JPS6132561B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is designed to prevent any hindrance to the connection between the two, even if there is a misalignment between the axis of the non-condensable gas extraction pipe of the feed water heater and the center of the outlet provided in the bending plate. This invention relates to a feed water heater that employs means that do not cause

In currently used steam turbine plants, in order to effectively utilize the thermal energy possessed by the steam extracted from the intermediate stage, a feed water heater is used that heats the feed water using this steam. Its structure is as shown in FIG. 1, and the function of the feed water heater 1 can be summarized as follows. The water that has flowed into the lower chamber 3a of the water chamber 3 from the water supply inlet 2 flows into the heat transfer tube 4, and the water therein flows into the drain cooling section 5 located in the lower left half of the center of the main body body 1a in FIG. The water in the heat exchanger tube part 4b in the condensate part 6 is heated by the heat held by the condensate and flows through the heat exchanger tube part 4a, and the water in the heat exchanger tube part 4b in the condensate part 6 is given the latent heat of the steam and its temperature is increased, and the water temperature is increased in the superheat return part 7. Heat exchanger tube section 4 extending to
The process proceeds to step c, where the heated steam flowing in from the heated steam inlet 7a is given sensible heat and turned into high-temperature water, and this hot water enters the upper chamber 3b of the water chamber 3 and then flows out from the water supply outlet 8. do.

In this way, the feed water heater 1 gives the thermal energy possessed by the steam to the water supplied to the boiler, but when the steam is condensed in the condensing part 6, the non-condensable gas that fills the condensing part 6 It is necessary to discharge the water to the outside of the feed water heater 6. For this purpose, heat exchanger tubes 4a,
A plurality of suction ports are formed on the side surfaces of the support plates 9 of 4b and 4c (I consist of plates that support the superheat return section 7 and the drain cooling section 5, respectively, but for convenience of explanation, I will explain them as a single plate). Non-condensable gas extraction tube 1
0 is a column 12 in which state bolts 11 embedded in the support plate 9 are inserted at several locations in the condensing part 6.
The heat exchanger tubes 4 are supported together with the heat exchanger tubes 4 by further support plates 13, 14 supported by the support plates 13 and 14 (see FIG. 3. A discharge port 1 provided in a bending plate 16 via a pipe connecting pipe structure 15 as shown in FIG.
6a.

The internal structure of the feed water heater having such a structure is that the drain cooling section 5 and the superheat return section 7 are installed in the main body 1a, and the support plate 13, 14, as shown in more detail in FIG. Although it is assembled by inserting the heat tube section 4b, the assembly work up to the support plate 14 is performed on a reference stand, so it is difficult to position the axis of the non-condensable gas extraction tube 10 to the desired accuracy. It is easy to use. However, the portion from the supporting plate 14 to the bending plate 16 is supported in a cantilevered manner, and the pipe connecting pipe structure 15 is intended to eliminate as much as possible the influence of downward deflection caused by its own weight. However, since this pipe connecting pipe structure 15 has a structure in which a straight pipe 17, a bent pipe 18, a straight pipe 19, and a pipe joint 20 are joined together, the pipe connecting pipe structure 15 is originally curved. It is attached and the main body 1
Since a is a canned part, its cylindricity is poor, so even if the fitting tolerance between the internal structure and the main body shell 1a is made as small as possible, the distance between the central axis of the internal structure and the center of the bending plate 16 There is a drawback that the tip of the non-condensable gas extraction tube 10 is largely deviated from the center of the bending plate 16 due to a large deviation occurring in the position. For this reason, conventional technology has adopted a method of anticipating dimensional and assembly errors and enlarging the outlet to some extent, but there is a limit to increasing the hole diameter due to welding, and therefore the gap between the non-condensable gas extraction pipe and the There was a restriction that the gap could not be made too large. Due to this limitation, there is a need to keep each of the above-mentioned errors within desired values both in manufacturing and in assembly.

