Design And Construction Of A Solar Water Heater

ABSTRACT

Solar heating refers to the renewable energy system that collects energy from the sun in the form of heat rather than using the sun’s energy to produce electricity, as is the case with solar photovoltaics. Solar heating systems can be used to provide space heating and water heating to be used in residential, commercial, or industrial facilities.

In the case of solar water heating (SWH) systems, heated water is used in showers, kitchen and bathroom faucets, swimming pools, washing machines, Jacuzzis, and other appliances that require warm water. Solar space heating techniques circulate the heated liquid in a radiant heat system through piping in the walls or floors to allow the heat to naturally warm indoor spaces.

The basic components in home solar heating systems include: Collectors to take the heat from the sun and pass it to a fluid. The heat transfer fluid which takes the heat from the collector for use or storage. Heat exchangers to transfer the heat from the fluid to a home’s domestic water.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE STUDY

• OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• TYPES OF SOLAR HEATER
• PURPOSE OF THE PROJECT
• PROBLEM OF THE PROJECT
• DEFINITION SOLAR ENERGY
• USE OF SOLAR ENERGY
• PRINCIPLE OF APPLICATION
• ENVIRONMENTAL IMPACTS OF SOLAR SYSTEM
• CONCEPT OF HEATER
• SOLAR WATER HEATER FOR DOMESTIC USE
• THE BENEFIT OF SOLAR WATER HEATER

CHAPTER TWO

LITERATURE REVIEW

• REVIEW OF SOLAR WATER HEATING
• HISTORICAL BACKGROUND OF SOLAR WATER HEATER
• HISTORITICAL BACKGROUND OF PHOTOVOTAIC CELL
• THEORETICAL REVIEW OF SOLAR CELL
• REVIEW OF SOLAR CELL EFFICIENCY
• REVIEW OF SOLAR CELL MATERIALS
• TYPES OF SOLAR WATER HEATING SYSTEMS
• PASSIVE AND ACTIVE SYSTEMS

CHAPTER THREE

3.0     METHODOLOGY

3.1     BASICS OF WATER HEATER

3.2      MATERIALS AND METHODS

3.3      PRINCIPLE OF OPERATION OF A FLAT-PLATE SOLAR WATER HEATER

3.4      DESIGN ANALYSIS

3.5      SELECTION OF MATERIALS

3.6      DESIGN PICTURE

3.7      DESIGN DIAGRAM

3.8      SYSTEM DESIGN REQUIREMENTS

CHAPTER FOUR

• TESTING/RESULTS AND DISCUSSION
• SYSTEM SPECIFICATION AND INSTALLATION
• SELECTING A SOLAR WATER HEATER
• INSTALLING AND MAINTAINING THE SYSTEM
• IMPROVING ENERGY EFFICIENCY

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

Solar heating refers to the renewable energy system that collects energy from the sun in the form of heat rather than using the sun’s energy to produce electricity, as is the case with solar photovoltaics. Solar heating systems can be used to provide space heating and water heating to be used in residential, commercial, or industrial facilities.

SWH systems are designed to deliver hot water for most of the year. However, in winter there sometimes may not be sufficient solar heat gain to deliver sufficient hot water. In this case a gas or electric booster is used to heat the water.

In the case of solar water heating (SWH) systems, heated water is used in showers, kitchen and bathroom faucets, swimming pools, washing machines, Jacuzzis, and other appliances that require warm water. Solar space heating techniques circulate the heated liquid in a radiant heat system through piping in the walls or floors to allow the heat to naturally warm indoor spaces.

Today, there are also solar heaters that passively warm air instead of a liquid, which are commonly used in the UK and other European countries. By warming external air and then circulating it indoors, these systems provide a unique method of space heating using renewable energy.

1.2                                             OBJECTIVE OF THE PROJECT

The aim of this project is to design a device that can be used to heat water. The water heating can be used in residential, commercial, or industrial facilities.

• SIGNIFICANCE OF THE PROJECT

In Solar water heating (SWH) systems, heated water is used in showers, kitchen and bathroom faucets, swimming pools, washing machines, Jacuzzis, and other appliances that require warm water.

