Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F58/00—Domestic laundry dryers
  • D06F58/32—Control of operations performed in domestic laundry dryers 
  • D06F58/34—Control of operations performed in domestic laundry dryers  characterised by the purpose or target of the control
  • D06F58/36—Control of operational steps, e.g. for optimisation or improvement of operational steps depending on the condition of the laundry
  • D06F58/38—Control of operational steps, e.g. for optimisation or improvement of operational steps depending on the condition of the laundry of drying, e.g. to achieve the target humidity
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
  • D06F2103/28—Air properties
  • D06F2103/32—Temperature
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
  • D06F2103/50—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers related to heat pumps, e.g. pressure or flow rate
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F2105/00—Systems or parameters controlled or affected by the control systems of washing machines, washer-dryers or laundry dryers
  • D06F2105/26—Heat pumps
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F2105/00—Systems or parameters controlled or affected by the control systems of washing machines, washer-dryers or laundry dryers
  • D06F2105/30—Blowers
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F58/00—Domestic laundry dryers
  • D06F58/20—General details of domestic laundry dryers 
  • D06F58/206—Heat pump arrangements
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F58/00—Domestic laundry dryers
  • D06F58/32—Control of operations performed in domestic laundry dryers 
  • D06F58/34—Control of operations performed in domestic laundry dryers  characterised by the purpose or target of the control
  • D06F58/50—Responding to irregular working conditions, e.g. malfunctioning of blowers

Definitions

• the invention relates to a method for operating a laundry treatment apparatus and a laundry treatment apparatus having a heat pump system.
• EP 2 455 526 Al discloses a heat pump tumble dryer with a variable speed compressor.
• An operating or control unit for controlling a drying operation of the heat pump tumble dryer comprises a power sensor for measuring a power input to operate the compressor and a temperature sensor for measuring a temperature of a refrigerant of the heat pump system.
• the compressor is powered with a predetermined power input when the refrigerant temperature is lower than a predetermined threshold temperature.
• the compressor is operated at a lower power input than the predetermined power input to keep the temperature at the predetermined threshold temperature until a drying operation or cycle is completed.
• a cooling unit comprising a blower is provided to cool the heat pump system, including the compressor, when the temperature exceeds the predetermined threshold temperature.
• a method for operating a laundry treatment apparatus comprising a heat pump tumble dryer or a washing machine having a drying function.
• the apparatus comprises a heat pump system and a laundry treatment chamber (e.g. laundry drum) for treating laundry using process air.
• the heat pump system comprises a first heat exchanger (evaporator) for heating a refrigerant fluid, a second heat exchanger (condenser) for cooling the refrigerant fluid, an expansion device and a refrigerant loop, in which the refrigerant fluid is circulated through the first and second heat exchangers and the expansion device.
• a compressor is provided which is adapted to operate at variable speed and additionally or alternatively at variable power for circulating the refrigerant fluid through the refrigerant loop.
• the treatment apparatus further comprises a cooling air blower or cooling fan for conveying cooling air to the compressor, i.e. the cooling air blower is adapted to cool the compressor during a drying operation of the treatment apparatus.
• the blower removes heat from the heat pump system e.g. to provide that after a warm-up period at the beginning of a drying cycle the energy-efficient steady state or targeted operation state of the heat pump system is maintained during the drying operation.
• the method for operating the laundry treatment apparatus comprises monitoring a first temperature signal and activating the cooling air blower or increasing the conveying capacity of the cooling air blower when the first temperature signal exceeds a first temperature level, i.e. a first threshold temperature.
• a first temperature level i.e. a first threshold temperature.
• the treatment apparatus may have a first temperature sensor arranged in the cabinet or housing of the apparatus for detecting the first temperature signal.
• the control unit may be adapted to increase the conveying capacity of the cooling air blower by increasing a fan rotation speed and/or a fan duty cycle ratio.
• the first temperature signal is further monitored (i.e. after the first temperature level is exceeded), wherein the compressor speed and/or compressor power is reduced when the first temperature signal exceeds a second (predetermined) temperature level or threshold.
• the first temperature signal e.g. of the first temperature sensor
• the second temperature level is higher than the first temperature level. I.e. it is provided that the blower is started or the blower speed is increased before the compressor speed or power
• a second temperature signal may be monitored, e.g. a temperature signal from a different position in the apparatus than the first temperature signal, wherein the compressor speed and/or compressor power is reduced when the second temperature signal exceeds a second temperature level.
