Refrigeration Lab Report

ABSTRACT

The aim of our project is to improve coefficient of performance of system. To improve the coefficient of performance, it is to require that compressor work should decrease and refrigerating effect should increase. Modifications in condenser are meant to increase degree of sub-cooling of refrigerant which increased refrigerating effect or more cooling water is required in condenser. A vapour compression cycle that is used in most household refrigerators, freezers and cold storages. In this cycle a circulating refrigerant enters a compressor as low pressure vapour at or slightly above the temperature of the refrigerator interior. The vapour is compressed and exits the compressor as high-pressure superheated vapour. Generally Brines are

However, for the places where surrounding are at a temperature lower than the required condition, it has to be heated up. As every product require deferent storage temp for maintaining the quality of eatable or potable material. Keeping that aspect in view a low temp generating refrigeration system has been designed to maintain -22 °C. It is the process of removing heat from an enclosed space, or from a substance, and rejecting it elsewhere for the primary purpose of lowering the temperature of the enclosed space or substance and then maintaining that lower temperature. The term cooling refers generally to any natural or artificial process by which heat is dissipated. The process of artificially producing extreme cold temperatures is referred to as cryogenics. Cold is the absence of heat, hence in order to decrease a temperature, one "removes heat", rather than "adding cold." In order to satisfy the Second Law of Thermodynamics, some form of work must be performed to accomplish this. This work is traditionally done by mechanical work but can also be done by magnetism, laser or other means. However, all refrigeration uses the

In this cycle a circulating refrigerant enters a compressor as low pressure vapour at or slightly above the temperature of the refrigerator interior. The vapour is compressed and exits the compressor as high-pressure superheated vapour. The refrigerant, while passing through the condenser, gives up its latent heat to the surrounding condensing medium which is normally air or water. The condenser cools the refrigerant vapour, which then liquefies. This liquid refrigerant is forced through a metering or throttling device, also known as an expansion valve (essentially apin-hole sized constriction in the tubing) to an area of much lower pressure. The sudden decrease in pressure results in explosive-like flash evaporation of a portion(typically about half) of the liquid. During evaporation, the liquid vapour refrigerant absorbs its latent heat of vaporization from the product which is to be cooled. This phenomenon known as “auto-refrigeration”. The typically out of the Vapour compression system in shown in above