| With the improvement of people’s life, greenhouse vegetable becomes more important for vegetable consumption. However the supply of carbon dioxide plays a key role in greenhouse vegetable quality. Especially during autumn and winter season, greenhouse closed, which caused a negative influence on vegetables growth due to lack of CO2. There are many kinds of device for carbon dioxide fertilization-production. Most of them are based on chemical reaction or burning method. However, because of high costs, inconvenience, as well as pollution, it is significant to design an inexpensive, automatic and environmental-friendly device.By analyzing the produce CO2 in biomass fermentation, the overall structure of the double cavity layered fermentation is designed. The production of trial prototype is also finished. The material box, water adding, heating device, etc. are completed and met the basic design requirements.The control system is designed using the PLC and King View. And then, PLC and sensors are selected. The software is also adopted using top-down modular method. The main interface, the history curve, the alarm status, the out-report, are designed using King View. The network communication between PLC and KingView is completed through setting the setup of programming port. Finally the device supports manual and automatic control.Following experiments are carried out:The wheat straw and soymeal are considered as optimal material combination by comparing the differences in the organic compound content and gas production rate. Comparing the rate of gas production under different temperature, carbon/nitrogen ratio and moisture content, the fermentation conditions, air humidity in the device and the holding time are optimized. The reliability of the device is validated by comparing the temperature and humidity inside and outside the device. Meanwhile, the fermentation device could met demands of the greenhouse vegetable requirements by measuring the gas production during the experimental period. |
