CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of an earlier filing date of and the right of priority to Korean Patent Application No. 10-2018-0148960, filed on Nov. 27, 2018 the contents of which are incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a dish washer that heats washing water using a heat pump.

2. Description of the Related Art

A dish washer is a device that automatically washes and dries dishes using detergent or the like.

The dish washer may be configured to perform a process of washing, rinsing and drying dishes placed inside a main body thereof.

The dish washer may heat washing water using an electric heater provided in the main body.

However, the electric heater used in the dish washer has a problem that consumes a lot of power when washing and drying dishes.

In addition, high temperature washing water heated subsequent to the completion of washing is discharged to an outside of the dish washer, and thus there is a problem that energy loss occurs.

In order to solve the foregoing problems, a dish washer capable of reducing energy consumption by heating washing water using a heat pump has been developed.

Prior art document KR 10-2015-0108188 A (published Sep. 25, 2015) discloses a household appliance having a drying device. The dish washer in the prior art includes a heat pump system that suctions air through a suction port at an upper portion of a washing tank to heat the suctioned air using heat discharged from a condenser, and dries dishes by discharging the heated hot air into the washing tank through the discharge port disposed at a lower side of the washing tank.

However, the dish washer in the prior at dries dishes while hot air discharged into the inside of the washing tank moves from the discharge port of the washing tank to the suction port by natural convection, and thus there is a problem that the drying time is prolonged.

In addition, an additional fan for actively generating an air flow is not provided in the washing tank, and there is a limit in more quickly transferring the heat of hot air to dishes.

SUMMARY

The present disclosure has been made to solve the problems in the related art, an aspect of the present disclosure is to provide a dish washer capable of directly injecting hot air into dishes through a nozzle of an injection arm to improve the drying performance of the dishes.

Furthermore, another aspect of the present disclosure is to provide a dish washer provided with an air injection nozzle in addition to a washing water injection nozzle in the injection arm, in which a hole size of the air injection nozzle is larger than that of the washing water injection nozzle, to increase a flow rate of hot air to be supplied to dishes, thereby improving the drying performance.

In addition, still another aspect of the present disclosure is to provide a dish washer provided with a nozzle opening and closing portion in the injection arm, wherein the washing water injection nozzle and the air injection nozzle can be selectively opened and closed according to the washing stroke and the drying stroke.

Moreover, yet still another aspect of the present disclosure is to provide a dish washer capable of rotating the injection arm by an injection pressure of air even without the power of a motor to actively generate an air flow so as to improve the drying performance by the air flow, thereby reducing the drying time.

In order to achieve the foregoing objectives, a dish washer according to an embodiment of the present disclosure may include a washing tank having an accommodation space for storing dishes therein; an injection arm disposed inside the washing tank, and provided with a plurality of nozzles to inject washing water or air to the dishes according to a washing stroke and a drying stroke; a duct unit that defines a passage for delivering air to the injection arm; a suction fan that suctions the air and supplies the air to the injection arm; and an air heating element provided inside the duct unit to heat the air to be supplied to the injection arm, wherein the injection arm is rotatably mounted about a rotary shaft, and the plurality of nozzles rotate the injection arm by a pressure that injects the air.

According to an example associated with the present disclosure, the plurality of nozzles may include a first nozzle having an injection hole disposed to be inclined toward a counter rotation direction of the injection arm.

According to an example associated with the present disclosure, at least one first nozzle may be disposed at an outer end portion of the injection arm.

According to an example associated with the present disclosure, a plurality of first nozzles may be respectively arranged at opposite sides of the injection arm to each other about the rotary shaft, and the plurality of first nozzles disposed at opposite sides to each other may be arranged in opposite injection directions to each other.

According to an example associated with the present disclosure, the first nozzle may be disposed to be twisted in a direction crossing a circumference on which the injection arm rotates to inject the air in an oblique direction with respect to the circumference.

According to an example associated with the present disclosure, the plurality of nozzles may include a second nozzle having an injection hole vertically disposed toward the dishes.

According to an example associated with the present disclosure, the plurality of nozzles may include a third nozzle having an injection hole horizontally disposed in a counter rotation direction of the injection arm.

