WO2012062677A1

WO2012062677A1 - Thermoelectric heat pump laundry dryer

Info

Publication number: WO2012062677A1
Application number: PCT/EP2011/069481
Authority: WO
Inventors: Yavuz Sahin; Dogan Demirhan; Mehmet Kaya; Erdem An
Original assignee: Arcelik Anonim Sirketi
Priority date: 2010-11-10
Filing date: 2011-11-04
Publication date: 2012-05-18
Also published as: EP2638202A1; CN103201424A; EP2638202B1; CN103201424B

Abstract

The present invention relates to a laundry dryer (1) comprising a drum (2) wherein the laundry is placed, a drying duct (3) wherein the process air is circulated, a fan (4) providing the circulation of process air in the drying duct (3), a heater (5) that heats the process air, a condenser (6) that dehumidifies the process air and a thermoelectric heat pump (9) disposed in the drying duct (3), having a cold side (7) that condenses the process air passing there over by cooling it and a hot side (8) that heats the process air passing there over, a first inlet opening (10) that provides the process air moving through the drying duct (3) to enter the condenser (6) and a second inlet opening (110) that provides the said process air to enter the cold side (7).

Description

THERMOELECTRIC HEAT PUMP LAUNDRY DRYER

The present invention relates to a laundry dryer comprising a thermoelectric heat pump.

In laundry dryers wherein the drying air is circulated within a closed cycle, the drying air activated by a fan dehumidifies the laundry by being passed over the laundry and the water vapor in the air is condensed at the condenser. The drying air dehumidified at the condenser is then heated by being passed over the heater, thus hot and dry air is delivered unto the laundry. In laundry dryers generally air cooled type condensers are used. The air sucked by means of the cooling fan from the outer environment is delivered to the condenser and thus the drying air passing through the condenser is provided to be condensed by being cooled. In the state of the art, furthermore thermoelectric heat pumps are used in laundry dryers in addition to the condenser and the heater. The thermoelectric heat pumps are also named as Peltier element. The thermoelectric heat pumps have hot and cold sides and perform both the functions of condensing by cooling and also heating the drying air. While the hot side of the thermoelectric heat pumps used in laundry dryers assists the heater, the cold side assists the condenser. In the process of drying the laundry, the drying air is cooled by some amount while being passed over the condenser, afterwards is passed over the thermoelectric heat pump and thereby the dehumidification process of the drying air is accomplished in two stages. Similarly, the heating process is also realized in two stages. The drying air, which is almost completely dehumidified of the moisture contained therein by passing through the condenser and the cold side of the thermoelectric heat pump, is heated some amount by being passed over the hot side of the thermoelectric heat pump and afterwards the heating process is completed by the drying air being passed over the main heater. In the said laundry dryers wherein the heater, the condenser and the thermoelectric heat pump are used together, the problem of pressure loss arises due to the numerous paths and turns wherein the drying air circulates. The pressure of the drying air and the drying efficiency decrease while the drying air passes through the heat sinks composed of fins providing the heat transfer to be performed especially at the hot and cold sides of the thermoelectric heat pump.

In the German Patent Application No. DE102006005810, a Peltier element is disposed in the gap between two heat sinks. The sealing element is arranged between the Peltier element and the heat sink.

In the European Patent No. EP2004901, a laundry dryer comprising a thermoelectric heat pump is explained. The drying process air is directed from the cold side of the thermoelectric heat pump to the hot side by means of an air guidance device.

In the European Patent Application No. EP2029804, a laundry dryer is explained wherein the drying air is circulated in a closed channel system. The drying air is parallelly passed through the thermoelectric heat pump having cold side and hot side.

In the German Utility Model Application No. DE20101641, the drying air leaving the drum in a laundry dryer enters the condenser after passing through the cold surface of the Peltier element and the air leaving the condenser is delivered to the drum after passing through the hot surface of the Peltier element and the heater.

The aim of the present invention is the realization of a laundry dryer which comprises a thermoelectric heat pump and wherein the pressure losses that occur in the drying cycle are decreased.

The laundry dryer realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises a heater heating the drying air, a condenser condensing the drying air, a thermoelectric (Peltier) heat pump having a cold side performing the same function as the condenser and the hot side performing the same function as the heater, and the condenser and the cold side are positioned one above the other so as to operate as a single unit and the process air is sent from the drying duct to both the condenser and the cold side at the same time. Thus, pressure losses are reduced by shortening the process air path.

