WO2011022738A1

WO2011022738A1 - Liquid-gas heat exchanger

Info

Publication number: WO2011022738A1
Application number: PCT/AT2009/000427
Authority: WO
Inventors: Gerhard Kunze
Original assignee: Gerhard Kunze
Priority date: 2009-08-27
Filing date: 2009-11-11
Publication date: 2011-03-03

Abstract

The invention relates to a liquid-gas heat exchanger, comprising a packet of identical thin plates (1) that do not have thermal conduction ribs, through which liquid is moved in a serpentine shape by means of a pump, the heat exchanger having air gaps and spacers (2) between the plates (1), through which the air (7) to be temperature-controlled is moved by a fan (6), wherein the temperature-control medium (8) flows through the inside of the plates (1) over the whole area except for guide webs (12) and edge zones (11), wherein the liquid flow (8) of all plates (1) in planes parallel to the gas flow (7) follows a serpentine-shaped path (10), which is substantially oriented in the direction opposite the gas flow (7) and may not flow downward anywhere along the course of the path, while the liquid inflow (4) and the liquid outflow (5) of the plates occur orthogonally to the plate planes through common channels, which are formed in the air gaps by corresponding openings (3a, 3a') in the plates (1a) and passages (3c) in the spacers (2).

Description

Liquid-gas heat exchanger

Liquid-gas heat exchangers are heat exchangers in which heat is exchanged between a gas flow moved by a fan and a liquid flow moved by a pump. They are mainly used for the recovery of waste heat in the building ventilation. In the application and thus also in the design, they differ from pure heating or cooling fans. In the latter, either air should be brought to a predetermined temperature with the aid of water, which is preferably achieved by a significant excess of water, or hot water should be cooled by an air stream, which am

easiest with a clear excess of air happens. For real heat exchangers, on the other hand, the approximation (1) applies:

V _ι * p _ι * C ₁ n V ₂ * p ₂ * C ₂ (1) with: V ₁₁ V ₂ ... volume flows for the first and the second medium

P ₁ , p ₂ ... density for the first and the second medium

C _{1 1} C ₂ ... specific heat capacity for the first and second medium

If the process is to be reversible, as occurs in multi-stage processes, instead of the aforementioned approximation (1), even the equal sign must apply:

V ₁ * ρ _ι _ι * c = V ₂ * p * c ₂ ₂ (2)

In practice, however, is also spoken of water-air heat exchangers, if actually meant heating or cooling fan. This is because a system built for water-air heat exchange can very well be used as a heating or cooling fan, but this is not the other way around. In the present work, the term liquid-gas heat exchanger is therefore understood as a generic term for all applications mentioned, even if when weighing up the advantages and disadvantages of individual features of the building to the narrow definition according to equation (1) or (2) is intended.

In contrast to heat exchangers, in which similar media (liquid / liquid or gas / gas) are brought into contact with each other, the liquid-gas heat exchanger, in particular in the water-air heat exchanger from a very strong asymmetry. For example, for the water-air media pair, equation (2) means that the volume flow of the air is about 4000 times greater than that of the water. On the air side, this results in the basic problem of keeping the flow cross-section as large as possible and the flow resistance as small as possible. On the water side, there is a risk of dirt deposits and problems with tight air bubbles due to the slow flow.

Liquid-gas heat exchangers, in particular water-air heat exchangers, are usually represented by finned tubes. In this case, several finned tubes can be connected to a larger package. The air then flows through between the parallel ribs, that is, the heat flow between the water pipe and air is for the most part not directly, but flows a fairly long way through the rib surface. The thermal resistance in this way is not negligible. The argument that speaks anyway for this construction is that the thermal resistance at the transition between rib surface and air is in any case so large that the additional thermal resistance along the ribs is justifiable, if these ribs

makes correspondingly thick and / or good heat conducting material. Copper and aluminum are particularly suitable for this purpose. However, prices for these metals have risen sharply in recent years, and the search for alternatives has begun.

