Fluid agitating fin, method of fabricating the same and heat exchanger tube and heat exchanger or heat exchanging type gas cooling apparatus inwardly mounted with the fin
A fluid agitating plate fin is mounted to a heat exchanger tube to agitate a cooling fluid and to create a turbulent flow. Edges of the plate fins are opposed to each other and the opposed butted blade edges cross each other.
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1. Field of the Invention
The present invention relates to a structure of a fin for agitating a fluid in a heat exchanger, particularly, relates to a fluid agitating plate fin mounted to inside or outside of a heat exchanger tube in a heat changing type cooling apparatus and achieving an excellent heat exchanging function by increasing contact between a wall face of a heat exchanger tube and a fluid by bringing about an agitating operation of a turbulent flow or a vortex flow in the fluid comprising a cooled medium or a cooling medium flowing inside or outside of the heat exchanger tube, a method of fabricating the plate fin as well as a heat exchanger tube inwardly mounted with the plate fin and a heat exchanger or a heat exchanging type gas cooling apparatus constituted by being arranged with at least one piece of the heat exchanger tube.
2. Description of Related Art
In recent years, starting from an EGR cooler for recirculating exhaust gas of an automobile, there is frequently used a heat exchanger of various modes of fluids of liquid-liquid, liquid-gas, gas-gas and the like of a heat exchanger for recovering exhaust heat from exhaust gas, a fuel cooler, an oil cooler, an intercooler and the like, and inside of a heat exchanger tube in which the fluids flow is variously devised in order to efficiently radiate or absorb heat held by the fluids. For example, a method of taking out a portion of exhaust gas from an exhaust system of a diesel engine to return again to a suction system of the engine to be added to a mixture gas is referred to as EGR (Exhaust Gas Recirculation), there are achieved a number of effects of restraining generation of NOx (nitrogen oxide), reducing pump loss or reducing loss of heat radiated to a cooling solution in accordance with a temperature drop of combustion gas, increasing a specific heat ratio depending on change of an amount and a composition of a working gas, and increasing a cycle efficiency in accordance therewith and therefore, the method is widely adopted as an effective method for cleaning exhaust gas of the diesel engine and improving a heat efficiency thereof.
However, when a temperature of an EGR gas rises and an amount of the EGR gas is increased, durability of an EGR valve is deteriorated by heat operation thereof, there is brought about a concern of destructing the EGR valve at an early stage and therefore, a phenomenon of deteriorating fuel cost is brought about by reducing a charging efficiency in accordance with rise of a suction temperature such that it is necessary to constitute a water-cooled structure by providing a cooling system as a preventing measure thereagainst. In order to avoid such a situation, there is used an apparatus of cooling the EGR gas by a cooling solution of the engine, a cold medium or cooling wind for a car air conditioner, above all, there have been proposed a number of EGR gas cooling apparatus of a gas-liquid heat exchanging type for cooling the EGR gas constituting a gas by engine cooling water and as means for promoting the heat exchanging function, various modes of fins are inwardly mounted to a tube in which the EGR gas flows. For example, in a heat exchanger for exchanging heat between a gas and a liquid by arranging an outer tube for making the liquid flow on an outer side of an inner tube for making the gas flow, there are a double tube type heat exchanger [refer to, for example, JP-A-11-23181 (1 to 6 pages, FIGS. 1 and 2)] in which a metal corrugated plate is inserted into an inner tube as a fin, a double tube type heat exchanger [refer to, for example, JP-A-2000-111277 (1 to 12 pages, FIGS. 1 to 12)] constituted by an inner tube for making a cooled medium flow on an inner side, an outer tube provided to surround an outer periphery of the inner tube separately therefrom, and a heat radiating fin arranged at inside of the inner tube and having a thermal stress alleviating function, a double tube type heat exchanger [refer to, for example, JP-A-2003-21478 (1 to 8 pages, FIGS. 1 to 7)] constituted by an inner tube for making a cooled medium flow on an inner side, an outer tube provided to surround an outer periphery of the inner tube separately therefrom, and a cross fin arranged at inside of the inner tube and so on.
