Heat exchange flue and heat exchange equipment

Abstract

The present invention relates to a heat exchange flue and a heat exchange device including the heat exchange flue, such as a boiler. The heat exchange flue has a top smoke chamber, a bottom smoke chamber and a heat exchange section located therebetween, and the heat exchange section includes a central heat exchange tube bundle and a left flue and a right flue located on both sides of the heat exchange tube bundle. The left and right flues each have a plurality of smoke doors, the smoke doors in each side flue are arranged vertically at intervals, and the corresponding smoke doors in the left flue and the right flue are horizontally aligned; each smoke door has a smoke door frame defining a smoke outlet and a smoke outlet opening and closing device capable of selectively opening and closing the smoke outlet. The corresponding smoke doors of the left and right side flues are connected to a substantially horizontal smoke partition plate, thereby defining a horizontal flue section together with the adjacent smoke doors and smoke partition plates.

Description

Technical Field

[0001] The invention relates to a heat exchange flue and a heat exchange device including the heat exchange flue, such as a boiler. Technical Field

[0003] In the field of heat exchange equipment such as boilers, it is desirable to prevent smoke from accumulating dust and condensing on the heating surface (i.e., heat exchange tube bundle). To this end, some improvement schemes have been proposed in the prior art. For example, CN104344413B (such as Figure 1 The invention proposes to periodically reverse the direction of flue gas flow in the flue to remove the ash deposits on the heat exchange tubes.

[0004] Specifically, in the solution of CN104344413B, the smoke wall 1' defines a smoke duct, which is divided into multiple smoke duct sections by multiple horizontally oriented and vertically spaced smoke doors 3', and a heat exchange tube bundle (i.e., a heating surface) 2' is horizontally arranged in each smoke duct section. The switch state of the smoke inlet and outlet of each smoke door 3' is adjustable (by means of blades 4'), thereby allowing the smoke flow direction in the smoke duct to be reversed periodically, thereby removing the ash accumulation on the heat exchange tube (usually on the leeward side of the tube).

[0005] However, this solution still has some problems, such as:

[0006] Each smoke door 3' extends horizontally to cover the entire smoke duct cross section, such as Figure 2 As shown, the size of each single smoke door is too large, especially the frame (the long side may be as long as 10 to 20 meters, and the short side may be as long as several meters), which makes the manufacture, installation and maintenance of the smoke door difficult, and the thermal expansion and contraction effect further increases the difficulty of installation, and the amount of frame material (such as steel) required is too large, which leads to high manufacturing costs; and

[0007] No matter how the smoke door is adjusted, the flue gas will have to exchange heat with a part of the heating surface (i.e. a part of the heat exchange tube bundle). In this way, when the flue gas temperature is already low, passing through the heating surface will further reduce the flue gas temperature, which is easy to cause condensation, acid rot, ash adhesion and other problems that hinder heat exchange and even block the heating surface; and

[0008] When the flue gas flows along the serpentine flow path, due to the resistance of the heat exchange tube bundle on the heating surface, the flue gas velocity in each horizontal flue section gradually decreases, resulting in ash accumulation on the downstream heating surface or unsatisfactory cleaning effect.

[0009] Therefore, there is a need for improved solutions. Summary of the invention

[0010] The present invention is dedicated to providing a heat exchange flue and corresponding heat exchange equipment that can solve one of the above problems.

[0011] It should be noted that, in the present application, "heat receiving surface" and "heat exchange tube bundle" are synonymous.

