The composition of the air-conditioning automatic control system

(1) Sensor

Sensors are also called sensitive elements and transmitters, and the parameters that need to be adjusted are called adjusted parameters. The sensor senses the size of the adjusted parameter and sends a signal to the regulator in time. If the signal sent by the sensor does not match the signal required by the regulator, the transmitter needs to be used to convert the signal sent by the sensor into the standard signal required by the regulator. Therefore, the input of the sensor is the adjusted parameter, and the output is Heartbeat. There are many types of sensors. According to the control parameters, they are: temperature sensor, relative humidity sensor, pressure and differential pressure sensor, enthalpy value, moisture content transmitter, etc.

(2) Controller

It accepts the signal output by the sensor and compares it with the given value, and sends an adjustment signal to the actuator according to the set control mode. The difference between the actual measured value and the given value of the adjusted parameter at any time is called the deviation. The controller calculates the deviation according to a certain mode and gives the adjustment value.

Commonly used control modes are:

Two-position control-switch control (such as differential pressure switch, flow switch, etc.);

Proportional control (P)—The adjustment amount is proportional to the deviation;

Integral control (I)—The adjustment value is proportional to the integral of the deviation over time;

Differential control (D)—The adjustment quantity is proportional to the derivative of the deviation with respect to time.

(3) Executive adjustment mechanism

The executive adjusting mechanism drives the adjusting mechanism according to the adjusting signal from the controller, such as the contactor, the motor of the electric valve, the electromagnet of the solenoid valve, and the pneumatic membrane part, etc., all belong to the actuator.

The adjustment mechanism is closely connected with the executive mechanism, sometimes combined into a whole, called the executive adjustment mechanism. Such as valves for adjusting air volume, valves on cold and heating medium pipelines, electric heaters, etc.

Features:

Realizing the automation of the air-conditioning system can not only improve the quality of adjustment, reduce the consumption of cold and heat, and save energy, but also reduce labor intensity, reduce operating personnel, and improve labor productivity and technical management. The degree of automation of the air-conditioning system is also an important aspect that reflects the advancement of air-conditioning technology. Therefore, with the development of automatic adjustment technology and electronic technology, the automatic adjustment of air conditioning systems will surely be more widely used.