EP0520309A1 - Evaporator for a compressor-refrigerator - Google Patents

Abstract

Characteristic of the invention is that an at least partially outside of the evaporator plate (11) partially in the suction tube (10), directly or indirectly held on the evaporator guide tube (8) slightly larger inner diameter than the outer diameter of the throttle capillary tube (7) and much smaller outer diameter than that of the inner diameter of the suction tube (10), the throttle capillary tube (7) is inserted from the outside into the guide tube (8) and the compressor-side end region of the inner jacket of the guide tube (8) within a first one, in the guide tube (8) lying length section (L1) of the coolant supply line with the assigned area of the outer jacket of the throttle capillary tube (7) is pressure-tight and ends in the guide tube (8), and that the guide tube (8) a second length section (L2) of the coolant supply line with the capillary Flow cross section expanded cross section image et, and that the interior of the guide tube (8) determined by the expanded second length section is connected to the inlet region (3) of the coolant channel. <IMAGE>

Description

The invention relates to an evaporator for a compressor cooling device, the evaporator made from a two-layer evaporator board having a coolant channel running between the layers in a meandering manner, in the inlet area of which a small diameter coolant supply line, which acts as a throttle and can be connected to the pressure side of the compressor in the coolant circuit, opens out. and whose outlet area ends in a suction pipe of larger diameter, which can be connected to the suction side of the compressor, a length section of the coolant supply line lying inside the outlet area and inside the suction pipe, the wall of which breaks through the coolant supply line, the coolant supply line also continuing over a substantial part of its length is designed as a throttle capillary tube with a capillary flow cross-section. Evaporators of this type are known, for example, from DE-AS 12 42 646 and are widely used in household refrigerators.

The invention is now concerned with the coolant circuit, in particular with the coolant inlet into the evaporator, which takes place in the known cooling devices via a long throttle capillary tube corresponding to the required throttling effect, which according to the prior art is the coolant supply line. This throttle-capillary tube is routed regularly into the inlet area of the coolant channel through a corresponding inlet connection and, in the case of the so-called single-tube connection, also lies in the outlet area of the coolant channel with a section of its length. The coolant channel itself runs in a meandering manner in an originally flat evaporator board, which was made from two aluminum sheets welded together, for example by the so-called roll bond process, and then formed into the refrigerator compartment and closes on the outlet side with an aluminum pipe socket, the so-called intake pipe, which is inserted pressure-tight into the channel end.

The throttle capillary tube is so long today in the majority of the refrigerator types manufactured that it can only be accommodated in the inlet area of the coolant channel of the evaporator to a small extent and for the most part is often outside the evaporator with a partial length of several meters. This part length is regularly wound up like a capillary ring to form a capillary curl.

With the recent introduction of new refrigerants, which have different material properties than the previous ones, but also show their own transition behavior from the liquid to the gaseous phase in the coolant circuit, the throttling distance had to be extended with the same capillary tube inner diameter, which further increased the capillary curl.

A first production simplification has already been achieved by using throttle capillary tubes for evaporators of various types, all of which have an outer diameter of, for example, 1.9 mm, and with inner diameters of, for example, 0.55 to 1.05 mm, which allow a type-specific adaptation. In this way, at least connections of the throttle capillary tube or openings can be designed uniformly for this. The dragging of the capillary curl in the final stages of production, however, continues to be a hindrance, just as the capillary curl unfavorably determines the packing density of the evaporators during transport to the cooling device manufacturers.

The object of the invention is to simplify the variety in the manufacture of the evaporators caused by the numerous types of cooling devices and to take into account the consequences of using new coolants of lower viscosity.

According to the invention it is therefore proposed that an at least partially outside of the evaporator board partially in the intake manifold, held directly or indirectly on the evaporator The guide tube is provided with a slightly larger inner diameter than the outer diameter of the throttle capillary tube and a substantially smaller outer diameter than that of the inner diameter of the suction tube,
that the throttle capillary tube is inserted into the guide tube from the outside and the compressor-side end area of the inner jacket of the guide tube is connected in a pressure-tight manner to the assigned area of the outer jacket of the throttle capillary tube within a first length section of the coolant supply line and ends in the guide tube,
that the guide tube forms a second length section of the coolant supply line with a cross section which is enlarged compared to the capillary flow cross-section, and that the interior space of the guide tube determined by the expanded second length section is connected to the inlet region of the coolant channel.

