CN214700730U - Air preheater for incinerator - Google Patents

Abstract

The utility model relates to an air preheater for burning furnace burns, include: the flue gas heat exchanger comprises a shell, at least one heat exchange pipe and an air flow path, wherein the at least one heat exchange pipe is arranged in the shell and used for flue gas to pass through, and the air flow path is isolated from the heat exchange pipe and used for air flow to pass through; an inlet smoke box arranged near the first longitudinal end of the shell and provided with a smoke inlet for smoke to enter; an outlet smoke box arranged near the second longitudinal end of the shell and provided with a smoke outlet for smoke discharge; a primary air inlet disposed on the housing and proximate the flue gas outlet; a hot air outlet disposed on the housing and adjacent the flue gas inlet and offset from the main air inlet in the longitudinal direction; an air bypass inlet provided on the housing and disposed between the main air inlet and the hot air outlet in a longitudinal direction; a primary damper arranged to control the flow of air into the housing through the primary air inlet; and a bypass damper configured to control the flow of air into the housing through the air bypass inlet.

Description

Air preheater for incinerator

Technical Field

The utility model relates to an air preheater for burning furnace.

Background

The prior art air preheaters for incinerators generally only heat the combustion air of the incinerator to a given temperature inside them. Because the mass flow of the combustion air for the incinerator is fixed, the mass flow of the high-temperature flue gas is also fixed, and the heat exchange area of the air preheater cannot be changed, the temperature of the heated air outlet is also fixed, and the temperature of the heated air outlet cannot be basically adjusted. The temperature of the combustion air of the incinerator is not adjustable, so that the performance adjusting capability of the incinerator is limited, and the combustion efficiency of the incinerator is reduced.

In order to increase the performance conditioning capacity of the incinerator while taking into account the non-conditioning capacity of the conventional air preheater, other prior art related art divides the combustion air for the incinerator into two branches, one of which passes through the air preheater and the other passes over the air preheater, and then the combustion air in the two branches is mixed outside the air preheater and then enters the incinerator. Although the mode can meet the temperature regulation capability under the condition that the total combustion air mass flow of the incinerator is not changed, the following defects exist, and the practical application effect is seriously influenced: firstly, the temperature regulation range of combustion air is small; secondly, the high-temperature section of the air preheater and the heated air outlet region are always subjected to higher temperatures, which severely affects the service life of the installation and therefore the economic efficiency.

Therefore, there is a need for an air preheater capable of flexibly adjusting the temperature of air heated by the air preheater for an incinerator at the time of discharge in a wider range with a simple and easy-to-implement structure while effectively reducing the temperature of the high-temperature section of the air preheater.

SUMMERY OF THE UTILITY MODEL

To this end, according to a first aspect of the present invention, a new air preheater is proposed, which is capable of flexibly adjusting the temperature of air heated by an air preheater for an incinerator at the time of discharge in a wider range with a simple and easy-to-implement structure without adjusting a hot side medium (i.e., high temperature flue gas), without changing the mass flow rate of a heated side medium (i.e., heated air), and without changing the internal configuration of the air preheater, and which is very cost-effective. Simultaneously, for the mode of conventional at the outside mixed cold air of heat exchanger, according to the utility model discloses an air preheater can furthest reduce the temperature of the partial high temperature section of heat transfer to further extension air preheater life, this especially is greater than more than 600 ℃ and is greater than the application effect more obvious more than 600 ℃ to the combustion air temperature of burning furnace and heated air, has more economic benefits nature.

