| Project/Area Number |
02650166
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | Faculty of Science and Technology, Keio University |
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Principal Investigator |
SATO Haruki Department of Mechanical Engineering, Keio University, Associate Professor, 理工学部, 助教授 (70137983)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1991: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | New Working Fluids / CFC Alternatives / Calorimetry / Isobaric Specific Heat / Gases / Liquids / Thermal Energy / Heat Pumps / 熱力学性質 / HFCー152a / HCFCー142b / エネルギ-資源 / 液体熱物性 / 気体熱物性 |
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| Research Abstract |
Thermal energy at low temperature level should be utilized from the viewpoint of globally environmental problems. New working fluids for heatpump systems which can replace to existing working fluids such as ozonedepletion substances CFC-12 and CFC-114 must have good characteristics to achieve high efficiency systems for reducing CO_2 emissions. This study aims to reveal appropriate new working fluids for heat-pump systems which provide thermal energy at higher temperatures by measuring isobaric specific heat(c_p)of new working fluids.
The existing flow calorimeters for measuring c_p of liquids and gases were improved for getting reliable data with smaller amount of sample fluids.
Four c_p values of gaseous HFC-134a as a new working fluid were obtained at 333.15 K add 0.3-0.9 MPa. The uncertainties are <plus-minus>0.2% for the final c_p values, <plus-minus>5 mK for the temperature, and <plus-minus>4 kPa for the pressures.
In the liquid phase, 31 c_p values of HCFC-142b were measured at temperatures from 276 K to 350 K and pressures from 1 MPa to 3 MPa, while 36 c_p values of HFC-152a were measured at temperatures from 276 K to 360 K and pressures from 1.0 to 3.2 MPa. The uncertainties are estimated as <plus-minus>0.4% for c_p values of both HCFC-142b and HFC-152a, <plus-minus>13 mK in temperature, <plus-minus>3 kPa in pressure. Purity of samples used for both HCFC-142b and HFC-152a measurements was 99.95 mol%. Correlations of liquid c_p as a function of temperature and pressure were developed for both refrigerants on the basis of the measurements and c_p values for the saturated liquids of HCFC-142b and HFC-152a were derived from the correlations.
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