DE102019121400A1 - Heat pump clothes dryer or heat pump washer dryer - Google Patents

Abstract

The invention relates to a heat pump tumble dryer (1) or a heat pump washer dryer (1) with a washing drum, which is designed to hold laundry to be dried, and with a heat pump circuit, which is designed to dehumidify and heat the process air of a process air circuit, the process air circuit being formed is to convey the process air from the heat pump circuit to the laundry drum and back to the heat pump circuit, wherein the heat pump circuit has a compressor (3), further with a compressor fan (2), which is designed, the compressor (3) by means of at least one impeller (21) To supply ambient air (A), the compressor fan (2) having an alternating current motor (20) which is designed to drive the fan wheel (21), further with a control unit (22) which is designed to determine an actual temperature of a refrigerant of the heat pump circuit to get and the speed of the alternating current To regulate otors (20) as a function of the actual temperature of the refrigerant and a target temperature of the refrigerant. The heat pump washer dryer (1) or the heat pump washer dryer (1) is characterized in that the control unit (22) has an AC power controller (23) which is designed to provide a supply voltage for operating the AC motor (20), the control unit (22) being designed is to regulate the AC power controller (23) depending on the actual temperature of the refrigerant and the target temperature of the refrigerant.

Description

The invention relates to a heat pump washer dryer or a heat pump washer dryer according to the preamble of claim 1 and a control unit for use in such a heat pump washer dryer or in such a heat pump washer dryer according to claim 15.

With many electrical devices nowadays, the user pays great attention to energy efficiency, so that the energy efficiency of an electrical device in operation can be a significant factor in the purchase decision of the user as the end customer. This also applies to household appliances in general and in particular household appliances such as tumble dryers or washer-dryers, which can have a comparatively high energy requirement during operation.

In order to achieve the highest possible energy efficiency in operation, especially with tumble dryers and washer dryers, these are usually designed as heat pump devices, since heat pumps can basically be operated in a comparatively energy-efficient manner. Heat pump tumble dryers and heat pump washer dryers are therefore widespread on the market.

A heat pump basically consists of a closed heat pump circuit with a compressor (also called compressor), a condenser (also called condenser), a throttle such as an expansion valve or a capillary and an evaporator through which a refrigerant can be conveyed. These elements can therefore also be referred to as a refrigerant circuit or a refrigeration circuit. This heat pump circuit can be used to remove the moisture that was previously removed from the laundry from the process air of the tumble dryer, which runs in a closed process air circuit.

From the point of view of the process air circuit, the process air previously dehumidified and heated by the heat pump circuit, i.e. dried and heated, is fed via a fan of the heat pump circuit, the process air fan, through an air supply channel into a laundry drum of the tumble dryer. In the laundry drum, the laundry to be dried is usually moved by rotation by means of a drum drive so that the process air can reach the laundry as completely and evenly as possible. The process air absorbs moisture from the laundry and thereby dries it. The moist process air then returns to the heat pump circuit via an air return duct.

Inside the heat pump, the moisture extracted from the laundry is condensed from the process air in the evaporator and discharged to the outside in liquid form as condensate. The energy extracted from the process air is then fed back into the process air through the condenser, so that the process air, dehumidified and heated, can leave the heat pump circuit in the direction of the laundry drum. The process air cycle is closed in this way.

The heat pump is usually arranged on a so-called base plate of the tumble dryer and, together with the base plate, forms the floor module of the tumble dryer. The process air duct with the evaporator and the condenser of the heat pump circuit are usually arranged on the left on the base plate, viewed from the front from the perspective of a user. To the right of this are usually the compressor and the throttle of the heat pump circuit as well as the process air fan, which allows the process air of the process air circuit to circulate.

When operating a heat pump dryer, the compressor can generate additional thermal energy due to the internal losses. This thermal energy can get into the heat pump circuit and contribute to the fact that the refrigerant continues to heat up until it overheats and the compressor can shut down. This can lead to the complete failure of the heat pump device.