According to an embodiment of the utility model, a propose an air preheater for burning furnace, its special package that includes:

the heat exchanger comprises a shell, at least one heat exchange pipe and an air circulation path, wherein the shell is internally provided with the at least one heat exchange pipe for smoke to pass through, and the air circulation path is isolated from the at least one heat exchange pipe and used for air flow to pass through;

an inlet smoke box disposed adjacent the first longitudinal end of the housing and having a smoke inlet disposed therein for the entry of smoke;

an outlet smoke box disposed adjacent a second longitudinal end of the housing opposite the first longitudinal end and having a smoke outlet disposed thereon for the discharge of smoke;

a primary air inlet disposed on the housing and proximate the flue gas outlet;

a hot air outlet disposed on the housing and proximate to the flue gas inlet; and

an air bypass inlet disposed in the housing and disposed between the main air inlet and the hot air outlet in a longitudinal direction;

wherein the flue gas inlet and the flue gas outlet are in communication with the heat exchange tubes, and the main air inlet, the hot air outlet, and the air bypass inlet are in fluid communication with the air flow path;

wherein the air preheater further comprises:

a primary damper arranged to control the flow of air into the housing through the primary air inlet; and

a bypass damper configured to control the flow of air into the housing through the air bypass inlet.

Furthermore, the air preheater according to the present invention may further comprise one or more of the following features, taken alone or in combination.

In some embodiments, the air preheater further comprises an air inlet tee in communication with the main air inlet, and a bypass pipe between the air bypass inlet and the air inlet tee, wherein the primary air damper is disposed at a first connection between the main air inlet and the air inlet tee for controlling the air flow through the main air inlet, and the bypass damper is disposed at a second connection between the bypass pipe and the air inlet tee for controlling the air flow through the air bypass inlet.

In some embodiments, the main damper and/or the bypass damper are pneumatically actuated valves.

In some embodiments, the primary damper is a damper that opens when disabled, and/or the bypass damper is a damper that closes when disabled.

In some embodiments, the air preheater is provided with a mechanical limit stop that prevents the main damper from fully closing.

In some embodiments, the bypass adjustment damper includes a valve body and a rotary valve plate disposed in a through-hole of the valve body, the valve plate having a diameter slightly smaller than a diameter of the through-hole of the valve body. This ensures that a certain air leakage is ensured also in the closed position of the bypass regulating damper (in which case the valve plate is completely perpendicular to the central axis of the through-opening of the valve body).

In some embodiments, a plurality of heat exchange tubes for the passage of flue gas are provided in the accommodating space.

In some embodiments, the air flow path is formed between the plurality of heat exchange tubes and the housing wall.

In some embodiments, at least one baffle forming the air flow path is disposed on an interior face of the housing wall.

In some embodiments, a plurality of baffles are disposed on the interior face of the housing wall staggered in the longitudinal direction to form a spiral-rising air flow path in the longitudinal direction.

In some embodiments, an inlet tube sheet and an outlet tube sheet are disposed between the inlet and outlet smoke boxes, respectively, and respective longitudinal ends of the heat exchange tubes inserted through the respective longitudinal ends in the through holes in the inlet and outlet tube sheets, respectively.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present disclosure and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings may be obtained from the drawings without inventive effort. In the drawings:

fig. 1 shows a schematic longitudinal sectional view of an air preheater according to an embodiment of the present invention.

It should be noted that the components in the figures are not necessarily to scale.

List of reference numerals

1 air preheater

10 casing

11 heat exchange tube

13 flue gas inlet

14 flue gas outlet

17 first longitudinal end

18 second longitudinal end

15 inlet tube plate

16 outlet tube plate

23 air main inlet

22 air bypass inlet

24 hot air outlet

31 air inlet tee joint

32 by-pass pipe

33 inlet smoke box

34 outlet smoke box

35 baffle plate

P containing space

A shows the arrows of the flow of the flue gas

B arrows showing the flow of air

C arrows showing the flow of air in the air flow path

V1 main air adjusting valve

V2 bypass adjusting air valve

Detailed Description

An air preheater preheating adjustment system according to an embodiment of the present disclosure is described in detail below with reference to the accompanying drawings. To make the objects, technical solutions and advantages of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are some, but not all embodiments of the present disclosure.

