variavel0=<b>Luciano Amaury dos Santos</b> - lucianosantos@iae.cta.br Laboratório de Sistemas Térmicos - PUCPR
<b>Nathan Mendes</b> - nmendes@rla01.pucpr.br Laboratório de Sistemas Térmicos - PUCPR
<b>Cláudio Henrique Macedo Alves Filho</b> - claudio.alves1@gerdau.com.br Laboratório de Sistemas Térmicos - PUCPR
<b>Eduardo Alves Cardoso</b> - eduardo.aa.cardoso@electrolux.com.br Electrolux do Brasil S.A.
<b>Abstract.</b> This paper presents FRIGUS, a household refrigerator simulation program (today dedicated to one door products with refrigeration by mechanical compression of vapors), giving emphasis to the formulations used in it to describe the refrigeration system. The FRIGUS was until now endowed with three different models for the refrigeration system with different complexity levels. All these three models are quasi-static. The first one simply attributes percentages of the refrigeration capacity of the system that corresponds to the compressor power consumption an to the heat released by the compressor and the condenser. The second one solves a fourth-order system of non-linear equations that takes as input data, among others, the undercooling and the superheating degrees. The unknowns are the condensation and evaporation temperatures and the enthalpies at the compressor and the evaporator inlets. From these unknowns the compressor power consumption, the heat absorbed in evaporator and the heat released in the condenser can be calculated. The third model uses a fifth-order system of equations, that enable us to predict the capillary tube characteristics influence on refrigerator performance in terms of evaporation temperature and energy consumption. This last model describes also the influence of the refrigerant fluid charge in the refrigerating cycle performance. The paper is closed with some preliminary results and conclusions.
<b>Keywords.</b> refrigeration, thermal systems simulation, household refrigerator.