阅读说明：本技术 具有蒸发盘的制冷器具 (Refrigeration device having an evaporation pan ) 是由 张明 A·福格尔 A·莫尔纳 于 2019-01-30 设计创作，主要内容包括：本发明涉及一种制冷器具,具有壳体(1,2)和蒸发盘(12),所述壳体包围存放腔(3)和冷却所述存放腔(3)的蒸发器(8)并且包括使所述存放腔(3)和所述蒸发器(8)相对于周围环境隔离的隔热层(6),所述蒸发盘布置在所述存放腔(3)外部,以便接收从所述蒸发器(8)流出的冷凝水,在所述制冷器具中,至少一个加热板(17)与所述蒸发盘(12)由气隙(23)间隔开地在所述蒸发盘(12)的基面的至少一半上延伸。(The invention relates to a refrigerator having a housing (1, 2) which encloses a storage chamber (3) and an evaporator (8) which cools the storage chamber (3) and which comprises a heat-insulating layer (6) which insulates the storage chamber (3) and the evaporator (8) from the surroundings, and having an evaporation pan (12) which is arranged outside the storage chamber (3) in order to receive condensation water flowing out of the evaporator (8), wherein at least one heating plate (17) extends over at least half of the base area of the evaporation pan (12) at a distance from the evaporation pan (12) by an air gap (23).)

1. A refrigerator having a housing (1, 2) which encloses a storage chamber (3) and an evaporator (8) which cools the storage chamber (3) and which comprises a thermally insulating layer (6) which insulates the storage chamber (3) and the evaporator (8) from the surroundings and an evaporation tray (12) which is arranged outside the storage chamber (3) in order to collect condensation water flowing out of the evaporator (8),

it is characterized in that the preparation method is characterized in that,

at least one heating plate (17) extends over at least half of the base surface of the evaporation pan (12) in such a way that it is spaced apart from the evaporation pan (12) by an air gap.

2. The refrigeration appliance according to claim 1,

it is characterized in that the preparation method is characterized in that,

the heating plate (17) is heated by a heating coil (15).

3. The refrigeration appliance according to claim 2,

it is characterized in that the preparation method is characterized in that,

the heating coil (15) is a hot gas line (16) through which a compressed refrigerant flows.

4. The refrigeration appliance according to claim 2,

it is characterized in that the preparation method is characterized in that,

the heating coil (15) comprises a heating resistor.

5. The refrigeration appliance according to any one of claims 2 to 4,

it is characterized in that the preparation method is characterized in that,

the heating coil (15) has an operating temperature between 320K and 350K.

6. The refrigeration appliance according to any one of claims 2 to 5,

it is characterized in that the preparation method is characterized in that,

the heating coil (15) extends in a horizontal plane.

7. The refrigeration appliance according to any one of claims 2 to 6,

it is characterized in that the preparation method is characterized in that,

the heating plate (17) extends in a plane which is inclined at an angle of at most 30 DEG to the horizontal.

8. The refrigeration appliance according to any one of claims 2 to 7,

it is characterized in that the preparation method is characterized in that,

the heating plate (17) is arranged in physical contact with the heating coil (15).

9. The refrigeration appliance according to any one of claims 2 to 8,

it is characterized in that the preparation method is characterized in that,

the heating coil (15) extends in an intermediate space (23, 24) between the heating plate (17) and the evaporation pan (12).

10. The refrigeration appliance according to any one of claims 2 to 8,

it is characterized in that the preparation method is characterized in that,

the heating plate extends between the evaporation pan (12) and the heating coil (15).

11. The refrigeration appliance according to any one of claims 2 to 8 or 10,

it is characterized in that the preparation method is characterized in that,

the upper side of the heating plate (17) is in contact with the heat insulation layer.

Technical Field

The invention relates to a refrigerator, in particular a domestic refrigerator, having an evaporation pan for evaporating condensate which accumulates on the evaporator thereof during operation of the refrigerator.

