RU2600607C2 - Device and method for optimising combustion in partition lines of multi-chamber kiln for firing carbon blocks - Google Patents

Abstract

FIELD: fuel combustion methods.

SUBSTANCE: invention relates to a method for fuel combustion and optimizing combustion thereof in partition lines of a rotary-burner multi-chamber kiln for firing carbon blocks, said kiln comprising heating chambers, fuel required for firing carbon blocks being partially injected by at least two heating manifolds directly controlled by a master controller which controls inputs/outputs of said manifolds. Method comprises automatic identification, by master controller, of relative position of one manifold relative to others when said manifold is connected to a grid, and operation of injectors of heating manifolds being organised by distributing operating sequences of injectors individually over time.

EFFECT: preventing incomplete fuel combustion and improving quality of combustion.

10 cl, 7 dwg

Description

The invention relates to the field of multi-chamber furnaces, called “rotary flame furnaces”, for firing carbon blocks, in particular carbon anodes and cathodes, for the electrolysis of aluminum. In particular, an object of the invention is a method and apparatus for optimizing combustion in the partition lines of such a multi-chamber furnace.

Rotary flame furnaces for burning anodes are described, in particular, in patent application WO 2011/127042, which can be consulted for more information on this subject.

At the same time, we can briefly recall their design and principle of operation with reference to the FIGS. Described below. 1 and 2, where in FIG. 1 is a schematic plan view of a rotary flame furnace with open chambers, in this example with two flame torches, and FIG. 2 is a partial perspective view in cross section with a cutout of the internal structure of such a furnace.

The kiln (FAC) 1 contains two parallel shafts or galleries 1a and 1b, running along the longitudinal axis XX along the length of the furnace and each containing a series of transverse chambers 2 (perpendicular to the axis XX), separated from each other by transverse walls 3. By in its length, that is, in the transverse direction of the furnace 1, each chamber 2 is formed by the alternation of adjacent cells 4, which are made open in its upper part to ensure loading of carbon blocks intended for firing and unloading of cooled fired nnyh blocks and into which is placed a stack designed for calcining carbonaceous blocks 5 immersed in carbon powder and hollow heating partitions 6 with thin walls are generally kept at a distance from one another by transverse struts 6a. The hollow partitions 6 of the chamber 2 are in a longitudinal extension (parallel to the major axis XX of the furnace 1) of the hollow partitions 6 of the other chambers 3 of the same gallery 1a or 1b, and these hollow partitions 6 communicate with each other through the windows 7 in the upper part of their longitudinal walls opposite the longitudinal passages made at this level in the transverse walls 3, while the hollow partitions 6 form the longitudinal lines of the partitions located parallel to the major axis XX of the furnace and designed to circulate gaseous media in them (oxidizing air, combustible gases and ha Oring combustion products and fumes) that allows to provide preheating and calcining anodes 5 and subsequent cooling. The hollow partitions 6 further comprise bulkheads 8 for lengthening and more even distribution of the path of the gaseous products of combustion or fumes, and in their upper part these hollow partitions 6 are also equipped with openings 9 closed by removable covers and made in the crown of the furnace. The two kiln galleries 1a and 1b communicate at their longitudinal ends through the reversal channels 10, which allow gaseous media to move from one end of each line of hollow partitions 6 of one gallery 1a or 1b to the end of the corresponding line of hollow partitions 6 in another gallery 1a or 1b, forming thus, essentially rectangular contours of the lines of the hollow partitions 6.

The principle of using rotary flame furnaces, also called “progressive flame furnaces”, is to move the flame front from one chamber 2 to another chamber adjacent to it during one cycle, with each chamber 2 successively passing through the pre-heating stages, forced heating, full flame, then cooling (natural and then forced).

Anodes 5 are fired using one or more torches or groups of torches (in Fig. 2 two groups of torches are shown in the position in which one group in this example passes through thirteen cameras 2 of gallery 1a and the other through thirteen cameras 2 of gallery 1b) that move from one camera 2 to another camera 2.

Each torch or group of torches consists of five consecutive zones A-E, which, as shown in FIG. 1 for the flame of the gallery 1b, are located from the exit to the entrance relative to the direction of flow of gaseous media in the lines of the hollow partitions 6 and in the opposite direction during cyclic movements from chamber to chamber:

A) A preheating zone, which, if we look at the flame of the gallery 1a and taking into account the direction of rotation of the flame, is indicated by the arrow at the level of the reversal channel 10 at the end of the furnace 1 in the upper part of FIG. 1 contains:

- a suction ramp 11, equipped for each hollow partition 7 of the chamber 2, over which this suction ramp is located, with a system for measuring and regulating the flow of gases and fumes to each line of the hollow partitions 6, and in each suction nozzle 11a, which is fixedly connected to the suction ramp 11 and leaves it on the one hand and on the other hand enters the hole 9, respectively, of one of the hollow partitions 6 of this chamber 2, this system may include an adjustable shutter, rotated by the shutter drive, for adjusting Hovhan flow and flowmeter 12 located a little closer to the entry in the relevant pipe 11, a temperature sensor (thermocouple) 13 for measuring flue gas temperature at the intake, and

- a preheating measurement ramp 15, essentially parallel to the suction ramp 11 and located at the inlet of the latter, usually above the same chamber 2, and equipped with temperature sensors (thermocouples) and pressure sensors to obtain a static vacuum and temperature in each of the hollow partitions 6 this chamber 2, to provide an indication and regulation of this vacuum and this temperature of the preheating zone;

B) A heating zone comprising:

