JPS582A - Waste heat recovering boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waste heat recovery boiler that heats water using high-temperature exhaust gas from a gas turbine to generate steam for driving a steam turbine. The present invention relates to a waste heat recovery boiler that can eliminate various problems caused by thermal expansion of heat transfer tubes.

As shown in the figure, the waste heat recovery boiler l is supplied with high temperature exhaust from the gas turbine λ from below.

This high-temperature exhaust gas is sent to, for example, a superheater J or a pre-evaporator.

Denitration equipment! , high-pressure evaporator 4, high-pressure work; nomizer 7°; heating of the low-pressure evaporator t and 2 low-pressure economizers (O) In the process of exhausting air from the chimney through the equipment, the low-pressure and high-pressure steam drums installed outside the boiler l This is a device that heats water or steam from the condenser /4' of the steam turbine 13 or the steam turbine 13 to generate steam for driving the steam turbine /3 that rotates the generator 5 together with the gas turbine.

Denitration equipment for the waste heat recovery boiler mentioned above! The main components of the series of heating devices from the superheater 3 to the low-pressure economizer are a large number of heat exchanger tubes that meander and circulate within the boiler. is supported by support plates /4 and /4 arranged inside the boiler. Also, the above heat exchanger tube/! is 1 for each heating device.
There are not only books, but a large number of heat transfer tubes for each heating device, and as shown in FIGS. 2 and 3, there are many heat transfer tubes/! , /j#i 7 headers/ for each unit
? Kt is fixed and connected via header /7 to a cylindrical nozzle lq fixed so as to pass through the side plate /l of the boiler.

In other words, external piping and heat transfer tubes/! , /! The connection is made through the nozzle 19 and the spatula f/7 (see FIG. 1).

Therefore, the heat exchanger tube /j- in the boiler during plant operation.

The header 1, nozzle stub 9, etc. are heated to several hundred degrees, and as a result, the heat exchanger tube 15 thermally expands in the length direction.

However, if the number of 2 heat transfer tubes/jFi is very large, the weight is also large, so the support plate fixed inside the boiler/6
The frictional force between the heat exchanger tube /j and the heat exchanger tube /j acts in a direction that restricts the elongation of the heat exchanger tube /j-, and as a result, there is a risk that large stress will occur at the joint between the heat exchanger tube iz and the heat exchanger /j and cracks will occur. There is.

In addition, the axial force of the heat exchanger tube /3 in the direction of the header /3 is combined and applied to the joint between the boiler side plate /1 and the nozzle base /q via the header1, furthermore, K or .

The side plate/gK is kept at a relatively low temperature by the insulation material K (see Figure 2) lined inside the boiler.

A nozzle that expands thermally in the radial direction/? A great force is applied from
Which of these forces are 4bIll plate/l and nozzle/? This adversely affects the joints with the waste heat recovery boiler and reduces the reliability of the waste heat recovery boiler.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages and provide a waste heat recovery boiler that is free from the risk of cracking or high stress generation due to thermal expansion pressure of heat exchanger tubes, nozzles, etc.

Embodiments of the present invention will be described below with reference to FIGS. V and 5.

In Fig. V, the nozzle through hole 2/#'i opened in the side plate is shown. It has a diameter sufficient to fit the base/de loosely.

The nozzle head/9O boiler external protrusion that loosely fitted into the nozzle through hole ko/ and passed through the side plate/g is supported by the nozzle holder. This nozzle holder nFi, the bottom plate nK that is connected to the nozzle/de, and the cup-shaped member that has the nozzle joint hole Koda that fits with the nozzle head opened, and the opening is the nozzle through hole, 2/ Rather than being connected to the surrounding area, it is integrally attached to the outside of the board. That is, it penetrates the bottom plate n of the nozzle holder,
The nozzle holder is connected to the bottom plate HK by press-fitting or welding, for example, to the nozzle holder joining hole 5eyc, while maintaining the airtightness of the boiler can.
lK is indirectly supported.

The bottom plate 2J#i of the nozzle holder is sufficiently thin to maintain the necessary strength, and has a trap so that it can be slightly elastically deformed in the thickness direction, that is, in the axial direction of the nozzle holder 19.

On the other hand, on the inside of the nozzle holder, there are a plurality of radially arranged around the external opening of the nozzle through hole, with a small gap between the nozzle holder and the nozzle holder. Individual steady rest pieces are provided.

