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
  • D06F58/20—General details of domestic laundry dryers 
• • 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

Definitions

• the present application is directed to a household appliance for drying objects, in particular laundry.
• Appliances for drying laundry such as tumble dryers, generally comprise a drying chamber for accommodating therein the objects to be dried. Heated and dehumidified drying medium is guided through the drying chamber. Upon passing the drying chamber and objects, the heated and dehumidified drying medium takes up humidity and at the same time cools down. The drying medium then exits the drying chamber, thereby discharging humidity from the drying chamber and the objects.
• Heat pumps generally operate with refrigerants as working fluids.
• Traditional refrigerants such as
• Hydrochlorofluorocarbons HCFC
• Hydrofluorocarbons HFC
• GWP high global warning potential
• refrigerants can be toxic.
• refrigerants being far less harmful and toxic and having a reduced impact on the environment in terms of both ozone-destroying properties and global warning potential.
• a household appliance for drying objects in particular laundry, the appliance comprising a drying chamber adapted to accommodate therein the objects, and a first circuit for impinging the drying chamber with a drying medium in a circulating manner, and further comprising a heat pump with a second circuit for circulating a heat exchange medium, wherein the first and second circuit being coupled in a heat exchanging manner, and wherein the heat exchange medium being of hydro-fluoro-olefine type.
• the appliance which may in particular be a household tumble dryer, comprises a heat pump.
• a heat pump By this, residual heat from the drying medium exhausted from the drying chamber after impinging the objects to be dried can be extracted and, by adequately operating the heat pump, reused for heating drying medium prior to entering the drying chamber.
• the appliance can be operated with advantageous energy efficiency.
• drying medium can be air, in particular ambient air.
• the proposed heat exchange medium is of hydro-fluoro- olefine type (HFO-type) , which is particularly
• the proposed heat exchange medium can be used as a substitute for conventional heat exchange media, such as R134a refrigerant, the latter being by far more detrimental to the environment.
• R134a refrigerant such as R134a refrigerant
• appliances such as laundry dryers, in particular laundry tumble dryers.
• the heat exchange medium has at least one of preferred features mentioned below.
• the critical temperatures and temperature ranges are well suited for conditions prevailing with heat pump tumble dryers, such that safe operability of the appliance can be obtained.
• the advantages mentioned beforehand apply mutatis mutandis.
• the heat exchange medium has a global warming potential (GWP) index lying in a range from 1 to 15, preferably from 2 to 8, more preferably from 4 to 6 (equivalent carbon dioxide, which is a quantity that describes, for a given mixture and amount of greenhouse gas, the amount of CO 2 that would have the same global warming potential, the GWP of CO 2 is by convention equal to 1) .
• GWP index may be about 4
• GWP index may be about 6.
• the heat exchange medium has at least one of a lower flammability level (LFL) of about 6.2 Vol% and an upper flammability level (UFL) of about 12.3 Vol%.
• LFL lower flammability level
• UFL upper flammability level
• the heat exchange medium preferably has at least one of a minimum ignition energy (MIE) of more than 3000 mJ and a burning velocity (BV) of about 1.5 cm/s .
• MIE minimum ignition energy
• BV burning velocity
• the heat pump has a nominal cooling power between about 500 W and 3,500 W, in particular between 1,500 W and 3,500 W.
• Such nominal cooling power in combination with the proposed heat exchange media lead to excellent energy efficiency and drying efficiency.
• the heat pump comprises an evaporator heat exchanger for transferring heat from the drying medium to the heat exchange medium, and the appliance is adapted such that a nominal
• evaporator heat exchanger inlet temperature of the drying medium is about 30° C at the least.
• the mentioned heat exchanger inlet temperatures are particularly
• the heat pump comprises a liquefier heat exchanger for transferring heat from the heat exchange medium to the drying medium, and the appliance is adapted such that a nominal
• liquefier heat exchanger outlet temperature of the drying medium is about 100 °C at the most.
• the mentioned heat exchanger outlet temperatures are particularly
• the heat pump dryer 1 comprises a drying chamber 2, preferably a rotatable drum.
• the drying drum 2 accommodates wet laundry 3 to be dried.
• a drying medium 4 such as air, in particular comprising ambient air, is
• a drying medium circuit which, preferably forms a closed-loop circuit.
• the drying medium 4 heated to a temperature of 100 °C at the most and thereby having a comparatively low relative humidity is fed into the drying drum 2 and impinges the wet laundry 3.
