ES2373135B1 - DOMESTIC APPLIANCE THAT INCLUDES AN EXPANSION SYSTEM. - Google Patents

Abstract

Domestic apparatus comprising an expansion system. # The invention relates to a domestic apparatus 1 comprising a treatment chamber 2 for treating articles 3, a process air guide 5 for guiding process air through said treatment chamber 2, said process air guide 5 comprising a blower 6 to drive the process air, a heater 7 to heat the process air and placed upstream of said treatment chamber 2, and a heat pump 7, 8, 9 , 10, 11, wherein said heater 7 is a heat source 7 for transferring heat from a refrigerant circulating through said heat pump 7, 8, 9, 10, 11 to the process air, and where said heat pump 7, 8, 9, 10, 11 further comprises a heat sink 8 to transfer heat to the refrigerant, a compressor 9 to compress the refrigerant, an expansion system 10 to expand the refrigerant, and a refrigerant guide 11 to circulate the refrigerant to through said heat pump 7, 8, 9, 10, 11 in a closed circuit. Said expansion system 10 has a variable restriction, which can be controllable by a control unit 14 in response to signals from a sensor unit 15, 16.

Description

Domestic appliance comprising an expansion system.

The invention relates to a domestic apparatus comprising a treatment chamber for treating articles, a process air guide for guiding process air through said treatment chamber, said process air guide comprising a blower for driving the air of the process, a heater to heat the process air and placed upstream of said treatment chamber, and a heat pump, wherein said heater is a heat source for transferring heat from a refrigerant circulating through said heat pump to the process air, and wherein said heat pump further comprises a heat sink to transfer heat to the refrigerant, a compressor to compress the refrigerant, an expansion system to expand the refrigerant, and a refrigerant guide to circulate the refrigerant through said heat pump in a closed circuit.

Such a generic household appliance is disclosed in WO 2008/107266 A1. The disclosed apparatus is a household clothes dryer whose heat pump is a compressor type heat pump, which is characterized by having a refrigerant that is guided in a closed refrigerant guide. To effect heat absorption to the associated heat sink, the refrigerant is made to evaporate in the heat sink and, to release heat from the associated heat source, the refrigerant is made to liquefy in the heat source. To carry out the heat transport and that the evaporation and liquefaction processes take place at appropriate temperatures, the gaseous refrigerant is compressed when it passes from the heat sink to the heat source, and the liquid refrigerant is expanded in an expansion system when it returns from The heat source to the heat sink. According to the aforementioned document, a special selection of the compressor comprised by the heat pump and the refrigerant is made.

In WO 2008/119611 A1, a cleaning device for cleaning a heat sink of a heat pump of a clothes dryer is disclosed. A heatsink in a clothes dryer is subject to degradation by operation by small materials formed of particles comprising fragments of fibers and the like, usually called spinning or lint, and extracted from the laundry that is dried by the process air . In accordance with usual practice, a lint filter is placed in the process air guide upstream of the heat sink to capture a large part of the process air lint. Even so, a small but considerable fraction of the fluff will avoid being captured by the fluff filter, and will precipitate on the heat sink along with condensate formed from the moisture contained in the process air, which is formed by extract heat from the process air.

While each of the two documents cited above is related to a domestic appliance that has a process air guide, which is essentially closed in itself to guide the process air in an essentially closed circuit, WO 2008/110449 A1 exposes a domestic appliance that has a heat pump, and that has a process air guide, which is partially open.

In accordance with WO 2008/119608 A2 and WO 2008/086933 A1, a heat pump can be applied in a domestic appliance, in addition to electric or gas burner heaters and more common air / air heat exchangers. Such devices can be called "hybrids."

In accordance with WO 2007/141166 A1, the heat sink and heat source of a heat pump comprised of a domestic appliance can be arranged in a bifurcated process air guide, so that the process air passes through them as fl ow of two parts in parallel, unlike the more usual practice that requires that the airflow of the undivided process pass through the heat sink and the heat source in sequence.

To the extent that they are related to applying a compressor type heat pump to a household appliance, and also in accordance with general practice with domestic appliances with compressor type heat pumps, since they are marketed at the time of establishing the right of priority to the invention disclosed below, the heat pumps are equipped with components whose characteristics related to operation are fixed by the dimensioning and construction. Normal use of such household appliances will take place under a variety of environmental conditions defined by the location of the appliances and the seasons. Likewise, normal use itself will also incur a variety of operating conditions. For example, the operation of a clothes dryer with a heat pump will include an initial phase, where the components of the appliance and the same washing clothes to be dried will be brought to their proper operating temperatures, an almost stationary phase, in which most of the drying operation is carried out, and a finishing phase, in which the laundry is almost as dry as desired, and the extraction of residual moisture from the laundry requires raise the temperature of the process air, which passes through the laundry, above the level that had been continued throughout the almost stationary phase. Consequently, a heat pump structure must be found that allows the heat pump to be operated through all these phases, while also varying environmental conditions.

An objective of the present invention is to present a development of the apparatus as defined in the preamble of this application, which overcomes the specified disadvantages.

In order to meet this and other objectives, a domestic appliance is specified in the attached independent claim. Preferred embodiments of the household appliance according to the present invention are specified in the dependent claims and the subsequent description.

