JPH07190673A - Heat exchanger - Google Patents

Abstract

PURPOSE:To relieve the stress on a stub by a method wherein the inside diameter of a tube plate hole is made smaller than that of a heating tube, the inside diameter of a stab on the side of a fluid chamber is made equal to that of the tube plate hole, and the inside diameter of the stub on the heat exchanging chamber side is made equal to that of the heating tube, and the inside shape of the stab is formed into a tapered shape wherein the inside diameter thereof gradually decreases from the heat exchanging chamber toward the fluid chamber. CONSTITUTION:The hole diameter of a tube plate hole 7 provided in a tube plate body 1 is made smaller than the inside diameter of a heating tube 6, for example, the hole diameter of the hole 7 is set at about 1/3-1/10 of the inside diameter of the tube 6. The inside diameter of each st!Hb 8 on the side of a fluid chamber 4 is made equal to that of the hole 7. Further, the inside diameter of the stab 8 on the side of a heat exchanging chamber 5 is made equal to that of the tube 6. The internal shape of each stub 8 is formed into a tapered shape so that the inside diameter thereof gradually decreases from the chamber 5 toward the chamber 4, and taper angle is in the range of 15 deg.-30 deg..

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat exchanger.

[0002]

2. Description of the Related Art FIG. 2 shows an example of the structure of a tube plate portion of a conventional heat exchanger. Reference numeral 1 denotes a tube plate body, and the tube plate body 1 has one surface A side to the other surface B side. A plurality of tube plate holes 2 penetrating therethrough
Has been drilled.

On the other surface B side of the tube sheet body, a tubular stub portion 3 is integrally provided with the tube sheet body 1 so as to correspond to each tube sheet hole 2.

The one surface A side of the tube sheet body 1 is inside the fluid chamber 4, and the other surface B side of the tube sheet body 1 is inside the heat exchange chamber 5.

Further, at the tip of each stub 3,
The heat transfer tubes 6 are welded to each other, and heat exchange is performed between the primary fluid flowing from the fluid chamber 4 into each heat transfer tube 6 and the secondary fluid flowing in the heat exchange chamber 5 via each heat transfer tube 6. It is supposed to be.

[0006]

However, in the above-mentioned heat exchanger, a large stress is applied to the mating portion of the tube sheet body 1 and the stub portion 3 due to vibration or thermal expansion of the heat transfer tube 6 as compared with other portions. Because of the concentration, the tube sheet body 1 may be cracked or the stub portion 3 and the heat transfer tube 6 may be broken.

Further, in a heat exchange device in which a combination of substances that easily react with each other such as water and sodium is applied to the primary fluid and the secondary fluid, when the stub portion 3 or the heat transfer tube 6 is broken, Water (primary fluid) because the primary fluid is pressurized to a higher pressure than the secondary fluid
However, there is a problem in that the water flows into the heat exchange chamber 5 from the broken portion and suddenly reacts with sodium inside the heat exchange chamber 5.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a heat exchanger capable of relieving the stress acting on the stub portion of the tube sheet body by reducing the tube sheet hole. .

[0009]

SUMMARY OF THE INVENTION The present invention provides a tube sheet body having a plurality of tube sheet holes provided between a fluid chamber and a heat exchange chamber and penetrating from the fluid chamber side to the heat exchange chamber side. A tubular stub portion formed integrally with the tube sheet body so as to correspond to each tube sheet hole on the surface of the tube sheet body on the heat exchange chamber side, and a heat transfer tube connected to each of the stub portions. A heat exchanger configured to exchange heat between the primary fluid flowing into each heat transfer tube from the fluid chamber and the secondary fluid inside the heat exchange chamber via the heat transfer tube, The inner diameter of the plate hole is smaller than that of the heat transfer tube, the inner diameter of each stub on the fluid chamber side is equal to the inner diameter of the tube plate hole, and the inner diameter of each stub on the heat exchange chamber side is the inner diameter of the heat transfer tube. While forming the same as
The internal shape of each stub portion is formed so that the inner diameter gradually decreases from the heat exchange chamber side toward the fluid chamber side.

[0010]

Therefore, in the present invention, the ligament width (the distance between the outer circumferences of the adjacent tube sheet holes) increased by reducing the tube sheet hole diameter causes the tube sheet to vibrate or thermally expand due to vibrations or thermal expansion of the heat transfer tube. The concentration of stress acting on the periphery of the hole and the joint between the tube sheet body and the stub portion is relaxed. Further, the flow rate of the primary fluid is suppressed when the tube plate hole formed to have a diameter smaller than the inner diameter of the heat transfer tube naturally flows out from the fluid chamber to the heat transfer tube side.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view schematically showing an embodiment of the heat exchanger of the present invention. In the figure, the same parts as those in FIG.

