HEAT PUMP LAUNDRY DRYER

Description

[0001] The present invention relates to a heat pump laundry dryer comprising a variable speed compressor.

[0002] In heat pump laundry dryers, the heat pump used for drying the laundry is composed of a cooling line wherein the refrigerant flows, an evaporator, a condenser and a compressor that provides the circulation of the refrigerant by pressurizing it. The drying process is performed by passing the processing air over the laundry in the closed cycle. The condenser heats the processing air and the evaporator condenses the processing air. In the refrigerant cycle, the refrigerant delivered to the condenser from the compressor with increased pressure and temperature is delivered to the evaporator by passing through the expansion member, for example the capillary tube, or the expansion valve with decreased pressure. In heat pump laundry dryers, a variable speed compressor is required for reducing the duration of the drying process and the energy consumption. When the drying load increases according to the drying program selected by the user, the compressor is operated at high speed. A circuit board is used for adjusting the speed of the compressor and a heat sink is disposed on the circuit board for cooling the electronic elements through which high current flows. The current that flows through the circuit board used for adjusting the speed of the compressor varies depending on the speed of the compressor. The components heating up due to the high current on the compressor circuit board are cooled by natural convection by means of a heat sink placed on the circuit board. When the drying load increases in the heat pump laundry dryer, the temperature of the circuit board increases excessively depending on the increase in the speed of the compressor and the heat sink becomes insufficient for cooling the circuit board.

[0003] In the state of the art European Patent Application No. EP2312049, in the heat pump laundry dryer, the control circuit of the electric motor driving the drum, the processing air fan and/or the compressor, is at least partially placed between the evaporator and the condenser, inside the air stream circuit. The humid air passing through the evaporator without fully condensing condenses on the electronic control circuit and causes the control circuit to be damaged.
European Patent Application EP 2 527 518 A1 discloses an articles treatment apparatus having a refrigerant loop comprising a first heat exchanger for heating a refrigerant, a second heat exchanger for cooling the refrigerant, a refrigerant expansion device, and a compressor. A refrigerant condition detector such as a temperature sensor is arranged at or in fluid connection to the refrigerant loop, wherein a safety unit is configured to detect an overpressure state in the refrigerant loop.

[0004] The aim of the present invention is the realization of a heat pump laundry dryer comprising a variable speed compressor and wherein the circuit board that controls the compressor is prevented from overheating.

[0005] The heat pump laundry dryer realized in order to attain the aim of the present invention comprises a variable speed compressor the speed of which is adjusted by means of a circuit board according to the drying setting selected by the user and the amount of the laundry.

[0006] The components on the circuit board are cooled by a heat sink and a cooling fan that cools the heat sink by forced convection.

[0007] A temperature sensor placed on the circuit board or the heat sink detects the heating level of the circuit board. The temperature of the circuit board varies depending on the speed of the compressor and the control unit provides the cooling of the heat sink and hence the circuit board in accordance with the amount of increase in the temperature thereof by increasing/decreasing the speed of the cooling fan.

[0008] The control unit provides the speed of the cooling fan to be increased upon detecting by means of the temperature sensor that the temperature of the circuit board is higher than the predetermined limit value and provides the speed of the cooling fan to be decreased or the cooling fan to be stopped upon detecting that the temperature of the circuit board is lower than the limit value.

[0009] In an embodiment of the present invention, upon detecting that the temperature of the circuit board is high, the control unit decides that the temperature of the compressor is increased excessively and provides the speed of the compressor to be decreased or the speed of the processing air fan to be increased.

[0010] In another embodiment of the present invention, the control unit provides the speed of the compressor cooling fan to be increased upon detecting that the temperature of the circuit board is high.

[0011] In another embodiment of the present invention, the control unit decides that the condensing efficiency of the evaporator is low and the compressor is overheated by operating excessively upon detecting that the temperature of the circuit board is high. The control unit enables the flow rate of the refrigerant passing through the expansion member to be increased and decreases the compressor duty cycle by increasing the efficiency of the evaporator.

[0012] In another embodiment of the present invention, the circuit board is placed behind the front panel whereon the main control unit, the display and the buttons are mounted. Thus, the circuit board is positioned away from the compressor and prevented from being affected due to heat and moisture.

