CHAPTER 1

INTRODUCTION

In the past century, it has been seen that the consumption of non-renewable sources of

energy has caused more environmental damage than any other human activity. Electricity

generated from fossil fuels such as coal and crude oil has led to high concentrations of

harmful gases in the atmosphere. This has in turn led to many problems being faced today

such as ozone depletion and global warming. Vehicular pollution has also been a major

problem.

1.1 NON-RENEWABLE RESOURCES

A non-renewable resource (also known as a finite resource) is a resource that does not renew

itself at a sufficient rate for sustainable economic extraction in meaningful human

timeframes. An example is carbon-based, organically-derived fuel. The original organic

material, with the aid of heat and pressure, becomes a fuel such as oil or gas. Fossil

fuels (such as coal, petroleum, and natural gas), and certain aquifers are all examples of non-

renewable resources.

1.1.1 Petroleum

Oil, or petroleum, comes from the liquefied, fossilized remains of plants and animals that

lived hundreds of millions of years ago; once oil sources are depleted, they cannot be

replaced. Oil is an energy source that the world is very much dependent upon. It is used to

create fuels, such as gasoline, diesel and jet fuel. It is also used in the manufacturing of

plastics and industrial chemicals. Much of our oil is imported, creating a dependency on

sources that are unpredictable and costly. The environmental impacts of mining oil include

threats to waterways, plants and wildlife due to oil spills and increased infrastructure in

natural areas. The impacts of oil combustion include air pollution, smog and increased

greenhouse gas emissions. [1]

1.1.2 Coal

Coal is the most plentiful nonrenewable resource in the world and is used to create more than

half of the electricity used in the world is made when plant material has been compressed in

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bogs for millions of years. [1] The extraction of coal from surface and sub-surface mines

creates numerous problems for humans and the environment. Sub-surface mines are

dangerous for miners as tunnels can collapse and built-up gas can explode. They also create

subsidence, meaning that the ground level lowers when the coal is removed. Surface mining,

or strip-mining, causes erosion and water pollution and decreases biodiversity by reducing

plant and animal habitats. Additionally, the combustion of coal contributes to air pollution

and global climate change and creates a toxic ash as a byproduct. [1]

1.1.3 Natural Gas

Natural gas is the result of decomposing plants and animals that were trapped beneath rock

millions of years ago. This gas is drilled from the ground or extracted using dynamite and

then processed and piped through thousands of miles of pipelines for cooking, heating homes

and fueling vehicles. [2] Though natural gas is considered to be a relatively "clean" fossil

fuel, the environmental impacts of extracting it and installing pipelines include severe

disruption of wildlife habitat and groundwater contamination. [3]

1.1.4 Nuclear Energy

Although nuclear energy is often held up as a viable alternative to coal and oil, it is not a

renewable energy source. Nuclear power requires uranium, a radioactive metallic element

that must be mined from the earth and is not quickly replenished. Nuclear energy does not

create air pollution though combustion like fossil fuels. It does, however, produce radioactive

waste, which must be disposed of and which can cause problems for humans and ecosystems

for thousands of years. Additionally, accidents and leaks from nuclear power plants can have

catastrophic effects on the entire planet.[4]

1.2 RENEWABLE SOURCES

Therefore, alternative sources of energy have become very important and relevant to today’s

world. These sources, such as the sun and wind, can never be exhausted and therefore are

called renewable. They cause less emission and are available locally. Their use can, to a large

extent, reduce chemical, radioactive, and thermal pollution. They stand out as a viable source

of clean and limitless energy. These are also known as non-conventional sources of energy.

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Most of the renewable sources of energy are fairly non-polluting and considered clean though

biomass, a renewable source, is a major polluter indoors. Under the category of renewable

energy or non-conventional energy are such sources as the sun, wind, water, agricultural

residue, firewood, and animal dung.

Most renewable energy comes either directly or indirectly from the sun. Sunlight, or solar

energy, can be used directly for heating and lighting homes and other buildings, for

generating electricity, and for hot water heating, solar cooling, and a variety of commercial

and industrial uses.

The sun's heat also drives the winds and this energy, is captured with wind turbines. Then,

the winds and the sun's heat cause water to evaporate. When this water vapor turns into rain

or snow and flows downhill into rivers or streams, its energy can be captured

using hydroelectric power.

Along with the rain and snow, sunlight causes plants to grow. The organic matter that makes

up those plants is known as biomass. Biomass can be used to produce electricity,

transportation fuels, or chemicals. The use of biomass for any of these purposes is called bio

energy.

Hydrogen also can be found in many organic compounds, as well as water. It's the most

abundant element on the Earth. But it doesn't occur naturally as a gas. It's always combined

with other elements, such as with oxygen to make water. Once separated from another

element, hydrogen can be burned as a fuel or converted into electricity.

Not all renewable energy resources come from the sun. Geothermal energy taps the Earth's

internal heat for a variety of uses, including electric power production, and the heating and

cooling of buildings. And the energy of the ocean's tides come from the gravitational pull of

the moon and the sun upon the Earth.

In fact, ocean energy comes from a number of sources. In addition to tidal energy, there's the

energy of the ocean's waves, which are driven by both the tides and the winds. The sun also

warms the surface of the ocean more than the ocean depths, creating a temperature difference

that can be used as an energy source. All these forms of ocean energy can be used to produce

electricity.

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Renewable energy sources are just that, renewable. Fossil fuels are limited. While we still

have plenty at the present time, current oil reserves may only last another 30 to 70 years.

Fossil fuels are used much more quickly than they can be formed by nature. The sun is

expected to last another 4 or 5 billion years.

The main fossil fuels that are in use include coal, petroleum, lignite and natural gasses.

Renewable energy sources include solar, water, wind, geothermal and waste material. Solar

power is available for use almost anywhere. It does not take a great deal of sunlight to

produce solar power. Water, wind and geothermal power do have area limitations but fuel

from waste is unlimited. We produce more than enough waste.

Fossil fuels tend to be a "dirtier" source of power. While some fossil fuels do burn cleanly

most do not. Fossil fuels produce carbon dioxide when burned and some, like coal, also

produce sulphur dioxide, a source of acid rain. Renewable energy sources like the sun and

water are clean. Solar and hydropower do not produce harmful gasses. Wind energy does not

produce harmful gasses. Some uses of waste for energy will produce gasses but not to the

extent of fossil fuel sources.