Apart from the manufacturing problems of connecting the fins to a tube with good heat conduction, there is the physical problem that the heat which is to run from the water to the air (or vice versa) first spreads along the surface plane within the entire ridge got to. This necessarily creates a temperature gradient along the rib that does not allow optimal functioning of the heat exchanger. Namely, the air flow first moves from the rib edge to the central tube and then to the opposite rib edge. That is, on one half of the way, the temperature gradients of air and rib are in the same direction, on the other half of the way they are in opposite directions. In the case of a good heat exchanger, however, the temperature gradients of the media involved should always be in the same direction (as in a countercurrent heat exchanger).

Although one tries to keep the surface temperature of the ribs largely constant, by building them from very good heat conducting - and thus expensive - material, but also by only the temperature is stabilized within a single rib. Considering that a larger tube-and-tube heat exchanger normally consists of a coil that passes through all the parallel ribs in multiple turns and that the water within the tube continuously changes temperature, it is concluded that the airflow is confronted with a very complex temperature field is that in no case can be optimal.

In order to simplify the complex temperature field of finned tube heat exchangers, some published concepts attempt to combine liquid-flow plates with fins.

WO 2004 / 068052A1 comes closest to the present invention. In the process, the liquid flows through thermally conductive tubes, through which the tubes form complex serpentine systems, parallel to the air flow, forming the intervening "air flow areas" of thermally conductive fins, so that there is a problem with the heat being dissipated Path from the liquid medium to the gas must spread along a metal surface, resulting in a loss of temperature.

This suggests to those skilled in the conclusion that thermally conductive ribs, whether in combination with pipes or with plates, an evil that should be waived in principle. There are also corresponding liquid-gas heat exchanger in the literature, which dispense with thermally conductive ribs. An example of this is DE102004054006A1, in which a bundle of liquid-carrying pipes is placed in the parallel gas stream. In a later utility model of the same inventor DE202008000496U1 groups of such liquid-carrying pipes are combined into plates, each with a plurality of straight, parallel, through-flow channels by means of distribution areas and collecting areas.

The problem, however, is the distribution of the liquid on the mutually parallel tubes or channels, especially taking into account equation (2). In This is not a problem with a normal tube fin heat exchanger, because the flow cross section of the air is considerably larger than that of the water pipes involved. However, in a system with smooth plates without ribs, the air cross section may not be much larger than the flow area of the water. This means that the water or liquid flows extremely slowly. For the expert from the risk of dirt deposits and the problem that any air bubbles are not removed, whereby the flow of liquid through individual plates can come to a standstill.

Of course, it is also possible to reduce the cross-section of the liquid flow in a plate construction by reducing the inner diameter of the channels involved. If, however, a reduction by a factor of <0.001 is required, one encounters fundamental technical problems.

Another approach is to incorporate, instead of many straight and parallel channels, only one thin channel per plate, which pervades the plate in serpentines, because this single channel does not have to be as extremely thin as in the case of a plurality of straight, parallel channels.

From this point of view, the publication closest to the subject invention WO2007 / 127048A2, which describes an air-water heat exchanger having plates connected with adhesive strips describes. Unfortunately, the author's technical details are mainly limited to the description of his adhesive tape construction. A special narrowing of the channel cross sections is therefore not provided and would not be possible because of the thickness of the foam adhesive tape (about 3 mm). As can be seen from the descriptions of the drawings, serpentine channels are thought of as one of several possibilities, with the plates standing upright and the airflow being horizontal. Thus, the serpentine movements of the channels are up and down. The author is aware that this position could cause problems with air bubbles. Therefore, he suggests to connect adjacent Serpentinenrichtungsänderungen at the upper end of the plate through small openings with each other, so that the air could peel off. At a water flow rate of fractions of a millimeter per second (as can be calculated from its data), it can be assumed that the water flow resistance through said holes would also be so low that a substantial portion of the water is expected to be the shortest path through these holes and thus would not participate in the heat exchange process. A safe removal of air bubbles is only possible if the liquid flow on the one hand has a sufficiently small cross-section and on the other hand, the direction of movement of the liquid in the entire heat exchanger nowhere from top to bottom.

