CN1069960C - Method and apparatus for detecting combustion temperature profile in boiler chamber at power station - Google Patents

Abstract

The present invention relates to a detection method which is particularly suitable for detecting combustion temperature distribution of a boiler hearth of a power station. On the basis of television monitoring device of flame in a boiler hearth in a power station, a wavelength colour filter is put in an imaging light path to obtain images of flame radiation in single wavelength, the image signals are converted into electrical signals by a video camera, the electrical signals enter a computer through an image capture card, a high temperature thermocouple is adopted to realistically detect the temperature of a point in the boiler at the same time, the temperature is fed into the computer and then is calculated and processed by the computer to detect the distribution of a two-dimensional flame temperature field in the boiler in real time, and the distribution of a two-dimensional flame temperature field is displayed on a monitor.

Description

Furnace of power-plant boilers ignition temperature distribution detection method and device thereof

The present invention relates to a kind of detection method, particularly suitable furnace of power-plant boilers ignition temperature distributes and detects.

Image processing techniques and computer technology are applied to be a kind of new technology that occurs in recent years, but be in the laboratory test conceptual phase mostly that commerical test just just begins in the combustion monitoring system of station boiler.In this class technology important a kind of detection method based on stove in two-dimentional Flame Temperature Distribution detect, distribute with the duochrome method accounting temperature according to radiation law, the part that burner hearth is burnt and detecting in a certain respect is with the diagnosing combustion operating mode.For example: M.Shimoda, et al., Predition method of unburnt carbonfor coad fired utility boiler using image processing technique of combustionflame, IEEE Transaction on Energy Conversion, Vol.5, No.4, December, 1990.M.Shimoda in " adopting the coal burning boiler of power station uncompleted burned carbon prediction method of combustion flame image processing technique " (IEEE power conversion proceedings, the 5th rolled up for the 4th December nineteen ninety phase).

The shortcoming of this technology is: when accounting temperature, two required radiant energy obtain as far as possible simultaneously (one), and two width of cloth images are limited to the reason of hardware during respectively by computer acquisition, and its blanking time can not be very short.This contradiction is irreconcilable.For reaching real-time as much as possible, have on the speed of IMAQ and capacity, propose higher requirement, its cost is inevitable more and more higher.During (two) with double-contracting method accounting temperature, every temperature is calculated by the radiant energy that detects under two wavelength that send from this point.If these two wavelength are λ ₁, λ ₂, for certain 1 i, their spoke can be respectively E _{I λ 1}, E _{I λ 2}, its temperature T then _iComputing formula be: $T_i=\frac{C_2\[\frac{1}{{\mathrm{\λ}}_1}-\frac{1}{{\mathrm{\λ}}_2}\]}{\ln \[\frac{E_{\mathrm{i\λ}1}}{E_{\mathrm{i\λ}2}}{\left(\frac{{\mathrm{\λ}}_2}{{\mathrm{\λ}}_1}\right)}^5\]}$ C wherein ₂Be constant.Key is to obtain E _{I λ 1}And E _{I λ 2}This just need isolate two Fire Radiation signals under the wavelength before the imaging, require between imaging optical path, to plug a chopper wheel that drives by micro machine generally speaking, different parts is embedded with two wavelength colour filters on the dish, micro machine driving chopper wheel rotates at a high speed during work, the colour filter cutting imaging beam that has different wave length on the different chopper wheels constantly, obtain the flame radiation image under the different wave length, therefore need the accurate complicated optical-mechanical system of a cover, the scene is difficult to use, and poor reliability.

At the shortcoming that above-mentioned prior art exists, task of the present invention provides the burn detection method of two-dimentional flame temperature field of a kind of simple and practical furnace of power-plant boilers based on radiation law.

The present invention implements by following technical measures.

Furnace of power-plant boilers of the present invention is burnt the detection method of two-dimentional flame temperature field on the basis of furnace of power-plant boilers flame television monitoring device, in imaging optical path, put into the colour filter of a single wavelength, to obtain the flame radiation image under single wavelength, video camera enters computer with the picture signal switching electrical signals by image pick-up card.Simultaneously, the temperature of any in the employing pyrometer couple actual measurement stove, mould is gone into computer.Computer is passed to monitor with two-dimentional flame temperature field distribution in the stove that shows real-time detection after handling as calculated.The device of described method is, places a kind of single wavelength colour filter 2 between camera lens 1 and ccd video camera 4, establishes figure capture card 5 between video camera 4 and computer 6, and computer 6 connects with display monitor central monitoring system 7, and temperature element 8 connects with computer 6.The present invention is based on following principle, establishing the temperature that thermocouple records is T ₀, its radiant energy that is positioned on the flame image accordingly is E ₀, other are E from the radiant energy that flame image gets, and the wavelength in the corresponding colour filter is λ, and the temperature of corresponding calculated point is T $T=\frac{1}{\frac{1}{T_0}-\frac{\mathrm{\λ}}{C_2}\ln \frac{E}{E_0}}$ The furnace flame two-dimensional distribution of temperatures can be got thus, thereby diagnosis can be implemented stove internal combustion operating mode.

This bright and traditional high temperature radiation thermometer algorithm and burner hearth sees that the thermoelectricity technology of looking relatively has following advantage: (one) has broken through the limitation of only utilizing flame primary radiation signal aspect full furnace flame supervision.Calculate by the temperature field, finer supervision is carried out in burning, this is the progress of matter.(2) the two-dimensional temperature field computational methods with existing employing radiation law compare, the present invention cancels strict being used to and isolates the optics of the radiation image under the different wave length, mechanical system, make entire method simple unusually, very easily in existing flame television equipment, realize.(3) reduced requirement to image acquisition rates and capacity, because of almost gathering a flame radiation image under the wavelength simultaneously, the real-time of its temperature computation fundamentally must be improved.

Description of drawings is as follows:

Fig. 1 is a systematic schematic diagram of the present invention.

Claims (2)

1. furnace of power-plant boilers ignition temperature distribution detection method that adopts television monitoring device, it is characterized by on the basis of furnace of power-plant boilers flame television monitoring device, between camera lens and video camera, put into a kind of colour filter of single wavelength, to obtain the flame radiation image under single wavelength, video camera changes picture signal into the signal of telecommunication, enter computer by image collection card, adopt in the pyrometer couple actual measurement stove temperature of any simultaneously, mould people computer, machine is passed to the distribution of monitor with two-dimentional flame temperature field in the stove that shows real-time detection after calculating and handling as calculated.

2. according to a kind of station boiler temperature distributing detecting device of the described method of claim 1, it is made of camera lens, video camera, colour filter and monitor, it is characterized by the colour filter (2) of between camera lens (1) and ccd video camera (4), placing a kind of single wavelength, between video camera (4) and computer (6), establish image pick-up card (5), computer (6) connects with monitor (7), and temperature element (8) connects with computer (6).