Nepal Engineering College
Batho Chulho
CSIDC 2006
chulho
team
x
x
X
Shankar Pokharel
spokharel@gmail.com
Ankur Sharma
yowlanku(£>gmail.com
^
V
Aditya Chouhan
adityachouhanOOT^rediffmaiLcom
*
\
Dinesh Dangol
dinesh.dangol@rediffmail.com
V
Shishir Bashyal
sbashyal@yahoo.com
mentor
ta.
Final Report Nepal Engineering College
1 . Abstract
The socio-economic divide has unfortunately led to yet another threat called the digital
divide. The latest development in computer science is biased to industrialization and
sophistication providing an expensive solution to a problem often failing to address the
primary requirements of the society. In an effort to improve the living standard of the poor,
several developmental organizations have developed and promoted the use of energy
efficient- environment friendly cook-stoves using wood-fuel. But Batho Chulho is a step-
ahead of all such efforts in the sense that the presented model is the only computerized wood
fuel burning cook- stove ever developed.
Use of wood for cooking is the biggest cause of deforestation throughout the world.
Deforestation in turn is a major cause of environmental degradation. Wood is considered to
be a renewable energy in the sense that the loss due to consumption can be compensated by
plantation. But that has not been the case so far and deforestation is increasing at an alarming
rate.
Again to the negative consequences of forest wood as a fuel, the smoke produced directly
could be a great health hazard. As a matter of fact it can be easily conceived that improper
use of firewood have several short term and long-term effects directly imposed to the society
where there is no way out. Short term effects like indoor pollution accounts in emission of
Acrolein, CO, HCHO, NO x , Particulate, PAHs, VOC and countless other poisonous
substances resulting in Health hazards including eyes and respiratory tract irritation, heart
diseases , bronchial congestion, lung edema etc. moreover these substances are also
carcinogenic
In this project, we explored the possibility of using wood effectively for cooking so that
deforestation could be retarded as well as indoor air pollution is minimized. We come up with
a computerized cook-stove that burns briquette in a smart way to minimize the fuel
consumption. Apart from being fuel efficient, the present system also offers several ease-of-
use features that enhance the chances of its acceptance in rural communities where traditional
cook-stoves are an integral part of the culture. As the system is designed in a modular fashion
rather than designing a single basic model, the system can be configured according to the
budget and other relevant factors. Versatility has been a key concept in designing the system
and therefore not only the system is versatile (one can configure it) but with the use of the
system, cooking process becomes more versatile (one can adjust burning rate and time-to-
burn). Thanks to the embedded computer.
1 Batho Chulho means Smart Cook-stove in Nepalese and is Pronounced : /ba : t, 9o : tJu:lou /
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2. System Overview
Batho Chulho is a briquette fueled cook-stove integrated with an embedded system that
functions so as to make the cooking process more fuel-efficient and less time consuming. It
is equipped with sensors that measure the heat rate generation and actuators that control the
combustion process. The embedded system incorporates control routines that make the
system smart. Before going into the implementation details of the system, we present the
requirement analysis of the system.
2.1 System Requirements Analysis. Initially, the following requirements were
formulated for the system:
a. The system should offer better fuel efficiency than existing wood-fire cook stoves.
b. The product price should be reasonably low so that rural communities can afford it.
c. The cooking system parameters like rate of heat generation should be user adjustable.
d. The design should offer interactivity that is meaningful in rural context.
e. The power supply for the control system should be derived locally.
f. The initial ignition system should preferably be started with one-touch operation.
g. The combustion should halt immediately after the user commands the system to do so.
2.2 Design Methodology. Batho Chulho is a combination of research, hardware, and
software with some mechanical designs. The team members were assigned jobs according to
their matching interests and expertise. As the team members lacked expertise in cook-stoves,
they consulted several experts of the field. The result was the selection of the briquette
fuelled cook-stove as the platform for adding the computational features. In order to find
suitable development model for our case, we chose Rapid Application Development model
and modified it according to our own requirements. Before starting the parallel development
we worked together to have extensive study on the field for modeling. And then the tasks
were divided and pipelined with independent models and deadlines. While the mentor
supervised all the parallel works and did the formal technical review of the project. Each
module was intensively tested separately before the integration and final testing.
