JP2006002622A - Regenerator for gas turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regenerator for a gas turbine, excellent in miniaturization of a structure and maintainability while advantages such as long service life and high reliability are well used. <P>SOLUTION: This regenerator for the gas turbine comprises a cylindrical casing 12 guiding exhaust gas d in the gas turbine, and two or more heat transfer tubes 13 arranged in the casing 12 and guiding combustion air a. An opening 15 for taking out/in the heat transfer tube 13 is provided to the casing 12, and also a tube plate 14 closing the opening 15 is provided thereto. Further, the heat transfer tube 13 is formed into a U shape, and also the opening end of the heat transfer tube 13 is inserted and fixed in a hole 9 opened in the tube plate 14. Furthermore, a header 10 having a combustion air inlet 10a and a combustion air outlet 10b which are opposed to the opening ends 13a, 13b of the heat transfer tube 13 is arranged on the tube plate 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a regenerator for a gas turbine that preheats combustion air by exchanging heat between exhaust gas of the gas turbine and combustion air.

  In a so-called cogeneration system that extracts two or more secondary energies (electricity, heat, etc.) from primary energy (fuel), heat exchange between the exhaust gas of the gas turbine and the combustion air is performed by a regenerator to preheat the combustion air. To improve turbine efficiency, in other words, power generation efficiency. This type of regenerator performs heat exchange between gases and is called a gas turbine regenerator.

  This gas turbine regenerator has a heat transfer tube in a heat exchanger through which exhaust gas flows, and combustion air flows in the heat transfer tube. Generally, (1) plate fin type heat exchange (2) Plate type heat exchanger, (3) Primary surface type heat exchanger, and (4) Fin tube type heat exchanger from the viewpoint of heat exchange performance, Exchangers have been used. However, it has a fatal defect that it is weak against thermal fatigue and has a short life, and has a problem in reliability.

  Moreover, since the pressure loss is large on both the combustion air side and the exhaust gas side, the performance of the gas turbine may be deteriorated. Moreover, since the cross section of the flow path of the exhaust gas (secondary side) is smaller than that of the waste heat boiler, a connection duct for connection is required, which is disadvantageous in terms of space.

  In addition, the fin tube type heat exchanger of the above item (4) is widely used as a general-purpose heat exchanger such as a boiler or a cooler, but its shape is large (about the plate fin type heat exchanger). 5 times), but the actual performance as a gas turbine regenerator is not found.

On the other hand, the gas turbine regenerator has a heat exchange vessel through which exhaust gas flows, and a heat transfer tube through which combustion air flows in a tube disposed in the heat exchange vessel, and the heat transfer tube has a hairpin shape A gas turbine regenerator has been proposed in which an intermediate portion thereof is attached to the ceiling of a heat exchange vessel via a hanger (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2002-129799 (page 4-5, FIG. 8)

  However, this gas turbine regenerator is intended to be fixed to the ceiling by an appropriate means with the combustion air inlet joint pipe and the combustion air outlet joint pipe penetrating the ceiling of the heat exchanger. There is a problem that the combustion air inlet joint pipe, the combustion air outlet joint pipe, and the heat transfer tube connected between the two joint pipes cannot be easily taken out of the heat exchanger during maintenance.

  In addition, since the heat transfer tube meandering in the shape of a hairpin is attached to the ceiling of the heat exchange container using a bracket, a pin, or the like, there is a problem that it is an assembly operation in the heat exchanger and the maintenance becomes troublesome.

  The present invention has been made to solve such problems, and the object of the present invention is to reduce the size of the structure and maintainability while taking advantage of its long life and high reliability. It is possible to provide a gas turbine regenerator excellent in the above.

  In order to solve the above problems, the present invention is configured as follows.

  The regenerator for a gas turbine according to the first aspect of the present invention includes a cylindrical casing that guides the exhaust gas of the gas turbine, and a plurality of heat transfer tubes that are provided in the casing and guide combustion air. A regenerator for a gas turbine, wherein an opening for taking in and out the heat transfer tube is provided in the casing, a tube plate for sealing the opening is provided, and the heat transfer tube is further U-shaped. A combustion air inlet and a combustion air that are formed in a shape and are inserted and fixed in a hole provided in a tube plate, and the tube plate faces the opening end of the heat transfer tube. A regenerator for a gas turbine characterized in that a header having an outlet is provided.

