BOILER UNIT Russian patent published in 2023 - IPC F22B33/18 

FIELD: thermal power engineering.

SUBSTANCE: invention can be used in natural gas-firing boilers. The boiler unit contains a steam boiler with a firebox and a drum, a steam superheater, a water economizer, an air heater, a condensation surface heat exchanger, a tank for steam condensate from the exhaust combustion products with a hydraulic seal and a separation device-KO drum installed sequentially in the gas duct downstream of the air heater along the flow of the exhaust combustion products. A waste heat exchanger is installed in the gas duct upstream of the smoke exhaust fan. The boiler unit also contains a continuous blowdown expander, a pipeline for continuous removal of blowdown water from the boiler drum into the continuous blowdown expander, a steam line for removing secondary steam from the continuous blowdown expander, a pipeline for supplying concentrate from the continuous blowdown expander to the waste heat exchanger, and a tank-reservoir for collecting demineralized water released in a condensing surface heat exchanger from the exhaust combustion products when they are cooled below the dew point. The boiler unit is additionally equipped with a steam nozzle installed in the boiler furnace made in the form of a de Laval nozzle, and a steam line for supplying secondary steam from the continuous blowing expander to the steam nozzle for spraying secondary steam formed in the continuous blowing expander from the blowing water into the active combustion zone of organic fuel at a pressure of 0.2-0.25 MPa in an amount of 5-8% of the organic fuel flow to the boiler.

EFFECT: reduction in formation of thermal and fuel nitrogen oxides is achieved by reducing the temperature of combustion products and excess oxygen in the zone active combustion of organic fuel.

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