CN219389699U

CN219389699U - Screen type superheater

Info

Publication number: CN219389699U
Application number: CN202320344579.8U
Authority: CN
Inventors: 刘志伟; 郑庆飞; 罗潜
Original assignee: Gold East Paper Jiangsu Co Ltd
Current assignee: Gold East Paper Jiangsu Co Ltd
Priority date: 2023-02-28
Filing date: 2023-02-28
Publication date: 2023-07-21
Anticipated expiration: 2033-02-28

Abstract

The application discloses screen type superheater belongs to steam superheating device technical field. The screen type superheater comprises a header, a first pipeline unit, a second pipeline unit and a third pipeline unit, wherein the first pipeline unit, the second pipeline unit and the third pipeline unit are respectively provided with a plurality of U-shaped bent pipelines, and two opposite ends of the pipelines are connected to one side of the header; the third pipe unit includes a plurality of first loop pipes and second loop pipes. The screen type superheater reduces the difference between the longest path length and the shortest path length of steam flow, reduces the temperature difference of the pipe walls of all pipelines, can ensure that the highest temperature of the pipe walls of the main steam temperature boiler does not exceed the allowable wall temperature when the main steam temperature of the main steam boiler runs according to the design working condition, and prevents the pipelines from being damaged.

Description

Screen type superheater

Technical Field

The utility model relates to the technical field of steam superheating devices, in particular to a screen type superheater.

Background

The superheater is used as one of four pipes of the boiler and mainly used for heating saturated steam into superheated steam so as to improve the working capacity of the steam in the steam turbine, and the useful enthalpy of the steam in the steam turbine is increased, so that the cycle efficiency of the heat engine is improved. The screen superheater is arranged as an important component of the superheater system in a high temperature region within the furnace. The existing screen type superheater adopts a three-loop design, all the specifications of the pipelines are the same, but the length of the longest pipeline is about three times of that of the shortest pipeline due to different lengths of the pipelines, the fluid along-way resistance of the longer pipeline is large, the circulating steam quantity is relatively small, the heat exchange area is large, the heat absorption quantity is also large, the wall temperature of the pipeline is easy to exceed the allowable wall temperature, and the pipeline is damaged due to long-term high-temperature operation. In order to avoid pipe breakage caused by long-term super-allowable wall temperature operation of the pipeline, the operation temperature of main steam of the boiler needs to be reduced, so that the thermal efficiency is reduced. Therefore, how to prevent the damage of the tube of the screen superheater without reducing the operation temperature of the main steam of the boiler is a technical problem to be solved.

Disclosure of Invention

The utility model provides a screen superheater can solve the pipeline of boiler main steam temperature when operating according to the design operating mode and easily damaged problem.

In order to solve the technical problems, the application provides a screen type superheater, which comprises a header, a first pipeline unit, a second pipeline unit and a third pipeline unit, wherein the first pipeline unit, the second pipeline unit and the third pipeline unit are respectively provided with a plurality of U-shaped bent pipelines, and two opposite ends of the pipelines are connected to one side of the header; the third pipeline unit comprises a plurality of first loop pipelines and second loop pipelines, the arrangement area of the plurality of second loop pipelines is close to the arrangement area of the plurality of first loop pipelines, and the plurality of first loop pipelines and the plurality of second loop pipelines are sequentially arranged on one side of the header in a mode that the outer ring pipeline is semi-enclosed with the inner ring pipeline; the pipeline of the second pipeline unit is arranged on the outer side of the pipeline of the third pipeline unit in a surrounding mode; the pipeline of the first pipeline unit comprises a heating section and a pipe clamp section, the distance between the pipe clamp section and the header is smaller than the maximum distance between the pipeline of the second pipeline unit and the third pipeline unit and the header, the pipe clamp section transversely spans the second pipeline unit and the third pipeline unit, the pipelines of the second pipeline unit and the third pipeline unit are fixed on the pipe clamp section, the two sections of heating sections are respectively connected to the two opposite ends of the pipe clamp section, and the heating sections are arranged outside the pipeline of the second pipeline unit.

According to the screen type superheater provided by the application, the three-loop design of the traditional third pipeline unit is changed into the two-loop design, so that the difference between the longest path length and the shortest path length of steam flow is reduced, the temperature difference of the pipe walls of all pipelines is reduced, the highest temperature of the pipe walls of the main steam temperature of the boiler can be ensured not to exceed the allowable wall temperature when the main steam temperature of the boiler runs according to the design working condition, and the pipeline is prevented from being damaged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an embodiment of a screen superheater as provided herein;

FIG. 2 is a schematic view of an embodiment of a screen superheater setting adjustment provided herein;

FIG. 3 is a schematic cross-sectional view of an embodiment of an adjusting ring according to the present application from a view along the longitudinal direction of a pipe;

FIG. 4 is a schematic cross-sectional view of an embodiment of an adjusting ring according to the present application from a view along a lateral direction of a pipe;

FIG. 5 is a schematic cross-sectional view of an embodiment of a conditioner sheet according to the present application from a view along the longitudinal direction of a pipe;

fig. 6 is a schematic cross-sectional view of an embodiment of a regulator blade according to the present application from a view in a lateral direction of a pipe.

