Coal-fired boiler furnace gas sampling device and method

Abstract

The present application provides a sampling device and method for coal-fired boiler furnace gas, which comprises a sampling probe and a filter; further comprising: one end of a sampling tube is communicated with the sampling probe, and the other end is communicated with a switching module; the included angle between the gas flow direction in the sampling probe and the gas flow direction in the sampling tube is an acute angle; the switching module is used for selectively communicating the outlet of the sampling tube with a first gas source; a second gas source is sequentially connected with a valve and one end of the sampling probe, and the other end of the sampling probe allows entering into the furnace; a partition is arranged on a rotating shaft in the sampling probe, when the valve is closed, the partition separates the inside of the sampling probe into a first part and a second part, when the valve is opened, the gas provided by the second gas source drives the partition to rotate around the rotating shaft, and the gas sequentially passes through the first part and the second part. The present application has the advantages of good working reliability, etc.

Description

TECHNICAL FIELD

[0001] The present application relates to gas sampling, in particular to a sampling device and method for flue gas of a coal-fired boiler. BACKGROUND

[0002] In recent years, the combustion boiler of thermal power needs to be reformed for low-nitrogen combustion to reduce the generation of NOx of the boiler. In the process control of low-nitrogen combustion reform, CO in the atmosphere near the wall of the furnace needs to be detected for preventing the corrosion of the furnace wall. The working condition of the sample gas near the wall of the furnace belongs to high temperature (900-1100℃) and high dust (50g / m3). Due to the too large dust content, in-situ measurement cannot be adopted, and the measurement needs to be performed through sampling.

[0003] The sample gas enters a sampling probe from the furnace of the combustion boiler through a high-temperature sampling probe pipe, is filtered through a probe filter, and then enters a measurement chamber of a rear-end analyzer for measurement and analysis. The probe filter is periodically back-flushed through back-flushing.

[0004] Problems of the prior art method:

[0005] The dust content of the measured sample gas is large, the back-flushing effect of the probe is poor, the cavity of the sampling probe is accumulated and blocked by the dust, the sample gas flow entering the analyzer is reduced, and normal measurement cannot be performed. SUMMARY

[0006] In order to solve the above problems in the prior art, the present application provides a sampling device for flue gas of a coal-fired boiler.

[0007] The purpose of the present application is achieved by the following technical solutions:

[0008] The sampling device for flue gas of a coal-fired boiler comprises a sampling probe rod and a filter.

[0009] A sampling pipe, one end of which is communicated with the sampling probe rod, and the other end of which is communicated with a switching module; the included angle between the gas flow direction in the sampling probe rod and the gas flow direction in the sampling pipe is an acute angle;

[0010] The switching module is used for selectively communicating the outlet of the sampling pipe with a first gas source.

[0011] A second gas source and a valve, the second gas source being sequentially connected with the valve and one end of the sampling probe rod, and the other end of the sampling probe rod being allowed to enter the furnace.

[0012] An isolator is arranged on a rotating shaft in the sampling probe, when the valve is closed, the isolator separates the inside of the sampling probe into a first part and a second part, when the valve is opened, the gas provided by the second gas source drives the isolator to rotate around the rotating shaft, and the gas passes through the first part and the second part in turn.

[0013] The application also aims to provide a sampling method for the furnace gas of a coal-fired boiler.

[0014] The sampling method for the furnace gas of a coal-fired boiler comprises the following steps:

[0015] (A1) Switching module switching, closing valve, isolator separates the inside of the sampling probe into a first part and a second part;

[0016] (A2) The gas in the furnace enters the second part, deflects upward to enter the sampling tube, passes through the filter in a forward direction and is discharged from the sampling tube, and then is sent downstream through the switching module, and the deflection angle is an acute angle;

[0017] (A3) Opening the valve, closing the sampling tube, blowing gas enters the first part, pushing the isolator to rotate, and then entering the second part, carrying the particulate matters in the sampling probe into the furnace;

[0018] (A4) Closing the valve, the isolator is reset by external force or its own gravity, separating the inside of the sampling probe into a first part and a second part, and the switching module is switched;

[0019] (A5) Backflushing gas enters the sampling tube, reversely passes through the filter, and the particulate matters attached to the filter fall into the sampling probe.

