Patent Publication Number: US-2013230735-A1

Title: Method for producing a channel arrangement, a channel arrangement, use of a channel arrangement and a metal profile

Description:
FIELD OF THE INVENTION 
     The present invention relates to a method for producing a channel arrangement. The method comprises the steps a) arranging a first metal profile towards a second metal profile, said first metal profile comprises elongated trench-like portions mutually separated by flat portions, and b) joining the first metal profile to the second metal profile so that channels between these profiles are defined, which channels extend according to said trench-like portions, said channels being separated by flat regions. 
     Furthermore, the present invention relates to a channel arrangement, use of a channel arrangement and a metal profile. 
     PRIOR ART 
     A channel arrangement in here defined to comprise two or more channels separated by flat regions. The channel arrangement comprises preferably a material with high thermal conductivity, such as copper, aluminum, etcetera, wherein the flat regions are adapted to conduct heat to or from the channels. The channels are adapted to conduct a fluid, such as a cooling medium or a heat medium. Accordingly, the channel arrangement is adapted to absorb heat or radiate heat. 
     Such channel arrangements are used as heat exchangers in various technical applications, such as heat radiators in engines, computers, etcetera, and heat absorbers, such as in solar absorbers, etcetera. 
     The channels must have a material thickness that provides sufficient strength to maintain a certain pressure of the fluid within the channels. The flat regions between the channels must have a thickness that provides sufficient heat conduction rate to or from the channels. In most situations the desired pressure of the fluid within the channels requires a higher material thickness than the necessary material thickness of the flat regions. 
     Accordingly, a channel arrangement configured with higher material thickness of the channels than the material thickness of the flat regions provides a reduced material consumption for the channel arrangement with negligible reduction in performance when used in a heat exchanger. Furthermore, such channel arrangement has reduced weight. 
     In order to produce channel arrangement with complex geometry, such as channel arrangement where the material thickness of the channels is higher than the material thickness of the flat regions, extrusion is used. However, extrusion of channel arrangement is only possible for certain metals. For example, copper and copper alloys are difficult to extrude. Furthermore, the production rate by extruding channel arrangement may be insufficiently low for some metals. 
     In order to facilitate the manufacturing of channel arrangements of various types of metals a first metal profile and a second metal profile are used. The metal profiles are joined together by various joining methods, such as welding, rolling, etcetera. 
     A problem with manufacturing channel arrangement from the first and the second metal profile is that the material thickness of the channels is the same as the material thickness of the flat regions. Thereby, the channel arrangement is not using the material of the metal profiles optimally, which adds cost and weight to the channel arrangement. 
     EP1894660 discloses a method for manufacturing a channel arrangement by means of clad-rolling a first metal profile towards a second metal profile. Although their method is favorable and reliable, the manufactured channel arrangement is configured so that the material thickness of the channels is the same as the material thickness of the flat regions. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a method for producing a channel arrangement being improved in at least some aspect with respect to such methods already known. The object of the present invention is furthermore to provide an improved channel arrangement, use of the channel arrangement and an improved metal profile adapted to be manufactured into a channel arrangement. 
     This object is obtained by a method as defined by the preamble of claim  1 , wherein the method is characterized by using in step a) as at least one of said profiles a profile comprising an incipient cut to be located in at least one said flat region, and by comprising a further step c) carried out after step b) of removing material from said at least one flat region by means of said incipient cut, so that the thickness of at least a part of said at least one flat region becomes less than the sum of the thicknesses of the first and the second metal profile. 
     The incipient cut is adapted to enable a removal of the material from said at least one flat region. Thereby, the material thickness of said at least one flat region is reduced while the material thickness of the channels are maintained. Accordingly, the method enables a channel arrangement to be produced with reduced material consumption. Furthermore, the weight of the manufactured channel arrangement is reduced. 
     The term “incipient cut” refers to an arranged weakening in the strength of the material of the metal profile as compared with the strength of the remaining part of the metal profile. Thereby, the incipient cut is adapted to enable material to be removed from the at least one flat region. 