There are other environmental aspects to consider besides air quality when comparing fossil

fuel and renewable energy sources. Coal needs to be mined. This mining, when not done

properly, can damage the land that it is mined from. Coal mining can be dangerous to the

miners and have long lasting health effects. Oil must be drilled. Drilling for oil is also a

dangerous operation. Oil being transported can leak causing damage to both ocean life and

land.

While it is true that building power plants to produce energy from renewable resources is

initially costly, the cost can be less in the long run. Solar generators do not need to be moved

because the sun ran out in the particular area that plant is located in. The sun is not going to

run out. Oil rigs do need to be rebuilt in new locations. New mines need to be dug for new

coal. Most hydroelectric plants will not need to be moved to find new sources of water.

Unless a river is diverted, the water will be there.

In considering safety, there are issues that need to be dealt with in developing of use of

renewable energy. Wind power needs to be planned carefully so as not to disturb wildlife.

Hydroelectric plants need to be located to prevent damage to aquatic life. These issues can be

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dealt with by proper planning and location of plants. We have a incredible amount of

renewable energy sources to supply our needs. We only have to have the determination to

make use of them.[5]

1.3 USES OF SOLAR ENERGY

Solar energy is used everywhere throughout the globe. solar powered objects don't need

direct sunlight but daylight. Even behind clouds and rain you get light and one minute of

sunlight can last us many lifetimes.

The use of solar energy is becoming increasingly popular. Education, easily accessible

supplies and concern for energy savings has helped the boost of solar energy use. Microwave,

TV, radio, telemetry and radio telephones are using solar energy and so are residential homes.

1.3.1 Residential

The number of PV installations on buildings connected to the electricity grid has grown in

recent years. Government subsidy programs (particularly in Germany and Japan) and green

pricing policies of utilities or electricity service providers have stimulated demand. Demand

is also driven by the desire of individuals or companies to obtain their electricity from a

clean, non-polluting, renewable source. These consumers are usually willing to pay only a

small premium for renewable energy. Increasingly, the incentive is an attractive financial

return on the investment through the sale of solar electricity at premium feed-in tariff rates.

In solar systems connected to the electricity grid, the PV system supplies electricity to the

building, and any daytime excess may be exported to the grid. Batteries are not required

because the grid supplies any extra demand. However, to be independent of the grid supply,

battery storage is needed to provide power at night.

Holiday or vacation homes without access to the electricity grid can use solar systems more

cost-effectively than if the grid was extended to reach the location. Remote homes in sunny

locations can obtain reliable electricity to meet basic needs with a simple system comprising

of a PV panel, a rechargeable battery to store the energy captured during daylight hours, a

regulator (or charge controller), and the necessary wiring and switches. Such systems are

often called solar home systems (SHS).

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1.3.2 Commercial

On an office building, roof areas can be covered with glass PV modules, which can be semi-

transparent to provide shaded light. On a factory or warehouse, large roof areas are the best

location for solar modules. If the roof is flat, then arrays can be mounted using techniques

that do not breach the weatherproofed roof membrane. Also, skylights can be partially

covered with PV.

The vertical walls of office buildings provide several opportunities for PV incorporation, as

well as sunshades or balconies incorporating a PV system. Sunshades may have the PV

system mounted externally to the building, or have PV cells specially mounted between glass

sheets comprising the window.

1.3.3 Industrial

For many years, solar energy has been the power supply choice for industrial applications,

especially where power is required at remote locations. Because solar systems are highly

reliable and require little maintenance, they are ideal in distant or isolated places.

Solar energy is also frequently used for transportation signaling, such as offshore navigation

buoys, lighthouses, aircraft warning light structures, and increasingly in road traffic warning

signals. Solar is used to power environmental monitoring equipment and corrosion protection

systems for pipelines, well-heads, bridges, and other structures. For larger electrical loads, it

can be cost-effective to configure a hybrid power system that links the PV with a small diesel

generator.

1.3.4 Remote Applications

Remote buildings, such as schools, community halls, and clinics, can benefit from solar

energy. In developing regions, central power plants can provide electricity to homes via a

local wired network, or act as a battery charging station where members of the community

can bring batteries to be recharged.

PV systems can be used to pump water in remote areas as part of a portable water supply

system. Specialized solar water pumps are designed for submersible use or to float on open

water. Large-scale desalination plants can also be PV powered using an array of PV modules

with battery storage.

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PV systems are sometimes best configured with a small diesel generator in order to meet

heavy power requirements in off-grid locations. With a small diesel generator, the PV system

does not have to be sized to cope with the worst sunlight conditions during the year. The

diesel generator can provide back-up power that is minimized during the sunniest part of the

year by the PV system. This keeps fuel and maintenance costs low. 

1.4 BENEFITS OF SOLAR ENERGY

Solar energy is an important part of life and has been since the beginning of time.

Increasingly, man is learning how to harness this important resource and use it to replace

traditional energy sources.

Solar energy is an important part of almost every life process, if not, all life processes. Plants

and animals, alike, use solar energy to produce important nutrients in their cells. Plants use

the energy to produce the green chlorophyll that they need to survive, while humans use the

sun rays to produce vitamin D in their bodies. However, when man learned to actually

convert solar energy into usable energy, it became even more important.

Most renewable energy investments are spent on materials and workmanship to build and

maintain the facilities, rather than on costly energy imports. Renewable energy investments

are usually spent within the world, frequently in the same state, and often in the same town.

Since solar energy is completely natural, it is considered a clean energy source. It does not

disrupt the environment or create a threat to Eco-systems the way oil and some other energy

sources might. It does not cause greenhouse gases, air or water pollution. The small amount

of impact it does have on the environment is usually from the chemicals and solvents that are

used during the manufacture of the photovoltaic cells that are needed to convert the sun's

energy into electricity. This is a small problem compared to the huge impact that one oil spill

can have on the environment.

1.5 SOLAR THERMAL HEATER

Solar thermal heater – also called solar domestic hot water system can be a cost effective way

to generate hot water, which can be used for our home and industrial purpose also. And we

can be used it in any climate also but solar radiation should have.

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In a solar thermal heater have three main components:

1. Solar collector

2. Heat exchanger

3. Storage tank

Solar collector

Solar collector is a important part of the solar thermal system. Solar collector is also two

types of flat plate collector and focusing collector.

Solar radiation incident upon the transparent surface of the solar collector is transmitted

through this surface. And coolant flows inside the tubes in a solar collector, which will be

heated. This flow goes to heat exchanger. The tubes are usually made of copper, but in our

solar collector we used channel, which is made of mild steel. It is black painted to help

absorb solar radiation. The solar collector is usually insulated to avoid heat losses.