- several identical heating ramps 16, namely two or preferably three, as shown in FIG. 1 or more depending on the duration of the cycle; each of them is equipped with burners or nozzles for fuel injection (liquid or gaseous) and temperature sensors (thermocouples), while each of the ramps 16 is located on one of the chambers of the corresponding number of adjacent chambers 2 so that the nozzles of each heating ramp 16 go into holes 9 of the hollow partitions 6 for fuel injection into them;

C) A purge or free cooling zone comprising:

- the so-called "zero point ramp" 17, located above the chamber 2 directly at its inlet above the heating ramp 16 closest to the inlet and equipped with pressure sensors for measuring pressure in each of the hollow partitions 6 of this chamber 2 in order to ensure regulation of this pressure; and

- discharge ramp 18, equipped with electric fans, equipped with a device that allows you to adjust the flow of ambient air pumped into each of the hollow partitions 6 of the chamber 2 at the inlet of the partition located under the zero point ramp 17 so that the flow rate of the ambient air pumped into these hollow partitions 6, it was possible to adjust to obtain the required pressure (with a slight excess of pressure or with a small vacuum) at the level of the zero point ramp 17;

D) A forced cooling zone extending to three chambers 2 at the inlet of the discharge ramp 18 and containing in this example two parallel cooling ramps 19, each of which is equipped with electric fans and discharge nozzles that pump ambient air into the hollow partitions 6 of the corresponding chamber 2; and

E) The working area located at the inlet of the cooling ramp 19 and allowing the loading and unloading of the anodes 5 into the furnace, as well as the maintenance of the chambers 2.

At the entrance of the heating ramp 16, the injection ramp 18 and the forced cooling ramp or ramp 19 contains nozzles for supplying combustion air with electric fans, and these nozzles are connected through openings 9 to the hollow partitions 6 of the respective chambers 2. At the outlet of the heating ramp 16 there is a suction ramp 11 to remove gaseous products of combustion and fumes, collectively referred to by the term "flue gases", which circulate in the lines of the hollow partitions 6.

The heating and burning of the anodes 5 are ensured simultaneously by burning fuel (gaseous or liquid) with controlled injection through the heating ramps 16 and essentially to the same extent by burning volatile substances (such as polycyclic aromatic hydrocarbons) emitted by the anode resins 5, in cells 4 of chambers 2 in zones of preheating and heating, and these volatile substances, which are mainly combustible and propagating in cells 4, can pass into two adjacent hollow partitions 5 through passages made in these partitions, using residual oxidizing air present at this level among the flue gases in these hollow partitions 6.

Thus, the circulation of air and flue gases occurs along the lines of the hollow partitions 6, and the vacuum created at the outlet of the heating zone B by the suction ramp 11 at the output end of the preheating zone A allows controlling the flow of flue gases inside the hollow partitions 6, while the air entering from the cooling zones C and D through the cooling ramps 19 and especially through the injection ramp 18, is preheated in the hollow partitions 6, cooling along the way the anodes 5, calcined in adjacent cells 4, and serves as an oxidizing agent, hen comes into a zone in the heating.

In the process of firing the anodes 5, the complex of ramps 11-19 and the associated instrumentation and equipment are cyclically (for example, approximately every 24 hours) moved from the chamber 2, while each chamber 2 thus provides sequentially: in zone A of the preliminary heating - the function of loading untreated carbon blocks 5, then in zone A preheating - the function of natural preheating flue gas fuels and vapors of resins that leave the cells 4, going into the hollow partitions 6, taking into account the discharge living in the hollow partitions of 6 chambers 2 in the preheating zone A, then in the heating or firing zone B, the function of heating the blocks 5 to about 1100 ° and, finally, in the cooling zones C and D, the function of cooling the calcined blocks 5 with ambient air and, accordingly, heating of this air, which forms the oxidizing agent for furnace 1, while the forced cooling zone D in the direction opposite to the direction of flame movement and flue gas circulation is followed by the discharge zone E of the cooled carbon blocks 5, then, if necessary, raw carbonaceous blocks are narrow in the cell 4.

The method of regulating the FAC furnace mainly involves controlling the temperature and / or pressure in the zones of preheating A, heating B and purging or free cooling C of furnace 1 according to predetermined rules.

The flue gases removed from the flame through the suction ramps 11 enter the chimney 20, for example a cylindrical chimney partially shown in FIG. 2, with a smoke channel 21, which may have a U-shape in plan (shown in dashed line in FIG. 1) or may extend around a furnace and the outlet 22 of which directs the suction and collection flue gases to a smoke treatment center (CTF), which the drawings are not shown, as it does not apply to the invention.

In order to give the anodes (carbon blocks) their optimal characteristics and, therefore, basically ensure the achievement of the final firing temperature, the well-known furnace line of this type is mainly designed to supply fuel to the heating ramps 16 regardless of the rarefaction conditions, traction and the hydraulic conditions in the partitions 6, in resulting in incomplete combustion in a significant and even a large number of lines of hollow partitions 6. In turn, this leads to an increase in operating costs not only for overrun rank fuel, but also because of the contamination of the suction hoods and ducts, in which the pressure is reduced due to the deposition of unburned carbon that is also fraught with potential risk of ignition and burning process disturbances.

The nozzles of the heating ramp are distributed in pairs, that is, two nozzles per partition. The number of nozzles in the ramp is thus equal to twice the number of partitions, for example, is fourteen nozzles per seven partitions. For a heating zone equipped with three ramps, a total of six nozzles inject fuel into one partition.

The fuel supply equipment of the heating ramp 16 is adapted to the nature of the fuel used, in particular, depending on whether it is gaseous, like natural gas, or liquid, like fuel oil. To simplify the description of the invention in the future it will be considered that the fuel is gaseous.

