WO2015155009A1

WO2015155009A1 - Dryer having a low-vibration heat pump, and method for operating said dryer

Info

Publication number: WO2015155009A1
Application number: PCT/EP2015/056416
Authority: WO
Inventors: Marcus Simon; Gianfranco Cesar ZUAZO RODRIGUEZ
Original assignee: BSH Hausgeräte GmbH
Priority date: 2014-04-07
Filing date: 2015-03-25
Publication date: 2015-10-15
Also published as: PL3129540T3; EP3129540A1; EP3129540B1; DE102014206650A1

Abstract

The invention relates to a dryer 1 having a drum 2 for laundry items to be dried; a process-air circuit 3; a fan 12 for conveying process air; a control unit 4; and a heat pump circuit 8, 9, 10, 11, 20, 22 comprising an evaporator 8, a condenser 9, a throttle 10, a compressor 11 and a pipe system 20, 22 interconnecting the above, a vibration generator 5 being provided, which is in mechanical contact with the pipe system 20, 22.

Description

Dryer with a low-vibration heat pump and method of operation

The invention relates to a dryer with a low-vibration heat pump and a method for its operation. In particular, the invention relates to a dryer with a drum for items to be dried; a process air cycle; a blower for conveying process air; a control unit and a heat pump cycle comprising an evaporator, a condenser, a throttle, a compressor and a piping system connecting them; and a preferred method for its operation.

In a dryer air (so-called process air) by a fan via a heater in a moist objects containing drying chamber, usually a drum, passed. There, the hot air absorbs moisture from the objects to be dried. After passing through the drying chamber, the then warm moist process air is passed into a heat exchanger, which is generally preceded by a filter, in particular a lint filter, for filtering out dirt particles, in particular lint in the case of a tumble dryer or washer dryer.

This drying process is very energy-intensive, since as a rule, the process air is energetically lost before the application of heat to the objects to be dried when cooling the process air in the heat exchanger process heat. When using a heat pump, this energy loss is significantly reduced. The heat pump can serve to extract heat from the moist, warm process air, which is supplied by a corresponding heat sink, and to conduct this heat by means of a suitable pumping device to a heat source from which it returns to the process air before it acts on the objects to be dried. Alternatively, heat can also be removed by means of the heat sink from an environment of the dryer and fed to the process air via the heat source. In a dryer equipped with a compressor-type heat pump (also referred to herein as a "compressor type"), the cooling of the warm, moisture-laden process air essentially takes place in a heat sink Evaporator of the heat pump where the heat transferred is used to evaporate a refrigerant circulating in the heat pump. The vaporized refrigerant reaches the compressor where it is compressed. The refrigerant circulating in the refrigerant circuit is driven by the compressor, which supplies the energy necessary to operate the pumping process. From the compressor, the refrigerant passes to the condenser, where it is liquefied with the release of heat. The heat released heats the process air. The liquefied refrigerant flows through a throttle, where its internal pressure is reduced, back to the evaporator, which closes the circuit. The throttle is in particular executable as a valve, aperture or capillary. Often the heat pump cycle is operated capillary tube controlled. The condensed in the evaporator from the process air water is then generally collected in a suitable container.

A heat pump tumble dryer generally includes a closed process air loop and a heat pump loop (also referred to herein as a "refrigerant loop"). The heat pump cycle, in addition to the two heat exchangers evaporator and condenser and the compressor (compressor) and the throttle in particular also a pipe system connecting these parts. The operation of the compressor introduces mechanical vibrations at certain frequencies (i.e., acceleration values) and amplitudes (i.e., deflections) into the heat pump cycle. In this case, the resonance frequencies of the heat pump cycle are taken into account in the design of the piping system to allow the longest possible and safe operation of the heat pump cycle and thus the dryer. Measures to compensate for the generated mechanical vibrations (also referred to herein as "vibrations") are already known.

