JPH102694A - Heat exchanger - Google Patents

Abstract

(57) [Problem] To provide a heat exchanger capable of preventing occurrence of an inlet attack at an inlet portion of a heat transfer tube that damages an inner wall of the heat transfer tube, and performing a flaw detection inspection and the like easily and with high accuracy. SOLUTION: A straightening tube 20 whose inner diameter gradually changes from an inflow-side large-diameter portion 21 to an outflow-side small-diameter portion 22 is inserted into an inlet portion of the heat transfer tube 16 with the outflow-side small-diameter portion 22 inside. It is configured to be detachably attached to a bell mouth portion 16A protruding from the tube plate 15 of the heat transfer tube 16 at the engaging portion 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger such as a shell-and-tube heat exchanger, and more particularly to a protection structure for preventing damage to an inner wall of a heat transfer tube due to an inlet attack generated at a fluid inlet portion of the heat transfer tube.

[0002]

2. Description of the Related Art One of the heat exchangers provided with a heat transfer tube group is a shell and tube type heat exchanger.

For example, as shown in FIG. 3, a heat exchanger equipped with a U-tube type heat transfer tube group has a secondary fluid inlet 11A at the side.
An intermediate body 13 forming a water chamber 12 is connected to an opening end of the body 11 which is a pressure vessel having a secondary fluid outlet 11B, and the water chamber 12 is divided by a partition plate 14 into two water chambers 12A, 12A.
A primary fluid inlet 13A and a primary fluid outlet 13B are provided in each of the water chambers 12A and 12B, and a plurality of water chambers 12A and 12B are provided with two ends fixed to a tube sheet 15 interposed between the body 11 and the intermediate body 13. A U-shaped heat transfer tube 16 is arranged in the body 11 with the intermediate portion supported by a plurality of baffle plates 17.

One end of the heat transfer tube 16 has an inlet side water chamber 12A.
And the other end is opened to the outlet side water chamber 12B, and the primary fluid: A flowing into the inlet side water chamber 12A from the primary fluid inlet 13A flows through the heat transfer pipe 16 to the outlet side water. The secondary fluid flowing into the body 11 from the secondary fluid inlet 11A while being discharged from the primary fluid outlet 13B after reaching the chamber 12B: B flows outside the heat transfer tube 16 while meandering by the baffle plate 17, and the secondary fluid outlet Leaked from 11B,
Thereby, heat exchange between the primary fluid and the secondary fluid is performed.

In the heat exchanger having such a heat transfer tube 16, the primary fluid: A flowing through the heat transfer tube 16 passes through the water chamber 12 (the inlet side water chamber 12 A) and enters the inlet portion (the inlet side water) of the heat transfer tube 16. A so-called inlet attack due to turbulent flow when flowing from the opening to the chamber 12A) may break the protective coating inside the inlet of the heat transfer tube 16 and cause damage such as corrosion due to electrochemical action.

For this reason, as shown in an enlarged sectional view of the portion in FIG. 4, a protective tube 20 made of a synthetic resin or the like is fixed to the inner periphery of the inlet portion of the heat transfer tube 16 with an adhesive, and It is done to prevent itself from being damaged.

[0007]

However, in the heat exchanger as described above, it is necessary to periodically inspect the heat transfer tube 16 for damage depending on the use condition of the fluid, and the inspection is performed by an interpolation type eddy current flaw detector. When performing the test, since the protective tube 20 is inserted and fixed at the inlet of the heat transfer tube 16, a flaw detection test must be performed using a probe having a diameter smaller by the thickness thereof.
There is a problem that the accuracy of the flaw detection is reduced by the smaller the diameter of the probe.

Accordingly, the protective cylinder 20 fixed with an adhesive is used.
Eddy current inspection is performed with a probe corresponding to the inner diameter of the heat transfer tube 16 by screwing a bolt and removing it with a jack, etc., and removing the very large number of protective cylinders 20 becomes a serious task. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and prevents the occurrence of an inlet attack at an inlet portion of a heat transfer tube that damages the inner wall of the heat transfer tube, and also facilitates flaw detection inspection and the like. Another object of the present invention is to provide a heat exchanger that can perform the process with high accuracy.