Background

In order to prevent the evaporation pan from overflowing, the evaporation pan must be able to evaporate the condensate evenly at least as quickly as it is replenished from the evaporator. A heat source is required for this. It has long been known to use a compressor, which is usually present in refrigeration appliances, as a heat source by mounting an evaporation pan on the compressor.

Efforts by manufacturers to increase the energy efficiency of refrigeration appliances have resulted in significant improvements in their insulation performance. Thereby, not only the energy consumption of the compressor is reduced, but also its heating power available to the evaporating pan, while the amount of condensed water to be evaporated remains the same. Improvements in compressor efficiency also contribute to a reduction in heating power, which can contribute to evaporation.

Thus, proposals such as from DE 10228739 a1 or US 5881566A that optimize the heat transfer from the compressor to the evaporation pan by optimization of the contact between the two do not solve this problem for a long time.

A sustainable solution is known from WO 2009/152862 a1, which makes available the heat of the refrigerant heated by adiabatic compression in the compressor for the heating of the evaporation pan in that a pipe, in which the compressed refrigerant circulates, sinks from above into the evaporation pan and thus gives off the heat of the refrigerant directly to the condensed water located in the evaporation pan.

However, this approach has two fundamental disadvantages. On the one hand, increased demands are made on the choice of the material of the tube, since said material cannot corrode when it comes into contact with the water of the evaporation pan, and the two different metals are not allowed to come into contact with the water of the evaporation pan in such a way that a galvanic cell is formed. On the other hand, the pipe effectively emits heat only when it comes into contact with water. In order to be able to heat the water effectively also in the case of low water levels, the pipes must therefore be sunk as far as possible into the evaporation pan. However, in case the water level is high, this results in that the supplied heat is dispersed over the entire contents of the evaporation pan. However, only the temperature of the water surface is decisive for the rate of evaporation. Thus, the higher the water level in the evaporation pan, the more heating power is required in order to bring it to a given value.

Disclosure of Invention

The object of the invention is to provide a refrigerator having an evaporation pan which ensures a high evaporation rate with a low energy input, irrespective of the quality of the heat insulation surrounding the storage chamber of the refrigerator and irrespective of the efficiency of the compressor driving the refrigerant circuit.

This task is solved in such a way that: the refrigeration device has a housing which surrounds a storage chamber and an evaporator which cools the storage chamber and comprises a heat insulation layer which insulates the storage chamber and the evaporator from the surroundings, and has an evaporation pan which is arranged outside the storage chamber in order to collect condensation water flowing out of the evaporator, wherein at least one heating plate is provided which extends over at least half of the base area of the evaporation pan at a distance from the evaporation pan by an air gap.

The heat radiation emitted from the heating plate reaches the evaporation pan from above and is absorbed by the thin surface layer of water. Since the heating plate covers a large part of the evaporation pan, the radiation heats a corresponding large part of the water surface in the evaporation pan and promotes evaporation there. Since the heat radiation is supplied to the water from above, the water surface is heated more strongly than in the deeper regions, so that a stable temperature stratification occurs in the water of the evaporation pan, without such convection occurring: the heat is also dissipated in the region of the water remote from the surface by said convection. Thus, it is sufficient to deliver significantly less energy to achieve the same magnitude of evaporation rate than is conventionally the case from below. Since the heating plate does not come into contact with the water of the evaporation pan under normal operating conditions, there is no such increased risk of corrosion: this risk of corrosion may be taken into account when selecting the material of the heating plate.

For heating the heating plate, a heating coil (Heizschlange) may be provided. In order to achieve an energy-efficient refrigeration device, the heating coil can be formed by a hot gas line through which a compressed refrigerant flows. It is possible that a heating coil in which the heating resistor extends would be more cost effective. Since the contact of the heating coil with the water is neither necessary nor desirable, no costly measures are required for electrically insulating the heating coil from the water.

