До оцінки ефективності процесів інтенсифікації теплопередачі в теплообмінних апаратах

The heat transfer augmentation in the heat exchangers is applied in order to reduce their weight-size parameters. To evaluate the efficiency of augmentation processes the different indices are used. It is shown that most of the indices are based on the heat transfer coefficient and they do not take into account the heat transfer features. This approach is valid, if the systems are considered, in which the heat transfer only from one side of the heat transfer surface is important (for example in the cooling blade systems of gas turbines). However, the performance of a certain type of augmenters in the waste-heat boilers of power plants or regenerators of gas turbine engines technologically influence on the heat transfer from the other side of the heat transfer surface. This makes it necessary to take into account the features of the heat transfer processes on both sides of the heat transfer surface. On the basis of the synthesis of existing ones the new index is proposed which is based on the overall heat transfer coefficient. To verify the proposed index the computer modeling in the ANSYS CFX system were carried out. The internal ring rollings were considered as the augmenters. The results showed a decrease of heat transfer augmentation to 21% by means of heat transfer processes.На основе анализа показателей эффективности интенсификации теплоотдачи предложен критерий оценки эффективности процессов теплопередачи в теплообменных аппаратах.На основі аналізу показників ефективності інтенсифікації тепловіддачі запропоновано критерій оцінки ефективності процесів теплопередачі в теплообмінних апаратах