The Research Of The Network Controlling System For The Aquatic Grocery Refrigeratory

The topic of the dissertation root in the actual cold storage project of Guangdong Food & Aquatic Products Import & Export Group of Zhongshan. This dissertation starts with a theoretical analysis of operation principles of the refrigeration system and establishes a mathematic model of evaporator by employing least-squares in a broad sense. And it also makes a simulating study of the established model by using fuzzy control and PID control. The advantages of fuzzy control are quite obvious through the analysis of simulation outputThe refrigeration system of the cold storage is a very complicated energy transmitting system. In the following session the dissertation makes a comprehensive introduction of the overall design plan of the system from the perspective of hardware and software. In the aspect of hardware design, it begins with the major tasks and main functions of the controlling system followed by the controlling plan of the system. Then it further elaborates on the hardware design of each unit in the system detailed and provides the electric circuit diagram in the appendix. In the aspect of software designing, it begins with the software design process laying stress on the control of the liquid supply valve of the refrigeration system with the employment of fuzzy control. It is an intelligent control process of the system, which is achieved by getting the fuzzy general control diagram of the system through fuzzificating the output value of the system and fuzzificating calculation of the control diagram of the given system. Only if the temperature of the system is available by sampling in the real system, the output value is achievable by diagram checking.The controlling system mentioned in this desseration has the advantages of centralized display operation management, controllability vs. scattering, feasibility, convenience, good extention, ect . At the same time, the introduction of fuzzy control to realize automatic temperature adjustment of the cold storage and rational allocation of energy resources greatly improves the stability, reliability and refrigeration efficiency of the system.