高,造成溴化锂溶液结晶的出现。太阳有效辐射强度对机组制冷性能影响显著,辐射强度从550 W/m2增至990 W/m2时,制冷量由5 kW增至16 kW,在设计参数下,小型太阳能吸收式制冷机的性能系数可达到0.70。     

新型1.x级溴化锂吸收式制冷机循环

文中介绍了一种新型1．x级溴化锂吸收式制冷机循环。该新型循环在原有两级溴化锂吸收式制冷循环基础上增加了一个附加高压发生器．使部分流体按单效循环工作．同时可将热源进出口温差加大到25～30℃左右，在热水进出口温度为85℃和60℃时，热力系数COP则能达到0．58左右。该循环非常适合于利用太阳能等低势热能制冷，能够产生显著的节能和环保效果。     

溴化锂水溶液热物性计算可视化程序

根据国内外有关溴化锂水溶液的热物理性数据,编制了溴化锂水溶液的热物性计算程序软件,与实验数据对比显示较好的吻合性,采用混合编程的方法,实现了计算程序的可视化,适用于化锂吸收式制冷的性能分析与计算,以及对溴化锂吸收式制冷机的在线检测。     

模拟太阳能驱动吸收式装置的试验研究

报道了溴化锂吸收式制冷和供热两用装置在由模拟太阳能集热器提供的６７－７５℃热水驱动下，实施制冷循环及Ⅱ型热泵循环的试验研究结果。给出了驱动热水温度为定值及变值时吸收式装置的性能和经济指标随运转参数的变化关系，并分析了经济运行工况、制冷量与供热量间匹配关系及系统的节能效果。     

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。     

热水型双效压缩吸收式制冷循环热力分析

通过对太原地区中央空调运行费用的调查,得出热水型溴化锂机组运行费用相对较小。针对集中供热热水用于溴化锂吸收式制冷时的温度不匹配问题,提出在双效并联循环中增加一个加压装置的办法,通过补偿一部分电能以扩大双效循环对热源温度的适用范围,从而使得双效溴化锂吸收式制冷可以使用集中供热一次热源作为驱动能源。     

太阳能吸收式空调系统在别墅中的应用

根据别墅建筑的特点,建立一套太阳能与小型溴化锂吸收式制冷机相结合的制冷／热泵系统。该系统可为别墅建筑实现夏季制冷、冬季供暖以及全年提供生活用热水多项功能。介绍了整个系统的形式及其工作原理以及如何选择太阳能集热器和吸收式制冷机,并指出了系统的初投资较高、系统效率较低等不足;建议了提高制冷机制冷系数的措施以提高系统的总效率。     

用于太阳能空调的板型溴化锂吸收式制冷机

溴化锂吸收式制冷循环用于太阳能空调需要解决的主要问题是循环系统要适合集热器所能提供的热水温度范围，和提高溴冷机本身性能并降低其制造成本。板型(包括板壳式、板式、板翅式)换热器用于溴冷机具有效率高、结构紧凑、轻巧和成本较低等优点，已被本课题组研制的1台3kW板型单效溴冷机实验样机所证实。     

Computer modeling and parametric study of a double effect generation absorption refrigeration cycle

This paper presents as assessment based on steady-state thermodynamic analysis and computer modeling of a double effect generation absorption refrigeration cycle for solar air-conditioning. The system consists of a second effect generator between the generator and condenser of the single effect absorption cycle and two solution heat exchangers between the absorber and the two generators. A numerical computer modeling of a water LiBr system based on the solution of simultaneous heat, mass and material balance equations for various components of the system has been carried out. The influences of component temperatures and heat exchanger effectiveness on the cooling coefficients of performance and component heat transfer rates have been investigated to obtain optimum operating conditions for the proposed air-conditioning system. Further, the single and double effect absorption cycles are compared with each other as well as with an ideal absorption cycle operating over the same range of temperatures.     

太阳能驱动风冷喷射式绝热吸收制冷循环研究

为改善太阳能吸收制冷循环性能并解决太阳能吸收制冷机风冷化问题,提出一种太阳能驱动的风冷喷射式绝热吸收制冷循环,通过喷射式绝热吸收器实现吸收过程的传热传质分别强化,同时回收高压溶液节流损失和再循环溶液的余压,以进一步增强吸收效果.构建组成循环各部件热力学数学模型,探讨了环境温度、发生温度、蒸发温度以及喷射器对新循环的影响...     

