EP3870017A1

EP3870017A1 - A heat pump dishwasher with improved evaporator performance

Info

Publication number: EP3870017A1
Application number: EP19779426.6A
Authority: EP
Inventors: Onur Poyraz; Emre SAGLICAN; Ahmet Alptekin; Erkan KUTUK
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2018-10-24
Filing date: 2019-09-24
Publication date: 2021-09-01
Also published as: WO2020083592A1

Abstract

The present invention relates to a dishwasher (1) comprising a body; a circulation pump (2) which provides the delivery of the washing water into the washing environment in the tub; at least one rack (3) wherein the items to be washed are placed; at least one spray arm (4) which provides the delivery of the washing water to the racks (3); a heat pump system (5) providing the heating of the washing water and having a compressor (7) which performs the refrigerant cycle; a condenser (8) which is used for heating the washing water; an evaporator (9) which draws heat from the outer environment and transfers the same to the condenser (8) by means of the compressor (7); at least one fan (10) which provides the heat transfer by blowing the ambient air onto the evaporator (9); and a discharge duct (11) with the top thereof open which is disposed under the evaporator (9) and wherein the water condensing on the evaporator (9) is collected to be discharged to the outer environment afterwards.

Description

A HEAT PUMP DISHWASHER WITH IMPROVED EVAPORATOR PERFORMANCE

The present invention relates to a heat pump dishwasher.
The heat pump system in the heat pump dishwashers is composed of a compressor which pressurizes the refrigerant and provides the circulation thereof, flow tubes wherein the refrigerant circulates, a condenser, an evaporator, and an expansion element. In the heat pump dishwashers, the water heating process is realized by means of the heat pump system. The washing water accumulated under the tub is delivered to the water heating receptacle which contains the condenser by means of the circulation pump. The evaporator in the heat pump system draws heat from the environment while the compressor delivers heat to the condenser, and the condenser transfers heat to the washing water. The heat pump system is positioned on the casing under the machine. The ambient air is delivered to the evaporator by means of at least one fan. The ambient air delivered by the fans condenses while passing over the cold evaporator surfaces, and the condensate is collected in the discharge duct under the evaporator and then discharged to the outer environment. In order to use the evaporator in an efficient manner, the entire air blown by the fans is required to pass over the evaporator. While passing over the evaporator during the operation of the heat pump, the air blown by the fans is also directed towards the discharge duct disposed under the evaporator. When the air blown to pass over the evaporator passes over the discharge duct, the amount of heat transferred to the evaporator from the air decreases. In order to transfer the desired of heat to the evaporator, the flow rate of the air is required to be increased, which in turn increases the energy consumption of the fans. Moreover, as the thermal absorption capacity of the evaporator decreases, the amount of energy to be consumed by the compressor to heat the washing water to the desired temperature increases. The air flow directed towards the discharge duct may sweep the water from over the surface. The water swept by the air overflows from the air duct opening to the environment, causing the floor to get wet.
The Patent No. EP2702199 (B1) relates to a heat pump laundry dryer comprising a base plate which is placed under the evaporator and which enables the condensate accumulating thereon to be delivered to the drain channel, and an air guide which extends from the base plate towards the lower surface of the evaporator and which enables the processing air passing through the gap under the evaporator to be guided into the evaporator.
The aim of the present invention is the realization of a heat pump dishwasher wherein the operational conditions of the evaporator are improved.
The dishwasher realized in order to attain the aim of the present invention is comprises a compressor, a condenser, an evaporator, and a discharge duct wherein the water condensing on the evaporator is collected. The washing water is heated by the condenser. In the dishwasher of the present invention, a separating plate is placed between the lower surface of the evaporator and the discharge duct. The separating plate partially covers the discharge duct and prevents the air blown by the evaporator fans from entering the discharge duct. The ambient air delivered by the fans passes over the evaporator without getting in contact with the water, thus improving the performance of the evaporator.
The heat pump dishwasher realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 - is the schematic view of a heat pump dishwasher.
Figure 2 - is the partial view of the casing region wherein the evaporator is disposed.
Figure 3 - is the top perspective view of the evaporator separating plate.
Figure 4 - is the bottom perspective view of the evaporator separating plate.
Figure 5 - is the partial view of the casing region wherein the evaporator is disposed from another angle.
Figure 6 - is the partial view of the separating plate with holes and barriers thereon.
Figure 7 - is the partial view of the casing whereon the evaporator is disposed.
The elements illustrated in the figures are numbered as follows:

Dishwasher
Circulation pump
Rack
Spray arm
Heat pump system
Casing
Compressor
Condenser
Evaporator
Fan
Discharge duct
Separating plate
Side wall
Hanging means
Housing
Pin
Retainer
Groove
Hole
Barrier
Heater

The dishwasher (1) comprises a body; a circulation pump (2) which provides the delivery of the washing water into the washing environment in the tub; at least one rack (3) wherein the items to be washed are placed; at least one spray arm (4) which provides the delivery of the washing water to the racks (3); a heat pump system (5) which heats the washing water; and a casing (6) which is positioned under the body and which supports the heat pump system (5).
The heat pump system (5) comprises a compressor (7) which performs the refrigerant cycle; a condenser (8) which is used for heating the washing water; an evaporator (9) which draws heat from the outer environment and transfers the same to the condenser (8) by means of the compressor (7); at least one fan (10) which provides the heat transfer by blowing the ambient air onto the evaporator (9); and an expansion element, for example a capillary tube or an expansion valve, which is disposed between the condenser (8) and the evaporator (9).
The dishwasher (1) further comprises a discharge duct (11) with the top thereof open which is disposed on the casing (6) under the evaporator (9) and wherein the water condensing on the evaporator (9) is collected to be discharged to the outer environment afterwards (Figure 1).
The dishwasher (1) of the present invention comprises a separating plate (12) which is disposed on the casing (6) between the lower surface of the evaporator (9) and the discharge duct (11), which partially covers the discharge duct (11), which prevents the air from entering the discharge duct by separating the evaporator (9) and the discharge duct (11) in the flow direction of the fan blown by the fans (10) towards the evaporator (9), and which guides almost the entire air to the evaporator (9).
In the heat pump dishwasher (1), the evaporator (9) draws heat from the ambient air blown by the fans (10) and condenses the same. The water condensing on the evaporator (9) trickles down to be collected in the discharge duct (11) and then is discharged. The air blown by the fans (10) towards the evaporator (9) inevitably moves towards the discharge duct (11). The separating plate (12) prevents the air from entering the discharge duct (11) and guides the same towards the evaporator (9). The separating plate (12), which is disposed over the discharge duct (11) under the evaporator (9), separates the ambient air blown by the fans (10) towards the evaporator (9) from the condensate, prevents any contact between the air and the condensate, and enables almost the entire air to pass over the evaporator (9) and to be discharged to the outer environment without getting humid. Thus, the thermal absorption capacity of the evaporator (9) is increased.
The separating plate (12) comprises a side wall (13) which enables the former to engage with the casing (6) and which extends upwards by bending at a right angle from one edge; a hanging means (14) which is formed by bending the upper edge of the side wall (13) downwards and which engages with the casing (6); and at least one pin (16) which extends downwards from the lower surface and which is seated into the housings (15) arranged on the base of the discharge duct (11) while the separating plate (12) is being mounted onto the casing (6). The dishwasher (1) further comprises at least one retainer (17) which is arranged on the casing (6) and which grips at least one edge of the separating plate (12). The hanging means (14), the pins (16), the housings (15) and the retainer (17) enable the separating plate (12) to be mounted onto the casing (6) without using any connection element such as bolt, etc.
In an embodiment of the present invention, the dishwasher (1) comprises a groove (18) which is arranged between the separating plate (12) and the casing (6) and which enables the water condensing on the evaporator (9) and flowing onto the separating plate (12) to be transferred into the discharge duct (11).
In another embodiment of the present invention, the separating plate (12) is disposed on the casing (6) under the evaporator (9) in an inclined manner so as to make the water flow into the groove (18). Said inclination is easily obtained by shortening the pins (16) under the separating plate (12).
In another embodiment of the present invention, the separating plate (12) comprises at least one hole (19) which is arranged on the lower surface thereof and which enables the water condensing on the evaporator (9) and flowing onto the separating plate (12) to be transferred into the discharge duct (11).
In another embodiment of the present invention, the separating plate (12) comprises at least one barrier (20) which extends in an inclined manner from the edges of the holes (19) towards the lower surface of the evaporator (9) in the direction of the air flow, which prevents the air from passing through the holes (19) into the discharge duct (11) and from sweeping the water in the discharge duct (11), and which enables the air to be directed into the evaporator (9).
In another embodiment of the present invention, a heater (21) is integrated onto the separating plate (12) (Figure 5). The heater (21) evaporates the water on the separating plate (12) surface, thus the blown air is discharged without getting humid. In case frost forms on the evaporator (9) surfaces, when the heater (21) is operated, the frost layer melts to be collected in the discharge duct (11). When the heat pump system (5) is desired to be operated at high speed or with high capacity, the heater (21) can be used as a heat source in addition to the evaporator (9). Thus, the operation time of the heat pump system (5) is shortened or the temperature of the washing water can be increased. The tubes through which the hot water discharged at the end of the washing process or the refrigerant pipe at the outlet of the condenser (8) can be used as the heater (21). In this embodiment, the refrigerant can be cooled more at the outlet of the condenser (8), thus increasing the thermal absorption capacity of the evaporator (9).
In the heat pump dishwasher (1), the separating plate (12) positioned under the evaporator (9) prevents the ambient air delivered towards the evaporator (9) from being guided into the discharge duct (11) provided under the evaporator (9). Air passage into the discharge duct (11) is prevented. The flow rate of the air passing through the fins of the evaporator (9) is increased, thus improving the thermal absorption capacity of the evaporator (9) and hence the efficiency of the heat pump system (5). The water in the discharge duct (11) is prevented from being swept an overflowing due to air flow.