To avoid this, it is advisable to operate the heat pump circuit in a narrow thermal working area. It is therefore known to cool the compressor or to dissipate the excess heat energy. For this purpose, a compressor fan can be used, which directs air from the interior of the heat pump device onto the compressor and can thereby increase the heat output of the compressor to the environment. In other words, overheating of the heat pump circuit and in particular of the compressor can be avoided by the fact that the control unit of the tumble dryer regulates the temperature of the compressor by switching on a further blower as a compressor fan, which is usually integrated in the lower area of the front wall of the tumble dryer on the base plate . During operation, the compressor fan can suck in ambient air into the tumble dryer and blow it over the compressor and over the drum drive, which usually drives the process air fan at the same time. This air flow can then exit the tumble dryer again below the drum and process air fan drive. The compressor fan is Usually designed as a separate and self-sufficient functional unit and can also be referred to as a cooling air fan.

In other words, a cooling air fan is usually used in a heat pump dryer in order to dissipate the excess energy from the heat pump circuit. For this purpose, the refrigerant is regulated to a specific temperature setpoint.

The setting and determination of an exact temperature setpoint of the refrigerant can be important for the most efficient possible design of the drying process as well as for the coordination of the built-in components of the heat pump circuit. The excess running time of the cooling air fan until a lower limit value of a two-point control of the cooling air fan is reached can impair the energy balance of the heat pump and thus the entire heat pump device and thus increase the overall energy consumption. The drying time can also be negatively influenced by incorrect parameterization and design of the heat pump if the actual value of the temperature of the refrigerant in the heat pump circuit permanently deviates from a determined target value of the refrigerant.

The use of alternating current-operated fans (AC cooling air fans) is known as the compressor fan or cooling air fan. The control for the AC cooling air fan on the part of power electronics is usually performed by a relay that switches the supply voltage of a shaded-pole motor directly. The control signal of a microcontroller for the AC cooling air fan is usually raised to a voltage level of 15 V with an NPN Darlinqton transistor. The relay usually requires a control voltage of at least 12 V for safe switching of the load contacts.

The manipulated variable is usually determined by comparing the measured refrigerant temperature at a measuring point with the set limit values of the two-point controller. If the refrigerant temperature exceeds the upper limit value, the output of the microcontroller is switched to "High" so that the relay picks up and the shaded-pole motor runs at its nominal speed. If the set limit value is not reached, the microcontroller switches the output to "Low" and the relay drops out.

The greatest advantage of this system lies in the cost-effective control of the AC motor and in the low price of the shaded pole motor as an AC motor itself.

The disadvantage of the above-described system of an AC fan with shaded pole motor and two-point controller is primarily the poor controllability of the refrigerant temperature. The fluctuating actual temperature of the refrigerant can have negative effects on the energy consumption of the entire system. With each cooling process, i.e. during operation of the cooling air fan, the energy can be withdrawn from the process, which has to be added again afterwards.

On the other hand, a DC-operated fan (DC cooling air fan) can be used as the compressor fan or cooling air fan. The control of the DC cooling air fan usually varies the speed of the DC cooling air fan via the level of the supply voltage. Theoretically, the speed and thus the volume flow can be set over a voltage range of e.g. approx. 5 V to approx. 13.5 V. A voltage of at least 7 V is usually required to ensure that the DC cooling air fan starts more reliably. The voltage is provided by a switched-mode power supply on a circuit board and is a maximum of 16 V. The manipulated variable at the output of a microcontroller is changed by means of pulse width modulation. A power mosfet can be used to provide the power for the DC motor of the DC cooling air blower.

The pulse-width-modulated supply voltage is made available to the DC motor, smoothed by several capacitors and coils. The direct current motor must usually not exceed a maximum power of 14 watts. To ensure that the maximum power is not exceeded, a current measurement is necessary to control the DC motor. The current is measured continuously and the power is calculated. If this is too high, the current is limited by the hardware circuit. Redundant current and voltage monitoring is required in order to detect faults and to be able to put the system into a safe state at an early stage.

A PI controller can be used in the control to calculate the manipulated variable. The control deviation between the measured actual temperature of the refrigerant and the specified target value for the temperature of the refrigerant is determined and stored.

The greatest advantage of this system is its comparatively good controllability.

The disadvantage of the system described above when using this type of DC cooling air fan with a direct current motor is above all the higher purchase price compared to an AC cooling air fan with a shaded pole motor as an alternating current motor. Activation with the generation of the variable AC voltage is also an increased cost factor, as is the need for a power limitation for safety reasons.

