ENERGY FROM THE SUN. SOLAR THERMAL TECHNOLOGIES EDUCATION MODULE (sth01pp)

Transcription

1 ENERGY FROM THE SUN SOLAR THERMAL TECHNOLOGIES EDUCATION MODULE (sth0pp) CACTUS MOON EDUCATION, LLC Cactus Moon Cactus Moon

2 INDEX Slide Slide Slide Slide 6 Slide 7 8 Slide 9-0 Slide - Slide - 6 Slide 7-0 Front Sheet Index Solar Thermal Technologies Solar Power Tower Solar Parabolic Trough Dish Stirling Solar Chimney Solar Heating and Cooling Solar Water Heating Cactus Moon Cactus Moon

3 Solar Thermal Technologies Solar Thermal technologies use the heat from the sun as a source of energy to produce electricity, provide hot water or provide space heating and cooling. Solar collectors harvest the sun s energy and use it to heat a transfer liquid. The transfer liquid takes the solar energy from the solar collector field to the operating system where the heat energy is used. Cactus Moon Cactus Moon

4 Solar Power Tower In a power tower system a field of computer controlled mirrors (heliostats) concentrates the sun s energy onto a boiler or receiver on the top of a large tower. The heat transfer liquid is pumped up to the receiver where it is heated by the concentrated solar energy. The hot liquid is then used to boil water and make steam which is used to power a turbine/generator and make electricity The heat transfer liquid can be mineral oil or a mixture of molten sodium and potassium nitrate salts. Cactus Moon Cactus Moon

5 Solar Power Tower using mineral oil as the heat transfer liquid Cold oil is pumped up the tower into the receiver The sun s energy is concentrated onto the receiver by the heliostats The oil is heated as it passes through the receiver The hot oil is used to boil water in the steam generator 6 The steam is used to power the turbine/generator The oil is repumped up the tower to be heated again 6 Cactus Moon Cactus Moon

6 Solar Power Tower using molten salt as the heat transfer liquid Cold (00º F) salt is pumped from the cold salt storage tank up the tower and into the receiver The sun s energy is concentrated onto the receiver by the heliostats The salt mixture is heated to over,000º F as it passes through the receiver Hot salt is drawn as needed to boil water in the steam generator The steam is used to power the turbine/generator The salt mixture is pumped to the cold salt storage tank ready to be pumped back up the tower to be heated again The hot (,000º F) salt mixture is stored in the hot salt storage tank By making more hot salt than is needed to keep the turbine/generator running during the sunshine hours, the salt in the hot salt storage tank can be used to power the turbine/generator after the sun has set. This is an example of thermal energy storage. Cactus Moon Cactus Moon

7 Solar Parabolic Trough In a parabolic trough system, long rows of curved mirrors concentrate the sun s energy onto pipes carrying the heat transfer liquid. As the liquid makes its way through the solar collector field it is heated. When the liquid leaves the solar collector field it is hot enough to boil water and make steam. The steam is used to power a turbine/generator and make electricity. Cactus Moon Cactus Moon

8 Solar Parabolic Trough The solar collection field is made up of long mirrors shaped in the form of a parabola with pipes running along the focal line of the parabolas The hot oil is used to boil water in a steam generator The steam is used to power a turbine/generator The mirrors concentrate the sun s energy onto the pipes 6 6 The oil is pumped back into the solar field to be heated again Oil is pumped through the pipes and is heated as it runs through the solar field Cactus Moon Cactus Moon

9 Dish Stirling Solar Heat Engine Instead of using the heat from the sun to heat a liquid, the captured heat can be used to power a heat-engine The most common heat engine used in solar applications is the Stirling Engine. The engine is a completely sealed unit and contains a number of cylinders containing pistons which are connected to a crankshaft which is, in turn, connected to an electrical generator. As the pistons are made to travel up and down they turn the crankshaft and generator and produce electricity. The pistons are powered by the expansion of a gas on top of them. Heat causes the gas to expand and drive the piston down its cylinder and so turn the generator. Cactus Moon Cactus Moon

10 Dish Stirling Solar Heat Engine A large, concave, parabolic mirror concentrates the sun s energy onto a thermal receiver located at the focus of the mirror. The piston is connected to a crank shaft which turns and drives an electric generator. The thermal receiver directs the heat energy into the Stirling heat engine where it heats a gas inside the engine. The gas expands and pushes a piston down a cylinder. The expanded gas is cooled and allows the piston to return to the top of the cylinder. Cactus Moon Cactus Moon

11 Solar Chimney A solar chimney uses the fact that hot air rises. The energy from the sun is used to heat air and the hot air is directed into and up a centrally located chimney. The moving air mass can be used to power wind turbines placed in the path of the moving air. Wind speeds of 0 mph can be created within a solar chimney system The wind turbines generate electricity Cactus Moon Cactus Moon

