Method for controlling a laundry dryer including a fan motor for driving a drying air stream fan with a variable speed

Patent metadata

Field	Value
Publication number	US-9758921-B2
Application number	US-201314647243-A
Country	US
Kind code	B2
Filing date	Nov 18, 2013
Priority date	Nov 26, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A method is provided for controlling a laundry dryer including a fan motor ( 26 ) for driving a drying air stream fan ( 18 ) with a variable speed (vf) and a drum motor ( 28 ) for driving a laundry drum ( 12 ). The method comprises the steps of setting a predetermined course for the speed (vd) of the drum motor ( 28 ), maintaining the speed (vd) of the drum motor ( 28 ) according to the predetermined course for the speed (vd) of said drum motor ( 28 ), detecting a power (Pd) or a current absorbed by the drum motor ( 28 ), and controlling the speed (vf) of the fan motor ( 26 ) on the basis of the absorbed power (Pd) or current of the drum motor ( 28 ). The speed (vf) of the fan motor ( 26 ) increases with a decreasing absorbed power (Pd) or current of the drum motor ( 28 ) and/or the speed (vf) of the fan motor ( 26 ) decreases with an increasing absorbed power (Pd) or current of the drum motor ( 28 ).

First claim

The invention claimed is:

1. A method for controlling a laundry dryer including a fan motor for driving a drying air stream fan with a variable speed (vf) and a drum motor for driving a laundry drum, said method comprising the steps of:
setting a predetermined course for the speed (vd) of the drum motor,
maintaining the speed (vd) of the drum motor according to the predetermined course for the speed (vd) of said drum motor,
detecting a power (Pd) or a current absorbed by the drum motor, and
controlling the speed (vf) of the fan motor on the basis of the absorbed power (Pd) or current of the drum motor, wherein
the speed (vf) of the fan motor increases with a decreasing absorbed power (Pd) or current of the drum motor and/or
the speed (vf) of the fan motor decreases with an increasing absorbed power (Pd) or current of the drum motor.

2. The method according to claim 1 , wherein the steps of setting the predetermined course for the speed (vd) of the drum motor and of maintaining the speed (vd) of the drum motor according to the predetermined course for the speed (vd) of said drum motor comprise controlling an inverter motor according to a predetermined speed profile.

3. The method according to claim 1 , wherein the speed (vf) of the fan motor starts with a predetermined speed value, and after starting the fan motor with said predetermined speed value, the speed (vf) of the fan motor is modified on the basis of the absorbed power (Pd) or current of the drum motor.

4. The method according to claim 1 , wherein the step of controlling the speed (vf) of the fan motor on the basis of the absorbed power (Pd) or current of the drum motor occurs after a drying cycle starting phase including the step of detecting the power (Pd) or current absorbed by the drum motor, respectively.

5. The method according to claim 1 , wherein the course for the speed (vd) of the drum motor is a periodic function, and said periodic function oscillates around an average value of the speed (vd).

6. The method according to claim 1 , wherein the speed (vf) of the fan motor increases linearly with the decreasing absorbed power (Pd) or current of the drum motor, respectively, and/or the speed (vf) of the fan motor decreases linearly with the increasing absorbed power (Pd) or current of the drum motor, respectively.

7. The method according to claim 1 , wherein a maximum level for the speed (vf) of the fan motor is defined, and said maximum level depends on the noise generated by the air steam fan and/or on the power absorbed by the fan motor and/or on the flow rate generated by the fan motor.

8. The method according to claim 1 , wherein the method is provided for a laundry dryer with a heat pump system, and a rotation speed or power of a compressor of said heat pump system is controlled in dependence of the speed (vf) of the fan motor, and the rotation speed or power of the compressor increases with an increasing speed (vf) of the fan motor.

9. A laundry dryer including a drying air stream circuit with a laundry drum and a drying air stream fan, wherein:
the laundry dryer comprises a drum motor for driving the laundry drum,
the laundry dryer comprises a fan motor for driving the drying air stream fan,
the laundry dryer comprises a control unit for controlling the speed (vf) of the fan motor and the speed (vd) of the drum motor,
the control unit is configured to set a predetermined course for the speed (vd) or the power (Pd) of the drum motor,
the control unit is configured to maintain the speed (vd) or power (Pd), respectively, of the drum motor according to the predetermined course,
the control unit is configured to detect the power (Pd) or current absorbed by the drum motor or the speed (vd) of said drum motor,
the control unit is configured to control the speed (vf) of the fan motor on the basis of the power (Pd) or current absorbed by the drum motor or the speed (vd) of said drum motor, so that:
the speed (vf) of the fan motor increases with a decreasing power (Pd) or current absorbed by the drum motor or with an increasing speed (vd) of said drum motor, respectively, and/or
the speed (vf) of the fan motor decreases with an increasing power (Pd) or current absorbed by the drum motor or with a decreasing speed (vd) of said drum motor, respectively; and
wherein the laundry dryer is configured to carry out the method according to claim 1 .

10. The laundry dryer according to claim 9 , wherein the fan motor is an inverter motor.

11. The laundry dryer according to claim 9 , wherein a heat pump system with a refrigerant compressor is provided.

12. The laundry dryer according to claim 11 , wherein the control unit is adapted to adjust the rotation speed or power of said refrigerant compressor in dependence of the speed of the fan motor.

13. A laundry dryer including a drying air stream circuit with a laundry drum and a drying air stream fan, wherein:
the laundry dryer comprises a drum motor for driving the laundry drum,
the laundry dryer comprises a fan motor for driving the drying air stream fan,
the laundry dryer comprises a control unit for controlling the speed (vf) of the fan motor and the speed (vd) of the drum motor,
the control unit is configured to set a predetermined course for the speed (vd) or the power (Pd) of the drum motor,
the control unit is configured to maintain the speed (vd) or power (Pd), respectively, of the drum motor according to the predetermined course,
the control unit is configured to detect the power (Pd) or current absorbed by the drum motor or the speed (vd) of said drum motor,
the control unit is configured to control the speed (vf) of the fan motor on the basis of the power (Pd) or current absorbed by the drum motor or the speed (vd) of said drum motor, so that:
the speed (vf) of the fan motor increases with a decreasing power (Pd) or current absorbed by the drum motor or with an increasing speed (vd) of said drum motor, respectively, and/or
the speed (vf) of the fan motor decreases with an increasing power (Pd) or current absorbed by the drum motor or with a decreasing speed (vd) of said drum motor, respectively; and

wherein the laundry dryer is configured to carry out a method comprising the steps of:
setting a predetermined course for the power (Pd) of the drum motor,
maintaining the speed (vd) of the drum motor according to the predetermined course for the power (Pd) of said drum motor,
detecting a speed (vd) of the drum motor, and
controlling the speed (vf) of the fan motor on the basis of the speed (vd) of the drum motor, wherein
the speed (vf) of the fan motor increases with an increasing speed (vd) of the drum motor, and/or
the speed (vf) of the fan motor decreases with a decreasing speed (vd) of the drum motor.

Assignees

• Electrolux Home Products Corp Nv

Inventors

• Bison Alberto
• Cavarretta Francesco
• Ugel Maurizio
• Vignocchi Massimiliano

Classifications

• D06F2103/50

  related to heat pumps, e.g. pressure or flow rate · CPC title

• D06F2103/36

  Flow or velocity · CPC title

• D06F2105/24

  Flow or velocity · CPC title

• D06F2105/26

  Heat pumps · CPC title

• D06F2105/46

  Drum speed; Actuation of motors, e.g. starting or interrupting · CPC title