الفهرس | Only 14 pages are availabe for public view |
Abstract This thesis aims to develop and implement a static modelling for fermentation rooms of large bakeries. Due to the large dimension of the fermentation room, it requires several numbers of monitoring points for estimating average conditions of air quality. Optimum sensor location is the first step for successful air quality control inside fermentation room. The simulation of temperature and relative humidity distribution inside the fermentation room enables the operators to predict temperature and relative humidity in different locations and levels to select suitable sensor locations. In addition, it is an attempt to evaluate internal air quality of fermentation processing rooms in terms of temperature distribution, relative humidity distribution, air velocity magnitude and carbon dioxide concentration to keep internal air quality at such a condition of 34 °C and (90-95) % relative humidity. These represent the best conditions for enzymes and microorganisms production during the fermentation process. As for simulation modelling, different models are adopted and expanded by Ansys Fluent 17.2 program. Some simulated results are validated by measurements with good agreement where a case study was conducted in a large proofer in Cairo, Egypt. A number of different models on the air distribution in large fermentation rooms are introduced. That included the inlet-outlet air ports distribution models, different air entrance speed models and different air entrance angle models. This thesis investigated the effect of these parameters on proofing room internal air temperature distribution, relative humidity distribution and carbon dioxide mass fraction variations by this simulation. These models enable fermentation room designers to select optimum design conditions and sensor locations inside the room according to simulation results. The results showed that in order to maintain optimum fermentation room conditions, inlet air quality should be the same as the room’s desired conditions, and the number of air outlet ports should be 27% to 50% of the number of air inlet ports. It is an attempt to improve the energy consumption in fermentation rooms by changing air supply conditions. Significant amounts of energy are saved during the summer and winter seasons, with the percentages coming in at 62.5% and 21.6% respectively. from this simulation 160 to 220 cfin/ton, which corresponds to an indoor Co2 concentration of 485 ppm seems to be adequate for fermentation proofing room with side wall ventilation ports. Therefore, this flow rate reflects the minimum required ventilation rate for fermentation proofing room future design. |