The invention thus presents the problem of providing a heat pump washer dryer or a heat pump washer dryer of the type described at the outset, so that the advantages of the systems described above can be achieved together. More precisely, a heat pump washer dryer or a heat pump washer dryer of the type described at the outset is to be provided, which has a comparatively good controllability as previously known from DC cooling air fans at reduced costs. The controllability should preferably be improved compared to known DC cooling air blowers at reduced costs. At least an alternative to known heat pump washer dryers or heat pump washer dryers should be created.

According to the invention, this problem is solved by a heat pump washer dryer or a heat pump washer dryer with the features of claim 1 and by a control unit with the features of claim 15. Advantageous refinements and developments of the invention emerge from the following subclaims.

Thus, the invention relates to a heat pump laundry dryer or a heat pump washer dryer with a laundry drum, which is designed to receive laundry to be dried, and with a heat pump circuit, which is designed to dehumidify and heat the process air of a process air circuit, wherein the process air circuit is designed to take the process air from to convey the heat pump circuit to the laundry drum and back to the heat pump circuit, the heat pump circuit having a compressor, further with a compressor fan, which is designed to supply ambient air to the compressor by means of at least one impeller, the compressor fan having an AC motor which is designed to drive the impeller , further with a control unit which is designed to obtain an actual temperature of a refrigerant of the heat pump circuit and the speed of the AC motor as a function of the actual temperature d there to regulate refrigerant and a target temperature of the refrigerant.

The heat pump washer dryer or heat pump washer dryer is characterized in that the control unit has an AC power controller, which is designed to provide a supply voltage for operating the AC motor, the control unit being designed to control the AC power controller as a function of the actual temperature of the refrigerant and the target temperature of the refrigerant to regulate.

In this way, the quality of the regulation of the refrigerant temperature can be improved compared to known regulating structures of alternating current motors and even compared to known regulating structures of direct current motors. This can be done comparatively easily, which can keep the costs of the control unit according to the invention low. The costs of the compressor fan can also be kept comparatively low by using an AC motor.

According to one aspect of the invention, the AC power controller is designed to switch the supply voltage by means of at least one triac. The term “Triac” is an abbreviation for “Triode for Alternating Current”, which can also be referred to as a bidirectional thyristor triode or a symistor.

According to a further aspect of the invention, the AC power controller is designed to switch the supply voltage by means of at least one opto-triac and by means of at least one power triac. An opto-triac is to be understood as two anti-parallel photo-thyristors which are optically switched on. An opto-triac can also be called a photo-triac. Since a light-emitting diode is used instead of a control electrode to flood the pn junctions with charge carriers via the photoelectric effect and thus make them conductive, an opto-triac can be used to electrically isolate the control and load circuits, whereby loads can be controlled, without the control circuit posing a risk from the mains voltage.

According to a further aspect of the invention, the control unit has a phase control which is designed to set the phase angle of the supply voltage.

According to a further aspect of the invention, the phase control is designed as network zero crossing detection.

According to a further aspect of the invention, the network zero crossing detection has at least one bridge rectifier and at least one optocoupler.

According to a further aspect of the invention, the phase angle of the supply voltage is preferably dependent on at least one relationship stored in the control unit at least one characteristic curve stored in the control unit, specified between the phase angle of the supply voltage and the volume flow of the compressor fan.

According to a further aspect of the invention, the relationship, preferably the characteristic curve, was determined experimentally.

According to a further aspect of the invention, the control unit has a protective circuit which is designed to attenuate voltage edges and / or voltage peaks of the supply voltage.

According to a further aspect of the invention, the protective circuit has at least one RC element and at least one varistor.

According to a further aspect of the invention, the control unit has a PI controller which is designed to generate a manipulated variable as a function of the detected actual temperature of the refrigerant and the setpoint temperature of the refrigerant, the manipulated variable being the speed of the AC motor adjust.

According to a further aspect of the invention, the PI controller has an anti-wind function.

According to a further aspect of the invention, the PI controller has an override control function.

According to a further aspect of the invention, the AC motor is a shaded pole motor. This can enable a particularly inexpensive implementation.

