CN2720426Y

CN2720426Y - Device for detecting fly-ash carbon-containing amount from power plant boiler

Info

Publication number: CN2720426Y
Application number: CN 200420064588
Authority: CN
Inventors: 孟金来
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-01
Filing date: 2004-06-01
Publication date: 2005-08-24
Anticipated expiration: 2014-06-01

Abstract

A device for detecting carbon content in fly ashes from power plant boiler comprises a cylinder sampling head which is installed in a boiler discharge flue and a U-tube differential pressure gage, a cyclone receiver and an ash sample processor which are installed on the exterior of the discharge flue. A microwave measurement head is installed on the exterior of the wall of an ash bucket of the ash sample processor. A weighted fly ash flapper is installed at the exit end of the ash bucket. The exit of the ash bucket is connected with the discharge flue above an air preheater via an ash discharge pipe. The top end of the cyclone receiver is connected with the discharge flue below the air preheater via a pipeline and a valve for regulating the flow velocity of flue gas. The utility model takes the flue gas pressure difference at the entrance and exit of the gas flue of the air preheater as dynamic force of a fly ash sampler. The flue gas in the boiler flue is led into the cyclone receiver with constant velocity. As flue gas flow rotates in the cyclone receiver, ash particles in the flue gas are swung on the receiver wall and fall and gather. When the ash particles reach a given quantity, they are detected by the microwave measurement head. The device has simple structure, isokinetic sampling, good representativeness of ash sample, no rotary machines, and easy installation and maintenance.

Description

Boiler of power plant unburned carbon in flue dust pick-up unit

Technical field

The utility model relates to a kind of device that detects carbon content from the flue dust that the generating plant fuel boiler is discharged, and belongs to the adjusting control technology field in the combustion apparatus.

Background technology

Containing unburnt carbon in the flue dust flying dust that the fuel-burning power plant coal-burning boiler is discharged, is the second largest loss in the boiler combustion, and the online carbon content that quick and precisely detects in the flying dust is significant to the burning efficiency that improves boiler.Present detection method has lab analysis method and Microwave Measurement method, and the former collects a certain amount of flying dust sample at the scene with the collision type sampler, records carbon content after the calcination of laboratory.The ash sample that this sampler is got is representative poor, and the fine particle in the flying dust flies away because of momentum is little; Need the regular hour in the laboratory measurement analysis, have the hysteresis problem adjusting the control fired state.The latter measures in the microwave detecting device of flying dust through ash pipeline freely falls to flue outside of collecting with the collision type sampler, surveys and then sends flying dust back to flue again by the ash discharge motor.Here exist ash sample representative poor too, and measured once in general 3～5 minutes, belong to discrete on-line measurement, also have the hysteresis problem; This measuring method needs equipment such as ash discharge blower fan, solenoid valve vibrator, and functional reliability is low, and maintenance is big, and temperature reduces behind the flue because of ash sample leaves, and is easy to generate the stifled grey problem of dewfall.

The utility model content

The utility model provides a kind of online bypass sampling, synchronous detection in order to overcome the defective of prior art, and boiler of power plant unburned carbon in flue dust pick-up unit simple in structure.

The utility model boiler of power plant unburned carbon in flue dust pick-up unit, comprising the smokejack inner cylindrical tube sampling head that is installed between boiler and the air preheater, stretch out outside the smokejack through circular arc corner and pipeline the lower end of sampling head, and be communicated with it along the tangential direction of tubular cyclone trap upper end barrel, the lower end of cyclone trap is communicated with the ash sample processor; The lower end of ash sample processor is communicated with by the smokejack of ash releasing tube with the air preheater top, and the cyclone trap top is communicated with the smokejack of air preheater below by pipeline and flue gas flow rate variable valve again; One end of two stopple coupons respectively be installed in the smokejack outer wall on the two ends of U type pipe differential manometer be communicated with, wherein the other end of a stopple coupon pass smokejack be placed in sampling head near, and in the pipeline that the other end of another root stopple coupon penetrates with sampling head is connected, be placed in the sampling head.

The utility model boiler of power plant unburned carbon in flue dust pick-up unit, wherein the ash sample processor is the Weight type processor, it comprises ash bucket, microwave measurement head and flying dust flapper; The ash bucket upper end is a broadening formation, and the lower end is a cylindrical drum, and the microwave measurement head is housed on the cylindrical drum periphery, and Weight type flying dust flapper is housed on nozzle.

The utility model boiler of power plant unburned carbon in flue dust pick-up unit, wherein the ash sample processor is the continuous flow processor, it comprises the bypass ash bucket that measurement ash bucket and top are communicated with it, and the upper end of measuring ash bucket and bypass ash bucket is toroidal, and its lower end is cylindrical drum; And the outlet of cyclone trap is equipped with the microwave measurement head to the locating tab assembly ash bucket on the cylindrical drum periphery of described measurement ash bucket.

