EP0758732B1 - Refrigerator - Google Patents

Description

The invention relates to a refrigerator with a normal cold room, preferably with a normal cold room and a freezer compartment, whose evaporator consists of two evaporator sections connected in series with pipe sections carrying the refrigerant, of which the section in which the with a control device provided compressor that introduces refrigerant, the freezer compartment assigned.

For standard cooling units with a normal cold room and a 3-star freezer compartment are the coherent evaporator system and the insulation of the device designed so that at normal freezing temperatures (+16 ° C to +32 ° C) at certain positions of the temperature in the normal cold room regulating thermostats at least -18 ° C, while the normal cold room according to the position of the thermostat Temperatures between 0 ° C and +5 ° C. For example 25 ° C ambient temperature and a temperature of 5 ° C of the normal cold room, this means a temperature difference from the ambient temperature to the normal cold room of 20 K and to 3-star freezer compartment of 43 K. Based on these values, the Strength of insulation around the 3-star freezer compartment of the refrigerator as a rule, thicker than around the normal cold room.

Problems with maintaining the minimum temperature of -18 ° C in Freezer compartment arise at lower ambient temperatures because for example at 10 ° C ambient temperature the difference of Ambient temperature to the temperature of the normal cold room at 5 ° C is only 5 K and 28 K to the freezer.

The usual control of a refrigerator with freezer takes place by a thermostat, the temperature sensor of which is in the normal cold room and preferably located on the evaporator plate. The Switch-on values of this thermostat are designed so that the Evaporator section for the normal cold room in every switch-off phase defrosting the compressor. To do this, the temperature on the surface the evaporator of the normal cold room at least above 0 ° C increase. Switch-on values of the thermostat at 3 ° C are common up to 5 ° C. This means that in the case where the switch-on value of the thermostat is, for example, 5 ° C, at one The ambient temperature drops below 5 ° C at all no longer switches on, so that the temperature inevitably increases in the freezer. The goods in the freezer compartment can then heat until thawing so that the cooling device is no longer is fully functional. Even at ambient temperatures above 5 ° C to about 9 ° C there are still significant problems, the required Observe the minimum temperature in the freezer compartment because of the relative Duty cycle of the compressor is too short for to provide the evaporator compartment with the required cooling capacity.

To ensure that the minimum temperature in the freezer is maintained even when the ambient temperature it drops below the normal temperature, i.e. below 16 ° C known, the relative duty cycle of the compressor to the minimum to coordinate the required cooling capacity of the freezer compartment. In cooling devices that are highly insulated for the purpose of saving energy the cooling requirement for the refrigerator compartment is very small. Because the cold room evaporator connected in series with the freezer evaporator is, the cold room evaporator also receives due to the on Cold requirement of the freezer compartment coordinated relative duty cycle the compressor has a relatively large amount of refrigerant. In order not to overcool the normal cold room, the cold room evaporator is made very small. The cold room evaporator forms in addition to its function as a heat exchanger Dehumidification plate, on which the condensate is deposited, so that the condensed water is targeted from the cold room evaporator drain in gutters and over them, for example for evaporation to the compressor can.

At high ambient temperatures and / or high humidity and / or high door opening frequency can be caused by the small Cooling space evaporator formed dehumidification area become too small, so that there is condensation on other parts of the Cold room can come, preferably on the cooling compartment ceiling, which is due to the neighboring freezer compartment on a lower one are below the dew point temperature can, and on the glass plates. Condensate forms on others Place as on the cold room evaporator plate, the condensed out Water is not deliberately drained, but drips undesirably also on the refrigerated goods.

The problem of unwanted condensation in other places than on the cold room evaporator plate is not just about Refrigerators with a normal cold room and a freezer compartment, but also for refrigerators that do not have a freezer compartment.

The object of the invention is therefore a refrigerator of the beginning to create specified type, in which one leads to a dripping Condensation on parts of the refrigerator other than that Cold room evaporator is prevented.

According to the invention, this object is achieved at the beginning with a cooling device specified type solved in that the normal cold room assigned evaporator or evaporator section from a plate consists of a good heat-conducting material, the size of which is used for Dehumidification required area is designed, and that the plate thus connected to the pipe section carrying the refrigerant is that the temperature distribution is essentially the same the cooling capacity required for the normal cold room becomes.

Is the cooling capacity of the normal cold room through a small fed cooled area, there is the disadvantage that the Cooling capacity per surface is too large. Such a small chilled one Area with high cooling capacity leads to dehumidification essentially only in the vicinity of the cooling surface, so that the moisture in the areas of the normal cold room enriches that of the area supplying the cooling capacity are further away. The supply of cooling power through a Small area also has the disadvantage that it is too freezing of this surface can occur, which reduces the cooling capacity sinks.