Another problem with WO2007 / 127048A2 as well as DE202008000496U1 is the technical design of the liquid supply for the flow-through plates from the side. This requires complex (probably expensive) and geometrically complex connecting parts, which are prone to leak in practice probably. This is also clear to the inventor of WO2007 / 127048A2. He recommends coating the critical areas with a suitable adhesive or sealant as a preventative measure. Such a construction certainly has no high life expectancy.

Another type of liquid-flow plates to supply with liquid can be found in DE102005037708A1. However, this is not a liquid-gas heat exchanger, but between the flow-through plates, a solid adsorbent is to be tempered. Thus, the questions about the direction of flow and the Flow rate irrelevant to this invention. Original is the way the plates are supplied with fluid through congruent inlet and outlet bores connected by sleeve-shaped collection channels that also serve as spacers. This dual function is certainly expedient and looks easy, but has the problematic consequence that the static fixation of the plates takes place to a large extent on these sleeves and plate holes. The inventor therefore proposes additional stabilizing elements at these points, the incorporation of which into the plates (see his claim 18) can be described as expensive.

In the PCT application WO 2009/097639 (based on Austrian Patent Application AT195 / 2008), a method is developed to represent hydraulic and hydropneumatic systems from compact plate packs, largely without pipe joints, whereby the production of relatively complex concepts is easy and cheap. In particular, it is thereby also possible to build water heat exchangers with extremely high efficiency. However, this method only relates to externally sealed media moving within the mold plates described therein, while being separated from other mold plates and their media by separation or insulation boards.

According to the invention, this concept for liquid-gas heat exchangers must be extended to allow additional gaps for the gaseous medium between plate groups.

According to the invention, a liquid-gas heat exchanger consists of a set of thin parallel plate combinations, which are traversed serpentinely in their interior over the entire surface of liquid, the path is oriented substantially in the opposite direction to the air flow and nowhere along its course may lead downwards, with thin columns between the plates (typically 1-2 mm) for the gas flow in between.

According to the invention, the inflow and outflow of water of the plates are orthogonal to the plate plane by common channels, which through

corresponding openings are formed in the plates and passages in the spacers in the air gaps.

Each of the flow-through plate combinations according to the invention consists of 3 or 2 partial plates. These partial plates of each plate combination have thicknesses of the order of 0.2-0.5 mm.

In the case of a combination of 3 sub-panels, the middle of each of these panel combinations is a panel with cut-out channels and holes such that the remaining ridges or guides ensure that the water in all panels is serpentine, parallel to the respective adjacent panel combination and substantially opposite to the flow The air flows between the plates, the liquid, to avoid stuck gas bubbles always only upwards or horizontally but never allowed to flow down. Water can pass from one plate into the neighboring plate at the necessary connection points between the plates. This ensures that about the same amount of water flows through all plates.

In a further development of the invention, the said plate combinations can also be produced by a combination of two mutually mirror-symmetrical partial plates. These Partial plates are molded or deep-drawn, so that over its entire surface one or more shallow channels separated by narrow webs arise, which corresponds to the shape of the webs of the middle of the 3 part plates in the first form of the invention and which guarantee the composition of the sub-plates to heat exchanger plates in that the liquid flows in all the plates of the heat exchanger in parallel serpentine and substantially opposite to the flow of air between the plate pairs. At the edges and contact points of the webs, the partial plates are folded, pressed, welded, soldered or otherwise as firmly and tightly connected. If the entire plate pack is held together under slight pressure from the outside, welding or soldering of the webs is not absolutely necessary, since the pressure differences of the flowing medium within a plate are so small that the danger that the medium on the way from one serpentine loop to the next takes the shortest path across the jetty, is almost impossible.

In a further development of the invention, it is possible to deep-draw only one of the two partial plates as just described, instead of the two mutually mirror-symmetrical partial plates, while the associated second partial plate remains flat. At the edges and contact points of the webs then these part plates are folded, pressed, welded, soldered or otherwise as firmly and sufficiently tightly connected.

