JPS59167621A - Catalyst burner - Google Patents

Abstract

PURPOSE:To eliminate the need for a heating source available from the outside, to prevent production of KOX caused thereby, and to eliminate consumption of power, by a method wherein the air is preheated by utilizing the heat of combustion gas during combustion. CONSTITUTION:During ignition of a catalyst burner 5, with a 3-way valve 20 operated, fuel A is guided to a preheating burner 19 and is ignited and burnt. High temperature combustion gas C, produced by this flame combustion, is arrested by a heat exchanger 14 through an exhaust system 13, a part thereof is sucked through a suction hole 16 to an air feed system 11 to be mixed in the air B, the rest flows along the air feed system 11, and preheats the air B flowing in the air feed system 11, for combustion. The combustion gas C, which passes through the heat exchanger and flows along the air feed system 11, is exhausted from an exhaust hole 17, and thereafter, it heats a reaction device 7 to preheat a catalyst 6 located therein. When fuel A is increased in temperature to a value sufficient enough to allow contact combustion at the surface of the catalyst 6, with the 3-way valve 20 controlled, the supply of the fuel A is shifted to a fuel nozzle 10 from the preheating burner 19. Such shift causes air-fuel mixture of the fuel A and the preheated air B to flow to the catalyst 6 which is preheated to efficient temperature, and causes the fuel to be ignited without an ignition source to continue combustion.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a catalytic combustor, and particularly to a catalytic combustor that can preheat the air by effectively applying the heat of combustion gas to the combustion air supplied to the catalyst. Related to catalytic combustor.

[Technical background of the invention] LNG, NGL that can be easily vaporized in the presence of a suitable catalyst
Catalytic combustion methods for flameless combustion of , LPG, Pfuza, kerosene, etc. have recently been rapidly attracting attention. This is the first
As shown in the figure, LP was added to the reactor 2 filled with the catalyst 1.
A device that supplies a mixer of fuel A, such as G, and air B, which is blown by Ia3, and causes combustion to occur on the contact surface without producing a flame, and discharges high-temperature combustion gas C. It is.

Compared to normal flame combustion, the catalytic combustion method has the following characteristics: ■ The generation of NOx is very small. ■ - The generation of unburned substances such as carbon oxide (Co) and hydrocarbons is minute. ■ Low temperature. -i complete combustion at +H (900~1200℃)
It has advantages such as stable combustion in a wide range of fuel and air mixture ratios and no localized high temperatures. Because of this advantage, they are currently being used or are being used in a wide range of applications, from space heaters to gas turbines.

Tokoro(・Natural Nonozu (NGL) whose main component is methane
> When surface combustion is performed using a catalytic combustor, due to the poor combustibility of methane, it is necessary to heat the mixture of fuel and air to a temperature of several hundred degrees centigrade before entering the reactor. be.

Therefore, conventionally, as shown in Fig. 1, an air preheater 4 is installed in the air supply system to feed preheated air into the reactor 2, thereby bringing the catalyst 1 to a predetermined temperature necessary for continuing catalytic combustion. keeping. Usually, the air preheater 4 is preheated using combustion gas or an electric heater.

[Problem with Background Art J However, the scouring using the preheating burner is accompanied by the generation of NOx due to the preheating barb, which impairs the advantage of ultra-low NOx combustion, which is one of the characteristics of the catalytic combustor.

In this case, it is possible to reduce NOx by using the a3 and j preheating burners for fuel lean combustion, but the lean combustion method is technically very difficult.

In addition, electric power-based scrubbing requires a large amount of electric power for continuity, which has the disadvantage of extremely high running costs.

[Object of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to preheat air using the heat of combustion gas during combustion, thereby eliminating the need for an external heating source. The object of the present invention is to provide a simple catalytic combustor of 1 IvJ structure that can eliminate the generation of NOx and power consumption caused by this.

[Summary of the Invention] According to the present invention, the above object is achieved as follows. That is, in a catalytic combustor that supplies a mixture of fuel and preheated air to a catalyst to perform catalytic combustion and exhaust combustion gas, the catalytic combustor is provided in the exhaust system of the catalytic combustor,
A heat exchanger is installed in the exhaust system on the upstream side of the heat exchanger to preheat the air with combustion gas exhausted to the exhaust system, and the fuel is introduced and combusted at the time of ignition. Draw a preheating burner for supplying combustion gas to the heat exchanger. Therefore, in the case of a famous dog, the air is preheated with the combustion gas from the combustion of the preheating burner, and on the other hand, during combustion, the air is preheated with the combustion gas of the catalytic combustion, and 1) the temperature necessary for continuous combustion is maintained. Like 6. : 1 shot.