     According to one embodiment of the invention, said incipient cut at least partly encloses the material to be removed. Thereby enabling the at least partly encloses the material to be removed. 
     According to one embodiment of the invention, said incipient cut extends along one of the elongated trench-like portions. Thereby, a large part of said at least one flat region is adapted to be removed. 
     According to one embodiment of the invention, said incipient cut forms at least one loop, wherein material located within the loop is adapted to be removed by means of the incipient cut. By means of the loop formed incipient cut a part of the material between a first side and a second side of the metal profile may be removed. Furthermore, the loop formed incipient cut may be arranged in a complex form that forms a complex remaining pattern on said at least one flat region. 
     According to one embodiment of the invention, the loop formed incipient cut is arranged to form a recession in the at least one flat region, which recession is arranged to accommodate the reception a fin structure for absorbing or radiate heat. The recession facilitates positioning of the fin structure on said at least one flat region. 
     According to one embodiment of the invention, said incipient cut intrudes a certain depth into the thickness of one of the first and the second metal profile, which depth is less than the thickness of the one of the first and the second metal profile along which the incipient cut extends. The intruding depth of the incipient cut is arranged so that the metal profile with the incipient cut is allowed to be handled and joined towards another metal profile without that the material at the incipient cut breaks and forms an edge. 
     According to one embodiment of the invention, said incipient cut intrudes from a top side and a lower side into the thickness of one of the first and the second metal profile. 
     According to one embodiment of the invention, an intruding part of the incipient cut, which intruding part intrudes the certain depth into the thickness of one of the first and the second metal profile, is provided intermittent along the extent of said incipient cut. 
     According to one embodiment of the invention, said intruding part intrudes fully through the thickness of one of the first and the second metal profile, wherein the intruding part is provided intermittent along the extent of said incipient cut. 
     According to one embodiment of the invention, the step c) comprises gripping a part of the material to be removed and pulling that part of the material in a direction along which the incipient cut extends. Accordingly, the incipient cut is adapted to allow the material at the incipient cut to break and form an edge when the material to be removed is being pulled. 
     According to one embodiment of the invention, said incipient cut is arranged on one of the first and the second metal profile. 
     According to one embodiment of the invention, wherein the first metal profile is joined to the second metal profile while forming a plurality of joints in said flat regions and said at least one flat region comprises a first joint adjacent to one of two adjacent channels and a second joint adjacent to the other of the two channels, wherein said incipient cut is adapted to be located between the first and the second joint. Accordingly, the incipient cut is arranged so that first and the second joint is maintained unaffected when removing the material from the at least one flat region. 
     According to one embodiment of the invention, the incipient cut is arranged at a distance from the first and the second joint so that the integrity of the joints are maintained when removing the material from the at least one flat region. 
     According to one embodiment of the invention, wherein the joining of the first metal profile to the second metal profile comprises clad-rolling the flat portions of the first metal profile towards the second metal profile. By means of clad-rolling the metal profiles are joined together in an efficient and costeffective manner. 
     According to one embodiment of the invention, wherein the second metal profile comprises a flat portion adapted to form said flat region. 
     According to one embodiment of the invention, wherein the second metal profile has a form corresponding to that of the first metal profile. The expression “a form corresponding to” refers to that the form of the second metal profile is substantially the same as the form of the first metal profile, and regardless if the second profile is provided with the incipient cut or not. 
     The object is further obtained by a channel arrangement according to the preamble of claim  11 . The channel arrangement is characterized in that at least a part of one said flat region of the channel arrangement has a thickness being less than the sum of the thicknesses of the first and second metal profile by having material removed from one of the profiles on that location. Thereby, the material consumption and the weight of the channel arrangement are reduced in comparison to prior art channel arrangement. 
     According to one embodiment of the invention, said one flat region comprises a first joint adjacent to one of two adjacent channels and a second joint adjacent to the other of the two channels, wherein the arrangement comprises an edge between the first and the second joint, which edge was formed when removing material located at least partly enclosed by an incipient cut. 