Heat exchanger

Working principle of the heat exchanger is exchange the energy from one fluid to another

fluid.

So that hot water is flows in a copper tube in a heat exchanger. In heat exchanger water will

have heated after some time. It is made of insulting material like plastic.

Storage tank

We fill water in a storage tank. These systems are used to heat water for swimming pools as

well as for domestic cooking and cleaning needs.

1.5.1 Advantage

Generate electricity

By the help of solar energy we can generate electricity using solar cell (which is convert the

solar energy into electricity). Tidal energy wave energy also found from the solar energy

Save Energy

By using the sun’s free energy we can reduce our hot water energy consumption by 50% to

90% depending on where we live. That’s up to 90% less gas or electricity which needs to be

produced.

Save water heating costs

Reducing our energy usage will give us real dollar savings every day. An average home can

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expect to save money off its energy bills year after year. And with the way energy costs are

increasing around the world, the savings could be even greater in the future.

Save the environment

Not only will we make big savings on our energy costs, using the sun’s free energy is great

for the environment. A family of four with a Solar water heater can save up to 3 or 4 tonnes

of greenhouse gas emissions compared to a conventional electric water heater. That’s the

same as taking a small car off the road, so we can imagine the benefits for our future

generations and the future of the planet.

1.5.2 Problems

1. Initial cost of the solar water heater is high.

2. Unavailability of solar energy during winter season, rainy season and cloudiness

environment .

3. Scaling problem occurs to use of normal water. Due to the scaling problem, life of

collector is reduced. If water supply is of hard water or acidic water a solar water heater will

be rendered useless after a while because the interiors of the solar collector may get corroded.

4. The defects of solar water heater is the installation is complex. If the installation of  solar

water heater is improper, it will affect the appearance of housing, quality, and the city's face

of the city. As solar heat collector is installed outdoors, the maintenance is troublesome.

1.6 CHAPTER PLAN

1.6.1 Introduction

In this chapter firstly we discussed about renewable and non renewable energy sources. Non

renewable sources, these are limited sources. Examples of the non renewable sources are like

petroleum, coal, natural gas, nuclear energy and certain aquifers.

Later we discussed about renewable sources. These sources have infinite. No shortage occurs.

In these sources have no emission problem occurs and availability occur everywhere.

Solar energy, tidal energy, wave energy, bio energy, geothermal energy, ocean energy, wind

energy is examples of renewable sources. And we described about these energy sources.

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1.6.2 Review of literature

In this chapter we discussed about the solar water heating system. Solar water heating system

is a device that uses solar energy for hot water production. Later we discussed that production

of solar water heater and where it uses.

After that we described about types of solar water heating system. It mainly two types

1. Natural circulation systems and

2. Forced circulation system

Natural circulation system

In a natural circulation system natural fluid flows. This system works on the thermosyphon

solar system.

Forced circulation system

If the thermosyphon system cannot be used for climate, structural, or architectural reason a

forced circulation required. So that in this system we need pressure for flowing water.

After that we discussed about the components of solar water heater using secondary fluid.

Solar collector

Tubes

Heat exchanger

Water container

Solar collector

solar radiations fall on the solar collector. So that secondary fluid flows in the solar collector

channels. Fluid will be heated. It is upper surface pained from black color. And lower surface

is attached to the insulating material.

After that in it described about types of collector

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Tubes

We took two types tubes Plastic tube and copper tube.

Heat exchanger

It is made of insulating material like plastic.

Water container

Use of container is store the water.

1.6.3 Materials and methods

In this chapter we discussed about material properties those we used.

We discussed about mild steel, which use for making solar collector And we discussed about

properties of copper tube.

Later on we discussed about secondary fluid. In this system we used distilled water because

of higher specific heat and higher boiling point.

And no scaling problem occurs.

After that in a calculation part we assume the all efficiencies and design the solar collector

and heat exchanger.

We found the total heat to heat water.

1.6.4 Result and discussion

In this topic we have discussed about all our calculation result. Final analysis has been made

in this topic which is further tested by special techniques and devices. All the calculation and

results are discussed in this topic.

We have discussed the result of following calculation as follows

Collector area

Collector dimension and material

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Channel dimension

Stand design

Tube design of heat exchanger

Storage tank dimension

1.6.5 Conclusion and suggestion

In this topic we have concluded what we have studied and what the final result we obtained.

In this we have suggested some points to improve the efficiency, to increase the capacity, to

maintain accuracy etc.

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CHAPTER 2

REVIEW OF LITERATURE

2.1 SOLAR WATER HEATING

A solar water heating system (SWH) is the device that uses solar energy for hot

water production. Solar water heating system (SWH) is renewable energy technology

and has been used in many countries of the world. This natural energy is absolutely free and

the supply is unlimited in the day whenever there is sunlight. The usage of this Energy does

not produce any pollutant and therefore is most Environment Friendly. In Residential

countries, energy consumption in the building sector need of high energy Budget. Most

energy is needed production of hot water and space heating. Hot water is important for

bathing and for washing, utensils and other domestic purpose in urban as well as in country

areas. Heating water is usually burning by firewood in the country areas and by fossil fuel

energy such as kerosene oil, petroleum gas (LPG), coal and electricity in metropolitan areas.

In this consider, consumption of solar energy through solar water heating (SWH) systems can

be replace to reducing energy amount required.(Staff, D., and Campbell, S., 1978)

SWH is approve and readily available technology use renewable energy for Conventional

water heating. A lot of types of SWH are available and can be used in much application.

Domestic hot water usually uses small system applications while larger systems are used in

industrial applications. There are two types of water heating systems based on the type of the

circulation: natural circulation and forced circulation. Natural circulation solar water heaters

are simple in design and low cost. Forced circulation water heaters are used in freezing

climates and for commercial and industrial process heat. (Staff, D., and Campbell, S., 1978)

[5]

Suitable design of solar water heating system is will give maximum benefit to the user,

mainly for a large system. Designing solar hot water system need suitable sizing of different

components and must considering on solar insulations and hot water demand. In this review,

the effect of sizing of part on the system is studied and a novel strategy for the system part is

proposed to improve the design and performance of solar water heating systems.