• the laundry dryer apparatus comprises a second temperature sensor arranged in the housing of the apparatus. I.e. the second temperature sensor is arranged at a position different of the position of the first temperature sensor.
• the first and second temperature levels or thresholds are preferably set such that it is provided that the first measure or step to remove excess heat from the heat pump system is activating the cooling air blower before the compressor power or speed is reduced in a second step.
• the decision whether a second temperature level is exceeded may be determined on either the first temperature signal (of the first temperature sensor) or the second temperature signal (of the second temperature sensor) or a combination thereof.
• the second temperature level i.e. the second threshold temperature
• the first and second temperature signal i.e. on signals of two or more temperature sensors at different positions in the housing of the treatment apparatus.
• the second temperature level may be a mean value of the first and second temperature signal.
• the decision whether the first temperature level is exceeded may only be determined in dependency of the first temperature signal or sensor, respectively.
• the first temperature signal and the second temperature signal which are used to determine whether the first or second temperature level are exceeded may be a condenser output temperature, an electronic board (e.g. a PCB or a board as described in more detail below) temperature, temperatures of the heat pump system, e.g. a refrigerant temperature at the compressor output or process air flow temperature, or a combination of these temperatures.
• a condenser output temperature e.g. a PCB or a board as described in more detail below
• temperatures of the heat pump system e.g. a refrigerant temperature at the compressor output or process air flow temperature, or a combination of these temperatures.
• a first step for removing excess heat from compressor is activating the cooling blower or increasing its cooling capacity, e.g. by increasing a fan rotation speed and/or a fan duty cycle ratio. Only if a second temperature level is exceeded, the compressor speed or power is reduced. When reducing compressor speed or power more time is required to dry a laundry load, i.e. the duration of a drying cycle is increased. In other words the drying performance of the treatment apparatus deteriorates.
• the above described method prevents or at least minimizes such a deterioration of the drying performance by providing that reduction of compressor speed or power is minimized. I.e.
• the compressor speed and/or the compressor power is
• a linear reduction or a progressive reduction of the compressor speed or power is provided with a temperature increase of the first or second temperature signal.
• a linear0 or progressive reduction is provided in dependency of a combination of the first and
• the compressor speed is smoothly adapted to requirements of the drying operation which extends a service life of the compressor.
• the compressor speed and/or compressor power is reduced until the compressor speed and/or compressor power reaches a predefined minimum value and/or until the first temperature signal or the second temperature signal exceeds a third temperature level.
• a minimum speed value and/or minimum power value By operating the compressor at a minimum speed value and/or minimum power value a o reliable operation of the compressor is provided, while at the same time heat input from the (operating) compressor into the heat pump system is minimized.
• a minimum value for compressor speed and/or power is determined by the minimum speed/power necessary for effectively operating the compressor and/or for operating the compressor without damage.
• the compressor power may be maintained constant until or up to a temperature where the first temperature signal or the second temperature signal reaches the first or second temperature level from the lower temperature side and when the first temperature signal or the second temperature signal exceeds the first or second temperature level the compressor speed is controlled in dependency of the first temperature signal or second temperature o signal.
• a combined power and speed control is applied to the compressor, i.e. up to the first or second temperature level a power target control is applied and when the first or second temperature level is exceeded a speed control is applied.
• the compressor speed is decreased when the first or second temperature signal increases as described above.
• the compressor speed linearly decreases with increasing (first 5 and/or second) temperature signal.
• the compressor speed and the compressor power are reduced in dependency of the first temperature signal or second temperature signal, wherein over a first temperature range above the second temperature level the compressor speed is controlled in dependency of the first temperature signal or second temperature signal, and over a second temperature range, which is above the second temperature level and which is different of the first temperature range, the compressor power is controlled in dependency of the first temperature signal or second temperature signal.
• a first temperature range above the second temperature level the compressor speed is controlled in dependency of the first temperature signal or second temperature signal
• a second temperature range which is above the second temperature level and which is different of the first temperature range
• the compressor power is controlled in dependency of the first temperature signal or second temperature signal.
• the temporal gradient or averaged temporal gradient of the change of the compressor speed and/or compressor power is below a predefined maximum gradient. I.e. sudden operation changes for operating the compressor are avoided, thus increasing service life of the compressor.