Between the throttle capillary tube and the guide tube, a gap the size of a soldering fit is regularly set, the filling of which is used to connect the tubes when soldering.

The invention enables extensive standardization of the evaporator production and basically allows the separate production of the still throttle-capillary tube-free evaporator and the associated capillary tubes up to a final assembly in which the capillary tube is installed in the guide tube, that is, inserted as far as possible into or through this and finally being soldered to this. The length, type and installation of the guide tubes in the evaporator boards can be reduced to a small number of construction variants, thus simplifying the production process.

Another embodiment of the invention is set out in claim 2, in which the guide tube with a soldering gap fit on the evaporator side is attached to a further capillary tube and is connected to the latter in a pressure-tight manner, the further capillary tube being the connection between the interior of the second length section with the inlet area and a third, on the evaporator side forms the last longitudinal section of the coolant supply line. Here, according to claim 3, the throttle capillary forms the further capillary tube, which ends near its wall opening in the guide tube attached to the evaporator, in the other side of which the throttle capillary tube is inserted. Establishing this connection can be the last manufacturing step at the evaporator manufacturer or a manufacturing step at the refrigerator manufacturer. It is important for a standardization of the evaporator production that one and the same inner diameter can be selected for the further capillary tube in all evaporators of a type range, in order then to make the necessary adjustment with individual type-dependent variable inner diameters of the throttle capillary tube.

If the guide tube is made a little longer and if it is guided from the outside into the coolant channel into the entrance area of the coolant channel, a coolant supply line can result which has a total of two length sections of different inner diameters. It is irrelevant that the relatively short last section of the coolant supply line can only exert a slight throttling effect, but instead enables the coolant to be introduced into the coolant channel in a manner which is favorable for flow.

Very many of the evaporators of cooling devices that are common today, as is shown, for example, in German Utility Model No. 74 31 690, have a single-pipe connection, namely with evaporators in which the inlet and outlet pipes are partially nested. The embodiment of the invention according to claim 5 is concerned with evaporators which have a specially designed single-pipe connection, in which a suction pipe made of aluminum and a connecting pipe bent in its central region are provided made of copper and the intermediate pipe in Arch approximately in the extension of the intake pipe axis has a wall opening for the coolant supply line lying partly in the intermediate pipe, partly in the suction pipe and partly in a section of the coolant channel. It is provided according to the invention that the guide tube made of copper is inserted into the wall opening of the intermediate tube and is tightly welded or soldered to the intermediate tube wall.
It should be mentioned that in the case of evaporators, an intermediate tube made of copper, which is bent in an S-shape in its central region, is often welded or soldered to the straight intake manifold, with the wall opening in the intake manifold-side first bend and also approximately in the extension of the intake manifold axis.

The embodiment of the invention according to claim 6 provides that a section of the guide tube lying in the coolant channel is longer than a section of the capillary tube lying in the coolant channel. This in turn leads to the above-mentioned favorable design of the internal outflow conditions.

Finally, the embodiment according to claim 7 provides that the guide tube has a constriction as an inner stop for fixing the evaporator-side end of the throttle capillary tube. This can lie behind the opening of the intermediate pipe and thus within the area formed by the intermediate pipe, the suction pipe and the coolant channel, as seen in the inflow direction.

It is also expedient to expand the outer end of the guide tube, into which the throttle capillary tube is inserted during production, in a funnel shape. This also makes soldering easier.

Overall, the invention makes it possible to easily adapt to different design requirements of the cooling device manufacturers.

The invention is explained below using exemplary embodiments.