[0020] Compared with the prior art, the application has the beneficial effects that:

[0021] 1. It has a self-cleaning function;

[0022] By opening (pushing the isolator) and closing the valve, the self-cleaning and sampling states are entered respectively; when the valve is opened, the outlet of the sampling tube is closed, the blowing gas pushes the isolator to rotate, so that the blowing gas carries the particulate matters in the second part into the furnace, thereby cleaning the linear sampling probe;

[0023] In the rotation of the isolator, the vibration of the filter core with elasticity is driven, so that the particulate matters attached to the filter core fall off, thereby better cleaning the filter core and the sampling probe;

[0024] The back-blowing gas cleans the filter element from inside to outside, so that the particles attached to the filter element fall off, thereby better cleaning the filter element and the sampling probe rod;

[0025] 2. Good cleaning effect;

[0026] In the cleaning state, the sampling tube outlet is closed, and the isolation piece blocks the inlet of the sampling tube under the action of the purge gas, reducing the volume of the purge gas entering the sampling tube and increasing the cleaning effect; in the sampling state, the isolation piece rotates downward and isolates the first part and the second part under the action of external force or its own gravity, reducing the dead volume (i.e. the volume of the first part) of sampling and improving the response speed of sample sampling;

[0027] The included angle between the sampling tube and the sampling probe rod is an acute angle, so that part of the particles in the furnace gas in the second part fall off due to inertia impact on the isolation piece, effectively reducing the particle content in the gas entering the sampling tube. BRIEF DESCRIPTION OF DRAWINGS

[0028] The disclosure of the present application will become more apparent with reference to the drawings. It is readily understood by those skilled in the art that the drawings are only used to illustrate the technical solutions of the present application, and are not intended to limit the protection scope of the present application. In the drawings:

[0029] Figure 1 is a structural schematic view of a sampling device for furnace gas of a coal-fired boiler according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] Figure 1 The following description describes optional embodiments of the present application to teach those skilled in the art how to implement and reproduce the present application. Some conventional aspects have been simplified or omitted in order to explain the technical solutions of the present application. Those skilled in the art should understand that variations or substitutions derived from these embodiments will be within the scope of the present application. Those skilled in the art should understand that the following features can be combined in various ways to form multiple variations of the present application. Thus, the present application is not limited to the following optional embodiments, but is only limited by the claims and their equivalents.

[0031] Example 1

[0032] Figure 1 A structural view of a sampling device for furnace gas of a coal-fired boiler according to an embodiment of the present application is schematically shown, as shown in Figure 1 The sampling device for furnace gas of a coal-fired boiler comprises:

[0033] a sampling probe rod 10 and a filter 41;

[0034] A sampling tube 21, one end of which is communicated with the sampling probe 10, and the other end of which is communicated with a switching module; the included angle between the gas flow direction in the sampling probe 10 and the gas flow direction in the sampling tube 21 is an acute angle;

[0035] The switching module is used for selectively communicating the outlet of the sampling tube 21 with a first gas source;

[0036] A second gas source 61 and a valve 62, the second gas source 61 is connected with the valve 62 and one end of the sampling probe 10 in sequence, and the other end of the sampling probe 10 is allowed to enter the furnace 1;

[0037] An isolating piece 31 is arranged on the rotating shaft in the sampling probe 10, when the valve 62 is closed, the isolating piece 31 divides the inside of the sampling probe 10 into a first part 12 and a second part 11, after the furnace gas passes through the second part 11, the gas flows into the sampling tube 21 after being deflected, when the valve 62 is opened, the gas provided by the second gas source 61 drives the isolating piece 31 to rotate around the rotating shaft, and the gas passes through the first part 12 and the second part 11 in sequence.

