JPH08145503A - Heat exchanger - Google Patents

Abstract

PURPOSE: To eliminate a leakage of water or a refrigerant from a partitioning part without enlarging the thickness of a packing or a tube plate, by constructing a partitioning member in a shape corresponding to the amount of strain caused on the occasion when heat transfer tubes are subjected to tube expansion and fixed by the tube plate in a part wherein the partitioning member is fitted. CONSTITUTION: In the case when a flow passage of cooling water for exhausting heat is made common, a plurality of heat exchangers 5a and 5b for condensation are connected through the intermediary of an intermediate flange 9 having a partitioning member 15 dividing the passage of the cooling water. By pressing this partitioning member 15 beforehand so that it may come into contact with an equilateral triangle, a strain is absorbed by the partitioning member 15 of the intermediate flange. The base of this equilateral triangle is made equal to the inside diameter D of a cylinder part of the heat exchanger for condensation and angles on the opposite sides of the base are made θ (θ = arc tan (2σmax/D). Herein σmax denotes the maximum amount of the strain determined experimentally with the thickness, diameter and quality of a tube plate and the sequence of tube expansion machining fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, and more particularly to a shell-and-tube heat exchanger for refrigeration equipment.

[0002]

2. Description of the Related Art As shown in Japanese Patent Laid-Open No. 4-116358, a conventional shell-and-tube condenser heat exchanger for a water-cooled refrigerating apparatus is a cooling water for discharging heat in a plurality of independent refrigerating cycles. In order to share the flow path of
Due to the limitation of the external dimensions, it is manufactured by combining a plurality of condensers that are short in the longitudinal direction and thick in the circumferential direction in series.
In this type of condenser, when assembling a plurality of condensers in series, it was necessary to arrange an intermediate flange having a partition member for partitioning the cooling water passage.

[0003]

In the above-mentioned prior art,
As long as the intermediate flange is thick and the outer dimensions of the tube sheet are the same as those of the heat exchanger for condensation, there is almost no distortion of the tube sheet, but due to dimensional restrictions in the longitudinal direction, the heat transfer tube should be as long as possible. If the structure that minimizes the thickness of the intermediate flange is adopted, the external dimensions of the tube sheet on the side connecting the intermediate flange are
The structure is such that the outer diameter of the condensing heat exchanger body is made larger, and the bolts are tightened at the circumferential portion having the outer diameter of the condensing heat exchanger body or more.

As a result, the tube flange on the side of the intermediate flange has a larger outer dimension, so that when the heat transfer tube is expanded and fixed, a larger strain is generated in this tube sheet. At this time, since the partition member of the conventional intermediate flange is on the same plane as the circumferential portion, the circumferential portion of the intermediate flange and the tube sheet do not adhere to each other, and there is a problem that water leakage occurs when cooling water is passed. . For this reason, it is necessary to increase the thickness of the packing inserted between the tube sheet and the intermediate flange more than necessary, or to perform additional work to grind the partition member of the intermediate flange according to the amount of strain after water leakage is detected.

Further, in the heat exchanger for evaporation, in which a plurality of refrigeration cycles are integrated, it is necessary to provide a partition part for partitioning these cycles and a partition part for partitioning the refrigerant side inlet part and the outlet part. Similarly, in the refrigerant chamber having this partition portion, the structure is such that bolts are tightened at the circumferential portion having the outer diameter of the heat exchanger body portion for evaporation or more. As a result, the tube sheet on the refrigerant chamber side having the partition portion has a larger outer diameter dimension, and thus, when the heat transfer tube is expanded and fixed, a larger strain is generated in the tube sheet. At this time, since the refrigerant chamber having the conventional partitioning portion is on the same plane as the circumferential portion, there is a problem that the circumferential portion of the refrigerant chamber and the tube plate do not adhere to each other and the refrigerant leaks from the circumferential portion. . For this reason, the tube sheet is made thicker than necessary to prevent distortion.

An object of the present invention is to prevent water leakage or refrigerant leakage in the partition portion without increasing the thickness of the packing or the tube sheet, thus eliminating the need for additional cutting work of the partition member after water leakage or refrigerant leakage occurs. To obtain a heat exchanger.