Accordingly, according to the invention, a domestic apparatus comprising a treatment chamber for treating articles, a process air guide for guiding process air through said treatment chamber, said air guide comprising process a blower to drive the process air, a heater to heat the process air and placed upstream of said treatment chamber, and a heat pump, where said heater is a heat source for transferring heat from a circulating refrigerant through said heat pump to the process air, and wherein said heat pump further comprises a heat sink to transfer heat to the refrigerant, a compressor to compress the refrigerant, an expansion system to expand the refrigerant, and a refrigerant guide to circulate the refrigerant through said heat pump in a closed circuit. In addition, said expansion system has a variable restriction.

According to the invention, a variable expansion system replaces known expansion systems with set dimensional and constructive parameters, to produce flexibility of operation for the domestic appliance in view of adapting to the changing environment and requirements related to operation.

An effective operating parameter of the expansion system is a restriction, which is measured as a decrease in the pressure generated by the liquid refrigerant that flows through at a nominal temperature and a nominal mass flow. In the case of an expansion system given by a single extender, different embodiments such as ejector or hole, on the one hand, and capillaries of different lengths and different diameters, on the other hand, may result in the same restriction. Therefore, the invention does not impose an a priori limitation on constructive details of the expansion system. It can be noted that variable expansion systems are known for non-relevant applications, such as refrigeration appliances.

The invention will allow a domestic appliance to adapt to a variety of ambient temperatures, to ensure proper operation at ambient temperatures ranging between 5 ° C and 35 ° C, 23 ° C being a nominal temperature. Likewise, changes in the operating parameters that occur through a process for treating items in the apparatus can be adapted, modifying the characteristics of the heat pump as given by the restriction of the expansion system, in order to better adapt the scheme and functional settings of the heat pump to relevant operating conditions and thus obtain a better efficiency of operation and possibly a shorter duration of the treatment processes.

In accordance with a preferred embodiment of the invention, the home appliance comprises a control unit connected to said expansion system, and a sensor unit associated with said heat pump, to control the restriction of said expansion system in response to signals communicated to said control unit by said sensor unit. Thus, the expansion system can be controlled in response to relevant operating conditions of the heat pump. In order to allow and carry out such control, a plurality of options are given. As a first example, the expansion system may have a restriction that is controllable by electronic means. In such a case, the control unit may be an autonomous electronic circuit, or it may be included in a system control unit that performs the global control of the apparatus, including interacting with a user to display information related to the operation, select programs of operation to treat items placed in the apparatus, and set operating parameters for such programs.

In accordance with a more preferred embodiment of the invention, said sensor unit specified in the preceding paragraph comprises a status sensor for sensing a state of said heat pump. Even more preferably, said status sensor is a temperature sensor to perceive a process temperature within said refrigerant guide. Even more preferably, the process temperature is a coolant temperature when leaving said heatsink, and said control unit is preset to control said expansion system to retain a given overheating in the coolant leaving said heatsink. In this context, it should be noted that in the normal operation of the apparatus, including the heatsink, where the refrigerant enters the heatsink in a liquid state, to be evaporated while flowing through the heatsink to form a gas, such gas a certain amount will be heated to a temperature that is above the boiling temperature of the refrigerant under the given pressure condition. The difference in boiling temperature at the temperature of the gaseous refrigerant when leaving the heatsink is defined to be overheating. A heat pump, as it is known to be incorporated in a clothes dryer, will not allow any control through normal use during a drying process. Thus, overheating will change under changing operating conditions. By applying an arrangement as presented here, overheating control has been made possible, including control to retain overheating at a certain and desired value.

In accordance with another preferred embodiment of the invention, said sensor unit comprises an ambient temperature sensor for sensing an ambient temperature of said apparatus. This allows taking into account the relevant environmental conditions to put the device into operation, including the heat pump, and also allows the modification of the operating mode in response to environmental conditions. Since any heat pump will require an amount of energy input for its operation, which must, in turn, be dissipated to its surroundings, the ambient temperature is a functional parameter for the heat pump since it affects that dissipation. According to the invention, the ambient temperature can be considered when operating the heat pump. More preferably in this regard, said control unit is preset to set said restriction to a nominal value if the ambient temperature is essentially equal to a given normal ambient temperature, and where said control unit is preset to set said restriction in a value that exceeds said nominal value, if the ambient temperature is essentially different from said normal ambient temperature. A preferred setting for operation may provide for the expansion system in a normal restriction at a normal room temperature, which may be a normal room temperature that can be found in a normal home, and increase the restriction above the normal restriction. , both at ambient temperatures greater than and below normal ambient temperature. When the ambient temperature is excessively high, a thermal load on the heat pump is high, and the compressor on the heat pump may incur unduly high thermal load. By increasing the restriction, a mass flow of the refrigerant circulating through the heat pump will be reduced, and simultaneously the load on the compressor will be reduced. When the ambient temperature is excessively low, the thermal load on the heat pump is low. On the other hand, it can be difficult to determine the total evaporation of the refrigerant when it flows through the heat sink. By increasing the restriction and thus reducing the mass flow of the circulating refrigerant, the introduction of liquid to be evaporated in the heat sink is reduced, thereby mitigating the problem of determining the total evaporation.

According to another preferred embodiment of the invention, said expansion system comprises at least two expansion units, which are variably geared in said refrigerant guide by said control unit. This allows an expansion system to be applied, where a selection between several values set for the restriction is possible simply by switching. More preferably, said expansion system comprises an expansion unit, which comprises a first extender, and a valve controllable by said control unit and connected in series. More preferably, the expansion system may include a second extender connected in parallel to said expansion unit. Such an embodiment ensures that a connection state that results in a complete disconnection of the expansion system cannot be produced, thereby providing a safety measure. Even more preferably, a plurality of expansion units connected in parallel to each other can be provided in the expansion system, thereby providing an extended range of restriction variability, to improve the system's adaptability to various relative requirements. to operation Even more preferably, said expansion unit comprises a multiplicity of first extenders, wherein said first extenders are connected in parallel to each other through a multi-way distribution valve controllable by said control unit, thus simplifying the means of connection, while maintaining a high level of variability.

