1. A method for detecting leakage and stopping leakage without disturbance in a furnace under the running state of a boiler economizer is characterized by comprising the following steps:

(1) online leakage detection for realizing non-shutdown of leakage in economizer furnace in running state of circulating fluidized bed boiler

Acquiring the temperature of the economizer in real time through an acquisition unit, transmitting acquired information to a data processing unit, judging whether the acquired information is different from an initially set temperature or not through the data processing unit, and if the acquired information is different from the initially set temperature, preliminarily determining that the area leaks;

dismantling the economizer header protection plate at the leakage area in the economizer furnace determined in the step I, and numbering the pipes on the upper part of the economizer header pipe seats in the area;

marking a plurality of contour lines on each pipe, wherein the distance between every two contour lines is 2-3mm, and measuring and recording the outer surface temperature of the pipe at the position of each contour line one by one;

fourthly, in the numerical value recording process, if the temperature of the outer surface of a certain pipe is higher than the temperature of other pipes, the pipe of the economizer tube panel can be accurately judged to be leaked;

(2) leakage stoppage of leakage pipe panel in coal economizer of circulating fluidized bed boiler in running state

Firstly, leaking stoppage is carried out on a leaking tube panel tube under pressure, and the inlet end and the outlet end of the leaking tube panel tube of the coal economizer in the furnace are blocked under pressure;

secondly, a hole is formed in the upper part of the inlet of the plugging tube panel, and if no overflow water exists in the hole, successful plugging is confirmed.

2. The method for detecting the leakage and stopping the leakage of the boiler in the running state of the boiler economizer as claimed in claim 1, wherein in the step (1), the step (i) further comprises the step of collecting the humidity.

3. The method for detecting leakage and stopping leakage without disturbance in the furnace under the operating state of the boiler economizer as recited in claim 1, wherein the collecting unit is a thermometer.

4. The method for detecting leakage and stopping leakage without disturbance in a furnace under the running state of a boiler economizer as claimed in claim 1, wherein the data processing unit is a microprocessor.

5. The method of claim 4, wherein the microprocessor is a DCS.

6. The method of claim 1, wherein the number of contour lines per tube is 10.

Background

The economizer and the superheater of the circulating fluidized bed boiler are important four-tube parts of the boiler, the single-stage economizer is formed by more than 100 tube panel pairs, the pitch of the tube panels is generally designed to be 30-40 mm, the height of the tube panels is generally designed to be more than 1200mm, the operating temperature of the economizer is about 400 ℃, once the tube panels of the economizer leak during the operation of the boiler, the boiler must be shut down for maintenance, the shortest time required for only maintaining leak points is 96 hours, and the economic loss directly caused by one boiler shutdown is more than 100 ten thousand yuan.

The blowing-out maintenance procedure comprises the following steps:

1. and (3) stopping the boiler for 48 hours, reducing the temperature at the tail part of the boiler, namely the economizer part, from 400 ℃ to below 50 ℃, allowing a maintainer to enter a leak point part to perform a hydraulic pressure test, and plugging the leak tube panel at the straight tube of the header pipe seat after accurately determining the leak point (namely finding a single-panel leak point in more than 100 groups of tube panels).

2. And (4) performing a hydraulic test again after the leakage tube panel is blocked, and operating by igniting the boiler again after the hydraulic test is qualified.

In view of this, designing and manufacturing a method for detecting leakage in a furnace and stopping leakage without disturbance under the operating state of a boiler economizer (namely, directly detecting leakage and stopping leakage without stopping the furnace) is very important in actual production and operation.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a method for detecting leakage in a furnace and stopping leakage without disturbance in the running state of a boiler economizer.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a method for detecting leakage and stopping leakage without disturbance in a boiler under the running state of a boiler economizer comprises the following steps:

(1) leakage detection of in-furnace coal economizer in running state of circulating fluidized bed boiler

Acquiring the temperature of the economizer in real time through an acquisition unit, transmitting acquired information to a data processing unit, judging whether the acquired information is different from an initially set temperature or not through the data processing unit, and if the acquired information is different from the initially set temperature, preliminarily determining that the area leaks;

dismantling the tube panel header protection plate at the leakage area determined in the step I, and numbering the tubes on the upper part of the tube seats of the economizer header in the area, such as the No. 1 and No. 2 in the north;

marking a plurality of contour lines on each pipe, wherein the distance between every two contour lines is 2-3mm, and measuring and recording the outer surface temperature of the pipe at the position of each contour line one by one;

fourthly, in the recorded numerical values (the recorded data are 10 groups), if the temperature of the outer surfaces of the ten groups of certain pipes is higher than that of other pipes (the specific temperature difference is more than 30 ℃), the leakage of the pipes of the pipe panel of the economizer can be accurately judged;

(2) leakage stoppage of economizer tube panel under circulating fluidized bed boiler operation state

Firstly, leaking stoppage is carried out on a leakage pipe panel under pressure;

secondly, operating equipment, forming a hole (the aperture is preferably phi 6) at the upper part of the inlet of the plugging pipe, and if no overflow water exists in the hole, confirming that plugging is successful.

