The heat sinks are gravity protection systems without electrical components that eliminate excess heat generated by the solar thermal systems, both as flat panels with vacuum tubes.
Heat sinks by gravity comprise thermostatic valve pre-set to 90 ° C provided with a mechanical actuator expansion, heat exchanger and natural convection flow by gravity.
Comply with total reliability, technical requirements of the building code, section 126.96.36.199.1 HE4, the RITE, Barcelona Solar Ordinance Inspection Guide OST, V 2.0.-July 11, 2007, the UNE EN 12828 for limit the outlet temperature of the solar collectors at 105 ° C and all other ordinances applied in the Spanish territory.
Its performance does not depend on valves, pumps, fans or power supply.
The heat sinks by gravity prolong the life of the facility and eliminate corrective maintenance interventions as they avoid problems:
- Corrosion and scale on the inside of the air intake manifold by
- Cavitation of electric
- Degradation selective surfaces of the manifolds
- Fluid Degradation calorportante
- Higher pressures and fluid losses calorportante
- Installation Aging
- Installation Heat stress (avoiding big jumps in temperature between room temperature and manifold)
- By far the maintenance of the installation itself is performed by static dissipation.
DESCRIPTION OF OPERATION OF GRAVITY HEAT SINKS:
It was considered a temperature of 90 ° C as the boundary conditions of operation of a solar thermal system with flat plate collectors. The system is composed of: thermostatic valve with 4-way air cyclone separator and bypass tube, copper heat exchanger finned at 3 and 6 batteries tubes valve. Allows operating three different possibilities:
The heat-bearing fluid passes exclusively for the collector. The check valve prevents flow through the heat exchanger. With temperatures below 90 ° C the valve opens the flow of water into the system and remains closed the road to the heat exchanger.
Partial dissipation pump (low energy demand):
In times of high solar contribution and low heat demand, typical summer situation, and when the temperature of the exhaust manifold is located around 90 ° C, the valve starts opening the way to the sink and produces cooling of the fluid. From this point, the valve will pass more or less to the heatsink, depending on the outlet temperature. The bypass pipe plays the role of heat exchanger return. The higher the temperature, the larger section to the exchanger desalida under way for the installation, and vice versa. The dual valve plunger will automatically position, always keeping the temperaturalímite recorded, 90 ° C.
Dissipation Gravity (pump stop):
When you disconnect the pump assembly (malfunction, power failure, absence for a vacation in schools, etc.) quickly, the fluid in the collector reaches the maximum temperature setpoint, 90 ° C. The valve, which at rest is always open when the pump stops working, it automatically sets the gravity circulation THERMOSIPHON between the collector outward, the bypass tube and the return of the collector. The water flows through the bypass tube in the opposite direction, and transmits the valve sensor of the higher temperature fluid. The valve opens the way to the cold Yeste exchanger in its entire surface. As in the casoanterior, the valve will automatically position the thermal limit, approximately, 60 ° C, between the collector and fluid temperature. The return cold water exchanger of higher specific gravity than hot manifolds, generates sufficient pressure to establish fluid flow, thereby dissipating no more power is regulated due to the gravity.