JPS5949447A - Heat exchanger for combustion equipment - Google Patents

Abstract

PURPOSE:To effect an effective heat exchange and reduce the resistance of the flow of heat medium by a method wherein an endothermic body, provided with a multitude of fins in parallel, is constituted so that each fins are received between opposing fins and high-temperature gas flows through a path between the fins under meandering between the endothermic bodies. CONSTITUTION:The flat plate-like endothermic body 2 is arranged with a multitude of fins 3 in parallel on the surface thereof while the heat exchanger is constituted by locating the endothermic bodies 2 so that the fins 3 thereof are being opposed and located alternately. Curved parts 7 are constituted by the fins 3 and the endothermic bodies 2. The high-temperature gas 8, which is another heat medium supplied from a high-temperature gas supplying part 5 into the main frame 1 of the heat exchanger, passes through a high-temperature gas path 9 constituted by clearances between the fins 3, 3. Thereafter, the gas 8 collides against the surface of the endothermic body 2, turns the flow direction thereof by substantially 360 degrees, passes again through the high-temperature gas path 9 at the downstream of the high-temperature gas 8 and is discharged from a discharging part 6.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat exchanger for combustion equipment that exchanges heat of high-temperature combustion gas as a heat source with water or other liquid such as C and is used as a water heater or space heater. It is related to.

2. Description of the Related Art Conventional Structures and Problems Conventionally, Finnish heat exchangers have been widely used in combustion equipment as heat exchangers between liquids such as water and gases. This heat exchanger has a larger heat transfer area than the fin VC, and even when a heat medium that is difficult to transfer heat, such as gas, passes over the fin surface, it can exchange a large amount of heat (j1), making it compact as a heat exchanger. It was characterized by being able to

On the other hand, in this type of heat exchanger, a heat medium flows between the fins, and in order to increase the heat transfer area, a method has been adopted in which the fin gaps are narrowed. As a result, a temperature boundary layer develops in the heat medium flowing between the fins, making it difficult to exchange heat effectively.
7 ((There was a tendency to become vc.

Purpose of the Invention JII provides a heat exchanger for combustion equipment that prevents the development of the aforementioned boundary layer, improves Cζ to effectively exchange heat, and further reduces resistance to the flow of heat medium. It is something.

Structure of the Invention The heat exchanger of the present invention has a large number of fins arranged in parallel V? c; The provided heat absorber is constructed so that each fin fits between the fins facing each other, and the high temperature gas passage constructed between the fins is constructed with a high R21,
The gas flows in a meandering manner between the heat absorbers. In order to prevent the development of a boundary layer of the heat medium passing through the hot gas passage, the heat medium is disturbed by colliding with the heat medium f). In order to make the disturbance effect more effective, the curved part that constitutes the collision part is made wider than the high-temperature gas passage. Additionally, the fin base and tip have a smooth shape to reduce ventilation resistance in this area. Furthermore, a fin #I paddle protrusion was provided to prevent the heat medium from slipping off at the tip of the fin.

Description of Examples In Fig. 1, 1 is a heat exchanger body, 2 is a heat absorbing body constituting the heat exchanger body, 3 is a fin provided on the heat absorbing body, and 4 is a heat absorbing body provided on the heat absorbing body. It is a heat absorbing tube. This heat exchanger transfers heat from the high-temperature gas, which is one heat medium, passing through the fin surface to the fin surface, through the fin interior, the heat absorbing body, and the heat absorbing tube, and from the surface of the heat absorbing tube, the heat is transferred from the other heat medium, which is a low temperature gas. It exchanges heat with the liquid. Reference numerals 6 and 6 are a high-humidity gas supply section and an exhaust section, respectively.

A large number of twins 3 are arranged in parallel on the surface of a heat absorbing body 20 configured in a flat plate shape, and the portions of the heat absorbing body 2 provided with fins face each other so that the facing fins are located on the paternal side. 1. The fins 3 and the heat absorbing body 2 constitute a bent portion 7.

High-temperature gas 8I1., which is one heat medium, is supplied from the high-temperature gas supply section 6 to the heat exchanger main body. It passes through a high-temperature gas passage 9 formed by a gap between L fins. After that, it collides with the surface of the heat absorbing body 2, turns into a circle with a flow direction change angle of approximately 360 degrees, passes through the high temperature gas passage 9 downstream of the high temperature gas, and is emitted from the exhaust part 6 while meandering. . , as shown in FIG. 2, at this time, the high temperature gas passage 10 between the fins.