For example, EP 2 628 838 A1 describes a household appliance with a drying device such as a tumble dryer, a washer dryer or a dishwashing machine, the drying being carried out by or with the assistance of a heat pump arrangement which includes a rotary compressor, in particular a rotary compressor, and wherein at least one compressor is used as a vibration damper oscillatory mass assigned is net whose natural frequency is tuned to the torsional vibrations generated by the compressor. In this case, the compressor preferably comprises an at least approximately hollow cylindrical stator and the oscillatory mass is arranged at least around a part of the stator jacket around. EP 2 559 804 A1 and WO 2013/024127 A1 each describe a domestic appliance, in particular a dryer, which comprises a drive unit for a heat pump, in particular a compressor. In order to achieve a lower energy consumption and better stability by reducing the vibration energy, the drive unit is connected via a mechanical fastening device with another component of the household appliance. The mechanical fastening device comprises an elastic grommet. Also described is a method for operating the drive unit in the household appliance, in which a drive speed, in particular the rotational speed of a compressor, is limited to a value below a threshold value.

JP 201 1 - 177 312 A describes a motor drive unit with a motor in which a vibration detector (vibration detector) is installed at a predetermined position in the motor and indicates a mechanical vibration of the motor, and a vibration output corrector which corrects the output of the vibration detector , This should be done during operation of the engine vibration suppression to avoid noise and to prevent deterioration of the machine.

U.S. Patent 5,836,165 describes an adaptive feedforward control system and method for reducing vibration generated by a pair of opposed reciprocating pistons, the control system being controlled by a sensor, in particular a vibration sensor, through the compressor pistons measures generated vibration forces and then generates correction signals, which are passed into the piston drive motors to compensate for the vibrations.

US Pat. No. 6,131,394 describes a system and method for active vibration control in a cryogenic cooling system, in particular in an electromechanical cooling system (EMC). EP 2 460 929 A1 describes a tumble dryer with a heat pump device which is coupled as a separate functional module to a side wall of the tumble dryer housing to guide the process air through the functional module, wherein the functional module comprises a separate housing and releasably coupled to the tumble dryer housing by means of the module housing is. Preferably, between the side wall of the dryer housing and the dryer-facing wall of the functional module housing surrounding the opening a seal for sealing the process air circuit is arranged. As a result, vibrations from the heat pump module are not transmitted to the larger side walls of the dryer housing, thus avoiding unpleasant noises.

The publication DE 10 2012 105 670 A1 describes a domestic appliance with a drying device, such as a tumble dryer, washer-dryer or dishwasher, wherein the drying is carried out by or with the assistance of a heat pump assembly comprising a rotary compressor, in particular a rotary compressor, by means of pipelines for transporting the refrigerant in the heat pump assembly is integrated. The high-pressure pipe is designed to receive the torsional vibrations generated by the compressor from the compressor to the heat exchanger meandering and / or spiral. The pipeline is arranged in two approximately mutually perpendicular planes, wherein a pipeline section lies in the first plane and a second pipeline section lies in the second plane.

The publication DE 10 201 1 079 443 A1 describes a method for operating a heat pump dryer, in particular a circulating air heat pump dryer, wherein at least one operating parameter (ω, P) of a compressor is monitored, the compressor either with a constant speed ω or a constant power P is operated and the power P or the rotational speed ω is monitored accordingly. The operating parameters are monitored for abnormal increases or decreases in order to quickly detect a fault condition and take action. The publication DE 10 2008 01 1 454 A1 describes a compression heat pump with a compressor, a condenser, a decompression device, an evaporator, a closed piping circuit for connecting the aforementioned components, a circulating through the piping circuit and the above components refrigerant and a control device for controlling a Heat pump process, wherein the compressor is connected to a connected to the controller for controlling sensor for monitoring the operation of the compressor. The sensor measures operating parameters of the compressor and the control unit compares the measured values with at least one predefinable limit value. If a limit value is exceeded, the heat pump process is changed via an actuator in the heat pump cycle in such a way that the measured values fall below the limit value.

Against this background, it was an object of the present invention to provide a tumble dryer (also abbreviated herein as a "dryer") with a heat pump, in which mechanical vibrations in the refrigerant circuit can be compensated in an efficient manner and a method for operating this should also be provided dryer.