[0038] In order to make the isolating piece 31 accurately return (divide the inside of the sampling probe 10 into the first part 12 and the second part 11), further, the isolating piece 31 is arranged in the sampling probe 10 in an inclined manner.

[0039] In order to facilitate the rotation of the isolating piece 31, further, the rotating shaft is arranged at the connection 22 between the sampling tube 21 and the linear sampling probe 10.

[0040] In order to shake the filter core of the filter 41 when the isolating piece 31 rotates, further, the sampling device of the furnace gas of the coal-fired boiler further comprises:

[0041] A rotating arm 32, one end of which is arranged on the isolating piece 31 through a rotating shaft, and the other end of which is connected with the filter core of the filter 41, and the filter core has elasticity.

[0042] In order to reduce the temperature of the sampling gas, further, the sampling device of the furnace gas of the coal-fired boiler further comprises:

[0043] A ring-shaped component 51, which has two openings and wraps the sampling tube 21, and forms a layer isolated from the outside between the sampling tube 21 and the ring-shaped component 51, when the cooling medium is injected and discharged into the layer through the two openings, the temperature of the gas downstream of the filter core in the sampling tube 21 is effectively reduced.

[0044] The sampling method of the coal-fired boiler furnace gas comprises the following steps:

[0045] (A1) The switching module is switched, the valve 62 is closed, and the partition piece 31 divides the sampling probe 10 into the first part 12 and the second part 11;

[0046] (A2) The gas in the furnace 1 enters the second part 11, flows to the sampling pipe 21 after being upwardly deflected, is discharged from the sampling pipe 21 after being positively passed through the filter 41, and is then sent to the downstream by the switching module, and the deflection angle is an acute angle;

[0047] (A3) The valve 62 is opened, the sampling pipe 21 is closed, the purge gas enters the first part 12, the partition piece 31 is rotated, and then enters the second part 11, and carries the particulate matters in the sampling probe 10 into the furnace 1;

[0048] (A4) The valve 62 is closed, the partition piece 31 is reset under the action of an external force or its own gravity, the sampling probe 10 is divided into the first part 12 and the second part 11, and the switching module is switched;

[0049] (A5) The back-blowing gas enters the sampling pipe 21, reversely passes through the filter 41, and the particulate matters attached to the filter 41 fall into the sampling probe 10.

[0050] In order to better clean the particulate matters on the filter 41, further, in step (A3), the rotating partition piece 31 pushes the filter 41 core with elasticity, and the particulate matters attached to the core fall into the sampling probe 10.

[0051] In order to better clean the particulate matters in the sampling probe 10, further, the sampling method of the coal-fired boiler furnace gas further comprises the following steps:

[0052] (A6) The valve 62 is opened, the sampling pipe 21 is closed, the purge gas enters the first part 12, the partition piece 31 is rotated around the rotating shaft, and then enters the second part 11, and carries the particulate matters in the sampling probe 10 into the furnace 1;

[0053] The flow rate of the back-blowing gas is less than that of the purge gas.

[0054] Embodiment 2

[0055] The application example of the sampling device and method of the coal-fired boiler furnace gas according to Embodiment 1 in a thermal power plant.

[0056] In this application example, as Figure 1As shown, the sampling probe 10 is in a straight line, the bottom end of the sampling tube 21 is communicated with the sampling probe 10, and is inclined upward, so that the gas in the sampling probe 10 is deflected into the sampling tube 21 in an oblique upward direction, and the deflection angle is 45 degrees; the filter 41 is arranged in the sampling tube 21, the filter element adopts a folded stainless steel wire mesh, the rotating shaft is arranged at the connection position of the sampling tube 21 and the sampling probe 10, and the oval isolating piece 31 is arranged on the rotating shaft, so that the isolating piece 31 is reset under the action of gravity (without external force) and divides the sampling probe 10 into the first part 12 and the second part 11; one end of the rotating arm 32 is arranged on the isolating piece 31 through a rotating shaft, and the other end is connected with the filter element; the second gas source 61 is sequentially connected with the valve 62 and the first part 12; the switching module is used for selectively connecting the outlet of the sampling tube 21 with the downstream, or connecting the first gas source, or closing, the blowback gas flow provided by the first gas source is smaller than the sweeping gas flow provided by the second gas source 61; the annular component 51 surrounds the sampling tube 21, so that a sandwich layer is formed between the sampling tube 21 and the annular component 51, which is isolated from the outside, the cooling water enters the sandwich layer from one opening of the annular component 51 and is discharged from another opening after absorbing heat, so as to reduce the temperature of the gas in the sampling tube 21.

