CN112377895B - Adjustable double-bed anti-corrosion external high-temperature superheater ash return device and method - Google Patents

Abstract

The invention discloses an adjustable double-bed anti-corrosion external high-temperature superheater ash returning device and method. According to the invention, the circulating flow of the ash returning device can be effectively adjusted by adjusting the partition plates to different heights, so that the bed temperature can be flexibly adjusted, and the phenomenon that components such as glass contained in the garbage fuel are molten at high temperature, adhere to a heat exchange pipe or block a slag discharge port and harm the safe operation of the incinerator is avoided; the corrosion caused by the corrosion of the superheater tube bundle by high-temperature acid gas containing HCI and the like is avoided; and the movement of ash in the device is in a bubbling fluidized bed state, and the heat exchange coefficient is higher than that of a superheater arranged on a boiler flue, so that the metal consumption of the superheater can be greatly reduced, and the device is suitable for a circulating fluidized bed garbage incinerator.

Description

Adjustable double-bed anti-corrosion external high-temperature superheater ash return device and method

Technical Field

The invention belongs to the field of design of external high-temperature superheaters of circulating fluidized beds, and particularly relates to an adjustable double-bed anti-corrosion external high-temperature superheater ash return device and method.

Background

In recent years, the waste incineration of a circulating fluidized bed becomes an efficient and environment-friendly treatment mode, the waste has wide sources and higher chlorine content than that of coal, high-temperature flue gas containing corrosive gases such as HCI and the like is generated during incineration, heating surfaces such as a superheater in a tail flue are easy to corrode, heat exchange efficiency is reduced, and long-time safe operation of a unit is damaged. The device mainly comprises heating surfaces such as a superheater and a reheater.

The circulation flow of the external heat exchanger is adjusted in time along with the temperature in the hearth: when the temperature in the hearth is higher, the circulation flow rate is increased, and the temperature in the hearth is reduced by using the cold ash after heat exchange; when the temperature in the hearth is lower, the circulating flow rate is reduced, and the temperature in the hearth is increased.

At present, two types of mechanical valves and non-mechanical valves (pneumatic type) are mainly adopted for flow regulation of circulating ash, the mechanical valves such as cone valves have good performance and are flexible to regulate, but the problems of blockage, abrasion, erosion and the like are easy to occur due to long-time operation in high-temperature ash, the valves are required to be replaced every half year on average, and the cost is very high, so that the non-mechanical valves (pneumatic type) are adopted for regulation in more and more boiler designs at present, and the regulation is carried out by utilizing the action of fluidized air. Non-mechanical valve (pneumatic) regulation is also generally divided into two types, one is that an external heat exchanger and a material returning device are separated; one type is only an external heat exchanger, the external heat exchanger is used for shunting high-temperature ash separated by the cyclone separator, and one part of the high-temperature ash directly returns to the hearth in a high-temperature ash form through a material returning device; the other part of the gas flows through the external heat exchanger and then returns to the hearth in a low-temperature mode, and the purpose of adjusting the temperature of the hearth is realized through flow distribution of the two loops; the latter is that the high-temperature hot ash separated by the cyclone separator is returned to the hearth after heat exchange by the external heat exchanger, the temperature and pressure parameters of the garbage incinerator are lower, and the latter is adopted in more forms at present.

In the existing patent document of external heat exchanger design of garbage incinerator, for example, in the technical scheme of external fluidized bed heat exchanger disclosed in patent document No. 02285753.2, a part of superheater tube bundles are vertically arranged, the height of material bed is adjusted by changing air volume, and the heat exchange amount is adjusted in a mode of directly influencing the contact area of superheater and high-temperature bed material particles, so that the superheater tube bundles are easily heated unevenly, part of heated surface can not fully exchange heat with the bed material, the upper side and the lower side of the tube bundles form a large temperature difference, and huge thermal stress is generated to damage the tube bundles, thereby threatening the safety of the operation process. In the scheme document of the adjustable external heat exchanger of the circulating fluidized bed boiler disclosed in the patent document with the application (patent) number of 201110242512.5, the gate plate is connected with the actuating mechanism by utilizing the threaded connecting rod device, the purpose of adjusting the bed temperature and the heat absorption capacity is realized by adjusting the height of the gate plate and changing the flow of the ash on the heated surface, but the threaded connecting rod mechanism is easily blocked by high-temperature bed materials and generates slag bonding, so that the normal lifting of the gate plate is influenced, the long-time stable operation is not facilitated, and the ash in the threaded connecting rod mechanism is treated, and the additional operation cost is increased.

