KR100304240B1 - Regenerative regenerative burner system and its operation method - Google Patents

Abstract

Fuel nozzles 7 and 71 are provided between the two flow paths 5a and 5b or 5a 'and 5b', and the flow paths 5a and 5b and 5a 'and 5' are respectively stored in the heat accumulators 9a and 5b. 9b) fuel nozzles 7 and 7 'are continuously supplied to two burners 1 and 1' connected to 9a 'and 9b', and each burner 1 and 1 'is at least Combustion air is supplied to either of the flow paths 5a or 5b, 5a 'or 5b' to continuously burn the combustion state to the respective burners 1 and 1 ', and also to flow paths 5a and 5b. , 5a 'and 5b') exhaust the exhaust gas in the furnace and repeat the heat storage and air preheating.

The burners 1 and 1 'are always kept in a combustion state, and exhaust gas in the furnace is exhausted from at least one of the flow paths 5a, 5b, 5a', and 5b ', so that the pressure in the furnace and the oxygen concentration in the furnace are kept constant. It is possible.

Description

Regenerative Regenerative Burner System and Its Operation Method

1 is a cross-sectional view of the burner.

2 is a front view of the burner.

3 is a configuration diagram of a regenerative burner system.

4 is an explanatory diagram of a burner system operating method.

5 is another explanatory diagram of a burner system operating method.

6 is an explanatory view of the opening and closing operation of the on-off valve.

7 is a configuration diagram of a conventional regenerative burner system.

8 is a view showing an operating state of a conventional regenerative burner system.

* Explanation of symbols for main parts of the drawings

1, 1 ': burner 2: burner body

3: primary combustion tile 5a, 5b: flow path

6a, 6b: hole 7: fuel nozzle

8a, 8b: connector 9a, 9b: heat storage

10a, 10b: heat storage body 11: fuel control valve

12: fuel supply device 13a, 13b, 14a, 14b, 17a, 17b: on-off valve

15: air control valve 16: air supply fan (combustion air supply device)

18: exhaust gas control valve 19: exhaust pen (exhaust device)

The present invention relates to a regenerative regenerative burner system for recovering heat of furnace exhaust gas and preheating combustion air, and a method of operating the same.

As the heat storage regenerative burner system, a conventional one shown in FIG. 7 is known.

This regenerative regenerative burner system is equipped with four burners 20a-20d in a unit system, and the fuel nozzles 21a-21d of each burner 20a-20d are each an on-off valve. It is connected to the fuel supply apparatus 24 via 22a-22d and the fuel control valve 23, and the flow paths 25a-25d are respectively connected to the exit side of the heat accumulators 26a-26d. The heat accumulators 26a to 26d have two entry ports, one of which is connected to the blower 29 via the on / off valves 27a to 27d and the air control valve 28, respectively. The other entry hole is connected to the fan 32 via the on / off valves 30a to 30d and the exhaust gas control valve 31, respectively. Furthermore, the heat storage 26a-26d has the heat storage agent comprised from ceramic etc., respectively.

In the above regenerative regenerative burner system, burners 20a and 20b, burners 20c and 20d operate in pairs, and each burner 20a to 20d operates as shown in Table 1 below. The combustion operation of Mode A and Mode B is repeated every certain time. Moreover, 0 in Table 1 means open state of on-off valve, and × means closed state of on-off valve.

TABLE 1

That is, in the combustion operation of the mode A, the open / close valves 22a and 22c are opened to supply fuel gas to the burners 20a and 20c, and the open / close valves 22b and 22d are closed to stop the supply of fuel gas. In addition, open / close valves 27a and 27c are opened to supply combustion air to burners 20a and 20c, and open / close valves 27b and 27d are closed to supply combustion air to burners 20b and 20d. . In addition, the shutoff valves 30a and 30c are closed to open the shutoff valves 30b and 30d.

Fuel gas and combustion air are supplied to the burners 20a and 20c, and these are injected into the furnace (not shown) and combusted. At this time, the combustion air supplied from the blower 29 is preheated by the heat recovered by the heat storages 26a and 26c at the time of the combustion operation of the mode B, and is supplied to the burners 20a and 20c at a high temperature. . On the other hand, the burners 20b and 20d suck the combustion exhaust gas in the furnace as the fan 32 is driven, and the heat of the exhaust gas is recovered from the heat storages 26b and 26d.