According to the invention, the spacers for the air gaps can be formed by folding or bulging the deep-drawn sheets, wherein the liquid passages are guided from one plate to its neighboring plate by such bulges, which are then connected directly to each other in this case.

According to the invention, each of the liquid-conducting plates can consist of a combination of two plastic foils welded together, the welds having a shape which corresponds to the middle sub-plate in the plate version of three sub-plates.

If the liquid-conducting plates consist of a combination of two plastic foils welded together, the spacers for the air gaps can be welded according to the invention by folding or bulging of the air gaps

Plastic films are formed, whereby the liquid feedthroughs are guided from plate to plate through such bulges, which are then welded directly to the adjacent plate in this case.

According to the invention, it is advantageous in the case of very thin plates through which water flows, in particular when using plastic films, when the plates have one or more weak bends, because this causes the part plates to be stiffened. Placing a curvature axis in the direction of air flow, the angle of curvature can be large, since this means no additional air resistance. Conversely, at

Curves in other directions to note that excessive curvature can be an obstacle to the flow of air.

To further improve the invention, it is advantageous to ensure that the liquid flow through all the plates of a heat exchanger is the same. In contrast to a conventional liquid-gas heat exchanger tube-base based flows in the heat exchanger according to the invention, the liquid simultaneously over many parallel paths. According to the invention it is therefore important to have the same flow resistance in all ways, which is achieved in that each of the flow-through plates has an input and an output that all plates have identical shape and are combined into a package that all inputs and all outputs are in parallel alignment and that the liquid medium enters the package at the entrance to the first plate from below and leaves this at the output of the last plate upwards.

According to the invention, the removal of gas bubbles is further facilitated by allowing the liquid to flow from bottom to top. In practice, this means that you tilt the heat exchanger slightly laterally, so that the liquid inputs of all plates at the bottom and the liquid outlets are at the top. You can also put the plates completely vertical, only then would the air flow run vertically from top to bottom, which is not always practical.

According to the invention, it is advantageous for larger heat exchangers to subdivide the liquid-flow plates into parallel sections, each section then having its own plate inputs and outputs, so that a compact package of parallel-connected heat exchangers is produced.

In a further development of the invention, the surfaces of the liquid-flowed plates may be coated with a material having a low surface tension at the e.g. when Teflon (PTFE) - nothing can adhere, coat.

Due to this simple structure of flat elements, which are simple and cheap to manufacture, the plate body of some radiators differs from

Central heating, which are also flowed through by water, but consist of heavyweight, cast, molded or milled parts. Of the

Heat exchanger according to the invention has only a fraction of the size and weight of a comparable heater of the same power. Water-flow type radiator of the conventional type require a heating water temperature, the 20 - is 3O ⁰ C over target room temperature. The heat exchanger according to the invention is able to reach a discharge temperature of the air, which differs only by 1 ° C from the inflow temperature of the water. This is due, in particular, to the serpentine movement of the liquid proposed by the invention in countercurrent to the gas stream.

An essential advantage of this invention is that the design ensures a uniform temperature gradient along the plates and thus optimal heat transfer, which causes a heat exchanger according to the invention in comparison to a liquid-gas heat exchanger with finned tubes with the same size better heat transfer and so that has a much better temperature efficiency. While a good finned-tube air-cooled heat exchanger typically has a 70% temperature efficiency, a heat exchanger of the same size and air and water flow strengths achieves a temperature efficiency in excess of 97%, as evidenced by calculation and experimental measurement.

The advantage of joining the liquid-flow-through plates, each consisting of 3 partial plates, is that such plates can be produced easily and inexpensively by water jet or laser cutting in small workshops.

The advantage of joining together the liquid-flow-through plates, each consisting of 2 partial plates, is that it is possible to produce such plates even more cheaply on a large industrial scale. The advantage in the case of liquid-flow plates made of 2 partial plates to make one of the two plates even, consists in the cost savings, because only half of all partial plates must be thermoformed.

