JPH0335988Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an inner cylinder of a combustor used in a gas turbine, a jet engine, etc.

BACKGROUND ART Conventional combustor inner cylinders include those shown in FIGS. 2a to 2c, in which cooling air 03 that flows in through cooling air holes 02 bored in a shell 01,
It collides with the lip 04 to form a uniform film, thereby cooling the inner wall surface of the shell.

Problems that the invention aims to solve Recently, however, in order to improve the efficiency of gas turbines and jet engines, the combustor outlet temperature has been increased.
The temperature is increasing to 1200-1500℃. In such a high-temperature combustor, a problem arises in that the combustor inner cylinder cannot be cooled down to a permissible wall temperature or less using only the conventional film cooling described above.

As a countermeasure to this problem, it is being considered to adopt a so-called composite cooling configuration that would combine convection cooling from the outside of the wall of the combustor inner cylinder with film cooling from inside the wall, but at present, it is difficult to avoid thermal stress, vibration stress, etc. The reality is that no concrete structure has yet been developed that takes into account strength against such factors.

Therefore, the present invention aims to provide a specific combustor inner cylinder having a composite cooling configuration that can sufficiently withstand thermal stress, vibration stress, and other intensities.

Means for Solving the Problems The present invention involves inserting a ring-shaped wall member having a large number of axially extending fins along the circumferential direction of the outer wall surface into the shell, and at the upstream end of the wall member for air flow. a tapered portion formed in the shell is engaged with and adhered to a tapered portion formed in the middle portion of the shell;
A plurality of cooling air holes are formed in the shell so as to be located upstream of the grooves formed between the fins.

According to the above means, the cooling air flows in from each cooling air hole of the shell, and then flows through the grooves formed between each of the many fins of the wall member to cool the outer wall surface of the wall member. , and then flows to film-cool the inner wall surface of the next wall member.

Embodiment A preferred embodiment of the present invention will be described in detail below with reference to the drawings.

In Figs. 1a to 1c, reference numeral 1 denotes a shell of a combustor inner cylinder integrally formed into a cylindrical shape, and tapered portions 2 are formed at appropriate intervals in the middle of the shell. 4 is a large number of fins 5 extending in the axial direction.
are a plurality of ring-shaped wall members that are integrally formed along the circumferential direction of the outer wall surface, and these wall members are made of casting and are respectively inserted into the shell 1 one after another, and the air flow upstream side thereof is A tapered part 6 formed at the end at substantially the same angle as the shell taper part 2 is engaged with the associated shell taper part 2, and is bonded by a brazing material 7 which is inserted between these tapered parts and heated to an elevated temperature. ing.

The large number of cooling air holes 3 are located at the upstream side of the air flow of the groove 9 formed between the large number of fins 5, in this embodiment, the shell flat portion on the larger diameter side of the tapered portion 2. It is perforated in shell 1. Each groove 9 forms a convective cooling air passage between the shell 1 and the wall member 4.

Thus, the cooling air 8 flows in from the cooling air hole 3 of the shell 1, and then flows into the shell 1 and the wall member 4.
The air flows through the convection cooling air passage 9 formed between the wall member 4 to cool the outer wall surface of the wall member 4, and then flows to film-cool the inner wall surface of the wall member 4 in the next stage.

Effects of the invention As detailed above, according to the invention, a ring-shaped wall member with outer fins is inserted into the shell of the combustor inner cylinder, and this wall member is cooled by convection from the outside, and the cooling air is used to cool the wall member from the outside. Since the next-stage wall member is film-cooled from the inside, so-called composite cooling, the cooling effect is extremely large, and it can be optimally applied to high-temperature combustors where the outlet temperature is about 1200 to 1500°C.

Furthermore, according to the present invention, the shell is not directly exposed to high-temperature gas, so it is maintained at air temperature, but the shell serves as a strength member, so the strength is increased. Further, since the shell and the ring-shaped wall member with fins are engaged with each other by the tapered portions formed on both of them, the adhesion is enhanced and the precision of fitting is maintained at a high level. Moreover, since the ring-shaped wall member with fins can be manufactured by casting, it has the advantage of being inexpensive.

Moreover, according to the present invention, the wall member is ring-shaped and is not divided in the circumferential direction, so the wall member has high rigidity and excellent strength, and there are no connecting parts in the circumferential direction. Therefore, there is an advantage that there are no problems such as air leakage or sealing from this connection.

In addition, since this wall member is attached to the shell at the upstream end of the air flow, the wall member is most effectively cooled by the film cooling air supplied from the previous stage, and the wall temperature of this part of the wall member is low. Since there is no temperature difference with the shell, the thermal stress at this attachment part is very small, which is a favorable advantage in terms of strength.

Furthermore, by supporting the wall member at the upstream end of the air flow, which is at a low temperature, there is no need to take measures against thermal expansion, so it is possible to fix the wall member around the entire circumference at the upstream end of the air flow. This allows for reliable fixed support and even greater strength.

In addition, by fixing the wall member all around at its air flow upstream end in this way, the support strength at the air flow upstream end is large, and since the wall member is continuous on the circumference, the wall member can be It is sufficient to support only the upstream end of the air flow, and the opposite end, that is, the downstream end of the air flow, has the advantage of being free.

Furthermore, according to the present invention, the flow rate of cooling air flowing into the grooves (cooling air passages) formed between the fins of the wall member is constant, so the cooling performance of all passages is constant and uniform cooling performance is achieved. can get. and,
Basically, by providing one cooling air hole corresponding to one cooling air passage, there is an advantage that a smaller amount of cooling air can be supplied.

[Brief explanation of drawings]

Fig. 1a is a cross-sectional view of the upper half of the combustor inner cylinder according to the present invention, Fig. 1b is an enlarged view of a part of Fig. 1a, and Fig. 1c is a cross-sectional view of the upper half of Fig. 1b.
Figure 2a is a cross-sectional view showing the upper half of the conventional combustor inner cylinder, Figure 2b is an enlarged view of a part of Figure 2a, and Figure 2c is the cross-sectional view of Figure 2b. −
It is a sectional view taken along the c line. DESCRIPTION OF SYMBOLS 1... Shell, 2... Taper part, 3... Cooling air hole, 4... Ring-shaped wall member, 5... Fin,
6...Tapered part, 7...Low, 8...Cooling air,
9...Groove (air passage for convection cooling).

Claims (1)

[Scope of utility model registration request] A ring-shaped wall member having a large number of axially extending fins along the circumferential direction of the outer wall surface is inserted into the shell, and a tapered portion formed at the air flow upstream end of this wall member is inserted into the middle part of the shell. A plurality of cooling air holes are formed in the shell so as to be engaged with and adhered to the formed tapered portions, and are located in the upstream portion of the air flow of the groove formed between each of the fins. The combustor inner cylinder.