The preferred operating temperature of the heating coil is in the range between 320K and 350K. This operating temperature provides thermal radiation with an intensity maximum at a wavelength of 7mm to 8mm, according to the Wienschen displacement law (Wienschen Verschiebungsgesetz). The average penetration depth of these wavelengths in water is about 10^-4m, that is to say, in a layer of water having a thickness of less than 1mm, is sufficient to absorb this radiation almost completely. Since the thermal effect of the radiation is thus concentrated directly on the surface of the water in the evaporation pan, a small amount of energy is sufficient to significantly increase the surface temperature of the water and thus its evaporation rate.

In order to heat the water surface uniformly, the heating coils and/or the heating plates should each extend in a horizontal plane, i.e. at the same distance from the water surface.

In the case of a heating plate, a slight inclination is expedient in order to make it easier for warm, moisture-saturated air to flow out of the air gap above the evaporation pan. Such an inclination angle with respect to the horizontal should not exceed 30 deg..

According to a preferred embodiment of the invention, the heating plate is arranged in physical contact with the heating coil (in)Kontakt) to be heated by direct heat transfer from the heating coil to the heating plate.

If the heating coil and the heating plate are in contact with each other, it may be desirable that the heating coil be inclined in the same manner as the heating plate.

The heating coil may extend in the intermediate space between the heating plate and the evaporation pan. Thus, in the above-mentioned case of direct physical contact, heat can radiate not only directly from the heating coil down onto the horizontal plane, but also up to the heating plate and from there onto the horizontal plane.

Even if there is no contact between the heating plate and the evaporation pan, the heating plate can divert the heat radiation emitted upwards from the heating coil downwards towards the water of the evaporation pan, either in such a way that it heats up by absorbing the radiation of the heating coil and thus emits heat radiation corresponding to its temperature, or in such a way that it reflects the heat radiation of the heating coil. The second alternative is more efficient because the heated heating plate also dissipates heat to the surrounding air. Therefore, the reflectivity of the heating plate for the thermal radiation of the heating coil should preferably be at least 90%.

Alternatively, the heating plate may also extend between the evaporation pan and the heating coil. Such heating plates do not reflect the radiation of the heating coil to the evaporation pan, but heat it only by absorbing the radiation and subsequently emitting thermal radiation.

In contrast, if the heating plate is heated by physical contact with the heating coil, a high reflectivity of the emission of thermal radiation is detrimental. Thus, in this case, at least the underside of the heating plate should have a high IR absorption of preferably at least 90%.

In order to minimize heat losses due to heat flow from the heating plate to the surrounding air, the upper side of the heating plate may be in contact with an insulating layer.

By mounting the heating coils in the channels of the insulation, heat loss from the heating coils can be minimized in ways other than through the heating plate.

To form such a channel, insulation may be molded onto the heating coil and the heating plate. This can occur before the heating coil and heating plate are installed in the refrigeration appliance; thus, the insulation layer, the heating plate and the heating coil can be connected as an assembly which is subsequently installed as a unit in the refrigeration appliance.

Alternatively, the heating plate is in contact with such a thermally insulating layer: the insulating layer can be a one-piece component of an insulating layer surrounding a storage chamber of the refrigeration device. In particular, the insulating layer can form a top cover of the machine compartment of the housing when the evaporation pan is mounted in the machine compartment in a known manner.

The evaporation pan may be mounted on the compressor to also utilize the waste heat of the compressor to promote evaporation.

Drawings

Further features and advantages of the invention emerge from the following description of an embodiment with reference to the accompanying drawing. The drawing shows that:

fig. 1 shows a schematic cross section through a domestic refrigeration appliance according to a first configuration of the invention;

fig. 2 shows a section through a heating coil and a heating plate arranged above it according to a variant of the first configuration;

fig. 3 shows a section through a machine compartment of a refrigeration appliance according to a second configuration; and

fig. 4 shows a section similar to fig. 3 according to an embodiment of the second configuration.