[0012] According to one aspect of the present invention, a heat exchange flue is provided, which has a top smoke chamber, a bottom smoke chamber and a heat exchange section located therebetween, the heat exchange section including a central heat exchange tube bundle and a left flue and a right flue located on both sides of the heat exchange tube bundle; the top smoke chamber is surrounded by a peripheral smoke wall, which collects smoke from upstream and allows the smoke to flow into the left flue and / or the right flue; the bottom smoke chamber is also surrounded by a peripheral smoke wall, which collects smoke from the left flue and / or the right flue and discharges it downstream; the left and right flues are respectively vertically cylindrical, and are respectively bounded by the peripheral smoke wall and the heat exchange tube bundle; the left and right flues each have a plurality of smoke doors, the smoke doors in each side flue are arranged vertically at intervals, and the corresponding smoke doors in the left flue and the right flue are horizontally aligned; each smoke door A smoke door frame defining a smoke outlet and a smoke outlet opening and closing device capable of selectively opening and closing the smoke outlet; wherein each smoke door frame is hollow and horizontally arranged, and has an outer contour consistent with the cross-sectional shape of the left and right side flues, and its periphery is respectively air-tightly connected to the peripheral smoke wall and the portion corresponding to the heat exchange tube bundle is air-tightly connected to a substantially horizontal smoke barrier plate, the front and rear sides of the smoke barrier plate are air-tightly connected to the front and rear smoke walls, and the left and right sides are respectively air-tightly connected to the corresponding left and right smoke door frames, so that the left and right smoke doors and the corresponding smoke barrier plates of each layer and the left and right smoke doors and the corresponding smoke barrier plates of the adjacent layer all define a horizontal flue section; when the heat exchange tube bundle is oriented to intersect with the smoke barrier plate, the smoke barrier plate is provided with holes for the heat exchange tubes to pass through, and the holes are substantially air-tight to the heat exchange tubes.

[0013] The present invention also provides a heat exchange device having the heat exchange flue as described above, which may be a boiler.

[0014] According to the present invention, firstly, by transforming the main flue into a "sandwich" structure with left and right flues and a heating surface in the middle, and designing the smoke door to be a narrow structure installed only in the left and right flues, the structure and size of the smoke door are greatly simplified, and the disassembly, assembly, and maintenance are convenient. Secondly, with the help of this "sandwich" structure, it is possible to achieve direct smoke flow in the left and / or right flues (such as Figure 7 As shown), there is no heat exchange with the heating surface, the load is adjusted to the maximum extent, the smoke temperature is ensured, and condensation is prevented; thirdly, due to this "sandwich" structure, a larger space is defined at both ends of each horizontal flue section corresponding to each side flue, and at this time, inspection doors can be opened on the smoke walls at both ends to facilitate the installation of each layer of smoke doors and the inspection of the smoke doors and the heating surface; in addition, each layer of smoke doors can be opened and closed independently, so that the flow path of the flue gas flow in the heat exchange section is diverse; finally, according to a preferred embodiment, the height of the horizontal flue section becomes smaller step by step, so as to ensure that the downstream smoke flow rate will not drop too much, and to ensure that the low-temperature section of the heating surface does not accumulate ash. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic front view of a heat exchange flue according to the prior art.

[0016] Figure 2 To pass through Figure 1 Schematic cross-sectional view of the smoke door of the heat exchange flue along the A'-A' direction.

[0017] Figure 3 It is a schematic front view of an embodiment of a heat exchange flue according to the present invention.

[0018] Figure 4 Based on Figure 3 A schematic cross-sectional view of a heat exchange flue along AA shows a smoke door frame and a possible smoke port opening and closing device.

[0019] Figure 5 Shows Figure 4 Some parts of the flue gas outlet opening and closing device.

[0020] Figure 6 Another possible smoke outlet opening and closing device is shown.

[0021] Figure 7 A possible operation mode of the heat exchange flue according to the present invention is shown.

[0022] Figure 8 Another possible operation mode of the heat exchange flue according to the present invention is shown. DETAILED DESCRIPTION

[0023] The present invention relates to a heat exchange flue, such as Figure 3 As shown, it has a top smoke chamber 1, a bottom smoke chamber 10 and a heat exchange section H therebetween. The heat exchange section H includes a heat exchange tube bundle (i.e., a heating surface) 4 in the middle and a left flue 5 and a right flue 12 on both sides of the heat exchange tube bundle 4.

