SU1545072A1 - Method of automatic protection of steam boiler of drum type - Google Patents

Abstract

The invention makes it possible to increase the reliability of protection of a steam drum boiler with a boiling type economizer, since besides the moisture content of the medium, the economizer measures the level in the drum of the boiler and opens the continuous blowdown valve with steam content and the level equal to the first extremely high values the first extremely high, and the value of the level lower than the second extremely high, reduce the feedwater supply, and with steam content or a level equal to the second extremely high value u, cut off the fuel supply. 1 il.

Description

The invention relates to the automatic protection of low and medium pressure steam drum stationary boilers with boiling economizer.

The purpose of the invention is to increase the reliability of protection of a steam boiler with a boiling type economizer when operating in a variable mode.

The drawing shows a diagram of an automatic protection system for a steam boiler that implements the proposed method.

The system consists of a logic device 1, a power controller 2, a controller 3 for continuous purging of sensors 4 and 5 of steam content, sensors 6 and 7 of level, settings for 8 and 9 of steam content of settings 10 and 11 of level. The sensors 4 and 5 of steam content have different settings. Both contact devices are connected in series according to the scheme I. In this case, the contact device of the sensor 4 is configured to achieve the first extremely high fx0 value by the steam content corresponding to the specified value set using the setting device 8, the contact device of the sensor 5 is adjusted to achieve the second maximum high steam value by ) corresponding to the specified, set using the setting device 9 (ix),

Sensors 6 and 7 also have two settings. Both contact devices are connected in series according to the scheme I. H, - the first extremely high value of the level in the boiler drum; H is the second extremely high level value (emergency).

The limit values of the parameters depend on the design of the boiler, the type of fuel burned, the mode of operation and other features. The settings for these values are selected for each boiler during System Setup.

If the value of the steam content of the working body at the exit from the boiling economizer reaches fxf, .a the sign of the level is less than | na, the logic device 1 is activated, which affects the feed regulator 2, which increases the feed water supply. If by the time the signal | x arrives at the logic device, the level in the drum of the boiler reaches 4H2, logic device 1 stops affecting (the power regulator).

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If the value of the steam content of the working fluid at the outlet of the boiling economizer reaches fx4 and the level in the boiler drum Ht, logic device 1 (circuit I) is activated, which affects the boiler blow-off valve through the blower regulator 3, in order to eliminate reprocessing.

If the value of steam content reaches 1x2, the protection system cuts off the fuel. If the value of the level in the drum

the boiler reaches | H4 (OR scheme), the protection system also cuts off the fuel.

Claims (1)

Invention Formula Method of automatic protection of a steam drum boiler with an econoMise-1 boiling type rum by measuring the moisture content of the working medium behind the economizer and supplying it with a cooling coolant when the signal exceeds the moisture content of a given value | characterized by the fact that, in order to increase reliability, the level of the drum of the boiler is additionally measured and, with moisture content and a level equal to the first extremely high values, a clalan of continuous blowing is opened, increasing the feed water supply at a level below the second extremely high the value and the achievement of moisture content above the first maximum allowable, and at a moisture content or level equal to the second extremely high value, cut off the fuel supply.