KR101736334B1 - Soot blower and method for cleaning heat exchanger - Google Patents

Abstract

According to the present invention, a soot blower includes: a lance tube including one end reciprocating in one direction on a surface of at least one inlet of a first flow passage and a second flow passage of a rotary regenerative heat exchanger; a driving unit connected to the lance tube so as to reciprocate the lance tube in one direction; a first nozzle connected to the one end of the lance tube so as to inject steam into the inlet; and a second nozzle adjacent to the first nozzle and connected to the one end of the lance tube and configured to inject solid particles into the inlet. Accordingly, the present invention can easily clean a rotary regenerative heat exchanger.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a soot blower and a rotary regenerative heat exchanger,

The present invention relates to a soot blower and a method of cleaning a rotary regenerative heat exchanger.

Exhaust gases from boilers, such as coal, oil, gas, or combustible materials, contain nitrogen oxides that must be removed before they are released into the atmosphere as an environmental element.

In order to remove the nitrogen oxides contained in the exhaust gas, a selective non-catalytic reduction (SNCR) method in which a reducing agent such as ammonia is injected directly into the boiler furnace, a selective catalytic reduction (SCR) ).

Among them, the selective catalytic reduction method is a method in which nitrogen oxides (NOx) contained in the exhaust gas are mixed with a reducing agent such as ammonia, and then the catalyst is converted to nitrogen and water.

The general arrangement of pollution prevention facilities in power generation facilities and industrial boilers is shown in FIG.

1 is a general boiler layout diagram in which pollution prevention facilities are installed.

As shown in FIG. 1, the exhaust gas discharged from the boiler passes through the catalyst layer of the SCR through the carbon burner, and thereafter the air preheater (GAH), the dust collector (EP) and the gas reheater (GGH) And is discharged to the exhaust port.

Generally, sulfur dioxide (SO ₂ ) and sulfur trioxide (SO ₃ ) are included in the exhaust gas when coal or heavy oil is burned in a boiler. Part of sulfur dioxide (SO ₃ ) is oxidized to sulfur trioxide when passed through SCR as shown in the following (1) The sulfur trioxide concentration in the exhaust gas flowing into the exhaust gas GAH increases.

_{(1) 2SO 2 + O 2} → 2SO 3

On the other hand, water exists in the exhaust gas, and a part of ammonia injected into the SCR reacts with sulfur trioxide and water to form an ammonium sulfate salt as shown in the following (2).

(2) NH ₃ + SO ₃ + H ₂ O → NH ₄ HSO ₄

Ammonium sulfate has high stickiness and combines with dust in the exhaust gas to block the exhaust gas passage of the air preheater (GAH) to increase the pressure loss of the boiler. For this reason, the discharge concentration of unreacted ammonia during SCR operation is limited to 2 to 3 ppm or less. However, in many installations, the flow path of the air preheater (GAH) is often clogged during SCR operation.

In addition, there is a gas reheater (GGH) at the front end and the rear end of the desulfurization facility (FGD), and gypsum is scattered in the desulfurization facility (FGD), and the flow path of the gas reheating (GGH) is frequently clogged.

Each of the air preheater (GAH) and the gas reheater (GGH) includes a first flow path through which a low temperature fluid passes and a second flow path through which a high temperature fluid passes, Type heat exchanger.

Conventionally, an air preheater (GAH) and a gas reheater (GGH) are cleaned using a soot blower that injects high-pressure water in order to eliminate clogging of the air preheater (GAH) and the gas reheater (GGH).

One embodiment of the present invention seeks to provide a soot blower and a method of cleaning a rotary regenerative heat exchanger that easily cleans the rotary regenerative heat exchanger.

One side includes a soot blower for cleaning a rotary regenerative heat exchanger including a first flow path through which the first fluid passes and a second flow path through which the second fluid passes and performs heat exchange between the first fluid and the second fluid A lance tube having one end reciprocating in one direction on a surface of at least one of the first flow path and the second flow path, a driving part connected to the lance tube to reciprocate the lance tube in the one direction, A first nozzle connected to the one end of the lance tube to inject steam into the inlet and a second nozzle connected to one end of the lance tube adjacent to the first nozzle, A soot blower including a nozzle is provided.

The soot blower may further include a first tube communicating with the first nozzle through the inside of the lance tube, and a second tube penetrating the inside of the lance tube and communicating with the second nozzle.

The soot blower further includes a steam supply part connected to the first tube and supplying the steam to the first tube and a solid particle supply part connected to the second tube and supplying the solid particles to the second tube .

The solid particle supply unit may include a plurality of sub-particle supply units, and each of the plurality of sub-particle supply units may supply different solid particles to the second tube.

