EP2639538A1

EP2639538A1 - Heat-exchanger cover

Info

Publication number: EP2639538A1
Application number: EP12159179.6A
Authority: EP
Inventors: VIAN Alessandro; SOLERIO Daniele
Original assignee: Electrolux Home Products Corp NV
Current assignee: Electrolux Home Products Corp NV
Priority date: 2012-03-13
Filing date: 2012-03-13
Publication date: 2013-09-18

Abstract

An electric appliance (100) is proposed. The electric appliance comprises a heat exchanger assembly (300,300₁,300₂ ) for the exchange of heat between an operative fluid and a refrigerant fluid. The heat exchanger assembly comprises a piping (305) for containing the refrigerant fluid, and at least one heat-radiating member (310₁,310₂ ) configured for being flown by the operative fluid along an operative direction (x) and comprising fitting seats (315) for fitting the piping (305) thereinto along a piping fitting direction (y) different from the operative direction; the piping comprises elbow-bent pipe portions protruding beyond at least one surface of the at least one heat-radiating member along the fitting direction, said fitting seats being elongated-shaped for allowing the elbow-bent pipe portions to pass therethrough upon fitting of the piping and comprising filled portions filled by the piping and free portions free from the piping. In the solution according to one or more embodiments of the present invention, the heat exchanger assembly further comprises at least one covering member (405₁,405₂) associated with the at least one free surface of the at least one heat-radiating member and configured for covering said free portions of the fitting seats.

Description

Field of the invention

The present invention generally relates to household and/or professional appliances provided with heat exchanger assembly for performing refrigerating, conditioning or heating functions. More particularly, the present invention relates to an improved finned-pack heat exchanger assembly for such household and/or professional appliances.

Background of the invention

Heat exchanger assembly is a widespread solution intended to implement refrigerating, conditioning or heating functions of a wide class of household and/or professional appliances (in the following, appliances). Among them, a relatively recent group of appliances making use of heat exchanger assembly is represented by laundry treatment appliances implementing laundry drying functions, such as laundry dryers (to which reference will be made hereinafter by way of example only) or washer/dryers, which are generally configured for removing moisture from a laundry load (comprising articles such as clothes and other textiles), e.g. shortly after cleaning/washing thereof.
Most of the currently marketed laundry dryers comprise a drying chamber configured for causing drying air (usually, properly heated cool, dry, ambient air) circulating therethrough to evaporate the moisture from the laundry load.
In modern laundry dryers, the heat exchanger assembly is generally part of a so-called heat pump device, typically a closed-loop heat-pump device.
Broadly speaking, the heat pump device substantially makes use of a refrigerant circuit for effectively transferring thermal energy from a first side at a lower temperature (also referred to as cool side), to a second side at a higher temperature (also referred to as hot side). A common type of heat pump device exploits physical properties of a volatile evaporating and condensing fluid (known as refrigerant fluid or refrigerant), which is made to flow in the refrigerant circuit, and comprises a compressor, a pressure-lowering device, and the heat exchanger assembly, the latter typically including both an evaporator - where the refrigerant absorbs heat thereby being vaporized - and a condenser - where the refrigerant releases heat thereby being condensed. In operation, the refrigerant, at a gaseous state, is pressurized, hence heated up, and circulated towards the hot side of the circuit by the compressor, where the hot and highly pressurized vapor is cooled in the condenser, until it condenses into a high pressure, moderate temperature liquid. The condensed refrigerant then passes through the pressure-lowering device (such as an expansion valve), and the corresponding low pressure, expanded liquid refrigerant then enters the evaporator, wherein the fluid absorbs heat and boils. The refrigerant then returns to the compressor and the cycle of above is repeated.
In a usual laundry dryer with heat pump device, the air leaving the drying chamber with decreased temperature and increased humidity with respect to the incoming hot air (hereinafter, also referred to as dump air), is passed first through the evaporator where it is further cooled down and dehydrated, and then through the condenser where, upon reheating, it forms the hot drying air to be fed inside the drying chamber for evaporating moisture from the laundry load therein.
A widely used solution of heat exchanger assembly is so-called finned-pack heat exchanger assembly, which generally comprises a e.g. copper piping inside which the refrigerant is made to flow, and a finned-pack including a plurality of heat-conducting (e.g., metal) plates (or fins) acting as a heat-radiating member for allowing even and rapid heat radiation/distribution between the dump air and the refrigerant. As known, each fin is provided with through-openings, which define, together with corresponding through-openings of all the other fins, respective seats, extending from mutually opposite end fins of the pack, along a piping fitting direction substantially orthogonal with respect to a main flow direction of the dump air through the heat exchanger assembly; thus, upon insertion of the piping into the seats, the fins are mechanically spaced apart from each other for allowing the dump air to flow therethrough thereby enabling said heat exchange.
Due to piping volume occupation issues, the piping is substantially coil-shaped, i.e. it is provided with both straight pipe portions and elbow-bent pipe portions connecting adjacent straight pipe portions to each other. Thus, effective insertion of such a piping into the seats is a task to face during manufacturing of the laundry dryer.
As known, this is achieved by two different approaches.
According to a first approach, the seats are circular-shaped in order to match the straight pipe portions. Thus, for assembling the finned-pack heat exchanger assembly, the straight pipe portions are first inserted into the circular seats such as to at least slightly protrude from the end fins of the pack along the fitting direction, and the elbow-bent pipe portions are then welded between the protruding ends of adjacent straight pipe portions according to the desired coiled arrangement.
Instead, according to a second approach, the seats are elongated-shaped in order to allow the whole piping (including both the straight pipe portions and the elbow-bent pipe portions already welded thereto) to be inserted completely thereinto and by a single operation.

