Forward Engineering ofA Solar Powered Refrigeration for a small family&A Solar Powered Refrigeration System for community food storageAndBusiness Plan

Notes please:You have to consider the extent and accuracy of the work and the submitted report. You are required to incorporate in your report plots and any other results to demonstrate your analysis. You are expected to provide a critical discussion of results and your findings. You should consider using quantitative evaluation of the system behaviour as much as possible.

Furthermore, evidence of collusion with others will be considered as plagiarism.

ReferencesEnsure your report is correctly referenced.

Please avoid plagiarism

Part – 1:

Objective – Development of a New product for Sustainable Development.

Issues – What is the current practice in suggestion new product

area? What is the science and technology used in current

products and how do we integrate Renewables into perform suggested function?

What other technology is required in companion products to achieve the overall function?

What technologies are used in the design/manufacture of the product?

What is the best Energy Source to power this product? What about the competitor products? Make use of the

internet. What is the market of this product? Can this product make

enough profits for a commercial venture in sustainable development of the society?

What are likely modes of failure for this product? Are there other technologies that could be used to

improve the function of the device? What happens at the end of the product-life; Recycling,

Environmental effects, etc. What is the typical selling price of the product? How do you write a comprehensive Business Plan to start

a new venture? What is the total cost of this new venture?

Anything you consider relevant! Part - 2:

Objective – To perform product analysis on a new product (solar powered fridge) and to undertake design, evaluation, modelling and planning of this product.

Have to be considered – Using engineering techniques, establish what function the product

performs and how it is achieved. Examine marketing material, existing product information and the product functions to inform your investigation.

Establish how the product can safely and conveniently be powered using most convenient Renewables.

Use the previous market analysis to identify possible product performance improvements or market differentiation.

Following detailed analysis of existing products, use resources such as the Internet and your own knowledge to identify electronic elements of the device that you can use, construct and integrate for this particular product.

This Individual Business Plan has to be:1. Exactly 8 Word Processed A4 pages.2. New Times Romans.3. Font size 12.

To achieve a (70%) or above,

All objectives will have been achieved, possibly surpassed.

Quantitative and analytical procedures will be completely rigorous; showing a high level of analytical competence presentations will be excellent.

Conclusions will show a higher than normal level of insight.

The work might be described as “exemplary”.

Forward Engineering ofA Solar Powered Refrigeration for a small family

&A Solar Powered Refrigeration System for

community food storageAnd

Business Plan

Abstract

The majority of the refrigeration and air conditioning systems produce the coolingeffect through an electricity-driven mechanical compression cycle. The operationof these systems are responsible for 10 to 20 % of the worldwide electricity consumption,and because the production of electricity by thermal plants causes air pollution, adding to the greenhouse effect, there is a growing interest on other types of refrigeration system that can use more environmentally friendly sources of energy. In sorption refrigeration, the cooling effect is obtained with a heat-driven cycle, which can operate with relative low-grade heat sources like waste heat or solar energy.

Executive Summary

“Our mission at Citrus refrigeration is to provide exclusive and innovative design solutions to the general consumer-specific requirements in the UK and around the world”.

Introduction

Citrus Refrigeration is a developer of exclusive and innovative designs in refrigeration for the retail sectors. The registered address for the company is: Citrus Refrigeration LTD, Unit B1, Edward Street, Doncaster, South Yorkshire, DN3 7GB. Citrus Refrigeration is a Private Limited Company with two shareholders and was chosen due to its legal benefits and to help ease the start-up costs and any losses made.

The board members of Citrus refrigeration:

(Managing Director/Technical Director) (Customer Services Director) (Logistics and Supply Chain Director)

Citrus Refrigeration is a ‘Matrix’ structured organisation with the Managing Director overlooking the company. The company is organised such that the each operation of each product is overlooked by a dedicated manager, making full use of the managers potential to effectively develop and distribute each product.

