PHYSICS INVESTIGATORY PROJECT
NAME: GARGEE BOSE
CLASS: XI
SEC: BS2
ROLL NO.- 18
SERIAL TOPIC OF DISCUSSION PAGE NO. TEACHER’S
NO. SIGNATURE
1 ACKNOWLEDGEMENT 1
2 INTRODUCTION 2
3 PRINCIPLE 3
4 MATERIALS REQUIRED 4
5 PROCEDURE 5-6
6 CONCLUSION 7
7 BIBLIOGRAPHY 8
ACKNOWLEDGEMENT
I am extremely thankful to my physics teacher
Mr Sandeep Majumdar for the constant
support, motivation and insights provided
throughout the project.
I would like to express my heartfelt gratitude to
our Principal Mrs Sanghamitra Banerjee for
permitting me to move ahead with this project.
My special thanks to my parents and classmates
for assisting me during the making of this
model and in making accurate measurements.
The encouragement from my teacher, principal
and friends was invaluable. I will always remain
grateful for their support.
Vaccines are crucial for preventing infectious
diseases, but their effectiveness relies on proper
storage at controlled temperatures (typically 2-8°C).
In off-grid areas, access to reliable refrigeration is
limited, leading to vaccine spoilage and reduced
immunization coverage.
Objective:
Develop a solar-powered refrigeration system for
vaccine storage in off-grid areas, ensuring optimal
vaccine efficacy and availability.
Goals:
1. Design a solar-powered refrigeration system for
vaccine storage.
2. Ensure optimal temperature control (2-8°C) for
vaccine efficacy.
3. Develop a cost-effective and energy-efficient
solution.
4. Test the system's performance in off-grid settings.
Methodology:
1. Research existing solar-powered refrigeration
technologies and vaccine storage requirements.
2. Design a solar-powered refrigeration system using
efficient components (e.g., solar panels, battery
storage, DC-powered refrigeration unit).
3. Optimize system sizing and configuration for off-
grid areas.
4. Develop a temperature monitoring and control
system to ensure optimal vaccine storage conditions.
5. Test the system in a controlled environment and in
off-grid settings.
6. Evaluate the system's performance, energy
efficiency, and cost-effectiveness.
1. Photo-voltaic effect:
Principle: Solar panels use the photovoltaic effect
to convert sunlight into electricity. When
sunlight hits the solar cells (usually made of
silicon), photons from the light knock electrons
loose, creating a flow of electricity.
Relevance: This electricity is used to power the
refrigeration system.
2. Thermodynamic refrigeration cycle:
Principle: The refrigerator works on the basic
thermodynamic refrigeration cycle, where a
refrigerant absorbs heat from the interior of the
refrigerator and releases it outside.
Key Steps:
Compression: The refrigerant is compressed,
raising its temperature.
Condensation: The high-temperature refrigerant
releases heat to the environment as it condenses
into a liquid.
Expansion: The liquid refrigerant is allowed to
expand, cooling it rapidly.
Evaporation: The cold refrigerant absorbs heat
from the refrigerator, cooling the stored vaccines.
3. Energy Storage (Battery Backup):
Principle: Since solar energy is intermittent (i.e.,
not available at night or during cloudy weather), a
battery backup stores excess electricity generated
during sunny hours.
Relevance: This ensures a continuous power
supply for the refrigerator, even during periods
without sunlight, maintaining the required
temperature for vaccine storage.
4. Temperature Control:
Principle: Precise temperature control is critical
for vaccine storage. A thermostat monitors the
temperature inside the refrigerator and adjusts
the cooling system to ensure it remains within the
required range.
Relevance: Maintaining the cold chain is essential
to preserving vaccine efficacy, and solar energy
offers a sustainable way to achieve this in remote
or energy-limited areas.
Solar panel
Charge controller
Battery bank
DC-powered refrigeration unit
Insulated vaccine storage
compartment
Copper or aluminum tubing
Insulation materials
Refrigerant
Compressor and expansion valve
Deep cycle batteries
Battery management system (BMS)
Insulated container
Temperature monitoring and control
system
DC-DC converter
Load management system
Step 1: Research and Design
Study existing solar-powered refrigeration systems and
their components
Determine the required cooling capacity for vaccine
storage (e.g., 50 liters)
Choose a suitable refrigeration cycle (e.g., vapor
compression, absorption)
Design a solar-powered refrigeration system with the
following components:
Solar panel
Charge controller: This device regulates the voltage and
current coming from the solar panels to the batteries,
preventing overcharging and extending battery life.