In FIG. 3 schematically shows an example of a known heating ramp 16 for gaseous fuels. This figure shows 4 pairs of nozzles 23, given that the ramp 16 is usually equipped with 7-10 pairs. The nozzles 23 are connected to one fuel pipe installed on the heating ramp 16 and connected to the factory network through a hose 26 and a quick nozzle 25. In front of each nozzle 23 there is an on / off electric valve 37 for individual control of each nozzle 23. The ramp supply pipe contains a quick connector 25 , hose 26, filter 27, general safety electric fan 28, bypass circuit of this common safety electric fan, including needle valve 29 and electric valve, allowing roller tightness of the pipeline, flow measuring organ 31 (optional), pressure regulator 32 (optional), pressure switch 33 with actuation at the minimum threshold pressure, pressure switch 34 with actuation at the maximum threshold pressure, pressure sensor 35. This main circuit feeds all nozzles 23, in front of each of which there is a manual valve 36, an electric valve 37 and a hose 38.

In FIG. 4 schematically shows a known furnace in a vertical section along the longitudinal axis XX in the middle of the hollow partition 6. This example includes 3 consecutive heating ramps 16a, 16b and 16c. The injection ramp 18 circulates fresh air to cool the calcined anodes and the flow of oxygen to burn the fuel injected through the heating ramps 16a, 16b, 16c. The flow of air and then flue gas in the partition 6 is schematically shown by a dashed line. The openings 9 of the chambers 2, located between the discharge ramp 18 and the heating ramps 16a, 16b, 16c, are closed to limit the leakage of injection air. At the entrance of the first heating ramp 16c, there is a ramp 17, called a “zero point ramp”. For this partition 6 and these heating ramps 16a, 16b, 16c, pairs of nozzles 23a1, 23a2, 23b1, 23b2, 23c1, 23c2 and thermocouples 24a, 24b, 24 s for measuring the temperature in the partition are shown. For each heating ramp 16a, 16b, 16c, corresponding nozzles are installed in two openings 9, separated by an opening 9, which remains free and is covered by a lid. Thermocouples 24 are installed at the nozzle exit in the direction of gas flow. At the end of the flame path there is a suction ramp 11 in front of which a preheating measurement ramp 15 is installed.

On average, the heating ramp 16 operates at approximately 30% of its total capacity. To limit the cost, dimensions and weight of the ramp 16, its pipeline is designed for a nominal fuel consumption equivalent to 30% of the flow rate that would be needed to simultaneously supply all the nozzles 23 of this ramp 16 at their rated power. If you simultaneously open a large number of nozzles 23, then the throughput of the ramp 16 is not enough, and there is an uncontrolled drop in gas pressure. This pressure drop leads to a decrease in flame length and may result in a deterioration in combustion quality. This phenomenon is especially evident with gaseous fuel, since in the case of liquid fuel it is compensated by a pump mounted on a ramp 16, which maintains pressure and forces a 3-5-fold volume of injected liquid fuel to continuously circulate in the pipeline.

Fuel injection is pulsating (in the form of pulses). Typically, the injection power is modulated by changing the closing time of the automatic valves 37 of the nozzles 23. It can also be modulated by changing the duration of the opening of the valves 37. When the nozzle 23 is open, 100% of its power is injected and its maximum flow rate is consumed. For example, in the case of natural gas, the injection duration generally ranges from 0.5 to 4 s, while in the case of fuel oil, the injection duration generally ranges from 30 to 150 ms.

In the embodiment, the injection power can also be modulated by changing the supply pressure of the injectors 23 with fuel, for example, using a pressure regulator 32 installed on the supply pipe of each ramp 16. This solution allows you to change the flame length depending on the pressure level, while a weak pressure gives more short flame than during operation at nominal pressure. Therefore, it affects the distribution of calories in partitions 6 and the temperature profile along the height of each partition 6.

The gross injection power is calculated using an incremental PID block for each pair of nozzles of each ramp 16, that is, for each partition 6. Depending on the deviation between the temperature measured by the thermocouple 24 of the ramp 16 of the corresponding partition 6, and the set value set by the operator, the PID the block calculates the change in the total gross command. This change, added to the previous gross command, gives a general gross command ranging from 0 to 100%. Moreover, this command is limited depending on the lower and upper permissible limits set by the operator for the ramp 16.

The distribution of this power between two nozzles, for example 23a1 and 23a2 for the ramp 16, is carried out, for example, based on the ratio parameter specified by the operator. The ratio must always be respected, for which the permissible upper and lower limits for the ramp 16 are calculated. After that, the system adjusts this total power to comply with the maximum power limit that was fixed for the partition 6. This maximum limit is set either by the operator or the combustion monitoring module.

The value of the final total power is supplied to the automatic control / control ramp 16 along with the values of the ratio and duration of the pulse. The machine calculates the closing time for the input nozzle (for example, 23a2) and the output nozzle (for example, 23a1) so that the injection power matches the ratio and the total power. The calculated values of the pulses are transmitted to the nozzles 23.

In the known solutions, there is no very accurate synchronization of the rhythm with other pairs of nozzles 23 of other ramps 16 located on the same partition 6. Since the combustion air mainly comes from the inlet (is pumped by the injection ramp 18), the oxygen content in it decreases between the first heating ramp ( such as 16c) and the latter (such as 16a). Depending on the injection cycle between the nozzles 23 installed on the same partition 6, situations arise when the nozzles 23 inject into the same volume of air as the previous nozzles, while the oxygen content in the indicated volume is low. This leads either to a shift in ignition relative to the injection site, or to incomplete combustion of the injected fuel and to the accumulation of underburning. This phenomenon manifests itself more with gaseous fuels than with liquid fuels, due to the longer injection time.