The solution of this object is achieved according to this invention by a dryer and a method for operating a dryer with the features of the respective independent claim. Preferred embodiments of the inventive method and of the dryer according to the invention are listed in respective dependent claims, wherein preferred embodiments of the dryer according to the invention correspond to preferred embodiments of the method according to the invention and vice versa, even if this is not explicitly stated herein.

The invention thus relates to a dryer with a drum for laundry to be dried; a process air cycle; a blower for conveying process air; a control unit; and a heat pump cycle comprising an evaporator, a condenser, a throttle, a compressor, and a piping system connecting the same, and having a vibration transmitter in mechanical contact with the piping system. In general, the vibration transmitter is in mechanical contact with the point in the pipeline system where the greatest mechanical vibrations occur. In a preferred embodiment of the dryer according to the invention, therefore, the vibration sensor is located at a curved point of the pipeline system, ie at a point at which a pipeline is not rectilinear but has a more or less large curvature, eg a loop or a bend.

The vibration generator generally has the task of compensating as completely as possible the mechanical vibrations occurring during operation of the heat pump cycle. The vibration generator thus differs from the compressor in that the undesired vibrations generated by the compressor are at least partially compensated by counter vibrations generated by the vibration generator. Thus, the vibration generator can also be referred to as an active vibration compensator. Within the scope of this task, the vibration generator is not restricted according to the invention. Preferably, however, the vibration generator comprises an electric motor, wherein the vibration generator as the electric motor preferably has a linear electric motor with an imbalance. Such linear electric motors are used for example in electric toothbrushes.

The mechanical contact of the vibration generator with the piping system can be realized in different ways, depending in particular on the design of the vibration generator. Thus, an electric linear motor with an imbalance can be attached directly to a corresponding point of the pipeline system. The "restless" running of the electric motor can then be transmitted directly to the pipeline system, or alternatively, for example, a crank drive can be present, which is driven by an electric motor Such a crank drive may comprise, for example, a flywheel to which a crank rod is articulated eccentrically The connecting rod can in turn be connected in an articulated manner to the piping system and mechanical vibrations in the heat pump circuit can then be compensated via the control device and vibration programs V _n stored there for different situations for the vibration transmitter. In a preferred embodiment of the dryer, a temperature sensor S ^T WPK for direct or indirect measurement of a temperature T _{K of} the refrigerant is arranged in the dryer. In this case, the temperature sensor is preferably arranged in the heat pump cycle, in particular in direct contact with the refrigerant. The one or more temperature sensors preferably have an elongate body with a temperature sensitive tip. A preferred temperature sensor is an NTC sensor.

The term "sensor" as used herein means a single sensor or a system of sensors, Moreover, according to the invention, it is preferred that a relationship between a refrigerant temperature T _K and various vibration programs V _{n of} the vibration generator is stored in the control unit of the dryer. This relationship will usually depend on the location of the attachment of the vibration generator and in particular on the location of the mechanical contact between the vibration generator and the heat pump cycle.

The compressor used in the heat pump cycle is not restricted according to the invention. Preferably, however, the compressor is a variable capacity compressor and more preferably a variable speed compressor. Suitable compressors are, for example, screw compressors and rotary piston compressors. According to the invention, the compressor used is preferably a rotary piston compressor.

Moreover, it is inventively preferred that in the control unit, a relationship between a power P _v or a speed U _{v of} the compressor and various vibration programs V _{n of} the vibration generator is stored.

By means of the vibration generator mechanical vibrations in the refrigerant circuit can be compensated, the occurrence of which had previously been determined. The determination of vibrations can be done in different ways.

According to a preferred embodiment of the invention may be for a dryer in advance for different setup conditions or operating conditions, in particular a different operation of the heat pump cycle, location and operating parameter Depending on the course of mechanical vibrations are measured. Subsequently, these location and operating parameter-dependent vibration measurement results (vibration signals) can be stored for subsequent operation of the dryer in the control unit of the dryer. In this embodiment, therefore, the permanent presence of a vibration sensor in the dryer is not required lent.