12 Solar Chimney A large greenhouse captures the solar energy and heats up the air inside the greenhouse The moving hot air can be used to spin wind turbines located at the base of the chimney The greenhouse is designed in Such a way that the hot air can move into the center of the greenhouse and up a large centrally located chimney. The wind turbines generate electricity Cactus Moon Cactus Moon

13 Solar Heating and Cooling - Solar energy can be captured and used to provide space heating in the Winter and space cooling in the Summer. The solar collector field is made up from long rows of curved mirrors which concentrate the sun s energy onto pipes carrying a heat transfer liquid. The transfer liquid is heated as it makes its way through the solar collector field and transfers the heat to water in a large hot water storage tank. Hot water from the storage tank can be used to provide space heat in the Winter months and can be used as the heat source for an absorption chiller to provide space cooling in the Summer months. Cactus Moon Cactus Moon

14 The solar collection field is made up of long mirrors shaped in the form of a parabola with pipes running along the focal line of the parabolas The mirrors concentrate the sun s energy onto the pipes A mixture of ethylene glycol (anti-freeze) and water is pumped through the pipes and is heated as it runs through the solar field The hot glycol mixture is used to heat up water contained in a hot water storage tank Solar Heating and Cooling - 7 The glycol mixture is returned to the solar field to be heated again Cactus Moon Cactus Moon 7 In the Summer, the hot water in the storage tank can be used as the heat source to power an absorption chiller. The absorption chiller is used to cool the water circulating in the HVAC system cooling loop 6 6 In the Winter, the hot water in the storage tank can be used to heat up water circulating in the HVAC system heating loop.

15 Solar Heating and Cooling - For small solar heating and cooling systems (less than 0 tons of cooling) a solar collector field made of flat plate collectors can be used. The flat plate collectors are made of copper pipes that absorb the heat from the sun when the sun shines on them. A heat transfer liquid typically a water and ethylene glycol (antifreeze) mixture is used to transfer heat from the solar collector field to a hot water storage tank. Hot water from the storage tank can be used to provide space heat in the Winter months and can be used as the heat source for an absorption chiller to provide space cooling in the Summer months. Cactus Moon Cactus Moon

16 Solar Heating and Cooling - The solar collection system is made up of flatplate solar water heaters (solar collectors) containing copper pipes The pipes are painted black and absorb heat from the sun when the sun shines on them A mixture of ethylene glycol (anti-freeze) and water is heated as it is pumped through the copper pipes 7 In the Summer, the hot water in the storage tank can be used as the heat source to power an absorption chiller. The absorption chiller is used to cool the water circulating in the HVAC system In the Winter, the hot water in the storage tank can be used to heat up water circulating in the HVAC system heating loop. Cactus Moon cooling loop Cactus Moon 7 6 The hot glycol mixture is used to heat up water contained in a hot water storage tank The glycol mixture is returned to the solar field to be heated again 6

17 Solar Water Heating - Residential One of the simplest uses of solar energy is to heat water. Just about every home in the USA uses hot water for bathing, laundry etc and solar energy can provide a supply of hot water for these and other activities. For small, residential, solar water heating systems flat plate solar collectors can be used. The flat plate collectors are made of copper pipes that absorb the heat from the sun when the sun shines on them. A heat transfer liquid typically water or a water and ethylene glycol (antifreeze) mixture is used to transfer heat from the solar collector field to a hot water storage tank. Hot water from the storage tank can then be used in the residence. Cactus Moon Cactus Moon

18 Solar Water Heating - Residential A flat plate solar collector contains copper pipes that are painted black The heated water flows through a heat exchanger in the hot water storage tank and heats the water in the tank Water is pumped through the pipes and is heated when the sun shines on the collector The hot water in the tank is available to be used in the residence Cactus Moon Cactus Moon

19 Solar Water Heating - Commercial Larger solar water heating systems for commercial or industrial use typically use a solar collector field made up from long rows of curved mirrors which concentrate the sun s energy onto pipes carrying a heat transfer liquid. The heat transfer liquid is heated as it makes its way through the solar collector field and transfers the heat to water in a large hot water storage tank. Hot water from the storage tank can be used for many commercial purposes such as laundries, kitchens, health club showers. Cactus Moon Cactus Moon

20 Solar Water Heating - Commercial The solar collection field is made up of long mirrors shaped in the form of a parabola with pipes running along the focal line of the parabolas. The mirrors concentrate the sun s energy onto the pipes A mixture of ethylene glycol (anti-freeze) and water is pumped through the pipes and is heated as runs through the solar field The hot glycol mixture is used to heat up water contained in water storage tank The hot water in the tank is available to be used for laundry, showers or other applications Cactus Moon Cactus Moon