Control System Research And Development Of Small And Medium Sized Horizontal Biogas Dry Fermentation Device

With the increasing demand for energy and the constantly changing of ecological environment, building safe, stable, economical and clean modern energy industry system has become an important part of Energy development “twelfth five-year” plan of the State Council. Biogas has surely become a key rural renewable energy construction project. And to realize the automation and intelligentization of biogas engineering work plays a vital role for the whole biogas production,which can improve production efficiency, production security and simplify the production process. This paper takes small and medium sizeds horizontal biogas dry fermentation device as the research object, by means of advanced computer technology,combines with Siemens PLC, frequency converter, touch screen and other control elements.We have developed the automatic control system of the device, so as to realize the real-time monitoring biogas production process and reduce the manual operation, thus more accurate grasp of biogas fermentation condition, improve the security and productivity and promote the further development and application of biogas project in China.The main contents are as follows:(1) This paper makes an analysis to the dry anaerobic methane fermentation process. As to the requirements for the control of dry methane fermentation system,we put forward the control programs for small and medium sized biogas dry fermentation system which including the control function of the drum, the material, mixing, lifting and feed material.(2) Through the analysis of process and programs,we list the relevant data needed to collected and the points needed to pay attention to. Combined with these characteristics, this paper analyses and selects the main hardware equipment,such as PLC, touch screen, frequency converter, executive component and sensors. And according to the selected elements,it designs material mixing equipment, feeding device, lifting device, discharge device, drum gear and the system circuit diagram of signal light, and determines the wiring scheme PLC inputs and outputs.(3) The biogas dry fermentation system uses PLC as the core controller,which determines communication between the frequency converter and PLC. And the system software programming based on modular control is accomplished. Through the Human Machine Interaction, it mainly realizes the monitoring of frequency converter, temperature, flow, water valve opening and closing, motor speed and motor start-stop.We have designed the touch screen that includes an automatic interface, manual control interface, alarm interface, settings screen and history interface and carried out experimental debugging to realize the automatic control of whole biogas dry fermentation monitoring system at last.Dry fermentation biogas control system have been used in Tropical Agricultural Sciences Institute of Agricultural Machinery biogas experiments, this system has been proved effective and feasible.