In the waste heat recovery boiler according to one embodiment of the present invention configured as described above, the thermal expansion of the heat exchanger tubes 3.3 in the direction of 3, 3 and 7 and in the nozzle stub direction is as follows.

As shown by the broken line in FIG. V, this is absorbed by the elastic deformation of the bottom plate n of the nozzle holder.

Also, the radial displacement or vibration of the nozzle/de is the above-mentioned piece: L! r, is restrained by MK, and the unreasonable force applied to the bottom plate n of the nozzle holder is alleviated.

FIG. 5 shows a modified embodiment of the present invention, in which the bottom plate k of the nozzle holder is not made thin, but instead a pleat is formed over the entire length of the K@ surface. Nozzle holder-KM
It has been given m-character.

In the one shown in Figure 1, the thermal expansion of the heat exchanger tube /,1 is absorbed by the elastic deformation of the folded portion, so compared to the one shown in Figure V, the heat exchanger tube /j is very long and its It has the advantage that it can be applied even when the amount of thermal expansion is large.

As is clear from the above description, one aspect of the present invention is to attach the nozzle to the boiler side plate through a nozzle support that is flexible in the axial direction of the nozzle, without directly fixing the nozzle to the boiler side plate. Because of the pressure, the thermal expansion of the heat exchanger tube group in the direction toward the direction during boiler operation is absorbed by the elastic deformation of the nozzle support.
Excessive stress concentration at the joint between the heat exchanger tube and the header and the risk of cracking or damage to the joint due to this can be prevented.

In addition, a relatively large gap is maintained between the nozzle head and the inner peripheral surface of the nozzle passage hole on the boiler side plate, so the side plate, which is kept relatively cool by the insulation, and the nozzle head, which becomes hot, are There is no generation of thermal stress due to differences in thermal expansion, and it is possible to prevent cracks in the nozzle stub, which could conventionally occur due to this thermal stress.

It has various effects such as.

[Brief explanation of the drawing]

Figure 7 is a system diagram of a combined cycle power plant that combines a waste heat recovery boiler, a gas turbine, and a steam turbine. Figure 2 is a diagrammatic cross-sectional view of the header and nozzle connection. Figure 97 is the diagram shown in Figure 1. Sectional view along line m-III, section V
The figure is a diagrammatic cross-sectional view of the connecting portion of the waste heat recovery boiler according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view similar to FIG. V showing a modified embodiment of the present invention. be. /...waste heat recovery boiler, gas l-bin for use, /θ...
・Exhaust port, /j...heat exchanger tube, /A-...support plate,
/7...Heh, da. /G...Side plate, /q...Nozzle holder, 〃...Insulation material, /...Nozzle holder through hole, =...Nozzle holder, Mouth...Bottom plate, Comment...Pipe Base joint hole. Seat...piece, purpose...fold. Applicant's agent Inomata Seimaku 21 yen 1 tail 3 illustrations 4 illustrations

Claims (1)

[Scope of Claims] / A sealed can body with a supply port for high-temperature exhaust gas from a gas turbine in the lower part and an exhaust port in the top part, and a heat insulating material pasted on the inner surface, and a meandering part inside the can body. A large number of heat exchanger tubes arranged in a small pile, and a header with multiple heat exchanger tubes for each heating unit connected to each other, pass through one side plate of the can body, and interconnect the header and the piping outside the can body. In the case where the nozzle head is loosely fitted into the nozzle through hole opening in the side plate of the can body, and the nozzle head is loosely fitted into the nozzle head through hole opening in the can body side plate, and the nozzle head is connected to the can body by the nozzle joint hole in the bottom surface. Open it. A cup-shaped member with an opening connected to the outer surface of the side plate of the can.
The nozzle is supported by a flexible nozzle support in the nozzle axis direction, and on the other hand, a swing is provided at the external opening of the nozzle through hole so as to surround the nozzle and the nozzle while maintaining a space between the nozzle and the nozzle. A waste heat recovery boiler characterized by the provision of a stopper. Claim 1 characterized in that
Waste heat recovery boiler as described in section. J. Claim 1, characterized in that a pleat is formed on the side surface of the nozzle holder, and the elastic deformation of the pleat allows the nozzle holder to have flexibility. The waste heat recovery boiler described.