CN203203008U - Upright pulverized coal corner tube type boiler - Google Patents

Abstract

The utility model discloses an upright pulverized coal corner tube type boiler. The upright pulverized coal corner tube type boiler comprises combustors, a boiler combustion chamber, a high temperature air preheater, a coal economizer, a low temperature air preheater, a convection bank, an upper collection tank, a top collection tank, a boiler barrel and a lower collection tank; the lower collection tank is arranged at the bottom of a boiler body; and the upper collection tank and the top collection tank which are arranged at the top of the boiler body are communicated with each other through steam communicating pipes. The upright pulverized coal corner tube type boiler is characterized in that the combustors are arranged at the top of the boiler body; the boiler body is in an upright corner membrane wall type structure; four down pipes are arranged at four corners of the boiler body; two ends of the four down pipes and an membrane wall are respectively communicated with the upper collection tank and the lower collection tank; the convection bank is arranged on the external side of the membrane wall; the top of the convection bank is communicated with a smoke outlet of the combustion chamber; and the bottom of the convection bank is communicated with the high temperature air preheater. The upright pulverized coal corner tube type boiler has the advantages of being compact in whole structure, simple in shape arrangement, small in occupying area, low in steel consumption, large in water circulation pressure difference and safe and reliable in water circulation and the like.

Description

A Vertical Pulverized Coal Corner Tube Boiler

technical field

The utility model belongs to the field of coal-fired industrial boilers, and in particular relates to a vertical pulverized coal corner tube boiler which uses pulverized coal, urban sludge and biomass as fuel for generating steam.

Background technique

my country's energy structure is dominated by coal. For a long time in the future, coal-fired industrial boilers will still be the leading product of industrial boilers.

The traditional industrial coal-fired boilers are mainly layer-fired boilers. The disadvantages are low combustion efficiency and serious pollution, which makes it difficult to meet the requirements of energy saving, emission reduction and pollutant discharge.

Pulverized coal combustion is one of the efficient and clean combustion methods of coal, and its combustion efficiency can reach more than 96%. It is a mature combustion technology and is widely used in large-scale power plant boilers. In recent years, pulverized coal combustion has also been applied in industrial boilers, all of which adopt horizontal internal combustion shell structure D-type double drum water pipe structure or vertical pulverized coal furnace with burners arranged at the bottom. But there are certain deficiencies:

1) The combustion is not uniform enough, and the temperature difference between front and back is relatively large, which is not conducive to reducing the content of NO _X.

2) The load adjustment range is small, and only a single fuel - pulverized coal can be used.

3) It is inconvenient to clean up boiler ash and slag.

4) The boiler room occupies a large area.

5) The bottom of the furnace is prone to coking.

6) It is difficult to overhaul the burner.

Contents of the invention

The utility model aims at the deficiency of the existing horizontal pulverized coal boiler, and provides a novel vertical pulverized coal corner tube boiler.

The utility model is realized through the following technical solutions: a vertical pulverized coal corner tube boiler, including a burner, a boiler body, a high-temperature air preheater, an economizer, a low-temperature air preheater, a convection tube bundle, an upper set box, top header, drum and lower header, the lower header is arranged at the bottom of the boiler body, the upper header and the top header are arranged at the top of the boiler body, and communicated through the steam connecting pipe; It is characterized in that the burner is arranged on the top of the boiler body; the boiler body adopts a vertical membrane water wall structure, and four downcomers are arranged at the four corners, and the two ends of the downcomer and the membrane water wall are respectively It communicates with the upper header and the lower header; the convection tube bundle is arranged on the outside of the membrane water wall, the bottom of which communicates with the smoke outlet of the furnace, and the top communicates with the high-temperature air preheater; the The top header communicates with the steam space of the drum; the upper header communicates with the water space of the drum.

In the vertical pulverized coal corner tube boiler of the utility model, pulverized coal or urban sludge is sprayed into the vertical furnace through the top burner by the primary wind, and at the same time, the high temperature after being heated by the low temperature air preheater and the high temperature air preheater The air also enters the burner and mixes with the powdered fuel and enters the furnace for violent suspension combustion; and two levels of tertiary air are arranged in the furnace to ensure that the furnace has sufficient oxygen and fuel to react and burn. The high-temperature flue gas after combustion and heat exchange in the furnace turns 180° upwards and enters the convection tube bundle for convective heat exchange. The flue gas then enters the high-temperature air preheater, economizer and air-low temperature air preheater in sequence, and then is discharged into the flue gas purification system. .