[0024] The heat exchange tube bundle 4 is preferably oriented vertically, that is, the axis is substantially vertical, but it can also be oriented horizontally and substantially extending forward and backward, or any orientation between the vertical orientation and the substantially extending horizontal orientation. That is, the axis of the heat exchange tube bundle is positioned in a substantially extending vertical plane, thereby allowing the flue gas to laterally flush the surface of the heat exchange tube.

[0025] The top smoke chamber 1 is surrounded by a peripheral smoke wall 20, which collects smoke from upstream and allows the smoke to flow into the left flue 5 and / or the right flue 12. The bottom smoke chamber 10 is also surrounded by a peripheral smoke wall 20, which collects smoke from the left flue 5 and / or the right flue 12 and discharges it downstream.

[0026] The left and right flues 5 and 12 are located on the left and right sides of the heating surface 4, respectively, and are in the shape of vertical cylinders (such as Figure 4 For example, it has a rectangular cross-section in a top view, and is limited by peripheral smoke walls (for example, three smoke walls 20, namely, left / right smoke walls, front smoke wall, and rear smoke wall) and a heating surface 4.

[0027] The left and right side flues 5, 12 each have a plurality of (at least two) flue doors 3, the flue doors 3 in each side flue are vertically spaced apart, and the corresponding flue doors 3 in the left flue and the right flue are roughly horizontally aligned.

[0028] Each smoke door 3 has a smoke door frame 13 defining the smoke port 2 and a smoke port opening and closing device capable of selectively opening and closing the smoke port.

[0029] like Figure 3 and 4 As shown, the smoke door frame 13 is hollow and horizontally arranged, and has an outer contour consistent with the cross-sectional shape of the left and right flues (for example, a rectangle, or other shapes), and its periphery is respectively airtightly connected to the surrounding smoke walls (for example, in the case of a rectangle, three of its four sides are respectively connected to the three smoke walls 20 of the left or right smoke wall, the front smoke wall, and the rear smoke wall), and the portion corresponding to the heat exchange tube bundle 4 (for example, the fourth side in the case of a rectangle) is airtightly connected to a roughly horizontal smoke partition board 6.

[0030] According to a feasible embodiment, the smoke-blocking plate 6 is a plate member, for example, made of steel, with holes (when intersecting with the heat exchange tube bundle 4 of the heating surface - for example, when the tube bundle is arranged vertically, the holes and the tube are roughly airtight) or without holes (when not intersecting with the heat exchange tube bundle of the heating surface - for example, when the tube bundle is arranged horizontally), and its front and rear sides are airtightly fixedly connected to the corresponding front and rear smoke walls 20, and the left and right sides are respectively airtightly connected to the corresponding left and right smoke door frames 13. Thus, the left and right smoke doors 3 and corresponding smoke-blocking plates 6 of each layer and the left and right smoke doors 3 and corresponding smoke-blocking plates 6 of the adjacent layers define a horizontal flue section.

[0031] The top smoke-blocking plate 6 has no holes, so that smoke from the top smoke chamber 1 can only enter the left and / or right flues through the top left smoke door and / or right smoke door and cannot directly enter the heating surface.

[0032] Due to the above structure of the present invention, a large space is defined at both ends of each horizontal flue section corresponding to each side flue, and an inspection door 7 (such as Figure 1 As shown in the figure, it is convenient for operators to install, maintain and overhaul. At this time, operators can easily enter and exit the flues on each side, thereby installing the smoke doors 3 on each layer and overhauling the smoke doors 3 and the heating surface 4.