[0007]

The above-mentioned object of the present invention is as follows.
A heat transfer tube group divided into a plurality of groups in which the flow directions of the fluid in the heat transfer tube are opposite to each other, and a tube plate provided at both ends of the heat transfer tube group for penetrating the heat transfer tube group and expanding and fixing the tube. , A shell-and-tube heat exchanger having the heat transfer tube group and a tubular body containing the tube sheet is connected in series with a tubular intermediate flange so that one end of the tube group is inside the intermediate flange. A heat exchanger having a partition member mounted between the tube plates so as to divide the passage inside the intermediate flange for each flow direction of the fluid, and the partition member is mounted to the partition member. This is achieved by forming a part of the tube plate in a shape corresponding to the amount of strain generated when the heat transfer tube is expanded and fixed.

Further, a heat transfer tube group which is divided into a plurality of groups in which the flow directions of the fluid in the heat transfer tube are opposite to each other, and a tube which is provided at both ends of the heat transfer tube group and penetrates through the heat transfer tube group Inlet / outlet of fluid in the heat transfer tube by connecting tubular flanges on both sides of a shell-and-tube heat exchanger having a tube plate to be fixed and a tube body containing the heat transfer tube group and the tube plate In the heat exchanger having a partition member attached to the tube sheet so as to divide the passage inside the flange for each fluid flow direction, the partition member is a portion to which the partition member is attached. This can also be achieved by forming the tube plate into a shape corresponding to the amount of strain generated when the heat transfer tube is expanded and fixed.

[0009]

According to the present invention, it is a determining factor of the amount of distortion of the tube sheet that is generated when the heat transfer tube is expanded and fixed to the partition member, which is attached so as to divide the passage for each fluid flow direction. The tube sheet thickness, diameter, material, and tube expansion processing order are fixed, and a shape corresponding to the experimentally obtained strain amount or a shape calculated from the strain amount is processed in advance. As a result, the distortion of the tube sheet that occurs when the heat transfer tube is expanded and fixed to the tube sheet is absorbed by the partition member, and the degree of adhesion between the partition member and the tube sheet is improved. Therefore, the water leakage or the refrigerant leakage from the partition member is eliminated, the thickness of the packing inserted between the tube sheet and the partition member may be the minimum necessary, and the partition member, which was used after the water leakage or the refrigerant leakage was found, is scraped off. Additional work is eliminated.

Further, it is not necessary to increase the thickness of the tube sheet more than necessary in order to prevent distortion.

[0011]

EXAMPLE An example of the present invention will be described below. FIG. 1 is a system diagram of a refrigeration system. The configuration is a refrigeration cycle including a compressor 1, a condensing heat exchanger 2, an expansion valve 3, and an evaporating heat exchanger 4. In the refrigerating apparatus having a plurality of independent refrigerating cycles, the condensing heat exchanger 2 has the structure shown in FIG. 2 in order to share the flow path of the cooling water for exhausting heat.

The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 flows from the refrigerant inlet 11 into the condensing heat exchanger bodies 5a and 5b. This gas refrigerant is used for condensing heat exchanger bodies 5a and 5b.
Heat is exchanged with the plurality of heat transfer tubes 7 arranged inside, condensed, and dropped. The dropped liquid refrigerant passes through the expansion valve 3 shown in FIG. 1 after being discharged from the refrigerant outlet 12, and then passes through the evaporation heat exchanger 4
And returns to the compressor 1. In the case of a refrigerating apparatus having a plurality of independent refrigeration cycles, the same number of condenser heat exchangers as the refrigeration cycles are required. At this time, when the cooling water flow path for exhausting heat is shared, a plurality of condensing heat exchangers are connected via an intermediate flange 9 having a partition member 15 for partitioning the cooling water passage.

