Flue gas circulating device of energy-saving steam boiler

Abstract

The utility model belongs to the technical field of small vertical steam boilers with membrane wall structures, and discloses an energy-saving steam boiler flue gas circulating device which comprises an inner flue, the top of the inner flue is communicated with a burner through a burner mounting hole, and the top of the inner flue is provided with a gas inlet. The bottom of the inner flue is communicated with the outer flue through a bottom smoke passing hole, the side face of the top of the outer flue is connected with a plurality of sections of zigzag middle flues, the tail portions of the middle flues are communicated with the top of the waste heat recovery cavity, and a heat exchanger is fixed in the waste heat recovery cavity and used for recovering waste heat of smoke. The device has the beneficial effects that dust in flue gas is deposited and collected; the tail portion of the middle flue communicates with the top of the waste heat recovery cavity, smoke enters the waste heat recovery cavity from the top of the waste heat recovery cavity, the smoke is pushed by follow-up smoke to flow downwards, compared with upward flowing, the smoke stays for a longer time in the waste heat recovery cavity, and heat exchange of the smoke in the heat exchanger is better facilitated.

Description

Technical Field

[0001] This utility model belongs to the technical field of small vertical steam boilers with membrane wall structure, and particularly relates to an energy-saving steam boiler flue gas circulation device. Background Technology

[0002] Small vertical steam boilers with membrane wall structures have a compact structure, and after the flue gas passes through the steam generation structure, a large amount of waste heat is still retained in the subsequent flue gas. However, the existing waste heat recovery technology equipment is too large to be used in small energy-saving boilers, and its cost is also too high to be used in conjunction with small energy-saving boilers. When these devices are used in conjunction with small energy-saving boilers, the small flue gas volume of the small boilers means that heat exchange cannot be fully utilized in these devices, resulting in serious waste heat loss and incomplete waste heat recovery. Summary of the Invention

[0003] The purpose of this utility model embodiment is to provide an energy-saving steam boiler flue gas circulation device, which aims to solve the technical problems of small boilers having small flue gas volume, insufficient heat exchange in existing waste heat recovery equipment, serious waste heat loss, and inability to fully recover waste heat.

[0004] The present invention is implemented as follows:

[0005] An energy-saving steam boiler flue gas circulation device includes an inner flue, the top of which is connected to a burner through a burner mounting hole, and the bottom of which is connected to an outer flue through a bottom flue hole. The top side of the outer flue is connected to multiple tortuous intermediate flues, and the tail of the intermediate flues is connected to the top of a waste heat recovery chamber. A heat exchanger is fixed inside the waste heat recovery chamber for recovering waste heat from the flue gas.

[0006] Furthermore, the multiple tortuous intermediate flues are sequentially connected to the first flue, the second flue, the third flue, and the fourth flue, and the axes of the first flue, the second flue, the third flue, and the fourth flue are not on the same straight line.

[0007] Furthermore, the multi-segment tortuous intermediate flue includes a horizontal first flue, which is connected to a vertical second flue, which is connected to a horizontal third flue, and which is connected to a vertical fourth flue.

[0008] Furthermore, the heat exchanger is fixed to the top of the waste heat recovery chamber formed by the third wall panel and the second wall panel.

[0009] Furthermore, at least one of the first flue, the second flue, the third flue, and the fourth flue is equipped with a guide vane.

[0010] Furthermore, the air guide plate includes a central fixed shaft, and spiral air guide blades are evenly distributed around the circumference of the fixed shaft.

[0011] The positive effects of this invention are as follows: The burner generates a flame, and the resulting high-temperature gas flows downwards into the inner flue through the burner mounting hole. Guided by the bottom smoke passage, it enters the bottom of the outer flue and then rises along the outer flue. The high-temperature gas in the outer flue, closer to the side furthest from the middle flue, rises to the top layer of the outer flue due to the suction effect of the outer flue chimney and the obstruction of the membrane wall, before flowing towards the middle flue. Upon entering the multi-sectioned, tortuous middle flue, the sudden expansion, contraction, or turning of the flow channel creates localized low-speed zones. This design promotes the deposition of dust particles, allowing dust particles from the high-temperature combustion gas to settle in the multi-section, winding intermediate flue, thus achieving the deposition and collection of dust in the flue gas. The tail end of the intermediate flue is connected to the top of the waste heat recovery chamber, and the flue gas enters the waste heat recovery chamber from the top. Since the flue gas naturally floats upward, in this invention, the flue gas flows downward under the impetus of subsequent flue gas. Compared to upward flow, the flue gas stays in the waste heat recovery chamber for a longer time, which is more conducive to heat exchange in the heat exchanger. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of an energy-saving steam boiler flue gas circulation device according to this utility model;

[0013] Figure 2 yes Figure 1 The diagram shows a cross-sectional view of an energy-saving steam boiler flue gas circulation device according to this utility model, and also illustrates the structure of the insulation layer.

