JP2006329585A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the replacement frequency of tube plates by minimizing heat conduction from heat exchanger tubes to the tube plates. <P>SOLUTION: A large number of heat exchanger tubes 12 are juxtaposed between a pair of tube plates 11 in a state of both ends being inserted into through-holes 11a formed in the pair of tube plates 11, and tubular collars 13 jointed to the heat exchanger tubes 12 and tube plates 11 are provided between the outer peripheral surface of both ends of the heat exchanger tubes 12 and the inner peripheral surfaces of the through holes 11a of the tube plates 11. One end of an insert tube 14 is inserted inside at least one of both ends of each heat exchanger tube 12, and the outer peripheral surface of the one end is provided with a heat insulating material 14a to face the whole inner peripheral surface region of the collar 13 through the heat exchanger tube 12. A low temperature fluid L is allowed to pass between the pair of tube plates 11 while a high temperature fluid H is allowed to pass in the heat transfer tubes 12 and insert tubes 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchanger in which a large number of heat transfer tubes are arranged in parallel between a pair of tube plates.

  As this type of heat exchanger, for example, as shown in Patent Documents 1 and 2 below, a large number of heat transfer tubes are formed between a pair of tube plates, and through holes in which both end portions are respectively formed in the pair of tube plates. The structure inserted in parallel and arranged side by side is known. This heat exchanger is provided in, for example, a sludge incineration facility, a gas turbine facility, etc., and conventionally, a low temperature fluid is allowed to pass between the pair of tube plates while a high temperature fluid is allowed to pass through the heat transfer tubes. It is used.

Such a heat exchanger has a problem that heat is conducted from the high-temperature heat transfer tube to the low-temperature tube plate, and the tube plate is likely to be thermally deteriorated.
As a means for solving such a problem, conventionally, a portion of the outer peripheral surface of the heat transfer tube that faces the inner peripheral surface of the through hole of the tube plate and an inner peripheral surface of the through hole of the tube plate In the meantime, a tubular collar is provided by being joined to the heat transfer tube and the tube plate in a state where the inner peripheral surface thereof is not in contact with the outer peripheral surface of the heat transfer tube. The collar is provided such that one end thereof is joined to the outer peripheral surface of the heat transfer tube, and the outer peripheral surface of the collar is joined to the peripheral edge of the opening of the through hole on the surface of the tube plate.
As a result, the heat transfer path from the heat transfer tube to the tube plate is minimized, and the tube plate can be prevented from becoming hot.
Japanese Patent Laid-Open No. 9-42889 Japanese Utility Model Publication No. 5-34475

  However, in the conventional heat exchanger, the collar is provided, and the inner peripheral surface thereof and the outer peripheral surface of the heat transfer tube are made non-contact to minimize the heat transfer path from the heat transfer tube to the tube sheet. However, as described above, since the collar is joined to the heat transfer tube and the tube plate, the heat of the heat transfer tube is conducted to the tube plate through each joint, and the heat deterioration of the tube plate is not changed. Could not be effectively suppressed. For this reason, it is generally necessary to periodically replace the tube sheet.

  The present invention has been made under such a background, and provides a heat exchanger capable of minimizing heat conduction from the heat transfer tube to the tube plate and reducing the tube plate replacement frequency. The purpose is to do.

  In order to solve such problems and achieve the above-mentioned object, the heat exchanger of the present invention has a large number of heat transfer tubes between a pair of tube plates, and both end portions thereof are formed on the pair of tube plates. Tubular pipes joined to these heat transfer tubes and the tube plate between the outer peripheral surfaces of both ends of the heat transfer tube and the inner peripheral surface of the through hole of the tube plate. A collar is provided, and one end portion of an insert tube is inserted inside at least one of both end portions of the heat transfer tube, and the heat transfer tube is disposed on the outer peripheral surface of the one end portion over the entire inner peripheral surface of the collar. A heat insulating material is provided so as to face each other.