In the cooling device according to the invention, the cooling capacity per Reduced area of the evaporator plate, so that it the required Cooling capacity with a reduced surface temperature supplies. According to the invention that is the normal cold room assigned evaporator plate designed so large that it forms a sufficiently large dehumidification area, and secondly kept at such a temperature that it needed the Cooling power supplies.

The pipe section carrying the refrigerant can be used with the cooling space evaporator plate only over part of its length and / or over Heat poorer conductive material, such that the normal cold room despite the enlarged plate due to thermal Decoupling only the required cooling capacity is supplied.

According to a preferred embodiment of the invention, that the connected to the evaporator plate of the normal cold room or running in this plate and leading the refrigerant Pipe section corresponding to the heat output to be transferred Has length. The pipe section can be clamped or conventional connections directly to the evaporator plate connected or integrated into the plate as is the case with roll or Z-bond evaporator boards is.

According to a preferred embodiment of the invention, that the refrigerant pipe section at least is connected to the plate over part of its length, or runs in this and that the plate with recesses or window-like Breakthroughs is provided. Through these recesses can be the total area that the evaporator plate its outline after occupies, enlarge it further so that the flat Area over which the cooling capacity is supplied, still further is enlarged.

The plate is expediently provided with rows of cutouts, the pipe sections carrying the refrigerant between run in rows.

The pipe sections carrying the refrigerant expediently run, apart from the marginal rows, only between every other row of recesses. This way, in each section of the evaporator plate, which has the rows of recesses is provided, the cold is introduced only from one side, so that there is a particularly good, even temperature distribution comes over the plate.

Condensed moisture condenses on parts of which Temperature is below the dew point temperature. During the The compressor's switch-off times increase the temperature of the evaporator plate of the refrigerator to above 0 ° C, which means defrosting the evaporator plate and the pipe section laid on it or the cold room walls behind which the evaporator is foamed is required. It is therefore possible that temporarily for example during the compressor shutdown times the cooling compartment ceiling has a temperature below that of Evaporator plate and is below the dew point temperature. Yet may change during times when the temperature may the cooling compartment ceiling temporarily below that of the evaporator plate not so much moisture condenses on the cooling compartment ceiling, that it can drip. In another Embodiment of the invention is therefore provided that the thermal Coupling of the pipe section assigned to the normal cold room selected on the evaporator plate of the normal cold room is that their temperature is substantially below the dew point temperature lies. The size of the evaporator plate and their thermal coupling to the refrigerant Pipe section expediently chosen so that on the Condensate that temporarily forms the cooling compartment ceiling evaporates again and then settles on the evaporator plate of the normal cold room, if their temperature after restarting the compressor again below the dew point temperature and the temperature the cooling compartment ceiling is located.

According to the invention, the one that is assigned to the normal cold room Evaporator plate designed so large that it is sufficient forms large dehumidification area, and so thermally to the the refrigerant pipe section coupled or at complete heat-conducting connection with the evaporator plate only run so long that the surface temperature of the evaporator plate is just below the dew point. So that leaves a significantly larger surface area in the normal cold room, arrange an evaporator plate forming a heat exchanger or due to a much larger wall area of the normal cold room, if the evaporator is foamed in behind the cold room wall, supply the cooling capacity without the cooling capacity for the Normal cold room becomes too large and the cold room temperature as a result sinks too far.

Is the breakthrough evaporator plate behind one Foamed cold room wall, the wall surface can be the cooling capacity is supplied to the normal cooling room, clearly enlarge. The recesses themselves are made by the existing plastic wall of the normal cold room closed so that the temperature during the switch-on phases the compressor from the edges of the recesses to their middle Areas gradually decreases, so that the recessed Areas still participate in the transmission of the cooling capacity.

The arrangement of the recesses in the evaporator plate enables once the direct connection of the refrigerant leading Pipe section with this or the integration of this Section in this, so the reproducibility of the transfer the cooling capacity on the evaporator plate is cheaper than with a point-only coupling or a coupling only over short distances or insulating materials to the evaporator plate. By arranging the recesses in the evaporator plate this can be done over a larger area stretch the inside of the normal cold room.

The type of thermal coupling of the pipe section to the evaporator plate or the length of that connected to the evaporator plate Leave the pipe section and the size of the evaporator plate calculate for the different types of cooling units or also determine empirically. In any case, the surface of the evaporator plate of the normal cold room so large that they its function as a dehumidifying plate, the thermal coupling of the dehumidification and evaporator plate the pipe section carrying the refrigerant or its length to make and choose that the cooling capacity is not too gets high and still during the start-up phases of the compressor the dew point temperature is fallen below.