• Different gradients or gradient values may be applied for the increase and decrease of the compressor speed and/or power, wherein the different gradients provide a smooth operation of the compressor during changing compressor speed and/or power.
• a predefined maximum gradient and/or the gradient as such may be depending on one or more of the following: an operation state of the laundry treatment apparatus, an operation state of the heat pump system, a program cycle, a selected program for laundry treatment, a third temperature signal of the heat pump system, or a user input or selection input by a user of the laundry treatment apparatus.
• a user selection may be a selected cycle, a selected cycle option or drying program type (e.g. fast-drying or night operation (silent and slow mode), a residual laundry humidity, final humidity or drying level (e.g. extra-dry or iron-aid having a higher residual laundry humidity), a laundry amount (input by user or detected by a weight sensor of the treatment apparatus (e.g. laundry dryer), a laundry type (e.g. cotton, wool etc.), an energy-saving option, a drying process time-saving option (e.g. eco-mode, rapid), and the laundry amount.
• a selected cycle option or drying program type e.g. fast-drying or night operation (s
• the method comprises monitoring the first temperature signal or the second temperature signal and switching off the compressor (i) if the first temperature signal or the second temperature signal exceeds a fourth temperature level, and/or (ii) if the first temperature signal or the second temperature signal exceeds the third temperature level or a temperature level higher than the third temperature level for a predefined time period.
• the compressor is switched-off immediately after exceeding a predetermined (fourth) temperature level, or the compressor is switched-off after exceeding the third or a higher (e.g. fourth) temperature level for a predefined time.
• the compressor is switched-off and -on repeatedly for short-periods, when the (third or fourth) temperature level is only exceeded for short period(s).
• the fourth temperature level is higher than the third temperature level.
• This embodiment provides a safety switch- off function to prevent a damage of the compressor or heat pump system during a drying operation.
• the compressor when the compressor was switched-off, the compressor is switched-on again under one or more of the following conditions: (i) the compressor was switched-off for a predetermined time period, and/or (ii) the first temperature signal or second temperature signal falls below a fifth temperature level.
• the fifth temperature level is lower than the fourth temperature level.
• the compressor is switched-on at a safe temperature level, i.e. below the switch-off temperature level.
• the fifth temperature level is lower than the third temperature level.
• the first temperature signal exceeds the first temperature level, or the reduction of the compressor speed and/or compressor power is suppressed as long as the first temperature signal does not exceed the first temperature level.
• the first temperature signal has to exceed the first temperature level before the compressor speed and/or power is reduced, i.e. the first temperature level has a higher weight than the second temperature level.
• the cooling air blower is in any case activated before compressor speed or power is reduced.
• the level of at least one of the first, the second, the third, the fourth and the fifth temperature level is depending on one or more of the following: an operation state of the laundry treatment apparatus, an operation state of the heat pump system, a program cycle, a selected program for laundry treatment, a third temperature signal of the heat pump system, and a user input or selection input by a user of the laundry treatment apparatus.
• the blower may be switched off, if the first temperature signal or the second temperature signal falls below a sixth temperature level. Alternatively the blower conveyance capacity may be reduced if the first temperature signal or the second temperature signal is decreasing.
• the sixth temperature level is lower than the first temperature level, such that it is provided that the compressor is cooled down to a safe operating temperature level below the first temperature level before the blower is switched-off. It is preferred that the blower conveyance capacity (i.e. blower speed) is reduced only to a minimum value after which the blower is switched off. Thereby it is avoided that the blower is operated at inefficient speeds or conveyance capacities.
• the first temperature signal or the second temperature signal may be a signal
• a refrigerant fluid outlet position at the first or second heat exchanger an electronic board or inverter position of an electronic board or inverter controlling a component of the heat pump system
• an electronic board or inverter position of an electronic board or inverter controlling a motor for driving the laundry treatment chamber being a drum
• a refrigerant fluid outlet position at the compressor the
• a laundry treatment apparatus in particular heat pump tumble dryer or washing machine having a drying function
• the apparatus comprises a heat pump system, a control unit adapted to control the operation of the heat pump system and a laundry treatment chamber for treating laundry using process air
• the heat pump system comprises: a first heat exchanger for cooling a refrigerant fluid, a second heat exchanger for heating the refrigerant fluid, an expansion device, a refrigerant loop, in which the refrigerant fluid is circulated through the first and second heat exchangers and the expansion device, and a compressor for circulating the refrigerant fluid through the refrigerant loop, wherein the compressor is adapted to be operated at different compressor speeds and/or different compressor powers under the control of the control.
