RU2596686C2 - Method for controlling a combustion and/or gasification device - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to a method for controlling combustion or gasification device (VB) for small-sized solid fuels (BS) with spreader feeder (WB). Device (VB) has combustion chamber (BK) and grate (R) with two grate zones. Flame edge (GK) is formed in one of the grate zones. Actual position of flame edge (GK) is monitored using optical camera (K). If the actual position of the flame edge (GK) deviates from a target position, the supply (LV1, LV2) of a primary air quantity (PL1, PL2) and/or a primary recirculation quantity (RL1, RL2), into the combustion chamber (BK) is modified in a controlled manner. Analysis of the snapshots and thus an analysis of the actual position of glowing fire edge (GK) is performed by means of colour evaluation using virtual sensors that assume at least three states, especially a positive state, a warning state and an error state depending on the determined actual colour values, the virtual sensors are arranged in rows.

EFFECT: high efficiency and simple method of automation of burnout of the ash.

3 cl, 1 dwg

Description

FIELD OF TECHNOLOGY

The present invention generally relates to the field of devices for combustion or gasification, in particular to the thermal use of various solid combustible materials. In particular, the present invention relates to a method for controlling a device for burning and / or gasifying small-sized solid combustible materials with mechanical casting. The device for burning or gasification contains at least one combustion or gasification chamber, as well as a grate with at least two grate zones (for example, with a combustion or gasification zone as the first zone and with a burnout zone as the second zone), located in the longitudinal direction of the grate. Moreover, in one of the grate zones, in particular, in the so-called burnout zone, a so-called burnout border is formed.

BACKGROUND

Devices for burning and / or gasification for heat treatment of various solid combustible materials are used, for example, when combining the production of thermal and electric energy in industry and / or in municipalities. At the same time, solid combustible materials are, for example, residual materials (e.g. wood, waste, fiber materials, pre-treated waste, dry sewage sludge, special (environmentally friendly) combustible materials), which are usually disposed of, for example, as waste in mass incineration plants. Such devices are used, for example, in the paper industry for the production of electricity and / or steam for drying cardboard, in municipalities for the production of green energy from biomass waste or for the disposal of sewage sludge in sewage treatment plants, or in plants for burning or gasifying biomass.

The burning or gasification of solid combustible materials supplied to the device for burning or gasification in small pieces, for example, by throwing, i.e. The so-called mechanical casting usually occurs on the grate. During mechanical casting, most often small-sized solid combustible material is thrown into the combustion or gasification chamber and is thus distributed over the grate using the so-called mechanical casting device, i.e. impeller installed in the spreader.

At the same time, at least two zones are formed on the grate, located in the longitudinal direction of the grate. For example, a so-called combustion or gasification zone occurs, which occupies about 4/5 of the surface of the grate, and a so-called burnout area, covering 1/5 of the surface of the grate. The combustion or gasification zone is characterized by uniform burning over a large area. Combustible material is burned or gasified in it from top to bottom. New combustible material is constantly being added, which enters the burning environment and immediately ignites. No combustible material is thrown into the burnout zone. The burnout zone is characterized by the so-called burn-out border, beyond which burn-out takes place, and the temperature and color of the ash outside the burn-out border quickly decrease. Rather, it only burns out the ash, which is then fed to the so-called ash removal.

The regulation of such a device for combustion or gasification is carried out, for example, in the form of regulation of the supplied amount of air, for example in the form of the so-called primary, secondary and tertiary air. The amount of air supplied is regulated, for example, depending on the set power, moisture content in the combustible material and the measured reaction parameters (for example, temperature above the grate, temperature at the end of the burnout zone, etc.). Additionally, with the help of these parameters the ratio of the so-called primary air to the amount of so-called primary recirculation air and to the amount of so-called secondary circulation air are also regulated. In this case, the so-called primary air refers to the amount of air that is supplied directly under the zone of the grate. In a combustion or gasification device (such as, for example, a bottom gasification device), primary air is usually supplied from under the grate and thereby has a significant effect on combustion or gasification on the grate and thus on burnout. The so-called secondary air is usually supplied from above and serves, for example, for the so-called subsequent oxidation of gases formed on the grate. The amount of recirculation air is, for example, the amount of exhaust or flue gas (for example, from the supplied primary air) by which the optimization of combustion or gasification processes can continue through recirculation. Moreover, the entire amount of air (for example, primary air, primary recirculated air) for regulating combustion or gasification can be given, for example, in one single zone under the grate. However, air (for example, primary air, primary recirculation air) can also be supplied zonally if, for example, the grate is physically longitudinally divided into at least two zones, so that these zones can be operated separately.