Battery bank: A group of batteries that store the
electricity generated by the solar panels.
DC-powered refrigeration unit: The DC Condensing Unit
is a direct expansion subsystem (without evaporator). It
consists of micro dc compressor (12V/24V/48V) with
R134A coolant, smallest condenser and radiator, filter
drier, expansion valve or capillary, driver board and other
refrigeration parts.
The DC Condensing Unit is developed aim to satisfy the
growing market who wants ideal vapor-compression
refrigeration cycle, to meet their compact device's small
cooling demand.
RIGID DC Condensing Unit system enables the most
compact designed cooling system. It uses micro
refrigeration compressor, which eliminates the use of a
secondary coolant loop. This configuration enables the
small dc cooling unit and uses the refrigerant to directly
cool the desired equipment or device via a cold plate.
Step 2: Building the Refrigeration Unit
Fabricate the heat exchangers (evaporator, condenser,
and absorber)
Assemble the refrigeration unit using the compressor,
expansion valve, and refrigerant
Install the insulation materials and refrigerant lines
PROCEDURE CONTD.
Step 3: Solar Energy Storage and
Power Conditioning
Connect the solar panel to the charge controller and
battery bank
Install the battery management system (BMS) to
monitor and control battery charging/discharging
Add a DC-DC converter to regulate the output
voltage for the refrigeration unit
Step 4: Vaccine Storage Compartment
and Temperature Control
Build the insulated vaccine storage compartment
Install temperature sensors and a temperature
monitoring system
Implement a temperature control system to maintain
the optimal temperature range (2-8°C)
Step 5: System Integration and Testing
Connect the solar panel, battery bank, and
refrigeration unit
Test the system's performance and temperature
control
Calibrate the temperature monitoring and control
system
Step 6: Nighttime Operation and
Energy Storage
Use the battery bank to store excess energy
generated during the day
Implement a load management system to optimize
energy usage and minimize waste
Consider adding a backup power source (e.g., diesel
generator) for extended periods of low solar
radiation.
The development of a solar-powered refrigerator for
vaccine storage is a significant step towards
addressing global healthcare challenges, particularly
in regions with limited access to reliable electricity.
This project highlights the immense potential of
renewable energy, specifically solar power, to
improve cold chain logistics in areas where
consistent refrigeration is critical to preserving
vaccines and other temperature-sensitive medical
supplies.
Throughout this project, the design and
implementation of the solar-powered refrigerator
demonstrated how sustainable technology can be
harnessed to solve real-world problems. The system
relies on photovoltaic panels to convert solar energy
into electrical power, which is stored in batteries
and used to regulate the internal temperature of the
refrigerator. This ensures a stable, low-temperature
environment necessary to maintain the potency and
efficacy of vaccines, even in off-grid or remote
locations.
One of the most important advantages of this
solution is its capacity to function independently of
conventional power sources. In many developing
regions or disaster-stricken areas, the lack of stable
electricity can severely hinder vaccine distribution
efforts. By integrating solar power, the project offers
a more sustainable and dependable method of
refrigeration, which in turn enhances the resilience
of healthcare infrastructure in vulnerable
communities.
Moreover, this project proves the feasibility of
implementing green technologies in the healthcare
sector. It aligns with the global commitment to
reducing carbon footprints and mitigating climate
change by minimizing reliance on fossil fuels. In
addition to its environmental benefits, the cost-
effectiveness of solar power over time adds further
value, as it reduces operational costs compared to
fuel-based alternatives.
In conclusion, the solar-powered refrigerator not
only serves as a critical solution for vaccine storage
but also exemplifies the broader potential of
renewable energy in improving healthcare
accessibility and sustainability. This project serves
as a blueprint for future innovations that can
simultaneously tackle public health and
environmental challenges.
BIBLIOGRAPHY
Books:
Move fast with Physics – Class XII (SL Arora)
NCERT Textbook Physics; Class XII
Newspapers:
The Hindu
Websites:
extranet.who.int
www.ijert.org
www.sciencedirect.com