• a control unit of the treatment apparatus is adapted to implement a method according to any of the above described embodiments.
• the treatment apparatus does not necessarily comprise a cooling air blower.
• the above described methods for operating a treatment apparatus may be implemented in this treatment apparatus with the exception features relating to operating a cooling air blower.
• a compressor speed control and/or power control may be
• a laundry treatment apparatus in particular heat pump tumble dryer or washing machine having a drying function
• the apparatus comprises a heat pump system, a control unit adapted to control the operation of the heat pump system and a laundry treatment chamber for treating laundry using process air
• the heat pump system comprises: a first heat exchanger for cooling a refrigerant fluid, a second heat exchanger for heating the refrigerant fluid, an expansion device, a refrigerant loop, in which the refrigerant fluid is circulated through the first and second heat exchangers and the expansion device, and a compressor for circulating the refrigerant fluid through the refrigerant loop, wherein the compressor is adapted to be operated at o different compressor speeds and/or different compressor powers under the control of the control unit, and wherein the apparatus further comprises: a cooling air blower for conveying cooling air to the compressor, a first temperature sensor for detecting a first temperature at a first position in the cabinet of the laundry treatment apparatus and for providing a first temperature signal
• the control unit is adapted to operate the cooling air blower in dependency of the first temperature signal.
• the control unit is adapted to activate the blower if the first temperature signal exceeds a first temperature level.
• the control o unit is adapted to control the speed and/or the power of the compressor in dependency of the first temperature signal or the second temperature signal. If the compressor is operated in dependency of the first temperature signal, the control unit starts to change or changes the speed and/or power of the compressor at a second level of the first temperature signal which is higher than the first level of the first temperature signal at which the control unit 5 starts or activates the cooling air blower. I.e.
• the blower is activated and only in a second step the compressor speed and/or power is changed, e.g. reduced.
• the control unit is adapted to control the treatment apparatus according to any of the above described o embodiments of the method for operating a treatment apparatus.
• control unit is adapted to operate the compressor at maximum speed and/or power, if the first temperature signal or the second temperature signal or a combination of the first and second temperature signal is below a second temperature level, and/or the 5 control unit is adapted to control the reduction of the compressor speed and/or power, if the first temperature signal or the second temperature signal or a combination of the first and second temperature signal exceeds a second temperature level.
• the laundry treatment apparatus comprises a first 5 temperature sensor for providing the first temperature signal or a first temperature sensor for providing the first temperature signal and a second temperature sensor for providing the second temperature signal, wherein the first and second temperature sensors are arranged at different positions within the cabinet of the apparatus.
• the first temperature sensor and, if applicable the second temperature sensor is arranged at one of the following laundry o treatment components or one of the following laundry treatment positions: the heat pump system, the refrigerant loop, the first heat exchanger, the second heat exchanger, the expansion device, the compressor, an electronic board for powering the motor of the compressor, an electronic board for powering the motor for driving the drum being the laundry treatment compartment and/or process air blower and a position within a process 5 air channel for detecting the process air temperature.
• the first and/or second temperature sensor may be arranged at any component of the refrigerant loop, i.e. the heat pump system, wherein it is preferred that the refrigerant temperature or a temperature corresponding to the refrigerant temperature is detected.
• Fig. 1 a schematic view of a laundry treatment apparatus having a heat pump o system
• Fig. 2 a schematic block diagram of components of the apparatus of Fig. 1 ,
• FIG. 3 a graph schematically illustrating the compressor speed in relation to 5 temperature according to a first embodiment
• Fig. 4 a graph schematically illustrating the compressor speed in relation to temperature according to a second embodiment
• Fig. 5 a graph schematically illustrating the compressor speed in relation to
• Fig. 6 a graph schematically illustrating in combination the compressor speed, the compressor power and the cooling air blower control in relation to temperature according to a fourth embodiment.
• Fig. 1 depicts in a schematic representation a laundry treatment apparatus 2 which in this embodiment is a heat pump tumble dryer.