As a result of regulation of the air supply, for example, conditions must be achieved for uniform combustion in the combustion zone or for uniform gasification in the gasification zone on the grate, as well as complete burnout of the ash (for example, to a residual carbon content of less than 1%). In addition, with the help of appropriate regulation, it is necessary to prevent the burning ash from falling into ash removal. In order to prevent burning ash from getting into ash removal, constant monitoring and control over the position of the burnout border is necessary. Currently, such control of the burnout boundary is usually carried out manually. This means that the position is monitored by service personnel, for example, at regular walks, and then, in accordance with this position of the burn-in limit, for example, the air supply is further adjusted. True, this procedure is very costly, time-consuming, and inaccurate under certain conditions, since maintenance personnel must accurately monitor the burnout boundary, and partially carry out the corresponding actions manually, after which the burnout boundary must again be precisely controlled.

In conventional combustion or burning on a grate, in which combustible material is supplied, for example, by means of a pushing system and burned, being laid out on the grate, usually without forming an unambiguous burnout border, for example, combustion chamber monitoring systems are used. In these systems, the combustible material, before it flares up approximately in the middle of the grate and begins to burn, is first heated. As a result of burning in a relatively cramped space, high temperatures occur locally, as a result of which, however, large pieces of slag are formed on the grate, which then, partly continuing to smolder inside, are quenched during ash removal in a "water bed".

In such systems, for example, using thermal chambers (for example, by measuring infrared radiation), the temperature profile above the grate is determined, and then the corresponding control processes, in particular the local air supply, are determined from this temperature profile. Thus, these systems have the disadvantage that such thermal or infrared cameras are relatively expensive and their use, in particular, for determining and regulating the position of the boundary, is very expensive, since an appropriate expensive additional analysis of the temperature profile must be carried out to determine the position of the burnout boundary.

In addition, in industrial combustion devices, such as incinerators, for monitoring the temperature distribution or image of the flame, and thus outside the burnout, the so-called chambers of the furnace or firing space are used. With the help of these fire chamber cameras, through the corresponding data processing units, the burn-in boundary can be determined or set in the sense of being within a predetermined range. True, these cameras are (infrared) cameras specially designed for the conditions of the device for combustion. However, the use of these (infrared) cameras to determine the position of the burnout boundary is also costly and is associated with high costs.

SUMMARY OF THE INVENTION

Therefore, the invention is based on the task of creating a method for regulating a device for burning or gasifying solid combustible materials, in which the position of the burn-out boundary used for appropriate regulation is determined in a simple and economical way.

The solution to this problem is carried out using the method of the above type, in which by means of at least one optical camera the actual position of the burn-out border is tracked. Then, when the actual position of the burnout boundary deviates from the set position in the combustion chamber of the control or combustion device, a controlled change in the air supply is made, in particular, the amount of so-called primary and / or so-called primary recirculation air.

The main aspect of the proposed solution according to the invention is that the actual position of the burnout border is set simply. In this case, depending on the established actual position of the burn-out border or its deviation from the set position, a corresponding change in the air supply is made. In this case, the supply, for example, of all air, i.e. quantities of primary and primary recirculation air, may increase or decrease, i.e. to shift the burnout boundary in the direction of a predetermined position, for example, a certain amount of primary air can be taken back with an increase in the amount of recirculated air or an increase in the amount of primary air with a decrease in the amount of recirculated air. Thus, the burnout of ash is automated in a simple and economical way, the required amount of air (for example, primary, recirculated air) is optimized and the ash is completely burned out (for example, to a residual carbon content of less than 1%). Additionally, it is prevented that ash burns out on ash removal. The device for burning by the method according to the invention automatically responds to changes in the properties of burnout, for example, as a result of changes in the properties of combustible materials.

