WO2018050541A1

WO2018050541A1 - A household appliance having a cleaning unit for a heat exchanger

Info

Publication number: WO2018050541A1
Application number: PCT/EP2017/072474
Authority: WO
Inventors: Semih Atli; Dogan Kilinc; Tolga Yegin
Original assignee: BSH Hausgeräte GmbH
Priority date: 2016-09-19
Filing date: 2017-09-07
Publication date: 2018-03-22

Abstract

The present invention proposes a household appliance with a heat exchanger assembly (101) including a pipe (102) for receiving a cooling fluid of a respective cooling cycle, the pipe (102) having an outer heat transfer surface (S) for thermal interaction with air; wherein the refrigerator is further provided with a cleaning unit (2) comprising an outlet line (21) for sucking air away from the heat exchanger assembly (101), an impeller (23) having friction surfaces (22) shaped and positioned for being driven in accordance with frictional forces resulting from air stream when air is sucked through the outlet line (21), and a sweeper (24) coupled with the impeller (23) such that the sweeper (24) moves in accordance with any motion of the impeller (23).

Description

SPECIFICATION

A HOUSEHOLD APPLIANCE HAVING A CLEANING UNIT FOR A HEAT EXCHANGER

Technical Field of the Invention

The present invention relates to a household appliance, and more particularly to an improved refrigerator provided with a novel heat exchanger cleaning unit; and the cleaning unit itself.

Background of the Invention

The efficiency of a refrigerator heat exchanger such as a condenser is affected by the respective overall heat transfer coefficient which includes thermal conductivity of the solid material constituting condenser coil or its extensions (e.g. fins or wires for providing an extended heat transfer surface area) defining outer heat transfer surfaces thereof. Said thermal conductivity practically decreases as low thermal conductivity materials such as domestic dust deposit on said solid material (usually comprising metals), which has intrinsically a higher thermal conductivity when compared to the domestic dust. As a result, heat transfer rate from higher thermal conductivity heat transfer surfaces covered with a lower thermal conductivity deposit decreases due to increased heat transfer resistance caused by the covering material.

Especially by multi port extruded (MPE) condensers, which are employed for an efficient and rapid heat transfer by having highly detailed surfaces with fine recesses and protrusions, are even more prone to catch domestic dust. Therefore the heat removal capacity of such condensers dramatically decreases over time. In such case a manual cleaning procedure is applied by uncovering and exposing the condenserr. Yet, surfaces and extensions of the condensers, especially of the MPE condensers are delicate and this procedure can easily damage the condenser and its extensions. DE 10 2008 019 359 Al discloses example of refrigerators with MPE heat exchangers.

Objects of the Invention

Primary object of the present invention is to overcome the abovementioned shortcomings of the prior art. Another object of the present invention is provision of a low maintenance cost and production cost of household appliance having a heat exchanger assembly, along with easily maintained energy efficiency thereof. Summary of the Invention

The present invention proposes as an independent aspect, a household appliance with a heat exchanger assembly including a pipe for receiving a cooling fluid of a respective cooling cycle, the pipe having an outer heat transfer surface for thermal interaction with air; wherein the appliance is provided with a cleaning unit comprising an outlet line for sucking air away from the heat exchanger assembly, an impeller having friction surfaces shaped and positioned for being driven in accordance with frictional forces resulting from air stream when air is sucked through the outlet line, and a sweeper coupled with the impeller such that the sweeper moves in accordance with any motion of the impeller. The outlet line may be for being coupled with a suction line of a vacuum cleaner. When a vacuum cleaner in operation is attached to the outlet line, air flowing towards the vacuum cleaner drives the impeller and thus the sweeper. The movement of the sweeper causes turbulence of air in vicinity of dust collecting surfaces. Air turbulation causes drag forces around deposited dust and as a result, dust can be torn off from where it was deposited, and then removed along with air directed to the vacuum cleaner. Accordingly, the overall heat transfer coefficient around the heat transfer surfaces of the heat exchanger can be maintained high by a facilitated removal of low thermal conductivity depositions (e.g. dust) thereon. Efficient heat transfer around the heat exchanger of the household appliance can be maintained by an easy cleaning procedure including the steps of attaching an air suction line of a vacuum cleaner to the outlet line and operating the vacuum cleaner. Thus the household appliance can be maintained energy efficient without necessitating additional costs such as technical service personnel charges, only by using an already present household vacuum cleaner. The outlet line may also be extended until an outer wall of the household appliance accessible to a user, so the user may clean the heat exchanger assembly without need to move the household appliance, for example out of a niche.

The appliance according to the present invention does not require any exposition of heat transfer surfaces by disassembling the appliance, and it is highly convenient to perform cleaning of the dust collecting surfaces around the heat exchanger assembly. Necessity of intervention using inflexible solid objects (such as a vacuum cleaner pipe) onto delicate heat transfer surfaces is eliminated by the present invention.

