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 invention relates to a condensation dryer with a drying chamber for the objects to be dried, a process air circuit in which there is a heater for heating the process air and the heated process air can be performed by means of a blower on the objects to be dried, an air-to-air heat exchanger and a heat pump cycle with an evaporator, a compressor and a condenser, and a method for its operation.
• Tumble dryers whose operation is based on the condensation of the evaporated by means of warm process air moisture of the laundry from the process air discharged from the laundry - so-called condensation dryer - need no hose for removing the moisture-laden process air and are very popular because they are in indoor bathrooms or Laundry rooms can be used by larger residential complexes. This applies both to tumble dryers intended specifically for drying laundry and to so-called laundry dryers, namely appliances which can both wash and dry laundry. Any subsequent reference to a "tumble dryer” or “condenser dryer” therefore applies to both a drying and a washing and drying device.
• process air In a condensation dryer air (so-called process air) is passed through a fan via a heater in a wet laundry containing drum as a drying chamber. The hot air absorbs moisture from the laundry to be dried. After passing through the drum, the now moist process air is directed into a heat exchanger, which is usually preceded by a lint filter.
• the moist process air is cooled, for example by a separately guided cooling air flow, so that the moisture contained in the process air condenses as water.
• the condensed water is then generally collected in a suitable container for later disposal, and the cooled and dried air is returned to the heater and then to the drum.
• This drying process is energy-intensive, since the heat extracted during cooling of the process air in the heat exchanger is energetically lost to the process, at least when this heat is dissipated in a cooling air flow. By using a heat pump, this energy loss can be significantly reduced.
• the cooling of the warm, moisture-laden process air is carried out substantially in a m first heat exchanger of the heat pump, in particular an evaporator, where the heat transferred to evaporate a refrigerant used in the heat pump is used.
• Such vaporized due to the heating refrigerant is fed via a compressor to a second heat exchanger, in the given case and hereinafter also called “condenser", the heat pump, where due to the condensation of the gaseous refrigerant heat is released, which in turn for heating the process air before entering the
• the liquefied refrigerant passes back to the evaporator through a restrictor, which reduces its pressure, where it evaporates, recovering heat from the process air.
• a condensation dryer with a closed process air circuit which is equipped with a heat pump.
• the heat pump is designed as a device operating according to the absorber principle whose absorber forms a third heat exchanger whose coolant flows through the primary circuit and via whose secondary circuit the process air flowing from the second heat exchanger is returned to the secondary circuit of the first heat exchanger.
• Common heat pumps use compressor units as described above. These usually work optimally in a certain temperature range.
• the problem with the use of a compressor heat pump in the condensation dryer are usually the high temperatures in the condenser, which lead due to the process that the compressor must be switched off and / or the efficiency of the heat pump deteriorates. This problem is even greater if the compressor is supported by an additional heating in the process air circuit, to a faster and / or higher heating of the process air and thus shorter Drying times to achieve.
• One way to control and / or reduce the refrigerant temperatures in the heat pump cycle is therefore desirable.
• the compressor can be cooled by an additional fan.
• the refrigerant can be additionally cooled after the condenser.
• An object of the invention is therefore to provide a condensation dryer of the type specified in the beginning, in which an optimal refrigerant temperature can be easily adjusted.
• a condensation dryer is to be provided, which makes it possible to reduce the refrigerant temperature in the condenser.
• a method for operating such a condensation dryer is to be specified.
• Preferred embodiments of the condensation dryer according to the invention are listed in the claims 2 to 8. Preferred embodiments of the condensation dryer correspond to corresponding preferred embodiments of the method.
• An object of the invention is thus a condensation dryer with a drying chamber for the objects to be dried, generally laundry, a process air circuit in which a heater for heating the process air is and the heated process air can be guided by means of a blower over the objects to be dried, an air-air heat exchanger and a heat pump circuit with an evaporator, a compressor and a condenser, wherein in the heat pump circuit between the condenser and the evaporator, an additional heat exchanger is located, which is operatively coupled to the air-air heat exchanger.
• an additional heat exchanger is integrated into the condensation dryer equipped as a "hybrid" with both a heat pump circuit and with an air-to-air heat exchanger, the invention being based on the recognition that the Air-to-air heat exchanger and in particular the connected channels for process air or cooling air provide sufficient heat sinks to dissipate without affecting the drying process any excess heat from the heat pump circuit, this excess does not necessarily have to be lost or substantially.
• the additional heat exchanger is arranged in a process air channel between the evaporator and the condenser.
• the additional heat exchanger is between the condenser and an expansion valve, through which the liquefied refrigerant is expanded to a lower internal pressure in order to then evaporate in the evaporator can.