     According to one embodiment of the invention, the first and the second metal profile consist of metal with high thermal conductivity. Preferably, the first and the second metal profile consist of copper or aluminum, or alloys thereof. By means of using a metal with high thermal conductivity in the metal profiles the heat conduction rate between the channels and the flat regions are high, which improves the efficiency when the channel arrangement is used in a heat exchanger. 
     According to one embodiment of the invention, the first and the second metal profile is adapted to form channels with circular cross section. The circular cross section of the channels enables a high pressure of the fluid to be conducted therein. 
     According to one embodiment of the invention, the material thickness of each of the first and the second metal profile is less than 1 mm, preferably less than 0.7 mm. 
     According to one embodiment of the invention, the material thickness of each of the first and the second metal profile is more than 0.3 mm, preferably more than 0.5 mm. 
     According to one embodiment of the invention, the first and the second metal profile is adapted to form channels with a cross section of less than 10 mm 2 , preferably less than 7 mm 2 . 
     According to one embodiment of the invention, the first and the second metal profile is adapted to form channels with a cross section of more than 3 mm 2 , preferably more than 5 mm 2 . 
     The object is further obtained by the use of a channel arrangement for conducting fluid in said channels thereof. According to one embodiment of the invention, the channel arrangement is used in a solar absorber. 
     The object is further obtained by a metal profile according to the preamble of claim  15 , wherein one of said metal profiles comprises an incipient cut in at least one said flat portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be explained more closely by the description of different embodiments of the invention and with reference to the appended figures. 
         FIG. 1   a  shows a metal profile comprising two incipient cuts. 
         FIG. 1   b  shows a detail view of the incipient cut in the encircled area of  FIG. 1   a.    
         FIG. 1   c  shows a metal profile comprising an incipient cut. 
         FIG. 2   a  shows a channel arrangement comprising a first and a second metal profile arranged toward each other and joined together. 
         FIG. 2   b  shows a channel arrangement comprising a first and a second metal profile arranged toward each other and joined together. 
         FIG. 2   c  shows a channel arrangement comprising a first and a second metal profile arranged toward each other and joined together. 
         FIG. 3   a  shows the channel arrangement in  FIG. 2   a  having had material removed from the first metal profile. 
         FIG. 3   b  shows the channel arrangement in  FIG. 2   b  having had material removed from the first metal profile. 
         FIG. 3   c  shows the channel arrangement in  FIG. 2   c  having had material removed from the first metal profile. 
         FIG. 4  shows rolling mill for manufacturing a channel arrangement. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
       FIG. 1   a  shows a metal profile  1  seen from a side view. The metal profile  1  comprises two elongated trench-like portions  3  and three flat portions  5 . 
     Each of the trench-like portions  3  comprises a longitudinal axis L. The flat portions  5  are located next to each side of the trench-like portions  3 . The flat portions  5  extend along the longitudinal axis L of the trench-like portions  3 . 
     One of the flat portions  5  is located between the two adjacent trench-like portions  3  and comprises a first incipient cut  10   a  and a second incipient cut  10   b . The other two flat portions  5  are located on the opposite side of the respective trench-like portions  3 . 
     The metal profile  1  has preferably been formed from a flat metal sheet. The thickness of the metal profile  1  is substantially uniform. Accordingly, the material thickness of the trench-like portions  3  and the flat portions  5  are essentially the same. 
     The metal profile  1  comprises four sides. The trench-like portions  3  extends from a first side S 1  to a second side S 2 . The longitudinal axis of the trench-like portions  3  is perpendicular to the first side S 1  and the second side S 2 , and parallel with a third side S 3  and a fourth side S 4  of the metal profile  1 . In an embodiment the trench-like portions  3  extend a longer distance in comparison to the length of first side S 1  and the second side S 2 . 
