共查询到20条相似文献,搜索用时 15 毫秒
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R22与其替代工质的性能比较与分析 总被引:7,自引:0,他引:7
1前言传统的单工质蒸气压缩理论循环分析认为在冷凝器和蒸发器中,制冷剂的冷凝温度和蒸发温度等于相变温度,而忽略了压缩机进出口的过热段以及冷凝器出口过冷段的温度变化,直接造成了人们对回热循环和过热循环的认识偏差,产生了许多误解,其评价标准是有缺陷的。本文以变温热源的可逆循环为基础,考虑了在实际中是可以利用的过热段以及过冷段的温度变化,假设在冷凝器和蒸发器中,制冷剂与外界高、低温热源无换热温差,使循环更接近可逆循环。以此为基础的当量温度法可完善单工质的理论循环分析,同时可用于朗肯循环与劳伦兹循环之间的… 相似文献
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《Heat Recovery Systems and CHP》1991,11(6):563-572
This communication presents some studies on hybrid vapor-compression (V-C) and solid/liquid desiccant solar air-conditioning systems. Desiccants are used to bring the humidity within the comfort range by partially converting the latent heat load (LHL) into sensible heat load and then meeting this load with conventional V-C cycle. In both the options of hybrid systems consisting of vapor-compression and solid/liquid desiccant cycles, heat rejected from the condenser of the V-C cycle is used to regenerate the desiccants to improve the coefficient of performance (COP) of the systems. A thermodynamic assessment and technoeconomic feasibility study of hybrid V-C and solid/liquid desiccant solar air-conditioning systems have been presented. It is found that a hybrid system with desiccant cycle is more promising under high latent heat load and higher ambient humidity conditions and significant energy saving can be achieved over standard V-C cooling systems. 相似文献
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本文提出了一种供热温度为80~100℃的新型空气源高温热泵循环(EIHP),该循环采用非共沸混合工质R290/R600a,利用内部自复叠技术和喷射器提升循环性能。针对EIHP循环建立了相应的热力学计算模型,并与传统热泵循环(CHP)进行了对比研究。根据计算结果,当冷凝器出口温度为100℃,蒸发器出口温度从25℃下降到-10℃时,相较于CHP循环,EIHP循环的COP提高了15%~27%,压缩机压比降低了20%~46%,容积制热量提高了22%~51%。此外,本文还研究了冷凝器出口温度,工质配比等参数对循环性能的影响情况。 相似文献
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Experimental investigation of a thermoacoustic-Stirling refrigerator driven by a thermoacoustic-Stirling heat engine 总被引:1,自引:0,他引:1
In this paper, a thermally-driven thermoacoustic refrigerator system without any moving part is reported. This refrigeration system consists of a thermoacoustic-Stirling heat engine and a thermoacoustic-Stirling refrigerator; that is, the former is the driving source for the latter. Both the subsystems are designed to operate on traveling-wave mode. In the experiment, it was found that the DC-flows had significant negative effect on the heat engine and the refrigerator. To suppress these DC-flows, two flexible membranes were inserted into the two subsystems and worked very well. Then extensive experiments were made to test the influence of different parameters on refrigeration performance of the whole system. The system has so far achieved a no-load temperature of -65 degrees C, a cooling capacity of about 270 W at -20 degrees C and 405 W at 0 degrees C; in fact, the result showed a good prospect of the refrigeration system in room-temperature cooling such as food refrigeration and air-conditioning. 相似文献
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建立了蒸气压缩/喷射制冷循环稳定运行时两相喷射器的热力学模型,以常压沸点相差较大的制冷剂为工质,比较了两相喷射器引射室压降最优范围的差异,并在同一工况下,研究了不同工质压缩/喷射制冷循环的性能。结果表明:喷射器引射室压降存在最佳范围使压缩/喷射制冷循环性能接近最优值;在相同工况下不同制冷工质这个最佳范围不相同;在同一工况下,当采用压缩/喷射制冷循环时,不同工质的循环性能系数和单位容积制冷能力相比基本循环均增强了。研究结果为压缩/喷射制冷循环制冷工质的选择及两相喷射器结构的优化设计提供理论参考。 相似文献
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带有高压储液器的制冷系统建模研究 总被引:1,自引:1,他引:0
通过对制冷系统循环特性、变工况特性和参数间耦合特性的分析,遵循热力学基本定律和能量、动量、质量守恒定律,采用稳态和动态建模相结合的方法建立压缩式制冷系统的数学模型。针对换热器建模难点采用分相区和移动边界相结合的方法建立其集总参数动态模型,并且冷凝器与高压储液器相结合,构成冷凝器加储液器的整体部件,文中建立的制冷系统的整体模型,反映了制冷系统工况变化时制冷剂质量的重新分配及其对状态变量的影响,提高了系统建模的精度,最后通过实验对所建模型的准确性进行了验证。 相似文献
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混合式除湿空调节能特性研究 总被引:10,自引:0,他引:10
本文提出了一种集固体转轮干燥剂除湿、间接蒸发冷却和蒸汽压缩制冷于一体的混合式除湿空调系统,以转轮除湿器RDCH程序为计算基础,建立了该系统性能计算模型,在ARI条什进行了热湿过程分析。结果表明,与相同条件下的蒸汽压缩系统相比,混合系统的制冷量增加了20%,电力COP增加了约30%。混合系统的优点还表现在能削减蒸汽压缩子系统的结构尺寸、降低电耗和减小冷凝空气流量等方面。还对干燥剂除湿和蒸发冷却过程的影响进行了分析。 相似文献
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《Heat Recovery Systems and CHP》1994,14(6):599-612
This paper presents a system of regenerative heating incorporating an absorption heat pump in a Rankine steam cycle which can improve cycle efficiency. A simulation has been performed to estimate the Rankine cycle efficiency in the proposed Absorption Heat Pump Regeneration (AHPRG) heating system using the working pair R213-DMETEG. The results show that the cycle efficiency can be improved considerably without reducing the work output by the incorporation of AHPRG for low-temperature heating of steam condensate. Further, the temperature of the heat-pump evaporator which absorbs the heat rejected at the steam condenser plays a predominant role in the cycle efficiency. 相似文献
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