Study
and
Planning
Construction
team #n
Modelling
Integration
and
Testing
Construction
Jan 25th Feb 24th
Modified RAD Life Cycle Model " Batho Chulho'
Fig 2.1: Modified RAD Model Used for Batho Chulho Development.
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2.3 Innovation. Engineering is not just about developing a good gadget but it is about
designing an appropriate solution for real world problems. Keeping this in mind, Batho
Chulho has been designed to address the multidimensional scope of the problem. We claim
that the project is first of its kind. The project not only helps to protect (by minimizing the
production of air contaminants during combustion) and preserve (by increasing the cooking
efficiency, it helps to minimize deforestation) the environment but also helps to improve the
livelihood of the rural community. Even though hundreds of researches have been done and
many final designs are prescribed for fuel- efficient, eco-friendly wood fire cook-stoves, they
have not reached the end-user at desirable volume. The main reason is their complexity of
operation, economical feasibility and appropriateness. If the proposed solutions were able to
hive the user friendliness and appropriateness virtually there was no need to design any stove
whatsoever. This study helped us to visualize our problem domain clearly.
2.4 PrOJGCt Impact. The project Batho Chulho plays a significant role in environmental
protection and preservation due to the fact that:
i. As fire- wood is relatively easily available locally and cost effective as well most of the
lower-middle and lower class people, which comprises a significant world population,
cook on fire-wood. Thus even a slight improvement on the traditional technology and
efficient use of wood make a significant impact in the global environmental scenario.
ii. Burning briquette, a processed form of wood-fuel, is much more energy efficient than
burning the wood directly and emits much less environmental pollutants like CO.
Moreover, it can be easily obtained from wood in the rural areas. Despite all this benefits,
briquette cook-stoves have not been able to displace the traditional wood-fire cook-stoves
as people hesitate to change their ancient cooking-culture. Batho Chulho uses briquette
as fuel and at the same time provides a set of easy to use features (like combustion
control, auto-ignition and timers). These additional features possible due to the
integration of computational module encourage the users to abandon the traditional cook-
stoves and use much more fuel-efficient technology thereby decreasing the rate of
deforestation.
iii. Several studies on improving the cooking-efficiency conclude that the efficiency of a
cook-stove ultimately depends on the cooking-habit of the user. Since the burning of the
briquette is not controlled in traditional stoves it results in waste of energy produced on
situations like low energy requirements and cooking intervals. The energy also goes
waste after the cooking is over as the combustion continues until the existing supply of
fuel does not burn out. Batho Chulho provides smartness to the cook-stove and provides
abstraction to the user. As a result, the cooking-efficiency of the stove is no more user-
dependent.
iv. Due to the ease-of-use features integrated in Batho-Chulho, the system demands very
little attention from the user and thus the user can keep themselves busy with other jobs
while cooking. As women are the user in most of the cases, they will be able to save some
time for other tasks like nurturing their children or being involved in some sort of income
generating activity. This way, the use of Batho Chulho helps to improve the livelihood of
the people.
The effort to minimize wood consumption is therefore important for conservation of the
environment, which can be easily incorporated by efficient use of briquette. Our goal is to
study existing improved cook-stoves to select the best design and add computer components
making cook- stove smart enough to control the system achieving results discussed above.
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chulho
3. Implementation and Engineering Consideration:
3.1 System Overview. The Batho Chulho comprises of several modules working together.
At a glance the general glimpse of the system is as in figure below.
Batho Chulho System
1.
2.
3.
4.
5.
6.
7.
8.
9.
Control Panel
Vent Controller Housing
Battery Housing
Circuit Housing
Air Inlet Vent
Thermal Seal
Ignition Unit Housing
Secondary Air Inlet
Briquette Housing Chamber
10. Igniter Fuel Tank
11. Briquette
12. Secondary Air Opening
13. Pot Holder and Refractive
Layer
Fig 3.1: General Diagram of Batho Chulho System.
The base of the system consists of the embedded system circuitry. This arrangement appears
to contradict the natures' principle of placing the mind in the top. The arrangement is
preferable for the reason that the bottom of the cook- stove can be easily isolated from the
heat in the cook-stove. The basement chamber consists three housings for circuit, power
supply and air supply vent controller.
The most of the free space resides inside the second part, which is the primary air flow
chamber. We have placed the control and display panel outside this chamber because it
requires the most of wiring with system core unit and this is the region most visible and
accessible. At the mean time this region is also isolated from the heat produced during
combustion. As the chamber consists two of the most important parts, i.e. primary air flow
unit and the ignition unit, we name this chamber as the primary chamber.