[0010]

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, a heat exchanger according to the present invention has a rectifier in which an inner diameter of a heat transfer tube is gradually reduced to an inner diameter smaller than that of the heat transfer tube. The tubular member is inserted with the small diameter portion inside, and is detachably engaged with and attached to an enlarged diameter portion protruding from the outer surface of the tube plate of the heat transfer tube.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an enlarged sectional view of an inlet / outlet portion of a primary fluid according to an embodiment of the heat exchanger according to the present invention, and FIG. 2 is an enlarged sectional view of an inlet portion of a heat transfer tube.

The illustrated heat exchanger 10 is a U-shaped shell-and-tube type heat exchanger, and a heat exchanger tube 16 is fixed to the opening side of a body 11 as a pressure vessel via a tube plate 15. The intermediate cylinder 13 is fastened by tightening, and the other end opening of the intermediate cylinder is closed by the end plate 18.
Is formed.

The water chamber 12 is partitioned into two chambers, an inlet water chamber 12A and an outlet water chamber 12B, by a partition plate 14 disposed at the center thereof. A primary fluid outlet 13B is formed in each of the side water chambers 12B.

Although not shown, the heat transfer tube 16 has a U
Water chamber 12A, each of which is bent in the shape of a
And it is fitted and fixed to the tube sheet 15 so as to open to the outlet side water chamber 12B.

In the heat exchanger 10 having the above-described structure, the primary fluid A flowing from the primary fluid inlet 13A into the inlet side water chamber 12A reaches the outlet side water chamber 12B via the heat transfer tube 16 and is discharged from the primary fluid outlet 13B. The heat exchange is performed between the secondary fluid flowing into the body 11 from a secondary fluid inlet (not shown).

Here, an opening end of the heat transfer tube 16 to the inlet side water chamber 12A, which is an inlet portion, protrudes from the outer surface of the tube sheet 15 toward the inlet side water chamber 12A by a predetermined amount, and the protrusion is tapered. A rectifying cylinder 20 as a rectifying cylinder member is mounted here.

As shown in FIG. 2, the flow straightening tube 20 has a funnel that gradually reduces the diameter by gradually drawing a curved surface from an inflow-side large-diameter portion 21 having an inner diameter larger than the inner diameter of the heat transfer tube 16 to an outflow-side small-diameter portion 22 having a smaller inner diameter. The inner diameter of the outflow-side small-diameter portion 22 is set to be smaller than the inner diameter of the heat transfer tube 16 by a predetermined amount, and the length of the outflow-side small-diameter portion 22 is determined by the turbulent flow. This is set so that the aperture can be squeezed smoothly without the occurrence of.

A heat transfer tube 1 is provided on the outer peripheral side of the inflow-side large-diameter portion 21.
An engaging portion 23 is formed to engage with the bell mouth-shaped portion 16A, which is the entrance portion of No. 6.

The engaging portion 23 is provided on the outer peripheral side of the inflow-side large-diameter portion 21 via a disk-shaped flange 23A at the outer end thereof.
3B is provided, and the return claw 23B is a cylindrical member having a predetermined width, and the heat transfer tube 1B is provided between the return claw 23B and the outer surface of the rectifying tube main body.
6 is formed so as to have a space having a shape corresponding to the bell mouth-like portion 16A which is the entrance portion.

The rectifying cylinder 20 having the above-described structure is provided with
The return claw 23B is elastically deformed in the radially expanding direction so as to engage with the bell mouth-shaped portion 16A, which is the inlet portion of the heat transfer tube 16, and is mounted so as not to fall off. As a result, the outflow-side small-diameter portion 22 is located a predetermined distance behind the inlet end of the heat transfer tube 16. The length of the flow control cylinder 16 and the opening diameter of the outlet-side small-diameter portion 22 (that is, the taper from the inlet-side large-diameter portion 21 to the outlet-side small-diameter portion 22) depend on the flow rate of the primary fluid: A and the inlet attack due to structural factors. Is set appropriately so that no occurrence occurs.