In accordance with yet another preferred embodiment of the invention, said expansion system is a variable expansion device controllable by said control unit. By way of preferred example, said expansion device comprises a variable expansion valve. In particular, said expansion valve is a thermostatic expansion device. Even more preferably, said thermostatic expansion device has an associated temperature sensor coupled to said process air guide at an outlet of said treatment chamber to perceive an air temperature of the process air when leaving said treatment chamber. , and wherein said thermostatic expansion device is provided to vary said restriction from a relatively low restriction at a low air temperature to a relatively high restriction at an elevated air temperature. Likewise, preferably, said expansion system is a multiplicity of thermostatic expansion devices, and wherein said thermostatic expansion devices are connected in parallel to each other through a multi-way distribution valve controllable by said control unit.

According to the invention, variable valves are preferred for use as expansion units, although they may require providing an electronic control, which may be an autonomous unit or a part of an electronic system control unit as explained hereinbefore. In addition, a variable expansion device can be applied that is marketed as a stand-alone unit, which includes sensor and control means, to vary a restriction in response to a state variable, which is, in general, a temperature, such and as perceived by the sensor means. In this regard, the sensor means can be applied as a status sensor or ambient temperature sensor, as explained here before. Likewise, other control modes can be implemented using such a variable expansion device. As a precaution, it should be noted that the term "thermostatic expansion device" is known to a person skilled in the art, due to the application of such devices in self-regulated refrigeration circuits in freezers or refrigerators. In addition, the relative property of being "thermostatic" is not really a property of the expansion device itself, but of the complete cooling circuit that includes the device.

As an example, a typical drying process can be considered as it is carried out in a common clothes drying apparatus. Immediately after commissioning, the drying process will begin with the heating phase, in which the components included in the process air circuit will change their temperatures to operating values, and the items to be dried will be heated at a high operating temperature. To keep the duration of the process short, it is desirable to keep the warm-up phase short. Therefore, a relatively high restriction in the expansion system is desired to achieve a relatively high refrigerant pressure in the heat source leading to a high refrigerant condensation temperature, at a high temperature difference between the refrigerant and the air of the process in the heat source, and to a heat transfer to the air of the process increased, accordingly. Also, the highly restricted refrigerant fl ow will reduce the amount to be evaporated in the heatsink, and also the resulting cooling of the process air in the heatsink. As soon as the components have reached their respective operating temperatures, an almost stationary phase will follow the heating phase. In the almost stationary phase, only small changes in operating temperatures will occur, and the restriction of the expansion system can be set at a reduced nominal value (which may still be dependent on the environmental conditions as explained here above). When the drying process approaches its end, all moisture has been evaporated from the surfaces of the items to be dried, and the remaining moisture must be extracted from deep within the textile fibers that constitute the items. This brings an additional burden on the process, which manifests itself in another increase in the operating temperature of the articles, the components in their environment and the process air that flows from them. This temperature increase indicates a transition from the almost stationary phase to a terminal phase of the drying process. In general, this phase is short with little influence on the duration of the whole drying process. In addition, an increased restriction would be desirable to reduce the evaporation temperature of the refrigerant in the heatsink, and improve the extraction of moisture from the process air. Therefore, and disregarding the desires for the finishing phase specified above, an autonomous variable expansion device, or a plurality of such devices, in particular, selectable through a distribution valve in response to environmental conditions, can be applied in the inventive apparatus for such purpose. The function of such a device would be to reduce the restriction in case of temperature increase. If the particular requirements for the terminal phase also had to be taken into account, the addition of a switchable extender made as indicated hereinbefore may be effective.

In accordance with yet another preferred embodiment of the invention, said process air guide within the inventive apparatus is essentially closed in itself to guide the process air in an essentially closed circuit, the apparatus thereby providing a tumble dryer. closed circuit or condenser type dryer.

In accordance with yet another preferred embodiment of the invention, said heat sink is a cooler placed in said process air guide to cool the process air after leaving said treatment chamber to extract moisture from said process air, again according to the characteristics of a condenser dryer. More preferably, said cooler has a condensate collector placed beneath it to collect condensate that precipitates from the process air within said cooler, to collect moisture extracted from the articles by operating the inventive apparatus.

In accordance with yet another preferred embodiment of the invention, said treatment chamber is a rotating drum for stirring the articles placed therein for treatment.

Other details and advantages of the invention are drawn from the following description of preferred embodiments, which are also shown in the figures of the attached drawing. In particular:

Figure 1 shows a household appliance, as materialized in a clothes dryer, and with an expansion device with variable restriction;

Figure 2 shows a first embodiment of an expansion device, which has a variable restriction;

Figure 3 shows a second embodiment of an expansion device, which has a variable restriction; Y

Figure 4 as a variable expansion device incorporated in an expansion device with a variable restriction.

