EA017367B1 - Household appliance comprising a first air conduit and a heat pump - Google Patents

Abstract

The invention relates to a household appliance 1 comprising a housing 2, a drying chamber 3 for drying wet articles 6 therein, a first air conduit 7 for guiding process air drawn into said housing 2 to dry the articles 6 and a heat pump 12, 13, 14, 15, 16, 17, said heat pump 12, 13, 14, 15, 16, 17 comprising a heat sink 14 for transferring heat into said heat pump 12, 13, 14, 15, 16, 17, a heat source 13 coupled to said first air conduit 7 for transferring heat from said heat pump 12, 13, 14, 15, 16, 17 into the process air, and a heat transfer device 12, 15, 16, 17 for transferring heat from said heat sink 14 to said heat source 13. Said heat sink 14 is coupled to a second air conduit 18 for guiding secondary air drawn into said housing 2, for transferring heat from the secondary air into said heat pump 12, 13, 14, 15, 16, 17.

Description

Technical field

The present invention relates to a household appliance including a housing; a drying chamber for drying wet objects therein; primary air duct for directing process air supplied to said housing for drying objects; and a heat pump comprising a heat sink for transferring heat to said heat pump, a heat source coupled to said primary air duct for transferring heat from said heat pump to process air, and a heat transfer device for transferring heat from said heat sink to said heat source.

State of the art

A household appliance of this type is presented in the abstract of Japanese Patent Publication 1P 2004089415 A and is contained in the Japanese Patent Abstracts Database.

A household appliance for drying wet objects, including a heat pump, is presented in document EP 0467188 B1. This document contains a detailed description of a household appliance made in the form of a dryer for drying items, namely wet laundry. The document indicates many details of such a household appliance that may be necessary or, in any case, preferred in the manufacture or use of the appliance. Accordingly, the entire contents of this document is incorporated into this description by reference.

A related type of household appliance is known from AO 2006/029953 A1, which describes a dishwasher with respect to a clothes dryer or combination washer dryer, document No. 19738735 C2, which discloses a household appliance with a different type of heat pump, as well as documents EP 1672294 A2 and EP 1672295 A2, the latter two disclosing air conditioning devices that contain cooling circuits, in certain respects similar to the heat pumps discussed in the present description.

Drying wet objects in a household appliance generally requires the evaporation of moisture from objects and the transfer of the vapors thus formed by a stream of heated process air. Such process air saturated with vapors can be removed from the device or subjected to a condensation process in order to extract evaporated moisture in liquid form for its collection and removal. Such a condensation process, in turn, requires cooling of the process air, thereby extracting heat. This heat can again be simply removed from the device, however, to maintain low energy consumption, it may be desirable to utilize this heat, at least some of it. For this purpose, a household appliance was developed, including a heat pump, which utilizes the energy received from the process air. To this end, the heat pump includes a heat sink used to cool the process air with the moisture contained therein and thereby extract heat from the process air. In addition, the heat pump includes a heat source used to heat the process air before feeding it to objects intended for drying in order to extract moisture from them. Finally, the heat pump includes a heat transfer device for transferring heat from the heat sink to the heat source, thereby completing the desired heat recovery.

In an exemplary heat pump, also known from the aforementioned documents, the heat transfer device includes a heat transfer circuit comprising a heat transfer agent or a refrigerant constantly circulating through a heat sink and a heat source. The heat pump operates by evaporating the liquid coolant in the heat sink under the action of heat extracted from the process air flowing through the heat sink, and then compressing this liquid coolant and re-releasing heat energy from it that is returned to the process air in the heat source. This heat release causes the liquid coolant in the gaseous phase to condense or liquefy. The liquefied liquid coolant to reduce its internal pressure is passed through the nozzle and then sent again to the heat sink for new evaporation and heat recovery. Technological air, as a rule, circulates in a substantially closed circuit or closed circuit of technological air, with the exception of the device known from the above-mentioned abstract of document 1P 2004089415 A, which describes an open cycle of supply of technological air. Although it may be appropriate or even necessary to open a closed process air circuit at least from time to time, as described in document EP 0467188 B1, the relevant IEC standards (1ES, 1p1etpayop1 E1ec1go1ec11shsa1 Sottschyop - International Electrotechnical Commission, IEC) require that the drying machine , claimed to utilize moisture through condensation, provided a moisture leak rate below 20% of its total. In addition, in such household appliances, including heat pumps, the problems are the high cost of manufacture, the relatively large time required to dry a normal loading portion of linen or items for drying, and the possible threats to the environment that may be caused by liquid coolants used in such devices. To mitigate these threats, associated primarily with ozone-depleting or enhancing the greenhouse effect of such compounds or with their flammability, often used in the past chlorinated hydrocarbons are currently prohibited by the relevant legislation.