In a further preferred embodiment of the invention, however, mechanical vibrations are measured at their occurrence and then compensated as soon as possible. For this purpose, a vibration sensor is preferably mounted in the heat pump cycle. The vibration sensor generally measures mechanical vibrations in the heat pump cycle, wherein the measured mechanical vibration signals are then transmitted to the control device usually for evaluation.

In the present invention, and in particular also in the two aforementioned embodiments, it is preferred that a relationship between measured vibration signals of the vibration sensor and different vibration programs V _{n of} the vibration generator is stored in the control unit.

In the dryer according to the invention, the control unit is preferably set up to switch off the dryer when a measured vibration signal of an optionally present vibration sensor has a critical vibration limit value V | _im attained or exceeded. This can ensure that overheating of the dryer and / or a mechanical impairment of dryer components can be prevented in case of operationally high mechanical vibrations, which indicate a malfunctioning operation of the heat pump cycle and / or a not properly running drying program.

The dryer of the invention preferably also has an optical and / or acoustic display device which can display to the user of the dryer a Schwingungskompen- sation by the operation of the vibration generator. Here, in particular, a degree of vibration compensation can be displayed appropriately. In Ausfüh Forms of the invention in which a vibration sensor is present in the refrigerant circuit can also be displayed when a measured vibration signal of the vibration sensor has a critical vibration limit V | _im attained or exceeded. Finally, an optical and / or acoustic display device also allows the display of eg operating parameters and / or an expected duration of the drying process.

The dryer according to the invention generally has a condensate tray for collecting the condensate occurring in the evaporator and optionally in another heat exchanger. From the condensate pan, the condensate is disposed of either by manual emptying or by pumping by means of a condensate pump in a condensate tank, which in turn can be emptied manually, or directly into a sewer system.

In the dryer according to the invention, a heat pump and an air-air heat exchanger can be used simultaneously. In this case, the heat pump and the air-air heat exchanger can complement one another during the cooling of moist, warm process air, for example by the fact that the air-air heat exchanger is used in particular in the event of an imminent overheating of the refrigerant.

For more rapid heating of the process air, an electric heater may additionally be present in the dryer according to the invention. If the dryer comprises an additional electric heater in one embodiment, a faster heating of the process air and thus a faster drying process in the dryer are possible. However, this would affect a possible energy savings.

The invention also relates to a method for operating a dryer with a drum for laundry to be dried; a process air cycle; a blower for conveying process air; a control unit; and a heat pump cycle comprising an evaporator, a condenser, a throttle, a compressor and a piping system connecting them; where a vibrational is present, which is in mechanical contact with the piping system; comprising the steps

(A) Performing a drying program for drying the wet laundry, wherein dry process air is heated and then fed into the drum;

(B) operation of the heat pump cycle by a refrigerant is moved by means of the compressor in the circulation and humid process air from the drum on the evaporator with condensation condensed moisture and then reheated at the condenser, wherein in the heat pump cycle mechanical vibrations are generated; and

(c) compensation of detected vibrations in the heat pump cycle by the vibration generator performs a vibration program V _n .

In a preferred embodiment of this method, the mechanical vibrations generated during operation (b) of the heat pump cycle are measured by means of a vibration sensor and based on a relationship stored in the control unit between measured vibration signals of the vibration sensor and different vibration programs V _{n of} the vibration generator, the vibration generator performs a vibration program V _n , In this case, "carrying out a vibration program V _n " generally means that the control unit activates the vibration transmitter in such a way that it generates vibrations of specific frequency and intensity according to the vibration program V _n and transmits them to the pipeline system in order to compensate as completely as possible for the mechanical vibrations occurring there ,

In the method according to the invention, it is also preferred that a temperature T _{K of} the refrigerant is measured by means of a temperature sensor S ^T _W PK arranged in the heat pump cycle. In the method according to the invention, a power-dependent compressor and even more preferably a variable-speed compressor is preferably used whose speed ω _{κ is} varied, for example, as a function of a measured refrigerant temperature T _R. Preferably, in this embodiment of the method according to the invention a speed ω _{κ of} a variable speed compressor depending on the measured temperature T _{K is} varied based on a stored in the control unit relationship between the speed ω _κ and the measured refrigerant temperature T _K , wherein the speed ω _κ with increasing Temperature T _K decreases.