  According to this invention, since the heat insulating material is opposed to the entire area of the inner peripheral surface of the collar via the heat transfer tube, the heat exchanger allows the high-temperature fluid to pass through the heat transfer tube while When a low-temperature fluid is allowed to pass between a pair of tube plates, a portion of the outer peripheral surface of the heat transfer tube where the heat insulating material is not located inside, that is, the heat of the high-temperature fluid does not go through the heat insulating material. It is possible to avoid the inner peripheral surface of the collar from facing the directly conducted portion. Therefore, the amount of heat conducted from the heat transfer tube to the collar is reduced, it becomes possible to suppress the temperature of the collar from becoming high, and the tube plate joined to this collar can be prevented from becoming high temperature, The tube sheet can have a long life and the frequency of replacement can be reduced.

  Furthermore, since this heat insulating material is provided not in the heat transfer tube but in the insert tube, when it becomes necessary to replace the heat insulating material due to heat deterioration or the like, the replacement time is minimized. Can be suppressed. That is, by preparing in advance another insert tube provided with a new heat insulating material on the outer peripheral surface of the one end thereof, after removing from the heat transfer tube together with the insert tube having the heat-degraded heat insulating material, Another insert tube can be inserted and attached inside the heat transfer tube.

Also, an outer peripheral surface of one end portion of the insert tube is provided with a flange portion protruding radially outward, and the insert tube is disposed on the inner side of the heat transfer tube, on the end surface of the flange portion and the end of the heat transfer tube. You may insert in the state which contacted the part opening surface.
In this case, it is possible to easily and highly accurately position the insert tube in the tube axis direction with respect to the heat transfer tube, and the above-mentioned effects can be easily realized without taking the time for mounting the insert tube. The time required for exchanging the insert tube can be minimized.

Furthermore, a stopper member that protrudes radially outward and supports the heat insulating material may be provided on an outer peripheral surface at one end of the insert pipe.
In this case, when the heat exchanger is used and when the insert pipe is replaced, it is possible to prevent the heat insulating material from being detached from the insert pipe and fitting inside the heat transfer pipe. It is possible to minimize the time required, and to avoid the occurrence of a problem that the high-temperature fluid does not flow or becomes difficult to flow through the heat transfer tube.

  Heat conduction from the heat transfer tube to the tube sheet can be suppressed to a minimum, and the replacement frequency of the tube sheet can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. 2 shows an upper portion of the heat exchanger tube 12 and the like surrounded by a two-dot chain line in the heat exchanger 10 of FIG. Hereinafter, details of the upper portion will be described.
In the heat exchanger 10 of the present embodiment, a large number of heat transfer tubes 12 are arranged between a pair of tube plates 11 such that both end portions thereof are inserted into through holes 11a formed in the pair of tube plates 11 and 11, respectively. ing. The tube plate 11 is made of, for example, stainless steel.

  Further, a tubular collar 13 joined to the heat transfer tube 12 and the tube plate 11 is provided between the outer peripheral surfaces of both ends of the heat transfer tube 12 and the inner peripheral surface of the through hole 11 a of the tube plate 11. The collar 13 protrudes from the back surface 11 e of the tube plate 11, and the upper end portion thereof is positioned closer to the tube plate 11 than the end opening surface 12 a of the heat transfer tube 12, and its inner peripheral surface is the heat transfer tube 12. The heat transfer tube 12 and the tube plate 11 are joined to each other by welding in a state where they are not in contact with the outer peripheral surface and the outer peripheral surface is in contact with the inner peripheral surface of the through hole 11a of the tube plate 11. That is, the collar 13 is welded to the upper end of the collar 13 and the outer peripheral surface of the heat transfer tube 12, and the outer peripheral surface of the collar 13 is welded to the peripheral edge of the through hole 11 a in the back surface 11 e of the tube plate 11. Is provided. The collar 13 is formed of stainless steel.