Disclosure of Invention

The invention mainly aims to overcome the defects of the prior art and provides an adjustable double-bed anti-corrosion external high-temperature superheater ash returning device and a method thereof, so as to solve the problem that the existing external heat exchanger device of a garbage incinerator is easy to be corroded by high-temperature acid gas, and the height of a partition wall is adjustable, so that the functions of flexibly adjusting the flow rate of circulating ash and the temperature of a hearth are realized.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention firstly provides an adjustable double-bed anti-corrosion external high-temperature superheater ash return device which comprises an ash return device body, wherein an air distribution plate is arranged at the bottom of the ash return device body, and an air cap is arranged on the air distribution plate; a liftable partition wall is arranged in the ash returning device body, the partition wall divides the ash returning device body into a heat exchange chamber positioned at the rear side and a material returning chamber positioned at the front side, and the heat exchange chamber and the material returning chamber are communicated with each other through a channel formed between the bottom of the partition wall and the air distribution plate; the lower part of the air distribution plate is provided with a heat exchange air chamber and a material returning air chamber; the heat exchange air chamber is positioned right below the heat exchange chamber and communicated with the heat exchange chamber through an air distribution plate; the material returning air chamber is positioned right below the material returning chamber and communicated with the material returning air chamber through an air distribution plate; the heat exchange air chamber and the material returning air chamber are not communicated with each other;

the heat exchange chamber is characterized in that a feeding hole is formed in the rear side of the top of the heat exchange chamber, a heat exchange tube bundle is arranged in the heat exchange chamber in front of the feeding hole, and a material returning hole is formed in the front side of the material returning chamber.

In a preferred embodiment of the invention, a hook rope is connected above the partition wall, the hook rope is controlled by a hydraulic lifting device arranged at the top of the ash returning device body, the partition wall can be controlled to move up and down by controlling the hydraulic lifting device and the hook rope, the communication area of the heat exchange chamber and the material returning chamber is changed, and therefore the circulating ash returning amount is adjusted.

In a preferred embodiment of the invention, no heat exchange tube bundle is arranged right below the feed inlet, so that scouring wear is avoided, and the heat exchange tube bundle is arranged in the front area right below the feed inlet; the heat exchange tube bundle in the heat exchange chamber is vertically arranged from the top of the ash returning device body downwards.

In a preferred embodiment of the invention, the heat exchange air chamber and the material returning air chamber are respectively provided with a heat exchange air chamber inlet and a material returning air chamber inlet; the heat exchange air chamber and the material returning air chamber are both designed to be arranged in a contraction section along the flow direction to form a pressure equalizing air chamber.

In a preferred embodiment of the invention, the central line of the small hole of the hood forms an angle of 0-15 degrees downwards with the horizontal direction.

Furthermore, the blast cap adopts a double-layer or single-layer blast cap. The blast caps can be arranged in rows, and the adjacent two rows of blast caps are arranged in a staggered manner. Furthermore, each hood is provided with four or six small holes.

In a preferred embodiment of the invention, the heat exchange chamber and the return chamber are respectively provided with a slag discharge pipe on the bottom air distribution plate. Furthermore, the slag discharge pipe is arranged on the air distribution plate at the bottom of the central position of each air chamber.

The invention also provides a working method of the adjustable double-bed anti-corrosion external high-temperature superheater ash return device, wherein a feed inlet is communicated with the separation device, and a material return port is communicated with a hearth through a material return pipe;

when the device works, high-temperature circulating ash materials are separated by the separating device and then enter the heat exchange chamber from the feeding hole, air supplied into the heat exchange chamber from the inlet of the heat exchange chamber is uniformly sprayed out in a fluidized air mode from small holes of the hood after passing through the hood and then enters the heat exchange chamber, the air supply quantity at the inlet of the heat exchange chamber is adjusted to adjust the fluidized air speed in the heat exchange chamber, the ash materials exchange heat with the heat exchange tube bundle under the action of the fluidized air in the heat exchange chamber, and the low-temperature ash materials after heat exchange flow into the material returning chamber from the heat exchange chamber through a channel below the partition wall;

in the material returning chamber, air supplied into the material returning chamber from an inlet of the material returning chamber passes through the hood and is uniformly sprayed out in a fluidized air mode from the small holes of the hood, and under the action of the fluidized air, ash in the material returning chamber returns to a hearth through the material returning port and the material returning pipe to participate in the next material circulation flow;

when the circulating ash recycling device works, the sectional area of an ash material circulating channel in the ash recycling device body can be changed by adjusting the vertical height of the partition wall, so that the flow of circulating ash materials is adjusted, and the heat absorption capacity of a tube bundle of the superheater can be adjusted by adjusting the vertical height of the partition wall, so that the temperature of a bed and the ash material is adjusted; the slag discharge pipes at the bottoms of the heat exchange chamber and the material return chamber are opened during working, and slag is discharged from the bottom.