Next, when a predetermined time typically 20 to 120 seconds have elapsed in the state of the mode A, the mode B is switched to the combustion state of the mode B, and the on-off valves 22b and 22d are opened opposite to the state of the mode A to open and close the valve 22a. , 22c) is closed. Moreover, on-off valves 27b and 27d are opened, on-off valves 27a and 27c are closed, on-off valves 30b and 30d are closed, and on-off valves 30a and 30c are opened.

The combustion air supplied from the blower 29 is preheated in the heat storages 26b and 26d, injected into the furnace from the burners 20b and 20d together with the fuel gas, and burned. The exhaust gas in the furnace sucked by the burners 20a and 20c is heat-exchanged by the heat storages 26a and 26c and exhausted.

As described above, in the regenerative regenerative burner system, a pair of burners 20a, 20c, 20b, and 20d are alternately converted into a combustion state and an exhaust state, and the heat recovered at the exhaust is preheated. It can be used to achieve a high efficiency combustion.

However, in the regenerative burner system, the fuel control valve 23 is first closed at the end of combustion, and the air control valve 28 is closed after a predetermined time. At the start of combustion, the air control valve 28 is first opened and the fuel control valve 23 is opened after a predetermined time elapses.

The reason for this is to avoid the state of supplying only the fuel in the furnace as the combustion air precedes the fuel gas at all times.

As a result, as shown in FIG. 8, the oxygen concentration in the furnace temporarily rises at the time of mode switching, resulting in a decrease in energy saving effect or an oxidation loss of the heat treatment material.

In addition, since each burner repeats the combustion state and the non-combustion state, the internal pressure of the furnace increases momentarily with the ignition shock during burner ignition, and in this case, a high temperature atmosphere is released from the furnace opening, There has been a problem that deterioration, heat loss of the component parts occurs, or the air flows into the furnace as the pressure decreases momentarily, resulting in energy loss.

Moreover, at least four burners are required for the operation of the conventional system, and two burners are used for combustion and exhaust gas, resulting in a large number of burners, which are restricted in terms of their attachment and placement, resulting in a cost increase. . In addition, since the switching valve of the fuel gas and its switching control are required, since the equipment is complicated and expensive, high reliability has been required regarding the sealing property of the gas switching valve.

SUMMARY OF THE INVENTION The present invention has been accomplished to solve the above problems, and is a method of operating a regenerative burner system, comprising two burners each having a fuel nozzle between two flow paths and connecting the flow paths to a heat storage device, respectively. In the system in units of, each of the fuel nozzles is continuously supplied with fuel, and each burner supplies combustion air to at least one of the flow paths to continue the combustion state at each burner. The exhaust gas is exhausted from at least one of the flow paths to repeat the heat storage and the air preheating.

The regenerative regenerative burner system of the present application includes two burners each provided with a fuel nozzle between two flow paths, four heat accumulators each provided with two entry holes, a fuel supply device, and combustion air. An advanced device and an exhaust device are provided, and the fuel nozzle is connected to the fuel supply device via a control valve, and the outlet of the heat accumulator is connected to the flow path, respectively, and the inlet on one side of the heat accumulator is connected. Is connected to the combustion air supply device via two combustion air on / off valves and control valves arranged in parallel with each other, and the other opening is connected to the exhaust device via an exhaust gas on / off valve and a control valve. It is in units of.

EXAMPLE

Next, embodiments of the present invention will be described with reference to the accompanying drawings.

1 and 2 show the regenerative regenerative burner 1 (hereinafter referred to as burner 1), and the main body 2 of the burner 1 is composed of known refractory materials. A concave primary combustion tile 3 is formed on the front surface of the main body 2 (opposing part of the furnace), and the fuel nozzle 7 is provided in the nozzle insertion hole 4 provided in the substantially center of the primary combustion tile 93. ) Is inserted. In the main body 2, flow paths 5a and 5b are formed in contact with the front and rear surfaces with the primary combustion tiles interposed therebetween, and these flow paths 5a and 5b and the primary combustion tiles 3 have several holes ( It communicates through 6a ... 6a) and (6b ... 6b).

3 shows a regenerative regenerative burner system (hereinafter referred to as burner system) including two burners 1 and 1 '.