• Free hot water – an average sunny day in Nigeria generate sufficient solar energy to provide all your hot water without using electricity.
• Save Money – approximately 50% of your electricity bill could be saved. Using solar water heater systems could drastically reduce the size of installed generator sets.
• An investment – solar water hearing system will add value to your property.
• Environmental Friendly – solar energy is clean energy. No pollution.
• Self-sufficiency – with a solar water heating system you are protected from the ever-increasing cost and erratic.
• This system is easy to install and require very little maintenance.
• This system has long life hence gives value for your investment. A solar water heater can wok trouble free for up-to 20 years.

1.4                                               TYPES OF SOLAR HEATER

These are two solar thermal techniques that are commonly used:

• Passive solar heating: This technique relies on the natural tendency for water to circulate freely as some of it warms (in the sun) while some cools. There are no mechanical parts used in passive solar heating systems.
• Active solar heating: In these systems, pumps and other mechanical components use electricity to circulate water or a heat medium through the system.

1.5                                              PURPOSE OF THE PROJECT

Solar water heating systems include storage tanks and solar collectors. Solar water heaters use the sun to heat either water or a heat-transfer fluid in the collector. However, the main purpose of this device is to design a device provides a reliable source of hot water

1.6                                          PROBLEM OF THE PROJECT

• Additional roof top space is required to install the solar heater.
• Working of solar heaters depends up on abundance and availability of direct sun light.
• It heats only in day time, however if the storage tank is well insulated, heated water can be stored and used even at night.
• It will not be very helpful in rainy season or foggy days.

1.7                              DEFINITION SOLAR ENERGY

Solar energy is the light which comes in form of electromagnetic radiation. Electromagnetic radiation is a wave like phenomenon that move energy across distance.

Solar energy is the most abundant continuing source of energy available to the human race. Solar energy is not being used as primary sources of fuel energy but a large research and development effort has being underway to develop economical systems to harness solar energy as a major source of energy particularly for the heating and cooling of buildings.

Solar has the following advantage

1. i)         It is very attractive
2. ii)      It is non polluting

iii)      It is non deflectable (not quickly use)

1. iv)      It is reliable and free.

On the other hand, solar energy has this disadvantage

It is not constant for terrestrial application.

Solar energy can be converted directly into other form of energy in their separate conversion process, they are:

1)           THE HELIOTHERMAL PROCESS : This is absorption of solar radiation and conversion of the energy into thermal energy is the only solar conversion that has a theoretical conversion efficiency of 100%

2)           THE HELIOCHEMICAL PROCESS: This is the photosynthetic reaction. The reaction is the sources all biomass and fossil fuel.

3)           THE HELIOELECTRICAL PROCESS: This is the production of electricity by photovoltaic  or solar cells.

It is estimated that the rate at which solar energy arrives at the earth is about 1.72 x 10MW. The amount of solar energy incident on a horizontal surface range from 3.5 to 7kwh/m²/day. About 30% of the total amount is reflected to space, 47% is converted to low temperature heat and reradiated to space and 23% powers the evaporation/ precipitation cycle of the biosphere. Less than ¹/² % is represented in the kinetic energy of the wind and waves and in photosynthetic storage in plant.

1.8                                   USE OF SOLAR ENERGY

Over the years solar energy has been put to several uses ranging from drying of cloth and agricultural product to sun tanning the body and of course for food preservation. Other areas of solar energy use is air conditioning for cooling and heating of a building for human comfort using absorption cooling system.

Other area of uses of solar energy is solar cooler, warming pools, operating engine pumps, solar furnace and generating of electricity.

1.9                              PRINCIPLE OF APPLICATION

Energy received from the sun comes in form of light but not all the rays are visible to human eye. When the sun radiation hits an object, solid or liquid, these rays are absorbed, refracted and reflected. The absorbed rays are transformed into thermal energy which aids the object to get warm and heat is stored in the object.

