JP3633667B2 - Support structure of heat transfer panel in exhaust heat recovery boiler - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an exhaust heat recovery boiler, and more particularly to a heat transfer panel support structure in an exhaust heat recovery boiler.
[0002]
[Prior art]
In recent years, combined cycles combining the Brayton cycle and Rankine cycle, and repowering that increases output by combining a gas turbine with an existing boiler, have become increasingly popular. FIG. 5 is an overall configuration diagram of an exhaust heat recovery combined cycle power plant that is one of the combined cycles. The exhaust of the gas turbine 1 is led to an exhaust heat recovery boiler 2 (HRSG: Heat Recovery Steam Generator). The steam is generated by generating steam to drive the steam turbine 3. This combined cycle takes advantage of the advantages of high gas turbine maximum utilization temperature and steam turbine minimum utilization temperature, and has high thermal and partial load efficiency, short start / stop time, It has the characteristics such as few. The exhaust heat recovery boiler shown in this figure is also applied to repowering in order to recover the exhaust heat of the gas turbine.
[0003]
FIG. 6 is an overall configuration diagram of a conventional exhaust heat recovery boiler. As shown in this figure, a conventional exhaust heat recovery boiler includes a boiler body 4 lined with a heat insulating material, and a plurality of (three in this figure) vertically placed on a gantry 4a in the body. Each heat transfer panel 5 is composed of upper and lower horizontal headers 5a and 5b (manifold) and a number of vertical heat transfer tubes 5c connecting the headers. The inside of the boiler body is partitioned by the partition plate 4b into an exhaust gas passage through which high-temperature exhaust gas (for example, 650 ° C.) from the gas turbine flows and a storage portion of the upper and lower headers so that each header is not directly exposed to the high-temperature exhaust gas. It has become. A panel support 6 is provided below the lower header 5b. The panel support 6 is supported by a gantry 4a to support the weight of the heat transfer panel. In addition, boiler feed water sequentially flows upward from the downstream side to the vertical heat transfer tubes 5c of each heat transfer panel 5 and is heated by the high temperature exhaust gas to become high temperature water or steam, thereby recovering the heat in the exhaust gas. Yes.
[0004]
FIG. 7 is a panel front view of the exhaust heat recovery boiler of FIG. In the large exhaust heat recovery boiler, the flow path cross section of the high-temperature gas is about 10 m × 10 m, for example, each heat transfer panel is heavy, and the horizontal length of the lower header 5b is also long.
[0005]
[Problems to be solved by the invention]
In the conventional exhaust heat recovery boiler described above, the heat transfer panel thermally expands (or contracts) in the width direction at the time of start-up or stop, so that the panel support 6 needs to slide horizontally on the gantry 4a. However, since high temperature exhaust gas (about 650 ° C) flows around the gantry 4a from the gap of the partition plate 4b, the sliding surface of the gantry 4a becomes almost the same high temperature, and the sliding friction coefficient after holding for a long time is extremely high. (For example, 2 or more), 2 and stick slip and 3 partial diffusion coupling occurred, and there was a problem that the heat transfer panel 5 did not slide smoothly on the gantry 4a (heat transfer panel support member).
[0006]
For this reason, an excessive horizontal force (for example, about 40 to 60 tons, more than twice its own weight) acts on the heat transfer panel due to an increase in the friction coefficient or diffusion bonding, or a stick slip causes heat to rise during cooling and heating. There is a problem that the expansion is suddenly released and an impact load is applied together with a severe impact sound (for example, a sound of “bakin” or “dawn”), which may cause cracks or the like in each part. This phenomenon occurs even in a relatively small exhaust heat recovery boiler, but is particularly important as the size increases.
[0007]
The sliding surface of the gantry described above receives a high surface pressure of 50 to 70 kg / cm ² while being exposed to a high temperature of, for example, about 650 ° C. or more. For this reason, the above-mentioned phenomenon cannot be avoided with ordinary materials, and conventionally, measures such as dividing the heat transfer panel in the width direction, increasing the strength of each part of the boiler, and frequently performing maintenance have been taken. . However, these measures have problems such as a complicated structure, an increased weight, a larger apparatus, and an excessive manufacturing cost.
[0008]
The present invention has been developed to solve such problems. That is, the object of the present invention is to reduce the amount of high-temperature oxidation of the sliding surface, eliminate stick slip and diffusion bonding, and heat transfer in the exhaust heat recovery boiler that can smoothly expand the heat transfer panel under high temperature and high surface pressure. It is to provide a panel support structure.
[0009]
[Means for Solving the Problems]
According to the present invention, it has a plurality of heat transfer panels arranged vertically in the boiler body and spaced apart along the horizontally flowing exhaust gas, and each heat transfer panel has upper and lower horizontal tubes. A heat transfer panel support structure for an exhaust heat recovery boiler, comprising a header and a number of vertical heat transfer tubes connected between the horizontal headers, wherein the upper end is rigidly connected to the lower header and extends vertically. A water supply pipe, a horizontal water supply pipe which is rigidly connected to the lower end of the vertical water supply pipe and extends substantially horizontally in parallel with the lower header, and a support provided directly below the horizontal water supply pipe so as to be capable of thermal expansion A structure for supporting a heat transfer panel in an exhaust heat recovery boiler, comprising a frame and a heat insulating material surrounding the support frame, wherein water is supplied to a lower header through a horizontal water supply pipe and a vertical water supply pipe Is provided.