[0014] Figure 3 yes Figure 2 The diagram shows the structure of the air guide plate of the energy-saving steam boiler flue gas circulation device of this utility model.

[0015] Legend: 1—Top heating chamber, 2—Upper heating chamber, 3—Furnace shell, 4—Baffle plate, 5—Outer flue, 6—Burner mounting hole, 7—Burner, 8—Inner flue, 9—Membrane wall, 10—Bottom flue, 11—First wall panel, 12—Second wall panel, 13—Smoke outlet, 14—Waste heat recovery chamber, 15—Heat exchanger, 16—Third wall panel, 17—Fourth flue, 18—Top wall panel, 19—Third flue, 20—Second flue, 21—First flue, 22—Flame, 23—Guide plate, 2301—Fixed shaft, 2302—Spiral guide vane, 24—First insulation layer, 25—Second insulation layer, 26—Third insulation layer. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0017] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0019] like Figures 1 to 3 The diagram shown is a structural diagram of an energy-saving steam boiler flue gas circulation device provided in an embodiment of this utility model. It includes an inner flue 8, the top of which is connected to a burner 7 through a burner mounting hole 6, and the bottom of which is connected to an outer flue 5 through a bottom flue hole 10. The top side of the outer flue 5 is connected to multiple tortuous intermediate flues, and the tail of the intermediate flues is connected to the top of a waste heat recovery chamber 14. A heat exchanger is fixed inside the waste heat recovery chamber 14 for recovering waste heat from the flue gas.

[0020] In this embodiment of the invention, the burner 7 generates a flame 22, and the resulting high-temperature gas flows downward through the burner mounting hole 6 into the inner flue 8. Guided by the bottom smoke passage 10, it enters the bottom of the outer flue 5 and then rises along the outer flue 5. The high-temperature gas in the outer flue, closer to the side away from the middle flue, rises to the top layer of the outer flue due to the suction effect of the outer flue chimney and the obstruction of the membrane wall 9, before flowing towards the middle flue. Upon entering the multi-section tortuous middle flue, the sudden expansion, contraction, or turning of the flow channel can create a low-speed zone locally, promoting… Dust particles are deposited in the flue gas, which is made up of dust particles in the high-temperature combustion gas in the multi-section, tortuous intermediate flue. This achieves the deposition and collection of dust in the flue gas. The tail end of the intermediate flue is connected to the top of the waste heat recovery chamber 14. The flue gas enters the waste heat recovery chamber 14 from the top. Since the flue gas naturally floats upward, in this invention, the flue gas flows downward under the impetus of the subsequent flue gas. Compared with upward flow, the flue gas stays in the waste heat recovery chamber 14 for a longer time, which is more conducive to heat exchange in the heat exchanger 15.

[0021] Specifically, such as Figures 1 to 3 The diagram shows an energy-saving steam boiler flue gas circulation device, including an inner flue 8 and an outer flue 5. The inner flue is surrounded by a cylindrical membrane wall 9, and the outer flue 5 is an annular flue formed by the furnace shell 3 and the membrane wall 9. The top surface of the inner flue 8 is sealed. The top of the inner flue 8 is connected to the burner 7 through the burner mounting hole 6, and the bottom of the inner flue 8 is provided with a bottom smoke passage hole 10. The bottom of the inner flue 8 is connected to the outer flue 5 through the bottom smoke passage hole 10. The top side of the outer flue 5 is connected to multiple tortuous intermediate flues, and the tail of the intermediate flues is connected to the top of the waste heat recovery chamber 14. A heat exchanger is fixed in the waste heat recovery chamber 14 for recovering the waste heat of the flue gas.

[0022] Among them, the multiple winding intermediate flues are connected in sequence to the first flue 21, the second flue 20, the second flue 20 and the fourth flue 17, and the axes of the first flue 21, the second flue 20, the second flue 20 and the fourth flue 17 are not on the same straight line.