The utility model boiler of power plant unburned carbon in flue dust pick-up unit, wherein the ash sample processor is regulated processor automatically for connecting to read to flow, and it comprises by great circle column casing epimere, roundlet column casing hypomere and hyperbolic-type interlude and interconnects the ash bucket that forms; On hypomere cylindrical shell periphery, the microwave measurement head is housed, two flying dust flappers is housed symmetrically at the hypomere tube port position.

The utility model boiler of power plant unburned carbon in flue dust pick-up unit, wherein it also comprises purging wind regime delivery outlet, it is located at air preheater secondary air exit.

The utility model boiler of power plant unburned carbon in flue dust pick-up unit, the flue gas pressures difference of import and export of gas flue of utilizing the air preheater in the boiler combustion equipment is as the power of fly ash sampler, in the introducing cyclone trap with the flue gas constant speed in the boiler flue, because flue gas stream rotation within it, soot particle is thrown under centrifugal action and falls on the wall and collect in the flue gas, when reaching a certain amount of, and detect by the microwave measurement head.This apparatus structure is simple, the isokinetic sampling, and the ash sample representativeness is good, no rotary machine, installation and maintenance are easy.Flue gas stream temperature height (the general temperature of flue gas is more than 350 ℃), the good fluidity of flying dust is difficult for the stifled ash of dewfall.

Description of drawings

Fig. 1 is the utility model unburned carbon in flue dust pick-up unit and purges wind regime structural principle synoptic diagram;

Fig. 2 is a Weight type ash sample processor structure principle schematic in the utility model;

Fig. 3 is a continous way ash sample processor structure principle schematic in the utility model;

Fig. 4 regulates ash sample processor structure principle schematic automatically for continuous flow in the utility model.

Specific implementation method

As seen from Figure 1, pick-up unit of the present utility model is mounted in the bypass type structure of outside between the smokejack 3 of boiler and the air preheater 9, it comprises the cylindrical drum sampling head 1 in the smokejack 3 that is installed between boiler and the air preheater 9, the outside of smokejack 3 is stretched out in the lower end of this sampling head 1 through circular arc corner and pipeline, and be communicated with it along the tangential direction of tubular cyclone trap 5 upper end barrels, the lower end of cyclone trap 5 is communicated with ash sample processor 6, the lower end of ash sample processor 6 is communicated with the smokejack 3 of air preheater 9 tops by ash releasing tube 7, and cyclone trap 5 tops are communicated with the smokejack 3 of air preheater 9 belows by pipeline and flue gas stream variable valve 8.One end of two stopple coupons 2 respectively be installed in exhausting duct 3 outer walls on the two ends of U type pipe differential manometer 4 be communicated with, wherein the other end of a stopple coupon 2 pass smokejack 3 be placed in sampling head 1 near, and the other end of another root stopple coupon 2 penetrates in the pipeline that is connected with sampling head 1, is placed in the sampling head 1.

Testing process of the present utility model is: the pressure reduction of flue gases stream makes flying dust tangentially enter rotation in the cyclone trap 5 in the smokejack 3, and granular flying dust is thrown to wall and falls and enter in the ash sample processor 6 under action of centrifugal force.The flue gas stream flow velocity that enters this pick-up unit is regulated by electromagnetic type variable valve 8, and the family curve of setting variable valve 8 and close by the drag characteristic curve of the air preheater 9 of bypass; Thereby the drag characteristic of the sampling system of this device is similar to the drag characteristic of air preheater, when the boiler unit load changes, flue gas flow rate also changes, the flue gas flow rate that enters the pick-up unit sampling also carries out equivalent by the principle of similitude and changes, realize the isokinetic sampling, detected ash sample representativeness is good.Ash sample processor 6 is the Weight type processor, comprises that the upper end is the ash bucket 10 of cylindrical drum for broadening formation, lower end, in the cylindrical drum periphery of ash bucket 10 microwave measurement 11 is housed, and Weight type flying dust flapper 12 is housed on nozzle, sees shown in Figure 2.When having the flying dust of certain density in the cylindrical drum, microwave measurement 11 carbon content that can detect in the soot particle.Weight type flying dust flapper 12 is an existing product, it is made of the baffle plate and the fixed rotating shaft of weight, cylinder nozzle, the baffle plate and the connected adjustable weight that are the cylinder nozzle are fixed on the nozzle wall by the rotating shaft in the middle of it, regulate the position of weight by designing requirement, when the flying dust in the tube does not reach the designing requirement value, flapper closure, one-shot measurement is carried out in microwave measurement 11.When reaching, baffle plate is opened, the flying dust of measuring is flow back in the gas flue 3 through ash releasing tube 7, and under the action of gravity of weight, 12 repositions of Weight type flying dust flapper, the flapper closure nozzle enters next measuring process.

