The study of the influence of the degree of contamination of low-temperature heating surfaces on the intensity of convective heat transfer during the burning of non-design fuel based on computer modeling has been carried out. The results of the analysis showed that the amount of deposits varies depending on the temperature of the heat carriers in the air heater. A new method for calculating the thermophysical parameters of the heat transfer process has been developed on the basis of the ANSYS software package, which makes it possible to obtain a complete description of complex heat transfer processes in the boiler air heater. In the developed computational three-dimensional thermophysical model of a recuperative tubular air heater, there is no tube wall; the created thermal resistance of the wall is taken into account by introducing the coefficient of effective thermal conductivity of the flue gas flow.

This article is devoted to the problem of a high level of oncological diseases of the population of the Republic of Kazakhstan. The analysis of the presented statistical data indicates an annual increase in the number of detection of registered oncological diseases in the population of the Republic of Kazakhstan. With regard to our region, the annual increase in the number of cancer detection in the population of the Abai region, which is undoubtedly due to the existence of the former Semipalatinsk nuclear test site on this territory, leads to the need for further research to improve the prediction of the treatment process of patients with cancer. Currently, the method of radioiodotherapy presented in the work is actively used for the treatment of oncological diseases, and in particular thyroid cancer. This method of treatment allows you to destroy cancer cells, surgical removal of which is not possible. An accurate calculation of the activity of the drug to be taken by the patient allows you to reduce the dose load on the patient and at the same time achieve the desired therapeutic effect. The paper presents formulas that are used to calculate the radiation dose of patients for the successful treatment of thyroid cancer. This method of treatment is carried out in the department of "Radionuclide Therapy" of the Center for Nuclear Medicine and Oncology of Semey.

The purpose of this work is to establish the operating conditions of the boiler unit to ensure efficient combustion of nondesign Karazhyra coal. The main factors determining the efficiency of the boiler unit are the qualitative composition of the fuel being burned, the behavior of the mineral part of the fuel during combustion, the level of the fuel combustion temperature, the duration of the interaction of high temperatures on the mineral part, the properly organized method of fuel combustion and the design features of the combustion chamber. To achieve this goal, it is necessary to conduct a comprehensive study of the boiler operation using the example of burning non-design coal from the Karazhyra mine in a KV-T-116.3 -150 TEC-1 boiler in Semey. As a result of the conducted research, qualitative parameters of operation in real conditions of the boiler unit during the combustion of non-design Karazhyra coal with variable heat output were obtained. The analysis of the data obtained during the combustion of non-design coals will allow us to further develop a number of practical recommendations for optimizing the operation of cleaning agents installed on the boiler.