The heat exchanger assembly can comprise a condenser. The present invention is further advantageous in this case, since condensers of household appliances (e.g. refrigerators, coolers, or freezers) are usually positioned at a lower level of the appliance, which results in excessive dust collection on dust collecting surfaces e.g. heat transfer surfaces such as fins, wirings or pipes of such condenser. In such case, necessity of dust removal operation arises frequently.

The heat exchanger assembly can have a multi-port extruded (MPE) condenser. Some of the advantages attributable to MPE condensers are design flexibility and facilitated formation of high ratios of heat transfer surface area per volumetric capacity. This type of condensers are more compact and detailed (by having fine recesses and protrusions for effective heat transfer via corresponding increased heat transfer surface area) than the conventional condensers, and highly delicate by being possibly extruded from a relatively soft material. Therefore the cleaning unit of the household appliance according to the present invention is even further advantageous in this case. The sweeper can be coupled with a brush made of a material with possibly lower rigidity than that of said outer heat transfer surfaces. In this case, dust deposited on the outer heat transfer surfaces can be further removed by friction forces applied by the brush in addition to the turbulent air. In an embodiment, the impeller has a mainly circular configuration where the friction surfaces are circularly distributed around a rotation axis; the outlet line has an opening to the vicinity of friction surfaces; and the sweeper is configured and positioned to be movable around said rotation axis in accordance with any rotational movement the impeller. In operation, a maximum load distance and thus a maximum torque can be achieved for moving the sweeper by air rubbing the friction surfaces of the impeller and flowing towards the vacuum cleaner.

In an embodiment according to the present invention, for at least partially preventing arrival of dust inside the heat exchanger assembly and providing deposition of dust on an air inlet side of the heat exchanger assembly during the operation of the heat exchanger assembly, a mesh filter can be provided between the heat exchanger assembly and the sweeper, more particularly between the outer heat transfer surface and the sweeper. If a brush is used, the mesh filter can be provided between the heat exchanger assembly and the brush. In use, the mesh filter may be provided on the air inlet side of the heat exchanger assembly and collects dust first and at least partly prevents it from arriving and depositing onto outer heat transfer surfaces of the heat exchanger. The present embodiment enables removal of dust from the surfaces of mesh filter, mesh filter can easily kept clean with the cleaning procedure described above; and since dust is restrained from arriving to the outer heat transfer surfaces, efficient airflow through the heat exchanger and efficient heat transfer can be achieved with the present embodiment. Furthermore, with this embodiment, such surfaces can be kept from any possible hazards from the objects (such as the sweeper and/or the brush) in case where the motion of the sweeper and/or the brush deviates from a presumed motion range. Hence, the household appliance is rendered even more long- lasting according to the present embodiment.

The heat exchanger assembly and/or cleaning unit may have a fixing member to attach the both to each other. The fixing member may be any member providing force-fit or form-fit connection.

The invention also proposes an additional independent aspect that is a cleaning unit for a heat exchanger assembly of a household appliance, comprising an outlet line for sucking air away from the heat exchanger assembly, an impeller having friction surfaces shaped and positioned for being driven in accordance with frictional forces resulting from air stream when air is sucked through the outlet line, and a sweeper coupled with the impeller such that the sweeper moves in accordance with any motion of the impeller. Advantages related to the cleaning unit, usage of the cleaning unit and dependant advantages aspects or features related to the cleaning unit are identical to ones explained above for the cleaning unit.

Brief Description of the Figures

The figures, whose brief explanations are herewith provided, are solely intended for providing a better understanding of the present invention and are as such not intended to define the scope of protection or the context in which said scope is to be interpreted in the absence of the description.

Fig. 1 is an exploded perspective view of a heat exchanger and a respective cleaning unit of a household appliance according to the present invention with a mesh filter. Fig.2 is a perspective view of the assembly of a heat exchanger and a respective cleaning unit according to the present invention without a mesh filter.

Fig.3 is a front view of the assembly of a heat exchanger and a respective cleaning unit according to the present invention without a mesh filter.

Fig.4 is an A-A section view of Fig. 3. Fig.5 is a rear perspective view of a cleaning unit to be employed according to the present invention without a mesh filter.

Detailed Description of the Invention

Referring now the figures outlined before, the present invention proposes a household appliance such as a refrigerator, cooler or freezer or a combination thereof; provided with a heat exchanger assembly (101) including a pipe (102)for receiving a cooling fluid of a respective refrigeration cycle, the pipe (102) having an outer heat transfer surface (S) for thermal interaction with air comprising outer surface of the pipe (102) and fins provided between neighboring pipe (102) sections; wherein the refrigerator is further provided with a cleaning unit (2) comprising an outlet line (21) for being coupled with a suction line of a vacuum cleaner, an impeller (23) having friction surfaces (22) shaped and positioned for being driven in accordance with frictional forces resulting from air stream when air is passed through the outlet line (21), and a sweeper (24) coupled with the impeller (23) such that the sweeper (24) moves in accordance with any motion of the impeller (23). The impeller (23) and the sweeper (24) are single-piece in the figures.