The business objectives for Citrus Refrigeration are:

Development of industry specific products through research and design To compete against and out-perform other respected manufacturers of similar

products through research and designThe business strategy for Citrus refrigeration:

Maximise revenue by continually monitoring costs and reviewing the market Further development of products and introduce them to different industries

The green fridge is a solar powered fridge primarily designed to be targeted at 3 rd

world countries to combat the needs of refrigeration in areas void of electricity. This novelty that is often taken for granted will greatly ease many of problems faced due to lack of refrigeration:

Agriculture and dairies - Removal of field heat immediately after harvesting crops, storage of fruit, flowers, vegetables, milk, meat, and cooling during transport

Retail trades - Sale of fresh foods, fish and cold drinks Buildings, computer installations - Air conditioning and air regulation Domestic - Food and drink storage Health clinics - Storage of blood, vaccines and medicine

Competitors

The main competitors would include the major electrical brands producing refrigeration units such as Bosch, AEG, and Hotpoint etc. However these brands do not offer the products we offer and have not researched into moving towards the 3rd

world or towards standalone solar/sorption refrigeration.

Costings

Estimated costs on a monthly basis: This is an estimation, if we sell 150 units at £70, this would give us a total sales of £10,500.

By calculation (monthly) we have come to the conclusion that:

Fixed costs = £8000Variable Costs = £2000

Fixed costs + (Variable Costs * Quantity) = Total Costs £8000 + (£14x 150) = £10,100

Contribution = £10,100 – £2000 = £8,100

Break even point: Total Costs / (Contribution/Total Sales)The break even point is: 8,000 / (8,100/10,100)8100 / 0.8 = 10,000 (where 0.8 or 80% of our expenditures goes onto fixed costs)Break even point = £10,000

Selling price = £10,100 / 150 = £67.40Selling price = £67.40

Now to find out number of units to reach break even point = Break even point / Selling Price£10,000 / £67.40 = 148 Units

If we sell 148 units are sold at £67.40 we will break even in the first month at break even point of £10,000 where our estimation proven correct

How Refrigeration Works

When pumping the tires on a bicycle, you will notice that the pump soon gets hot. The reason for this is that gases heat up when it is compressed. To make the tire support the weight of the bicycle and the rider, air must be compressed using high pressure. Pumping makes the air and the pump itself, very warm. This is because as you compress the air, the harder it becomes to carry on pumping. The energy used in pumping is converted into potential energy within the compressed gas. The gas/air within the tire is at a higher pressure and higher temperature than the cooler air around it. If a gas is compressed into half the volume, the heat energy within the molecules fills only half as much space, and therefore the temperature of the gas rises.

When a gas is released from high pressure, it is a lot cooler for exactly the opposite reason – when you release the gas it is able to expand and occupy much more volume. The heat energy that the molecules in the gas had occupied is now able to divide across a much greater volume and so the temperature of the gas falls.

The Heating and Cooling Cycle

By compressing gases, they become warmer by letting them expand, we make them cooler. How can

we use this handy bit of physics to shift heat from the inside of a refrigerator? Suppose we made a pipe that was partly inside a refrigerator and partly outside it, and sealed so it was a continuous loop. And suppose we filled the pipe with a gas. Inside the refrigerator, we could make the pipe gradually get wider, so the gas would expand and cool as it flowed through it. Outside the refrigerator, we could have something like a bicycle pump to compress the gas and release its heat. If the gas flowed round and round the loop, expanding when it was inside the refrigerator and compressing when it was outside, it would constantly pick up heat from the inside and carry it to the outside like a heat conveyor belt. (WOODFORD, Chris, 2012)

How refrigeration works

Figure 1 - Gases get hotter when you compress into lesser volume

The coolant is a liquid as it enters the expansion valve. As it passes through, the sudden drop in pressure makes it expand, cool, and turn into a gas (just like a liquid aerosol turns into a cool gas when you spray it out of a can).

As the coolant flows around the chiller cabinet (usually around a pipe buried in the back wall), it absorbs and removes heat from the food inside.

The compressor squeezes the coolant, raising its temperature and pressure. It's now a hot, high-pressure gas.

The coolant flows through thin pipes on the back of the fridge, giving out its heat and cooling back into a liquid as it does so.

The coolant flows back into the expansion valve and the cycle repeats itself. So heat is constantly picked up from inside the refrigerator and put down again outside it.

