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Nepal Engineering College 

Batho Chulho 

CSIDC 2006 






Shankar Pokharel 

Ankur Sharma 




Aditya Chouhan 




Dinesh Dangol 


Shishir Bashyal 



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 

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 

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. 





team #n 






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 

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- 

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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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 



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 

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 


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. 





Combustion Control 




Automatic Ignition 


Conditional (due to 
unavailability of ignition fuel) 


System Timer 




Alphanumeric Display 


Conditional (due to illiteracy) 


Automatic briquette 



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 

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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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 

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 



Sensor Data 

Output System J 

A < , A 

Control Status ) Info Display U 



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. 


1. Airflow Vent at 
100% closed state 

2. Airflow Vent Partially 

3. Motor /Vent 

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. 


Start Batho Chulho 



f Read user Input ") 

C Read fuet status ") 
adequate fuel 

inadequate fuel 

C Validate User input ") Q Report Error j 

f Start initial ignitionj 


Read Sensor Status 

status ok s^^status not ok 
C Continue burning 
f^ ! me eta P se ^ \ _ time remaining 

k y^^^statut 

i x 



actuate controllers 



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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Batho Chufho 



mode of operation 


primary fuel 

secondary fuel 


circuit status 

readtsmp( } 
getventsatu$( ) 
setventstatusf ) 
getu$erinput( ) 
displayinfb( ) 
getcircuitstatu$( ) 
settime( ) 
getfueistatu$( ) 

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 



Holds the temperature related 
information of the system. 



Stores time related values of the system 
which includes uptime set by user. 


Modeof operation 

Stores the operation mode set by user in 
the control panel. 



Store the status of the vent. 



Value to indicate the remaining briquette 
to be burnt. 


Secondary _fuel 

Value to indicate the level of the 
remaining igniter fuel, kerosene. 



Stores information about battery power. 


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 



Initializes the Batho Chulho system. 



Gets current temperature value from 
the sensor. 



Reads current time from the timer 
and find the difference of the time set 
by settime method. 



Read the mode knob position to find 
out the user's mode of operation. 



Reads the current vent status. 



Sets the vent to required position 
calculated by the software. 



Scans the user input and assign the 
corresponding data in the respective 



Displays the information in the LCD 



Reads the current status of the 



Sets the remaining time to turn off 
the system. 



Set the mode of operation according 
to the user input. 



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 



'em Core Sensor 

initBCO K I 
i i 

I I 

I seffimef ) \j 

i A 

i i 

1 setmodef ) \i 

J getfuel$tatu$( ) ' -- 


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 

■ ■ 



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. 


Cost in US$ 



Stove Prototype 


Stepper Motor 


Other Circuit Components 


Ignition System 


LCD Panel 


Stove Hardwares 




Development Cost 






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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The test result for the Batho Chulho. 

□ Frying Mode 

□ Shimmering 

□ Traditional 

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 

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 

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] , , 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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