Evaluation of the thermal degradation process within the steam power plants heat exchangers

The consequence of the deposits presence on the heat transfer surface of the following heat exchangers: shell-and-tube condensers, the regenerative feed water exchangers, are commonly the loss of heat exchanger capacity, owing to the high value of heat conductive resistance of fouling. The process is more often defined as the thermal (heat) degradation of a given heat transfer device. The symptoms of heat degradation are usually defined as the difference between the values of thermal-flow parameters for the current and the reference state. Moreover, this process always entails an increase in the cost of energy conversion, leading to increasing the emission output of greenhouse gases consequently increasing the environmental degradation. It is worth mentioning that deposits settled on the waterside of heat transfer surface could also initiate the process of tubes obliteration. This phenomenon is characteristic for condensers cooled by seawater in particular. Reducing internal diameter of any single heat exchanger pipe by the deposits cause the rise in flow resistance and also reduce the condenser cooling water pump capacity. Ultimately, it leads to the reduction in water flow rate, resulting in an additional increase in the resistance of heat transfer. Furthermore, reducing the flow rate of cooling water causes the enhancement of the fouling settling rate. The paper describes the above-mentioned phenomena and presents the quantitative determinants of the thermal degradation description for heat exchangers based on the results of the author’s own experimental research.

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Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę.