DESIGN AND FABRICATION OF A DEEP FREEZER

ABSTRACT

This project is on the design and fabrication of deep freezer for the preservation of items/products and making the items to cool. The project is able to develop a simple efficient economical and environmental friendly refrigeration system (A freezer) towards better technological advancement in Nigeria. This project modifies the existing refrigeration system with the use of R-600a which is ozone friendly, and non-contaminant like previous refrigerant of the hydrofluoric-carbon, HFC and CFC like R-12, and R22 which has been phased out according tothe general convection at Britain in 1996. The cooling load obtained was 10682KW, and co-efficient of performance be minimized. The material used were mild steel and the inner pipe of the cabinet i.e. evaporator in order to minimize corrosion. For the better improvement of this work, low power consumption of the compressor refrigeration was used so as to maintain the rate of cooling and freezing of large items/products. And the outer dimensions are: length-1245mm, breadth-895mm-0. 895m, Height-906mm-0.96m and the inner dimensions are Iength-1225mm-1.225m; Breadth-895mm-0.895m, Height-886mm- 0.886m.

TABLE OF CONTENTS

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Abstract v

Table of content vi

CHAPTER ONE: REFRIGERATION

1.0 Introduction 1

1.1 Literature Review 2

1.2 General Definition and Development 3

1.3 Purpose and Scope of Refrigerator 4

1.4 Objectives of the Project 7

CHAPTER TWO: TYPES OF REFRIGERATOR SYSTEM

2.0 Types of Refrigerator System 8

2.1 The Vapor Compression Refrigeration System 8

2.2 The Vapor Absorption Refrigeration System 9

CHAPTER THREE: DESCRIPTION OF THE COMPONENTS PARTS

3.0 Description of the Components Parts 13

3.1 Compressor 13

3.2 The Condenser 16

3.3 The Evaporator 17

3.4 Pressure Gauges and Thermometers 19

3.5 Strainer/Drier 19

3.6 The Capillary Tube 20

CHAPTER FOUR: DESIGN CRITERIA, CALCULATION AND ELECTION OF EQUIPMENT

4.0 Design Criteria, Calculation and Selection of Equipment 21

4.1 The Evaporator Cabinet 21

4.2 Design Condition 22

4.3 Evaporator for Cabinet Casing 23

4.4 Conducted Heat 27

4.5 Refrigerant Piping Design 28

4.6 Calculations of Component Parts 32

4.7 Refrigerator Load Estimation 40

4.8 Refrigerant Used 41

4.9 Determination of the Flow Rate 47

4.10 Heat Balance for the System 48

4.11 Co-efficient of Performance 50

CHAPTER FIVE: FABRICATION DETAILS

5.1 The External Cabinet and Material Select 53

5.2 Insulation 53

5.3 Compressor Base 55

5.4 Condenser 55

5.5 Assembly of Part 55

5.6 Lubricants in Refrigeration System 56

5.7 Trouble Shooting in Domestic Refrigerator 57

5.8 Bill of Engineering Materials and Evaluation (BEME) 59

CHAPTER SIX: CONCLUSION AND RECOMMENDATION

6.0 Conclusion 60

6.1 Recommendation 60

References 62