Compared with the prior art, the invention has the following advantages:

(1) the invention can be applied to the heating surface of the high-temperature superheater of the incinerator of the garbage power plant. The circulating flow of the ash returning device can be effectively adjusted by adjusting the partition plates to different heights, so that the residence and heat exchange time of high-temperature ash in the ash returning device is adjusted, the purpose of adjusting the heat absorption capacity of a superheater tube bundle in an external heat exchanger is achieved, the flexible adjustment of the bed temperature and the ash temperature is facilitated, and the situation that components such as glass contained in garbage fuel are molten at high temperature, adhere to a heat exchange tube or block a slag discharge port and harm the safe operation of the incinerator is avoided; the corrosion caused by the corrosion of the superheater tube bundle by high-temperature acid gas containing HCI and the like is avoided; and the ash material in the ash returning device of the external high-temperature superheater moves in a bubbling fluidized bed state, and the heat exchange coefficient is higher than that of the superheater arranged on the flue of the boiler, so that the metal consumption of the superheater can be greatly reduced, and the device is suitable for a circulating fluidized bed garbage incinerator.

(2) Divide into heat transfer room and returning charge room two parts with external high temperature over heater ash return device, and partition wall top and external heat exchanger bottom form ash material circulation passageway, have increased the dwell time of ash material in outer heat exchanger, are favorable to heat exchange tube bank and high temperature ash material abundant heat transfer, improve heat exchange efficiency.

(3) The heat exchange tube bundle is arranged in the heat exchange chamber and is not directly arranged below the feeding hole, so that the tube bundle is prevented from being abraded under the condition that high-temperature ash is washed for a long time.

(4) The bottoms of the heat exchange chamber and the material returning chamber respectively correspond to the heat exchange air chamber and the material returning air chamber, so that the fluidization air speed of a local area can be flexibly adjusted, and the material returning flow and the hearth bed temperature can be conveniently adjusted.

Drawings

FIG. 1 is a schematic structural diagram of an adjustable double-bed anti-corrosion external high-temperature superheater ash returning device.

Fig. 2 is a sectional view a-a of fig. 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indications (such as up, down, left, right, front, and rear … …) in the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the figure), and if the specific posture is changed, the directional indication is changed accordingly.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," "disposed" and the like are to be construed broadly, e.g., "secured" may be a fixed connection, a removable connection, or an integral part; the connection can be mechanical connection, electrical connection, physical connection or wireless communication connection; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The present invention will be described in further detail below with reference to the accompanying drawings.

As shown in fig. 1, which is a schematic structural diagram of an adjustable double-bed anti-corrosion external high-temperature superheater ash returning device in an embodiment of the present invention, the adjustable double-bed anti-corrosion external high-temperature superheater ash returning device includes a feed inlet 1, a heat exchange chamber 2, a high-temperature superheater tube panel 3, a material returning chamber 4, a material returning port 5, an air cap 6, an air distribution plate 7, a heat exchange air chamber 8, a heat exchange air chamber inlet 9, a material returning air chamber 10, a material returning air chamber inlet 11, a partition wall 12, a hook rope 13, a hydraulic lifting device 14, and a slag discharge pipe 15.

The specific structure of the ash returning device of the high-temperature superheater in the embodiment is as follows: adjustable double bed anticorrosion external high temperature over heater returns grey device is equipped with a feed inlet 1, set up the rear upside of this ash device of returning, heat transfer chamber 2 is linked together with feed inlet 1, heat transfer tube bank 3 has been arranged in heat transfer chamber 2 in feed inlet 1 the place ahead, heat transfer tube bank 3 is arranged perpendicularly downwards by returning grey device top, heat transfer chamber 2 and returning charge room 4 are separated by partition wall 12 within a definite time, partition wall 12 is arranged perpendicularly downwards by returning grey device top, form the intercommunication passageway between bottom and air distribution plate 7. In the whole boiler circulation loop, the feeding port 1 is communicated with the cyclone separator, the material returning port 5 is communicated with the hearth through a material returning pipe, and the material returning port, the hearth, the external heat exchanger and the like form an ash side complete circulation loop.

