Pump water heaters (system with forced circulation or open circuit): In this category of solar water heaters whose number is indirect (with top collector and double-walled tank), a pump can be used for better circulation. This water heater is usually used for large systems, it is also used in home systems.
In this case, the storage tank can be built anywhere in the building and installed on the collectors. The pump is placed in the way of entering the cold solution to the collectors. This solution returns after being heated by the absorbent plates of the collectors. In this type of solar systems, due to adding a circulation pump to the fluid circulation circuit, efficiency and output can be improved significantly. In this type of system, the storage source is used separately from the collectors and in the closest place to the place of consumption.
Also, this system is connected to a temperature controller, which orders the pump to turn off and on when needed.
The way the controller works is that the difference (T∆) between the output of the collector and the output of the tank is measured, and after comparing with the TD set on this controller (depending on the collector, the amount of T∆ varies), the command to disconnect or connect the circulation operation (turn off or turn on the pump) in the circuit.
In this series of Solarkar solar water heaters, the fluid action in the closed cycle of the collectors is performed by a small pump. Therefore, the tank stored in the system can be placed below the collectors and inside the building, and only solar collectors are installed on the roof. become
In the experimental system, a hidden tank is installed inside the solar tank as a storage tank. When the pump is cut off by the controller controller, the water in the collectors opens into the tank due to the height difference and the collectors are empty of water. are. Therefore, there is no need for antifreeze in winter and the system does not boil in summer.
In closed circuit systems, a small open or closed expansion source should be installed in the system system and anti-feed should also be used.
In this series of solar water heaters, the auxiliary system for compensating in emergency situations when solar energy is not needed can be electric or a gas burner, which is widely used in areas with municipal gas piping. .
Solar water heaters with gas supplement were designed and manufactured for the first time in Iran by the engineers of Solarkar Company and have been registered as an invention.
Solarkar pumped solar water heaters are equipped with an intelligent control system for optimal operation of the device pump. This control system also has the ability to display the temperature in the tank and collector. If it exists in the collectors, it will be activated.
In Solarkar pumped water heaters, the pump and the control system and the size of the necessary components in this water heater are built inside. With this work, in addition to making the water heater more beautiful, it will be done quickly and easily.