JPH09159149A - Heat accumulative burner, its combustion method and its combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion system in which a heat accumulative type burner is provided with some heat accumulative members having different heat-resistant temperatures and a temperature of each of the heat accumulative members can be controlled in compliance with a heat accumulative member having a low heat-resistant temperature. SOLUTION: This heat accumulative burner 1 is made such that a burner tile 4 is provided with an air nozzle 5 and a fuel nozzle 6 opened at a heating furnace side, heat accumulative members 13, 14 of multi-layers are stored in a heat accumulative member storing container 3 connected to the air nozzle 5, the fuel nozzle 6 is provided with a fuel shielding valve 7, one of pipes 12 is provided with a combustion air shielding valve 8, the other of the pipes is provided with a combustion discharged gas shielding valve 9, and a thermometer 15 is arranged between the heat accumulative members 13, 14. Then, a detected output of the thermometer 15 is inputted to a control device 16, they are compared and calculated to each other, and a fuel shielding valve 7, a combustion air shielding valve 8 and a combustion discharged gas shielding valve 9 are controlled in response to a control output of the control device 16 so as to prevent the value from exceeding the heat-resistant temperature of the heat accumulative member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative burner, a combustion method therefor, and a combustion apparatus therefor, and more particularly to a regenerative burner equipped with a multi-stage regenerator, in which the temperature due to the accumulation of sensible heat of combustion exhaust gas The present invention relates to a heat storage type burner that does not exceed the heat resistant temperature of a body, its combustion method, and its combustion device.

[0002]

2. Description of the Related Art FIG. 7 shows an example of a conventional regenerative burner. Explaining with reference to the figure, the regenerative burner 1
In the burner tile 4, the air nozzle 5 and the fuel nozzle 6 are opened to the heating furnace 2 side, the air nozzle 5 is connected to the heat storage container 3, and the heat storage container 3 is provided with a honeycomb thin tube. The heat storage body 10 is stored. A flow passage 1 a communicating with the air nozzle 5 is formed in one of the heat storage container 3, and a flow passage 1 b is formed in the other, and the flow passage 1 b is connected to the pipe 12. The pipe 12 is branched and provided with a combustion air cutoff valve 8 on one side and a combustion exhaust gas cutoff valve 9 on the other side. The fuel nozzle 6 is provided with a fuel cutoff valve 7. A thermometer 11 is arranged in the flow path 1b. A burner tile 4 of a heat storage type burner is provided on the furnace wall of the heating furnace 2, and usually the heating furnace 2 is equipped with at least a pair of heat storage type burners. The pair of regenerative burners are controlled so that the combustion operation and the combustion exhaust gas discharging operation are alternately repeated at a preset cycle to perform alternating combustion.

During the combustion operation of the regenerative burner, the fuel cutoff valve 7 is opened, fuel is injected from the fuel nozzle 6 into the heating furnace 2, the combustion air cutoff valve 8 is opened, and the combustion exhaust gas cutoff valve 9 is closed. After being set to the state, the combustion air is preheated by the heat storage body 10 and ejected into the heating furnace 2 to be mixed with fuel and burned. On the other hand, in the combustion exhaust gas discharge operation period, the fuel cutoff valve 7 and the combustion air cutoff valve 8 are closed and the combustion exhaust gas cutoff valve 9 is set to the open state, and the combustion blower gas is sucked out of the furnace by the exhaust blower and discharged. doing. When the combustion exhaust gas in the furnace is sucked and discharged by the exhaust blower, the combustion exhaust gas flows into the heat storage body 10, and the sensible heat of the combustion exhaust gas is stored in the heat storage body 10. The combustion operation (preheating of combustion air) and the discharge operation of combustion exhaust gas (accumulation of sensible heat of combustion exhaust gas in the heat storage body) are performed in a preset cycle, for example, 3
It is repeated alternately at intervals of 0 seconds to 2 minutes.

Next, referring to FIG. 8, the combustion state of the heating furnace equipped with the regenerative burner will be described with reference to FIG. The horizontal axis of FIG. 8 represents time and the vertical axis represents temperature. In FIG. 8, a regenerative burner 1 having a combustion capacity of 800,000 KCal / h is installed in a heating furnace 2, and the calorific value is 2700 Kc.
It shows the temperature change when the fuel of al / Nm ³ is burned. In the figure, the temperature change on the flow passage 1a side (high temperature side) of the heat storage type burner 1 is shown, and the flow passage 1b of the heat storage type burner 1 is shown.
The temperature change on the side (low temperature side) is shown. Indicates the furnace temperature. The regenerator 10 of the regenerative burner 1 used in this heating furnace 2 has a cross-sectional area of about 0.3 m ² and a height of about 0.4 m ² .
m.