In an embodiment of the present invention, the diameter of the drying duct is increased so as to be connected to both the condenser and the cold side. The air flow cross sectional area in the drying duct increases before the condenser and the cold side, the flow rate of the drying duct decreases and the condensing efficiency of the condenser and the cold side increase depending on the decreased air flow rate.

In another embodiment of the present invention, the flow direction of the process air traversing the hot side from end to end is rotated 180 degrees by disposing a vertical guide at the outlet of the hot side of the thermoelectric heat pump and the drying air leaving the hot side traverses the hot side for a second time and in the reverse direction by being once more sent to the hot side and is sent to the drum. Thus, the necessity for forming an additional flow path occurring due to the drying air that leaves the hot side staying at a distance from the drum inlet is eliminated and the drying air is provided to leave the hot side from its end near the drum inlet, that is the end through which the drying air enters. In this embodiment, furthermore a separator horizontally extending to the middle of the fins is disposed and air flow in opposite directions is facilitated.

In another embodiment of the present invention, the laundry dryer comprises a horizontal guide that is placed at one end of the hot side and that provides the process air traversing the hot side from end to end to be horizontally returned by the side of the hot side. In this embodiment, empty volumes next to the hot side are used to send the air leaving the hot side to the drum and the air flow path is prevented from occupying much space in the vertical direction.

In another embodiment of the present invention, an inner guide separating the process air flow leaving the condenser and the cold side is placed at the portion of the drying duct that connects the condenser and the cold side with the hot side, and vortexes, thus pressure losses are decreased at this region.

In the laundry dryer of the present invention, by passing the process air through the cold side of the thermoelectric heat pump and the condenser at the same time, the air flow path is shortened, pressure losses are decreased and condensing efficiency of the condenser and the cold side is increased.

The laundry dryer 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 laundry dryer.

Figure 2 - is the schematic view of a laundry dryer in another embodiment of the present invention.

Figure 3 - is the schematic view of a laundry dryer drum and the hot side of a thermoelectric heat pump and a horizontal guide disposed there below.

Figure 4 - is the schematic view of a laundry dryer drum and the hot sides of two thermoelectric heat pumps and a horizontal guide disposed there below.

The elements illustrated in the figures are numbered as follows:

Laundry dryer
Drum
Drying duct
Fan
Heater
Condenser
Cold side
Hot side
Thermoelectric heat pump
110. Inlet opening
Vertical guide
Separator
Inner guide
Horizontal guide

The laundry dryer (1) comprises a body, a drum (2) wherein the laundry is placed, a drying duct (3) wherein the process air is circulated, a fan (4) providing the circulation of the process air in the drying duct (3), a heater (5) that heats the process air, a condenser (6) that dehumidifies the moisture in the process air and a thermoelectric heat pump (9) disposed in the drying duct (3), having a cold side (7) that condenses the process air passing there over by cooling it and a hot side (8) that heats the process air passing there over.

The laundry dryer (1) furthermore comprises a first inlet opening (10) providing the process air moving through the drying duct (3) to enter the condenser (6) and a second inlet opening (110) providing the said process air to enter the cold side (7).

The thermoelectric heat pump (9) is positioned horizontally inside the body of the laundry dryer (1), the cold side (7) is situated below, and the hot side (8) above, and the condenser (6) is situated under the cold side (7), at the lowermost place inside the body of the laundry dryer (1). The said elements are arranged one above the other from the drum (2) towards the base in the order as the hot side (8) – the cold side (7) – the condenser (6).

The laundry dryer (1) of the present invention comprises

- the condenser (6) and the cold side (7) that are adjacently placed one above the other such that their inlet openings (10, 110) are in the same direction and

- the drying duct (3) that is connected to the condenser (6) and the cold side (7), that provides the process air to pass through the inlet openings (10, 110) at the same time and to parallelly flow through the condenser (6) and the cold side (7) in the same direction and that guides the process air leaving the condenser (6) and the cold side (7) to the hot side (8) by joining it (Figure 1, Figure 2).