[0033] In one embodiment, Figure 4As shown, each smoke door 3 has a smoke port 2 (a rectangular opening in the figure) defined by a smoke door frame 13, and the corresponding smoke port opening and closing device comprises: a rotating shaft 23; a flap 22, which is fixedly connected to the rotating shaft 23 to rotate with it to close or open at least a part of the smoke port; a plurality of support plates 21 for rotatably supporting the rotating shaft 23; and a rotating shaft driving device 24. The support plate 21 is in the shape of a long strip, and both ends are fixedly connected to opposite sides of the smoke door frame 13 respectively.

[0034] In a more specific embodiment, Figure 4 and Figure 5 As shown, the shaft driving device includes: a transmission bracket 19 fixed relative to the smoke door frame 13 (for example, fixed on the smoke wall); a rocker arm 15 rotatably supported by the transmission bracket 19, one end of the rocker arm 15 is fixedly connected to the shaft 23, and the other end is pivotally connected to a driving connecting rod 16, and the driving connecting rod 16 is optionally connected to a driver 24.

[0035] When in use, the driving link 16 is moved to a predetermined position by manpower (if there is no driver 24) or the driver 24, thereby driving the rocker arm 15 to rotate relative to the transmission bracket 19, thereby driving the rotating shaft 23 to rotate, and then driving the flap 22 to flip, so as to close or open the smoke outlet 2. The predetermined position can be achieved by an appropriate stopper.

[0036] Those skilled in the art should understand that the driving device of the rotating shaft 23 can be various. For example, the rotating shaft 23 itself can extend outside the flue or extend outside the flue with the help of a rod connected thereto, and then the rotation of the rotating shaft 23 can be achieved with the help of belt drive, chain drive, gear drive and other mechanisms.

[0037] In a possible embodiment, each smoke door frame 13 has a plurality of parallel rotating shafts 23, and these shafts 23 are linked to each other so that the flaps 22 on these rotating shafts can dock with each other or partially overlap to cover the entire smoke outlet similar to shutters, thereby achieving the closure of the entire smoke outlet.

[0038] In another embodiment, Figure 6As shown, each smoke door frame 13 has a group of fixed gates 62 spaced apart, and a smoke port is defined between adjacent fixed gates. The smoke port opening and closing device includes: a pull rod 64; a group of sliding gates 63 fixed on the pull rod 64 and arranged at intervals along the pull rod; a plurality of support plates (not shown, similar to the support plate 21) for reciprocatingly supporting the pull rod 64; and a driving device 65 for driving the pull rod to move back and forth. The fixed gates 62 and the sliding gates 63 are spaced apart. The size of the sliding gate 63 is slightly larger than the size of the smoke port. Thus, when the pull rod 64 is pulled back and forth to a predetermined position, the sliding gate 3 can block or open the smoke port. The predetermined position can be achieved by an appropriate stopper.

[0039] The smoke port opening and closing devices of the smoke door frames on the left and right sides can be operated in a linked manner or independently.

[0040] According to the present invention, the heat exchange flue can be configured to allow the flue gas to pass through each horizontal flue section in sequence along a serpentine path, such as Figure 1 or all the smoke doors of the left flue are in the open position and all the smoke doors of the right flue are in the closed position, so that the flue gas does not pass through the heat exchange tube bundle but flows directly through the left flue, as shown in FIG. Figure 7 or conversely, all the smoke doors of the right flue are in the open position and all the smoke doors of the left flue are in the closed position, so that the smoke does not pass through the heat exchange tube bundle but directly flows through the right flue (not shown); or all the smoke doors are in the open position, so that the smoke passes through the left and right flues at the same time without passing through the heat exchange tube bundle (not shown); or the opening and closing of each smoke door in the left and right flues is appropriately set according to the load conditions, so that the smoke only passes through part of the horizontal flue section instead of all of the horizontal flue sections, such as Figure 8 shown.