To limit fluctuations in fuel pressure in the heating ramp 16, at best, an initial offset is made when starting different pairs of nozzles 23 mounted on the same ramp 16, but this offset is not supported.

Limitations are associated with the fact that the nozzles 23 are often controlled by an independent device, such as an electronic board, specially designed for this application, which generates pulses depending on the frequency transmitted by the automatic ramp 16, which does not allow you to accurately set the rhythm of the pairs in relation to each other. Often, the nozzle 23 is directly controlled by the ramp automaton 16. In this case, setting the exact rhythm on the ramp 16 is possible, but the processing power and the relative slowness of updating the outputs of the automata limit the ability to precisely set the rhythm. The relatively slow connection between the machines and the scatter of the controls do not allow for accurate synchronization between different heating ramps 16.

In FIG. 5 is a schematic representation of an example of a known rotating flame monitoring-control system. The control is provided by two redundant central computers CCS-A 42a & CCS-B 42b, which transmit commands for execution to the machines 45 located on each ramp 11, 15, 16, 17 and 18. These machines 45 directly control the drives, in particular the shutters on ramp 11, nozzles 23 on the heating ramps 16 and fans on the ramp 18. Communication between the various control devices is via a communication network, which may be wired or, for example, type WiFi. Central computers calculate the commands for each drive depending on the setpoints entered earlier by the operators and on the measurements received from the 45 ramp machines. Then these commands are sent to each machine 45 that executes them. A Layer 1 communication network between central computers 42a & 42b and ramp machines 45 includes Ethernet switches 40 and WiFi 43 access points that are distributed in the workshop building. Each machine 45 is connected to a WiFi network through a user (44), while the internal Ethernet network of the ramp provides data exchange via an Ethernet switch 46 between the WiFi user 44, the local screen 47 and the speed controllers 48 in the case of a pressure ramp 18. Auxiliary machine 43 (located, for example, in the electrical equipment room) allows you to collect data from elements that serve the furnace, such as a smoke treatment center.

The DMS 41 computer archives process data and is connected to CCS 42a & 42b computers through a switch 40, which is part of a Layer 2 Ethernet network. This network can be connected to a factory network to retrieve and use data from Layer 3 systems.

Monitoring of the process is provided by means of control screens 39, which can be taken out, for example, to the control room, if necessary, through a dedicated network (KVM network). These screens 39 show real-time data coming from CCS 42a & 42b computers, as well as archived data coming from DMS 41.

To address the aforementioned disadvantages, the invention provides a method for optimizing combustion in the partition lines of a multi-chamber furnace, called a “rotary flame furnace”, for burning carbon blocks. The furnace contains a series of chambers of preheating, heating, free cooling and forced cooling, located in a row along the longitudinal axis XX of the furnace. Each chamber consists of adjacent to each other and transversely to the specified longitudinal axis XX and alternating cells in which the carbon blocks are intended for firing, and of hollow heating partitions communicating and arranged in line with the walls of other chambers parallel to the longitudinal axis XX of the furnace, in which cooling and oxidizing air and gaseous combustion products circulate. The suction ramp is connected during preheating with each of the partitions of the first chamber, respectively, by one of the discharge pipes. The necessary oxidizing air partially enters through the discharge ramp of the free cooling zone, connected with at least one fan, and partially seeps due to vacuum through the partition lines. The fuel necessary for firing the carbon blocks is partially injected through at least two heating ramps, each of which is located at least over one of the two adjacent chambers of the heating zone and which are configured to inject fuel into each of the partitions of the corresponding chamber heating zones. At least the heating ramps are controlled directly by the control controller by controlling the inputs / outputs of said ramps. The method includes automatic identification by the control controller of the relative position of one heating ramp relative to the others during the connection of the indicated heating ramp to the network, and the operation of the nozzles of the heating ramps is ordered by individually distributing the nozzle operating cycles in time.

The technology of the real-time core and the real-time network makes it possible to set the rhythm, since the real-time core has time with an absolutely defined cycle and with a constant duration.

The control controller performs the calculation of commands, reading data directly at the inputs, and independently provides control of the outputs associated with the drives. Thus, at least automatic devices are excluded in the heating ramps.

During each cycle, the control controller collects all the input data before starting the calculation, and then positions all the outputs before starting a new cycle.

Thus, all the outputs that control the nozzles distributed on different heating ramps are controlled by only one controller, and with high speed and accurate and reliable rhythm, which is made possible by using the real-time core and real-time network.

The choice of actions and the corresponding positioning of the outputs are carried out in order of priority tasks.

The real-time network is fundamental, as it allows for the real reading of all inputs and recording of all outputs at each stage of the cycle.

According to an exemplary embodiment of the invention, the ramp monitoring / control functions are programmed in a software machine.

According to an example embodiment of the invention, the control controller is a personal computer.

A real-time network connecting, in particular, a control controller and input / output ramps, is, for example, an Ethernet network.

According to another exemplary embodiment of the invention, the Twincat real-time core is connected to a real-time Ethernet network.

In addition, the method in accordance with the invention is characterized in that the time distribution of the operating cycles of the nozzles is carried out in such a way that the nozzle only works when the volume of gas under the nozzle has a sufficient oxygen content to allow combustion of the injected fuel.

Thus, the method in accordance with the invention is characterized in that the temporary distribution of the operating cycles of the nozzles is carried out in such a way as to limit the formation of underburning, in particular, CO.

The general algorithm allows optimizing the injection rhythm in order to simultaneously optimize the presence of air in the partitions, as well as maintaining a controlled fuel consumption in the pipelines of each heating ramp to maintain homogeneous injection characteristics. Thus, the temporary distribution of the operating cycles of the nozzles is carried out in such a way as to limit fluctuations in fuel consumption in each heating ramp. In addition, a temporary distribution is carried out by limiting the number of simultaneously operating nozzles to a maximum number, the specified maximum number being the number that leads to the nominal fuel consumption in the specified ramp.