- 1 017367 PTO. To quantify the potential caused by the greenhouse effect of conventional refrigerants, each of the well-known or commonly used refrigerants was assigned a reference index of the so-called global warming potential (С1оЬа1 Аатшд ΡοΙοηΙίαΙδ - global warming potentials, hereinafter abbreviated as: САР шйех - GWP index, two GWP index) or K744, was taken equal to 1.

The extraction of moisture from objects intended for drying using process air is only effective if the process air is heated above normal ambient temperature, preferably to a temperature above 60 ° C. This temperature will be reduced by the evaporation process to a certain lower temperature. In any case, it can be expected that a temperature near or above 35 ° C at the inlet of the evaporative heat exchanger will cause a problem in the operation of the heat pump using the above-described liquid coolant, and designed in accordance with the practice adopted in the field of refrigeration technology, consisting in the fact that the compressors and liquid refrigerants (collectively referred to as liquid coolants in this description) used in conventional refrigeration practice are not suitable for the intended purpose. There were suggestions that a return to refrigerants with very high critical temperatures can help to guarantee their operation at temperatures up to 60 ° C, but so far there have been no solid studies and recommendations on this subject. Other measures that have been used to solve this problem include removing excess heat from the device by evaporating warm process air with replacing it with cooler air and turning on additional heat exchangers to select the excess heat of the liquid coolant using suitable additional heat exchangers. However, all these measures are associated with a further increase in the complexity and cost of the device.

A detailed list of GWP indices of well-known refrigerants is given in the 8o1cap-Rigaoys1 Mapia1 YasGgschsgaOop apy-Sopyyushpd Tesypoduodu N. N. Visyt1y's manual, 1. Ne11tapp, N. Koshd, apy S. Msitet, 2 ^ply . 08/2000 (Guide to solkans used in refrigeration and air conditioning technology). The quantitative classification of refrigerants from the point of view of their flammability, expressed by the lower flammability index, is given in the European standard IEC 1EC 60335-2-40, No8eo1i apytat E1ec1g1ca1 ArrNapsek - 8aGe1u - ratsi1e1a2e1a2Ge2Ge2Ge1a2Ge5G2G2G2a2 Ritrk, Al-Sopyyyupeg apy Ieyit1yigG1eg8, Eyyup 4.2 2005-07, Appeh VV - Ta1e VV.1 (Safety of household and similar electrical appliances: special requirements for electric heat pumps, air conditioners and dehumidifiers). Relevant information on refrigerants, or liquid coolants, can also be found in US Standard A8HKAE 34, which includes the profile nomenclature of such compounds and their classification according to the degree of safety and toxicity.

The dryer described in the aforementioned Japanese abstract has an open air duct for the process air that is supplied to the dryer, heated in a heat source of the heat pump, and driven through objects to be dried that are rolled in a rotating drum. The process air is then passed through a heat pump heat sink to cool and extract moisture from the process air through condensation. And finally, process air is discharged from the dryer. Since in this dryer, at least a portion of the moisture recovered from the washed items is collected in liquid form, the dryer requires operator intervention to remove the collected liquid. This, in any case, is unusual and inconvenient for the operator, who does not have to worry about the disposal of any waste in a conventional clothes dryer with an open process air duct. In addition to the problem of liquid waste removal, the dryer disclosed in this Japanese abstract requires the use of a special filter to remove fibrous or dusty residues, commonly referred to as fibers, from the process air leaving the washing drum. As a rule, the process air stream extracts a lot of fibers from the laundry during drying, which settle on all duct structures and other parts through which the process air that carries the fibers passes and adhere there due to the moisture released from the process air. To avoid clogging of the heat sink with fibers, it is necessary to place a special fiber filter upstream of the heat sink in order to catch as many fibers as possible, and this filter also requires the attention of the operator, who must then remove the collected fibers. This may be another drawback of such a dryer.

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Disclosure of invention

Thus, the object of the present invention is to propose a household appliance defined in the introductory part of the present description, including a heat pump, designed in such a way as to reduce the problems described above and allow faster drying of items at reasonable costs. In particular, it is an object of the present invention to provide a household appliance as defined above, which makes it possible to at least substantially avoid the formation of liquid condensate. Equally, it is an object of the present invention to provide a household appliance as defined above that avoids the need for filtering fibers.

