Farm ventilation fan, ventilator, constant temperature and humidity Chinese large screen centralized controller

Overview of the composition of the air conditioning centralized control and self-control system:

Air conditioning, abbreviated as air conditioning centralized control, aims to create a comfortable indoor atmospheric environment that makes people feel more comfortable in the environment.

Air conditioning is the process of sending a certain quality of processed and treated air into the indoor environment to meet the required atmospheric standards.

The process of air conditioning: air purification → temperature treatment → humidity treatment → pressure treatment → air volume treatment → cleanliness treatment.

The composition of the HVAC centralized control and self-control system includes the HVAC cold and heat source systems, variable air volume systems, and purification systems;

The content of HVAC centralized control and automatic control: HVAC consists of air heating, cooling, humidification, dehumidification, air purification, air volume regulation equipment, as well as cooling, heating, and purification equipment for air conditioning.

The controlled parameters mainly include air temperature, humidity, pressure, air freshness, airflow direction, etc. In terms of cold and heat sources, they mainly include cold and hot water temperature and steam pressure. Sometimes it is necessary to measure and control the pressure difference between the supply and return water main pipes, measure the temperature and flow rate of the supply and return water, and so on. While controlling these parameters, it is also necessary to centrally control the main parameters and monitor the operating status, accident status, and alarms of various mechanical and electrical equipment.

With the rapid development of computer board (microcomputer) control technology and communication technology, computer board control is widely used in the control system of refrigeration, heating and air conditioning equipment, and the automatic processing and control functions of electronic devices are applied to mechanical devices. Mechanical, electronic, information and other related technologies are applied to organically organize, infiltrate and synthesize the entire control system, achieving optimized control of the entire system. This control method is no longer the original single technology, single function control method, but a brand new control method with composite technology, composite function, and high degree of automation. Products that adopt this control method generally have multiple functions such as automatic control, automatic compensation, automatic verification, automatic adjustment, self diagnosis, self recovery, and intelligence.

The laws of centralized control and automatic control of computer boards (microcomputers): Continuous control laws can be divided into proportional, proportional integral, proportional derivative, and proportional integral derivative control laws. Proportion, integral, and derivative are represented by P, I, and D respectively. Therefore, PID control is proportional integral derivative control.

Centralized control and self-control of air conditioning units:

(1) Start sequence control: Open the fresh air damper, return air damper, and exhaust air damper → Start the supply fan → Start the return fan → Open the cold and hot water regulating valve → Open the humidification valve.

(2) Shutdown sequence control: Close the humidification valve → Close the cold and hot water regulating valve → Stop the air supply fan → Close the fresh air damper, return air damper, and exhaust air damper.

Operation control of refrigeration station system:

Start sequence: cooling tower fan → cooling water pump → chilled water pump → chiller unit

Stop sequence: chiller unit → delay → chilled water pump → cooling water pump → cooling tower fan