According to a particular embodiment of the invention, the method also involves optimizing combustion in fuel nozzles during the time indicated by D in a furnace containing the number N of nozzles distributed over the baffles and heating ramps of the furnace. Nozzles operate by pulses on the principle of "all or nothing" and with modulation of duration. For each of the N nozzles, the operating time Δi is determined, less than or equal to D, while the values of the operating time Δi are derived depending on the energy needs of the furnace, and they are issued by the furnace control-control system. Moreover, according to the method:

- the duration of the operation Δi of the nozzle is divided into a number of pulses, while the sum of the values of the duration of the pulses is equal to the duration of the Δi of the specified nozzle;

- the operating procedure is determined by the temporal distribution of pulses for each of the N nozzles individually and encoded in the form of a binary time function pi, which corresponds to 1 when the nozzle with serial number i produces a pulse at time s, and otherwise corresponds to 0;

- the operating procedure is calculated at the time T of the calculation, taking into account the required values of the operating time Δi of the nozzles, while the pulses of the nozzle occur no earlier than the initial moment ti following the moment T, and no later than the time ti + D;

- the initial moments ti of each nozzle depend on the relative position of the nozzles of one partition and on the flow rate Vk of the gaseous products of combustion in this partition.

Preferably, the operation order is calculated as follows:

/ a / choose any initial order,

/ b / each nozzle is assigned a serial number i from 1 to N,

/ c / for the nozzle with serial number i equal to 1, choose the distribution of the working pulses of this nozzle, which allow to maximize the function Uk, which characterizes the oxygen content in the gaseous products of combustion after the last nozzle of one partition during the time interval between the moments tk and tk + D, where tk is the moment corresponding to the last nozzle of this partition, while the pulses of the other nozzles preserve the positions of the original order, and as a result get the order of operation with the optimal distribution of the pulse owls for nozzle with serial number i equal to 1,

/ d / step / c / is repeated based on the final order of step / c /, sequentially examining nozzles with a serial number i exceeding 1, to a nozzle with a serial number N.

The method may include the following additional steps:

/ e / using the operating procedure defined in step / d / as the initial order, each nozzle is assigned a new serial number i from 1 to N and steps / c / and / d /, / f / are repeated, the resulting operating procedure is compared with the original order and the best of the two is selected as the order of work.

/ g / steps / e / and / f / are repeated many times with the number of times compatible with the calculation time between the calculation moment T and the first of the initial moments ti of nozzles of one partition.

Using these additional steps, the best operation order of the step / f / is determined, in which the total fuel consumption in each ramp obtained as a result of the distribution of the work of the ram nozzles does not exceed the maximum possible fuel consumption in the specified ramp.

Depending on the temperature setpoints set by the operator and the readable temperature values for each partition, in combination with auxiliary measurements such as CO or air flow in the partitions, the injection matrix is calculated using the computing power of the control controller. Then it is transferred to the remote outputs on each of the heating ramps to control the nozzles.

A subject of the invention is also a combustion optimization device in partition lines.

In addition to the distinguishing features described above, the invention also has other distinctive features, discussed in more detail below in connection with non-limiting examples of execution, described with reference to the accompanying drawings.

The first five figures have been described above for known technical solutions, namely:

in FIG. 1 schematically shows the design of a furnace with two rotating torches and with open chambers, a plan view;

in FIG. 2 schematically shows the internal structure of the furnace of FIG. 1 is a partial perspective and cross-sectional view with a cutaway;

in FIG. 3 is a liquid diagram illustrating an example of a heating ramp;

in FIG. 4 is a partial schematic longitudinal sectional view illustrating the location of ramps on the partition line;

in FIG. 5 schematically shows a known control-control system;

in FIG. 6 schematically shows a control-control system in accordance with the invention;

in FIG. 7 is a chronogram illustrating the operation of a nozzle over a given time.

As shown in FIG. 6, the control-control system according to the invention comprises, for example, a data archiving computer DMS 41 and at least two CCS 42a & 42b controllers. These machines are interconnected using an Ethernet 40 switch, which forms a Layer 2 Ethernet network. Each of the controllers 42a and 42b contains a real-time machine that controls through the Layer 1 real-time Ethernet network the remote I / O blocks 52 that are equipped ramps 11, 15, 16, 17 and 18, as well as an auxiliary machine 43.

The ramps 11, 15, 16, 17 and 18 are connected to the real-time network using a wire that is connected to junction boxes 51 installed opposite each chamber 2 of the furnace 1.

Method monitoring is provided using control screens 39, which can be displayed using a dedicated network, if necessary, (KVM network). On these screens 39, data coming from CCS 42a & 42b controllers, as well as archived data coming from DMS 41 are displayed in real time. Additional screens 50 are installed in the workshop building to ensure monitoring of the method. On these screens 50, data from the CCS 42a & 42b controllers is displayed in real time. They are connected to the real-time network through specially allocated groups of inputs / outputs 52.

The control controller 42a, 42b automatically identifies the relative position of the frame with respect to other ramps at the time of connecting the specified ramp to the network.

For this, according to an embodiment, during the start-up of the system, the theoretical duration of the firing cycle, the initial position of the flame and the theoretical configuration of each flame are introduced into it.

By “theoretical configuration of each flame” should be understood the relative position of the ramps inside one flame.

Based on the theoretical cycle time, relative position, theoretical flame configuration and current date and time, the control controller 42a, 42b continuously calculates for each torch theoretical positions recognized, for example, by the number indicating the section in the furnace 1 for different types of ramps 11, 15 , 16, 17, 18, which he will need to control the method of firing using a flame.

