CN210463080U

CN210463080U - Novel air heater system of coal fired power plant

Info

Publication number: CN210463080U
Application number: CN201920619299.7U
Authority: CN
Inventors: 王帅; 王学同; 路昆; 王凯
Original assignee: Huadian Electric Power Research Institute Co Ltd
Current assignee: Huadian Electric Power Research Institute Co Ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-05-05
Anticipated expiration: 2029-04-30

Abstract

The utility model discloses a novel air preheater system of a coal-fired power plant, an inlet main flue is communicated with a branch flue A and a branch flue B which are parallel, a tubular air preheater is arranged on the branch flue A, the branch flue B passes through a rotary air preheater, and an adjusting baffle is arranged inside the branch flue B; the primary air inlet pipeline and the primary air outlet pipeline are both connected with the tubular air preheater, and the secondary air pipeline penetrates through the rotary air preheater; the inlet end of the primary air bypass is connected with a primary air outlet pipeline, and the outlet end of the primary air bypass is connected with an outlet of a secondary air pipeline. The utility model discloses an utilize tubular air heater and two storehouse rotary air heater to make up side by side, realize that primary air system and flue gas are isolated, the influence of the primary air to the air preheater rate of leaking out that has reduced great pressure to adopt two kinds of means of primary air bypass and adjusting the baffle, can adjust hot primary air temperature respectively, realized the zero volume of mixing of cold wind.

Description

Novel air heater system of coal fired power plant

Technical Field

The utility model relates to a novel air heater system of coal fired power plant.

Background

At present, a smoke system of a coal-fired boiler of a large power station is generally provided with 2 3 rotary air preheaters with separated cabins, wherein 3 cabin types are respectively corresponding to a flue, a primary air channel and a secondary air channel, but the air leakage rate of the air preheater of the 3 rotary air preheaters is larger due to the sealing problem, if the smoke system is a Chinese patent with the application number of 201721321397.X, the main reason is that the primary air pressure is 10KPa and is about 4 times of the secondary air pressure, the primary air pressure is higher, the primary air is easy to leak to the smoke side, and the contribution to the air leakage rate is the largest. The large air leakage rate of the air preheater easily causes the power consumption of the induced draft fan and the primary fan to increase, and for the unit with insufficient rated output of the fan, the large air leakage rate can seriously affect the load carrying capacity of the unit.

Cold wind gets into the powder process system after air heater heats, and in order to ensure the dry of powder process system and exert oneself, hot wind temperature all has certain surplus, simultaneously in order to guarantee coal pulverizer export wind powder temperature in the explosion-proof requirement of safety, has designed cold wind bypass device once, opens big cold wind door once, can reduce coal pulverizer export wind powder temperature. For the existing three-bin rotary air preheater system and the air supply system, hot primary air can only be completely removed from the pulverizing system, and when the heat carried by the primary air is greater than pulverizing drying output, the hot primary air volume can only be reduced, and the cold primary air volume is increased for adjustment. However, the increase of the cold primary air volume entering the pulverizing system can cause the reduction of the air volume passing through the air preheater, the rise of the exhaust gas temperature and the reduction of the boiler efficiency.

In order to realize lower air leakage rate of the air preheater and no mixing of cold air in a powder making system, the problem that the air preheater system and the powder making system of the coal-fired boiler of the power station are difficult to solve at present is solved, so that the development of a novel air preheater system and a novel air preheater method for the coal-fired power plant is necessary to realize the lower air leakage rate and the zero mixing amount of the cold air.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the above-mentioned not enough that exists among the prior art, and provide a coal fired power plant's novel air heater system, utilize tubular air heater and two storehouse rotary air heater to make up side by side into novel air heater system, realized that primary air system and flue gas are isolated, reduced the influence of the primary air of great pressure to air heater rate of leaking to adopt two kinds of means of primary air bypass and adjusting the baffle, can adjust hot primary air wind temperature respectively, realized the zero volume of mixing of cold wind.

The utility model provides a technical scheme that above-mentioned problem adopted is: a novel air preheater system of a coal-fired power plant is characterized by comprising an inlet main flue, a tubular air preheater, a rotary air preheater, an outlet main flue, a primary air bypass, a primary air inlet pipeline, a primary air outlet pipeline and a secondary air pipeline; the inlet main flue is communicated with an A branch flue and a B branch flue which are parallel, wherein a tubular air preheater for heating cold primary air is arranged on the A branch flue, the B branch flue penetrates through a rotary air preheater for rotary heating cold secondary air, and an adjusting baffle is arranged inside the B branch flue; at the bottom of the tubular air preheater and the rotary air preheater, the branch flue A and the branch flue B are communicated with the outlet main flue; a primary air inlet pressure gauge is arranged on the primary air inlet pipeline, the primary air inlet pipeline is connected with the tubular air preheater, a thermometer is arranged on the primary air outlet pipeline, and the primary air outlet pipeline is connected with the tubular air preheater; the secondary air pipeline penetrates through the rotary air preheater, and a secondary air inlet pressure gauge and a secondary air outlet pressure gauge are arranged on the secondary air pipeline; the inlet end of the primary air bypass is connected with the primary air outlet pipeline, and the outlet end of the primary air bypass is connected with the outlet of the secondary air pipeline.

