JP2001254940A - High-temperature air generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-temperature air generator for inhibiting the rate of excess air for combustion and improving a heat exchange efficiency. SOLUTION: One portion of an exhaust gas that is discharged during the heating process of a heat-storing body 2 in a heat-storing air heater 3 is re- circulated, thus reducing the temperature of the combustion gas that is circulated to the heat-storing body 2 to a specific temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-temperature air generator.

[0002]

2. Description of the Related Art Generally, as shown in FIGS. 3 and 4, a conventional high-temperature air generating apparatus mixes fuel injected from a burner 1 with combustion air and burns the mixture, thereby converting a high-temperature combustion gas into ceramics. After the heat storage element 2 is heated by flowing through the heat storage element 2, a heat storage type air heater 3 that generates high-temperature air by flowing air through the heat storage element 2 is provided in parallel, During the heating process of the regenerator 2 in the regenerative air heater 3, the process of generating high-temperature air in the other regenerative air heater 3 is performed, and during the process of generating high-temperature air in one regenerative air heater 3, The operation of the regenerative air heater 3 is alternately switched so as to continuously generate high-temperature air so that the regenerative air heater 3 performs the heating step of the regenerator 2 in the regenerative air heater 3. I have.

Each of the burners 1 has a three-way switching valve 4
The fuel supply branch line 6 connected to the fuel supply line 5 is connected by switching, and the combustion chamber 7 of the regenerative air heater 3 to which the burner 1 is connected is burned by switching the three-way switching valve 8, respectively. A combustion air supply branch line 10 connected to a supply air supply line 9 is connected to the regenerator 2 side of the regenerative air heater 3 by switching a four-way switching valve 11 to an air introduction line 12 or an air introduction line 12. An introduction / exhaust line 14 connected to the exhaust line 13 is connected.

A required portion in the middle of the regenerative air heater 3 is communicated by a communication path 15.
Outflow path 16 leading to a gasifier not shown
Is formed, and the generated high-temperature air is supplied to the gasifier or the like from the outlet path 16.

In the high-temperature air generator as described above,
With the three-way switching valve 4, the three-way switching valve 8, and the four-way switching valve 11 switched to the positions shown in FIG. 3, fuel is transferred from the fuel supply line 5 to the three-way switching valve 4 and one of the fuel supply branch lines 6. The combustion air is supplied from the combustion air supply line 9 through the three-way switching valve 8 and the one combustion air supply branch line 10 while being supplied to the burner 1 of one regenerative air heater 3 and injected therethrough. One regenerative air heater 3
When the fuel is supplied to the wind box 7, the fuel injected from the burner 1 and the combustion air are mixed and burned, and the high-temperature combustion gas passes through the heat storage body 2 of one regenerative air heater 3, After heating the heat storage body 2, the heat storage body 2 is discharged from one of the introduction / discharge lines 14 to the outside via the four-way switching valve 11 and the exhaust line 13.

In the state shown in FIG. 3, the required time (for example,
After the elapse of about 30 [sec], the heat storage body 2 of one of the heat storage air heaters 3 has reached a required temperature (for example, 1200 to 130).
0 [° C.]), the three-way switching valve 4, the three-way switching valve 8, and the four-way switching valve 11 are switched from the position shown in FIG. 3 to the position shown in FIG. 12 flows through the four-way switching valve 11 and one of the introduction / discharge lines 14 to the heated one heat storage body 2, whereby about 1000
High-temperature air of about [° C.] is generated and supplied from the communication path 15 to the gasifier (not shown) via the outlet path 16.

