JP3591970B2 - Multi-tube heat exchanger - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to heat transfer tubes used for effective heat exchange, and heating, cooling, exhaust heat recovery, or steam, boilers or other high-temperature water-based air conditioning, hot water supply, or pools, for example, for chemical plants and food plants. Multi-tube heat exchangers using the heat transfer tubes used in a wide range of fields, such as for heating and heating in hot springs, and for heating and cooling air, exhaust gas, CFCs or hydraulic equipment, etc. It is.
[0002]
[Prior art]
Conventionally, as this type of heat transfer tube (P '), as shown in FIG. 4, a tube having smooth inner and outer peripheral surfaces each having a circular cross section is generally used. When assembling a tubular heat exchanger, as shown in FIGS. 5 and 6, the heat transfer tubes (P ') are arranged in a bundle and are housed inside the body (11) as a heat exchanger.
[0003]
[Problems to be solved by the invention]
However, in such a conventional technique, the flow of the fluid inside the heat transfer tube (P ') is made to be substantially straight due to the simple circular inner peripheral surface and the constant sectional area of the fluid passage. Therefore, the boundary layer of the flow generated near the inner peripheral surface is made thicker, and heat exchange is caused by impurities such as water scale, oil scum, dirt, dust, soot, etc. adhered to the inner peripheral surface for a long period of time. This has led to a reduction in efficiency, and in connection with the reduction in efficiency, there has generally been a problem that the entire product must be increased in size and weight.
[0004]
Further, when the outer peripheral surface of the heat transfer tube is smooth, even if the baffle plate (13) is inside the body (11), the fluid flowing outside the heat transfer tube (P ') flowing from the inflow hole (11') is: As shown by the dotted lines in FIGS. 5 and 6, since the gas flows in a sine curve and takes the shortest distance and flows out of the outlet hole (11 ″), the contact time with the outer peripheral surface of the heat transfer tube (P ′) is short. Therefore, the heat exchange efficiency is not sufficient, and an improvement has been required.
[0005]
The present invention has been made in view of the above-mentioned problems of the prior art, and increases the contact time between a fluid and a heat transfer tube by increasing the surface area per unit length on the inner and outer peripheral surfaces, particularly on the inner peripheral surface. The turbulent flow function is produced near the inner peripheral surface and the inner and outer peripheral surfaces by changing the fluid passage area to make the boundary layer of the flow as thin as possible, and at the same time, the scale of the inner peripheral surface due to the promotion of the turbulence, the soapstock, Multi-tubular heat exchange that can increase the heat exchange efficiency over a long period of time by reducing the adhesion of impurities such as dirt or dust, soot, etc., and make the whole product relatively small and lightweight. It is intended to provide a vessel.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the multi-tubular heat exchanger according to the present invention has an inflow hole wall and an outflow hole wall communicating with the inside, on the outer peripheral side near the end portion where both end portions are separated by partition walls. A large number of heat transfer tubes penetrating a baffle plate and maintaining a mutual flow gap are arranged in a bundle in a longitudinal direction inside the body, and both ends are penetrated and fixed to at least one of the partition walls. A heat exchanger configured to further seal the outside of the partition wall with at least one bonnet and to provide the bonnet with an inlet and an outlet that communicate with an internal heat transfer tube; Spiral corrugated surfaces having different winding directions on the outer peripheral surface having the same phase as that of the heat transfer tube are alternately provided along the length direction, and the spiral corrugated surfaces of the heat transfer tubes are the same between the baffle plates. It is characterized by being configured in a direction. It is intended.
[0007]
Since the present invention is configured in this manner, the inner peripheral surface, particularly the inner peripheral surface, is formed by a spiral corrugated surface having the same phase as the inner peripheral surface of the heat transfer tube and having a different winding direction on the outer peripheral surface. As the surface area per unit length of the heat transfer tube increases, the contact time of the fluid with the heat transfer tube increases, and at the same time, the area of the fluid passage changes. To reduce the boundary layer of the flow in the vicinity, as much as possible, and to reduce or eliminate the adhesion of impurities such as scale, grease, dirt, etc., or dust on the inner peripheral surface due to the promotion of turbulence. As a result, the heat exchange efficiency is increased over a long period of time, and the improvement in the efficiency results in a relatively small and light-weight product as a whole.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an enlarged plan view showing one embodiment of a single heat transfer tube of a multi-tube heat exchanger according to the present invention, with a part cut away. FIG. FIG. 3 is a longitudinal sectional view of a multi-tube heat exchanger according to another embodiment of the present invention, with a part of the embodiment being omitted; FIG. 3 is a diagram corresponding to FIG. 2 showing another embodiment of the multi-tube heat exchanger according to the present invention. .
[0009]
The heat transfer tube (P) according to the present invention is made of various metal materials such as Ti, SUS or Cu material, and has a structure of winding corrugated surfaces (6) and (6 ') as shown in FIG. The tube is provided with a smooth surface (7) having a predetermined width on a non-spiral portion whose direction changes.
[0010]
A multi-tube heat exchanger using such a heat transfer tube (P), as shown in FIGS.