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2.2 SOLAR WATER HEATING SYSTEM

Energy application from the sun to heat water is nothing new. Solar water heaters have been

use since the 1800s. The difference in configuration is most modern solar water heaters are

placing in the roof with resembles to sky. Solar water heaters are an environmentally and to

reduce energy bills. (Staff, D., and Campbell, S.,1978)

Solar water heaters come in different configurations in the design, cost,

performance, and level of system. Most systems have auxiliary sources such as electricity or

gas. A solar water heating system has a part of a insulated water storage tank, a solar

collector, a back-up energy source, and a pump and controls. (Staff, D., and Campbell,S.,

1978)

2.3 TYPES OF SOLAR WATER HEATING SYSTEM

There are basically two types of solar water heating system(D. Yogi Goswami, Jan F.Kreider,

1999)

2.3.1 Natural Circulation Systems (thermosyphon solar system)

The natural tendency of a less dense fluid to rise above a denser fluid can be used in a simple

solar water heater to cause fluid motion through a collector. The density difference is created

within the solar collector where heat is added to the liquid. In the system shown in Figure 2.1

as water gets heated in collector, it rises to the tank and the cooler water from the tank moves

to the bottom of the collector, setting up a6 natural circulation loop. It also called a

thermosyphon loop. Since these water heaters not use a pump, it is a passive water heater. For

the thermosyphon to work, the storage tank must be located higher than the collector. (D.

Yogi Goswami, Jan F. Kreider, 1999)

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Figure 2.1: Natural circulation system (thermosyphon)

[D. Yogi Goswami, Jan F. Kreider, 1999]

Since the driving force in a thermosyphon system is only a small density difference and not a

pump, larger-than-normal plumbing fixtures must be used to reduce pipe friction losses. In

general, one pipe size larger than normal would be uses with a pump system are satisfactory.

Since the hot-water system load vary little during a year, the angle of tilt is that equal to the

latitude, that is, 40° . The temperature difference between the collector inlet water and

collector outlet water is usually 8-11°C during the middle of a sunny day. After sunset, a

thermosyphon system can reverse its flow direction and lose heat to the environments during

the night. To avoid reverse flow, the top header of the absorber should be at least 30cm below

the cold leg fitting on the storage tank, as shown; otherwise a check valve would be needed. .

(D. Yogi Goswami, Jan F. Kreider, 1999) Several features inherent in thermosyphon design

unit utility. If it’s to be operated in a freezing climate, a non freezing fluid must be used,

which in turn requires heat exchanges between collector and portable water storage. (If

portable water is not required, the collector can be drained during cold period instead). Heat

exchanger of either the shell-and-tube type or the immersion-coil type required higher flow

rates for efficient operation than a thermosyphon can provide.

usually limited to non freezing climates. For mild freeze climates, a heat exchanger coil

welded to the outer surface of the tank and filled with antifreeze may work well. .(D.Yogi

Goswami, Jan F. Kreider, 1999)

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2.3.2 Forced-Circulation System

If a thermosyphon system cannot be used for climatic, structural, or architectural reason, a

forced- circulation system is required. In order to accommodate the thermal expansion of

water from heating, a small(about 2 gallon capacity) expansion tank and a pressure relief

valve are provided in the solar loop. Because water always stays in the collector of this

system, antifreeze (propylene glycol or ethylene glycol) is required for location where

freezing condition can occur. During stagnation condition (in summer), the temperature in the

collector can become very high, causing the pressure in the loop to increase. This can cause

leak in the loop unless some fluid is allowed to escape through a pressure-release valve.

Whether the result of leaks or of draining, air enters the loop causing the pumps to run

dry. This disadvantage can be overcome in a closed loop drain back system which is not

pressurized. In this system, when the pump shut off, the water in the collector drain back into

a small holding tank while the air in the holding tank goes up to fill the collector. The holding

tank can be located where freezing does not occur, but still at a high level to reduce pumping

power. In all three configuration differential controller measures the temperature differential

between the solar collector and the storage, and turns the circulation pump on when the

differential goes below a set limit (usually 2°C).

Alternatively, a photovoltaic (PV) panel and d DC pump may be used. The PV panel

turns on the pump only when the solar radiation is above a minimum level. Therefore,

the differential controller and the temperature sensors may be eliminated. . (D. Yogi

Goswami, Jan F. Kreider, 1999)

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Figure 2.2: Three configurations of forced circulation systems: (1) open loop, (2) closedloop,

and (3) closed loop with drain back.

[D. Yogi Goswami, Jan F. Kreider, 199]

Figure 2.2 show in an open loop system the solar loop is at atmospheric pressure, therefore,

the collectors are empty when they are not providing useful heat. A disadvantage of the

system is the high pumping power required to pump the water to the collector every time the

collectors become hot. This disadvantage is overcome in the pressurized closed loop system

since the pump has to overcome only the resistance of the pipes. In this system, the solar loop

remains filled with water under pressure. (D.Yogi Goswami, Jan F. Kreider, 1999)

2.4 COMPONENTS OF SOLAR WATER HEATER USING

SECONDARY FLUID

Solar collector

Tubes

Heat exchanger

Water container

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2.4.1 SOLAR COLLECTOR

1. Solar collector:  Solar collector is a device for the absorption of solar radiation for

the heating of water or buildings or the production of electricity.

2. Types of solar collector:

Figure- 2.3

2.4.1.1 Non-concentrating collectors or flat plate collectors

Flat-plate collectors are very common and are available as liquid-based and air-

based collectors.  These collectors are better suited for moderate temperature applications

where the demand temperature is 30-70C and/or for applications that require heat during the

winter months. The liquid-based collectors are most commonly used for the heating

of domestic and commercial hot water, buildings, and indoor swimming pools. The air-

based collectors are used for the heating of buildings, ventilation air and crop-drying.

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SOLAR THERMA

L COLLECT

OR

CONCENTRATING COLLECTORS-for high heat -regions with

more than 2.500W/m2

annual sunshine

NON-CONCENTRATI

NG COLLECTORS - for low heat-e.g. flat plate

collector

Figure 2.4

In this type of collector a flat absorber efficiently transforms sunlight into heat. To

minimize heat escaping, the plate is located between a glazing (glass pane or transparent

material) and an insulating panel. The glazing is chosen so that a maximum amount of

sunlight will pass though it and reach the absorber. 

