Liangxi Xie

Numerical Modeling of Contact Pressure in Vane Seals

The sealing contact pressure is one important parameter in evaluating the sealing performance of vane seals. The paper proposes a new numerical approximation method to calculate contact pressures in vane seals. The model considers the fact that the seal, made by the elastomeric rubber, is nearly incompressible and can’t be compressed in three principal directions at the same time. Being compressed in two of the three principle directions, e.g. in y and z directions, the seal expands in the third direction, namely, the x-direction. With reasonable results derived in the model, the width of the vane groove for the seal should be a little wider than the initial width of the seal. The results are in consistent with classical sealing theories and experiments on O-ring seals.Copyright

Research of Intelligent Control of Air Compressor at Constant Pressure

The air separation plays an extremely important role in the development of metallurgical industry. And the air compressor which provides not only the required pressure air for the cooling equipment and refrigeration plant but also the raw material required for the separation plant is a key device in the air separation plant. Utilization of the air compressor is extremely extensive in many significant departments such as the metallurgy, oil and chemical industry. The air compressor system is a time-varying, delay and nonlinear complex system. Defects in the traditional control method and controller lead to the pressure instability of the compressed air outputted from the air compressor in volatile gas-consumption situations, sometimes a wide range of fluctuation arising, for gas consumption in the industrial field is irregular. Therefore, the working state of the air compressor becomes unstable. In general, electric energy consumption of the air compressor system working in the stable state counts up to about twenty percentages of the total energy consumption in the enterprise. Moreover, energy consumption in the unstable state is more. It results in both a waste of resources and greater energy consumption. Therefore, guaranteeing the output pressure of the air compressor system steady is extraordinarily significant for improving efficiency and saving energy for the overall air separation system. The turbine compressor system was taken as the research object to analyze its characteristics and control requirements. DCS control technology applied to the system, the ECS-700 system of SUPCON was utilized into configuring the air compressor system and monitoring real-time values of important parameters in the various components. According to the working characteristics of the air compressor system, the fuzzy control theory, as one of the modern control theories, was applied to the constant pressure control system to design a fuzzy pressure controller. The simulation results showed that the controller not only was more convenient and effective but also provided a certain directive significance and reference for control of other parameters of the air compressor system.

Numerical study of the contact pressure of window-type vane seals: Part I

The contact pressure at the sealing surface is one of the most important parameters for evaluating the sealing performance of vane seals. This article – which appears in two instalments – looks at the development of a numerical model of the contact pressure for window-type vane seals. It also provides details of a parametric calculation that was performed to study the effects of certain parameters on contact pressure. The first part, which appears here, describes the computational model and its application, including initial data and the section shape of the vane seals.

Intelligent Control System of BOF Steelmaking

0n the basis of analyzing BOF steelmaking characteristics, a prediction model and control model based on neural network were established. Taking endpoint temperature and endpoint carbon content as control target, oxygen-blown volume and added coolant were calculated, then endpoint control of convert steelmaking was realized. Simulation results show that the simulation result of endpoint temperature and carbon content are satisfying and control strategy is very effective. The application results demonstrate the efficiency of the method.

Research on fuzzy intelligent control of coke oven temperature

Coke oven production has the characteristic of nonlinear, large inertia, large disturbances highly-coup ling and so on. The control method of “Intermittent heating control” was adopted in traditional heating control system of coke, and cannot satisfy the command of heating control on coke oven. The control principle of combining the “intermittent heating control” with the heating gas flow adjustment was adopted according to analyzing the difficulty and strategy of heating control on coke oven. On the basis of studying deficiency of the existing control strategy, fuzzy control was proposed to establish heating intelligent control of coke oven. The algorithm of intelligent fuzzy immune PID control was designed and simulation of coke oven production was carried. The results show that the intelligent fuzzy immune PID control has the advantages of shorter adjustment time, quicker response time, higher anti-interference ability better dynamic property and stability. It can reduce effectively the fluctuation of coke oven temperature, has better control property and practical value.

Numerical Simulation of Heavy Rail Quenching Process

Heat-treatment i s emphasized for its important role to qualify the heavy rail. The temperature and stress field of U71Mn heavy rail during the quenching process were simulated by the FEM software and various kinds of factors that may influence temperature and stress field distribut ion were investigated . The result shows that the main factors influenc ing the temperature and stress field distribut ion were the heating and holding time, as well as the pressure of air blast during the coo l ing, whose values would directly influence the final performance of the heavy rail after the heat treatment. It is significantly valuable for the choice of relevant parameters for the heat treatment of U71Mn heavy rail.

Remote monitoring and diagnosis system of rolling mill based on CORBA and SOAP/Web service technology

A detailed solution to the remote monitoring and diagnosis system for a rolling mill is introduced. The hardware and software structure of remote monitoring and diagnosis system is presented. The structure of the system is made up of four subsystems, namely online monitoring subsystem, data servo subsystem, database service subsystem and www server subsystem. Software module of system includes seven parts, namely online monitoring module, data query module, fault information query module, trend analysis module, diagnosis analysis module, engineer station module and eigenvalue query module. The system adopts B/S model and integrates CORBA technology with SOAP/Web Service technology. It makes dynamic display and traversing for a great deal of on-line data and Firewall traversal possible. It has run a long time that proves that the system interface is friendly and easy to use. It has better security, good portability, expandability and stability. It can judge the running-condition of a rolling mill in real time.

Energy Efficiency Evaluation for Iron and Steel High Energy Consumption Enterprise

In order to optimize the allocation of energy resources, reduce enterprise’s energy consumption and achieve the goals of energy conservation and emission reduction, energy efficiency evaluation indicator structure and evaluation method which are fit for iron and steel high energy consumption enterprise are proposed, an energy efficiency evaluation system is designed for iron and steel high energy consumption enterprise to simulate the dynamic behaviors of energy use and consumption during the production process. The system has the function of data acquisition, statistical analysis and prediction. During the coke oven production process, this system is applied to the process from coal material to coke cake, and its feasibility is shown.

Intelligent Diagnosis of Abnormal Work Condition in Coke Oven Heating Process by Case-Based Reasoning

For reducing the fault ratio of coke oven heating process, based on the analysis of the fault mechanism and case-based reasoning (CBR), an intelligent abnormal work condition diagnosis model is proposed for the coke oven heating process. The probability of the typical fault and their operation guidance with the help of case-based reasoning technology is obtained. The knowledge representation of case and the structure of case-based are studied, and the algorithms of retrieval, learning and reuse are discussed. The proposed abnormal work condition diagnosis system is successfully applied to the coke oven heating process, the fault ratios during production process is decreased, and the proved benefit is achieved.

Fault diagnosis system using case-based reasoning and neural networks for coke oven heating process

For reducing the fault ratio of coke oven heating process, based on the analysis of the fault mechanism and combination of case-based reasoning (CBR) and neural networks, an intelligent fault diagnosis method is proposed for the coke oven heating process. The prediction model of the process variables based on neural networks performs to predict key technical parameters as the fault symptoms that is hard to measure online. The probability of the typical fault and their operation guidance with the help of case-based reasoning technology is obtained. The proposed fault diagnosis system is successfully applied to the coke oven heating process, the fault ratios during production process is decreased, and the proved benefit is achieved.