Detailed Description

The utility model is described in further detail below with reference to the drawings and examples. It is specifically noted that the following examples are only for illustrating the present utility model, but do not limit the scope of the present utility model. Likewise, the following examples are only some, but not all, of the examples of the present utility model, and all other examples, which a person of ordinary skill in the art would obtain without making any inventive effort, are within the scope of the present utility model.

In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. The terms "first," "second," "third," and the like in the embodiments of the present application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", and "a third" may explicitly or implicitly include at least one such feature. All directional indications (such as up, down, left, right, front, back … …) in the embodiments of the present application are merely used to explain the relative positional relationship, movement, etc. between the components in a particular gesture (as shown in the drawings), and if the particular gesture changes, the directional indication changes accordingly. The terms "comprising" and "having" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may alternatively include other steps or elements not listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the utility model. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

The application provides a screen superheater. Referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of a screen superheater provided in the present application. The screen superheater 100 may include a header 10, a first pipe unit 20, a second pipe unit 30, and a third pipe unit 40, and the first pipe unit 20, the second pipe unit 30, and the third pipe unit 40 are each provided with a plurality of pipes bent in a U shape, and opposite ends of the plurality of pipes are connected to one side of the header 10. The screen superheater 100 is placed in the furnace, steam enters from one end of the duct, and the steam flowing in the duct is heated to superheated steam and then exits from the opposite end.

The third pipe unit 40 includes a plurality of first loop pipes 41 and second loop pipes 42, and steam flows out from the first loop pipes 41 through the second loop pipes 42, that is, the pipes of the third pipe unit 40 are of a two-loop design, and the flow path length of the steam in the pipes of the third pipe unit 40 is equal to the sum of the lengths of the first loop pipes 41 and the second loop pipes 42. The arrangement region of the plurality of second circuit pipes 42 is immediately adjacent to the arrangement region of the plurality of first circuit pipes 41, and the plurality of first circuit pipes 41 and the plurality of second circuit pipes 42 are sequentially arranged on one side of the header 10 in such a manner that the outer ring pipe is semi-enclosed with the inner ring pipe, respectively.

The pipes of the second pipe unit 30 are surrounded on the outer side of the pipes of the third pipe unit 40, and the pipes of the second pipe unit 30 form an outer skeleton of the screen superheater 100, thereby enhancing the integrity of the screen superheater 100. Since the pipes of the second pipe unit 30 have only one circuit, it is understood that the flow path length of the steam in the pipes of the second pipe unit 30 is smaller than that in the pipes of the third pipe unit 40.

The pipeline of the first pipeline unit 20 comprises a heating section 21 and a pipe clamp section 22, the distance between the pipe clamp section 22 and the header 10 is smaller than the maximum distance between the pipelines of the second pipeline unit 30 and the third pipeline unit 40 and the header 10, the pipe clamp section 22 transversely spans the pipelines of the second pipeline unit 30 and the third pipeline unit 40, the pipelines of the second pipeline unit 30 and the third pipeline unit 40 are fixed on the pipe clamp section 22, the two sections of heating sections 21 are respectively connected at two opposite ends of the pipe clamp section 22, and the heating sections 21 are arranged outside the pipelines of the second pipeline unit 30. The piping of the first piping unit 20 connects the piping of the second piping unit 30 and the third piping unit 40 as a whole, further enhancing the integrity of the screen superheater 100. The number of the pipes of the first pipe unit 20 and the second pipe unit 30 may be plural, and preferably, the number of the pipes of the first pipe unit 20 and the second pipe unit 30 is 2. Since the distance of the pipe clamp section 22 from the header 10 is smaller than the maximum distance of the second pipe unit 30 from the header 10, the heating section 21 is arranged outside the pipes of the second pipe unit 30, and it is understood that the flow path length of the steam in the pipes of the first pipe unit 20 is smaller than the flow path length in the pipes of the second pipe unit 30.

