Tuesday, 6 September 2016

Performance Evaluation Of Solar Cookers

The project report is on testing and evaluating a number of different solar cookers using different parameters and under different prevailing situation. The working temperature of the cooker used for the performance evaluation is 145oc and efficiency of the heat absorbed is 0.27. Statistically it is observed that the solar cooker with double or multi-reflector tested was carried out in the morning at around 9:30am, is equal to the solar angle carried out in the afternoon at around 2:30pm. The test was carried out that the solar hour angle in the morning of around 9.30am is equal to the solar hour angle in the afternoon around 2.30pm. The cooker is portable and the dimension of the outer wall is; length (L) 15300mm, Breadth (B) is 640mm and the Height (H) is 120mm.

Table of contents

1.0 Introduction           
1.1 Solar Systems                
1.2 Needs for solar energy
1.3 Literature review
1.4 Objective of the present work

2.1.1 Electrical System
2.1.2 Mechanical System
2.1.3 Electro/Mechanical System
2.1.4 Pneumatic System
2.2  Analysis of solar source  
2.3  Choice of alternative  
2.4  Green house effect
2.5  Type of solar energy collector

3.1 General description and its working principle
3.2 System component and material consideration
3.3 Cycle description 

4.0  Performance and testing of cookers
4.1  Definition of terms and basic geometric consideration and calculation
4.2  Evaluation of cookers
4.3  Selection of the best design

5.0 Conclusion
5.1 Recommendation and suggestion 
5.2   Reverence


The use of solar energy to cook food presents a viable alternative to the use of firewood, kerosene, and other fuels traditionally used in developing countries for the purpose of preparing food.  While certainly, solar cookers cannot entirely halt the use of combustible fuels for food preparation, it can be shown that properly applied, solar cooking can be used as an effective mitigation tool with regards to global climate change, deforestation, and economic debasement of the world’s poorest people. The continuous increase in the level of green house gas (GHG) emissions and the increase is fuel prices are the main driving force to utilize various source of renewable energy.

Among the clean energy technologies, solar energy is recognized as one of the most promising choice since it is free and provides clean and environmental friendly energy. The earth receives 3.85 million of solar energy each year solar energy offers a wide variety of applications in order to harness the available energy, solar cooking is considered as one of the simplest, the most viable and attractive options in term of the utilization of solar energy.
Solar cookers suggest clean and free cooking which is attraction for either modern urban life as alternative free and clean energy and rural living in developing countries that are grappled with lacks of the energy.
Firewood is use as fuel in family cooking in rural. In India 47% of the energy for home cooking comes from wood, and in many Africa countries, this value is higher than 75%, such as in Mali or Burkina Faso, where it reach 95% over 50% of the population in Nicaragua use wood as fuel for cooking. And over 53% of the country’s overall energy consumption comes from wood {GHA, 2003} Similar situation has been reported in other countries, such as Ethopia, Peru, and Indonesia. Wood cut for cooking purposes contributes to the 16 million hectares of forest destroyed annual In nearest Future, the large-scale introduction of solar energy system, directly converting solar radiation into heat can be looked forward to.
The continuous increase in the level of greenhouse gas emissions and increase in fuel price are the main driving forces behind efforts to more effectively utilize various sources of renewable energy.

Most of the thickly populated countries are blessed with abundant solar radiation daily in the range of 5-7KWH/M² and have more than 275 sunny days in a year.

Background of the study

Solar Cookers are used round the world to cook food and pasteurize water for safe drinking. They use a free renewable energy source and do not pollute the environment.
Solar Cooker are particularly useful when other sources of fuel are unavailable or to prevent the use of fossil fuels.
Solar Cooking does not require any electricity but use solar thermal energy to cook the food. This means that you can use a solar oven anywhere that has lots of sun.

A solar cooker is a device which uses the energy of direct sun rays {which is the heat from the sun} to heat, cook or pasteurize food or drink. The vast majority of solar cookers presently in use are relatively cheap, low-teach devices. Because they use no fuel and cost nothing to operate, many nonprofit organizations are promoting their use worldwide in order to help reduce fuel cost {for low income people} and air pollutions, and to slow down the deforestation and desertification caused by gathering firewood for cooking, solar cookers are classified into direct and indirect solar cookers depending upon the heat transfer mechanism use for the solar radiation directly in the cooking process while the indirect cooker use a heat transfer fluid to transfer the heat from the collector to the cooking unit.

Cooking with energy of the sun is not a new or novel idea. According to Halacy and Halacy the first scientist to experiment with solar cooking was a German physicist named Ischirnhausen [1651-1708]. He used a large lens to focus the sun’s rays and boil water in a clay scientist Horace de sausure who also discovered that wooden “hotboxes” he built produced enough heat to cook fruit. French scientist Ducurla improved on the hotbox design by adding mirrors to reflect more sunlight and insulating the box. The first book on the subject “solar energy and its industrial Applications” Was published by August mouchot in 1877, mouchot designed and built solar cookers for French soldiers in Africa and in 1878 exhibited a solar concentrator at the Paris exhibit. The first recorded solar cooker to be used on South Africa soil was probably by Sir John Herschel during a scientific expedition to the Cape of Good Hope in 1885.

