The integrated application of modular air conditioning units in textile factories involves using modular air conditioning units for the supply air section and textile axial flow fans to draw and filter air from the trench before returning it to the surface. A spray section is designed in the middle of the modular air conditioning unit, where chilled water is directly pumped by a circulating water pump to avoid energy waste. Differential pressure sensors are installed in both the supply and return air sections, and both the supply and return air fans are controlled by frequency converters. Technical Requirements and System Structure : 1. Technical Requirements: Supply air temperature: 18℃~27℃±1℃; Supply air humidity: 50%~65%±5%. 2. Electrical Structure: The system is designed with outdoor fresh air detection sensors and indoor temperature and humidity detection sensors; fresh air and return air are automatically controlled by damper actuators; chilled water is automatically controlled by electric two-way valves; supply and return air are controlled by frequency converters to achieve the purpose of controlling temperature, humidity, and air volume. The field controller can be a HONEYWELL XL50 controller with a C-BUS communication interface. The host computer can be equipped with a WINDOWS 2000 operating system and EBI system software. The communication converter can be a MOXA A53 from Taiwan. Control Principle and Method : 1. Control Principle: 1) After the fresh air temperature and humidity sensor measures the temperature and humidity, the system automatically calculates the fresh air enthalpy value as a condition for dividing the operating area and control. The indoor temperature and humidity sensor detects the current indoor value and calculates the virtual dew point and dew point enthalpy value. 2) Based on the fresh air enthalpy value and the deviation value of the virtual dew point temperature, the PID algorithm adjusts the opening of the fresh, return, and exhaust air valves and the surface cooling valve. 3) According to the divided operating area and running area, the frequency converter is automatically controlled (or manually adjusted) to regulate the supply and return air volume, enabling the equipment to operate efficiently and economically, meeting the control requirements of air exchange rate and temperature and humidity, and maximizing energy savings. 2. DDC Program Implementation: DDC control is divided into several major categories, including switching logic, control schemes, timing functions, and mathematical editing. The principle of control is essentially the integration of PID control algorithms into many control modules. Programming is done graphically, making it simple and reliable. Centralized Monitoring System: The entire system consists of three basic layers: a central monitoring station, DDC field controllers (lower-level machines), and field sensors and actuators. Adhering to the principle of "distributed control, centralized management," controllers distributed in the field achieve real-time monitoring of the field air conditioning equipment. Equipped with a human-machine interface, they monitor the operating status of the air conditioning system and complete process parameter settings, and can operate independently in the field. Multiple controllers are networked through a network communication interface, achieving centralized monitoring and management at the central station using a computer. As needed, it can be combined with industrial control and communication networks to incorporate management data into a database, forming a three-level integrated system of management, monitoring, and field levels, meeting the needs of enterprise production and management. The use of an automatic control system in textile air conditioning can reduce the drawbacks of human operation, bringing management and technical improvements, and reliably meeting production process requirements. The application of DDC direct digital control systems in textile air conditioning is mature; developers find programming convenient, control is simple, and control is safe and reliable. It allows users to easily manage operations, data, alarms, reports, and overall operations, improving enterprises' ability to apply new technologies and manage comprehensively.