Thus, the following detailed description of the embodiments of the present disclosure, presented in conjunction with the figures, is not intended to limit the scope of the claimed disclosure, but is merely representative of selected embodiments of the disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

The singular forms include the plural unless the context otherwise dictates otherwise. Throughout the specification, the terms "comprises," "comprising," "has," "having," "includes," "including," "having," "including," and the like are used herein to specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

In addition, even though terms including ordinal numbers such as "first", "second", etc., may be used to describe various elements, the elements are not limited by the terms, and the terms are used only to distinguish one element from another. For example, a first component could be termed a second component, and, similarly, a second component could be termed a first component, without departing from the scope of the present disclosure.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, or orientations or positional relationships that are conventionally placed when the disclosed products are used, or orientations or positional relationships that are conventionally understood by those skilled in the art, and are used merely for convenience of describing and simplifying the present disclosure, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present disclosure.

As shown in fig. 1, an air preheater 1 for an incinerator according to an embodiment of the present invention includes a housing 10, an inlet header 33, and an outlet header 34. Wherein the inlet smoke box 33 is arranged near the first longitudinal end 17 of the housing 10 and wherein the inlet smoke box 33 is provided with a smoke inlet 13 for the entrance of smoke, such as high temperature smoke, having a temperature, such as in the range of 850-900 ℃; an outlet smoke box 34 is provided adjacent the second longitudinal end 18 of the housing 10 opposite the first longitudinal end 17, and a smoke outlet (14) is provided in the outlet smoke box 34 for discharging smoke therefrom.

At least one heat exchange tube 11 for the passage of flue gas and communicating with both the inlet header tank 33 and the outlet header tank 34 is provided in the casing 10, for example, a plurality of heat exchange tubes 11 for the passage of flue gas are provided, and the plurality of heat exchange tubes 11 may be arranged in parallel with each other and extend in the longitudinal direction of the casing 10. In the present description, the longitudinal direction refers to the main extension direction of the housing 10 of the air preheater 1. In a specific embodiment, the plurality of heat exchange tubes 11 are arranged regularly, for example uniformly, in the housing 10. More specifically, the plurality of heat exchange tubes 11 are disposed with equal gaps therebetween, while gaps also exist between the heat exchange tubes 11 and the housing wall 10. As such, the plurality of heat exchange tubes 11 may have a honeycomb-shaped structure in a sectional view taken perpendicular to the longitudinal direction.

Further, an air flow path for air flow passage is defined in the casing 10, which is isolated from the heat exchange tubes 11 for flue gas passage, for example, provided between the heat exchange tubes 11, between the heat exchange tubes 11 and the casing wall. Furthermore, in order to direct the flow of the air flow so as to allow a more efficient heat exchange between the air and the flue gases, baffles 35 may be provided on the inner face of the housing wall. In a more specific embodiment, a plurality of baffles are provided on the inner face of the housing wall, staggered in the longitudinal direction, to form a helically ascending air flow path in the longitudinal direction between the heat exchange tubes 11, between the heat exchange tubes 11 and the housing wall, to guide the flow of air, as schematically illustrated in fig. 1 by helical arrows C.

Further, as shown in fig. 1, a main air inlet 23 and a bypass air inlet 22 for air to enter the casing 10 and a hot air outlet 24 for air to exit the casing 10 are further provided in the casing 10, and the main air inlet 23, the bypass air inlet 22 and the hot air outlet 24 are all communicated with the air circulation path. In a more specific embodiment, the main air inlet 23 is disposed adjacent the flue gas outlet 14 and the hot air outlet 24 is disposed adjacent the flue gas inlet 13, the bypass air inlet 22 is disposed between the main air inlet 23 and the hot air outlet 24 in the longitudinal direction, and both the main air inlet 23 and the bypass air inlet 22 are offset from the hot air outlet 24 in the longitudinal direction.

Thus, as shown by arrow a in fig. 1, when the air preheater 1 according to the present invention is in operation, flue gas can enter the inlet smoke box 33 through the flue gas inlet 13, and then enter the heat exchange tube 11 communicating with the inlet smoke box 33 and travel along the heat exchange tube 11, finally reach the outlet smoke box 34 also communicating with the heat exchange tube 11, and be discharged via the flue gas outlet 14 provided on the outlet smoke box 34. Meanwhile, as shown by an arrow B in fig. 1, air to be heated may enter the housing 10 through the air main inlet 23 and the air bypass inlet 22, and heat-exchange with the flue gas circulating within the heat exchange pipe 11 while traveling along the air circulation path in the housing 10, and finally exit the housing 10 through the hot air outlet 24 in the form of heated air.