To reduce greenhouse gas emissions from the burning of animal dung and un-sustainably harvested wood.
To protect the local environment, which is experiencing deforestation from the collection of wood for fuel.
To reduce the danger of home fires.
To reduce the time that children and the elderly have to spend in search of dung and firewood for fuel
To reduce smoke inhalation
To reduce the time spent cooking (as food can be placed in a pot and left while other chores are completed).
School-age children who are kept at home to help with chores and collection of firewood can return to school.
Improvement in health of women and children due to reduced smoke inhalation.
Improvement in the local environment.

Nearly one third of the World’s population depends on wood and charcoal for cooking fuels the large majority using these fuels primarily because they poor. This number of people using resources that are not expanding at the rate in which they are exploited is a catastrophe waiting to hapen. Thus the sustainable use of nature resources [including among other things, land, water bodies, the air forests and precious minerals] has been a prominent feature of development discourse the world over for a long time now    this is not accidental, as the very survival of the human race depends on how it uses and exploits natural resources now, and protects them for the benefit of posterity.
The problem of the poor is compounded by the relatively high proportion of family expenditure on fuel for cooking food. By promoting solar cooking solutions, SCI hopes to simultaneously relieve the conflict between the needs of the poor and the global effort to conserve dwindling forest resources, and to ameliorate the misery and hopelessness faced by the poor, by releasing resources that can subsequently be spend on other crucial need such as education medicine, tools, seed and food.

While many developing countries have favorable conditions to develop and use this energy, the place at which the full potential of these resources can be developed will be eventually determined by the ability of the countries to
    i.        Develop adequate data on sources and use of this energy.
  ii.        Enhance their technical capabilities.
iii.        Design system that can deliver to a large number of energy planning and programming.

There are limited researches on performance evaluate of solar cooker, yet a brief of the literature review shown the degree to which researches in developing area have analyses the performance of cookers which are limited to either collapsible umbrella reflector type or hot box type.

In the case of the simple box with no reflectors, the energy entering the aperture can be given simply as:
Where Aaperture represents the area of the ‘window’ of glazing material that is facing the sun (assumed perpendicular in this equation), tglazing is the transmissivity of the glazing material, and Isolar is the value of the global solar radiation perpendicular to the collector.

This deceptively simple equation assumes that the collector is normal to the incident radiation.  In reality, the apparent area of the collector will change with the angle of the sun, as the collector will appear smaller when the angle between the normal of the collector and sun is large.  This variation is given by:

Where q is the solar azimuth[1] and f represents the difference between the solar elevation[2] angle and the collector tilt angle[3].  Knowledge of the minimum and maximum values for the azimuth and elevation on a given day allow the integration of the above equation to obtain a daily energy input into

the solar cooker.
 [Waltenborg frank [1196]. The previous researchers evidently did not find, good design and was compelled to present the fit concept like collapsible. [10] for people who prefer the African sun stove solar cooker need to modify it and made it more efficient and the modified cooker with foam glass insulation could heat oil up to 200ºc and boil one liter of water in 45minute.

From our research we found out that no tricky solar cooker is the best solution need to be use worldwide but the improvement needed for future research is proper storage capacity that can save the energy receive from sunlight for a longer period e.g. evening or night cooking. Solar cookers are used around the world to cook food and pasteurize water safe drinking. They use a free renewable energy source and do not pollute the environment.

A solar cooker is device which use the energy of direct sun light, it slow down the deforestation and desertification caused by gathering firewood for cooking, solar cookers are classified into direct and indirect solar cookers depending upon the heat transfer mechanism use for the solar radiation directly in the cooking process while the direct solar cooker use a heat transfer fluid to transfer the heat from the collector to the cooking unit.

So therefore the research is embark in other to encourage the word in the use of solar cooker because the benefit of solar cooking can be easily identify such as less time or money spent in buying firewood and less the spent cooking over a smoke – producing fire. Data detailed from the field was analyzed along time evaluation objectives and other desired themes identified by sea.

The two most significant sources of energy are the nuclear and solar energy. Nuclear energy requires advanced technology and costly mean for its safe and reliable utilization and may have undesirable wastes in return. While solar energy shows promise of becoming a dependable energy source without near requirement of a highly technical and specialized nature.

The greenhouse effect results in the heating of enclosed spaces into which the sunshine through a transparent material such as glass in plastic, visible light easily passes through the glass and is absorbed and reflected by materials within the enclosed space.   
These research is embark in other to encourage the world in the use of solar cooker because the benefits of solar cooker can easily identify such as less time or money spent in buying firewood and less the spent cooking over a smoke-producing fire.

The improvement of the welfare of the World’s poverty stricken individuals in one major motivating factor behind the numerous non-profit around the World and other environmental boons that occurs, In nearly all developing countries at 20% of energy comes from burning Woods, in most the figure is more than 40% and in many, nearly 100% [http://solarcoooking.org/market.htm].
 Because of this the united nation environmental programme estimates the annual deforestation rate due to fire wood collection and much of it in tropical or sub-tropical regions with abundant solar energy. [keer, Barbara.(1992)] A solar cooker can be said to have multiple uses beside cooking, this include canning, drying, pasteurize water etc.

Finally the main purpose of the research was both judge the merits of the specific solar cooker being considered and to reveal common principal that can be applied to general solar cooker design.