The present invention also relates to a control unit for use in a heat pump washer dryer or in a heat pump washer dryer as described above. The control unit has an AC power controller, which is designed to provide a supply voltage for operating an AC motor of a compressor fan of the heat pump washer dryer or the heat pump washer dryer, the control unit being designed to obtain an actual temperature of a refrigerant of a heat pump circuit of the heat pump washer dryer or the heat pump washer dryer and where the control unit is also designed to regulate the AC power controller as a function of the actual temperature of the refrigerant and a target temperature of the refrigerant. In this way, a control unit can be provided in order to be able to realize a heat pump washer dryer or a heat pump washer dryer as described above, so that its properties and advantages described above can be used.

In other words, according to the invention, the supply voltage of the AC blower cannot be controlled by a relay, as is already known, but via an AC power controller which can switch the supply voltage by means of a triac. Phase control can be implemented through the addition of network zero crossing detection. Depending on the phase control angle, the speed and thus also the volume flow of the fan can be varied.

A PI anti-wind-up controller with override control function can determine the volume flow to be set from the temperature difference between the measured NTC temperature and the setpoint temperature. The manipulated variable can be the volume flow to be set. The control angle can be determined in a microcontroller via a characteristic curve determined on the volume flow test stand, which can set the measured volume flow and the set control angle in relation to one another. Each fan can have its own characteristic. The microcontroller can evaluate the periodically occurring peak at the collector of the optocoupler as a zero crossing. The height of the resistors can determine the width of the peak. The heights of the resistances can be calculated and validated using a simulation.

By adding an assembly variant to a circuit board of the control unit and by replacing an existing, known AC fan control, even the costs for an existing cost-optimized system with AC fan and relay control can be undercut. For the variant of an AC fan, only the grid zero crossing detection can be equipped. The PI controller can be designed purely software-based.

Another aspect is the special controller structure, the controller parameters of which can be device-dependent and not fan-dependent. Accordingly, the PI controller can be developed independently of the fan and the fan can be replaced as required. The interface between controller and actuator can be the volume flow to be set.

The network zero crossing detection for setting the phase angle can be omitted for a two-point control and only equipped for the variant with PI controller. Accordingly, these layout variants can be omitted and only two assembly variants can result.

The advantages lie in the better controllability of the system compared to the known systems described above. A significant advantage results from the significantly lower price of the system compared to the regulated DC fan. Another advantage can be the modular structure of the topology, so that the controller can be developed and tested independently of the fan. This means that the fan can be exchanged at any time without changing the controller.

• 1 einen Längsschnitt durch den Bereich einer Grundplatte eines Wärmepumpenwäschetrockners oder eines Wärmepumpenwaschtrockner;
• 2 ein Schaltbild eines Wechselstromstellers;
• 3 ein Schaltbild einer Phasenanschnittsteuerung;
• 4 ein Schaltbild eines PI-Regler;
• 5 einen Temperaturverlauf des Kältemittels einer realen bekannten DC-Kompressorgebläse- Regelung
• 6 einen Temperaturverlauf des Kältemittels einer simulierten erfindungsgemäßen AC- Kompressorgebläse-Regelung;
• 7 einen Temperaturverlauf des Kältemittels einer realen erfindungsgemäßen AC-Kompressorgebläse-Regelung;
• 8 einen Volumenstromverlauf des Kältemittels einer simulierten erfindungsgemäßen AC-Kompressorgebläse-Regelung; und
• 9 einen Volumenstromverlauf des Kältemittels einer realen erfindungsgemäßen AC-Kompressorgebläse-Regelung.

An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows

• 1 a longitudinal section through the area of a base plate of a heat pump clothes dryer or a heat pump washer dryer;
• 2 a circuit diagram of an AC power controller;
• 3 a circuit diagram of a phase control;
• 4th a circuit diagram of a PI controller;
• 5 a temperature profile of the refrigerant of a real known DC compressor fan control
• 6th a temperature profile of the refrigerant of a simulated AC compressor fan control according to the invention;
• 7th a temperature profile of the refrigerant of a real AC compressor fan control according to the invention;
• 8th a volume flow profile of the refrigerant of a simulated AC compressor fan control according to the invention; and
• 9 a volume flow profile of the refrigerant of a real AC compressor fan control according to the invention.

The above figures are viewed in Cartesian coordinates. It extends in a longitudinal direction X which also called depth X can be designated. A transverse direction (not shown), which can also be referred to as the width, extends perpendicular to the longitudinal direction. Perpendicular to both the longitudinal direction X as well as a vertical direction extends to the transverse direction Z which also called height Z can be designated.