Figure 2.5- solar flat plate collector

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2.4.1.2 Concentrating solar collectors

By using reflectors to concentrate sunlight on the absorber of a solar collector, the size of the

absorber can be dramatically reduced, which reduces heat losses and increases efficiency at

high temperatures. Another advantage is that reflectors can cost substantially less per unit

area than collectors. This class of collector is used for high-temperature applications such as

steam production for the generation of electricity and thermal detoxification. These collectors

are best suited to climates that have an abundance of clear sky days and therefore are not so

common in Canada.  Stationary concentrating collectors may be liquid-based, air-based, or

even an oven such as a solar cooker. There are four basic types of concentrating collectors:

1. Parabolic trough

2. Parabolic dish

3. Power tower

4. Stationary concentrating collectors

Figure 2.6

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Figure 2.7-Parabolic concentrating collector

2.4.2 TUBES

In a solar water heating system using secondary fuel use two types of tubes.

i. Plastic tube

ii. Copper tube

2.4.2.1 Plastic tube

In plastic tube there is advantage of reduction of heat loss due to insulation.

2.4.2.2 Copper tube

Copper is an excellent electrical conductor. Most of its uses are based on this property or the

fact that it is also a good thermal conductor. However, many of its applications also rely on

one or more of its other properties. For example, it wouldn't make very good water and gas

pipes if it were highly reactive. On this page, we look at these other properties:

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a good electrical conductor

a good thermal conductor

corrosion resistant

antibacterial

easily joined

ductile

tough

non magnetic

attractive colour

easy to alloy

recyclable

catalytic

2.4.3 HEAT EXCHANGER

Heat exchangers work because heat naturally flows from higher temperature to lower

temperatures. Therefore if a hot fluid and a cold fluid are separated by a heat conducting

surface heat can be transferred from the hot fluid to the cold fluid.

Figure 2.8-Simplified Heat Exchanger

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2.5 SOME IMPORTANT DEFINITIONS

2.5.1 Poles of the earth

The ends of the axis of rotation of the earth mark two important points on the earth’s surface.

they are called the poles of the earth, one as north, while the other as south.

2.5.2 Earth’s equator

An equator is the intersection of a sphere's surface with the plane perpendicular to the

sphere's axis of rotation and midway between the poles. The Equator usually refers to

the Earth's equator: an imaginary line on the Earth's surface equidistant from the North

Pole and South Pole, dividing the Earth into the Northern Hemisphere and Southern

Hemisphere. Other planets and astronomical bodies have equators similarly defined.

2.5.3 Meridian

A meridian (or line of longitude) is the half of an imaginary great circle on the Earth's

surface terminated by the North Pole and the South Pole, connecting points of

equal longitude. 

2.5.4 Longitude

Longitude is a geographic coordinate that specifies the east-west position of a point on the

Earth's surface.

2.5.5 Latitude

In geography, latitude (φ) is a geographic coordinate that specifies the north-south position

of a point on the Earth's surface. Latitude is an angle (defined below) which ranges from 0° at

the Equator to 90° (North or South) at the poles. Lines of constant latitude, or parallels, run

east–west as circles parallel to the equator. Latitude is used together with longitude to specify

the precise location of features on the surface of the Earth. 

23

2.5.6 Prime meridian

The prime meridian is the planet’s line of zero degrees longitude. Slicing the earth along the

circle of the prime meridian would divide it into the Eastern and Western hemispheres.

Figure 2.9-Geometetry of earth

2.6 BASICS EARTH SUN ANGLES

2.6.1 Declination

The declination is the angular position of the sun at solar noon, with respect to the plane of

the equator. Its value in degrees is given by Cooper’s equation:

δ = 23.45 * sin [360 / 365 * (284 + n)]

Where n is the day of year (i.e. n =1 for January 1, n =32 for February 1, etc.). Declination

varies between -23.45° on December 21 and +23.45° on June 21.

2.6.2 Solar hour angle and sunset hour angle

The solar hour angle is the angular displacement of the sun east or west of the local

meridian; morning negative, afternoon positive. The solar hour angle is equal to zero at solar

noon and varies by 15 degrees per hour from solar noon. For example at 7 a.m.(solar time2)

24

the solar hour angle is equal to –75° (7 a.m. is five hours from noon; five times 15 is equal to

75, with a negative sign because it is morning).

The sunset hour angle ω is the solar hour angle corresponding to the time when the

sun sets. It is given by the following equation:

ω = 15°(12-Time)

Where δ is the declination, calculated through equation and ψ is the latitude

of the site, specified by the user. Solar time is the time based on the apparent

motion of the sun across the sky. Solar noon corresponds to the moment.

2.6.3 Slope

It is the angle between horizontal and the plane. It is denoted by s.

2.6.4 Incident angle

Incident angle is the angle being measured between the beam of the rays and normal to the

plane. It is denoted by.

2.6.5 Surface azimuth angle

It is an angular measurement in a spherical coordinate system. The vector from an observer

(origin) to a point of interest is projected perpendicularly onto a reference plane; the angle

between the projected vector and a reference vector on the reference plane is called the

azimuth.

Figure 2.10- Surface azimuth angle

25

2.6.6 Altitude angle or solar altitude

Solar Altitude is the angular height of the sun measured from the Horizon.  Above the

horizon is positive, below is negative.  The sun directly in the centre of the sky has a Solar

Altitude of 90 degrees.

Figure 2.11- Altitude angle

2.6.7 Zenith angle

The solar zenith angle is the angle measured from directly overhead to the geometric centre

of the sun's disc, as described using a horizontal coordinate system. The solar elevation

angle is the altitude of the sun, the angle between the horizon and the centre of the sun's disc.

If we write θs for the solar zenith angle, the solar elevation angle αs = 90° – θs.

The solar zenith angle, θs is estimated using results from spherical trigonometry.

Where

θs is the solar zenith angle

h is the hour angle, in the local solar time.

26

δ is the current declination of the Sun

φ is the local latitude.

Figure 2.12

27

CHAPTER 3

MATERIALS AND METHODS

3.1 DESCRIPTION OF SOLAR WATER HEATING SYSTEMS

A solar water heater consists of a solar collector to collect solar energy, an insulated storage

tank to store the hot water, and piping. Broadly, the solar water heating systems are of two

types, namely, closed loop system and open loop system. In the first one, heat exchangers are

installed to protect the system from hard water obtained from bore wells or from freezing

temperatures in the cold regions. In the other type - either thermosyphon or forced circulation

system- the water in the system is open to the atmosphere at one point or other. The

thermosyphon systems are simple and relatively inexpensive. Thermosyphon system relies on

the natural circulation of water between the collector and the storage tank. They are more

suitable for domestic and small institutional systems, provided the water is treated and

potable in quality. The forced circulation systems employ electrical pumps to circulate the

water through collectors and storage tanks. The choice of system depends on heat

requirement, weather conditions, heat transfer fluid quality, space availability, and annual

solar radiation, etc. The schematic of hot water systems are shown in figures 3.1 and 3.2

respectively.

