Essay On Refrigeration

INTRODUCTION TO REFRIGERATION

1.1 What is a Refrigeration System?

The mechanism used for lowering or producing low temp. in a body or a space, whose temp. is already below the temp. of its surrounding, is called the refrigeration system. Here the heat is being generally pumped from low level to the higher one & is rejected at high temp. The term refrigeration may be defined as the process of removing heat from a substance under controlled conditions. It also includes the process of reducing heat & maintaining the temp. of a body below the general temp. of its surroundings. In other words the refrigeration means a continued extraction of heat from a body whose temp is already below the temp. of its surroundings. A refrigerator is a reversed

The working fluid refrigerant used in this refrigeration system readily evaporates & condenses or changes alternatively between the vapour & liquid phases without leaving the refrigerating plant.During evaporation it absorbs heat from the cold body or in condensing or cooling it rejects heat to the external hot body. The heat absorbed from cold body during evaporation is used as its latent heat for converting it from liquid to vapour. Thus a cooling effect is created in working fluid. This system of refrigeration thus act as latent heat pump since its pump its latent heat from the cold body or brine & rejects it or deliver it to the external hot body or the cooling medium. According to the law of thermodynamics , this can be done only on the expenditure of energy which is supplied to the system in the form of electrical energy driving the compressor. The vapour compression cycle is used in most of the modern refrigeration systems in large industrial plants.The vapour in this cycle is circulated through the various components of the system, where it undergoes a number of changes in its state or