The present invention provides a solution embodied in a household appliance as defined in an independent claim. Preferred embodiments of the present invention are defined in the dependent claims.

In accordance with the present invention, there is provided a household appliance including a housing; a drying chamber for drying wet objects therein; primary air duct for directing process air supplied to said housing for drying objects; and a heat pump comprising a heat sink for transferring heat to said heat pump, a heat source coupled to said primary air duct for transferring heat from said heat pump to process air, and a heat transfer device for transferring heat from said heat sink to said heat source. In this device, said heat sink is connected to a secondary air duct for directing secondary air supplied to said housing to transfer heat from the secondary air to said heat pump.

An advantage of the present invention is that the heat extracted from the secondary air received from the environment of the device will generally result in significantly less condensation than when heat is extracted from the process air, which is purposefully saturated with moisture to a maximum or close to maximum humidity.

In addition, an advantage of the present invention is that the air introduced into the device from the environment is colder than the process air coming out of the drying chamber with drying objects, which, as a rule, carries at least a portion of the thermal energy transferred to the process air during heating it before entering the drying chamber. Accordingly, the present invention provides a certain degree of heat leakage from the device, which balances the excess heat produced by the heat pump according to the fundamental laws of thermodynamics. Thus, the present invention contributes to the stabilization of the drying process of objects by providing a balance between the release of excess heat inside the device and heat removal from the device. This is of paramount importance in the main stage of the drying process, when all the initial heating operations of the device and its elements are completed and it is desirable that the drying process proceed in a quasi-stationary mode.

And in addition, the process air is removed from the device after only a single pass through the drying chamber around the items intended for drying, and, if possible, without passing by any other functionally active components of the device. Therefore, there is no significant risk of clogging with fibers, and therefore, a special fiber filter is generally not required. An exception may be the case when the process air supply fan is located downstream of the drying chamber. However, it can be expected that the flow through such a fan will be turbulent, and this turbulence of the flow will at least substantially prevent the settling of fibers within the fan.

In a preferred embodiment of the present invention, said heat transfer device includes a heat transfer circuit comprising a heat transfer fluid circulating in said heat transfer circuit, a compressor for compressing said heat transfer fluid and circulating said heat transfer fluid, and a nozzle for decompressing said fluid coolant. Moreover, said heat sink is an evaporator for transferring heat from the process air to said liquid coolant by evaporating said heat-transfer fluid, and said heat source is a fluidizer for transferring heat from said liquid coolant to process air by liquefying said heat-transfer fluid. Accordingly, said heat pump is a known compressor type heat pump, used in particular in refrigeration and freezer installations, which makes it possible to designate the heat transfer fluid used in such a heat pump as refrigerant.

According to one preferred embodiment, which is one of the further developments of the previous embodiment of the present invention, said heat transfer fluid includes a fluorinated hydrocarbon compound. In particular, said liquid coolant is selected from the group comprising refrigerants K134a, K152a, K.290, K407C and K410L.

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If K134a and K152a are mono compounds of fluorinated hydrocarbon, then K407C and K410L are mixtures of such compounds. In turn, K290, or propane, is an alkane, i.e. hydrocarbon mono compound. It has the corresponding physical properties, which makes it extremely suitable for the application discussed here. In particular, the propane GWP index is 3, i.e. extremely low in comparison with the GWP index of a conventional liquid coolant K134a, equal to 1300. Of course, the use of highly combustible propane requires special protection of the system from the danger of fire. In order to combine lower flammability and a rather low GWP index, K152a is particularly preferred.

In a further preferred embodiment of the present invention, said drying chamber is a rotary drum.

According to another preferred embodiment of the present invention, the device is in the form of a drying machine for drying wet laundry. Other embodiments of the device in accordance with the present invention are provided, namely, in the form of a washer-dryer for washing and drying clothes or in the form of a dishwasher.

According to another preferred embodiment of the present invention, said secondary air duct is connected to said heat transfer device for transferring heat transferred from said heat transfer device to said secondary air. This embodiment has the advantage that it contains chilled secondary air used for some cooling of the components of the heat pump, which control the thermodynamic process and, thus, serve to introduce additional energy necessary for the implementation of this process. For this purpose, it is preferable to mention the secondary air duct so that the secondary air passes through said heat sink before passing through said circulation means. But it is even more preferable that said primary air duct and said secondary air duct are connected to one exhaust duct for discharging said process air and said secondary air from said casing. In such an embodiment, said exhaust duct may include a single fan for discharging said process air and said secondary air.

