单效溴化锂吸收式制冷循环吸收特性与工况关系的研究

以单效溴化锂吸收式制冷机为研究对象,对溴化锂水溶液的热力性质参数进行了计算机模拟。通过模拟计算,得到了求解溴化锂水溶液热力参数的较为精确的计算方法。溴化锂吸收式制冷机是以水为制冷剂,溴化锂为吸收剂,通过消耗热能来实现制冷目的的。通过对单效循环的仿真模拟计算,实现了对机组在不同工作工况下的性能预测。为进一步利用数字和模拟手段深入研究溴化锂吸收式制冷机组奠定了良好的基础。     

溴化锂吸收式制冷循环的计算与分析

本文通过对国产溴化锂水溶液物性的实测数据进行回归分析,提出了溴化锂水溶液的平衡方程和焓-浓度方程。进而介绍了利用这两个方程在电子计算机上进行溴化锂吸收式制冷循环热力计算的方法。计算表明,采用上述方法较之查图表手算,既迅速又准确。文中还分析了吸收式制冷机所适用的热源温度。     

太阳能吸收式串联流程制冷系统与性能分析

本文提出了一种串联流程的以太阳能与燃气双热源供热的溴化锂吸收式制冷系统。介绍了当前太阳能吸收式制冷的发展概况。对双热源制冷系统原理进行介绍,简述了制冷机内工质循环流程,并模拟分析了系统的热力性能,得到高压发生器与低压发生器在不同放气范围时系统制冷系数与双热源的供热分配情况。分析了一天内不同时段制冷系统运行特性在不同太阳辐照度下的变化特点。结果证明太阳能与燃气双热源串联流程溴化锂吸收式制冷方案具有节能高效的优势。     

强吸水性离子液体-水工质对吸收式制冷循环性能分析

离子液体的出现,为吸收式制冷循环工质的改进开辟了新途径。以离子液体-水为工质对的吸收式制冷循环性能与离子液体的吸湿性能密切相关,因此筛选两种对水有极强吸收性能的离子液体：1-乙基-3-甲基咪唑醋酸盐（[EMIm]Ac）、1-己基-3-甲基咪唑氯盐（[HMIm]Cl）,对其水溶液吸收式制冷循环进行研究。首先对离子液体水溶液热力学特性（蒸汽压、比热、比焓等）进行了研究,然后分析吸收式制冷循环的性能系数。研究结果表明这两种离子液体-水工质对单效吸收循环可工作于较高温度条件下,其性能系数大大优于现今国内外学者所研究的离子液体,其中[EMIm]Ac水溶液优于[HMIm]Cl水溶液。与传统工质溴化锂-水比较,[EMIm]Ac-水工质对在发生温度为100℃时具有相当的循环性能系数,且在较高温度条件下优于传统溴化锂-水的性能系数。然而该离子液体水溶液优势只在较高发生温度时才能体现,要实现技术上的进一步突破,应着重筛选低温区蒸汽压特性优良的水溶性离子液体。     

Water—lithium bromide—lithium nitrate三元工双效吸收式制冷循环的研究质

比较了水-溴化锂-硝酸锂三元工质与传统的水一溴化锂工质的双效吸收式制冷循环,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。     

Water-lithium bromide-lithium nitrate三元工质双效吸收式制冷循环的研究

比较了水-溴化锂-硝酸锂三元工质与传统的水-溴化锂工质的双效吸收式制冷循环,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,尤其在商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.     

塑料换热技术在溴化锂吸收式制冷机上的应用展望

溴化锂吸收式制冷机在工业中有着广泛的应用,但换热装置腐蚀及其引起的冷量衰减一直以来是人们难以解决的问题.根据现有的溴化锂吸收式制冷机组的性能,结合塑料换热装置的一些特点,提出了采用塑料换热装置代替金属换热装置来解决溴化锂吸收式制冷机的这个难题;并以研制一台制冷量为3.49×104W的溴化锂吸收式制冷机组为例,对塑料换热装置的溴化锂吸收式制冷机组与传统金属溴化锂吸收式制冷机组相关部件的参数进行比较.通过对溴化锂吸收式制冷机组的传热面积、管道阻力的计算和安全强度的校核,发现塑料换热装置应用在溴化锂吸收式制冷机上是可行的,塑料换热技术在溴化锂吸收式制冷机上有着较好的应用前景.     

