JP4165333B2 - Combustion control method and combustion control apparatus for tubular flame burner - Google Patents

Description

  The present invention relates to a burner provided in a furnace or a combustor.

  A burner provided in a furnace or a combustor has a tubular combustion chamber with one end opened, and a nozzle for blowing fuel gas and a nozzle for blowing oxygen-containing gas in the vicinity of the closed end of the combustion chamber are provided inside the combustion chamber. A tubular flame burner provided in the tangential direction of the peripheral surface is shown (for example, see Patent Document 1).

In this tubular flame burner, a stable flame is formed in the burner in a high-speed swirling flow, so that downsizing of the combustion equipment is achieved, the temperature variation of the combustion flame is small, and a local high temperature region is generated. In addition to being difficult to form, the burner is capable of stable combustion even when the oxygen ratio or air ratio is lowered. Therefore, the burner can reduce environmental pollution sources such as harmful substances such as NOx, unburned components such as hydrocarbons, and smoke.
JP-A-11-281015

  However, the above tubular flame burner has the following problems.

  That is, in the above-described tubular flame burner, in order to form a tubular flame, a supply nozzle that is elongated in the tube axis direction is connected to an elongated slit in the tube axis direction provided in the tubular combustion chamber, and is connected in the tangential direction. Fuel gas and oxygen-containing gas are blown into the tubular combustion chamber while blowing strong swirl. Therefore, there exists a problem that the pressure loss in a slit part becomes comparatively high. In other words, since the supply pressure of the fuel gas and the oxygen-containing gas is usually fixed, when increasing the combustion load, it is necessary to increase the supply flow rate of the fuel gas and the oxygen-containing gas. The pressure loss in the slit portion also increases in proportion to the square, and the combustion load cannot be increased so much.

  In addition, if the slit cross-sectional area is increased in order to reduce the pressure loss in the slit portion, the tangent to the circumferential surface of the combustion chamber is reduced when the supply flow rate of the fuel gas and the oxygen-containing gas is reduced to cope with a small combustion load. The fuel gas and the oxygen-containing gas blowing speed in the direction are remarkably reduced, and a tubular flame cannot be formed. Conversely, there is a disadvantage that the generation amount of NOx, soot and the like increases.

  As described above, in the conventional tubular flame burner, the supply flow rates of the fuel gas and the oxygen-containing gas are increased / decreased in accordance with the increase / decrease of the combustion load, but at this time, an appropriate blowing speed is not always obtained. In some cases, it is difficult to perform stable combustion over a wide combustion load range.

  The present invention has been made to solve the above problems, and in a tubular flame burner in which a tubular flame is formed in a tubular combustion chamber, the supply flow rates of fuel and oxygen-containing gas according to the increase or decrease of the combustion load. An object of the present invention is to provide a combustion control method and a combustion control apparatus for a tubular flame burner that can obtain an appropriate blowing speed of fuel and oxygen-containing gas even when the fuel pressure is increased or decreased, and that enables stable combustion in a wider combustion load range. It is what.

  In order to solve the above problems, the present invention has the following features.

[1] A tubular combustion chamber having an open end, and a plurality of fuel injection nozzles and oxygen-containing gas injection nozzles in a circumferential direction and / or a longitudinal direction in which a nozzle injection port opens on the inner surface of the combustion chamber, In a combustion control method for a tubular flame burner in which the injection direction of each fuel injection nozzle and oxygen-containing gas injection nozzle is substantially the same as the tangential direction of the circumferential surface of the combustion chamber, an open / close valve is provided on the supply pipe connected to each nozzle Depending on the combustion load of the tubular flame burner, the on-off valve is configured so that the injection speed from each nozzle is in the range of the allowable maximum flow rate determined from the pressure loss and the minimum flow rate required to form the tubular flame. A combustion control method for a tubular flame burner, characterized by controlling the opening and closing of the flame.

[2] A tubular combustion chamber having an open end, and a nozzle for injecting a premixed gas composed of a plurality of fuel gases and oxygen-containing gas in the circumferential direction and / or longitudinal direction in which a nozzle injection port opens on the inner surface of the combustion chamber In a combustion control method for a tubular flame burner in which the injection direction of each nozzle is substantially coincident with the tangential direction of the circumferential surface of the combustion chamber, an on-off valve is provided in a supply pipe connected to each nozzle, and the combustion load of the tubular flame burner The on-off valve is controlled to open and close so that the injection speed from each nozzle is in a range between an allowable maximum flow rate determined from pressure loss and a minimum flow rate required to form a tubular flame. A method for controlling the combustion of a tubular flame burner.

[3] A tubular combustion chamber having an open end, and a plurality of fuel injection nozzles and oxygen-containing gas injection nozzles in a circumferential direction and / or a longitudinal direction in which nozzle nozzles are opened on the inner surface of the combustion chamber, A tubular flame burner in which the injection direction of each fuel injection nozzle and the oxygen-containing gas injection nozzle is substantially coincident with the tangential direction of the circumferential surface of the combustion chamber; an on-off valve provided in a supply pipe connected to each nozzle; Depending on the combustion load of the flame burner, the on-off valve is opened and closed so that the injection speed from each nozzle is in the range of the maximum allowable flow rate determined from pressure loss and the minimum flow rate required to form a tubular flame. A combustion control device for a tubular flame burner, characterized by comprising control means for controlling.