[0023] Preferably, the multi-segmented intermediate flue includes a horizontal first flue 21, which is connected to a vertical second flue 20. The vertical second flue 20 is connected to a horizontal third flue 19, and the horizontal third flue 19 is connected to a vertical fourth flue 17; wherein, for example... Figure 1 As shown, the first wall panel 11 and the second wall panel 12, which are of different heights, together with the top wall panel 18, form the first flue 21, the second flue 20, and the fourth flue 17.

[0024] The heat exchanger 15 is fixed to the top of the waste heat recovery chamber 14 formed by the third wall plate 16 and the second wall plate 12.

[0025] After the flue gas completes heat exchange in the heat exchanger 15, it enters other downstream equipment or is vented through the flue gas outlet 13 at the bottom of the waste heat recovery chamber 14.

[0026] Preferably, at least one of the first flue 21, the second flue 20, and the fourth flue 17 is provided with a guide vane 23.

[0027] Preferably, the air guide plate 23 includes a central fixed shaft 2301, and spiral air guide blades 2302 are evenly distributed around the circumference of the fixed shaft 2301. After the flue gas passes through the outer flue, the temperature of the flue gas entering the multiple tortuous intermediate flues is different because the distance between the outer flue and the intermediate flue is different. When the flue gas passes through the air guide plate 23, the flue gas is agitated, and the flue gas is mixed. In the preferred embodiment, the spiral air guide blades 2302 can form the flue gas into a spiral flow flue gas, and the flue gas is agitated and mixed to achieve temperature uniformity, which facilitates heat exchange of the flue gas in the heat exchanger 15.

[0028] Preferably, the top of the furnace shell 3 is separated into an upper heating chamber 2 by a removable partition 4. The top of the upper heating chamber 2 is provided with a top heating chamber 1. The heating and heat preservation or heat insulation of the top steam component can be achieved by removing the removable partition 4.

[0029] The foregoing has broadly outlined some aspects and features of the various embodiments and should be interpreted as merely illustrative of potential applications. Other beneficial results can be obtained by applying the disclosed information in different ways or by combining aspects of the disclosed embodiments. Further aspects and a more complete understanding can be obtained based on the detailed description of exemplary embodiments with reference to the accompanying drawings, within the scope defined by the claims.

[0030] The above embodiments provide a detailed description of the present invention. Of course, the above description is not intended to limit the present invention, nor is the present invention limited to the examples described above. Any changes, modifications, additions, reductions, or substitutions made by those skilled in the art within the scope of the present invention are also within the protection scope of the present invention.

Claims

1. An energy saving steam boiler flue gas recirculation device, characterized by, The energy-saving steam boiler flue gas circulation device includes an inner flue, the top of which is connected to the burner through a burner mounting hole, and the bottom of which is connected to the outer flue through a bottom flue hole. The top side of the outer flue is connected to multiple tortuous intermediate flues, and the tail of the intermediate flues is connected to the top of the waste heat recovery chamber. A heat exchanger is fixed inside the waste heat recovery chamber for recovering waste heat from the flue gas.

2. The energy-saving flue gas circulating device for steam boiler according to claim 1, characterized in that, The multiple tortuous intermediate flues are connected sequentially to the first flue, the second flue, the third flue, and the fourth flue, and the axes of the first flue, the second flue, the third flue, and the fourth flue are not on the same straight line.

3. The energy-saving flue gas circulating device for steam boiler according to claim 2, characterized in that, The multi-segmented intermediate flue includes a horizontal first flue, which is connected to a vertical second flue, which is connected to a horizontal third flue, and the horizontal third flue is connected to a vertical fourth flue.

4. The energy-saving flue gas circulating device for steam boiler according to claim 3, characterized in that, The heat exchanger is fixed to the top of the waste heat recovery chamber formed by the third and second wall panels.

5. The energy-saving flue gas recycling device for steam boiler according to any one of claims 2 to 4, characterized in that, At least one of the first flue, the second flue, the third flue, and the fourth flue is equipped with a guide vane.

6. The energy-saving flue gas circulating device for steam boiler according to claim 5, characterized in that, The air guide plate includes a central fixed shaft, and spiral air guide blades are evenly distributed around the circumference of the fixed shaft.

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