SUMMARY OF INVENTIONIn the above-described respective background arts, in cases of the EGR gas coolers of the doubletube type disclosed in JP-A-11-23181 (1 to 6 pages, FIGS. 1 and 2), JP-A-2000-111277 (1 to 12 pages, FIGS. 1 to 12), JP-A-2003-21478 (1 to 8 pages, FIGS. 1 to 7), although a corresponding result is expected in dividing the flow of the gas into slender streams to increase an area of being brought into contact with the fin by inwardly mounting the corrugated fin or the cross fin, an inner peripheral face of an inner face of a pipe constituting the EGR gas flow path is frequently smooth over a total length in a length direction, heat transfer at a vicinity of a center of the pipe becomes insufficient, further, the gas flow flows straight along the EGR gas pipe and therefore, there poses a problem that turbulent formation of the gas flow becomes insufficient, a boundary layer of a heat conducting face is not thinned sufficiently and the heat conducting function becomes more or less deficient.
Further, in recent times, in various heat exchanger tubes mounted not only to the EGR gas cooling apparatus but also other cooling apparatus of a heat exchange type including the EGR gas cooling apparatus, there have been proposed a number of fin structures for achieving a further increase in a heat exchange efficiency inwardly mounted to heat exchanger tubes as shown by
A fluid agitating plate fin according to a first aspect of the present invention to resolve the above-described problem is mounted to inside or outside of a heat exchanger tube for making a fluid comprising a cooled medium or a cooling medium flowing at the inside or the outside of the heat exchanger tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges are mounted to the inside or the outside of the heat exchanger tube to cross each other.
Further, the present invention is characterized in that the fluid agitating plate fins inwardly mounted into the heat exchanger tube to make the blade edges opposedly cross each other upward and downward may be worked respectively individually upward and downward in the fluid agitating plate fin.
Further, the present invention is characterized in that the fluid agitating plate fins inwardly mounted to the heat exchanger tube to make the blade edges opposedly cross each other upward and downward may be respectively simultaneously worked upward and downward at the plate material and inwardly mounted thereto by folding a center portion of the plate material in the fluid agitating plate fin.
Further, the present invention is characterized in that the fluid agitating plate fins inwardly mounted to the heat exchanger tube by making the blade edges opposedly cross each other upward and downward may be inwardly mounted thereto by overlapping the blade edges with a face pressure therebetween or inwardly mounted thereto with an interval between the respective blade edges in the fluid agitating plate fin.
Further, in the plate fin according to the present invention, it is preferable that when portions of the plate fins for making the blade edges opposedly cross each other upward and downward are predicted, the predicted portions of making the blade edges cross each other are previously formed with bonding portions of a notch, a recess and projection or the like, and the upward and the downward plate fins are integrally bonded by way of the bonding portions.
Further, a method of fabricating a fluid agitating plate fin according to a second aspect of the invention is characterized in a fluid agitating plate fin mounted to inside or outside of a heat exchanger tube for making a fluid comprising a cooled medium or a cooling medium flowing at the inside or the outside of the heat exchanger tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein by forming a plurality of predetermined notched portions at a plate material comprising a thin plate and raising remaining notched portions of the notched portions orthogonally to a surface of the plate material, a plurality of plate fins are formed at the surface of the plate material.
Further, the present invention is characterized in that means for forming the notched portion at the plate material is any of a mechanical working method of pressing or the like or a chemical working method by etching or the like or an optical method of a laser beam or the like in the method of fabricating the fluid agitating plate fin.
Further, a heat exchanger according to a third aspect of the present invention is characterized in being arranged with at least one piece of a heat exchanger tube mounted with a fluid agitating plate fin mounted to inside or outside of the heat exchanger tube for making a fluid comprising a cooled medium or a cooling medium flowing in the heat exchanger tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges cross each other.
Further, a heat exchange type gas cooling apparatus according to a fourth aspect of the present invention is a heat exchange type gas cooling apparatus constituted by being arranged with at least one piece or more of heat exchanger tubes which are intersected with a flow direction of a gas flowing in a gas pipe and in which a cooling medium flows and being mounted with a fluid agitating plate fin contiguous to an outer periphery of the heat exchanger tube, wherein the plate fins are mounted thereto such that blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges cross each other.
A heat exchanger tube according to a fifth aspect of the present invention is a heat exchanger tube constituted by being inwardly mounted with a fluid agitating plate fin for making a fluid comprising a cooled medium or a cooling medium flowing in a tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein the fluid agitating plate fins are inwardly mounted thereto such that blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges cross each other.
