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Evaporation heat transfer characteristics inside the U-bend of the smooth and the microfin tube using alternative refrigerant

Journal Article:

Abstract

The present work experimentally investigated the effects of mass flux, heat flux, inlet quality on the heat transfer performance inside the U-bend of smooth and microfin tube using R-22 and R-407C refrigerants. The parameters were 200 and 400 kg/m{sup 2} s for mass flux, 6 and 12 kw/m{sup 2} for heat flux, 0.1 and 0.2 for inlet quality under the pressure of 0.65 MPa. The apparatus consisted of the test section of four straight sections and three U-bends, preheater, condenser, refrigerant pump, mass flow meter etc. The average heat transfer coefficient at the downstream straight section after U-bend was affected by U-bend due to the centrifugal force and mixing of two-phase flow in the U-bend. The average heat transfer coefficient at the U-bend was 4{approx}33 % higher than that at the straight section. The average heat transfer coefficients were affected in the order of mass flux, heat flux and inlet quality. The average heat transfer coefficients in the microfin tube were lager by 19{approx}49 % and 33{approx}69 % than that in the smooth tube at the straight section and at the U-bend separately. The average heat transfer coefficients for R-407C were larger by 33{approx}41 % and 17{approx}29% than that for  More>>
Authors:
Cho, K N; [1]  Kim, B G [2] 
  1. Sung Kyun Kwan University, Seoul (Korea, Republic of)
  2. Sung Kyun Kwan University Graduate School, Seoul (Korea, Republic of)
Publication Date:
Sep 01, 1997
Product Type:
Journal Article
Reference Number:
SCA: 420400; PA: KR-98:000295; EDB-98:052699; SN: 98001940367
Resource Relation:
Journal Name: Transactions of the Korean Society of Mechanical Engineers; Journal Volume: 21; Journal Issue: 9; Other Information: PBD: Sep 1997
Subject:
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; REFRIGERANTS; HEAT TRANSFER; EVAPORATION; HEAT FLUX; FINS
OSTI ID:
595216
Country of Origin:
Korea, Republic of
Language:
Korean
Other Identifying Numbers:
Journal ID: TSMED4; ISSN 1225-5963; TRN: KR9800295
Submitting Site:
KR
Size:
pp. 1207-1217
Announcement Date:

Journal Article:

Citation Formats

Cho, K N, and Kim, B G. Evaporation heat transfer characteristics inside the U-bend of the smooth and the microfin tube using alternative refrigerant. Korea, Republic of: N. p., 1997. Web.
Cho, K N, & Kim, B G. Evaporation heat transfer characteristics inside the U-bend of the smooth and the microfin tube using alternative refrigerant. Korea, Republic of.
Cho, K N, and Kim, B G. 1997. "Evaporation heat transfer characteristics inside the U-bend of the smooth and the microfin tube using alternative refrigerant." Korea, Republic of.
@misc{etde_595216,
title = {Evaporation heat transfer characteristics inside the U-bend of the smooth and the microfin tube using alternative refrigerant}
author = {Cho, K N, and Kim, B G}
abstractNote = {The present work experimentally investigated the effects of mass flux, heat flux, inlet quality on the heat transfer performance inside the U-bend of smooth and microfin tube using R-22 and R-407C refrigerants. The parameters were 200 and 400 kg/m{sup 2} s for mass flux, 6 and 12 kw/m{sup 2} for heat flux, 0.1 and 0.2 for inlet quality under the pressure of 0.65 MPa. The apparatus consisted of the test section of four straight sections and three U-bends, preheater, condenser, refrigerant pump, mass flow meter etc. The average heat transfer coefficient at the downstream straight section after U-bend was affected by U-bend due to the centrifugal force and mixing of two-phase flow in the U-bend. The average heat transfer coefficient at the U-bend was 4{approx}33 % higher than that at the straight section. The average heat transfer coefficients were affected in the order of mass flux, heat flux and inlet quality. The average heat transfer coefficients in the microfin tube were lager by 19{approx}49 % and 33{approx}69 % than that in the smooth tube at the straight section and at the U-bend separately. The average heat transfer coefficients for R-407C were larger by 33{approx}41 % and 17{approx}29% than that for R-22 in the smooth tube and the microfin tube separately. (author). 24 refs., 9 figs.}
journal = {Transactions of the Korean Society of Mechanical Engineers}
issue = {9}
volume = {21}
journal type = {AC}
place = {Korea, Republic of}
year = {1997}
month = {Sep}
}