The different solid particles may include at least one of dry ice pellets, ice particles, and sand.

The driving unit may include a sliding guide unit positioned on the lance tube, a sliding unit reciprocating along the sliding guide unit, and a connection unit connecting the sliding unit and the lance tube.

The second nozzle may be longer than the first nozzle.

The second nozzle may have a shape different from that of the first nozzle.

The soot blower may further include a longer nozzle protector which is located at an outermost portion of the lance tube adjacent to the second nozzle and is longer than the second nozzle.

And a nozzle maintenance chamber surrounding the one end of the lance tube adjacent to the driving unit.

The nozzle maintenance chamber may include a gate exposing the first nozzle and the second nozzle.

And a guide rail extending in one direction adjacent to the nozzle maintenance chamber and supporting the lance tube.

The guide rail may include an opening exposing the first nozzle and the second nozzle along the one direction.

The one side includes a first flow path through which the first fluid passes and a second flow path through which the second fluid passes, and a cleaning process for cleaning a rotary regenerative heat exchanger that performs heat exchange between the first fluid and the second fluid The method of claim 1, further comprising the steps of: spraying steam on one surface of an inlet of at least one of the first flow path and the second flow path in one direction; and spraying solid particles on the surface of the inlet The method comprising the steps of:

The step of spraying the steam may include spraying high temperature steam at a steam temperature of 90 to 300 캜 and a pressure of 10 to 50 kg / cm 2 g on the surface of the inlet.

The step of spraying the solid particles may include spraying dry ice pellets onto the surface of the inlet at a pressure of 0.5 kg / cm 2 g to 20 kg / cm 2 g, and spraying dry ice pellets at a pressure of 0.5 kg / / Cm < 2 > g.

The speed of reciprocation along the one direction on the surface of the inlet may be variable.

A soot blower and a rotary regeneration heat exchanger cleaning method for easily cleaning a rotary regeneration heat exchanger are provided.

1 is a general boiler layout diagram in which pollution prevention facilities are installed.
2 is a view showing a soot blower according to an embodiment for cleaning a rotary regenerative heat exchanger.
3 is a view of a soot blower according to one embodiment.
FIG. 4 is a bottom view of the nozzle maintenance chamber shown in FIG. 3. FIG.
5 is a view showing an example of the first nozzle and the second nozzle shown in Fig.
6 is a view showing a soot blower according to another embodiment.
7 is a front view of the guide rail shown in Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

In addition, since the sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for convenience of explanation, the present invention is not necessarily limited to those shown in the drawings. In the drawings, the thickness is enlarged to clearly represent the layers and regions. In the drawings, for the convenience of explanation, the thicknesses of some layers and regions are exaggerated.

Also, to be "on " the reference portion is located above or below the reference portion and does not necessarily mean" on "

Also, throughout the specification, when an element is referred to as "including" an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

Hereinafter, a soot blower according to one embodiment will be described with reference to FIGS. 2 to 5. FIG.

2 is a view showing a soot blower according to an embodiment for cleaning a rotary regenerative heat exchanger.

As shown in FIG. 2, sole blower 1000 according to one embodiment cleans rotary regenerative heat exchanger 10. The rotary regenerative heat exchanger 10 includes a first flow path 11 through which the first fluid Fl passes and a second flow path 12 through which the second fluid F2 passes. And the second fluid F2. The first flow path 11 of the rotary regeneration heat exchanger 10 includes a first inlet 11a through which the first fluid F1 flows and a second flow path 12 through which the second fluid F2 flows And the second inlet 12a. Here, the rotary regeneration heat exchanger 10 may be, but not limited to, an air preheater (GAH) or a gas reheater (GGH) of a general boiler equipped with an anti-pollution facility. The rotary regenerative heat exchanger 10 may have various conventional forms.

3 is a view of a soot blower according to one embodiment.

3 is a more detailed illustration of the soot blower 1000 shown in Fig.

2 and 3, the soot blower 1000 includes a plurality of soot blowers 1000, each of which is connected to a first inlet 11a of the first flow path 11 of the rotary regenerative heat exchanger 10 ) And the second inlet (12a) of the second flow path (12). The soot blower 1000 includes a lance tube 100, a driving unit 200, a first nozzle 300, a second nozzle 400, a first tube 500, a second tube 600, a vapor supply unit 700, A solid particle supply unit 800, a nozzle protector 900, and a nozzle maintenance chamber 950.

The lance tube 100 is connected to at least one of the first inlet 11a and the second inlet 12a of the rotary regeneration heat exchanger 10, which is an inlet of at least one of the first and second flow paths 11 and 12, And one end portion 101 that reciprocates along the direction X in the X direction.

