A Correction Method for Fuel Quantity of Supercritical Once-through Boiler by Feedwater Temperature Change

Abstract

The invention discloses a correction method for the fuel quantity of a supercritical once-through boiler during the change of feed water temperature. The correction method has the characteristics by comprising the links of inputting of basic parameters and operation and structure parameters, calculation of hot air temperature at an air preheater outlet after the change of the feed water temperature, and calculation of water temperature at an economizer outlet and heat balance of a hearth after the change of the feed water temperature. The basic parameters and the operation and structure parameters of the boiler are input, the deviation of feed water temperature of the supercritical once-through boiler is given, and the hot air temperature at the air preheater outlet after the change of thefeed water temperature is determined according to a differential deviation method. The water temperature of the economizer outlet after the change of the feed water temperature is determined. The fuel quantity after the change of the feed water temperature is determined through heat balance of the hearth, and the whole calculation process is conducted through an iterative calculation method. Quantitative precise instructions can be achieved for the fuel quantity after the change of the feed water temperature of the supercritical once-through boiler, and the effect of precise adjustment of thefuel quantity according to the coal-water ratio after the change of the feed water temperature of the supercritical once-through boiler is achieved.

Description

technical field [0001] The invention relates to the field of thermal equipment performance state monitoring and diagnosis, in particular to a method for correcting the fuel quantity of a supercritical once-through boiler due to feedwater temperature changes. Background technique [0002] Power plant boiler feed water temperature is an important technical index reflecting the economics of power plant operation, and also an important technical parameter for boiler economic diagnosis and boiler operation optimization. When the supercritical boiler operates in the supercritical pressure range, the water wall is actually equivalent to the superheater. When the feed water temperature changes, the supercritical once-through boiler mainly controls the middle point temperature by adjusting the coal-water ratio, and then controls the main steam temperature. . Therefore, in a sense, the coal-water ratio has the greatest influence on the temperature change characteristics of superheate...

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Problems solved by technology

[0006] In view of the current problems and defects that cannot accurately reflect the quantitative influence of once-through boiler feed water temperature changes on fuel quantity, in order to effectively guide boiler operators to operate after feed water temperature changes, especially after removing the high-pressure heater and putting into operation No. 0 high-pressure heater The action of the coal-water ratio, on the basis of defining the flue gas side heat exchange efficiency from the furnace outlet to the economizer inlet, the present invention starts from the furnace heat balance, and combines the differential deviation theory to propose a kind of feedwater temperature change on the supercritical once-through boiler fuel Quantitative correction calculation method of quantity influence, so as to avoid the problem of having to solve boiler efficiency and boiler fuel quantity at the same time, and realize accurate quantitative indication of fuel quantity adjustment of supercritical once-through boiler after feedwater temperature changes

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