In this burner system, the fuel nozzle 7 of the burner 1 is connected to the fuel supply apparatus 12 via the fuel control valve 11, and the flow paths 5a and 5b are respectively a heat storage body 10a. , 10b) to the exit holes of the heat accumulators 9a and 9b. The heat accumulators 9a and 9b are provided with two entry holes, one entry hole, and one opening hole each having a closing valve 13a, 14a, 13b, and 14b arranged in parallel. Is connected to the air control valve 15 via the air control valve 15 and the air supply fan 16 as the combustion air supply device via the air control valve 15, and the other inlet openings are the on / off valves 17a and 17b, respectively. The exhaust gas control valves 18 are connected to the exhaust fan 19 as an exhaust device via the exhaust gas control valve 18.

Moreover, burner 1 'is connected similarly, About the component connected to burner 1', each code | symbol is attached | subjected with ",", and it distinguishes suitably. An operation method of the burner system configured as described above will also be described with reference to FIGS. 4 to 6.

Moreover, FIG. 4 shows fuel injection amount, air injection amount, exhaust gas exhaust amount, and discharge state and air supply state in each step. The solid line is the supply state of combustion air, the dotted line is the exhaust state of exhaust gas, and the dashed-dotted line. Indicates the state of fuel injection, the arrow pointing to the right side of the drawing indicates the state of injection toward the furnace, and the arrow pointing to the left side of the figure indicates the state of exhaust gas from the furnace to the outside of the furnace. .

5 shows the supply amount of fuel and combustion air and the exhaust amount of exhaust gas, and the solid line shows the supply state and the dotted line shows the exhaust state. 6 shows the open / close state of each open / close valve, 0 has shown the open state, and x has shown the closed state.

The operation method is composed of eight steps, and these eight steps are repeatedly executed. However, the time required for steps 2, 4, 6, and 8 is set shorter than that for steps 1, 3, 5, and 7, and each valve operation is timer-controlled in accordance with a preprogrammed control content.

First, step 1 (S1) is in a normal operation state, and the fuel control valve 11, the air control valve 15, and the exhaust gas control valve 18 are 100% open and are in a rated combustion state. Is set. In addition, the on-off valves 13a, 14a, and 17b are opened to the burner 1, and the on-off valves 17a, 13b, and 14b are closed. In addition, on / off valves 13a ', 14a', and 17b 'are closed with burner 1'.

Accordingly, fuel gas is supplied from the fuel supply device 12 to the fuel nozzles 7 and 7 'of each burner 1 and 1' and injected into the furnace. Moreover, combustion air is supplied from the air supply fan 16 to the flow paths 5a and 5b 'of each burner 1 and 1', and is injected into the flow paths 3 and 3 'so that a part of the combustion air is It is injected into the primary combustion tiles 3 and 3 'from the holes 6a and 6b', stirred and mixed with fuel gas, and primary combustion is performed. Next, the combustion air injected directly from the flow paths 5a and 5b 'is mixed by contact with the fuel gas and secondary combustion is performed. In other words, the fuel gas is burned in two stages to reduce the NOx. Moreover, in the following description, description of this two stage combustion is abbreviate | omitted.

On the other hand, the exhaust gas in the furnace is drawn from the flow paths 5b and 5a 'according to the driving of the exhaust fan 19, and the sucked exhaust gas is exhausted through the heat storages 9b and 9a' and at the same time the exhaust gas is discharged. The heat is lost to the heat accumulators 10b and 10a 'and recovered.

In step 2 (S2), the fuel control valve 11 is tightened to 50% open and at the same time, the air control valve 15 and the exhaust gas control valve 18 are also clamped to 50% open. Switch to non-rated combustion. In addition, the on-off valves 14a and 14b are opened with respect to the burner 1, and the on-off valves 13a, 17a, 13b, and 17b are closed. In addition, for the burner 1 ', each on-off valve is set in the same state as step 1.

Accordingly, in the burner 1, combustion air is supplied to the two flow paths 5a and 5b, respectively, but the supply amount of the combustion air to each of the flow paths 5a and 5b is supplied to the flow path 5a in the first step S1. It is limited to 25% of the air volume, i.e. 50% in total. In burner 1 ', combustion air is supplied only to one flow path 5b', and the supply amount is limited to 50%. Therefore, the supply amount of the combustion gas and the combustion air and the exhaust gas are maintained in equilibrium in an unrated combustion state.