  The gas turbine regenerator according to claim 2 is characterized in that the cross section of the exhaust gas passage of the casing is the same as or similar to the cross section of the exhaust gas passage of the waste heat boiler. Regenerator.

  A gas turbine regenerator according to a third aspect of the invention is a gas turbine regenerator characterized in that the gas turbine regenerator according to the first aspect is used as a unit unit.

  In the gas turbine regenerator according to the invention described in claim 4, the unit units are arranged in series, and the combustion air outlet portion and the combustion air inlet portion of the adjacent unit units are connected by a connecting pipe. The gas turbine regenerator according to claim 3, wherein the regenerator is a gas turbine regenerator.

  As described above, the gas turbine regenerator according to the first aspect of the present invention has a cylindrical casing that guides the exhaust gas of the gas turbine, and a large number that is provided in the casing and guides combustion air. A regenerator for a gas turbine comprising a heat transfer tube, wherein an opening for inserting and removing the heat transfer tube is provided in the casing, a tube plate for sealing the opening is provided, and the heat transfer is further provided. Combustion air which forms a heat tube in a U-shape, inserts and fixes the opening end of the heat transfer tube into a hole provided in the tube plate, and opposes the tube plate to the opening end of the heat transfer tube A header having an inlet and a combustion air outlet is provided.

  Therefore, it has many effects as follows.

That is,
(A) As described above, by making the tube through which combustion air passes U-shaped, thermal fatigue damage due to thermal expansion or the like can be avoided. For this reason, the lifetime is greatly extended, and the reliability is remarkably improved.

  (B) By making the header common, the tube bundle portion can be taken out with the regenerator casing installed. This facilitates inspection and maintenance of the regenerator.

  (C) The regenerator of the present system is particularly advantageous when applied to an intermediate cooling cycle type gas turbine. Compared to the simple cycle type, the regenerator of the primary side (combustion air) and the secondary side fluid (of the gas turbine) The temperature difference from the exhaust gas) can be about 1.5 times or more. For this reason, the heat exchanger dimensional difference with another system can be suppressed.

  Since the gas turbine regenerator according to the invention of claim 2 has the exhaust gas passage cross section of the casing the same as or similar to the exhaust gas passage cross section of the waste heat boiler, the casing of the regenerator and the waste heat boiler are directly It became possible to connect. As a result, the installation space for the regenerator can be reduced.

  The gas turbine regenerator according to the invention of claim 3 can be standardized by using the gas turbine regenerator of claim 1 as a unit unit. As a result, it has become possible to reduce the cost and increase the design cost due to the increase in capacity.

  Further, as described above, by making the regenerator into unit units, it is possible to maintain reliability without requiring a special structural change even when the size is increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, 1 is a gas turbine device, 2 is a generator, 3 is a regenerator, and 4 is a waste heat boiler. As shown in FIG. 2, the gas turbine device 1 includes a compressor 6, a turbine 7, and a combustor 8.

  As shown in FIG. 2, the intake air (combustion air) a is compressed by the compressor 6 of the gas turbine device 1 to become compressed air a ′, and is then preheated by the regenerator 3 to be preheated at high pressure. The high-pressure preheated air a ″ and the fuel b are supplied to the combustor 8 and burned violently in the combustor 8.

  The high-temperature and high-pressure combustion gas c obtained by the combustor 8 is introduced into the turbine 7 to operate the turbine 7, the compressor 6 and the generator 2. The electric power generated by the generator 2 is supplied to the customer.

  As described above, the exhaust gas d discharged from the turbine 7 is preheated with the compressed air a ′ in the regenerator 3 and then introduced into the waste heat boiler 4, and the heat energy is recovered by the waste heat boiler 4. .

  As shown in FIG. 3, the regenerator 3 includes a header 10, a tube bundle 11, and a casing 12. A large number of paired tubes or plate-type tubes are used for the tube bundle 11. For example, as shown in FIG. 5, the pair tube 13 includes an outer tube 13 ′ and an inner tube 13 ″ in a side view.

  The tube bundle 11 is provided in the casing 12 as shown in FIG. In addition, the pair tubes 13 ′ and 13 ″ constituting the tube bundle 11 are each formed in a U shape and are suspended from the tube plate 14. For this reason, they are not restrained by thermal expansion or the like. It has a structure.

