An Experimental Investigation of Pressure Drop and Heat Transfer in an In-Tube Condensation System of Ammonia with and Without Miscible Oil in Smooth and Enhanced Tubes

Komandiwirya, H.B.; Hrnjak, P.S.; Newell, T.A.

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https://hdl.handle.net/2142/13413 Copy

Description

Title

An Experimental Investigation of Pressure Drop and Heat Transfer in an In-Tube Condensation System of Ammonia with and Without Miscible Oil in Smooth and Enhanced Tubes

Author(s)

• Komandiwirya, H.B.
• Hrnjak, P.S.
• Newell, T.A.

Issue Date

2005-04

Keyword(s)

• heat transfer
• pressure drop
• ammonia

Abstract

Measurements of pressure drop and heat transfer coefficient were taken for smooth and internally enhanced smooth sections. Pure ammonia was used in both smooth and enhanced tubes, whereas ammonia mixed with oil only used in smooth tubes. The inside diameter of the tubes are 8.1 mm. The mass fluxes were varied from 20 to 270 kg/m2-s (15 to 1999 klbm/ft2-hr) and inlet quality was varied from 0 to 95%. The test section heat fluxes ranges from 2.0 to 10.0 kW/m2 (635 to 3175 Btu/ft2-hr). The majority of data points were taken at inlet refrigerant temperature of 35°C (95°F). The data is then compared to several pressure drop and heat transfer correlations to understand the characteristic of the test sections. Experimental data shows variation along the circumferential of the test section, which will be discussed more thoroughly. Oil has effects of lowering the heat transfer coefficient and increasing the pressure drop. Microfin tube has positive and negative effects on the heat transfer coefficient, depending on the fin height.

Publisher

Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Air Conditioning and Refrigeration Center CR-54

Type of Resource

text

Language

en

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http://hdl.handle.net/2142/13413

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