JPH06323541A - Flame holder structure for combustor - Google Patents

Abstract

PURPOSE:To prevent any crack and deterioration of a title structure both due to thermal stress by providing a heat insulation member on the surface of a member constituting the title structure, and altering the thickness of the heat insulation member in order to control the amount of heat transferred to a flame holder as needed. CONSTITUTION:A heat insulation member 8 having a smaller heat conductivity than that of chief members of a flame holder 1 is provided on the surface of a flame holder device end 2 being the surface to be heated and facing the flame. The thickness of the heat insulation member 8 is altered radially and circumferentially according to the distribution of the amount of heat transferred from the flame holding device end 2 to control the amount of heat transferred to the flame holder 1 for uniforming the temperature distribution in the flame holder 1. Simultaneously, the wall thickness of a flame holder body 1 is uniformed with respect to a flame surface so as to uniform the heat capacity of the flame holder 1. Hereby, the surface area for reception of heat is increased. The surface area for reception of heat is thus increased, whereby the density of the transferred heat from the surface to be heated is reduced to uniformhu the temperature distribution in the flame holder 1. Thus, the amount of the heat entering the flame holder 1 is interrupted or reduced without affecting the flame holding performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame holder structure for a combustor, and more particularly to a flame holder structure with improved flame holding performance.

[0002]

2. Description of the Related Art A conventional technique is to stabilize a premixed flame by providing a flame stabilizer (vortex generator) at the outlet of the premixer (premix chamber) as described in JP-A-59-129330. I was trying.
In this flame stabilizer, the flame stabilizer is heated to a high temperature in order to generate a circulating flow of high-temperature combustion gas on the downstream side of the flame stabilizer, but consideration is given to making the temperature distribution of the flame stabilizer uniform. Didn't.

[0003]

The flame stabilizer provided at the outlet end of the premixer holds the flame by generating a swirling flow of the combustion gas at the flame stabilizer end (the downstream side of the flame stabilizer), The combustion of the premix combustor is stabilized. However, the flame stabilizer is heated from the end of the flame stabilizer facing the flame by the high-temperature flame held, and the flame stabilizer becomes high temperature.

The flame stabilizer changes its temperature level from a low temperature state to a high temperature state at room temperature when the combustor is ignited, a continuous high temperature state during combustion, and a high temperature state to a low temperature state at room temperature when extinguishing the fire. As the temperature difference, the length of time of exposure to high temperatures, the temperature distribution, and the number of repetitions of high and low temperatures shown below increase, the material of the flame stabilizer deteriorates, greatly affecting the life of the flame stabilizer. Temperature difference = (flame stabilizer temperature at the time of combustion)-(flame stabilizer temperature at the time of combustion stop) Conventional flame stabilizers are made of heat-resistant alloys, stainless steel, etc. as materials that can withstand high temperatures. As shown in Table 1, these materials have low thermal conductivity.

[0005]

[Table 1]

Therefore, as shown in FIG. 1, if the flame state is unbalanced, the flame stabilizer tends to have a temperature distribution. The air 5 and the fuel ejected from the ejection port 4 of the premixing nozzle 3 are mixed in the mixer 7 to form the premixed gas 6. The concentration distribution (fuel air ratio distribution) of the mixture is the radial direction of the mixer 7. There is a distribution in both the circumferential direction, so that the flame has a temperature distribution, and the amount of heat penetrating from the flame stabilizer end 2 can be distributed. Up to now, since the intruding heat amount control means was not provided in the heated portion (flame holder end 2) of the flame holder 1, there was a problem regarding the life of the flame holder.

[0007]

A heat insulating material having a thermal conductivity smaller than that of a flame stabilizer member is provided on the flame stabilizer end surface of the heated surface facing the flame. If necessary, the thickness of the heat insulating material provided on the end surface of the flame stabilizer is changed so that the temperature distribution of the flame stabilizer becomes uniform. If the flame stabilizer has a partial temperature distribution,
The heat insulating material is provided only on the end surface of the flame stabilizer.

[0008]

[Function] Since the heat insulating material having a smaller thermal conductivity than that of the flame stabilizer member is provided on the flame stabilizer surface of the heated surface facing the flame, the surface temperature of the heat insulating material facing the flame surface is the heat insulating material. Although it is in the same or slightly hot state as in the case without heat, the heat penetration from the heated surface of the flame stabilizer is shielded by the heat insulating material provided, and the amount of heat entering the flame stabilizer is reduced. As a result, the surface temperature of the heat insulating material has conventionally risen to a slightly higher level, so that the amount of heat entering the flame stabilizer can be blocked or reduced without affecting the flame holding performance.