Fig. 1

einen Verdampfer eines Kühlgerätes mit einem Einrohranschluß,

Fig. 2

einen Einrohranschluß für einen Verdampfer

Fig. 3

einen weiteren Einrohranschluß für einen Verdampfer

Fig. 4

eine Ausgestaltung des Einrohranschlusses eines Verdampfers für ein Kühlgerät

Fig. 5

eine weitere Ausgestaltung eines Einrohranschlusses

In der gemäß Fig. 1 aus zwei aufeinander liegenden, bis auf die Kanalbereiche miteinander verbundenen Aluminiumblechen hergestellten Verdampferplatine 1 verläuft ein Kühlmittelkanal 2, zu dem ein Einlaßbereich 3 und ein Auslaßbereich 4 gehören. Ein Pfeil 5 deutet die Einströmrichtung, ein weiterer Pfeil 6 deutet die Ausströmrichtung an.It shows in a schematic and fully or partially cut representation:

Fig. 1

an evaporator of a cooling device with a single pipe connection,

Fig. 2

a single pipe connection for an evaporator

Fig. 3

another one-pipe connection for an evaporator

Fig. 4

an embodiment of the one-pipe connection of an evaporator for a cooling device

Fig. 5

a further embodiment of a single pipe connection

A coolant channel 2, to which an inlet area 3 and an outlet area 4 belong, runs in the evaporator board 1, which is produced according to FIG. An arrow 5 indicates the inflow direction, another arrow 6 indicates the outflow direction.

The inlet area of the coolant channel 2 is fed via a throttle capillary tube 7. This throttle capillary tube 7, which is regularly made of copper, is inserted in a guide tube 8, also made of copper, which is connected to an inlet tube 9 made of aluminum by Cu / Al soldering and is held indirectly by the evaporator plate 1 by the inlet tube 9. While evaporators of cooling devices are regularly shaped into a cooling compartment, FIG. 1 shows a flat evaporator, the coolant channel 2 of which is partially indicated by a broken line. The partly in the intermediate tube 11, the guide tube 8 penetrates the tube wall of the intermediate tube 11 in the S-shaped bend 14 and ends in the suction tube 10, which is held in the evaporator board via a soldered connection 16.

A solder joint 17 holds the throttle capillary tube 7 and a further solder joint 18 holds the further capillary tube 12 in the guide tube 8. The further capillary tube 12 is guided up to and beyond an inlet region 3 and outlet region 4 narrowing point 19 in the channel system. The constriction 19 forms the internal fixation of the coolant supply line, while the external fixation takes place in an opening 20 in the tube wall of the intermediate tube 11, into which the guide tube 8 is soldered.

A suction pipe 10 with a substantially larger inner diameter than the inlet pipe 9 serves for the coolant outlet.

2 and 3, so-called. Single-tube connections are shown, which - except for the insertion of the throttle-capillary tube 7 - are produced and installed in an evaporator board.

In these single-pipe connections, a soldered intermediate pipe made of copper connects to the suction pipe 10 made of aluminum. In the suction tube 10 and in the intermediate tube 11 there is another capillary tube 12, which in an approximately S-shaped curvature 14 of the intermediate tube 11 leads through the wall of the intermediate tube to the outside and is inserted into the end of the guide tube 8 on the evaporator side. The guide tube 8 is held on the intermediate tube 11 via an element 13.

The throttle capillary 7 is inserted into the other end of the guide tube 8 at a distance from the further capillary tube 12. The throttle capillary tube 7 and the further throttle capillary 12 are connected to the guide tube 8 by soldering. Suitable measures must be taken when soldering so that the capillaries are not accidentally closed by solder.

In the evaporator production, the intake manifold connections shown in FIGS. 2 and 3 are first produced, but still without the throttle capillary tube 7, and then attached to the evaporator board 1. The choke capillary tube 7 is only installed when the evaporator is otherwise finished.

The structural unit shown without throttle - capillary tube represents a standard intake manifold connection which can be used for many types of evaporator and in which the further capillary tube 12 has, for example, an inner diameter of 1.1 mm. This standard intake manifold connection is now supplemented with a wide variety of throttles - capillary tubes 7, which correspond only to the outer capillary tube 12, namely with throttle - capillary tubes 7 having a more or less small inner diameter and different lengths.

In Fig. 3, a capillary curl 15 is indicated and shown how particularly long capillary tubes 7 are spatially compressed. 3 shows that the coolant supply line here is composed of the large length section L1, the second length section L2, a short area in the guide tube 8 and the third length section of the further capillary tube 12.

The configurations shown in FIGS. 4 and 5 are of fundamentally simpler construction, in which the guide tube 8 itself is guided to the narrow point 19 and beyond it into the inlet area 3.

