Renewable thermal cool chain
Project Summary Renewable Thermal Cool Chain is an innovative approach to renewable refrigeration of perishable items. Problem: Using any renewable energy source forces us to use batteries as an energy storage unit. This causes the use of renewable ene
2025-06-28 16:34:47 - Adil Khan
Renewable thermal cool chain
Project Area of Specialization Mechanical EngineeringProject SummaryProject Summary
Renewable Thermal Cool Chain is an innovative approach to renewable refrigeration of perishable items.
Problem: Using any renewable energy source forces us to use batteries as an energy storage unit. This causes the use of renewable energy for farmers, dairy producers and many others to be too costly.
Solution: In order to reduce the cost for any application of refrigeration using renewable energy we have replaced the battery, which is chemical energy storage, with brine at -20 C, which is thermal energy storage. For this purpose we have designed a specifically engineering container that will use conventional currents to cool down any items in the refrigerator. The cost of brine is minimal as it is fundamentally a mixture of water and salt, with salt making up only 5-10 % of the solution.
Details: In a conventional system using solar energy as an example, the solar energy is used to power the refrigerator and charge the battery simultaneously. The battery is necessary in order to run the fridge during the night. Our system on the other hand, will use solar energy to only reduce the temperature of brine solution from room temp to -20 C. During which the temperate of any items in the fridge will begin to reduce as well. When the desirable temperature is reached the system will stop the brine from flowing anymore in the chamber. After which brine will be cooled down to -20 C. Now during the night the brine at -20 C will be used to maintain the temperature of items in the fridge, as a result the whole system will reach thermal equilibrium equal to 4-5 C by the next morning, after which the cycle will continue.
Our project is based on a refrigerator having two containers, one of which will be used as a storage tank for the foods to be kept. Further, there will be a compressor which is a conventional one with the fridge. We will use the brine solution as the coolant which will flow within the pipes between the containers. A brine solution will cool the food or any other perishable items. The pipe through which brine will flow will be of a conducting material and we will use food-grade steel for our containers. The containers are to be placed in the refrigerator so will be designed per the size of the refrigerator. Our main aim is to preserve food or any other eatables under prescribed conditions provided by WHO standards. Furthermore, we are using a thermostat to maintain a desirable temperature.
Project ObjectivesEngineering Objective:
Our objective is to design and manufacture a refrigeration system that runs on renewable energy but instead of using battery to store energy it will use themal energy.
Innovation Objective:
Our goal is to design a new innovative technology that will completely change the way the world looks at cold chain operations. This will not only be cleaner than other solution but also be much cheaper.
In the industrial food supply chain, cold storage is one of the most important processes where there is a huge but still unused potential for employing renewable energy technologies. The integration of rooftop photovoltaic affects the design and performance of refrigerated automated warehouses, which are becoming the preferred choice for frozen food storage facilities. For the reference case in northeastern Italy show that photovoltaic installation can lead to both yearly total cost and energy savings. The objectives of this project are to facilitate the farmers and the cool chain industries to preserve food for longer period of time, as almost 40% of the food rots during the transportation. This project will not only facilitates the preservation of food but also reduce the impact of environment changes as it is environment friendly. The most important feature about it is that it is customizable that means it can be designed according to the applications and type of food to be preserved as the temperature can be varied according to the type of food.
Industrial Objective:
The cold storage industry is an energy hog. Globally, cold storage facilities have the highest energy demand per cubic foot and the third highest energy consumption of any industrial category spending over $30 billion annually. With volatile energy costs, the industry is looking for better technologies that provide greater energy savings and additional benefits. This project will save lots of energy especially in the night time as the excess energy can be stored in the batteries. This will create a huge impact in the cold chain industries. It is cost efficient as well as have high performance with an incredible feature of variable temperature and customization. This project can store huge amount of food and has the ability to store food for a longer period of time in a cheap cost. It is very helpful in minimizing the pollution and harmful effect in the environment as it is renewable and has almost zero environmental pollution.
Project Implementation MethodProject Implementation Method
Research & Design:
We have already completed this phase. During the last 2 months we designed and researched the different solutions to energy storage. We decided to use brine with 5-10 % salt concentration, which is an innovation and a cheap source with higher efficiency than other sources. We have designed the schematic for the refrigeration system. We have specially designed the container for brine that will encourage convection flow. The design itself has a huge role in the convention of heat.
Manufacturing:
The only component to be manufactured is the container, it may need a few final touches and testing after the first model is manufactured. The container will be housed in a deep freezer and will use a compressor, evaporator and condenser of the freezer. All other components will be purchased from the market and our easily available in the market.
Prototype:
Once the container is manufactured and the components have been purchased we can start assembling the system. We will test the exact brine concentration needed for most efficiency. This prototype is generalize for variable applications and can be used for small and large quantities of product.
Installation:
The prototype may be installed in any application we have listed. This step will mainly focus on improving the operation cost and efficiency of the system. We will also try to keep commercial consumers in mind during testing. This can be customize according to the application.
Production:
Once we have established our concept we can begin large scale manufacturing on the project. This project can be implemented in various food centers, companies, farm, pharmaceutical companies etc.
