دانلود رایگان مقاله انگلیسی بررسی عددی جریان آب در سیستم های خنک کننده نیروگاه - الزویر 2018

Abstract

The paper presents a mathematical model for studying series-parallel hydraulic systems. The analytical approach is based on a set of non-linear algebraic equations solved using numerical techniques. As a result of the iterative process, a set of volumetric flow rates is obtained for the water flows through all the branches of the hydraulic system investigated. As examples of the practical applications, the following are investigated: a cooling system of a power boiler’s auxiliary devices and a closed cooling system containing condensers and cooling towers. In the first example, the calculations show the influence of changes in the characteristics of circulating pumps or elbows on the total cooling water flow rate in the installation analyzed. Such an approach makes it possible to analyze different variants of the modernization of the system studied, as well as to indicate its critical elements. In second case, knowledge about the water distribution in the cooling system can improve cooling processes inside cooling towers and, in this way, have a direct influence on better pressure conditions inside condensers. The results of numerical modelling are useful during modernization of the installation. By examining various solutions, an investor can choose the optimal variant of the reconstruction of the installation from the economic point of view.

6. Conclusions

The examples of calculations presented indicate that mathematical models are useful and reliable tools for analyzing flows in different types of hydraulic systems. After a validation process, the models can be used to verify possible variants for retrofits of cooling installations as well as to indicate, for example, its critical elements or the directions of the flows in individual branches. This information could be valuable for investors who would like to make rational investment decisions related to the modernization of the hydraulic installation. Moreover, the software based on the mathematical models can be implemented to the monitoring system of power units and used for diagnostics for the system, indicating the deviations from its nominal operation.