The advantage of forming the spacers for the air gaps by folding or bulging the deep-drawn sheets is that plates and spacers can be manufactured in one operation.

Another advantage of this invention is that the building material of a heat exchanger according to the invention has virtually no effect on the performance. In the conventional tube fin heat exchanger, the opposite is the case. It takes metals such as copper or aluminum, because very good heat conductive materials significantly improve the efficiency. This is because the total thermal resistance of the three thermal resistors

- Transfer water to the plate

- Line inside the plate

- Transition plate to the air

composed. In a tube fin heat exchanger, only the thermal resistance between water and plate is small, the other two heat resistances are large. Specifically, the thermal resistance within the plate is large because the heat must flow several centimeters along a very thin plate.

In the heat exchanger according to the invention, however, the heat flows across the plate surface - this is a short path with a large cross-section. Consequently, this average of the three thermal resistances is negligibly small, regardless of whether the specific thermal conductivity of the plate material is large or small. This results in the

Possibility to use cheap and easily processable plastics instead of expensive metals like copper.

The advantage of building the heat exchanger made of plastic is that raw material and production method are cheap and there is no corrosion.

The slight curvature of the plates according to the invention is advantageous because it stiffens the construction of such a heat exchanger without additional structural means.

The same length according to the invention with the same cross section of all fluid paths to prevent individual paths are flowed through stronger than others. In practice, this would mean that different plates would have different temperatures in the heat exchanger, whereby the heat transfer between the two media would no longer be optimal.

The slightly tilted construction according to the invention, as well as the provision that the path of the liquid must nowhere lead downwards, has the advantage that any gas bubbles are transported away with certainty. Fixed gas bubbles would namely on the one hand reduce the active area of the heat exchanger and on the other hand increase the flow resistance of the liquid through individual plates, with different plates in the heat exchanger would have different temperatures, whereby the heat transfer between the two media would not be optimal. The advantage according to the invention in the case of larger heat exchangers to subdivide the liquid-flow-through plates into parallel sections is that thereby the mathematical optimization of the heat exchanger dimensions less

Restrictions are imposed.

The advantage of the inventive coating of the heat exchanger plates with a Teflon-like material results from the requirements of the optimization calculations. Accordingly, a heat exchanger with the same power and the same temperature efficiency can be built smaller, the narrower the columns for the gas flow. If lightly contaminated normal ambient air is used as the gas, these gaps are normally kept at least 2 mm wide for easy cleaning with compressed air or water jet. A specially coated surface would be less likely to stain and be easier to clean.

This would allow smaller air gaps.

The pictures

Fig. 1. shows the entire system, the plate block including water connections and

Fan.

Fig. 1a shows the plate block of Fig. 1 for a case in which the plates are curved.

Fig. 2 shows an exploded view of a section of the plate block, where the

Sequence of the part plates can be seen.

FIG. 3 shows an even smaller section of FIG. 2 with a smaller distortion due to the explosion. It can be seen the structure of the liquid passage through the plates.

Fig. 4 shows a typical middle sub-plate (mold plate), which liquid from the

Inlet opening to the outlet opening of the plate passes.

Fig. 5 shows a combination of 2 welded plastic plates, which fulfill the functions of the heat exchanger plates according to the invention in the same way.

Fig. 6 shows a deep-drawn sheet metal plate

Fig. 7 shows 3 details (a, b, c) of a cross section through a heat exchanger with deep-drawn plates.

Fig. 8 shows 3 details (a, b, c) of a cross section through a heat exchanger with a

Combination of deep-drawn plates with flat plates.

Fig. 9 shows a sectional view of a heat exchanger assembly.

Fig. 10 shows a side tilted heat exchanger.

Fig. 11 shows a deep-drawn plate for larger heat exchangers.

In detail, the illustrations show:

Fig.1: The liquid-traversed plates -1-, separated by spacers -2-, arranged in a stack. The water comes through the inflow -4- in the first plate, and distributed over the recesses -3c- in the spacers -2- from plate to plate. Within each plate, the liquid flows in the main flow direction -8- to the liquid outlet -5-, this way

Serpentine has, by which is ensured that the liquid is steady and monotone against the gas direction -7- progressing from -4- to -5- moves. By a blower -6- a gas flow -7- is generated, which is the Fiüssigkeitsströmungsrichtung -8- predominantly opposite.

