Waste heat recovery device of steam boiler

Abstract

The utility model belongs to the technical field of waste heat treatment of steam boilers, and discloses a waste heat recovery device of a steam boiler, which comprises a shell and a normal-pressure energy saver fixed in the shell, a smoke inlet hole is arranged at the top of the shell, a smoke outlet hole is arranged at the bottom of the shell, and smoke enters the normal-pressure energy saver from the top surface of the normal-pressure energy saver and then is discharged from the smoke outlet hole. The normal-pressure energy saver comprises a supporting shell, medium pipes are arranged in the supporting shell in an array mode, and the outer sides of the medium pipes are sleeved with fin assemblies. The heat of the flue gas is transferred to a medium in the medium pipe through the fin assembly and the pipe wall of the medium pipe, so that waste heat recovery is realized; the constant-pressure energy saver has the advantages that smoke enters the constant-pressure energy saver from the top face of the constant-pressure energy saver and then is exhausted from the smoke outlet holes, heat of the smoke is transmitted to media in the medium pipes through the fin assemblies and the pipe walls of the medium pipes, waste heat recovery is achieved, the contact area of the smoke and the medium pipes is increased due to the sheet-shaped area of the fin assemblies, and the heat utilization rate of the smoke is increased. Therefore, the heat exchange efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of waste heat treatment technology for steam boilers, and particularly relates to a waste heat recovery device for steam boilers. Background Technology

[0002] With the advancement of the coal-to-gas policy, the size of steam boilers is becoming smaller and smaller. Correspondingly, the utilization of waste heat from steam boilers is also changing as the boiler size decreases.

[0003] Among them, Chinese utility model patent CN200820116395.1 discloses that "due to the adoption of the above technical solution, the coal smoke of this utility model first circulates from top to bottom through the rotating flue. During the circulation process, since the rotating flue pipe is located in the furnace water jacket, the heat energy in the high-temperature coal smoke is fully absorbed by the water, and then discharged through the chimney, which greatly reduces heat loss, improves thermal efficiency, and saves energy."

[0004] In the article "Typical Design and Simulation Analysis of Drag Reduction Optimization of Boiler Tail Flue" by Wu Lingling, published in the 13th issue of Science and Technology in 2020, it was found that "the original flue gas first flows from the left and right sides of the lower part of the air preheater, then flows forward, then flows upward again, then flows forward again, and enters the dust collector inlet."

[0005] An article titled "Application of Desulfurization, Denitrification, and Dust Removal Technology for Coke Oven Flue Gas" published on the National Energy Information Platform on November 28, 2019, discloses that "ammonia gas from the liquid ammonia station and air from the dilution fan are fully mixed in an ammonia / air mixer and then enter the SCR denitrification reactor together with the coke oven flue gas. The mixed flue gas in the reactor flows vertically downwards. The reactor inlet is equipped with an airflow equalization device and a rectification device to ensure a uniform airflow field. The reactor is equipped with a special medium-low temperature catalyst with an activity temperature of 230℃~300℃. The catalyst can meet the requirement of achieving a denitrification efficiency of over 87.5% when the flue gas volume is at its maximum."

[0006] Therefore, it can be concluded that the design of flue gas flowing from top to bottom is common knowledge.

[0007] Chinese invention patent CN201811080827.2 discloses a flue gas waste heat steam generation device, including a flue gas waste heat steam generator, a gas collection box, and an atmospheric pressure energy saver. This invention combines the flue gas waste heat steam generator and the atmospheric pressure energy saver, achieving two-stage utilization of flue gas waste heat, significantly improving energy efficiency. The flue gas waste heat steam generator directly heats the steam water pipe to generate steam, which is then sent to the gas collection box. The atmospheric pressure energy saver preheats the water fed into the flue gas waste heat steam generator using the flue gas waste heat.

[0008] This patent enables the reuse of flue gas waste heat and places the atmospheric pressure energy saver at the bottom of the steam boiler, saving space. The inventor discovered that existing flue gas waste heat recovery devices do not fully recover and utilize the waste heat. Summary of the Invention

[0009] The purpose of this utility model embodiment is to provide a waste heat recovery device for a steam boiler, aiming to solve the problem that existing flue gas waste heat recovery devices do not fully recover and utilize waste heat when developing a steam boiler device, and to solve the technical problem of fully recovering waste heat from steam boiler devices.

[0010] The present invention is implemented as follows:

[0011] A waste heat recovery device for a steam boiler includes a shell and an atmospheric pressure economizer fixed inside the shell. The top of the shell has a flue gas inlet and the bottom of the shell has a flue gas outlet. The top surface of the atmospheric pressure economizer is open and connected to the flue gas inlet. Flue gas enters the atmospheric pressure economizer from the top surface and is discharged from the flue gas outlet. The atmospheric pressure economizer includes a support shell, and medium tubes are arrayed inside the support shell. Fin assemblies are sleeved on the outside of the medium tubes. The heat of the flue gas is transferred to the medium inside the medium tubes through the fin assemblies and the tube wall of the medium tubes, thereby realizing waste heat recovery.