Here, the one direction X may be a direction intersecting the moving direction of the first fluid F1 through the rotary regenerative heat exchanger 10, but is not limited thereto.

The driving unit 200 is connected to the lance tube 100 to reciprocate the lance tube 100 in one direction X. The driving unit 200 includes a sliding guide unit 210, a sliding unit 220, and a connecting unit 230.

The sliding guide portion 210 is positioned on the lance tube 100 and extends along one direction X.

The sliding portion 220 reciprocates in the one direction X along the sliding guide portion 210. At least one of the sliding portion 220 and the sliding guide portion 210 may include a driving unit such as a motor.

The connecting portion 230 connects the sliding portion 220 and the lance tube 100 and the connecting portion 230 causes the one end 101 of the lance tube 100 to move along the reciprocating motion of the sliding portion 220. And reciprocates in the direction X.

The first nozzle 300 is connected to one end 101 of the lance tube 100 to inject steam into the first inlet 11a and the second inlet 12a. The first nozzle 300 injects high-temperature steam at a steam temperature of 90 ° C. to 300 ° C. and a pressure of 10 kg / cm 2 to 50 kg / cm 2 g on the surfaces of the first inlet 11a and the second inlet 12a But is not limited thereto.

The second nozzle 400 is connected to the one end 101 of the lance tube 100 adjacent to the first nozzle 300 and injects the solid particles into the first inlet 11a and the second inlet 12a . The second nozzle 400 may eject solid particles including at least one of dry ice pellets, ice particles, and sand. The second nozzle 400 injects dry ice pellets onto the surfaces of the first inlet 11a and the second inlet 12a at a pressure of 0.5 kg / cm2g to 20 kg / cm2g, or the first inlet 11a, And the second inlet 12a may be sprayed with ice granules or sand at a pressure of 0.5 kg / cm 2 g to 30 kg / cm 2 g, but the present invention is not limited thereto.

On the other hand, the second nozzle 400 can inject high-pressure water onto the surfaces of the first inlet 11a and the second inlet 12a.

The second nozzle 400 is longer than the first nozzle 300 and the solid particles injected from the second nozzle 400 are injected into the first inlet 11a at a lower pressure relative to the vapor jetted from the first nozzle 300, And the second inlet 12a.

The second nozzle 400 may have a shape different from that of the first nozzle 300, but is not limited thereto.

The first tube 500 penetrates the inside of the lance tube 100 and communicates with the first nozzle 300.

The second tube 600 is adjacent to the first tube 500 and penetrates the inside of the lance tube 100. The second tube 600 communicates with the second nozzle 400.

The steam supply unit 700 is connected to the first tube 500 and supplies high-temperature steam to the first tube 500.

The solid particle supply unit 800 is connected to the second tube 600 and supplies solid particles including at least one of dry ice pellets, ice particles, and sand to the second tube 600. The solid particle supply unit 800 includes a first sub-particle supply unit 810, a second sub-particle supply unit 820, and a third sub-particle supply unit 830, which are a plurality of sub-particle supply units.

The first sub-particle supplying unit 810 supplies the dry ice pellets to the second tube 600, supplies the ice particles to the second sub-particle supplying unit 820, the second tube 600, 830 feeds the sand to the second tube 600. That is, each of the plurality of sub-particle supply units supplies at least one of dry ice pellets, ice particles, and sand, which are different solid particles, to the second tube 600.

The nozzle protector 900 is located at the outermost portion 102 of the lance tube 100 adjacent to the second nozzle 400 and is longer than the second nozzle 400. The nozzle protector 900 prevents the first nozzle 300 and the second nozzle 400 from being damaged by external interference when the lance tube 100 reciprocates in one direction X. [

The nozzle maintenance chamber 950 surrounds the one end 101 of the lance tube 100 adjacent to the driving unit 200. The nozzle maintenance chamber 950 is located in the movement path of the lance tube 100 moving in one direction X. [

FIG. 4 is a bottom view of the nozzle maintenance chamber shown in FIG. 3. FIG.

4, the nozzle maintenance chamber 950 is located within the movement path of the lance tube 100 moving in one direction X and surrounds the one end 101 of the lance tube 100, 1 nozzle 300 and a gate 951 exposing the second nozzle 400. [ Through the gate 951, the first nozzle 300 and the second nozzle 400 can be replaced with nozzles of a selected type.

5 is a view showing an example of the first nozzle and the second nozzle shown in Fig.

