HIGH PERFORMANCE TRANSCRITICAL HEAT PUMP CYCLE USING CARBON DIOXIDE AS A REFRIGERANT

使用二氧化碳作为制冷剂的高性能跨临界热泵循环

基本信息

批准号：
14350102
负责人：
HIHARA Eiji
金额：
$ 9.34万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350102/
关键词：
HEAT PUMP CARBON DIOXIDE COP EJECTOR HEAT EXCHANGER エジェクター

项目摘要

Research and development of the expansion power recovery mechanism called an ejector, which is expected to improve the COP of carbon dioxide heat pumps, were performed. Based on the research result to a supersonic nozzle, the whole ejector system was actually designed, the actual ejector type heat pump incorporating it was manufactured, the performance test was performed, and analysis to the experimental result was performed. The following things were clarified by these research results. First, the performance of ejector in an ejector cycle is determined from the balance of the pressure increase due to the shock wave, which is produced at the mixing part and the diffuser, and the pressure loss characteristics covering the whole passage of the suction flow, from an ejector exit to the suction part of ejector through a gas-liquid separator, an expansion valve, and an evaporator. Moreover, the method of controlling the expansion valve, which is installed in suction line, for making COP optimal was clarified. The effect of the size of mixing part can be explained based on the above-mentioned balance, and the optimum size of the mixing part can also be predicted theoretically. Experimental results can be explained with sufficient accuracy by assuming nozzle efficiency and diffuser efficiency appropriately. The low viscosity of carbon dioxide showed that the length of mixing part did not have large effect on the efficiency.About the improvement in efficiency of the heat exchanger, which uses carbon dioxide as an operation medium, the performance of evaporation heat transfer was investigated using heat transfer tubes with 1-6mm ID. Heat transfer characteristics in case lubricant oil was included were also investigated. Following experimental correlations were obtained from the experimental results ; the pre-dry out heat transfer before dry out occurs, the quality when dry out generates, and the post dry out heat transfer after dry out generating.

研究开发了被称为喷射器的膨胀动力回收机构，有望提高二氧化碳热泵的COP。基于对超音速喷嘴的研究成果，对整个喷射系统进行了实际设计，制造了包含该系统的实际喷射式热泵，并进行了性能测试，并对实验结果进行了分析。这些研究结果阐明了以下几点。首先，喷射器循环中喷射器的性能由混合部和扩散器处产生的冲击波引起的压力增加与覆盖吸入流整个通道的压力损失特性的平衡来确定，从喷射器出口经气液分离器、膨胀阀、蒸发器到达喷射器吸入部分。此外，还阐明了控制安装在吸入管路上的膨胀阀以使 COP 达到最佳值的方法。基于上述平衡可以解释混合部尺寸的影响，并且也可以从理论上预测混合部的最佳尺寸。通过适当地假设喷嘴效率和扩散器效率，可以足够准确地解释实验结果。二氧化碳的低粘度表明混合部分的长度对效率没有太大影响。针对以二氧化碳作为操作介质的换热器效率的提高，采用以下方法研究了蒸发换热性能：内径为 1-6mm 的传热管。还研究了包含润滑油的情况下的传热特性。由实验结果得出以下实验相关性；干燥发生前的预干燥传热、干燥发生时的质量、干燥发生后的干燥后传热。

项目成果

期刊论文数量（22）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

超臨界圧二酸化炭素冷却熱伝達率の測定手法に関する検討

超临界压力二氧化碳冷却传热系数测量方法研究

DOI：
发表时间：
2004
期刊：
日本冷凍空調学会年次大会講演論文集
影响因子：
0
作者：
党超鋲;王剣鋒;飛原英治
通讯作者：
飛原英治

超臨界二酸化炭素の冷却熱伝達に与えるオイルの影響

油对超临界二氧化碳冷却传热的影响

DOI：
发表时间：
2004
期刊：
第41回日本伝熱シンポジウム講演論文集
影响因子：
0
作者：
福岡賢;大薮貴之;党超鋲;王剣鋒;飛原英治
通讯作者：
飛原英治

Study on CO2 ejector system to improve heat pump efficiency

提高热泵效率的CO2喷射系统研究

DOI：
发表时间：
2004
期刊：
The International Symposium on New Refrigerants and Environmental Technology
影响因子：
0
作者：
Satoshi AKAGI;Chao-Bin DANG;Jianfeng WANG;Eiji HIHARA
通讯作者：
Eiji HIHARA

二酸化炭素冷凍サイクルにおける二相流エジェクタの特性

二氧化碳制冷循环两相流喷射器的特点