This project has the following advantages:

1) The boiler body is arranged in a vertical corner tube structure, and four large-diameter downpipes are arranged at the four corners. The downpipe is not only a water circulation pipeline, but also supports the entire boiler, so there is no need to set up a supporting steel frame. The overall structure is compact and the shape Simple layout, small footprint and low steel consumption.

2) The furnace adopts a membrane wall structure, the furnace wall only needs insulation materials, the overall sealing, good insulation performance, and less air leakage.

3) The pressure difference of the boiler water circulation is large, and the water circulation is safe and reliable.

4) The upper header and the top header are connected with the steam connecting pipe and connected to the drum at the same time, the steam-water mixture enters the upper header from the heating surface, and the steam-water pre-separation occurs in the upper header, and the steam passes through the steam connecting pipe to the top header Enter the steam space in the upper part of the drum. Since the upper headers are all connected at the high water level of the drum, the steam directly enters the drum without passing through the water space, thereby avoiding the generation of foam, and the steam entering the drum has been pre-separated, therefore, Greatly improved the quality of steam.

5) Another particularly important feature of the utility model is that the burner is arranged on the top. This structure makes the utility model also have the following beneficial technical effects:

5.1) It can reduce the height of the boiler foundation, shorten the construction time and reduce the construction cost.

5.2) The shape of the flame matches the size of the furnace, and the flame does not touch the wall; it prevents the flame from scouring the membrane water wall and prolongs the service life of the boiler.

5.3) After the powder fuel is burned, the remaining ash is absorbed and cooled by the membrane water wall, and there is no high-temperature heat source to reheat; therefore, the temperature of the ash falling into the ash hopper is relatively low, which effectively prevents coking at the bottom of the furnace.

5.4) The flow direction of the furnace flame is consistent with the gravity direction of the powder fuel, and the hot ash cannot fall into the burner area by gravity, which effectively avoids the coking phenomenon of the burner caused by the hot ash and greatly improves the service life of the burner.

5.5) The bottom of the furnace is convenient for ash and slag discharge and an automatic slag discharge machine is arranged to reduce the labor intensity of laborers and improve the efficiency of slag discharge.

As a further improvement of the utility model, there are two burners. The advantage of the dual burner arrangement is that each burner can be controlled independently, which greatly improves the stability of combustion and the performance of load regulation, and can use more than two kinds of fuel at the same time.

As a further improvement of the utility model, the convection tube bundle adopts flag surface tubes. The convection heating surface adopts flag surface tubes, and the flag surface tubes are vertically arranged in a row at a certain angle. The heating surface is sufficient, the circulation is reliable, the flue gas is washed smoothly, and it is not easy to accumulate dust, which prolongs the service life of the boiler.

As a further improvement of the utility model, the staged combustion technology is adopted, and two stages of tertiary air are sequentially sent into the furnace, so that the entire temperature field is uniform, which can effectively prevent the furnace from coking and reduce the formation of nitrogen oxides.

Description of drawings

Fig. 1 is a structural diagram of a vertical pulverized coal corner tube boiler of the present invention.

Fig. 2 is a sectional view taken along line A-A of Fig. 1 .

In the figure, 1-low temperature air preheater, 2-coal economizer, 3-convection tube bundle, 4-high temperature air preheater, 5-upper header, 6-steam connecting pipe, 7-top header, 8- Drum, 9-explosion-proof door, 10-first-level tertiary air, 11-second-level tertiary air, 12-downcomer, 13-furnace, 14-lower header, 15-cleaning port, 16-inspection door, 17- Burner, 18 - furnace smoke outlet.

Detailed ways

Referring to Fig. 1, a vertical pulverized coal corner tube boiler includes two burners 17, a boiler furnace 13, a high temperature air preheater 4, an economizer 2, a low temperature air preheater 1, a convection tube bundle 3, an upper Header 5, top header 7, drum 8 and lower header 14, the lower header 14 is arranged at the bottom of the boiler body, and the upper header 5 and top header 7 are arranged at the top of the boiler body , and communicated through the steam connecting pipe 6; the burner 17 is arranged on the top of the boiler body; the boiler body adopts a vertical corner tube structure membrane water wall, and four downcomers 12 are arranged at the four corners. The two ends of the tube 12 and the membrane water wall are connected with the upper header 5 and the lower header 14 respectively; On the outside, the bottom of the convection tube bundle 3 communicates with the furnace smoke outlet 18, the top communicates with the high-temperature air preheater 4, the flue gas inlet end of the economizer 2 communicates with the other end of the high-temperature air preheater 4, and the outlet end Connected to the low-temperature air preheater 1; the top header 7 communicates with the steam space of the drum 8; the upper header 5 communicates with the water space of the drum 8.