In the drawing, Figure 1 shows a household appliance 1 which is incorporated as a clothes dryer 1. The clothes dryer 1 comprises a treatment chamber 2, which is con fi gured as a drum 2, where the items 3 to be placed are placed. to be dried, in this case, the laundry clothes 3. The details and accessories, such as a door and a drive mechanism, as they are commonly associated with such a drum 2, are not shown for simplicity. The drum 2 is rotatable about an axis 4 to stir the laundry clothes 3 through the process air that flows along to extract the moisture from the laundry clothes 3. The process air to dry the clothes laundry clothes 3 is guided by a process air guide 5. The process air guide 5 comprises a blower 6, which conducts the process air in an essentially closed circuit. In this respect, "essentially closed" means that the process air guide 5 is maintained at a pressure essentially equal to the pressure of the environment of the apparatus 1, but is not hermetically sealed against the environment, although without any functionally relevant leakage, by means of which air would be exchanged between the process air guide5 and the environment. The process air guide 5 includes a heater 7, or heat source 7, placed upstream of the drum 2 to heat the process air before entering the drum 2. Current downstream of the drum 2, the process air guide 5 It includes a cooler 8 or heat sink 8, where heat is removed from the process air after leaving the drum 2. The process air guide 5 may include other components in accordance with usual practice. In particular, temperature sensors and a lint filter may be present, but they are not shown in Figure 1 for simplicity.

The heat source 7 and the heat sink 8 are made as heat exchangers 7 and 8 to exchange heat with the process air passing through. The heat source 7 and the heat sink 8 are also included in a heat pump 7, 8, 9, 10, 11. This provides for recovering heat extracted from the process air in the heat sink 8 by pumping said heat to the heat source 7, where it is transferred back to the process air. While such a heat pump process cannot function on its own, but necessarily requires an introduction of additional energy to be effective, as provided by the laws of thermodynamics, such a process greatly reduces the required energy input. to evaporate all moisture from the laundry clothes 3 contained in the drum 3. The heat pump 7, 8, 9, 10, 11 includes, in addition to the heat source 7 and the heat sink 8, a compressor 9 to compress a refrigerant that is circulated through the heat pump 7, 8, 9, 10, 11 in a closed circuit, an expansion system 10 to carry out an internal pressure reduction within the circulating refrigerant, and a refrigerant guide 11 , which guides the refrigerant while it is circulating. The refrigerant can be selected from a variety of chemical compounds and compositions, whose aptitude for the purpose is known in the art. In particular, the refrigerant may be a hydrocarbon compound, such as propane (R290 in terms of the commonly used ASHRAE standards), a fluorinated hydrocarbon compound, such as R134a and R152a, or a mixture of such fluorinated hydrocarbon compounds, like the R407C and the R410A; The compounds are indicated in terms of the commonly used ASHRAE standards. In operation, the refrigerant will exit the heat sink 8 in gaseous form, to be guided to the compressor 9 by the refrigerant guide

11. The compressor 9 will compress the gaseous refrigerant, and send it to the heat source 7. In the heat source 7, the refrigerant will release heat to the air from the process that flows through and, consequently, will condense into a liquid form. After leaving the heat source 7, the liquid refrigerant passes through the expansion system 10, which is configured, in a known manner, as a choke or restriction. The most common form of device that can be used as an expansion system 10 is a capillary 10, that is, a tube of considerable length with a very small cross section. The expansion system 10 serves to reduce the internal pressure of the liquid refrigerant. Next, the refrigerant enters the heatsink 8 in liquid form, and will absorb heat from the process air that flows through. The heat absorbed in the liquid refrigerant will cause the refrigerant to evaporate into a gaseous form, thus completing a complete circulation cycle. Due to the differences in the internal pressure of the refrigerant between the heat source 7 and the heat sink 8, the condensation of the refrigerant will take place at a temperature considerably higher than its evaporation, as a prerequisite for the heat pump process used to start the clothes dryer 1.

The extraction of moisture from the laundry clothes 3 is carried out by the process air, and the humidity collected by the process air will be extracted from the process air in the heat sink 8. There, heat is extracted from the air in the process. process, causing the moisture contained in it in the vapor form to condense and form a condensate, which precipitates from the process air. This condensate is collected in a condensate line 12, and transported to the condensate collector 13. After the end of a drying process, the condensate collector 13 can be emptied, and the condensate discarded in any appropriate manner.

A special feature of the apparatus shown in Figure 1 is that the expansion system 10 has a definite restriction to determine the amount of flow of a condensate under pressure and given temperature conditions, which is variable by operating a control unit 14 speci fi c. For this purpose, the control unit 14 is connected to a sensor unit 15, 16, which comprises a status sensor 15 for determining a coolant temperature when it exits the heatsink 8, and an ambient temperature sensor 16, the which determines a temperature around the apparatus 1. In accordance with the signals obtained from these sensors 15 and 16, the control unit 14 will set the restriction of the expansion system 10 to vary the operating conditions of the heat pump 7, 8 , 9, 10, 11 in response to these signals.

The expansion system 10 with its variable restriction allows the apparatus 1 to adapt to a variety of ambient temperatures, to ensure proper operation at ambient temperatures ranging between 5 ° C and 35 ° C, 23 ° C being a nominal temperature. Likewise, changes in the operating parameters that occur through a process to treat the articles 3 in the apparatus 1 can be adapted, modifying characteristics of the heat pump 6, 7, 8, 9, 10, 11 as they are given by the restriction of the expansion system 10, to better adapt the scheme and functional settings of the heat pump 6, 7, 8, 9, 10, 11 to relevant operating conditions and thus obtain a better operating efficiency and possibly a shorter duration of treatment processes.

