【 Weak current College 】 DDC in air conditioning and humidity control system---Power By 【 China power house network 】

Combined air conditioner in the textile mills of integrated applications, the air portion of the combined air-conditioning units, air part adopts textile waste suction blower from filtered back to the wind, a combined air-conditioning unit middle segment design with shower, cold water through a direct hit to the circulating pump, spray to avoid the waste of energy; air supply and return air segments are designed pressure sensor, air supply and return air blower all adopt Inverter control.

Technical requirements and system structure

1. technical requirements

Air temperature: 18 ° c-27 ° c ± 1 ° c; send rheumatism degrees: 50%-65% ± 5%.

2. electrical structure

The project design have outdoor fresh air detection sensor, indoor temperature and humidity sensor, fresh air, back to the style used air valve actuator control; frozen water electric two-way valve automatic control; air and back to the style used for the inverter control, to achieve control of temperature and humidity and air. Site controller can choose HONEYWELLXL50 controller with C-BUS communication interface, upper monitoring computer can install WINDOWS2000 operating system, configure the EBI system software, communication converters can choose Taiwan MOXA company A53.

Control theory and methods

1. control principle

1) consists of fresh air temperature and humidity sensors for the determination of temperature and humidity, the system automatically calculates the fresh air enthalpy value as a condition of zoning and control of conditions, the indoor temperature and humidity sensor to detect the current indoor values and calculate the virtual dew point and dew point enthalpy value.

2) based on fresh air enthalpy and virtual dew-point temperature deviation value, the PID algorithm to adjust the new, Hui, exhaust valve to open degree and cooling valve to open degree.

3) according to the Division of State regional and run area, automatically control the inverter (can also be manually adjustable) to send, to air, so that the device is highly effective, economical, and meet the breathing frequency and temperature and humidity control requirements, and maximize energy efficiency.

2.DDC program implementation

DDC control into a switch logic and control programme, time functions, mathematical editing, and several other categories, the principle of control in fact is the PID control algorithm integration enables many control module, the program uses a graphical way, simple and reliable.

Centralized monitoring system

The entire system consists of a central monitoring station, DDC field controller (slave), locale sensor and actuator is composed of three basic levels. In the spirit of "decentralized control, centralized management" principle in the field of the controller on the scene and air conditioning equipment, real-time monitoring, and man-machine interface, monitor the operational status of the air conditioning system and complete the process parameter is set to function independently in the field. Multiple controller over the network communication interface networking at the central station computer centralized monitoring and management, and may, as necessary, in combination with industrial control and communications network that will manage the data into a database, form the management level, monitoring, level, field-level three-level integration system to meet the enterprise production and management needs.

Textile air-conditioning automatic control system reduces the disadvantages for operations, management and technical upgrading, reliable production process meets the requirements. DDC direct digital control systems in textile air-conditioning application is mature, developers programming convenience, control, control of safe and reliable. It allows users to easily carry out operations management, data management, alert management, report management, integratedmanagement, improve enterprise's new technologies and comprehensive management capabilities.