• the tumble dryer comprises a heat pump system 4, including in a closed refrigerant loop 6 in this order of refrigerant flow B: a first heat exchanger 10 acting as evaporator for evaporating the refrigerant R and cooling process air, a compressor 14, a second heat exchanger 12 acting as condenser for cooling the refrigerant R and heating the process air, and an expansion device 16 from where the refrigerant R is returned to the first heat exchanger 10.
• the heat pump system 4 forms a refrigerant loop 6 through which the refrigerant R is circulated by the compressor 14 as indicated by arrow B. If the refrigerant R in the heat pump system 4 is operated in the transcritical or totally supercritical state, the first and second heat exchanger 10, 12 can act as gas heater and gas cooler, respectively.
• the expansion device 16 is a controllable valve that operates under the control of a control unit 30 (Fig. 2) to adapt the flow resistance for the refrigerant R in dependency of operating states of the heat pump system 4.
• the expansion device 16 may be a fixed, non-controllable device like a capillary tube.
• the process air flow within the treatment apparatus 2 is guided through a compartment 18 of the treatment apparatus 2, i.e. through a compartment 18 for receiving articles to be treated, e.g. a drum 18.
• the articles to be treated are textiles, laundry 19, clothes, shoes or the like. In the embodiments here these are preferably textiles, laundry or clothes.
• the process air flow is indicated by arrows A in Fig. 1 and is driven by a process air blower 8 or fan.
• the process air channel 20 guides the process air flow A outside the drum 18 and includes different sections, including the section forming the battery channel 20a in which the first and second heat exchangers 10, 12 are arranged.
• the process air exiting the second heat exchanger 12 flows into a rear channel 20b in which the process air blower 8 is arranged.
• the air conveyed by blower 8 is guided upward in a rising channel 20c to the backside of the drum 18.
• the air exiting the drum 18 through the drum outlet (which is the loading opening of the drum) is filtered by a fluff filter 22 arranged close to the drum outlet in or at the channel 20.
• the first heat exchanger 10 transfers heat from process air A to the refrigerant R. By cooling the process air to lower temperatures, humidity from the process air condenses at the first heat exchanger 10, is collected there and drained to a condensate collector 26.
• the process air which is cooled and dehumidified o after passing the first heat exchanger 10 passes subsequently through the second heat exchanger 12 where heat is transferred from the refrigerant R to the process air.
• the process air is sucked from exchanger 12 by the blower 8 and is driven into the drum 18 where it heats up the laundry 19 and receives the humidity therefrom.
• the process air exits the drum 18 and is guided in front channel 20d back to the first heat exchanger 10.
• the 5 main components of the heat pump system 4 are arranged in a base section 5 or basement of the dryer 2.
• the dryer 2 comprises a first temperature sensor 28 for monitoring or detecting a temperature of the refrigerant R (or of a temperature dependent on the refrigerant o temperature) at the compressor output to provide a first temperature signal Tl for the control unit 30.
• a second temperature sensor 29 is provided to monitor or detect the temperature of an electronic board of the control unit 30, which provides a second temperature signal T2 for the control unit 30.
• only one temperature sensor is provided.
• the one or more temperature sensors may be
• a cooling air blower 24 or fan unit is arranged close to the compressor 14 to remove heat from the compressor 14, i.e.
• the cooling air flow C which is an ambient air flow in the embodiments, is actively driven by the cooling air blower 24 and is taking heat from (the surface of) the compressor 14.
• the air blower 24 comprises a blower or fan 36 which is driven by a fan motor 34 controlled by the control unit 30 of the dryer 2.
• An electronic board (e.g. inverter) or power relay for powering the fan motor 34 under the control of unit 30 is not separately shown.
• the circuit board (e.g. inverter) for powering the process air and/or drum motor or the circuit board (e.g. inverter) for powering the compressor motor under power and/or speed control of the unit 30 are not separately shown.
• the cooling air C conveyed by the cooling air blower 24 is entering the cabinet or housing 3 of the dryer 2 through one or more ambient air inlet openings 40.
• a cooling air inlet 40 is provided at the lower bottom region at the base section 5 of the housing 3.
• One or more outlet openings 42 for discharging cooling air are provided at the dryer housing 3, for example at the bottom of base section 5 and/or at an upper region of the rear cover forming part of housing 3.
• the blower 36 directs the cooling air flow C mainly towards the compressor, however a portion of the air flow and/or the air flow that has passed the compressor circulates within the dryer housing 3 where it induces an air exchange of internal air with ambient air sucked in by the blower.