塑料管单效溴化锂吸收式制冷机理论与实验研究

溴化锂吸收式制冷机在工业中有着广泛的应用,但传热管腐蚀及其引起的拎量衰减一直以来是人们难以解决的问题。采用塑料传热管代替铜传热管有望解决这个难题。分析了单效溴化锂吸收式制冷机的理论循环,对塑料管单效溴化锂吸收式制冷机进行了热力计算和传热计算,设计了塑料管单效溴化锂吸收式制冷机的结构,为塑料管单效溴化锂吸收式制冷机的实验性能测试提供参考依据。     

中低温废热水驱动吸收式装置的试验研究及节能效果分析

本文介绍了溴化锂吸收式制冷和供热两用装置,在６５℃－９０℃废热水驱动下,实施制制冷循环及Ⅱ型热泵循环的试验研究结果,文内给出了吸收制冷循环和Ⅱ型热泵循环的热力系数,系统一次能源利用率、稀溶液浓度和放汽范围及负荷水温度的变化关系。并分析了不同驱动热水温度下的经济运行工况,制冷循环制冷量与Ⅱ型热泵循环供热量间的区配关系及系统的节能效果。     

三效溴化锂吸收式制冷机概述

溴化锂吸收式制冷机是以热能为动力,水为制冷剂,溴化锂水溶液为吸收剂制取空调或工艺用冷(热)水的制冷设备。这种制冷机因为热能为动力,能源利用的范围广,特别是余热、废热、排热的利用使溴化锂吸收式制冷机具要节能的特性。同时,因为水为制冷工     

两级双效溴化锂制冷-热泵复合循环

在热电冷联产系统中,溴化锂吸收式制冷机在制冷过程中排放了大量的废热,这些废热品味低,难以直接回收利用。在此提出了两级双效溴化锂制冷-热泵复合循环,该循环具有冷凝温度较高的特点,便于直接回收冷凝排放热。系统以背压汽轮机的背压蒸汽为热源,制冷的同时利用循环所排出的废热加热锅炉补充水至较高温度。以具有相同功效的双效溴冷机与单效溴化锂热泵联合运行作为对比循环,制冷-热泵复合循环系统省去了一台蒸发器与冷凝器,减少了两个换热温差,并且通过热力计算、能量分析和分析表明,该循环的能量利用率与效率均有很大的提高,效率比对比循环提高了45%。     

Industrial absorption refrigeration plants with storage facilities

Waste heat can be used for refrigeration purposes by means of either the absorption refrigeration system or the mechanical compression systems driven by a Rankine cycle. If the heating, or the duty, is intermittent the absorption refrigeration system can incorporate the storage of liquid refrigerant and weak solution with thermodynamic and operational advantages. The working principle of such an absorption refrigeration plant with the binary system NH₃---H₂O are explained and compared with conventional methods.     

Industrial absorption refrigeration plants with storage facilitiesInstallations frigorifiques à absorption industrielles avec dispositifs de stockage

Waste heat can be used for refrigeration purposes by means of either the absorption refrigeration system or the mechanical compression systems driven by a Rankine cycle. If the heating, or the duty, is intermittent the absorption refrigeration system can incorporate the storage of liquid refrigerant and weak solution with thermodynamic and operational advantages. The working principle of such an absorption refrigeration plant with the binary system NH₃H₂O are explained and compared with conventional methods.     