In this embodiment, the diameter of the plurality of tube sheet holes 7 formed in the tube sheet body 1 is smaller than the inner diameter of the heat transfer tube 6 (for example, about 1/3 to 1/10 of the inner diameter of the heat transfer tube). ), The inner diameter of each stub portion 8 communicating with the tube plate hole 7 on the fluid chamber 4 side is the same as the hole diameter of the tube sheet hole 7, and the inner diameter of each stub portion 8 on the heat exchange chamber 5 side is transferred. The inner diameter of the heat pipe 6 is the same as that of the heat pipe 6, and the inner shape of each stub portion 8 is tapered such that the inner diameter gradually decreases from the heat exchange chamber 5 side toward the fluid chamber 4 side (about 15
The angle is 30 ° to 30 °).

Then, the primary fluid and the heat flowing from the fluid chamber 4 into the heat transfer tubes 6 through the respective tube sheet holes 7 provided in the tube sheet body 1 and the stub portion 8 communicating with the tube sheet holes 7. Heat is exchanged with the secondary fluid flowing in the exchange chamber 5 via each heat transfer tube 6.

According to the above, since the tube sheet holes 7 are made small, the interval between the outer circumferences of the adjacent tube sheet holes 7, that is, the so-called ligament width (S shown in FIG. 1) becomes large, so that the tube sheet holes 7 are formed.
The concentration of the stress acting on the periphery and the joining portion between the tube sheet body 1 and the stub portion 8 is relieved, and the occurrence of cracks in the tube sheet body 1 and the breakage of the stub portion 8 and the heat transfer tube 6 can be prevented.

Further, since the flow rate of the primary fluid is regulated between the tube sheet hole 7 having a smaller diameter than the conventional tube sheet hole 2 and the fluid chamber side of the stub portion 8, the stub portion 8 and the transmission should be prevented. Even if the heat pipe 6 is damaged and an accident occurs in which the primary fluid flows into the heat exchange chamber 5 from the damaged portion, if the pumping of the primary fluid is stopped, the tube sheet hole 7 and the stub portion 8 are removed. The flow rate of the primary fluid passing through is suppressed, and the flow rate of the primary fluid flowing out of the damaged portion into the heat exchange chamber 5 is drastically reduced.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0018]

According to the heat exchanger of the present invention, various excellent effects as described below can be obtained.

I) Since the ligament width is increased, it is possible to reduce the plate thickness of the tube sheet main body, which is conventionally thick to maintain the strength of the tube sheet main body.

II) By increasing the ligament width, it is possible to relieve the concentration of stress acting around the tube sheet hole and at the joint between the tube sheet body and the stub portion, so that the tube sheet body cracks and the stub portion. It is possible to prevent breakage accidents of the heat transfer tube.

III) Since the tube plate hole has a hole diameter smaller than the inner diameter of the heat transfer tube, the stub portion or the heat transfer tube may be damaged, and the primary fluid may flow into the heat exchange chamber from the damaged portion. Even if an accident occurs, if the pumping of the primary fluid is stopped, the flow rate of the primary fluid passing through the tube sheet hole and the stub is suppressed, and the flow rate of the primary fluid flowing out from the damaged part into the heat exchange chamber. Is drastically reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing an embodiment of a heat exchanger of the present invention.

FIG. 2 is a cross-sectional view schematically showing an example of a conventional heat exchanger.

[Explanation of symbols]

 1 Tube Plate Main Body 4 Fluid Chamber 5 Heat Exchange Chamber 6 Heat Transfer Tube 7 Tube Plate Hole 8 Stub Section

Claims (1)

[Claims] 1. A tube sheet body having a plurality of tube sheet holes penetrating from the fluid chamber side to the heat exchange chamber side, the tube sheet body being provided between the fluid chamber and the heat exchange chamber, and the heat exchange chamber side of the tube sheet body. A tubular stub portion formed integrally with the tube sheet main body so as to correspond to each tube sheet hole on its surface, and heat transfer tubes connected to the stub portion, respectively. In a heat exchanger configured to perform heat exchange between the primary fluid flowing into the heat transfer tube and the secondary fluid inside the heat exchange chamber via the heat transfer tube, the inner diameter of each tube sheet hole is set to The inner diameter on the fluid chamber side of each stub is made equal to the inner diameter of the tube plate hole, and the inner diameter on the heat exchange chamber side of each stub is made equal to the inner diameter of the heat transfer tube. The internal shape of the part is formed so that the inner diameter gradually decreases from the heat exchange chamber side toward the fluid chamber side. And a heat exchanger.