Summary of invention

The Applicant has realized that the known devised and practiced solutions are not satisfactory for modern technological requirements.
In fact, the Applicant has found that the first approach makes assembling operations long and prone to errors and manufacturing defects, due to the not negligible number of welding to be manually performed by an operator after fitting the piping, whereas the second approach, although being easily practicable by manufacturing and assembling sight, makes efficiency of the finned-pack heat exchanger assembly anything but satisfactory.
In fact, as the elbow-bent pipe portions protruding from opposite end fins are typically arranged according to reciprocally different orientations (substantially due to piping volume occupation issues), the elongated through-openings of all the fins of the finned-pack are arranged according to a "universal" grid allowing said complete insertion of the whole piping by a single operation.
The Applicant has found that, after finned-pack/piping mounting, such through-openings arrangement causes the seats to be only partially filled/occupied by piping, so that unfilled/unoccupied parts of the seats cause a certain percentage of dump air flowing in the main flow direction to laterally escape outside the heat exchanger assembly by the through-openings of the end fins. This causes air vortices, whirling motions, turbulences, and air stagnation in a free space between the end fins and walls of a base member (or base) typically enclosing the heat exchanger assembly. If follows that the drying air output the heat exchanger assembly available for performing drying operations is decreased in speed and temperature with respect to the incoming dump air, which involves low efficiency in terms of drying operation (as the speed and the temperature of the drying air affect the time required for performing it) and electric energy wasting (as the laundry appliance employs more time for drying the laundry load or because more electric energy should be needed for increasing the speed and/or the temperature of the drying air up to the required speed and/or temperature for performing the drying operation within prescribed times).
Moreover, a certain percentage of stagnating air (and hence of dump air flowing in the main flow direction) is caused to laterally leak outside the base (e.g., through corresponding slots thereof typically provided for piping connections). This further reduces efficiency of the heat exchanger assembly, as the amount of air available for flowing therethrough (i.e., from the evaporator to the condenser) decreases at each cycle by said lateral air leakage from the heat exchanger assembly.
Last but not least, as air leakage comprises partially cooled down and dehydrated dump air through the evaporator (hence, air with a relevant degree of humidity) as well as partially heated up hot air through the condenser (hence, air with a relatively high temperature), various components, such as electronic boards, possibly reached by such humid/hot leakage air may be damaged even after a relatively low period of use, thus impairing reliability of the whole appliance.
The Applicant has tackled the problem of devising a satisfactory solution able to overcome the above-discussed drawbacks.
In particular, one or more aspects of the solution according to specific embodiments of the invention are set out in the independent claims, with advantageous features of the same solution that are indicated in the dependent claims (with any advantageous feature provided with reference to a specific aspect of the solution according to an embodiment of the invention that applies mutatis mutandis to any other aspect thereof).
An aspect of the solution according to one or more embodiments of the present invention relates to an electric appliance. The electric appliance comprises a heat exchanger assembly for the exchange of heat between an operative fluid and a refrigerant fluid. The heat exchanger assembly comprises a piping for containing the refrigerant fluid, and at least one heat-radiating member configured for being flown by the operative fluid along an operative direction and comprising fitting seats for fitting the piping thereinto along a piping fitting direction different from the operative direction; the piping comprises elbow-bent pipe portions protruding beyond at least one surface of the at least one heat-radiating member along the fitting direction, said fitting seats being elongated-shaped for allowing the elbow-bent pipe portions to pass therethrough upon fitting of the piping and comprising filled portions filled by the piping and free portions free from the piping. In the solution according to one or more embodiments of the present invention, the heat exchanger assembly further comprises at least one covering member associated with the at least one free surface of the at least one heat-radiating member and configured for covering said free portions of the fitting seats.
In an embodiment of the present invention, said at least one surface comprises a first surface and each elbow-bent pipe portion protruding beyond the first surface is fitted between engaging portions of a pair of adjacent fitting seats. In such case, the at least one covering member may comprises a first covering member associated with the first surface, the first covering member comprising at least one through-slot arranged for matching a corresponding elbow-bent pipe portion thereby allowing it to pass therethrough for fixing the first covering member to the first surface.
For example, the at least one through-slot may be shaped so as to substantially define the orthogonal projection of the corresponding elbow-bent pipe portion on the first surface.
In an embodiment of the present invention, said at least one surface further comprises a second surface opposite the first surface, with each elbow-bent pipe portion protruding beyond the second surface that is fitted between engaging portions of a respective same fitting seat. In such case, the at least one covering member may comprise a second covering member associated with the second surface, the second covering member comprising finger portions arranged for passing under the elbow-bent pipe portions protruding beyond the second surface.
According to a preferred, not limiting embodiment, each heat-radiating member may comprise a plurality of parallel heat-conducting fins extending in packed arrangement from an end fin to a further end fin opposite to said end fin along the fitting direction. Said fins are preferably spaced apart from one another for allowing the operative fluid to flow therethrough. An exposed surface of said end fin and of said further end fin defining the first surface and the second surface, respectively, of the at least one heat radiating member.
Each fin may comprise elongated through openings defining, together with corresponding elongated through openings of the other fins of the respective heat-radiating member, said fitting seats.
Preferably, although not necessarily, each through opening comprises at least one collar member each one adapted to substantially encircle a predefined outer surface part of the piping upon fitting thereof. According to a particularly advantageous embodiment, each collar member further comprises at least one slit for improving an adhesion surface thereof with the piping.
The at least covering member and/or the at least one collar member may be made of aluminum and/or plastic material and/or a combination thereof.
For example, the electric appliance may be a laundry dryer.
In an embodiment of the present invention, the heat exchanger assembly comprises a heating member at which the refrigerant fluid is evaporated thereby absorbing heat from the operative fluid, and a cooling member at which the refrigerant fluid is condensed thereby releasing heat to the operative fluid.
The appliance may further comprise a drying chamber for housing a laundry load to be dried. In an embodiment of the present invention, the operative fluid input the heat exchanger assembly comprises dump air coming from the drying chamber, whereas the operative fluid output the heat exchanger assembly comprises drying air to be fed into the drying chamber for enabling moisture evaporation from the laundry load therewithin.
The appliance may also comprise a base having a lower shell comprising a housing for accommodating the heat exchanger assembly, and an upper shell adapted to be coupled to the lower shell for properly enclosing the heat exchanger assembly therebetween.
Another aspect of the solution according to one or more embodiments of the present invention relates to a further electric appliance. Such electric appliance comprises a heat exchanger assembly for the exchange of heat between an operative fluid and a refrigerant fluid. The heat exchanger assembly comprises a piping for containing the refrigerant fluid, and at least one heat-radiating member configured for being flown by the operative fluid along an operative direction and comprising fitting seats for fitting the piping thereinto along a piping fitting direction different from the operative direction; each fitting seat (or some of them) comprises at least one collar member each one adapted to substantially encircle a predefined outer surface part of the piping upon fitting thereof. In the solution according to one or more embodiments of the present invention each collar member further comprises at least one slit for improving an adhesion surface thereof with the piping.
Thanks to the present invention, air vortices, turbulences and air stagnation between the heat exchanger assembly and the walls of the base enclosing it are considerably reduced or even substantially zeroed, as well as the percentage of dump air laterally leaking from the heat exchanger assembly through the base. This increases efficiency of the heat exchanger assembly, reduces the time employed by the laundry appliance for drying the laundry load (thus involving electric energy saving), and ensures reliability of the appliance as the various components thereof, including the most fragile ones (such as the electronic boards), are not reached by humid and/or hot leakage air any longer.