When the fluid agitating plate fin according to the present invention is mounted to the inside or the outside of the heat exchanger tube in which the cooled medium or the cooling medium flows, the blade edges of plate fins are butted to be opposed to each other upward and downward, the respective butted blade edges are integrated to cross each other and therefore, the fluid comprising a gas or a liquid flowing at the inside or the outside of the heat exchanger tube brings about the turbulent flow or the vortex flow by complicatedly agitating flowing lines thereof, the laminar flow is exfoliated and effective agitation is repeated. Therefore, the fluid flowing at the inside or the outside of the heat exchanger tube is repeatedly brought into contact with the wall face of the heat exchanger tube, heat exchange with the cooling medium or the cooled medium at the outer peripheral face of the heat exchanger tube is efficiently promoted and the excellent cooling efficiency is ensured. Further, according to the heat exchanger of the invention arranged with at least one piece of the heat exchanger tube according to the present invention inwardly mounted with the plate fin, the fluid flowing in the heat exchanger tube is repeatedly brought into contact with the wall face of the heat exchanger tube, heat exchange to the cooling medium at the outer peripheral face of the heat exchanger tube is efficiently promoted and the excellent cooling efficiency is ensured. Further, the method of fabricating the fluid agitating plate fin according to the present invention is by extremely simple working means of forming the plurality of plate fins at the surface of the plate material by forming the plurality of predetermined notched portions at the plate material comprising the thin plate and raising the remaining notched portions of the notched portions orthogonally to the surface of the plate material, in addition thereto, also in integrating the plate fin to the heat exchanger tube, the plate fin can easily be mounted inwardly not only to the flat heat exchanger tube but also a circular tube or a deformed tube and therefore, the plate fin can preferably be mounted as the fluid agitating plate fin mounted to the inside or the outside of the heat exchanger tube of not only the heat exchange type cooling apparatus but also a heat exchanger of a cooler for a fuel, an oil cooler, an intercooler or the like and at the same time, by the excellent heat exchange function and by forming the core by the plate fin per se, the plate fin contributes to solid formation of the apparatus to enable to constitute the small-sized and light-weighted formation, compact formation of the apparatus is realized and the apparatus can easily be installed in a limited space.
BRIEF DESCRIPTION OF DRAWINGS
Although embodiments of the invention will be explained further in details in reference to the attached drawings as follows, the invention is not constrained thereby. Further, a design can freely be changed within a range of the gist of the invention.
Embodiment 1 According to a fluid agitating plate fin 3 according to a first embodiment of the invention, as shown by
Although according to the fluid agitating plate fin 3 of the embodiment, heights of the fins butted to be opposed to each other upward and downward are formed respectively by the same height, the invention is not restricted thereby, and it is not hampered that the heights differ from each other as in heights h-1, h-2 of the upward and the downward fins as shown by
There is provided a fluid agitating plate fin 3a as shown by
A fluid agitating plate fin 3b is provided similar to Embodiment 1 except that a shape of the fluid agitating plate fin formed to a plate material is formed by bending a shape of a blade edge 4b in a longitudinal direction in place of the fluid agitating plate fins 3 and 3a provided by Embodiment 1 or Embodiment 2, and when a heat exchanger tube inwardly mounted with the fluid agitating fin 3b is constituted by using the fin 3b and is mounted to an EGR gas cooling apparatus to be subjected to a cooling test similar to Embodiment 1, it is confirmed that a cooling efficiency is further increased in comparison with that of Embodiment 1.
Embodiment 4 A fluid agitating plate fin is formed similar to Embodiment 2 except that in place of a constitution of folding to overlap the rectangular plate material at the center folding portion 1a-3 in the lateral width direction in Embodiment 2, a folding portion 1e-3 is provided to vertically divide a plate material 1e in a longitudinal direction thereof as shown by
[Other Application Examples]
Although means for fixedly attaching the fluid agitating plate fins provided in the respective embodiments based on the invention are arbitrary and not particularly restricted, for example, as shown by
An oil cooler 20 is constituted by providing an oil inlet 5e-5 and an oil outlet 5e-6 as shown by
Further, although in
As is apparent from the above-described respective embodiments as well as application examples thereof, the fluid agitating plate fin according to the invention is extremely facilitated in working the plate fin per se and the plate fin can easily be mounted inwardly not only to the flat heat exchanger tube but also the heat exchanger tube comprising a circular tube or other deformed tube. Further, by mounting the heat exchanger tube inwardly mounted with the fluid agitating plate fin provided by the invention, the cooling apparatus of the heat exchange type starting from the EGR gas cooling apparatus achieves an excellent cooling efficiency despite a simple structure thereof. Therefore, since the apparatus can be constituted by light-weighted and small-sized formation, the apparatus can flexibly deal not only with the EGR gas cooling apparatus for an automobile but also with a case in which object conditions of a cooled medium and a cooling medium are changed in viscosities or temperatures thereof as in converted into gas-gas, gas-liquid, liquid-liquid and wide use thereof can be expected such that the apparatus can be diverted sufficiently also as other gas cooling apparatus, or a cooling apparatus of a liquid of oil, fuel or the like.