• a portion of this air exchange cooling cools electronic boards (like the electronic board of the control unit, the power board for the drum and/or process air blower, and/or the inverter for powering the compressor motor).
• thermodynamic balance is achieved between the closed loops of the process air loop and refrigerant loop 6.
• the electrical power consumed by the compressor 14 and which is not transformed to work power by compressing the refrigerant is removed from the heat pump system 4, i.e. heat power of the compressor is balanced in the - under ideal conditions - closed loops of refrigerant and process air.
• the heat deposited by the compressor 14 in the refrigerant loop 6 is balanced by the cooling air blower 24 to prevent overheating.
• the heat pump system 4 After starting the dryer 2 from a cold or ambient state the heat pump system 4 runs through a warm-up phase before reaching the steady state (i.e. normal mode after the warm-up period). As the heat pump system operation status changes (depending mainly on the refrigerant temperature) in the warm-up phase, cooling requirement over time changes.
• Fig. 2 shows a schematic block diagram of components of the dryer of Fig. 1 illustrating the control of the dryer components.
• the control unit 30 is adapted to control the operation of the components of the dryer 2, i.e. the drum motor 32, the compressor 14, the valve 16 (optionally) and the fan motor 34, according to the selected program.
• a user Via an input panel 38 a user may select a drying program or cycle, e.g. FAST, ECONOMY, IRON- AID.
• control unit 30 is adapted to control the air blower 24 and the compressor 14 (speed and/or power) such that after a warm-up period a balanced state of the heat pump system 4 is maintained by operating the air blower 24 and compressor 14 for example as described below.
• a detected or monitored first temperature signal Tl exceeds a first temperature level TL1 the cooling air blower 24 is switched-on to remove heat from the heat pump system 4.
• the detected temperature signal Tl may be received from the first or the second temperature sensor 28, 29 or may be a combined temperature signal of the 5 temperature signals of both temperature sensors 28, 29.
• control unit 30 is adapted to calculate a mean value of the temperature signals of the first and second temperature sensors 28, 29 to obtain the (first) temperature signal Tl used for deciding whether the first temperature level TL1 is exceeded. Only when a monitored second temperature signal T2 exceeds a predetermined second temperature level TL2 the o compressor (target) speed or the compressor (target) power is reduced.
• the origin of the monitored temperature signals described above and below may change from e.g. detecting a first temperature signal Tl of the first sensor 28 for activating the air blower 24 to detecting a second temperature signal T2 of the second sensor 29 for
• the temperature signals used for deciding whether a temperature level is exceeded may be selected from the first or second sensor 28, 29 or may be a combination of temperature signals from both sensors 28, 29 as described above. o
• the origin of monitored temperature signals used for deciding whether a temperature level is exceeded may be the same for each temperature level or may change depending on the respective temperature level or threshold. I.e. for each temperature level decision a temperature signal of the first or second sensor 28, 29 or combination of temperature signals from the
• 5 temperature sensors 28, 29 may be used.
• only one temperature sensor, e.g. sensor 28, is provided and only one temperature signal is used to decide whether the temperature levels are exceeded or whether the temperature signal falls below temperature levels.
• only one reference sign Ti' is used for all monitored temperature signals which are used to decide whether a respective temperature level TL1..TL4 is exceeded (or vice versa whether the signal is below the temperature level), bearing in mind that the origin of the respective temperature signals may be the same for each temperature level decision or may change in dependency of the respective temperature level as described above.
• I.e. for each decision concerning the temperature levels as described above and below the respective monitored temperature signal Ti may be a signal of the first temperature sensor 28, the second temperature sensor 29 or a combined temperature signal of both sensors 28, 29.
• a detected temperature signal Ti (of the first and/or second temperature sensor 28, 29) continues to grow above a third temperature level TL3 - despite reduced compressor speed/power and activated air blower - the compressor 14 is operated at a predetermined minimum speed (Min rpm) which is a predetermined minimum speed at which the compressor 14 still works effectively. Should a detected temperature signal Ti rise above a fourth temperature level TL4, then the compressor 14 is switched-off to prevent damage of components of the heat pump system 4.
• Min rpm a predetermined minimum speed
• Fig. 3 shows a graph schematically illustrating compressor speed in relation to a detected temperature according to a first embodiment.
• the detected temperature may be received from either the first or the second temperature sensors 28, 29 or may be a combination of temperature signals from both sensors 28, 29, in particular depending on the respective temperature level.