According to another preferred embodiment of the present invention, said housing is open for air to flow into said housing, and said secondary air duct has an inlet located inside said housing. When the inlet of the secondary duct is located inside the housing, air that could absorb some heat dissipated by the components of the device, including the drying chamber, the heat source and parts of the primary air duct, is sucked into the secondary air duct and then cooled by the heat sink. And since the heat extracted by the heat sink is returned to the drying process through a heat source, this heat return contributes to the utilization of the scattered heat and to the corresponding increase in the efficiency of the drying process. Further, since the air inside the enclosure is heated to some extent by dissipated heat, more advantages can be obtained when the instrument is placed in a relatively cold environment. In such an environment, cooling secondary air sucked from the environment can lower the temperature of such secondary air below 0 ° C and cause ice to form in or around the heat sink. This ice, in turn, can reduce the efficiency of the heat sink. Some preheating of the secondary air will at least significantly reduce the risk of ice formation.

According to another preferred embodiment of the present invention, said secondary air duct has two inlet openings, of which the first inlet is oriented in the direction of said heat transfer device, and the second inlet is oriented in the direction of an engine serving to drive a first fan arranged in said primary air duct and a second fan located in said secondary air duct. Thus, the heat dissipated by the two main heat sources is utilized by sucking air from areas near these sources into the secondary air duct. Even more preferably, said drying chamber is a rotary drum driven by said motor. Thus, only one engine provides the drive of the moving components of the device, with the exception of the heat transfer device, which contributes to the localized generation of excess heat, which can, in turn, be disposed of using appropriately localized means. A preferred example of such localized means is, according to yet another more preferred embodiment, said second fan, made in the form of a dual-flow fan, giving two streams, each of the inlet openings located at the respective one of these streams.

According to another preferred embodiment of the present invention, the device includes a bypass duct connecting said primary air duct and said secondary air duct, as well as switching means for selectively guiding a part

- 4 017367 of said process air to said secondary air duct via said bypass duct. More preferably, said bypass duct is connected to said primary air duct between said heat source and said drying chamber, and that said bypass duct is connected to said secondary air duct upstream of said heat sink. Even more preferably, the household appliance includes a temperature sensor for detecting a temperature in said heat sink and a control device connected to said thermal sensor and said switching means. Further, said control device is configured to control said switching means to direct a portion of said process air to said secondary air duct, provided that the temperature measured by said temperature sensor is below a predetermined limit temperature. But it is even more preferable that the household appliance includes a condensate sensor located in said secondary air duct, said condensate sensor being connected to said heat sink to detect condensate formed in said heat sink, and said control device is connected to said condensate sensor and said thermal a pump and is configured to control said heat pump in response to detection signals received from said condensate sensor. And even more preferably, said control device is connected to circulation means included in the heat pump, and that said control device is arranged to control said heat pump by controlling said circulation means.

In a domestic appliance including such a bypass duct, operation modes can be adapted to various environmental and operating conditions. So, in the case of a very low ambient temperature, the secondary air stream can be mixed with part of the process air diverted upstream of the drying chamber to avoid the prevailing low temperatures of the process air passing through the heat sink, which can cause ice to form in the heat sink, which can reduce the secondary air duct clearance and damage the operation of the heat pump. Further, the bypass duct can be used for the operation of freezing from ice (de-icing), during which the heat pump is turned off, and the process air discharged into the bypass duct after passing through the heat source passes through the heat sink to thaw the ice formed there. Such an anti-icing operation can also be used to provide some preheating of the heat sink before starting the drying process by directing warm process air discharged through the bypass duct to pass through the heat sink. Such warm process air can be obtained by heating the process air using an additional heater, described below. In addition, to avoid ice formation inside the appliance, a bypass duct can also be used to prevent excess condensation in the heat sink, which can occur in a relatively warm and humid surrounding atmosphere. The same secondary processes as just described can be used to control the temperature in the heat sink to avoid excessive condensation. The application of these secondary processes can be controlled by the control device of the household appliance using the special sensors described above.

According to another preferred embodiment of the present invention, the device includes a heater located in said primary air duct upstream of said drying chamber, for selectively heating said process air.

A separate heater can be used to obtain quick pre-heating of the device during the operational phase of heating, as well as to provide some additional heating in a stationary mode of operation. Such additional heating can be used in order to avoid ice formation or excessive condensation in the heat sink when used in parallel with the bypass duct described above.

