Anti-vortex safety structure for inlet end of downcomer in steam pocket

Abstract

The utility model discloses an anti-vortex safety structure at an inlet end of a downcomer in a steam pocket, which comprises the downcomer arranged on the steam pocket, a plurality of partition plates are fixedly arranged in an in-pipe channel of the downcomer at the inlet end of the downcomer, and the in-pipe channel at the inlet end of the downcomer is divided into a plurality of sub-channels by the partition plates. The top inlet of each sub-channel is communicated with the inlet end of the downcomer, and the bottom outlet of each sub-channel is communicated with the in-pipe channel of the downcomer below each partition plate; and a steel screen for covering the inlet end of the downcomer is also fixedly arranged at the inlet end of the downcomer. Vortex is relieved through cooperation of the partition plates and the steel screen, it is guaranteed that the downcomer does not carry steam, and smooth water circulation is guaranteed. In addition, internal components such as bolts and nuts can be prevented from falling into the downcomer, maintenance personnel can be prevented from falling into the downcomer, and the safety performance is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to converter waste heat boiler equipment technical field especially relates to a steam pocket inside downcomer import end anti-vortex safety structure. BACKGROUND

[0002] The steam pocket is a main component of the converter vaporization cooling device of the converter waste heat boiler, which separates the steam in the steam-water mixture entering the steam pocket through the riser to ensure that the quality of the delivered steam meets the requirements, and stores a certain amount of water to ensure the smooth end and safe shutdown of the converter blowing when the water supply is interrupted due to an accident.

[0003] The riser, the downcomer, the steam pocket associated with them, and the upper and lower headers are collectively referred to as a circulating loop. The flow process formed by the difference in specific gravity of the working medium in the downcomer and the riser is called natural circulation. During operation, the water in the steam pocket enters the downcomer from different directions at different flow rates. A rotating vortex is usually formed at the inlet end of the downcomer. The center of the rotating vortex has low pressure and is funnel-shaped. When the water level in the steam pocket is low or the inlet flow rate of the downcomer is high or the diameter of the downcomer is large, a vortex funnel is easily formed. If the rotation is strong and the water level is low, the bottom of the vortex funnel extends into the internal passage of the downcomer, which can bring part of the steam into the downcomer. The presence of steam in the downcomer increases the resistance, which is equivalent to adding a negative flow pressure head to the circulating loop, reducing the water circulation pressure head and adversely affecting water circulation. This can slow down or even stop the water flow, making it difficult to reliably supply water to the downcomer and the water-cooled wall, which can cause overheating and burnout accidents in the water-cooled wall. SUMMARY

[0004] The utility model provides a kind of steam pocket inside downcomer import end anti-vortex safety structure to prevent downcomer from being brought with a large amount of steam.

[0005] To solve the problem of vortex funnel formation at the inlet end of the downcomer in the traditional structure, the utility model provides a steam pocket inside downcomer import end anti-vortex safety structure, which includes a downcomer arranged on the steam pocket. The downcomer is vertically placed, and the open top of the downcomer is the inlet end of the downcomer. The inlet end of the downcomer is sealed and extends into the steam pocket from the through hole at the bottom of the steam pocket. The inlet end of the downcomer is higher than the inner wall of the steam pocket at the position where the downcomer is located. A plurality of partitions are fixedly arranged in the internal passage of the downcomer at the inlet end of the downcomer. Each partition separates the internal passage at the inlet end of the downcomer into a plurality of sub-passages. The top inlet of each sub-passage is in communication with the inlet end of the downcomer, and the bottom outlet of each sub-passage is in communication with the internal passage of the downcomer below each partition. A steel mesh is also fixedly arranged at the inlet end of the downcomer, which covers the inlet end of the downcomer.

[0006] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the plurality of baffles are combined to form a cross grid structure with four sub-channels.

[0007] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the plurality of baffles are combined to form a cross grid structure with four sub-channels.

[0008] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the plurality of baffles are combined to form a cross grid structure with four sub-channels.

[0009] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the plurality of baffles are combined to form a cross grid structure with four sub-channels.

[0010] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the plurality of baffles are combined to form a cross grid structure with four sub-channels.