As is apparent from this figure, the average temperature on the high temperature side of the heat storage body 10 is the temperature inside the furnace shown in (about 1230).
C.), which is slightly lower by about 50.degree. C. (about 1180.degree. C.), and the fluctuation range of the temperature is about 30.degree. On the other hand, the average temperature on the low temperature side of the heat storage body 10 is about 200 ° C., and the fluctuation range of the temperature is about 100 ° C. Thus, the temperature difference between the high temperature side and the low temperature side of the heat storage body 10 is about 980 ° C. Therefore, since the high temperature side of the heat storage body 10 has a value close to the maximum furnace temperature of the heating furnace, a heat resistant material that can withstand this temperature is used, and it is necessary that it can withstand a temperature difference of about 980 ° C. There is. Also, in the actual heating furnace operation,
A thermometer 11 is provided in the flow path 1b of the heat storage type burner 1, and the temperature measurement value is observed to control the heat storage body temperature so as not to exceed the heat resistant temperature of the combustion exhaust gas cutoff valve 9.

[0006]

In the conventional regenerative burner, the material of the regenerator needs to be made of a heat-resistant material capable of withstanding the maximum temperature of the heating furnace, and an expensive material is required. There was a drawback that the capital investment was expensive. From such a viewpoint, the heat storage body is divided and the heat storage body on the low temperature side is made of a heat storage material made of an inexpensive material and having a low heat resistant temperature to reduce the manufacturing cost. On the other hand, a heat storage material having a low heat resistant temperature is formed of a material that cannot withstand a high temperature close to the temperature inside the furnace on the high temperature side. Therefore, in the actual operation of the heating furnace, the temperature of the combustion exhaust gas discharged from the heat storage body is measured so as not to exceed the heat resistant temperature of the heat storage body and the combustion exhaust gas cutoff valve, and the measured value is a preset value. The combustion exhaust gas is sucked in and discharged to the outside of the furnace.

However, if the temperature in the heating furnace changes, the temperature inside the furnace of the heat storage material fluctuates greatly, and the deviation from the furnace temperature increases. However, even though the temperature inside the heating furnace is rising, the temperature on the heat storage body outlet side of the combustion exhaust gas is adjusted to a preset temperature, so that the heat exchange efficiency of the heating furnace is substantially reduced. There are drawbacks. Also, if the heat storage body is concerned about melting due to the accumulation of sensible heat of the combustion exhaust gas and the temperature of the heat storage body is set to a low temperature, water, sulfur content, etc. contained in the combustion exhaust gas are condensed, and so-called drain is generated. It has the drawback of corroding equipment. Therefore, it is necessary to control the temperature so that it does not exceed the heat resistant temperature of the heat storage body and does not lower the heat exchange efficiency of the heating furnace. Further, the temperature must be set to a temperature at which the drainage does not occur in the heat storage body or the pipe.

The present invention has been made in view of the above problems, and a heat storage type burner is provided with heat storage bodies having different heat-resistant temperatures, and the heat storage body temperature can be controlled in accordance with the heat storage body having a low heat-resistant temperature. An object of the present invention is to provide a burner, a combustion method thereof, and a combustion apparatus thereof. Further, the present invention does not reduce the heat exchange efficiency of the heating furnace, and the temperature of the combustion exhaust gas passing through the heat storage body is equal to or lower than the heat resistant temperature of the heat storage body and is equal to or higher than the temperature at which the drainage does not occur in the heat storage body or the pipe. An object of the present invention is to provide a heat storage type burner capable of controlling combustion exhaust gas discharge, its combustion method and its combustion device.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and provides a combustion method for a regenerative burner having a multistage regenerator according to claim 1.
The multi-stage heat storage body comprises a first heat storage body having a high heat resistant temperature and a second heat storage body having a low heat resistant temperature, and the temperature detecting means has the first heat storage means.
A heat storage type burner provided between the heat storage body and the second heat storage body, wherein the temperature detection means is arranged between the high temperature heat resistant heat storage body and the low temperature heat resistant heat storage body to generate combustion exhaust gas. It is a regenerative burner that can be controlled so that the heat storage body for low temperature heat resistance does not melt due to the heat generated by the accumulation of sensible heat.

Further, according to a second aspect of the present invention, in a regenerative burner including a multi-stage heat storage body, a temperature detection means for measuring a temperature between the multi-stage heat storage bodies is provided, and an output of the temperature detection means. Is a combustion method of a regenerative burner characterized by controlling the suction flow rate and / or the suction time of the flue gas during the flue gas discharge operation of the regenerative burner that performs alternating combustion based on By controlling the suction flow rate and / or suction time of the combustion exhaust gas during the discharge period, the amount of sensible heat of the combustion exhaust gas accumulated in the heat storage body is controlled, the internal temperature of the heat storage body is controlled, and melting of the heat storage body is prevented. In addition, the combustion exhaust gas cutoff valve is prevented from thermal destruction.

