Start-up method with circulating-stove-water pump monotube boiler near steam heating boilers

Abstract

This invention declares a starting process of once-through boiler with by neighboring steam heating in which the high pressure heater is connected by the pipeline receiving exogenous heating steam. The mentioned process includes: heating the water in the unit boiler with the exogenous steam through the high pressure heater, heating the heat delivery surface of the boiler indirectly when starting up at cold, warm or hot status, starting the boiler water circulating pump and air-gas system when the temperature is close to the saturation temperature of the exogenous steam, ignition of the boiler, increasing the thermal load with bypass system after the is started, switching off the fuel when the thermal load of the coal exceeds the minimum oil-break thermal load and switching to the general starting process; when starting at the extreme hot status, ignition of the boiler after purging, after the coal pulverizing system is started, switching off the fuel when the thermal load of the coal exceeds the minimum oil-break thermal load and switching to the general starting process. The starting process will shorten the starting duration, and save fuel, coal and water.

Description

technical field [0001] The invention relates to the field of thermal coal-fired generator sets, in particular to a method for heating and starting a DC furnace of a steam turbine generator set. technical background [0002] With the increasingly mature technology of coal-fired power plants and the continuous improvement of environmental protection requirements such as energy conservation and emission reduction, supercritical and ultra-supercritical parameters are generally used for large thermal power units, so the once-through furnace has become the only choice. The start-up method of the DC furnace is different from that of the conventional drum furnace. From the perspective of the world, at present, the atmosphere expansion vessel type or the furnace water circulation pump type are mostly used. These two start-up methods have their own advantages and disadvantages. The start-up method of a once-through furnace with a boiler water circulation pump has small heat loss and ...

AI Technical Summary

Problems solved by technology

However, this technology belongs to cold furnace cold air ignition, and about 50% to 65% of the coal in the ignition stage is wasted because it cannot be burned.

If a large amount of unburned pulverized coal remains inside or at the tail of the boiler, it will become a major hidden danger to the safety of the boiler

In addition, due to the low combustion rate of pulverized coal ignited by plasma under cold furnace conditions and the long combustion range of the flame, it is easy to cause permanent damage to the part of the convection heating surface when the evaporation is low.

In addition, existing plasma ignition technology requires that the burner angle cannot be oscillated, thereby limiting the method of adjusting the temperature of the reheat steam

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