| 摘要 |
A valve and actuator assembly includes a valve to control a flow of liquid into a coil, and an actuator to control the valve. The assembly includes a first temperature sensor to sense the temperature of liquid flowing through the valve, a second temperature sensor to sense the temperature of air surrounding the coil, and a flow meter to measure a flow rate of liquid through the valve. The actuator includes a module that receives data from the first and second temperature sensors and from the flow meter, and determines, based on data received from the flow meter and temperature sensors, a likelihood that the liquid in the coil will freeze. The actuator operates the valve to allow a minimum flow of the liquid through the valve and coil during a potential freeze condition. The minimum flow is sufficient to prevent the liquid in the coil from freezing. |
