共查询到20条相似文献,搜索用时 109 毫秒
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1引言吸收压缩式(SC)热泵是一种适用于变温热源的高效复合式热泵系统,比常规压缩式热泵具有工作范围广,工作压力低以及较高COP值等特点。文献出对以R22-DMA为工质的SC热泵进行了实验研究。本文则对新型工质R22-DMA的热力学性质进行研究整理,给出计算二元系统的蒸汽压、烩、摘等的实用公式;并对以其为工质的一种新型SC热泵循环进行计算机模拟优化分析,给出了实际SC热泵在典型制冷工况下的制冷性能及其优化条件。2R22-DMA的热力学性质2.1汽波相平衡R22-DMA二元系统的汽液相平衡实验数据较缺乏,文献[2]给出部分温度… 相似文献
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《工程热物理学报》2021,42(7):1651-1658
根据温湿度独立控制空调系统所需冷量的品位不同,提出了一种冷量梯级利用的太阳能吸收/压缩复叠双温制冷系统,由太阳能溴化锂单效吸收制冷子系统、高温冷水循环子系统和水冷压缩制冷子系统复叠而成。建立了新系统的热力学数学模型,分析太阳能溴化锂单效吸收制冷子系统蒸发温度、发生温度和环境温度对新系统性能影响,并与传统的太阳能溴化锂单效吸收制冷(SSAR)系统和太阳能吸收/压缩复叠制冷(SAC-CR)系统进行性能比较。结果表明,存在最优的发生温度和环境温度使系统所需集热面积最小,新系统所需集热器面积均低于传统SAC-CR和SSAR系统,且新系统功耗显著低于传统SAC-CR系统,为面向温湿度独立控制空调系统应用的吸收/压缩复叠双温制冷机组研制提供理论依据。 相似文献
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以空调系统能耗系数CEC(Coefficient of Energy Consumption)即空调设备全年总能量消耗量与假想空调负荷累计值之比作为空调系统能耗性能评价指标,对天津地区某典型办公大楼建筑空调系统选用水源热泵和溴化锂冷热水机组条件下的能耗状况进行计算与分析。并证明了与采用水源热泵的空调系统相比较,采用溴化锂冷水机组的空调系统节电不节能。 相似文献
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《Heat Recovery Systems and CHP》1988,8(2):87-93
A thermodynamic analysis of the vapour absorption heat pump working on R22-DMETEG pair is made and the results are presented in the form of graphs and correlations. These data can be used to estimate the idealised system performance parameters such as heat quantities, flow rates, pump work, COP and second law efficiency. The procedure for using the data for above computations is described. 相似文献
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《Heat Recovery Systems and CHP》1991,11(5):341-350
The operating temperatures in the absorption heat pump system fix the absorber and the generator concentration for a given working pair. Derived thermodynamic design data, including Carnot coefficients of performance and enthalpy-based coefficients of performance, with and without an economizer heat exchanger for possible combinations of operating temperatures, are presented for water-lithium iodide absorption systems for cooling. The effects of operating temperatures as well as economizer heat exchanger on the performance of an absorption cooler are illustrated graphically. 相似文献
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《Heat Recovery Systems and CHP》1991,11(4):255-262
This communication presents an investigation of the thermodynamic design and feasibility assessment of hybrid double-absorption solar cooling systems. The systems considered are conventional closed-cycle and open-cycle absorption systems with an additional open-absorber component through which the process room air is passed, cooled and dehumidified. The cooling produced in the evaporator is utilized to remove heat from the open absorber as well as the process air being circulated. Thermodynamic modelling of system components for a fixed set of operating conditions and with water-LiBr as working fluid have been carried out and the system COP predicted as a function of regenerator temperature, mass flow ratio and latent heat load in the process air and the ambient air. A comparative study of the open and closed cycle options has been made and detailed parametric results are presented. It is concluded that the hybrid double-absorption solar cooling systems are better in performance than conventional systems and an open-cycle double-absorption system is even more attractive and cost effective as compared to closed-cycle option. 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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《Heat Recovery Systems and CHP》1994,14(3):265-272
An absorption heat transformer using the working pair trifluoroethanol-pyrrolidone (TFE-Pyr) is described. Trifluoroethanol is used as the working fluid and pyrrolidone is used as the absorbent. A computer simulation model is developed for the thermodynamic analysis of the heat transformer. By the verification of a group of experimental measurements, the model is used to investigate the influences of various operating conditions, design parameters and component dimensions on the performance of the heat transformer. Conclusions on the heat transformer are made according to the results of the thermodynamic assessment. 相似文献
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设计了一台以氯化钙/活性炭复合吸附剂和氨作为吸附工质对的多功能热管型吸附制冷机组,采用一种新型的基于二次回热的二级循环方式来降低驱动热源的温度梯度,吸附床的加热解吸、冷却吸附及回热过程均由无外加驱动力的多功能热管工作完成.研究结果表明:当解吸温度为103℃及冷却水温度为30℃时,回热型二级循环相对传统二级循环可显著提高机组的工作性能,制冷系数COP及单位质量吸附剂制冷功率SCP提高幅度均在23%以上;相对单级循环,二级吸附循环的最大优点在于能有效利用更低品位的余热和可再生能源作为驱动热源进行制冷,吸附制冷技术在低温热源场合的应用提供了有效途径. 相似文献
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Innovative use of nanoparticles in synthesis to form hybrid nanofluids is of great interest recently. This generation of nanofluids is known to improve some thermal characteristics deliberately. In the present study, evaporative behavior of hybrid nanofluids is investigated experimentally. In boiling-mode cooling systems, longer lengths of dryouts are more preferred. In this regard, enhancing the value of heat of evaporation is a target. The experiments are implemented at temperature ranging from 90 to 155?C and in the solid volume fraction range of 0–3%. It is found that the use of hybrid nanofluids to enhance the fluid stability and in consequence the fluid latent heat of evaporation (LHE) is rational just at high working pressures (higher than 400 kPa). The most effective hybrid nanofluid in this study is 2% Ag–Au, which results in max increase of 8.7% in the latent heat of evaporation. 相似文献