According to an example associated with the present disclosure, the plurality of nozzles may be arranged to have a narrower distance therebetween as located away from the rotary shaft to an outer end portion of the injection arm.

According to an example associated with the present disclosure, the dish washer may further include a circulation passage that delivers the washing water to the injection arm; and an air delivery passage that connects the duct unit and the circulation passage to deliver the air to the injection arm.

According to an example associated with the present disclosure, the dish washer may further include a non-return valve provided in the air delivery passage.

According to an example associated with the present disclosure, the dish washer may further include an injection arm connection pipe, one side of which is connected in communication with a central portion of the injection arm, and the other side of which is connected in communication with the circulation passage, wherein the washing water or the air moves from the circulation passage to the injection arm through the injection arm connection pipe.

According to an example associated with the present disclosure, a plurality of the injection arms may be arranged to be spaced apart from one another in a vertical direction inside the washing tank.

According to an example associated with the present disclosure, the air heating element may be a heat pump system, and the heat pump system may further include a compressor that circulates refrigerant; a condenser provided inside the duct unit to discharge the heat of the refrigerant compressed in the compressor to the air; an expansion apparatus that expands refrigerant condensed in the condenser; and an evaporator that evaporates refrigerant received from the expansion apparatus to deliver the refrigerant to the compressor.

According to an example associated with the present disclosure, the dish washer may further include a heat exchange chamber that accommodates the evaporator and stores water therein to exchange heat between the water and the evaporator.

According to another example associated with the present disclosure, the air heating element may be an electric heater provided inside the duct unit.

According to still another example associated with the present disclosure, the air heating element may include a condenser provided inside the duct unit; and an electric heater provided inside the duct unit to further selectively heat air heated from the condenser.

According to an example associated with the present disclosure, the dish washer may further include a controller that controls the operation of the condenser, wherein the controller operates the heat pump system during a washing stroke to preheat the air prior to a drying stroke.

The effects of a dish washer having a heat pump according to the present disclosure will be described as follows.

First, a first nozzle for washing water and a second nozzle for air, which are arranged to have different hole sizes in an injection arm portion, may be selectively opened and closed according to the washing stroke and the drying stroke, thereby opening the first nozzle to inject washing water to dishes with the injection arm so as to wash the dishes during the washing stroke.

Second, the second nozzle may be opened to inject heated air to dishes through an injection arm to dry the dishes during the drying stroke.

Third, hot air may increase flow rate while passing through the air nozzle (second nozzle) having a larger hole size than the washing water nozzle (first nozzle), thereby improving the drying performance.

Fourth, as hot air passes through the injection arm, the flow rate may increase and hot air may be blown out to dishes at an increased injection pressure through the plurality of nozzles, thereby transferring more heat to the dishes more quickly than a drying method by natural convection inside a washing tank in the related art.

Fifth, as an air injection pressure of the nozzles increases, the injection arm may obtain momentum by a reaction force against injecting air, thereby rotating the injection arm without the need for a motor or the like.

Sixth, as the injection arm rotates, a flow of air may be generated inside the washing tank to maximize the heat exchange performance between dishes and hot air, thereby greatly reducing the drying time of the dishes.

Seventh, the injection arm may be rotated by momentum due to an injection pressure of air, and a flow rate of air injected through the injection holes of the nozzles may further increase by a rotational speed of the injection arm rather than an injection speed of air injected from the nozzles to actively generate an air flow inside the washing tank, thereby significantly improving the drying performance.

Eighth, each of the plurality of nozzles may be arranged to be twisted at a predetermined angle with respect to a tangential direction of the circumference along a rotation direction of the injection arm to inject air in a direction crossing the circumference in an oblique direction, and the plurality of nozzles respectively arranged at both end portions of the injection arm with respect to the center of the injection arm may inject air in opposite directions, thereby increasing a rotational force (torque) due to the injection pressure of the air to more actively generate an air flow.

Ninth, an inclination angle of the injection holes of the nozzles may increase in a vertical direction as the nozzles are arranged closer to the center of the injection arm, and the inclination angle of the injection holes of the nozzles may decrease in a horizontal direction as the nozzles are arranged away from the center of the injection arm thereby improving the heat transfer efficiency due to an air flow as well as increasing an amount of air injected to dishes to reduce the drying time.

