ABSTRACT

            This write up is a detail of the process and information of plan for the physical realization of the construction of the 1M3 mobile deep freezer. It is divided into chapters, which discussed extensively the practical refrigeration cycle with full attention given to design factors working principle and choice of material. The method used in fabrication, assembly and driving the safety requirement was not left out. 

TABLE OF CONTENT

Chapter One 

1.0              Introduction                                                                                                   

1.1              The application of the refrigeration principle                         

1.2               Purpose of the project                                                                                   

1.3              benefits of the project                                                            

Chapter Two

2.0              Literature Review                                                                                          

2.1              Specification of the problem                                                              

2.2              Conditions for use                                                                                         

2.3              Characteristics of the project                                                 

Chapter Three

3.0              Synthesis of Solution                                                                         

3.1              Theory of Design and Analysis                                                                     

3.2              Determination of C. O. P. of Refrigeration                           

Chapter Four

4.0              Construction and Material Selection                                                 

4.1              Description of Material Selection                                                      

4.2              Assembly of the work or project                                                       

Chapter Five

5.0              Cost of Analysis                                                                                            

5.1              Conclusion                                                                                         

References                                                                                         

LIST OF SYMBOLS

M                     =          Mass

A                     =          Area

V                     =          Volume

L                      =          Length

W                    =          Width

H                     =          Height

S                      =          Entropy

M                     =          Mass flow rate

G                     =          Gravity

E                      =          Density

D                     =          Diameter

E                      =          Enthalpy

Hf                    =          Latent heat of fusion

U                     =          Internal energy

T                      =          Temperature difference

T                      =          Temperature

H.P                  =          Horse power

K                     =          Thickness of Materials

Vo                   =          Swept volume

Cop                 =          Coefficient of performance

C                     =          Specific heat

AC                  =          Alternating current   

 
CHAPTER ONE

1.0              INTRODUCTION

A mobile deep freezer is not a different deep freezer than a refrigeration that is portable (i.e can be moved from one place to another with little application has to be with the production and control of temperature lower than atmospheric. Thus refrigeration is the process of removing heat from a lower temperature.

By its nature heat from a body at a higher temperature to another at a lower temperature but the reverse is the case; it requires external energy to be accomplished.

The refrigeration is accomplished by various methods, such as the vapour compression system, absorption system and steam jet refrigeration cycle. In this project only vapour refrigerating compression system shall be discussed as it is the method used to accomplish to the raising of standards of living of all chastise of people.

Although refrigeration is primarily of thermodynamics but the advances made in refrigeration in recent years are the result of a team approach in which technicians, craft persons, engineers scientists and others from other phases of engineering pool skill and knowledge in the design, manufacture, application and operation of the refrigeration complete knowledge of thermodynamics and properties of refrigeration must be known before the complete cycle analysis can be made.

1.1              THE APPLICATION OF THE REFRIGERATION PRINCIPLE

The application of the refrigeration principle is limitless. The most common used and one that is readily recognized is the preservation of food. Almost all products in the home, on form in industries of in the laboratories are in some ways affected by refrigeration. Thus refrigeration has become an essential commodity in modern living as no family will afford to miss it.

1.2              PURPOSE OF THE PROJECT

The objectives and purpose of the project is to achieve the following viz:

a.                   To design and construct portable domestic cooling equipment that would improve on existing design taken into consideration.

b.                  To design and construct a cooling system that is efficient with little or no complexity in maintenance.

c.                   To design and construct cooling equipment that is economical, with a reduced height.

1.3              BENEFITS OF THE PROJECT

Foodstuff can be preserved with the deep freezer for a very long time to avoid being spoilt before usage.

The design and fabrication of the mobile deep freeze has broadened our practical knowledge and we can be self reliance, if one may decide to go into production in the rear future and acts as a consultant. We can equally work efficiently without or with little guidance. 

ELECTRICAL SYSTEM IN THE REFRIGERATOR

            The power supply from the plug goes to the thermostat, from it to the fuse (overload), from it to the common terminal of the relay of the compressor system using a compressor. In the 1850s there were much development on vapour compression systems and later the introduction of ammonia as a refrigerant enabled efficiency and reliability to be much improved.

            In retrospect refrigerants themselves did more than anything to hold up the development of refrigeration some that are available that time were poisonous or explosive, or both other functions only at pressing so high as to acquire compressors and systems component to be constructed like battle ships, prime movers to noted, this gives a refrigerant a disadvantage. A break through was attained when Thomas Midgly and his associates discovered dichloride flour methane CECl2F2. In three days when tested, it confirm positive function of a refrigerant and it was code named R12.

            The boom of refrigeration were then refracted by world war II but its end made manufacturing facilities available and there was a boom in refrigeration industries and its commercial outlets bigger and better and stores were needed at the docks certainly. Industries use refrigeration in making antibodies and cooling moved in machines churning out such diverse product as condles and golf balls.

            The rapid expansion in refrigeration was accompanied by an almost equal dramatic increase, in air conditioning equipment sales to cinema and theaters, office buildings and bolds hospital air terminal buildings, departmental stores banks and shops, large and small. And the demand grew up for household goods.