The liquefied refrigerant is sent to the evaporator via a capillary tube fed, which forms a throttle body. Because that liquefied Refrigerant has a relatively high temperature which leads the liquefied refrigerant to the capillary tube Line in the suction line through which the compressor evaporated refrigerant is sucked out of the evaporator. This will the liquefied refrigerant is cooled because the one in the intake manifold Refrigerant vapor is still on a proportionate basis low temperature. Nevertheless, this is in the capillary tube relaxed refrigerant before this still on a higher Temperature so that the residual heat of the refrigerant is dissipated must become what worsens the energy balance.

To the residual heat of the liquefied refrigerant in a favorable way exploit is, according to a preferred embodiment Invention, for which independent protection is claimed, provided that a section of the liquefied refrigerant to the Capillary tube leading line in a thermally conductive connection with the normal cold room evaporator plate. This configuration leads to the fact that a part of the liquefied refrigerant the residual heat is removed, which has energetic advantages and leads to an improvement in efficiency, and that the cold room evaporator plate Heat is supplied so that its cooling capacity is reduced in a desirable manner. This feed of heat to the cold room evaporator plate is not only in the Vaporizer plate according to the invention expedient, which only with reduced Heat conduction to the pipe section carrying the refrigerant is coupled, but also with conventional cooling devices with 3-star subject. Because with cooling devices it is known at ambient temperatures below normal ambient temperatures a heating device in the normal cold room or behind the wall to arrange the normal cold room, the heat the normal cold room feeds if due to the too small temperature difference between the temperature of the normal cold room and the ambient temperature a temperature that ensures the target temperature in the freezer compartment, relative duty cycle of the compressor is no longer reached becomes. The supply of heat to the cold room evaporator a section of the conduit carrying the liquefied refrigerant can therefore be an additional heating device in the normal cold room make redundant.

For cooling units with a normal cold room and a freezer compartment, whose evaporator consists of two evaporator sections connected in series exist, the transition area of the evaporator is between the deep-freeze evaporator section and the normal cold room evaporator section, located in the area of the normal cold room, critical because this transition area is on a deeper level Temperature as the main area of the freezer evaporator is located, so that this transition part in an undesirable manner tends to freeze. To freeze this critical Avoid the transitional area of the evaporator a further preferred embodiment of the invention, for the independent protection is claimed, provided that a Section of the liquefied refrigerant leading to the capillary Pipe in the transition area between the two evaporator sections is installed in or near the normal cold room. This liquefied refrigerant is expediently located leading line section in thermally conductive connection with the Transition area, so that it is ensured that this critical Transition area during compressor downtimes defrosts.

Fig. 1

eine perspektivische Ansicht eines Kühlgeräts, teilweise im Schnitt, der mit der erfindungsgemäß vergrößerten Entfeuchtungsverdampferplatte versehen ist,

Fig. 2

eine Draufsicht auf eine hinter der Rückwand des Normalkühlraums eingeschäumte und mit Aussparungen versehene Verdampferplatte,

Fig. 3

eine Rückansicht eines üblichen Kühlgeräts mit einem Normalkühlraum und einem Tiefkühlfach und

Fig. 4

einen Schnitt durch das Kühlgerät längs der Linie II-II in Fig. 3.

An embodiment of the invention is explained below with reference to the drawing. In this shows

Fig. 1

2 shows a perspective view of a cooling device, partly in section, which is provided with the dehumidification evaporator plate enlarged according to the invention,

Fig. 2

a plan view of an evaporator plate which is foamed in behind the rear wall of the normal cooling space and provided with cutouts,

Fig. 3

a rear view of a conventional refrigerator with a normal cold room and a freezer and

Fig. 4

a section through the cooling device along the line II-II in Fig. 3rd

The cooling device shown schematically with reference to FIGS. 3 and 4 Conventional type consists of a housing 1 with an outer shell and Inner shell, with the space between the shells to Thermal insulation is foamed with a polyurethane foam. The U-shaped curved evaporator section assigned to the freezer compartment 2 3 is arranged behind the shell of the freezer compartment and foamed. Also the evaporator section assigned to the normal cooling space 4 5 is behind the inner normal cold room shell foamed. Both evaporator sections 3, 5 are made of one common roll or Z-bond evaporator board bent out and connected to each other by a narrow board strip 6, in which the lines are arranged through which the two Evaporator sections are connected in series with each other.

The condenser is in the usual way behind the rear wall of the refrigerator 7 arranged and in a niche of the refrigerator housing The compressor 8 is located on the cold room evaporator section a thermostat 9 is arranged, which the starting frequency controls the compressor.

In the known cooling device shown in FIGS. 3 and 4 there is only a very small dehumidification area provided formed by the area of the rear wall of the normal cold room behind which the normal cold room evaporator section is located. As a result, a cooling device of this type can at high ambient temperatures and / or high humidity and / or high door opening frequency condensate on the cooling compartment ceiling below of the freezer or on glass plates so that Can drain water.