Brief Description of the Drawings

Detailed descriptions of preferred embodiments of the invention are given below with reference to the accompanying figures. The figures show schematic images of a household appliance, namely:

in FIG. 1 shows a first embodiment of a household appliance;

in FIG. 2 shows an arrangement of components of a second embodiment of a household appliance;

in FIG. 3 shows an arrangement of components of a third embodiment of a household appliance;

in FIG. 4 shows some features of a fourth embodiment of a household appliance.

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The implementation of the invention

In FIG. 1 shows a household appliance 1, including a housing 2, which contains all the components of the appliance 1 described below, and located in the corresponding household environment. The device 1, further includes a drying chamber 3, made in the form of a drum 3, rotating around an axis 4 of rotation. Access to the drum 3 can be through the door 5 for loading items 6 intended for drying, which are wet items of clothing (linen) 6. After drying, items of clothing 6 can also be removed through the door 5.

To dry garments 6, air is supplied to the device 1 through the primary air duct 7 by the first fan 8, driven by the engine 9. To prevent dust and other dirt from entering the garments 6, the primary air duct 7 is equipped with a filter 10. The process air supplied through the air duct 7 primary air, can be heated by an electric heater 11. The electric heater 11 can be replaced by a heater operating by burning liquid or gas fuel, in accordance with the current level of knowledge in the field of su yl machines for laundry. In this case, the heater 11 is only an auxiliary component, and the main heating of the process air is carried out by the heat pump 12, 13, 14, 15, 16, 17, which includes a heat source 13, which forms part of the primary air duct 7. In accordance with the current level of knowledge, device 1 can be defined as an exhaust type clothes dryer, since the process air supplied through the primary air duct 7 moves in an open circuit: air is supplied to the device 1 through the primary air duct 7, passes through objects 6 only once and then ejected from appliance 1.

The heat pump 12, 13, 14, 15, 16, 17, in addition to the heat source 13 and the heat sink 14 connected to the secondary air duct 18, includes a heat transfer device 12, 15, 16, 17, including a heat transfer circuit 12 containing a liquid coolant the circulation of which is carried out by the compressor 15, driven by the compressor engine 16, and the nozzle 17. The operation of such a heat pump 12, 13, 14, 15, 16, 17 is known to specialists with modern technology. In any case, the liquid coolant, which may be one of the group of refrigerants P134a. P152a B290, B407C and K4-10L, enters the heat sink 14 in the liquid phase, where it evaporates, taking heat from the secondary air flowing through the secondary air duct 18, to which the heat sink 14 belongs. After evaporation in the heat sink 14, the heat transfer fluid passes through the compressor 15, which compresses the liquid coolant to increase both its internal pressure and its temperature. After that, the compressed liquid coolant enters the heat source 13, in which it is liquefied, giving off heat to the process air flowing through the primary air duct 7. After exiting the heat source 13, the liquefied liquid heat carrier, while continuing to move along the heat transfer circuit 12, passes through the nozzle 17, which reduces the internal pressure of the liquefied liquid heat carrier. Said nozzle 17 should be considered as a means including a nozzle 17 in its own form, a capillary tube and a shut-off valve. Downstream of the nozzle 17, the liquefied liquid coolant with reduced internal pressure is sent back to the heat sink 14 to complete the cycle of the heat transfer circuit 12. As a result, due to the operation of the heat pump 12, 13, 14, 15, 16, 17, the process air flowing through the primary air duct 7 is heated by heat extracted from the secondary air flowing through the secondary air duct 18. Thus, it is the heat extracted from the atmosphere surrounding the device 1 that is transferred to the process air in order to heat for drying the clothes 6 in the drum 3.

It can be noted that the heat pump shown in FIG. 1 and the following drawings, should be considered as a possible option for other designs that can be used to transfer heat from secondary air to process air; examples of such designs are known in the art. Examples include, among others, thermoelectric heat pumps and adsorption type heat pumps.

The secondary air duct 18 has an inlet 19 that is not open directly to the surrounding atmosphere 1. On the contrary, the inlet 19 is located inside the housing 2, so that air from the inner space of the housing 2 is sucked into the secondary air duct 18. In the housing 2, in turn, there are openings 20 in the form of small slots 20 or a similar shape through which air from the atmosphere surrounding the device 1 can enter the housing 2 and replace air sucked into the secondary air duct 18. The advantage of this design has been explained in detail above, the main of which is the utilization of heat transferred to this air from the drum 3, the duct 7 of the primary air and the heat source 13.

