DE60130946T2 - Improved high performance evaporator for refrigerators and freezers - Google Patents

Abstract

An evaporator made using the Roll-Bond technique, that is: by joining two sheets of aluminium (1A, 1B) with a channel system pattern traced between them by means of a detachment layer (D), so that the welding between the two sheets is only carried out on those surfaces where the said detachment layer (S) is not applied; the said channel system is created by injecting a fluid under pressure in the areas where the detachment layer (D) is applied, in order to separate the sheets and create a gap between them in the said areas in order to form the channel system (C) according to the size and shape determined by the mould and die; characterised by the fact that; the surfaces of the mould and/or die which correspond to the said channel system are corrugated so that, during the expansion phase in order to create the said channel system, the final layout of the said channel system takes up a similarly corrugated form (N). <IMAGE>

Description

object This patent is an improved high performance evaporator, especially for, but not limited on, refrigerators, freezers and freezers.

scope of application

The Patent is preferably, but not necessarily exclusively, in Range of refrigerators and Frozen devices is used, in which there is an internal cooling system There, with a condenser and compressor outside the freezer unit and an evaporator in the freezer.

State of the art

Evaporator for refrigerators, freezers or freezers are widespread, and their goal is the area around the freezer unit Remove heat where they are housed by evaporation the liquid in the cooling circuit, which is located inside.

The Evaporators are usually by welding together made of two aluminum sheets to form a channel system, the one gradually has increasing cross-section, so that, on the basis of the law of fluid mechanics for gases PV = RT (pressure × volume = Constant × temperature, where the temperature indicates the absolute temperature), in the state an increase in volume and a pressure drop, there is a drop in temperature.

Of the fall in temperature in the duct system of the evaporator leads to a cooling of the area around (fridge or Gefrierfachein unit) due to the heat exchange by conduction and convection between the air outside the duct system.

Around the efficiency of heat exchange can improve the channel system in different sections and tracks are formed to achieve the best possible performance.

The most used system to make the evaporators, that is Well-known roll cladding method, which involves the attachment of a replacement pattern anticipates, for example, by screen printing, according to the predetermined Structure of the channel system, on one of the inner surfaces of the two aluminum sheets, which are welded together in which one connects the two sheets and by hot rolling welded together in the areas not the detachment pattern followed by an annealing cycle and the injection, under pressure, of a liquid between the two Sheets clamped between two expansion-limiting plates to make the finished channel system.

The Channel systems, as already said, have a progressively variable Cross section and different tracks according to many different designs, around the highest Heat exchange efficiency to obtain.

Other solutions envisage the use of copper sheets instead of aluminum, however It is well known that pure aluminum (over 99.5%) has high conductivity and that it is connected by using the roll cladding technique can be. Furthermore has aluminum good wear resistance properties and better non-toxic properties than other metals, e.g. As copper and copper alloys (eg brass).

disadvantage

Despite all efforts, it has not been possible to improve the efficiency of the heat exchange beyond the limits of the above-mentioned features, not even using the teachings of US-A-3172194 , The latter discloses a heat transfer device, more particularly a heat exchange tube with molded ribs. Their aim is: a heat exchange tube for boilers, refrigerators, condensers and the like with outer fins. Occasionally, when said rib attachment, a corrugated inner surface is realized. But this process is complicated and expensive and does not allow to automatically create an evaporator in a traditional cheap Walzplattierverfahren, moreover said corrugation is perpendicular to the channel, that is an obstacle to the advancement of the river.

Object of the invention

aim this invention is the abovementioned limitations to overcome, without revolutionizing the production cycle of roll plate technology to have to, and in particular, a higher heat exchange with the same dimensions and masses as usual Guarantee evaporators.