[0010]
According to a preferred embodiment of the present invention, the horizontal water supply pipe has a plurality of horizontal support surfaces, and the support frame has a horizontal upper surface that supports the support surface of the horizontal water supply pipe . Moreover, it is preferable that the support surface of the said horizontal water supply pipe is provided in the position corresponding to a vertical water supply pipe.
[0011]
[Action]
According to the configuration of the present invention, a plurality of vertical water supply pipes and a horizontal water supply pipe extending horizontally in parallel to the lower header are rigidly connected to the lower part of the lower header of the heat transfer panel. By supporting the horizontal water supply pipe so as to be capable of thermal expansion, the entire heat transfer panel can be supported so as to be capable of thermal expansion in the length direction of the lower header . Further, since water is supplied to the lower header through the horizontal water supply pipe and the vertical water supply pipe, the horizontal water supply pipe and the vertical water supply pipe are made to have substantially the same temperature (for example, 200 to 300) as the lower header by the water supply flowing inside. C.). Furthermore, since the support frame is provided directly under the horizontal water supply pipe and this part is surrounded by the heat insulating material, the support water frame is cooled by the horizontal water supply pipe and the temperature rise due to the high temperature exhaust gas is prevented by the heat insulating material. As a result, the amount of high-temperature oxidation of the sliding surface of the support frame can be reduced, stick slip and diffusion bonding can be eliminated, and the heat transfer panel can be expanded smoothly under high temperature and high surface pressure.
[0012]
【Example】
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and used for the common part in each figure.
FIG. 1 is an overall configuration diagram of an exhaust heat recovery boiler having a heat transfer panel support structure according to the present invention. In this figure, the exhaust heat recovery boiler 10 has three heat transfer panels 7, 8, and 9 in the boiler body 4, and each heat transfer panel is arranged vertically and spaced along the exhaust gas flowing horizontally. Are arranged apart from each other. Each heat transfer panel is composed of upper and lower horizontal headers 5a and 5b (manifold) and a number of vertical heat transfer tubes 5c connecting the horizontal headers.
[0013]
Further in FIG. 1, downcomer 11a flowing water down pipe pulling 5b upstream from the upper pipe pulling 5a on the downstream side between the heat transfer panels 7, 8, 9 are al provided. Further, low temperature (about 180 to 200 ° C.) water is introduced from the outside into the lower header 5b of the most downstream heat transfer panel 9 from the feed water inlet line 11b, and the upper header 5a of the most upstream heat transfer panel 7 is introduced. Is heated to a high temperature of, for example, 300 ° C. or higher, and steam or high-temperature water is supplied to a main boiler (not shown) or the like via a feed water outlet line 11c. Note that the present invention is not limited to three heat transfer panels, and may be two or four or more.
[0014]
2 is a front view of a panel of a large exhaust heat recovery boiler having a heat transfer panel support structure of the present invention, FIG. 3 is a partially enlarged view of FIG. 2 showing the support structure of the most upstream or intermediate heat transfer panel, FIG. These are the A section enlarged views of FIG.
In FIG. 2, the lower header 5b of the most downstream heat transfer panel 9 is supplied with low-temperature (about 180 to 200 ° C.) feed water from the outside through the feed water inlet line 11b as in FIG. Moreover, as shown in FIG. 3, water supply is supplied to the most upstream and intermediate heat transfer panels 7 and 8 from the downstream upper header 5a through the downpipe 11a. In the large exhaust heat recovery boiler as shown in FIG. 2, the cross section of the high-temperature gas passage is, for example, about 10 m × 10 m or more, the weight of each heat transfer panel is heavy (for example, 20 to 30 tons), and the lower pipe The horizontal length of the shift 5b is, for example, 4 to 5 m or longer even when the heat transfer panels are separately provided on the left and right as shown in this figure.
[0015]
1 to 4, in the heat transfer panel support structure of the present invention, a plurality of vertical water supply pipes 12 whose upper ends are rigidly connected to the lower header by welding or the like and vertically extended downward, and lower ends of the vertical water supply pipes 12 A horizontal water supply pipe 14 that is rigidly connected to the lower header 5b and extends substantially horizontally, a support base 16 that is provided directly below the horizontal water supply pipe 14 and supports the horizontal water supply pipe 14, and a heat insulating material that surrounds the support base 16 18. Further, water is supplied to the lower header 5b through the horizontal water supply pipe 14 and the vertical water supply pipe 12.