The status sensor 15 is a temperature sensor 15 for sensing a process temperature within the refrigerant guide 11. The process temperature is a temperature of the refrigerant when leaving the heat sink 8, and the control unit 14 is pre-set to check the expansion system 10, to retain a given overheating in the refrigerant leaving the heatsink 8. In this context, it should be noted that in normal operation of the apparatus 1, including the heatsink 8, where the refrigerant enters the heatsink thermal 8 in a liquid state, to be evaporated while flowing through the heat sink 8 to form a gas, such gas will be heated a certain amount to a temperature that is above the boiling temperature of the refrigerant under the given pressure condition. The difference in boiling temperature at the temperature of the gaseous refrigerant when leaving the heatsink 8 is defined to be overheating. Generally, overheating will change under changing operating conditions. By applying an arrangement as presented here, overheating control is possible, including control to retain overheating at a given and desired value.

In addition, the sensor unit 15, 16 comprises the ambient temperature sensor 16 to perceive an ambient temperature of the apparatus 1. This allows taking into account the relevant environmental conditions for operating the apparatus 1, including the heat pump 6, 7 , 8, 9, 10, 11, and also allows the modification of the operating mode in response to environmental conditions. Since the heat pump 6, 7, 8, 9, 10, 11 necessarily requires an amount of energy input for its operation, which must be, in turn, dissipated from its surroundings, the ambient temperature is a functional parameter for operation, since it affects that dissipation. In this case, the ambient temperature can be considered when operating the heat pump 6, 7, 8, 9, 10, the restriction being set in the expansion device 10. In particular, the control unit 14 is pre-set to set the restriction at a nominal value if the ambient temperature is essentially equal to a given normal ambient temperature, and the control unit 14 is preset to set said restriction to a value that exceeds said nominal value, if the ambient temperature is essentially different from said normal room temperature. A preferred setting for operation may provide for expansion system 10 in a normal restriction at a normal room temperature, which may be a usual room temperature that can be found in a normal home, and increase the restriction above the restriction. normal, both at higher and lower ambient temperatures than normal ambient temperatures. When the ambient temperature is excessively high, a thermal load on the heat pump 6, 7, 8, 9, 10, 11 is high, and the compressor 9 may incur unduly high thermal load. By increasing the restriction, a mass flow of the refrigerant flowing through the heat pump 6, 7, 8, 9, 10, 11 will be reduced, and simultaneously the load on the compressor 9 will be reduced. When the ambient temperature is excessively low, the thermal load on the heat pump 6, 7, 8, 9, 10, 11 is low. On the other hand, it can be difficult to determine the total evaporation of the refrigerant when it flows through the heat sink 8. By increasing the restriction and thus reducing the mass flow of the circulating refrigerant, the introduction of liquid to evaporate is reduced in the heatsink 8, thereby mitigating the problem of determining total evaporation.

Referring to the construction details of the expansion system 10 and the control unit 14, common practice, as is known to those skilled in the art, provides numerous options. For example, the expansion system 10 can be realized as a valve 10, the restriction of which can be varied continuously by electronic means. In such a case, the control unit 14 could be an electronic circuit, which could operate independently of other components of the apparatus 1, or, alternatively, be incorporated in an electronic control unit of the apparatus 17, which is used commonly, both for the control of the operation of the apparatus 1, and for interacting with a user or operator by displaying information related to the process and receiving through appropriate input means, controlling information to select a program for a predefined drying process or set a parameter related to such a program. For simplicity, no display or input media are shown. Common practice also provides for autonomous units that include an expansion system 10 and a control unit 14, for example, in the form of a "thermostatic expansion device", which are commonly used in freezers and refrigerators.

Figure 2 shows an example of an expansion system 10, which comprises two expansion units 18, 19, each of which comprises a first extender 18, possibly a capillary 18, and a switching valve 19 connected in series . Both expansion units 18, 19 are connected in parallel, and a second extender 20 is connected in parallel to both units 18, 19. Both switching valves 19 can be switched from closed to open by the control unit 14, thus providing a total of four different restrictions available to define operating parameters for the heat pump 7, 8, 9, 10, 11 as exemplified in Figure 1.

Figure 3 shows an alternative expansion system 10 for use in the refrigerant guide 11 between the heat source 7 and the heat sink 8. Again, the expansion system 10 comprises expansion units 18, each constituted from a single extender 18, and all extenders 18 connected to a distribution valve 21 controllable by the control unit 14, which can selectively activate each of the extenders 18 for use in the heat pump 7, 8, 9, 10 , 11 as exemplified in Figure 1.

Figure 4 shows another example of a variable expansion system 10 incorporated in a thermostatic expansion device. This device includes a continuously variable valve 10 included in the refrigerant guide 11. It also includes a process air temperature sensor 22, which is connected in this case to the process air guide 5 to perceive a temperature of the process air when it exits the treatment chamber 2. Here, the process air temperature sensor 22 is simply a bulb, which is filled with a working fluid 24 that will serve to perceive a temperature to which it is exposed . In principle, the temperature sensor 22 can be placed in any location that is considered useful for its operation to control the variable valve 10. The temperature sensor 22 is connected to a chamber 14 that serves as a control unit 14. Within the chamber 14, a movable diaphragm 23 separates a space filled by the working fluid, and communicates with the interior of the bulb 22, of a part of the space filled by air. The diaphragm 23 contacts a push bar 25, which, in turn, serves to set the restriction of the variable valve 10. When the temperature of the process air at the outlet of the drum 2, and perceived by the bulb 22, changes, the working fluid 24 will expand or contract and move the diaphragm 23 correspondingly. This movement is transmitted to the variable valve 10 by the push bar 25, and will cause a change in the restriction of the variable valve 10 in response to a change in the process air temperature. Thus, an adaptation of the operation of the heat pump 7, 8, 9, 10, 11 is carried out in response to the process air temperature at the outlet of the drum 2.

