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FUNDAMENTAL STUFY OF A SMALL-SCALE HEAT PUMP

Research Project

Project/Area Number 11450083
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Thermal engineering
Research InstitutionTHE UNIVERSITY OF TOKYO

Principal Investigator

HIHARA Eiji  THE UNIVERSITY OF TOKYO, GRADUATE SCHOOL OF FRONTIER SCIENCES, PROFESSOR, 大学院・新領域創成科学研究科, 教授 (00156613)

Co-Investigator(Kenkyū-buntansha) DAIGUJI Hirofumi  THE UNIVERSITY OF TOKYO, GRADUATE SCHOOL OF FRONTIER SCIENCES, LECTURER, 大学院・新領域創成科学研究科, 講師 (10302754)
Project Period (FY) 1999 – 2001
Project Status Completed (Fiscal Year 2001)
Budget Amount *help
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2000: ¥4,800,000 (Direct Cost: ¥4,800,000)
KeywordsHeat pump / Heat exchanger / Small diameter tube / Micro-channel / 微小機構 / 圧縮機
Research Abstract

Size reduction of heat exchangers is one of the most important technologies for micro-scale heat pumps. In order to develop small-scale heat pumps, in this study fundamental research of small-scale heat exchangers were executed, which include heat transfer and pressure loss characteristics in small diameter heat transfer tubes, distribution of gas liquid two-phase flow at a T-junction and measurement and simulation of heat exchangers with small diameter tubes.
(1) For boiling heat transfer and pressure drop characteristics inside small diameter tubes, the diameter of heat transfer tubes were varied between 0.5 and 3 mm ID, and the HFC134a was selected as a working fluid. For smaller diameter tubes than 1mmID, heat transfer coefficients were deteriorated due to dry out in the quality range higher than 0.5. When the vapor quality at the inlet of the evaporator is less than 0.1, the flow pattern becomes intermittent and heat transfer performance decreases significantly.
(2) Phase separation of gas-liquid two-phase flow at an impacting tee was investigated experimentally and theoretically. It was found that if the flow rates in the branches were different, phase separation was observed. Based on the principle of minimum energy dissipation, a thermodynamic model was derived. The results of the model were qualitatively in good agreement with the experimental behavior of impacting flows.
(3) The performance of fined small tube heat exchangers was investigated both experimentally and theoretically. The Inner diameters of tubes were 1.0mm, 2.1mm and 4.0mm. Calculation results show that the volume of a 2.0mm tube heat exchanger can be reduced to 33% of that of a 4mm tube heat exchanger with the same capacity. The flow distribution in a branching unit strongly affects the exchanged heat.

Report

(4 results)
  • 2001 Annual Research Report   Final Research Report Summary
  • 2000 Annual Research Report
  • 1999 Annual Research Report
  • Research Products

    (8 results)

All Other

All Publications (8 results)

  • [Publications] 党 超鋲: "細管を用いたチューブフィン熱交換器の研究"日本冷凍空調学会論文集. 18・2. 143-151 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] 藤田 勇: "T字管における気液二相流の分配に関する研究"日本冷凍空調学会論文集. 17・1. 37-45 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Chaobin DANG: "Finned Small Diameter Tube Heat Exchanger"Transactions of JSRAE. 18-2. 143-151 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Isamu FUJ1TA: "Split of Gas-Liquid Two-Phase Flow at an Impacting Tee"Transactions of JSRAE. 17-1. 37-45 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] 党 超鋲: "細管を用いたチューブフィン熱交換器の研究"日本冷凍空調学会論文集. 18・2. 143-151 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] 斎藤静雄: "冷媒の水平細管内沸騰熱伝達に関する研究"第37回日本伝熱シンポジウム講演論文集. 3. 687-688 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] 田中信吾: "二酸化炭素の水平管内沸騰熱伝達に関する研究"第37回日本伝熱シンポジウム講演論文集. 3. 689-690 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] 藤田勇: "T字管における気液二相流の分配に関する研究"日本冷凍空調学会論文集. 17・1. 37-45 (2000)

    • Related Report
      2000 Annual Research Report

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Published: 2000-04-01   Modified: 2016-04-21  

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