• the exchange of heat takes place in the additional heat exchanger between the liquid refrigerant and the relatively cool process air.
• the additional heat exchanger is not simply an extension of the condenser.
• the refrigerant is partly in the liquid and partly in the gaseous phase, which is why a temperature is set in the condenser, which corresponds to the boiling point of the refrigerant at the given pressure in the condenser.
• a lower temperature than this can not be achieved in the condenser; even if it is structurally enlarged.
• the liquid refrigerant from the two-phase mixture is removed purely, its temperature can be lowered by a further heat exchange as needed. This is known as "subcooling.” This is what happens in the additional heat exchanger which, for that reason, can not be considered part of the condenser, even if it is placed in close proximity to the condenser.
• the additional heat exchanger is located in a cooling air channel of the air-to-air heat exchanger.
• the additional heat exchanger is generally in two channels, one of these channels according to the invention is the heat pump cycle and the other channel is the cooling air duct or the process air duct.
• more than one additional heat exchanger may be present in the heat pump cycle.
• a first additional heat exchanger located in the process air duct, and a second additional heat exchanger can be located in the cooling air duct.
• an additional heat exchanger is located in the cooling air duct, it is arranged in a first preferred embodiment between a cooling fan and the air-air heat exchanger.
• the additional heat exchanger is arranged in the cooling air channel on the side facing away from the cooling fan side of the air-to-air heat exchanger.
• the additional heat exchanger is arranged in the cooling air duct on the side of a cooling fan facing away from the air-air heat exchanger.
• the refrigerant used in the heat pump cycle is preferably selected from the group consisting of a butane / isopropane mixture, carbon dioxide and a fluorohydrocarbon compound.
• the air-to-air heat exchanger is removable. This is particularly advantageous because a removable heat exchanger can be cleaned more easily from lint.
• the invention also relates to a method for operating a condensation dryer just described, is conducted in the process air by means of a blower in a process air circuit, wherein the heat exchange between the heat pump and the process air circuit is supported by the additional heat exchanger between the condenser and the evaporator.
• Preferred embodiments of the condensation dryer according to the invention correspond to preferred embodiments of the method according to the invention and vice versa, even if not indicated in detail in the present case.
• the heat pump in the condensation dryer according to the invention has, in addition to evaporator, condenser and compressor in the flow direction of the refrigerant between the condenser and the evaporator, an expansion valve (also referred to as throttle valve or throttle) on.
• an expansion valve also referred to as throttle valve or throttle
• the refrigerant used in the heat pump preferably circulates in the heat pump circuit with a turbulent flow.
• a turbulent flow may be adjusted by a suitable structural design of a flow channel and / or by suitable drive means (e.g., compressor).
• the temperature of the refrigerant of the heat pump, in particular in the condenser, according to the invention is generally kept within the permissible range via the control of heat pump and additional heat exchanger. Since there is a heater in the process air circuit according to the invention before entering the drying chamber, the control of the heat pump is preferably carried out in coordination with the control of the heating.
• process air and cooling air or process air and refrigerant in the heat pump are each passed through the corresponding heat exchangers in a crossflow or countercurrent process.
• an improved adjustability of the temperature of the refrigerant in the heat pump, in particular in the condenser is given by the combination of a heat pump with the additional heat exchanger and with an air-air heat exchanger.
• a drying chamber laundry drum
• process air is first cooled in an air-to-air heat exchanger, where it can precipitate moisture in the form of condensed water.
• the already slightly cooled process air is supplied to the evaporator of the heat pump cycle, where the process air is additionally cooled. Due to the use of the heat pump in the process air circuit upstream air-to-air heat exchanger, the refrigerant of the heat pump is heated less.
• the heater used in the condensation dryer according to the invention is preferably a two-stage heater.
• the control of this heater is also used in a preferred embodiment of the invention for controlling the temperature of the refrigerant.
• the invention has the advantage that the temperature of the refrigerant in the heat pump can be easily controlled.
• the temperature of the refrigerant can be regulated so that the heat pump and in particular the condenser work in an optimal temperature range. This allows the operation of the condensation dryer with a more favorable energy balance.
• the heat pump is spared.
• the requirements for the compressor of the heat pump may be lower at a lower refrigerant temperature.
• FIGS. 1 to 5 Further details of the invention will become apparent from the following description of non-limiting embodiments of the condensation dryer according to the invention and a method to be used in this condensation dryer. Reference is made to FIGS. 1 to 5.
• Fig. 1 shows a vertical section through a condensation dryer
• Fig. 2 shows a schematic representation of the process air circuit and the heat pump circuit for the embodiment of a condensation dryer shown in Figure 1;
• Fig. 3 shows a schematic representation of the process air circuit and the heat pump circuit for a second embodiment of the condensation dryer;
• FIG. 4 shows a schematic representation of the process air circuit and the heat pump circuit for a third embodiment of the condensation dryer