[4] A tubular combustion chamber having an open end, and a nozzle for injecting a premixed gas composed of a plurality of fuel gases and oxygen-containing gas in the circumferential direction and / or longitudinal direction in which nozzle nozzles are opened on the inner surface of the combustion chamber A tubular flame burner in which the injection direction of each nozzle substantially coincides with the tangential direction of the peripheral surface of the combustion chamber, an on-off valve provided in a supply pipe connected to each nozzle, and the combustion load of the tubular flame burner Control means for controlling the opening and closing of the on-off valve so that the injection speed from each nozzle falls within a range between an allowable maximum flow rate determined from pressure loss and a minimum flow rate necessary for forming a tubular flame. A combustion control device for a tubular flame burner, characterized in that:

  In the present invention, a nozzle for injecting fuel and oxygen-containing gas into the combustion chamber so as to obtain a predetermined injection speed even if the overall supply flow rate of fuel and oxygen-containing gas is increased or decreased in response to increase or decrease in combustion load. The number of nozzles or the number of nozzles for injecting a premixed mixture of fuel gas and oxygen-containing gas into the combustion chamber is appropriately selected, so that stable combustion can be performed in a wider combustion load range.

(First embodiment)
A first embodiment of the present invention is shown in FIGS. 1 is a side view of a tubular flame burner used in this embodiment, FIG. 2A is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 2B is a view taken along the line BB in FIG. FIG. FIG. 3 is an overall configuration diagram of the combustion control device for the tubular flame burner according to this embodiment, and FIG. 4 is an explanatory diagram for explaining the combustion control method for the tubular flame burner according to this embodiment.

  In FIG. 1, reference numeral 10 denotes a tubular combustion chamber, the tip 10a of which is opened to serve as an exhaust port for combustion exhaust gas. Then, attachment portions A and B for nozzles for blowing fuel gas into the combustion chamber 10 and nozzles for blowing oxygen-containing gas are provided at two locations in the tube axis direction near the rear end 10b.

  In the nozzle mounting portion A, as shown in FIGS. 1 and 2A, elongated slits 12 along the tube axis direction are formed at four locations in the circumferential direction of the combustion chamber 10 as nozzle injection ports to the combustion chamber 10. In addition, flat nozzles 11a, 11b, 11c, and 11d that are elongated in the tube axis direction are connected to the respective slits 12. The injection directions of the nozzles 11 a, 11 b, 11 c, and 11 d are provided so as to be tangential to the inner peripheral surface of the combustion chamber 10 and in the same rotational direction. Of these four nozzles, two nozzles 11a and 11c are fuel gas blowing nozzles, and two nozzles 11b and 11d are oxygen-containing gas blowing nozzles.

  Fuel gas is blown from the fuel gas blowing nozzles 11 a and 11 c at a high speed toward the tangential direction of the inner circumferential surface of the combustion chamber 10, and oxygen-containing gas is blown from the oxygen-containing gas blowing nozzles 11 b and 11 d to the inner circumference of the combustion chamber 10. A swirling flow is formed while the fuel gas and the oxygen-containing gas are efficiently mixed in a region close to the inner peripheral surface of the combustion chamber 10 while being blown at high speed toward the tangential direction of the surface. When the mixed gas in the swirl flow is ignited by an ignition device (not shown) such as an ignition plug or a parrot burner, a tubular flame is generated in the combustion chamber 10.

  Similarly, in the nozzle mounting portion B, as shown in FIGS. 1 and 2B, four elongated slits 14 along the tube axis direction as nozzle injection ports to the combustion chamber 10 are provided at four locations in the circumferential direction of the combustion chamber 10. The flat nozzles 13a, 13b, 13c, 13d that are elongated in the tube axis direction are connected to the slits 14, respectively. The injection directions of the nozzles 13 a, 13 b, 13 c, and 13 d are provided so as to be tangential to the inner peripheral surface of the combustion chamber 10 and in the same rotational direction. Of these four nozzles, two nozzles 13a and 13c are fuel gas injection nozzles, and two nozzles 13b and 13d are oxygen-containing gas injection nozzles.

  Fuel gas is blown from the fuel gas blowing nozzles 13 a and 13 c at a high speed toward the tangential direction of the inner peripheral surface of the combustion chamber 10, and oxygen-containing gas is blown from the oxygen-containing gas blowing nozzles 13 b and 13 d to the inner circumference of the combustion chamber 10. A swirling flow is formed while the fuel gas and the oxygen-containing gas are efficiently mixed in a region close to the inner peripheral surface of the combustion chamber 10 while being blown at high speed toward the tangential direction of the surface. When the mixed gas in the swirl flow is ignited by an ignition device (not shown) such as an ignition plug or a parrot burner, a tubular flame is generated in the combustion chamber 10.

  Therefore, in this embodiment, two fuel gas injection nozzles and two oxygen-containing gas injection nozzles are provided on the same pipe circumference, and two rows are provided in the tube axis direction. Therefore, the fuel gas injection nozzle and the oxygen-containing nozzle are provided. Each of the four gas blowing nozzles is provided.

  The oxygen-containing gas mentioned above refers to a gas that supplies oxygen for combustion, such as air, oxygen, oxygen-enriched air, oxygen / exhaust gas mixture gas.

