JPS6020095A - Support construction of heat transmitting tube - Google Patents

Abstract

PURPOSE:To enable to support a heat transmitting tube satisfactory for a long term by a method wherein a supporting part of a heat transmitting tube is formed with an inner metal fitting and an outer metal fitting, which support the heat transmitting tube, and both fittings are joined together through a sliding surface, which has a spherical surface. CONSTITUTION:A supporting part is formed with a heat transmitting tube supporting inner metal fitting 19 and a heat transmitting tube supporting outer metal fitting 20, and both fitting 19, 20 are joined together through the sliding surface, which has the spherical surface. By this, the occurring stress and wearing quantity can be reduced, because the heat transmitting tube supporting inner fitting 19 revolves in the spherical slide surface, and follows to the change of the angle of the heat transmitting tube 5. Accordingly, the heat transmitting tube 5 can be supported satisfactory for a long term.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger tube support structure, particularly to a heat exchanger tube support structure for a straight tube portion of a heat exchanger tube of a shul-and-tube type heat exchanger.

As a heat exchanger for a fast breeder reactor, a helical coil steam generator is known, in which a heat transfer tube is composed of a downcomer pipe, a lower communication pipe, a helical coil pipe, and an upper communication pipe. A heating medium such as high-temperature liquid metal sodium is introduced into the annular region consisting of the inner shroud and the outer shroud.
-Water is introduced into the heat transfer tube through a water condensation ring header placed at the top of the blade body. The water inside the heat transfer tube exchanges heat with the high-temperature sodium flowing down outside the tube, and is preheated, boiled, and superheated to become high-temperature, high-pressure superheated steam, which is sent from the steam outlet nozzle to the turbine.

There is a method of supporting and fixing the straight part of the heat exchanger tube in such a heat exchanger using a hollow hole structure having a predetermined length in the tube axis direction, but this method is difficult to support the heat exchanger tube during rated operation. If a relative displacement occurs between the heat transfer tube and the heat transfer tube due to the difference in thermal expansion, the stress generated in the heat transfer tube will further increase, and the wear in the heat transfer tube may cause a large amount of thinning, which may affect the integrity of the heat transfer tube. It has the disadvantage of making things worse.

The present invention solves all of the above-mentioned drawbacks, and provides a heat transfer pipe and heat exchanger that has high soundness over its life by minimizing stress generated at the support portion of each heat transfer tube and thinning due to wear. The purpose is to provide the following.

The uninvented method is characterized in that, as a method of supporting the straight section of the heat transfer tube, the angular displacement of the ridged heat tube is restrained and the friction of the sliding section is changed to 9 friction of rollers via bearings. It is something to do.

Hereinafter, the present invention will be explained with reference to all the drawings.

Figure 1 shows the internal structure of a fast breeder reactor heat exchanger that incorporates multiple helical coiled heat exchanger tubes.
High-temperature liquid metal sodium, which is a heating medium, is introduced into the shell 2 through several sodium inlet nozzles 12 provided at the upper part of the shell 2 supported by a support skirt, and is introduced into the shell 2 through the heat exchanger tubes 5.
The riser pipe portion 5A (helical coil shape) flows down entirely within the heat conversion region 18 formed between the internal shroud 11 and the cylindrical thermal MM plate 8, becomes low temperature, and is attached to the lower fuselage head plate. Sodium exits from outlet nozzle 15. On the other hand, the water supply flows from several water supply headers 9 arranged in the upper part of the shell 2 and is distributed to the downcomer pipe portions 5B of each heat transfer tube 5. The water in the heat exchanger tubes 5 once descends through the downcomer pipe section 5B, turns around at the lower part of the fuselage, and rises within the riser pipe section 5A, which is wound in the form of a helical coil at a constant regular pitch in place of the internal shroud 11. do. At this time, the feed water flowing in at a low temperature exchanges heat with the high temperature sodium flowing down in the heat exchange area 18, is preheated, boiled, and superheated, and becomes superheated steam at a high pressure and is collected in the steam header. The steam is sent from the steam outlet nozzle to the turbine (not shown).