According to the third aspect of the present invention, the regenerative burner comprises a multi-stage regenerator, an air nozzle opened to the burner tile, a fuel nozzle, and temperature detecting means installed between the regenerators. A fuel cutoff valve for supplying fuel to the fuel nozzle, a combustion air cutoff valve for supplying combustion air to the air nozzle, a combustion exhaust gas cutoff valve for discharging combustion exhaust gas, and a combustion exhaust gas outside the furnace via the heat storage body In the combustion method of the regenerative burner, which comprises a combustion exhaust gas suction means for discharging, an air supply means for supplying preheated air to the air nozzle through the heat storage body, and a control means, based on the control means, The fuel cutoff valve and the combustion air cutoff valve are closed, the combustion exhaust gas cutoff valve is opened, and the heat storage burner is set to the discharge operation state of the combustion exhaust gas, and the inside of the heat storage body of the heat storage burner is set. In a combustion method for a regenerative burner, the suction flow rate and / or the suction time of the combustion exhaust gas passing through the heat storage body is adjusted by the combustion exhaust gas suction means so that the degree is within a preset temperature range. Yes, the sensible heat accumulation amount of the combustion exhaust gas accumulated in the heat storage body is controlled, and the sensible heat accumulation amount of the combustion exhaust gas accumulated in the heat storage body is changed by changing the combustion exhaust gas discharge operation period or the discharge flow rate. Since the accumulation time is controlled and it is possible to cope with a sharp change in the temperature inside the furnace, it is possible to prevent melting of the heat storage body and prevent thermal destruction of the combustion exhaust gas cutoff valve.

The invention described in claim 4 is the same as the invention described in claim 3.
In the combustion method of the regenerative burner described in (1), the temperature (T ₁₅ ) at the position where the temperature detecting means is arranged satisfies the following equation.

T _S ≧ T ₁₅ ≧ (T _S −X) where T _S : heat-resistant temperature of heat storage body T ₁₅ : heat storage body temperature X: control range of heat storage body internal temperature

According to the fourth aspect of the present invention, the maximum allowable temperature of the internal temperature of the heat storage body is set, and the internal temperature of the heat storage body is controlled so as to be within a preset temperature range. It is possible to prevent the heat storage body from melting without reducing the heat exchange efficiency of the furnace.

According to a fifth aspect of the present invention, in a combustion device of a regenerative burner having a multistage regenerator, combustion switching control for alternately switching a combustion operation period and a flue gas discharge operation period of the heat storage burner. Means, a temperature detecting means arranged between the multi-stage heat storage bodies, a combustion exhaust gas suction means for sucking combustion exhaust gas outside the furnace, and a temperature (T ₁₅ ) detected by the temperature detection means as a heat resistant temperature of the heat storage body. And a temperature difference comparison means for comparing with the minimum set temperature, and a control means for controlling the combustion exhaust gas suction means based on the temperature difference comparison means to control the suction flow rate and / or suction time of the combustion exhaust gas. It is a combustion device of a regenerative burner characterized by being provided, and the amount of sensible heat and / or the storage time of sensible heat of the combustion exhaust gas stored inside the heat storage body are controlled.

The invention according to claim 6 is the same as that of claim 4
In the combustion apparatus of the heat storage type burner provided with the multi-stage heat storage body described in [1], the temperature difference comparison means is means for performing arithmetic processing of the following equation.

T _S ≧ T ₁₅ ≧ (T _S −X) where T _S : heat resistant temperature of the heat storage body T ₁₅ : heat storage body temperature X: control range of the heat storage body internal temperature

According to the sixth aspect of the present invention, the maximum temperature of the internal temperature of the heat storage body is set to a permissible range, and the internal temperature of the heat storage body is controlled so as to be within a preset temperature range. It is possible to prevent the heat storage body from melting without reducing the heat exchange efficiency of the furnace.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing the outline of a heat storage type burner and its combustion device according to the present invention. Referring to FIG. 1, the regenerative burner 1 has an air nozzle 5 and a fuel nozzle 6 provided in a burner tile 4 which are open to the inside of a heating furnace, and the air nozzle 5 is connected to a heat storage container 3 to store a heat storage container. 3, heat storage bodies 13 and 14 provided with honeycomb thin tubes are stacked and stored in multiple stages. A channel 1a communicating with the air nozzle 5 is formed in one of the heat storage container 3, and a pipe 12 is connected to the other channel 1b. The pipe 12 is branched and provided with a combustion air cutoff valve 8 on one side and a combustion exhaust gas cutoff valve 9 on the other side. The fuel nozzle 6 is provided with a fuel cutoff valve 7.
A thermometer 15 is provided between the heat storage bodies 13 and 14. A burner tile 4 is mounted on the furnace wall of the heating furnace 2, and the heating furnace 2 is equipped with at least a pair of regenerative burners. The heat storage body 13 is made of alumina, mullite, SiC,
A high heat resistant material having a high heat resistant temperature such as a mixture of alumina and titanium oxide is used, and the heat storage body 14 is formed of a heat resistant material such as alumina, mullite or cordierite. The heat storage body 14 is made of a material having lower heat resistance than the heat storage body 13.