Claims
1. A fluid agitating plate fin mounted to inside or outside of a heat exchanger tube for making a fluid comprising a cooled medium or a cooling medium flowing at the inside or the outside of the heat exchanger tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges are mounted to the inside or the outside of the heat exchanger tube to cross each other.
2. The fluid agitating plate fin according to claim 1, wherein a thin plate constituting the plate material is a thin plate made of a metal.
3. The fluid agitating plate fin according to claim 1, wherein the fluid agitating plate fins inwardly mounted into the heat exchanger tube to make the blade edges opposedly cross each other upward and downward are worked respectively individually upward and downward.
4. The fluid agitating plate fin according to claim 1, wherein the fluid agitating plate fins inwardly mounted to the heat exchanger tube to make the blade edges opposedly cross each other upward and downward are respectively simultaneously worked upward and downward at the plate material and inwardly mounted thereto by folding a center portion of the plate material.
5. The fluid agitating plate fin according to claim 1, wherein the fluid agitating plate fins inwardly mounted to the heat exchanger tube by making the blade edges opposedly cross each other upward and downward are inwardly mounted thereto by overlapping the blade edges with a face pressure therebetween or inwardly mounted thereto with an interval between the respective blade edges.
6. The fluid agitating plate fin according to claim 1, wherein when portions of the plate fins for making the blade edges opposedly cross each other upward and downward are predicted, the portions of making the blade edges cross each other are previously formed with bonding portions of a notch, a recess and projection or the like, and the upward and the downward plate fins are integrally bonded by way of the bonding portions.
7. The fluid agitating plate fin according to claim 1, wherein a shape of the blade edge of the plate fin may be a linear shape or a curved shape in a length direction and directions of crossing the plate fins may stay the same or may alternately be changed.
8. The fluid agitating plate fin according to claim 1, wherein that the heat transfer tube inwardly mounted with the plate fin is a flat tube, a circular tube or other deformed tube.
9. The fluid agitating plate fin according to claim 1, wherein that means for mounting the plate fin into the heat exchanger tube is pertinently selected from soldering, welding, adhering using an adhering agent and other bonding means.
10. A method of fabricating a fluid agitating plate fin wherein a fluid agitating plate fin mounted to inside or outside of a heat exchanger tube for making a fluid comprising a cooled medium or a cooling medium flowing at the inside or the outside of the heat exchanger tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein by forming a plurality of predetermined notched portions at a plate material comprising a thin plate and raising remaining notched portions of the notched portions orthogonally to a surface of the plate material, a plurality of plate fins are formed at the surface of the plate material.
11. The method of fabricating a fluid agitating plate fin according to claim 10, wherein means for forming the notched portion at the plate material is any of a mechanical working method of pressing or the like or a chemical working method by etching or the like or an optical method of a laser beam or the like.
12. A heat exchanger arranged with at least one piece of a heat exchanger tube mounted with a fluid agitating plate fin mounted to inside or outside of the heat exchanger tube for making a fluid comprising a cooled medium or a cooling medium flowing in the heat exchanger tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges cross each other.
13. A heat exchange type gas cooling apparatus constituted by being arranged with at least one piece or more of heat exchanger tubes which are intersected with a flow direction of a gas flowing in a gas pipe and in which a cooling medium flows and being mounted with a fluid agitating plate fin contiguous to an outer periphery of the heat exchanger tube, wherein the plate fins are mounted thereto such that blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges cross each other.
14. A heat exchanger tube constituted by being inwardly mounted with a fluid agitating plate fin for making a fluid comprising a cooled medium or a cooling medium flowing in a tube bring about an agitating operation of a turbulent flow or a vortex flow, wherein the fluid agitating plate fins are inwardly mounted thereto such that blade edges of the plate fins are butted to be opposed to each other upward and downward and the respective butted blade edges cross each other.
Type: Application
Filed: Jul 21, 2005
Publication Date: Jan 26, 2006
Applicant: Usui Kokusai Sangyo Kaisha Limited (Sunto-gun)
Inventors: Yasuaki Hashimoto (Izu-shi), Tadahiro Goto (Fuji-shi)
Application Number: 11/186,576
International Classification: F28F 13/12 (20060101);