WO2016145924A1

WO2016145924A1 - Pyrolysis and gasification combined device of circulating fluidized bed

Info

Publication number: WO2016145924A1
Application number: PCT/CN2015/099461
Authority: WO
Inventors: 任燕丽; 巩李明; 孙登科; 王锦生; 陈健陵; 陈勇军; 苏虎; 聂立
Original assignee: 东方电气集团东方锅炉股份有限公司
Priority date: 2015-03-18
Filing date: 2015-12-29
Publication date: 2016-09-22
Also published as: CN204574013U

Abstract

Disclosed is a pyrolysis and gasification combined device of a circulating fluidized bed. The pyrolysis gasification combined device has an H shape in a bilaterally symmetrical arrangement with a boiler furnace (9) being the symmetrical line or the centre of symmetry. A side coal bunker (12) is connected to a pyrolysis and gasification furnace (1) and a back feed leg of a boiler back feeder (8) respectively. The boiler back feeder (8) is connected to the boiler furnace (9) via the back feed leg thereof. The side coal bunker (12) is arranged away from the boiler furnace (9). A cyclone separator (10) is arranged close to the boiler furnace (9). The pyrolysis and gasification furnace (1) is arranged between the side coal bunker (12) and the boiler furnace (9). A first stage separator (2), a second stage separator (3), a material returning device (5), a first stage material returning device (6) and a second stage material returning device (7) are arranged between the pyrolysis and gasification furnace (1) and the boiler furnace (9). The present pyrolysis and gasification combined device of a circulating fluidized bed employs a combined method where a H-shaped arrangement is added to the pyrolysis and gasification furnaces (1) arranged on both sides. Both the back feed leg of the boiler back feeder (8) and the pyrolysis and gasification furnace (1) of the circulating fluidized bed are combined to feed materials by arranging the side coal bunker (12), so that the connection devices between the boiler, the side coal bunker (12) and the pyrolysis and gasification furnace (1) are more simple and reliable.

Description

[Name of invention established by ISA according to Rule 37.2] Circulating fluidized bed pyrolysis gasification combined device

Technical field

The utility model relates to a large circulating fluidized bed pyrolysis gasification combined device, belonging to the technical field of fluidized bed.

Background technique

The grading and conversion of the pyrolysis combustion of the circulating fluidized bed boiler is to closely connect the circulating fluidized bed boiler and the pyrolysis gasification furnace in terms of performance and structure to realize the coal polygeneration. Coal polygeneration technology organically combines coal pyrolysis, gasification, combustion, synthesis and other processes, and improves coal utilization efficiency, environmental efficiency and economy by leaps and bounds, truly solves the problem of efficient and clean utilization of coal in China, and meets the national A major demand for economic development.

The circulating fluidized bed boiler pyrolysis combustion grading and conversion devices that have been put into operation at present are all small-capacity and are all retrofit projects, and the pyrolysis gasification furnace is added later. Therefore, in terms of structural arrangement, there is no optimal match between the circulating fluidized bed boiler and the pyrolysis gasification furnace, resulting in a complicated structure of the connecting device between the circulating fluidized bed boiler and the pyrolysis gasification furnace. Structural problems such as complex systems and complex material returning devices.

With the development of large-scale circulating fluidized bed boilers, the boiler structure has become more and more complex, and the number of pyrolysis gasifiers equipped with circulating fluidized bed boilers has also increased. Therefore, the problem of structurally optimal matching between the circulating fluidized bed boiler and the pyrolysis gasification furnace has to be considered, and in order to save the floor space of the unit, it is necessary to consider putting the pyrolysis gasification furnace into the steel frame of the boiler.

At present, the domestic layout of circulating fluidized bed boilers of 350MW and below is the three-span arrangement of furnace + cyclone + tail flue, and the front wall coal feeding mode is adopted. This kind of front wall coal supply + three-span arrangement has many problems when combined with pyrolysis gasifier.