The hook rope 13 is connected above the partition wall 12, the hook rope 13 is controlled by the hydraulic lifting device 14, the partition wall 12 can be controlled to move up and down by controlling the hydraulic lifting device 14 and the hook rope 13, the communication area of the heat exchange chamber 2 and the material returning chamber 4 is changed, and therefore the circulating ash returning amount is adjusted.

The blast caps 6 are arranged on the air distribution plate in the heat exchange chamber 2 and the material returning chamber 4, the blast caps 6 can adopt single-layer or double-layer blast caps according to actual operation parameters, 4 holes or 6 holes can be arranged in each layer, the small hole direction of each blast cap is inclined downwards by 0-15 degrees along the horizontal line direction, the bottom ash material of the air distribution plate and the edge wall of the ash returning device are convenient to sweep, and the ash material at the corner is prevented from forming a dead zone which is not fluidized.

When the air conditioner works, fluidized air enters the heat exchange air chamber 8 and the material returning air chamber 10 from the heat exchange air chamber inlet 9 and the material returning air chamber inlet 11 respectively, the heat exchange air chamber 8 is not communicated with the material returning air chamber 10, and the fluidized air enters the heat exchange chamber 2 and the material returning chamber 4 through the air caps 6 on the air distribution plate 7. The heat exchange air chamber 8 and the material returning air chamber 10 are both designed to be arranged in a contraction section along the flow direction to form a pressure equalizing air chamber.

When the device works, high-temperature circulating ash is separated by the separating device and then enters the heat exchange chamber 2 from the feeding port 1, air supplied into the heat exchange chamber 8 from the heat exchange chamber inlet 9 passes through the hood 6 and then is uniformly sprayed out from the hood small holes in a fluidized air mode to enter the heat exchange chamber 2, the included angle between the central line of the hood small holes and the horizontal direction is 0-15 degrees downwards, the ash is prevented from flowing into the small holes under the action of the fluidized air to block the hoods, the adjacent two rows of hoods are arranged in a staggered mode, and the fluidized air speed in the heat exchange chamber 2 can be adjusted by adjusting the air supply quantity of the heat exchange chamber inlet 9. The heat exchange is carried out between the low-temperature ash and the heat exchange tube bundle 3 under the action of the fluidized air in the heat exchange chamber 2, the low-temperature ash after heat exchange flows into the material returning chamber 4 from the heat exchange chamber 2 through a channel below the partition wall 12, and the ash returns to the hearth through the material returning opening 5 under the action of the fluidized air in the material returning chamber 4 to participate in the next material circulation process.

During operation, the slag discharge pipes 15 in the heat exchange chamber 2 and the material return chamber 4 are opened, so that slag can be discharged from the bottom conveniently.

This example adjustable double bed anticorrosion external high temperature over heater ash return device, the partition wall 12 that accessible guy rope 13 was adjusted has been increased, can utilize hydraulic pressure elevating gear 14 to suspend guy rope 13 in midair, the partition wall 12 is connected to the other end of guy rope 13, drive guy rope 13 through operating hydraulic pressure elevating gear 14, adjust partition wall 12 upper and lower height, thereby the function of adjusting the material return volume, realized the regulation to circulation flow, and then realized the dwell time of high temperature ash material in ash return device and the regulation with heat exchange tube bank 3's contact time, thereby reach the purpose of adjusting the interior over heater tube bank endotherm of external heat exchanger, be favorable to nimble regulation bed temperature and ash material temperature. According to the invention, the external heat exchanger and the return ash returning device are not required to be arranged separately or adjusted by adopting a mechanical valve, so that the cost of overall operation and maintenance is reduced, and the accuracy of operation regulation and control is improved.

The adjustable double-bed corrosion-resistant external high-temperature superheater ash returning device of the invention is described in detail above, and specifically, the working principle, the flow and the specific features of the invention are explained, and the above description is only used to help understanding the core idea of the invention, and meanwhile, for a person skilled in the art, by adopting the idea of the invention, corresponding modifications may be made in specific implementation and application scope of the invention. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (8)

