Patent Publication Number: US-2006016582-A1

Title: 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

Description:
BACKGROUND OF THE INVENTION  
      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 INVENTION  
      In 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  FIGS. 16A  to  16 D for making a fluid mainly comprising a cooled medium flow bring about an agitating operation to achieve respective initially expected results. For example, in  FIG. 16A , by providing a number of projections  30  at an inner face of a flat heat exchanger tube  50 , a cooled medium g flowing in the tube is made to bring about a turbulent flow in accordance with an agitating operation to increase the heat exchanging function to a cooling medium at an outer peripheral face of the heat exchanger tube  50 . Further, in  FIG. 16B , there is constructed a constitution in which a wavy plate fin  30   a  is inwardly mounted to a flat heat exchanger tube  50   a , a cooled medium g flowing in the tube is meandered, in  FIG. 16C , a fin  30   b  in a spiral shape is inwardly mounted to a heat exchanger tube  50   b  in a cylindrical shape and a cooled medium g is swirled to bring about a vortex flow, in  FIG. 16D , by integrating a baffle  30   c  in a flat heat exchanger tube  50   c , a cooled medium g flowing in the heat exchanger tube  50   c  is forced to meander alternately to prolong a time period of staying in the tube to thereby promote an efficient heat exchange efficiency. Although the background arts are devised to promote an increase in the heat exchange efficiency by forcibly bringing about a turbulent flow or a vortex flow in the cooled medium flowing in the heat exchanger tube by forming recesses or projections or wrinkles directly on the inner face of the heat exchanger tube or inwardly mounting the plate fin or the baffle in various shapes thereto, whereas difficulties are required in working or attaching method thereof, the sufficient function cannot be achieved to pose a serious problem desired to improve further. It is a predetermined object of the invention to resolve the problem to provide a fluid agitating fin excellent in a cooling efficiency and capable of being easily integrated to heat exchanger tubes having different shapes despite that the fins are extremely simply worked and despite a simple structure, a method of fabricating the fin as well as a heat exchanger tube inwardly mounted with the fin, and a heat exchanger or a heat exchange type gas cooling apparatus arranged with at least one of the heat exchanger tube.  
      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  
       FIG. 1A  is a schematic partially enlarged perspective view for explaining a plate fin for agitating a fluid according to an embodiment of the invention, showing a state of providing a notched portion at a plate material of a thin plate by pressing or the like.  
       FIG. 1B  is a schematic partially enlarged perspective view for explaining the plate fin for agitating a fluid according to the embodiment of the invention and is a perspective view showing a state of forming a plurality of the plate fins by raising the notched portions orthogonally to a surface of the plate material.  
       FIG. 2  is a front view showing a state of inserting the plate fins provided by the embodiment into a flat heat exchanger tube by making the plate fins opposed to each other.  
       FIG. 3  is a partially enlarged plane view taken along a line A-A of  FIG. 2 .  
       FIG. 4  is a partially enlarged front view showing a state of inserting a plate fin provided by an application example based on the embodiment into a flat heat exchanger tube.  
       FIG. 5A  is a partially enlarged perspective view schematically showing a state of working a plate fin for agitating a fluid according to other embodiment of the invention, showing a state before being overlapped by butting blade edges thereof.  
       FIG. 5B  is a partially enlarged perspective view schematically showing a state of working the plate fin for agitating a fluid according to other embodiment of the invention and is a perspective view showing a state of overlapping the plate fins.  
       FIG. 6A  is a partially enlarged front view partially exemplifying a state of butting the blade edges of the plate fins for agitating a fluid according to an application example based on the embodiment, showing a state in which there is a gap between the blade edges.  
       FIG. 6B  is a partially enlarged front view partially exemplifying a state of butting the blade edges of the plate fins for agitating a fluid according to an application example based on the embodiment, showing a state in which there is not a gap between the blade edges.  
       FIG. 6C  is a partially enlarged front view partially exemplifying a state of butting blade edges of plate fins for agitating a fluid according to an application example based on the embodiment, showing a state of fitting integrally upward and downward by a projection provided at the blade edge.  
       FIG. 6D  is a partially enlarged front view partially exemplifying a state of butting the blade edges of the plate fins for agitating a fluid according to an application example based on the embodiment and a front view showing a state of fitting.  
       FIG. 7  is a partially enlarged perspective view schematically showing still other embodiment according to the invention.  
