JPS5924140A - Heat exchanger - Google Patents

Abstract

PURPOSE:To miniaturize the device, increase the efficiency and prevent the local heating thereof by promoting the turbulent flow of high-temperature combustion gas by a method wherein a flow path regulating body is arranged at the down stream side in the main body of the heat exchanger, formed integrally with a plurality of inner fins therein into the axial direction thereof, and a plurality of flow disturbing bodies are attached to the outer periphery of the flow regulating body between the inner fins. CONSTITUTION:High temperature combustion gas, generated in a combustion chamber 19 by forming combustion flame 20, passes the outer periphery of the flow regulating body 14 as shown by an arrow sign 30 and is discharged to atmosphere from an exhaust port 22 through an exhausting part 8. When a fan 27 for convection is started in this process by a thermostat provided at a part in the heat exchanger 6, the high temperature combustion gas of 800- 1,200 deg.C, generated in the combustion chamber 19, is introduced to the outer periphery of the flow path regulating body 14 after a part of the heat thereof is absorbed by the inner wall of the combustion chamber 19. In this case, effective heat transmissions are effected at the inner surface of the inner fins 10 and the main body 9 of the heat exchanger by the promotion of turbulent flow of the flow disturbing body 15, the heat thereof is exchanged with convection air flow 29 passing through the outer periphery of the heat exchanger 6, the temperature of the combustion gas is reduced remarkably to 150-200 deg.C and the combustion gas is discharged from the exhaust port.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat exchanger that can be used in general heaters that completely burns gas or liquid fuel and exchanges heat between the combustion gas and indoor air.

Structure of conventional example and its problems Conventionally, this type of heat exchanger is as shown in Figs. 1 and 2.
A plurality of internal fins 2 are integrally formed from an extruded shape in the axial direction of the inner surface of the heat exchanger main body 1, and after the external fins 3 are wrapped around the outer peripheral surface of the heat exchanger body 1, they are fixed by furnace brazing or the like. ing. Inside the heat exchanger body 1, a truncated conical intermediate cylinder 4 is entirely disposed, and one end is provided with a burner 6. burner 5
The high-temperature combustion gas burned in the internal fins 2 absorbs heat when passing through the internal fins 2, and exchanges heat with the convection air flow in the external fins 3.

However, this type of heat exchange structure has the following drawbacks.

(1) This is a configuration in which heat transfer is promoted by increasing the heat absorption area of the internal fins or by increasing the flow velocity of the combustion gas, without providing any wave disturbance bodies between the internal fins.

However, with this configuration, it is difficult to form small gaps between internal fins due to the strength constraints of the mold during extrusion processing, and it is not possible to expect an improvement in heat transfer due to an increase in the combustion gas flow rate, resulting in a high degree of thermal efficiency. can't get it.

(2) Since the total heat transfer area on the gas side increases, it is necessary to increase the number and height of the internal fins to secure the area, resulting in higher material costs and a lack of compactness of the heat exchanger.

(37) Even if the total heat transfer area on the gas side is increased, a high degree of thermal efficiency cannot be achieved due to the above-mentioned reason 1.

(4) As the heat transfer area on the gas side increases, the internal fins facing the burner flame intensively receive radiant heat, resulting in locally abnormally high temperatures, leading to υ melting that causes deformation, etc.
This caused problems in terms of durability. This has the disadvantage that the small flame comes into direct contact with the internal fins, which cools the flame and generates a large amount of coke.

(5) After the external fins are wrapped and processed, the entire process is brazed in a furnace, resulting in relatively high manufacturing costs.

Purpose of the Invention The present invention eliminates these conventional disadvantages, and improves the size and efficiency by promoting turbulent flow of combustion gas in the upper part, prevents local heating by equalizing the heat exchanger temperature, and improves durability. The aim is to obtain a low-cost heat exchanger at the same time.

Structure of the Invention In order to achieve all of the above objects, the present invention provides a flow path regulating body entirely disposed on the downstream side of the heat exchanger body, which is formed integrally with a plurality of internal fins in the inner axial direction. A plurality of turbulent fluids are installed between internal fins on the outer circumference of the body.

This configuration promotes the turbulent flow of combustion gas in the upper part of the heat exchanger body downstream of the approximately middle part of the heat exchanger body, and prevents the development of a thermal boundary layer on the inner fin surface to maintain an effective thermal contact state. A high degree of thermal efficiency (coefficient of 93 or higher) can be achieved with a relatively small gas side heat transfer area.