It should be noted that, because the main air inlet 23 and the bypass air inlet 22 are disposed at different positions of the housing 10 in the longitudinal direction, the first air stream entering the housing 10 through the main air inlet 23 will be heated to a different extent than the second air stream entering the housing 10 through the bypass air inlet 22, and the first and second air streams heated to different extents will be mixed at the hot air outlet 24 and exit the housing 10, thereby enabling flexible adjustment of the temperature of the heated air as it exits through the hot air outlet over a larger range (e.g., 450 ℃ to 650 ℃). Further, the provision of the main air inlet 23 and the bypass air inlet 22 and the hot air outlet 24 in this manner enables the air circulating in the air flow path of the casing 10 to be convected with the flue gas in the heat exchange tubes 11, so that sufficient and efficient heat exchange between the air and the flue gas can be ensured.

In addition, in the air preheater 1 according to the embodiment of the present invention, the position of the air bypass inlet 22 can be adjusted according to actual needs. For example, in one particular embodiment, the air bypass inlet 22 is disposed a first distance from the hot air outlet 24 that is one-third of a second distance from the main air inlet 23 to the hot air outlet 24. Of course, the first distance may be set to be one half, one quarter, etc. of the second distance according to actual needs.

Therefore, according to the utility model discloses an air preheater can be under the condition of not adjusting high temperature flue gas, not changing the mass flow of the air of treating heating and not changing air preheater's inner structure owing to the setting of bypass air entry, with the temperature of the air of simple easy to implement when discharging of adjusting in a flexible way in bigger scope through air preheater, has cost-effectiveness. Simultaneously, for the mode of conventional at the outside mixed cold air of heat exchanger, according to the utility model discloses an air preheater can furthest reduce the temperature of the partial high temperature section of heat transfer to further extension air preheater life, this is especially more obvious to being greater than the application effect more than 600 ℃ by the heating temperature, has more economic benefits nature.

In a more specific embodiment, and as shown in fig. 1, an inlet tube sheet 15 and an outlet tube sheet 16 are provided between the inlet header tank 33 and the outlet header tank 34, respectively, and the heat exchange tubes 11 are inserted through their respective longitudinal ends into through holes in the inlet tube sheet 15 and the outlet tube sheet 16, respectively, to thereby achieve the fixation of the heat exchange tubes 11 and the communication with the inlet header tank 33 and the outlet header tank 34. In a particular embodiment, as shown in fig. 1, the inlet and outlet tube sheets 15, 16 may cover the entire cross-section of the shell in a direction perpendicular to the longitudinal direction and may serve as connections between the inlet and outlet headers 33, 34, respectively, and the shell 10.

More specifically, as shown in fig. 1, the main air inlet 23, the air bypass inlet 22 and the hot air outlet 24 are each provided between the inlet tube sheet 15 and the outlet tube sheet 16, and achieve isolation between the heat exchange tubes 11 for the passage of the flue gas and the air flow path, and isolation between the air flow path and the inlet and outlet headers 33 and 34.

Furthermore, as shown in fig. 1, the air preheater 1 according to the embodiment of the present invention further includes a main adjusting damper V1 and a bypass adjusting damper V2 for controlling the flow rate of the first air stream entering the casing 10 through the main air inlet 23 and the flow rate of the second air stream entering the casing 10 through the bypass air inlet 22, respectively. Thus, by controlling the flow of the first air stream entering the housing 10 through the main air inlet 23 and the flow of the second air stream entering the housing 10 through the bypass air inlet 22 by adjusting the main damper V1 and the bypass damper V2 without adjusting the parameters of the flue gas (e.g., temperature and mass flow) and without changing the overall configuration of the housing of the air preheater and the internal heat exchange tube arrangement, different proportions of the differently heated first and second air streams can be achieved at the hot air outlet 24, thereby enabling flexible adjustment of the temperature of the heated air as it exits through the hot air outlet to a greater extent.

