Design and Fabrication of Domestic Refrigeration Unit

Thesis Abstract

Abstract

The object of the project is to design, fabricate and assemble an economically priced '' domestic refrigeration unit'' having, aesthetic look efficient and small in size.

This unit is unique in the sense that it body is in the form of a bucket which works as an evaporator and easy in transport from one place to another place.

This unit can be utilized in a heavy duty manufacturing shop consist 25 to 35 workers as a sources cold water and to store eatables things. The basic idea behind refrigeration is to slow down the activity of bacteria (which all food contains) so that it takes longer for the bacteria to spoil the food.

There are five basic parts of our refrigeration unit

• Compressor

• Heat- exchanging pipes - serpentine or coiled set of pipes outside the unit.

• Expansion valve

• Heat- exchanging pipes - serpentine or coiled set of pipes inside the unit

• Refrigerant pipes - liquid that evaporates inside the refrigerator to create the cold temperatures

Domestic refrigeration is rather limited in scope, being concerned primarily with household refrigerators and home freezers. However, because the number of units in services is quite large, domestic refrigeration represents a signification portion of the refrigeration industry.

Domestic units are usually small in size, having horse power ratings of between 1/20 and ½ hp, and of the hermetically sealed type.

The domestic refrigerator, in our case, is a small, compact unit, which works on the principle of vapour compression system. It has been designed as per economical considerations for a middle-class family. This unit is unique in the sense that its body is in the form of a bucket (plastic) which works as an evaporator.

For fabricating the unit, initially a plastic bucket of conical cross-section with 90 liters capacity was purchased. The diameter of the upper portion of bucket is 45 cm while that of lower surface is 37 cm since the material of the bucket, therefore certain material was necessary to conduct heat for cooling purpose inside the bucket. Therefore, a sheet-metal internal container (evaporator) of conical cross-section was designed.