Description of the invention

• – er hergestellt wird, indem man zwei Aluminiumbleche verbindet, zwischen die mittels einer Ablösungsschicht ein Kanalsystemmuster gezeichnet ist, so dass die beiden Bleche nur an den Stellen verbunden sind, wo die besagte Ablösungsschicht nicht aufgebracht ist;
• – das besagte Kanalsystem geschaffen wird, indem man eine Flüssigkeit unter Druck in die Bereiche injiziert, in denen die Ablösungsschicht aufgebracht ist, um die Bleche zu trennen und eine Lücke dazwischen in den besagten Bereichen zu schaffen, um in den ausdehnungshemmenden Platten das Kanalsystem zu bilden; die Oberflächen entweder einer oder beider Platten wellenförmig ist, so dass während der Ausdehnungsphase, um das besagte Kanalsystem zu schaffen, das dadurch gekennzeichnet ist, dass die Endform des Kanalsystems, das eine ähnlich wellenförmige Oberfläche hat, gebildet wird, besagte Riffelung in dem Kanalsystem geneigte querlaufende Wellenbewegungen verwirklicht, um ein turbulente, mehr oder weniger schraubenförmige oder gewundene Bewegung der Flüssigkeit zu erzeugen, die in dem besagten Kanalsystem zirkuliert, während sie vorankommt.

The problem is solved as claimed in the claims by an evaporator made using the roll cladding technique, wherein:

• - It is made by connecting two aluminum sheets, between which a channel system pattern is drawn by means of a release layer, so that the two sheets only in the places are connected, where said release layer is not applied;
• - said channel system is provided by injecting a liquid under pressure in the areas in which the release layer is applied to separate the sheets and to create a gap between them in said areas to form the channel system in the expansion-inhibiting plates ; the surfaces of either or both plates are undulating, such that during the expansion phase to provide said channel system, characterized in that the final shape of the channel system having a similar undulating surface is formed, said corrugation is inclined in the channel system Transverse wave movements are realized to produce a turbulent, more or less helical or tortuous movement of the liquid circulating in said channel system as it progresses.

The Advantages obtained by using this system are in Formation of the said channel system, so that, compared with evaporators same size, one larger surface area in contact with the coolant comes.

Furthermore elevated the inclined wavy Profile of the surface, obtained in the channel system containing the evaporation coil forms not only strongly the surface area for the heat exchange, but also causes a turbulent motion in the cooling liquid, the heat exchange even more increased.

The Production method provides, as already stated, that the channel system, which results from the roll plating process is formed by High pressure air injected into the sandwich structure, the upper Aluminum sheet, a detachment pattern made of heat resistant Ink and a lower aluminum sheet.

The Both sheets are preheated and Hot rolling welded together, followed by a cold rolling cycle.

In the sandwich structure will be after a suitable annealing treatment High-pressure air injected, which is the separation of the two aluminum sheets caused at the points where the detachment ink pattern applied is, and thus forms the channel system.

The Deformation in the above areas, that is, where the welding process has not occurred, forms the inclined wavy pattern, this means, wavy inclined at the channels, and leads so to the required magnification in the surface area and turbulent motion when the fluid passes through it.

If the magnification during the Air injection cycle performed will be, the outer surfaces of the Channel system against the wavy surface the boundary plate or plates are pressed, thus defining the undulating end surface.

The surface The plate or plates also forms their rough surface to the Outer surface of the channel system down when compressed be, and thus forms a corresponding corrugation also on the inside of the duct system because of the constant thickness of the deformed aluminum sheet. The Channel system therefore assumes the same corrugation as the expansion-inhibiting Plates pressed against it and is deformed. The forms that can be formed are different type or size, depending on the shape of the surface, against which the evaporator channel system is extended.

Of the The advantage is that the said corrugations are inclined transversely to the Coolant, which traverses the system, a turbulent, helical or to give a tortuous movement.

On this way are the molecules the liquid forced to perform a train the longer is considered the orbit of the sewer system, with a better flow against the walls the channels, what to a considerable Increase in heat exchange leads.

Description of an application the invention

These and other advantages, with the aid of the attached drawings, outlined in the following description of a typical application of the system, their details are to be considered as an example and not as a limitation.

1 Figure 3 is a three-dimensional view of a portion of an evaporator created by the features of this invention.

2 is a cross section through a channel in the channel system.

3 is a longitudinal view of the channel as in 2 shown.

• 1A und 1B bezeichnen das obere und das untere Aluminiumblech des Verdampfers.
• "S" bezeichnet die flache geschweißte Zone zwischen den Blechen "1A" und "1B"
• "D" gibt die Innenseite des Kanalsystems an, von denen eine von dem Abtrennmuster bedeckt wird.
• "C" bezeichnet das Kanalsystem.
• "N" bezeichnet die geneigte wellenförmige Form entlang dem Kanalsystem entsprechend dieser Erfindung.