In general, when using a variable-capacity compressor on reaching or exceeding a maximum allowable refrigerant temperature T _K M ^max, the power P of the variable-power compressor is reduced.

The value of T _K M ^max depends on the type of refrigerant and on the location of the temperature sensor in the heat pump cycle. For example, T _K M ^{max may be} very close to a maximum temperature specified by the manufacturer of a refrigerant for efficient and safe use of the refrigerant. Another factor may be the maximum allowable coil temperature of the drive motor of the compressor. This is influenced by the insulation used and is for example 1 15 ° C. Another limiting factor affecting T _K M ^max is the lubricant used in the compressor. Another important factor is the pressure of the gaseous refrigerant behind the compressor, which must be compared with the strength of the tubes used.

The invention has numerous advantages. Thus, the invention makes it possible for a dryer with a heat pump to be operated with low vibration or virtually vibration-free. This allows a longer life of the dryer, since its components are mechanically less stressed. In addition, the invention enables a better design of the drying process, in that drying programs can be carried out more efficiently, for example by not having to take into account certain resonance frequencies in the dryer. In this context, the invention also allows a more flexible design of the piping system, for example, a more direct piping, which can enable a Materialersparniss. Finally, in a dryer according to the invention or in a drying program carried out in such a dryer, a significant noise reduction is possible. The dryer according to the invention also has the advantage that it allows a safe execution of a drying program, wherein in embodiments and different setup conditions can be optimally taken into account.

Further details of the invention will become apparent from the following description of an embodiment of a dryer and a method using this dryer. Reference is made to FIGS. 1 and 2.

1 shows a vertical section through a dryer according to a first embodiment. and

Fig. 2 is a three-dimensional overview of a heat pump cycle.

1 shows a vertical section through a dryer according to a first embodiment, in which both a temperature sensor for measuring the temperature of the refrigerant and a vibration sensor for measuring vibrations in the refrigerant circuit are arranged in the refrigerant circuit. Other embodiments are conceivable.

The dryer 1 shown in FIG. 1 according to a first embodiment has a rotatable about a horizontal axis drum 2 as a drying chamber within which drivers 14 are mounted for movement of laundry items not shown here during a drum rotation. Process air is guided by means of a blower 12 through the drum 2 in a process air circuit 3. After passing through the drum 2, the moist, warm process air is passed into the evaporator 8 of a heat pump 8, 9, 10, 11, which also has a compressor 11, in this case a variable-speed compressor, a throttle 10 and a condenser 9 , Evaporator 8, condenser 9, throttle 10 and compressor 1 1 are interconnected by a piping system 20. In the refrigerant circuit in the embodiment shown here in addition to a vibration sensor 5, a vibration sensor, ie vibration sensor 7 and a temperature sensor S ^T _W PK 6 are available. In the embodiment shown here, the vibration generator 5 is arranged in the pipe section 22 between compressor 1 1 and condenser 9. The vibration transmitter 5 is in mechanical contact with the pipeline System 20,22, so that he can stimulate the piping system to compensate for mechanical vibrations occurring there to opposite vibrations. In addition, in the embodiment shown here, the vibration transmitter 5 is located at a curved point 25 of the pipeline system 20,22.

A method for operating this dryer comprises the steps:

(A) performing a drying program for drying the wet laundry, wherein dry process air is heated and then fed into the drum 2;

(B) operation of the heat pump cycle 8,9, 10, 1 1, 20,22 by a refrigerant is moved by means of the compressor 1 1 in the circulation and humid process air from the drum 2 at the evaporator 8 cooled to condense moisture and then the condenser 9 is reheated, wherein in the heat pump cycle 8.9, 10, 1 1, 20,22 mechanical vibrations are generated; and

(C) compensation in the heat pump cycle 8,9,10, 1 1, 20,22 determined mechanical vibrations by the vibration generator 5 performs a vibration program V _n .

