JPS5946423A - Gas turbine combustor - Google Patents

Abstract

PURPOSE:To provide the titled device with an capability of maintaining a preset low ignition temperature, by arranging a group of columns transversely across a gaseous mixture stream between catalysts of honeycomb structure. CONSTITUTION:A visible radiation ray emitted between an upstream and a downstream sections can be shielded by a group of columns arranged in a zigzag manner between two catalysts of honeycomb structure. Moreover, a gaseous mixture is caused to change its flowing direction upon its collision with columns, resulting in bringing about a further mixing action. As a result, it is relatively easy to control the flow velocity of gaseous mixture at an even level after passed across the group of columns. The diameter, number and installation pitches etc., of columns may be determined with a basis on the magnitude of pressure drop required with an arrangement 8. The replacement of arrangements 8 can be performed conveniently by premounting the group of columns as a unit upon a cylinder which can be inserted into the inner diameter of combustion.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a gas turbine combustor used in a gas turbine combustion system, and more specifically, to a gas turbine combustor used in a gas turbine combustion system, and more specifically, to a gas turbine combustor for reducing nitrogen oxides (hereinafter referred to as NOx) generated during combustion. The present invention relates to a catalytic combustion type gas turbine combustor that has a small amount of combustion and has good combustion efficiency.

[Technical background of the invention and its problems]

In recent years, with the depletion of petroleum resources and the like, various alternative energies have been required, and on the other hand, efficient use of energy resources has been required. Examples of systems that can meet these demands include gas turbine/steam turbine combined cycle power generation systems that use natural gas as fuel, coal gasification gas turbine/steam turbine combined cycle power generation systems, etc., which are currently being considered. .

These gas turbine/steam turbine combined cycle power generation systems have higher power generation efficiency than conventional steam turbine power generation systems that use fossil fuels, so natural gas production is expected to increase in the future. It is expected to be a power generation system that can effectively convert fuels such as coal and gasified gas into electricity3. is ignited using a spark plug or the like to achieve homogeneous combustion. An example of such a combustor is shown in FIG. In the combustor shown in FIG. 1, fuel injected from a fuel nozzle 1 is mixed with combustion air 3, reaches a spark plug 2, and is ignited to be combusted. Then, the combusted gas is cooled and diluted to a predetermined turbine inlet temperature by adding cooling air 4 and dilution air 5, and then injected into the gas turbine from a turbine nozzle 6.

One of the serious problems with such conventional combustors is that a large amount of NOx gas is produced during combustion of fuel.

The reason why the above-mentioned NOx is generated is due to the existence of a high temperature section during combustion of fuel. NOx is normally produced when there is no nitrogen component in the fuel.
Nitrogen and oxygen in the combustion air react and generate according to the formula shown below.

N2+02.2NO The above reaction (as the temperature increases, the reaction shifts to the right side, and the formation of nitric oxide (No) increases by j97. The - part of No is further oxidized to produce nitrogen dioxide (NO2). .

Figure 2112 shows the temperature distribution in the fluid flow direction in a conventional gas turbine combustor. As shown in the figure, the temperature distribution within the combustor has a maximum value, and after reaching the maximum temperature, it is cooled down to a predetermined turbine inlet temperature by cooling and dilution air. Since the maximum temperature inside the combustor can reach as high as 2000° C., the amount of NOx produced rapidly increases around this temperature. As described above, the conventional gas turbine combustor has a problem in that a large amount of NOx is produced due to the presence of a partially high-temperature section. Therefore, a flue gas denitrification device or the like must be provided, which poses problems such as the device becoming complicated.

In order to solve these problems with gas turbine combustors, various combustion systems are being studied.

If the amount of NOx generated can be reduced, the flue gas denitrification device can be omitted or simplified, and examples of combustion methods aimed at such a reduction in NOx include the following. Namely, (1) a method that uses steam or water injection, (2) a two-stage combustion method that introduces combustion and waste air in two stages and combusts the fuel, and (3) an exhaust gas recirculation method. Methods are not necessarily one-size-fits-all; method (1) has poor thermal efficiency because steam or water is injected, and method (2) introduces air in two stages, so The amount of air introduced must be carefully adjusted, and the maximum temperature inside the combustion chamber is still not low enough, so the effect of reducing NOXfii is not sufficient. Furthermore, although method (3) can be used for combustion under atmospheric pressure, it has problems such as being unsuitable for combustion under high pressure such as in a gas turbine combustor. There is.