[0057] The sampling method of the coal-fired boiler furnace gas of the embodiment of the present application, that is, the working method of the sampling device of the embodiment, comprises the following steps:

[0058] (A1) The switching module is switched, the sampling tube 21 is communicated with the downstream, the valve 62 is closed, and the isolating piece 31 is arranged in the sampling probe 10 in an inclined manner under the action of its own gravity, so as to divide the sampling probe 10 into the first part 12 and the second part 11;

[0059] (A2) The gas in the furnace 1 enters the second part 11, is deflected upward to enter the sampling tube 21, is discharged from the sampling tube 21 after passing through the filter 41 in a forward direction, and is then sent to the downstream through the switching module, and the deflection angle is an acute angle;

[0060] (A3) The valve 62 is opened, the outlet of the sampling tube 21 is closed by the switching module, the sweeping gas provided by the second gas source 61 enters the first part 12, rotates the isolating piece 31 (at this time, the first part 12 and the second part 11 are communicated, and the isolating piece also blocks the inlet of the sampling tube 21 to a certain extent), and then enters the second part 11 to carry the particulate matters in the sampling probe 10 into the furnace 1;

[0061] When the isolating piece 31 rotates, the rotating arm 32 pushes the filter element, and the particulate matters attached to the filter element fall off;

[0062] (A4) Close the valve 62, the partition 31 is returned by its gravity, the sampling probe 10 is divided into the first part 12 and the second part 11, the switching module is switched, the outlet of the sampling tube 21 is communicated with the first gas source;

[0063] (A5) The back flushing gas provided by the first gas source enters the sampling tube 21, reversely passes through the filter 41, and the particles attached on the filter 41 fall in the sampling probe 10;

[0064] (A6) Open the valve 62, the switching module is switched, the outlet of the sampling tube 21 is closed, the purge gas provided by the second gas source 61 enters the first part 12, drives the partition 31 to rotate around the rotating shaft, and then enters the second part 11, carries the particles in the sampling probe 10 into the furnace 1;

[0065] The flow of the back flushing gas is less than the flow of the purge gas.

[0066] Embodiment 3

[0067] The application example of the sampling device and method of the furnace gas of the coal-fired boiler according to the embodiment 1 of the present application is different from the embodiment 2, which is:

[0068] 1. A spring is arranged on the partition, the spring is not contacted with the filter core, when the purge gas provided by the first gas source enters the first part, the partition is driven to rotate, the spring pushes the filter core to deform, the particles attached on the filter core fall, when the partition is returned, the spring is separated from the filter core, the filter core is returned and vibrated due to the elasticity, and the particles attached on the filter core fall.

[0069] 2. The first gas source and the second gas source are shared, and the purge gas with the larger flow provided by the second gas source is continuously used.

[0070] The sampling method of the furnace gas of the coal-fired boiler according to the embodiment of the present application, namely the working method of the sampling device of the embodiment, comprises the following steps:

[0071] (A1) The switching module is switched, the sampling tube 21 is communicated with the downstream, the valve 62 is closed, the partition 31 is obliquely arranged in the sampling probe 10 under the action of its gravity, and the sampling probe 10 is divided into the first part 12 and the second part 11;

[0072] (A2) The gas in the furnace 1 enters the second part 11, is deflected upwards to enter the sampling tube 21, is discharged from the sampling tube 21 after passing through the filter 41 in a forward direction, and is then sent to the downstream through the switching module, and the deflection angle is an acute angle;