Preferably, the adjusting baffle is positioned at the inlet of the rotary air preheater, and the opening degree of the adjusting baffle is controlled by an electric actuator.

Preferably, an electric adjustable valve and a bypass pressure gauge are sequentially arranged on the primary air bypass along the airflow direction.

Preferably, the tubular air preheater is internally provided with a partition plate and a fin heat exchange tube.

Preferably, the rotary air preheater is of a two-bin type.

The working method of the novel air preheater system of the coal-fired power plant is characterized by comprising the following steps:

firstly, cold primary air enters a primary air inlet pipeline from a cold primary air inlet, countercurrent heat exchange is carried out between the inside of a tubular air preheater and flue gas inside a branch flue A, and most hot primary air enters a coal mill from a primary air outlet pipeline through a hot primary air outlet after temperature rise;

secondly, cold secondary air enters a secondary air pipeline from a cold secondary air inlet, exchanges heat with flue gas entering a branch flue B of the rotary air preheater, becomes hot secondary air after being heated, and is discharged from a hot secondary air outlet;

and step three, a small part of the heated hot primary air enters a secondary air pipeline through a primary air bypass, is mixed with the hot secondary air and is discharged from a hot secondary air outlet in the step one.

In the working process, the electric adjustable valve controls the flow of hot primary air entering the secondary air pipeline, and the adjusting baffle plate adjusts and distributes the flow of flue gas entering the A branch flue and the B branch flue.

Compared with the prior art, the utility model, have following advantage and effect:

1) the novel air preheater system is formed by combining the tubular air preheater and the two-bin rotary air preheater in parallel, so that a primary air system and smoke are isolated, the influence of primary air with larger pressure on the air leakage rate of the air preheater is reduced, and the power consumption of an induced draft fan and a primary fan is reduced.

2) The hot primary air temperature can be respectively adjusted by adopting two means of a primary air bypass and an adjusting baffle, so that zero mixing amount of cold air is realized, the smoke exhaust temperature is reduced, the boiler efficiency is improved, the adjusting means is richer, and the adjusting space is more flexible.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

In the figure: the device comprises an inlet main flue 1, an A branch flue 2, a B branch flue 3, an adjusting baffle 4, a tubular air preheater 5, a rotary air preheater 6, an outlet main flue 7, a flue gas inlet 8, a flue gas outlet 9, a primary air bypass 10, an electric adjustable valve 11, a bypass pressure gauge 12, a cold primary air inlet 51, a primary air inlet pressure gauge 52, a primary air inlet pipeline 53, a partition plate 54, a fin heat exchange tube 55, a primary air outlet pipeline 56, a thermometer 57, a hot primary air outlet 58, a cold secondary air inlet 61, a secondary air pipeline 62, a secondary air inlet pressure gauge 63, a secondary air outlet pressure gauge 64 and a hot secondary air outlet 65.

Detailed Description

The present invention will be described in further detail by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not intended to limit the present invention.

Referring to fig. 1, the novel air preheater system of the coal-fired power plant in the embodiment includes an inlet main flue 1, a tubular air preheater 5, a rotary air preheater 6, an outlet main flue 7, a primary air bypass 10, a primary air inlet pipe 53, a primary air outlet pipe 56, and a secondary air pipe 62.

The inlet main flue 1 is communicated with an A branch flue 2 and a B branch flue 3 which are parallel, wherein a tubular air preheater 5 for heating cold primary air is arranged on the A branch flue 2, the B branch flue 3 penetrates through a rotary air preheater 6 for rotary heating cold secondary air, and an adjusting baffle 4 is arranged in the B branch flue 3; at the bottom of the tubular air preheater 5 and the rotary air preheater 6, the branch flues A2 and B3 are communicated with an outlet main flue 7; a primary air inlet pressure gauge 52 is arranged on the primary air inlet pipeline 53, the primary air inlet pipeline 53 is connected with the tubular air preheater 5, a thermometer 57 is arranged on the primary air outlet pipeline 56, and the primary air outlet pipeline 56 is connected with the tubular air preheater 5; the secondary air pipeline 62 penetrates through the rotary air preheater 6, and a secondary air inlet pressure gauge 63 and a secondary air outlet pressure gauge 64 are arranged on the secondary air pipeline 62; the inlet end of the primary air bypass 10 is connected to the primary air outlet duct 56 and the outlet end of the primary air bypass 10 is connected to the outlet of the secondary air duct 62.