As shown in FIGS. 5A, 5B, and 5C, each of the first nozzle 300 and the second nozzle 400 may have various shapes. The discharge port of each of the first nozzle 300 and the second nozzle 400 may have various shapes such as a rectangular shape, a circular shape, a rectangular shape, an elliptical shape, a polygonal shape, and the like. The lancet 400 may be connected to one end 101 of the lance tube 100 through the gate 951 shown in Fig.

The soot blower 1000 according to one embodiment includes a lance tube 100 reciprocating in one direction X corresponding to the rotary regenerative heat exchanger 10, a first end 101 of the lance tube 100, And a second nozzle 400 for spraying the selected solid particles adjacent to the first nozzle 300 to clean the rotary regenerative heat exchanger 10 The rotary regeneration heat exchanger 10 can be easily cleaned by selecting steam, dry ice pellets, ice granules, sand, high-pressure water or the like depending on the working environment.

For example, the principle of removing the ammonium sulfate, dust, or dysplasia attached to the rotary regenerative heat exchanger 10 using dry ice pellets is as follows. When the dry ice pellet is sprayed at a high speed through the second nozzle 400 and impinges on the surface of the rotary regenerative heat exchanger 10, the dry ice pellet causes the ammonium sulfate, which is attached to the rotary regenerative heat exchanger 10, At -78 [deg.] C). The frozen ammonium sulfate salt shrinks due to the difference in ambient temperature and causes a lot of cracks. The dry ice pellets penetrate through these cracks through the ammonium sulfate salts and simultaneously sublimate while expanding the volume by more than 800 times so that only the ammonium sulfate salt is lifted up. Foreign substances frozen at extremely low temperatures are easily separated from the surface of the rotary regenerative heat exchanger 10 and discharged.

Hereinafter, a soot blower according to another embodiment will be described with reference to Figs. 6 and 7. Fig.

Hereinafter, a portion different from the soot blower according to the above-described embodiment will be described.

6 is a view showing a soot blower according to another embodiment. 7 is a front view of the guide rail shown in Fig.

6 and 7, the sole blower 1000 according to another embodiment further includes a guide rail 970.

The guide rail 970 extends in one direction X adjacent to the nozzle maintenance chamber 950 and supports the lance tube 100 reciprocating in one direction X. [ The lance tube 100 is prevented from sagging when the lance tube 100 reciprocates by the guide rails 970. The guide rail 970 includes an opening 971 for exposing the first nozzle 300 and the second nozzle 400 and the opening 971 extends along one direction X. [ The guide rail 970 may have various shapes and may be formed in any shape as long as it can support the lance tube 100 and guide the reciprocating movement of the lance tube 100 in one direction X .

Hereinafter, a cleaning method of the rotary regenerative heat exchanger according to another embodiment will be described.

The method of cleaning the rotary regenerative heat exchanger according to another embodiment may be performed using a soot blower according to the above-described embodiment, or a soot blower according to another embodiment.

First, a first flow path through which a first fluid flows and a second flow path through which a second fluid flows, and a first flow path and a second flow path of a rotary regenerative heat exchanger performing heat exchange between the first fluid and the second fluid, And reciprocates along one direction on the surface of at least one inlet of the flow passage and injects steam.

Specifically, the step of spraying the steam may include spraying a high temperature steam at a steam temperature of 90 to 300 캜 and a pressure of 10 to 50 kg / cm 2 g on the surface of the inlet.

Next, the solid particles are sprayed on the surface of the inlet port by reciprocating in one direction.

Specifically, the step of spraying the solid particles includes spraying dry ice pellets to the surface of the inlet at a pressure of 0.5 kg / cm 2 g to 20 kg / cm 2 g, and spraying the dry ice pellets at a pressure of 0.5 kg / Lt; RTI ID = 0.0 > g / cm2. ≪ / RTI >

In addition, the high pressure water can be injected and reciprocated along one direction on the surface of the inlet.

The speed of reciprocation along one direction on the surface of the above-described inlet may be variable.

For example, when the diameter of the rotary regenerative heat exchanger is 14.274 mm and the rotational speed is 1.28 rpm, the moving linear velocity of the outer heat element outside the rotary regenerative heat exchanger is calculated to be about 650 mm / sec, The amount of the cleaning medium per unit thermal element area is much smaller than that in the case where the cleaning medium is stopped. Therefore, when the soot blower is operated during the operation of the rotary regenerative heat exchanger, the cleaning effect may be deteriorated.

Such a phenomenon is accompanied by a large diameter of the rotary regenerative heat exchanger, and as the rotational speed is increased, the linear velocity of the heat element becomes larger and the amount of the washing substance per unit area of the thermal element becomes smaller.