In this heat storage type burner, the temperature of the heat storage body is measured by a thermometer 15 provided between the heat storage bodies 13 and 14. That is, the temperature of the hottest part of the heat storage body 14 is detected. The detection output of the thermometer 15 is input to the control device 16. In the control device 16, the heat storage body temperature is subjected to comparison calculation processing, and the combustion exhaust gas cutoff valve 9 is based on the output result.
The opening and closing of the exhaust gas and the flow rate of the combustion exhaust gas are controlled to prevent the heat storage body 14 from melting due to the accumulation of the sensible heat of the combustion exhaust gas. The control device 16 mainly has a control means for allowing the regenerative burner to alternately switch the combustion operation and the combustion exhaust gas discharge operation at a predetermined cycle. Further, the control device 16 controls the heat storage body temperature by detecting the heat storage body temperature and controlling the combustion exhaust gas flow rate while keeping the combustion exhaust gas discharge operation period constant. Further, as another method of controlling the heat storage body temperature, the heat storage body temperature is controlled by controlling the time during which the combustion exhaust gas discharge operation is performed while keeping the suction flow rate of the combustion exhaust gas constant based on the output of the thermometer 15 (heat storage body temperature). To do. Further, as another method of controlling the heat storage body temperature, the heat storage body temperature is controlled by controlling the suction flow rate of the combustion exhaust gas and the suction time of the combustion exhaust gas. The details of the control of the heat storage body temperature will be described below.

Next, with reference to FIG. 2, a combustion system of a heat storage type burner including a piping system of the heat storage type burner and its control system will be described. 2 shows a pair of regenerative burners installed in the heating furnace, and the regenerative burner has a bent flow path for combustion air and the like, but it is substantially the same as the regenerative burner of FIG. Is. In the figure, the heating furnace 2
Of the heat storage type burner 1a is provided with a fuel cutoff valve 7a, and one of the pipes branched from the pipe 12a is provided with a combustion air cutoff valve 8a. A combustion exhaust gas cutoff valve 9a is provided in the other pipe. Heat storage body 13a,
A thermometer 15a is provided between 14a. Similarly, for the regenerative burner 1b, the fuel nozzle 6b is provided with a fuel cutoff valve 7b, one pipe branched from the pipe 12b is provided with a combustion air cutoff valve 8b, and the other pipe is provided with a combustion exhaust gas cutoff valve 9b. A thermometer 15b is provided between the heat storage bodies 13b and 14b. Thermometer 15a, 15
The detection output of b is input to the control device 16. It should be noted that P indicates an object to be heated such as a steel plate in the heating furnace 2, and F indicates a flame.

The detection outputs of the thermometers 15a and 15b are input to the control device 16 and processed. A comparison calculation process is performed to determine whether or not the maximum temperature of the heat storage body temperature is equal to or lower than the heat resistant temperature of the heat storage bodies 14a and 14b and is within a temperature range in which drainage does not occur. The combustion exhaust gas suction flow rate and / or the combustion exhaust gas suction time in the alternating combustion period are controlled based on the comparison calculation processing result. The control device 16 stores a control program for alternating combustion of the pair of regenerative burners 1a and 1b and a control program for controlling the temperature of the regenerator in the storage device of the control device 16.

Further, the combustion operation (preheating) and the combustion exhaust gas discharging operation (heat storage operation) by the alternating combustion of the heat storage type burner will be described in detail with reference to FIG. This alternating combustion is performed under the control of the control device 16. In the figure,
The regenerative burner 1a is in a combustion operation state, opens the fuel cutoff valve 7a, injects fuel from the fuel nozzle 6a into the heating furnace 2, simultaneously opens the combustion air cutoff valve 8a, and closes the combustion exhaust gas cutoff valve 9a. The combustion air is preheated by the heat storage bodies 13a and 14a, jetted into the heating furnace 2, mixed with fuel, and burned. On the other hand, the regenerative burner 1b is in a combustion exhaust gas discharge operation period, the combustion cutoff valve 7b and the combustion air cutoff valve 8b are closed, and the combustion exhaust gas cutoff valve 9b is opened.
The exhaust blower 17 sucks the combustion exhaust gas outside the furnace. When the combustion exhaust gas in the furnace is sucked by the exhaust blower 17, the combustion exhaust gas passes through the heat storage bodies 13b and 14b through the air nozzle 5b, and the sensible heat of the combustion exhaust gas is stored in the heat storage bodies 13b and 14b. . The heat stored in the heat storage body depends on the suction flow rate and / or the suction time of the combustion exhaust gas. The cycle of this combustion operation and the combustion exhaust gas discharge operation is alternately repeated, for example, for 30 seconds to 2 minutes.

