Experimentally validated models of refrigerant distribution in microchannel heat exchangers used to evaluate charge reduction of various working fluids

Padilla, Yadira

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https://hdl.handle.net/2142/34318 Copy

Description

Title

Experimentally validated models of refrigerant distribution in microchannel heat exchangers used to evaluate charge reduction of various working fluids

Author(s)

Padilla, Yadira

Issue Date

2012-09-18T21:11:07Z

Director of Research (if dissertation) or Advisor (if thesis)

Hrnjak, Predrag S.

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• microchannel
• refrigerant charge
• modeling heat exchangers

Abstract

This thesis presents experimentally validated simulation models developed to obtain accurate prediction of microchannel heat exchanger performance and charge. Effects of using various correlations are presented and discussed with focus on microchannel condensers and evaporators. Experiments with different refrigerants including R290, R717, R1234yf, and R134a are used to validate the models. The experimentally validated models are used to compare the charge of various refrigerants. The procedure for charge reduction analysis described in the thesis is the reduction of the internal (refrigerant) volume of the condenser or evaporator until a pressure drop is obtained that results in a specified percent decrease in COP from the same refrigeration cycle with no pressure drop. Furthermore, the effect of mass flux on charge is studied and discussed. Lastly, prediction of charge in headers is explored and correlations for predicting charge in headers of microchannel condensers are presented.

Graduation Semester

2012-08

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http://hdl.handle.net/2142/34318

Copyright and License Information

Copyright 2012 Yadira Padilla

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