A kind of operation method adopting heating surface section return water boiler

Abstract

The invention provides a boiler with segmented water returning of the heating surface adopted and an operation method of the boiler. The boiler comprises a hearth, a dust remover, an air preheater, multiple stages of convection pipes and multiple stages of water return collection tanks. The operation method comprises the steps that the three stages of convection pipes are connected in parallel for boiler water returning. According to the boiler with segmented water returning of the heating surface adopted and the operation method of the boiler, the water returning distribution amount of each convection pipe can be adjusted according to changes of loads of the boiler, the eject smoke temperature of the boiler is controlled well, low-temperature corrosion of the tail heating surface is avoided, safety of materials is ensured, the overall thermal efficiency of the boiler is improved, the purposes of energy conservation and emission reduction are achieved, and at the same time, the denitration technological requirements can be met.

Description

technical field [0001] The invention belongs to the field of boilers, and relates to a boiler adopting segmented return water on a heating surface and an operation method thereof. Background technique [0002] At present, the boiler products on the market adopt the single-stage return water method. Under the rated working condition, the exhaust gas temperature is about 150 ℃, and the boiler thermal efficiency is about 83%. However, when the load of the boiler changes, the exhaust gas temperature at the tail cannot be well controlled. Especially during low-load operation, the tail exhaust gas temperature is too low, which can cause low-temperature corrosion of the heating surface, and the safety of materials cannot be guaranteed, and it also leads to an increase in the initial NOx emission concentration and fly ash combustible content in the flue gas at the boiler outlet. High, NOx concentration is 400-500mg / Nm 3 Even higher, it cannot meet the requirements of the denitrifi...

AI Technical Summary

Problems solved by technology

[0016] However, in the prior art, the single-stage return water method is usually adopted, which does not take into account the change of the boiler load. When the load of the boiler changes, the exhaust gas temperature at the tail cannot be well controlled by the return water, resulting in Low thermal efficiency, high initial emission concentration of sulfur compounds and NOx

Especially during low-load operation, the exhaust gas temperature at the tail is too low, which can also cause low-temperature corrosion of the heating surface, and the safety of materials cannot be guaranteed.

In addition, the design of the key parts of the boiler in this field is also lack of pertinence, resulting in high maintenance costs of the boiler

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