溴化锂吸收式制冷技术研究进展

回顾了近十年来有关溴化锂吸收式制冷技术的发展及主要研究成果。H₂O/LiBr作为一种广泛应用的吸收式制冷工质对,具有优良的热力学性能与环保特性,但存在结晶、腐蚀和循环性能低等问题。文章简述了醇类、盐混合物、离子液体及纳米颗粒等添加剂对H₂O/LiBr溶液传热传质、防结晶及防腐蚀等性能的提升;介绍了关键部件吸收器和发生器的理论及实验研究现状;回顾了吸收式制冷系统循环优化的研究成果。通过归纳分析,总结溴化锂吸收式制冷技术存在的一些问题及未来发展趋势,为后续的研究提供参考。     

Thermodynamic performances of [mmim]DMP/Methanol absorption refrigeration

In order to study the theoretical cycle characteristic of [mmim]DMP(1-methyl-3-methylimidazolium dimethylphosphate)/methanol absorption refrigeration,the modified UNIFAC group contribution model and the Wilson model are established through correlating the experimental vapor pressure data of [mmim]DMP/methanol at T=280～370K and methanol mole fraction x=0.529～0.965.Thermodynamic performances of absorption refrigeration utilizing [mmim]DMP/methanol,LiBr/H2O and H2O/NH3 are investigated and compared with each other under the same operating conditions.From the results,some conclusions are obtained as follows:1)the circulation ratio of the [mmim]DMP /methanol absorption refrigeration is higher than that of the LiBr/H2O absorption refrigeration,but still can be acceptable and tolerable.2)The COP of the [mmim]DMP/methanol absorption refrigeration is smaller than that of the LiBr/H2O absorption refrigeration,while it is higher than that of the H2O/NH3 absorption refrigeration under most operating conditions.3)The[mmim]DMP/methanol absorption refrigeration are still available with high COP when the heat source temperature is too high to drive LiBr/H2O absorption refrigeration.     

吸收式制冷循环利用低品位热能的研究现状和发展趋势

介绍吸收式制冷循环利用低品位热能的研究现状和发展趋势。阐述吸收式制冷系统对太阳能、工业余热、生物质能和地热能四种能源的利用情况,并主要从低品位热能的选择、吸收式制冷循环系统的优化和吸收器的优化三方面分析该系统存在的问题和发展趋势。     

Research on performance of mixed absorption refrigeration for solar air-conditioning

A novel lithium bromide/water mixed absorption refrigeration cycle that is suitable for the utilization of solar air-conditioning and can overcome the drawbacks of low system overall efficiency of traditional solar absorption refrigeration air-condition systems is presented. The accessorial high pressure generator was added in the cycle. The lithium bromide solution flowing out from the high pressure generator was mixed with the solution from the low pressure absorber to increase lithium bromide solution concentration and decrease pressure in the high pressure absorber. The performance of a mixed absorption refrigeration cycle was analyzed. The theoretical analysis shows that the highest COP is 0.61, while the highest available temperature difference of heat resource is 33.2°C. The whole coefficient of performance of the solar air-conditioning using mixed absorption cycle is 94.5% higher than that of two-stage absorption. The advantages of solar air-conditioning can be markedly made use of by the cycle.     

Simulation research on an EAX (Evaporator-Absorber-Exchange) absorption refrigeration cycle

There are some heat sources whose temperature is much higher than the limited generation temperature of conventional single effect absorption refrigeration cycle but lower than that of conventional double effect absorption refrigeration cycle. These heat sources can not be utilized efficiently by prior cycles. To make efficient use of these heat sources, this paper proposed an EAX (Evaporator-Absorber-Exchange) absorption refrigeration cycle. The proposed cycle can make use of the condensing heat of the vapor separated from high temperature generator to make additional refrigeration. Therefore, the COP (Coefficient of Performance) of the proposed cycle is much higher than that of the conventional single effect cycle. Simulation results show that the COP of the EAX cycle can be 40% higher than that of the conventional single effect cycle at some simulated conditions.     

First and second law investigations of a new solar‐assisted thermodynamic cycle for triple effect refrigeration

This investigation is persuaded for the first and second law analyses of a new solar‐driven triple‐effect refrigeration cycle using Duratherm 600 oil (Duratherm Extended Life Fluid, NY, USA) as the heat transfer fluid is performed. The proposed cycle is an integration of ejector, absorption, and cascaded refrigeration cycles that could produce refrigeration output of different magnitude at different temperature simultaneously. Both exergy destruction and losses in each component and hence in the overall system are determined to identify the causes and locations of the thermodynamic imperfection. The effects of some influenced parameters such as hot oil outlet temperature, refrigerant turbine inlet pressure, and the evaporator temperature of ejector and cascaded refrigeration cycle have been observed on the first and second law performances. It is found that maximum irreversibility occurs in central receiver as 52.5% and the second largest irreversibility of 25% occurs in heliostat field. The second law efficiency of the solar driven triple effect refrigeration cycle is 2%, which is much lower than its first law efficiency of 11.5%. Analysis clearly shows that performance evaluation based on the first law analysis is inadequate and hence, more meaningful evaluation must be included in the second law analysis. Copyright © 2013 John Wiley & Sons, Ltd.