[0013] In the laundry dryer of the present invention, the circuit board that operates the variable speed compressor is cooled in accordance with the changes in the compressor speed and the components on the circuit board are prevented from being damaged. The efficiency of the compressor is increased by adjusting the speeds of the compressor, the processing air fan and/or the drum motor and energy consumption is reduced.

[0014] The laundry dryer realized in order to attain the aim of the present invention is illustrated in the attached figure, where:

[0015] Figure 1 - is the schematic view of a heat pump laundry dryer comprising variable speed compressor.

[0016] The elements illustrated in the figure are numbered as follows:

1.

Laundry dryer

2.

Drum

3.

Processing air fan

4.

Air circulation duct

5.

Compressor

6.

Evaporator

7.

Condenser

8.

Expansion member

9.

Circuit board

10.

Heat sink

11.

Control unit

12.

Temperature sensor

13.

Cooling fan

14.

Compressor fan

15.

Front panel

[0017] The heat pump laundry dryer (1) comprises a drum (2) wherein the laundry to be dried is placed, a processing air fan (3), an air circulation duct (4) wherein the air cycle is performed by means of the processing air fan (3), a variable speed compressor (5) that performs the refrigerant cycle, that provides the suction and discharge of the refrigerant, the speed of which is adjusted in accordance with the drying load, an evaporator (6) that cools and condenses the processing air, a condenser (7) that provides the processing air to be heated, an expansion member (8) disposed on the cooling line, between the condenser (7) and the evaporator (6), a circuit board (9) that drives the compressor (5), a heat sink (10) that provides the components on the circuit board (9) to be cooled and a control unit (11) that regulates the operation of the laundry dryer (1).

[0018] The laundry dryer (1) of the present invention comprises

• a temperature sensor (12) placed on the circuit board (9) or the heat sink (10) and that detects the temperature of the compressor (5) circuit board (9),
• a cooling fan (13) placed near the heat sink (10) and that provides the circuit board (9) to be cooled by forced convection over the heat sink (10) and
• a control unit (11) that changes the speed of the cooling fan (13) according to the data received from the temperature sensor (12) and thus provides the circuit board (9) to be cooled in accordance with the heating level thereof that changes depending on the changes in the speed of the compressor (5).

[0019] In the laundry dryer (1) of the present invention, a variable speed compressor (5), which is also known as "inverter" type, is used. The circuit board (9) changes the speed (rpm) of the compressor (5) in accordance with the drying program selection of the user. When drying load increases, the compressor (5) is operated at high speed. When the speed of the compressor (5) is increased, the temperature of the components on the circuit board (9) also increase and the temperature sensor (12) that is directly placed on the circuit board (9) or on the heat sink (10) detects the increase of temperature in the circuit board (9).

[0020] The control unit (11) increases the speed of the cooling fan (13) and thus speeds up the cooling of the circuit board (9) upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the limit value predetermined by the experimental studies and recorded in the memory thereof.

[0021] The control unit (11) decreases the speed of the cooling fan (13) or stops the cooling fan (13) upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is lower than the predetermined limit value and thus prevents unnecessary energy consumption.

[0022] In an embodiment of the present invention, upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value, the control unit (11) decides that the temperature of the compressor (5) is increased and sends command to the circuit board (9) and thus provides the speed of the compressor (5) to be decreased and prevents the compressor (5) from overheating.

[0023] In another embodiment of the present invention, upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value, the control unit (11) decides that the temperature of the compressor (5) is increased and increases the speed of the processing air by increasing the speed of the processing air fan (3) and thus provides the load of the compressor (5) to be reduced and prevents the compressor (5) from overheating. The electric motor (not illustrated in the figures) that drives the processing air fan (3) drives the drum (2) as well, when the speed of the processing air fan (3) is increased, the speed of the drum (2) is also increased, a greater amount of the drying load is compensated by the processing air cycle and the load of the compressor (5) is reduced.

[0024] In another embodiment of the present invention, the laundry dryer (1) comprises a compressor fan (14) that provides the compressor (5) to be cooled, and upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value, the control unit (11) decides that the temperature of the compressor (5) is increased and increases the speed of the compressor fan (14).