  And in this embodiment, the lower end part of the insert pipe 14 is inserted inside the both ends of the heat exchanger tube 12 toward the inside from each edge part opening surface 12a. On the outer peripheral surface of the lower end portion of the insert tube 14 inserted into the heat transfer tube 12, a heat insulating material 14a is provided over the entire length in the tube axis direction. The heat insulating material 14 a is formed of, for example, ceramic bulk felt, and the size in the tube axis direction is larger than the size of the collar 13 in the tube axis direction.

  Further, a flange portion 14b protruding outward in the radial direction is provided at the upper end of the outer peripheral surface of the lower end portion of the insert pipe 14. The flange portion 14b has an annular shape in plan view, and the lower end portion of the insert tube 14 is inserted inside the flange portion 14b. Then, the other end surface of the flange portion 14b facing the lower end of the insert tube 14 (the inner end in the tube axis direction of the heat transfer tube 12) is opposite to the outer end surface of the insert tube 14. ing. Moreover, the upper end of the heat insulating material 14a and the said one end surface of the collar part 14b are contact | abutted.

  Furthermore, a stopper member 14c that protrudes radially outward and supports the heat insulating material 14a from below is provided on the outer peripheral surface of the lower end of the insert tube 14. The amount of protrusion of the stopper member 14c from the outer peripheral surface of the insert tube 14 toward the radially outer side is equal to or less than the thickness in the radial direction of the heat insulating material 14a. The outer diameters of the stopper member 14c and the heat insulating material 14a are transmitted. The inner diameter of the heat pipe 12 is set to be equal to or less. Further, the outer diameter of the flange portion 14b is larger than the inner diameter of the heat transfer tube 12 and not more than the outer diameter.

  In the above configuration, when the insert tube 14 is disposed in the heat transfer tube 12 with the lower end portion thereof being inserted into the heat transfer tube 12 from the end opening surface 12a of the heat transfer tube 12, the one of the flange portions 14b. The end surface and the end opening surface 12a of the heat transfer tube 12 are brought into contact with each other. Further, the heat insulating material 14 a is configured to face the entire inner peripheral surface of the collar 13 through the heat transfer tube 12. In the present embodiment, the portion where the upper end portion of the collar 13 and the outer peripheral surface of the heat transfer tube 12 are joined by welding is also opposed to the heat insulating material 14 a via the heat transfer tube 12. Further, the lower end of the heat insulating material 14 a is positioned below the lower end of the collar 13.

And while letting the high temperature fluid H pass through the inside of the heat exchanger tube 12 and the insert tube 14, the low temperature fluid L is allowed to pass between the pair of tube plates 11.
In the heat exchanger 10 shown in FIG. 1, the lower portion of the heat transfer tube 12 and the like is upside down from the upper portion described above.
Moreover, in the high temperature side tube plate 11, that is, the heat transfer tube 12, of the pair of tube plates 11, the high temperature fluid H before being cooled by the low temperature fluid L passing between the tube plates 11 is located inside. A heat insulating material 11b is disposed on the upper surface 11e side of the tube plate 11 into which one end is inserted.

  As described above, according to the heat exchanger 10 according to the present embodiment, the heat insulating material 14a is opposed to the entire inner peripheral surface of the collar 13 through the heat transfer tube 12, so that the outer peripheral surface of the heat transfer tube 12 is Of these, it is possible to avoid the inner peripheral surface of the collar 13 from facing the portion where the heat insulating material 14a is not located inside, that is, the portion where the heat of the high-temperature fluid H is directly conducted without passing through the heat insulating material 14a. It becomes possible. Accordingly, the amount of heat conducted from the heat transfer tube 12 to the collar 13 is reduced, and it is possible to suppress the temperature of the collar 13 from becoming high, and the tube plate 11 joined and in contact with the collar 13 becomes high. This can be suppressed, the life of the tube plate 11 can be extended, and the replacement frequency can be reduced.

  Furthermore, since the heat insulating material 14a is provided not in the heat transfer tube 12 but in the insert tube 14, when the heat insulating material 14a needs to be replaced due to deterioration due to heat, the replacement time is reduced. It can be minimized. That is, by preparing in advance another insert pipe 14 provided with a new heat insulating material 14a on the outer peripheral surface thereof at the lower end, the entire insert pipe 14 having the heat-insulated heat insulating material 14a is removed from the heat transfer pipe 12 at the time of replacement. After that, the other insert tube 14 can be inserted and attached inside the heat transfer tube 12.