• Fig. 5 shows a schematic representation of the process air circuit and the heat pump circuit for a fourth embodiment of the condensation dryer.
• drying 1 shows a vertically sectioned condensation dryer 1 (hereinafter abbreviated to "dryer") in which an additional heat exchanger 16 both in the heat pump circuit 13, 14, 15, 16, 17 and in the cooling air channel 12 of an air-to-air heat exchanger 1 1, 12. This additional heat exchanger 16 is thus functionally coupled to the air-air heat exchanger 11, 12.
• the dryer 1 shown in FIG. 1 has a drum rotatable about a horizontal axis as a drying chamber 3, inside which drivers 4 are fastened for moving laundry during a drum rotation.
• Process air is conducted by means of a blower 19 via a heater 18, by a drum 3, an air-air heat exchanger 1 1, 12 and a heat pump 13, 14, 15 in an air channel 2 in a closed circuit (process air circuit 2).
• the moist, warm process air is cooled and reheated after condensation of moisture contained in the process air.
• heated air from the heater 18, ie from the side of the drum 3 opposite a dryer door 5 is passed through the perforated bottom into the drum 3, where it comes into contact with the laundry to be dried and flows through the filling opening of the drum 3 to a lint filter 6 within a filling door closing the filling opening 5. Subsequently, the air flow is deflected in the dryer door 5 down and passed from the air duct 2 to the air-air heat exchanger 1 1, 12. There condenses due to cooling the absorbed by the process air from the laundry moisture and is collected in a dashed line in Figure 1 condensate tank 21 from which they can be disposed of.
• the somewhat cooled process air to the evaporator 13 of a heat pump 13, 14, 15 out, where it is further cooled.
• the refrigerant of the heat pump evaporated in the evaporator 13 is conducted to the condenser 15 via a compressor 14.
• condenser 15 the refrigerant liquefies with heat being released to the process air.
• the refrigerant which is now in liquid form, subsequently becomes an additional refrigerant Heat exchanger 16 out, which is in the cooling air passage 12 of the air-to-air heat exchanger 1 1, 12 between this and a cooling (air) blower 20, and from there via a throttle valve 17 in turn to the evaporator 13, whereby the refrigerant circuit is closed.
• the cooling air is taken from the room air and, after passing through the air-air heat exchanger 1 1, 12 again supplied to the room air.
• the drum 3 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 7, wherein the drum 3 rests with a brim on a sliding strip 8 on the bearing plate 7 and is held at the front end.
• the control of the condensation dryer via a control device 10, which can be controlled by the user via an operating unit 9.
• Figure 2 shows a schematic representation of the process air circuit and the heat pump circuit for the embodiment of a condensation dryer shown in Fig. 1. While the process air in the closed process air circuit 2 and the refrigerant in the closed heat pump circuit of the heat pump 13, 14, 15 is performed, the air used for cooling in the air-air heat exchanger 1 1, 12 air is taken from the room air, via the cooling fan 20 after passage through the additional heat exchanger 16 to the air-to-air heat exchanger 1 1, 12 passed and then fed back to the room air.
• Fig. 3 shows a schematic representation of the process air circuit and the heat pump circuit for a second embodiment of the condensation dryer with an additional heat exchanger 16, which is operatively coupled to the air-air heat exchanger 1 1, 12.
• the additional heat exchanger 16 is also in the cooling air passage 12 of the air-to-air heat exchanger 1 1, 12, but in the cooling air passage 12 on the side facing away from the cooling fan 20 of the air-to-air heat exchanger 1 1, 12th
• Fig. 4 shows a schematic representation of the process air circuit and the heat pump circuit for a third embodiment of the condensation dryer.
• the air-air heat exchanger 1 1, 12 functionally coupled additional heat exchanger 16 in the cooling air channel 12 on the air-air heat exchanger 1 1, 12 opposite side of the cooling fan 20 is arranged.
• the heat exchanger 16 is thus in the intake of the cooling air.
• Fig. 5 shows a schematic representation of the process air circuit and the heat pump circuit for a fourth embodiment of the condensation dryer.
• the additional heat exchanger 16 which is functionally coupled to the air-air heat exchanger 1 1, 12, in the process air duct 11 between the evaporator 13 upstream expansion valve 17 and the condenser 15 is arranged.
• the exchange of heat takes place in the additional heat exchanger 16 between the liquid refrigerant and the relatively cool process air.
• the additional heat exchanger 16 is not simply an extension of the condenser 15.
• the refrigerant is present in a two-phase mixture partly in the liquid and partly in the gaseous phase. Therefore, there is a temperature that corresponds to the boiling point of the refrigerant at the given pressure in the condenser 15. A lower temperature than this can not be achieved in the condenser 15.
• Increased or decreased supply of heat into the condenser 15 is compensated without changing the temperature by a shift in the balance between the proportions of the liquid and gaseous refrigerant in the two-phase mixture.

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

Applications Claiming Priority (2)

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• 2007
  • 2007-01-15 DE DE102007002181A patent/DE102007002181B3/de not_active Expired - Fee Related
  • 2007-12-19 US US12/522,067 patent/US9212450B2/en not_active Expired - Fee Related
  • 2007-12-19 AT AT07857803T patent/ATE479792T1/de active
  • 2007-12-19 EP EP07857803A patent/EP2115208B1/fr active Active
  • 2007-12-19 WO PCT/EP2007/064180 patent/WO2008086933A1/fr not_active Ceased
  • 2007-12-19 DE DE502007004970T patent/DE502007004970D1/de active Active

Non-Patent Citations (1)

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