Preferably, in the process of detecting the leakage of the coal economizer in the furnace in the running state of the circulating fluidized bed boiler, the step (i) further comprises acquiring humidity. The temperature and humidity information is collected through the thermometer and the hygrometer, the collected information is transmitted to the data processing unit, the data processing unit judges whether the collected information is different from the initially set temperature and humidity, and if the collected information is different from the initially set temperature and humidity, the leakage of the area is preliminarily determined.

Preferably, the collection unit is a thermometer.

Preferably, the data processing unit is a microprocessor.

Further preferably, the microprocessor is a DCS.

Preferably, the number of contours on each tube is 10.

Compared with the prior art, the invention has the beneficial effects that:

1. the method can accurately detect the unique leakage position (such as the 1 st group or the 2 nd group) of the tube panel of the economizer in the boiler and implement the leakage stoppage without stopping the boiler under the normal running state of the boiler, thereby avoiding the unplanned stopping of the boiler and greatly reducing the loss;

2. the method disclosed by the invention is simple to operate, accurate in judgment method and high in accuracy.

Detailed Description

The invention is further illustrated, but is not intended to be limited, by the following examples.

Example 1

The method for detecting and stopping leakage of the economizer tube panel on line is completed through the following processes when the economizer tube panel leaks in the operating state of the circulating fluidized bed boiler, and specifically comprises the following steps:

(1) leakage detection of economizer in running state of circulating fluidized bed boiler

Firstly, acquiring the temperature of an economizer in real time through a thermometer, transmitting the acquired information to a DCS (distributed control system) processor, judging that the temperature of an area A is different by the DCS processor, primarily determining that the area A leaks, and transmitting the leaked area to a display unit (specifically a display);

secondly, poking wet ash in the area A by tamping, determining the leakage position again, removing the tube panel header protection plate at the area A determined in the step I, and numbering the tubes at the upper part of tube seats of the economizer header in the area, wherein the area A is provided with 116 pipelines which are numbered from 1 to 116 in sequence;

measuring and recording outlet temperatures (shown in table 1) of the header of pipelines No. 1-116 one by one, marking 10 contour lines on each pipe by stone strokes, and enabling the interval between every two contour lines to be 2-3mm, measuring and recording the temperature of the outer surface of the pipe at the position of the 10 contour lines one by one, wherein the measured temperature data of all numbered pipes is 10;

fourthly, according to the data recorded in the table 1, the leakage position of the tube panel of the economizer (namely the tube with the number of 5) can be accurately judged by finding that the 10 measured temperatures of the tube with the number of 5 (the outlet of the header) are all more than 30 ℃ higher than the measured temperatures of other tubes;

it should be noted that: the data are given in table 1, numbering is used from the most northern tube, so the table is presented as north 1, north 2, etc.

TABLE 1 Economizer leakage header outlet pipe temperature measurement

(2) Leakage stoppage of leakage pipe panel of coal economizer of circulating fluidized bed boiler

Firstly, performing pressurized plugging on a leakage pipe panel (the pressurized plugging is performed by adopting the conventional technology in the field, and the detailed description is omitted);

secondly, operating equipment, forming phi 6 holes in the inlet part of the plugging tube panel, and if no overflow water exists in the holes, confirming that plugging is successful.

If the leak stoppage fails, the process of leaking the leak stoppage under pressure is repeated.

As can be seen from the above table, the ten temperature values measured on the outer surface of the No. 5 th pipeline in the north are all higher than the outer surface temperatures of other pipelines by more than 30 ℃, and during data collection during temperature measurement, the test data are abnormally fluctuated when the outer surface temperature of the pipeline leaks (the abnormal fluctuation data indicate that the outer surface temperature of the pipeline is instantaneously fluctuated between 180 ℃ and-239 ℃), so that the abnormal increase of the outer surface temperature of the leaking pipeline can be accurately judged, and the pipeline screen is the leaked pipeline screen (pipeline) in the furnace.

The theoretical basis for judgment is as follows: after the tube panel of the coal economizer leaks, the flow velocity of steam and water in the tube is accelerated due to the leakage of the single tube panel, and the heat exchange quantity of the pipeline is increased, so that the temperature of the outer surface of the leaked pipeline is increased.

The leakage detecting and plugging method is carried out in the running state of the boiler equipment, so that the economic loss caused by unplanned furnace shutdown is avoided by over 100 ten thousand yuan.

Example 2

This example differs from example 1 in that: the humidity test is added.

It should be noted that: the technology of leaking stoppage under pressure adopts the conventional technology in the field; the DCS processor is used, and the connection mode of the DCS processor, the acquisition unit (thermometer and hygrometer) and the display is realized by adopting the conventional technology in the field, and the detailed description is omitted.