1 1. Introduction: Improved cooking stove has brought a revolution in Bangladesh which reduced time and money consumption, produces minimum Carbon dioxide and saves from health disorder. Dependency on fuel consumption has significantly reduced. Many organizations, specifically GIZ, big NGO’s and even the root level NGO’s have come forward working together. Many initiatives have been taken by the Government of Bangladesh. Cow dung, jute sticks, other agricultural waste, wood – 90% of all Bangladeshis still employ these traditional fuels for cooking, and most use inefficient and poorly ventilated clay stoves that produce smoke, carbon monoxide, and carcinogens; the particulate pollution levels may be 30-35 times higher than accepted guidelines. The women, who cook over these stoves and their small children, are exposed to these high levels of toxins for between three and seven hours a day. The World Health Organization has estimated that 46,000 women and children die each year in Bangladesh as a direct result of exposure to indoor air pollution, while millions more suffer from respiratory diseases, tuberculosis, asthma, cardiovascular disease, eye problems, and lung cancer. 70% of the victims of indoor air pollution are children under five. The best immediate way of addressing this urgent problem is the rapid and widespread introduction of improved cooking stoves: stoves that burn biomass much more efficiently and – even more importantly – are designed to draw off the smoke and toxins, thus creating a safe environment for women and children. General Energy Situation in Bangladesh: Power: Installed capacity: 10000 MW (Operating: 8000 MW) Natural Gas: 11 tcf, Consumption: 500 bcf/a Coal reserve: 2 billion ton 50% of total energy supply is provided by biomass 40% of HHs: connected to grid electricity (rural area, 20%) 6% of the HHs: natural gas, primarily in urban areas For cooking: >90% depend on biomass, e.g. rice husks, jute sticks, cow dung, wood. The way is traditional, inefficient 2. Improved Cooking Stove (ICS): A stove is the combination of heat generation and heat transfer to a cooking pot. Cook stoves are commonly called “improved” if they are more “efficient” than the traditional cook stoves. “Efficient” mean Energy efficiency. The core question concerning the efficiency of two alternative stoves is: “With which of the two stoves do I use less fuel to prepare my meal?” Traditional Cooking Stove: These stoves may be built under ground or over ground. Heat transfer to the cooking pot is very low, resulting into low efficiency. Mud-built cylinder with three raised points. Because of the large size of the
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
1. Introduction:
Improved cooking stove has brought a revolution in Bangladesh which reduced time and money
consumption, produces minimum Carbon dioxide and saves from health disorder. Dependency on fuel
consumption has significantly reduced. Many organizations, specifically GIZ, big NGO’s and even the root
level NGO’s have come forward working together. Many initiatives have been taken by the Government of
Bangladesh. Cow dung, jute sticks, other agricultural waste, wood – 90% of all Bangladeshis still employ
these traditional fuels for cooking, and most use inefficient and poorly ventilated clay stoves that produce
smoke, carbon monoxide, and carcinogens; the particulate pollution levels may be 30-35 times higher than
accepted guidelines.
The women, who cook over these stoves and their small children, are exposed to these high levels of toxins
for between three and seven hours a day. The World Health Organization has estimated that 46,000
women and children die each year in Bangladesh as a direct result of exposure to indoor air pollution, while
millions more suffer from respiratory diseases, tuberculosis, asthma, cardiovascular disease, eye problems,
and lung cancer. 70% of the victims of indoor air pollution are children under five. The best immediate way
of addressing this urgent problem is the rapid and widespread introduction of improved cooking stoves:
stoves that burn biomass much more efficiently and – even more importantly – are designed to draw off
the smoke and toxins, thus creating a safe environment for women and children.
with chimney (on the ground); improved double-mouth cooking stove coupled with chimney (half-
underground); and improved double mouth cooking stove coupled with chimney suitable for large-scale
cooking and other heating purposes. The following strategies were adopted for the programme.
1. Advertisements in mass media.
2. Seminars
3. Training courses
4. Demonstrations
The Ministry of Science and Information & Communication Technology since its inception has being putting
its best efforts into popularizing the renewable energy technologies developed by BCSIR in the country. The
ministry has been regularly arranging seminars on ‘‘Application and dissemination of appropriate
technologies developed in the country’’ since 1986 at the district/upazila (sub-district) administrative levels
of the country. During these seminars, along with other technologies improved stove technology is being
exhibited to the common people.
9
To popularize the improved stoves, IFRD has developed two training course manuals on ‘‘Improved stoves’’.
One course is of 1-week duration and the other of 4-day duration. Scientists of IFRD have till now
conducted over 215 training courses on improved stove technology and trained about 10,000 men and
women from different government, semi-government and non-governmental organizations of the country.
Most of the trained personnel are now engaged in dissemination of improved stoves in different parts of
the country.
IFRD has successfully completed two Annual Development Programme (ADP) projects on dissemination of
improved cook stoves in the country. Both the projects were implemented jointly by BCSIR, Ansar-VDP (VDP
means Village Defense Party) and Bangladesh Rural Development Board (BRDB), as detailed in Table 1.
Some of the main objectives of the projects are given below:
1. To save traditional fuels by popularizing the improved stoves and eliminate air pollution in rural areas of
Bangladesh.
2. To develop skilled manpower for dissemination of improved stoves through training courses.
3. To create awareness about the effectiveness and usefulness of improved stoves through massive
advertisement campaigns using various media.
