JPH09210340A - Flue drift preventing apparatus for coal-fired boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the erosion of a heat transfer tube wall by providing a drift preventive plate covering the tube front surface at the flue wall side of' the tube front surface of the foremost row to the gas flow of the tube bent of the end of a panel-like heat transfer tube group. SOLUTION: A plurality of drift preventive plates 4 of horizontal section state are installed in a gap between the flue wall 1 and a panel-like heat transfer tube group 2 disposed to cross a gas flow substantially perpendicularly to the gas flow. The plates 4 are disposed at the wall 1 side at the front surface side of the tube of foremost row to the gas flow of the tube bent at the end of the group 2, and covers the front surface side of the tube end to the gas flow. Accordingly, the gas flowing resistance between the tube bent of the group 2 and the wall 1 is increased, the erosion of the wall of the group 2 is reduced without increasing the flow rate of the gas containing combustion ash to the gap, thereby making it possible to increase the life of a boiler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is installed in a flue part of a coal-fired boiler used for business or private power generation,
TECHNICAL FIELD The present invention relates to a coal-fired boiler flue portion drift prevention device that prevents drift and erosion of a gas flow.

[0002]

2. Description of the Related Art FIG. 6 is a vertical sectional view of a flue portion of a conventional coal-fired boiler. A flat plate-shaped non-uniform flow prevention plate 3 that extends from the flue wall 1 above and below the panel-shaped heat transfer tube group 2, respectively.
Are installed horizontally.

[0003]

In the prior art coal-fired boiler flue portion shown in FIG. 6, in the vicinity of the upper deviation prevention plate, as shown by the gas flow streamline 5 in FIG. , The gas flow exists apart from the flue wall, but on the downstream side of the upper drift prevention plate, it is biased in the gap between the flue wall with a small flow resistance and the end of the panel-shaped heat transfer tube group, The gas flow rate in this gap increases.

Due to the increased gas flow velocity and the amount of combustion ash, the erosion of the wall of the heat transfer tube is promoted, a hole is eventually formed, and the steam inside is ejected.

The present invention is intended to provide a coal fired boiler flue portion drift prevention device which can solve the above problems.

[0006]

SUMMARY OF THE INVENTION A coal-fired boiler flue part drift prevention device of the present invention is a flue gas duct on the front side of a front row of pipes against a gas flow at a bent portion of an end of a panel-shaped heat transfer tube group. It is characterized in that it is provided with a drift prevention plate which is arranged at a site on the wall side and covers the front side of the pipe against the gas flow.

According to the present invention, the panel-shaped heat transfer tube group is arranged at the flue wall side of the front side of the tubes in the front row with respect to the gas flow in the bent portion of the tube, and the front side of the tubes with respect to the gas flow. A drift prevention plate that covers the side is provided, and the drift prevention plate fills the space between the end of the panel-shaped heat transfer tube group and the flue wall. As a result, the flow resistance to the gas flow containing the combustion ash increases, and the flow rate of the gas flow containing the combustion ash that flows unevenly in this space can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. As shown by the arrow 5 from the upper side to the lower side, in the clearance between the flue wall 1 through which the gas flows and the panel-shaped heat transfer tube group 2 arranged so as to cross the gas flow, the gas flow is substantially vertical to the horizontal direction. A plurality of drift prevention plates 4 each having a cross section having a helix shape are installed. As shown in FIG. 2, one end of each of the plurality of drift prevention plates 4 is supported by the flue wall 1. Each non-uniform flow prevention plate 4 is arranged at a site on the side of the flue wall 1 on the front side of the tubes in the front row with respect to the gas flow of the tube bends of the end tubes of the panel-shaped heat transfer tube group 2, and It covers the front side of the tube end to the flow. As in the conventional device shown in FIG. 6, 3 is a flat plate-shaped upper and lower drift prevention plates horizontally arranged above and below the panel-shaped heat transfer tube group 2 so as to project from the flue wall. ..

In this embodiment, since the non-uniform flow prevention plate 4 having the above-described structure is provided, the gas flow resistance between the bent portion of the end of the panel-shaped heat transfer tube group 2 and the flue wall 1 is increased. , The gas flow 5 does not enter between the panel-shaped heat transfer tube group 2 and the flue wall 1, and as shown in FIG.
It becomes a parallel flow.

Therefore, since the flow rate of the gas containing the combustion ash to the gap between the end of the panel-shaped heat transfer tube group 2 and the flue wall 1 is not increased, the wall of the heat transfer tube group 2 is prevented. Erosion can be reduced and boiler life can be increased.

The second and third embodiments of the present invention will be described with reference to FIGS. 4 and 5. In the second embodiment of the present invention shown in FIG. 4, a drift prevention plate 4 having an arc-shaped cross section is used in place of the drift prevention plate of the first embodiment of the present invention, and shown in FIG. In the third embodiment of the present invention, a perforated flat plate-shaped drift prevention plate having a large number of holes 4a is used in place of the drift prevention plate of the first embodiment of the present invention. The same action and effect as those of the first embodiment can be obtained.

[0012]

Since the present invention has the constitutions described in the claims, the gas flow resistance in the gap between the end of the bent portion of the panel-shaped heat transfer tube group and the flue wall is increased. Can be made. As a result, the gas flow containing combustion ash does not flow into the gap between the end of the panel-shaped heat transfer tube group and the flue wall. Therefore, since the flow rate of the gas containing the combustion ash into the gap between the end of the panel-shaped heat transfer tube group and the flue wall is not increased, the erosion of the wall of the heat transfer tube group is reduced and the life of the boiler is reduced. Can be increased.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a first embodiment of the present invention.

FIG. 2 is a partially enlarged vertical sectional view of the same embodiment.

FIG. 3 (a) and FIG. 3 (b) are a partially enlarged vertical sectional view and a partially enlarged plan view, respectively, of the same embodiment.

FIG. 4 (a) and FIG. 4 (b) are a partial plan view and a partial vertical sectional view, respectively, of a second embodiment of the present invention.

FIG. 5 (a) and FIG. 5 (b) are a partial plan view and a partial vertical sectional view, respectively, of a third embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view of a conventional drift prevention device for a coal-fired boiler flue portion.

[Explanation of symbols]

 1 Flue wall 2 Panel-shaped heat transfer tube 4 Anti-uniformity plate 5 Gas flow

Claims (1)

[Claims] 1. A panel-shaped heat transfer tube group is arranged at a flue wall side portion on the front side of the tubes in the front row with respect to the gas flow at the bent portion of the tube, and the front side of the tubes with respect to the gas flow is A coal-fired boiler flue portion drift prevention device, which is provided with a drift prevention plate for covering.