By suppressing the gas-side heat transfer area on the upstream side of the heat exchanger main body, it is possible to prevent a local temperature rise due to radiant heat, etc., and to equalize the heat exchanger temperature.

A low-cost heat exchanger can be obtained by integrally constructing the heat exchanger main body from an extruded section, press-fitting external fins, and inserting a plurality of turbulent fluids.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below using the field surfaces shown in FIGS. 3 to 7. Note that the same parts as in FIGS. 3 and 4 in the above figures are given the same numbers.

In the figure, a heat exchanger 6 is provided with a burner 7 integrated with a combustion fan at one end, and an exhaust section 8 at the other end, which are coaxially connected integrally. Reference numeral 9 denotes a heat exchanger main body integrally constructed from an extruded aluminum member or the like, and a plurality of internal fins 10 are provided in the axial direction of the inner surface. Burner T with internal fins 10
Part of the side has been removed by cutting. One end of the heat exchanger main body 9 is connected to the flange part of the burner 7, and the other end is connected to the flange part of the burner 7.
1 and are fixed by etching.

Reference numeral 12 denotes a plurality of external fins provided on the outer periphery of the heat exchanger main body 9, which are made of square aluminum plates and have a par IJ ring part 1 in the center.
3 is mechanically press-fitted into the outer circumferential surface of the heat exchanger main body 9 and fixed thereto. 14 is the central part inside the heat exchanger main body 9;
It is a flow path regulating body provided downstream from the substantially intermediate portion, and has a cylindrical shape with a crown protruding from the exhaust portion 8 . Reference numeral 15 denotes a plurality of ripple elements disposed between the internal fins 10 on the outer periphery of the flow path regulating body 14, which are composed of bent pieces having a plurality of bent parts 16, and are arranged from the ends of the internal fins 1o. 7 Insert as shown in Figure 7,
The constricted portions 17 and enlarged portions 18 are formed alternately. 19 is a combustion chamber configured on the upstream side of the heat exchanger main body 9, 20 is a flame formed in the combustion chamber 19, 21 is a gasket, 22 is an exhaust port, 23 is an ignition electrode provided in a part of the burner 7, 24 is a flame rod that performs combustion detection. 2
5 is a constant oil level device that supplies oil to the burner γ via an electromagnetic pump 26. 27 is a convection blower constituted by a cross flow fan or the like, 28 is a motor, 29 is a convection air flow, 3o is a combustion gas flow, and 31 is a housing.

In the above configuration, when fuel is supplied into the burner 7 by driving the combustion fan and electromagnetic pump 26 of the burner 7 and ignited by the ignition electrode 23, a combustion flame 20 is formed and combustion is sustained. The high-temperature combustion gas generated within the combustion chamber 19 passes through the outer circumference of the flow path regulating body 14 as indicated by an arrow 3o, and is discharged to the outside air via the exhaust portion 8 through the exhaust gas 022. During this process, when the convection blower 27 is started by a thermostat (not shown) installed in a part of the heat exchanger 6, the high temperature combustion gas of 800 to 1200°C generated in the combustion chamber 19 is transferred to the combustion chamber 19. After a portion of the heat is absorbed by the inner wall, it is guided to the outer circumference of the flow path regulator 14 . At this time, effective heat transfer is performed between the internal fins 1o and the inner surface of the heat exchanger body 9 by promoting the turbulent flow of the turbulent fluid 15, and heat exchange is performed with the convection air flow 29 passing through the outer periphery of the heat exchanger 6. , combustion gas temperature is 150~2
It drops to 00'C and large IJ and is discharged from the exhaust port.

In this embodiment, a structure of a bent piece having a plurality of bent parts 16 is shown as the ripple body 15, but in addition to this, a large number of cut and raised pieces are alternately provided on a band-shaped plate piece, and this plate piece is It may be bent into a letter shape.

Further, as other wave disturbance bodies, a large number of protrusions may be provided on the outer periphery of the flow path regulating body 14 and positioned between it and the internal fins 1o.

Furthermore, although a capped cylinder is shown as the flow path regulating body 14 in this embodiment, it may also be constructed of firebrick, ceramic, or the like.

Furthermore, in this embodiment, the heat exchanger main body 9 is integrally constructed from an extruded aluminum section, and external fins of an aluminum plate are mechanically press-fitted and fixed around the main body 9, thereby constructing the heat exchanger 6. However, as another means, it is also possible to configure the heat exchanger body 9 including the internal fins 10 and the external fins 12 integrally using aluminum die-casting.