  Then, as shown in FIG. 3, the fuel gas supply to the nozzles 11a, 11c, 13a, 13c is turned on and off in the piping for supplying the fuel gas to the fuel gas injection nozzles 11a, 11c, 13a, 13c. On-off valves 15a, 15c, 16a, and 16c are provided, and in the piping for supplying oxygen-containing gas to the oxygen-containing gas blowing nozzles 11b, 11d, 13b, and 13d, to the nozzles 11b, 11d, 13b, and 13d, respectively. On-off valves 15b, 15d, 16b, and 16d for turning on and off the supply of the oxygen-containing gas are provided.

  A supply control device 20 is provided for controlling the opening and closing of the on-off valves 15a, 15b, 15c, 15d, 16a, 16b, 16c, and 16d. By the on-off control, the combustion chamber 10 contains fuel gas and oxygen. The nozzle that blows gas can be selected.

  In addition, a fuel gas flow rate adjusting valve 17 for adjusting the overall supply flow rate of the fuel gas supplied to the fuel gas blowing nozzles 11a, 11c, 13a, and 13c is provided in the pipe for supplying the fuel gas. An oxygen-containing gas flow rate adjusting valve 18 for adjusting the overall supply flow rate of the oxygen-containing gas supplied to the oxygen-containing gas blowing nozzles 11b, 11d, 13b, and 13d is provided in the piping for supplying the containing gas. The fuel gas flow rate adjustment valve 17 and the oxygen-containing gas flow rate adjustment valve 18 are controlled by a supply control device 20 to adjust the overall flow rates of the supplied fuel gas and oxygen-containing gas in accordance with the combustion load. That is, when the combustion load is small, the opening of the fuel gas flow rate adjustment valve 17 and the oxygen-containing gas flow rate adjustment valve 18 is reduced to reduce the overall supply flow rate, and when the combustion load is large, the fuel gas flow rate adjustment valve 17 and The total supply flow rate is increased by widening the opening of the oxygen-containing gas flow rate adjustment valve 18.

  The total supply flow rate of the fuel gas and the oxygen-containing gas is measured by the fuel gas flow meter 21 and the oxygen-containing gas flow meter 22, and the measured value is sent to the supply control device 20 to adjust the fuel gas flow rate. The valve 17 and the oxygen-containing gas flow rate adjustment valve 18 are used for opening adjustment.

  A method for controlling the combustion of the tubular flame burner using the combustion control device for the tubular flame burner configured as described above will be described with reference to FIGS.

  In this tubular flame burner combustion control method, the initial flow rates of the fuel gas and the oxygen-containing gas blown into the combustion chamber 10 according to the combustion load are the maximum allowable flow rate Vp determined from the pressure loss, and the tubular flame is formed. The number of nozzles used for injecting the fuel gas and the oxygen-containing gas is selected so as to be in the range of the required minimum flow velocity Vq.

  That is, when increasing the total supply flow rate of the fuel gas and oxygen-containing gas blown into the combustion chamber 10 according to the combustion load, the on-off valve 15a is opened and the other three on-off valves 15c, 16a, 16c are closed. Thus, the fuel gas is blown only from the fuel gas blowing nozzle 11a, the on-off valve 15b is opened, the other three on-off valves 15d, 16b, and 16d are closed, and the oxygen-containing gas is drawn only from the oxygen-containing gas blowing nozzle 11b. When the fuel gas is blown, all of the supplied fuel gas flow rate is concentrated and blown from one fuel gas blowing nozzle 11a, and all of the supplied oxygen-containing gas flow rate is concentrated to one. Since the oxygen-containing gas blowing nozzle 11b is blown, the initial flow from the blowing nozzles 11a and 11b as shown by the line L1 in FIG. It is with increasing total supply flow, i.e., rapidly increases with increasing combustion load. As a result, the minimum flow velocity Vq required to form the tubular flame can be reached immediately, but the allowable maximum flow velocity Vp determined from the pressure loss is quickly exceeded.

  On the other hand, the two on-off valves 15a and 15c are opened and the remaining two on-off valves 16a and 16c are closed so that the fuel gas is blown from the two fuel gas blowing nozzles 11a and 11c. When the two on-off valves 15b and 15d are opened and the remaining two on-off valves 16b and 16d are closed and oxygen-containing gas is blown from the two oxygen-containing gas blowing nozzles 11b and 11d, 1/2 of the fuel gas flow rate is dispersed and blown from the two fuel gas blowing nozzles 11a and 11c, and 1/2 of the supplied oxygen-containing gas flow rate is dispersed and two oxygen-containing gases Since the air is blown from the blow nozzles 11b and 11d, the initial flow velocity from the blow nozzle is increased with the increase in the total supply flow rate, as shown by the line L2 in FIG. To increase relatively slowly with the increase of baked load. Compared to the case where each of the one blowing nozzles 11a and 11b is used, the increase rate is ½. As a result, the minimum flow velocity Vq required to form the tubular flame is reached relatively slowly, but exceeding the allowable maximum flow velocity Vp determined from the pressure loss is also relatively slow.

  Further, the four on-off valves 15a, 15c, 16a, 16c are all opened so that the fuel gas is blown from the four fuel gas blowing nozzles 11a, 11c, 13a, 13c, and the four on-off valves 15b, 15d. , 16b, 16d are opened, and oxygen-containing gas is blown from the four oxygen-containing gas blowing nozzles 11b, 11d, 13b, 13d. Dispersed and injected from four fuel gas injection nozzles 11a, 11c, 13a, and 13c, and ¼ of the supplied oxygen-containing gas flow rate is dispersed to provide four oxygen-containing gas injection nozzles 11b, 11d, and 13b. 13d, the initial flow velocity from the blowing nozzle increases the overall supply flow rate as shown by the line L3 in FIG. 4 (a). It, i.e., very slowly increases with increasing combustion load. Compared to the case where each one of the blowing nozzles 11a and 11b is used, the increase rate is 1/4. As a result, reaching the minimum flow velocity Vq necessary to form the tubular flame is considerably slow, but exceeding the allowable maximum flow velocity Vp determined from the pressure loss is also considerably slow.