The primary chamber is roofed by the briquette holder. Then there comes the briquette
housing chamber. The inner wall of the chamber above the briquette holder is insulated with
a refractory material so that so that the heat produced does not escape via the outer metal
cover. The refractory material used is made up of a mixture of clay and ash and the
arrangement is called the refractive molding.
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Without a defined boundary with the briquette holding chamber secondary burning chamber
starts. This is to ensure the design requirement that the secondary burning chamber should
have air inlets just over the burning surface to ensure the proper oxidization of hazardous gas
like Carbon Monoxide (CO). Outside this chamber there lies the igniter fuel in loneliness as it
is not to be in direct contact with outer casing to avoid any chances of accidental ignition due
to the heat inside.
At the topmost part of the system, there is a parabolic pot holder with an opening of diameter
14cm in the middle as compared to the standard 13 cm diameter of the briquette. The handle
can be attached and covers can be provided for users as per the requirement. Both
components are not shown for brevity.
The usual scenario could be ex
user and novice of a svstem
(It 's the evening time and my dad is in the kitchen, my little sister enters the scene. Dad
is ready with tea kettle and heading towards "Batho Chulho").
Sister: Dad will you please teach me how to use this stove.
Dad: Why not my dear, come here.
Sis: Okay dad, how do you turn it ON?
Dad: This it the trigger, when you press it downward the briquette is ignited inside.
Sis: Oh! It sound easy, let me try. (She presses the trigger downward.). Is that all papa.
Dad: No my child, you can select the modes to operate and OFF timer.
Sis: where is it then?
Dad: See, (turn stoves slightly to face Control/display Unit). These two Knobs are
adjustable.
Sis: wait dad I can easily figure out which knobs is for timer and which is for mode.
Wow there is a display unit too. But what are other displays. Do I need them?
Dad: Well others display are to see fuel status and you need them because when the
status show empty you need to refill them.
Sis: Thanks dad it 's really a nice stove, and easy to use too.
3.2 System Modules. The Batho Chulho design team faced a tough design challenge.
The nature of the project imposed three constraints in the design: functionality, cost and
appropriateness. A design that is fully functional would cost higher and therefore the product
would not be feasible. On the other hand, an auto-ignition system that requires kerosene for
initial ignition would not be feasible owing to the fact that kerosene is not readily available in
all regions. An intensive survey would be required to workout a tradeoff that would be
suitable for all target regions. Even then, the design would be a compromise in terms of
functionality. Therefore, instead of working out a specific design, a modular approach was
adopted. Under this design principle, each subsystem of the system is considered to be an
independent module. A module will have its own functionality, cost and appropriateness
associated with it. Based on these three measures, a module will be classified as 'Required ,
'Optional' or 'Not Required '. A Required module is that which provides functionality worth
the cost of the module and at the same time is appropriate in all target regions. The
combustion control module is an example of a required module as it is the module that makes
the system fuel efficient at considerable cost. The kerosene based initial ignition system on
the other hand is an Optional module for the reason that unavailability of kerosene in some
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reasons make it inappropriate for those reasons and thus the module can be omitted. The table
below summarizes the classification of all modules of Batho Chulho.
Table 3.1: General Classification of Modules of Batho Chulho.
Functionality
Cost
Appropriateness
Classification
Combustion Control
Medium
Appropriate
Required
Automatic Ignition
Medium
Conditional (due to
unavailability of ignition fuel)
Optional
System Timer
Low
Appropriate
Required
Alphanumeric Display
Low
Conditional (due to illiteracy)
Optional
Automatic briquette
feeding
High
Appropriate
Not Required
Batho Chulho system has been designed keeping in mind the above facts considerations. The
UML approach has been used as far as possible for efficient design and presentation of the
system.
3.3 User Interaction. Since the system is targeted for the poorer half of the world
population, usually with less or no education, the user interaction should be trivial rather than
instructive. Next benefit of using this approach is that the time needed for overall operation is
drastically minimized so that the time could be utilized some something more productive.
User attention is necessary only at four incidents in the entire usage cycle. The scenario for
user interaction is easily explained using the use case diagram that follows.
Use Case Diagram "Batho Chulho"
Fig 3.2: Use Case Diagram of Batho Chulho.
