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[report整理] SENEWS-2011-04-25

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[Homework]【整理】SENEWS-2011-04-25

This is the voa special english technology report.
Solar water heaters are used around the world and are not very difficult to build.The system we're going to describe is based on the design developed some years ago in Afganstan.Since then, it has been built and used in many countries.It can heat seventeen litres of water to sixty degrees Celsius.It can do this between sunrise and moon on the clear day with average air temprature of thirty-two degrees celsius.
There are two parts of solar water heater.
one part is made of a sheet of metal painted black, blace services they can hotter in the sun than surfaces painted any other color.This black metal plate is called collector. The collector is placed in container with the water. There are several kinds of metal sheet they can be used for the collector.corrugated metal will work very well,corrugated sheets are often used as roofs on housing.once the water is heated,it is kept hot with insulation material.this allows the water to stay in warm for a long time.
The second part of the solar water heater holds the water for the system.This storaged tank can be a container that holds above one hundred litres. Two rubble pipes are retouched to the water storage tank,one pipe leads the water into the system, the other leads water flow out.when the water heater is working correctly, water will flow from the storage tank to the collector and back again.
You can use the hot water at the top of the tank for washing and cleaning,you can change the flow of water so that the temperature is hard to warm as design.
This solar water heater is easy to build and operate.It will last about two years before the rubble pipes need to be replaced.
There is also something else we will leave to make the solar water heater work, the sun, as you might imagine, the heater will heat water only on sunny days. You can get more information about solar water heaters and other project from enterpriseworks viter.This group works internationaly to fight poverty. the website is enterpriseworks.org, choose the links for news and resources then click on publications.





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