[0073] (A3) open the valve 62, the switch module closes the outlet of the sampling tube 21, the purge gas from the second gas source 61 enters the first part 12, pushes the isolator 31 to rotate (at this time, the first part 12 and the second part 11 are connected, and the isolator also blocks the inlet of the sampling tube 21 to some extent), and then enters the second part 11, carries the particles in the sampling probe 10 into the furnace 1;

[0074] When the isolator 31 rotates, the spring pushes the filter core, and the particles attached to the filter core fall off;

[0075] (A4) close the valve 62, the isolator 31 returns to the original position under the action of its own gravity, divides the sampling probe 10 into the first part 12 and the second part 11, and the switch module switches, so that the outlet of the sampling tube 21 is connected to the second gas source;

[0076] (A5) the purge gas from the second gas source enters the sampling tube 21, reversely passes through the filter 41, and the particles attached to the filter 41 fall into the sampling probe 10, and the purge gas carries the particles in the sampling tube 21 and the second part 11 into the furnace 1.

Claims

1. A device for sampling flue gas of a coal-fired boiler furnace, the device comprising a sampling lance and a filter; characterized in that, The sampling device for the furnace gas of the coal-fired boiler further comprises: a sampling tube, one end of which is communicated with the sampling probe, and the other end of which is communicated with the switching module; the included angle between the gas flow direction in the sampling probe and the gas flow direction in the sampling tube is an acute angle; the switching module is used for selectively communicating the outlet of the sampling tube with the first gas source; a second gas source and a valve, the second gas source is sequentially connected with the valve and one end of the sampling probe, and the other end of the sampling probe is allowed to enter the furnace; an isolator, which is obliquely arranged on the rotating shaft in the sampling probe, separates the inside of the sampling probe into a first part and a second part when the valve is closed, and drives the isolator to rotate around the rotating shaft by the gas provided by the second gas source when the valve is opened, and the gas sequentially passes through the first part and the second part; the rotating shaft is arranged at the connection between the sampling tube and the linear sampling probe; a rotating arm, one end of which is arranged on the isolator through a rotating shaft, and the other end of which is connected with the filter element of the filter, and the filter element has elasticity.

2. A device for sampling flue gases from a coal-fired boiler furnace according to claim 1, characterised in that, The filter element is a folded stainless steel wire mesh.

3. The apparatus for sampling the gases from the combustion zone of a coal-fired boiler as defined in claim 1, wherein, The sampling device for the furnace gas of the coal-fired boiler further comprises: a ring-shaped component, which has two openings and wraps the sampling tube to form a sandwiched layer isolated from the outside between the sampling tube and the ring-shaped component.

4. The sampling method for the furnace gas of the coal-fired boiler implemented by the sampling device according to claim 1, comprising the following steps: (A1) switching of the switching module, closing of the valve, and separation of the isolator into a first part and a second part in the sampling probe; (A2) the gas in the furnace enters the second part, deflects upward to enter the sampling tube, and is discharged from the sampling tube after passing through the filter in the positive direction, and then is sent to the downstream through the switching module, and the deflection angle is an acute angle; (A3) opening of the valve, closing of the sampling tube, and entry of the purge gas into the first part to drive the isolator to rotate, and then into the second part to carry the particulate matters in the sampling probe into the furnace; (A4) closing of the valve, return of the isolator to the original position under the action of external force or gravity to separate the sampling probe into a first part and a second part, and switching of the switching module; (A5) entry of the backflushing gas into the sampling tube, reverse passage through the filter, and falling of the particulate matters attached to the filter into the sampling probe.

5. The method of claim 4, wherein, In step (A3), the rotating isolator pushes the filter element with elasticity, and the particulate matters attached to the filter element fall into the sampling probe.

6. The method of claim 4, wherein, The sampling method for the furnace gas of the coal-fired boiler further comprises the following steps: (A6) opening of the valve, closing of the sampling tube, entry of the purge gas into the first part to drive the isolator to rotate around the rotating shaft, and then into the second part to carry the particulate matters in the sampling probe into the furnace; The flow rate of the backflushing gas is less than that of the purge gas.

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