Denoted in the figures 1 the evaporator.

• 1A and 1B designate the upper and lower aluminum sheets of the evaporator.
• "S" denotes the flat welded zone between the sheets " 1A " and " 1B "
• "D" indicates the inside of the channel system, one of which is covered by the separation pattern.
• "C" denotes the channel system.
• "N" refers to the inclined undulating shape along the channel system according to this invention.

The said corrugations are more or less inclined to one helical To form turbulence zone.

The best turbulence shape is the one with inclined corrugation and / or ribbing, that of the liquid a basically helical (convoluted), gives turbulent motion. In this way, the heat exchange even higher, not only because of the increase the surface area, but also because of the turbulent, helical movement the liquid, while she goes through the canal system.

On this way are the molecules the liquid forced a longer one Track, as compared to the center line of the channel to perform, and so on the efficiency is undoubtedly higher.

• – durch Verbindung zweier Aluminiumbleche (1A. 1B) mit einem Kanalmuster mittels Aufbringung einer Ablösungsschicht (d), so dass, wenn die beiden Bleche durch Schweißen verbunden sind, das Schweißen nur an den Oberflächen durchgeführt wird, auf denen die Ablösungsschicht (S) nicht aufgebracht worden ist,
• – wobei sie durch Autogenschweißen mittels eines Anwärmverfahrens und Warmwalzen verbunden werden, gefolgt von einem Kaltwalzverfahren und einem Glühverfahren,
• – wobei das Kanalsystem gebildet wird, indem man Flüssigkeit unter Druck in die Bereiche injiziert, in denen die Ablösungsschicht (d) aufgebracht wurde, um die beiden Bleche zu trennen und eine Lücke in den besagten Bereichen zu bilden, um das Kanalsystem (C) entsprechend einer Größe und Form zu bilden, die von den ausdehnungshemmenden Platten bestimmt wird.

wobei:

• – die Oberflächen der Platten sind wellenförmig, um das Kanalsystem durch eine Ausdehnungsphase zu bilden, in der
• – die Endform des Kanalsystems eine ähnlich wellenförmige Form (n) annimmt.

As claimed, the invention relates to a process using the roll cladding method ( 1 ) Evaporator, that is:

• - by joining two aluminum sheets ( 1A , 1B ) having a channel pattern by applying a release layer (d) so that when the two sheets are joined by welding, the welding is performed only on the surfaces to which the release layer (S) has not been applied,
• They are joined by autogenous welding by means of a heating method and hot rolling, followed by a cold rolling method and an annealing method,
• - wherein the channel system is formed by injecting liquid under pressure in the areas in which the separation layer (d) was applied to separate the two sheets and to form a gap in said areas to the channel system (C) accordingly to form a size and shape that is determined by the expansion-inhibiting plates.

in which:

• The surfaces of the plates are undulating to form the channel system by an expansion phase, in which
• - The final shape of the channel system assumes a similar wave-like shape (s).

Of the The advantage is that the said corrugation (s) in the channel system (C) is formed to the coolant, which traverses the channel system (C), a helical turbulent To give movement.

One Another advantage is that the said ribbing also ribs or transverse shafts (n) has.

at the solution The said corrugation also has transversely inclined ribs or waves (n) to the liquid, which circulates in the channel system (C) as it progresses to give turbulent, more or less helical movement.

With these combinations can achieved optimum results in terms of increased efficiency be, with the same size of the evaporator and the same energy consumption of the equipment. Alternatively, devices can with the same heat exchange capacity with less heat Power consumption can be obtained.

