Analytical and experimental examination of microwave defrosting method on commercial refrigerator evaporators

Defrosting of domestic refrigerator evaporator coils is currently done with external electrical heaters of various designs using a combination of convection, radiation, and conduction. These designs put unnecessary heat into the refrigerators during the defrosting process and the heat must be taken out again by the compressor work. Radiation, which has a fundamentally different mechanism from conduction and convection, can have significant advantages over traditional defrosting methods since it doesn’t heat up the air inside evaporator. Defrosting experiments are done to find out the effectiveness of microwave defrosting in a commercial microwave oven. Frost is formed on the small aluminum evaporator with a controlled temperature and mass and thaws out in the microwave oven while measuring the defrosting conditions. Temperature and geometry of defrosting conditions are discussed by changing the frost temperature and magnetron positions to the evaporator. Later, Monte Carlo simulations are performed to find out the uniformity of defrost in a two-dimensional slot. Various incoming angles and surface conditions are compared to find out the best condition. The fundamental mechanisms of microwave oven defrosting and experiment results are presented in detail.

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

• Kim, Jong Woo

Contributors dc:contributor

• Brewster, M. Quinn

• Defrosting
• Radiative Melting
• Microwave Defrosting
• Evaporator Defrosting
• Evaporator Thawing

Statement dc:rights

• Copyright 2012 Jong Woo Kim

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/34300

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/34300