How Solar Panels Work

Solar panels are designed to take the energy from the sun and convert it into electricity. Solar energy is a totally renewable energy source and using this energy will never affect the environment. The sun’s rays transmit both heat and light. The heat can be used to produce hot water for homes and the light can be used for photovoltaic applications, i.e. solar panels. (TheScience of Solar: Solar Energy - The Basics,2009)

The sun’s rays hit the solar cells and heat them up causing an atomic reaction that generates electricity. This solar power goes to the inverter where it is converted to AC current that can be used around the home or be sold back to the power companies.

The most important part of solar panels are the silicon solar cells. Silicon is made of atoms with charged electrons. The most common design of solar panels today uses two different types of

silicon. This is to create negative and positive charged atoms. To create a negative charge, the silicon is combined with Boron, and to create a positive charge, the silicon is combined with Phosphorus.

This combination of different solar cells creates more electrons in the positively charged silicon and lesser electrons in the negatively charged silicon. The positively charged silicon cells are sandwiched with the negatively charged silicon cells. This configuration enables a reaction that produces electricity when the silicon cells are exposed to sunlight.

Figure 3 Silicon atom found in solar cells

Figure 2 Breakdown of parts associated with solar panelling

Solar Panel Production

Solar cells are carefully placed in a series of rows. Individual cells are connected using a thin conductive strip. This strip is woven over and under each silicon cell so that every cell in the solar panel is connected and creates an electric circuit. The solar cells are then covered with a heavy duty piece of glass and framed using an aluminium frame.On the back of every solar panel are two leads. These leads are used to connect individual solar panels together to form an array of solar panels which are connected to the solar inverter.

Generating Electricity

The particles of light which travel from the sun to earth every day, are called photons. Photons take approximately 7 seconds to get from the sun to your roof. When the sun shines on solar panels, the photons cause a reaction and thus the process of solar energy begins

1. The photons from the sun hit the solar cells, they loosen some of the electrons which surround the atoms in the silicon solar cells. The negative charged electrons separate from their atoms in the silicon cells (Figure 4).2. Loose electrons now migrate through the electrical current to an available electron gap in the silicon cells. This reaction happens as long the sun hits the solar panels (Figure 5).3. Throughout the day, this process is repeated and the electrons flow in one direction constantly leaving atoms and filling the gaps with different atoms. This flow of electrons creates an electrical current known as Solar Power (Figure 6). (How Do Solar PanelsWork, 2011)

Figure 4 Electron leaving a Silicon atom, creating a gap

Figure 5 Electron closing the gap in left in the Silicon atom (How Do Solar Panels Work, 2011)

Figure 4 Production of solar panels

The Green Fridge

The Green Fridge is a solar powered fridge that uses cleaver conventional cooling methods combined with the use of solar technology to enhance the cooling effect. Batteries are attached to the unit to store the energy generated from the sun during daylight hours which can then be used to power the fridge during the night. As temperatures are much lower during the night, it is far easier to keep the fridge cool. Fridges, freezers and air conditioning units are by far one of the biggest culprits in energy consuming appliances used around the world, counting for approximately 10-20% of the world’s electricity consumption. Due to the production of electricity by thermal plants which causes air pollution and the green-house effect, a growing interest in other ways of refrigeration must be sought; systems that use more energy efficient methods of cooling, reducing electricity consumption. This is where ‘Sorption Refrigeration’ comes in. In sorption refrigeration the cooling effect is obtained by a heat-driven cycle such as a low-grade heat source or solar panels. (ROGÉRIO, Oliveir G., 2011, p.1).

In every household the fridge is left on 24 hours a day, 7 days a week throughout the year resulting in a great need to find alternative, efficient yet effective methods of cooling.

The domestic fridge is the fifth most energy consuming device in a home according to How Stuff Works article on “5 Energy-hungry appliances” (LAYTON, Julia, 2009) .

Sorption Units

What is Sorption Refrigeration?

The adsorption refrigeration is based on the evaporation and condensation of a refrigerant combined with adsorption or chemical reaction.