[0012] Furthermore, the housing includes a protective plate and an insulation layer sandwiched between the protective plates.

[0013] Furthermore, the support shell contains arrays of medium tubes arranged in a rectangular straight line or a rectangular staggered arrangement.

[0014] Furthermore, the medium pipe is divided into straight pipe sections and curved pipe sections, which are alternately connected to form a complete medium pipe.

[0015] Furthermore, the support shell is in the shape of a rectangular cylinder.

[0016] Furthermore, the support shell includes a front perforated plate, a first side plate, a second side plate, and a rear perforated plate; the front perforated plate and the rear perforated plate are symmetrically arranged, and the front perforated plate and the rear perforated plate are provided with accommodating holes for the medium tube in pairs, so as to realize the array arrangement of the medium tube in the support shell.

[0017] Furthermore, the fin assembly includes a plurality of fins evenly distributed on the outside of the medium tube, with a spacing A between adjacent fins, the spacing A being greater than 3 mm.

[0018] Furthermore, the fin assembly includes fins spirally arranged on the outside of the medium tube, the spiral fins forming a spiral flue for the flue gas, along which the flue gas flows.

[0019] The positive effects of this utility model are as follows: after the flue gas enters the atmospheric pressure energy-saving device from the top surface, it is discharged from the flue gas outlet. The heat of the flue gas is transferred to the medium inside the medium tube through the fin assembly and the tube wall of the medium tube, realizing the recovery of waste heat. Since the fin assembly increases the contact area between the flue gas and the medium tube due to the increased fin area, the heat exchange efficiency is improved, further improving the utilization rate of waste heat and achieving the purpose of energy saving. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a waste heat recovery device for a steam boiler according to the present invention;

[0021] Figure 2 yes Figure 1 The image shows a front view of the atmospheric pressure energy-saving device in a waste heat recovery device for a steam boiler according to this utility model;

[0022] Figure 3 yes Figure 2 The image shows a top view of a waste heat recovery device for a steam boiler according to this utility model.

[0023] Figure 4 yes Figure 2 The diagram shows a cross-sectional view (AA) of a waste heat recovery device for a steam boiler according to this utility model.

[0024] Figure 5 yes Figure 4 or Figure 2 Schematic diagram of the medium-dielectric tube;

[0025] Figure 6 yes Figure 5 A schematic diagram of the second embodiment of the structure of the middle fin;

[0026] Legend: 1—Shell, 2—Insulation layer, 3—Smoke outlet, 4—Base, 5—Ambient pressure economizer, 501—First flange, 502—Medium pipe, 5021—Fin, 503—Support shell, 504—Second flange, 5041—T-connector, 505—Third flange, 506—Straight connector, 507—Outlet end, 508—Fin assembly, 509—Inlet end, 6—Smoke inlet, 7—Top surface of ambient pressure economizer. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0028] 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.

[0029] 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.

[0030] like Figures 1 to 5 The diagram shows the structure of a waste heat recovery device for a steam boiler according to an embodiment of this utility model. It includes a housing 1 and an atmospheric pressure energy-saving device 5 fixed within the housing 1. The top of the housing 1 has a flue gas inlet 6, and the bottom of the housing has a flue gas outlet 3. The top surface 7 of the atmospheric pressure energy-saving device is open and connected to the flue gas inlet 6. Flue gas enters the atmospheric pressure energy-saving device from the top surface 7 and is discharged from the flue gas outlet 3. The atmospheric pressure energy-saving device 5 includes a support shell 503, within which a medium tube 502 is arrayed. A fin assembly 508 is fitted onto the outer side of the medium tube 502. The heat from the flue gas is transferred to the medium inside the medium tube 502 through the fin assembly 508 and the tube wall of the medium tube 502, thus achieving waste heat recovery.

[0031] In this embodiment of the invention, flue gas enters the atmospheric pressure energy-saving device from the top surface 7 and is discharged from the flue gas outlet 3. The heat of the flue gas is transferred to the medium inside the medium tube 502 through the fin assembly 508 and the tube wall of the medium tube 502. Compared with the prior art, the flue gas flows through the atmospheric pressure energy-saving device from top to bottom, and its flow speed is slower, which is more conducive to heat exchange and waste heat recovery. Since the fin assembly increases the contact area between the flue gas and the medium tube, the efficiency of heat exchange is improved, further improving the utilization rate of waste heat and achieving the purpose of energy saving.

