JPS5823559B2 - Heat exchanger - Google Patents

Abstract

In a heat exchanger unit with a plurality of tubes for the circulation of a first fluid and a inner sleeve for the circulation of a second fluid a transverse partition-wall is disposed between the outer shell and the inner sleeve assuming said circulations. Said transverse partition-wall delimits two annular spaces which communicate respectively with external ducts for the admission and discharge of the fluids. The ducts are immediately adjacent to said transverse partition-wall in order to avoid differential expansion under both steady state and transient flow conditions between the outer shell and the tubes of the heat exchanger unit.

Description

[Detailed description of the invention] The present invention relates to heat exchangers.

The present invention is disclosed in Japanese Patent Application No. 46-11398 (Japanese Patent Publication No. 54-1
a bundle of tubes for circulating a first fluid, an inner sleeve surrounding the bundle of tubes, and a sleeve for allowing the first fluid to enter and exit the bundle of tubes, as disclosed in Japanese Patent Publication No. 7363); an outer sleeve spaced apart from the inner sleeve; and a second sleeve disposed in the outer sleeve.
a heat exchanger having an external conduit section for the entry and exit of a fluid; such that the differential thermal expansion between the sheath and the tubes is minimized during both steady flow and transient flow conditions of the device; The purpose is to

To achieve this objective, the invention provides a bundle of tubes, an inner sleeve surrounding said bundle of tubes, and a first fluid supply to said bundle of tubes provided at each end of said inner sleeve. a heat exchange outer sleeve spaced from the inner sleeve; and a jacket provided over the inner sleeve and extending downwardly between the sleeve and the outer sleeve. a partition wall extending laterally between the jacket and the outer cylinder; two annular spaces, an upper space and a lower space, formed between the partition wall, the jacket, and the outer cylinder; an external conduit portion for ingress and egress of a second fluid, the conduit portion opening into the space, the conduit portion opening proximately adjacent to the partition wall in both steady flow conditions and transient flow conditions; A heat exchanger unit is obtained, characterized in that the difference in thermal expansion between the outer cylinder and the tube is minimized.

In a preferred embodiment, the partition wall includes a support ring fixed on the jacket and a second fluid provided outside the partition wall in the annular space to prevent circulation of a second fluid in the vicinity of the partition wall. two sets of radial fins, the external conduit section for ingress and egress of a second fluid being fluidly and thermally isolated from each other and from the bundle of tubes; There is.

In addition, a steam generator is configured by connecting a plurality of the heat exchanger units 1 to 1, the first heat exchanger is used for heating and evaporation, the second heat exchanger is used for superheating, and the third heat exchanger is used for heating and evaporation. The vessel is subjected to reheating, and the length of the piping for the second fluid is shortened by the arrangement of the conduit section for the inlet and outlet of the second fluid of each heat exchanger unit, and the length of the piping for the second fluid is shortened. Heat exchanger units can be connected.

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

As shown in Figures 1 and 2, each heat exchanger unit consists of an outer cylinder 1, which is usually arranged vertically, and a number of straight tubes 2 arranged in a shape inside the outer cylinder 1. ing.

The ends of each tube are welded to a bottom tube plate 4 and a top tube plate 5, respectively, which are fixed to both upper and lower ends of the outer cylinder 1.

These tube sheets are arranged in parallel to the circuit of the first heat transfer fluid, in this case water in liquid or vapor form.

A second heat transfer fluid consisting of liquid sodium is in sleeve 1.
2 to contact the tube and reflux.

In order to ensure the reflux of this liquid sodium,
The sleeve 12 is formed with one or several inlet openings 15 in its upper part and outlet openings 15a in its lower part, while water flows from the inlet nozzle 8 through the tube 2 to the outlet nozzle 9. It is assumed that it will proceed upwards.

The annular chamber formed between the outer cylinder 1 and the sleeve 12 is divided into upper and lower parts by a partition wall 20 to form an inlet side space 21 and an outlet side space 22.

The outer cylinder 1 is provided with a liquid sodium inlet nozzle 6 and a liquid sodium outlet nozzle 7, which open into the two spaces 21, 22, respectively.

In order to prevent unnecessary heat exchange and thermal stress from occurring that would hinder the proper operation of the device, the spaces 21 and 22 are
A thermal screen is formed across the K.

In the embodiment shown in Figure 1, the thermal screen has its top welded to sleeve 12 within space 21, and its lower end is open to allow for thermal expansion and extends laterally. It consists of a jacket 23 provided with a dab 24.

Further, the outer cylinder 1 is formed with a fin 25 extending laterally inward.

Refluxing liquid sodium remains in these fin areas.

The partition wall 20 consists of a laterally projecting ring 26 which rests on a flange 27 on the outer cylinder 1 and supports the weight of the jacket 23.

