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

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.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Padilla, Yadira

Contributors dc:contributor

• Hrnjak, Predrag S.

• microchannel
• refrigerant charge
• modeling heat exchangers

Statement dc:rights

• Copyright 2012 Yadira Padilla

Language dc:language

en

Handle dc:identifier

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

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/34318