SU1765614A1 - Steam boiler baffle cleaners monitoring - Google Patents

Abstract

Usage: in the field of energy, in the operation of steam boilers at power plants. Essence: measure the temperature of the flue gases behind the superheater, calculate the heat balance, determine the temperature of the gases at the outlet of the furnace and calculate the thermal efficiency of the furnace screens based on them, determine the reference value of the efficiency ratio of the screens 1p0 from the gases behind the superheater after blowing. and its current value Vw in operation and at a value VreK / Vo 0.85 include a blower, and the value of the coefficient is determined by the ratio: hex to 0 / at (1-0t / A) 5/3, where VCcp / o FCTT3a; BP - estimated fuel consumption; VCcp is the average heat capacity of the combustion products; a0 4.9 kcal / m2h K; FCT is the surface area of the walls of the furnace; ST - the degree of blackness of the furnace; Ta is the adiabatic burning temperature; T t-the temperature of the gases at the inlet of the furnace; 0T T t / Ta, 96 M

Description

The invention relates to the field of power engineering and can be used to automatically control the process of cleaning the heating surface of the furnace of steam boilers.

There are known methods for controlling cleaning devices that use the temperature of the working fluid at various points of the evaporation circuit as a parameter determining the slag process (US Patent No. 3276437 Cl. 122-392 publ. 04.10.66).

By varying the temperature of the working medium, the level of slagging is judged and the means of cleaning are controlled. These methods are characterized by a number of disadvantages: the methods are not applicable to drum boilers.

type where the water temperature in the furnace screens is a constant value; In direct-flow boilers, the change in temperature of the working fluid in the furnace screens depends not only on the contamination of the heating surface, but also on the load of the boiler and the pressure of the medium and therefore cannot serve as an objective indicator the presence of slag firebox.

The closest analogue of our invention is the device according to a. with. No. 515912 F 22 V 27/56 l for determining the degree of contamination of the heating surface, consisting of several thermocouples located on the latter, characterized in that, in order to improve the measurement accuracy, one of the thermocouples used as the control one is equipped with a tube.

VI ON SL O

J

a supply agent for cleaning a portion of the pipe on which the reference thermocouple is located. The described device has the following disadvantages:

1. The temperature of the heating surface of the direct-flow boiler depends not only on the thickness of the contaminants, but also on a number of other factors:

- of the intensity of the heat flow, depending on the load and the mode of operation of the boiler;

- from internal deposits in pipes of oxides of iron, copper and scum. In view of this, the readings of the reference thermocouples will change over time.

2. To obtain reliable data on the degree of contamination of all the walls of the furnace, it will be necessary to install a large number of thermocouples in the environment of high temperature gases, including control gases with pipes that supply the blowing agent.

This bulky thermocouple system will require for its operation a constant supply of air (steam) from an external source.

3. For boilers with natural circulation of water, the temperature of the walls of the pipes of the screens is almost constant, does not depend much on pollution, because it is determined by the high heat transfer coefficient of boiling water. The difference between the readings of the working and control thermocouples will not be sufficient to make confident decisions about blowing the heating surface.

The aim of the invention is to increase the reliability of diagnosing contamination (slagging) of the furnace.

The goal is achieved by the method of controlling the means of cleaning the screens of steam boilers equipped with a control system with an information and computer complex, which consists in measuring the flow rates of the hot and intermediate steam, the injection flow rate, the flue gas temperature behind the superheaters, calculating the heat balance of the boiler, and determining the temperature gases at the outlet of the furnace, based on their calculation of the coefficient of thermal efficiency of the furnace screens and the periodic inclusion of blasting screens when the furnace is soiled, according to the flow rate pa, its temperature and the temperature of the gases in the superheater sootblowing time after the preceding reference value is determined tyQ screens efficiency coefficient and its current value hex tech operation, obduaku include a value of the ratio of the coefficients

  0.85,

and the value of the coefficient is determined by the ratio:

/ l -VOL-ETLB / Z gek-- Sd)

Where

B p V Ser ° O FCT Ta3

Overhead line

ten

five

0

five

0

five

0

five

0

BP - estimated fuel consumption; VCcp is the average heat capacity of the combustion products; ОЬ 4,9 10 kcal / m-hK; RSt - the surface area of the walls of the furnace; at- the degree of blackness of the furnace; Ta is the adiabatic burning temperature; T t - the gas temperature at the outlet

from the firebox; 0t T t / Ta; , 96 MSCHO / Ta) 12, M (0.59 ... 0.5) x t, x t is the ratio of the installation of the burners from the bottom of the furnace to the height of the entire furnace.

The distinctive features of the inventive method from the prototype make it possible to consider it to meet the novelty criterion, and their absence in the well-known counterparts corresponds to the criterion of significant differences.