During this time, the fuel is supplied from the fuel supply line 5 to the burner 1 of the other regenerative air heater 3 via the three-way switching valve 4 and the other fuel supply branch line 6, and is injected there. Is supplied from the combustion air supply line 9 to the wind box 7 of the other regenerative air heater 3 via the three-way switching valve 8 and the other combustion air supply branch line 10, and the fuel injected from the burner 1 And combustion air are mixed and burned, and the high-temperature combustion gas is supplied to the other regenerative air heater 3.
After heating the heat storage element 2 and heating the heat storage element 2, the heat is discharged from the other introduction / discharge line 14 to the outside via the four-way switching valve 11 and the exhaust line 13, and the state shown in FIG. When a required time (for example, about 30 [sec]) elapses and the heat storage body 2 of the other regenerative air heater 3 reaches a required temperature (for example, about 1200 to 1300 [° C.]), the three-way switching valve is used. 4 and 3 way switching valve 8 and 4 way switching valve 11
Are switched from the position shown in FIG. 4 to the position shown in FIG. 3 again, and air flows from the air introduction line 12 to the four-way switching valve 11 and the other introduction / discharge line 1.
4 through the other heat storage element 2 which is heated, thereby generating high-temperature air of about 1000 [° C.]. Etc., and thereafter, the same operation as described above is repeatedly performed, and the supply of high-temperature air is continuously performed.

[0008]

In the case of the conventional high-temperature air generator as described above, when fuel is burned with a normal theoretical air amount, the adiabatic flame temperature rises to nearly 2000 [° C.], The life of the heat storage body 2 is shortened, and the combustion temperature of about 1200 to 1300 [° C] is sufficient to obtain high temperature air of about 1000 [° C]. At present, the combustion air is supplied to the wind box 7 of the regenerative air heater 3 to perform combustion, or the combustion air is burned with an appropriate excess air to release heat from the combustion part casing. In the case of using excessively large amount of combustion air or radiating heat, a heat exchange efficiency of only about 60 to 65 [%] is obtained, and the efficiency is poor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-temperature air generator capable of suppressing an excess air ratio for combustion and improving heat exchange efficiency.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a method of mixing a fuel injected from a burner and combustion air, burning the mixture, and flowing a high-temperature combustion gas through the regenerator to heat the regenerator. By circulating air through the heat storage body, a regenerative air heater that generates high-temperature air is provided in parallel,
During the heating process of the regenerator in one regenerative air heater, the process of generating high-temperature air in the other regenerative air heater is performed, and during the process of generating high-temperature air in one regenerative air heater, the other In a high-temperature air generator configured to generate high-temperature air continuously by alternately switching the operation of the regenerative air heaters so that the heat-storage body is heated in the regenerative air heater, A part of the exhaust gas discharged during the heating process of the regenerator in the heat storage device is injected into the burner downstream of the burner and recirculated to lower the temperature of the combustion gas flowing through the regenerator to a predetermined temperature. The present invention relates to a high-temperature air generating device characterized in that:

According to the above means, the following effects can be obtained.

In the regenerative air heaters arranged side by side,
The fuel injected from the burner of one regenerative air heater and the combustion air are mixed and burnt, and the high-temperature combustion gas flows through the regenerator of one regenerative air heater to heat the regenerator. After that, switching is performed, the fuel injected from the burner of the other regenerative air heater and the combustion air are mixed and burnt, and the high-temperature combustion gas is stored in the regenerator of the other regenerative air heater. The heat accumulator is heated by flowing through the heat accumulator, and the heating process of the heat accumulator in one heat accumulating air heater and the heating process of the heat accumulator in the other heat accumulating air heater are alternately repeated,
During the heating process of the regenerator in the other regenerative air heater, air is circulated through the heated regenerator of the one regenerative air heater to generate high-temperature air. During the heating process of the regenerator in the above, air is circulated to the regenerator of the other heated regenerative air heater, and high-temperature air is generated, whereby high-temperature air is continuously generated. During the heating process of the regenerator in the regenerative air heater, a part of the exhaust gas discharged is injected into the combustion downstream region of the burner and recirculated. Even if the excess rate of air is reduced to the same level as that of a normal boiler, the temperature of the heat storage body of the regenerative air heater does not increase more than necessary, and the heat exchange efficiency can be improved.