It may be advantageous for very thin sheets through which liquid flows, particularly when using plastic films, if the plates have one or more weak bends to stiffen the structure. In this case, however, all plates A- should remain identical in shape and sections in parallel, that is, the support holders -2- are the same everywhere.

Fig.2: Each plate -1- consists of 3 partial plates -1a, 1b, 1a and is separated by spacers -2- from the neighboring plates -1-. The middle sub-plate -1b- forces the liquid through its webs -12- to a serpentine path on which it is steadily and monotonously progressing from the liquid inlet -3b- to the liquid outlet -3b ¹ - is performed. All 2 plate types -1a, 1b- and the spacers -2- have at the corresponding points liquid passages -3a, 3b, 3c-. The liquid outlet -3a'- (in the picture only partially visible) is constructed identically

Fig.3: This figure shows above all the liquid passage through the plates -1-. The openings -3a and -3b are congruent. The opening of the middle plate -3b- has a restricted flow -15- to the -Fidsswegsweg -10-, whereby it should be ensured that the liquid flow through all plates is approximately equal. In the Ausnehmuπgeπ -3c- of the spacers can be sealing rings -3c "- insert, if you do not want to connect the plates -1- firmly, but compresses the whole package from the outside as in a conventional bolted plate heat exchanger.

4: This illustration shows a middle plate -1b- »n of the plan view. This partial plate consists only of a closed outer edge -11- and webs -12-.

Connected to the outer edge -11-, the liquid openings are outwardly -3b, 3b'- with the restricted passage -15- to the liquid path -10-. Since a regular and reproducible small opening -15- is not easy to accomplish with the methods of blank punching or laser cutting, it helps to insert into the liquid opening -3b- a standard spring washer -9-, a wave washer or a similar elastic element which in the compressed state is a little thinner than the plate thickness of -1b-. Then the flow restriction is not at the constriction -15- but at the recess of the inserted ring.

Fig. 5 .: The figure shows the design of a heat exchanger plate -1- of two welded plastic films. In the concrete example, there are several parallel ones

Fluid paths -10-, which are separated from each other by the welds -14-.

In particular, when using plastic films, it may be advantageous to use a plurality of short parallel liquid paths in order to keep the pressure drop in the liquid flow as small as possible so that the films do not deform. At the inlets and outlets -3a, 3a'- of each liquid path -10- there are bumps with passages which communicate with such openings of the adjacent plates e.g. be tightly connected by welding. In order to keep elastic deflection of the thin plates as small as possible, there are additional spacers in the form of folds or bulges -2a of the films.

Fig. 6: The figure shows a deep-drawn sheet metal plate -1a in plan view. The inclined surface pieces are hatched, all other surfaces are parallel to the picture plane. From the originally flat sheet metal plate, the edges -11- and the webs -12- remain unchanged in their initial plane, while the serpentine channel -10- is deep drawn into a second plane. The spacers -2-, as well as the inlet and outlet openings -3a are formed as nubs, which are a little further deep drawn to a third level. The liquid flow -8- flows in the drawing through the upper left opening -3a in the direction of arrow -8- to the lower right opening -3a'-. The gas flow direction is indicated by arrows -7-. The line SS 'denotes the sectional plane of the cross section of FIG. 7.

Fig. 7 shows 3 details of a cross section through the deep-drawn plate of Fig. 6. Die

Drawings Figures 7a, 7b and 7c refer to the same section plane taken along the line SS ¹ .

Fig. 7a shows a cross section through a single plate -1a. You recognize edge

-11- and webs -12-, which lie in the first level. The outer wall of the channels -10-, which lies in a second plane, as well as the inlet opening -3a and the spacers

-2-, which lie in a third level.