[0011] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the plurality of baffles are combined to form a cross grid structure with four sub-channels.

[0012] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the fixing structure of the steel mesh at the inlet end of the downcomer is that the steel mesh at the inlet end of the downcomer is fixed to the outer wall of the downcomer by a plurality of L-shaped connecting pieces.

[0013] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein a plurality of round steels are arranged at the inlet end of the downcomer, and the two ends of each round steel are fixed to the outer wall of the downcomer at the inlet end of the downcomer after being bent or folded.

[0014] Further, the aforementioned safety structure for preventing vortex at the inlet end of the downcomer in the steam drum, wherein the plurality of round steels are combined to form a top cover structure with four connecting arms, and the four connecting arms are uniformly and spacedly arranged around the outer wall of the downcomer. The top cover structure has a reinforcing effect and further improves the overall strength, thereby prolonging the service life and reducing the use cost. Preferably, two round steels are combined to form the top cover structure with four connecting arms, wherein the two round steels are folded into V-shaped structures and have connecting feet, the bending angle β between the two connecting arms of the round steel is 120±2°, and β is preferably 120°.

[0015] The beneficial effects of the steam drum safety structure for preventing vortex at the inlet end of the downcomer are as follows: ① the vortex is reduced by the cooperation of the baffles and the steel mesh, so that the downcomer does not carry steam, and the problems of increased resistance, reduced effective pressure head of natural circulation, and slow or stagnant water flow caused by the downcomer carrying steam are avoided, thereby ensuring smooth water circulation; ② the cooperation of the baffles and the steel mesh can prevent internal components such as bolts and nuts from falling into the downcomer, thereby preventing the water cooling wall from being blocked and the pipe from being burst, and ensuring smooth water circulation; in addition, the cooperation of the baffles and the steel mesh can also prevent maintenance personnel from falling into the downcomer, thereby ensuring personal safety; ③ the inclined through holes can drain the water in the steam drum when the steam drum is overhauled or maintained, thereby facilitating construction operation; in addition, if the blowdown pipe in the steam drum cannot drain all the sludge and garbage in the steam drum, the inclined through holes can also drain the sludge and garbage in the steam drum. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic view of the steam drum safety structure for preventing vortex at the inlet end of the downcomer.

[0017] Figure 2 is Figure 1 is a local enlarged structural schematic view of part A in FIG. 1.

[0018] Figure 3 is Figure 1Part B of the local enlarged structure diagram.

[0019] Figure 4 is Figure 1 Part B of the local enlarged structure diagram.

[0020] Figure 5 is the structure diagram of L-shaped connecting piece.

[0021] Figure 6 is the structure diagram of round steel.

[0022] Wherein:

[0023] 1, downcomer; 10, pipe passage; 11, first round hole passage; 12, conical passage; 13, rounded surface; 14, second round hole passage; 2, steam drum; 3, inclined through hole; 4, steel mesh; 5, baffle; 6, round steel; 61, connecting arm; 62, connecting foot; 7, L-shaped connecting piece. DETAILED DESCRIPTION

[0024] The technical scheme of the utility model is described in further detail below in combination with the drawings and preferred embodiments.

[0025] The steam drum inlet end anti-vortex safety structure described in the embodiment, as shown in Figure 1 and Figure 4 , comprises: a downcomer 1 arranged on a steam drum 2, a plurality of baffles 5 are fixedly arranged in a pipe passage 10 of the downcomer 1 at an inlet end of the downcomer 1, each baffle 5 separates the pipe passage 10 at the inlet end of the downcomer 1 into a plurality of sub-passages, the top inlet of each sub-passage is in communication with the inlet end of the downcomer 1, and the bottom outlet of each sub-passage is in communication with the pipe passage 10 of the downcomer 1 below each baffle 5; a steel mesh 4 is also fixedly arranged at the inlet end of the downcomer 1, and the steel mesh 4 covers the inlet end of the downcomer 1.

[0026] Among them, the combination of the baffles 5 forms a cross grid structure with four sub-passages.

