What is included in the building automation system?

Building automation refers to electrical equipment in buildings, such as elevators, pumps, fans, air conditioners, etc. Its main working nature is strong electric drive. Usually these devices are open working, that is to say no closed loop is formed. As long as the power is turned on, the equipment is working. As for the working status, process, energy consumption, etc., it is impossible to obtain data online in time, let alone reasonable use and energy conservation. Now the building automation is to monitor the above-mentioned electrical equipment online, set the corresponding sensor, travel switch, photoelectric control, etc., to detect the working state of the equipment, and return to the central computer of the control room through the line, and the analysis result is obtained by the computer. Then return to the device terminal for mediation.

Intelligent buildings often start with building automation control systems. There are a large number of electrical equipment inside the intelligent building, such as: air conditioning equipment, lighting equipment and water supply and drainage system equipment required for environmental comfort. These equipments are scattered and scattered: many, that is, the number of objects controlled, monitored and measured is large. As many as hundreds to tens of thousands; scattered, that is, these devices are scattered in layers and corners. If decentralized management is used, local control, monitoring and measurement are hard to imagine. In order to rationally use equipment, save energy, save manpower, and ensure the safe operation of equipment, it is naturally proposed how to strengthen the management of equipment.

Common equipment

Central monitoring station

The central management workstation system consists of a PC host, a color large-screen display and a printer. It is the core of the BAS system and can be directly connected to the Ethernet. The electromechanical equipment monitored in the entire building is centrally managed and displayed here. The built-in working software provides the operator with a pull-down menu, man-machine dialogue, and dynamic display graphics to provide users with a very good, easy-to-learn interface. The operation is simple, the operator does not need any prior software knowledge, and can manage the entire control system through mouse and keyboard operations.

sensor

The sensor is the primary device in the automatic control system, and it directly connects with the measured object. Its role is to make sense of the changes in the measured parameters and to signal the appropriate. There are generally three requirements when selecting a sensor: high accuracy, high stability, and high sensitivity.

1. Temperature sensor: The main contact temperature sensor used in building engineering, such as thermal resistance, thermocouple, PTC silicon sensor.

2. Pressure sensor: A commonly used electric pressure sensor converts the measured pressure change into various electrical quantity changes such as resistance and inductance, thereby achieving indirect measurement of pressure. Commonly used are differential pressure switches, gauge pressure sensors, static pressure sensors, and the like.

3. Flow sensor: A commonly used electromagnetic flowmeter generates an induced electromotive force in a conductor that moves in a magnetic field and cuts magnetic lines of force. This induced electromotive force is linear with the volumetric flow of the fluid. If it is retrofit, it can also use ultrasonic flowmeter for easy installation and maintenance.

4. Humidity sensor: used to measure the relative humidity of indoor air.

5. Liquid level sensor: used to control the upper and lower liquid level of water tank, pool, etc.

6. Air valve actuator: used to control the damper installed in the fresh air and return air, which can be used for both switch control and opening control.

7. Water pipe valve actuator: It is used with the valve. It has two types: switch type and regulation type. The switch type is generally large in diameter. It is used to control the opening and closing of process piping of various systems in the hot and cold station, and between various working conditions. Switching, etc.; the adjustment type is mainly used to control the flow rate. In the air conditioning unit, the return water flow rate and the steam humidification flow rate are controlled according to the temperature and humidity setting value of the controller, so that the temperature and humidity are maintained at the set value.

Field controller

The field controller, also known as DDC, is a controller for monitoring and controlling the electromechanical equipment in the system.