Ii mentioned above! ': 'f, :I'i: Both methods are based on a homogeneous reaction that occurs only in the gas phase. , catalytic combustion method) has been proposed. The catalytic combustion method uses J'1lli'L to combust a mixture of fuel and air. According to this method, combustion can be started at a relatively low temperature, no cooling air is required, and the combustion air adds j1η.
The maximum temperature is lower, and therefore it is possible to significantly reduce the amount of NOx generated. In addition, the turbine inlet temperature remains the same as that of the conventional one, and the fuel can be completely combusted. Figure 3 is a conceptual diagram of such a catalytic combustion type combustor. 7 is filled with a catalyst body having a honeycomb structure.The same equipment or material as in Fig. 1 is given the same reference numeral.Fig. 4 shows the above-mentioned gas turbine combustion system. This shows the temperature distribution inside each combustor for a: conventional combustion method, b: two-stage combustion method, and C: catalytic combustion method. and the maximum temperature is low,
It can be seen that a heterogeneous combustion reaction gradually occurs from a low temperature, and combustion progresses with a homogeneous combustion reaction halfway through.

In the catalytic combustion processes currently being investigated, separating the catalyst into upstream MIL and upstream portions offers several distinct advantages. For example, it is possible to use a different catalyst composition in each catalyst section, which is particularly advantageous in reserved upstream sections where a low ignition point is desired. Also, in the higher temperature downstream section, the catalyst structure can be used for one cycle without much expense. For example, a highly active but less thermally stable catalyst composition can be used in the 1 m upstream section, while a less active catalyst composition can be used in the downstream section.

Thus, catalysts are usually designed to react within a predetermined reaction temperature range. If a certain temperature range is exceeded, the catalytic activity is destroyed or is no longer effective. Particularly in catalytic combustion, the temperature at the lower end of the gas pipe is so high that the activity of the upstream catalyst may be destroyed or become ineffective.

Below the catalyst, the heat transfer from )il, 1111 to the upstream side is mainly determined by heat transfer by both conduction and radiation. The temperature of the original upstream part of stable pA is
By considering the following two terms, the generally accepted principle of heat transfer can be expressed as 411q.

That is, (1) from the lower part 611 of the catalyst device 2θ:C
The rate of heat transfer due to heat transfer in the first part of the catalytic converter, and (2) the upper OiL from the lower υIC part of the catalyst device.
Considering the heat transfer rate due to thermal radiation transfer to jλ13 minutes) 4J
, and 41L is calculated. The rate of heat transfer by conduction is proportional to the eddy IW difference between the upstream and downstream parts, while the rate of heat transfer by radiation is proportional to the fourth power of the downstream temperature and the fourth power of the upstream temperature.
Proportional to the difference in powers. In this way, when the upstream temperature is very high, the temperature at the beginning is determined primarily by radiation heat transfer, and as a result, the temperature at the beginning of the touch Y is determined by heat conduction alone. be higher than

In particular, heat transfer by radiation in honeycomb catalysts is
It is generally carried out by a visible route from the downstream part to the upstream part.

For this reason, in the catalyst/first firing, it is safe to prevent heat transfer from the downstream portion of the catalyst to the upstream tK[≦min] and radiation heat transfer.

[Project] Objective J Objective of the present invention C2 Eliminate and stabilize the above-mentioned problems /ζ
An object of the present invention is to provide a catalytic combustion type gas turbine capable of maintaining a low ignition temperature.

[Summary of the invention]

The gas turbine combustor of the present invention is a ψ-sintering type gas turbine combustor in which a gas mixture of fuel and air is combusted using two or more honeycomb structure catalyst bodies. The advantage is that a group of cylinders is arranged between the 1q catalyst bodies at right angles to the mixture gas.

The present invention will be explained in more detail below.

Ico1 used in the gas turbine combustor of the present invention!
74ik device 31. As shown in Figure 2135,
Cylindrical cylinders 1 and 1 are placed on the upstream and lower portions 66 and 1 of the honeycomb structure catalyst bodies, respectively, which are attached separately to the upper and lower portions.

The present invention provides a honeycomb-shaped catalyst j having a catalyst arrangement consisting of an upstream portion and a downstream portion; 1. : Depends on the formation of the position. Each honeycomb section has a plurality of porous mono-solid refractory frameworks 41 with gas flow grooves extending therethrough.
The structure is included as a support.