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chufho
Initially user starts the system by pressing a trigger button and initializes the input parameter
considered for cooking using the control panel. Sometimes, the user may have to monitor the
system to insure that task given to the system is accomplished or not. Generally, it involves
the length of time preset by user for the system to operate. The user also may interact with
system in order to change the required parameter afterwards during the use. Typically, this
may be the case when user wants to switch from one mode to other or the case when
accidentally user initializes wrong input parameters. Besides, there is status information
provided to user so the necessary operation could go smoothly. That status information may
include the status of primary, secondary fuel or power supply indicators. If the steps
explained above are duly fulfilled by a particular user the system is guaranteed to run
seamlessly.
3.4 System architecture. The easiest way to model a system is to find out the systems and
subsystems it consists of. In our system we have used the deployment diagram of UML
approach to relate every subsystems and units in hierarchical and relational order.
The main system core works with system control core and user input subsystem. By its name
we can depict what the system really does. System control core is the core hardware and
contains actual functional mechanism of cooking and efficient control of cooking. Even
though this system interacts actively with user input subsystem that is only a communication
consideration handled through a mediator which is exactly the parent of these two systems
which in this case is a microprocessor incorporated.
BC System Core
System Control Core
<£
r
Sensor Data
Output System J
A < , A
Control Status ) Info Display U
Temp
Airflow
Deployment Diagram "Batho Chulho"
Fig 3.3: The Deployment Diagram of Batho Chulho.
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The system control core could be actually divided into two halves as represented in diagram
below. The cook control unit and sensor unit. The coordination between these two units is
done through the database stored at memory location at the instant of operation. The cook
control unit utilizes the data in order to effectively run the system as per user settings. The
databases are updated in real time basis. In our system we have actually used three basic
sensing mechanisms for temperature, time and airflow respectively.
Similarly cook control unit consists of timing control and heat control subunits. Timing
control is a function of the relation between the user input settings and software which keeps
the updated timing data of the system operation. The main function of this unit is to control
system uptime.
The heat control directly associates itself with mode of operation set by user and current
temperature of the cooking system sensed by the sensor unit. Its main function is to maintain
the defined temperature by controlling the primary air flow.
The user interaction subsystem has input and output systems. The user settings are actually
received by this unit which is the basis for the main system functionality. The output
subsystem is mainly intended to pass the message to user about actual control status and the
status of the inputs the user is giving to the system. It is the role of user to coordinate between
these systems.
3.5 Hardware Unit.
3.5.1 Briquette is the primary fuel of the Batho Chulho. So a brief description is given here.
Briquette is made up of grinded charcoal banded with some binding material in a cylindrical
shape with 19 holes in it. It is 13cm in diameter and about 7cm in height which makes its
weight to about 400gms when soil is used as binding material in 4: 1 ratio. A typical briquette
lasts for about 2 hrs. This is about twice the average cooking time for a family of five. The
briquette could be easily constructed manually using a mould and hence could be easily
manufactured at a large scale industrially.
Ignition Unit
1. Briquette Burning End
2. Igniter Fuel Valve
3. Igniter Fuel Pipe
4. Ordinary Gas Lighter
5. Casing
6. Trigger Switch
Fig 3.4: The Ignition Unit of Batho Chulho.
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3.5.2 Ignition Unit has two functionalities, one is to start the ignition of the briquette and the
other is to switch on the system. This is done by a trigger switch which is mechanically
connected with igniter fuel valve and the primary igniter. The primary igniter is a locally
available gas lighter. In case of unavailability of the gas lighter users can directly ignite with
any other means of fire like match sticks. When the trigger is switched it switches on the
system in the meantime it also opens the valve of the ignition fuel, which is kerosene in a
tank attached with the stove. There is such a mechanism that the fuel soaks the briquette
which is then ignited with the igniter.
3.5.3 Airflow Vent Control Unit controls the heat of the stove by controlling the burning
rate of the briquette. The burning rate is controlled by controlling the air flow inside the
burning chamber. There are two types of air flow namely, Primary air and Secondary air. The
inlet for both types of air supply is the same. From the chamber some holes have been made
up to the upper end of the briquette to supply the secondary air. So, both of the air supplies
are controlled through the same vent control. The airflow vent is completely software
controlled. The controlling software uses the fuggy engine. The fuzzy engine takes data from
temperature sensor and the current vent status as input and output for vent controller for
desired status as output. The more about it is explained in software part.