1 shows a longitudinal section through the area of a base plate 13 a heat pump tumble dryer 1 or a heat pump washer dryer 1 . A heat pump tumble dryer is intended as an example below 1 to be viewed as.

The heat pump tumble dryer 1 has a housing 10 on, which one with a housing front 11 , according to the representation of the 1 in the deep X to the left, facing a user. The front of the case 11 in the deep X the housing faces away 10 a case back 12 on. In height Z becomes the case 10 through the base plate 13 limited on which the housing 10 stands up on a surface (not shown).

In height Z in the upper area of the housing 10 there is a laundry drum for receiving laundry to be dried (not shown), which can be opened through a closable opening on the front of the housing 11 can be filled with laundry (not shown). To drive the laundry drum is inside the housing 10 a drum drive 4th arranged, which is connected to the laundry drum such that the drum drive 4th can drive the laundry drum to rotate.

Inside the case 10 a heat pump circuit and a process air circuit are also arranged (not shown) in order to dry the laundry located in the laundry drum. The heat pump circuit includes a compressor 3 on, which also works as a compressor 3 or as a heater 3 can be designated. It is also a compressor fan 2 provided, which also works as a cooling air fan 2 , as a compressor fan 2 or as a desuperheater fan 2 can be designated. The compressor fan 2 is used if necessary by means of a fan wheel 21st Ambient air A. the compressor 3 feed and thereby to cool it. The ambient air A. can through an air inlet opening 14th on the front of the housing 11 inside the case 10 of the heat pump tumble dryer 1 enter by by the fan wheel 21st of the compressor fan 2 is sucked in and through an air outlet opening 15th on the back of the case 12 back into the vicinity of the heat pump tumble dryer 1 step out. On the way of the ambient air A. through the inside of the heat pump tumble dryer 1 the ambient air can pass through A. at least the compressor 2 flow around it to cool it, and also the drum drive 4th flow around it to cool it down too.

The compressor fan 2 has an AC motor 20th on, which also works as an AC motor 20th can be referred to and in the present case as a shaded pole motor 20th is realized. Due to the use of the AC motor 20th can the compressor fan 2 also as an AC compressor fan 2 , as an AC cooling air fan 2 , as an AC compressor fan 2 or as an AC desuperheater fan 2 are designated.

The compressor fan 2 also has a control unit 22nd which by means of a PI controller 25th , see. 4th , receives an actual temperature of a refrigerant of the heat pump circuit, compares it with a predetermined setpoint temperature of the refrigerant and, depending on this difference, a manipulated variable for operating the AC motor 20th generated. This manipulated variable acts on an AC power controller 23 the control unit 22nd , see. 2 , which is a supply voltage of the AC motor 20th switched by means of a triac. The control unit 22nd also has a phase control 24 on, cf. 3 , which a network zero crossing detection 24 realized. Depending on the phase control angle, the speed of the AC motor can 20th and thus also the volume flow of the compressor fan 2 can be varied.

For a comparison of several measured value curves of the temperature of the refrigerant of a real known DC compressor fan control, see 5 , and a simulated control of the AC motor according to the invention 20th of the compressor fan 2 , please refer 6th , with a real applied control of the AC motor according to the invention 20th of the compressor fan 2 , please refer 7th , show the 5 to 7th . Like in particular the comparison of the 5 and 7th can be seen, can in this way by means of the control unit according to the invention 2 in the heat pump tumble dryer according to the invention 1 a significantly improved controllability of the AC motor 20th of the compressor fan 2 can be achieved in comparison to a known regulation of a DC motor of a compressor fan. The real volume flow also corresponds to the actual control of the alternating current motor according to the invention 20th of the compressor fan 2 , please refer 9 , very good to the corresponding simulated volume flow, cf. 8th . This can be achieved comparatively inexpensively, which in addition to the components of the control unit 22nd also the low cost of the AC motor 2 in comparison to a DC motor.

List of reference symbols

A.

