JPS59176590A - High-temperature sealing device for heat exchanger of rotary and heat regenerative type - Google Patents

Abstract

PURPOSE:To provide in high productivity a high-temperature sealing device for a heat exchanger of rotary and heat regenerative type, not in need of using any sealing material which has sliding property in extremely high-temperature, by cooling the sealing device by letting bypassed low-temperature gas pass through it. CONSTITUTION:A long channel 10 is provided to the sliding surface of a cross rib part 7b of sealing device 7 with a core 1. The part 7b is usually called a cross bar. The sealing device 7 insulates and separates high-temperature gas from low-temperature gas. One end of the long channel 10 is closed, while the other end is opened to the side of a flow path 3 for high-temperature gas by a connecting channel 10a. With such an arrangement, when the core 1 starts rotating, low-temperature gas under high-pressure is fed into the flow path 1a of a core 1 which is composed of fine honeycomb, passing through a flow path 5 for low-temperature gas, being heated, and flowing out of the core 1 into a flow path 6. But part of low-temperature gas is entrapped in the flow path 1a as carry-over gas and flows into the long channel 10. When the core 1 further rotates, the entrapped carry-over gas flows out of the flow path 1a into the flow path 3, because the path 1a is opened to the path 3, as the entrapment by the cross rib part 7b is released. In such a manner the cross rib part 7b of a sealing device can be cooled off by the carry-over gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-temperature sealing device for a rotary regenerative heat exchanger used in a gas turbine engine or the like.

In recent years, with the aim of increasing the efficiency of gas turbine engines, the maximum cycle temperature has increased (1,300 to 1,400°C or higher), and the temperature at the inlet of the heat exchanger has also increased to 1,000 to 1,200°C. Materials and techniques suitable for sealing such high-temperature gases have not yet been developed, and their development has been strongly desired.

Fig. 1 and Fig. 2 conceptually show a rotary regenerative heat exchanger, in which a large number of honeycomb-like channels 1a are arranged in the rotation axis X direction.
A core 1 having a core 1 is driven and rotated from the outside by a drive device (not shown) via an integrally fixed ring gear 2, and high-temperature gas flowing from a high-temperature gas flow path 3 flows through a flow path 1a of the core 1. It passes in the direction of arrow A and flows out into the exhaust duct 1 .

On the other hand, the low temperature gas (including air) in the low temperature gas flow path 5 also passes through the flow path 1a of the core 1 in the direction of arrow B and flows out into the flow path 6. heat is given by

Further, a sealing member 7 constituted by a ring portion 7a and a horizontal rib-like portion 7b and a half-ring-shaped sealing member 8 slide in contact with each other on both sides of the core 1, thereby separating the high-temperature gas flow and the low-temperature gas flow. Isolated.

Note that S is the casing of the rotary regenerative heat exchanger.

In a rotary regenerative heat exchanger with such a configuration,
Since the side where the high temperature gas flows in is also the discharge side of the low temperature gas which has become high in temperature due to heat exchange, the high temperature side sealing member 7 becomes significantly hotter than the low temperature side sealing member 8.

Conventionally, high-temperature sealing devices used in such high-temperature parts have a metal brace fixed to the casing, and nickel oxide is used as the base material for the high-temperature seal.

Either a sealing member such as calcium fluoride is coated by thermal spraying or the like and this sealing member is brought into sliding contact with the core 1, or a metal holder is fixed to the casing, the sealing member is inserted into this holder, and the sealing member is fixed. One of the methods used was to bring the core 1 into sliding contact with the core 1.

However, both have a structure in which the seal member is fixed to the metal base material, and the material of the seal member itself has poor heat resistance and wear resistance, so when the inlet temperature of high-temperature gas increases, the metal base material deforms and the seal member There are drawbacks such as loss of sealing function due to loss of flatness, risk of the sealing member peeling off from the metal base material, and significant wear of the sealing member itself.

In addition, in order to solve these drawbacks, if fine ceramics, etc., which have excellent heat resistance and wear resistance, are used as the sealing material, the hardness of fine ceramics is extremely high, so the wear of the core will be significantly increased, making it difficult to use. There were some drawbacks that I could not tolerate.