  Based on the above relationship, in this combustion control method, the initial flow rates of the fuel gas and oxygen-containing gas blown into the combustion chamber 10 according to the combustion load are the allowable maximum flow rate Vp determined from the pressure loss, The supply control device 20 controls the opening and closing of the on-off valves 15a, 15b, 15c, 15d, 16a, 16b, 16c, and 16d so as to be in the range of the minimum flow velocity Vq necessary for forming the tubular flame, and the fuel gas And the number of nozzles used for blowing the oxygen-containing gas.

  That is, as shown in FIG. 4B, from a predetermined minimum combustion load to a load of about 1/4, a fuel gas injection nozzle and an oxygen-containing gas injection nozzle are used one by one, and from about 1/4 Up to about 1/2 combustion load, 2 nozzles are used each, and from about 1/2 to the predetermined maximum combustion load, 4 nozzles are used each.

  As a result, as indicated by line M in FIG. 4 (a), the initial flow velocity from the blowing nozzle falls within the range of the allowable maximum flow velocity Vp determined from the pressure loss and the minimum flow velocity Vq necessary for forming the tubular flame. It is possible to ensure that the pressure loss does not become excessively large while always staying and maintaining the required high speed.

  As described above, in this embodiment, two fuel gas injection nozzles and two oxygen-containing gas injection nozzles are mounted on the same circumference of the tubular combustion chamber 10 and provided in two rows in the tube axis direction. The number of nozzles to be used from the plurality of fuel gas injection nozzles and oxygen-containing gas injection nozzles can be changed according to the increase or decrease of the combustion load even if the overall supply flow rate of the fuel and oxygen-containing gas is increased or decreased. Since it is selected appropriately by opening and closing and a predetermined blowing speed is obtained, it is possible to achieve both a decrease in pressure loss when the supply flow rate increases and a holding of the turning force when the supply flow rate decreases. Is possible.

  In this embodiment, two fuel gas injection nozzles and two oxygen-containing gas injection nozzles are mounted on the same pipe circumference and provided in two rows in the pipe axis direction. The number of columns in the direction may be appropriately set as necessary.

  Furthermore, the cross-sectional shape of the combustion chamber is not limited to a circle, and may be a polygon that is equal to or greater than a quadrangle, and fuel gas and oxygen-containing gas may be blown in the tangential direction of the inscribed circle of the polygon.

  In this embodiment, the fuel gas injection nozzle and the oxygen-containing gas injection nozzle are provided such that the injection direction coincides with the tangential direction of the combustion chamber peripheral surface, but it does not necessarily match the tangential direction of the combustion chamber peripheral surface. The injection direction may be deviated from the tangential direction of the circumferential surface of the combustion chamber to such an extent that a swirl flow of gas can be formed in the combustion chamber.

  In this embodiment, a slit is provided along the tube axis direction as an injection port to the combustion chamber, and a flat fuel gas injection nozzle and an oxygen-containing gas injection nozzle are connected to the slit. A plurality of small holes may be arranged in the direction of the tube axis as nozzles of the nozzles, and nozzles for injecting fuel gas or oxygen-containing gas may be connected to the small hole rows.

  In this embodiment, fuel gas is blown in, but liquid fuel may be blown in. As the liquid fuel, those which vaporize at a relatively low temperature such as kerosene, light oil, alcohol, A heavy oil and the like are suitable.

(Second Embodiment)
A second embodiment of the present invention is shown in FIG. FIG. 5 is an overall configuration diagram of a combustion control device for a tubular flame burner according to this embodiment.

  In the first embodiment described above, as shown in FIG. 3, the overall flow rate of the fuel gas supplied to the nozzle of the attachment portion A and / or the nozzle of the attachment portion B and the overall flow rate of the oxygen-containing gas are adjusted. In contrast, in this embodiment, the flow rate of the fuel gas to be supplied and the flow rate of the oxygen-containing gas can be adjusted separately with respect to the nozzle of the attachment portion A and the nozzle of the attachment portion B. Yes.

  That is, as shown in FIG. 5, the fuel gas flow rate adjusting valve 17a for adjusting the flow rate of the fuel gas supplied to the fuel gas blowing nozzles 11a and 11c is provided in the pipe for supplying the fuel gas to the nozzle of the attachment portion A. And an oxygen-containing gas flow rate adjusting valve for adjusting the flow rate of the oxygen-containing gas supplied to the oxygen-containing gas blowing nozzles 11b and 11d in the pipe for supplying the oxygen-containing gas to the nozzle of the attachment portion A. 18a is provided. The fuel gas flow rate adjusting valve 17a and the oxygen-containing gas flow rate adjusting valve 18a are controlled by the supply control device 20a so that the flow rates of the fuel gas and the oxygen-containing gas supplied to the nozzle of the attachment portion A can be adjusted. The supply flow rates of the fuel gas and the oxygen-containing gas are measured by the fuel gas flow meter 21a and the oxygen-containing gas flow meter 22a. The measured values are sent to the supply control device 20a, and the fuel gas flow rate adjusting valve 17a and It is used for adjusting the opening of the oxygen-containing gas flow rate adjusting valve 18a.

