Study On The Divergence Characteristics And Controlling Mode For Concentration Field Of Carbon Dioxide In The Case Of Industrialized Plant Of Volvariella Volvacea In Typical Climatic Northern Area

Volvariella volvacea, origins from south of China, is a kind of mushroom which have to grow in the environment of high temperature and humidity. It can be found in such subtropical area as Guangdong, Guangxi, Fujian, Hunan, Taiwan, Hainan and Sichuan Provinces. Due to its high quality for nutrition, medicine and profit, researchers focus on the experimental research which tries to grow Volvariella volvacea in northern area. Volvariella volvacea is greatly sensitive to temperature, humidity, wind speed, illumination and other surrounding factors; therefore the requirement to the environment of volvariella volvacea room is quite strict in winter season in northern area. CFD model software is used in this thesis to numerical simulation and modeling of carbon dioxide concentration field inside the volvariella volvacea room in winter season in northern area.This thesis mainly focuses on the divergence and concentration controlling of carbon dioxide which is produced by volvariella volvacea. The Airpak software of CFD software system is used to simula(?)e the environment inside the volvariella volvacea room. In the first step, a model, which can satisfy the temperature and flow field requirements for volvariella volvacea, is established based on the optimal heating mode and uniform ventilation style which was gotten from another model built by former researchers. The optimal ventilation which can control the concentration of carbon dioxide perfectly is obtained by simulation and discussion about the relationship between ventilation mode and concentration of carbon dioxide. Secondly, the divergence of carbon dioxide produced by volvariella volvacea can be calculated on the base of ventilation rate to the concentration of carbon dioxide which is measured inside the volvariella volvacea room experimentally. In the end, the methods are obtained to control the concentration of carbon dioxide due to the requirements for the growth of volvariella volvacea.The result of numerical simulation, which reveals the optimal ventilation rate, is applied in the volvariella volvacea room. The experimental data reveals the ventilation rate is quite suitable to the growth of volvariella volvacea. It also reveals the real divergence of carbon dioxide in the different growth period of volvariella volvacea. The optimal methods to control the concentration are found, which can remove indoor contamination effectively so as to satisfy the concentration demand of carbon dioxide in the volvariella volvacea room.