[0025] In another embodiment of the present invention, the expansion member (8) is an expansion valve wherein the flow of the refrigerant can be adjusted, and upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value, the control unit (11) decides that the evaporator (6) cannot perform sufficient condensing and provides the flow rate of the refrigerant passing through the expansion member (8) to be increased. Thus, the condensing effectiveness of the evaporator (6) is increased and overheating is prevented by reducing the compressor (5) duty cycle.

[0026] In an embodiment of the present invention, the laundry dryer (1) comprises a front panel (15) whereon the control unit (11), the display and the buttons (not shown in the figures) are mounted and the circuit board (9) is placed near the control unit (11), behind the front panel (15). The circuit board (9) is positioned away from the area where the compressor (5) is disposed and thus prevented from being affected due to heat and moisture.

[0027] In the laundry dryer (1) of the present invention, the components on the circuit board (9) that drives the variable speed compressor (5) are prevented from being damaged due to overheating. The efficiency of the compressor (5) is increased by adjusting the speeds of the compressor (5), the processing air fan (3) and/or the drum (2) motor and energy consumption is reduced.

Claims

1. A laundry dryer (1) comprising

- a drum (2),

- a processing air fan (3),

- an air circulation duct (4),

- a variable speed compressor (5) that performs the refrigerant cycle, the speed of which is adjusted in accordance with the drying load,

- an evaporator (6) that cools and condenses the processing air,

- a condenser (7) that provides the processing air to be heated,

- an expansion member (8) disposed between the condenser (7) and the evaporator (6),

- a circuit board (9) that drives the compressor (5),

- a heat sink (10) that provides the components on the circuit board (9) to be cooled,

- a control unit (11),

- a temperature sensor (12) placed on the circuit board (9) or the heat sink (10) and that detects the temperature of the circuit board (9),

characterized by

- a cooling fan (13) placed near the heat sink (10) and that provides the circuit board (9) to be cooled by forced convection and

- the control unit (11) that provides the speed of the cooling fan (13) to be changed according to the data received from the temperature sensor (12) and thus provides the circuit board (9) to be cooled in accordance with the heating level thereof that changes depending on the speed of the compressor (5).

2. The laundry dryer (1) as in Claim 1, characterized by the control unit (11) that provides the speed of the cooling fan (13) to be increased upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value.

3. The laundry dryer (1) as in Claim 1, characterized by the control unit (11) that provides the speed of the cooling fan (13) to be decreased or the cooling fan (13) to be stopped upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is lower than the predetermined limit value.

4. The laundry dryer (1) as in any one of the above claims, characterized by the control unit (11) that decides that the temperature of the compressor (5) is increased and provides the speed of the compressor (5) to be decreased by sending command to the circuit board (9) upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value.

5. The laundry dryer (1) as in any one of the above claims, characterized by the control unit (11) that provides the speed of the processing air fan (3) to be increased upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value.

6. The laundry dryer (1) as in any one of the above claims, characterized by a compressor fan (14) providing the compressor (5) to be cooled and by the control unit (11) that provides the speed of the compressor fan (14) to be increased upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value.

7. The laundry dryer (1) as in any one of the above claims, characterized by the expansion member (8) which is an expansion valve wherein the flow of the refrigerant can be adjusted and by the control unit (11) that decides that the evaporator (6) cannot perform sufficient condensing and provides the flow rate of the refrigerant passing through the expansion member (8) to be increased upon detecting by means of the temperature sensor (12) that the temperature of the circuit board (9) is higher than the predetermined limit value.

8. The laundry dryer (1) as in any one of the above claims, characterized by a front panel (15) whereon the control unit (11), the display and the buttons are mounted and by the circuit board (9) placed near the control unit (11), behind the front panel (15).