  Similarly, a fuel gas flow rate adjustment valve 17b for adjusting the flow rate of the fuel gas supplied to the fuel gas blowing nozzles 13a and 13c is provided in the pipe for supplying the fuel gas to the nozzle of the attachment portion B. An oxygen-containing gas flow rate adjusting valve 18b for adjusting the flow rate of the oxygen-containing gas supplied to the oxygen-containing gas blowing nozzles 14b and 14d is provided in the pipe for supplying the oxygen-containing gas to the nozzle of the attachment portion B. . The fuel gas flow rate adjustment valve 17b and the oxygen-containing gas flow rate adjustment valve 18b are controlled by the supply control device 20b so that the flow rates of the fuel gas and the oxygen-containing gas supplied to the nozzles of the attachment portion B can be adjusted. The supply flow rates of the fuel gas and the oxygen-containing gas are measured by the fuel gas flow meter 21b and the oxygen-containing gas flow meter 22b, and the measured values are sent to the supply control device 20b, and the fuel gas flow rate adjusting valve 17b and It is used for adjusting the opening of the oxygen-containing gas flow rate adjusting valve 18b.

  The overall supply flow rates of the fuel gas and the oxygen-containing gas can be adjusted in cooperation with the supply control device 20a to the nozzle of the attachment portion A and the supply control device 20b to the nozzle of the attachment portion B.

  In the pipe for supplying the fuel gas to the fuel gas injection nozzles 11a, 11c of the attachment portion A, on-off valves 15a, 15c for turning on and off the supply of the fuel gas to the respective nozzles 11a, 11c are provided. In the piping for supplying oxygen-containing gas to the oxygen-containing gas blowing nozzles 11b, 11d of the attachment portion A, on-off valves 15b, 15d for turning on and off the supply of the oxygen-containing gas to the respective nozzles 11b, 11d are provided. The opening / closing valves 15a, 15b, 15c and 15d are controlled by the supply control device 20a.

  Further, in the piping for supplying the fuel gas to the fuel gas blowing nozzles 13a, 13c of the attachment portion B, on-off valves 16a, 16c for turning on and off the supply of the fuel gas to the respective nozzles 13a, 13c are provided, In the piping for supplying oxygen-containing gas to the oxygen-containing gas blowing nozzles 13b and 13d of the attachment portion B, on-off valves 16b and 16d for turning on and off the supply of oxygen-containing gas to the respective nozzles 13b and 13d are provided. The opening / closing valves 16a, 16b, 16c and 16d are controlled by the supply control device 20b.

  By such opening / closing control by the supply control device 20a and the supply control device 20b, it is possible to select a nozzle that blows fuel gas and oxygen-containing gas into the combustion chamber 10.

  Therefore, in this embodiment, even if the overall supply flow rate of the fuel and the oxygen-containing gas is increased or decreased in response to the increase or decrease in the combustion load, the nozzles used from the plurality of fuel gas injection nozzles and oxygen-containing gas injection nozzles Is appropriately selected by opening and closing the on-off valve and the flow rate supplied to the nozzle is adjusted by the flow rate adjusting valve so that a predetermined blowing speed can be obtained. It is possible to achieve both reduction in pressure loss and retention of turning force when the supply flow rate is reduced.

(Third embodiment)
A third embodiment of the present invention is shown in FIGS. 6 is a side view of the tubular flame burner used in this embodiment, FIG. 7A is a cross-sectional view taken along the line AA in FIG. 6, and FIG. 7B is a view taken along the line BB in FIG. FIG. FIG. 8 is an overall configuration diagram of a combustion control device for a tubular flame burner according to this embodiment.

  In FIG. 6, reference numeral 10 denotes a tubular combustion chamber, the tip 10a of which is opened and serves as an exhaust port for combustion exhaust gas. Then, attachment portions A and B for nozzles for blowing fuel gas into the combustion chamber 10 and nozzles for blowing oxygen-containing gas are provided at two locations in the tube axis direction near the rear end 10b.

  In the nozzle attachment portion A, as shown in FIGS. 6 and 7A, elongated slits 32 along the tube axis direction are formed at two locations in the circumferential direction of the combustion chamber 10 as nozzle injection ports to the combustion chamber 10. The flat nozzles 31a and 31b that are elongated in the tube axis direction are connected to the slits 32, respectively. The injection directions of the respective nozzles 31 a and 31 b are provided so as to be tangential to the inner peripheral surface of the combustion chamber 10 and in the same rotational direction. The nozzles 31a and 31b are supplied with a premixed gas in which a fuel gas and an oxygen-containing gas are mixed in advance.

  Then, the premixed gas is blown at high speed from the premixed gas blowing nozzles 31 a and 31 b supplied with the premixed gas toward the tangential direction of the inner peripheral surface of the combustion chamber 10, and the region close to the inner peripheral surface of the combustion chamber 10. In this way, a swirl flow is formed. When the premixed gas in the swirl flow is ignited by an ignition device (not shown) such as an ignition plug or a pilot burner, a tubular flame is generated in the combustion chamber 10.