In the burner 1, the fuel gas injected from the fuel nozzle 7 and the combustion air injected from the flow paths 5a and 5b are mixed and burned, and in the burner 1 ', the fuel gas injected from the fuel nozzle 7' is burned. The fuel gas and combustion air injected from the flow path 5b 'are mixed and combusted. At this time, the combustion air supplied to the flow path 5b of the burner 1 is preheated by the heat accumulated in the heat storage agent 10b. The burner 1 'acts on combustion as preheated air by flowing half of the air of step 1 (S1) in the flow path 5b'. It is sucked in the exhaust gas flow path 5a 'of the burner 1,1'.

In step 3 (S3), the fuel control valve 11, the air control valve 15, and the exhaust gas control valve 18 are 100% open and set to the rated combustion state. 17a, 13b, 14b are opened, and opening valves 13a, 14a, 17b are closed. In addition, the on-off valves of the burner 1 are set in the same state as the steps 1 and 2.

In the burner 1, the fuel gas injected from the fuel nozzle 7 and the combustion air injected from the toll 5b are mixed, and in the burner 1 ', the fuel sag injected from the fuel nozzle 7' Combustion air injected from the flow path 5b 'is mixed and combusted. At this time, the heat of the exhaust gas is recovered to the heat storage bodies 10a and 10a ', and the combustion air supplied to the flow paths 5b and 5b' is preheated by the heat accumulated in the heat storage bodies 10b and 10b '.

In step 4 (S4), the fuel control valve 11, the air control valve 15, and the exhaust gas control valve 18 are tightened to 50% open state, respectively, and are set to the non-rated combustion state. On the contrary, each open / close valve is set in the same state as in Step 3 (S3). The on-off valves 14a 'and 14b' are opened to the burner 1 ', and the on-off valves 13a', 17a ', 13b', and 17b 'are closed.

In the burner 1, the fuel gas injected from the fuel nozzle 7 and the combustion air injected from the flow path 5b are mixed, and in the burner 1 ', the fuel gas injected from the fuel nozzle 7' Combustion air injected from the flow paths 5a 'and 5b' is mixed and burned. The heat of the exhaust gas continues to be recovered to the heat storage body 10a in step 3 (S3), and is supplied to the flow paths 5b, 5a ', and 5b' by heat accumulated in the heat storage bodies 10b, 10a ', and 10b'. The combustion air is preheated.

In step 5 (S5), the fuel control valve 11, the combustion air control valve 15, and the exhaust gas control valve 18 are 100% open and set to the rated combustion state, and each opening and closing with respect to the burner 1 is performed. The valve is set in the same state as in Step 3 (S3) and Step 4 (S4). The on-off valves 13a ', 14b' and 17b 'are opened to the burner 1', and the on-off valves 17a ', 13b' and 14b 'are closed.

In the burner 1, the combustion air injected from the flow path 5b is mixed and combusted with the fuel gas, and in the burner 1 ', the combustion air injected from the flow path 5a' is mixed and combusted with the fuel gas. The heat of the exhaust gas is recovered in the heat accumulators 10a 'and 10b' and the combustion air is preheated by the heat accumulated in the heat accumulators 10b and 10a '.

In step 6 (S6), the fuel control valve 11, the air control valve 15, and the exhaust gas control valve 18 are each opened to 50% and set to the non-rated combustion state, and the burner 1 The on-off valves 14a and 14b are opened, and the open valves 13a, 17a, 13b, and 17b are closed. In addition, with respect to burner 1 ', each on-off valve is set to the same state as step 5 (S5).

In the burner 1, the combustion air injected from the flow paths 5a and 5b is mixed and combusted with the fuel gas. In the burner 1 ', the combustion air injected from the flow path 5a' is mixed with the fuel gas and combusted. do. The heat of the exhaust gas is recovered to the heat storage body 10b ', and combustion air is preheated by the heat accumulated in the heat storage body 10a, 10b, 10a'.

In step 7 (S7), the fuel control valve 11, the air control valve 15, and the exhaust gas control valve 18 are 100% open at each time, and are set to the rated combustion state, and the open / close valve with respect to the burner 1 13a, 14a, 17b are opened, and closing valves 17a, 13b, 14b are closed. In addition, with respect to burner 1 ', each open / close valve is set to the same state as step 5 (S5) and step 6 (S6).