Sorption refrigerators work similar in principle to mechanically-compressed refrigerators which both use compression and evaporation and in some cases

Figure 7 - Breakdown of sorption refrigeration

Figure 6 Electron cycle in silicon solar cells creating solar power (How Do Solar Panels Work, 2011)

expansion. The difference being in which the way refrigerant leaves the evaporator at low pressure and ends with high pressure – this process in a mechanical unit will be driven by a compression motor, but in a sorption refrigerator this is achieved using thermal power. The heat supplied to a sorption unit can be from any heat source.

The design is very simple in its operation- it is made of two cylinders, one inside the other. The outer cylinder can be made of almost anything on hand, cardboard, wood or plastic, typically, with ventilation holes to allow the greatest possible sun access. The inner cylinder is metal. The space in between the inner and outer cylinders can be filled with materials like wool, sand or dirt.

The heat source for sorption units can be the sun. In a simple version, the heating phase ends at sunset, and the refrigeration phase occurs during the night. If the sun fails to shine for a few days, ice made on previous days can act as a store.

The Green fridge however makes use of sorption and combines solar power to drive a motor to assist in the refrigeration process controlled by a thermostat to boost the cooling effect when the temperature drops beyond the threshold.

Figure 7 shows how the sorbent bed is heated by external means results in refrigerant (sometimes water) vapor flows into the ‘cold box’. Figure 8 explains how coolant from within the box is heated and vaporised which then flows into the sorbent bed.

Discussion

Refrigeration is a crucial part of the modern world and with fossil fuels on the verge of being extinct; now is the time to invest in this technology and gain the leading edge towards a world reliant on renewable energy. Many developments towards solar energy have been made with advances continually being made towards more efficient solar paneling. Government incentives towards a renewable future have also driven the UK towards a more self sufficient energy source. Many respected manufacturers in the motor industry particularly have taken a great interest in paving a way for the future generations to come. We believe our move into the renewable market will provide a sufficient boost towards the global climate and also provide great ease to those less fortunate. The Green fridge can prove to be a great success in any part of the world. It has the potential to meet the needs of domestic and industrial applications with the current development of high efficiency solar panels.

Figure 9 - The cooling phase of sorption units at night

Figure 8 The heating phase of sorption during the day

Conclusion

References

How Do Solar Panels Work. 2011. [online]. [Accessed Wednesday 24th April 2013]. Available from World Wide Web: <http://www.australiansolarquotes.com.au/buyers-guide/the-basics-on-solar/how-solar-panels-work/>

LAYTON, Julia. 2009. "5 Energy-hungry Appliances". [online]. [Accessed Wednesday 1st May 2013]. Available from World Wide Web: <http://science.howstuffworks.com/environmental/green-tech/sustainable/5-energy-hungry-appliances.htm>

ROGÉRIO, Oliveir G. 2011. Nova Publishers. [online]. [Accessed Monday 29th April 2013]. Available from World Wide Web: <https://www.novapublishers.com/catalog/product_info.php?products_id=22023>

The Science of Solar: Solar Energy - The Basics. 2009. [online]. [Accessed Tuesday 30th April 2013]. Available from World Wide Web: <http://www.dowcorning.com/content/publishedlit/06-10028-01.pdf>

WOODFORD, Chris. 2012. Refrigerators. [online]. [Accessed Saturday 25th April 2013]. Available from World Wide Web: <http://www.explainthatstuff.com/refrigerator.html>

http://www.which.co.uk/energy/saving-money/guides/how-to-use-less-electricity/buying-energy-efficient-appliances/

https://www.novapublishers.com/catalog/product_info.php?products_id=22023

http://www.which.co.uk/energy/saving-money/guides/how-to-use-less-electricity/buying-energy-efficient-appliances/

Private limited

Doncaster

Normal fridge operating at 117 KWH = 117 'Units'is the annual usage - so at about 12p per unit, it will cost roughly £14.00 per year to run.That used 40W while running and with the thermostat cycling on and off, probably ran about 50% of the time, so 20W average.

20W x 24 hours per day x 365 days = 175200 WH or 175 KWH, so 117 sounds reasonable for the smaller version.

Figure 6 - Solar Refrigerator, image courtesy of NASA How stuff works

(Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption

http://energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-use