The structure of the intermediate flange 9 is shown in FIG.
Cooling water necessary for condensing the gas refrigerant flows in from the cooling water inlet 13 of the cooling water inlet / outlet side flange 10, passes through the inside of the heat transfer tube 7 in the condensing heat exchanger body portion 5b, and reaches the intermediate flange 9 Flow into the condensing heat exchanger 5a, and are turned back at the cooling water turning back flange 8, and again the condensing heat exchanger 5a,
It passes through the intermediate flange 9 and the condensing heat exchanger 5b and flows out from the cooling water outlet 14. The heat transfer tubes 7 in the heat exchangers 5a and 5b for condensing are fixed to the tube plate 6 by expanding. At this time, expansion occurs in the heat transfer tube due to the tube expansion process, and the reaction force generated by the expansion acts as pressure on the tube sheet 6 to act.
Distortion occurs. Here, the amount of strain that occurs in the tube sheet 6 is determined by the thickness, diameter, material, and expansion order of the tube sheet, but here it is assumed that the strain as shown in FIG. 4 has occurred.

In the present invention, as shown in FIG. 5, the partition member 15 for partitioning the cooling water passage of the intermediate flange is pre-pressed so as to come into contact with the isosceles triangle. 15 will be absorbed. In this isosceles triangle, the bottom is the inner diameter D of the condensing heat exchanger body, and the angles on both sides of the bottom are θ (θ =
arc tan (2σmax / D)). Here, σmax is the maximum value of the strain amount experimentally obtained by fixing the thickness, the diameter, the material of the tube sheet, and the tube expansion processing order.

Further, as shown in FIG. 6, a radius R (R = a / 2sin θ, a ² calculated from the experimentally obtained maximum value σmax of strain amount and the inner diameter D of the body of the heat exchanger for condensation is used. = σma
^{x 2 + D 2/4,} θ = arc tan in contact with (2σmax / D)) becomes an arc, by pre-pressing the intermediate flange of the partition member 15, the strain is absorbed by the partition member 15 of the intermediate flange Will be.

Therefore, the partition member 15 for partitioning the cooling water passage of the intermediate flange 9 is preliminarily processed to have a shape in consideration of the distortion of the tube sheet 6 generated when the heat transfer tube 7 is expanded and fixed to the tube sheet 6. Adhesion between the circumferential portion of the flange 9 and the tube sheet 6 is improved, water leak from the circumferential portion of the intermediate flange, which was likely to occur when cooling water is passed, is eliminated, and the effect of quality improvement is obtained. Further, the cost of the material is reduced by optimizing the thickness of the packing, and the cost is reduced by shortening the processing time by eliminating the additional work after the water leak is discovered. Further, the intermediate flange in which the partition member 15 is preliminarily processed into a shape in consideration of the distortion of the tube sheet 6 is not limited to the connection between the condensing heat exchangers, and may be used for the connection between the condensing heat exchanger and the cooling water inlet / outlet flange. The same effect can be obtained.

The refrigerant having passed through the expansion valve 3 enters the heat exchanger 4 for evaporation. The structure of this evaporation heat exchanger is shown in FIG. The function of this heat exchanger for evaporation is that, with the heat exchanger for condensation described above, the cooling water passage portion becomes the evaporation refrigerant passage portion, and the refrigerant passage portion is the reverse of the cold water passage portion, but as a heat exchanger, Since the processing order, heat transfer tube fixing, tube plate thickness, and shape are the same, similar effects can be obtained.

[0018]

According to the present invention, the determinant of the amount of distortion of the tube sheet that is generated when the heat transfer tube is expanded and fixed to the partition member, which is installed so as to divide the passage for each fluid flow direction. That is, the thickness, diameter, material, and tube expansion processing order of the tube sheet are fixed, and a shape corresponding to the strain amount experimentally obtained or a shape calculated from the strain amount is processed in advance. As a result, the distortion of the tube sheet that occurs when the heat transfer tube is expanded and fixed to the tube sheet is absorbed by the partition member, and the degree of adhesion between the partition member and the tube sheet is improved. Therefore, there is no water leakage or refrigerant leakage from the partition part, the thickness of the packing inserted between the tube sheet and the partition member may be the minimum necessary, and the partition member that was used after the water leakage or refrigerant leakage was found is scraped off. Additional work is eliminated. As a result, an effect of quality improvement is produced by eliminating water leakage or refrigerant leakage from the partition section.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a refrigerating apparatus for carrying out the present invention.