To transmit an image of the burn-out border in order to determine its actual position, the optical camera can, for example, be introduced into the combustion chamber of a combustion or gasification device. In this way, an optimal viewing angle is achieved at which it is possible to simultaneously transmit images of the flame, the burnout boundary and the grate in the combustion or gasification chamber. As a result, the optical camera in a simple way provides the receipt and transmission of informative images of the firing space for analysis, i.e. determining the position of the burnout border In this case, the camera or optics for transmitting images in order to avoid heating or heating is ideally placed in a specially cooled case or cooled.

Alternatively, the chamber can also be installed, for example, outside the combustion or gasification chamber. In this case, it may be preferable that the transmission is carried out through one of the so-called peepholes, in particular through the peephole in the so-called furnace door. In this case, the optical camera is mounted on a tripod outside the combustion chamber. When transmitting images through the peephole (for example, in the furnace door), the viewing angle of the camera also allows you to simultaneously take off the flame, the burn-out border and the grate.

Since in the case of peepholes in the combustion or gasification chamber, the matter may reach ash deposits, which may interfere with the transmission of images, an air nozzle may be used to ensure that the field of view of the optical camera is clear. Using compressed air, for example, the eye window through which the camera transmits images can be cleaned of ash, and thereby visibility restrictions, for example, due to ash, can very easily be removed.

Ideally, a processor coupled to the camera is used for image analysis. Thus, the camera using the appropriate software can be very simply programmed, for example, to analyze the image and thereby to determine the position of the burn-out border. In this case, the combination of the processor with the camera can be formed, for example, depending on the position of the camera. If the optical camera is located or is located, for example, in the combustion chamber, then the processor can be installed outside the combustion chamber, i.e. devices for burning or gasification. If the optical chamber is located outside the combustion chamber of the device for combustion or gasification, the processor may, for example, be integrated into the optical chamber.

One of the advantageous improved embodiments of the method according to the invention provides that the image analysis and thereby the analysis of the actual position of the burn-out border is carried out using the so-called color processing. With the so-called color processing, small fragments of the image are analyzed and a color difference is generated with respect to the previously determined reference colors. Thus, by using various color data in the combustion chamber, for example, regarding the flame, the burnout border, the grate, etc., the position of the burnout border can be very easily and relatively accurately determined.

In this case, it is preferable that virtual sensors are used for color processing, according to which, depending on the established actual color data, at least three states, in particular, operating, alarm and emergency states, are received and which are installed in rows.

Virtual sensors, also called software sensors, are software implemented sensors. For example, in a camera for image analysis, virtual sensors can very easily be implemented in the camera processor using programming. Virtual sensors measure or calculate values that are derived from quantities measured by real sensors using an empirically studied or physical model. Virtual sensors are ideally used in applications in which real sensors are either too expensive or cannot be used, for example, due to environmental conditions (for example, heating of the combustion device, dust load from the ash side, etc.) or due to the threat of too rapid wear. Thus, in a simple and economical way, color processing of the camera image and determination of the position of the burnout border can be carried out.

One of the suitable embodiments of the method according to the invention provides that, using virtual sensors, the actual color indices of small image fragments are compared with predetermined reference indicators for these image fragments, so that if the freely determined limit value is exceeded in terms of the color difference between the actual and reference color indicators the sensor was installed in an emergency state and that as a result of the analysis of individual conditions It determines the actual position of the afterburner border. The sensor states can be analyzed very simply, for example, using a test program, and conclusions can be drawn from this regarding the current position of the burnout boundary. In particular, by installing virtual sensors in rows in accordance with the rows of sensors can be given, for example, the position of the borders of the burnout, which can then be issued, for example, according to the test program.