As shown in Fig. 1, the entire pyrolysis gasification combined device has a symmetrical line symmetry in the front wall connection, that is, the symmetrical center line P of the boiler in the figure is symmetrically distributed, and is axially symmetric. The pyrolysis gasification furnace 1 is symmetrically disposed on both sides of the symmetry line P and disposed between the cyclones 10. The coal bunker 12 is disposed on the front wall, and the coal bunker 12 is connected to the boiler grate 9 through the boiler front coal feeding device 11 , and the coal bunker 12 and the pre-furnace coal feeding device 11 are disposed on the front side of the boiler grate 9 , and the pyrolysis gasification furnace 1 , first-stage gas separator 2, two-stage gas separator 3, high-temperature ash passage 4, returning device 5, primary returning device 6, secondary returning device 7, boiler returning device 8 and cyclone separator 10 On the rear side of the boiler furnace 9. The boiler furnace 9 is connected to the boiler returner 8, and the boiler returner 8 is connected to the pyrolysis gasification furnace 1 through the high temperature ash passage 4; the high temperature ash of the heated fuel in the pyrolysis gasification furnace 1 is from the circulation through the high temperature ash passage 4 Boiler returner 8 for fluidized bed boilers. The fuel is thermally decomposed in the pyrolysis gasification furnace 1 to generate semi-coke and crude gas, and the semi-coke is connected to the boiler furnace 9 through the returning device 5; the crude gas is connected to the first-stage gas separator 2 through the upper portion of the degassing furnace 1 Stage gas separator 2 takes most of the semi-coke separator in the crude gas and passes it through The level returning device 6 is connected to the boiler furnace 9; the clean gas with a small amount of fine particles is again separated into the secondary gas separator 3 through the upper end of the primary gas separator 2, and the secondary gas separator 3 passes. The secondary return device 7 is connected to the boiler furnace 9. The cyclone separator 10 is connected to the high temperature ash passage 4 through a rewinder, and the high temperature ash passage 4 is connected to the pyrolysis gasification furnace 1.

The focus of the pyrolysis gasification unit arrangement is: a three-span arrangement. It has the following shortcomings:

1. Since the coal bunker and the pyrolysis gasifier are respectively disposed on the front and rear sides of the boiler furnace, the coal bunker cannot directly supply coal to the pyrolysis gasifier, and two operation modes cannot be realized.

2. This three-span arrangement is such that the pyrolysis gasification furnace 1 needs to be arranged behind the boiler furnace 9, the cyclone separator 10 is connected to the pyrolysis gasification furnace 1, and the boiler returner 8 is used to feed the boiler furnace 9 times. And the pyrolysis gasification furnace 1 needs the return of the returning device, therefore, the cyclone separator 10, the boiler returner 8 and the returning device all require space, and this arrangement makes the pyrolysis gasification furnace and The space between the boiler furnaces becomes narrow and it is very difficult to arrange the following components between the two: the high temperature between the cyclone 10, the boiler returner 8, the returner 8 and the pyrolysis gasifier 1 Ash channel 4, first stage gas separator of pyrolysis gasifier 2, secondary gas separator 3, returning device 5, returning device 6, secondary returning device 7 and other systems brought by the boiler, such as two Secondary wind system and so on.

3. There is still a safety problem in this arrangement. The pyrolysis gasifier belongs to the chemical container, and the gas produced is a flammable and explosive gas. There is a safety hazard between the boiler equipment.

As shown in Fig. 2, the entire pyrolysis gasification combined device has a symmetrical line symmetry in the front wall connection, that is, the boiler symmetry center line P in the figure is used as a symmetry line, and is axially symmetrically distributed. Since the fluidized bed is a three-dimensional structure in which part of the structure is not shown in Fig. 2, the same components will be described using the names and serial numbers in Fig. 1. The pyrolysis gasification furnace 1 is symmetrically disposed on both sides of the symmetry line P and disposed outside the cyclone separator 10. The coal bunker 12 is disposed on the front wall, and the coal bunker 12 is connected to the boiler grate 9 through the boiler front coal feeding device 11 , and the coal bunker 12 and the pre-furnace coal feeding device 11 are disposed on the front side of the boiler grate 9 , and the pyrolysis gasification furnace 1 , first-stage gas separator 2, two-stage gas separator 3, high-temperature ash passage 4, returning device 5, primary returning device 6, secondary returning device 7, boiler returning device 8 and cyclone separator 10 On the rear side of the boiler furnace 9. The boiler furnace 9 is connected to the boiler returner 8, and the boiler returner 8 feeds the furnace directly through the return leg. The boiler hopper 8 is connected to the pyrolysis gasification furnace 1 through a high temperature ash passage 4; the high temperature ash for heating the fuel in the pyrolysis gasification furnace 1 is a boiler hopper 8 from a circulating fluidized bed boiler through a high temperature ash passage 4. The fuel is thermally decomposed in the pyrolysis gasification furnace 1 to generate semi-coke and crude gas, and the semi-coke is connected to the boiler furnace 9 through the returning device 5; the crude gas is connected to the first-stage gas separator 2 through the upper portion of the degassing furnace 1 The stage gas separator 2 takes most of the semi-coke separator in the crude gas and enters the boiler furnace 9 through the primary return device 6; the clean gas with a small portion of fine particles passes through the primary gas separator 2 The upper end is connected to the secondary gas separator 3 for separation again, and the secondary gas separator 3 is connected to the boiler furnace 9 through the secondary returning device 7. Cyclone separator 10 passes high temperature The ash passages 4 are connected, and the high temperature ash passages 4 are connected to the pyrolysis gasification furnace 1.

