Solar Hot Water
Thermosiphon Solar System with vacuum solar collector tubes
The thermosiphon solar system has the following advantages:
- The vacuum technology of CPC solar collectors is internationally the most advanced level of development in the area of solar water heating. (CPC = Composite Parabolic Concentration)
- Apart from the sun, no other energy source is required.
- The system is automatic, it does not require regulation.
The sun's rays come directly to the vacuum tube and are directed by means of the mirrors towards them. Direct radiation, as well as indirect radiation from clouds, is transformed into heat.
Diffuse light transformation is primarily supported by the high-tech CPC mirror. The heat is transferred directly to the water inside the collection tubes. Due to the high thermal insulation factor of the vacuum around the collector, no heat can escape from the system.
All collector tubes end in the stainless steel tank. The hot water in the collection pipes immediately begins to circulate in the tank and gradually heats up all the water inside the accumulation tank.
The tank is fully insulated with polyurethane foam, so that the heat gained cannot escape as quickly.
CPC (Composite Parabolic Concentration) mirrors concentrate sunlight optimally on the collection tube.
- 1.-When there is only diffuse light (with clouds) the solar rays are concentrated in the tube.
- 2.-When there is sun (noon) the rays are concentrated in the tube through the mirror
- 3.-When there is sun in the afternoon or in the morning) the energy is also concentrated in the collecting tube
The collector tube together with the CPC mirror allow to generate much more energy than a simple collector tube.
Thermosiphon solar system
View: CPC mirrors and thermosiphon tube
at the entrance to the tank
1.- Reflection of the solar rays in the CPC mirrors
with diffused light
2.-Reflection of the solar rays in the CPC mirrors with direct light (noon)
3.-Reflection of the solar rays in the CPC mirrors with direct light (in the afternoon)
Principio del sistema solar termosifón
El agua caliente sube en el tubo colector directamente al tanque, y el agua fría del tanque baja por el tubo. Otra vez se repite este proceso.
Las ventajas del sistema solar termosifón son:
- El agua caliente va directamente al tanque (no va por una tubería externa, que se enfría o que bloquea su corriente)
- El tubo doble con aislamiento al vacío casi no se enfría, porque solamente permite entrar los rayos solares por el vacío, pero el calor no puede salir otra vez, porque necesita el aire (que no hay) como conductor.
- Como resultado se genera más calor
WHAT IS DIFFERENT IN OUR SYSTEMS
"Normal" solar energy panels for water heating have a flat metal plate and a "fixed" water pipe under the plate as a "composite" collector.
Assuming that this flat panel would be of high quality, its efficiency is still lower than with the TermoSiphon system.
Quality criteria for flat panels:
- The flat plate collector must be entirely made of copper or aluminum (good thermal conductor)
- The water pipe must also be made of copper
- The tube must be welded to the flange (rivets, glue, etc. do not guarantee good thermal contact)
- The glass must be "anti-reflective" so that it does not function as a mirror.
- The pipe to and from the tank must be of a large diameter and insulated to guarantee the internal flow of the system (panel - tank)
In any case, the flat panel cools much more, because it does not have a vacuum isolation zone like the ThermoSiphon system.
Central System with vacuum tube panels
The collectors are in a central location on the roof, and the storage tank with the solar station is close to the consumers in a central location.