If rb t' is made small, the flow velocity of the high temperature gas 8 increases and the amount of heat exchange tends to increase, but if it is too small, dirt, scale, etc. will stick to the passage and obstruct the flow of the high temperature gas 8. 1.Ma/ko, fin length 12 (il-dog) If you listen closely, the heat transfer area of the fin is large, and the amount of heat transferred from the high temperature gas 8 to the fin is large.On the other hand, as the fin becomes longer, the fin As the temperature rises, the thickness of the fin is increased to prevent the temperature of the fin from rising to -.Furthermore, even if the plate 1.7 is thin, it still effectively transmits heat, so the fin becomes the tip. The thickness of the board is 1'/total thickness is 2.

FIG. 3 shows the temperature distribution of the high temperature gas 8 flowing between the fins. As it passes between the fins, the gradient of temperature T near the fin wall gradually becomes smoother in the order of A, B, and C. In other words, a temperature boundary layer develops near the fins. Before it is completely developed, it collides with the collision part 13 of the heat absorber 2, and the temperature boundary layer is destroyed by the disturbance of the high temperature gas. Thereafter, the high-temperature gas flows while creating a temperature boundary layer with E and F, and collides again with the fat protrusion 13' of the heat absorbing body. As a result, the number of heat transfer claws at the collision portions 13 and 13' increases, and since there is little development of a temperature boundary layer between the fins after the collision, the heat transfer of the high-temperature gas is large. Bend 70 Passage 11J near this visit
t is larger than the width t' of the high-temperature gas passage 10, and the high-temperature gas is agitated by 47, which is ejected from [1] t' of the narrow high-temperature gas passage 10 into the curved part of the wide space. . By making the fin base 16 and the fin tip 16 curved, high temperature forces can be reduced.

Smooth the curve, and add 1, f' at the 15th part of the fin tip.
By preventing f4 gas from peeling off and at the same time making the first part of the fin curve +lii, retention of high temperature gas at the fin base 16 is prevented.

The hot gas passage 10rl]t' preferably has the same length from one turn to the next turn downstream of the hot gas. This is because when [1] spreads in the downstream direction, the high temperature horn flow breaks off on the fin surface, and the heat exchanger itself becomes stiff.

On the contrary, as 1] becomes narrower, the resistance of the high-retention force increases. Heat from the high-temperature gas 8 to the fins 3 (conducts inside the fin, is transferred to a low-temperature liquid such as water, and is used as a heat source for hot water supply or space heating; it I>).

As shown in FIG. 2, minute protrusions 18 are provided on the fin surface parallel to the heat absorbing body 2 and perpendicular to the flow direction of the high temperature gas. This protrusion 18 increases the amount of heat transfer on the fin surface. This protrusion 18 prevents the high-pressure gas flow from blowing up on the fin surface.

Effects of the Invention In the present invention, the temperature boundary layer of high-temperature gas is destroyed, and jπ
A highly efficient heat exchanger can be obtained by preventing the development of an interfacial layer and also by preventing the generation of a circulating flow of high-temperature gas.

4. Explanation of drawings 1. FIG. 1 is a partial cross-sectional perspective view of a heat exchanger according to one practical example of the present invention, FIG. 2 is a detailed view of the main part of FIG. 1, and FIG. It is a functional explanatory diagram of the invention.

1... Heat exchanger body, 3... Fin, 7
...Bent part, 9...High humidity gas passage, 16.
...Fin tip part, 16...Fin base.

Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (2)

[Claims] (1) A heat absorbing body having a large number of parallel fins on a flat plate is opposed to each other so that the fins are alternately positioned to form a high temperature gas passage, and a heat medium passage for exchanging heat with the high temperature gas is formed in the heat absorbing body. , the fin is made gradually thinner in the direction of the tip, and the curved part and the tip are curved surfaces without corners, and the curved part consisting of the base and tip g1t of the fin is wider than the gap between the fins. Heat exchanger for combustion equipment. (2) The heat exchanger for combustion equipment according to claim 1, wherein minute protrusions are provided on the wall surface of the high-temperature gas passage at right angles to the gas flow direction.