[0027] The preferred scheme in the present scheme is that the number of baffles 5 is three, which are respectively a first baffle, a second baffle and a third baffle; the two ends of the first baffle are fixed on the inner tube wall of the downcomer 1; one end of the second baffle is fixed on the inner tube wall of the downcomer 1, and the other end of the second baffle is fixed on the first baffle; one end of the third baffle is fixed on the inner tube wall of the downcomer 1, and the other end of the third baffle is fixed on the first baffle. Among them, the connection mode between the first baffle, the second baffle and the third baffle and the connection mode between the first baffle, the second baffle and the third baffle and the inner tube wall of the downcomer 1 are both welding modes.

[0028] As shown in Figure 1 andFigure 2 As shown in the embodiment, the in-pipe passage at the inlet end of the downcomer 1 is composed of the first circular hole passage 11, the conical passage 12 and the second circular hole passage 14 from top to bottom; the diameter of the first circular hole passage 11 is greater than that of the second circular hole passage 14, the large end diameter of the conical passage 12 is equal to that of the first circular hole passage 11, and the small end of the conical passage 12 is connected with the second circular hole passage 14 through the rounded surface 13; the outer profile of each baffle plate corresponds to and matches the profiles of the first circular hole passage 11, the conical passage 12 and the second circular hole passage 14 at the inlet end of the downcomer 1.

[0029] More preferably, the top inlet of each sub-passage has the same size and shape, and the top inlet and the bottom outlet of each sub-passage also have the same size and shape.

[0030] The vortex is mitigated by the cooperation of each baffle plate and the steel mesh 4, so that the downcomer 1 does not carry steam, and the phenomena of increased resistance, reduced effective pressure head of natural circulation, and slow or stagnant water flow caused by the downcomer 1 carrying steam are avoided, thereby ensuring smooth water circulation.

[0031] In addition to the above advantages, the cooperation of each baffle plate and the steel mesh 4 can prevent internal components such as bolts and nuts from falling into the downcomer 1, causing the water cooling wall to be blocked and other problems such as pipe explosion, thereby ensuring smooth water circulation; in addition, the cooperation of each baffle plate and the steel mesh 4 can also prevent maintenance personnel from falling into the downcomer, thereby ensuring personal safety and improving safety performance.

[0032] As shown in the embodiment, the top inlet of each sub-passage has the same size and shape, and the top inlet and the bottom outlet of each sub-passage also have the same size and shape. Figure 1 and Figure 3 As shown in the embodiment, a plurality of inclined through holes 3 are formed in the outer wall of the downcomer 1 and penetrate the inner wall of the downcomer 1, and the inlet of each inclined through hole 3 is located at the connection between the outer wall of the downcomer 1 and the inner wall of the drum 2.

[0033] Preferably, the inclination angle α of each inclined through hole 3 with respect to the horizontal plane is 15±2°, and more preferably, the inclination angle α of each inclined through hole 3 is 15°.

[0034] When the drum is being overhauled or maintained, the water in the drum 2 needs to be drained completely. Since the inlet end of the downcomer 1 is higher than the inner wall of the drum 2 at the position where the downcomer 1 is located, the downcomer 1 blocks the discharge of part of the water. Here, the inclined through holes 3 are optimally arranged, so that the water in the drum 2 can be completely drained when the drum is being overhauled or maintained, thereby facilitating construction operation.

[0035] Likewise, the problem of depositing sludge and other garbage will also occur when the steam drum is discharged, and the existence of sludge and other garbage is not conducive to water circulation. If the sludge and other garbage in the steam drum 2 cannot be completely discharged through the blowdown pipe in the steam drum 2, the sludge and other garbage in the steam drum 2 can also be completely discharged through the inclined through holes 3, thereby ensuring smooth water circulation.

[0036] There are various ways to fix the steel sheet mesh 4 to the fixed structure at the inlet end of the downcomer 1, such as directly welding the steel sheet mesh to the downcomer 1, but considering the stability of the overall fixation, the present scheme adopts the following fixation method: as shown in Figure 4 and Figure 5 In the present embodiment, the fixed structure of the steel sheet mesh 4 at the inlet end of the downcomer 1 is that the steel sheet mesh 4 placed at the inlet end of the downcomer 1 is fixed to the outer pipe wall of the downcomer 1 through a plurality of L-shaped connecting pieces 7. The fixed connection between each L-shaped connecting piece 7 and the steel sheet mesh 4 and the fixed connection between each L-shaped connecting piece 7 and the outer pipe wall of the downcomer 1 are both achieved by welding.