From the point of view of equipment, each ramp 11, 15, 16, 17, 18 contains a head part, identified by a single number, and inputs / outputs. The control controller 42a, 42b uses a correspondence table, which, based on this number, allows it to identify the ramp, as well as its type (suction, heating, etc.).

The wired network around the furnace 1 includes a series of network switches.

Each section of the furnace 1 is equipped with a single network connector, to which a ramp located in this section is connected. This connector during installation is connected to the input identified by the number of one of the switches included in the local network. The pair formed by the section number and the input number of the switch is the only one and is entered during the installation of the local network in the correspondence table that the control controller 42a, 42b will use.

The control controller 42a, 42b continuously monitors the various inputs of the switches to detect any changes, such as connecting or disconnecting the ramp 11, 15, 16, 17, 18. When a ramp is detected, the control controller 42a, 42b determines the head part number of this ramp, which it combines with the input number of the switch, which allows him to associate the section number with this ramp. Thus, the control controller 42a, 42b identifies the position of each ramp in the furnace 1 relative to the other ramps at the time of connection.

Then, based on the identification of the position of each ramp 11, 15, 16, 17, 18, the control controller 42a, 42b can compare the actual position with the theoretical position that he calculated and decide whether or not to confirm the connection of the frame and, therefore, about it management.

According to the invention, six nozzles 23 located on one line of partition walls 6 are controlled depending on each other, as well as depending on nozzles 23 located on other lines of partition walls 6. The order of opening of nozzles 23 and the choice of pulse duration allow optimizing the operation of each heating ramp 16 and the work of the whole flame.

In particular, in order to optimize the combustion of fuel in the nozzles 23, we consider the duration of the optimization time D of the furnace 1 equipped with nozzles 23. Let us mark the parameters associated with the nozzle 23 of the serial number i, where i is from 1 to N, with N being the total number nozzles 23 of the furnace 1, distributed among the number R of the heating ramps 16 and the number M of partitions 6 of the furnace 1. For example, in the case where the furnace 1 contains two galleries 1a and 1b, three heating ramps 16 for each gallery, each heating ramp containing four couples nozzles 23, i.e. connected to four partitions 6 in each gallery, as shown in FIG. 2 and 3, the total number N of nozzles in furnace 1 will be forty-eight.

Hereinafter, the terms “first” and “last” will be used with respect to the direction of flame propagation, it being understood that the first nozzle for this partition is the one that receives air first, which is injected by discharge ramp 18.

The nozzles 23 operate by pulses on the principle of "all or nothing" and with modulation of the duration.

The duration Δi, less than or equal to the duration D optimization, is associated with the nozzle 23 with the serial number i. The duration Δi of each nozzle 23 is determined in accordance with the energy needs of the furnace 1. It is issued by the control-control system 42a, 42b of the furnace 1.

The duration Δi of the nozzle 23 with the serial number i is divided into a number of pulses, designated Ki, so that the sum of the values of the duration Ki of pulses is equal to the duration Δi.

In this case, the operation procedure is determined by the time distribution Ki of pulses for each nozzle 23 individually and is encoded as a binary time function pi (s), where s denotes a time that is 1 if the nozzle 23 with serial number i produces a pulse, otherwise it equal to 0. The function pi (s) is shown in FIG. 7.

The operating procedure is calculated at the time T of the calculation, taking into account the required operating time Δi of the nozzles 23.

Ki pulses of the nozzle 23 with serial number i occur not earlier than the initial moment ti following the moment of calculating T, and not later than the moment ti + D. In other words, the first pulse of the nozzle 23 with serial number i starts no earlier than the initial moment ti, and the last pulse ends no later than the moment ti + D.

The initial moments ti of each nozzle 23 depend on the relative position of the nozzles 23 of one partition 6 and on the flow rate Vk of the gaseous products of combustion in this partition 6. In what follows, the index k will indicate that it is a parameter associated with the partition with serial number k, where k ranges from 1 to M.

In this case, the operation order of the nozzles 23 for a given partition 6 with serial number k is calculated by performing the following steps:

/ a / choose any initial order of the nozzles 23 in the partition 6 with the serial number k,

/ b / each nozzle 23 is assigned a serial number i from 1 to N, for example, depending on the relative position of the nozzles 23 in the direction of flame movement in this partition 6 with the serial number k,

/ s / for the first nozzle, which is assigned serial number 1, choose the distribution Ki of working pulses of this nozzle 23, which allows you to maximize the function Uk (s) characterizing the oxygen content in the gaseous products of combustion after the last nozzle of the partition 6 with serial number k for the time interval between the moments tk and tk + D, where tk is the moment of the first pulse of the last nozzle of the septum 6 under consideration with serial number k, while the pulses of other nozzles with serial number i exceeding 1 retain the polarity the initial order, and as a result, they get the order of work with the optimal distribution of pulses for each nozzle with serial number 1,

/ d / step / c / is repeated based on the final order of step / c /, sequentially examining nozzles with a higher serial number up to the nozzle with serial number N.

Preferably, the combustion optimization method comprises the following additional steps:

/ e / using the operating procedure defined in step / d / as the initial order, assign a new serial number i from 1 to N to each nozzle and repeat steps / c / and / d /,

/ f / the resulting work order is compared with the original order and the best of the two is selected as the work order.

/ g / steps / e / and / f / are repeated many times with the number of times compatible with the calculation time between the moment T of the calculation and the first of the times ti of the beginning of the first pulse of the nozzles 23.

