ABSTRACT

This work on the construction and fabrication of a mobile deep freezer revolves around the concept of refrigeration. The concept of refrigeration revolves around the reverse Carnot cycle. This is a cycle involving isentropic expansion (at the throttling valve), isothermal expansion (at the evaporator), isentropic compression (at the compressor) and isothermal compressor ( at the condenser) Compression raises the temperatures of the refrigerant above that of its natural surrounding so that it can give up its heat in a heat exchanger to a heat sink such as air or water (condenser). Expansion lowers the refrigerant temperature below the temperature that is to be produced inside the cooling compartment.

CHAPTER ONE

INTRODUCTION

The main objective of this project is to construct and fabricate a deep freezer. The purpose of a deep freezer is to extract as mush heat from the cold body as possible with the expenditure of as little work as possible. In the refrigeration cycle, a substance called the refrigerant is compressed, cooled and then expanded. In expanding the refrigerant absorbs heat its surrounding (the cooling compartment) to provide refrigeration. After the refrigerant absorbs heat from the source, the cycle is repeated. 

The second chapter of these write-up ushers in a precise review of the history and literature of refrigeration from ancient man to modern day or contemporary man (i.e modern refrigerating equipment).Chapter three deals in detail on the methods of calculating refrigeration equipment. Chapter four sequentially gives the overview of the factors, qualities and properties considered in choice decision of the material components (both standard/ranging engineering materials) used for the fabrication and the steps undergone in the assembly of the components to form the refrigerating equipment.

The fifth chapter analysis the material and labour cost incurred in the course of undertaking this project. Chapter six, summmarily is a low down of the maintenance and use instructions to be strictly adhered to in order to make the most effective, economic and efficient use of the refrigerating equipment as well as enable the equipment complete its service life. There is also a provision in this part for the notification of the usual defects observed or experienced during use and the corresponding panacea for them. Included is the reference for future consultancy which helps the student or reader who decides to embark on further research or a fact finding mission on innovations that may add as a filling to this work or to the topic as a whole.This write-up within its scope is moderate sufficient to the educate the reader on the design and fabrication of a deep freezer.