The function of the combustion apparatus of the regenerative burner shown in FIG. 2 can be shown by the functional block diagram shown in FIG. In FIG. 3, the control device 16 includes a combustion switching means a for alternating combustion of the regenerative burner, a temperature difference comparison means b for obtaining an output for controlling the temperature of the regenerator, a combustion exhaust gas suction flow rate setting means c, and a switching operation. A time setting means (suction time setting) d is provided. The storage device 19 is loaded with the allowable temperature range (X) of the heat resistant temperature (T _S ) of the heat storage body and the heat storage body temperature (T ₁₅ ). The storage device 19 may be either an internal storage device or an external storage device.

An operation start signal from the combustion start signal input means 20 is caused by the combustion switching means a to cause the regenerative burner 1 to start combustion. The output from the temperature detection means (thermometer) 15 is input to the temperature difference comparison means b, and the temperature difference comparison means b
The arithmetic processing shown in the following formula is being performed. (T _S ) ≧ (T ₁₅ ) ≧ (T _S −X) (1) where T _S : heat-resistant temperature of heat storage body T ₁₅ : heat storage body temperature X: allowable temperature range of heat storage body

When the heat storage temperature (T _S ) exceeds the range of the expression (1) by the temperature difference comparison means b, the combustion exhaust gas suction flow rate setting means c and / or the switching time setting means d are used to draw the combustion exhaust gas suction. The heat storage body temperature (T ₁₅ ) is adjusted by adjusting the means (exhaust blower) 17 or the exhaust gas cutoff valves 9a, 9b to control the suction time and / or the suction amount of the combustion exhaust gas. Details of the control of the heat storage body temperature will be described below.

Next, regarding the combustion method of the regenerative burner,
Description will be made with reference to the flowchart of FIG. 4, the above embodiment, and the functional block diagram of FIG. In FIG. 4, in step S1, the heat-resistant temperature (T _S ) of the heat storage body and the control range X of the heat storage body temperature are input from the key 20 and written in the storage device 19. X is the allowable range of the maximum temperature of the heat storage body. When the input of step S1 is completed, the process proceeds to step S2, the alternating combustion of the regenerative burner is started, and the steady operation is started. Then, it progresses to step S3, measures the heat storage body temperature (T ₁₅ ) of the heat storage type burner, and proceeds to step S4. In step S4, comparison calculation processing means [T _S ≧ T ₁₅ ].
The heat storage body temperature (T ₁₅ ) and the heat resistant temperature of the heat storage body (T _S ).
The temperature of the heat storage body (T ₁₅ ) exceeds the heat-resistant temperature (T _S ) of the heat storage body, and the temperature of the heat storage body (T ₁₅ ) is determined.
_{If 15} ) exceeds the heat-resistant temperature (T _S ) of the heat storage body,
In step S6, the combustion exhaust gas suction means (exhaust blower) 17 is controlled.

Control by the combustion exhaust gas suction means (exhaust blower) 17 is performed when the combustion exhaust gas suction time is constant and the combustion exhaust gas suction flow rate is changed, and when the combustion exhaust gas suction flow rate is constant and the combustion exhaust gas suction time is changed. In some cases, both the combustion exhaust gas suction time and the variable combustion exhaust gas suction flow rate are controlled. After any of these control methods is performed, the process proceeds to step S3. If step S4 is satisfied, the process proceeds to step S5. In step S5, it is determined by comparison calculation processing [T ₁₅ ≧ (T _S −X)] whether the heat storage body temperature (T ₁₅ ) is equal to or higher than the allowable minimum temperature (T _S −X). It Heat storage temperature (T ₁₅ )
Is less than (T _S −X), step S6
In step S3, the control described above is performed and step S3 follows. In step S5, (T ₁₅ ) ≧ (T _S
-X) is satisfied, that is, steps S4 and S
5, the condition of the formula (1) [(T _S ) ≧ (T ₁₅ ) ≧
If (T _S −X)] is satisfied, the process proceeds to step S7. In step S7, it is determined whether or not to continue the combustion in the heating furnace. If the combustion is to be continued, the process proceeds to step S3 and the same operation is performed. If it does not continue, the process moves to the control program for ending the combustion control of the heating furnace. By controlling in this way, the heat storage body is controlled so as not to exceed the heat resistant temperature, and the temperature is controlled so that drainage does not occur.