Fig. 7b shows two joined plates -1a-which are placed in mirror image one above the other, thereby forming a liquid-flowed plate -1- with the channel -10- is formed.

Fig. 7c shows a plurality of liquid-flowed plates -1-, which lie on one another, wherein an air gap -7- is kept free by the spacers -2- as well as by the bulged inlet opening -3a between the plates -1-. The arrows -7- give the

Gas flow direction on.

8 shows 3 details of a cross section of a non-mirror-image plate assembly, in which a deep-drawn sheet, as in Fig. 6 with a flat sheet to a

liquid-flowed plate -1- is combined. The drawings Fig. 8a, Fig. 8b and Fig. 8c refer to the same sectional plane along the line S S 'in Fig. 6.

Fig. 8a shows a cross section through a deep-drawn sheet -1a and a still separate flat sheet -1c-. One recognizes edge -11- and webs -12-, which lie in the first level. The outer wall of the channels -10-, which lies in a second plane, and the inlet opening -3a and the spacer -2-, which come to rest in a third plane.

Fig. 8b shows two assembled sheets, a deep-drawn sheet -1a and a flat sheet -1c, which are superimposed with congruent openings 3a-one above the other, so that thereby a liquid-flow plate -1- with the channel -10- is formed ,

8c shows a plurality of liquid-flowed plates -1- in non-mirror-image construction, which lie on one another, wherein an air gap is kept free by the spacers -2- as well as by the bulged inlet opening -3a between the plates -1-. The arrows -7- indicate the gas flow direction.

Fig. 9 shows a schematic vertical section through a heat exchanger according to the invention, which is designed so that all parallel fluid paths -8- are the same length. The liquid enters the heat exchanger at the entrance of the first plate -4-, spreads over the escape of the inlet openings through the liquid passages -3c- on all plate entrances, flows through these parallel -8-, after which all these parallel paths -8- in the Escape the output openings -3c'- open where they join the output current -5-. Fig. 10 shows a vertical section through a heat exchanger according to the invention, which is designed so that the liquid can flow from bottom to top, whereby they can carry along air bubbles easier. In this case, the heat exchanger is slightly tilted sideways, so that the liquid entrances -3c of all plates at the bottom and the liquid outlets -3c'- come to lie at the top. The liquid enters the heat exchanger at the inlet of the first plate 4-, flows upwardly through the escape of the inlet openings -3c- through the liquid passages -3c- to all plate entrances, flows through them substantially upwards, even if these paths are horizontal Serpentines include, parallel -8-, after which all these parallel paths -8- in the likewise upward-oriented alignment of the exit openings -3c'- open, where they join the output current -5-, which comes to rest at the highest point.

Fig. 11 shows a deep-drawn plate for larger heat exchangers. In the example, three parallel channels -10- are accommodated on a disk. Each of these channels has one input -3a and one output -3a'-. The individual webs are bounded by the analogous webs -12- and surrounded jointly by the outer wall -11-. From such a deep-drawn plate -1a can be formed either analogously to Figure 7 with a mirror image plate -1a or analogous to FIG. 8 with a flat plate -1c- a large liquid-flowed plate -1-. From a plurality of such plates -1- arises a large heat exchanger, which consists of parallel sections of parallel heat exchangers, each section having its own plate inputs and outputs.

Claims

claims

1) liquid-gas heat exchanger, consisting of a package of identical thin plates (1) without heat conducting ribs, is moved through the serpentine with a pump liquid, with air gaps and Abstandhaltem (2) between the plates (1), through which the tempered Air (7) by a blower (6) is moved, characterized in that the plates (1) inside of the guide webs (12) and edge zones (11) over the entire surface through the tempering medium (8) are flowed through, wherein the liquid flow (8) of all plates (1) in parallel planes to the gas flow (7) follows a serpentine path (10) which is oriented substantially in the direction opposite to the gas flow (7) and is not allowed to flow downwardly along its course, during the flow of liquid ( 4) and the liquid drain (5) of the plates orthogonal to the

Plate levels by common channels formed by corresponding openings (3a, 3a ') in the plates (1a) and passages (3c) in the spacers (2) in the air gaps.