In this embodiment, the internal fins 1 on the outer periphery of the flow path regulator 14 are
By promoting turbulent flow by the turbulent body 16 positioned between 0 and 0, a high thermal efficiency (93% or more) can be achieved by preventing the development of a temperature boundary layer on the heat transfer surface and improving thermal contact.

In addition, since the circumferential pitch of the internal fins 1o is configured to be relatively large and the thermal efficiency is ensured by promoting turbulence as described above on the downstream side of the heat exchanger main body 9, the gas side heat transfer area on the upstream side is This makes it possible to suppress heat absorption due to radiant heat, etc. on the peripheral wall of the combustion chamber 190, and prevent abnormal calorific heat in parts of the heat exchanger. 300'
C, and durability can be ensured over a long period of time.

Furthermore, the heat exchanger main body 9 is integrally constructed including the internal fins 10, and is constructed from a relatively inexpensive aluminum extrusion, and when the temperature of the heat exchanger decreases, the external fins 12 are mechanically press-fitted. It can be fixed only by processing, and there is no need for processing for winding or brazing in a furnace as in the past, so the manufacturing cost of the heat exchanger can be significantly reduced.

Furthermore, by interposing the heat exchanger 6 between the burner 7 and the exhaust section 8 and arranging them integrally, it is possible to equalize the hot air blowing temperature as a hot air fan, thereby improving comfort.

Effects of the Invention As is clear from the above explanation, the heat exchanger of the present invention includes: 1. A flow path regulating body is disposed on the downstream side of the heat exchanger body in which internal fins are formed in the axial direction of the inner surface, and this outer peripheral portion By disposing turbulent fluid between the internal fins of the combustion gas, the gas side heat transfer to the heat transfer surface is improved by promoting the turbulence of the combustion gas and increasing the flow velocity, and a high degree of thermal efficiency (coefficient of 93 or higher) can be achieved.

2. The structure reduces the heat receiving area on the upstream side of the heat exchanger body and promotes heat transfer on the downstream side, so it maintains thermal efficiency and prevents localized heat loss in the heat exchanger temperature.
The durability of the heat exchanger can be improved by maintaining a uniform temperature at a low temperature of 0°C.

3 By arranging every two pitches of the internal fins of the waver body consisting of folded pieces with multiple bends, high efficiency can be achieved by repeating the expansion and contraction flow of combustion gas and improving gas side heat transfer. . Furthermore, it has excellent workability and assemblability and can be manufactured at low cost.

4 By providing the crested cylindrical flow path regulating body protruding from the exhaust section, the high temperature combustion gas is uniformly guided to the heat transfer surface of the outer periphery of the flow channel regulating body, and the annular flow path in the exhaust section is This structure promotes turbulent flow and provides high thermal efficiency.

It has excellent effects such as:

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a conventional heat exchanger, Fig. 2 is a cross-sectional view taken along the line A-A' in Fig. 1, and Fig. 3 shows a heat exchanger according to an embodiment of the present invention with a hot air fan installed. 4 is a vertical sectional view of the heat exchanger, FIG. 5 is a sectional view taken along the line B-B' in FIG. 4, FIG. 6 is a perspective view of the ripple body of the heat exchanger, and FIG. The figure is a front view showing how the ripple elements are attached to the internal fins of the heat exchanger.0 6... Heat exchanger, 7... Burner, 8...
...Exhaust section, 9...Heat exchanger body, 10
...Internal fin, 12...External fin, 14...Flow path regulating body, 15...Wipple body, 16...Bending part . Name of agent Patent attorney Satoshi Nakao and 1 other person 1st
Figure Haha Figure 2 Figure 5 Figure 6

Claims (4)

[Claims] (1) A burner is integrally connected to one end of the heat exchanger body and an exhaust part is connected to the other end, and a means for exchanging heat with the high-temperature fluid is provided.
Between a plurality of internal fins arranged in the axial direction of the inner surface of the heat exchanger main body, a plurality of external fins provided in the circumferential direction of the outer peripheral surface, and an internal fin of the outer peripheral part of the flow path regulator on the downstream side of the heat exchanger main body. A heat exchanger equipped with a ripple element. (2) The heat exchanger according to claim 1, wherein the wave disrupting body is constituted by a bent piece having a plurality of bent parts. (3) The heat exchanger according to claim 1 or 2, wherein the ripple body is inserted from the fin end through the internal fins at every two pitches of the circumferential pitch of the internal fins. (4) The heat exchanger according to claim 1, wherein a capped intermediate cylinder is provided as a flow path regulating body so as to protrude from the exhaust portion.