The design of a dynamic simulation system of a liquid chemical filling process
The flow sheet and operation principle of a liquid filling process was briefly discussed, and the dynamic simulation mathematic models of the filling process were developed in detail using the mass balance equations, gas state equations and historical process data. Based on the intelligent process control (IPC) simulation mode, the overall structure and the development scheme of the filling process simulation system was designed. A dynamic simulation system of the filling process was successfully developed, by taking a typical SCADA (supervisory control and data acquisition) configuration software named Century Star as GUI (graphical user interface) development platform, and integrating with a DLL (dynamic link library) function program to perform the calculation of the simulation models programmed using Visual C++. The development of the simulation GUI included the design and Command Language programming of simulated process flow sheet diagrams, simulation command buttons and their displaying diagrams, and the operation and parameters adjustment diagrams of all kinds of manipulators in the process flow sheets. The overall simulation operation of the filling process was fairly good achieved. Then some comprehensive and systematic simulation tests of the filling process were carried out. The simulation results show that the simulation system could satisfy the filling process research and design requirements very well, and the main process operation parameters were optimized through these simulation tests.
SDG-based Model Validation in Chemical Process Simulation
Abstract Signed direct graph (SDG) theory provides algorithms and methods that can be applied directly to chemical process modeling and analysis to validate simulation models, and is a basis for the development of a software environment that can automate the validation activity. This paper is concentrated on the pretreatment of the model validation. We use the validation scenarios and standard sequences generated by well-established SDG model to validate the trends fitted from the simulation model. The results are helpful to find potential problems, assess possible bugs in the simulation model and solve the problem effectively. A case study on a simulation model of boiler is presented to demonstrate the effectiveness of this method.
Mechanical behaviour and durability of high volume fly ash cementitious composites
The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles. KEYWORDS. Cementitious matrix; Raw fly ash; Second layer particles; Third layer particles.