Electric control valves are an important execution unit instrument in industrial automation process control. Compared with traditional control valves, they have obvious advantages: electric control valves are energy-saving, environmentally friendly (no carbon emissions), and are quick and easy to install (no need for complicated pneumatic pipelines and air pump workstations).
The actuator receives the command signal of the control valves and converts it into the corresponding angular displacement or linear displacement by the actuator to manipulate the adjustment mechanism, so as to change the energy or material that the controlled object enters and exits to realize the automatic control of the process. Actuators often work under high temperature, high pressure, deep cold, strong corrosion, high viscosity, easy crystallization, flashing, cavitation, high pressure difference, etc., and the use conditions are harsh. Therefore, it is the weak link of the entire control system.
In modern air-conditioning system design, more and more air-conditioning systems adopt automatic control for energy exchange, that is, according to changes in room temperature, the amount of hot/cold water or air volume supplied by the system is adjusted accordingly to achieve the required room temperature.
In a complete control loop, room temperature or return air temperature sensors, controllers and actuators are needed. In the water system, the electric control valves are the most commonly used actuator.
Air handling unit control: The electric control valves are composed of a driver and a valve body. According to the signal requirements of the controller, the valve can be opened or closed to adjust the flow rate to achieve the purpose of adjusting energy.