The focus of the pyrolysis gasification unit arrangement is: a three-span arrangement. The pyrolysis gasification furnace 1 is symmetrically arranged on both outer sides of the entire pyrolysis gasification combined device, and the cyclone separator 10 is disposed between the two pyrolysis gasification furnaces 1. This arrangement allows the returning device 5 between the pyrolysis gasification furnace 1 and the boiler furnace 9, the primary gas separator 2 and the primary returning device 6, the secondary gas separator 3 and the boiler furnace 9 of the boiler furnace 9. The secondary returning device 7 can only be fed from both sides of the boiler. However, the furnace width of a large circulating fluidized bed boiler is generally about 30 m. Therefore, if the pyrolysis gasification furnace 1 and the boiler furnace 9 can only be fed into the combustible solid product obtained by low-temperature carbonization of the coal from both sides of the furnace, that is, the semi-coke This will result in uneven distribution of fuel in the furnace. There are more fuels along the width of the furnace and less fuel in the middle. This will result in uneven distribution of furnace bed temperature, local high temperature coking and even over-temperature bursting, which will damage the safe and reliable operation of the boiler. The accident occurred.

In summary, the existing arrangement can not balance the coal feeding in front of the boiler and the coal in the pyrolysis gasification furnace, and the coal feeding system is very complicated, the feeding system is difficult to arrange and the reliability is low.

Utility model content

The utility model aims to provide a large-scale circulating fluidized bed pyrolysis gasification combined device, which adopts a combination of an H-type arrangement and a pyrolysis gasification furnace arranged on both sides, so as to solve the problem that the existing gasification combined device cannot be taken into consideration. The boilers in front of the coal and pyrolysis gasifiers on both sides of the coal, coal feeding system and returning system complex, low reliability technical problems, to achieve the optimal size of large circulating fluidized bed boilers and pyrolysis gasifiers match.

The object of the utility model is achieved by the following technical solutions: a large-scale circulating fluidized bed pyrolysis gasification combined device, including a boiler furnace, a pyrolysis gasification furnace, a first-stage gas separator, a secondary gas separator, and a high-temperature ash The channel, the returning device, the primary returning device, the secondary returning device, the boiler returning device, the cyclone separator and the side coal bunker, and the pyrolysis gasification combined device uses the boiler furnace as a symmetry line or a symmetrical center, and is distributed to the left and right. H-shaped; the side coal bunker is respectively connected with the returning legs of the pyrolysis gasification furnace and the boiler returning device, and the boiler returning device is connected to the boiler furnace through the returning leg; the lateral coal bunker is disposed away from the boiler furnace The cyclone separator is disposed near the boiler furnace, and the pyrolysis gasification furnace is disposed between the side coal bunker and the boiler furnace, the first gas separator, the second gas separator, the return device, the primary return device and the second The grade returning device is disposed between the pyrolysis gasifier and the boiler furnace.

As a preferred mode, the boiler cyclone separators are arranged axially symmetrically on both sides of the boiler hearth according to the center line of the boiler, or are arranged on both sides of the boiler furnace in a centrally symmetric arrangement according to the center of the boiler furnace.