       FIG. 8  is a partially enlarged front view showing an example of attaching a plate fin according to the invention to a heat exchanger tube.  
       FIG. 9  is a partially enlarged perspective view of a plate fin for agitating a fluid according to still other embodiment of the invention.  
       FIG. 10A  is a partially enlarged perspective view schematically showing a plate fin for agitating a fluid according to still other embodiment of the invention, forming the plate fin in the same direction.  
       FIG. 10B  is a partially enlarged perspective view schematically showing a plate fin for agitating a fluid of still other embodiment according to the invention, and a perspective view showing a constitution formed by alternately crossing the plate fins.  
       FIG. 11  is a perspective view showing a state of inwardly mounting a plate fin for agitating a fluid of the invention to a flat heat exchanger tube and integrating a plurality of the heat exchanger tubes to an EGR cooler (shell and tubes type heat exchanger).  
       FIG. 12A  is a perspective view showing an oil cooler inwardly mounting a plate fin for agitating a fluid of the invention to a flat heat exchanger tube and using a single heat exchanger tube and schematically showing a state of the single heat exchanger tube before being integrated to a radiator bottom jacket.  
       FIG. 12B  is a side view showing the oil cooler inwardly mounting the plate fin for agitating a fluid of the invention to the flat heat exchanger tube and using the single heat exchanger tube and schematically showing a state of forming the oil cooler by integrating the single heat exchanger tube into the radiator bottom jacket.  
       FIG. 13  is a vertical side sectional view showing a state of mounting a plate fin for agitating a fluid to an outer peripheral face of a flat heat exchanger tube of an EGR gas cooling apparatus according to still other embodiment of the invention.  
       FIG. 14  is a horizontal front view of an EGR gas cooling apparatus according to the embodiment.  
       FIG. 15  is a partially broken perspective view showing an embodiment of integrating a plate fin according to the invention to a plate type heat exchanger.  
       FIG. 16A  is a schematic perspective view for explaining a heat exchanger tube inwardly mounted with an agitating fin structure of a prior art and is a view showing a flat heat exchanger tube formed with a projection at a wall face of the heat exchanger tube.  
       FIG. 16B  is a schematic perspective view for explaining a heat exchanger tube inwardly mounted with an agitating fin structure of a prior art and is a view showing a state of inwardly mounting a plate fin of a wavy type to a flat heat exchanger tube.  
       FIG. 16C  is a schematic perspective view for explaining a heat exchanger tube inwardly mounted with an agitating fin structure of a prior art and is a view showing a constitution of inwardly mounting a strip type fin spirally at an inner peripheral face of a circular heat exchanger tube.  
       FIG. 16D  is a schematic perspective view for explaining a heat exchanger tube inwardly mounted with an agitating fin structure of a prior art and is a perspective view showing a constitution for forming a baffle at an inner peripheral face of a flat heat exchanger tube. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
      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  FIG. 1 , thin plates comprising austenite species stainless steel of SUS 304, SUS 316 or the like having a thickness of about 0.1 through 0.5 mm are worked in a rectangular shape having a predetermined dimension to provide a plurality of plate materials, two sheets of the plate materials are pressed to form a plurality of notched portion  2  substantially in a channel-like shape having a predetermined dimension directions of which alternately differ as shown by  FIG. 1A . Next, remaining notched portions of the notched portion  2  are cut to be raised to be orthogonal to a surface of the plate member to provide a plate  1  formed with fluid agitating plate fins  3  directions of which differ alternately at respective rows and blade edge  4  of which are constituted by linear lines inclined to a longitudinal direction. Thereafter, by preparing two sheets of the provided plates  1  and butting the blade edge  4  of the plate fins  3  formed at the respective plates  1  to be respectively opposed to each other upward and downward to insert into a flat heat exchanger tube  5 , the flat heat exchanger tube  5  inwardly mounted with the fluid agitating fins  3  to overlap upward and downward as shown by  FIG. 2  is finished. There are prepared a plurality of the flat heat exchanger tubes formed by crossingly integrating the blade edges  4  of the plate fins  3  at inside of the heat exchanger tube  5  respectively upward and downward as shown by  FIG. 3  and bringing the blade edges into close contact with each other by extruding or pressing as needed, the plurality of flat heat exchanger tubes are integrated into a cooling jacket C constituting a gas flow path in an EGR gas cooling apparatus (shell and tubes type heat exchanger)  10  as shown by  FIG. 11  to be subjected to a cooling function test, as a result, it is confirmed that an EGR gas g at high temperature flowing in the heat exchanger tube  5   d  via a bonnet D- 1  is complicatedly agitated by operation of the inwardly mounted fluid agitating plate fins, a turbulent flow or a vortex flow is generated at a stream line of the gas g, all of laminar flows are exfoliated, heat exchange to the cooling jacket C at an outer periphery of the heat exchanger tube is effectively promoted, and the EGR gas g reaching a bonnet D- 2  on an outlet side is effectively cooled to an initial set temperature.  