-(There is.)

3 Embodiments of the Invention] Hereinafter, a preferred embodiment of the catalytic combustor according to the present invention will be described.
explain.

FIG. 2 shows an embodiment of the present invention, and is a schematic i-side view.

As shown in the figure, the catalytic combustor 5 is equipped with a reactor 7 filled with a catalyst 6, and on the upstream side of this reactor 7 there is a fuel A
A mixture supply system 8 for supplying a mixture of air B and preheated air B is connected to the mixture supply system 8.This mixture supply system 8 is connected to a fuel mixture supply system 8 for supplying the above-mentioned fuel, for example, natural gas whose main component is methane. (Jl, the fuel nozzle 10 connected to the yarn feeder 9 and the air supply system 11 that supplies the air are connected together,
A blower 12 is connected to the upstream side of the air supply system 11.

On the other hand, a 4Jl gas system 13 is connected to the downstream side of the reactor 7 for discharging the combustion gas C of the fuel catalytically combusted in the presence of the catalyst 6. This exhaust system 13 is extended and disposed so as to go around directly below the reactor 7, and the exhaust system 13 located directly below preheats the air flowing through the air supply system 11 by the combustion gas exhausted to this exhaust system 13. A heat exchanger 14 is provided for this purpose. This heat exchanger 14 includes, for example, an air supply system 1 in the exhaust system 13 as shown in the figure.
A double pipe system running ``1'' is suitable because of its simple structure. The heat exchanger 14 was provided in this way because the combustion gas generated by catalytic combustion is at a high temperature, and the heat
This is because, since the temperature is large, heat can be effectively exchanged with the low-temperature air.

In addition, a throttle 1 is provided in the middle of the air supply system 11 in the heat exchanger 14.
5 is formed, and an intake hole 1G is provided in this throttle 15 (by pulling a part of the combustion gas into the air supply system 11 through the intake hole 16 using the negative pressure generated when air passes through the throttle 15). If the sea urchin combustion scum is introduced into the internal air supply system 11, the heat of the combustion scum will be directly absorbed into the internal air supply system 11.
The temperature of the air being browned becomes very high. Exhaust system 13 for discharging the remainder of combustion residue out of the system 1〕1 pore 1
7 is an exhaust system 13Q that goes under the reactor 7] catalyst 6
The catalyst is heated by the combustion residue after heat exchange.

A preheating burner 19 is provided in the exhaust system 13 on the upstream side of the heat exchanger 14, and is ignited and burned by the ignition of the ignition plug 18 provided therein. A branch system 21 branched and extended from the fuel supply system 9 through a three-way valve 20 is connected to the preheating burner 19, and by switching the three-way valve 20, fuel A can be supplied to the preheating burner 19 or the fuel nozzle 10 alternatively. It is now possible to supply. The reason why the preheating burner 19 is provided downstream of the catalyst 6 is to prevent the high temperature combustion gas generated by combustion in the preheating burner 19 from coming into direct contact with the catalyst 6, and also to supply it to the heat exchanger 14. be.

As described above, the overall framework of the catalytic combustor 5 is composed of the reactor 7, the exhaust system 13, the heat exchanger 14, and the mixture supply system 8, but it is preferable that the shape of the catalytic combustor 5 is modified from the viewpoint of thermal efficiency and compactness. As shown in FIG. 2, it is preferable to form a hollow body in which the combustion gas discharged outside the system is confined in the central space and can escape only from both sides of the reactor 7 at the top.

The operation of the present invention having the above configuration will be described.

When igniting the catalytic combustor 5, the three-way valve 20 is operated to supply fuel A.
is guided to the preheating burner 19 (ignited and combusted). The high-temperature combustion gas C resulting from this flame combustion flows through the exhaust system 13 and reaches the heat exchanger 14, and a portion is taken into the air supply system 11 through the intake hole 16 and becomes air. B is mixed into the air supply system 11.
The combustion air B flowing in the air supply system 11 is preheated automatically and indirectly. In addition, the air supply system 11
The heat-exchanged combustion gas C flowing along the reactor 7 is discharged from the exhaust hole 17, and then heats the reactor 7 and preheats the catalyst 6 inside. When the air B to be supplied to the reactor 7 reaches a temperature sufficient for fuel A to undergo catalytic combustion on the surface of the catalyst 6, the three-way valve 2° is operated to stop the supply of fuel A from the preheating harp. 9 to the fuel nozzle 10. This switching (the touch C1 is preheated to a temperature of 1.6
Then, a mixture of fuel A and preheated air B flows, and the fuel ignites without an ignition source and continues to burn.