As a preferred mode, the boiler return feeder is disposed on the front and rear sides of the pyrolysis gasification furnace, and the boiler return feeder is connected to the pyrolysis gasification furnace through the high temperature ash passage.

As a preferred mode, the discharge end of the cyclone is connected to the return.

As a preferred mode, the pyrolysis gasification unit is disposed within the range of the boiler steel frame.

As a preferred mode, the bottom end of the pyrolysis gasifier is connected to the boiler hearth through a returning device.

As a further preferred mode, the upper portion of the pyrolysis gasification furnace is connected to the primary gas separator, and the lower end of the primary gas separator is connected to the boiler furnace through a primary return device.

As a further preferred mode, the upper end of the primary gas separator is connected to the secondary gas separator, and the secondary separator is connected to the boiler furnace through a secondary return device.

In the large circulating fluidized bed pyrolysis gasification combined device of the utility model:

(1). The pyrolysis gasification combined device adopts the H-shaped symmetrical arrangement with the boiler furnace as the symmetry, and the cyclone separator closely related to the pyrolysis gasification furnace is arranged on both sides of the boiler furnace, so that the pyrolysis gasification The furnace can be arranged in the range of the boiler steel frame on both sides, ensuring the safe operation of the whole system, and also facilitating the return from the boiler returner to the pyrolysis gasifier, from the pyrolysis gasifier to the boiler furnace. The layout of the material system.

(2). The side coal bunker is used, and the side bunkers are arranged on the left and right sides of the boiler grate. The arrangement of the side coal bunker is beneficial to the fact that the pyrolysis gasifier is not put into operation, and the fuel such as coal is directly sent to the return leg of the circulating fluidized bed boiler for the boiler to feed the coal, and the pyrolysis gasification furnace is also beneficial. During transportation, fuel such as coal is directly sent to pyrolysis gasification for pyrolysis. Compared with the arrangement of the three-span + front side coal bunker, the design and post-maintenance of the coal feeding system is simpler and more reliable.

(3). The arrangement of the cyclone separator adopts two modes: one is arranged in an axisymmetric manner according to the center line of the boiler, and the other is arranged symmetrically according to the center of the furnace hearth. The latter arrangement is intended to take into account that when the furnace depth dimension is large, the arrangement can be such that the flue gas distribution from the furnace to the cyclone is more uniform.

Compared with the prior art, the utility model has the beneficial effects that the large-scale circulating fluidized bed pyrolysis gasification combined device of the utility model adopts an H-type arrangement + a pyrolysis gasification furnace arranged on both sides, so that The pyrolysis gasification furnace is arranged in the steel frame of the boiler, and is arranged through the side coal bunker to take into consideration the return leg feeding of the circulating fluidized bed boiler returning device and the pyrolysis gasification furnace feeding; in the pyrolysis gasification device At the time of commissioning, the fuel is fed from the pyrolysis gasifiers on both sides of the boiler, making the connection between the boiler and the pyrolysis gasifier simpler and more reliable.

DRAWINGS

1 is a schematic view of a conventional fluidized bed pyrolysis gasification combined device;

2 is a second schematic view of a conventional fluidized bed pyrolysis gasification combined device;

Figure 3 is a schematic view showing the fluidized bed pyrolysis gasification combined device of the present invention arranged in an axisymmetric manner according to the center line of the boiler;

Figure 4 is a schematic view showing the fluidized bed pyrolysis gasification combined device of the present invention arranged symmetrically according to the center of the boiler hearth;

Figure 5 is a center-symmetrical cloth of the cyclone separator in the fluidized bed pyrolysis gasification combined device of the present invention according to the center of the boiler furnace Set

Figure 6 is a schematic flow chart of the fluidized bed pyrolysis gasification combined device of the present invention.

In the figure: pyrolysis gasifier-1, primary gas separator-2, secondary gas separator-3, high temperature ash channel-4, returning device-5, primary return device-6, secondary return Feeder-7, Boiler Returner-8, Boiler Furnace-9, Cyclone-10, Side Bunker-12.

detailed description

In order to make the objects, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

All of the features disclosed in the specification, or the steps of all methods or processes disclosed, in addition to mutually exclusive features and/or steps, may be combined in any manner, unless otherwise stated, may be otherwise equivalent or have similar Alternative features of the object are replaced, i.e., one of the series of equivalent or similar features of each feature, unless specifically stated.