• the compressor 14 is operated at a predetermined target speed (Target rpm).
• a monitored (first) temperature signal Ti - e.g. a refrigerant temperature at the compressor outlet - increases 5 above a first temperature level TL1 or threshold temperature
• the cooling air blower 24 is activated to remove excess heat from the compressor 14, i.e. from the heat pump system, while the compressor speed is maintained at target speed.
• a monitored (first) temperature signal Ti - e.g. a refrigerant temperature at the compressor outlet - increases 5 above a first temperature level TL1 or threshold temperature
• the cooling air blower 24 is activated to remove excess heat from the compressor 14, i.e. from the heat pump system, while the
• Fig. 4 shows a graph schematically illustrating compressor speed in relation to temperature according to a second embodiment.
• the compressor 14 is operated at a predetermined target speed.
• the cooling air blower 24 is activated as described above.
• the compressor speed is not reduced immediately to a minimum speed value (Min rpm).
• the compressor speed is o linearly decreased from the target speed to a minimum speed in temperature region II, i.e. between the second and a third temperature level TL2, TL3.
• the compressor 14 is operated at the minimum speed value (region III).
• a temperature signal Ti exceeds the fourth temperature level TL4 the compressor 14 is switched-off for safety reasons.
• the compressor 14 is 5 controlled by speed.
• the compressor 14 may be controlled by power (not depicted) in a similar manner.
• Fig. 5 shows a graph schematically illustrating compressor speed in relation to temperature according to a third embodiment. In contrast to the embodiment of Fig. 4 which shows a speed target control over the whole temperature range, Fig. 5 shows a combination of power target control (region I) and speed target control (regions II, III).
• a power target control is applied to the compressor 14 below the second temperature level TL2, i.e. the compressor is operated in temperature region I at constant power.
• the compressor power is controlled at the beginning of the drying cycle a predetermined value of power is supplied to the compressor 14 which helps in increasing the refrigerant pressure in the refrigerant loop branch between the compressor 14 and the expansion device 16 to reach nominal or desired working conditions of the heat pump system 4 as soon as possible.
• the compressor speed decreases because as refrigerant temperature and pressure increases. With an increasing refrigerant pressure, a higher portion of the motor power is consumed for the compressing work and consequently the rotation speed decreases.
• Fig. 6 shows a graph schematically illustrating compressor speed, compressor power and cooling air blower control in relation to a detected temperature Ti of a fourth embodiment.
• a monitored temperature signal Ti exceeds a first temperature level TL1 the cooling air blower 24 is switched-on and remains activated.
• the blower 24 is switched-off. I.e. it is ensured that the cooling air blower 24 is switched-off at a save temperature level.
• the power target control is depicted, i.e. the compressor 14 is operated at constant power while the compressor speed is reduced with increasing temperature as described above.
• temperature region I i.e. the temperature region up to the second temperature level TL2
• the compressor 14 is operated at target power as described above with respect to Fig. 5.
• temperature regions II and III speed target control is implemented as described above.
• the compressor control changes back from speed target control to power target control as described above, i.e. in temperature region I the compressor 14 is again operated at target power.
• the detected temperature signal Ti falls below the switch-off temperature level TL1' the cooling blower 24 is switched-off while the compressor is operated at target power.
• a temperature hysteresis may be provided for switching the blower motor 34 on at the higher temperature TL1 and off at the lower temperature TL1'.
• the compressor safety deactivation is set to the higher hysteresis temperature TL4 and the compressor activation in the high temperature regime III is set at the lower hysteresis temperature TL4'. In both cases a permanent switching on and off of the blower motor 34 and the compressor motor 14 is avoided.
• first heat exchanger evaporator
• second heat exchanger condenser

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• 2012
  • 2012-11-16 EP EP12192958.2A patent/EP2733255A1/en not_active Withdrawn
• 2013
  • 2013-11-13 WO PCT/EP2013/073761 patent/WO2014076149A1/en active Application Filing
  • 2013-11-13 AU AU2013346813A patent/AU2013346813B2/en active Active
  • 2013-11-13 EP EP13789569.4A patent/EP2920353B1/en active Active
  • 2013-11-13 CN CN201380065529.5A patent/CN104854272B/zh active Active
  • 2013-11-13 PL PL13789569T patent/PL2920353T3/pl unknown

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