Phase Change Characteristics of Alternative Refrigerants in Double-tube Heat Exchanger

双管换热器替代工质的相变特性

• 批准号: 02452127
• 负责人: FUJII Tetsu
• 金额: $ 3.39万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02452127/
• 关键词: Phase change; Double-tube evaporator; Double-tube condenser; Alternative refrigerants; Nonazeotropic refrigerant mixture; Smooth tube; Grooved tube; Transient response

In this research project condensation and evaporation of alternative refrigerants and nonazeotropic refrigerant mixtures have been investigated experimentally to obtain the basic data which are necessary to develop heat pump/refrigeration systems using environmentally acceptable refrigerants as working fluids. Pure refrigerants of HCFC22, CFC114, CFC12 and HFC134a and nonazeotropic refrigerant mixtures (NARMs) of HCFC22 and CFC114 were used as working fluids. The double-tube heat exchangers were used as test condenser and evaporator. The results are as follows :(1) The condensation heat transfer coefficient of pure refrigerants is correlated well with the equation obtained by modifying a semi-empirical equation of Nozu et al.(2) For condensation of NARMs, a correlation equation of vapor mass transfer is obtained under some assumptions, and a new method to predict the heat transfer characteristics in a double-tube condenser is proposed.(3) The evaporation heat transfer coefficient of pure refrigerants in the annular flow regime is correlated well with the equation obtained by developing Chen's idea.(4) A correlation equation for evaporation heat transfer coefficient of NARMs is also obtained by modifying the equation of pure refrigerants.(5) Transient characteristics of evaporation heat transfer and pressure drop of HCFC 22 in a double-tube heat exchanger are obtained and it is found that the transient heat transfer coefficient is lower than that for steady flow.

在该研究项目中，对替代制冷剂和非共沸制冷剂混合物的冷凝和蒸发进行了实验研究，以获得开发使用环境可接受的制冷剂作为工作流体的热泵/制冷系统所需的基本数据。使用HCFC22、CFC114、CFC12和HFC134a的纯制冷剂以及HCFC22和CFC114的非共沸制冷剂混合物(NARM)作为工作流体。双管式换热器用作测试冷凝器和蒸发器。结果如下：（1）纯制冷剂的冷凝传热系数与修改Nozu等人的半经验方程得到的方程有很好的相关性。（2）对于NARMs的冷凝，蒸汽质量的相关方程在一定的假设条件下得到了传热系数，并提出了一种预测双管式冷凝器传热特性的新方法。(3)纯制冷剂在环形流态下的蒸发传热系数与下式得到的方程有很好的相关性：发展陈的想法。(4)通过修改纯制冷剂的方程，还得到了NARMs蒸发传热系数的相关方程。(5)双管换热器中HCFC 22的蒸发传热和压降的瞬态特性为得到的结果表明，瞬态传热系数低于稳态流传热系数。

项目成果

小山 繁,高 雷,今村 巨城,藤井 哲: "非共沸混合冷媒HCFC22+CFC114の水平平滑管内凝縮" 日本機械学会論文集. 57. 2032-2038 (1991)

Shigeru Koyama、Rai Taka、Koshiro Imamura、Satoshi Fujii：“非共沸混合制冷剂 HCFC22+CFC114 水平光滑管道中的冷凝”，日本机械工程师学会会刊 57。2032-2038（1991 年）。

Sh. KOYAMA, L. GAO and T. FUJII: "Engancement of In-Tube Condensation on Non-Azeotropic Refrigerant mixtures With a Micto-Fin Tube" Proc. 18th Int. Cong. Refrig.Paper No. 54.

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高松 洋,桃木 悟,平岡 晋,小山 繁,藤井 哲: "冷媒の水平平滑管内蒸発熱伝達におよぼす伝熱面汚れの影響" 日本冷凍協会論文集. (1991)

Hiroshi Takamatsu、Satoru Momoki、Susumu Hiraoka、Shigeru Koyama 和 Satoshi Fujii：“传热表面污染对水平光滑管中制冷剂蒸发传热的影响”日本制冷协会会刊（1991 年）。

小山 繁,高 雷,今村 巨城,藤井 哲: "非共沸混合冷媒HCFC22+CFC114の水平平滑管内凝縮" 日本機械学会論文集. (1991)

Shigeru Koyama、Rai Taka、Koshiro Imamura、Satoshi Fujii：“非共沸混合制冷剂 HCFC22+CFC114 水平光滑管道中的冷凝”日本机械工程师学会会刊（1991 年）。

H. TAKAMATSU, S. MOMOKI and T. FUJII: "Comparison of Evaporation Heat Transfer and Pressure Drop in a Horizontal Smooth Tube for HFC134a and CFC12" Proc. 18th Int. Cong. Refrig.Paper No. 56.

H. TAKAMATSU、S. MOMOKI 和 T. FUJII：“HFC134a 和 CFC12 水平光滑管中蒸发传热和压降的比较”Proc。