Ansprüche

1. Wäschetrockner (1), umfassend

- eine Trommel (2),

- ein Prozessluftgebläse (3),

- eine Luftzirkulationsleitung (4),

- einen Kompressor mit variabler Drehzahl (5), der den Kühlzyklus ausführt und dessen Drehzahl gemäß der zu trocknenden Ladung eingestellt wird,

- einen Verdampfer (6), der die Prozessluft kühlt und kondensiert,

- einen Kondensator (7), der dafür sorgt, dass die Prozessluft erwärmt wird,

- ein Expansionselement (8), das zwischen dem Kondensator (7) und dem Verdampfer (6) angeordnet ist,

- eine Leiterplatte (9), die den Kompressor (5) antreibt,

- eine Wärmesenke (10), die dafür sorgt, dass die Komponenten an der Leiterplatte (9) gekühlt werden,

- eine Steuereinheit (11),

- einen Temperatursensor (12), der an der Leiterplatte (9) oder der Wärmesenke (10) angeordnet ist und die Temperatur der Leiterplatte (9) misst,

dadurch gekennzeichnet, dass

- ein Kühlgebläse (13), das nahe der Wärmesenke (10) angeordnet ist und dafür sorgt, dass die Leiterplatte (9) mittels Zwangskonvektion gekühlt wird, und

- die Steuereinheit (11), die dafür sorgt, dass die Drehzahl des Kühlgebläses (13) gemäß Daten geändert wird, die von dem Temperatursensor (12) empfangen werden, und so dafür sorgt, dass die Leiterplatte (9) gemäß ihrem Erwärmungsgrad gekühlt wird, der sich je nach Drehzahl des Kompressors (5) ändert.

2. Wäschetrockner(1) nach Anspruch 1, dadurch gekennzeichnet, dass die Steuereinheit (11) dafür sorgt, dass die Drehzahl des Kühlgebläses (13) erhöht wird, wenn durch den Temperatursensor (12) gemessen wird, dass die Temperatur der Leiterplatte (9) höher als ein vorgegebener Grenzwert ist.

3. Wäschetrockner (1) nach Anspruch 1, dadurch gekennzeichnet, dass die Steuereinheit (11) dafür sorgt, dass die Drehzahl des Kühlgebläses (13) reduziert wird oder das Kühlgebläse (13) angehalten wird, wenn durch den Temperatursensor (12) gemessen wird, dass die Temperatur der Leiterplatte (9) niedriger als der vorgegebene Grenzwert ist.

4. Wäschetrockner (1) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass die Steuereinheit (11) entscheidet, dass die Temperatur des Kompressors (5) sich erhöht hat, und dafür sorgt, dass die Drehzahl des Kompressors (5) reduziert wird, indem sie einen Befehl an die Leiterplatte (9) sendet, wenn durch den Temperatursensor (12) gemessen wird, dass die Temperatur der Leiterplatte (9) höher als der vorgegebene Grenzwert ist.

5. Wäschetrockner (1) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass die Steuereinheit (11) dafür sorgt, dass die Drehzahl des Prozessluftgebläses (3) erhöht wird, wenn durch den Temperatursensor (12) gemessen wird, dass die Temperatur der Leiterplatte (9) höher als der vorgegebene Grenzwert ist.

6. Wäschetrockner (1) nach einem der vorangehenden Ansprüche, gekennzeichnet durch ein Kompressorgebläse (14), das dafür sorgt, dass der Kompressor (5) gekühlt wird, und dadurch, dass die Steuereinheit (11) dafür sorgt, dass die Drehzahl des Kompressorgebläses (14) erhöht wird, wenn durch den Temperatursensor (12) gemessen wird, dass die Temperatur der Leiterplatte (9) höher als der vorgegebene Grenzwert ist.

7. Wäschetrockner (1) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass das Expansionselement (8) ein Expansionsventil ist, in dem der Fluss des Kältemittels eingestellt werden kann, und dass die Steuereinheit (11) entscheidet, dass der Verdampfer (6) keine ausreichende Kondensation bereitstellen kann, und dafür sorgt, dass die Durchflussrate des Kähltemittels durch das Expansionselement (8) erhöht wird, wenn durch den Temperatursensor (12) gemessen wird, dass die Temperatur der Leiterplatte (9) höher als der vorgegebene Grenzwert ist.

8. Wäschetrockner (1) nach einem der vorangehenden Ansprüche, gekennzeichnet durch eine Frontblende (15), an der die Steuereinheit (11), die Anzeige und die Tasten angebracht sind, und dadurch, dass die Leiterplatte (9) in der Nähe der Steuereinheit (11) hinter der Frontblende (15) angeordnet ist.