If it is assumed that part of the exhaust gas discharged during the heating process of the regenerator in the regenerative air heater is not injected into the downstream area of combustion by the burner but is injected into the combustion area of the burner, When trying to burn by injecting fuel from the burner of the type air heater, exhaust gas may be mixed in, and the oxygen concentration in the combustion air may be significantly reduced, resulting in unstable combustion. In the case of the present invention, since a part of the exhaust gas is introduced into the downstream of the combustion in the burner, there is no concern that the combustion in the burner is hindered, and the combustion in the burner can be stabilized.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention. In the drawings, the portions denoted by the same reference numerals as those in FIGS. 3 and 4 represent the same components. 3 and FIG. 4 is the same as the conventional one, but the feature of this illustrated example is that, as shown in FIG. 1 and FIG. The point is that the temperature of the combustion gas flowing through the regenerator 2 is reduced to a predetermined temperature by introducing a part of the discharged exhaust gas into the downstream region of combustion in the burner 1 and recirculating the exhaust gas.

In the illustrated example, an exhaust gas recirculation line 18 is branched from a downstream side of an exhaust gas fan 17 provided in the exhaust line 13, and an exhaust line 13 downstream of a branch portion of the exhaust gas recirculation line 18 is provided. Flow control valve 1 on the way
9, a flow control valve 20 is provided in the exhaust gas recirculation line 18, and the exhaust gas recirculation line 18 is branched into two exhaust gas recirculation lines 22 via a three-way switching valve 21. The recirculation line 22 is connected to the center of one regenerative air heater 3 (downstream of combustion in one burner 1), and the other exhaust gas recirculation line 22 is connected to the center of the other regenerative air heater 3. (The downstream side of the combustion in the other burner 1).

Next, the operation of the above illustrated example will be described.

With the three-way switching valve 4, three-way switching valve 8, and four-way switching valve 11 switched to the positions shown in FIG. 1, fuel is supplied from the fuel supply line 5 to the three-way switching valve 4 and one fuel supply branch line. 6, the combustion air is supplied from the regenerative air heater 3 to the burner 1 of the regenerative air heater 3 and injected therefrom, while the combustion air is supplied from the combustion air supply line 9 to the three-way switching valve 8 and the one combustion air supply branch line 10. When the fuel is supplied to the wind box 7 of one regenerative air heater 3 through the air, the fuel injected from the burner 1 and the combustion air are mixed and burnt, and the high-temperature combustion gas is heated by the one regenerative air heater. After passing through the heat storage unit 2 of the vessel 3 and heating the heat storage unit 2, the heat storage unit 2 is discharged from one introduction / discharge line 14 to the outside via the four-way switching valve 11 and the exhaust line 13.

Here, the three-way switching valve 21 is switched to the position shown in FIG. 1 and the opening of the flow control valve 19 in the exhaust line 13 and the opening of the flow control valve 20 in the exhaust gas recirculation line 18. Is adjusted, a part of the exhaust gas discharged during the heating process of the regenerator 2 in one regenerative air heater 3 is injected into the combustion downstream region of the burner 1 and recirculated. Wind box 7 of air heater 3
Even if the excess rate of the combustion air supplied to the regenerative air heater 3 is reduced to about 5 to 10% as in a normal boiler, the temperature of the regenerator 2 of the regenerative air heater 3 is 1200 to 1300.
It is suppressed to about [° C.], does not increase more than necessary, and the heat exchange efficiency can be improved to about 90%.

In the state shown in FIG. 1, the required time (for example, 30
[Sec], the three-way switching valve 4, three-way switching valve 8, and four-way switching valve 11 are switched from the position shown in FIG. 1 to the position shown in FIG. The heat is passed through the heated one heat storage unit 2 through the valve 11 and the one introduction / discharge line 14, thereby generating high-temperature air of about 1000 [° C.]. After that, it is supplied to a gasifier not shown.