  Similarly, also in the nozzle attachment portion B, as shown in FIGS. 6 and 7B, two elongated slits 34 along the tube axis direction are provided in the circumferential direction of the combustion chamber 10 as nozzle injection ports to the combustion chamber 10. The flat nozzles 33a and 33b that are elongated in the tube axis direction are connected to the slits 34, respectively. The injection directions of the nozzles 33a and 33b are provided so as to be in the tangential direction of the inner peripheral surface of the combustion chamber 10 and in the same rotational direction. The nozzles 31a and 31b are supplied with a premixed gas in which a fuel gas and an oxygen-containing gas are mixed in advance.

  Then, the premixed gas is blown at high speed from the premixed gas blowing nozzles 33 a and 33 b supplied with the premixed gas toward the tangential direction of the inner peripheral surface of the combustion chamber 10, and is a region close to the inner peripheral surface of the combustion chamber 10. In this way, a swirl flow is formed. When the premixed gas in the swirl flow is ignited by an ignition device (not shown) such as an ignition plug or a pilot burner, a tubular flame is generated in the combustion chamber 10.

  Therefore, in this embodiment, two premixed gas blowing nozzles are provided on the same pipe circumference, and two nozzles are provided in the tube axis direction, so that four premixed gas blowing nozzles are provided. It will be.

  Then, as shown in FIG. 8, in the pipe for supplying the premixed gas to the premixed gas blowing nozzles 31a, 31b, 33a, 33b, the supply of the premixed gas to the respective nozzles 31a, 31b, 33a, 33b. On / off valves 35a, 35b, 36a, 36b for turning on and off the gas, and gas mixers 37a, 37b, 38a, 38b for premixing the fuel gas and the oxygen-containing gas in advance are provided.

  Opening / closing control of the on / off valves 35a, 35b, 36a, 36b is performed by the supply control device 20, and the nozzle for blowing the premixed gas into the combustion chamber 10 can be selected by the opening / closing control.

  In the pipe for supplying the fuel gas to the gas mixers 37a, 37b, 38a, 38b, a fuel gas flow rate adjusting valve 17 for adjusting the entire flow rate of the supplied fuel gas is provided, and the gas mixers 37a, An oxygen-containing gas flow rate adjusting valve 18 for adjusting the overall flow rate of the oxygen-containing gas to be supplied is provided in the piping for supplying the oxygen-containing gas to 37b, 38a, and 38b. The fuel gas flow rate adjustment valve 17 and the oxygen-containing gas flow rate adjustment valve 18 are controlled by a supply control device 20 to adjust the overall flow rates of the supplied fuel gas and oxygen-containing gas in accordance with the combustion load. That is, when the combustion load is small, the opening of the fuel gas flow rate adjustment valve 17 and the oxygen-containing gas flow rate adjustment valve 18 is reduced to reduce the overall supply flow rate, and when the combustion load is large, the fuel gas flow rate adjustment valve 17 and The total supply flow rate is increased by widening the opening of the oxygen-containing gas flow rate adjustment valve 18.

  The total supply flow rate of the fuel gas and the oxygen-containing gas is measured by the fuel gas flow meter 21 and the oxygen-containing gas flow meter 22, and the measured value is sent to the supply control device 20 to adjust the fuel gas flow rate. The valve 17 and the oxygen-containing gas flow rate adjustment valve 18 are used for opening adjustment.

  A combustion control method using the tubular flame burner combustion control apparatus configured as described above is the same as that in the first embodiment.

  That is, according to the combustion load, the initial flow rate of the premixed gas blown into the combustion chamber 10 is in a range between the allowable maximum flow rate Vp determined from the pressure loss and the minimum flow rate Vq necessary for forming the tubular flame. Further, the supply control device 20 controls the opening / closing of the on-off valves 35a, 35b, 36a, 36b to determine the number of nozzles used for blowing the premixed gas.

  For example, one premixed gas injection nozzle is used from a predetermined minimum combustion load to about 1/4 load, and two premixed gas injections are performed from about 1/4 to about 1/2 combustion load. Nozzles are used, and from about 1/2 to a predetermined maximum combustion load, four premixed gas injection nozzles are used.

  As a result, the initial flow velocity from the blowing nozzle is always within the range of the allowable maximum flow velocity Vp determined from the pressure loss and the minimum flow velocity Vq necessary for forming the tubular flame, and the pressure loss is maintained while maintaining the necessary high speed. Can be prevented from becoming excessively large.

  Thus, in this embodiment, two premixed gas injection nozzles are mounted on the same circumference of the tubular combustion chamber 10, and two nozzles are provided in the tube axis direction to cope with increase / decrease in combustion load. Therefore, even if the total supply flow rate of the premixed gas is increased or decreased, the number of nozzles to be used is appropriately selected from the plurality of premixed gas blowing nozzles by opening and closing the on-off valve to obtain a predetermined blowing speed. Thus, it is possible to achieve both a decrease in pressure loss when the supply flow rate is increased and a holding of the turning force when the supply flow rate is reduced.

  In this embodiment, two premixed gas blowing nozzles are mounted on the same pipe circumference and provided in two rows in the tube axis direction. However, the number in the tube circumference direction and the number of rows in the tube axis direction are necessary. What is necessary is just to set suitably according to.

  Furthermore, the cross-sectional shape of the combustion chamber is not limited to a circle, and may be a polygon that is equal to or greater than a quadrangle, and the premixed gas may be blown in the tangential direction of the inscribed circle of the polygon.