Claims

A dishwasher (1) comprising a body; a circulation pump (2); at least one rack (3); at least one spray arm (4); a heat pump system (5) which heats the washing water; and a compressor (7), a condenser (8), an evaporator (9) which draws heat from the outer environment and transfers the same to the condenser (8) by means of the compressor (7), and at least one fan (10) which provides the heat transfer by blowing the ambient air onto the evaporator (9), which all together form the heat pump system (5); a casing (6) which is positioned under the body under the evaporator (9) and which supports the heat pump system (5); and a discharge duct (11) with the top open which is arranged under the evaporator (9) and wherein the water condensing on the evaporator (9) is collected, characterized by

- a separating plate (12) which is disposed on the casing (6) between the lower surface of the evaporator (9) and the discharge duct (11), which partially covers the discharge duct (11), which prevents the air from entering the discharge duct by separating the evaporator (9) and the discharge duct (11) in the flow direction of the fan blown by the fans (10) towards the evaporator (9), and which guides almost the entire air to the evaporator (9).
A dishwasher (1) as in Claim 1, characterized by the separating plate (12) comprising a side wall (13) which extends upwards by bending at a right angle from one edge and a hanging means (14) which is formed by bending the upper edge of the side wall (13) downwards and which engages with the casing (6).
A dishwasher (1) as in Claim 1 or 2, characterized by the separating plate (12) comprising at least one pin (16) which extends downwards from the lower surface and which is seated into the housings (15) arranged on the base of the discharge duct (11).
A dishwasher (1) as in Claim 1 or 2, characterized by at least one retainer (17) which is arranged on the casing (6) and which grips at least one edge of the separating plate (12).
A dishwasher (1) as in Claim 1 or 2, characterized by a groove (18) which is arranged between the separating plate (12) and the casing (6) and which enables the water condensing on the evaporator (9) and flowing onto the separating plate (12) to be transferred into the discharge duct (11).
A dishwasher (1) as in Claim 1 or 2, characterized by the separating plate (12) comprising at least one hole (19) which is arranged on the lower surface thereof and which enables the water condensing on the evaporator (9) and flowing onto the separating plate (12) to be transferred into the discharge duct (11).
A dishwasher (1) as in Claim 6, characterized by the separating plate (12) comprising at least one barrier (20) which extends in an inclined manner from the edges of the holes (19) towards the lower surface of the evaporator (9) in the direction of the air flow.
A dishwasher (1) as in Claim 1, characterized by the separating plate (12) whereon a heater (21) is integrated.
A dishwasher (1) as in Claim 8, characterized by the separating plate (12) wherein the tubes through which the hot water discharged at the end of the washing process are used as the heater (21).
A dishwasher (1) as in Claim 8, characterized by the separating plate (12) wherein the refrigerant pipe at the outlet of the condenser (8) is used as the heater.