Collection

Solar radiation is “captured” by a solar collector.

Transfer

Circulating fluids transfer this energy to a storage tank circulation can be natural

(thermosiphon systems) or forced using a circulator (low-head pump).

Storage

Hot water is stored until it is needed at a later time in a mechanical room, or on the roof in the

case of a thermosiphon system.

28

Figure 3.1- Schematic of thermosyphon type solar water heating system

Figure 3.2: Schematic of indirect active open loop solar water heating system

3.2 MATERIAL OF FLAT PLATE COLLECTOR

We have chosen mild steel for flat plate collector.

Mild steel is a type of steel that contains only a small amount of carbon and other elements.

It is softer and can be shaped more easily than higher carbon steels. It also bends a long way

29

instead of breaking because it is ductile. It is used in nails and some types of wire, it can be

used to make bottle openers, chairs, staplers, staples, railings and most common metal

products. Its name comes from the fact it only has less carbon than steel.

Some mild steel properties and uses:

Mild steel has a maximum limit of 0.2% carbon. The proportions of manganese (1.65%),

copper (0.6%) and silicon (0.6%) are approximately fixed, while the proportions of

cobalt, chromium, niobium, molybdenum, titanium, nickel, tungsten, vanadium and

zirconium are not.

A higher amount of carbon makes steels different from low carbon mild-type steels. A

greater amount of carbon makes steel stronger, harder and very slightly stiffer than a low

carbon steel. However, the strength and hardness comes at the price of a decrease in the

ductility of this alloy. Carbon atoms get trapped in the interstitial sites of the iron lattice

and make it stronger.

What is known as mildest grade of carbon steel or 'mild steel' is typically low carbon

steel with a comparatively low amount of carbon (0.16% to 0.2%). It has ferromagnetic

properties, which make it ideal for manufacture of many products.

The calculated average industry grade mild steel density is 7.85 gm/cm3. Its Young's

modulus, which is a measure of its stiffness, is around 210,000 MPa.

Mild steel is the cheapest and most versatile form of steel and serves every application

which requires a bulk amount of steel.

The low amount of alloying elements, also makes mild steel vulnerable to rust. Naturally,

people prefer stainless steel over mild steel, when they want a rust free material. Mild

steel is also used in construction as structural steel. It is also widely used in the car

manufacturing industry.

Mild steel is used in almost all forms of industrial applications and industrial manufacturing.

It is a cheaper alternative to steel, but still better than iron.

30

3.3 SECONDARY FLUID

We will use distilled water as a secondary fuel.

3.3.1 Definition

The pure, distilled water is missing a lot of components. Compared to conventional water, for

example, with river water, the distillate water is missing a whole range of dissolved salts and

gases with river water, the distillate water is missing a whole range of dissolved salts and

gases.

And to be more precise, there is no pure water in the nature, even though water is the most

common compound on the Earth. This paradox is explained quite simply: everything that we

call water is nothing more than aqueous solutions of various substances. Water is a perfect

solvent, and this kills it – in a chemically pure form the water is nowhere to be found. Even

the rainfall on its short way to the ground has time to dissolve the oxygen and carbon dioxide,

mix with dust and smoke. The transparent raindrops contain up to 0.005% impurities.

In the rivers the impurities are more. In the average city river, the dry residue can be 0.0124

oz or 350 mg per liter. In the oceans, the salt concentration can be up to 4%, but in the

underground brine – more than 20%.

With few exceptions, the ordinary water is not such a deficiency thing. But for the distillate

water, indeed, there is a demand. It’s needed in scientific laboratories and in pharmacy, for

car owners in content of different chemicals and cleaners, and in household for steam irons.

Finally, without the distilled water, many technological processes in chemical production

wouldn’t be possible. For example, only the technical needs for the production of one

kilogram of PET plastic require up to 4.62 gallons or 17.5 liters of pure water.

This is the distillate of the highest quality, containing tiny amounts of impurities. However,

sometimes the acceptable impurity level is up to 0.05%. However, this water also should be

obtained.

31

3.3.2 PROPERTIES

3.3.2.1 Heat capacity and heats of vaporization and fusion

Water has a very high specific heat capacity – the second highest among all the heteroatomic

species (after ammonia), as well as a high heat of vaporization (40.65 kJ/mol or 2257 kJ/kg at

the normal boiling point), both of which are a result of the extensive hydrogen

bonding between its molecules.

3.3.2.2 Density of water

The density of water is approximately one gram per cubic centimeter. It is dependent on its

temperature.  When cooled from room temperature liquid water becomes increasingly dense,

as with other substances, but at approximately 4 °C (39 °F), pure water reaches its maximum

density. As it is cooled further, it expands to become less dense.

3.3.2.3 Miscibility and condensation

Water is miscible with many liquids, for example ethanol in all proportions, forming a single

homogeneous liquid. On the other hand, water and most oils are immiscible usually forming

layers according to increasing density from the top.

As a gas, water vapor is completely miscible with air On the other hand the maximum water

vapor pressure that is thermodynamically stable with the liquid (or solid) at a given

temperature is relatively low compared with total atmospheric pressure. For example, if the

vapor partial pressure is 2% of atmospheric pressure and the air is cooled from 25 °C,

starting at about 22 °C water will start to condense, defining the dew point, and

creating fog or dew. 

3.3.2.4 Compressibility

The compressibility of water is a function of pressure and temperature. At 0 °C, at the limit of

zero pressure, the compressibility is 5.1×10−10 Pa−1.[29] At the zero-pressure limit, the

compressibility reaches a minimum of 4.4×10−10 Pa−1 around 45 °C before increasing again

with increasing temperature. As the pressure is increased, the compressibility decreases,

being 3.9×10−10 Pa−1 at 0 °C and 100 MPa.

32

3.3.2.5 Triple point

The temperature and pressure at which solid, liquid, and gaseous water coexist in equilibrium

is called that triple point of water.The triple point is at a temperature of 273.16 K (0.01 °C)

by convention, and at a pressure of 611.73 Pa.

3.3.2.6 Electrical conductivity

Pure water containing no exogenous ions is an excellent insulator, but not even "deionized"

water is completely free of ions. Water undergoes auto-ionization in the liquid state, when

two water molecules form one hydroxide anion (OH−) and one hydronium cation(H3O+).

Because water is such a good solvent, it almost always has some solute dissolved in it, often

a salt. If water has even a tiny amount of such an impurity, then it can conduct electricity far

more readily.