4. To reduce deforestation and maintain the ecological balance of the country through the massive use of
improved stoves.
5. To involve various governments, semi-government and non-governmental organizations in dissemination
programmes of improved stoves.
6. To improve hygienic conditions in the kitchen. At present, the dissemination of improved cook stoves is
being carried out by IFRD, along with its R&D activities. Some government, semi-government and non-
governmental organizations are also carrying out dissemination in a limited way throughout the country.
The Program Sustainable Energy for Development (SED), supported by the Bangladesh Ministry of Power,
Energy, and Mineral Resources and the German Federal Ministry for Economic Cooperation and
Development, through the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, is doing
that too. Various models of improved cooking stoves have been developed in different countries. In
Bangladesh, it was a group of scientists at the Institute of Fuel Research and Development (IFRD) of the
Bangladesh Council of Scientific and Industrial Research, led by Dr. A. M. Hasan Rashid Khan, who worked
with rural women in the early 1980s to adjust the clay, water, and cow dung stoves they routinely build and
use: The simple addition of a grate at the correct depth, which focuses the fire on the bottom of the
utensils and small air holes in the wall of the stove just below the grate reduces the biomass required to
cook a meal by 50%. The addition of a chimney eliminates the smoke and particles which so threaten the
health of women and children near the stove. The cost: around 800 takas (8 euros).
10
Existing Design & Testing of ICS:
Improved Single Mouth Cooking Stove (Portable)
This model, also called Model 1, was developed by BCSIR in 1982. The model and the actual stove in use are
shown in the Figure 6.1. This is suitable for wood, branches, cow dung cake, briquettes etc; and can be used
for cooking throughout the year. Main parts of this model are a structure, grate and lid for covering the ash
outlet.
Figure: Dimension of Single Mouth ICS (Portable)
Improved Single Mouth Cooking Stove (Half underground):
This model, designed by BCSIR in 1983, is the fixed version of the Model 1. If installed inside the kitchen it
can be used round the year. If installed outside it is suitable for use in the dry season only. Main parts of
this model are: structure, grate and two perforated lids for covering the ash outlets.
11
Figure: Dimensions of Single Mouth ICS (Half underground)
Common Problems of Existing ICS: Fixed type so site selection is an important issue and required a space of at least 2-3 foot to set up. Required installation, hence additional cost of installation, labour charge are concerned issues After installation required certain time for ensuring stove is thoroughly rubbed else wet and partially
damp stove consume large amount of fuel and flexibility Chimney blockage by deposition of soot on the inner wall and cause flame and hot flue gas coming out
through feed hole during cooking instead of releasing through chimney
Body fracture/crack due to heat pressure after continuous use of stove for a week Required smoothen the ICS body with mud or cow dung after 5-7 days of use for preventing body
corrosion. Advance preparation of cooking stuff is required, so after cooking one item immediately another item
has to place in stove to save energy of the stove. (Heat trapping system absent) For double mouth ICS both mouth should be in use cooking at same time whereas it is tough to manage
cooking simultaneously in two mouths. If the combustion chamber, which is, first mouth of ICS is overstuffed with fuel then there is no
sufficient space available for air to get in.
12
After using for long time, the diameter of hole of grate becomes larger, as a result some piece of firewood will fall down through the grate without burning, which ultimately increase the fuel use
Due to the corrosion of cement or mud the air inlet or feed hole dimension may change which may result improper combustion, excess firewood use, smoke exit through these holes and in case longer time for cooking.
Factors beyond the design Concern
Heat transfer into the pot & Heat Trapping
Handling of the fuel
Handling of the stove
Management of the cooking process
Cooking environment
Ten Design Principles of ICS
Principle-1: Whenever possible, insulate around the fire using lightweight, heat-resistant materials.
Principle-2: Place an insulated short chimney right above the fire.
13
Principle-3: Heat and burn the tips of the sticks as they enter the fire.
Principle-4: High and low heat are created by how many sticks are pushed into the fire.
Principle- 5: Maintain a good fast draft through the burning fuel.
14
Principle-6: Too little draft being pulled into the fire will result in smoke and excess charcoal.
Principle-7: The opening into the fire, the size of the spaces within the stove through which hot air flows,
and the chimney should all be about the same size.
Principle-8: Use a grate under the fire.
15
Principle-9: Insulate the heat flow path.
Principle-10: Maximize heat transfer to the pot with properly sized gaps.
Different steps in making a portable improved stove
Target arenas where we did the development ;
1. Efficiency Improvement
2. Economic feasibility
3. Hygiene Concern
4. Environmental Issues
5. User friendliness
16
Efficiency improvement
For improving the efficiency we can consider the following table:
Proposed ICS Design
Materials for Making ICS
1. Steel Sheet
2. Glass wool
Challenges solutions
1. Minimize heat loss through combustion
chamber and chimney.
1. Use porous materials.
2. Maintain an optimum draft. 2. Longer chimney.
3. Assure maximum contact of flue gas to the
pot.
3. Using skirt.
4. Adequate air flow to combustion chamber. 4. Maintain air hole equal to chimney diameter.
5.Assuring lighter(less mass)
Combustion chamber and chimney.
5. Ceramic, mud clay with saw dust or coal powder
(must withstand 200-225 degree Celsius temp).
6. Separation of fuel residues. 6. Using grate to separate residues and air flow.