Next, with reference to FIG. 5, a method for controlling the temperature of the regenerator will be specifically described. First, the results of measuring the internal temperature of the heat storage medium under various combustion exhaust gas discharge conditions will be described. 5A to 5C, the horizontal axis represents the flow direction of the combustion exhaust gas and the vertical axis represents the temperature.
The dots in the figure indicate the temperature measurement points of the heat storage body, where is the maximum temperature (when heat storage is completed), and is the minimum temperature (when combustion is completed). Further, (I) shows the heat storage body 13 on the high temperature side (inside the furnace), and (II) shows the heat storage body 14 on the low temperature side (combustion air inlet side). T _S
Indicates the heat resistant temperature of the heat storage body (II) on the low temperature side.

FIG. 5A shows the case where the furnace combustion gas suction amount and the combustion air flow rate are controlled at an appropriate ratio at a furnace temperature of 1300 ° C., and the temperature distribution of the heat storage body shows an S shape. There is. The maximum temperature of the heat storage body (I) on the furnace side of the heat storage body is about 1
250 ± 20 ° C., and the minimum temperature of the heat storage body of the heat storage body (II) is about 220 ± 50 ° C. The temperature at the boundary between the heat storage bodies (I) and (II) is about 1050 to 950 ° C. In this embodiment, the heat-resistant temperature (T _S ) of the heat storage body (II) is 110.
Since it is 0 ° C., the heat storage body (II) does not melt in this state. The preheating air temperature is about 1250 ° C., the heat exchange efficiency of the heating furnace is not deteriorated, the function of the heat storage body can be sufficiently achieved, and the drain does not occur on the low temperature side of the heat storage body.

FIG. 5B shows that the furnace temperature of the heating furnace is 1300.
It shows a case where the flow rate of combustion air is increased by 15% as compared with the amount of combustion exhaust gas suctioned at ℃. In this case, the temperature of the heat storage body does not rise, and the maximum temperature of the heat storage body (I) is about 11
50 ± 50 ° C., and the minimum temperature of the heat storage body of the heat storage body (II) is about 100 ± 20 ° C. The temperature at the boundary between the heat storage bodies (I) and (II) was about 750 to 450 ° C. The boundary temperature is about 750 ° C. and does not reach the melting temperature, but under such conditions, drainage is generated in the low temperature part of the heat storage body, which is not preferable.

FIG. 5C shows that the furnace temperature of the heating furnace is 1300.
The temperature distribution is in the case of increasing the suction amount of combustion exhaust gas in the furnace by about 15% only for a short time as compared with the case of FIG. 5A. In this case, the temperature of the heat storage body is higher in the heat storage body (II) than in the case of (A). The maximum temperature of the heat storage body (I) is about 1270 ± 10 ° C. and tends to rise without converging to a constant value, and the minimum temperature of the heat storage body of the heat storage body (II) is about 375 ± 125 ° C. The temperature at the boundary between the heat storage bodies (I) and (II) is about 1200 to 1
150 ° C. Temperature at which the heat storage body (II) melts (Ts
) Has been reached.

As is apparent from FIGS. 5A to 5C,
It has been found that the temperature variation ΔT at the boundary between the heat storage bodies (I) and (II) is much larger than the change in the temperature of the highest temperature portion and the temperature of the lowest temperature portion. From this result, it can be understood that the position of the thermometer 15 is preferably provided between the heat storage bodies 13 and 14 as shown in FIG. 1 in order to measure the temperature of the heat storage body of the heat storage type burner.

Next, a method of controlling the temperature of the heat storage body will be described based on the result of FIG. (1) With the regenerative burner operated under appropriate conditions,
When the operating conditions are changed to increase the burner combustion load, the flow rates of fuel and combustion air increase, and
As shown in (B), the temperature of the regenerator decreases and the temperature of the preheated combustion air also decreases. In such a combustion state, the heat exchange efficiency may be deteriorated and drain may be generated. In such a case, the temperature of the regenerator is measured by the thermometer 15, the situation is judged by the controller 16, and the combustion exhaust gas suction amount is increased so that the temperature distribution shown in FIG. Then, the combustion exhaust gas cutoff valve 9 and the exhaust blower 17 are commanded and operated to control the temperature distribution of the heat storage body.

(2) When the heat storage type burner is operated under appropriate conditions and the operating conditions are changed so as to reduce the burner combustion load, the flow rates of fuel and combustion air decrease, and FIG. As shown in (C), the heat storage body temperature rises. In such a combustion state, the heat storage body may melt. Therefore, the temperature of the regenerator is measured by the thermometer 15, the situation is judged by the control device 16, and the combustion exhaust gas cutoff valve is reduced so that the combustion exhaust gas suction amount is reduced so that the temperature distribution shown in FIG. 9 and the exhaust blower 17 are operated to control the temperature distribution of the heat storage body.