BRIEF DESCRIPTION OF THE DRAWING

Below the invention is schematically explained as an example with reference to the attached FIG. 1. Moreover, in FIG. 1 shows a diagram of the implementation of the method according to the invention on the example of a device for burning or gasifying small-sized solid combustible materials with mechanical casting.

SUMMARY OF THE INVENTION

In FIG. 1 illustrates, by way of example, a device VB for burning or gasifying solid fine liquefied combustible materials BS equipped for carrying out the method according to the invention. The device VB contains at least one combustion chamber VK, as well as a grate R, on which the combustion or gasification of combustible materials BS takes place. The combustible materials BS are mechanically thrown for combustion or gasification into the combustion chamber VK using the so-called mechanical spreader and are thus evenly distributed over the grate R.

The grate R, on which the combustible combustible materials BS and ash A are located, can be divided into at least two grate zones located in the longitudinal direction of the grate R. The grate zones of this kind are, in particular, the so-called combustion or gasification zone, which occupies for example, about 4/5 of the surface of the grate, and the so-called burnout area, covering about 1/5 of the surface of the grate. The combustion or gasification zone of the grate grate R is characterized by the burning or gasification of combustible materials BS over a large area, burned from top to bottom and at the same time constantly sprinkled by mechanical casting of WB. No combustible BS materials are no longer thrown into the burnout zone. Therefore, the burnout zone is characterized by the so-called burn-out boundary GK. At this border, GK, the afterburning ends, the temperature drops rapidly, and the color of ash A changes, since there is more likely to be the so-called burn-out and cooling of ash A. Thereafter, the burnt ash A goes to ash removal.

The regulation of the device VB for combustion or gasification is in the form of regulation of the air supply LV1, LV2 depending on the input parameters, such as a given power, moisture content in combustible materials, combustion parameters, etc., between the primary PL1, PL2, with secondary and under known conditions tertiary air, a distinction can be made, with the primary air supply PL1, PL2 going directly for combustion or gasification from under the grate S. As reaction parameters at different points T, the measurements eratury may be measured, for example, temperatures in the combustion chamber VC as shown for example in FIG. 1, above the grate R in the combustion / gasification zone or in the burnout zone, at the outlet of the exhaust gas AB, etc. Using the input parameters, the ratio of the primary air PL1, PL2 to the so-called primary recirculation air RL1, RL2, as well as to the so-called secondary circulation air, is also regulated.

In the combustion or gasification apparatus VB shown in FIG. 1, by way of example, for simplicity, only primary air supply PL1, PL2 or primary recirculation air RL1, RL2, controlled by the method according to the invention, is shown.

In the device VB for burning or gasification with mechanical casting WB, it is possible, for example, to refuse to supply all the air LV1, LV2, consisting of primary and recirculated air, into one single zone under the grate. In more advanced combustion or gasification VB devices, such as, for example, the VB device shown as an example in FIG. 1, air is separately supplied to at least two zones, such as, for example, to a combustion / gasification zone, a burn-out zone, etc. Air is supplied to the combustion or gasification zone from the first supply LV1, consisting of the first primary air PL1 and the first recirculated air RL1. For the burnout zone, a second supply LV2 is used, including a second primary air PL2 and a second recirculation air RL2. By appropriately regulating the air supply LV1, LV2, the burning ash A must not be allowed to reach AS ash. This means that the position of the burnout border GK must be constantly monitored.

At least one optical camera K is provided for such monitoring. With this camera K, in the first step 1 of the method, for example, images of the combustion chamber VK, in particular, the burnout border GK, are transmitted through one of the so-called eyes in the combustion device VB, and in this way, the current or actual position of the burn-out border GK is constantly monitored. In this way, changes in the actual position of the burnout border GK are set easily. To transmit the image, the camera K can, for example, be mounted on a tripod or, for example, inserted into the combustion chamber VK.