[0041] According to one solution of the present invention, the vertical distance between adjacent smoke doors 3 in each side smoke duct of the left and right smoke ducts 5 and 12 gradually decreases from top to bottom, thereby making the vertical height of each horizontal smoke duct section gradually decrease from top to bottom. Figure 1 , 7 , 8 (see especially Figure 8 It can be easily understood that a>b>c in the figure, a, b, c represent the vertical heights of the horizontal flue sections of each layer respectively). Thus, it is ensured that the downstream flue gas still has a relatively high velocity after multiple turns and multiple passes through the heating surface, thereby reducing or avoiding dust accumulation on the heat exchange tubes.

[0042] Finally, it should be noted that according to the present invention, the heat exchange tube bundle of the heating surface is preferably oriented vertically, so as to further avoid dust accumulation due to gravity. However, other orientations are also possible, as long as the flue gas in the horizontal flue section roughly flushes the heat exchange tube bundle horizontally.

[0043] According to the present invention, firstly, by transforming the main flue into a "sandwich" structure with left and right flues and a heating surface in the middle, and designing the smoke door to be a narrow structure installed only in the left and right flues, the structure and size of the smoke door are greatly simplified, and the disassembly, assembly, and maintenance are convenient. Secondly, with the help of this "sandwich" structure, it is possible to achieve direct smoke flow in the left and / or right flues (such as Figure 7 As shown), there is no heat exchange with the heating surface, the load is adjusted to the maximum extent, the smoke temperature is ensured, and condensation is prevented; thirdly, due to this "sandwich" structure, a larger space is defined at both ends of each horizontal flue section corresponding to each side flue, and at this time, inspection doors can be opened on the smoke walls at both ends to facilitate the installation of each layer of smoke doors and the inspection of the smoke doors and the heating surface; in addition, each layer of smoke doors can be opened and closed independently, so that the flow path of the flue gas flow in the heat exchange section is diverse; finally, according to a preferred embodiment, the height of the horizontal flue section becomes smaller step by step, so as to ensure that the downstream smoke flow rate will not drop too much, and to ensure that the low-temperature section of the heating surface does not accumulate ash.

Claims

1. A heat exchange flue, comprising a top smoke chamber, a bottom smoke chamber and a heat exchange section located therebetween, wherein the heat exchange section comprises a heat exchange tube bundle located in the middle and a left flue and a right flue located on both sides of the heat exchange tube bundle; The top smoke chamber is surrounded by a peripheral smoke wall, which collects smoke from upstream and allows the smoke to flow into the left flue and / or the right flue; The bottom smoke chamber is also surrounded by a peripheral smoke wall, which collects smoke from the left flue and / or the right flue and discharges it downstream; The left and right flues are vertically cylindrical and are bounded by surrounding smoke walls and heat exchange tube bundles respectively; The left and right flues each have a plurality of smoke doors, the smoke doors in each side flue are arranged vertically at intervals, and the corresponding smoke doors in the left flue and the right flue are horizontally aligned; each smoke door has a smoke door frame defining a smoke outlet and a smoke outlet opening and closing device capable of selectively opening and closing the smoke outlet; in, Each smoke door frame is hollow and arranged horizontally, and has an outer contour consistent with the cross-sectional shape of the left and right flues. Its periphery is respectively connected to the peripheral smoke wall in an airtight manner, and the portion corresponding to the heat exchange tube bundle is respectively connected to a substantially horizontal smoke partition plate in an airtight manner; the front and rear sides of the smoke partition plate are respectively connected to the front and rear smoke walls in an airtight manner, and the left and right sides are respectively connected to the corresponding left and right smoke door frames in an airtight manner, so that the left and right smoke doors and the corresponding smoke partition plates of each layer and the left and right smoke doors and the corresponding smoke partition plates of the adjacent layer define a horizontal flue section; when the heat exchange tube bundle is oriented to intersect with the smoke partition plate, the smoke partition plate is provided with a hole for the heat exchange tube to pass through, and the hole is substantially airtight with the heat exchange tube; Among them, the smoke gates can be configured to: allow the smoke to pass through each horizontal flue section in sequence along a serpentine path; or all the smoke gates of the left flue are in an open position and all the smoke gates of the right flue are in a closed position at the same time, so that the smoke flows directly through the left flue without passing through the heat exchange tube bundle; or all the smoke gates of the right flue are in an open position and all the smoke gates of the left flue are in a closed position at the same time, so that the smoke flows directly through the right flue without passing through the heat exchange tube bundle; or all the smoke gates are in an open position, so that the smoke passes through the left and right flues at the same time without passing through the heat exchange tube bundle; or the opening and closing of the smoke gates of the left and right flues are appropriately set, so that the smoke passes only part but not all of the horizontal flue sections.