(3) If the temperature inside the heating furnace rises while the regenerative burner is operated under appropriate conditions, the temperature of the regenerator may rise and the regenerator may melt. In such a combustion state, the thermometer 15 detects an increase in the temperature of the heat storage body, and the control device 16 performs an operation of reducing the suction amount of the combustion exhaust gas so as to approach FIG. 5 (A). The blower 17 is instructed and operated to control the temperature distribution of the heat storage body.

In each of the combustion methods of the regenerative burner in the above embodiments, the temperature inside the regenerator is measured by the thermometer 15, the temperature of the regenerator is detected, and the combustion exhaust gas suction amount is detected based on the controller 16. By operating the combustion exhaust gas cutoff valve 9 and the exhaust blower 17 to increase / decrease, the heat storage temperature distribution is improved. However, such a control method is effective when the change in the regenerator temperature measured by the thermometer is slow, but when the change in the regenerator temperature is steep, the response of the temperature control of the regenerator is responsive. Becomes worse. In such a case, the response characteristics are improved by simultaneously increasing or decreasing the combustion exhaust gas suction time in addition to increasing or decreasing the combustion exhaust gas flow rate. For example, it is performed by the equation (2). That is, the heat storage body temperature can be controlled by controlling the exhaust gas flow rate for discharging the combustion exhaust gas and adjusting the operation time (t *) of the exhaust blower to control the suction time. Operating time of this discharge blower (t
*) Is equal to the combustion exhaust gas discharge time in alternating combustion.
That is, the time required to change the heat storage body temperature by ΔQ is
The time (to-t *) is the adjusted time Δt.

T * = α · to · (Q + ΔQ) / Q (2) However, Q: Reference combustion exhaust gas suction amount [Nm ³ /
h] ΔQ: Increase / decrease amount of combustion exhaust gas [Nm ³ / h] to: Reference combustion exhaust gas suction time [h] t *: Changed combustion exhaust gas suction time [h] α: Coefficient for adjusting control gain

Further, the present embodiment is not limited to the heat storage type burner shown in FIG. 1, and may be the heat storage type burner shown in FIG. This will be described with reference to FIG. In FIG. 6, the same parts as those in FIG. 1 are designated by the same reference numerals. In the same figure, in the heat storage type burner 1, the heat storage bodies 13 and 14 are housed in the heat storage body storage container 3, and the thermometer 15 is provided between the heat storage bodies 13 and 14, as in the above embodiment, and the thermometer 15 The temperature of the regenerator is measured by. One end of the pipe 12 is connected to the regenerative burner 1, and the other end thereof is connected to the switching valve 18. The piping of the other regenerative burner is connected to the switching valve 18, and the exhaust blower 19 of the combustion exhaust gas exhaust system and the blower blower 20 of the combustion air supply system are connected. In FIG. 6, the combustion exhaust gas is discharged from the blower 1 through the regenerative burner 1.
9 shows the state of being discharged to the outside of the furnace via 9 and the combustion exhaust gas is sucked by the exhaust blower 19 through the flow passage 1b of the heat storage container 3, the pipe 12 and the switching valve 18 and discharged to the outside of the furnace. Has been done.

The detection output of the heat storage temperature of the thermometer 15 is input to the control device 16. The control device 16, as in the above example, is within the range of the allowable minimum temperature (T _S -X) a control program and the regenerator temperature from the heat-resistant temperature of the heat storage body (T _S) for the alternate combustion operation It is determined whether or not. In the control device 16, as in the above-described embodiment, the thermometer 1
According to the detection output of No. 5, the suction flow rate of the combustion exhaust gas and / or the discharge operation time are controlled, and the heat storage body temperature is controlled. That is, based on the control output from the control device 16, the switching valve 18 and the exhaust blower 19 are operated to control the suction time and the suction flow rate of the combustion exhaust gas, and the heat storage body temperature is controlled.

In the above embodiment, the heat storage body has a multi-layered structure with two heat storage bodies, but it is clear that the heat storage body may have three or more heat storage bodies. Further, a plurality of fuel nozzles of the regenerative burner may be provided.

[0042]

As described above, according to the present invention,
Since the heat storage body temperature distribution is appropriately maintained and the heat storage body having a low heat resistant temperature can be prevented from melting, there is an advantage that a heat storage type burner provided with an inexpensive heat storage body and a combustion device therefor can be provided. Further, according to the present invention, even if the combustion conditions of the heating furnace and the temperature inside the heating furnace are changed, the temperature between the heat accumulators of the multi-layer structure is measured, so that the temperature distribution is controlled to an appropriate temperature distribution. Even if the temperature changes, there is an advantage that the deviation between the preheated air temperature and the furnace temperature obtained can be minimized, and the heat exchange efficiency of the heating furnace is not deteriorated. That is, it is possible to operate the heating furnace in a stable manner, eliminate the failure of the regenerative burner, and significantly reduce the maintenance cost. Further, according to the present invention, there is an advantage that a cheaper material can be selected as the material of the heat storage body on the low temperature side, and there is an effect that an increase in cost of the heat storage type burner or the combustion equipment can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a regenerative burner and its combustion device according to the present invention.