      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  FIG. 4 . However, in this case, it is indispensable that a sum (h- 1 +h- 2 ) of the heights of the fins falls in a range of not exceeding an inner diameter h- 3  of a short diameter portion of the flat heat exchanger tube. Further, although according to the embodiment, as the plate material for forming the fin, the thin plate of the austenite species stainless steel is adopted, it is not hampered to select the material pertinently from other metal material so far as the material is material having a constant mechanical strength, excellent in heat resistance, corrosion resistance and heat conductivity and excellent in workability. Further, although the means for forming the notched portion  2  according to the embodiment efficiently forms the notched portion  2  by pressing, as a method of working to form the notched portion, the notched portion can also be machined mechanically, further, the notched portion can be formed by etching by chemical means in a solution corrosive for the plate material by providing a predetermined masking or can be formed optically by laser light ray or the like.  
     Embodiment 2  
      There is provided a fluid agitating plate fin  3   a  as shown by  FIG. 5B  similar to embodiment 1 except that a plate material constituted by connecting two sheets of the plate materials in Embodiment 1 in a longitudinal direction is prepared, predetermined notched portions are provided at plate materials on the left and on the right of a boundary of a center folding portion  1   a - 3 , a fluid agitating fin  3   a  as shown by  FIG. 5A  is formed after raising remaining notched portions of the outer notched portions, thereafter, the plate material is folded at the center folding portions  1   a - 3 , and respective blade edges  4   a  of the fluid agitating fins  3   a  formed at a plate  1  ( 1   a - 1 ) and a plate  2  ( 1   a - 2 ) are butted to be opposed to each other, a heat exchanger tube inwardly mounted with the plate fin  3   a  is finished similar to Embodiment 1 to be subjected to a cooling test by an EGR gas cooling apparatus (shell and tubes type heat exchanger) similar to Embodiment 1, as a result, it is confirmed that a cooling efficiency substantially equivalent to that of Embodiment 1 is achieved.  
     Embodiment 3  
      A fluid agitating plate fin  3   b  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  4   b  in a longitudinal direction in place of the fluid agitating plate fins  3  and  3   a  provided by Embodiment 1 or Embodiment 2, and when a heat exchanger tube inwardly mounted with the fluid agitating fin  3   b  is constituted by using the fin  3   b  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  1   a - 3  in the lateral width direction in Embodiment 2, a folding portion  1   e - 3  is provided to vertically divide a plate material  1   e  in a longitudinal direction thereof as shown by  FIG. 10A , and a shape of a blade edge  4   e  is directed in the same direction on the left and on the right to be subjected to a cooling test under a condition substantially the same as that of Embodiment 2, as a result, it is confirmed that a function equivalent to that of Embodiment 2 is achieved. Further, a fluid agitating fin shown in  FIG. 10B  is an application example of the embodiment, a fluid agitating plate fin is formed similar to Embodiment 4 except that fins  3   f  on the left side and on the right side are formed to cross alternately and is subjected to a cooling test under the same condition, as a result, a cooling function superior to that of the embodiment is confirmed.  
      [Other Application Examples] 
       FIG. 6  shows constitutions exemplifying states of blade edges of fluid agitating plate fins according to respective embodiments of the invention,  FIG. 5A  shows a constitution having a constant gap at the blade edge  4 , and  FIG. 5B  shows a constitution in which the blade edges  4  are butted to each other with a constant face pressure and brought into close contact with each other without a gap therebetween. When the same crossing portions are predicted beforehand at blade edges illustrated in  FIG. 5C  and  FIG. 5D , by previously providing predetermined bonding portions at the blade edges as in a projected portion  4   x  and a notch  4   y  shown in  FIG. 5C  and a projected portion  4   x - 1  and a notch  4   y - 1  shown in  FIG. 5D , when the blade edges are inwardly mounted into a heat exchanger tube or the like, the blade edges are integrated thereto integrally upward and downward via the bonding portion. Therefore, by forming a supporter (core) between plate fins formed by thin plates and between a plate fin and a heat exchanger tube forming an outer frame, rigidity (solidity) is promoted, a reinforcement member is not needed, which contributes to small-sized and light-weighted formation of the apparatus as a whole.  
