SU1288438A1 - Method of controlling temperature of superheated steam in steam generator - Google Patents

Abstract

The invention relates to a power system and can be used in steam generators having multi-stage steam superheaters with a series-connected surface and injection, or two injection steam-coolers and working on several types of fuel. The purpose of the invention is to increase accuracy. The surface steam superheater temperature regulators are controlled by regulator 1, which receives signals from the cooling water flow sensor 5 and the separator device 6. The last signal is the ratio of the amount of heat given off by the flue gases to the superheater to the steam flow. The set value of the superheated steam t-outlet at the outlet of the superheater is maintained by the regulator 12, which acts on the condensate injection valve 14 into the injection desuperheater 13. At the regulator 12, signals are given on the steam-re at the outlet of the steam generator, according to the rate of change - steam vapors for injection steam simulator, as well as the rate of change in the ratio of the amount of heat given off by the flue gases to the superheater, to the steam consumption. 1 il. % (L 00 Pit.vavo Od 00

Description

The invention relates to a power system, and can be used to regulate the temperature of superheated steam in a steam generator having a multi-stage superheater with a series-connected surface and injection or two injecting superheaters.

The aim of the invention is to improve the accuracy of regulation.

The drawing shows the scheme of the automatic control system that implements the proposed method;

The system contains the regulator 1 of the surface desuperheater 2, which controls the retaining valve 3 and the valve 4 of the surface desuperheater, receives a signal from the cooling water flow sensor 5, a separating device 6 is also connected to the controller 1, receiving a signal from the steam flow sensor 7 and a signal from multiplying device 8, the inputs of which are connected to the sensor 9 of the temperature difference between the flue gases at the inlet and outlet of the superheater 10 and to the sensor 11 of the flue gas flow.

A regulator 12 injecting a desuperheater 13 controlling the condensate injection valve 14 is connected to a steam temperature sensor 15 at the outlet of the superheater 5 via a differentiator 16 with a steam temperature sensor 17 behind the injecting steam cooler, and also through a differentiator 18 with a divider device 19, whose inputs connected to the sensor 7 steam flow and multiplying device 20, which is connected to the sensor 21 of the temperature difference between the flue gases at the inlet and outlet of the superheater 10 and the sensor 22 of the flue gas flow.

The method is carried out as follows.

The controller 1 receives a signal from the cooling water flow sensor 5 and a signal from the separator device 6, which is the ratio of the amount of heat given off by the flue gases to the steam superheater (the product of the flue gas consumption and the temperature difference between the flue gases at the inlet and outlet of the steam superheater) and, by acting on valves 3 and 4, it regulates the temperature of the steam downstream of the surface desuperheater.

The controller 12 receives a signal on

the steam temperature at the outlet of the steam generator from sensor 15, according to the rate of change in steam temperature downstream of the injection cooler from sensor 17 through differentiator 16,

and through the differentiator 18, the signal from the separator device 19, which represents the rate of change in the ratio of the amount of heat given off by the flue gases to the superheater - (product of the flue gas flow and the temperature difference between the flue gases at the inlet and outlet of the superheater) 5 to the steam flow. The regulator 12 acts on the valve

14 injecting condensate into the injection desuperheater 13, maintaining the set temperature of the superheated steam at the outlet of the steam vapor 25

warmer

Claims (1)

Invention Formula The method of controlling the temperature of superheated steam in a steam generator, operating simultaneously on several types of fuel and having a multi-stage steam superheater and steam coolers installed between its stages by varying the cooling water flow rates by changing the steam temperature at the steam superheater outlet, the rate of change of the steam temperature at the inlet to the last superheater stage and speed changes in the correction parameter — the product of flue gas consumption by the difference in flue gas temperature at the inlet and outlet of the superheater for the last supercooler; superheater, characterized in that, in order to increase the control accuracy, the steam consumption is additionally measured, determine the ratio of the product of the flue gas flow to the difference in temperature of the flue gases at the entrance. and the output of the superheater to the steam consumption, the rate of change after him and with an increase in the ratio and ratio of cooling water increase the cooling flow rate on the last steam, cooler, and at the water on the penultimate desalination reduce accordingly The driver, at the same time increasing the cooling water flow rate by vapor-proportional to the rate of increase of the ladder.