JPS62190306A - Exhaust-heat recovery heat exchanger - 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] [Object of the Invention] (Industrial Application Field) The present invention relates to an exhaust heat recovery heat exchanger that uses exhaust gas from a gas turbine to generate and heat steam for driving a steam turbine, for example. In particular, the present invention relates to an exhaust heat recovery heat exchanger that has an improved header drum that collects thin tubes for water distribution in the drum.

(Prior Art) Recently, a combined cycle has been known that uses the exhaust heat of a high-efficiency gas turbine to drive a steam turbine.

As an antagonistic heat recovery heat exchanger used in such a combined cycle, for example, the one shown in FIG. 11 is known. FIG. 11 schematically shows the overall configuration of the exhaust heat recovery heat exchanger 1. That is, the exhaust heat recovery heat exchanger 1 has a gas passage 3 in a box-shaped box 2 through which exhaust gas passes.
The exhaust gas is configured to flow upward from the bottom of the box 2. A large number of finned thin tubes 4 are arranged in this box 2, and the drum water passing through the thin tubes 4 is heated by heat exchange with exhaust gas. The ends of each of the thin tubes 4 are gathered in a pair of header drums 5 within the box 2. One of the header drums 5 (for example, the upper one) is set as the inflow side, and the drum water flowing from the inlet header drum 5 is distributed to the thin tubes 4 and circulated, heated by heat exchange, and then the outflow side The steam turbine is supplied to a steam turbine (not shown) from the shift drum 5 (for example, the lower one).

FIG. 12 is an enlarged plan view of the header drum 5 shown in FIG. 11.

In FIG. 12, reference numeral 6 denotes a header drum main body, and a communicating pipe 7 for inflow and outflow of drum water is connected to the middle part of the header drum main body. Also,
A nozzle stand 8 is provided protruding from the peripheral wall portion of this header drum main body 6,
The thin tube 4 described above is connected to this nozzle holder 8 . Inspection nipples 9 are protruded from both ends of the header drum body 6. This inspection nipple 9 is composed of an inspection nipple main body 9a and a cap 9b welded to its tip.

FIG. 13 is an enlarged view of the inspection nipple 9, with a portion shown in a cut section. That is, the header drum main body 6, the inspection nipple main body 9a, and the cap 9b each have a welded portion 1Qa.
, 10t).

By the way, inside the finned thin tube 4 and header drum 5, the steam temperature is 100 to 600°C, and the internal pressure is 10°C.
~BOK'j/aAP1 degree severe operating conditions. For this reason, it is desirable to inspect the inside of the header drum 5 as much as possible, and the inspection nipple 9 is used for this purpose. That is, during periodic inspections, etc., the welded portion 10b on the tip side of the inspection nipple body 9a is cut and inspected visually or internally. An internal inspection is performed using lt or the like.

However, depending on the header drum 5 having the above-mentioned inspection nipple 9, after cutting the welded part 10b and performing an internal inspection, the tip of the inspection nipple main body 9a and the cap 9b are grooved, and Thereafter, it is necessary to weld again to make the inspection nipple 9 into a closed structure. Since such cutting and welding must be performed inside the box-shaped box 2, work efficiency is greatly improved.
In addition, there is a risk that chips may enter the header drum body 6 during cutting or beveling, and in addition, a new cap 9b is required every time inspection is performed, and the soundness of the welded part is checked by non-destructive inspection etc. after welding. Work such as confirmation is required.

Note that FIG. 14 shows another conventional example of the exhaust heat recovery heat exchanger, and FIG. 15 is a diagram corresponding to FIG. 12 showing an enlarged view of the @-shifting drum shown in FIG. 14.

In the Kanyoze zedrum shown in Figs. 14 and 15,
An inspection nipple 9 is provided to protrude upward from the peripheral wall of the header drum body 6. Other configurations are shown in Figures 11 to 13.
It is almost the same as shown in the figure. That is, the inspection nipple 9 is composed of a cylindrical inspection nipple main body 9a and a cap 9b welded to the tip thereof. Therefore, the only difference is the mounting position and angle of the inspection nipple 9, but there is no difference in that cutting, rewelding, etc. are required during inspection.

In addition, in the structure shown in FIGS. 14 and 15, the sealed inspection nipple 9 is provided in an upright position at the top of the header drum body 6, so that it can be easily inspected after product manufacturing or internal inspection. There is a problem when performing a pressure test after welding. That is, when conducting a pressure test, water is injected into the header drum 5 to obtain a predetermined test pressure under the usage conditions shown in the drawings, that is, with the header drum main body 6 held horizontally. be. In this case, since the inspection nipple 9 faces upward and is closed, air accumulates in the upper end of the inspection nipple 9, and it takes time for the test pressure to rise to a predetermined level, and the pressure during the test There are problems such as instability.

(Problems to be Solved by the Invention) In the conventional exhaust heat recovery heat exchanger, when inspecting the inner surface of the header drum 5, the welded portion 1 of the inspection nipple 9
In addition to cutting the 0b, it is troublesome to perform groove processing and re-welding after welding inspection. Additionally, it is necessary to conduct non-destructive testing to ensure the integrity of the re-welded portion.

