JPS6043105A - Crossover pipe device - Google Patents

Abstract

PURPOSE:To eliminate a blancing chamber and to reduce the weight and pressure loss of the title device by providing a part having a flexibility in vertical and horizontal directions at one of vertical pipelines of the crossover pipe of the tandem compound type steam turbine. CONSTITUTION:In the crossover pipe device which connects a steam outlet of a middle pressure turbine of the tandem compound type steam turbine to a steam inlet of a low-pressure steam inlet, a tie rod type elongation absorbing part is provided in the vertical pipe P1. The elongation absorbing part is formed in such a manner that omega type bellows 32 and 33 are disposed on both ends of a short pipe 31, and both ends of each of bellow 32 and 33 are pinched by tie rod plates 34, 35 and tie rod bolts 36. Spherical machining is applied to the contact surfaces of clamping nuts 37a, 37b and nut seals 38a, 38b, and a parallelogram is formed by the bolts 36 and the tie rod plate 34 to absorb the elongation quantity A.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a tandem compound steam turbine.
It relates to the cross-over pipe that connects the steam outlet of the intermediate-pressure turbine and the steam inlet of the low-pressure turbine.

[Technical background of the invention and its problems]

There are various types of so-called tandem compound steam turbines, which are operated by arranging a steam turbine and a generator on the Illill, depending on the capacity.

Figures 1 and 2 show examples of the arrangement of such tandem compound steam turbines.
It has separate high pressure casing 1 and medium pressure casing 2,
The high-pressure casing 11, the intermediate-pressure casing 2, the low-pressure casings 3a and 3b, and the generator 4 are arranged in series on a shaft 5.

The high pressure casing 1 and the intermediate pressure casing 2 are connected to piping 7 via a boiler reheater 6. In addition, the double flow type medium pressure casing 20 has two steam outlets and a low pressure case/knob 3.
The steam inlets a and 3b are connected by a crossover pipe 8. Figure 2 shows a type used in a steam turbine with a smaller capacity than that shown in Figure 1, with high pressure section 1.
1 and the intermediate pressure section 12 are made into a counterflow type integrated casing, and the low pressure casing 13 and the generator 14 are arranged in series on the shaft 15 to operate the tandem compound type evaporator 4-bin. The high pressure section 11 and the intermediate pressure section 12 are connected by a piping 17 via a boiler reheater 16, and the steam outlet of the intermediate pressure section 12 and the steam inlet of the low pressure turbine 13 are connected by a crossover pipe 18. In the tandem compound steam turbine configured as described above, it is necessary to connect the steam outlet of the intermediate pressure turbines 2, 12 and the steam inlet of the low pressure turbines 3a, 3b, 13 with a steam pipe. It is called a crossover pipe because it has two vertical pipes P, , P2 and one horizontal pipe P3 that run above the nine turbines.Required conditions for the pipes that make up the lossover pipe: The following two are mentioned. Firstly, the pipes should be structured to minimize pressure loss to effectively utilize the energy of the steam flowing through the pipes, and secondly, the pipes should be structured to minimize pressure loss. It is possible to operate under low stress by absorbing the elongation of the overtube itself. Considering the connection point between the casing and the crossover g, the temperature on the low-pressure casing side is low, and the materials of the casing and the crossover pipe are different, so there is a difference in the elongation of the two. The elongation absorbed by the crossover pipe is the difference between the elongation of this casing and the elongation of the crossover pipe itself. FIG. 3 shows a crossover pipe conventionally used in small capacity tandem compound steam turbines. The crossover pipe is compressed with the steam inlet 21 of the low pressure turbine as a fixed point, by the difference between the amount of movement of the medium pressure Tahin steam outlet 22 and the amount of expansion of the crossover pipe itself. As this expansion difference A occurs, the bellows 23 is compressed by that amount. The bellows 24 is then extended by the amount of movement transmitted by the tie rod bolt 25.

iL7. constituted by the bellows 24 and the tube body 2'61c. In order to prevent the bellows 23 from breaking due to internal pressure thrust acting on the elbows 27a and 27b, an opening 28 is provided in the elbow 27b to balance the pressure.

As a result, the internal pressure thrust acts on the end plate at the rear of the tube body 26 and fixes the tie rod bolt 25 to the body V of the crossover tube body, thereby preventing breakage of the bellows.