Benefits of the Project Benefits of the Project:-
Transportation of food:
During transportation lots of food rots, this causes deficiency of food and increase in prices, the transportation of food is itself expensive and due to the dynamic parts of the vehicle it causes harmful impact on the environment. Current cold chain solution rely heavily on refrigerated trucks which use toxic refigerant gases. This project can counter this.
This project will save food from rotting as it is renewable and have wide applications of storing different types of food, like vegetables, fruits, meat, fish, milk etc.
- Beneficial for farmers:
Farmers of Pakistan are facing lots of trouble in storing their crops and milk, as there is a problem of electricity shortage and in the end they have no choice left but to sell it to the companies and different shopkeepers at a low rate. This will help them save their crops, milk, etc from getting rot and can be able to sell their product at market prices. They will also be able to sale their product directly to the costumers. The issue of electricity can be overcome by using solar panels or other renewable source and with out thermal cooling technology no batteries will be needed for 24/7 coolling.
- Beneficial for companies:
Different companies have the problem to preserve their product like meat and fruits etc also faces the problem of preserving large amount of food, this project will solve this issue as it is customizable and can be modified according to the application. This project is also beneficial in regards of cost, another big problem of companies is the cost of the equipment, this project is also cost effective and require little maintenance.
- Environment friendly:
This project is environment friendly as it is based on renewable source of energy and has no impact on the environment. Nowadays, technology is shifting towards renewable energy, this project will play a very helping hand in reducing environment pollution.
- Beneficial in medical sciences:
Lots of pharmaceutical companies have problems in storing medicines and different products as these products are stored at low temperatures this will help them in storing their product at its required temperatures. This can be helpful in morgues to store and preserve bodies.
Technical Details of Final DeliverableCalculations have been done assuming the use case of milk, as milk is the most common perishable item and it has strict WHO standards. For renewable energy we have assumed to solar but any other means can be utilized for this application.
Schematic of Renewable Thermal Cool Chain
Deep Freezer Details:
Selected Model: WDFT 315TL - 425 Liters Cool Bank Series
Specifications:
Calculations:
Volume of milk container:
Vol of milk container = L*B*H
Vol of milk container = 67*64*51
| Vol of milk container = 218688 cm3 |
Volume of brine container:
Vol of brine solution container = Vol of milk container - Vol of step
Vol of brine solution container = 218688 – (25*51*32)
| Vol of brine solution container= 177888 cm3 |
Weight of 1 liter (l) of pure water at temperature 4 °C = 1 kilogram (kg)
?218.66 lit=218.66 kg (for milk )
Similarly ?
177.883 Liters = 177.883 kg (for brine)
The working of the design is such that as the first step the brine will be cooled from room temperature to -25C. Secondly the milk will be cooled to 4C.. When both these steps are completed the third step will be to cool brine from 4C to -25C because during the night the equilibrium will be at about 4C and not room temperature.
To minimize power input we will have to extend the time taken to cool brine rather than trying to cool milk directly using compressor. For this reason brine will be cooled in 5 hours while milk in 2.5 hours.
Energy calculations:
Cooling Milk from 38.33 C to 4 C:
Thermal Energy of Milk = mc?t
Thermal Energy of Milk = 200 X 3.89 X (38.33-4)
Thermal Energy of Milk = 26708.74 kJ
Power = Energy/Time = 26708.74/ (2.5 X 3600) = 2.967 kW
Cooling Brine From 4 C To -26 C:
Thermal Energy of Brine= 125.287 X 4.18 X (4+26)
Thermal Energy of Brine = 15710.9898 kJ
Power = Energy/Time = 15710.9898/ (5 X 3600) = 0.873 kW
During the day the compressor will be cooling the milk and the brine, therefore the power needed will be,
Total power needed = 2.967+0.873 = 3.84 =
3.84 kW
Power in hp = 5.147 hp
CONVERT TO RTON
3.84/3.5=1.097 Rton
CONVERT IN KW
1.097*1.8=1.97KW
P= 1.97*746
P=1.47 Hp
Volume of brine in pipes:
Dia of pipe = 5.08 cm = 2 inches
Radius of pipe = 0.0254 m
Length of pipe = 6.096 m
Dia of loops = 45 cm = 0.45 m = 17.7165 inches
Radius of loops = 0.225 m
Volume of pipe = 3.142 x 0.0254 x 6.096
Volume of pipe = 12.35 liters
Total Pipe Length = Length of loop + distance between containers
6.096 = Length of loop + 2(0.14)
Length of loop = 5.816
Length of pipe = 2*(3.141)*r*n
5.816 = 2*(3.141)*0.225*n
n = 4 loops
Distance between loops = 3 cm
Distance from top and bottom edge = 1.5 cm
Volume Needed in Brine Container = 125.87 – 12.35 = 113.52 liters
Dimensions of Brine Container:
Length = 0.63 m = 63 cm = 24.8031 inches
Width = 0.45 m = 45 cm = 17.7165 inches
Height = 0.40 m = 40 cm = 15.748 inches
Dimensions of Milk Container:
Length = 64 cm = 25.1969 inches
Width = 50 cm = 19.685 inches
Height = 67 cm = 25.1969 inches
Isometric View
Top View
Front View
Side View
Vol of milk container = 218688 cm3 =218.688 Liters
Vol of brine solution container= 177888 cm3 =177.883 Liters
| Vol of brine solution container= 177888 cm3 |