The process air leaving the drum (2) and moving through the drying duct (3) enters both the condenser (6) and the cold side (7) that are disposed on the flow path and that are adjacent and one above the other through the openings (10, 110) In other words, the condenser (6) and the cold side (7) are connected in parallel to each other in the process air flow direction in the drying duct (3) and work as a single condensing unit. The inlet openings (10, 110) positioned one above the other at the same level serve as a separator (12), the process air traverses the condenser (6) and the cold side (7) from end to end by entering both and without being separated by any additional separator (12), and flow in the condenser (6) and the cold side (7) does not mix with each other. The hot side (8) is connected to both the condenser (6) and the cold side (7). The process air leaving the condenser (6) and the cold side (7) joins and is guided to the hot side (8) by the drying duct (3). By means of the process air being separated by the inlet openings (10, 110) and then simultaneously flowing through the condenser (6) and the cold side (7), the total flow path of the process air in the laundry dryer (1) is shortened and pressure losses are decreased.

In an embodiment of the present invention, the drying duct (3) is connected to the condenser (6) and the cold side (7) by increasing the air flow cross sectional area (D) at least near the inlet openings (10, 110) so as to surround the inlet openings (10, 110). Since the cross sectional area (D) of the drying duct (3) is increased, the flow rate of the process air at this region decreases and the condensing efficiency of the condenser (6) and the cold side (7) increases depending on the decreasing air flow rate.

In another embodiment of the present invention, the laundry dryer (1) comprises a vertical guide (11) that is disposed at one end of the hot side (8) and that rotates 180 degrees the flow direction of the process air coming from the condenser (6) and the cold side (7) and traversing the hot side (8) from end to end and guides it again into the hot side (8) such that it flows in the opposite direction, and furthermore a separator (12) that prevents the air flows in opposite directions from mixing with each other in the hot side (8) by separating the hot side (8) into two parts (Figure 2).

In a version of this embodiment, the fins (F) of the hot side (8) extend upwards in the vertical direction and the separator (12) separates the fins (F) of the hot side (8) into one lower and one upper part by extending horizontally in the middle of the fins (F) (Figure 2).

In another embodiment of the present invention, the laundry dryer (1) comprises a horizontal guide (14) that is disposed at one end of the hot side (8) and that provides the process air coming from the condenser (6) and the cold side (7) and traversing the hot side (8) from end to end to be horizontally returned by the side of the hot side (8) below the drum (2) (Figure 3).

In a version of this embodiment, the laundry dryer (1) comprises two hot sides (8) disposed side by side at the lower side of the drum (2) and the horizontal guide (14) that is disposed at one end of the hot sides (8) and that joins the process air coming from the condenser (6) and the cold side (7) and traversing the hot sides (8) from end to end and provides it to be returned from between the two hot sides (8) (Figure 4).

If the portion of the drying duct (3) that carries the process air leaving the drum (2), for example, is at the left of the drum (2), the process air moves to the right of the drum (2) after leaving the condenser (6) and the cold side (7) since it flows in the condenser (6) and the cold side (7) at the same time. Since the hot side (8) is connected in series to the condenser (6) and the cold side (7) and due to the one-above-the-other arrangement in the body, the process air passing through the hot side (8) once again comes to the left side of the drum (2). Since the part through which the process air enters into the drum (2) is at the right of the drum (2), the process air stays at a distance from the outlet of the hot side (8) and it is required to transport the process air leaving the hot side (8) from the left side thereof to the right side of the drum (2) again. And this means forming a new flow path that carries the process air from left to right in the limited volume below the drum (2). Moreover, the condenser (6), the cold side (7) and the hot side (8), all disposed below the drum (2), occupy much space in the vertical direction in the body of the laundry dryer (1) together with the drying duct (3). The embodiment explained in

Claims

3, 4, 5 and 6 shortens the flow path of the process air, thus preventing the pressure losses and offers a solution to the above-mentioned problem. The expressions “right” and “left” mentioned above are used such that the problem can be easily understood by the present figure references.

In another embodiment of the present invention, the laundry dryer (1) comprises an inner guide (13) that is disposed at the portion of the drying duct (3) connecting the condenser (6) and the cold side (7) with the hot side (8) and that guides the process air flows leaving the condenser (6) and the cold side (7) to the hot side (8) by separating them (Figure 1). Thus, vortexes generated as a result of rotating the flow direction of the process air 180 degrees at the portion of the drying duct (3) connecting the condenser (6) and the cold side (7) to the hot side (8) and pressure losses occurring at this area as a result of this are decreased.