Since the amount of heat entering the flame stabilizer can be changed by changing the thickness of the heat insulating material, the temperature distribution of the flame stabilizer can be adjusted. At this time, even if the thickness of the heat insulating material is changed, the surface temperature of the heat insulating material facing the flame hardly changes, so that the flame holding performance of the flame stabilizer can be maintained well.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention is shown in FIGS. 1 is a cross-sectional view of a flame stabilizer in which a heat insulating material 8 is provided on the surface of the flame stabilizer in the premixed combustor that faces the flame, and FIG.
FIG.

Combustion air 5 and jet port 4 of premixing nozzle 3
Further ejected fuel is mixed in the mixer 7 to form a premixed gas 6. The flame stabilizer 1 holds a flame by generating a high-temperature circulating flow in the downstream of the flame stabilizer end 2. Therefore, the flame stabilizer end 2 becomes a heated portion and is exposed to a high temperature, and the temperature of the flame stabilizer 1 becomes high. A heat insulating material 8 having a thermal conductivity smaller than that of the main constituent member of the flame stabilizer 1 is provided on the surface of the flame stabilizer end 2 which is a heated surface facing the flame. The surface temperature of the heat insulating material 8 facing the flame is the same as that without the heat insulating material 8 or is high due to the reduced thermal conductivity, so the flame holding performance of the flame stabilizer 1 is equal to or higher than that. is there.

On the other hand, the heat insulating material 8 blocks the heat entering the flame stabilizer end 2 and reduces the amount of heat entering the flame stabilizer 1. Figure 3
In the embodiment shown in FIG. 4, the thickness of the heat insulating material 8 provided on the surface to be heated 2 of the flame stabilizer 1 is set in the radial direction and the circumferential direction according to the distribution of the amount of heat entering from the flame stabilizer end 2. To control the amount of heat entering the flame stabilizer 1 so that the temperature of the flame stabilizer 1 becomes uniform. The example in FIG. 3C shows a case where two types of heat insulating materials are provided on the surface of the flame stabilizer end 2. In the embodiment of FIG. 3 (f), a heat insulating material 8 is provided on the surface of the heated end 2 of the flame stabilizer 1,
In this example, the amount of heat entering the flame stabilizer is controlled and the thickness of the flame stabilizer main body 1 is made uniform with respect to the flame surface so that the heat capacity of the flame stabilizer 1 becomes uniform, thereby increasing the heat receiving area. Insulation 8
By increasing the heat receiving area, the heat density penetrating from the heating surface is reduced, and the temperature distribution of the flame stabilizer is made uniform. FIG. 4 is an example of a case where the flame stabilizer of the premixed combustor shown in FIG. 1 is adopted as a gas turbine combustor. It is desirable that the heat insulating material has not only a lower thermal conductivity than that of the flame stabilizer member but also a ceramic, a superalloy or the like having heat resistance and temperature resistance.

[0013]

According to the present invention, the heat insulating material is provided on the surface of the member constituting the flame stabilizer, and if necessary, the heat insulating material is provided with varying thickness in order to control the amount of heat entering the flame stabilizer. Therefore, the heat change of the flame stabilizer due to uneven temperature distribution of the flame stabilizer can be eliminated, and the crack generation and deterioration due to thermal stress are eliminated, so that the combustion performance does not change due to the deformation of the flame stabilizer, and the life of the flame stabilizer is reduced. Can be maintained for a long time. The temperature of the end surface of the heat insulating material facing the flame is the same as before, or the surface temperature rises because the heat conductivity of the heat insulating material is smaller than the heat conductivity of the flame stabilizer member, so the flame retaining performance as a flame stabilizer is conventional. To improve.

[Brief description of drawings]

FIG. 1 is a sectional view of a flame stabilizer of a premixed combustor.

FIG. 2 is a side view of the flame stabilizer shown in FIG.

FIG. 3 is a cross-sectional view of a flame stabilizer provided with a heat insulating material.

FIG. 4 is a cross-sectional view of a flame stabilizer when the flame stabilizer of the premixed combustor shown in FIG. 1 is adopted as a gas turbine combustor.

[Explanation of symbols]

1 ... Flame stabilizer, 2 ... Flame stabilizer end, 3 ... Premixing nozzle, 4 ... Jet port, 5 ... Air, 6 ... Premixture, 7 ... Mixer, 8 ... Insulating material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiharu Nakayama 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory

Claims (3)

[Claims] 1. A flame stabilizer for a combustor, wherein a heat insulating material is provided on a surface of a member forming the flame stabilizer for the combustor. 2. A flame stabilizer for a combustor according to claim 1, wherein a heat insulating material having a varied thickness is provided on a surface of the member constituting the flame stabilizer of the combustor. 3. The flame holder for a combustor according to claim 1, wherein a heat insulating material is partially provided on a surface of the member forming the flame holder of the combustor.