During this time, fuel is supplied from the fuel supply line 5 to the burner 1 of the other regenerative air heater 3 via the three-way switching valve 4 and the other fuel supply branch line 6, and is injected there. Is supplied from the combustion air supply line 9 to the wind box 7 of the other regenerative air heater 3 via the three-way switching valve 8 and the other combustion air supply branch line 10, and the fuel injected from the burner 1 And combustion air are mixed and burned, and the high-temperature combustion gas is supplied to the other regenerative air heater 3.
After passing through the heat storage body 2 and heating the heat storage body 2, the heat is discharged from the other introduction / discharge line 14 to the outside through the four-way switching valve 11 and the exhaust line 13. At this time, the three-way switching is performed. The valve 21 is switched from the position shown in FIG. 1 to the position shown in FIG.
Opening of flow control valve 19 on the way and exhaust gas recirculation line 18
By adjusting the opening of the flow control valve 20 on the way,
Part of the exhaust gas discharged during the heating process of the heat storage unit 2 in the other heat storage air heater 3 is injected into the downstream area of combustion in the burner 1 and recirculated, so that the wind box of the heat storage air heater 3 Even if the excess rate of the combustion air supplied to 7 is reduced to about 5 to 10% as in a normal boiler, the temperature of the heat storage body 2 of the regenerative air heater 3 is 1200 to 130
It is suppressed to about 0 [° C], does not rise more than necessary,
Heat exchange efficiency can be improved to about 90%.

In the state shown in FIG. 2, the required time (for example, 30
[Sec], the three-way switching valve 4, three-way switching valve 8, four-way switching valve 11, and three-way switching valve 21 are respectively switched from the position shown in FIG. 2 to the position shown in FIG. The high-temperature air of about 1000 [° C.] is generated from the introduction line 12 through the four-way switching valve 11 and the other introduction / discharge line 14 to the other heated heat storage body 2, thereby generating a communication passage. Fifteen
The gas is supplied to a gasifier (not shown) through the outlet path 16 and thereafter, the same operation as described above is repeatedly performed, and the high-temperature air is continuously supplied.

Suppose that the exhaust gas recirculation line 22 is located at the center of the regenerative air heater 3 (downstream of combustion in one burner 1).
Is connected to the wind box 7 of the burner 1, when the fuel is injected from the burner 1 of the regenerative air heater 3 and burned, the exhaust gas is mixed and burnt. Although the oxygen concentration in the service air may be significantly reduced and combustion may become unstable, the exhaust gas recirculation line 22
Is connected to the central portion of the regenerative air heater 3 (downstream of combustion in one burner 1), so there is no concern that combustion in the burner 1 will be hindered, and combustion in the burner 1 will be stabilized. It becomes possible.

In this way, the excess air rate for combustion can be suppressed, and the heat exchange efficiency can be improved.

Incidentally, the high-temperature air generating device of the present invention is not limited to the above illustrated example, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0026]

As described above, according to the high-temperature air generating apparatus of the present invention, an excellent effect that the excess air ratio for combustion can be suppressed and the heat exchange efficiency can be improved can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of an example of an embodiment of the present invention, showing a state in which one burner is burned.

FIG. 2 is an overall schematic configuration diagram of an example of an embodiment of the present invention, showing a state where the other burner is burned.

FIG. 3 is an overall schematic configuration diagram of a conventional example, showing a state in which one burner is burned.

FIG. 4 is an overall schematic configuration diagram of a conventional example, showing a state in which the other burner is burned.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burner 2 Heat storage body 3 Heat storage air heater 18 Exhaust gas recirculation line 21 Three-way switching valve 22 Exhaust gas recirculation line

Claims (1)

[Claims] The fuel injected from a burner and combustion air are mixed and burned, and high-temperature combustion gas is passed through the heat accumulator to heat the heat accumulator and then distribute air to the heat accumulator. By doing so, a regenerative air heater that generates high-temperature air is provided in parallel, and during the heating process of the regenerator in one regenerative air heater, the process of generating high-temperature air in the other regenerative air heater is performed. And, during the process of generating high-temperature air in one regenerative air heater, the heating process of the heat storage body in the other regenerative air heater is performed,
In a high-temperature air generator configured to generate high-temperature air continuously by alternately switching the operation of a regenerative air heater, a part of exhaust gas discharged during a heating process of a regenerator in the regenerative air heater A high-temperature air generator characterized in that the temperature of the combustion gas circulated through the heat storage body is reduced to a predetermined temperature by introducing the gas into the downstream region of combustion in the burner and recirculating the same.