The Design And Implementation Of The New Type CO₂ Elimination Device Control System

The CO₂ elimination technology can be widely used in the agriculture CA Room. It can control the gas concentration level, improve the storage quality of the fruit and vegetables and extend their storage life. It can also highly increase the economic added value of the fruit. It has comprehensive social benefit and economic benefit. According to the deep research of the CO₂ elimination technology and the customer feedback, the New Type CO₂ Elimination Device adopts the solid state macromolecule resin as sobbing material. It has advantages of simple process flow, little environment contamination and low control concentration.Based on analyses of operating principle and process flow of the New Type CO₂ Elimination Device, this article provided the control requirement of simple operation,reliable running and adjustable concentration. The author adopts the advanced PLC+ HMI control system to the computer control system design. This made the process be fully automatic controls and personal intervened. It uses the Siemens S7-300 PLC and MP370 touch screen as the hardware configuration and with the use of Siemens Step7 software design wrap and touch screen configuration software Protool, it developed the PLC control program and monitor interface. Through the application of the New Type CO₂ Elimination Device, we can see that: The running is stable and reliable and the operation is simple. The control strategy is perfect and the control logic is exact. The process control of structured design mode has better expansibility and maintainability. It has several operating mode, such as manually single operation, manually cycle operation and CO₂ concentration self-regulation operation and so on. It can be switched freely and satisfy different application demand of debugging, operating and maintaining. The touch screen provides convenient man-machine interface for site operation and realizes necessary manual intervention. The monitor program has several configuration interfaces and shows all the status information and parameter of the process flow. It is convenient for the operating personnel to fully master the running status. Also it can save the operating data and query the history data.At different CA rooms, due to different quantities and types of the fruit, the requirement of the CO₂ concentration is different. Through the touch screen, the control concentration and other controlling parameter of the New Type CO₂ Elimination Device can be adjusted freely. This made the device have better environmental adaptation and commonality and can meet different market demands.