Further, there are problems such as the need for a new cap 9b and the intrusion of chips.

The present invention has been made in view of the above circumstances, and it is possible to improve the structure of the inspection nipple and make it extremely easy to open and close the inspection port when inspecting the inner surface of the header drum. It is an object of the present invention to provide an exhaust heat recovery heat exchanger that can eliminate the need for the heat exchanger and eliminate the conventional problems such as the intrusion of chips.

[Structure of the invention]

(Means for solving the problem) This defense consists of a box that forms a gas flow path through which the cultivation gas passes, and a large number of fins installed inside the box that heat the drum water that circulates inside. In an exhaust heat recovery heat exchanger having thin tubes and a header drum that connects the thin tubes within the box end, an inspection nipple for internal inspection of the header drum is configured with a cap removably attached to the inspection nipple body. That is.

(Function) Since the cap is removably attached to the inspection nipple of the header drum, it is possible to omit the trouble of cutting and rewelding the inspection nipple when inspecting the inner surface of the header drum. Therefore, the work can be done quickly and easily since a simple attachment/detachment operation is required, and there is no need to prepare new parts, and the fear of intrusion of chips and the like is also eliminated.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

Fig. 1 shows an enlarged view of the header drum part of the exhaust heat recovery heat exchanger according to this embodiment, and Fig. 2 shows an enlarged part of the inspection nipple part of the header drum main body in Fig. 1. It shows. Note that the box that constitutes the gas flow path through which the exhaust gas passes and the finned thin tubes that are installed in this box and that heat the drum water that circulates inside are the same as the conventional one shown in Figure 11. Therefore, the explanation will be omitted.

Header drum 11 of the exhaust heat recovery heat exchanger according to this embodiment
Here, a communicating pipe 13 is provided protruding from the central portion of the header drum body 12, and a large number of nozzles 14 are provided protruding from the peripheral wall, and thin tubes (not shown) are connected to each of the nozzles 14. Note that the communication pipe 13 is connected to a drum water supply pipe, a steam derivation pipe, or the like (not shown). Small-diameter cylindrical inspection nipples 15 are protruded from both ends of the header drum body 12, respectively. The inspection nipple 15 includes an inspection nipple main body 15a and a flange 15b connected to the distal end of the inspection nipple body 15a, and has a flange-type cap 16 removably attached to the flange 15b.

That is, as shown in FIG. 2, the inspection nipple 15 is fixed to the tip of the inspection nipple main body 15a by a fillet weld 17, and this flange 15b has a large number of bolt insertion holes 18 in its surrounding area. A protruding edge 19 is formed at the center of the surface portion. On the other hand, cap 16
is a blind plate-like one, and the bolt insertion hole 18 of the flange 15b is
It has a bolt insertion hole 20 in its periphery corresponding to the flange 15b, and a protruding surface part 21 on the side facing the flange 15b.

Then, the protruding edge 19 of the flange 15b and the cap 16
The bolt 23 as a fastening member is inserted into the bolt insertion hole 18°2 with the gasket 22 inserted between the protruding surface portion 21 of the
0 and tightens the flange 15b and cap 16 together with the nut 24. The gasket 22 is made of a material with high heat resistance and high pressure resistance.

According to such a configuration, when inspecting the inside of the header drum 11, the tip of the inspection nipple body 15a is removed by releasing the tightening by the bolts 23 and the bolts 24 and removing the cap 16 from the flange 15b. By opening the opening, work can be done easily and quickly. That is,
It is possible to omit the troublesome work of cutting the welded parts as in the conventional method.

Furthermore, after the inspection is completed, the tip opening of the inspection nipple body 15a can be closed by tightening the cap 16 onto the flange 15b again with the bolts 23 and nuts 24, so that chamfering, rewelding, etc. It also eliminates the need for time and effort. Therefore, there is no need to prepare a new cap, and there is no risk of chips entering the header drum 11.Furthermore, the soundness of the welded part can be confirmed by simply re-welding. Such troublesome inspection work can also be omitted.

In the above embodiment, the inspection nipple 15 was provided coaxially at both ends of the header drum main body 12, but the present invention is not limited to such a configuration, and the inspection nipple 15 is provided coaxially with the inspection nipple 15 at both ends of the header drum main body 12. This can also be achieved in the same manner in the case where the inspection nipples 15 are provided, for example, upwardly on the peripheral wall portions near both ends of the shifting drum body 12. Even with such an embodiment, the same effects as those of the above embodiment can be achieved.

Further, in each of the above embodiments, the cap 16 is of a flange type and is fastened to the open end of the inspection nipple 15 via a fastening member consisting of a bolt 23 and a nut 24, but the present invention is not necessarily limited to such a structure. I can't.