Since the heat sink 14 provides significant cooling of the secondary air, condensation of moisture contained in such secondary air should be expected in the heat sink 14. Therefore, and also in accordance with the current level of knowledge, the heat sink 14 is designed so that it is possible to collect such condensate and to divert it to the condensate collector 21 to remove it after the drying process.

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The secondary air duct 18 includes a cooler portion 22 arranged in functional communication with the compressor 15 and compressor engine 16 to provide some cooling for these components. This cooling avoids the accumulation of excess heat in the heat transfer circuit 12 and ensures the stable operation of the heat transfer circuit 12.

The primary air duct 7 and the secondary air duct 18 are combined into a single exhaust duct 23 downstream of the drum 3 and the cooler portion 22, respectively. The first fan 8 is located inside the exhaust duct 23 for the simultaneous suction of both process air through the primary air duct 7 and secondary air through the secondary air duct 18.

To ensure the degree of controllability of the device 1, a temperature sensor 24 is placed in the heat sink 14 to measure the local temperature in the heat sink 14. Similarly, a condensate sensor 25 is placed in the condensate collector 21 to monitor the formation of condensate in the heat sink 14. Using these sensors 24 and 25, the operation of the heat sink 14 can be controlled in order to avoid undesirably low temperatures in the heat sink 14, which can lead to the formation of ice in the secondary air duct 18. The temperature sensor 24 can be used to directly monitor the temperature in the heat sink 14, and the condensate sensor 25 can be used to monitor the operating conditions in the heat sink 14 indirectly by evaluating the condensate generated during the operation of the device 1. Details were described above. It should be noted that the shown sensors 24 and 25 do not exhaust the total number of sensors present in the device 1 and used to ensure full control of its operation. In accordance with the current state of the art, additional sensors can be used, in particular, sensors in the primary air duct 7 for monitoring the temperature of the laundry 6 and serving thereby controlling the operation of the device 1. In any case, such control is carried out by the control device 26 connected to all controlled functional components of the device 1 connecting lines 27, providing, depending on the needs, the supply of power or reception of signals.

In FIG. 2 shows a development of the embodiment shown in FIG. 1, and only the components important in this context are shown. You can see that in this embodiment, the secondary air duct 18 does not suck in air from the interior of the housing 2, but directly from the atmosphere surrounding the device 1. The most important role is played by the bypass duct 28 connecting the primary air duct 7 and the secondary air duct 18 and leaving the primary air duct 7 downstream of the heat source 13, in particular even downstream of the heater 11, but upstream of the drum 3. Thus, the bypass duct 28 allows part of the process air to flow into the secondary air duct 18 after heating in the heat source 13 and the optional heater 11. This gives, for example, the advantage that avoids the undesirably low temperature in the heat sink 14, monitored by the temperature sensor 24, by increasing the temperature of the secondary air in the heat sink 14. Similarly, the heat sink 14 and adjacent portions of the secondary air duct 18 can be preheated at the heating stage during drying by controlling the switching means 29 (represented by the valve 29 as an example) in the bypass duct 28 for cutting off the secondary air duct 18 from its regular inlet 19 for suction lko air, already preheated heat source 13 and / or heater 11. Such preheating can also be carried out in the stationary state of the drying process; however, the normal operation of the heat pump 12, 13, 14, 15, 16, 17 must be interrupted to prevent further cooling in the heat sink 14, however, the air will still be heated for at least some time using the residual heat contained in heat source 13. In all cases, both described and described above, the bypass duct 28 can be very useful, helping to avoid undesirable operating conditions in the heat sink 14. Of course, the embodiment shown in FIG. 2 also includes a control device 26 for controlling the various components mentioned here by means of corresponding connecting lines 27.

In FIG. 3 shows an alternative embodiment of the device 1, characterized in that in it the primary air duct 7 and the secondary air duct 18 are separated from each other. It should be noted that this embodiment can be further developed by incorporating a bypass duct 28 and switching means 29 into it, as shown in FIG. 2. With respect to the primary air duct 7, it should be noted that the exhaust sleeve 30 is connected to the outlet 31 of the primary air duct 7. Typically, the process air discharged from the primary air duct 7 contains a significant amount of moisture. Accordingly, such process air should not be discharged into the environment directly surrounding the device 1, in order to avoid the loss of the mentioned moisture in this environment. If device 1 is installed in a building, it is common practice to provide a duct through which such process air can be removed from the building. In turn, such an air duct, as a rule, includes a more or less flexible sleeve 30 for connection to the device 1. Of course, when the device 1 shown in FIG. 1 or 2, the use of such a sleeve 30 should also be provided.