As a support structure for the plurality of heat exchanger tubes 5 used in this type of heat exchanger, heat exchanger? f; fIiIi There is a structure in which a heat exchanger tube support part having a predetermined length in the 11 direction and provided with a hole having an assembly clearance with respect to the outer diameter of the heat exchanger tube is fixed to a heat shielding plate. In this structure, when a relative displacement occurs between the heat exchanger tubes 5 and the heat shielding plate to which the heat exchanger tube support part is fixed during operation, the downcomer pipe section in particular is connected to the riser pipe through the lower connecting box structure. Therefore, not only the axial displacement of the heat exchanger tube but also the angular displacement of the heat exchanger tube becomes a problem. In other words, in such a heat transfer/a support structure, displacement in the axial direction of the heat transfer tube does not occur, but angular displacement is restricted, so in some cases, the upper and lower ends of the heat transfer tube support part There is a possibility that the heat exchanger tube 5 and the heat exchanger tube support part may slide in a portion of the heat exchanger tube, which may cause stress and significant wear on the heat exchanger tube.

FIG. 2 shows a heat exchanger tube support structure according to the present invention. The heat tube support part k is connected to the heat transfer 1' support inner metal fitting 19.
The heat exchanger tube 1) consists of a support outer fitting 20,
The λ fitting 19 and the single-heat tube outer fitting 20 are in contact with each other with a sliding amount of .11 times the spherical surface. After freezing, the heat transfer tube inner fitting 19 has a hole with a predetermined length and clearance in the tube axis direction.
A heat transfer tube is placed between these holes. During operation, the displacement in the axial direction of the heat exchanger tube is not restrained, which is similar to the conventional structure, but when the heat exchanger tube attempts to make an angular displacement, the heat exchanger tube support inner fitting 19 rotates on the spherical sliding surface. It has a structure that follows the angular displacement of the heat exchanger tube and does not require any restraints. Therefore, the stress generated and the amount of wear at the support portion of the heat exchanger tube can be reduced to a small extent, and the long-term integrity of the heat exchanger tube is ensured.

In addition, FIG. 3 shows that in the heat exchanger tube support structure according to the present invention shown in FIG.
This is necessary for the purpose of further reducing the occurrence of wear during heat transfer 'a' and displacement in the axial direction.

As described above, in the present invention, the stress generated and thinning caused by wear are reduced, particularly in the support section of the heat transfer straight section, so that the long-term soundness of the heat transfer tube can be ensured.

[Brief explanation of the drawings] Fig. 1 is a longitudinal view of the heat exchanger of a fast breeder reactor with helical coil heat transfer. It is a partial sectional view of the heat exchanger tube support structure of the tube part. 2... Body, 5... Heat exchanger tube, 19... Heat exchanger tube support inner fitting, 20... Heat exchanger tube support structure tool, 21...・Bearing. Silk (Ku A 2 concave

Claims (2)

[Claims] 1. In the straight heat transfer tube part of the heat exchanger that is composed of multiple heat transfer tubes and a body, a heat transfer U support inner metal fitting having a through hole with a hole diameter slightly larger than the outside diameter of the heat transfer tube. A heat exchanger tube support structure comprising: an outer heat exchanger tube support fitting that is combined with the inner support fitting through a spherical contact surface or a sliding surface. 2. The straight heat transfer tube part of the heat exchanger, which is composed of one case or several floors of heat transfer tubes and a body, has a through hole with a hole diameter slightly larger than the outside diameter of the heat transfer pad, and A heat transfer device with a plurality of balls inside the hole to reduce axial sliding resistance.
1. A heat exchanger tube support structure comprising an inner metal fitting for supporting heat exchanger tubes, and an outer metal fitting for supporting heat exchanger tubes which is combined with the inner metal fitting via a spherical contact surface or a sliding surface.