In figures, the heat exchanger assembly (101) has a multi-port extruded (MPE) condenser and a fan (104) to suck air through the condenser.

The sweeper (24) is coupled with a brush (25).

The impeller (23) has a mainly circular configuration where the friction surfaces (22) are circularly distributed around a rotation axis (O); the outlet line (21) has an opening to the vicinity of friction surfaces (22); and the sweeper is configured and positioned to be movable around said rotation axis in accordance with any rotational movement the impeller.

For restraining arrival and deposition of dust, which may be conducted during the lifetime of the household appliance onto the outer heat transfer surface (S), a mesh filter (3) can be provided between the outer heat transfer surface (S) and the impeller (23).

The impeller (23) is provided in a housing (26) of the cleaning unit (2). The housing (26) has a circular space around the rotation axis (0) defined by a circular inner wall (27) as corresponding to the shape of the impeller (23). The housing (26) is a rectangular shape as covering all of the air inlet side (103) of the heat exchanger assembly (101). The outlet line (21) of the cleaning unit (2) extends as a pipe with a free end and starting from the inner wall (27) of the cleaning unit (2) as illustrated in Fig. 1. Thus, air is sucked from inner space of the housing (26) toward outside of the cleaning unit (2). A connection pin (28) for the sweeper (24) is provided on the center of the housing (26) and fixed by multiple arms extending from the inner wall (27) of the housing (26) to the center, thus to the connection pin (28). The connection between the connection pin (28) and the sweeper (24) is achieved by a form-fit, particularly snap-fit connection.

Reference Signs

101. Heat exchanger assembly

102. Pipe

103. Air inlet side

2. Cleaning unit

21. Outlet line

22. Friction surface

23. Impeller

24. Sweeper

25. Brush

26. Housing

27. Inner wall

3. Mesh filter

S. Outer heat transfer surface O. Rotation axis

Claims

1. A household appliance with a heat exchanger assembly (101) including a pipe (102) for receiving a cooling fluid of a respective cooling cycle, the pipe (102) having an outer heat transfer surface (S) for thermal interaction with air; wherein the refrigerator is further provided with a cleaning unit (2) comprising

- an outlet line (21) for sucking air away from the heat exchanger assembly (101),

- an impeller (23) having friction surfaces (22) shaped and positioned for being driven in accordance with frictional forces resulting from air stream when air is sucked through the outlet line (21), and

- a sweeper (24) coupled with the impeller (23) such that the sweeper (24) moves in accordance with any motion of the impeller (23).

2. Household appliance according to the claim 1, wherein the heat exchanger assembly (101) comprises a condenser.

3. Household appliance according to the claim 1 or 2, wherein the heat exchanger assembly (101) comprises a multi-port extruded condenser.

4. Household appliance according to any one of the preceding claims, wherein the sweeper (24) is coupled with a brush (25).

5. Household appliance according to any one of the preceding claims, wherein the impeller (23) has a mainly circular configuration where the friction surfaces (22) are circularly distributed around a rotation axis (O); the outlet line (21) has an opening to the vicinity of friction surfaces (22); and the sweeper (24) is configured and positioned to be movable around said rotation axis (O) in accordance with any rotational movement the impeller (23).

6. Household appliance according to any one of the preceding claims, wherein a mesh filter (3) is provided between the heat exchanger assembly (101) and the cleaning unit (2).

7. Household appliance according to the claim 6, wherein the mesh filter (3) is provided between the heat exchanger assembly (101) and the sweeper (24).

8. Household appliance according to the claim 6 or 7, wherein the mesh filter (3) is provided on an air inlet side (103) of the heat exchanger assembly (101).

9. A cleaning unit (2) for a heat exchanger assembly (101) of a household appliance, characterized by comprising;

10. Cleaning unit according to the claim 9, wherein the sweeper (24) is coupled with a brush (25).

11. Cleaning unit according to the claim 9 or 10, wherein the impeller (23) has a mainly circular configuration where the friction surfaces (22) are circularly distributed around a rotation axis (O); the outlet line (21) has an opening to the vicinity of friction surfaces (22); and the sweeper (24) is configured and positioned to be movable around said rotation axis in accordance with any rotational movement the impeller (23).

12. Cleaning unit according to any one of the claims 9-11, wherein a mesh filter (3) is provided between the heat exchanger assembly (101) and the cleaning unit (2).

13. Cleaning unit according to the claim 12, wherein the mesh filter (3) is provided between the heat exchanger assembly (101) and the sweeper (24).

14. Cleaning unit according to any one of the claims 9-13, wherein the heat exchanger assembly (101) comprises a condenser, particularly a multi-port extruded condenser.