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Since the secondary air duct 18 is at least substantially separated from the primary air duct 7, the secondary air duct 18 includes a separate second fan 32 for supplying secondary air through the duct. It should be noted that it may be desirable to drive both fans, 8 and 32, from one engine 9, as shown in FIG. 1. It should also be noted that the section 22 of the cooler of the secondary air duct 18 is made as a casing, inside which are located the means 15 and 16 of the circulation of the heat pump 12, 13, 14, 15, 16, 17, in particular the compressor 15 and the compressor motor 16.

In FIG. 4, for example, some details of a household appliance 1 are shown, namely, some components located in its lower part. The device 1 has a housing 2, and inside this housing 2 are all the functional components of the device, including the primary air duct 7 with the first fan 8, the engine 9 and various other components, including components included in the heat pump 12, 13, 14, 15, 16, 17: a heat source 13, which in this case also determines the inlet of the primary air duct 7, a heat sink 14 located in the secondary air duct 18, and a compressor 15. The first fan 8, designed as a radial single-flow fan p, delivers the process air after it is heated in the heat source 13 upward to the drum 3 (see other drawings) located above the part of the structure shown in FIG. 4. After passing the drum 3 and the wet clothes placed in it for drying, the process air returns to the section of the primary air duct 7 located in the upper right part of FIG. 4, and is withdrawn from the device 1 through the exhaust duct 23. The secondary air duct 18 has two inlets 19 located at the respective inlets of the second fan 32, made in the form of a double-flow radial fan with two inflows from opposite sides. Thus, the second fan 32 can suck in secondary air both from the area around the compressor 15 and from the area around the engine 9 using a single drive shaft 33 to drive both the first fan 8 and the second fan 32. This design gives the advantage that the excess heat from the compressor 15, as well as the excess heat from the engine 9, is discharged through the secondary air duct 18, as well as the additional benefit that the secondary air to be cooled in the heat sink is initially several It is only warmed up, and this can prevent the excessive formation of liquid condensate or even ice in the heat sink 14. After the passage of the heat sink 14, the secondary air is directed to the exhaust duct 23, where it can connect to the process air. To further simplify and, accordingly, to benefit, the engine 9 is also used to drive the drum 3 through a belt drive connecting the drum 3 with a drive pulley 34 located on the drive shaft 33.

In any case, household appliances, presented in detail in the present description, in that they provide for the reuse (recovery) of at least a significant portion of the heat used in the drying process, while retaining all the known positive features of conventional exhaust-type appliances designed for drying.

Reference List

- household appliance, dryer;

- housing;

- drying chamber, drum;

- axis of rotation;

- door;

- wet objects, linen;

- primary air duct;

- first fan;

- engine;

- filter;

- heater;

- heat transfer device, heat transfer circuit;

- liquefier, heat source;

- evaporator, heat sink;

- heat transfer device, compressor;

- heat transfer device, compressor engine;

- heat transfer device, nozzle;

- duct of secondary air;

- inlet of the secondary air duct;

- gap in the housing;

- condensate collector;

- cooler section;

- exhaust duct;

- thermal sensor;

- condensate sensor;

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- control device;

- connecting line;

- bypass duct;

- switching means, valve;

- graduation sleeve;

- the outlet of the primary air duct;

- second fan;

- drive shaft;

- drive pulley.

Claims (20)