The annular chamber formed between the sleeve 12 and the outer cylinder 1 allows the device of the invention to operate effectively.

The bundle of tubes is introduced into the barrel along with upper and lower tube sheets and sleeves.

As explained above, by separating the annular space into two parts and refluxing the liquid sodium, it is possible to reflux the liquid sodium in an appropriate state both during steady operation and during transient operation of the device, and to maintain local reflux. Is there a difference in thermal expansion?
It never occurs.

This is regardless of whether sodium remains in the space due to thermal inertia.

In order to compensate for the difference in thermal expansion during operation, a compensating curved portion is formed near one end of the tube, and in this case, it is generally formed in the upper portion of the tube as shown in Figure 1. do.

A sleeve 12 surrounding the tube extends to a position below the bend of the tube.

With this configuration, the curved part of the tube can be sufficiently expanded and curved within a wide space inside the outer cylinder, and furthermore, this curved part is located above the part where sodium flows. As a result, the flow is kept quiet, and if necessary, a neutral gas can be incorporated into this part.

As shown in FIG. 2, the curved portion to compensate for thermal expansion is configured to divide the tube bundle into a central bundle and two bundles outside of it to offset the stress on the upper tube sheet 5. It is better.

The heat exchanger units shown in Box 1 and FIG. 2 are connected in plural units and inserted into a liquid metal circuit as shown in FIG.
Configuring it as a steam generator consisting of

The dotted lines in the figure show the pipe paths used in conventional heat exchangers, and the solid lines show the pipes according to the invention.

The hot sodium passes from the heat exchanger 31, which is at a height level comparable to the lower part of the heat exchanger according to the invention, to the pump 32 while being cooled.

The pump 32 is located at a height corresponding to the top of the heat exchanger unit of the present invention.

From this figure, the ratio of 1. Obviously, the length of the pipe can be much shorter.

FIG. 3 shows a case where the heat exchanger is used as a steam generator in a nuclear power plant and the reactor is cooled with liquid sodium or other liquid alkali metal.

Through the action of a heat exchanger, heat is transferred from the high-temperature sodium to the water, which is then vaporized and cooled.

As shown in FIG. 3, a steam generator is constructed by collecting one or more heat exchangers according to the present invention, and each heat exchanger unit is used for heating, vaporizing, superheating, resuperheating (in this case (not shown) are placed in parallel in the circuit.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a heat exchanger unit according to the invention, FIG. 2 is a cross-sectional view of the unit shown in FIG. 1, and FIG. 3 is a diagram showing the use of heat exchangers according to the invention in parallel. It is a schematic diagram showing a case. In the figure, reference numerals 1...outer cylinder, 2...tube, 4°5...tube plate, 12...sleeve, 15, 15a... ...Aperture, 8, 9...
・Water inflow and outflow nozzles, 6, 7... Inflow and outflow nozzles for sodium, 21, 22... Annular space, 23... Jacket, 24° 25
...Fin, 26...Ring, 27...
...Flange.

Claims (1)

[Claims] 1. A bundle of tubes, an inner sleeve surrounding the bundle of tubes, and openings provided at both ends of the inner sleeve for allowing a first fluid to enter and exit the bundle of tubes. a heat exchange outer cylinder spaced apart from the inner sleeve; a jacket provided on the inner sleeve and extending downwardly between the sleeve and the outer cylinder; a partition wall extending laterally between the outer cylinder; two annular spaces, an upper space and a lower space, formed between the partition wall, the jacket, and the outer cylinder; and an annular space opened to the space. an external conduit section for ingress and egress of a second fluid, the conduit section opening immediately adjacent to the partition wall and extending between the outer cylinder and the tube in both steady flow conditions and transient flow conditions. A heat exchanger unit characterized in that the thermal expansion difference between the two is minimized. 2 a support ring on which the partition wall is fixed on the jacket; and two sets of radii disposed outside the partition wall in the annular space to prevent circulation of a second fluid in the vicinity of the partition wall. directional fins, wherein said external conduit portions for ingress and egress of a second fluid are fluidly and thermally isolated from each other and from said bundle of tubes. A heat exchanger unit according to claim 1. 3 Construct a steam generator by connecting a plurality of the heat exchanger units 1-1 The first heat exchanger is used for heating and evaporation,
The second heat exchanger serves for superheating, the third heat exchanger serves for reheating, and the arrangement of said conduit sections for the inlet and outlet of the second fluid of each heat exchanger unit provides piping for the second fluid. A group of heat exchanger units according to claim 1, characterized in that the lengths of the heat exchanger units are shortened and the heat exchanger units for evaporation, superheating and resuperheating are connected.