  In this embodiment, the premixed gas injection nozzle is provided so that the injection direction coincides with the tangential direction of the circumferential surface of the combustion chamber, but does not necessarily coincide with the tangential direction of the circumferential surface of the combustion chamber. The injection direction may deviate from the tangential direction of the circumferential surface of the combustion chamber to such an extent that a swirl flow of gas can be formed in the chamber.

  In this embodiment, a slit is provided along the tube axis direction as an injection port to the combustion chamber, and a flat-shaped premixed gas injection nozzle is connected to the slit, but a plurality of injection ports to the combustion chamber are provided. These small holes may be arranged in the tube axis direction, and a nozzle for blowing premixed gas into the small hole row may be connected.

  In this embodiment, the fuel gas obtained by preheating and gasifying the liquid fuel may be used. As the liquid fuel, those which vaporize at a relatively low temperature such as kerosene, light oil, alcohol, A heavy oil and the like are suitable.

(Fourth embodiment)
A fourth embodiment of the present invention is shown in FIG. FIG. 9 is an overall configuration diagram of a combustion control device for a tubular flame burner according to this embodiment.

  In the above-described third embodiment, as shown in FIG. 8, the entire flow rate and oxygen content of the fuel gas supplied to the premixed gas blowing nozzle of the mounting portion A and / or the premixed gas blowing nozzle of the mounting portion B Whereas the overall gas flow rate is adjusted, in this embodiment, the flow rate of the fuel gas to be supplied and the flow rate of the oxygen-containing gas are further set to the premixed gas blowing nozzle of the mounting portion A and the mounting portion B. The premixed gas blowing nozzle can be adjusted separately.

  That is, as shown in FIG. 9, a fuel gas flow rate adjusting valve 17a for adjusting the flow rate of the supplied fuel gas is provided in the pipe for supplying the fuel gas to the premixed gas blowing nozzles 31a, 31b of the attachment portion A. An oxygen-containing gas flow rate adjusting valve 18a for adjusting the flow rate of the oxygen-containing gas to be supplied is provided in the pipe for supplying the oxygen-containing gas to the premixed gas blowing nozzles 31a and 31b of the attachment portion A. It has been. The fuel gas flow rate adjustment valve 17a and the oxygen-containing gas flow rate adjustment valve 18a are controlled by the supply control device 20a so that the flow rates of the fuel gas and the oxygen-containing gas supplied to the premixed gas blowing nozzles 31a and 31b of the attachment portion A can be adjusted. It has become. The supply flow rates of the fuel gas and the oxygen-containing gas are measured by the fuel gas flow meter 21a and the oxygen-containing gas flow meter 22a. The measured values are sent to the supply control device 20a, and the fuel gas flow rate adjusting valve 17a and It is used for adjusting the opening of the oxygen-containing gas flow rate adjusting valve 18a.

  Similarly, a fuel gas flow rate adjusting valve 17b for adjusting the flow rate of the supplied fuel gas is provided in the pipe for supplying the fuel gas to the premixed gas blowing nozzles 33a and 33b of the mounting portion B. An oxygen-containing gas flow rate adjusting valve 18b for adjusting the flow rate of the oxygen-containing gas to be supplied is provided in the pipe for supplying the oxygen-containing gas to the premixed gas blowing nozzles 33a and 33b of the part B. The fuel gas flow rate adjusting valve 17b and the oxygen-containing gas flow rate adjusting valve 18b are controlled by the supply control device 20b so that the flow rates of the fuel gas and the oxygen-containing gas supplied to the premixed gas blowing nozzles 33a and 33b of the mounting portion B can be adjusted. It has become. The supply flow rates of the fuel gas and the oxygen-containing gas are measured by the fuel gas flow meter 21b and the oxygen-containing gas flow meter 22b, and the measured values are sent to the supply control device 20b, and the fuel gas flow rate adjusting valve 17b and It is used for adjusting the opening of the oxygen-containing gas flow rate adjusting valve 18b.

  Then, in conjunction with the supply control device 20a to the premixed gas blowing nozzles 31a and 31b of the mounting portion A and the supply control device 20b to the premixed gas blowing nozzles 33a and 33b of the mounting portion B, the fuel gas and oxygen are contained. The total gas supply flow rate can be adjusted.

  In the pipe for supplying the premixed gas from the gas mixer 37a to the premixed gas blowing nozzle 31a of the attachment portion A, an open / close valve 35a for turning on and off the supply of the premixed gas to the premixed gas blowing nozzle 31a is provided. Opening / closing that turns on and off the supply of the premixed gas to the premixed gas blowing nozzle 31b in the pipe for supplying the premixed gas from the gas mixer 37b to the premixed gas blowing nozzle 31b of the attachment portion A. A valve 35b is provided.

  In addition, in the pipe for supplying the premixed gas from the gas mixer 38a to the premixed gas blowing nozzle 33a of the mounting portion B, there is an on-off valve 36a for turning on and off the supply of the premixed gas to the premixed gas blowing nozzle 33a. An opening / closing unit that opens and closes the supply of the premixed gas to the premixed gas blowing nozzle 33b in the pipe for supplying the premixed gas from the gas mixer 38b to the premixed gas blowing nozzle 33b of the mounting portion B. A valve 36b is provided.

  Open / close control of the open / close valves 35a and 35b is performed by the supply control device 20a, and open / close control of the open / close valves 36a and 36b is performed by the supply control device 20a. The nozzle that blows the premixed gas into the combustion chamber 10 can be selected by the opening / closing control.

