JPH04190094A - Heat exchanger - Google Patents

Abstract

PURPOSE:To prevent the deformation of fins from the base parts thereof when substances such as sand grains and the like which are included in heat exchanging fluid are collided against pin-type fins at the fore part of the upstream side of a heat exchanger by a method wherein the sections in the bases of the fins at the fore parts of the upstream side of heat exchanging fluid are increased by forming them longer in the flow direction of the heat exchanging fluid than the sections of the other fins. CONSTITUTION:A plurality of fins 3 are arranged on a tube 1 in a plurality of rows along the flow direction of heat exchanging fluid. The section of pin type fins 3a at the fore part of the upstream side of heat exchanging fluid are formed so as to be rectangular shape and the sectional area of the same is increased than the sectional area of fins 3b at the downstream side of the heat exchanging fluid which are provided with same square or rectangular configuration. The long sides of the sections of the fins 3a at the fore part of the upstream side are positioned in the flow direction of the heat exchanging fluid substantially and are longer than the long sides of the downstream side fins 3b while the short sides of the sections are provided with the same length as the length of the short sides of the downstream side fins 3b substantially. According to this method, the fins 3a will never be deformed since the strength thereof is sufficiently high when substances such as sand grains and the like which are included in the heat exchanging fluid during the running of vehicles are collided against them whereby gaps between fins will never be clogged by the substances such as the sand grains and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a heat exchanger using fins, and particularly to a technique for preventing a decrease in heat transfer coefficient of the fins due to use.

(Prior Art) As a conventional heat exchanger, there is one as shown in the perspective view of FIG. That is, this heat exchanger has a plurality of pin-shaped fins 2 with a square or rectangular cross section erected on the outer wall as a heat transfer surface of a tube 1, and these fins 2 are connected to a heat exchange fluid indicated by an arrow. They are arranged in multiple rows along the flow direction.

(Problem to be Solved by the Invention) By the way, in order to increase the heat transfer area of the fins of a heat exchanger, it is sufficient to provide a large number of thin fins. It was elongated and had a square or rectangular cross section with sides of about 1 mm to 2 mm. Therefore, when this fin is used in a car's radiator, etc., when objects such as sand grains, tire debris, iron pieces, plastic, etc. hit the fin while the car is running, it will cause damage to the fin. It is relatively easy to deform from the base, and there is a possibility that objects such as sand grains can get into the gaps between the fins and cause clogging. As a result, the resistance of the heat exchange fluid increases, resulting in a decrease in the flow rate of the secondary fluid, resulting in a decrease in the heat transfer coefficient of the fins and, in turn, a problem in that the heat exchange performance decreases.

Therefore, it was considered to attach a fine mesh wire mesh to the front of the radiator to prevent objects such as sand grains from entering the radiator, but the wire mesh would instead act as a resistance to the heat exchange fluid, reducing the flow rate of the heat exchange fluid. Therefore, the expected improvement in heat exchange performance could not be obtained.

The present invention has been made in view of the above-mentioned points. When an object such as sand grains contained in a heat exchange fluid hits a fin while a vehicle is running, the fin does not deform from the base, and the gap between the fins is maintained. The purpose of the present invention is to provide a heat exchanger that can suppress clogging.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a heat transfer surface with a large number of pin-shaped fins protruding at predetermined intervals, and a flow that crosses the fins. A heat exchanger that exchanges heat with a heat exchange fluid, wherein a cross section at the base of at least a front fin on the upstream side of the heat exchange fluid among the plurality of fins is arranged so that the flow of the heat exchange fluid is higher than the cross section of the other fins. The structure is such that it is made longer and larger in the direction.

(Function) With the above configuration, even if objects such as sand grains contained in the heat exchange fluid hit the pin-shaped fins at the front of the upstream side, the cross-sectional area at the base of the fins is sufficiently large, so the fins will move away from the base. It will not be deformed.

(Example) Hereinafter, the present invention will be explained based on the drawings.

Note that the same reference numerals are used for the same configurations as those in the conventional example described above.