Detailed Description

Fig. 1 shows a cross section through a refrigerator as an example of a domestic refrigeration appliance, to which the invention may be applied. The cabinet of the refrigerator comprises a body 1 and a door 2, said body 1 and door 2 enclosing a storage cavity 3 and comprising in a usual way: a rigid housing 4; an inner container 5 formed by deep drawing of plastic, wherein the inner container 5 and the outer shell 4 are combined into a hollow body; an insulating layer 6 filled in the hollow body and made of foam material. The housing 4 of the body 1 comprises a plurality of plate-like elements which are interconnected one above the other, including those which delimit a machine room 7 adjacent to the bottom at the back side of the body 1.

Above the machine chamber 7, an evaporator 8 is arranged which cools the storage chamber 3. Fig. 1 shows an exemplary cold wall evaporator (Coldwall-Verdampfer), however any other evaporator design is also conceivable. Below the surface on which the condensate condenses during operation, here the rear wall 9 of the inner container 5, there is provided a trough 10 in the inner container 5, which trough 10 collects the condensate flowing down from this surface and feeds it via a channel 11 intersecting the insulating layer 6 to an evaporation pan 12 in the machine room 7.

The evaporator 8 is connected in a refrigerant circuit with a compressor 13 and with a liquefier 14. A compressor 13 is installed in the machine room 7. The evaporation pan 12 is mounted on a compressor 13 in order to absorb the heat released by this compressor 13 when it is operating and thus to heat the condensed water collected in the evaporation pan 12.

Above the level of the evaporation pan 12, heating coils 15 are mounted in a spaced manner by an air gap 23. The heating coil 15 comprises a metal tube extending meanderingly in a horizontal plane, which is heated by a heating resistor extending therein or, as part of a refrigerant circuit, by a compressed refrigerant circulating therein. Depending on the required power, the heating coil 15 through which the refrigerant flows can be inserted in the refrigerant circuit between the compressor 13 and the liquefier 14, between the two parts of the liquefier 14, or between the liquefier 14 and the throttle point. The position of the heating coil 15 in the refrigerant circuit is selected in each case such that the surface temperature of the line converges to a value between 320K and 350K when the compressor 13 is in operation. If the heating coil 15 is electrically heated, the surface temperature can be lower, since there is also heat available during the time when the compressor 13 is not running.

In order for the heating coil 15 to efficiently emit heat from the interior of the pipe as radiant heat, the surface of the pipe should be strongly absorbing for the heat radiation. Since metals reflect thermal radiation well, the lines are provided for this purpose with an absorbing coating.

The heating coil 15 has a channel that emits thermal radiation uniformly in all directions. In order that the upwardly emitted radiation can also reach the water in the evaporation pan 12, a metal surface 16 is then arranged above the heating coil 15, spaced apart from the heating coil 15 by a second air gap 24, said metal surface 16 acting as a heating plate 17 in such a way that the metal surface 16 reflects the radiation of the heating coil 15 downwards. Such a surface 16 covers at least half, preferably the entire base surface of the evaporation pan 12 and projects beyond the edge thereof.

In the configuration of fig. 1, the heating plate 17 is mounted on the top cover of the machine room 7 without being in direct contact with the heating coil 15; the heating plate 17 can be formed, for example, from a metal foil (in particular an aluminum foil) by means of which the elements of the housing 4 forming the cover are covered over a large area. The dimensions of the foil are preferably larger than those of the evaporation pan 12, for example, the top cover of the machine room 7 can be completely covered by means of the foil, so that it is ensured that: although the foil and the evaporation pan 12 are inserted at different times, the evaporation pan 12 is still covered by the foil over its entire base surface without any gaps.

In the simplest case, the housing element and the heating plate 17 fixed thereto are substantially flat. The heat radiation emitted steeply upwards is then reflected by the heating plate 17 into the evaporation pan 12 and is absorbed by the water when it reaches the water there. However, the heat radiation reflected by the heating plate 17 at an angle strongly deviating from the vertical does not reach the water in the evaporation pan 12 in most cases and is lost unutilized. To avoid this, the heating plate 17 can (as shown in fig. 2) have an uneven underside provided with grooves 18, which grooves 18 follow the course of the heating coil 15 and cause the upwardly directed radiation of the heating coil 15 to be focused downward when reflected.