2. The heat exchange flue according to claim 1, wherein: The top smoke baffle has no holes, so that the smoke from the top smoke chamber can only enter the left and / or right flues through the top left smoke door and / or right smoke door and cannot directly enter the heat exchange tube bundle.

3. The heat exchange flue according to claim 1, wherein: Inspection doors are provided on the smoke walls at both ends of each horizontal smoke duct section corresponding to each side smoke duct to allow operators to enter and exit the side smoke ducts.

4. The heat exchange flue according to claim 1, wherein: Each smoke door has a smoke outlet defined by a smoke door frame. The smoke port opening and closing device comprises: a rotating shaft; a flap member fixedly connected to the rotating shaft to rotate with the rotating shaft to close or open at least a part of the smoke port; a plurality of support plates for rotatably supporting the rotating shaft; and a rotating shaft driving device.

5. The heat exchange flue according to claim 4, wherein: The support plate is in the shape of a long strip, and both ends are fixedly connected to the opposite sides of the smoke door frame.

6. The heat exchange flue according to claim 4, wherein: The shaft driving device includes: a transmission bracket fixed relative to the smoke door frame; a rocker arm rotatably supported by the transmission bracket, one end of the rocker arm is fixedly connected to the shaft, and the other end is pivotally connected to a driving connecting rod, and the driving connecting rod is connected to a driver.

7. The heat exchange flue according to claim 4, wherein: The rotating shaft itself extends to the outside of the flue or extends to the outside of the flue with the help of a rod connected thereto, and then the rotation of the rotating shaft is realized with the help of a belt transmission device, a chain transmission device or a gear transmission device as a rotating shaft driving device.

8. The heat exchange flue according to claim 4, wherein: Each smoke door frame has a plurality of rotating shafts arranged in parallel, and these shafts are linked to each other so that the flaps on these rotating shafts can be butted against each other or partially overlap to cover the entire smoke outlet, thereby achieving closure of the entire smoke outlet.

9. The heat exchange flue according to claim 1, wherein: The smoke door frame has a set of spaced apart fixed dampers, and adjacent fixed dampers define smoke ports; The smoke port opening and closing device comprises: a pull rod; a group of sliding shutter plates fixed on the pull rod and arranged at intervals along the pull rod; a plurality of support plates for reciprocatingly supporting the pull rod; and a driving device for driving the pull rod to reciprocate; Each fixed gate plate is arranged at intervals from each sliding gate plate, and the size of each sliding gate plate is slightly larger than the size of the smoke outlet. Therefore, when the pull rod is reciprocatedly pulled to a predetermined position, the sliding gate plate can block or open the smoke outlet.

10. The heat exchange flue according to claim 1, wherein: The smoke port opening and closing devices of each smoke door frame operate in a linked manner or independently.

11. The heat exchange flue according to claim 1, wherein: The vertical height of each horizontal flue section gradually decreases from top to bottom.

12. The heat exchange flue according to claim 1, wherein: The axis of the heat exchange tube bundle is positioned in a vertical plane extending substantially front to back, thereby allowing the flue gas flowing through the horizontal flue section to flush the heat exchange tube bundle substantially transversely.

13. A heat exchange device comprising a heat exchange flue as claimed in any one of the preceding claims.

14. The heat exchange device according to claim 13, which is a boiler.

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