The long arrows shown in FIG. 1 in the process air circuit 3 indicate the flow direction of the air, while the arrows shown in FIG. 1 in the refrigerant circuit indicate the flow direction of the refrigerant.

The vaporized in the evaporator 8 refrigerant heat pump 8,9, 10, 1 1 is passed through the speed-dependent compressor 1 1 to the condenser 9. In the condenser 9, the refrigerant liquefies with heat being released to the process air flowing in the process air circuit 3. The present in liquid form refrigerant is passed through the throttle 10 in turn to the evaporator 8, whereby the refrigerant circuit is closed. The temperature sensor S ^T _W PK 6 between evaporator 8 and compressor 1 1 measures in this embodiment, the temperature T _{K of} the refrigerant. This allows that for the operation of the vibration generator 5, the temperature T _{K of} the refrigerant can be taken into account, for which purpose a corresponding relationship is stored in the control unit. In the embodiment shown in FIG. 1, in addition to the condenser 9, an electric heater 18 is provided, which can be used for a more rapid heating of the process air. In other equivalent embodiments, the electric heater 18 may be omitted. In the dryer 1 of FIG. 1, heated air from the rear, ie, from the side of the drum 2 opposite the filling opening 17, passes through the perforated base into the drum 2, coming from there the laundry, not shown here, in contact and flows through the filling opening of the drum 2 to a lint filter 21 within the access door 17. Subsequently, the process air flow in the access door 17 is deflected downward. The process air is supplied in the process air circuit 3 to the evaporator 8, in which the warm, laden with moisture process air is cooled. The separated moisture is collected in a condensate collection container 23, from where it can be removed, for example by pumping.

The drum 2 is mounted in the embodiment shown in FIG. 1 at the rear bottom by means of a pivot bearing and front by means of a bearing plate 18, the drum 3 rests with a brim on a sliding strip 19 on the bearing plate 18 and is held at the front end. The control of the condensation dryer via a control unit 4, which can be controlled by the user via an operating unit 24.

An optical / acoustic display device 16 allows the user of the dryer 1, the display of the operation of the vibration generator 5, in particular also the scope of the compensation of vibrations of the heat pump cycle. In addition, here, the display device 16 indicates when a measured vibration signal of the vibration sensor 7 has a critical vibration threshold V | _im attained or exceeded. In addition, the display of eg operating parameters and / or an expected duration of the drying process is possible. In the method according to the invention process air is repeatedly circulated through the process air circuit 3 until preferably a desired degree of drying of the laundry is achieved. The dryer of Fig. 1 allows accurate and reliable control of the operation of the heat pump and in particular the vibrations of the refrigerant circuit.

Fig. 2 shows a three-dimensional overview of a heat pump cycle, as it can be used in a further embodiment of a dryer. The heat pump cycle here comprises an evaporator 8, a compressor 1 1, here a variable-speed compressor, a throttle 10 and a condenser 9. Evaporator 8, condenser 9, throttle 10 and compressor 1 1 are interconnected by a piping system 20. In the refrigerant circuit in the embodiment shown here in addition to a vibration sensor 5, a temperature sensor S ^T _W PK 6 is present. In the embodiment shown here, the vibration generator 5 is arranged in the pipe section 22 between compressor 1 1 and condenser 9. The vibration transmitter 5 is in mechanical contact with the pipeline system 20, 22, so that it can excite the pipeline system to compensate for mechanical vibrations occurring there against these oscillations. The double arrows show the direction of mechanical vibrations of the piping system 20, 22nd

reference numeral

1 dryer

2 drum

3 process air circulation

4 control unit

5 vibration transmitter

6 Temperature sensor S ^T _W PK in the refrigerant circuit for measuring a temperature T _{K of} the refrigerant

7 vibration sensor

8 evaporator

9 liquefier

10 throttle

1 1 compressor, variable capacity compressor

12 blowers

13 Electric heater

14 laundry pickup

15 operating device

16 optical / acoustic display device

17 access door

18 end shield

19 sliding strips

20 piping system

21 lint filter

22 Pipe section between compressor and condenser

23 condensate collecting container; Drain pan

24 operating unit

25 curved point of the piping system

Claims

Dryer (1) with a drum (2) for items to be dried; a process air circuit (3); a blower (12) for conveying process air; a control unit (4); and a heat pump cycle (8, 9, 10, 1, 20, 22) comprising an evaporator (8), a condenser (9), a throttle (10), a compressor (11) and a pipeline system (20) connecting the same , 22); characterized in that a vibration generator (5) is provided, which is in mechanical contact with the piping system (20,22).

