| 摘要 |
<p>A solar heating system includes an absorber panel (1) connected to a water supply tank. A valve (10,11) is located in each of feed and exhaust connections (3,6) and at least the inlet valve (10) is temperature responsive so as to close when the temperature of the panel contents falls below a first predetermined temperature. The outlet valve (11) may be temperature or flow responsive so as to close under the temperature or flow conditions prevailing when the inlet valve (10) closes and thereby isolate the panel (1) from the tank (2). A temperature responsive dump valve which may be incorporated in the valve (10) is connected to the panel (1) and opens when the temperature of the panel contents falls below a second predetermined temperature which is lower than the first predetermined temperature and thereby empties the panel contents. The combined inlet and dump valve (10) has a temperature responsive element which controls both a primary valve member and a secondary valve member. The primary valve member controls flow between inlet and outlet ports (13,14) of the valve (10) and the secondary valve member controls flow between the outlet port (14) and a dump port (12). The temperature responsive element has a part exposed externally of the valve body and is substantially insulated against the influence of temperature conditions existing within the body of the valve (10).</p> |