If the camera K is installed, for example, outside the combustion chamber VK, then images can be transmitted through the so-called peephole, in particular, the peephole in the so-called combustion door. This eye to assess the current or actual position of the burnout border GK has a corresponding viewing angle of the flame, the burnout border GK and the grate R. To transmit the image through the window of the eye, the field of view of the camera K must remain free, for example, of ash deposits, dust particles, etc. d. For this, an air nozzle is used, for example. With constant use, the chamber K must be cooled, because due to the strong thermal radiation of the combustion or gasification device VB, heating can occur and thereby damage the chamber K.

As an alternative to this, the optical chamber K can, for example, be introduced into the combustion chamber VK of the combustion or gasification device VB. In addition, the chamber K is protected, for example, by a specially cooled case or cooling system. As a result of the installation in the combustion chamber VK or in the firing space, an optimal and sufficiently large viewing angle is provided for transferring the flame, the burnout border GK and the grate R, which allow even better estimation of the position of the burnout border GK than the viewing angle through the eye.

In the second step 2 of the method, based on the image transmission, it is established whether there is a deviation of the actual position of the burn-out border GK from the predetermined position and by how much. For this, the camera K, if it is installed outside the combustion chamber VK, may contain, for example, an integrated processor P for analyzing the transmitted images. If the chamber K is introduced into the combustion chamber VK, then the processor P, as shown by way of example in FIG. 1 is mounted separately from the chamber K outside the combustion chamber VK and connected to the chamber K. In addition, it is also possible that the chamber K and / or the processor P are connected via a network connection (for example, via a network cable), for example, to a processing device and / or a data output device (for example, with a personal computer, etc.), with which the service personnel of the combustion or gasification device VB can constantly monitor the burnout border GR.

To analyze the transmitted images and thereby the actual position of the burn-out border GK, the so-called color processing is used in the second step 2 of the method. Using virtual sensors, small fragments of the corresponding image are analyzed, in particular, color data of these image fragments. In this case, the virtual sensors are ideally installed in rows, and, for example, each row is brought into correspondence with the position of the burn-out border, which in this case can be issued or shown to maintenance personnel. Thanks to the determined reference color data for the respective positions of the virtual sensors, for example, a predetermined position GK of the burn-out boundary can be set.

A virtual sensor can take three states: an operating state when the analyzed color indicator corresponds to a predetermined reference color indicator, an alarm state when a color difference appears relative to a predetermined reference color indicator, which, however, still remains, for example, within certain limits or does not fall below a freely definable limit value, and an emergency condition when the color difference is relative to a predetermined reference color indicator exceeds a freely definable limit value. Then, by analyzing the respective states of the sensors (for example, using a test program, etc.), the current actual position or the deviation of the burn-out border GK from the predetermined position can be determined from the corresponding transmitted image. Then, as a result of the analysis of several sequentially transmitted images, changes in the actual position of the burnout border GK can be established (for example, in which direction the burnout border is shifted, etc.).

In addition, the virtual sensors must also take into account brightness fluctuations, for example, as a result of short-term ignition in the combustion chamber VK, so that the virtual sensors do not show an emergency condition erroneously. To prevent this, different tolerances may be set for various combustible materials (e.g., wood, waste, wood-fiber materials, pre-treated waste, dry solids, special environmentally friendly combustible materials, etc.). Additionally, for example, with the help of a buffer device, when a certain position of the burnout boundary is output, it is possible to prevent falsification of the image analysis result, i.e. the issuance of a false actual position of the border GK afterburning. Thanks to the buffer device, data or changes in the position of the burnout boundary are perceived only after a long determined period of time. Those. the buffer device provides the actual position of the burn-out boundary GK only when the corresponding virtual sensors are in a certain state (for example, in emergency, operational state, etc.) for a certain period of time (for example, several minutes).

Then, in the third step 3 of the method, depending on the deviation of the burn-out boundary GK from the set position, an adjustable change in the air supply is made by means of its supply LV1, LV2 to the combustion chamber VK. In this case, accordingly, in particular, the primary air or the amount of primary air PL1, Pl2 and / or the primary recirculation air (its amount) RL1, RL2, supplied from under the grate R.

