SU1564469A1 - Furnace device - Google Patents

Abstract

The invention relates to power engineering and can be used in boilers for generating steam when burning municipal solid waste. The purpose of the invention is to increase reliability by intensifying the combustion process. The combustion device for incineration of solid waste contains a combustion chamber 1, a mechanical grill 2, a cooling chamber for combustion products 3, a loading window 4, a slag removal window 5, evaporation heating surfaces with collectors and front and rear walls 6, gas-oil burners 7. Secondary air blowing nozzles 8 are installed on the front wall in two rows at an angle of 10-30 ° to the vertical and on the rear wall in one row at an angle of 40-60 ° to the vertical. The ratio of the nozzle pitch to the equivalent nozzle diameter is 6-8, and the ratio of the cross-sectional area of the nozzles to the cross-sectional area of the cooling chamber is 0.012-0.015. 1 tab., 2 Il.

Description

The invention relates to energy and can be used in boilers for steam generation when burning municipal solid waste (MSW).

The purpose of the invention is to increase reliability by intensifying the combustion process.

AIG.1 shows a schematic of a furnace; 2, 3 and 4 - dependence of the coefficient of uneven temperature field on the installation of secondary blow nozzles.

The combustion device for MSW combustion contains a combustion chamber 1, a mechanical grill 2, a combustion products cooling chamber 3, a TVD loading window 4, a slag removal window 5, evaporation heating surfaces with collectors and inclined parts on the front and rear walls 6, gas oil burners 7, secondary air blow nozzles 8 are installed on the inclined part of the front wall in "

two rows at an angle of 10-30 ° to the vertical and on the rear wall in one row at an angle of 40-60 ° to the vertical, the ratio of the pitch of the nozzles to the equivalent diameter of the nozzle being 6-8, and the ratio of the area of the nozzles to the area cooling chamber cross sections

about

4

ABOUT

with

Let 0,012-0,015, the supply of primary air 9.

The combustion device operates as follows.

MSW is loaded through the window 4 into the combustion chamber 1, where combustion takes place on the mechanical grill 2 using the primary air supply 9. Slag is removed through the window 5. Primary air 9 is supplied to the lower part of the rolls, secondary air is fed through the nozzle 8 for mixing and afterburning the gaseous products of combustion of MSW, which ensures a uniform floor temperature of the products of combustion at the entrance to the cooling chamber 3 and reduces the amount of harmful emissions due to their afterburning during mixing. The burners 7 operate on natural gas or fuel oil during the boiler firing, as well as when burning MSW with high humidity. When incinerating MSW, the water is heated in the evaporative heating surface 6 and turns into steam.

At the aerodynamic stand, an experimental study was conducted of the dependence of the intensity of mixing of secondary air with its products on the installation site of the secondary air blow nozzles, the geometric characteristics of the nozzles and their location in the combustion device.

The bulk of the experiments to work out the optimal location of the secondary air intake of air was carried out on an isothermal air model of a combustion device for incineration of SOLID WASTE WASTE. IS-

The following model is made in the scale of 1: 10 - with respect to the full dimensions of the combustion device, which are 4000 mm in depth and 4080 mm in width.

The experiments were carried out according to the generally accepted method of reverse thermal modeling.

The simulation was carried out in compliance with the similarity criteria in the model and on the tour:

V-d

.-.

and q

fiL-JJ HerJL, PCH-WCH

d is the depth of the cooling chamber; 55 q is the ratio of the dynamic pressure of the secondary air to the demolition of the flue gas flow;

5 0 5

0

d

five

Pt Psn of secondary air density and drift flow, respectively; Secondary air velocity

and demolition flow. In the case of isothermal mixing modeling with observance of a geometric similarity, the problem was reduced to finding options for supplying secondary air with more complete mixing of jets of secondary air with a drift flow. Secondary air for the purpose of tint Heated to 80 ° C.

The experiment was conducted by changing the number of secondary air blow nozzles on the model from 6 to 10 pcs. The nozzles were sized from mm to mm, the ratio of the nozzle pitch F to the equivalent diameter of the nozzle d eq changed from 3.9 to 8.3, while the ratio of the total cross section of the nozzles fgT 6 to the total cross-sectional area of the cooling chamber F0 varied in the range of 0.0098-0.025; the coals and the inclination of the nozzles on the inclined part of the front wall varied in the range of 7-35 °, and the angle of inclination of the nozzles on the rear wall varied in the range of 37-65 ° to the vertical.

The effectiveness of the model was evaluated using the coefficient of non-uniformity of the temperature field in the control

cross section at the entrance to the cooling chamber

Ј (t, - - t)

$

n teT-tCH)

- 100%,

where is the number of measurement points in the section;

t. - average temperature at x const (where x is the distance from the front wall over the depth of the cooling chamber); t is the average temperature in the section; t "t is the secondary temperature

air;

tCH is the temperature of the drift flow (primary air supplied under the grate). The table shows the installation options for nozzles on the model under study.

The test results for options for installing nozzles in accordance with the table presented in figure 2, 3 and 4.

As can be seen from the graphs of FIG. 2 dependence of magnitude M01KS on angles “x ,,

Sig and O (e is fairly conservative. Special are the ranges of angles from and Ng less than 10 ° and more than 30 °, and the angle about (e less than 40 ° and greater than 60 °. In the first case, the jets are directed to the walls of the hearth and the front and, spreading through them, not mixing with the drift, flow into the cooling chamber. In the second case, with increasing angles

 and d g over 30

More than 60 ° jets are directed directly to the inlet portion of the cooling chamber, which drastically reduces the residence time of the secondary air jets in the furnace and therefore degrades the quality of mixing.

FIG. 3 shows graphs of the change in magnitude, kc from the magnitude of S / d, s

max apt v - a distinct minimum

Max values in the range of steps 5.5–7. The mechanism of the dependence of the mixing quality on the installation pitch of the nozzles is associated with the optimization of such Lactors, such as the ejection of the diverging flow by the jet, the surface of the jet, the range of the jet, and the geometry of the mixing chamber. The range of the jet depends on the parameter FeT in / F0, the graph of the effect of which on the value of cP is presented in Figure 4. How vidYALS {S

but from the graph, the best mixing quality was achieved in the range of variation of the F8r value. 8 / F0 0.012-0, OJ5, when the MILS does not exceed 7.5%, which corresponds to the non-uniformity of the temperature field in the control section of 33 G, and is an indicator

almost complete mixing of the streams.

As a result of the analysis of experimental data, it was established that an intensive mixing of jets of secondary air with a stream of combustion products (demolition stream) occurs with sufficiently long-range jets arranged in several rows and mixed relative to each other across the width of the furnace and overlapping the cross section in depth .

Claims (1)

Invention Formula A combustion device for incineration of solid household waste containing a combustion chamber, a mechanical grill, a cooling chamber, a municipal solid waste loading window, a slag removal window, evaporative heating surfaces with collectors, gas-oil burners, secondary air blast nozzles and primary air supply, 5 characterized in that, in order to intensify the combustion process by increasing the completeness of mixing the combustion products with secondary air, the blow nozzles of the latter 0 are installed on the front wall in two rows at an angle of J0-30 ° to the vertical and on the rear wall in one row at an angle of 40-60 to the vertical, while the ratio of the nozzle tag to the equivalent diameter of the 5 RU nozzle is 6-8, and the ratio of the nozzle cross-sectional area to the cross-sectional area of the cooling chamber is 0,012-0,015. five 0 / 1 Fig.Z 0.012 9.016 0.020 ZFffg ft fig l