[0016]
As shown in FIG. 4, the horizontal water supply pipe 14 has a plurality of horizontal support surfaces 14 a, and the support base 16 has a horizontal upper surface 16 a that supports the support surface 14 a of the horizontal water supply pipe 14. Yes. With this configuration, the support surface 14a of the vertical water supply pipe slides horizontally on the upper surface 16a of the support frame 16, so that the horizontal water supply pipe 14 can be supported by the support frame 16 so as to be thermally expandable.
[0017]
Furthermore, as shown in FIGS. 2 to 4, the support surface 14a of the horizontal water supply pipe 14, et provided at a position corresponding to the vertical water supply pipe 12 is, act a large bending moment in the vertical water supply pipe 12 and the horizontal water supply pipe 14 Without any change, the entire weight of the heat transfer panels 7, 8, 9 is transmitted to the support frame 16 via the support surface 14a.
[0018]
With the above-described configuration, the plurality of vertical water supply pipes 12 and the horizontal water supply pipe 14 extending horizontally in parallel with the lower header 5b are rigidly connected by welding or the like below the lower header 5b of the heat transfer panels 7, 8, 9. Therefore, by supporting the horizontal water supply pipe 14 by the support base 16 so as to be capable of thermal expansion, the entire heat transfer panel can be supported so as to be capable of thermal expansion in the length direction of the lower header (left and right in FIG. 2). it can.
Further, since water is supplied to the lower header 5b through the horizontal water supply pipe 14 and the vertical water supply pipe 12, the horizontal water supply pipe 14 and the vertical water supply pipe 12 are substantially the same as the lower header 5b by the water supply flowing inside. It can cool to temperature (for example, 200-300 degreeC).
[0019]
Furthermore, since the support frame 16 is provided immediately below the horizontal water supply pipe 14 and this portion is surrounded by the heat insulating material 18, the support frame 16 is cooled by the horizontal water supply pipe 14, and is heated by the high temperature exhaust gas by the heat insulating material 18. Temperature rise can be prevented, which reduces the amount of high-temperature oxidation on the sliding surface of the support frame, eliminates stick slip and diffusion bonding, and allows the heat transfer panel to thermally expand smoothly under high temperature and high surface pressure. it can.
[0020]
Of course, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.
[0021]
【The invention's effect】
As described above, the heat transfer panel support structure in the exhaust heat recovery boiler of the present invention reduces the amount of high-temperature oxidation on the sliding surface, eliminates stick slip and diffusion bonding, and smoothes the heat transfer panel under high temperature and high surface pressure. It has excellent effects such as thermal expansion.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an exhaust heat recovery boiler having a heat transfer panel support structure according to the present invention.
FIG. 2 is a panel front view of a large exhaust heat recovery boiler having a heat transfer panel support structure of the present invention.
3 is a partially enlarged view of FIG. 2 showing a support structure for the most upstream or intermediate heat transfer panel.
4 is an enlarged view of a part A in FIG. 3;
FIG. 5 is an overall mixture diagram of a conventional exhaust heat recovery combined cycle power plant.
FIG. 6 is an overall configuration diagram of a conventional exhaust heat recovery boiler.
FIG. 7 is a panel front view of a conventional large exhaust heat recovery boiler.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Waste heat recovery boiler 3 Steam turbine 4 Boiler main body 4a Mounting frame 4b Partition plate 5 Heat transfer panel 5a Upper header 5b Lower header 5c Vertical heat transfer tube 6 Panel support part 7, 8, 9 Heat transfer panel 10 Waste heat Recovery boiler 11a Precipitation pipe 11b Water supply inlet line 11c Water supply outlet line 12 Vertical water supply pipe 14 Horizontal water supply pipe 14a Support surface 16 Support frame 16a Upper surface 18 Heat insulating material

Claims (3)

A plurality of heat transfer panels arranged vertically in the boiler body and spaced apart along the horizontally flowing exhaust gas, each heat transfer panel comprising an upper and lower horizontal header and the horizontal header A heat transfer panel support structure in an exhaust heat recovery boiler, consisting of a number of vertical heat transfer tubes connected between,
A plurality of vertical water supply pipes whose upper ends are in rigid contact with the lower header and extend downward, a horizontal water supply pipe which is rigidly in contact with the lower ends of the vertical water supply pipes and extends substantially horizontally in parallel with the lower header, and a horizontal water supply pipe Provided with a support frame that is provided directly below the support frame and supports the horizontal water supply pipe so as to be thermally expandable, and a heat insulating material that surrounds the support frame, and water is supplied to the lower header through the horizontal water supply pipe and the vertical water supply pipe. A support structure for a heat transfer panel in an exhaust heat recovery boiler. The exhaust heat recovery according to claim 1, wherein the horizontal water supply pipe has a plurality of horizontal support surfaces, and the support frame has a horizontal upper surface that supports the support surface of the horizontal water supply pipe. Support structure for heat transfer panel in boiler. The support structure of the heat transfer panel in the exhaust heat recovery boiler according to claim 1, wherein the support surface of the horizontal water supply pipe is provided at a position corresponding to the vertical water supply pipe.

Images