  Further, a flange portion 14b protruding radially outward is provided at the upper end of the outer peripheral surface of the lower end portion of the insert tube 14, and the one end surface of the flange portion 14b and the end opening surface 12a of the heat transfer tube 12 are provided. Since they are in contact with each other, it is possible to easily and highly accurately position the insert tube 14 in the tube axis direction with respect to the heat transfer tube 12, and the above-described effects can be easily achieved without taking the time for mounting the insert tube 14. This can be realized, and the time required for replacing the insert tube 14 can be minimized.

  Furthermore, since a stopper member 14c that protrudes radially outward and supports the heat insulating material 14a from below is provided on the outer peripheral surface of the lower end of the insert tube 14, the heat exchanger 10 is used and the insert tube 14 is replaced. Sometimes, it becomes possible to avoid the heat insulating material 14a coming off the insert tube 14 and fitting inside the heat transfer tube 12, and the time required for the replacement of the insert tube 14 can be minimized, It is possible to avoid a problem that the high-temperature fluid H does not flow or becomes difficult to flow through the heat transfer tube 12.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the configuration is shown in which the end opening surface 12a of the heat transfer tube 12 is positioned at a position protruding from the back surface 11e opposite to the opposite surface 11d of the pair of tube plates 11. Instead, the end opening surface 12a of the heat transfer tube 12 may be positioned on the back surface 11e of the pair of tube plates 11.

Moreover, in the said embodiment, although the structure which provided the collar part 14b in the upper end in the lower end part outer peripheral surface of the insert pipe 14 was shown, this collar part 14b does not need to be provided.
Furthermore, although the structure which provided the stopper member 14c which protrudes to radial direction outward and supports the heat insulating material 14a from the downward direction was shown in the lower end outer peripheral surface of the insert pipe 14, it is applicable also in the structure which does not provide this stopper member 14c. It is.
Furthermore, as in the above-described embodiment, the present invention can be applied to a configuration in which the heat transfer tubes 12 and the like are oriented horizontally instead of the heat exchanger 10 in which the heat transfer tubes 12 and the like are oriented vertically.

  Heat conduction from the heat transfer tube to the tube sheet can be suppressed to a minimum, and the replacement frequency of the tube sheet can be reduced.

It is a principal part schematic sectional drawing of the heat exchanger shown as one Embodiment of this invention. In the heat exchanger of FIG. 1, it is an A section expanded sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat exchanger 11 Tube plate 11a Through-hole 12 Heat transfer tube 12a End opening surface of heat transfer tube 13 Collar 14 Insert tube 14a Heat insulating material 14b Eave part 14c Stopper member H High temperature fluid L Low temperature fluid

Claims (3)

A large number of heat transfer tubes are arranged between a pair of tube plates, with both end portions thereof being inserted in parallel through through holes formed in the pair of tube plates, and outer peripheral surfaces of both end portions of the heat transfer tubes, and the tube Between the through hole inner peripheral surface of the plate, a tubular collar joined to these heat transfer tubes and the tube plate is provided,
One end of an insert tube is inserted inside at least one of both ends of the heat transfer tube, and the outer peripheral surface of the one end is opposed to the entire inner peripheral surface of the collar via the heat transfer tube. A heat exchanger characterized in that a heat insulating material is provided. The heat exchanger according to claim 1, wherein
An outer peripheral surface of one end portion of the insert tube is provided with a flange portion protruding radially outward, and the insert tube has an end surface of the flange portion and an end opening of the heat transfer tube inside the heat transfer tube. A heat exchanger, wherein the heat exchanger is inserted in contact with the surface. The heat exchanger according to claim 1 or 2,
A heat exchanger characterized in that a stopper member is provided on an outer peripheral surface at one end of the insert pipe so as to protrude radially outward and support the heat insulating material.

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