The software directs the rotation of the motor unit which rotates the butterfly vent from 0%
opening to 100% opening with discrete angles. The system is explained in figure below. The
shape of the air inlet ensures the efficient flow of the air into the chamber, which is then
supplied to primary and secondary burning of the briquette. To burn the briquette in
maximum rate the vent is completely opened and to extinguish it the vent is completely
closed. The principle is as simple as that the air, Oxygen being specific, is responsible for the
burning of the briquette. So the intermediate openings control the rate of burning controlling
the heat energy at the base of the pot. The vent opening is controlled by the software in the
microcontroller ordering the stepper motor to rotate in the required steps.
9
1. Airflow Vent at
100% closed state
2. Airflow Vent Partially
Open
3. Motor /Vent
Arrangment
Fig 3.5: The Airflow Vent Control ofBatho Chulho.
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3.5.4 Control Panel/ Display Unit which we also used to call UI unit (User Interface) is the
unit to interact with the user. Control panel consists of simple control knobs each for
controlling cook mode and time. When the knobs are turned clockwise the respective values
are incremented and vice versa. Simple potentiometer and ADC circuits have been
implemented to get the user values up to the system core. The GUI of the system consists of a
LED and LCD panel. LCD panel is divided into three sections. First section shows the
current mode in increasing amount of heat to be produced by the system. And second section
shows the desired system uptime settings. Which gradually decreases as the time passes by.
Both of them show the fuzzy levels. The purpose of LED is as simple to glow when the
system is ON and working.
Control Panel / Display Un
LCD Panel
Cook Mode Indicator
Timing Indicator
Battery Power Indicator
Control Knob (mode)
Control Panel Base
Indicator Icons
Briqutte Indicator
Igniter Fuel Indicator
10. Power LED
11. Control Knob (time)
Fig 3.6: The Control Panel and Display Unit ofBatho Chulho.
The third section shows the fuel status and battery power. The briquette status is shown with
the help of counter which stores in second the time from which a new one is inserted and the
level is decremented knowing that typical briquette lasts for about 2 hours during normal
operation. The mechanism for showing igniter fuel level is a small system designed by one of
our enthusiastic junior using simple level sensor. Battery status is also shown in the right top
corner of the display unit as shown.
3.5.5 Circuitry and Power Supply. Batho Chulho uses AT89C55 microcontroller as the
central processing and controlling unit in coordination with ADC0808 analog to digital
converter. The whole system is powered by a 9V power supply. It includes a stepper motor to
control the primary and secondary vents. The circuit chamber is water proof to avoid the
damages due to accidents. This was required because kitchens are usually moist and damp.
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3.6 Software Unit. The main task of software unit of Batho Chulho is to act as a
middleman to process, user input and sensor data smartly to effectively actuate different
activities in the system.
In Batho Chulho software complexity is relatively less than hardware in terms of design
perspective. However, actual implementation was little bit tedious as sixteen bit text based
display compilers were to use which have less debugging features.
The UML diagrams were mainly used to model and implement the software unit. For
explanation purpose the whole system is represented as a large class with all necessary data
and functions, sequence diagram was used to model actual flow sequence. To determine the
actual procedures activity diagram was constructed.
C
Start Batho Chulho
1
4
f Read user Input ")
C Read fuet status ")
adequate fuel
inadequate fuel
C Validate User input ") Q Report Error j
f Start initial ignitionj
c
Read Sensor Status
status ok s^^status not ok
C Continue burning
f^ ! me eta P se ^ \ _ time remaining
k y^^^statut
i x
)
7\
actuate controllers
>
y\
Activity Diagram "Batho Chulho"
Fig 3.7: The Activity Diagram of Batho Chulho
3.6.1 Batho Chulho Class. The Class of the module is designed so compactly that the
software and the related data should fit in the small memory of the microcontroller. But we
haven't omitted any functionality required. The Class formation was also one of the most
challenging tasks for the team. The basic elements, data variables and methods, of the Batho
Chulho class are presented in class diagram below.
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chufho
a
Batho Chufho
temprature
time
mode of operation
vent
primary fuel
secondary fuel
power
circuit status
initBC()
readtsmp( }
readtime()
getmode()
getventsatu$( )
setventstatusf )
getu$erinput( )
displayinfb( )
getcircuitstatu$( )
settime( )
setmodsO
getfueistatu$( )
Class Diagram " Batho Chulho"
Fig 3.8: The Class Diagram of Batho Chulho.