4 and 5 show different embodiments of the invention, in which the inspection nipple 15 is mounted upwardly on the header drum 11, while the cap 16 is in the form of a threaded plug;
A screw hole 25 formed at the open end of the inspection nipple body 15a
It is designed to be screwed into the

With this configuration, similarly to the embodiment described above, the inspection nipple 15 can be opened and closed very easily and quickly, which is necessary when inspecting the inner surface of the header drum 11 using the cap 16. Moreover, according to this embodiment, as shown in FIGS. 4 and 5, when performing a pressure test, water 26 is injected into the header drum main body 12, and the pressure test is performed using the water pressure. In case, cap 16 is installed in advance.
With the inspection nipple 15 removed, the amount of water 26 injected m is gradually increased, air is removed from the inspection nipple 15, the inspection nipple 15 is sealed with the cap 16, and then the water 26 is pressurized. Pressure tests can be performed without being affected by air pockets. That is, the injection of the water 26 will not become unstable due to air pockets, and the water pressure will not fluctuate, making it possible to improve the reliability of the pressure test.

In the embodiment shown in FIGS. 4 and 5, the inspection nipple body 15 has a certain volume and covers the inspection nipple 15.
Although the present invention has a configuration in which the inspection nipple main body is omitted, the inspection nipple body may be omitted and the nipple may have no internal volume. That is, as shown in FIG. 6, the inspection nipple may be a plug having a female threaded hole 28, and a plug 29 serving as a stopper may be removably screwed into the hole 28 of the plug.

With such a configuration, it is possible to inspect the header drum 11 easily and quickly as in the previous embodiment, and as shown in FIG. When inspecting the inside of the header drum 11, the endoscope insertion portion 31 can be easily inserted into the header drum 11 through the inspection nipple 15 as a plug, using the small hole 28 as a guide.
It can be inserted inside.

7 to 10 show still other embodiments of the present invention.

In this embodiment, a guide rail 32 for guiding a family gift 1t30 is installed in the header drum body 12 of the header drum 11 having substantially the same configuration as that shown in FIG. This guide rail 32 is the inspection nipple 1
5 has a curved guide portion 32a inwardly, and the curved guide portion 32a has f! Install header drum body 12
A linear guide portion 32b is disposed inside. 33. As shown in FIG. 10, the curved guide portion 32a and the linear guide portion 32b have a butunnel-shaped cross section, and are designed to stably guide the endoscope insertion portion 31 to a predetermined position. (See Figures 7 to 9).

By providing the kite rail 32 in this manner, inspection work inside the header drum 11 can be performed more reliably.

〔Effect of the invention〕

As described above, according to the waste heat recovery heat exchanger according to the present invention, the inspection nipple for internal inspection of the header drum is removably attached to the inspection nipple body (the cap is removably attached to the inspection nipple body). Unlike the case caused by blockages, inspection work can be performed easily and reliably, and there is no need for replacement parts, and there is no fear of intrusion of chips, etc., thus improving work efficiency and reducing costs. A roar that has excellent effects.

[Brief explanation of drawings]

Fig. 1 is a plan view of the main part showing one embodiment of the present invention, Fig. 2 is an enlarged partial sectional view of the main part of Fig. 1, and Fig. 3 shows another embodiment of the invention. 4 is a partially sectional side view of another embodiment; FIG. 5 is a sectional view taken along the line v-v of FIG. 4; and FIG. 6 is a slightly different embodiment of the present invention. A side view showing the example in partial cross section, FIGS. 7 to 9 are explanatory diagrams showing other different embodiments, FIG. 10 is a cross-sectional view taken along line x-xr; 1 is a partially sectional front view of a conventional heat recovery heat exchanger, FIG. 12 is a plan view showing the structure of a conventional header drum, and FIG. 13 is an enlarged view of a portion of FIG. 12. FIG. 14 is a partial sectional view showing a different conventional example, and FIG. 15 is a plan view showing an enlarged part of FIG. 14. 2...Box, 3...Flow path, 4...Thin tube, 11
...header drum, 15...inspection nipple, 15a
...Inspection nipple body, 16...Cap, 23.
...Bolt, 24...Natsuto. Vines 9 Illustrations 15 Illustrations

Claims (1)

[Claims] 1. A box constituting a gas flow path through which exhaust gas passes;
In an exhaust heat recovery heat exchanger having a large number of capillary tubes with fins provided in the box to heat drum water circulating inside the box, and a header drum that connects the capillary tubes within an end of the box, the header drum is An exhaust heat recovery heat exchanger characterized in that an inspection nipple with a removably attached cap is provided in an area subject to internal inspection. 2. The exhaust heat recovery heat exchange according to claim 1, wherein the cap has a flange portion and is connected to the flange portion provided at the open end of the inspection nipple body via a fastening member. vessel. 3. The cap is formed into a plug-like shape with a thread carved on its outer periphery, and is screwed onto a threaded portion formed at the open end of the inspection nipple body, as set forth in claim 1. Exhaust heat recovery heat exchanger. 4. The exhaust heat recovery heat exchanger according to claim 1, wherein the inspection nipple is mounted upward on the header drum. 5. The exhaust heat recovery heat exchanger according to claim 1, wherein a guide portion for guiding an inspection device is provided in the header drum.