Example:

As shown in Figures 3, 4, 5, and 6, the left end of the drawing in Figures 3, 4, 5, and 6 is the front wall, and the lower end is the right side of the boiler. Large circulating fluidized bed pyrolysis gasification combined device, comprising boiler furnace 9, pyrolysis gasification furnace 1, primary gas separator 2, secondary gas separator 3, high temperature ash passage 4, returning device 5 The primary returning device 6, the secondary returning device 7, the boiler returning device 8, the cyclone separator 10 and the side coal bunker 12. The pyrolysis gasification combined device uses the boiler furnace 9 as a symmetrical line or a symmetrical center to form a H-shaped distribution on the left and right; the side coal bunker 12 is disposed away from the boiler furnace 9 and the side coal bunker 12 and the pyrolysis gasification furnace 1 respectively It is connected to the return leg of the boiler hopper 8, and the boiler hopper 8 is connected to the boiler kiln 9 through its return leg. The arrangement of the side coal bunker is beneficial to the fact that the pyrolysis gasifier is not put into operation, and the fuel such as coal is directly sent to the return leg of the circulating fluidized bed boiler for the boiler to feed the coal, and the pyrolysis gasification furnace is also beneficial. During transportation, fuel such as coal is directly sent to pyrolysis gasification for pyrolysis.

The cyclone separator 10 is disposed near the boiler furnace 9, the cyclone separator 10 is connected to the boiler furnace 9, the lower end of the cyclone separator 10 is connected to the return feeder 8, and the return feeder 8 passes through the high temperature ash passage 4 and the pyrolysis gasification furnace. 1 connected. The cyclone separator closely related to the pyrolysis gasification furnace is arranged on both sides of the boiler furnace, so that the pyrolysis gasification furnace can be arranged in the range of the boiler steel frame on both sides, ensuring the safe operation of the entire system, and also It facilitates the arrangement of the returning system from the boiler return to the pyrolysis gasifier, from the pyrolysis gasifier to the boiler furnace.

The cyclone separator 10 is arranged axially symmetrically on both sides of the boiler furnace 9 according to the boiler center line a, or according to the boiler furnace 9 The centers are arranged in a centrally symmetrical arrangement on both sides of the boiler hearth 9.

The pyrolysis gasification furnace 1 is disposed between the side coal bunker 12 and the boiler furnace 9, the first stage gas separator 2, the second stage gas separator 3, the returning device 5, the primary returning device 6 and the secondary returning device 7 is disposed between the pyrolysis gasification furnace 1 and the boiler furnace 9. The pyrolysis gasifier 1 is placed in a steel frame of the boiler. The bottom end of the pyrolysis gasification furnace 1 is connected to the boiler furnace 9 through a returning device 5; the upper portion of the pyrolysis gasification furnace 1 is connected to the first-stage gas separator 2, and the lower end of the primary gas separator 2 is passed through a primary returning device 6 is connected to the boiler furnace 9; the upper end of the primary gas separator 2 is connected to the secondary gas separator 3, and the lower end of the secondary separator 3 is connected to the boiler furnace 9 through the secondary returning device 7. The boiler returner 8 is disposed on the front and rear sides of the pyrolysis gasification furnace 1, and the boiler returner 8 is connected to the pyrolysis gasification furnace 1 through the high temperature ash passage 4. This arrangement facilitates the placement of the return device under the gas separator.

The large-scale circulating fluidized bed pyrolysis gasification combined device with the above structure can realize the following two operation modes: 1. The pyrolysis gasification furnace is put into operation. At this time, the coal is not sent to the furnace of the circulating fluidized bed boiler, but is sent to the pyrolysis gasification furnace, and the semi-coke after pyrolysis of the pyrolysis gasification furnace is passed through the pyrolysis gasification furnace and the gas separator thereof. The device is sent to the furnace of the circulating fluidized bed boiler for combustion as a fuel; 2. The pyrolysis gasification furnace is shut down, and the circulating fluidized bed boiler is separately operated. At this point, the coal is directly fed into the furnace through the return leg for combustion.