In one particular embodiment, as shown in fig. 1, the air preheater 1 is vertical. In this case, the longitudinal direction thereof coincides with the vertical direction, and the heat exchange tubes 11 for passing the flue gas therethrough may be disposed vertically. More specifically, in this case the inlet smoke box 33 may be provided at the upper end of the housing 10, the outlet smoke box 34 being provided at the lower end of the housing 10; meanwhile, the air main inlet 23 is disposed near the lower end of the case 10, and the hot air outlet 24 is disposed near the upper end of the case 10. This makes it possible to utilize the greater density of the flue gas relative to the air, so that the flue gas and the air flow in a convective manner in the housing, thereby further promoting efficient heat exchange between the air and the flue gas.

In a specific embodiment, as shown in fig. 1, the air preheater 1 according to the present invention further comprises an air inlet tee 31 communicating with the main air inlet 23, the air inlet tee 31 being, for example, welded or tightly fitted in the main air inlet 23, or being sealingly connected in any other suitable fixing manner in the main air inlet 23. Furthermore, the air preheater 1 further comprises a bypass pipe 32 connected between the air inlet tee 31 and the air bypass inlet 22 outside the casing 10, and the bypass pipe 32 may be sealingly connected with the air inlet tee 31 and the air bypass inlet 22 in any suitable fixing manner. In this case, the main adjusting damper V1 may be provided in the air inlet tee 31, and the bypass adjusting damper V2 may be provided in the bypass pipe 32. This allows connection to the air source only through the air inlet tee 31, making the construction of the air preheater 1 simpler.

In a more specific embodiment, as shown in fig. 1, a primary damper V1 is disposed between the air inlet tee 31 and the primary air inlet 23, for example, at the connection between the air inlet tee 31 and the main air inlet 23, a bypass damper V2 is provided between the air inlet tee 31 and the bypass duct 32, for example, at the connection between the air inlet tee 31 and the bypass duct 32, so that, given an input mass flow of air to be heated, the air to be heated is divided in variable proportions into a first air flow entering the casing 10 through the main air inlet 23 and a second air flow entering the casing 10 through the bypass air inlet 22 by controlling the main adjusting damper V1 and the bypass adjusting damper V2 as required, so that mixed heated air in a wide temperature range can be obtained at the hot air outlet 24.

According to a particular embodiment, the main damper V1 is configured to remain at least partially open, preferably fully open, in the event of a failure, thereby ensuring that air to be heated can always enter the housing, preventing the risk of excessive temperatures in the housing. Alternatively, the main regulating damper may be provided with a stop member for preventing it from closing completely, for example a mechanical stop collar, and in any case this stop member ensures that the main regulating damper maintains a certain angular opening. Of course, other forms of stop member may be provided as long as they achieve such an effect. Further optionally, the bypass modulating damper V2 is a damper that closes upon failure. For example, the bypass adjusting damper V2 may have a valve body for mounting on the air preheater 1, more specifically, in the bypass pipe 32, and a valve plate rotating in a through hole of the valve body, which is a fully closed state of the bypass adjusting damper V2 when the valve plate is perpendicular to a center line of the through hole of the valve body. However, in order to prevent the temperature in the bypass pipe 32 from becoming excessively high to damage the bypass pipe and to employ the air bypass valve V2 of higher temperature resistance, the diameter of the valve plate may be set to be slightly smaller than the diameter of the valve body, so that a certain proportion of the amount of leakage to the bypass pipe 32 is ensured even in the fully closed state of the bypass adjusting valve V2, so that a certain amount of air to be heated (i.e., cold air) can still leak into the bypass pipe 32, reducing the operating temperature of the air bypass valve V2.

According to a specific embodiment, the main and optional bypass regulating dampers are pneumatic regulating valves. In addition, the main air adjusting valve and the bypass air adjusting valve can be manually controlled at the same time, so that the main air adjusting valve and the bypass air adjusting valve can be manually controlled when needed, and safety is further enhanced. Of course, the main and bypass register dampers may be any other suitable type of valve.