This invention has been made in view of the above points, and provides a high-temperature sealing device for a rotary regenerative heat exchanger that does not require a sealing member having extremely high-temperature sliding characteristics, has good productivity, and can be supplied at low cost. The purpose is to provide

Therefore, in the high temperature sealing device according to the present invention, a long - 3 = groove is provided in the sliding surface of the transverse rib-shaped portion of the sealing member against the core, one end of which is closed and the other end is open to the high temperature gas side. The sealing member is cooled by causing carryover gas from the side to flow out to the high temperature gas side through the long groove.

Hereinafter, the present invention will be described in detail with reference to FIGS. 3 to 5 of the accompanying drawings. Parts corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals. The explanation will be omitted.

In FIG. 3, a long groove 10 is provided on the sliding surface of the transverse rib-shaped portion 7b, usually called a crossbar, of the sealing member 7 that insulates and isolates high-temperature gas and low-temperature gas, and the core 1 slides on the core 1.
0 is closed, and the other end is opened to the high temperature gas flow path 3 side through the communication groove 10a. The rest of the structure is exactly the same as the conventional structure shown in FIGS. 1 and 2.

With the above configuration, when the core 1 starts rotating and high-pressure low-temperature gas flows into the fine honeycomb-like flow path 1a of the core 1 through the low-temperature gas flow path 5 shown in FIG. Although it is heated and flows out into the flow path 6, the outlet of some of the flow paths 1a is blocked by the horizontal rib-like portion 7b of the sealing member 7-4, so the low temperature gas that has flowed into the flow path 1d is It is trapped as a carryover gas in 1a and flows into the long groove 10.

On the other hand, the high-temperature gas in the high-temperature gas flow path 3 is also confined within the flow path 1a as a carryover gas and flows into the long groove 10, but since the high-temperature gas has a lower pressure than the low-temperature gas, there is a pressure gradient inside the long groove 10. occurs.

Here, when the core 1 further rotates, the carryover gas trapped in the flow path 1a is unblocked by the horizontal rib-shaped portion 7b and opens into the high temperature gas flow path 3, so that the pressure gradient in the long groove 10 increases. As a result, the low-temperature gas displaces the high-temperature gas and flows into the high-temperature gas flow path 3, thereby cooling the horizontal rib-shaped portion 7b of the seal member 7 and lowering the average temperature of the seal member 7.

As described above, according to the present invention, the sliding surface of the horizontal rib-shaped portion of the sealing member of the rotary regenerative heat exchanger with the core is closed at one end and opened to the high-temperature gas side. A long groove is provided to allow the low-temperature gas trapped in the honeycomb-like flow path in the rotating core to flow through the long groove to the high-temperature gas side, thereby cooling the sealing member and lowering its average temperature. , it is possible to obtain a long-life high-temperature sealing device without requiring the sealing member to have extremely high-temperature sliding characteristics.

Furthermore, since the structure is simple and no separate cooling device is required, productivity is good and the rotary regenerative heat exchanger can be supplied at low cost.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view conceptually showing the configuration of a rotary regenerative heat exchanger to which the present invention is applied; Fig. 2 is an exploded perspective view of the main parts similarly showing the gas flow state; FIG. 4 is a partially enlarged sectional view taken along line IV-IV in FIG. 6; FIG. 5 is a plan view showing the sliding surface side of a seal member showing an embodiment of the invention; 3 is a partially enlarged cross-sectional view taken along the line. 10. Core 3...High temperature gas flow path 5...
Low-temperature gas flow path 7...Seal member 7b...Horizontal rib-like portion 1o...Long groove 10a...Communication groove 7- Fig. 1 Fig. 2 Fig. 8- Fig. 3 Fig. 4 n Fig. 5

Claims (1)

[Claims] 1. A cylindrical core equipped with an axial passage through which a plurality of fluids involved in heat exchange pass, a drive device that rotates this core around a cylindrical axis, and insulating and isolating the plurality of fluids. In a rotary regenerative heat exchanger having a sealing member having a horizontal rib-like portion, one end of the horizontal rib-like portion of the sealing member that slides against the core is closed, and the other end faces the high-temperature gas side. A rotary regenerative heat storage system characterized in that a sealing member is cooled by providing an open long groove, guiding carryover gas from the low temperature gas side to the long groove and letting it flow out from the opening to the high temperature gas side. Exchanger high temperature sealing device.