FIG. 2 is a diagram showing another embodiment of the regenerative burner and its combustion device according to the present invention.

FIG. 3 is a functional block diagram of a combustion device for a regenerative burner according to the present invention.

FIG. 4 is a control flowchart of a combustion device of a heat storage type burner.

FIG. 5 is a diagram showing a temperature distribution characteristic of a heat storage body.

FIG. 6 is a view showing another embodiment of the combustion apparatus for the regenerative burner according to the present invention.

FIG. 7 is a diagram showing an example of a combustion method of a heat storage type burner of a conventional example and an example of a combustion apparatus thereof.

FIG. 8 is a diagram showing a combustion state of a heat storage type burner.

[Explanation of symbols]

 1 Heat Storage Burner 1a Flow Path (1b) 2 Heating Furnace 3 Heat Storage Container 4 Burner Tile 5 Air Nozzle 6 Fuel Nozzle 7 Fuel Cutoff Valve 8 Combustion Air Cutoff Valve 9 Combustion Exhaust Cutoff Valve 12 Piping 13 Heat Storage on High Temperature Side 14 Low temperature side heat storage body 15 Thermometer (temperature measuring means) 16 Control device (control means) 17 Exhaust blower (combustion exhaust gas suction means) 18 Switching valve 19 Exhaust blower (combustion exhaust gas suction means) 20 Blower blower

Claims (6)

[Claims] 1. A combustion method of a heat storage type burner comprising a multi-stage heat storage body, wherein the multi-stage heat storage body comprises a first heat storage body having a high heat resistant temperature and a second heat storage body having a low heat resistant temperature, and a temperature detecting means. Is the first
A regenerative burner provided between the regenerator and the second regenerator. 2. A combustion method of a heat storage type burner having a multi-stage heat storage body, comprising temperature detection means for measuring a temperature between the multi-stage heat storage bodies, and alternating combustion based on an output of the temperature detection means. Combustion method of a heat storage type burner, characterized in that a suction flow rate and / or a suction time of the combustion exhaust gas during the combustion exhaust gas discharging operation of the heat storage type burner are controlled. 3. A regenerative burner includes a multi-stage regenerator, an air nozzle opened in the burner tile, a fuel nozzle, and temperature detection means installed between the regenerators, and
A fuel cutoff valve for supplying fuel to the fuel nozzle, a combustion air cutoff valve for supplying combustion air to the air nozzle, a combustion exhaust gas cutoff valve for discharging combustion exhaust gas, and a combustion exhaust gas discharged to the outside of the furnace through the heat storage body. A combustion method for a regenerative burner comprising a combustion exhaust gas suction means, an air supply means for supplying preheated air to the air nozzle through the heat storage body, and a control means, wherein the fuel cutoff is based on the control means. The valve and the combustion air cutoff valve are closed, the combustion exhaust gas cutoff valve is opened, and the heat storage burner is set to the discharge operation state of the combustion exhaust gas, and the internal temperature of the heat storage body of the heat storage burner falls within a preset temperature range. As described above, the combustion flow rate of the combustion exhaust gas passing through the heat storage body and / or the suction time of the combustion exhaust gas are adjusted by the combustion exhaust gas suction means. . 4. The combustion method for a regenerative burner according to claim 3, wherein the temperature (T ₁₅ ) at the position where the temperature detecting means is arranged satisfies the following equation: Burner burning method. T _S ≧ T ₁₅ ≧ (T _S −X) where T _S : heat-resistant temperature of heat storage body T ₁₅ : heat storage body temperature X: control range of heat storage body temperature 5. In a combustion device of a heat storage type burner having a multi-stage heat storage body, combustion switching control means for alternately switching between a combustion operation period and a combustion exhaust gas discharge operation period of the heat storage type burner, and between the multi-stage heat storage bodies. Temperature detecting means disposed in the furnace, combustion exhaust gas sucking means for sucking combustion exhaust gas to the outside of the furnace, and a temperature difference for comparing the temperature (T ₁₅ ) detected by the temperature detecting means with the heat resistant temperature of the heat storage body and the minimum set temperature. A heat storage burner, comprising: a comparison unit; and a control unit that controls the combustion exhaust gas suction unit based on the temperature difference comparison unit to control the combustion exhaust gas suction flow rate and / or suction time. Combustion device. 6. A combustion apparatus for a regenerative burner comprising a multi-stage regenerator according to claim 5, wherein the temperature difference comparison means is a means for computing the following equation. Combustion device. T _S ≧ T ₁₅ ≧ (T _S −X) where T _S : heat-resistant temperature of heat storage body T ₁₅ : heat storage body temperature X: control range of heat storage body temperature