3.3.2.7 Electrolysis

Water can be split into its constituent elements, hydrogen and oxygen, by passing an electric

current through it. This process is called electrolysis. Water molecules naturally dissociate

into  H+ and  OH− ions, which are attracted toward the cathode and anode, respectively. At

the cathode, two H+ ions pick up electrons and form H2 gas. At the anode, four OH−ions

combine and release O2 gas, molecular water, and four electrons. The gases produced bubble

to the surface, where they can be collected. The standard potential of the water electrolysis

cell is 1.23 V at 25 °C.

3.3.2.8 Polarity and hydrogen bonding

Figure 3.3- the partial charges on the atoms in a water molecule

An important feature of water is its polar nature. The water molecule forms an angle, with

33

hydrogen atoms at the tips and oxygen at the vertex. This angle formed is 104.3 degrees as

opposed to the typical tetrahedral angle of 109 degrees.

3.3.2.9 Cohesion and adhesion

Water molecules stay close to each other (cohesion), due to the collective action of hydrogen

bonds between water molecules. These hydrogen bonds are constantly breaking, with new

bonds being formed with different water molecules; but at any given time in a sample of

liquid water, a large portion of the molecules are held together by such bonds. Water also has

high adhesion properties because of its polar nature. On extremely clean/smooth glass the

water may form a thin film because the molecular forces between glass and water molecules

(adhesive forces) are stronger than the cohesive forces.

3.3.2.10 Surface tension

Water has a high surface tension of 72.8 mN/m at room temperature, caused by the strong

cohesion between water molecules, the highest of the common non-ionic, non-metallic

liquids. This can be seen when small quantities of water are placed onto a sorption-free (non-

adsorbent and non-absorbent) surface, such as polyethylene or Teflon, and the water stays

together as drops. Just as significantly, air trapped in surface disturbances forms bubbles,

which sometimes last long enough to transfer gas molecules to the water.

3.3.2.11 Capillary action

Due to an interplay of the forces of adhesion and surface tension, water exhibits capillary

action whereby water rises into a narrow tube against the force of gravity.

3.3.2.12 Water as a solvent

Water is also a good solvent due to its polarity. Substances that will mix well and dissolve in

water (e.g. salts) are known as hydrophilic("water-loving") substances, while those that do

not mix well with water (e.g. fats and oils), are known as hydrophobic ("water-fearing")

substances. The ability of a substance to dissolve in water is determined by whether or not the

substance can match or better the strong attractive forces that water molecules generate

between other water molecules. If a substance has properties that do not allow it to overcome

these strong intermolecular forces, the molecules are "pushed out" from the water, and do not

dissolve.

34

3.3.2.13 Acidity in nature

Pure water has the concentration of hydroxide ions (OH−) equal to that of

the hydronium (H3O+) or hydrogen (H+) ions, which gives pH of 7 at 298 K. In practice,

pure water is very difficult to produce. 

3.4 CALCULATION

3.4.1 FLAT PLATE SOLAR COLLECTOR DESIGN

3.4.1.1 COLLECTOR AREA

Collector area is specified by using energy equation and considering the efficiency of

trapping, transfer and heat exchanger.

Heat required to heat water

Qwater=(m Cp ∆ T )

Total heat required

Qtotal= (mCp ∆ T )❑

Overall efficiency

= 1 x 2 x 3

Solar energy gain

Qs=I A st

From energy balance

(mCp ∆ T )water

❑ =I A s t

A s=(mCp ∆ T )water

I t

Through this calculations area of flat plate collector can be designed. This area is the exposed

area to sun rays.

3.4.2 HEAT EXCHANGER DESIGN

3.4.2.1 COPPER TUBE DESIGN

35

Area of copper tube is designed through using energy balance equation.

Heat available in hot fluid

Qf =(mC p ∆ T t)fluid

Mass flow rate

m=(ρAV )tube

Area of tube

Ai=π4

di2

Heat required for cold water

Qwater=(mC p ∆ T )water

From energy balance

(m Cp ∆ T )water = (m Cp ∆ T t )fluid

(∆T )fluid=(mCp∆ T )water

(mCpt )fluid

Heat transferred from hot fluid to cold water

Qnet=U Ac ∆ T mt

Mean temperature difference

[∆ T ]mean=[T i+T f

2 ]fluid

−[T i+T f

2 ]water

Overall heat transfer coefficient

U= 1

1h f

+[ ln (r2/r1)k ]

c

+ 1hw

From energy balance

U Ac ∆ T mt = (m Cp ∆ T )water

Copper tube area required

Ac=(mC p ∆ T )water

U ∆ T mt

As area of copper tube

Ac=π do Lc

Length of copper tube

Lc=Ac

π d o

36

Where

m = mass of water to heat in Kg

m = mass flow rate of hot fluid in Kg / s

C p = specific heat in Kj /KgK

ρ = density in Kg/m3

A s = surface area of collector in m2

Ac = surface area of copper tube in m2

U = overall heat transfer coefficient in W/m2 k

r2 = outer radius of copper tube in m

r1 = inner radius of copper tube in m

do = outer diameter of tube in m

d i = inner diameter of tube in m

Lc = length of tube in m

∆ T = temperature difference in k

∆ T m= mean temperature difference in k

V = velocity of hot fluid in m /s

h f= convective coefficient of fluid in W/m2 k

hw= convective coefficient of water in W/m2 k

t= time required to heat water in seconds.

3.5 FABRICATION

3.5.1 COLLECTOR

The various process followed in fabrication of collector are as follows

1) We took the metallic sheet.

2) Sheet was cut as per the required specification.

3) First sheet is corrugated in the form of in built channel.

4) The channel dimension we taken was 1×4mm.

5) Second sheet was retained flat of size 2.5×6 feet.

6) After this the two sheets are placed on each other and made fold from side and joined.

7) The welding is made along the sideways to avoid leaking problem.

8) Than it is allowed to cool and tested for leaking.

37

9) Upper and lower side of formed sheet containing channel is prepared to make a single

passage.

10) Two sheets are taken and bended in such a way that they can be further corrugated

and fit on the earlier to make a single passage through all channel.

11) Than the bend sheet pipe is adjusted on the ends of sheet.

12) Welding is made to avoid the leaking.

13) The fitting is made on ends of pipe to fill water and to circulate it.

14) Tee is joined on both ends.

15) One end of tee is closed to which was only used to empty tank and filling it.

16) On the other end of tee it is allowed to make connection.

17) Than black carbon spray is made on the collector to absorb sunlight.