Fig. 3 is the ash sample processor of continuous flowing type.It comprises measures the bypass ash bucket 14 that ash bucket 13 and top are communicated with, and microwave measurement 11 is contained in the cylindrical outer tube of measuring ash bucket 13.This processor is by the boiler minimum load, the minimum design of coal-fired dust burdening, what promptly issuable minimum flying dust amount designed in the boiler operatiopn.Microwave measurement 11 pairs of ash sample carbon content that directly flow through measurement ash bucket 13 are measured continuously.Equally, the ash sample of measuring flow back in the gas flue 3 through ash releasing tube 7.When boiler in high load capacity and burning during high-ash coal, the ash sample that cyclone trap 5 is collected is greater than measuring the ash sample amount that 13 in ash bucket can flow through, then ash sample flow back into the gas flue 3 from ash releasing tube 7 through bypass ash bucket 14.This continuous detecting result to the ash sample carbon content has actual directive significance to the fired state of adjusting boiler.

Fig. 4 regulates the ash sample processor automatically for continuous flow.It comprises by great circle column casing epimere 15, roundlet column casing hypomere 16 and hyperbolic-type interlude 17 and interconnects the ash bucket that forms; Microwave measurement 11 is housed on hypomere 16 cylindrical shell peripheries, and two Weight type flying dust flappers 12 is housed symmetrically at tube port position.The structural principle of flying dust flapper 12 is described the same with Fig. 2, but at this moment the cylindrical drum nozzle of hypomere 16 is blocked by two baffle plates, adjusts the weight position by microwave measurement 11 a detection requirement equally.The ash sample amount of collecting when cyclone trap 5 hour, ash sample is little to the pressure of baffle plate, then under the effect of counterweight balance power, nozzle opens little, the flying dust flow velocity is low, keeps certain ash sample amount in the tube, detects carbon content for microwave measurement 11.When the ash sample amount was big, baffle openings was big, and the flying dust flow velocity increases, but still can keep the ash sample amount that certain needs detect.Sort processor can satisfy and comes the ash sample amount constantly to take place to change significantly, and still keeps certain for measuring ash sample amount.

The utility model pick-up unit is in order to guarantee normal operation, and pipelines such as sampling need regularly to purge, and to prevent stifled ash, establishes in the secondary air exit of air preheater 9 and purges wind regime delivery outlet 18, is connected with blower, draws wind regime pipeline is regularly purged.This source temperature reaches more than 300 ℃, and the pressure height can reach more than the 1kpa, and the device for detecting distance distance is near, does not more need to increase separately equipment.

Claims

1, boiler of power plant unburned carbon in flue dust pick-up unit, it is characterized in that it comprises the interior cylindrical drum sampling head (1) of smokejack (3) that is installed between boiler and the air preheater (9), stretch out outside the described smokejack (3) through circular arc corner and pipeline the lower end of described sampling head (1), and be communicated with it along the tangential direction of tubular cyclone trap (5) upper end barrel, the lower end of described cyclone trap (5) is communicated with ash sample processor (6); The lower end of described ash sample processor (6) is communicated with by the smokejack (3) of ash releasing tube (7) with described air preheater (9) top, and described cyclone trap (5) top is communicated with the smokejack (3) of described air preheater (9) below by pipeline and flue gas flow rate variable valve (8) again; One end of two stopple coupons (2) respectively be installed in described smokejack (3) outer wall on the two ends of U type pipe differential manometer (4) be communicated with, wherein the other end of a stopple coupon (2) pass described smokejack (3) be placed in described sampling head (1) near, and the other end of another root stopple coupon (2) penetrates in the pipeline that is connected with described sampling head (1), is placed in the hydraucone of described sampling head (1).

2, boiler of power plant unburned carbon in flue dust pick-up unit according to claim 1 is characterized in that described ash sample processor (6) is the Weight type processor, and it comprises ash bucket (10), microwave measurement head (11) and flying dust flapper (12); Described ash bucket (10) upper end is a toroidal, and the lower end is a cylindrical drum, and microwave measurement head (11) is housed on the cylindrical drum periphery, and Weight type flying dust flapper (12) is housed on nozzle.

3, boiler of power plant unburned carbon in flue dust pick-up unit according to claim 1, it is characterized in that described ash sample processor (6) is the continuous flow processor, it comprises the bypass ash bucket (14) that measurement ash bucket (13) and top are communicated with it, the upper end of described measurement ash bucket (13) and bypass ash bucket (14) is toroidal, its lower end is cylindrical drum, and described measurement ash bucket (13) is aimed in the outlet of described cyclone trap (5); Microwave measurement head (11) is housed on the cylindrical drum periphery of described measurement ash bucket (13).

4, boiler of power plant unburned carbon in flue dust pick-up unit according to claim 1, it is characterized in that described ash sample processor (6) regulates processor automatically for connecting to read to flow, it comprises by great circle column casing epimere (15), roundlet column casing hypomere (16) and hyperbolic-type interlude (17) and interconnects the ash bucket that forms; On hypomere (16) cylindrical shell periphery, microwave measurement head (11) is housed, two described flying dust flappers (12) is housed symmetrically at hypomere (16) tube port position.

5, according to the described boiler of power plant unburned carbon in flue dust of one of claim 1～4 pick-up unit, it is characterized in that it also comprises purging wind regime delivery outlet (18), it is located at the exit of described air preheater (9) secondary air.