共查询到16条相似文献,搜索用时 265 毫秒
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提出了一套多功能CO2水源热泵驱动的溶液除湿新风系统,该系统以CO 2跨临界循环压缩机高温排气实现LiCl溶液再生,提高了热泵驱动溶液除湿系统的溶液再生效率,并以地下水为再冷源,减小了CO2跨临界循环节流损失.通过建立系统稳态数学模型,模拟分析了标准环境工况下,新风量、 除湿/再生内循环比、 溶液总流量、 再生空气流量等4个可控关键因素对系统性能的影响,并将系统应用于西安市某200 m2办公建筑,得到了4个可控参数设置的最佳组合. 相似文献
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关新 《建筑热能通风空调》2012,31(3):97-99
本文设计了一个由太阳能冷管和跨临界CO2热泵组成的联合供能系统,可以实现制冷+供热水、制热+供热水、单独制冷、单独制热、单独供热水的功能。夏天用太阳能冷管制冷并提供生活热水,当太阳能不足或阴雨天气时,由跨临界CO2系统替代;冬天用跨临界CO2热泵制热并提供热水;过渡季节晴天时由太阳能冷管提供热水,阴雨天气时由跨临界CO2系统替代。这是一种将太阳能冷管吸附式制冷技术和跨临界CO2热泵技术联合的可实现制冷、制热和供热水功能的联合系统,集空调热泵和热水器于一体,是一个利用新能源、环保节能的紧凑型系统。 相似文献
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天然环保型工质CO2在系统采用跨临界循环后,与传统制冷剂相比具有独特的优点.基于可持续发展观,CO:成为热泵热水器系统最有潜力的替代工质之一.近15年来,挪威等欧洲国家、日本和美国对CO:热泵热水器系统进行了广泛深入的研究.本文详细介绍了CO:热泵热水器样机的研究状况,总结了核心部件压缩机和换热器的研发现状,并探讨了有待进一步开展的研究内容. 相似文献
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运用当量温度概念对CO2跨临界水-水热泵供热系统进行了研究,指出根据实际情况选择气体冷却器的出口温度和压缩机的出口压力能提高系统的运行效率,并对供热过程中采用能量梯级利用进行了研究,结果表明对热水侧进行梯级利用可提高系统的制热性能系数。 相似文献
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在CO2跨临界循环系统中,节流损失相对较大。通过增加回热器的方法以提高跨临界CO2热泵系统的COP。根据相关的换热关联式对CO2热泵系统的回热器进行了设计计算并且进行了相关的实验研究。计算得到的回热器,长度为1.27 m,内管内径6 mm,外管内径13 mm,壁厚1 mm。并且在相同环境工况下,利用自行搭建的CO2热泵系统实验台,分别在有回热器与无回热器时进行了实验研究。实验结果表明:当系统引入回热器后,压缩机排气压力、温度上升,压缩机耗功上升速率加快,制热量增加速率亦加快,且制热量增加速率大于压缩机耗功增加速率,系统制热COP增加,带回热器时系统平均COP达到3.34,无回热器时系统平均COP为3.03,提高约10.2%。 相似文献
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In this study, a thermodynamic analysis on the performance of a transcritical cycle using azeotropic refrigerant mixtures of R32/R290 with mass fraction of 70/30 has been performed. The main purpose of this study is to theoretically verify the possibility of applying the chosen refrigerant mixture in small heat pumps for high temperature water heating applications. Performance evaluation has been carried out for a simple azeotropic mixture R32/R290 transcritical cycle by varying evaporator temperature, outlet temperature of gas cooler and compressor discharge pressure. Furthermore, the effects of an internal heat exchanger on the transcritical R32/R290 cycle have been presented at different operating conditions. The results show that high heating coefficient of performance (COPh) and volumetric heating capacity can be achieved by using this transcritical cycle. It is desirable to apply the chosen refrigerant mixture R32/R290 in small heat pump water heater for high temperature water heating applications, which may produce hot water with temperature up to 90 °C. 相似文献
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《Energy and Buildings》2004,36(7):690-695
A combined air conditioning and tap water heating plant using carbon dioxide (CO2) as refrigerant has been investigated theoretically and experimentally. The system is suitable for countries with year around cooling demand, such as Indonesia or Singapore, and a need for hot tap water. A unique CO2 transcritical cycle characteristic for heating process can afford an improvement to a CO2 air conditioning system when rejected heat from the system is recovered. Some parameters affecting performance of the combined system are discussed. 相似文献
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In the present study, vortex tube is used in transcritical vapour compression cycle as expansion device to improve the coefficient of performance (COP). The thermodynamic analysis has been performed using nitrous oxide in transcritical cycle with vortex tube (TCVT) and its results are compared with those of a transcritical cycle with expansion valve (TCEV). The evaporator and the gas cooler temperatures have been varied between ?55°C and 5°C and between 35°C and 60°C, respectively, for the analysis. The COP of the TCVT improves by 1.72–27.01% compared to TCEV. A decrease in evaporator temperature and an increase in gas cooler exit temperature result in a decrease in COP. The increase in cold mass fraction brings a negligible increase in maximum COP. The performance comparison of N2O and CO2 in TCVT shows that maximum cooling COP for N2O is higher than for CO2, but the optimum pressure required for N2O is lower than for CO2. 相似文献
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ABSTRACTThe thermodynamic analysis has been presented in this article using nitrous oxide as the refrigerant in a two-stage transcritical cycle with the vortex tube (TSTCVT) instead of the expansion valve and its results are compared with the two-stage transcritical cycle with the expansion valve (TSTCEV). The evaporator and the gas cooler temperature ranges in both the cycles have been considered between ?55°C to 5°C and 35°C to 60°C for the analysis. Gas cooler and intercooler pressures are simultaneously optimised to obtain the maximum cooling coefficient of performance (COP). The COP of the TSTCVT improves by 1.97–27.19% in comparison to TSTCEV. A decrease in evaporator temperature and an increase in gas cooler exit temperature reduce the COP of TSTCVT. The comparison of refrigerants N2O and CO2 in TSTCVT shows that N2O exhibits higher cooling COP, higher second law of efficiency and lower optimum gas cooler pressure under the considered operating conditions. 相似文献