Material flow:

The pyrolysis gasification furnace is not put into operation, and only the circulating fluidized bed boiler is put into operation, and the coal is transferred from the side coal bunker 12 to the boiler on the returning device 8 to the coal inlet to the boiler furnace 9.

When the pyrolysis gasification furnace is put into operation, the coal is transported from the side coal bunker 12 to the pyrolysis gasification furnace 1, and after pyrolysis in the pyrolysis gasification furnace 1, most of the semi-coke is returned through the lower part of the pyrolysis gasification furnace. The device 5 is returned to the furnace 9 as fuel for the boiler, and part of the semi-coke is separated by the primary gas separator 2 and sent to the furnace 9 through the primary return device 6 as the fuel of the boiler, and a very small portion of the semi-coke is passed through the secondary gas. The separator 3 is separated and sent to the furnace 9 for combustion via the secondary return device 7. Therefore, the arrangement of the side coal bunker 12 can simultaneously take into consideration the coal feeding of the boiler and the coal feeding of the pyrolysis gasification furnace, and the coal feeding system is simple and reliable. The high temperature ash separated by the boiler cyclone 10 is sent to the pyrolysis gasification furnace 1 through the high temperature ash passage 4 between the rewinder 8 and the pyrolysis gasification furnace 1 as a heat source to heat the coal in the pyrolysis gasification furnace. The coal is pyrolyzed and gasified.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the present invention. The scope of protection of utility models.

Claims

Large-scale circulating fluidized bed pyrolysis gasification combined device, including boiler furnace (9), pyrolysis gasification furnace (1), primary gas separator (2), secondary gas separator (3), high temperature ash Channel (4), return device (5), primary return device (6), secondary return device (7), boiler return device (8), cyclone separator (10) and side coal bunker (12 The characteristic is that the pyrolysis gasification combined device uses the boiler furnace (9) as a symmetry line or a symmetrical center to form an H shape distributed to the left and right; the side coal bunker (12) and the pyrolysis gasification furnace (1) Connected to the return leg of the boiler return (8), the boiler return (8) is connected to the boiler furnace (9) through its return leg; the side coal bunk (12) is placed away from the boiler furnace (9). The cyclone separator (10) is disposed near the boiler furnace (9), and the pyrolysis gasification furnace (1) is disposed between the side coal bunker (12) and the boiler furnace (9), the first gas separator (2), The secondary gas separator (3), the returning device (5), the primary returning device (6) and the secondary returning device (7) are disposed in the pyrolysis gasification furnace (1) and the boiler furnace (9) between.
The large circulating fluidized bed pyrolysis gasification combined device according to claim 1, characterized in that the boiler return device (8) is disposed on the front and rear sides of the pyrolysis gasification furnace (1), and the cyclone separator (10) The lower end is connected to the return feeder (8), and the return feeder (8) is connected to the pyrolysis gasifier (1) through the high temperature ash passage (4).
The large-scale circulating fluidized bed pyrolysis gasification combined device according to claim 1, characterized in that: a pyrolysis gasification furnace (1), a first-stage gas separator (2), a secondary gas separator (3), The returning device (5), the primary returning device (6) and the secondary returning device (7) are arranged on the steel frame of the boiler.
The large circulating fluidized bed pyrolysis gasification combined apparatus according to claim 1, wherein the bottom end of the pyrolysis gasification furnace (1) is connected to the boiler furnace (9) through a returning device (5).
The large-scale circulating fluidized bed pyrolysis gasification combined device according to claim 1, characterized in that the upper part of the pyrolysis gasification furnace (1) is connected to the first-stage gas separator (2), and the first-stage gas separator (2) The lower end is connected to the boiler furnace (9) through a primary return device (6).
The large-scale circulating fluidized bed pyrolysis gasification combined device according to claim 1, characterized in that: the upper end of the primary gas separator (2) is connected to the secondary gas separator (3), and the secondary gas separator (3) The lower end is connected to the boiler furnace (9) through a secondary return device (7).
The large-scale circulating fluidized bed pyrolysis gasification combined device according to claim 1, characterized in that: the cyclone separator (10) is arranged axially symmetrically on both sides of the boiler furnace (9) according to the center line of the boiler, or according to the boiler furnace The center of (9) is arranged in a centrally symmetric arrangement on both sides of the hearth furnace (9).