增压型溴化锂吸收式制冷（热泵）机组特性研究和溴化锂溶液热物性研究

溴化锂吸收式制冷是一种兼备环保与节能的制冷技术,已经得到广泛的重视和发展。本文介绍了关于溴化锂吸收式制冷的两方面研究,一方面是增压提效亚稳平衡型溴化锂吸收式制冷（热泵）机组特性研究,另一方面是添加剂对溴化锂溶液表面张力与传递性能的复合效应及其耦合机理研究。这两方面的研究均取得优异的成果。     

双效溴化锂吸收式制冷机热工参数控制的计算机仿真

本文对蒸汽双效溴化锂吸收式制冷机部分热工参数的动态特性进行了试验研究,得出了溴化锂吸收式制冷机冷媒水出口温度的阶跃响应曲线,利用两点法求出了被控对象的传递函数,建立了动态数学模型。控制器选用基于PID控制规律的数字控制器,设计了溴化锂吸收式制冷机热工参数控制的仿真系统。并对控制器的控制参数进行整定,得到了最佳控制结果。     

Mapping of optimum operating condition for LiBr–water refrigeration cycles

In this work, optimum operating condition maps are generated covering wide ranges of refrigeration and sink temperatures for single- and double-effect LiBr–water vapour absorption refrigeration cycle. These optimum condition maps will be useful to choose optimum operating conditions while designing LiBr–water cycle for desired applications. Methodology for generating such maps is discussed in detail, which can also be used for other absorption refrigeration cycles with various working fluids. Three configurations of LiBr–water absorption refrigeration cycles, single effect, double-effect series flow and double-effect parallel flow, are analysed with the most accurate thermodynamic property correlation available in the literature. Sensitivity of cycle performance to various operating variables such as generator, absorber and condenser temperatures is determined. Second law analysis shows that when a higher temperature heat source is available, double-effect cycles are more effective over single effect as they have higher coefficient of performance.     

The thermodynamic performance of a new solution cycle in double absorption heat transformer using water/lithium bromide as the working fluids

In this paper, a new solution cycle in the double absorption heat transformer is presented and the thermodynamic performance of this new cycle is simulated based on the thermodynamic properties of aqueous solution of lithium bromide. The results show that this new cycle is superior to the cycle being studied by some researchers. This new solution cycle has a wider range of operation in which the system maintains the high value of COP and has larger temperature lifts and operation stability. The relationship between the absorber and the absorbing evaporator is more independent and this makes the operation and control of the system more easier.     

新型CO2超音速两相膨胀制冷循环的理论研究

本文提出了以Laval喷管为核心部件的超音速两相膨胀机的概念,构建了以天然制冷剂CO2为工质的超音速两相膨胀制冷循环模型并对其进行理想循环热力学分析和模拟计算研究。结果表明：超音速两相膨胀机入口压力、入口温度和旋流分离段出口压力均对系统制冷性能有影响;在空调温区工况,CO2超音速两相膨胀制冷循环COP为6.69,是现有制冷性能相对最优的CO2跨临界制冷循环COP的1.63倍,且大幅降低系统压力;气液分离时液相速度损失对系统制冷性能有影响,系统COP由9.56减至6.01,相对卡诺效率由0.95减至0.60,但仍然保持在较高水平。通过初步的热力学分析和模拟计算研究表明,新型CO2超音速两相膨胀制冷循环具有较好的原理可行性和发展前景。     

Thermodynamic evaluation of new absorbent mixtures of lithium bromide and organic salts for absorption refrigeration machines

Mixtures of lithium bromide and organic salts of sodium and potassium (formate, acetate and lactate) have been evaluated as alternative absorbents for absorption refrigeration machines. The main objective is to overpass the limitations of lithium bromide and improve the characteristics and the efficiency of the refrigeration cycle. In order to select the mixture that presents better properties for its employment in absorption refrigeration cycles, a thermodynamic analysis have been done. Density, viscosity, enthalpies of dilution, solubility and vapour pressure data of the proposed mixtures have been measured. A simulation program has been developed to evaluate temperatures, heats exchanged in the different sections and the efficiency of the cycle.