The preheated air temperature required to continue catalytic combustion is secured by the combustion gas produced by catalytic combustion instead of the combustion scum in the preheating burner 19. .

By mixing some of the combustion residue with the air, the heat of the combustion gas can directly preheat the air, making it possible to preheat the air effectively.

In addition, since the catalyst is heated with the combustion gas after heat exchange, in combination with air preheating, the combustion temperature required to continue catalytic combustion can be obtained very easily and effectively.

Therefore, the preheating burner 19 burns until the catalyst 6 reaches a predetermined temperature. High-temperature combustion scum is obtained, and this combustion scum directly or indirectly preheats the air. The time it takes to reach a predetermined temperature can be extremely shortened. As a result, the amount of NOx generated during ignition caused by flame combustion can be reduced as much as possible.
Since the catalyst 6 is located on the downstream side of the catalyst 6, it is possible to prevent the catalyst 6 from being damaged by the combustion gas of the ignited noodles.

On the other hand, during catalytic combustion by the catalyst 6, the preheating source for the air B is the catalytic combustor 5 itself. Therefore, fuel efficiency is extremely good, there is no need for any unnecessary power consumption, and the original characteristic of ultra-low NOx combustion can be maintained, making the combustion gas released outside the system harmless. In addition, by switching between ignition and combustion using the three-way valve 20, the same fuel can be used, making it possible to simplify the structure of the fuel supply system. By installing the air filter in the first air system 13, the structure can be further simplified.

Hey,”-gf: In the example, the heat exchanger 14 is two-stranded [tube].
1^, but a spiral structure increases the surface area,
Since it is possible to further improve the heat exchange efficiency, various changes and modifications are possible without being limited to the illustrated example.

In addition, the holes in the intake holes 16 installed in the air supply system 11 are designed to prevent combustion from being inhibited by too much combustion gas being introduced through them, depending on the shape of the aperture and the amount of air blown. There is a bowl that must be eaten.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are achieved.

(1) With the exception of @Daisuke, the combustion gas of the combustor itself produced by the catalytic combustion of the catalyst is used as the air preheating source to ensure the air temperature necessary for continued combustion. Enables savings in -C traditionally required during combustion
The preheating heater and preheating burner can be omitted.

(2) Since no preheating burner is required during combustion except during ignition, low NOx emissions, which are the original characteristics of combustion, can be maintained.

(3) At the time of ignition, the combustion gas from the preheating burner is transferred to the heat exchanger l.
Since the supply is kept low and does not come into direct contact with the catalyst, the catalyst will not be damaged by high-temperature combustion gas.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a conventional catalytic combustor, and FIG. 2 is a schematic structural sectional view showing a preferred embodiment of the catalytic combustor according to the present invention. In the figure, 5 is a catalytic combustor, 6 is a catalyst, 11 is an air supply system, 13 is an exhaust system, 14 is a heat exchanger, 15 is a throttle, 16 is an intake hole, 17 is an exhaust hole, 19 is a preheating burner, A is fuel,
B is air and C is combustion gas. Patent No. 99 applicant Tokyo Shibaura Electric Co., Ltd. 71 representative patent attorney Kinuya (Mu 11 Figure 1 2 Figure 2)

Claims (1)

[Scope of Claims] 1) In a catalytic combustor that supplies a mixture of fuel and preheated air to a catalyst to perform catalytic combustion and discharge combustion scum, the catalytic combustor is provided in the exhaust system of the catalytic combustor. A heat exchanger is provided in the exhaust system on the upstream side of the heat exchanger for preheating the air with combustion gas exhausted to the exhaust system, and is installed in the exhaust system to introduce fuel at the time of ignition. and a preheating burner for supplying combustion scum to the heat exchanger. 2) A constriction is formed in the air supply system in the heat exchanger, and the constriction is provided with an intake hole through which a part of the combustion gas is taken in. Catalytic combustor as described in section. 3) The exhaust hole of the exhaust system is provided (opened) facing the catalyst so that the catalyst is heated by the combustion residue of the heat exchanger jIIAF2. Catalytic combustor as described.