  Thus, by making the pair tubes 13 ′ and 13 ″ U-shaped, the two tip portions, that is, the two open ends 13a and 13b can be attached to the common tube plate 14. To explain, the paired tubes 13 ′ and 13 ″ are fixed by inserting their tip opening ends 13 a and 13 b into holes 9 (not shown) provided in the tube plate 14.

  The tube sheet 14 is attached to the casing 12 so as to seal the opening 15 provided on the upper wall surface of the casing 12. Therefore, the tube plate 14 and the tube bundle 11 can be easily removed from the casing 12 during maintenance.

  Further, a header 10 having a combustion air inlet 10a and a combustion air outlet 10b is provided on the tube plate 14 to make the whole compact. The header 10 is configured such that the combustion air inlet 10 a faces one open end 13 a of the pair tube 13 and the combustion air outlet 10 b faces one open end 13 b of the pair tube 13.

  Thus, the combustion air a ′ introduced from the combustion air inlet 10a of the header 10 enters the pair tube 13 through one open end 13a of the pair tubes 13 ′ and 13 ″ and passes through the pair tube 13 ′. It is preheated by the exhaust gas d of the gas turbine. The preheated combustion air a "flows out from the other open end 13b of the pair tubes 13 'and 13" to the combustion air outlet 10b of the header 10.

  As shown in FIG. 4, the pair tubes 13 are shifted in phase by a half pitch with respect to the direction in which the exhaust gas d passes to efficiently recover thermal energy.

  The cross section of the exhaust gas passage of the casing 12 is the same as or similar to the cross section of the exhaust gas passage of the waste heat boiler 4, so that the regenerator 3 and the waste heat boiler 4 are directly connected to reduce the communication duct space. It has become.

  Further, when the heat exchange capacity increases, the regenerator 3 is made one unit unit 20 as shown in FIG. The unit units 20 are arranged in series, and the combustion air outlet 10b and the combustion air inlet 10a of the adjacent unit units 20 are connected to each other by the U-shaped connecting pipe 16 outside the header 10.

  Also, several plates (not shown) are attached to the tube bundle 11 to prevent the bare tube 13 from vibrating. Furthermore, it can be set as a plate tube type by attaching the heat transfer promotion plate 17 like FIG. Thereby, the heat transfer performance on the exhaust gas side (secondary side) can be improved without changing the overall size of the regenerator.

It is a side view of the cogeneration equipment containing the regenerator for gas turbines concerning the present invention. 1 is a configuration diagram of a cogeneration system including a gas turbine regenerator according to the present invention. FIG. It is a front view of the regenerator for gas turbines concerning this invention. FIG. 4 is an X-X ′ enlarged sectional view of FIG. 3. It is a principal part expanded sectional view of the regenerator for gas turbines concerning this invention. It is a principal part expanded sectional view at the time of attaching the regenerator for gas turbines which concerns on this invention in series. It is a principal part expansion perspective view of other embodiment of the regenerator for gas turbines which concerns on this invention.

Explanation of symbols

a Combustion air d Gas turbine exhaust gas 3 Regenerator 9 Hole
DESCRIPTION OF SYMBOLS 10 Header 10a Combustion air inlet 10b Combustion air outlet 12 Casing 13 Heat transfer tube 13a, 13b Open end of heat transfer tube 14 Tube sheet 15 Opening

Claims (4)

A gas turbine regenerator comprising a cylindrical casing for inducing exhaust gas from a gas turbine, and a plurality of heat transfer tubes provided in the casing and for inducing combustion air, An opening for taking in and out the heat transfer tube is provided, a tube plate for sealing the opening is provided, the heat transfer tube is formed in a U shape, and the open end of the heat transfer tube is formed as a tube plate And a header having a combustion air inlet and a combustion air outlet facing the opening end of the heat transfer tube. The header is regenerated for a gas turbine. vessel. The regenerator for a gas turbine according to claim 1, wherein a cross section of the exhaust gas passage of the casing is the same as or similar to a cross section of the exhaust gas passage of the waste heat boiler. The gas turbine regenerator according to claim 1 is a unit unit. The regenerator for a gas turbine according to claim 3, wherein the unit units are arranged in series, and the combustion air outlet and the combustion air inlet of adjacent unit units are connected by a connecting pipe.

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