The screen superheater 100 has a structure in which the pipe lengths of the first pipe unit 20, the second pipe unit 30, and the third pipe unit 40 are sequentially increased because the first pipe unit 20 and the second pipe unit 30 are required for enhancing the integrity thereof, and the third pipe unit 40 is generally designed as a multi-circuit pipe in order to heat steam by making full use of furnace space. However, the more the pipe loops of the third pipe unit 40 are, the greater the difference between the total length of the flow path of the steam in the pipes of the third pipe unit 40 and the flow path of the steam in the pipes of the first pipe unit 20 and the second pipe unit 30 is, and if all the pipes have the same specifications, the pipe wall temperature of the third pipe unit 40 is the highest, and as a result, the pipe wall temperature tends to exceed the allowable wall temperature, and the third pipe unit 40 becomes a weak point of safety of the screen superheater 100.

According to the screen type superheater 100 provided by the application, the three-loop design of the traditional third pipeline unit 40 is changed into the two-loop design, so that the difference between the longest path length and the shortest path length of steam flow is reduced, the temperature difference of the pipe walls of all pipelines is reduced, the highest temperature of the pipe walls of the main steam temperature of the boiler when the main steam temperature of the boiler runs according to the design working condition can be ensured not to exceed the allowable wall temperature, and the pipeline breakage is prevented.

The dust content of the flue gas in the hearth can reach 20g/m ³ The flow rate is 5-6m/s, the pipes of the first pipe unit 20 and the second pipe unit 30, which are positioned at the outer side as the supporting frame, are more easily worn relative to the pipes of the third pipe unit 40 positioned at the inner side, and in order to improve the service life of the screen superheater 100, in one embodiment, the pipe materials of the first pipe unit 20 and the second pipe unit 30 are T91 steel, and the pipe material of the third pipe unit 40 is 12Cr1MoV alloy steel. Allowed wall of 12Cr1MoV alloy steelThe temperature is 580 ℃, the allowable wall temperature of the T91 steel is 650 ℃, and the T91 steel has better wear resistance compared with 12Cr1MoV alloy steel. Although the T91 steel material has a higher allowable wall temperature than the 12Cr1MoV alloy steel, since the T91 steel material is far more expensive than the 12Cr1MoV alloy steel, it is not preferable to replace the pipe material of the third pipe unit 40 with the T91 steel material having a higher allowable wall temperature to prevent breakage of the pipe.

With continued reference to fig. 1, header 10 may include an inlet header 11, a mixing chamber 12, and an outlet header 13 connected in sequence, with steam entering the tubing from inlet header 11 and exiting outlet header 13 after being heated to superheated steam via the tubing. Wherein opposite ends of the pipes of the first pipe unit 20 and the second pipe unit 30 are connected to the inlet header 11 and the outlet header 13, respectively. Opposite ends of the first loop pipe 41 are connected to the inlet header 11 and the mixing chamber 12, respectively, and opposite ends of the second loop pipe 42 are connected to the mixing chamber 12 and the outlet header 13, respectively, i.e., the first loop pipe 41 and the second loop pipe 42 communicate through the mixing chamber 12.

To further reduce the maximum temperature difference between the pipe walls of the pipes, in one embodiment, the outer diameters of the pipes of the first pipe unit 20, the second pipe unit 30 and the third pipe unit 40 are the same, and the wall thicknesses of the pipes are different, so that the flow rates of the steam in the pipes are different to adapt to different heated areas of the pipes.

Specifically, the wall thicknesses of the first, second and third pipe units 20, 30 and 40 are respectively determined according to the calculation of the on-way resistance of the steam flowing in the pipes so that the temperature difference of the pipe walls of the pipes is not more than 50 ℃ when the main steam temperature of the boiler is operated according to the design working condition. The longer pipeline has large fluid resistance along the way, small flow velocity and large heating area, and needs to be provided with a larger pipe diameter. When the temperature difference of the pipe walls of the pipelines is not more than 50 ℃, the heat efficiency of the whole machine is improved.

The wall thickness of the first pipe unit 20 is greater than that of the second pipe unit 30, and the wall thickness of the second pipe unit 30 is greater than that of the third pipe unit 40, in correspondence with the lengths of the pipes of the screen superheater 100. While changing the wall thickness of the tube affects the heat transfer performance, its effect is small and negligible relative to the change in the tube cross section.

If the expected pipeline wall temperature difference is difficult to achieve by only adjusting the pipeline wall thickness through calculation, or the outlet pipeline wall temperature exceeds a set value in actual operation, fine adjustment can be performed by setting a regulating piece for regulating the steam flow. Referring to fig. 2, in some embodiments, an adjusting member 50 is disposed in the pipes of the first pipe unit 20 and the second pipe unit 30 for adjusting the steam flow in the pipes, and the adjusting member 50 is disposed at an end of the pipe near the steam inlet.

The adjusting member 50 may be an adjusting ring 51, as shown in fig. 3 and 4, the adjusting ring 51 is welded around the inner wall of the pipe, and the flow area of the adjusting ring 51 is selected according to resistance calculation and empirical formula.