CLAIM 1. Household appliance (1), comprising a housing (2); a drying chamber (3) for drying wet objects in it (6); primary air duct (7) for directing process air supplied to said housing (2) for the purpose of drying objects (6); and a heat pump comprising a heat sink (14) for transferring heat to said heat pump, a heat source (13) connected to said primary air duct (7) for transferring heat from said heat pump to process air, and heat transfer device (12, 15, 16, 17) for transferring heat from said heat sink (14) to said heat source (13), characterized in that said heat sink (14) is connected to a secondary air duct (18) to direct secondary air supplied to said housing (2) to transmit tep and from the secondary air to said heat pump. 2. Household appliance (1) according to claim 1, characterized in that said heat transfer device (12, 15, 16, 17) includes a heat transfer circuit (12) comprising a heat transfer fluid circulating in said heat transfer circuit (12), a compressor (15) for compressing said heat transfer fluid and for circulating said heat transfer fluid through said heat transfer circuit (12) and a nozzle (17) for decompression of said heat transfer fluid, and this heat sink (14) is an evaporator for heat transfer from air to the specified heat-transfer fluid by evaporating the heat-transfer fluid, and the heat source (13) is a liquefier for transferring heat from the heat-transfer fluid to the process air by liquefying the heat transfer fluid. 3. Household appliance (1) according to claim 2, characterized in that said heat-transfer fluid includes a fluorinated hydrocarbon compound. 4. Household appliance (1) in one of claims 2 or 3, characterized in that said heat-transfer fluid is selected from the group including refrigerants KT34a, KT52a, I290. K407C and Ε410Λ. 5. Household appliance (1) according to one of the preceding paragraphs, characterized in that said drying chamber (3) is a rotating drum (3). 6. Household appliance (1) according to one of the preceding paragraphs, characterized in that it is designed as a drying machine (1) for drying wet laundry (6). 7. A household appliance (1) according to one of the preceding claims, characterized in that said duct (18) of secondary air is connected to said heat transfer device (12, 15, 16, 17) for transferring heat transferred from said heat transfer device (12, 15, 16, 17) secondary air. 8. A household appliance (1) according to claim 7, characterized in that said air duct (18) of the secondary air is designed so that the secondary air passes through the said heat sink (14) before the passage of the said means (15, 16) of circulation. 9. Household appliance (1) according to one of claims 7 and 8, characterized in that said primary air duct (7) and said secondary air duct (18) are connected to one exhaust air duct (23) to output process air and secondary air from the specified body (2). 10. Household appliance (1) according to claim 9, characterized in that said exhaust duct (23) contains a single fan (8) for outputting process air and secondary air. 11. Household appliance (1) according to one of the preceding paragraphs, characterized in that said housing (2) is open to the air flow into said housing (2), and said air duct (18) of the secondary air has at least one inlet (19 ) located inside the specified housing (2). 12. A household appliance (1) according to claim 11, characterized in that said air duct (18) of secondary air has two inlets (19), of which the first inlet (19) is oriented in the direction of said heat transfer device (12, 15, 16, 17), and the second inlet (19) is oriented in the direction of the engine (9), which serves to drive the first fan (8) located in the specified primary air duct (7) and the second fan (32) placed in the specified air duct (18) secondary air. 13. A household appliance (1) according to claim 12, characterized in that said drying chamber (3) is a rotating drum (3) driven by said engine (9). - 9 017367 14. Household appliance (1) according to one of claims 12 and 13, characterized in that said second fan (32) is a double-flow fan (32) giving two streams, each of the inlets (19) located at the corresponding one of these streams. 15. A household appliance (1) according to one of the preceding claims, characterized in that it includes a bypass duct (28) connecting said primary air duct (7) and said secondary air duct (18), as well as switching means (29) for selectively directing a part of the process air into the specified air duct (18) of the secondary air through the said air duct (28) of the bypass. 16. A household appliance (1) according to claim 15, characterized in that said bypass duct (28) is connected to said primary air duct (7) between said heat source (13) and said drying chamber (3), with said duct ( 28) bypass is connected to the specified duct (18) of the secondary air upstream relative to the specified heat sink (14). 17. Household appliance (1) according to one of claims 15 and 16, characterized in that it includes a temperature sensor (24) for determining the temperature in the specified heat sink (14) and a control device (26) connected to the specified temperature sensor (24) and the indicated switching means (29), wherein said control device (26) is configured to control said switching means (29) to direct part of the process air to said secondary air duct (18) provided that the temperature measured by said thermal sensor (24) neither e predetermined limit temperature. 18. Household appliance (1) according to claim 17, characterized in that it includes a condensate sensor (25) placed in said duct (18) of secondary air, wherein said condensate sensor (25) is connected to said heat sink (14) for detecting condensate formed in said heat sink (14), and said control device (26) is connected to said condensate sensor (25) and said heat pump and configured to control said heat pump in response to detection signals received from said sensor (25 ) con ensata. 19. A household appliance (1) according to claim 18, characterized in that said control device (26) is connected to the circulation means (15, 16) included in said heat pump, and is adapted to control said heat pump by controlling said means (15, 16) circulation. 20. Household appliance (1) according to one of the preceding paragraphs, characterized in that it contains a heater (11) located in said duct (7) of primary air upstream from said drying chamber (3) for selective heating of said process air.