FIG. 1 is a perspective view showing an embodiment of a heat exchanger according to the present invention. In this figure, reference numeral 1 denotes a tube, and the tube has a plurality of fins 3 arranged in a plurality of rows along the flow direction of the heat exchange fluid, which is indicated by an arrow. The pin-shaped fins have a rectangular cross section of the upstream front fin 3a, and the cross section of the downstream fin 3b, which has the same shape as the conventional fin with a square or rectangular cross section, in order to increase strength. It is larger than the surface. Further, the long side of the front fin 3a on the upstream side is located generally in the flow direction of the heat exchange fluid and is longer than the side of the fin 3b on the downstream side, while the short side of the cross section is located downstream It is formed so that the side and length of the side fins 3b are approximately equal.

In such a configuration, even if an object such as sand particles contained in the heat exchange fluid hits the upstream front fin 3a while the vehicle is running, the strength of the fin is sufficiently large, so that the fin 3a
does not deform, so objects such as sand grains do not get stuck in the gaps between the fins.

FIG. 2 is a perspective view showing another embodiment of the heat exchanger according to the present invention. This figure differs from the embodiment in FIG. 1 only in the shape of the pin-shaped fin 4a at the front upstream side. That is, in FIGS. 1 and 2, the fin 4a of the embodiment shown in FIG. A notch inclined portion f is provided diagonally downward from portion d toward point e. In this way, the cross section of the fin 4a in FIG. 2 is equal to the cross section of the fin 3a in FIG. As a result, the cross section gradually decreases.

In such a configuration, when an object such as sand particles contained in the heat exchange fluid while the vehicle is running hits the fins 4a on the upstream front side, the cross section of the fins at the base is sufficiently large, so that the fins 4a are There is no deformation from the base. Therefore, clogging does not occur in the gaps between the fins, so the resistance of the heat exchange fluid does not increase and the flow rate does not decrease.

In addition, when an object such as a grain of sand hits the slope f of the fin 4a, the object such as the sand grain jumps diagonally upward, jumps over the fin 4a on the downstream side, and is extremely unlikely to remain between the fins. This also has the effect of reducing the impact force that the fins 4a receive.

Furthermore, in the embodiments of FIGS. 1 and 2, objects such as sand grains contained in the heat exchange fluid while the vehicle is running may hit the fins 3a, 4a on the upstream side, or the fins 3b on the downstream side. , 4b.

Moreover, the heat exchanger according to the embodiment of FIGS. 1 and 2 is
The bottle-shaped fins and the heat exchanger tube can be integrally molded, and these heat exchangers have a length of the side in the cross section of the fin at the upstream front part of the conventional heat exchanger described above. Since the upstream corner of the front fin tip of the upstream side is notched, it can be manufactured by almost the same process as the conventional heat exchanger described above.

[Effects of the Invention] As explained above, according to the present invention, when objects such as sand grains contained in the heat exchange fluid hit the pin-shaped fins at the upstream front part while the vehicle is running, the fins Since there is no deformation from the base, clogging between the fins can be suppressed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the heat exchanger according to the present invention, FIG. 2 is a perspective view showing another embodiment of the heat exchanger according to the present invention, and FIG. 3 is a perspective view showing a conventional heat exchanger. FIG. 4 is a perspective view showing a state in which the fins of a conventional heat exchanger are deformed when objects such as sand grains contained in the heat exchange fluid hit the fins of the conventional heat exchanger. 1...Tube 3m, 4a...Upstream side front fin 3b, 4b...Downstream side fin agent Patent attorney Hidekazu Miyoshi 1...Tube 3m, 4m...Upstream side front fin 3b, 4b...Downstream fin one piece / Figure 1 mountain ~ [Figure 2 + 1-')')-

Claims (1)

[Claims] A heat exchanger having a large number of pin-shaped fins protruding from a heat transfer surface at predetermined intervals and exchanging heat with a heat exchange fluid flowing across the fins, wherein at least one of the plurality of fins has a heat exchanger. A heat exchanger characterized in that the cross section at the base of the fin at the front part on the fluid upstream side is made longer and larger in the flow direction of the heat exchange fluid than the cross section of the other fins.