Thus, according to the heat exchanger 10 configured as described above, the primary fluid A flowing into the heat transfer tube 16 is:
It flows in from the inflow large-diameter portion 21 of the rectifying cylinder 20, is gradually narrowed, and is ejected from the outflow small-diameter portion 22 into the heat transfer tube 16, and smoothly without generating a vortex in the heat transfer tube 16 having a larger diameter than the outflow small-diameter portion 22. Flows to For this reason, an inlet attack does not occur to the inner peripheral wall of the inlet portion of the heat transfer tube 16, and the inner peripheral wall of the heat transfer tube 16 is not damaged.

When performing the eddy current inspection of the heat transfer tube 16,
The rectifying tube 20 is removed by releasing the engagement of the engaging portion 23 of the rectifying tube 20 with the bellmouth-shaped portion 16A, and the heat transfer tube 1 is removed.
By inserting a probe having a diameter corresponding to the inner diameter of No. 6, an inspection with high accuracy can be easily performed. That is, since the flow regulating tube 20 is engaged with the bell mouth-shaped portion 16A, which is the inlet portion of the heat transfer tube 16, at the engaging portion 23, and is not firmly fixed with an adhesive, it is easy to use. The inspection can be carried out by removing the probe and inserting a probe corresponding to the inner diameter of the heat transfer tube 16, and the work can be performed easily and the inspection accuracy can be improved.

In the above embodiment, the rectifying cylinder 20 has a funnel shape whose outer shape is formed in a funnel shape along the inner shape. However, the outer shape is not a tapered shape but a parallel column shape fitted to the heat transfer tube 16. And may be changed as appropriate.

In the above embodiment, the heat exchanger using a U-shaped tube as the heat transfer tube 16 has been described. However, it is needless to say that a straight tube may be used.

[0025]

As described above, according to the heat exchanger according to the present invention, the rectifying tube member whose inner diameter is gradually reduced to an inner diameter smaller than the heat transfer tube is provided at the inlet of the heat transfer tube. Is inserted inside and is detachably engaged with and attached to the enlarged diameter portion protruding from the outer surface of the tube plate of the heat transfer tube, so that the inflow fluid flowing into the heat transfer tube is restricted by the rectifying cylinder member. As a result, the heat flows smoothly without generating a vortex in the heat transfer tube, does not cause an inlet attack on the inner circumferential wall of the inlet of the heat transfer tube, and does not damage the inner circumferential wall of the heat transfer tube.

Further, the rectifying cylinder member can be easily removed, and in the case of a flaw detection inspection or the like, the rectifying cylinder member can be easily removed and the probe corresponding to the main body of the heat transfer tube can be inserted. It is possible to perform an accurate flaw detection inspection.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of an inlet / outlet portion of a primary fluid according to an embodiment of a heat exchanger according to the present invention.

FIG. 2 is an enlarged sectional view of an inlet / outlet portion of the primary fluid.

FIG. 3 is a longitudinal sectional view of a conventional heat exchanger.

FIG. 4 is a partially enlarged sectional view of an inlet portion of the heat transfer tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heat exchanger 16 Heat transfer tube 16A Bell mouth part (expansion part) 20 Rectifier cylinder (rectifier cylinder member) 22 Outflow side small diameter part (small diameter part)

Claims (1)

[Claims] At the inlet of the heat transfer tube, a rectifying tube member whose inner diameter is gradually reduced to an inner diameter smaller than the heat transfer tube is provided.
A heat exchanger characterized in that the heat exchanger is inserted with the small diameter portion inside, and is detachably engaged with and attached to an enlarged diameter portion protruding from the outer surface of the tube plate of the heat transfer tube.