The adjusting member 50 may also be an adjusting piece 52, as shown in fig. 5 and 6, the adjusting piece 52 is welded on the inner wall of the pipe, the adjusting piece 52 is provided with an adjusting hole 521, the flow area is adjusted by adjusting the opening area of the adjusting hole 521, and the number of the adjusting holes 521 may be a plurality, but the number is not too large, and the aperture is not less than 15mm, so as to prevent impurities in steam from blocking the adjusting holes 521.

The screen type superheater provided by the application has the following beneficial effects at least:

1. the screen type superheater 100 provided by the application reduces the temperature difference of the pipe walls of all the pipes by changing the three-circuit design of the traditional third pipe unit 40 into the two-circuit design, and can ensure that the highest temperature of the pipe walls does not exceed the allowable wall temperature when the main steam temperature of the boiler runs according to the design working condition, thereby preventing the pipe from being damaged.

2. The outer diameters of the first pipe unit 20, the second pipe unit 30 and the third pipe unit 40 are the same, and the wall thicknesses of the pipes are different, so that the flow of steam in the pipes is different, different heating areas of the pipes can be adapted, and the highest temperature difference of the pipe walls of the pipes is further reduced.

3. An adjusting member 50 is provided in the pipes of the first pipe unit 20 and the second pipe unit 30 to adjust the steam flow in the pipes, thereby adjusting the maximum temperature difference of the pipe walls of the pipes.

The foregoing description is only a partial embodiment of the present utility model, and is not intended to limit the scope of the present utility model, and all equivalent devices or equivalent processes using the descriptions and the drawings of the present utility model or directly or indirectly applied to other related technical fields are included in the scope of the present utility model.

Claims

1. A screen superheater, comprising:

the device comprises a header, a first pipeline unit, a second pipeline unit and a third pipeline unit, wherein the first pipeline unit, the second pipeline unit and the third pipeline unit are respectively provided with a plurality of U-shaped bent pipelines, and the opposite ends of the pipelines are connected to one side of the header;

the third pipeline unit comprises a plurality of first loop pipelines and second loop pipelines, the arrangement area of the plurality of second loop pipelines is close to the arrangement area of the plurality of first loop pipelines, and the plurality of first loop pipelines and the plurality of second loop pipelines are sequentially arranged on one side of the header in a mode that the outer ring pipelines are semi-enclosed with the inner ring pipelines respectively;

the pipeline of the second pipeline unit is arranged on the outer side of the pipeline of the third pipeline unit in a surrounding mode;

the pipeline of first pipeline unit includes heating section and pipe clamp section, pipe clamp section with the distance of collection case is less than the second pipeline unit and the pipeline of third pipeline unit with the maximum distance of collection case, pipe clamp section transversely strides across second pipeline unit and third pipeline unit, second pipeline unit and the pipeline of third pipeline unit is fixed pipe clamp section is last, two sections the heating section is connected respectively pipe clamp section's opposite ends, the heating section is arranged the pipeline outside of second pipeline unit.

2. The screen superheater of claim 1 wherein the header includes an inlet header, a mixing chamber, and an outlet header connected in sequence;

opposite ends of the pipes of the first pipe unit and the second pipe unit are respectively connected with the inlet header and the outlet header;

opposite ends of the first loop pipeline are respectively connected with the inlet header and the mixing chamber;

opposite ends of the second loop pipe are respectively connected with the mixing chamber and the outlet header.

3. The screen superheater of claim 1 wherein the first pipe unit, the second pipe unit and the third pipe unit are all identical in pipe outside diameter and different in pipe wall thickness.

4. A screen superheater as claimed in claim 3, wherein the wall thicknesses of the first, second and third pipe units are determined separately from calculation of on-way resistance of steam flowing in the pipes so that the difference in the pipe wall temperatures of the pipes when the main steam temperature of the boiler is operated under the design conditions is not more than 50 ℃.

5. A screen superheater as claimed in claim 3, wherein the first pipe unit has a pipe wall thickness greater than that of the second pipe unit, which is greater than that of the third pipe unit.

6. The screen superheater of any one of claims 1 to 5, wherein an adjusting member is provided in the pipes of the first pipe unit and the second pipe unit for adjusting the flow rate of steam in the pipes, the adjusting member being provided at an end of the pipes near the steam inlet.

7. The screen superheater of claim 6 wherein the adjustment member is an adjustment ring welded around the inner wall of the pipe.

8. The screen superheater of claim 6, wherein the regulating member is a regulating plate welded to an inner wall of the pipe, and the regulating plate is provided with a regulating hole.

9. The screen superheater of claim 1, wherein the number of tubes of both the first and second tube units is 2.

10. The screen superheater of claim 1, wherein the first and second pipe units are made of T91 steel, and the third pipe unit is made of 12Cr1MoVG alloy steel.