In the burner 1, the combustion air injected from the flow passage 5a is mixed and combusted with the fuel gas, and in the burner 1 ', the combustion air injected from the flow passage 5a' is mixed and combusted with the fuel gas. In addition, the exhaust gas 긔 heat is recovered to the heat accumulators 10b and 10b ', and combustion air is preheated by the heat accumulated in the heat accumulators 10a and 10a'.

In step 8 (S8), the fuel control valve 11, the combustion air control valve 15, and the exhaust gas control valve 18 are each clamped in an open state of 50% and set to an unrated combustion state, and the burner 1 With respect to each of the on-off valves are set in the same state as the step (7), the on-off valves 14a ', 14b' open to the burner 1 ', and the on-off valves 13a', 17a ', 13b', 17b ' ) Is closed.

In the burner 1, the combustion air injected from the flow passage 5a is mixed with the fuel gas, and in the burner 1 ', the combustion air injected from the flow passages 5a' and 5b 'is mixed with the fuel gas. Is burned. In addition, the heat of the exhaust gas is recovered to the heat storage agent 10b and the combustion air is preheated by the heat accumulated in the heat storage bodies 10a ', 10a', and 10b '.

As described above, in the operating method of the burner system, fuel gas is continuously supplied to the burners 1 and 1 'to be combusted, and the combustion air supply amount and the exhaust gas exhaust amount are adjusted according to the increase or decrease of the fuel gas. A stable combustion condition is continued without fluctuations in the furnace pressure or abrupt fluctuations of the oxygen in the furnace.

Moreover, the operating method of the burner system is not limited to the above embodiment, but any method may be used to repeat the air supply and the air discharge in the flow path while setting the burners 1 and 1 'continuously in the combustion state. .

In the non-rated combustion state, the supply amount of the fuel gas and combustion air and the exhaust gas emission amount are limited to 50% of the rated combustion state. However, if the capacity of the exhaust fan 10 is sufficient, it can be set to 50% or more. Of course it is. In addition, the structure of the burner is not limited to the above embodiment, and various regenerative regenerative types are used.

In addition, although two burners have been described as one unit in the embodiment, it is possible to configure a system using several units according to the size of the furnace. In the embodiment, the heat accumulators 9a and 9b are provided outside the burner 1, but these heat accumulators 9a and 9b may be incorporated in the flow paths 5a and 5b, respectively.

[Effects of the Invention]

As is clear from the above description, each burner in the operating method of the regenerative burner system according to the present invention is always kept in a combustion state to exhaust exhaust gas in the furnace from at least one of the flow paths. There is no ignition shock from the system, and the pressure in the furnace can be maintained at a constant pressure at all times.

In addition, since only the combustion air is supplied into the furnace, the oxygen concentration in the furnace can be kept constant at all times, so that adverse effects on the heat treatment material and oxidation loss can be prevented. Moreover, the number of burners can be satisfied with half of the conventional regenerative burner, and at the same time, the fuel switching valve and its switching control are eliminated, thereby improving stability. In addition, the regenerative burner system according to the present invention makes it possible to implement the above operation method.

Claims (2)

A regenerative regenerative burr having a combustion nozzle between the two flow paths, connected to each of the heat storage devices, supplying combustion air to one of the flow paths, and exhausting the exhaust gas from the other flow path. In a regenerative regenerative burner system having two sets of anner, fuel is continuously supplied to each fuel nozzle of each regenerative regenerative burner, and both regenerative regenerative burners are provided with combustion air in one flow path. The preheated combustion air is preheated by the heat accumulator, and the combustion state in which the heat accumulator is heated by exhausting the exhaust gas from the other flow path is switched every predetermined time, and either regenerative regenerative burr While the burner is in this combustion state, the other regenerative regenerative burner switches to the combustion state in which the combustion air is supplied to both flow paths in the combustion state. Method of operating a heat storage regenerative burner system with. A burner having two fuel nozzles disposed between the two, a heat storage each having two entry holes, a fuel supply device, a combustion air supply device, and an exhaust device; It connects to a fuel supply apparatus via a valve, and connects the exit hole of the said heat accumulator to a flow path, respectively, and interposes two combustion burner opening-closing valves and control valves which arranged one entrance hole of the said heat accumulator in parallel. Regenerative regenerative burner characterized in that it is connected to said combustion air supply apparatus and connected to said exhaust apparatus via the inlet hole exhaust gas on-off valve and a control valve on the other side. system.