Background. The main equipment of the thermal power plant (TPP) includes a E-120-7.0-500GM steam boiler produced by LLC “Belenergomash – BZEM” with a single-stage evaporation circuit. The operating mode of the thermal power plant has seasonal characteristics. During the period of February to the end of August the equipment is stopped as a reserve. Dosing of AMINAT PK-3 does not provide the required pH level in steam and feed water, so the reagent for water-chemical regime and preservation has been substituted with VTIAMIN KR-33. The complex reagent VTIAMIN KR-33 ensures both the maintenance of the required quality indicators of the coolant along the path and promotes the formation of a protective barrier film on the internal heating surfaces.
Materials and methods. To check water-chemical regime, the existing automatic chemical control system has been updated. Panels have been installed for automatic chemical control of pH value, electrical conductivity of direct and H-cationized samples. The filter material has been replaced and the mechanical filters have been connected. The first stage of the filter has been replaced, the second stage of the filter and final purification filters Н-OH have been installed.
Results. The authors have demonstrated the possibility to use boilers with seasonal operating modes and measuring the electrical conductivity of cooled water and steam samples as a chemical control of water chemistry. It is found out that dosing the VTIAMIN KR-33 reagent with periodic dosing of the VTIAMIN D-8 reagent into the boiler water prevent the precipitation of hardness salts and other impurities coming with the return condensate. Analysis of the indicators of the water chemistry regime at the thermal power plant when dosing the VTIAMIN KR-33 reagent at two points has shown that the pH value of the feed water is in the range of 8,8–9,0 and the indicators of the water chemistry regime in terms of the content of iron, silicic acid and sodium are also within the norm limits. The composition of the reagents is selected. Flexibility of water chemistry management is ensured. It has been shown that the dosage of the amine-containing reagent VTIAMIN neutralizes the negative effects of aggressive gases (carbon dioxide and oxygen) due to their binding and the formation of a protective film of the magnetite-amine type on heating surfaces.
Conclusions. Introduction of the water chemical regime when the equipment is stopped as a reserve does not require additional preservation measures.