       FIG. 1   b  shows a detail view of the first incipient cut  10   a  in the encircled area of  FIG. 1   a . The first incipient cut  10   a  intrudes a certain depth laterally into the metal profile  1 . The intruding depth is less than the thickness of the metal profile  1 . 
     The incipient cut  10   a ,  10   b  provides a weakening in the metal profile  1  that enables material between the first incipient cut  10   a  and the second incipient cut  10   b  to be removed. Upon removal of the material between the first incipient cut  10   a  and the second incipient cut  10   b  an edge is adapted to be formed, which edge extends along the length of the first incipient cut  10   a  and the second incipient cut  10   b.    
       FIG. 1   c  shows a side view of a metal profile  1  having the same form as the metal profile  1  in  FIG. 1   a . The metal profile  1  comprises an incipient cut  10   c  located in the flat portion between the two trench-like portions  3 . The incipient cut  10   c  extends in a loop, wherein material enclosed within the incipient cut  10   c  is adapted to be removed. 
     The incipient cut  10   c  provides a weakening in the metal profile  1  that enables material enclosed by the incipient cut  10   c  to be removed. Upon removal of the material enclosed by the incipient cut  10   c  an edge is adapted to be formed, which edge extends along the length of the incipient cut  10   c.    
     According to an embodiment of the invention the metal profile  1  comprises one or more loop formed incipient cuts  10   c  at the flat portions  5  of the metal profile  1 . The one or more loop formed incipient cuts  10   c  enables one or more of the enclosed material to be removed. 
     The metal profile  1  in  FIG. 1   a - 1   c  are adapted to be arranged towards and joined to another metal profile  1 , and thereby forming a channel arrangement with channels defined between the two metal profiles  1 . The material at least partly enclosed between the incipient cuts  10   a ,  10   b ,  10   c  is adapted to be removed. The flat portions  5  of the metal profile  1  and the other metal profile  1  are adapted to form flat regions. The channels of the channel arrangement are adapted to conduct a fluid. The flat regions of the channel arrangement are adapted to conduct heat to or from the channels. 
     It shall be understood that the metal profiles  1  in  FIG. 1   a - 1   c  are not restricted to two trench-like portions  3  but the metal profiles  1  may comprise any number in plurality of trench-like portions  3  that are mutually separated by flat portions  5 . Accordingly, it is possible to produce a channel arrangement comprising a large number of channels. Furthermore, it shall be understood that one or more of the flat portions  5  comprises the incipient cut  10   a ,  10   b ,  10   c  that enables removal of material. 
       FIG. 2   a  shows a channel arrangement  20  comprising a first metal profile  1   a  and a second metal profile  1   b  arranged toward each other and joined together. 
     The first metal profile  1   a  and the second metal profile  1   b  have the form of the metal profile  1  disclosed in  FIGS. 1   a  and  1   b . Accordingly, the profiles  1   a ,  1   b  comprises the plurality of trench-like portions  3  and plurality of flat regions  21 . 
     The first metal profile  1   a  comprises the first incipient cut  10   a  and the second incipient cut  10   b  located in the flat region  21  between the two trench-like ridges  3 . The second metal profile  1   b  lacks incipient cut. 
     The first metal profile  1   a  and the second metal profile  1   b  have been arranged so that the flat portions  5  of the first metal profile  1   a  and the second metal profile  1   b  abut each other and so that the trench-like portions  3  are directed in opposite directions, wherein the profiles  1   a ,  1   b  defines a first channel  22   a  and a second channel  22   b  between the profiles. The channels  22   a ,  22   b  are adapted to conduct a fluid. 
     The channel arrangement  20  comprises a plurality of joints  24  located in the flat regions  21  between the first metal profile  1   a  and the second metal profile  1   b . The joints  24  are arranged adjacent to each side of the channels  22   a ,  22   b.    
     The joints  24  are adapted to hold the first metal profile  1   a  and the second metal profile  1   b  together. Furthermore, the joints  24  are adapted to have sufficient strength to maintain a certain pressure of the fluid without leakage. 