  Therefore, also in this embodiment, the number of nozzles to be used from among the plurality of premixed gas injection nozzles can be determined by the opening / closing valve even if the total supply flow rate of the premixed gas is increased or decreased in accordance with the increase or decrease of the combustion load. By appropriately selecting the opening and closing and adjusting the flow rate supplied to the nozzle with the flow rate adjustment valve, it is possible to obtain a predetermined blowing speed, so that the pressure loss decreases and the supply flow rate when the supply flow rate increases It is possible to achieve both holding of the turning force when the pressure decreases.

It is a side view of the tubular flame burner used for the 1st Embodiment of the present invention. It is AA sectional drawing and BB sectional drawing of FIG. It is a whole block diagram of the combustion control apparatus of the tubular flame burner which concerns on the 1st Embodiment of this invention. It is explanatory drawing of the combustion control method in the 1st Embodiment of this invention. It is a whole block diagram of the combustion control apparatus of the tubular flame burner which concerns on the 2nd Embodiment of this invention. It is a side view of the tubular flame burner used for the 3rd Embodiment of this invention. It is AA sectional drawing and BB sectional drawing of FIG. It is a whole block diagram of the combustion control apparatus of the tubular flame burner which concerns on the 3rd Embodiment of this invention. It is a whole block diagram of the combustion control apparatus of the tubular flame burner which concerns on the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Combustion chamber 10a Front end of combustion chamber 10b Rear end of combustion chamber 11a, 11c Fuel gas injection nozzle 11b, 11d Oxygen-containing gas injection nozzle 12 Slit 13a, 13c Fuel gas injection nozzle 13b, 13d Oxygen-containing gas injection nozzle 14 Slit 15a, 15c Fuel gas on-off valve 15b, 15d Oxygen-containing gas on-off valve 16a, 16c Fuel gas on-off valve 16b, 16d Oxygen-containing gas on-off valve 17, 17a, 17b Fuel gas flow control valve 18, 18a, 18b Oxygen-containing Gas flow regulating valve 20, 20a, 20b Supply control device 21, 21a, 21b Fuel gas flow meter 22, 22a, 22b Oxygen-containing gas flow meter 31a, 31b Premixed gas blowing nozzle 32 Slit 33a, 33b Premixed gas Blow nozzle 34 Slit 35a, 35b, 36a, 36b Premixed gas on-off valve 37a, 37b, 38a, 38b Gas mixer

Claims (4)

A tubular combustion chamber having an open end, and a plurality of fuel injection nozzles and oxygen-containing gas injection nozzles in a circumferential direction and / or a longitudinal direction in which nozzle nozzles are opened on the inner surface of the combustion chamber, each fuel injection In the combustion control method for the tubular flame burner in which the injection direction of the nozzle for injecting the oxygen and the nozzle for injecting the oxygen-containing gas substantially coincides with the tangential direction of the peripheral surface of the combustion chamber, an open / close valve is provided in the supply pipe connected to each nozzle, and the tubular flame Depending on the combustion load of the burner, the on-off valve is controlled to open and close so that the injection speed from each nozzle is within the range of the maximum allowable flow rate determined from pressure loss and the minimum flow rate required to form a tubular flame. A method for controlling the combustion of a tubular flame burner. A tubular combustion chamber having an open end, and a nozzle for injecting a premixed gas composed of a plurality of fuel gases and oxygen-containing gas in the circumferential direction and / or longitudinal direction in which the nozzle injection port opens on the inner surface of the combustion chamber, In the method for controlling combustion of a tubular flame burner in which the injection direction of each nozzle is substantially coincident with the tangential direction of the circumferential surface of the combustion chamber, an open / close valve is provided in the supply pipe connected to each nozzle, and the combustion load of the tubular flame burner is set. The tubular valve is characterized in that the on-off valve is controlled to open and close so that the injection speed from each nozzle is in a range between an allowable maximum flow rate determined from pressure loss and a minimum flow rate required to form a tubular flame. Flame burner combustion control method. A tubular combustion chamber having an open end, and a plurality of fuel injection nozzles and oxygen-containing gas injection nozzles in a circumferential direction and / or a longitudinal direction in which nozzle nozzles are opened on the inner surface of the combustion chamber, each fuel injection A tubular flame burner in which the injection direction of the nozzle for injecting oxygen and the nozzle for injecting the oxygen-containing gas substantially coincides with the tangential direction of the peripheral surface of the combustion chamber, an on-off valve provided in a supply pipe connected to each nozzle, Control that opens and closes the on-off valve so that the injection speed from each nozzle is in a range between the maximum allowable flow rate determined from the pressure loss and the minimum flow rate required to form the tubular flame according to the combustion load. Means for controlling the combustion of a tubular flame burner. A tubular combustion chamber having an open end, and a nozzle for injecting a premixed gas composed of a plurality of fuel gases and oxygen-containing gas in the circumferential direction and / or longitudinal direction in which the nozzle injection port opens on the inner surface of the combustion chamber, A tubular flame burner in which the injection direction of each nozzle substantially coincides with the tangential direction of the circumferential surface of the combustion chamber, an on-off valve provided in a supply pipe connected to each nozzle, and the combustion load of the tubular flame burner, Control means for controlling opening and closing of the on-off valve so that the injection speed from the nozzle is within a range of an allowable maximum flow rate determined from pressure loss and a minimum flow rate required to form a tubular flame . A combustion control device for a tubular flame burner, characterized in that:

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