The portion constituted by the bellows 24 and the tube body 26Vc for the purpose of balancing the pressure in this manner is called a balance chamber. , when considering the elongation that occurs in the direction perpendicular to the turbine axis,
The amount of elongation of the casing in the direction perpendicular to the axis is caused by the difference in the internal temperature of the casings of the intermediate-pressure turbine and the low-pressure turbine and the difference in the coefficient of linear expansion due to the difference in materials. When a difference B occurs,
It is inevitable that stress will be generated in the tube body and elbow because there is no part to cope with the elongation in the direction perpendicular to the axis. There are also problems such as the presence of a dead balance chamber, which causes turbulence in the steam flow, and increased loss due to steam flowing into the balance chamber.

[Purpose of the invention]

The present invention was made in order to eliminate the drawbacks of the above-mentioned conventional structure, and has a simple structure, light weight, no turbulence of steam flow, and
It is an object of the present invention to provide a lossover pipe device that can be operated with low stress.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that one of the vertical conduits is provided with a portion that is flexible in the vertical and horizontal directions.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. M4 to FIG. As shown in FIG. 4, the present invention is arranged with a P+VC tie rod type elongation absorbing section perpendicular to the turbine axis on the intermediate pressure side. The elongation absorbing part is the short pipe 31's Ryozu Vζ
Omega-shaped (Ω-shaped) bellows 32.33 are arranged, and both ends of the bellows 32.33 are sandwiched between a tie rod plate 34.35 and a tie rod bolt 36Vc.

Figure 5 shows the details of the tightening part of the tie rod bolt, including the tightening nuts 37a, 37b and the nut 38a.
, 38b are spherically processed, and the nuts' spherical surfaces 38a and 38b are processed to have a smooth surface. When the tie rod bolt and nut beams expand in the axial direction, the tie rod plate 36 and the tie rod plate 34 as shown in FIG.
By forming a parallelogram, the p elongation iA is converted into an angular displacement and absorbed. Elongation difference B in the direction perpendicular to the axis considering the difference in elongation between low pressure casing and medium pressure casing
acts on the intermediate pressure side as shown in FIG. 4, by setting the gap C between the tie rod plate 34 and the nut 37b equal to the axis-perpendicular elongation -iB shown in FIG. The tie rod bolt 36 extends upward by an amount B
YC is forced to move equally. With this, Natsuto 3
Tie rod bolt 3 until 7b hits tie rod plate 34.
6 extends the bellows by 32.33 degrees by sliding.
It absorbs B and shrinks. The gap C between the nut 37a and the tie rod plate 34 is such that the tie rod plate 34 is lifted by the internal pressure thrust acting on the upper elbow, and the nine bellows 32 and 33 are returned to their original states on the nut 37a, with force acting on the tie rod plate 34. do not.

Elongation absorber - Il perpendicular to the entire turbine axis? :Whether the installed pipe is placed on the medium pressure side or the low pressure side is determined by the casing (effects of the invention). Therefore, it can be used at lower pressures, and by enlarging the balance chamber and replacing it with a simple pipe line, it reduces the chance of lid failure, saves material costs, reduces pressure loss, and utilizes the energy of steam. Since the cross-over tube device can be used for many purposes, an economically superior crossover tube device can be obtained.

[Brief explanation of drawings]

Figures 1 and 2 are block diagrams showing a Tampumco/Paran, do-type steam turbine device, Figure 3 is a front view showing the structure of a conventional crossover pipe, and Figure 4 is an embodiment of the present invention. 5 is an enlarged view showing the tie rod tightening nut shown in FIG. 4, and FIG. 6 is a front view showing the operation of the tie rod portion shown in FIG. 4 when it absorbs elongation. 2.12...Intermediate pressure turbine, 3a, 3b, 13...
Low pressure turbine, 21... Steam inlet, 22... Steam outlet, P,... Vertical pipe (medium pressure side), P2... Vertical pipe (low pressure side), P3, Horizontal pipe. Agent Patent Attorney Kensuke Chika (and 1 other person) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a crossover pipe device connecting the steam outlet of an intermediate pressure turbine and the steam inlet of a low pressure turbine of a tandem compound steam turbine, the cross-over pipe device is formed with two vertical pipes and one horizontal pipe. A cross oat; a tube device characterized by having a vertically and horizontally readable portion on one side;