Beer Fermentation Automation And Optimization Algorithm Application

Beer production, as one of the most important traditional industry, has been developing quickly in our country since 1970's with the development of civil economy and the improvement of standard of living. However, because of the complexity of the beer production, domestic breweries have many disadvantages when compared with breweries in advanced countries, such as outdated measurement and control equipments, low level of automation, instable product quality, etc. How to improve the integrated automation level in beer production becomes an urgent research project. Beer fermentation is one of the key steps of beer production. Thus, on the basis of some projects in breweries, this thesis investigated beer fermentation automation and optimzation algorithm applied in this process. It is an attempt to apply high technology to traditional industry and has importantly practical meaning.Following are the main contributions of this thesis.A. Beer fermentation is a dynamic process that must be guided along a temperature profile to obtain the desired results. Previous domestic references, which are in control field, on this subject focus on the application of advanced control to fermentation process in order to ensure the process following the temperature profile with smaller deviation. This paper, on the other hand, focuses on the search of the optimal temperature profle. Ant colony system algorithm was applied to optimize the kinetic model of this process. During a fixed period of fermentation time, a series of different temperature profiles of the mixture were constructed. An optimal one was chosen at last. Optimal temperature profile maximized the final ethanol production and minimized the byproducts concentration and spoilage risk. Satisfactory results were obtained, requiring not much computation effort.B. Nowadays many breweries in China still use outdated control systems, which can not satisfy the product need. Developing a completely new system costs a large amount of money. So, many factories decide to extend the capacity by reconstructing the existing system. These extension projects requiring persons who are familiar with old systemsand old developing tools, which are not used for several years. Based on the project of fermentation system in Xihu brewery, this paper dealt with the integration of the existing system (developed by SIEMENS S5 PLC) and the new system (developed by SIEMENS S7 PLC). Under the condition that the old system should be in order during the project, little changes was made to the original programes in the S5 PLC, proper communication method was adopted and finally this project was fulfilled successfully. This paper also investigated the software development of multiple panels and S7-200 PLC, and comparision and realization of tables in industrial control software. These experiences accumulated during research projects will have practical value for concerned engineers.