Immediately after commissioning, the typical drying process executed in the drying apparatus 1 will begin with the heating phase, in which the components included in the process air circuit 2, 5, 6, 7, 8 will change its ambient temperature temperatures to operating values, and items 3 to be dried will be heated to a high operating temperature. To keep the duration of the process short, it is desired to keep the warm-up phase short. Accordingly, a relatively high restriction is set in the expansion system 10 to achieve a relatively high pressure of the refrigerant in the heat source 7 which leads to a high refrigerant condensation temperature, a high temperature difference between the refrigerant and the process air in the heat source 7, and a heat transfer to the process air increased accordingly. Also, the highly restricted refrigerant fl ow will reduce the amount to be evaporated in the heatsink 8, and also the resulting cooling of the process air in the heatsink

8. As soon as components 2, 5, 6, 7, 8 have reached their respective operating temperatures, an almost stationary phase will follow the heating phase in the drying process. In the almost stationary phase, only small changes in operating temperatures will occur, and the restriction of the expansion system 10 can be set at a reduced nominal value (which can still be dependent on the environmental conditions as explained here above) . When the drying process approaches its end, all moisture has been evaporated from the surfaces of articles 3 to be dried, and the remaining moisture must be extracted from deep within the textile fibers that constitute articles 3. This brings an additional burden on the process, which manifests itself in another increase in the operating temperature of the articles 3, the components 2 in their environment, and the process air flowing from them. This temperature increase indicates a transition from the almost stationary phase to a terminal phase of the drying process. In general, this phase is short with little influence on the duration of the whole drying process. In addition, an increased restriction would be desirable to reduce the evaporation temperature of the refrigerant in the heatsink 8, and improve the extraction of moisture from the process air. Therefore, and disregarding the desires for the finishing phase specified above, an autonomous variable expansion device 10, or a plurality of such devices 10, in particular, selectors through distribution valve 21 in response to environmental conditions, may be applied in apparatus 1 for this purpose. The function of such device 10 would be to reduce the restriction in case of temperature increase. If the particular requirements for the terminal phase also had to be taken into account, the addition of a switchable extender as shown in Figure 4 may be effective.

In relation to the process air guide 5 within the apparatus 1 detailed herein, it is essentially closed in itself to guide the process air in an essentially closed circuit, thereby providing the apparatus 1 with a closed circuit dryer or dryer of the type of condensation Also, this should not be considered as a mandatory feature. The novel features disclosed here will lend themselves well to another type of apparatus, where the process air guide 5 is not essentially closed in itself, or where even multiple process air circuits 5 are implemented, parallel to each other. others.

To conclude, it turns out that the present invention, as defined in the appended claims, and as detailed and exemplified hereinbefore, enables novel embodiments of a household appliance, in particular a clothes dryer, and a heat pump contained therein, to further improve the effectiveness and duration of the treatment processes programmed for use in such apparatus.

List of reference numbers

one

Domestic appliance, clothes dryer

2

Treatment chamber, drum

3

Items to be dried, laundry clothes

4

Axis of rotation

5

Process air guide

6

Blower

7

Heater, heat source

8

Cooler, heatsink

9

Compressor

10

Expansion system

eleven

Refrigerant Guide

12

Condensate line

13

Condensate collector

14

Expansion System Control Unit

fifteen

Status sensor, coolant temperature sensor

16

Room temperature sensor

17

Device control unit

18

First extender

19

Switching valve

twenty

Second extender

twenty-one

Distribution valve

22

Process air temperature sensor

2. 3

Diaphragm

24

Working fluid

25

Push bar.

Claims (23)

one.

Domestic apparatus (1) comprising a treatment chamber (2) for treating articles (3), a process air guide (5) for guiding process air through said treatment chamber (2), said guide comprising process air (5) a blower (6) to drive the process air, a heater (7) to heat the process air and placed upstream of said treatment chamber (2), and a heat pump (7, 8, 9, 10, 11), wherein said heater (7) is a heat source (7) for transferring heat from a refrigerant circulating through said heat pump (7, 8, 9, 10, 11) to the process air, and wherein said heat pump (7, 8, 9, 10, 11) further comprises a heat sink (8) to transfer heat to the refrigerant, a compressor (9) to compress the refrigerant, an expansion system ( 10) to expand the refrigerant, and a refrigerant guide (11) to circulate the refrigerant through said heat pump (7, 8, 9, 10, 11) in a closed circuit, characterized in that said expansion system (10) has a variable restriction.

2.

Domestic appliance according to claim 1, comprising a control unit (14) connected to said expansion system (10), and a sensor unit (15, 16) associated with said heat pump (7, 8, 9, 10 , 11) to control the restriction of said expansion system (10) in response to signals communicated to said control unit (14) by said sensor unit (15, 16).

3.

Domestic appliance (1) according to claim 2, wherein said sensor unit (15, 16) comprises a status sensor (15) to perceive a state of said heat pump (7, 8, 9, 10, 11).

4. Domestic appliance according to claim 3, wherein said status sensor (15) is a temperature sensor (15) to perceive a process temperature within said refrigerant guide (11).

5.

Domestic appliance according to claim 4, wherein the process temperature is a temperature of the refrigerant when leaving said heatsink (8), and wherein said control unit (14) is preset to control said expansion system (10) to retain a overheating given in the refrigerant leaving said heat sink (8).

6.

Domestic appliance (1) according to one of claims 2 to 5, wherein said sensor unit (15, 16) comprises an ambient temperature sensor (16) for perceiving an ambient temperature of said apparatus (1).