The upstream and downstream sections are fixed relative to each other to reduce heat transfer between the sections. That is, protection against heat transfer is achieved by physically separating two parts of the catalytic converter from the downstream portion of the catalytic device. On the other hand, to reduce the radiative heat transfer from the downstream section to the upstream section is to use an arrangement if, which eliminates the visible radiation path line from the downstream section to the upstream section.

In preventing visible radiation from the downstream part to the upstream part, the F system used is required to (1)
(2) The arrangement must be such that the gas mixture has a mixing effect so that the gas mixture after passing through the arrangement is combusted uniformly, and (3) it is directed to the honeycomb catalyst body in the downstream portion. The amount of mixed gas flowing in is uniform.

(1) is essential for increasing the efficiency of the turbine, (2) is preventing high temperature generation due to partial combustion, and (3) is essential for increasing turbine efficiency.
This results in a partial decrease in the viscosity of the catalyst due to the difference in the amount of gas processed depending on the location of one contactor, resulting in a vassal state where the life of the catalyst is shortened.

To prevent heat radiation from the downstream part to the upper 151L part,
For example, two unaligned thin perforated plates have been proposed for self-layering, but these either do not meet any of the above problems or do not allow the structure of the combustor to be improved. It is a multiple MA, and a practical arrangement is 1 or 11.

Without the above points, the above problems
As a result, I found a group of columns with 7 bodies arranged.

That is, by arranging the cylinders in a 1,000-jb arrangement, it is possible to prevent visible radiation between the upstream portion and the lower υI-B portion. Furthermore, the mixed gas flow C collides with the cylinders to bring about a mixing action of the mixed gas, and it is relatively easy to equalize the flow velocity of the mixed gas after passing through the cylinders. On the other hand, pressure loss depends on the diameter, number, arrangement pitch, etc. of the cylinders, but
It is relatively small. Rather, it is sufficient to determine the diameter, number, arrangement pitch, etc. of the cylinders from the pressure loss required for the arrangement of the four bodies.

The cylinder is required to be made of a heat-resistant material, such as ceramics. Furthermore, the fixing of the cylinder B'1 is shown in FIG. In other words, it is convenient to replace the arrangement if the unit is pre-fixed to a cylinder that can be inserted into the inner diameter of the combustor.

From the foregoing, the present invention is based on the invention! Ji': physical distance P,
lf and the removal of visible directional lines between the downstream and upstream sections reduces heat conduction and radiative heat transfer from the downstream section to the preserved upstream section and prevents the upstream section of the catalyst from becoming overheated. Not only is it held against the catalytic converter for example? The two parts of :f are constructed from different catalyst compositions and from different catalyst substrates to obtain and maintain a low ignition temperature and to improve the efficiency of catalyst preparation and reaction with minimum cost. There is a unique advantage that has been realized.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of a normal gas turbine combustor, Fig. 2 is an explanatory diagram showing the temperature distribution of a normal gas turbine combustor, and Fig. 3 is a diagram of a catalytic combustion type gas turbine combustor. Figure 4 shows a typical gas turbine combustion engine 61. l'lW
(a), an explanatory diagram showing the respective temperature distributions in the two-stage gas turbine combustor (b) and the catalytic combustion type gas turbine combustion 27F (C), Fig. 5 (a), (b)
1A and 1B are conceptual diagrams and diagrams of the catalyst device section of the gas turbine combustor device of the present invention, and FIG. 1...Fuel nozzle 2...Spark plug 3.
・Combustion air 4...Cooling air 5...Dilution air 6...Turbine nozzle 7...Honeycomb structure catalyst body 8...Arrangement body agent Patent attorney Keisuke Norichika (and one other person)

Claims (1)

[Claims] combustors for burning fuel, each of the combustors having a combustion chamber having an inlet end for receiving fuel gas and compressed air and an outlet end for delivering motive gas; creating a restricted flow path to the outlet end, at least a downstream honeycomb catalyst portion along the flow path between the inlet end and the outlet end; and an upstream honeycomb catalyst portion separated from the catalyst portion. In a gas turbine combustor system having a catalyst structure consisting of sections, each honeycomb section is a porous unitary solid refractory frame structure having a plurality of unobstructed gas flow passages therethrough as a support. a group of cylinders arranged at right angles to the gas flow between the upstream section and the downstream section to reduce radiation heat transfer from the downstream section to the upstream section; A gas turbine combustor device characterized by equalizing the concentration distribution of a fluid between the two.