The exemplary embodiment of the air preheater proposed by the present invention has been described in detail with reference to the preferred embodiments, however, it will be understood by those skilled in the art that various modifications and changes can be made to the above specific embodiments without departing from the concept of the present invention, and various combinations of the various technical features and structures proposed by the present invention can be implemented without departing from the scope of the present invention.

The scope of the present disclosure is not defined by the above-described embodiments but is defined by the appended claims and equivalents thereof.

Claims (11)

1. An air preheater for an incinerator, characterized in that the air preheater (1) comprises:

a housing (10) in which at least one heat exchange tube (11) for the passage of flue gas and an air flow path isolated from the at least one heat exchange tube (11) for the passage of an air flow are provided;

an inlet smoke box (33) arranged near the first longitudinal end (17) of the housing (10) and provided with a smoke inlet (13) for the entrance of smoke thereon;

an outlet smoke box (34) arranged in the vicinity of a second longitudinal end (18) of the housing (10) opposite to the first longitudinal end (17) and provided thereon with a smoke outlet (14) for the exit of smoke;

a primary air inlet (23) provided on the housing (10) and adjacent to the flue gas outlet (14);

a hot air outlet (24) provided on the housing (10) and close to the flue gas inlet (13); and

an air bypass inlet (22) provided on the housing (10) and arranged in the longitudinal direction between the main air inlet (23) and the hot air outlet (24);

wherein the flue gas inlet (13) and the flue gas outlet (14) are in communication with the heat exchange tubes (11); the main air inlet (23), the hot air outlet (24) and the air bypass inlet (22) are in fluid communication with the air flow path;

wherein the air preheater (1) further comprises:

a primary damper (V1) arranged to control the flow of air into the housing (10) through the primary air inlet (23); and

a bypass damper (V2) configured to control the flow of air into the housing (10) through the air bypass inlet (22).

2. An air preheater for an incinerator according to claim 1, characterized in that the air preheater (1) further comprises an air inlet tee (31) communicating with the main air inlet (23), and a bypass pipe (32) between the air bypass inlet (22) and the air inlet tee (31), wherein the main damper (V1) is provided at a first connection between the main air inlet (23) and the air inlet tee (31) for controlling the air flow through the main air inlet (23), and the bypass damper (V2) is provided at a second connection between the bypass pipe (32) and the air inlet tee (31) for controlling the air flow of the air bypass inlet.

3. The air preheater for an incinerator according to claim 1 or 2, characterized in that the main adjusting damper (V1) and/or the bypass adjusting damper (V2) is a pneumatic adjusting damper.

4. The air preheater for an incinerator according to claim 1 or 2, characterized in that the main adjusting damper (V1) is a damper that opens in failure and/or the bypass adjusting damper (V2) is a damper that closes in failure.

5. An air preheater for an incinerator according to claim 4,

the air preheater is provided with a mechanical limit stop preventing the main damper (V1) from closing completely.

6. The air preheater for an incinerator according to claim 4, characterized in that the bypass damper (V2) comprises a valve body and a rotary valve plate disposed in the through hole of the valve body, the diameter of the valve plate being slightly smaller than the diameter of the through hole of the valve body.

7. An air preheater for an incinerator according to claim 1 or 2, characterized in that a plurality of heat exchange tubes for the passage of flue gas are provided in the housing space (P) of the casing (10).

8. The air preheater for an incinerator according to claim 7, wherein said air flow path is formed between said plurality of heat exchange tubes and said shell wall.

9. An air preheater for an incinerator according to claim 8, characterised in that at least one baffle (35) forming the air flow path is provided on the inner face of the housing wall.

10. An air preheater for an incinerator according to claim 9, wherein a plurality of baffles are provided in the interior face of the housing wall staggered in the longitudinal direction to form a spiral rising air flow path in the longitudinal direction.

11. The air preheater for an incinerator according to claim 1 or 2, characterized in that inlet and outlet tube sheets (15, 16) are provided between the respective longitudinal ends of the inlet and outlet headers (33, 34) and the heat exchange tubes (11), respectively, the heat exchange tubes (11) being inserted through the respective longitudinal ends in through holes in the inlet and outlet tube sheets (15, 16), respectively.

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