If, for example, in the second step 2 of the method, during the analysis of the transmitted images, it is established that the burnout boundary GK is shifted from the chamber K towards the combustion or gasification zone, then, for example, in the third step 3 of the method, the amount of primary air PL1, Pl2 is reduced, and the amount of recirculation air RL1, RL2 increases. If, however, in the second step 2 of the method, it is established that the burnout boundary GK is shifted in the ash direction AS, i.e. in the direction of the chamber K, then, for example, in the third step 3 of the method, the amount of primary air PL1, Pl2 increases, and the amount of recirculated air RL1, RL2 decreases. If the analysis of images transmitted in the second step 2 of the method shows, for example, that the burn-out boundary GK remains constant, but is not in the set position, then, for example, in the third step 3, the total amount of air (primary and recirculated air) PL1, Pl2, RL1, RL2, if the burnout boundary GK is shifted in the direction of the combustion or gasification zone, it may decrease, or the total amount of air (primary and recirculated air) PL1, Pl2, RL1, RL2, if the burnout boundary GK is shifted in the ash direction AS, may increase, and before The grate grating R. can additionally slow down. No interference with the supply of air to the combustion device VB LV1, LV2 will occur only if the transmitted images show that the burn-out boundary GK is in the set position.

Due to appropriate intervention in the air supply LV1, LV2 in the third step 3 of the method, for example, the burning ash is prevented from getting into the ash disposal AS, and thereby the temperature load on the unloading devices is reduced. Additionally, the complete burning out of ash A is ensured, and the combustion device VB can automatically respond to changes in burnout properties, for example, by changing the properties of combustible materials. In addition, by means of appropriate changes / adaptation of the analysis logic of the transmitted images or the corresponding sensor states (for example, using a test program, etc.), the so-called burn-out language can be recognized, which can appear, for example, in VB devices for burning or gasification with more than one impeller for mechanical casting WB.

LIST OF REFERENCE POSITIONS

VB device for combustion or gasification

AV exhaust gas outlet

VK combustion chamber

BS combustible materials

WB mechanical casting

K camera (optical)

P image analysis processor

GK burnout limit

R grate

A ash

LV1 air supply to the combustion zone

PL1 primary air for the combustion zone

RL1 primary recirculation air for the combustion zone

LV2 air supply to the burnout area

PL2 primary air for burnout area

RL2 Primary Recirculation Air for Burnout Area

AS ash removal

T temperature measurement points

1, 2, 3 steps of the method according to the invention.

Claims (3)

1. The method of regulation of the device (VB) for burning or gasification of small solid particulate combustible materials (BS) with mechanical casting (WB), and the device (VB) for burning or gasification contains at least one combustion chamber (VK) and the grate (R) ) with at least two grate zones located in the longitudinal direction of the grate (R), and moreover, in one of the grate zones a so-called burnout border (GK) is formed, and the actual position of the burnout border (GK) is controlled by at least one optical camera (K) and when the actual position of the burnout boundary (GK) deviates from the set position, an adjustable change in the air supply (LV1, LV2) is carried out in the form of the amount of so-called primary air (PL1, PL2) and / or the amount of so-called primary recirculation air (RL1, RL2), into the combustion chamber (VK), characterized in that the analysis of the transmitted images and thereby the analysis of the actual position of the burnout boundary (GK) is carried out using the so-called color processing via virtual sensors, which, depending on the actual color data, take at least three states - operational, alarm and emergency conditions, and are installed in rows. 2. The method according to p. 1, characterized in that for the analysis of transmitted images using a processor (P) connected to the camera (K). 3. The method according to p. 1, characterized in that by means of virtual sensors compare the actual color data of small fragments of images with the specified reference color data for these fragments of images, then when one arbitrarily determined limit value of the color index is exceeded by means of the color difference between the actual color index and with a reference color indicator, the corresponding sensor is put into emergency condition and, as a result of processing the data of individual sensor states, edelyayut actual position of the boundary (GK) has burnt out.

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