3.5.2 STAND

We made stand for the solar flat plate collector with hollow metallic pipe using welding

process. The angle for the collector stand is designed through the solar incident radiation.

The following process are used to make stand

1) Firstly the drawing for stand is made as per requirement.

2) The angle of collector is designed through calculation of solar incident angle.

3) The hollow metallic pipe of brought required dimension.

4) The pipe is cut as per required dimension.

5) One side of stand is made and rest is joined through welding.

6) Collector is placed on that to check its size.

7) Two legs of stand are joined through welding at required position.

8) Other two legs are made bigger to provide the proper angle.

9) Legs are interconnected through on pipe welded in between to provide strength.

10) The stand is inspected.

3.5.3 COPPER TUBE

We have designed the copper tube using energy balance equation and bend it in helical form

on bending machine. The diameter of helical ring of copper is less than that of storage tank to

be inserted and providing proper heat conduction.

The following process is used in fabrication of tube

1) Firstly we brought the copper tube of required dimension.

38

2) Tube is bended on machine using hydraulic mechanism.

3) Bending of tube is made in helical motion.

4) Diameter of tube is decided through the diameter of storage tank.

5) Tube is made out from tank and attached with coupling mechanism.

3.5.4 STORAGE TANK

We have used plastic tank of required capacity and in the plumbing shop we have made

connection in the storage tank. We have insulated the storage tank using insulating media as

thermocol.

The following process is used for fabrication of storage tank

1) Firstly we have designed the storage capacity of tank.

2) We brought the plastic tank of required dimension.

3) For the inlet valve we have used floating valve.

4) We firstly introduced hot rod into the tank of required dimension into the tank to

make the hole.

5) Than we filed the hole to the required dimension.

6) We brought the floating valve and inserted into it and made connection there.

7) We followed the same process and made connection for outlet.

8) We used plastic tap for the outlet connection.

9) The copper tube is also made out in the similar manner and used coupling mechanism

to prevent leaking.

10) We made stand to hold the tank integral with stand of collector to make it as a single

unit.

11) We used thick metallic wire to make stand of tank.

12) We took a wire and made it in circular form by beating to hold the tank in it.

13) Than we took three more wire and welded these wires on stand of collector and ring

to make stand.

14) The stand is checked for its strength to hold the filled tank.

3.5.5 FITTING

Fitting is done to assemble all the components to make it as single unit and effective

working.

The following process is used in fitting as follows

1) Firstly we brought the heat insulated pipe.

39

2) The pipe is cut as per the required dimension.

3) We brought the tees, elbow, reducer, connector etc to make the connection.

4) We joined the tee at the upper end of collector.

5) One end of tee is closed while the other end is attached to pipe.

6) The end of pipe is joined with elbow to give direction.

7) The end of elbow is attached to reducer which is attached to the copper pipe with

coupling mechanism.

8) The other end of copper pipe is connected to the pipe with coupling.

9) The pipe is attached to elbow and then connection is made for other end of collector.

10) The end of collector is attached with tee whose one end is used to empty the collector

and closed with cover .

11) Now the fitting is checked for leaking and other problems.

40

CHAPTER 4

RESULT AND DISCUSSION

4.1 RESULT

FROM PREVIOUS ASSUMPTION

❑1 = 60%

❑2 = 80%

❑3 = 80%

Velocity of fluid

V= .0007m/s

Density of fluid

ρ = 1000Kg/m3

FROM CALCULATION

From the calculation we got the following result

Heat required to heat water

Qwater=1885000

Overall efficiency

` = 38%

Solar energy gain required

Q=5387140 J

Collector surface area

A s=¿.8m2

Mass flow rate

m=5.49 ×10−4 Kg /s

Inner area of tube

Ai= .785 cm2

Outer area of tube

Ao=1.1309 cm2

41

Temperature difference of fluid

(∆T )fluid=38℃

Mean temperature difference

[∆ T ]mean=13.5℃

Overall heat transfer coefficient

U=154 W /m2 k

Copper tube area required

Ac=.049 m2

Length of copper tube

Lc=1.3 m

4.1.1 COLLECTOR DIMENSION

Material- mild steel

Length of the collector = 1524mm

Width of the collector = 609.6mm

Width of the channel = 40mm

Number of channel = 6

Height of channel = 1mm

Gap between channel = 50mm

4.1.2 TUBE DIMENSION

Material- copper

Length of the tube = 1500mm

Outer diameter of tube = 12mm

Inner diameter of tube = 10mm

4.1.3 STAND DIMENSION

Material- iron

FRONT SIDE

Length of tube = 304mm

Area of tube = 400 mm2

No of tube = 2

Gap between tubes = 640mm

REAR SIDE

42

Length of tube =1324mm

Area of tube = 400 mm2

No of tube = 2

Gap between tubes = 640mm

BASE

Length of base = 1525mm

Area of tube = 400 mm2

No of tube = 4

Width of the base = 640mm

FIGURES OF SOLAR WATER HEATER

FIGURE- 4.1 Rear view of project

Figure- 4.2 Front wiew

43

Figure- 4.3 Side view

Figure- 4.4 Collector face

Figure- 4.5 Heat exchanger

44

CHAPTER 5

CONCLUSION AND SUGESSTION

There is a problem of scale precipitation and scaling when we directly heat the water through

sun radiation which causes following problems

1) Scaling of collector

2) Decrease in heat transfer efficiency

3) Reduction in life of collector

4) Problem of removing the scaling

5) Improper heating

6) Lack of consistency

From this experiment and project analysis we have concluded that with the use of secondary

fluid as heat transfer media we can increase life of solar collector and hence reduce its

maintenance cost.

The problem associated with the conventional heater can be removed through this and we get

following advantage

1) No scaling in collector

2) Consistent working

3) Proper heating

4) Good efficiency

5) More life

We have designed the collector and heat exchanger using energy balance equation and found

a suitable design.

1) The collector efficiency was 38%.

2) Temperature change of cold water was 45 degree.

3) Heat transfer efficiency was 60%

4) Solar angle of radiation was 42 degree.

5) Material for collector was metallic sheet with carbon black painted.

6) Secondary fluid used was distilled water.

7) Media means of transfer was through copper tube.

45

SUGESSTION

1) With the use of fine metallic powder in secondary fluid we can increase sensible

heat capacity.

2) We can use sensor trapping for better solar rays collection.

3) We can also use glycol for secondary fluid.

4) We can also use latent heat system for industrial purpose.

5) Covering with glass can increase its efficiency.

46

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