The present invention was made in order to eliminate the above-mentioned drawbacks, and its purpose is to eliminate the need for high precision of each component, and to make centering work extremely easy so that there is no hindrance to welding. To provide a water heater.

The present invention will be explained below with reference to FIGS. 4 and 5. The outlet port 16a' shown in FIG. 4 (hereinafter referred to as the tube insertion hole) is opened to a size larger than the outer diameter of the non-condensable gas extraction tube 10 as will be described later. A shaped support member, such as a cylinder 41 (an embodiment of the cylinder will be described below) is fitted and airtightly attached, preferably welded, and its portion is indicated by 41a. An eccentric ring 42 is fitted onto the inner circumferential surface of the cylinder 41, airtightly attached, and preferably welded, and its portion is indicated by 42a. Then, the non-condensable gas extraction pipe 10 is inserted into a round pipe insertion hole 42b (see FIG. 6) formed in the eccentric ring 42, and is installed in an airtight manner, preferably by welding. The above-mentioned cylinder 41 has a multi-cylindrical structure, that is, a plurality of eccentric rings or concentric rings are arranged between the non-condensable gas extraction pipes and one eccentric ring is inserted between the cylinders. It may be a multi-tubular structure arranged concentrically or eccentrically with a ring interposed therebetween. The cylinder 41 may be cylindrical as described above, and therefore the eccentric ring or concentric ring described above may also have the same shape. Also, while other heating fluids may be used instead of hot air, the feed water heater can heat other fluids other than water.
Other fluids may also be used. In the support structure according to the present invention described above, the deviation between the center axis of the internal structure and the center of the bending plate 16 that occurs when the internal structure described above is installed in the main body shell 1a is one-dimensional in the vertical direction. As shown in FIG.
Even if the central axis of the internal structure is displaced from the central axis A to point B when there is no deviation, an eccentric ring 42 made with sufficient eccentricity to offset this deviation is attached to the cylinder 41. The problem of misalignment is solved by creating a pipe between the pipe and the non-condensable gas extraction pipe 10. Since the eccentric ring 42 is interposed between the cylinder 41 and the non-condensable gas extraction pipe 10 to make it appear as if there is no misalignment, it is natural that the inner circumferential cross-sectional area and the outer circumferential cross-sectional area of the cylinder 41 are area,
That is, the cross-sectional area of the cylinder insertion hole 16a' of the cover plate into which the cylinder 41 is fitted must be large enough to allow the above-mentioned deviation. Such a relationship also applies to the multi-tube structure.

In summary, according to the present invention, an eccentric ring is used in the cylindrical support member, for example, a cylinder, which has a cross-sectional area sufficient to absorb the deviation even if such deviation occurs. There is no problem in welding as in conventional methods. In this way, the deviation can be handled as if it were an apparent error within an allowable limit, and therefore the precision of each component can be relaxed within that limit.

[Brief explanation of the drawing]

Figure 1 is a partially sectional side view of a conventional feed water heater.
Fig. 2 is a longitudinal sectional view taken along the line of Fig. 1, Fig. 3 is a longitudinal sectional view taken along the line of Fig. 1, and Fig. 4 shows the main points of the present invention implemented in a feed water heater. FIG. 5 is a cross-sectional view taken along the line - in FIG. 4, and FIG. 6 is a diagram showing an eccentric ring used in the present invention. In the figure, 10 is a non-condensable gas extraction pipe, 16a' is an outlet, 41 is a cylinder, and 42 is an eccentric ring.

Claims (1)

[Claims] 1. In a feed water heater equipped with a non-condensable gas extraction pipe with one end facing the outside of the bending plate along the axis of the main body, an outlet for the non-condensable gas extraction pipe bored approximately at the center of the bending plate. A feed water heater comprising: a cylindrical support member that supports one end of the non-condensable gas extraction pipe via an eccentric ring.