JPS6086389A - Heat exchanger - Google Patents

Abstract

PURPOSE:To reduce pressure loss as well as turbulence of flow in accordance with the change of flow amount of heat transfer fluid and prevent deterioration of heat transfer performance by a method wherein fins, whose deflecting amount is changed in accordance with the force in the flow direction of the heat transfer fluid, are formed on the heat transfer surface in the heat exchanger utilized for refrigerating machine or the like. CONSTITUTION:The heat transfer wall 1 of a heat exchanger is formed with the fins 2 on the upper side surface thereof by cutting work. These fins 2 are worked so as to reduce the thickness thereof from the ends 3 of roots to the tip ends 4 thereof gradually and they are deformed elastically by the force of the heat transfer fluid. When the flow amount of the heat transfer fluid is increased, the fins 2 are deflected toward the heat transfer wall surface 1 side, therefore, the flow resistance of the fluid is reduced and the pressure loss of the fluid is reduced. On the contrary, when the flow amount is decreased, the force of the fluid is weakened, the fins 2 are deflected so as to rise up from the heat transfer wall surface 1 side until the force of the fluid balances with the force due to the elasticity of the fins 2 and the resistance of the flow is increased, therefore, the degree of turbulence of the heat transfer fluid is not reduced and the deterioration of the heat transfer performance may be reduced.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is directed to a fluid that exchanges heat depending on the operating conditions of the machine (hereinafter referred to as a heat transfer fluid), such as a heat exchanger used in a refrigerator or other machine. This invention relates to an improvement in a heat exchanger that changes the flow rate of a heat exchanger.

(B) Conventional technology Conventionally, in a heat exchanger, by fixing fins on the heat transfer surface, the heat transfer area is increased, and the fixed fins disturb the flow of the heat transfer fluid to increase the heat transfer rate. Means are known for increasing the heat exchanger performance.

However, in such conventional means, since the fins are fixed, increasing the flow rate of the heat transfer fluid increases the pressure loss, and conversely, decreasing the flow rate reduces the effect of disturbing the flow. This has the disadvantage that heat transfer performance deteriorates.

(C) Purpose of the Invention The present invention is capable of reducing pressure loss when the flow rate of heat transfer fluid increases, and also reduces deterioration in heat transfer performance when the flow rate of heat transfer fluid decreases. The purpose is to provide a heat exchanger that can.

B) Structure of the invention The non-invention is that fins are formed on the surface (heat transfer surface) of heat transfer tubes, heat transfer plates, etc. that are the constituent members of a heat exchanger, and that the fins absorb the force in the flow direction of the heat transfer fluid. It is configured to flex according to the

In the heat exchanger of the present invention, when the flow rate of the heat transfer fluid is increased and the force in the flow direction becomes stronger, the fins become thicker in the flow direction (bending and the flow resistance decreases, so the fins are fixed). Compared to conventional heat exchangers, it has the advantage of reducing the pressure loss of the heat transfer fluid and reducing the power required to flow the heat transfer fluid into the heat exchanger.Conversely, it also reduces the flow rate of the heat transfer fluid. When the force in the flow direction becomes weaker, the deflection of the fins in the flow direction becomes smaller and the turbulence of the flow is promoted.
Compared to conventional heat exchangers, the reduction in heat transfer performance can be reduced.

(E) Embodiment FIG. 1 shows an embodiment of the heat exchanger of the present invention, and is a schematic configuration diagram in which a part of the heat transfer wall of the heat exchanger is enlarged. In Fig. 1, (1) is a heat transfer wall of a heat exchanger, and fins (21, (2)...) are formed by cutting on the upper surface of this heat transfer wall.These fins (2L (2) ... is processed so that its wall thickness gradually becomes thinner from the base end (3) to the tip (4), and is elastically deformed by the force of the heat transfer fluid flowing in the direction of the arrow. .

Note that (5), (5), . . . are depressions formed on the surface of the heat transfer wall (1) by cutting.

In a heat exchanger configured in this way, when the flow rate of the heat transfer fluid is increased, the force of the fluid in the direction of the arrow becomes stronger.
Depending on the force, the fins (2), (2)...
1) Since the fins (2) and (2
)... reduces the resistance to flow in the direction of the arrow, reducing fluid pressure loss. As a result, compared to conventional heat exchangers with fixed fins, the power required for pumps and blowers to flow the heat transfer fluid into the heat exchanger can be reduced.
It becomes possible to use a pump or blower with a small capacity. Conversely, when the flow rate is decreased, the force of the fluid in the direction of the arrow becomes weaker, and this weakened force and fins (2), (2)...
The fins (2), (2), etc. are bent to rise from the heat transfer wall (1) side until the elastic force of ・ is balanced, and the flow resistance increases, causing turbulence in the heat transfer fluid. The degree of heat transfer does not decrease as much as in conventional heat exchangers, and the decrease in heat transfer performance can be reduced compared to conventional heat exchangers. Note that the deflection angle a shown in Figure 1 represents the case where the flow rate of the heat transfer fluid is at a standard value, and the specific value of this a depends on the type of heat transfer fluid and the type of equipment using the heat exchanger. Alternatively, it is selected as appropriate depending on the specifications. Also, the specific value a of a when the heat transfer fluid is not flowing. are similarly selected as appropriate. for example,
In an example in which water is used as the heat transfer fluid and a heat exchanger is used in a refrigerator that has an operating condition of cooling load O to 100%, ao
It is preferable to set the value of 90°.

FIG. 2 shows another embodiment of the heat exchanger of the present invention, in which the same components as in FIG. 1 are given the same figure numbers. In this embodiment, a base (3) having a large number of tongue-shaped fins (2), (2), etc. is fixed to the upper surface of a heat transfer wall (1) by welding or adhesive. , the base body and the fins (2), (2)... are made of spring steel or other elastic material.

Moreover, FIG. 3 is a schematic structural explanatory diagram of a heat exchanger tube, which is a component of the heat exchanger of the present invention, and a portion thereof is cut away. Third
In the example shown in the figure, a heat transfer fluid whose flow rate changes in the direction of the arrow is flowed inside the heat transfer tube (6), and the amount of deflection changes depending on the force in the flow direction of the heat transfer fluid on the inner wall surface of the heat transfer tube (6). Fin (2)
, (2)... are formed.

(f) Effects of the Invention As described above, the heat exchanger of the present invention has fins formed on the heat transfer surface whose deflection amount changes depending on the force in the flow direction of the heat transfer fluid, so that the fins are not rigid. Compared to conventional heat exchangers installed in the heat exchanger, changes in pressure loss and flow turbulence due to changes in the flow rate of the heat transfer fluid can be reduced, reducing the power required to send the heat transfer fluid to the heat exchanger and reducing heat transfer. This makes it possible to prevent deterioration of the heat transfer performance of the exchanger, and has high practical value.

[Brief explanation of drawings]

1 to 3 are diagrams showing embodiments of the heat exchanger of the present invention, FIGS. 1 and 2 are enlarged schematic configuration diagrams of the main parts of the heat exchanger of the present invention, and FIG. FIG. 2 is a schematic configuration diagram with a part of the heat exchanger tube of the heat exchanger of the present invention cut away. (1)...Heat transfer wall, (2), (2)...Fin,
(6)...den MIF.

Claims (1)

[Claims] (1) A heat exchanger characterized in that fins are formed on the surface of a heat exchanger tube, a heat exchanger plate, etc., the amount of deflection of which changes depending on the force in the flow direction of the fluid.