Therefore, when the heat exchanger is cleaned, the speed of the heat exchanger can be cleaned by using a current control device or by setting a speed reducer to lower the rotation speed. If the rotational speed of the heat exchanger is reduced to about 1/4 rpm, the linear velocity of the heat element outside the heat exchanger can be lowered to 160 mm / sec.

In order to increase the cleaning effect when the heat exchanger is cleaned, the following methods may be used so that the cleaning material per unit area of the thermal element passes as uniformly as possible.

When the rotary regenerative heat exchanger is a thermal element in the circumferential direction, the linear velocity is much faster than the central portion at the same rotation speed. In other words, when the moving speed of the soot blower is set to be constant, the cleaning liquid injected per unit area of the thermal element in the circumferential direction is smaller than that at the central portion, so the moving speed of the soot blower must be slow at the circumferential end, A cleaning liquid can be sprayed.

On the other hand, the clogging phenomenon of the rotary regenerative heat exchanger is analyzed and it is found that the dust and the gypsum plaster are piled up at the end of the circumference or the central part, Therefore, the moving velocity of the sootblower should be fast in the center and slow in the center and outer parts.

Considering the above two cases simultaneously, the optimum moving speed for each position of the sootblower in the rotary regenerative heat exchanger is calculated as shown in Table 1 below. The rotational speed was the case without deceleration and the degree of clogging of the thermal element was set to 2.0 near the outer periphery of the rotary regenerative heat exchanger and the rotor when the intermediate portion of the thermal element was set at the reference value 1.0. Of course, this value depends on the heat exchanger design and operating conditions.

(Table 1)

Table 1 shows that the nozzle moving speed of the soot blower at the periphery of the rotary regenerative heat exchanger should be 30% slower than the middle part.

In the case of spraying two cleaning liquids at the same time in the sootblower, for example, when hot steam and dry ice pellets are simultaneously sprayed, it is best to spray the high temperature steam to the thermal element first and spray the dry ice pellet to increase the cleaning effect . Conversely, the cleaning effect may be reduced.

The method of moving the sootblower was analyzed as moving at constant speed. It is also possible to move the sootblower moving speed step by step without moving the sootblower moving speed at a continuous speed. The sootblower 1000 is maintained after a predetermined interval, and the holding time can be calculated in consideration of the thermal element moving line speed and the degree of clogging considered above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of the right.

The first fluid F1, the first fluid 11, the second fluid F2, the second flow path 12, the rotary regeneration heat exchanger 10, the lance tube 100, the driving part 200, The nozzle 300, the second nozzle 400,

Claims (17)

A soot blower for cleaning a rotary regenerative heat exchanger including a first flow path through which a first fluid flows and a second flow path through which a second fluid flows and performing heat exchange between the first fluid and the second fluid,
A lance tube including one end reciprocating along one direction on a surface of at least one of the first flow path and the second flow path;
A driving unit connected to the lance tube to reciprocate the lance tube in one direction;
A first nozzle connected to the one end of the lance tube to inject steam into the inlet;
A second nozzle adjacent to the first nozzle and connected to one end of the lance tube, the second nozzle injecting solid particles into the inlet;
A first tube penetrating the interior of the lance tube and communicating with the first nozzle;
A second tube communicating with the second nozzle through the inside of the lance tube;
A steam supply unit connected to the first tube and supplying the steam to the first tube;
A solid particle supply unit connected to the second tube and supplying the solid particles to the second tube;
A longer nozzle protector located at an outermost portion of the lance tube adjacent to the second nozzle, the nozzle protector being longer than the second nozzle; And
A nozzle maintenance chamber surrounding the one end of the lance tube,
/ RTI >
Wherein the solid particle supply portion includes a plurality of sub-particle supply portions,
Wherein each of the plurality of sub-particle supply units supplies different solid particles to the second tube,
Wherein the different solid particles comprise at least one of dry ice pellets, ice particles, and sand,
Wherein the nozzle maintenance chamber includes a gate exposing the first nozzle and the second nozzle. delete delete delete delete The method of claim 1,
The driving unit includes:
A sliding guide portion positioned on the lance tube;
A sliding portion reciprocating along the sliding guide portion; And
A connecting portion connecting the sliding portion and the lance tube,
. The method of claim 1,
The second nozzle is longer than the first nozzle. The method of claim 1,
And the second nozzle has a shape different from that of the first nozzle. delete delete delete The method of claim 1,
Further comprising a guide rail extending in one direction adjacent to the nozzle maintenance chamber and supporting the lance tube. The method of claim 12,
And the guide rail includes an opening for exposing the first nozzle and the second nozzle along the one direction. delete delete delete delete

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