Ambient air

X

Longitudinal direction; depth

Z

vertical direction; height

1

Heat pump clothes dryer; Heat pump washer dryer

10

casing

11

Housing front

12

Case back

13

Base plate

14th

Air inlet opening for ambient air A

15th

Air outlet opening for ambient air A

2

(AC) compressor fans; (AC) cooling air fan; (AC) compressor fans; (AC) desuperheater fan

20th

AC motor; AC motor; Shaded pole motor

21st

Impeller

22nd

Control unit

23

AC power controller

24

Phase control; Network zero crossing detection

25th

PI controller

3

Compressor; Compressor; Heater

4th

Drum drive; Drum and fan drive

Claims (15)

Heat pump laundry dryer (1) or heat pump washer dryer (1), with a laundry drum that is designed to receive laundry to be dried, and with a heat pump circuit that is designed to dehumidify and heat the process air of a process air circuit, the process air circuit being designed to be the process air to convey from the heat pump circuit to the laundry drum and back to the heat pump circuit, wherein the heat pump circuit has a compressor (3), further with a compressor fan (2) which is designed to convey ambient air (A) to the compressor (3) by means of at least one fan wheel (21) feed, wherein the compressor fan (2) has an alternating current motor (20) which is designed to drive the fan wheel (21), further with a control unit (22) which is designed to receive an actual temperature of a refrigerant of the heat pump circuit and the Speed of the AC motor (20) depending on the Is to regulate the t temperature of the refrigerant and a target temperature of the refrigerant, characterized in that the control unit (22) has an AC power controller (23) which is designed to provide a supply voltage for operating the AC motor (20), the control unit ( 22) is designed to regulate the AC power controller (23) as a function of the actual temperature of the refrigerant and the setpoint temperature of the refrigerant. Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 1 , characterized in that the AC power controller (23) is designed to switch the supply voltage by means of at least one triac. Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 2 , characterized in that the AC power controller (23) is designed to switch the supply voltage by means of at least one opto-triac and by means of at least one power triac. Heat pump laundry dryer (1) or heat pump washer dryer (1) according to one of the preceding claims, characterized in that the control unit (22) has a phase control (24) which is designed to set the phase angle of the supply voltage. Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 4 , characterized in that the phase control (24) is designed as a network zero crossing detection (24). Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 5 , characterized in that the network zero crossing detection (24) has at least one bridge rectifier and at least one optocoupler. Heat pump washer dryer (1) or heat pump washer dryer (1) according to one of the Claims 4 to 6th , characterized in that the phase angle of the supply voltage is specified as a function of at least one relationship stored in the control unit (22), preferably at least one characteristic curve stored in the control unit (22), between the phase angle of the supply voltage and the volume flow of the compressor fan (2). Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 7 , characterized in that the relationship, preferably the characteristic curve, was determined experimentally. Heat pump washer dryer (1) or heat pump washer dryer (1) according to one of the preceding claims, characterized in that the control unit (22) has a protective circuit which is designed to dampen voltage edges and / or voltage peaks of the supply voltage. Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 9 , characterized in that the protective circuit has at least one RC element and at least one varistor. Heat pump washer dryer (1) or heat pump washer dryer (1) according to one of the preceding claims, characterized in that the control unit (22) has a PI controller (25) which is designed to provide a manipulated variable as a function of the detected actual temperature of the refrigerant and the To generate the setpoint temperature of the refrigerant, the manipulated variable being designed to set the speed of the AC motor (20). Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 11 , characterized in that the PI controller (25) has an anti-wind function. Heat pump washer dryer (1) or heat pump washer dryer (1) Claim 11 or 12 , characterized in that the PI controller (25) has an override control function. Heat pump laundry dryer (1) or heat pump washer dryer (1) according to one of the preceding claims, characterized in that the alternating current motor (20) is a shaded pole motor (20). Control unit (22) for use in a heat pump washer dryer (1) or in a heat pump washer dryer (1) according to one of the preceding claims, characterized in that the control unit (22) has an alternating current controller (23) which is designed to provide a supply voltage for operating a AC motor (20) of a compressor fan (2) of the heat pump washer dryer (1) or of the heat pump washer dryer (1), the control unit (22) being designed to provide an actual temperature of a refrigerant of a heat pump circuit of the heat pump washer dryer (1) or of the heat pump washer dryer (1) and wherein the control unit (22) is further designed to regulate the AC power controller (23) as a function of the actual temperature of the refrigerant and a target temperature of the refrigerant.

Images