共查询到15条相似文献,搜索用时 125 毫秒
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通过建立模型分析比较了CO2跨临界双级压缩带节流阀与带低压膨胀机制冷循环的性能.结果表明:双级压缩CO2跨临界带节流阀与带低压膨胀机制冷循环的最佳中间压力并不是高低压的几何平均值;在一定的气体冷却器出口温度下,双级压缩CO2跨临界带低压膨胀机制冷循环有一个最佳高压侧排气压力,与带节流阀循环相比,其最大COP可提高20%,但当高压侧压力低于最佳值时,低压膨胀机对系统COP的影响随着高压侧压力的减小而逐渐变得不明显;在双级压缩CO2跨临界带低压膨胀机制冷系统优化设计中,中间冷却应采用完全冷却型式. 相似文献
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通过用Yong分析方法对CO2跨临界制冷循环带节流阀和带膨胀机系统进行分析,发现节流阀的Yong损失较大,用膨胀机代替节流阀后,可使这部分损失降低,提高系统Yong效率。在带膨胀机的系统中,主要Yong损失发生在气体冷却器、压缩机和膨胀机,其中高压侧压力、气体冷却器出口温度以及蒸发温度对各部件的Yong损失和Yong效率都有不同程度的影响,在优化系统设计时应综合考虑这些参数。用Yong分析方法对系统性能进行评价,可为系统的改进提供理论依据。 相似文献
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Young Chul Kwon Dae Hoon Kim Jae Heon Lee Jun Young Choi Sang Jae Lee 《Journal of Mechanical Science and Technology》2009,23(3):698-706
This paper presents the heat transfer characteristics of the internal heat exchanger (IHX) for CO2 heat pump system. The influence on the IHX length, the mass flow rate, the shape of IHX, the operating condition, and the
oil concentration was investigated under a cooling condition. Four kinds of IHX with a coaxial type and a micro-channel type,
a mass flow meter, a pump, and a measurement system. With increasing of the IHX length, the capacity, the effectiveness, and
the pressure drop increased. For the mass flow rate, the capacity of micro-channel IHX are higher about 2 times than those
of coaxial IHX. The pressure drop was larger at cold-side than at hot-side. In the transcritical CO2 cycle, system performance is very sensitive to the IHX design. Design parameters are closely related with the capacity and
the pressure drop of CO2 heat pump system. Along the operating condition, the performance of CO2 IHXs is different remarkably. For oil concentration 1, 3, 5%, the capacity decreases and the pressure drop increased, as
compared with oil concentration 0%.
This paper was recommended for publication in revised form by Associate Editor Yong Tae Kang
Prof. Young-Chul Kwon received his B.S. degree in Precision Mechanical Engineering from Pusan National University, Korea, in 1989. He then received
his M.S. and Ph.D. degrees from POSTECH, in 1991 and 1996, respectively. Dr. Kwon is currently a Professor at the Division
of Mechanical Engineering at Sunmoon University in Chungnam, Korea. He serves as a chief of the Institute of Automation and
Energy Technology. Dr. Kwon’s research interests include heat exchanger, CO2 cycle, heat pump, and energy recovery ventilator for HVAC&R.
Mr. Dae-Hoon Kim is currently Doctoral student at the Mechanical Engineering from Hanyang University in Seoul, Korea. His research topics
include experimental and numerical of CO2 heatpump system. He has conducted a study on the Analysis of Refrigerating & Air-Conditioning Equipment Industry and Its
Forecasting Supervising and Testing for Performance of Refrigerator, Freezer and Air-Conditioner.
Prof. Jae-Heon Lee received his B.S. degree in Mechanical Engineering from Seoul National University, Korea, in 1971. He then received his M.S.
and Ph. D. degree from Seoul National University in 1977 and 1980, respectively. Dr. Lee is currently a Professor at the school
of Mechanical Engineering at Hanyang University in Seoul, Korea. Dr. Lee is currently a president at the Korea Institute research
interests include simulation of thermal fluid and Plant engineering and construction.
Dr. Jun-Young Choi received his B.S. degree in Mechanical Engineering from Yonsei University, Republic of Korea, in 1989. He then received his
M.S. and Ph. D. degrees from Yonsei University in 1991 and 1999, respectively. Dr. Choi is currently a chief researcher with
the 18 years experience on the energy performance testing of HVAC/R product. He is now assigned to the Energy Technology Center
at Basic Industry Division at Korea Testing Laboratory. He has been involved in the development of Design and Manufacturing
Technology for Air-Conditioner E.E.R. and Performance Testing Equipment for Cooling and Heating System with Non-CFCs, and
natural refrigerants. He has conducted a study on the Analysis of Refrigerating & Air-Conditioning Equipment Industry and
Its Forecasting Supervising and Testing for Performance of Refrigerator, Freezer and Air-Conditioner.
Dr. Sang Jae Lee received his Ph.D. degree in Mechanical Engineering from Hanyang University, KOREA, in 2008. Dr. Lee is currently a Researcher
at the Korea Institute of Industrial Technology in Cheonan, Korea. Dr. Lee’s research interests CO2 heatpump system, liquid desiccant air conditioning system and Micro heat exchanger. 相似文献
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应用于跨临界CO_2压缩循环的双转子滚动活塞式膨胀机的研究 总被引:1,自引:0,他引:1
由于二氧化碳制冷系统的制冷效率与人工合成制冷剂相比处于劣势,故采用跨临界循环,并利用膨胀机回收膨胀功以减少膨胀过程的能量损失,达到提高整个循环效率的目的。针对目前膨胀机存在的诸多问题,设计应用于跨临界CO2压缩循环的新型双转子滚动活塞膨胀机。该膨胀机的一级气缸始终与进气管连通,二级气缸始终与排气管相通,随着转子的转动在两气缸之间形成膨胀空间,因此,不需要专门的进气控制装置。对膨胀机的运行过程进行理论分析和设计计算,得出主要结构参数,并进行受力和力矩计算。分析结果表明,在膨胀过程中,一级转子的总力矩始终为正值,膨胀将结束时两转子的总力矩变为负值。在角度θ2之前,二级转子的驱动力矩大于一级转子的驱动力矩,在角度θ2之后,一级转子的驱动力矩更大。 相似文献