       FIG. 7  shows a state of inwardly mounting a fluid agitating plate fin  3   b  of the invention to a heat exchanger tube  5   b  comprising a circular tube, the plate fin  3   b  according to the example is inwardly mounted thereto by rounding, for example, the plate  1  provided in Embodiment 1 to insert thereinto, by inserting at least two sheets of the plates  1  and inwardly mounting the plates  1  thereinto by butting the blade edges  4   b  of the plate fins  3   b  to be opposed to each other to cross each other, even in the circular heat exchanger tube, a heat exchanging function equivalent to that of the flat heat exchanger tube in Embodiment 1 can be achieved.  
      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  FIG. 8 , means for attaching the plate fins to a flat heat exchanger tube  5   c  can pertinently be embodied by means of soldering, welding and adhering by an adhering agent and the like with respect to the bonding portions  6  and the  6 - 1 . Further, although in the above-described respective embodiments according to the invention, only the EGR gas constituting a cooled medium is exemplified as a fluid flowing in the heat exchanger tube, in other embodiments, as shown by, for example,  FIG. 13  and  FIG. 14 , cooling water constituting a cooling medium can be made to flow in a heat exchanger tube  5   f  and an outer side of the heat exchanger tube  5   f  can also be made to constitute a flow path g of a gas constituting a cooled medium, in this case, heat of the EGR gas brought into contact with an outer peripheral face of the heat exchanger tube  5   f  can be efficiently subjected to heat exchange by bringing about a turbulent flow or a vortex flow in the EGR gas flowing over an outer peripheral face of the heat exchanger tube  5   f.    
      An oil cooler  20  is constituted by providing an oil inlet  5   e - 5  and an oil outlet  5   e - 6  as shown by  FIG. 12A  to, for example, a single member  5   e  of a flat heat exchanger tube inwardly mounted with the fluid agitating plate fins provided by the above-described respective embodiments based on the invention, attaching side lids  5   e - 1  and  5   e - 2  at opening portions on both sides thereof, closing the opening portions by calking or welding or the like and dipping and fixing a total thereof in a radiator bottom jacket  6  as shown by  FIG. 12B  by soldering. It is confirmed that oil at high temperature constituting a cooled medium flowing from the oil inlet  5   e - 5  provided at the flat heat exchanger tube single member  5   e  is agitated by a plurality of fluid agitating fins  3   g  inwardly mounted to the flat single heat exchanger tube  5   e  and repeatedly brought into contact with a wall face of the heat exchanger tube  5   e  by bringing about a turbulent flow or a vortex flow, heat thereof is effectively exchanged to cooling water C constituting a cooling medium at an outer peripheral face of the heat exchanger tube and when the oil flows out from the oil outlet  5   e - 6 , the oil is cooled substantially to an initial set temperature.  
      Further, although in  FIG. 5  in Embodiment 2 and  FIG. 10  in Embodiment 5, directions of the notched portions are made to be symmetric on the left and on the right of the center folding portions  1   a - 3  and  1   e - 3 , the directions may be the same and the direction of cutting to raise the fin may be any direction.  
       FIG. 15  shows a state of inwardly mounting a fluid agitating plate fin  3   h  to a plate type heat exchanger  40  as still other application product based on the invention, according to the example, the fluid agitating fin  3   h  according to the invention is inwardly mounted between flat plates  40 - 3  partitioning a ceiling plate  40 - 4  and a bottom plate  40 - 5  by a plural number, it is confirmed thereby that a vortex flow or a turbulent flow is brought about at both of a gas g constituting the cooled medium flowing between the flat plates  40 - 3  and cooling water C constituting the cooling medium, heat exchange by way of the flat plates  40 - 3  is effectively promoted and an excellent cooling efficiency can be realized, in addition thereto, it is verified that the fluid agitating fin  3   h  forms a core between the ceiling plate  40 - 4  or the bottom plate  40 - 5  and the flat plate  40 - 3  or between the flat plates  40 - 3  to contribute to solid formation of the apparatus and small-sized and the light-weighted formation of the heat exchanger main body  40  is realized.  
      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.