The different entities are described in the following tables. The descriptions are more
generalized to include the information required to use them.
Table 3.2: General Description of Variables of Batho Chulho Class.
S. No. Variable Name Description
1.
Temperature
Holds the temperature related
information of the system.
2.
Time
Stores time related values of the system
which includes uptime set by user.
3.
Modeof operation
Stores the operation mode set by user in
the control panel.
4.
Vent
Store the status of the vent.
5.
Primary^fuel
Value to indicate the remaining briquette
to be burnt.
6.
Secondary _fuel
Value to indicate the level of the
remaining igniter fuel, kerosene.
7.
Power
Stores information about battery power.
8.
Circuit Status
Stores Boolean value for circuit status.
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Table 3.3: General Description of Methods of Batho Chulho Class.
S. No. Method Name Description
1.
initBC
Initializes the Batho Chulho system.
2.
readtemp
Gets current temperature value from
the sensor.
3.
readtime
Reads current time from the timer
and find the difference of the time set
by settime method.
4.
getmode
Read the mode knob position to find
out the user's mode of operation.
5.
getventstatus
Reads the current vent status.
6.
setventstatus
Sets the vent to required position
calculated by the software.
7.
getuserinput
Scans the user input and assign the
corresponding data in the respective
variables.
8.
displayinfo
Displays the information in the LCD
screen.
9.
getcircuitstatus
Reads the current status of the
circuit.
10.
settime
Sets the remaining time to turn off
the system.
11.
setmode
Set the mode of operation according
to the user input.
12.
getfuelstatus
Read the current status of the
primary fuel and the ignition fuel.
3.6.2 Software development tool. SDCC compiler was used to develop the entire software
coding and Topview Simulator was used to simulate the program during development.
3.6.3 Fuzzy Control. Generally a well known fact is that fuzzy control is incorporated in real
life problem as sophisticated means of control which gains a desired equilibrium through
digital logic system known as fuzzy. It would be irrational here to explain the fuzzy logic and
fuzzy sets, rather we can postulate some reason why we were lured towards fuzzy control
implication and how did we really used it.
Rate of heat generation during the briquette burning was not constant even though the system
was constrained through all other possible constants, well established fact for most of the
stoves locally build with local technology. But, the other side of story was actually in our
favor. The heat generation rate showed a pattern, if certain level of Constraint was forced (in
our case amount of air through Vent) the heat generation rate could easily categorized to
levels. And transition between them was sufficiently overlapped. And the use of stepper
motor for air flow vent controlling provided us enough discrete levels to control the amount
of heat control.
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Now the question was why should we not use fuzzy control? So we used the rate of heat
generation and Pot Base Temperature as feed back inputs. Immediately we divided the sets of
inputs as
Cook mode = {close, shimmer, cook, fry}
Temp = {cold, warm, hot, vhot}
Where Cook mode depicted the rate of heat generation desired and Temp was simply a
temperature feedback. We also divided the output in five level which were.
Control = {large positive, positive, zero, negative, large negative}
The output thus divided were simply the angle at which the stepper motor is to rotate the vent
controller. We then followed simple IF/THEN rules to construct fuzzy program for
controlling which stayed in tight loop sensing the temperature and current vent status and
actuating the stepper motor as necessary. The program was written in C style coding suitable
for programming a simple microcontroller.
3.6.4 Flow sequence of the program. When the user triggers the initBC method is invoked.
After that control is ready to get the user input. Then the user sets the time and mode of the
operation. Then control panel scans the status of fuel, and temperature form sensors. And
then checks for the valid time and mode. If mode is close or time is zero the routine exits.
User Control
panel
Sysi
'em Core Sensor
initBCO K I
i i
I I
I seffimef ) \j
i A
i i
1 setmodef ) \i
J getfuel$tatu$( ) ' --
?u
1 r
! !<
■ readiime()
l readtemp() i
1 1
\ getmode()
\ i<
1 getvent$atu$( ) |
I l
J \ setventstatusf )
^j i
1 |
7] [
1 I y a e tcirc uits ta tus{ )
i |2
: display info( )
1 1 ~"
1 1
■ ■
■
bop
Sequence Diagram "Batho Chulho"
Fig 3.9: The Sequence Flow Diagram of Batho Chulho.