• humidity of the wet laundry 3 is absorbed by the drying medium 4 thereby drying the laundry 3.
• the laundry 3 in the drying drum 2 generally has a
• the drying medium 4 also cools down, for example to temperatures of about 30°C.
• the drying medium 4 After having passed the drying drum 2, the drying medium 4, having a comparatively high relative humidity, exits the drying drum 2 and is further cooled down to condense excess humidity therefrom. After that, the drying medium 4 is recirculated through the drying drum 2. But before re-entering the drying drum 2, the drying medium 4 is heated up again, thereby reducing its relative humidity.
• the heat pump tumble dryer 1 For dehumidification and reheating the drying medium 4, the heat pump tumble dryer 1 comprises a heat pump unit 5.
• the heat pump unit 5 exemplarily comprises a heat exchange medium evaporator 6 and a heat exchange medium liquefier 7. Note that in the following, the term
• regeneratorant is also used as a synonym of the term “heat exchange medium”.
• the heat pump unit 5 further comprises a compressor 8 interconnected between the refrigerant evaporator 6 and refrigerant liquefier 7.
• a refrigerant evaporator outlet 9 is connected to a compressor inlet 10 and a compressor outlet 11 is connected to a refrigerant liquefier inlet 12.
• a refrigerant liquefier outlet 13 is connected via a throttling element 14, a capillary for example, to a refrigerant evaporator inlet 15.
• heat pump unit 5 heat is transferred from the refrigerant evaporator 6 to the refrigerant liquefier 7.
• a refrigerant i. e. a heat exchange medium, circulated in the heat pump unit closed circuit is heated up at the refrigerant evaporator 6 and cooled down at the refrigerant liquefier 7.
• evaporator 6 is used to cool down the drying medium 4 to condensate humidity, i. e. to dehumidify the drying medium 4 exiting the drying drum 2.
• the elevated temperature at the refrigerant liquefier 7 is used to reheat the drying medium 4 which in turn is then fed to the drying drum 2 for drying the laundry 3.
• the heat pump unit 5 may further comprise auxiliary heat exchangers for further optimizing energy efficiency.
• auxiliary refrigerant evaporator and an auxiliary refrigerant liquefier may be provided.
• the number of auxiliary refrigerant heat exchangers can be varied from one to nearly any arbitrary number.
• An auxiliary refrigerant evaporator may be used to speed up the heat-up phase of the heat pump dryer and a
• refrigerant liquefier may be used to balance the excess of energy of the heat pump dryer.
• the direction of refrigerant flow is indicated in Fig. 1 by small arrows, whilst the flow of drying medium 4 is indicated by larger and broader arrows.
• the heat pump tumble dryer 1 may comprise a fan 16 adapted and designed for circulating the drying medium 4 within the heat pump tumble dryer circuit .
• a refrigerant i.e. heat exchange medium
• hydro-fluoro-olefine comprising a tetra-fluoro-propene , in particular 1 , 1 , 1 , 2-tetra-fluoro-propene and/or 1 , 1 , 1 , 3-tetra-fluoro- propene
• hydro-fluoro- olefine comprising a tetra-fluoro-propene , in particular 1 , 1 , 1 , 2-tetra-fluoro-propene and/or 1 , 1 , 1 , 3-tetra-fluoro- propene
• the heat exchange medium has at least one of the following properties: critical temperature of about 90 °C to 115°C;
• critical pressure of about 25 to 40 bar, preferably 30 to 35 bar, more preferably 33 to 34 bar;
• nominal heat of vaporization of about 160 to 215 kJ/kg, preferably from 175 to 200 kJ/kg;
• global warming potential index of about 1 to 15, preferably of about 2 to 8, more preferably of about 4 to 6;
• the heat pump tumble dryer 1 can be operated in an energy efficient way, in particular in concert with a heat exchange medium as described beforehand, if at least one of - the heat pump unit 5 has a nominal cooling power between about 500 W and 3,500 W, in particular between 1,500 W and 3,500 W;
• temperature of the drying medium 4 is about 30° C at the least
• temperature of the drying medium 4 is 100 °C at the most.
• the proposed household appliance adapted to dry objects, in particular laundry 3 has excellent energy efficiency and environmental compatibility .

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Drying Of Solid Materials (AREA)
• Detail Structures Of Washing Machines And Dryers (AREA)

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Publications (1)

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ID=44318096

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• 2011
  • 2011-01-24 EP EP11151801.5A patent/EP2479337B1/en not_active Not-in-force
• 2012
  • 2012-01-11 AU AU2012210733A patent/AU2012210733A1/en not_active Abandoned
  • 2012-01-11 US US13/981,038 patent/US20140020257A1/en not_active Abandoned
  • 2012-01-11 RU RU2013138445/12A patent/RU2013138445A/ru not_active Application Discontinuation
  • 2012-01-11 BR BR112013018851A patent/BR112013018851A2/pt not_active IP Right Cessation
  • 2012-01-11 WO PCT/EP2012/050385 patent/WO2012100986A1/en active Application Filing
  • 2012-01-11 CN CN2012800062187A patent/CN103476983A/zh active Pending

Patent Citations (1)

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