The adjusting baffle 4 is positioned at the inlet of the rotary air preheater 6, and the opening degree of the adjusting baffle 4 is controlled by an electric actuator. An electric adjustable valve 11 and a bypass pressure gauge 12 are sequentially arranged on the primary air bypass 10 along the air flow direction. The interior of the tubular air preheater 5 is provided with a partition 54 and fin heat exchange tubes 55. The rotary air preheater 6 is of a two-bin type.

The process is as follows:

firstly, cold primary air enters a primary air inlet pipeline 53 from a cold primary air inlet 51, countercurrent heat exchange is carried out between the cold primary air and flue gas in the branch flue 2A in the tubular air preheater 5, and most hot primary air enters a coal mill from a primary air outlet pipeline 56 through a hot primary air outlet 58 after temperature rise;

step two, cold secondary air enters a secondary air pipeline 62 from a cold secondary air inlet 61, exchanges heat with the flue gas entering a branch flue gas channel B3 of the rotary air preheater 6, becomes hot secondary air after being heated, and is discharged from a hot secondary air outlet 65;

and thirdly, a small part of the heated hot primary air in the step one enters the secondary air pipeline 62 through the primary air bypass 10, is mixed with the hot secondary air and is discharged from the hot secondary air outlet 65.

In the working process, the smoke enters the inlet main flue 1 from the smoke inlet 8, then a part of smoke enters the branch flue 2A, the other part of smoke enters the branch flue 3B, and finally the smoke is combined and discharged from the outlet main flue 7 through the smoke outlet 9; the electric adjustable valve 11 controls the flow of hot primary air entering the secondary air pipeline 62, and the adjusting baffle 4 adjusts and distributes the flow of flue gas entering the A sub-flue 2 and the B sub-flue 3.

Although the present invention has been described with reference to the above embodiments, it should not be construed as being limited to the scope of the present invention, and any modifications made by those skilled in the art without departing from the spirit and scope of the present invention should be construed as being included in the following claims.

Claims

1. A novel air preheater system of a coal-fired power plant is characterized by comprising an inlet main flue (1), a tubular air preheater (5), a rotary air preheater (6), an outlet main flue (7), a primary air bypass (10), a primary air inlet pipeline (53), a primary air outlet pipeline (56) and a secondary air pipeline (62); the inlet main flue (1) is communicated with an A branch flue (2) and a B branch flue (3) which are parallel, wherein a tubular air preheater (5) for heating cold primary air is arranged on the A branch flue (2), the B branch flue (3) penetrates through a rotary air preheater (6) for rotary heating cold secondary air, and an adjusting baffle (4) is arranged inside the B branch flue (3); at the bottom of the tubular air preheater (5) and the rotary air preheater (6), the A sub-flue (2) and the B sub-flue (3) are communicated with an outlet main flue (7); a primary air inlet pressure gauge (52) is arranged on the primary air inlet pipeline (53), the primary air inlet pipeline (53) is connected with the tubular air preheater (5), a thermometer (57) is arranged on the primary air outlet pipeline (56), and the primary air outlet pipeline (56) is connected with the tubular air preheater (5); the secondary air pipeline (62) penetrates through the rotary air preheater (6), and a secondary air inlet pressure gauge (63) and a secondary air outlet pressure gauge (64) are arranged on the secondary air pipeline (62); the inlet end of the primary air bypass (10) is connected with a primary air outlet pipeline (56), and the outlet end of the primary air bypass (10) is connected with the outlet of a secondary air pipeline (62).

2. The novel air preheater system of the coal-fired power plant as set forth in claim 1, wherein the regulating damper (4) is located at an inlet of the rotary air preheater (6), and the opening degree of the regulating damper (4) is controlled by an electric actuator.

3. The novel air preheater system of a coal-fired power plant as set forth in claim 1, wherein an electrically adjustable valve (11) and a bypass pressure gauge (12) are sequentially provided in the primary air bypass (10) along the air flow direction.

4. The novel air preheater system for coal-fired power plant as claimed in claim 1, wherein the tubular air preheater (5) is internally provided with a partition plate (54) and a fin heat exchange tube (55).

5. The novel air preheater system of claim 1, wherein the rotary air preheater (6) is of the two-bin type.