     The joints  24  comprise a first joint  24   a  adjacent to the first channel  22   a  and a second joint  24   b  adjacent to the second channel  22   b . The first incipient cut  10   a  and the second incipient cut  10   b  are arranged between the first joint  24   a  and the second joint  24   b . The first incipient cut  10   a  and the second incipient cut  10   b  is adapted to enable removal of material  26  from the flat region  21  between the first channel  22   a  and the second channel  22   b.    
       FIG. 2   b  shows a channel arrangement  20  comprising a first metal profile  1   a  and a second metal profile  1   b  arranged toward each other and joined together. The first metal profile  1   a  in  FIG. 2   b  is the first metal profile  1   a  in  FIG. 1   c . The second metal profile  1   b  has the same form as the first metal profile  1   a  but lacks the incipient cut. 
     By means of the incipient cut  100   c  in the first metal profile  1   a , material enclosed by the loop formed incipient cut  10   c  is adapted to be removed from the channel arrangement  20 . 
       FIG. 2   c  shows a channel arrangement  20  comprising a first metal profile  1   a  and a second metal profile  1   b  arranged toward each other and joined together. 
     The first metal profile  1   a  in  FIG. 2   c  is the first metal profile  1   a  from  FIG. 1   a . Accordingly, the first metal profile  1   a  comprises the plurality of trench-like portions  3  and plurality of flat regions  21 . The second metal profile  1   b  comprises a flat sheet of metal. Accordingly, the second metal profile  1   b  lacks the trench-like portions  3 . The second metal profile  1   b  lacks the incipient cut. 
     The first metal profile  1   a  and the second metal profile  1   b  define channels  22   a ,  22   b . The cross section of the channels in  FIG. 2   c  is half of the cross section of the channels  22   a ,  22   b  in  FIG. 2   a.    
     It shall be understood that a single profile with trench-like portions  3  and flat portions  5  and another profile comprising at least flat portions  5  arranged towards each other are sufficient in order to define the channels  22   a ,  22   b  of the channel arrangement  20 . Furthermore, the incipient cut  10   a ,  10   b ,  10   c  for removal of material may be arranged in either the first metal profile  1   a  or the second metal profile  1   b.    
       FIG. 3   a  shows the channel arrangement  28  in  FIG. 2   a  having had the material between the first incipient cut  10   a  and the second incipient cut  10   b  removed from the first metal profile  1   a.    
     By means of the removal of the material  26 , the thickness of the flat region  21  between the first channel  22   a  and the second channel  22   b  of the channel arrangement has been reduced by the thickness of the first metal profile  1   a , wherein the thickness of a part of the flat region  21  has the thickness of the second metal profile  1   b.    
     As the material was removed from the flat region  21 , the first incipient cut  10   a  formed a first edge  30   a  and the second incipient cut  10   b  formed a second edge  30   b . Each of the first edge  30   a  and the second edge  30   b  extends along the respective first incipient cut  10   a  and second incipient cut  10   b.    
     By means of the removal of material  26  from the flat region  21  the material consumption of the channel arrangement  28  is reduced. Moreover, the weight of the channel arrangement  28  is reduced. 
       FIG. 3   b  shows the channel arrangement in  FIG. 2   b  having had material  26  removed from the first metal profile  1   a . The material  26  removed was enclosed by the loop formed incipient cut  10   c , wherein a corresponding loop formed edge  30  was formed. 
       FIG. 3   c  shows the channel arrangement in  FIG. 2   c  having had material  26  removed from the first metal profile  1   a . The material  26  that was located between the first incipient cut  10   a  and the second incipient cut  10   b  has been removed from the first metal profile  1   a.    
     The channel arrangement  28  in  FIG. 3   a - 3   c  is adapted to be used in a heat exchanger, preferably a solar absorber. By means of reducing the material consumption the cost of the heat exchanger is reduced. 
