In this article we will learn about the solar water heating system working and construction of solar collector.We will also know about the flate plate collectors and also concentrating collectors.
Solar Water Heating System Working
A solar water heater consists of a collector to collect solar energy and an insulated storage tank to store hot water. Heaters can be of three types solar collectors. These are different Types of solar collectors which is defined solar water heating system working.
Solar Water Heaters based on Flat Plate Collectors (FPC based SWH)
Here the solar radiation is absorbed by flat plate collectors, which consist of an insulated outer metallic box, covered on the top with glass sheet. Inside there are blackened metallic absorber (selectively coated) sheets with built in channels or riser tubes to carry water. The absorber absorbs the solar radiation and transfers the heat to the flowing water.
Solar Water Heaters based on Evacuated Tube Collectors (ETC based SWH)
Evacuated-tube collectors are made up of rows of parallel, transparent glass tubes. Each tube consists of a glass outer tube and an inner tube, or absorber, covered with a selective coating that absorbs solar energy well but inhibits radioactive heat loss. The air is withdrawn (“evacuated”) from the space between the tubes to form a vacuum, which eliminates conductive heat loss. These are main solar water heating system working.
Concentrating collectors for residential applications, are usually parabolic troughs that use mirred surfaces to concentrate the sun’s energy on an absorber tube (called a receiver) containing a heat-transfer fluid?
Most commercially available solar water heaters require a well-insulated storage tank. Many systems use converted electric water heater tanks or plumb the solar storage tank in series with the conventional water heater. In this arrangement, the solar water heater. Some solar water heaters use pumps to recirculate warm water from storage tanks through collectors and exposed piping. This is generally to protect the pipes from freezing when outside temperature drop to freezing. It is also solar water heating system working.
Solar Water Heating System Working
Solar water heating systems employing flat plate collectors are increasingly in use for domestic and industrial applications. The capacities of this system range from 100 liters to few thousand liters per day in typical applications. Hot water supply from 55 C to 75C is generally catered for. This is also solar water heating system working.
A thermally insulated hot-water storage tank is mounted above the collector. The heated water of the collector rises up to the hot water tank and replaces an equal quantity of cold water, which enters the collector the cycle repeats, resulting in all the water of the hot water tank getting heated up. When hot water is taken out from the hot water outlet, the same is replaced by cold water from a cold-water make up tank fixed above the hot water tank. The scheme is known as passive heating scheme as water is circulated in the loop naturally due to thermo-siphon action. When the collector is fixed above the level of the hot-water tank, a pump is required to induce circulation of water in the loop and the scheme will be known as active (or forced) solar thermal system. An auxiliary electrical immersion heater may be used as a backup for use during cloudy periods. In average Indian climate conditions, a solar water heater can be used for about 300 days in a year. A typical 100-litres per day (LPD) rooftop solar water heater costs approximately.
Hence these are solar water heating system working. We have studied about different types solar collectors like flate plate collectors, concentrating collectors etc.