As per the operating principle of the thermoelectric heat pump (9), for the hot side (8) operating efficiently, the air flow passing there over should be at high speeds. Since the cold side (7) performs condensing, the air flow passing there over should be at lower speeds for it operating efficiently. If the air passes through the hot side (8) and the cold side (7) of the thermoelectric heat pump (9) at the same speed, if the air flow rate is high, the cold side (7) operates inefficiently while the hot side (8) operates efficiently, and if the air flow rate is low, this time, the cold side (7) operates efficiently, while the hot side (8) operates inefficiently. In the embodiment of the present invention, the process air is provided to pass through the cold side (7) and the condenser (6) at lower speeds by increasing the cross sectional area (D) of the drying duct (3) such that the drying duct (3) can be connected to both the cold side (7) and the condenser (6), thus the efficiency of both the cold side (7) and the condenser (6) is increased. The process air is provided to pass through the hot side (8) at high speeds by decreasing the cross sectional area (D) of the drying duct (3) before the inlet of the hot side (8), thus the efficiency of the hot side (8) is increased. Moreover, since the condenser (6) and the cold side (7) operates as a single unit, they can be curvedly placed in the same direction, the condensing water of both can be collected in a common collecting container by using a single discharge line, thus separate condensing water collecting containers are not needed to be used for the condenser (6) and the cold side (7).

It is to be understood that the present invention is not limited by the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.

Claims

A laundry dryer (1) comprising a drum (2) wherein the laundry is placed, a drying duct (3) wherein the process air is circulated, a fan (4) providing the circulation of process air in the drying duct (3), a heater (5) that heats the process air, a condenser (6) that dehumidifies the process air and a thermoelectric heat pump (9) disposed in the drying duct (3), having a cold side (7) that condenses the process air passing there over by cooling it and a hot side (8) that heats the process air passing there over, a first inlet opening (10) that provides the process air moving through the drying duct (3) to enter the condenser (6) and a second inlet opening (110) that provides the said process air to enter the cold side (7).

characterized by

- the condenser (6) and the cold side (7) that are adjacently placed such that their inlet openings (10, 110) are in the same direction and

- the drying duct (3) that is connected to the condenser (6) and the cold side (7), that provides the process air to pass through the inlet openings (10, 110) and to parallelly flow through the condenser (6) and the cold side (7) and that guides the process air leaving the condenser (6) and the cold side (7) to the hot side (8) by joining it.
- A laundry dryer (1) as in Claim 1, characterized by the drying duct (3) that is connected to the condenser (6) and the cold side (7) by the air flow cross sectional area (D) thereof being increased so as to surround the inlet openings (10, 110).
- A laundry dryer (1) as in Claim 1 or 2, characterized by a vertical guide (11) that is disposed at one end of the hot side (8) and that rotates 180 degrees the flow direction of the process air coming from the condenser (6) and the cold side (7) and traversing the hot side (8) from end to end and guides it again into the hot side (8) and a separator (12) that prevents the air flows in opposite directions from mixing with each other in the hot side (8) by separating the hot side (8) into two parts.
- A laundry dryer (1) as in Claim 3, characterized by the hot side (8) the fins (F) of which extend upwards in the vertical direction and the separator (12) that separates the hot side (8) into one lower and one upper part by extending horizontally in the middle of the fins (F).
- A laundry dryer (1) as in Claim 1 or 2, characterized by a horizontal guide (14) that is disposed at one end of the hot side (8) and that provides the process air coming from the condenser (6) and the cold side (7) and traversing the hot side (8) from end to end to be horizontally returned by the side of the hot side (8).
- A laundry dryer (1) as in Claim 1, 2 or 5, characterized by two hot sides (8) disposed side by side and the horizontal guide (14) that is disposed at one end of the hot sides (8) and that joins the process air coming from the condenser (6) and the cold side (7) and traversing the hot sides (8) from end to end and provides it to be returned from between the two hot sides (8).
- A laundry dryer (1) as in any one of the above claims, characterized by an inner guide (13) that is disposed at the portion of the drying duct (3) connecting the condenser (6) and the cold side (7) with the hot side (8) and that guides the process air flows leaving the condenser (6) and the cold side (7) to the hot side (8) by separating them.