Design And Construction Of Solar Refrigerator System

ABSTRACT

This paper presents the design of a solar powered refrigeration system. The design of the system takes into account the solar sorption principles which include both the absorption and adsorption. The study identified major parts of solar refrigerator such as the solar panel, charge controller, inverter, battery, Stainless steel solar mounting bracket, Shelf edge Rear, basket handle, Vest frost hinge, Bottle rail, Plastic suspension, compressor and Metal sheet. The freezer is required to have power of 400W and work for ten hours (10hrs). The solar radiation as indicated in the map is (6.0-6.5) Kwh/m²/day. The total power 50% of the battery power. The batteries are to be connected in series –parallel to obtain the desired value. The above design makes it possible for us to select an inverter and a charge controller of the following specification. The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or circuitry. The charge regulator or battery regulator was used to limit the rate at which electric current is added to or drawn from electric cells. Research has been conducted and it has been proven that the design and construction of solar refrigeration system comes with several advantages. It helps in meeting the demand for energy conservation and the protection of the environment.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE STUDY
• STATEMENT OF THE PROBLEM
• AIM AND OBJECTIVES OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• LIMITATION OF THE PROJECT
• SCOPE OF THE PROJECT

CHAPTER TWO

2.0      LITERATURE REVIEW

2.1      REVIEW OF THE PROJECT

2.2      HISTORICAL BACKGROUND OF SOLAR CELLS

2.3      THEORY OF SOLAR CELLS

2.4      EFFICIENCIES OF SOLAR PANEL

2.5      REVIEW OF THE RELATED WORKS

CHAPTER THREE

3.0      MATERIALS AND METHOD

3.1      MATERIALS

3.2      METHOD

3.3      BLOCK DIAGRAM

3.4     ASSEMBLING SECTION OF THE WORK

3.5     DESIGN ANALYSIS

CHAPTER FOUR

4.0       RESULT ANALYSIS

4.1      CONSTRUCTION PROCEDURE AND TESTING ANALYSIS

4.2      ASSEMBLING OF SECTIONS

4.3      CONSRUCTION OF THE CASING

4.4     TESTING

4.6     RESULT

CHAPTER FIVE

• CONCLUSIONS
• RECOMMENDATION

REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

Renewable energies are energy that can be replaced by nature. The high cost and negative environmental impact of conventional energy generation methods have necessitate to looks in the direction of renewable energy. This is because renewable energy (RE) is freely abundant in nature and has little or no harm to our environment. There are several important reasons for considering solar energy as an energy resource to meet the needs of developing countries because most of the countries called developing are in or adjacent to the torrid and have good solar radiation available and energy is a critical need of these countries but they do not have widely distributed readily available supplies of conventional energy resources [12]. Therefore most of the developing countries are characterized by parched climates, dispersed and inaccessible populations and a lack of investment capital and are thus faced with practically invincible obstacles to the provision of energy by conventional means, for example, by electrification. In contrast to this solar energy is readily available and is already distributed to the potential users. This fabrication work is based on design and construction of solar powered refrigerator [12]. A solar powered refrigerator is a refrigerator which runs on energy directly provided by sun, and it includes photovoltaic or solar panel. Solar powered refrigerators are able to keep perishable goods such as meat and dairy cool in hot climates, and are used to keep much needed vaccines at their appropriate temperature to avoid spoilage. Solar-powered refrigerators are typically used in off-the-grid locations where utility provided AC power is not available [12].

In this project, we will concentrate only on designing a refrigeration system that uses solar energy as its main source of power. The design will also see the implementation of a prototype so as to help us in determining the viability of the project. Solar powered refrigeration system has been a subject that has received a lot of publicity in the recent past. Several governments have put in place mechanisms of controlling harmful emissions to the environment and also devise ways of controlling the amount of energy consumed. Designing a system that relies on entirely solar energy will help in achieving some of the goals for the developing countries of having a clean source of energy and also reduce their reliance on fossil fuels and national electricity grid. This study was therefore commissioned in order to design a system that could be used to provide an alternative to the traditional cooling systems that not only damages the environment through the emissions of CFCs and HCFCs that deplete the ozone layer but also reduce the stretching on the national electricity grid in terms of energy consumption. This paper therefore covers the design of the solar refrigeration system and also proposes a prototype that can be used to demonstrate the functionalities of the system.