• – man nimmt zwei Aluminiumbleche mit einer Reinheit von etwa 99.5% (1A, 1B);
• – man bringt auf einem der beiden Bleche, entsprechend einem vorherbestimmten Muster, eine Ablösungsschicht (D) an, die resistent gegen die Hitze ist, die während des Schweißens der beiden Bleche erzeugt wird, um das Schweißen in den Bereichen der Ablösungsschicht (D) zu vermeiden;
• – man fügt die beiden Bleche (1A, 1B) zusammen und unterwirft sie einem Anwärmzyklus und einem Warmwalzzyklus zum Autogenschweißen der Bereiche und Oberflächen, die in Kontakt sind und nicht von der Ablösungsschicht (d) bedeckt sind;
• – man führt einen Kaltwalzzyklus der Bleche durch, die zusammengeschweißt sind;
• – man führt einen Glühzyklus der Bleche durch;
• – man presst die wie oben beschrieben behandelten Bleche zwischen zwei ausdehnungshemmende Platten;
• – wobei die negativen Oberflächen der Platte(n) wellenförmig sind;
• – das Kanalsystem wird dann zwischen den Begrenzungsplatten gebildet, indem man Druckluft in die Bereiche injiziert, wo die Ablösungsschicht (d) aufgebracht wurde, um die Bleche zu trennen und eine Lücke in den Bereichen zu bilden, wo die Ablösungsschicht (d) aufgebracht wurde, und bildet so das Kanalsystem (C), so dass; die Endform, die von dem Kanalsystem auf dem Verdampfer gebildet wird, ähnlich wellenförmig (N) ist, so dass Wellen entstehen, die schraubenförmige Turbulenz in der vorrückenden Flüssigkeit erzeugt.

The production process is as follows:

• - takes two aluminum sheets with a purity of about 99.5% ( 1A . 1B );
• It is applied on one of the two sheets, according to a predetermined pattern, a release layer (D), which is resistant to the heat generated during the welding of the two sheets to the welding in the areas of the release layer (D) avoid;
• - you add the two sheets ( 1A . 1B ) and subjects them to a heating cycle and a hot rolling cycle to autogenously weld the areas and surfaces that are in contact and not covered by the release layer (d);
• - Perform a cold rolling cycle of the sheets, which are welded together;
• - one carries out an annealing cycle of the sheets;
• - Pressing the treated as described above sheets between two expansion-inhibiting plates;
• - wherein the negative surfaces of the plate (s) are undulating;
• The channel system is then formed between the boundary plates by injecting compressed air into the areas where the release layer (d) has been applied to separate the sheets and to form a gap in the areas where the release layer (d) has been applied, and thus forms the channel system (C), so that; the final shape formed by the channel system on the vaporizer is similarly undulating (N), so that waves are created which create helical turbulence in the advancing liquid.

• US 3172194 A [0010]

Patent documents cited in the specification

• US 3,172,194 A [0010]

Claims (2)

Evaporator, in particular for refrigerators or freezer chests, manufactured using the roll-plating method, in which: - the evaporator is produced by bonding two aluminum sheets ( 1A ; 1B ) with channels by application of a release layer (d), so that the joint is performed due to welding between the two sheets only on the surfaces where the release layer (d) has not been applied, - said channel system being formed by injecting liquid under pressure into the areas where the release layer (d) has been applied to separate the two sheets and to form a gap in said areas to form the channel system (C) according to a size and shape determined by the expansion - inhibiting plates, said plates being corrugated to form said channel system during the expansion phase, characterized in that the final shape of the channel system having a similar undulating surface (N) is formed, said corrugation being in the channel system inclined transverse waves (N) generated to a turbulent, more or less schraubenför to create moderate or tortuous motion of the liquid circulating in the channel system (C) as it progresses. Process for producing an evaporator according to claim 1, characterized in that it consists of the following phases: - use of two aluminum sheets with a purity of at least 99.5% ( 1A ; 1B ); Spreading one of the two sheets with a release layer (d) according to a predetermined pattern resistant to the heat generated during welding of the two sheets to avoid welding in the areas of said release layer (d) becomes; - joining the two sheets ( 1A ; 1B ) and warm-up cycle and hot rolling cycle for autogenously welding the areas and surfaces that are in contact and not covered by the release layer (d); - cold rolling cycle of the sheets which are welded together; - annealing cycle of the sheets; - Pressing the treated as described above sheets between two expansion-inhibiting plates; - One or the other surface of the expansion-inhibiting plates is wavy; Said channel system is then formed between said plates by injecting compressed air into the areas where the release layer (d) has been applied to separate said plates and to form a gap in the areas where the release layer (d) was applied, and so to form the channel system (C), so that; The final shape formed by the channel system formed on the evaporator is similarly undulating (N).