2) liquid-gas heat exchanger according to claim 1, characterized in that each of the water-carrying plates (1) consists of a combination of three flat thin partial plates (1 a, 1 b, 1 a), which bond together by pressing, soldering, welding or are firmly and tightly connected by another expedient method, all of these sub-panels having two or more inlets (3a, 3b) or outlets (3a ', 3b') for liquid and all sub-panels (1a, 1b, 1a) with respect to these inlet (3a, 3b) and outlet (3a ', 3b') are congruent and where the middle part plate (1b) has a closed outer wall (11) but are cut out of its interior paths or channels (10) passing through Webs (12) are separated from each other, which define the path of the liquid (8) from the inlet openings (3a) to the outlet openings (3a ¹ ).

3) liquid-gas heat exchanger according to claim 1, characterized in that each of the liquid-carrying plates (1) consists of a combination of two mirror-image deep-drawn folded, pressed, welded, soldered or otherwise closely interconnected sheets (1 a), wherein the shaping of these sheets (1a) is such that over its entire surface one or more shallow channels (10) separated by narrow webs (12) arise, and the shape of these webs (11, 12) of the middle of the 3 sub-panels (1b) to complete 2 corresponds.

4) liquid-gas heat exchanger according to claim 1, characterized in that each of the liquid-conducting plates (1) consists of a combination of a

deep-drawn plate (1a) with a flat plate (1c), which with respect to their inlet (3a) and outlet openings (3a ¹ ) congruent folded together, pressed, welded, soldered or otherwise sealed together.

5) Liquid-gas heat exchanger according to claims 3 or 4, characterized

in that the spacers (2) for the air gaps are formed by folding or bulging the thermoformed welded, soldered or otherwise closely interconnected sheets (1a), wherein the

Liquid feedthroughs (3a, 3a ') from a plate (1), sub-plate (1a) to its neighboring plate (1), sub-plate (1b or 1c) are guided through such bulges, which are then directly connected together in this case.

6) liquid-gas heat exchanger according to claim 1, characterized in that each of the water-carrying plates (1) of a combination of two with each other welded or glued plastic films or plates (1a), wherein the seams have a shape corresponding to the central part plate (1b) in claim 2.

7) liquid-gas heat exchanger according to claim 6, characterized in that the spacers (2) for the air gaps by folding or bulges of the welded plastic films (1 a) are formed, wherein the

Water passages from plate (1) to plate (1) by such bulges (3a, 3a ') are guided, which are then welded directly to the adjacent plate (1, 3a, 3a') in this case.

8) liquid-gas heat exchanger according to one of the above claims, characterized

characterized in that the used water-flow plates (1) each have one or more equal slight curvatures, whereby, however, all plates (1) remain identical in shape and partially parallel.

9) liquid-gas heat exchanger according to one of the above claims, characterized

characterized in that each of the flow-through plates (1) has an inlet (3a) and an outlet (3a '), and that the plates (1) are combined into a package so that all inlets (3a) and all outlets (3a ¹ ) are in parallel alignment with one another and that the liquid medium enters the package from below at the inlet into the first plate (4) and leaves it upwards at the outlet of the last plate (5).

10) liquid-gas heat exchanger according to one of the above claims, characterized

characterized in that one tilts the heat exchanger slightly laterally, so that the liquid inlets (3a) of all plates at the bottom and the liquid outlets (3a ¹ ) come to lie on top.

11) Liquid-gas heat exchanger according to one of the preceding claims,

characterized in that several such packages are grouped together such that each of the panels (1) is composed of two or more sections, each having an inlet (4) and an outlet (5), so that for each section separately all the inlets ( 3a) and all the outlets (3a ¹ ) lie in mutually parallel alignments, wherein the liquid flows of all sections are parallel to each other.

12) liquid-gas heat exchanger according to one of the preceding claims,

characterized in that the surfaces of the liquid-flow-through plates (1) are coated with a material having a low surface tension similar to the Teflon (PTFE), which can not adhere.