1. An adjustable double bed anti-corrosion external high temperature superheater ash return device, comprising the ash return device body, it is characterized in that, the bottom of the described ash return device body is provided with an air distribution plate (7), and the air distribution plate ( 7) A hood (6) is provided on it; a liftable partition wall (12) is arranged in the body of the ash return device, and the partition wall (12) divides the body of the ash return device into a heat exchange chamber (12) located on the rear side. 2) and the material return chamber (4) located on the front side, wherein the heat exchange chamber (2) and the material return chamber (4) communicate with the channel formed between the bottom of the partition wall (12) and the air distribution plate (7); The lower part of the air distribution plate (7) is provided with a heat exchange air chamber (8) and a material return air chamber (10); The plate (7) is connected; the material return air chamber (10) is located directly below the material return chamber (4), and the two are connected through the air distribution plate (7); the heat exchange air chamber (8) and the material return air The chambers (10) are not connected to each other; the heat exchange air chamber (8) and the material return air chamber (10) are respectively provided with a heat exchange air chamber inlet (9) and a material return air chamber inlet (11); the Both the heat exchange air chamber (8) and the material return air chamber (10) are designed to be arranged in a narrowed section along the flow direction to form an equal pressure air chamber; A hook cable (13) is connected above the partition wall, and the hook cable is controlled by a hydraulic lifting device (14) arranged on the top of the ash returning device body, and can be controlled by manipulating the hydraulic lifting device (14) and the hook cable (13). The partition wall (12) moves up and down to change the communication area between the heat exchange chamber (2) and the material-returning chamber (4), so as to adjust the amount of recycled ash; The heat exchange chamber (2) is provided with a feed port (1) on the rear side of the top, and a heat exchange tube bundle (3) is arranged in the heat exchange chamber (2) in front of the feed port (1). ) is provided with a return port (5). 2. The adjustable double bed anti-corrosion external high temperature superheater ash return device according to claim 1, characterized in that, the heat exchange tube bundle (3) is not arranged directly under the feed inlet (1), and the heat exchange tube bundle is not arranged. (3) Arranged in the front area directly below the feed inlet (1); the heat exchange tube bundle (3) in the heat exchange chamber (2) is vertically arranged downward from the top of the ash return device body. 3 . The adjustable double bed anti-corrosion external high temperature superheater ash return device according to claim 1 , wherein the center line of the small hole of the air cap and the horizontal direction are at an angle of 0 to 15 degrees downward. 4 . 4. The adjustable double bed anti-corrosion external high temperature superheater ash return device according to claim 1 or 3, characterized in that, the air cap adopts a double layer or a single layer air cap. 5. The adjustable double bed anti-corrosion external high temperature superheater ash return device according to claim 1 or 3, wherein the air caps are arranged in a row, and the air caps in two adjacent rows are arranged in a staggered row. 6. The adjustable double bed anti-corrosion external high temperature superheater ash return device according to claim 1, characterized in that the bottom air distribution plate (7) of the heat exchange chamber (2) and the material return chamber (4) ) are respectively arranged with slag discharge pipes (15). 7 . The adjustable double bed anti-corrosion external high temperature superheater ash return device according to claim 6 , wherein the slag discharge pipes are arranged on the air distribution plate at the bottom of the center of each air chamber. 8 . 8. A working method of the adjustable double bed anti-corrosion external high temperature superheater ash return device according to claim 1, characterized in that the feeding port (1) is communicated with the separation device, and the feeding port (5) passes through The return pipe is communicated with the furnace; During operation, the high-temperature circulating ash is separated by the separation device and then enters the heat exchange chamber (2) from the feed inlet (1), and the supply air entering the heat exchange air chamber (8) from the inlet (9) of the heat exchange air chamber passes through the air cap ( 6) After that, the air is uniformly ejected in the form of fluidized wind from the small holes of the air cap, and enters the heat exchange chamber (2), and the air supply volume at the inlet (9) of the heat exchange air chamber can be adjusted to adjust the fluidization wind speed in the heat exchange chamber (2). , under the action of the fluidizing wind in the heat exchange chamber (2), the ash material exchanges heat with the heat exchange tube bundle (3), and the low-temperature ash material after heat exchange passes through the channel under the partition wall (12) and is transferred from the heat exchange chamber (2). ) into the return chamber (4); In the material-returning chamber (4), the supply air entering the material-returning air chamber (10) from the inlet (11) of the material-returning air chamber passes through the air cap (6) and then is uniformly ejected in the form of fluidized air from the small holes of the air cap. Under the action of the fluidized air, the ash in the material returning chamber returns to the furnace through the material returning port (5) through the material returning pipe, and participates in the next material circulation process; During operation, by adjusting the upper and lower heights of the partition wall (12), the cross-sectional area of the ash material circulation channel in the body of the ash return device can be changed, thereby adjusting the circulating ash material flow. By adjusting the upper and lower heights of the partition wall (12), the superheater tube bundle can also be adjusted at the same time. Absorb heat to adjust the bed temperature and ash temperature; the slag discharge pipes at the bottom of the heat exchange chamber (2) and the material return chamber (4) are opened during operation, and the slag is discharged from the bottom.

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