The composition of the automatic control system for air conditioners

(Sensor) A sensor is also known as a sensitive element or a transmitter. The parameters that need to be adjusted are called controlled parameters. A sensor is responsible for sensing the magnitude of the controlled parameters and promptly sending a signal to the regulator. If the signal emitted by the sensitive element does not match the signal required by the regulator, then a transducer is used to convert the signal emitted by the sensitive element into the standard signal required by the regulator. Therefore, the input of a sensor is the controlled parameter, and the output is the detection signal. There are many types of sensors. According to the controlled parameters, there are: temperature sensors, relative humidity sensors, pressure and differential pressure sensors, enthalpy and moisture content transmitters, etc.

(2) Controller It receives the signals output by the sensors and compares them with the given values. Then, it sends control signals to the actuator according to the preset control mode. The difference between the actual measured value of the regulated parameter at any given moment and the given value is called the deviation. The controller calculates the deviation in a certain pattern and provides the adjustment quantity. The commonly used control modes are: Two-position control - Switch control (such as differential pressure switch, flow switch, etc.); Proportional control (P) - The adjustment quantity is directly proportional to the deviation; Integral Control (I) - The regulating quantity is proportional to the integral of the deviation over time; Differential Control (D) - The regulating quantity is proportional to the derivative of the deviation with respect to time.

(3) Execution regulating mechanism The actuating mechanism drives the regulating mechanism based on the regulating signal from the controller. Such mechanisms include contactors, the motors of electric valves, the electromagnets of solenoid valves, and the pneumatic diaphragm parts, etc., all of which fall under the category of actuating mechanisms. The regulating mechanism is closely connected with the executive mechanism. Sometimes they are combined into a single entity, known as the executive regulating mechanism. Examples include the valves for regulating air volume, the valves on the hot and cold medium pipelines, and the electric heaters.

Characteristics

The implementation of the automation of the air conditioning system can not only improve the regulation quality, reduce the consumption of cold and heat, save energy, but also alleviate the labor intensity, reduce the number of operators, and enhance the labor productivity and technical management level. The degree of automation of the air conditioning system is also an important aspect reflecting the advancement of air conditioning technology. Therefore, with the development of automatic regulation technology and electronic technology, the automatic regulation of the air conditioning system will surely be applied more widely.