Solar-powered refrigerator can be used to keep perishable goods such as meat and dairy cool in hot climates, and are used to keep much needed vaccines at their appropriate temperature to avoid spoilage. Solar-powered refrigerators may be most commonly used in the developing world to help mitigate poverty and climate change.

The output supply of the batteries and the solar panel is DC with voltage of about 12V. A typical solar system produces 300W or 600W of power depending upon the size of the desired refrigerator. The voltage regulator is connected to the battery to convert the low voltage DC supply to run the thermoelectric cooling unit.

1.2                                                  PROBLEM STATEMENT

In developing countries there is a growing interest in refrigeration for food and vaccine preservation. Simple solar refrigerators working without need for electricity supply would be very valuable in rural areas where there may be no electricity supply. Mechanical refrigerators powered by solar cells are available, but are too expensive. In the last twenty years, adsorption refrigerators using water as a refrigerant and Zeolite as an adsorber have been successfully developed. In areas with abundant sunshine, solar radiation is the most easily accessible energy source. Solar refrigerators can work independently of the electrical network. Extensive vaccination programmes are in progress throughout the developing world in the fight against common diseases. To be effective, these programmes must provide immunization services to rural areas. All vaccines have to be kept within a strict temperature range throughout transportation and storage. The provision of refrigeration for this aim is known as the vaccine cold chain. In Africa about 1800 solar refrigerators are used to store vaccines [13]. Usually, refrigeration is produced by a vapour compression cycle, which is driven by electric power produced or generated by solar cells. However, the investment of about USD 2000 is high and the population cannot afford such systems, in addition, the high-tech production of solar cells seems to be difficult in developing countries [13].

• AIM AND OBJECTIVES OF THE PROJECT

The aim of this work is to design and construct a solar powered refrigerator. The objectives are:

1. To make an effective refrigerator using solar
2. To build a refrigerator that can be used in rural areas that is pollution free, cost effective and low maintenance cost

• To identify an area of solar energy utilization useful to the developing countries

1. To select a suitable device for development and for a preliminary
2. To develop one or more prototype units demonstrating the usefulness and economic viability of solar energy for the designed purposes.

1.4                                         SIGNIFICANCE OF THE PROJECT

The advantages of the solar refrigerator are similar to the ones offered by the other solar energy devices. Since the solar refrigerator runs on solar energy there is lots of saving of electrical power that would have been produced by the conventional power plants causing lots of pollution. The solar energy is available freely, abundantly and is a clean source of energy. One of additional advantage is that the excess power produced by the solar refrigerator can be used for the other domestic purposes. The solar refrigerators can be very useful in far off remote places where there is no continuous supply of electricity.

1.5                                           LIMITATION OF THE PROJECT

The limitation of the solar refrigerator is that the production of power is not uniform since solar energy is not available throughout the day and it also changes in intensity during various times of the year. Hence, it can be used only in places where strong sun rays are available throughout the year and most parts of the day. The other major limitation of the solar refrigerator is the size of the solar collector occupying large areas of the home. To produce power sufficient for the refrigerator big solar panels are required. The solar collectors can be kept on the terrace, but still they will occupy lots of space.

A number of solar refrigerators have been developed, and they are being used successfully. However, the technology has not been developed to the stage for carrying out commercial production of the solar refrigerators. There are few companies manufacturing solar refrigerators, but high costs of the solar equipment, their low efficiency and their large sizes have not yet made them the popular choice.

1.6                                                 SCOPE OF THE PROJECT

The scope of the study covers building a solar refrigerator which is a refrigeration system that runs on the solar energy. Solar refrigerator does not use domestic power supply, rather use power produced by the solar panels. The solar refrigerator is built around a solar panel, charge controller, inverter, battery and a thermoelectric cooling system.