[0032] Specifically, such as Figures 1 to 5As shown, a waste heat recovery device for a steam boiler includes a shell 1 and an atmospheric pressure economizer 5 fixed inside the shell 1. The top of the shell 1 is provided with a flue gas inlet 6, and the bottom of the shell 1 is provided with a flue gas outlet 3. The top surface 7 of the atmospheric pressure economizer is open and connected to the flue gas inlet 6. Flue gas enters the atmospheric pressure economizer from the top surface 7 and is discharged from the flue gas outlet 3. The atmospheric pressure economizer 5 includes a support shell 503, and a medium tube 502 is arrayed inside the support shell 503. A fin assembly 508 is sleeved on the outside of the medium tube 502. The heat of the flue gas is transferred to the medium inside the medium tube 502 through the fin assembly 508 and the tube wall of the medium tube 502, thereby realizing waste heat recovery.

[0033] The housing 1 includes a protective plate and an insulation layer 2 sandwiched between the protective plates.

[0034] The support shell 503 contains media tubes 502 arranged in a rectangular straight line or a rectangular staggered arrangement. The media tubes 502 are divided into straight pipe sections and curved pipe sections, which are alternately connected to form a complete media tube 502.

[0035] The support shell 503 is in the shape of a rectangular tube.

[0036] The support shell 503 includes a front perforated plate 5031, a first side plate 5032, a second side plate 5033, and a rear perforated plate 5034; the front perforated plate 5031, the first side plate 5032, the second side plate 5033, and the rear perforated plate 5034 form a rectangular cylindrical shape; the front perforated plate 5031 and the rear perforated plate 5034 are symmetrically arranged, and the front perforated plate 5031 and the rear perforated plate 5034 are provided with paired receiving holes for the medium tube 502, so as to realize the array arrangement of the medium tube 502 in the support shell 503.

[0037] The inlet end 509 of the medium pipe 502 is fixed with a first flange 501 for connecting a pipe that provides medium to the medium pipe 502.

[0038] The outlet end 507 of the medium pipe 502 is connected to the second flange 504 and the third flange 505 respectively through the tee joint 5041. The second flange 504 and the third flange 505 are used to connect the medium transportation pipeline and to remove dirt for cleaning, respectively. Their connection order and position are not distinguished.

[0039] like Figure 5 As shown, the fin assembly 508 includes a plurality of fins 5021 evenly distributed on the outside of the medium tube 502, and a spacing A is provided between adjacent fins 5021. The spacing A is greater than 3 mm, preferably 3.5 mm ≤ 3A ≤ 10 mm.

[0040] like Figure 6As shown, this is a second embodiment of the fin assembly 508. The fin assembly 508 includes fins 5021 spirally arranged on the outside of the medium tube 502. The spiral fins 5021 form a spiral flue for the flue gas. The flue gas flows along the spiral flue. Compared with a straight flue, the spiral flue extends the flow length of the flue gas in the atmospheric pressure energy saver, improves the heat exchange time and exchange area, and is beneficial to energy saving.

[0041] 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.

[0042] 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. A waste heat recovery device for a steam boiler, characterized in that, The device includes a housing and an atmospheric pressure energy saver fixed inside the housing. The top of the housing has a smoke inlet and the bottom of the housing has a smoke outlet. The top surface of the atmospheric pressure energy saver is open and connected to the smoke inlet. The flue gas enters the atmospheric pressure energy saver from the top surface and is discharged from the smoke outlet. The atmospheric pressure energy saver includes a support shell, in which medium tubes are arrayed. Fin assemblies are sleeved on the outside of the medium tubes. The heat from the flue gas is transferred to the medium inside the medium tube through the finned assembly and the tube wall, thus achieving waste heat recovery.

2. The waste heat recovery device for a steam boiler according to claim 1, characterized in that, The housing includes a protective plate and an insulation layer sandwiched between the protective plates.

3. The waste heat recovery device for a steam boiler according to claim 2, characterized in that, The support shell contains media tubes arranged in a rectangular straight line or a rectangular staggered arrangement.

4. The waste heat recovery device for a steam boiler according to claim 3, characterized in that, The medium pipe is divided into straight pipe sections and curved pipe sections, which are connected alternately to form a complete medium pipe.

5. A waste heat recovery device for a steam boiler according to any one of claims 1 to 4, characterized in that, The support shell is rectangular.

6. The waste heat recovery device for a steam boiler according to claim 5, characterized in that, The support shell includes a front perforated plate, a first side plate, a second side plate, and a rear perforated plate; the front and rear perforated plates are symmetrically arranged, and the front and rear perforated plates are provided with accommodating holes for the medium tubes in pairs, so as to realize the array arrangement of the medium tubes in the support shell.

7. The waste heat recovery device for a steam boiler according to claim 6, characterized in that, The fin assembly includes a plurality of fins evenly distributed on the outside of the medium tube, with a spacing A between adjacent fins, the spacing A being greater than 3 mm.

8. The waste heat recovery device for a steam boiler according to claim 6, characterized in that, The fin assembly includes fins spirally arranged on the outside of the medium tube, the spiral fins forming a spiral flue for the flue gas, along which the flue gas flows.

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