Scale and Corrosion Prevention in Cooling Water Systems Part I : Calcium Carbonate
This paper presents the results of study that was undertaken to investigate the ability of a new antiscale, polyacrylamide in solving problems found in cooling water systems. The effects of the polymer on C-steel and copper dissolution in synthetic cooling water environment were studied through scale, Tafel, and Linear polarization measurements. The results obtained from this study showed that the new antiscale polymer can decrease scale build-up growth under experimental conditions. Both linear and Tafel polarization studies indicate that the polymer acted as an anodic type corrosion inhibitor on C-steel and mixed-type on copper, thus reducing metal dissolution. Morphological investigations of calcium carbonate deposits on both C-steel and copper surfaces were studied by optical microscopy. The polymer used in this study appears to have an excellent crystal modification effect on reducing calcium carbonate scale. The antiscale effect results from changes in crystallization behavior promoting bulk solution precipitation rather than formation of adherent scale.
Development of anti-scale poly(aspartic acid–citric acid) dual polymer systems for water treatment
The formation of calcium sulphate and calcium carbonate scale poses major problems in heat exchangers and water cooling systems, thereby affecting the performance of these types of equipment. In order to inhibit these scale formations, new types of biodegradable water soluble single polymer and dual poly(aspartic acid–citric acid) polymers were developed and tested. The effectiveness of single polymer and four different compositions of poly aspartic acid and citric acid dual polymer systems as scale inhibitors were evaluated. Details of the synthesis, thermal stability, scale inhibition and the morphological characterization of single and dual polymers are presented in this scientific paper. It was found that the calcium sulphate scale inhibition rate was in the range 76.06–91.45%, while the calcium carbonate scale inhibition rate observed was in the range 23.37–30.0% at 65–70 °C. The finding suggests that the water soluble dual polymers are very effective in sulphate scale inhibition in comparison of calcium carbonate scale inhibition.
Computer-Aided System of Virtual Testing of Gas Turbine Engines
The article describes the concept of a virtual lab that includes subsystem of gas turbine engine simulation, subsystem of experiment planning, subsystem of measurement errors simulation, subsystem of simulator identification and others. The basis for virtual lab development is the computer-aided system of thermogasdynamic research and analysis “ASTRA”. The features of gas turbine engine transient modes simulator are described. The principal difference between the simulators of transient and stationary modes of gas turbine engines is that the energy balance of the compressor and turbine becomes not applicable. The computer-aided system of virtual gas turbine engine testing was created using the developed transient modes simulator. This system solves the tasks of operational (throttling, speed, climatic, altitude) characteristics calculation, analysis of transient dynamics and selection of optimal control laws. Besides, the system of virtual gas turbine engine testing is a clear demonstration of gas turbine engine working process and the regularities of engine elements collaboration. The interface of the system of virtual gas turbine engine testing is described in the article and some screenshots of the interface elements are provided. The developed system of virtual gas turbine engine testing provides means for reducing the laboriousness of gas turbine engines testing. Besides, the implementation of this system in the learning process allows the diversification of lab works and therefore improve the quality of training.