CN105115990A

CN105115990A - Sampling-free detection method applied to microwave carbon examination and carried out at dust outlet of dry collector

Info

Publication number: CN105115990A
Application number: CN201510550719.7A
Authority: CN
Inventors: 王金铭; 解海龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-09-01
Filing date: 2015-09-01
Publication date: 2015-12-02

Abstract

The invention relates to a sampling-free detection method applied to on-line monitoring of unburned carbon in fly ash of a large coal-fired boiler. According to the method, the operation is carried out on the dust outlet of a dry collector of a boiler unit, and the method is suitable for a detection device adopting a microwave method testing principle. The method is characterized in that monitoring points are moved to an outlet below a dust hopper of a primary dry collector through a flue. A pair of microwave transmitting and receiving devices is mounted on the opposite sides of a cross section of a dust outlet channel, so that microwave beams pass through the cross section of the dust outlet channel, while the flue dust which flows through the cross section and intercepted by the dust collector is taken as a tested object. With the adoption of the method, the problems of dust blockage, influences on the detection result by various factors, poor representativeness of a dust sample, and the like are solved; the arrangement, operation and maintenance of the detection device are convenient; and meanwhile, due to the improvement on the work environment, the reliability of the device is greatly improved, and the service life of the device is greatly prolonged.

Description

Dry collector ash hole for microwave carbon determination exempts from sample detecting method

Technical field

The present invention relates to and a kind ofly exempt from sample detecting method for large coal-fired boiler unburned carbon in flue dust on-line monitoring, the method is implemented at dry collector (electrostatic or the sack cleaner) ash hole of boiler controller system, is applicable to the pick-up unit adopting " microwave method " Cleaning Principle.

Background technology

Unburned carbon in flue dust is the important indicator of reflection large coal-fired boiler performance driving economy, is also that Optimizing Combustion and low-nitrogen oxide discharging control indispensable foundation, therefore the on-line checkingi of this index is become to the focus of extensive concern.In existing detection method, because " microwave method " has the advantages such as test speed is fast, structure is simple, maintenance is little, engineering is adopted in a large number.At present, the test samples of the method all comes from boiler back end ductwork, has two kinds of sampling methods, but all there is the defect that cannot overcome, have a strong impact on applying of this product." microwave method " Cleaning Principle and method of sampling brief introduction as follows:

Cleaning Principle: the microwave of the carbon in flying dust to specific wavelength has absorption, when microwave is linear through decay and the unburned carbon in flue dust of its power during flying dust, this characteristic can be used to the carbon content of expression flying dust after demarcating.

The method of sampling:

1, with the flue gas in negative pressure extracting flue, after being separated, ash sample is obtained as tested object;

2, at flue both sides Microwave emission positioned opposite and receiving trap, make microbeam pass whole flue xsect, using flow through this cross section containing flying dust flue gas as tested object.

The defect of two kinds of method of samplings: the former is in extraction flue gas process, and extracting channel stifled ash often occurs and detection is interrupted; Although the latter avoids stifled ash, but the material of the microwave energy absorbing such as moisture in the middle of the distance of passing through due to microwave long (tens meters), flue space complex structure (support steel beam etc.), flue gas, microwave generation scattering, reflection and other material absorbing etc. are made to consume the process of microwave energy, make the number of the not unique corresponding unburned carbon in flue dust of the decay of its power, testing result deviation is very large.

Due to defect above, make the pick-up unit based on two kinds of method of samplings all not obtain the generally accreditation of user, engineering can not play its due effect.

Summary of the invention

In order to overcome the defect of traditional sampling method, the present invention proposes a kind of brand-new solution.

The technical scheme of the technical matters that the method will solve and employing is: monitoring point is moved to one-level dry collector ash dropping hopper lower exit port place.At the ash discharge channel cross-section opposite side at this place, a pair Microwave emission and receiving trap are installed, make microbeam pass ash discharge channel cross-section, will flying dust that this cross section separates through fly-ash separator be flowed through as tested object.

The beneficial effect that the present invention brings is:

1, owing to not needing sampling, stifled grey problem is thoroughly solved;

2, not water content etc. in microwave traverse distance short (within 400mm), therebetween have no occluder, flying dust, eliminates the interference of other factors to testing result;

3, dry dust removal (electrostatic or bag-type dust) is dedusting method most effective at present, the flying dust of more than 90 ~ 95% is captured, blending focus on ash dropping hopper ash hole place, it can be used as checked object, its typical sample is obviously better than " point type " sampling of flue;

The environment of 4, dedusting workplace is obviously better than near flue, and place is spacious, is convenient to the layout of detecting instrument, operation and maintenance, and equipment dependability and serviceable life are increased substantially.

So far, instant invention overcomes the shortcoming of traditional sampling mode, coordinate original detecting instrument can realize reliably, combustible content continuously in on-line checkingi boiler fly ash.

Accompanying drawing explanation

Accompanying drawing is embodiment of the present invention schematic diagram.

In figure: 1. flying dust 3. ash dropping hopper after fly-ash separator ash dropping hopper 2. dedusting separation exports 4. microwave launcher 5. microwave receiving device 6. pick-up unit control system.

Embodiment

Below in conjunction with drawings and Examples, the present invention is further described.

As shown in the figure: in the two side walls relative position perforate of the appropriate location, outlet 3 place of dry collector ash dropping hopper 1, microwave launcher 4 is installed in side, and opposite side installs microwave receiving device 5; The microwave power signal of stream oriented device transmitting and receiving sends pick-up unit control system 6 to.During detection, flying dust 2 after the microwave that microwave launcher 4 is launched is separated through dedusting, part is absorbed by the carbon in flying dust, remainder is received by microwave receiving device 5, and the microwave of microwave power signal through being embedded into pick-up unit control system 6 of stream oriented device (4,5) detects mathematical model and interrelated logic computing, arrangement provide testing result.

By above embodiment, achieve be applicable to microwave method unburned carbon in flue dust on-line monitoring exempt from sample detecting.

Claims

1. the dry collector ash hole for microwave carbon determination exempts from a sample detecting method, it is characterized in that monitoring point being moved to one-level dry collector ash dropping hopper lower exit port place, installs a pair Microwave emission and receiving trap at the ash discharge channel cross-section opposite side at this place.

2. the dry collector ash hole for microwave carbon determination according to claim 1 exempts from sample detecting method, during detection, microbeam is made to pass ash discharge channel cross-section, using flowing through flying dust that this cross section separates through fly-ash separator as tested object, after demarcating, provide flying marking numerical quantity according to microwave power attenuation degree.