FIG. 2 is a vertical sectional view of a heat exchanger according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the intermediate flange of the heat exchanger according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view of the tube sheet of the heat exchanger according to the embodiment of the present invention.

FIG. 5 is a sectional view of a partition member of the heat exchanger according to the embodiment of the present invention.

FIG. 6 is a sectional view of a partition member of a heat exchanger according to another embodiment of the present invention.

FIG. 7 is a vertical sectional view of a heat exchanger according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Compressor, 2 ... Condensing heat exchanger, 3 ... Expansion valve, 4 ... Evaporating heat exchanger, 5a, 5b ... Condensing heat exchanger body part, 6 ...
Tube plate, 7 ... Heat transfer tube, 8 ... Cooling water folding side flange, 9
... Intermediate flange, 10 ... Cooling water inlet / outlet side flange, 11
... Refrigerant inlet, 12 ... Refrigerant outlet, 13 ... Cooling water inlet, 14
... cooling water outlet, 15 ... partitioning member, 16 ... evaporation heat exchanger body, 17 ... refrigerant return side flange, 18 ... refrigerant inlet / outlet side flange, 19 ... cooling water inlet, 20 ... cooling water outlet, 21
... A partition that divides the refrigerant passage.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuji Yamashita 390 Muramatsu, Shimizu-shi, Shizuoka Hitachi Air Conditioning Systems Division (72) Inventor Tadanori Kajimoto 715 Miyakazo Shimizu, Shizuoka Kay Corporation Co., Ltd.

Claims (4)

[Claims] 1. A heat transfer tube group which is divided into a plurality of groups in which the flow directions of fluids in the heat transfer tube are opposite to each other, and a pipe which is provided at both ends of the heat transfer tube group and penetrates through the heat transfer tube group. A tube plate to be fixed, a shell-and-tube heat exchanger having a tubular body containing the heat transfer tube group and the tube plate is connected in series with a tubular intermediate flange, and the shell and tube type heat exchanger are connected to the inside of the intermediate flange. In a heat exchanger having a configuration in which one end of a tube group is opened, and the partition member is attached between the tube plates so as to divide a passage in the intermediate flange for each fluid flow direction, the partition member is A heat exchanger characterized in that a tube plate of a portion to which the partition member is attached is formed in a shape corresponding to a strain amount generated when the heat transfer tube is expanded and fixed. 2. A heat transfer tube group which is divided into a plurality of groups in which the flow directions of the fluid in the heat transfer tube are opposite to each other, and a pipe which is provided at both ends of the heat transfer tube group and penetrates through the heat transfer tube group. Inlet / outlet of fluid in the heat transfer tube by connecting tubular flanges on both sides of a shell-and-tube heat exchanger having a tube plate to be fixed and a tube body containing the heat transfer tube group and the tube plate In the heat exchanger having a partition member attached to the tube sheet so as to divide the passage inside the flange for each fluid flow direction, the partition member is a portion to which the partition member is attached. A heat exchanger characterized in that the tube plate has a shape corresponding to the amount of strain generated when expanding and fixing the heat transfer tube. 3. The method according to claim 1, wherein when the maximum strain amount of the tube sheet is σmax and the inner diameter when the body is a cylinder is D, a portion of the partition member which is in contact with the tube sheet is: Angle D at the base D and both sides of the base D (θ = arc tan
(2σmax / D)) A heat exchanger characterized by being processed so as to be in contact with an isosceles triangle of an isosceles triangle. 4. In claim 1 or 2, when the maximum strain amount of the tube sheet is σmax and the inner diameter when the body is cylindrical is D, the location of the partition member that contacts the tube sheet is: radius R (R = a / 2sinθ, a 2 = σmax 2 + D 2/4,
A heat exchanger characterized by being processed so as to contact an arc represented by θ = arc tan (2σmax / D)).