In the variant shown in fig. 2 as well as in the configuration of fig. 1, heat is released from the heating coil 15 to the air surrounding the heating coil 15, which causes the heated air to rise through the gaps between the pipe sections of the heating coil 15 running side by side to the plate 16 and causes a supplementary inflow of cooler air from below, which cools the heating coil 15 further.

Fig. 3 shows a schematic cross section through the machine compartment 7 of a refrigeration device according to a second embodiment of the invention, in which this heat flow is limited to a significant extent by the second plate 19, the gaps between the line sections of the heating coil 15 being sealed. In order to prevent air flow, it is not necessary for the plate 19 to have a large wall thickness, such a foil is sufficient: the position of the foil is only defined by the fixation of the foil to the heating coil 15. Preferably, however, the plate 19 is made of a material which conducts heat well, said plate 19 being sufficiently strong to be dimensionally stable, and the heating coil 15 being welded, glued or otherwise suitably fixed to said plate 19. Due to the large wall thickness, the heat that is transferred to the plate 19 by contact with the heating coil 15 can be evenly distributed over the plate 19. The plate 19 thus functions as a heating plate 17 in so far as the water in the evaporation pan 12 extending below the plate 19 is heated by the downwardly emitted thermal radiation of this plate 19.

The thermal radiation emitted upwards from the plate 19 reaches here on the plate 16 and is reflected by the plate 16 back to the plate 19. Thus, the heat can be substantially only given off downwards and mostly absorbed by the water of the evaporation pan 12.

The plate 19 is slightly inclined with respect to the horizontal in order to divert the hot and humid air rising from the evaporation pan 12 out of the air gap 23. The upper edge of the plate 19 faces the rear side of the body 1 in order to direct the diverted air out of the machine chamber 7.

Fig. 4 shows an expansion of the configuration of fig. 3 in a section similar to fig. 3. In order to minimize the heat loss caused by convection upwards from the heating coil 15, the heating coil 15 is here arranged in a downwardly open channel 20 of the insulation, in particular of the foam body 21. In order to also prevent upward losses caused by thermal radiation, these channels 20 can be provided with a reflective foil 22 (for example a metal foil or a metallized plastic foil).

These channels 20 are closed downwards by the heating plate 17. The lower side of the heating plate 17 emits thermal radiation which is received by the water of the evaporation pan 12 located therebelow; the heat loss on the upper side of the heating plate 17 is largely prevented by the reflective foil 22 and by the foam body 21.

Although these foam bodies 21 can be an essential part of the insulation 6, this can considerably complicate the assembly of the refrigerator, since in this case either the heating coil 5 is installed before the insulation 6 is produced or the heating coil 15 must be installed in a channel which has been left free in the insulation 6. To avoid this, the foam body 21 is then preferably embodied as a separate component from the insulating layer 6. In particular, the assembly comprising the heating plate 17, the heating coil 15 (and possibly the foil 22) and the body 21 of foam material can be prefabricated outside the refrigerator appliance by placing the heating plate 17, the heating coil 15 (and possibly the foil 22) into the die cavity and filling the remaining cavity of the die cavity with foam to form the body 21 of foam material.

Unlike the illustration of fig. 4, the foam body 21 can rest against that part of the housing 4 which forms the ceiling of the machine chamber 7 in order to thus help insulate the storage chamber 3 from heat released in the machine chamber 7.

List of reference numerals

1 main body

2 door

3 storage chamber

4 outer cover

5 inner container

6 thermal insulation layer

7 machine room

8 evaporator

9 rear wall

10 groove

11 channel

12 evaporating pan

13 compressor

14 liquefier

15 heating coil

16 surface

17 heating plate

18 grooves

19 plate

20 channel

21 foam body

22 foil