共查询到18条相似文献,搜索用时 281 毫秒
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本文对三元工质对水-溴化锂-硝酸锂及传统工质对水-溴化锂的制冷循环进行热力计算及比较。结果表明,在相同的工作条件下,水-溴化锂-硝酸锂制冷循环是优越的,其性能系数COP有明显的提高,且循环率f有所下降。 相似文献
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在较高的热源温度下,吸收制冷系统需采用双效再生流程提高制冷性能系数COP,从而却使只用氨作为制冷剂的系统再生操作压力大幅度增高.为克服这种缺陷,提出了一种新的吸收制冷系统,分别以水-溴化锂和氨-硝酸锂作为二个系统的工质,将二系统耦合组成双制冷温度双工质系统.对该系统的操作性能进行了热力学模拟,分析讨论了热源温度、冷却水温度和蒸发器2蒸发温度对系统操作性能的影响及系统适宜的操作条件.该系统操作稳定,在较宽的操作条件下,COP可以稳定在1.10以上,与类似条件下只用水-溴化锂作为工质的系统相当,但相应的制冷温度可低至-13℃以下,是一种很有开发应用前景的吸收制冷系统. 相似文献
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本文从回顾学术界对热电冷联产联供的讨论开始,到今年三个学术团体在常州市联合召开热电冷联学术交流会,谈到热电冷联产新技术在社会主义经济建设中的作用。但是,目前所说的热电冷联产的只是限局于溴化锂制冷进行空调,大大限制了热电冷新技术充份发挥效益,作者提出,应当扩宽热电冷联产联供的范围,以便使这项技术产生更大效益,这就是要发展氨吸收制冷,本文还对氨吸收制冷作简要介绍后,举出氨吸收制冷可以获得巨大经济效益的 相似文献
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采用离子液体[mmim]DMP-甲醇作为吸收式制冷系统工质对,运用文献提出的[mmim]DMP-甲醇二元溶液经验方程进行制冷循环计算研究,并将此系统的工作压力、COP等与相同工况下的溴化锂-水、氨-水制冷循环进行比较。研究结果表明:[mmim]DMP-甲醇工质对制冷系统工作压力要求适中,COP稍高于NH3/H2O系统,低于H2O/LiBr系统;[mmim]DMP-甲醇溶液对金属无腐蚀,其适用范围要大于H2O/LiBr系统,具有一定的应用价值。 相似文献
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一、前言太阳热制冷大多采用氨—水或水—溴化锂吸收式制冷的方式。由于这两种制冷方式系统较复杂、主机制造要求高、价格昂贵等,因而行家们试图寻求更具有竞争力的制冷方式。本文首先介绍利用一般平板形集热器, 相似文献
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在主要由热能来驱动的吸收式制冷系统中,目前普遍使用的有氨—水、水—溴化锂双组分吸收式制冷及氨—水—氢三组分连续扩散吸收制冷。前两者已广泛用于大型的制冷和空调系统;扩散吸收制冷循环在三十、四十年代,则以煤气冰箱型式得到过广泛的应用。这种制冷方式的特点是在系统中采用氨为致冷剂,水为吸收剂,并加入一定压力的惰性气体—氢。在装置中,氨、水蒸汽和氢的总压力在各个部分都相等。而在蒸发器 相似文献
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为克服在较高温度的热源下只用氨作为制冷剂时采用二级再生流程系统操作压力高的弊病,提出了一种新的吸收制冷系统.将水-溴化锂和氨-硝酸锂二系统耦合,在后者所组成的系统2中设置二个不同蒸发温度的蒸发器.对该系统的操作性能进行了热力学模拟,分析讨论了热源温度、冷却水温度和低温蒸发温度的影响及系统适宜的操作条件.在较高的热源温度和较宽的操作条件下,系统操作性能稳定,其制冷性能系数COP可以稳定在0.95以上,稍低于类似条件下只用水-溴化锂作为工质的二级再生系统,但相应的制冷温度分别为1℃和-5℃,是一种很有实用价值的吸收制冷系统. 相似文献
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垂直管内TFE/NMP降膜吸收过程中热质传递试验研究 总被引:2,自引:0,他引:2
作为一种新型的吸收式制冷工质时-TFE/NMP(2,2,2-trifluo-roethanol/N-methylpyrolidone,中文名:三氟乙醇/氮甲基吡咯烷酮),因其良好的工作特性而被国际制冷界所重视,但有关吸收式制冷/热泵系统运行中的一个重要环节-TFE/NMP降膜吸收过程中的传热、传质现象却有人进行过研究。在国家自然科学基金的资助下,我们建立了单根管吸试验台以研究TFE/NMP降膜吸收过程中热、质传递规律。在不同TFE/NMP溶液流量和不同冷却水流量条件下,测得两组试验数据,对试验数据进行处理并对其数据结果加以分析后,得出垂直管内TFE/NMP降膜吸收过程中热量和质量传递规律的一些特性。 相似文献
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吸收式制冷技术的研究与应用 总被引:1,自引:0,他引:1
简单回顾了吸收式制冷技术的发展背景;较详细地介绍了国内外吸收式制冷技术的研究热点,主要包括对新工质对、吸收循环、传热与传质、智能化控制方式等几方面的研究。目前,溴化锂吸收式机组已经被广泛地应用于空调系统,本文对其在国内外的应用现状进行了详细介绍,主要包括热电冷联产、直燃型吸收式冷热水机组、蒸汽型吸收式冷水机组、热水型吸收式冷水机组、太阳能吸收式机组等:最后对吸收式制冷技术的前景进行了展望。 相似文献
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Daliang Hong Guangming Chen Limin Tang Yijian He 《International Journal of Refrigeration》2011,34(7):1596-1603
This paper presents a novel ejector-absorption combined refrigeration cycle. When the temperature of the heat source is high enough, this cycle will work as a double-effect cycle. If the temperature of the heat source is lower than required temperature of heat source used to drive conventional double-effect absorption refrigeration cycle but much higher than required temperature of heat source used to drive conventional single-effect absorption refrigeration cycle, the COP of new cycle will also be higher than that of conventional single-effect absorption refrigeration cycle. Simulation results show that the COP of the cycle is 30% higher than that of the conventional single-effect absorption refrigeration cycle at some working conditions even in the later case. 相似文献
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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. 相似文献
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In this context, a two-stage absorption-transcritical hybrid refrigeration system is proposed. R744 is chosen as a refrigerant for the transcritical heat pump subsystem and LiBr-H2O working pair for the two-stage absorption refrigeration subsystem. Based on the mathematical and physical models, theoretical investigation is carried out on its performance. The main effects are discussed on COPnet (the ratio of cooling capacity powered by low-grade heat to the low-grade heat consumption for the hybrid system) and COPmt (the ratio of cooling capacity powered by mechanical work to the mechanical work consumption for the hybrid system). Comparing with the normal two-stage absorption refrigeration system, theoretical results show that COPnet could be improved up to about 55% when the refrigeration temperature is 7 °C. In addition, COPmt are more than 50% higher than that of the conventional transcritical refrigeration system. It is also found that both 45–55 °C low-grade heat and condensing heat could be used as actuating heat of the two-stage absorption refrigeration subsystem. 相似文献
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介绍了一个用柴油机驱动的复合制冷循环,即用柴油机主机带动压缩式循环,同时利用柴油机排气和缸套水的热量作源驱动吸收式循环。热力学分析和数值计算表明,此复合循环由于实现了不同品位热源的合理利用,减少了不可逆损失,其能效比普通式循环或直燃式吸收循环可分别提高19%和58%。 相似文献