[0037] In addition, in order to improve the strength at the inlet end of the downcomer 1, the present embodiment is provided with a plurality of round steels 6 at the inlet end of the downcomer 1, both ends of each round steel 6 being fixedly connected to the outer pipe wall of the downcomer 1 at the inlet end of the downcomer 1 after being bent or folded, and the arrangement of each round steel 6 plays a reinforcing role.

[0038] More preferably, the plurality of round steels 6 combine to form a roof structure with four connecting arms; the four connecting arms are evenly spaced around the outer pipe wall of the downcomer 1.

[0039] Further preferably, the present embodiment adopts two round steels bent into a V-shaped shape and having a connecting foot 62, which combine to form a roof structure with four connecting arms 61, as shown in Figure 6 The bending portion of the round steel 6 is a smooth circular arc transition, and the bending angle β between the two connecting arms 61 of the round steel 6 is 120±2°, preferably 120°.

[0040] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in any other form, and any modification or equivalent change made in accordance with the technical essence of the present application still falls within the scope of the present application.

Claims

1. A safety structure for preventing vortex in the inlet end of a downcomer in a drum, comprising: The application discloses a downcomer arranged on a steam pocket, characterized in that a plurality of partitions are fixedly arranged in the inner channel of the downcomer at the inlet end of the downcomer, each partition separates the inner channel at the inlet end of the downcomer into a plurality of sub-channels, the top inlet of each sub-channel is communicated with the inlet end of the downcomer, and the bottom outlet of each sub-channel is communicated with the inner channel of the downcomer below each partition; and a steel mesh is fixedly arranged at the inlet end of the downcomer, and the steel mesh covers the inlet end of the downcomer.

2. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 1, characterized in that: The partitions are combined to form a cross-shaped lattice structure with four sub-channels.

3. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 2, characterized in that: The partitions are three, namely a first partition, a second partition and a third partition; the two ends of the first partition are fixed to the inner wall of the downcomer; one end of the second partition is fixed to the inner wall of the downcomer, and the other end of the second partition is fixed to the first partition; one end of the third partition is fixed to the inner wall of the downcomer, and the other end of the third partition is fixed to the first partition.

4. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 1 or 2 or 3, characterized in that: The inner channel at the inlet end of the downcomer is sequentially composed of a first circular hole channel, a conical channel and a second circular hole channel from top to bottom; the diameter of the first circular hole channel is greater than that of the second circular hole channel, the large end diameter of the conical channel is equal to the diameter of the first circular hole channel, and the small end of the conical channel is smoothly connected with the second circular hole channel through a rounded surface; the outer contour of each partition is matched with the contour of the first circular hole channel, the conical channel and the second circular hole channel at the inlet end of the downcomer.

5. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 1 or 2 or 3, characterized in that: The top inlet of each sub-channel is uniform in size and shape, and the top inlet and the bottom outlet of each sub-channel are also uniform in size and shape.

6. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 1, characterized in that: A plurality of inclined through holes are formed in the outer wall of the downcomer and penetrate the inner wall of the downcomer, and the inlet of each inclined through hole is located at the connection between the outer wall of the downcomer and the inner wall of the steam pocket.

7. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 6, characterized in that: The inclined angle of each inclined through hole relative to the horizontal plane is 15±2°.

8. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 1, characterized in that: The fixing structure of the steel mesh at the inlet end of the downcomer is that the steel mesh at the inlet end of the downcomer is fixed to the outer wall of the downcomer through a plurality of L-shaped connecting pieces.

9. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 1, characterized in that: A plurality of round steels are arranged at the inlet end of the downcomer, and the two ends of each round steel are fixedly connected to the outer wall of the downcomer at the inlet end of the downcomer after being bent or folded.

10. The anti-vortex safety structure for the inlet end of the downcomer in the drum according to claim 9, characterized in that: The round steels are combined to form a top cover structure with four connecting arms, and the four connecting arms are uniformly and spacedly distributed around the outer wall of the downcomer.

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