Revendications

1. Un sèche-linge (1) comprenant :

- un tambour (2),

- un ventilateur d'air de processus (3),

- un conduit de circulation d'air (4),

- un compresseur à vitesse variable (5) qui effectue le cycle de fluide frigorigène, dont la vitesse est réglée conformément à la charge de séchage,

- un évaporateur (6) qui refroidit et condense l'air de processus,

- un condenseur (7) qui permet le chauffage de l'air de processus,

- un élément d'expansion (8) qui est disposé entre le condenseur (7) et l'évaporateur (6),

- une carte de circuit imprimée (9) qui entraîne le compresseur (5),

- un dissipateur thermique (10) qui permet le refroidissement des éléments sur la carte de circuit imprimée (9),

- une unité de commande (11)

- un capteur de température (12) qui est placé sur la carte de circuit imprimée (9) ou sur le dissipateur thermique (10) et qui détecte la température de la carte de circuit imprimée (9),

caractérisé par

- un ventilateur de refroidissement (13) qui est disposé à proximité du dissipateur thermique (10) et qui permet le refroidissement de la carte de circuit imprimée (9) par convection forcée et

- l'unité de commande (11) qui permet le changement de la vitesse du ventilateur de refroidissement (13) en fonction des données reçues du capteur de température (12) et donc permet le refroidissement de la carte de circuit imprimée (9) conformément au niveau de chauffage de celle-ci qui change en fonction de la vitesse du compresseur (5).

2. Un sèche-linge (1) selon la Revendication 1, caractérisé par l'unité de commande (11) qui permet l'augmentation de la vitesse du ventilateur de refroidissement (13) en détectant par le capteur de température (12) que la température de la carte de circuit imprimée (9) est supérieure à la valeur limite prédéterminée.

3. Un sèche-linge (1) selon la Revendication 1, caractérisé par l'unité de commande (11) qui permet la diminution de la vitesse du ventilateur de refroidissement (13) ou l'arrêt du ventilateur de refroidissement (13) en détectant par le capteur de température (12) que la température de la carte de circuit imprimée (9) est inférieure à la valeur limite prédéterminée.

4. Un sèche-linge (1) selon l'une quelconque des revendications précédentes, caractérisé par l'unité de commande (11) qui décide que la température du compresseur (5) est augmentée et permet la diminution de la vitesse du compresseur (5) par une commande délivrée à la carte de circuit imprimée (9) en détectant par le capteur de température (12) que la température de la carte de circuit imprimée (9) est supérieure à la valeur limite prédéterminée.

5. Un sèche-linge (1) selon la Revendication 1, caractérisé par l'unité de commande (11) qui permet l'augmentation de la vitesse du ventilateur d'air de processus (3) en détectant par le capteur de température (12) que la température de la carte de circuit imprimée (9) est supérieure à la valeur limite prédéterminée.

6. Un sèche-linge (1) selon la Revendication 1, caractérisé par un ventilateur de compresseur (14) qui permet le refroidissement du compresseur (5) et par l'unité de commande (11) qui permet l'augmentation de la vitesse du ventilateur de compresseur (14) en détectant par le capteur de température (12) que la température de la carte de circuit imprimée (9) est supérieure à la valeur limite prédéterminée.

7. Un sèche-linge (1) selon l'une quelconque des revendications précédentes, caractérisé par l'élément d'expansion (8) qui est une soupape d'expansion où l'écoulement du fluide frigorigène peut être ajustée et par l'unité de commande (11) qui décide que l'évaporateur (6) ne peut pas effectuer suffisamment de condensation et permet l'augmentation du débit du fluide frigorigène passant à travers l'élément d'expansion (8) en détectant par le capteur de température (12) que la température de la carte de circuit imprimée (9) est supérieure à la valeur limite prédéterminée.

8. Un sèche-linge (1) selon l'une quelconque des revendications précédentes, caractérisé par un panneau avant (15) sur lequel l'unité de commande (11), l'affichage et les boutons sont montés et par la carte de circuit imprimée (9) qui est disposée à proximité de l'unité de commande (11) derrière le panneau avant (15).

Drawing