Dryer (1) according to claim 1, characterized in that the vibration generator (5) is located at a curved point (25) of the pipeline system (20, 22).

Dryer (1) according to one of claims 1 and 2, characterized in that the vibration generator (5) comprises an electric motor.

Dryer (1) according to claim 3, characterized in that the vibration generator (5) has an electric linear motor with an imbalance as an electric motor.

Dryer (1) according to one of claims 1 to 4, characterized in that in the dryer, a temperature sensor S ^T _W PK (6) for direct or indirect measurement of a temperature T _{K of} the refrigerant is arranged.

Dryer (1) according to claim 5, characterized in that the temperature sensor S ^T WPK (6) in the heat pump cycle (8,9, 10, 1 1, 20,22) is arranged.

Dryer (1) according to one of claims 1 to 6, characterized in that in the control unit (4) a relationship between a refrigerant temperature T _K and various vibration programs V _{n of} the vibration generator (5) is deposited. Dryer (1) according to one of claims 1 to 7, characterized in that the compressor (1 1) is a variable-power compressor.

Dryer (1) according to claim 8, characterized in that the variable-power compressor (1 1) is a variable speed compressor.

Dryer (1) according to one of claims 7 to 9, characterized in that in the control unit (4) has a relationship between a power P _v or a speed U _{v of} the compressor (1 1) and different vibration programs V _{n of} the vibration generator (5) is deposited.

Dryer (1) according to one of claims 1 to 10, characterized in that in the heat pump cycle (8,9, 10,1 1, 20,22), a vibration sensor (7) is mounted.

Dryer (1) according to claim 1 1, characterized in that in the control unit (4) a relationship between measured vibration signals of the vibration sensor (7) and different vibration programs V _{n of} the vibration generator (5) is deposited.

Dryer (1) according to any one of claims 1 1 and 12, characterized in that the control unit (4) is arranged to turn off the dryer (1) when a measured vibration signal of the vibration sensor (7) has a critical vibration limit V | _im attained or exceeded.

Method for operating a dryer (1) with a drum (2) for items to be dried; a process air circuit (3); a blower (12) for conveying process air; a control unit (4); and a heat pump cycle (8, 9, 10, 11, 20, 22) comprising an evaporator (8), a condenser (9), a throttle (10), a compressor (11) and a pipeline system (20) connecting the same , 22); a vibration transmitter (5) is provided which is in mechanical contact with the piping system (20, 22); comprising the steps: (a) Perform a drying program to dry the wet ones

Laundry, wherein dry process air is heated and then fed into the drum (2);

(B) operation of the heat pump cycle (8,9, 10, 1 1, 20,22) by a refrigerant by means of the compressor (1 1) is moved in circulation and humid process air from the drum (2) on the evaporator (8) under Condensation of moisture cooled and then reheated at the condenser (9), wherein in the heat pump cycle (8,9, 10,11, 20,22) mechanical vibrations are generated; and

(c) compensation of in the heat pump cycle (8,9, 10, 1 1, 20,22) determined mechanical vibrations by the vibration generator (5) a

Vibration program V _n performed.

A method according to claim 14, characterized in that during operation (b) of the heat pump cycle (8,9, 10, 1 1, 20,22) resulting mechanical vibrations by means of a vibration sensor (7) are measured and based on a in the control unit (4 ) stored relationship between measured vibration signals of the vibration sensor (7) and different vibration programs V _{n of} the vibration generator (5) of the vibration generator (5) performs a vibration program V _n .