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If everything is OK up to now, then the current vent status is read and the desired vent status
is set. After finally checking the status of the circuit the display information are updated. And
the system runs in the loop until the exit condition is satisfied.
3.7 Cost The cost of the project is tabulated below. The total cost seems so less but this is
the actual cost rounded up. The cost needed to be less according to our design requirement
since the product is targeted for the poorer ones. And the stove can be even constructed in
less cost if some optional modules are not used.
Table 3.4: Cost of Batho Chulho.
Particulars
Cost in US$
Microcontroller(AT89C55)
2.00
Stove Prototype
4.00
Stepper Motor
5.00
Other Circuit Components
4.00
Ignition System
3.00
LCD Panel
8.00
Stove Hardwares
3.00
Battery
1.50
Development Cost
4.00
Misc
3.00
Total
37.50
And the running cost of the Batho Chulho is:
• $0. 15 for a normal briquette which lasts for two cooking sessions of general Nepali
family of 5 persons. But the cost is virtually $0.00 for those who make briquettes
themselves, since it can be made easily.
• $1.50 for battery which generally lasts for about 2 months for average Nepali family.
• $1.00 for kerosene and igniting lighter which lasts for about 2 months.
3.8 Testing and Verification. As out system design was modular, we designed and tested
each module separately. Then only we assembled them and tested finally. Here we show
some final test results, which proved the project as successful.
The stove was tested in two modes, Frying and Shimmering mode for Batho Chulho. And
the same test was carried for traditional stoves. The test results are drawn in the chart below.
The efficiency were calculated using standard water boiling test formula. The formula is:
Efficiency (%) =
(Initial mass of water x spec, heat of water (4.2kJ/kg. K)) x
(Boiling temp, of water (K) - Initial temp of water (K)) +
(Mass of evaporated water x Latent heat of water (2257 kJ/kg))
Mass of fuel used (kg) x Calorific value of the fuel (kJ/kg)
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Nepal Engineering College
The test result for the Batho Chulho.
□ Frying Mode
□ Shimmering
Mode
□ Traditional
Stove
5 10 15 20 25 30
Fig 3.10 Time (Minute) vs. Efficiency (%) Chart for Batho Chulho and Traditional Stove.
The traditional stove was monitored for 30 min and found that efficiency was about 1 8-20 %.
Time variable was not possible to vary because once burnt the briquette couldn't be stopped
in the traditional stoves.
Note: All of the above data were accounted discarding initial ignition and final stopping
time.
The test results of the system are summarized as:
1 . The efficiency of the briquette was found to be increased to about 30-35% in place of
1 8-20% in older prototypes.
2. The system ran properly for most of the runs with some adjustable and ignorable
errors.
3. The auto ignition system has not been full proof yet.
4. The metal casing was noticeably warm after the burning which is not required.
5. The life expectancy of battery was found to be acceptable.
6. The initial burning time has not yet been stabilized.
3.9 System Design Trade-offs
During our design we were buried with the trade-offs we needed to make so that the system
achieves its goals. Some of them worth mentioning are:
1 . Since we needed to design the system for the communities without electrical power
supply, we could not put more electrical components.
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Final Report Nepal Engineering College
2. The standard size of the briquette was larger to make auto feed mechanism and
smaller to make stove work for long time.
3.10 Team. Before diving in the ocean of work ahead, we thought it would be better to
discuss and subdivide the team so each could get fair share of job. We placed the mentor at
top of the tree as we all could access him practically without engaging him randomly. Beside
mentor also had to conduct Formal Technical Reviews time and again and collect
appointments and inspirations for us to get around.
We carefully examined interest and work done prior of each member and found that our
interest perfectly fitted together in some aspects and drastically differed in others which may
have been due to diversity in faculty and limited knowledge horizon. Finally we constructed
fine woven team structure. Our effort didn't go into vain. Team was productive as the
interconnection between the subdivided teams was strong. Beside that we agreed upon to
have a weekly progress meeting in which the result from Formal Technical Review was
analyzed and tallied upon with separate progress report of team. We also extend our gratitude
to Internet Conferencing which helped us a lot in our report preparation and finalization
phase as road outside was hot with ongoing political crisis and severe security measures were
being followed. Internet kept our team spirit alive as we shared and discussed the whole
report among ourselves being online. At arriving at the end of our work we were even called
"boring quads" by some of our pals.
