Secondary reheat boiler and steam temperature regulating method

Abstract

The invention discloses a secondary reheat boiler and a steam temperature regulating method. Through the method that high-temperature flue gas of an outlet of a furnace is directly introduced into a flue of the tail part of the boiler and then low-temperature reheat steam is heated, the temperature control accuracy and temperature regulating sensitivity of the reheat steam can be effectively improved, and that is, the secondary reheat steam temperature is regulated by regulating the flow rate of the flue gas entering the tail flue. Due to great thermal inertia of the secondary reheat boiler, in order to satisfy temperature stability control of the reheat steam in the fast variable load transient process, the flue gas at the high temperature can be directly introduced into the flue of the tail part of boiler, and then fast regulating of the reheat steam temperature is realized. According to the steam temperature regulating method, the quality of reheat steam parameters is effectively improved, the control precision of the reheat steam parameters can be improved, and the current situation of long control cycle and frequent fluctuation of the secondary reheat steam is improved; and frequent swing of the swinging angle of a burner (or frequent swing of a baffle of the tail part of the boiler) can be reduced by changing the flow rate of the flue gas entering the tail part, and thengreat significance is achieved for stable combustion in the boiler.

Description

technical field [0001] The invention belongs to the technical field of thermal control in thermal power plants, and in particular relates to a secondary reheating boiler and a steam temperature regulating method. Background technique [0002] The double reheat unit has the characteristics of high efficiency and environmental protection, and its installed capacity is growing in my country's thermal power industry. However, due to the more obvious thermal inertia of the double reheat unit, it is difficult to accurately control the temperature of the reheat steam. Especially at low load, the temperature of the secondary reheat steam is difficult to reach the design value level; when the unit is transiently sheared, the temperature control of the reheat steam is directly related to the safety of the unit. For this reason, it is particularly important to study the research strategy of the secondary reheating steam temperature. [0003] The traditional reheat steam temperature a...

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Problems solved by technology

[0004] The present invention just solves the problem that the reheat steam temperature of the secondary reheat unit is difficult to control, considers the main factors that cause the reheat steam temperature control to reach the set value, and finds out a boiler and control that can quickly and effectively improve the parameter quality of the boiler outlet steam method, the object of the present invention is to provide a double reheating boiler and a steam temperature adjustment method, which can fully ensure that the actual output steam quality control of the boiler during the load change process is up to standard, and ensure that the temperature of the reheat steam is between the set value during the load change process. The deviation is as small as possible, that is, the boiler parameter control is more precise

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