4, both the throttle capillary tube 7 and the guide tube 8 are partially in the inlet area 3 of the coolant channel 2, but the corresponding section of the throttle capillary tube 7 is shorter than the corresponding section of the guide tube 8. This difference forms the second length section here L2 of the coolant supply line.

5, the outer end of the guide tube 8 is expanded to form a funnel 21 and the guide tube 8 further has a constriction 22 as an inner stop for the throttle-capillary tube 7.

In Fig. 5 is provided on the evaporator-side end of the intermediate tube 11 thorning 23, into which the suction tube is inserted with a solder fit. A particularly reliable Cu / Al solder connection can be produced in this way.

Claims (9)

Evaporator for a compressor cooling device, the evaporator made from a two-layer evaporator board having a coolant channel running between the layers in a meandering manner, in the inlet area of which a small-diameter coolant supply line which acts as a throttle and which can be connected to the pressure side of the compressor in the coolant circuit, opens into its outlet area ends of a suction pipe of larger diameter, which can be connected to the suction side of the compressor, a length section of the coolant supply line lying within the outlet area and inside the suction pipe of the same, the wall of which breaks through the coolant supply line, the coolant supply line also continuing over a substantial part of its length as a throttle capillary tube is formed with a capillary flow cross-section, characterized in that

that an at least partially outside of the evaporator plate (1) partially in the suction tube (10), directly or indirectly held on the evaporator guide tube (8) slightly larger inside diameter than the outside diameter of the throttle capillary tube (7) and much smaller outside diameter than that of the inside diameter of the Suction pipe (10) is provided,

that the throttle capillary tube (7) is inserted from the outside into the guide tube (8) and the compressor-side end region of the inner jacket of the guide tube (8) within a first length section (L1) of the coolant supply line lying in the guide tube (8) with the assigned area of the Outer casing of the throttle capillary tube (7) is connected pressure-tight and ends in the guide tube (8),

that the guide tube (8) forms a second length section (L2) of the coolant supply line with a cross section which is enlarged compared to the capillary flow cross-section, and that the interior space of the guide tube (8) determined by the expanded second length section (L2) with the inlet region (3) of the coolant channel ( 2) is connected. Evaporator according to Claim 1, characterized in that the guide tube (8) with a soldering gap fit is plugged onto another capillary tube (12) on the evaporator side and is connected to the latter in a pressure-tight manner, the further capillary tube (12) connecting the interior of the second length section (L2) forms with the inlet region (3) and a third, longitudinal section (L3) of the coolant supply line on the evaporator side. Evaporator according to Claim 2, in which a throttle capillary is guided pressure-tight through the wall of the suction tube to the inlet area of the coolant channel, characterized in that the throttle capillary forms the further capillary tube (12) which is close to its wall opening (20) in the guide tube (20) fastened to the evaporator ( 8) ends, in the other side of which the throttle capillary tube (7) is inserted. Evaporator according to claim 1, characterized in that the guide tube (8) opens into the coolant channel (2) in the inlet area (3) of the coolant channel (2). Evaporator according to claim 4, with a single-pipe connection, in which an intake pipe made of aluminum and a connecting pipe connected to the suction pipe in its central region are provided intermediate pipe and the intermediate pipe in the arc and approximately in extension of the suction pipe axis, a wall opening for the partly in the intermediate pipe, partly Has coolant supply line located in the intake manifold and partially in a section of the coolant duct, characterized in that the guide tube (8) is made of copper, is inserted into the wall opening (14) of the intermediate tube (11) and is tightly welded or soldered to the intermediate tube wall. Evaporator according to one of claims 4 and 5, characterized in that a section of the guide tube (8) lying in the coolant channel (2) is longer than a section of the capillary tube (7) lying in the coolant channel (2). Evaporator according to one of claims 1 to 6, characterized in that the guide tube (8) has a constriction (22) as a stop for the evaporator-side end of the throttle capillary tube (7). Evaporator according to claim 7, in connection with an evaporator according to one of claims 4 to 6, characterized in that the constriction (22) seen in the inflow direction behind the opening (14) of the intermediate tube (11) and thus within the through the intermediate tube (11 ), the suction pipe (10) and the Inlet area (3) of the coolant channel (2) formed area. Evaporator according to one of claims 1 to 8, characterized in that the outer end of the guide tube (8) is expanded to form a funnel (21).

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