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Final Report Nepal Engineering College
4. Summary
4.1 Conclusion. The implementation of the project clearly revealed the fact that by using
computational control techniques, the cooking-efficiency of a cook-stove can be greatly
improved. The feature of the system is not just the improvement in the cooking efficiency but
also the ease-of use features that makes it much more accepted in rural communities where
other improved cook- stoves are not quite popular. The contribution in environmental
preservation is therefore achieved at two levels. Firstly, with smart control of the cook-stove,
the fuel is efficiently utilized, thereby saving the fuel. Secondly, the ease-of-use features
integrated in the system attract more users to abandon their traditional inefficient cooking
techniques and adopt more fuel efficient and less air polluting technique. With more than half
of the world population as the potential user, Batho Chulho can play a significant role in
protection and preservation of the environment.
Apart from the direct benefits to the society in terms of environment protection and
preservation, Batho Chulho also benefits the end user in three different ways. Firstly, as the
cooking is more efficient, the cost of cooking will be less as compared to existing cook-
stoves. The reduction in fuel consumption is such that the initial cost of the system will be
paid-back within a year of investment. Secondly, Batho Chulho uses the briquette as fuel and
therefore the pollution in the kitchen is minimized. Indoor pollution is considered to be a
major cause of health problems in developing world and hence Batho Chulho helps to reduce
health hazards due to pollution. Lastly, the Batho Chulho system is designed such that it
requires very little attention during cooking and therefore the end users can allocate more
time to other productive jobs.
Batho Chulho utilizes locally available renewable fuel, is easy to operate, and is
customizable according to budget and availability of the resources. This versatility provides
Batho Chulho a potential to gain popularity among the rural community worldwide.
4.2 Further Work. During the development of the project, we very well realized the fact
that we had propounded a field in which a lot can be done. The principal feature of the
project is its requirement for localization. As we target to replace all wood-fire cook- stoves
with Batho Chulho, we need to localize our system components accordingly. The present
work does not address the localization issue to the required degree. For example, in a place
where electricity is not readily available, we need to work-out appropriate source of
electricity. It could either be solar powered cells or batteries or hand generators. Similarly,
localization of the user interaction also needs to be addressed. We also plan to come up with
an indigenous ignition system so that kerosene, which is not widely available, is not required
for initial ignition.
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Final Report Nepal Engineering College
5. References
[1] "Plants and People of Nepal" by Narayan P Manandhar
ISBN: 0881925276 - Timber Press, 2002.
[2] "Global Environment Outlook 3" by United Nations Environment Programme
ISBN: 1853838454 - James & James/Earthscan, 2002.
[3] "Embedded Systems Design With 8051 Microcontrollers: Hardware and
Software" by Zdravko Karakehayov, Knud Smed Christensen, OLE Winther,
Karakehayov Karakehayov
ISBN: 0824776968 - Marcel Dekker, 1999
[4] "Fuzzy Logic for Embedded Systems Applications" by Ahmad Ibrahim
ISBN: 0750676051 - Newnes, 2003.
[5] "Proceedings of the First World Confernence on Biomass for Energy And
Industry" by James & James
ISBN: 1902916158 - James & James/Earthscan, 2001.
[6] "Environment, Energy, and Economy: Strategies for Sustainability" edited by
Yoichi Kaya, Keiichi Yokobori
ISBN: 9280809113 - United Nations University Press, 1997.
[7] "Living in the Environment with Infotrac: Principles, Connections, and
Solutions" by G Tyler Miller - Science
ISBN: 0534997295 - Thomson Brooks/Cole, 2004.
[8] "Software Engineering: A Practitioner's Approach" by Roger S Pressman
ISBN: 0071240837 - McGraw Hill, 2004.
[9] "UML Distilled: A Brief Guide to the Standard Object Modeling Language" by
Martin Fowler
ISBN: 0321 193687 - Addison- Wesley Professional, 2003.
[10] http://www.atmel.com , http://www.embedded.com , http://en.wikipedia.org etc.
Personal References
[a] Mr.Y. R. Mishra, CSRDT/nec, Nepal Engineering College, Nepal
[b] Mr. Ridhdhibir Kansakar, Center for Energy Studies , IOE, Nepal
[c] Dr. Krishna Raj Shrestha, RECAST, TU, Nepal
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