The combustion of the two burners 17 can be independently controlled, and the lower part of the furnace 13 is provided with an explosion-proof door 9 and a soot cleaning port 15, and two levels of tertiary air are arranged in the middle.

The working principle of the utility model is as follows:

Pulverized coal or urban sludge is sprayed into the vertical furnace 13 through the two burners 17 on the top by the primary wind, and at the same time, the high-temperature air heated by the low-temperature air preheater 1 and the high-temperature air preheater 4 also enters the burner 17 and the high-temperature air preheater 4. The powdered fuel is mixed into the furnace 13 for violent suspension combustion; and two levels of tertiary air are arranged in the furnace to ensure that the furnace has sufficient oxygen to react and burn with the fuel. After combustion and heat exchange in the furnace, the high-temperature flue gas turns 180° upward from the furnace smoke outlet 18 below the furnace 13 and enters the flag surface tube 3 for convective heat exchange, and then the flue gas enters the high-temperature air preheater 4 and the economizer in sequence 2 and the low-temperature air preheater 1 and then discharged into the flue gas purification system. In the flue gas cleaning system, the solid particles in the flue gas are removed, and the clean preheated air is sprayed into the vertical furnace 13 again from the two burners 17 . The high-temperature air preheater 4 and the low-temperature air preheater 1 can use the residual heat of the flue gas to preheat the air, so as to achieve the purpose of recycling and energy saving.

The upper header 5, the top header 7, the steam connecting pipe 6, the lower header 14, the membrane water wall of the furnace and the four downcomers 12 form a closed water circulation system. The upper header 5 and the top header 7 are connected with the steam connecting pipe 6 and connected to the drum 8 at the same time, the steam-water mixture rises from the heating surface of the membrane water wall into the upper header 5, and steam-water pre-separation occurs in the upper header 5 , the steam enters the steam space at the top of the drum 8 through the steam connecting pipe 6 to the top header 7 . Since the upper header 5 is connected at the high water level of the drum 8, the steam directly enters the drum without passing through the water space, thereby avoiding the generation of foam, and the steam entering the drum 8 has been pre-separated , Therefore, the quality of the steam is greatly improved. The water after pre-separation of steam and water in the upper header 5 flows into the lower header 14 from the four downcomers 12, and then enters the membrane water cooling wall to form a water cycle.

It should be understood that: the above-mentioned embodiment is only an illustration of the utility model, rather than a limitation of the utility model, and any utility model creation within the scope of the essential spirit of the utility model all falls within the protection scope of the utility model .

Claims (4)

1. vertical coal dust corner tube boiler, comprise burner (17), boiler furnace (13), high-temperature air preheater (4), economizer (2), low-temperature air preheater (1), convection bank (3), upper collecting chamber (5), top header (7), drum (8) and lower header (14), described lower header (14) is arranged on the bottom of boiler body, described upper collecting chamber (5) and top header (7) are arranged on the top of boiler body, and by vapour communicating pipe (6) UNICOM; It is characterized in that described burner (17) is arranged on the top of boiler body; Described boiler body adopts vertical film water cold wall structure, arranges 4 down-comers (12) for four jiaos, in the two ends of described down-comer (12) and fin panel casing respectively with described upper collecting chamber (5) and lower header (14) UNICOM; Described convection bank (3) is arranged on the outside of fin panel casing, its bottom and burner hearth outlet flue (18) UNICOM, top and described high-temperature air preheater (4) UNICOM; The air space UNICOM of described top header (7) and described drum (8); The hydrospace UNICOM of described upper collecting chamber (5) and described drum (8).

2. a kind of vertical coal dust corner tube boiler as claimed in claim 1 is characterized in that described burner (17) is two.

3. a kind of vertical coal dust corner tube boiler as claimed in claim 2 is characterized in that described two burners (17) all are arranged on the boiler body top.

4. such as any one described a kind of vertical coal dust corner tube boiler of claim 1-3, it is characterized in that described convection bank (3) employing flag facial canal, and in-line arrangement.

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