     It shall be understood that the channel arrangement  20  in  FIG. 2   a - 2   c  and the channel arrangements  28  in  FIG. 3   a - 3   c  are not restricted to two channels but the channel arrangement may comprise any number in plurality of channels that are separated by flat regions  21 . Accordingly, it is possible to produce channel arrangements  20 ,  28  comprising a large number of channels  22   a ,  22   b.    
       FIG. 4  shows a rolling mill  35  adapted to be used in the method for producing a channel arrangement  28  from a first metal profile  1   a  and a second metal profile  1   b.    
     In a first step, the process comprises forming the first metal profile a and the second metal profile  1   b . A first metal sheet  40   a  and a second metal sheet  40   b  are provided from first pair of collecting rolls  42  to a respective first pair of rolls  44 , which rolls  44  are adapted to form the first metal sheet  40   a  and the second metal sheet  40   b  into the first metal profile  1   a  and the second metal profile  1   b . The first pair of rolls  44  comprises protrusions and recessions that are adapted to form the trench-like portions  3  and the flat portions  5  of the first metal profile  1   a  and the second metal profile  1   b.    
     In a second step, the process comprises forming incipient cut  10   a ,  10   b ,  10   c  in at least one of the first metal profile  1   a  and the second metal profile  1   b . The first metal profile  1   a  and the second metal profile  1   b  is provided to a respective second pair of rolls  46 , which rolls  46  are adapted to form the incipient cut  10   a ,  10   b ,  10   c . The second pair of rolls  46  comprises cutting means adapted to cut into a part of the thickness of the at least one of the first metal profile  1   a  and the second metal profile  1   b.    
     In a third step, the process comprises a) arranging the first metal profile  1   a  towards a second metal profile  1   b  so that trench-like portions  3  of the first metal profile  1   a  are directed away from trench-like portions  3  of the second metal profile  1   b  and flat portions  5  of the first metal profile  1   a  are abutting flat portions  5  of the second metal profile  1   b.    
     In a forth step, the process comprises b) joining the metal profiles  1   a ,  1   b  so that channels  22   a ,  22   b  between the profiles  1   a ,  1   b  are formed, which channels extends according to the trench-like portions  3  of at least one of the first metal profile  1   a  and the second metal profile  1   b . The joining of the metal profiles  1   a ,  1   b  comprises providing the first metal profile  1   a  and the second metal profile  1   b  to a third pair of rolls  48  that form a plurality of joints  24  at flat regions  21  on each side of the channels  22   a ,  22   b.    
     In a fifth step, the process comprises c) gripping a part of the material  26  to be removed and pulling a part of the material  26  in a direction along which the incipient cut  10   a ,  10   b ,  10   c  extends, wherein the material  26  is removed from the flat region  21  so that the thickness of the flat region  21  becomes less than the sum of the thickness of the first metal profile  1   a  and the second metal profile  1   b . The material  26  to be removed is gripped and provided to a second collecting roll  50 . 
     In a sixth step, the process comprises collecting the produced channel arrangement  28  on a second collecting roll  52 . 
     The disclosed process in  FIG. 4  enables the channel arrangement  28  to be produced in a continuous manner. Accordingly, the channel arrangement  28  can be produced in a cost effective manner with reduced material consumption. 
     The present invention is not limited to the embodiments disclosed but may be varied and modified within the scope of the following claims. 
     For example, the channels  22   a ,  22   b  may have any type of form, such as circular cross section, rectangular cross section, etcetera. One and the same channel arrangement may also have channels with different shapes and/or cross section area. The joints  24 ,  24   a ,  24   b  may be arranged by various methods, such as welding, bracing, rolling, etcetera. 
     The incipient cut  10   a ,  10   b ,  10   c  may have various configurations, such as continuously or intermittent extending along the material  26  that is adapted to be removed from the at least one flat region  21 . The incipient cut  10   a ,  10   b ,  10   c  may partly or completely enclosing one or more material  26  that is adapted to be removed from the at least one flat region  21 .