**Abstract**

The article considers the questions of defining economically viable conditions of repair of the main equipment (power boilers and turbo-generators) of industrial heat power plants, the hallmark of which is its use for the purchase of energy (natural gas, coal) and secondary resources (coke oven, blast furnace, converter gases) with non thermal circuit, with the generators from units to tens of megawatts.

The developed optimization technique makes it possible to make optimal schedules for the output in the repair of generators and boilers according to the criterion of the minimum cost for the production of live steam necessary to cover the thermal and electrical load in the summer and winter of the power plant. In order to improve the accuracy of the calculations, the research group used technical and economic models of boilers and turbogenerators representing the dependence of steam production (for boilers) and power (for turbogenerators) on the cost of one cubic meter of steam. The models allow us to take into account the heterogeneity of the fuel used, the season of the thermal power plant, the operating characteristics of the equipment (mode maps of boilers and mode diagrams of turbine generators), which imposes restrictions on the conditions and excludes the possibility of obtaining emergency and/or deliberately unrealized conditions in the calculations. At present, the work performed the definition of the season (winter/summer), in which it is more economical to turn off the equipment for preventive maintenance.

The created algorithm is implemented in the original software product "KATRAN", which allows the calculation of normal, emergency modes and optimization of steady-state conditions. The implementation of the results of work in the conditions of the existing facility will make it possible to increase the efficiency of the installed units and reduce energy costs without additional capital investments in the equipment.

**Keywords**

Heat power plant, electrical power supply system, turbogenerating set, boiler, optimum condition, repair condition, scheduled preventive repair.

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