When the sun rays strike the mirror or the glass, it reflects the rays back to other material in its surroundings obeying the laws of optics, if the mirror or glass is shape in form of a cylinder or parabola.

The Edge ray principle states that “If a ray of light is perpendicular to a parabolic surface, it reflects the rays back to the focal point. If a material for example, absorbent pipe is placed at the focus, there will be increase of solar energy resulting to an increase in temperature and if this is done, the rays are said to be concentrated. This is the principle employed in this project.

1.9                             STORAGE OF SOLAR ENERGY

Storage is impedance in the research and use of solar energy since it cannot be stored in its original form. In order to use solar energy effectively. The thermal storage systems incorporate the use of fluid. .Also steam accumulator rocks which are capable of storing both sensible and latent heat, while chemical energy storage uses the output of the solar collector to provide a chemical that can be used until the energy is required like the photovoltaic cell in the generation of electrical energy from solar radiation.

1.10          ENVIRONMENTAL IMPACTS OF SOLAR SYSTEM

Solar systems are usually considered to be rather beneficial. One of the reasons for the use of solar energy is to reduce environmental pollution and associated costs for its control. However they are a negative impact which has been identified. These are some of the impacts of solar usage.

1)      AIR POLLUTION: The replacements of fossil fuel combustion with solar heat with reduce the emission of pollutants like CO₂ NO, SO₂, particulates, and unnamed hydrocarbons. However, certain solar systems using chemical reactants for storage or organic fluid for heat transport pose the threat of release of CO, SO₂, SO₃, hydrocarbon vapour and other noxious gases. A fire hazard may exist if overheated, organic working fluids are present near an ignition source form of air “pollution” exist near focus of larger solar reflectors or refractors. Human tissue would be destroyed upon only a short contact.

2)      LAND USE: One of the largest impacts of solar collection is the requirement of relatively large amounts of land. This represents a severe problem in industrialized area such as the North East of the United States. The land intensiveness of solar plant is offset to some extent because they do not generate solid or liquid waste requiring land for disposal. Collector fields producing shading not normally represented over large areas. Impacts on the local ecosystem include an increase of shade – seeking flora, which may impair collector function.

3)      THERMAL POLLUTION: Solar system elumiciate the local thermal pollution produced by fossil fuel combustion solar flux, formerly reflected or absorbed by the local environment, is partially collected and transported to a nearby solar- thermal conversion facility. Hence the thermal effects of solar plant are minor. If electric power by a solar plant is used hundreds of miles away in a city, some reductions in the local environment heat budget occur.

1.10                                   CONCEPT OF HEATER

Solar hot water is water heat by the use of solar radiation energy. Solar heating systems are generally composed of solar radiation collector to its point of usage. The systems may be used to heat water for a wide variety of uses including home, business and industrial uses.

Most solar water heater require a well insulated storage tank, solar storage tanks have an additional outlet and inlet connected to from the collector. The pressure at which all the water in the heater has been converted to steam.

1.11              SOLAR WATER HEATER FOR DOMESTIC USE

–              ­The utilization of solar energy for domestic hot water.

–              They can be used in any climate and the fuel they use sunshine is free

–              Solar water heating systems use free heat from the sun to warm domestic hot water.

–              Solar water heating can now reduce your domestic water.

1.12                               THE BENEFIT OF SOLAR WATER HEATER

–              HOT WATER THROUGHOUT THE YEAR: The system works all year round though you will need to heat the water further with a boiler or immersion heater during the winter months.

–              CUT YOUR BILL: Sunlight is free, so once you have paid for the initial installation your hot water cost will be reduced.

–              CUT YOUR CARBON FOOTPRINT: Solar hot water is a green renewable heating system and doesn’t release any harmful carbon dioxide or other pollutants.

1.13                      SOLAR WATER HEATING TECHNOLOGY

Solar water heating is a simple technology that uses free energy from the sun of heat water generally in collector mount.

There are two type of solar water heater (Active and Passive). Active system use electric pumps valves and controller to circulate water or they are more expensive than passive systems. Passive system move household water or a heat transfer liquid through the system without pumps.