Design and Fabrication of Parabolic trough concentrator

Project Title

Design and Fabrication of Parabolic trough concentrator

Project Area of Specialization Mechanical EngineeringProject Summary

Our FYP consists of designing and fabrication of solar parabolic Trough Collector; a device used to concentrate the solar radiations coming from the sun. As the race to renewable energy is on the rise new methods are being adopted to harness energy. One such method is the Parabolic Trough Collector (PTC).  A Parabolic Trough Collector is a linear concentrating system of long, parabolic shaped mirrors and a receiver tube placed along the focal axis of the parabola. This system harnesses the energy of the sun and converts it into thermal energy usually by heating any a working fluid.

The Parabolic Trough Consists of:

1. Parabolic Trough Concentrator
2. Receiver pipe
3. Supporting structure.

The collector is made of high reflectivity material to reflect most of the light. The light rays are concentrated on a receiver pipe. The receiver pipe has a working fluid with a high absorptivity to absorb maximum amount of thermal energy. This working fluid can be used to transfer heat energy by passing it through heat exchangers. This form of harnessing method is one of the more efficient ones yielding around 60-80 percent thermal efficiency. Using a concentrating ratio near 50, operating temperatures of 400 degree Celsius can be achieved with ease. Our selected region is Taxila, Pakistan with Latitude: 33.7408 and Longitude: 72.7858. With up to 250 sunshine days it is one of the optimal locations for the placement and study of the Solar Parabolic Trough. With the amount of heat generated the Parabolic Solar Concentrator can be used for:

Particularly in Pakistan following implementations can be done:

1. Low temperature Steam generation for Industrial Applications.
2. Powering Desalination Evaporators
3. Electricity generation
4. Preheating of boiler make-up water
5. Utility hot water production in foods industry
6. Hot water production for textile industry

The end application has of the harnessed energy has been left open and it is up to the end user to use it according to their need.

Project Objectives

Following are the main objectives of this project.

• Calculation of radiations at extraterrestrial and terrestrial surfaces.
• Mathematical modeling of a solar parabolic trough concentrator.
• Manufacturing and fabrication of small scale model of solar parabolic trough concentrator on the basis of resource constraints ,climatic conditions, material availability and cost considerations.
• To generate enough temperature that is used for room heating from parabolic trough concentrator.
• To generate maximum temperature with minimum cost.
• Compare theoretical and experimental results.

Project Implementation Method

Solar Parabolic-trough Collector systems are parabolic-shaped collectors made of reflecting materials. The collectors reflect the incident solar radiation onto its focal line toward a receiver evacuated tube that absorbs the concentrated solar energy to raise the temperature of the fluid inside it.

In our project as it is written above that parabolic trough Collector consists of parabolic sheet, receiver evacuated tube, heat exchanger, pumps, valves, sensors, reservoir and working fluid.

• The sheet will be made of made of cast iron and it is easily available in the market and then we perform operations on is to give it a shape of parabola after doing this we have to add a reflecting material on it and in our project we have decided to use Acrylic mirror(99 % efficient )or Mylar sheets (98% efficient) these reflecting surface will be added to the parabola all the calculations of radiations are previously done and the designing of our project have been done also using two software’s MATLAB and ANSYS.
• After that we have to design the receiver tube and for this we also we need evacuated tube in this tube our working fluid will circulate and absorb heat (Up to 400 degrees Celsius) as much as the fluid will have maximum absorptivity. The evacuated tube is used just because to minimize the losses of heat from the heated fluid present in the tube, outside there will be another tube in which the vacuum is present it will act as insulator to overcome heat losses after that the heated fluid will pass through the cross plate type heat exchanger which will transfer maximum heat to the water and steam will be generated.
• Reservoir will be used for the storage of working fluid.
• Two pumps will be used to circulate the working fluid and water, one will be used to circulate the working fluid inside evacuated tube to heat exchanger and other used to circulate the water inside the plate type heat exchanger for the production of steam.
• Three temperature sensors will be used at the inlet and outlet of evacuated tube for the measurement of temperature of working fluid and third sensor will be used at outlet of the heat exchanger for temperature measurement steam.
• Two flow sensors will be used at the inlet of receiver evacuated tube and inlet of heat exchanger for the flow measurement of water and valves will be used for the controlling of working fluid and water.

Benefits of the Project

Parabolic trough concentrator has many advantages. Some of them are listed below:

• In our country, almost 70% of electricity is being generated by using fossil fuels like crude oil, LPG and coal. This system is extensively used for the production of electricity worldwide because it is very helpful in reducing the amount of toxic gases like carbon dioxide, Sulphur dioxide and many hydrocarbons caused by burning of fossil fuels.
• This system is used for the desalination of water specially the areas near ocean. It is very helpful in reducing the cost of water because the ordinary method of desalination is very expensive and has directly influence on water prices. Our 50% population is below poverty line and can’t buy expensive water.
• This system is very useful in air conditioning applications both cooling and heating requirements and we can replace our traditional centralized air conditioning systems for a building operating on some fuel or electricity by this technology because of its environmental capabilities.
• This system can be used to replace traditional boilers run by burning fuel to generate steam in industries.

Parabolic trough concentrator is utilizing solar energy for its working so its negative environmental impacts are approximately zero. It is in accordance with the Paris Agreement 2014 and National Environmental Policy of Pakistan because this technology is fulfilling the criteria of minimizing air pollution and reducing the temperature of the earth.

Technical Details of Final Deliverable

•Achieve working fluid temperature of at least 150 Centigrade.

• Heating of Water for phase change to  low temperature Steam for Room heating via heat exchanger

• Sufficient room heating for the season of winter with outdoor temperatures of 10 Centigrade

• Achieve Thermal efficiency of >60%

• Be able to work effectively for the Winter Season 

• Less than 40% Thermal Losses

Final Deliverable of the Project Hardware SystemCore Industry Energy Other IndustriesCore Technology Clean TechOther TechnologiesSustainable Development Goals Affordable and Clean Energy, Industry, Innovation and Infrastructure, Climate ActionRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	79500
Metal Frame	Equipment	1	10000	10000
Parabolic reflecting surface(Aluminium sheet)	Equipment	2	1000	2000
Evacuated glass tube	Equipment	1	25000	25000
Hot fluid pump	Equipment	2	10000	20000
Heat Exchanger	Equipment	1	5000	5000
Pipe fitting	Equipment	2	500	1000
Storage tank	Equipment	2	1000	2000
Working fluid(oil)	Equipment	2	1000	2000
Temperature sensor	Equipment	2	1000	2000
Insulation	Equipment	2	500	1000
Printing thesis	Miscellaneous	5	500	2500
Panaflex	Miscellaneous	3	1000	3000
Transportation cost	Miscellaneous	1	4000	4000