7.

Domestic appliance (1) according to claim 6, wherein said control unit (14) is preset to set said restriction to a nominal value, if the ambient temperature is essentially equal to a given normal ambient temperature, and wherein said control unit ( 14) is set to set said restriction to a value that exceeds said nominal value, if the ambient temperature is essentially different from said normal ambient temperature.

8.

Domestic appliance (1) according to one of the preceding claims, wherein said expansion system (10) comprises at least two expansion units (18, 19, 21), which are variably geared in said refrigerant guide (11 ) by said control unit (14).

9.

Domestic apparatus (1) according to claim 8, wherein said expansion system (10) comprises an expansion unit (18, 19, 21), which comprises a first extender (18) and a valve (19) controllable by said unit control (14) and connected in series.

10.

Domestic appliance (1) according to claim 9, comprising a second extender (20) connected in parallel to said expansion unit (18, 19, 21).

eleven.

Domestic appliance (1) according to one of claims 9 and 10, comprising a plurality of expansion units (18, 19, 21) connected in parallel to each other.

12.

Domestic appliance (1) according to one of claims 9 and 10, wherein said expansion unit (18, 19, 21) comprises a multiplicity of first extenders (18), wherein said first extenders (18) are connected in parallel to each other. through a multi-way distribution valve (21) controllable by said control unit (14).

13.

Domestic appliance (1) according to one of claims 1 to 7, wherein said expansion system (10) is a variable expansion device (10) controllable by said control unit (14).

14.

Domestic appliance (1) according to claim 13, wherein said expansion system (10) comprises a variable expansion valve (10).

fifteen.

Domestic appliance (1) according to one of claims 13 and 14, wherein said expansion valve (10) is a thermostatic expansion device (10).

16.

Domestic apparatus according to claim 15, wherein said thermostatic expansion device (10) has an associated temperature sensor (22) coupled to said process air guide (5) at an outlet of said chamber of

treatment (2) to perceive an air temperature of the process air when leaving said treatment chamber (2), and where said thermostatic expansion device (10) is provided to vary said restriction from a relatively low restriction to a temperature of low air to a relatively high restriction at an elevated air temperature. 17. Home appliance (1) according to one of claims 13 to 16, wherein said expansion system (10) is a multiplicity of thermostatic expansion devices (10), and wherein said thermostatic expansion devices (10) are connected in parallel to each other through a multi-way distribution valve (21) controllable by said control unit (14).

18.

Domestic appliance (1) according to one of the preceding claims, wherein said process air guide (5) is essentially closed in itself.

19.

Domestic appliance (1) according to claim 17, wherein said heatsink (8) is a cooler (8) placed in said process air guide (5) to cool the process air after exiting said treatment chamber to extract the humidity of said process air.

twenty.

Domestic appliance according to claim 19, wherein said cooler (8) has a condensate collector (13) placed below it to collect condensate that precipitates from the process air within said cooler (8).

twenty-one.

Domestic apparatus (1) according to one of the preceding claims, wherein said treatment chamber (2) is a rotating drum (2) for stirring the articles (3) placed therein for treatment.

SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 200931159 SPAIN Date of submission of the application: 14.12.2009 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: See Additional Sheet RELEVANT DOCUMENTS

Category

56 Documents cited Claims Affected

X

EP 2058427 A1 (BSH APPLIANCES SPAIN) 13.05.2009, 1.18-21

paragraphs [0001,0005-0018,0021,0023,0025-0029]; Figure 1.

Y

2-4,8,13-17

Y

JP 2006212117 A (MATSUSHITA ELECTRIC IND CO LTD) 17.08.2006, 2-4

description; Figures 1,8,9.

Y

EN 1032506 U (FAGOR S COOP LTD) 01.05.1996, 8.13-17

page 2, lines 1-13; page 3, line 26 - page 4, line 32; page 5, lines 14-23; page 5,

line 34 - page 7, line 4; Figure 1.

X

DE 102007016076 A1 (BSH BOSCH SIEMENS HAUSGERAETE [DE]) 09.10.2008, 1-4,13,15,18-21

paragraphs [0001-0014.0019-0021.0027-0031.0034]; Figure 1.

X

ES 2158839 T3 (BSH BOSCH SIEMENS HAUSGERAETE; KULMBACHER KLIMAGERAETE) 1-4,13-15,18-21

16.09.2001, column 1, lines 3-17; column 1, line 56 - column 6, line 14; Figure 1.

X

DE 102005014842 A1 (LARE LUFT UND KAELTETECHNIK AP) 04.05.2006, 1,9,18-21

paragraphs [0001,0003,0004,0007,0008,0011-0018,0020,0025]; figures 2.4.

TO

WO 03074778 A1 (CEVIK AYLA) 12.09.2003, 1-7,9-15,18-20

page 1, lines 10-11; page 3, lines 8-23; page 4, line 2 - page 15, line 29; page 18,

line 2 - page 21, line 4; page 21, line 30 - page 26, line 12; figure 3.