One of the fluids passing through the inside of the cylindrical body (1) made of SUS, copper alloy, steel or the like into the outer peripheral side near the ends defined by the hub at both end portions separated by the partition walls (2, 2 '). And a plurality of baffle plates (3) formed in a partially circular shape in the longitudinal direction of the inside of the fuselage. And a plurality of the heat transfer tubes (P) are arranged in a bundle while mutually maintaining the flow gap of the one fluid, and both ends of the heat transfer tubes (P) are assembled with the partition walls (2, 2 '). (4, 4 ') are left and right bonnets which are fixed in a state where packing is laid outside the partition walls (2, 2') as shown in FIG. One of them is provided with an inlet (5) and an outlet (5 ') for the other fluid which communicates with the heat transfer tube (P), and each is sealed. Is made of Te. (9) is anticorrosive zinc rod member inside which is provided on one of the bonnet (4 '). The anticorrosive zinc rod member may be provided on both of the bonnet.
[0011]
Further, as another embodiment, the present invention can be applied to the multi-tube heat exchanger shown in FIG. In the heat exchanger shown in FIG. 3, one end of a body (1) formed in a bottomed cylindrical body having a spherical bottom surface is formed on the outer peripheral side near the end portion, which is defined by a partition wall (2). A plurality of baffle plates (3) each having an inflow hole wall (1 ') and an outflow hole wall (1 ") for passing fluid through the inside of the fuselage and having a shape of a broken circle extending in the longitudinal direction inside the body. A large number of substantially U-shaped heat transfer tubes (P) are arranged in a bundle while penetrating each other and maintaining the flow gap of the one fluid, and both ends of the heat transfer tubes (P) are divided into the partition walls (2). On the other hand, the bonnet (4) is positioned with the packing laid outside the partition wall (2), and the bonnet passes through the heat transfer pipe (P). The fluid inlet (5) and the outlet (5 ') are provided and sealed.
[0012]
The solid arrows indicate the flow directions of the respective fluids, and the solid arrows in FIG. 3 are arranged so that the winding directions of the corrugated surfaces (6 ') of the outer peripheral surfaces of the adjacent heat transfer tubes (P) are different. It shows a meandering flow of the outer fluid in the heat transfer tube, and more effectively exerts the heat exchange function in the heat transfer tube (P) not only on the inner peripheral surface but also on the outer peripheral surface, Further, as shown in FIGS. 2 and 3, the corrugated surface (6 ') of the outer peripheral surface of the heat transfer tube (P) is symmetrical with respect to the baffle plate (3) and is opened toward the free end of the baffle plate. With this arrangement, the outer fluid flows in an approximately Z-shape in the axial direction, so that the contact time between the fluid and the heat transfer tube is increased by increasing the surface area per unit length, and the heat exchange function on the outer peripheral surface is further improved. Be effective.
[0013]
【The invention's effect】
As described above, the shell-and-tube heat exchanger according to the present invention has the spiral corrugated surface (6) having the same phase as the inner peripheral surface of the heat transfer tube (P) and having different winding directions on the outer peripheral surface. The heat transfer tubes (P) are provided alternately in the longitudinal direction and the spiral corrugated surfaces (6) of the heat transfer tubes (P) have the same winding direction between the baffle plates (3). Due to the corrugated surface, the surface area per unit length on the inner and outer peripheral surfaces, particularly on the inner peripheral surface, is increased to increase the contact time of the fluid flowing near the tube wall of the heat transfer tube (P) with the tube wall, and As the relative velocity with respect to the wall increases, the area of the passage of the fluid increases and decreases. Therefore, a turbulent flow function is generated in the flow near the inner and outer peripheral surfaces of the heat transfer tube (P), particularly near the inner peripheral surface. The boundary layer of the flow of water can be made as thin as possible. It reduces and removes impurities such as dirt or dust, soot, etc., resulting in an increase in heat exchange efficiency over a long period of time, and the improvement in efficiency makes it possible to make the entire product relatively small and lightweight. It is a very useful multi-tube heat exchanger.
[Brief description of the drawings]
FIG. 1 is an enlarged plan view showing one embodiment of a single heat transfer tube of a multi-tube heat exchanger according to the present invention, partially cut away.
FIG. 2 is a vertical cross-sectional view of a multi-tube heat exchanger according to the present invention, with a part of the embodiment omitted;
FIG. 3 is a diagram corresponding to FIG. 2, showing another embodiment of the multitubular heat exchanger according to the present invention.
FIG. 4 is an enlarged plan view showing a part of a single heat transfer tube of a conventional multi-tube heat exchanger.
FIG. 5 is a longitudinal cross-sectional view partially showing an example of a conventional multi-tube heat exchanger.
FIG. 6 is a diagram corresponding to FIG. 5, showing another example of the conventional multi-tube heat exchanger.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Body 1 'Inlet hole wall 1 "Outlet hole wall 2 Partition wall 3 Baffle plate 4, 4' Bonnet 5 Inlet 5 'Outlet 6, 6' Corrugated surface 7 Smooth surface P Heat transfer tube

Claims (1)

On both sides of the fuselage having an inflow hole wall and an outflow hole wall communicating with the inside on the outer peripheral side near the end, which is divided by a partition wall on both sides, the baffle plate is penetrated through each other. A large number of heat transfer tubes holding the flow gap are arranged in a bundle, and both ends are penetrated and fixed to at least one of the partition walls, and the outside of the partition wall is sealed with at least one bonnet. In a heat exchanger in which a bonnet is provided with an inflow port and an outflow port communicating with an internal heat transfer tube, a spiral having the same phase as the inner circumferential surface of the heat transfer tube (P) and having a different winding direction on the outer circumferential surface. The corrugated surfaces (6) are alternately provided in the longitudinal direction, and the spiral corrugated surfaces (6) of the heat transfer tubes (P) have the same winding direction between the baffle plates (3). A multi-tube heat exchanger characterized by comprising.

Images