Parabolic Solar Collectors


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PARABOLIC SOLAR COLLECTORS
V. Ryan © 2005 - 2023

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Solar power is energy from the sun. Although the sun is 150 million kilometres away it is still extremely powerful. The amount of energy it provides for the earth in one minute is large enough to meet the earth’s energy needs for one year. The problem is in the development of technology that can harness this ‘free’ energy source.
	Solar collectors are one way of focussing the suns rays to heat up fluids. A typical array of solar collectors is seen opposite. They are basically unusually shaped mirrors (parabolic in shape) that focus the heat of the sun on a pipe carrying a special fluid. The temperature of the fluid in the pipe increases as it flows down the pipe, along the solar collectors. The pipe extends the entire length of the mirrors.
This type of set up works at its best in desert areas where there is no shortage of sunlight and very little cloud. The hot fluid in the pipe can be used, through a system of heat exchangers, to produce electricity or hot water.

HOW A PARABOLIC REFLECTOR FOCUSES THE HEAT

Parabolic collectors focus the heat of the sun by reflecting the sun’s rays on a ‘receiver’. The receiver is a complex tube that contains a transfer fluid. The fluid heats up as it travels along the receiver tube.
The angle of the parabolic collector is automated / motorised, so that it follows the height of the sun.

AUTOMATED SYSTEM - ALTERS PARABOLIC MIRROR ANGLE
ACCORDING TO THE TIME OF THE DAY

PARABOLIC SOLAR COLLECTORS PRODUCTION OF HOT WATER

As the transfer fluid flows along the central pipe / receiver it warms up due to the focussed sun’s heat and flows into the Heat Exchanger. The heat exchanger takes the heat from the fluid and transfers it to water. Hot water exists the heat exchanger (see below)r (see below)

TYPICAL HEAT EXCHANGER

HOT WATER TO STEAM TO ELECTRICITY

With the addition of a turbine generator, electricity can be generated. As the transfer fluid travels along the receiver / absorber tube it heats up, courtesy of the ‘concentrated’ sun light. It enters the heat exchanger where it raises the temperature of the water circulating around the internal pipes. The heated water is pumped to an additional heater. This raises the water temperature to a level that produces steam. It is the ‘pressurised’ steam, that drives the turbine, generating electricity.
The steam then condenses back to water and is recycled.

THE ELECTRICITY GENERATOR TURBINE




	The photographs show an arrangement of parabolic solar collectors. Notice the suns energy is focused on the water pipe at its centre.






ARRANGEMENT OF PARABOLIC SOLAR COLLECTORS - SPAIN




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