According to an additional distinguishing feature of the invention, for the best of the two orders of operation of stage III, make sure that the total fuel consumption of each of the R ramps 16 as a result of the distribution of the pulses of the nozzles 23 of the ramp 16 does not exceed the maximum possible flow rate of the specified ramp 16.

Indeed, as a rule, from the previous calculation of the order on the partitions 6, it follows that the nozzles 23 of one heating ramp 16 do not have the same distribution of pulses, therefore, it is necessary to verify that the calculation of the operation based on optimization depending on the oxygen content in each partition 6 corresponds to also the optimal performance of each ramp 16.

Thus, the calculation of the operating procedure allows you to optimize the temporal distribution of the pulses of the nozzle 23 on each partition 6 and for each heating ramp 16 in the entire furnace 1.

The time δti necessary for the gaseous products of combustion to pass with the speed Vk the distance di between the nozzle 23 with the serial number i of the partition 6 with the serial number k and the last nozzle 23 of this partition 6 with the serial number k is:

According to the invention, the interval between the moment ti corresponding to the nozzle 23 with the serial number i of the partition 6 with the serial number k and the moment tk corresponding to the last nozzle of the same partition with the serial number k is equal to the time required for the gaseous products of combustion to pass the distance between the two nozzles 23, that is:

Preferably, the time between the moment T of calculating the operation order and the moments ti of the first nozzles 23 of each partition 6 is less than one second.

According to the invention, the function Uk (s) characterizing the oxygen content in the control volume τ at time s after the last nozzle of the septum k is equal to the oxygen content Ck in the control volume τ before the first nozzle 23 of the septum 6 with serial number k minus the sum of the oxygen content qi, necessary for complete combustion by the working nozzle 23 with serial number i, when the control volume τ passes under the nozzle 23 with serial number i at the moment s - δti:

In other words, you need to make sure that the control volume τ has a sufficient oxygen content relative to the amount of fuel injected by the nozzle 23 with the serial number i of the partition 6 with the serial number k, when this control volume x passes under this nozzle 23 with the serial number i. Indeed, oxygen is consumed during combustion under nozzles 23 with a serial number below i of the partition 6 with serial number k. Thus, when the control volume τ passes under the last nozzle 23 of the partition 6 with the serial number k, the oxygen content in the control volume τ must be sufficient to provide a combustion reaction and, therefore, to limit the formation of underburning.

According to an example embodiment of the invention, maximizing the function Uk for the nozzle i consists in maximizing the total duration when the function Uk (s) is positive for the moments s of the interval

According to another embodiment of the invention, maximizing the function Uk for the nozzle i consists in maximizing the sum S of positive values Uk (s) over the interval

For example, the pulse duration of the nozzles 23 is from ½ second to 5 seconds, and the time between two consecutive pulses of the same nozzle 23 is from ½ second to 5 seconds.

Next, consider FIG. 7, which shows the function pi (s) characterizing the temporal distribution of the pulses of the nozzle 23 with serial number i during operation on the principle of "all or nothing."

For each nozzle 23 with serial number i, the function pi (s) is determined for the moments s of the time interval between the moments ti and ti + D.

According to an exemplary embodiment, the binary function pi is determined as a series of pulses of identical duration a and with a time interval b between pulses occurring between the moments ti + c and ti + Dc.

The time interval b between pulses can take one of ten of the following values: {0.5 s, 1 s, 1.5 s, 2 s, 2.5 s, 3 s, 3.5 s, 4 s, 4.5 s, 5 s}.

The time values a, b and c are interconnected by the following relationships:

Ki * a = Δi

and

Ki * a + (Ki-1) * b + 2 * c = D

The function pi is completely determined by the duration Δi and the choice of the time interval b between pulses.

For the duration of work Δi and depending on the choice of the value of b, and also taking into account the fact that the total duration of the pulses is Δi, the number of pulses Ki is equal to the integer part (Δi + D) / b, increased by 1:

From here we directly obtain the values of c and a

and

The choice of b is permissible only if the resulting duration a is from 0.5 to 5 s.

Thus, choosing an acceptable value for b, while the duration Δi is set depending on the equipment, the function pi (s) is completely determined. Thus, the function UK (s) is determined, after which the operation order can be calculated.

Claims (10)

