Research On Synthesizing Startup Operating Procedures With Three-tier Formal Fata Matrix

With the rapid progress made in technology, production plant for chemical industry becomes larger and larger, and the production processes become more and more complex. To satisfy the increasing stringent safety, energy shortage for chemical industry, energy utilization and operation optimization become more and more important. At present, the process operations for startup are carried out through manual operation relied on experience in nature. To persist in the sustainable development strategy for chemical industry, synthesis of operating procedures for chemical processes was presented to solve the problems of safety, wasting of resources and over much pollution. To the problem deciding whether the synthesize start-up operation procedure is proper or optimal, it was not usual to be proved from the theory. This paper proposes the method of start-up operation procedure with the three-tier formal data matrix. The contents are as following:1 According to the view of the cycle time of the running of process system, the process operation is classified into four types. And this paper points out that the biggest difference between the start-up operation and normal production is the state variables and operating variables of the process are dynamic changing. The new concept of the start-up operation procedure is proposed. In other words after applying the complex system start-up steps are proposed in this paper , the start-up process of a complex system can be approximately taken as the combination of a set of start-up operations of site systems or unite operations. So the start-up operation procedure can be taken as finding the optimal operation path from various existing paths, and making the system transfer from the given initial state to the goal state.2 This paper points out the two problems to be solved by the synthesize start-up operation: the problem of chemical engineering designing;and the problem of chemical engineering controlling. From the view of analyzing process system control block diagram, in order to escape from the limitation of previous manual operation of start-up process, the controlling regulation of the controller previous made is fixed, consisting of the tract of the operating variables and process controlled variables.3 The method of three-tier formal data matrix synthesize operating procedure is proposed, the row of the matrix is the discrete operating time which the system has experienced, the first level of the row is the value of the state variables, the second level is thevalue of the adjustable operating variables, and the third level is specific value of the state operating data of the equipment such as the openness of the valve. In this way , the controlled variables and operating variables can be described in the same matrix, using the optimal operating path solved by the principle of optimal control. The proper and optimal start-up operating procedure is achieved which is strictly approved by the classical principles.4 For choosing the optimal start-up time of the reaction tank , the Freedom-degree analysis is done, and the problem of optimizing the start-up is existing in the system where the number of the variables is larger than that of the equations. So there are a lot of operating paths making the system transfer from the initial state to the final state. In this case, according to the rules of the controlled variables and operating variables chosen and the specific character of the system, the controller is designed, after the track of the operating variables is solved the system can run to the goal state according to the path we hope. For the problem of calculating optimal temperature distribution of piston flow rectors, this paper proposes two new direct search algorithms: fmincon function and Genetic algorithm, basing on traditional iterative methods. Through the comparison of the results which shows all of the three methods can get the correct results, but compared with the traditional methods, the requirement on the initial value of the two new methods is not very strict, which is beneficial to solving such kinds of problems.