The Study On Germfree Measurement And Control Of Cone-shaped Beer Tank

Draft deer without pasteurization is getting favor from customers becauseof it's fresh taste and rich nutrition. And it's situation of sanitation is gettin g more care from correlative experts. Now, the germfree technique in the wh ole production process of draft beer is becoming more and more perfect exce pt the germfree measurement and control of fermentation temperature, the keyfactor to beer production. Traditional cut-in measurement will bring many sa nitation bland angles .Which doesn't meet the germfree demand. At the sametime, the simple P1D isn't fit to the multiplex requires of beer production. A imming at this actuality, this article developped the study on the germfree m easurement and control of cone-shaped beer tank. The main works and innova tive method are listed as follows:Built the experimental device for the multi-point measurement and contro 1 system of fermentation temperature. The device applied PCI-1716 and PCLD -789D of the ADVANTECH to get the multi-channel data, VB program was compiled to complete many functions such as getting and displaying of real-ti me data, controling the fermentation temperature , saving the history data etc. The author measures the imports and exports parameters of the beer tankjacket and the temperature of each point for measuring temperature in-tank d uring the cooling process, which will afford enough data samples for the rese arch of the beer tank heat-transfer mechanism.Analyze the heat transfer mechanism of the cone-shaped beer tank, and determinant it is the natural-convection heat transfer in the closed chamber. Es tablish the Navier—Stocks mathematic model on the basis of the mechanism .and analysis the temperature field by limited difference method and FLUENT.The author compares the measurement results during experiment with the cal culated results. It shows that use the method of grogram and the software FL UENT can both simulate the temperature distribution of the beer fermentationtank very well. So they have better value to industry application.The author sets up knowledge base between wall temperature To and insi de 0.2 m temperature T0.2 for getting T0.2 by measuring To on the basis of t emperature field distribution. The meaning of establishing the knowledge base, lies in realizing the germfree measurement because To may be the control va riable and perform the control of the fermentation temperature instead of T0.2, thus wall measurement replaces the cut-in measurement and sanitation blind angles are eliminated.The germfree measurement of fermentation temperature is realizedDevelop the application of GA to fermentation temperature control. Adop t GA to optimize the parameter of traditional PID.The optimized curver is pr oved to meet the demand of the industry better with quicker answer speeds s mailer overshoot and the deviation within ± 0.3 °C.