1. The method of firing carbon blocks (5) in a multi-chamber furnace (1) with a rotating flame containing a series of chambers (2) for preheating, heating, free cooling and forced cooling, arranged in a row along the longitudinal axis (XX) of the furnace (1) wherein each chamber (2) consists of alternating cells (4) located adjacent to each other and transversely to the indicated longitudinal axis (XX) with carbon blocks (5) located therein and made of hollow heating partitions (6), communicating and distributing They are connected in a line with partitions (6) of other chambers (2) parallel to the longitudinal axis (XX) of the furnace (1), made with the possibility of circulating cooling and oxidizing air and gaseous combustion products in them, a suction ramp (11) connected during preheating from each of the partitions (6) of the first chamber (2), respectively, through the suction pipes (11a), including the combustion of fuel in the lines of the partitions, while the necessary oxidizing air partially enters through the injection ramp (18) of the free cooling zone (C), at least one fan, and partially seeps due to rarefaction through the lines of the partitions (6), and the fuel necessary for firing the carbon blocks (5) is partially injected through at least two heating ramps (16) with nozzles (23), each of which at least one of the two respective adjacent chambers (2) of the heating zone is located and is configured to inject fuel into each of the partitions (6) of the corresponding chamber (2) of the heating zone (B), and controlling at least the heating ramps ( 16) by controlling their inputs / outputs by means of a control controller (42a, 42b) through a communication network, characterized in that the control controller (42a, 42b) automatically identifies the relative position of one heating ramp (16) relative to other ramps during the connection of said heating ramp with said communication network, while determining the sequence of operation of the nozzles (23) of the heating ramps (16) is carried out by individually distributing in time the operating cycles of the nozzles (23). 2. The method according to p. 1, characterized in that the temporary distribution of the operating cycles of the nozzles (23) is carried out in such a way that the nozzle (23) only works when the volume of gas under the specified nozzle (23) has a sufficient oxygen content to provide combustion of injected fuel. 3. The method according to p. 1, characterized in that the temporary distribution of the operating cycles of the nozzles (23) is carried out in such a way as to limit the formation of underburning, in particular WITH. 4. The method according to any one of paragraphs. 1-3, characterized in that the temporary distribution of the operating cycles of the nozzles (23) is carried out by limiting the number of simultaneously operating nozzles (23) of the heating ramp (16) to a maximum number, while the specified maximum number is the number that leads to the nominal fuel consumption in the specified heating ramp (16). 5. The method according to any one of paragraphs. 1-3, characterized in that the temporary distribution of the operating cycles of the nozzles (23) is carried out in such a way as to limit fluctuations in fuel consumption in each heating ramp (16). 6. The method according to any one of paragraphs. 1-3, characterized in that during the time D in the furnace (1) containing the number N of nozzles (23) distributed over the partitions (6) and the heating ramps (16) of the furnace (1), the nozzles (23) operate in pulses the principle is completely on or completely off and with modulation of the duration, while for each of the N nozzles (23), the operating time (Δi) is determined, less than or equal to D, while the values of the operating time (Δi) are derived depending on the energy needs of the furnace (1 ), which gives the controller (42A, 42b) of the furnace (1), and
- the duration (Δi) of the nozzle (23) is divided into a number of pulses, while the sum of the duration of the pulses is equal to the duration (Δi) of the specified nozzle (23),
- the operating procedure is determined by the temporal distribution of pulses for each of the N nozzles (23) individually and encoded in the form of a binary time function (pi), which corresponds to 1 when the nozzle (23) with serial number i produces a pulse at time s, and otherwise case - corresponds to 0,
- the operating procedure is calculated at the time (T) of the calculation taking into account the required values of the operating time (Δi) of the nozzles (23), while the pulses of the nozzle (23) occur no earlier than the initial moment (ti) following the moment (T), and no later moment ti + D,
- the initial moments (ti) of each nozzle depend on the relative position of the nozzles (23) of one partition (6) and on the speed (Vk) of the flow of gaseous products of combustion in this partition (6). 7. The method according to p. 6, characterized in that the operating procedure is calculated as follows:
a) choose any initial order,
b) each nozzle (23) is assigned a serial number (i) from 1 to N,
c) for the nozzle with a serial number (i) equal to 1, choose the distribution of the working pulses of this nozzle (23), which allow to maximize the function (Uk) characterizing the oxygen content in the gaseous products of combustion after the last nozzle of one partition (6) for a time interval between the moments tk and tk + D, where tk is the moment corresponding to the last nozzle (23) of this partition (6), while the pulses of the other nozzles (23) preserve the initial position and get the order of operation with the optimal distribution of impulses cos for nozzles (23) with sequence number (i), equal to 1,
d) repeat step c) based on the final order of step c), sequentially examining the nozzles (23) with a serial number (i) greater than 1, to the nozzle with a serial number N. 8. The method according to p. 7, characterized in that it further includes stages in which:
e) using the operating procedure defined in step d) as the initial order, each nozzle (23) is assigned a new serial number (i) from 1 to N and steps c) and d) are repeated,
f) the resulting work order is compared with the original order and the best of the two is selected as the work order,
g) steps e) and f) are repeated many times with the number of times compatible with the calculation time between the moment (T) of the calculation and the first of the initial moments (ti) of the nozzles (23) of one partition (6). 9. The method according to p. 8, characterized in that, as the best of the two operating orders selected in step f), the order is selected in which the total fuel consumption in each heating ramp (16) obtained as a result of the distribution of the pulses of the nozzles ( 23) the heating ramp (16) does not exceed the maximum possible fuel consumption in the specified heating ramp (16). 10. A multi-chamber furnace (1) with a rotating flame for burning carbon blocks (5), containing a series of chambers (2) of preheating, heating, free cooling and forced cooling, arranged in a row along the longitudinal axis (XX) of the furnace (1), each chamber (2) consists of adjacent to each other and transversely to the specified longitudinal axis (XX) and alternating cells (4) with carbon blocks (5) located for them to be fired, and of hollow heating partitions (6) communicating and located connected on the same straight line with partitions (6) of other chambers (2) parallel to the longitudinal axis (XX) of the furnace (1) and made with the possibility of circulating cooling and oxidizing air and gaseous combustion products in them, a device for burning fuel in the lines of the partitions, containing a suction a ramp (11) connected during pre-heating from each of the partitions (6) of the first chamber (2), respectively, through the suction pipes (11a), the injection ramp (18) of the free cooling zone (C) to supply part of the necessary oxidizing about air connected to at least one fan, while the oxidizing air partially seeps due to rarefaction through the lines of the partitions (6), and at least two heating ramps (16) for injecting through them part of the fuel necessary for burning carbon blocks ( 5), each of which is located at least one of two adjacent chambers (2) of the heating zone and is configured to inject fuel into each of the partitions (6) of the corresponding chamber (2) of the heating zone (B), the control controller (42a, 42b) for direct control of at least the heating ramps (16) by controlling their inputs / outputs and a communication network, characterized in that the control controller (42a, 42b) is configured to automatically identify the relative position of one heating ramp (16) relative to others during connection a heating ramp with said communication network and providing said relative position of the heating ramp (16) corresponding to reliable operation of the furnace (1).

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