Device and method utilizing start-up system drained water as heating source of air heater

Abstract

The invention provides a device and method utilizing start-up system drained water as a heating source of an air heater. The device comprises two connecting paths connected between a start-up system water storage tank and a flash vessel; according to one connecting path, the start-up system water storage tank is connected with the flash vessel through a water storage tank body and an air heater by-pass valve; according to the other connecting path, the start-up system water storage tank is connected with water inlets of both a primary-air air heater and a secondary-air air heater through the water storage tank body and an air heater valve correspondingly, and water outlets of both the primary-air air heater and the secondary-air air heater are connected with the flash vessel through an airheater back-water valve; a primary fan is connected with an air inlet of the primary-air air heater, a secondary fan is connected with an air inlet of the secondary-air air heater; and air outlets ofboth the primary-air air heater and the secondary-air air heater are connected with an air preheater. According to the device and method utilizing start-up system drained water as the heating sourceof the air heater, heat discharged by a start-up system can be effectively utilized, the heat loss is reduced, and the primary air temperature and the secondary air temperature are increased; and combustion of a boiler can be enhanced, and secondary burning and low-temperature corrosion of a train flue of a unit and the air preheater can also be weakened and avoided.

Description

technical field [0001] The invention belongs to the technical field of once-through boilers for thermal power units, and relates to a device and method for using drainage from a start-up system as a heating source for a heater. Background technique [0002] When the once-through boiler is started, due to the limitation of the start-up flow, the unit is in a wet state at the beginning of the start-up, so that the unit has a large amount of hot water heated by fuel. There are two main ways to discharge hot water: one is to discharge to the unit drainage tank or industrial wastewater system, causing waste of heat; the other is to discharge to the condenser, which wastes heat, and because the vacuum of the condenser is reduced, increasing The power consumption rate of the factory is reduced, and more energy is consumed. Both of these arrangements fail to make full use of the heat emitted by the starting system, resulting in waste of heat. [0003] Secondly, during the start-up...

AI Technical Summary

Problems solved by technology

This results in a huge waste of heat and water resources. Long-term low-load stable combustion results in low exhaust gas temperature, which can easily cause low-temperature corrosion and blockage of the air preheater, resulting in reduced reliability of equipment and even shutdown of the unit.

The combustion efficiency of the boiler is low, which easily leads to the secondary combustion of the tail flue and the air preheater

Images