The invention is as follows. The information processing complex (CPI) system uses standard thermocouples installed behind the heating surfaces of high and low pressure superheaters. On the basis of their readings and measurements of steam parameters using the devices of the heat shield of the boiler, using the IVC system, calculate the temperature of gases at the outlet of the furnace and on the basis of

Formulas CR - (-D-) are defined

This

the current value of the coefficient of thermal efficiency of the furnace (or pollution) was in operation before the furnace was blown and its reference value was r0 at the moment after the furnace was blown. When the value of the hex / Vo - 0.85 include blowing the furnace.

I. Initial version

Initial data (from the thermal calculation of the plant)

v 865 ° C; VC v 1868 kcal / kg Vm 1123 ° C; VCVm 2495-

VC2 V t VC3 V + -g- (12 - i 1) +

+ (I5T -if} -4.9 Tt4

Be

where, 9;

Vo 0 Ј 0.97 0.45 0.436

VC v m 1868 + 265 ° 1 ° 3 (766.8 - 653.3) +

+ 2186 1CP, 8481 812, g) -4.9 - 108 -0.9 -0.436 106 ° x

481 103481 103

x 13964 1868 + 624.8 + 162.7 - 160.9 2495kkal / kg

1173 +273 1613 +273

 0.77

, / „- ° 5 г1 п -Зй

09 0,296) ° 36

 1 0.45 ° 8

According to I - v table vm 1123 ° С

VCaV8 Qm QРн 0-q3-q "-qe 374OkCal / kg

1UU - Q4

Va 1613 ° C

ir - VCa Va VC2 V-m - 374 ° 2495 -

VL / Cp 1C-II 1111t,

Va -Vm

1613-1123

B0

 Bp VCcp 481 103 2.54

Ob FCT T i 4.9 10 8-7434 18863

 0.5

  1123 + 273 Q74 Um Ta 1613 + 273 Ul / 4

1L (l am v A

, 416

A 0.96M (HZO) 12 0.96 0.416 (lg§) 12 0.296

, „-0.5И - 0.74.5 / 3 n, s -09 0.296 ° 45

Option II

It gives Vm 1173 ° С35

By calculation in the rotating chamber, v will increase by 50 ° C versus variant I

v 865 +50 915 ° C; VCv 2014kkal / kg.

VC2v 2014 +2650 10. (766.8-653.4) + 481 103

+ 2186-CSG (848.1-812.3) -4.9 0.9 481 103

x 0.414-1060, 14464 2014 + 481 103

+ 624.8 + 162.7 - 175.9 2625kkal / kg - 1173 ° C

„G Sama va - US2 v m 3740 - 2625 9, with CP va-v m -1613-1176-2 55

R- 48M03-2.55 p

D о оТ - U, О

4.9-108-743418863

five

0

five

0

five

five

0

five

0

The temperature behind the furnace v m serves as an impulse for switching on the blow when the -f drops to 0.36.

The advantages of the inventive method compared with the prototype are as follows.

1. The calculated current value of the flow is an integral value characterizing the level of contamination of all surfaces of the firebox screens.

2. Measurement of gas temperatures behind superheaters is carried out using standard thermocouples installed in the zone of moderate gas temperatures (600 ° C), while a large number of thermocouples exposed to high gas temperatures are installed in the prototype method and therefore having a short service life, a part of these thermocouples requires a constant supply of a cooling agent (air or steam).

3. The independence of the readings of the efficiency factors of the screens from the fluctuations of the load and the boiler mode, while in the prototype method, the readings of thermocouples on the surface of the screens depend on the load and the mode of operation of the boiler.

The advantages listed above generally increase the reliability of diagnostics of the pollution of the furnace and are aimed at improving the reliability of the boiler and the efficiency of the number of inclusions in the IVR system.

Claims (1)

Claims The method of controlling the means of cleaning the screens of the furnace of steam boilers equipped with a control system with a computer complex consists of measuring the flow rates of the hot and intermediate steam, the injection flow rate, the flue gas temperature behind the superheaters, calculating the heat balance of the boiler, determining the gas temperature at the outlet of fireboxes, based on their calculation of the current coefficient of thermal efficiency of the firebox screens and the periodic activation of the screen blasting when the fire chamber is contaminated, In order to increase reliability of diagnostics zgne-BP - the estimated fuel consumption; neither (slagging) of the furnace, additionally in VCcp- the average heat capacity of the products is the moment after the previous blasting of the op-combustion; determine the reference value of the coefficient 4.9 kcal / m2 h -K; the effectiveness of 1p0 screens, compare it with 5 FCT - the surface area of the walls of the furnace; with the current value of the flow in operation, the degree of blackness of the furnace; and the blowing includes the ratio of the Tadiabatic temperature of burning factors; # heck / # - 085, T t is the gas temperature at the outlet of the furnace 1 ° 0 t t / Ta, - and the coefficient value is determined by the ratio, 96 M (1470 / Ta) 12, M (0.59 ... 0.5) xm; . В о Л - 0т 5 / Зхт - the ratio of the mounting height of the mount hex at A. Lock from the bottom of the furnace to the height of the entire furnace. 1b  BP VCcp where B 0 p% About FCT T i