Variable volume hot water storage for solar heater - uses variable volume tank with the entry of cold water controlled by a solenoid valve which is operated by a water temperature transducer

摘要

A variable water volume is established to maintain the water at constant temperature, and prevent the admission of cold water if the stored water temp. is not sufficiently high. The upper surface of the tank (2) has for its upper surface (1) a piston or membrane. A solenoid valve (4) is used to control water entry into the tank, and is controlled (3) by the temp. of the water. When the water is hot the solenoid valve admits more cold water, this process continuing while heating energy is available or until the maximum tank capacity is attained. When energy is no longer available there is no more cold water admitted when hot water is drawn off. A tap (9) can be used to bypass the solenoid valve to get the system started from cold.