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 11.01.2012

Examiner M. C. Fernández Rodríguez Page 1/5

REPORT OF THE STATE OF THE TECHNIQUE Application number: 200931159 CLASSIFICATION OBJECT OF THE APPLICATION D06F25 / 00 (2006.01) D06F58 / 02 (2006.01) D06F58 / 28 (2006.01) Minimum documentation sought (classification system followed by classification symbols) D06F Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENTIONS, EPODOC State of the Art Report Page 2/5  WRITTEN OPINION Application number: 200931159 Date of Written Opinion: 11.01.2012 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims 2-17 Claims 1, 18-21 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-21 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published. State of the Art Report Page 3/5  WRITTEN OPINION Application number: 200931159 1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

EP 2058427 A1 (BSH ELECTRICAL APPLIANCES SPAIN) 05/13/2009

D02

JP 2006212117 A (MATSUSHITA ELECTRIC IND CO LTD) 08/17/2006

D03

ES 1032506 U (FAGOR S COOP LTD) 01.05.1996

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement Document D01 (see D01, paragraphs [0001, 0005-0018, 0021, 0023, 0025-0029]; Figure 1.) discloses a domestic appliance (1, 2) comprising a treatment chamber (5) for treating articles ( 6), a process air guide (8) for guiding process air through said treatment chamber (5), said process air guide (8) comprising a blower (9) for driving process air, a heater (21) for heating process air and placed upstream of said treatment chamber (5), and a heat pump (12, 13, 14, 15, 16, 17, 18), wherein said heater (21 ) is a heat source (13) for transferring heat from a refrigerant that circulates through said heat pump (12, 13, 14, 15, 16, 17, 18) to the process air, and where said heat pump (12, 13, 14, 15, 16, 17, 18) further comprises a heat sink (12) to transfer heat to the refrigerant, a compressor (15) to compress the refrigerant, an expansion system (17) for expanding the refrigerant, and a refrigerant guide (14) to circulate the refrigerant through said heat pump (12, 13, 14, 15, 16, 17, 18) in a closed circuit, such that said expansion system ( 17) has a variable restriction. Therefore, it is considered that independent claim 1 is not new (Art.6 L11 / 86). Document D01 anticipates that the process air guide (14) is essentially closed in itself. Document D01 describes that the heat sink (12) is a cooler placed in said process air guide (8) to cool the process air after exiting said treatment chamber to extract moisture from said process air. Document D01 also describes that said cooler has a condensate collector (20) placed beneath it to collect condensate that precipitates from the process air (19) within said cooler. Document D01 discloses a domestic appliance (1, 2) where said treatment chamber (5) is a rotating drum for stirring the articles (6) placed therein for treatment. Therefore, claims 18 to 21 are considered to be novel (Art.6 L11 / 86). Document D01 discloses a domestic appliance (1,2) comprising a control unit (3) connected to said expansion system (17), and a sensor unit (28) associated with said heat pump (12, 13, 14, 15, 16, 17, 18), to control the restriction of said expansion system (17) in response to signals communicated to said control unit (3) by said sensor unit (28). Interpreting the claims, in the light of the description and the drawings, it is noted that document D01 does not disclose an autonomous control unit, in addition to that located on the front panel of the domestic appliance (3). However, document D02 (see D02, description; Figure 1, 8 and 9) describes a domestic appliance in which there is an autonomous control unit (19). It would be apparent to one skilled in the art to combine the characteristics disclosed by document D02 with those anticipated by document D01, to obtain the domestic appliance object of claim 2. Therefore, claim 2 is considered to have no inventive activity (Art .8 L11 / 86). Document D01 discloses that said sensor unit (28) comprises a status sensor (28) to perceive a state of said heat pump (12, 13, 14, 15, 16, 17, 18). Document D01 also discloses that said status sensor (28) is a temperature sensor (28) to perceive a process temperature within said refrigerant guide (14). Therefore, claims 3 and 4 are considered to have no inventive activity (Art. 8 L11 / 86). Claims 5 to 7 are considered to have obvious design options for a person skilled in the art, in view of the state of the art. Therefore, it is concluded that said claims 5, 6 and 7 lack inventive activity (Art.8 L11 / 86). State of the Art Report Page 4/5  WRITTEN OPINION Application number: 200931159 Document D03 (see D03, page 2, lines 1-13; page 3, line 26 -page 4, line 32; page 5, lines 14-23; page 5, line 34 -page 7, line 4; figure 1) discloses a domestic apparatus where said expansion system comprises at least two expansion units (11, 12, 18, 32), which can be variably engaged, in said refrigerant guide, by said control unit (13). It would be clear to a person skilled in the art the combination of the characteristics disclosed by document D03, with those anticipated in document D01, to obtain the domestic appliance object of claim 8. Therefore, claim 8 is considered to imply no activity. inventive (Art.8 L11 / 86). Claims 9 to 12 are considered to represent obvious design options, for one skilled in the art, in view of the prior art. Therefore, it is concluded that said claims 9, 10, 11 and 12 lack inventive activity (Art.8 L11 / 86). Document D03 discloses a domestic appliance, where said expansion system is a variable expansion device (11) controllable by said control unit (13). Document D03 also discloses that said expansion system comprises a variable expansion valve (13). Document D03 also discloses that said expansion valve (11) is a thermostatic expansion device. Document D03 describes that said thermostatic expansion device (11) has an associated temperature sensor, coupled to said process coolant guide at an outlet of said treatment chamber to perceive a process coolant temperature upon leaving said chamber of treatment, and where said thermostatic expansion device is provided to vary said restriction. Document D03 discloses that said expansion system is a multiplicity of thermostatic expansion devices, and wherein said thermostatic expansion devices are connected in parallel to each other through a multi-way distribution valve (11) controllable by said unit of control (13). It would be evident to a person skilled in the art the combination of the characteristics disclosed by document D03, with those anticipated in document D01, to obtain the domestic appliance object of any of claims 13 to 17. Therefore, it is considered that the claims 13 to 17 do not imply inventive activity (Art.8 L11 / 86). State of the Art Report Page 5/5