Features of scale formation in heat exchanger tubes

The paper focuses on the regularities of the process of scale formation and its influence on the efficiency of heat exchanger operation. Typically, the design of heat exchangers incorporates a constant surface reserve factor, in order to take into account the process of scale deposition. This leads to unreasonable increase in the consumption of non-ferrous metal. It is thus advisable that the regularities of the influence on the heat transfer of the thermal resistance of the scale layer as it increases over time be determined. Substantiated quantitative recommendations will enable excessive fuel consumption to be reduced and the efficiency of turbine units to be enhanced. The relevance of this study is the practical necessity of resolving these problems. The paper analyzes and identifies those factors which influence the formation of inorganic deposits in the tubes of turbine condensers. There is a certain inconsistency in the conclusions about the effect of heat load, water velocity and temperature, channel geometry and salt concentration in the coolant on scale deposition. This makes it difficult to predict a decrease in heat transfer during operation. This work establishes a dependency in calculating the intensity of scale formation in pipes with a change in the speed, temperature, hardness of heat carriers over a long period of time. It has been experimentally established that the decrease in thermal efficiency slows down due to a decrease in the intensity of scale formation, in the range of tested thermal loads with an increase in coolant speed. With an increase in the length of the pipe, water temperature and its hardness, the average amount of scale deposited on the surface of the wall increases. A quantitive comparison of the relative intensity of scale formation in smooth and rough pipes shows the advantage of profiled pipes of a certain geometry.