From Fig. 3 a refrigerator can be seen, in which a corresponding the small cooling requirement of the normal cold room in size reduced evaporator plate 10 arranged in the normal cold room whose lower edge is indicated by the dashed line 11 is. Although hanging freely in the normal cold room arranged evaporator plate the front and the Back are effective as dehumidifying surfaces, the entire range is sufficient Size of the dehumidification area due to the reduced normal cold room evaporator not out to the normal cold room completely to dehumidify and condensation, for example to prevent the normal cold room ceiling.

To ensure adequate dehumidification of the Ensuring the normal cold room is the normal cold room evaporator plate 10 around the dashed-line evaporator plate 12 enlarged, which is shown in dashed lines Bottom edge of the evaporator plate 10 connects in one piece. Around the cooling capacity through this type of enlargement of the evaporator plate not increase inadmissible for the normal cold room, is the evaporator plate 10, 12 only on the by Crosses 13 marked points connected to the evaporator plate.

The only point or section connection of the refrigerant leading coil 14 with the dehumidifying evaporator plate 10, 12 can in the usual way by spot welding, crimping, Glue or clamp connections.

Under the dehumidifier plate 10, 12 are more common Wise gutters for collecting and draining the dripping water intended.

From Fig. 4 is a schematic plan view of a behind the Evaporator plate 15 foamed into the rear wall of a normal cooling space seen. This consists of a so-called roll or Z-bond evaporator board, in the roughly rectangular course the pipe section 16 carrying the refrigerant is arranged. The board is with four rows of side by side rectangular recesses 17 provided. The horizontal run Branches of pipe sections 16 in the manner between the Rows of recesses 17 that each row has the cooling capacity only from one horizontal branch of the tube section 16 is fed. The influence of the vertical branches of the pipe section is neglected here. This could go through this bordering lateral, gap-shaped recesses diminished become. To ensure that each row of recesses 17 their cooling capacities essentially only from a horizontal one Branch of the pipe section, they run at a board with four rows of recesses between the first and second and between third and fourth rows, so that they are spaced from the top and bottom from a and from each other have a distance of aa.

Claims (10)

1. Refrigerator comprising a normal cooling space and a deep-freeze section, whose evaporator consists of two series-connected evaporator portions with tube portions carrying the refrigerant, of which the portion into which the compressor provided with a control means introduces the refrigerant is associated to the deep-freeze section,
   characterized in that the evaporator or evaporator portion associated to the normal cooling space consists of a plate made of a material with good thermal conductivity, the size of which plate being adapted to the area required for dehumidification, and
   that the plate is connected with the tube portion carrying the refrigerant such that the refrigerating capacity required for the normal cooling space is supplied to said plate with substantially the same temperature distribution.
2. The refrigerator as claimed in claim 1, characterized in that the tube portion carrying the refrigerant is connected with the cooling space evaporator plate only via part of its length and/or via material having a poorer thermal conductivity such that despite the enlarged plate only the required refrigerating capacity is supplied to the normal cooling space due to thermal uncoupling.
3. The refrigerator as claimed in claim 1, characterized in that the tube portion connected with the cooling space evaporator plate or extending in said plate has a length corresponding to the refrigerating capacity to be transmitted.
4. The refrigerator as claimed in claim 1, characterized in that the tube portion carrying the refrigerant is connected with the cooling space evaporator plate at least via part of its length or extends inside the same, and that the plate is provided with recesses or window-like openings.
5. The refrigerator as claimed in claim 3 or 4, characterized in that the cooling space evaporator plate is provided with rows of recesses and parts of the tube portion connected with the same extend between the rows.
6. The refrigerator as claimed in claim 5, characterized in that apart from the marginal rows parts of the tube portions only extend between every second row.
7. The refrigerator as claimed in any of claims 1 to 6, characterized in that the evaporator plate is embedded in foam behind at least one wall of the normal cooling space, preferably behind the rear wall.
8. The refrigerator as claimed in any of claims 1 to 7, characterized in that the thermal coupling of the tube portion associated to the normal cooling space to the normal cooling space evaporator plate or the length thereof connected with the same is chosen such that the temperature of the normal cooling space evaporator plate or the temperature of the normal cooling space wall, behind which the evaporator plate is embedded in foam, substantially lies below the dew point temperature.
9. The refrigerator as claimed in any of the preceding claims, characterized in that a portion of the line delivering liquefied refrigerant to the capillary tube is in heat-conducting connection with the normal cooling space evaporator plate.
10. The refrigerator as claimed in any of the preceding claims, characterized in that a portion of the line delivering liquefied refrigerant to the capillary tube is disposed in the transition region between the two evaporator portions in or close to the cooling space and is in heat-conducting connection with this transition region.

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