Brief description of the annexed drawings

These and other features and advantages of the solution according to one or more embodiments of the invention will be best understood with reference to the following detailed description, given purely by way of a non-restrictive indication, to be read in conjunction with the accompanying drawings (wherein corresponding elements are denoted with equal or similar references, and their explanation is not repeated for the sake of exposition brevity). In this respect, it is expressly understood that the figures are not necessarily drawn to scale (with some details that may be exaggerated and/or simplified) and that, unless otherwise indicated, they are simply used to conceptually illustrate the described structures and procedures. In particular:

Figure 1 schematically shows a perspective view with partially removed parts of an electric appliance wherein the solution according to one or more embodiments of the present invention may be applied;
Figure 2 schematically shows a perspective exploded view with removed parts of a heat pump device including a heat exchanger assembly wherein the solution according to one or more embodiments of the present invention may be applied;
Figure 3A schematically shows a front view of the heat exchanger assembly of Figure 2 and a close-up view of a part thereof;
Figure 3B schematically shows a rear view of part of the heat exchanger assembly of Figure 2 ;
Figures 4A and 4B schematically show perspective views of a heat exchanger assembly in a partly-assembled configuration and in an assembled configuration, respectively, according to an embodiment of the present invention;
Figure 5A schematically shows a perspective rear view of a part of a heat exchanger assembly according to another embodiment of the present invention, and
Figures 5B schematically show close-up views of the heat exchanger assembly of Figure 5A according to different configurations thereof.

Detailed description of preferred embodiments of the invention

Referring now to the drawings, Figure 1 schematically shows a perspective view with partially removed parts of an electric appliance (e.g., an electric household appliance), or appliance 100, wherein the solution according to one or more embodiments of the present invention may be applied. As will be best understood by the following description, the teachings of the present invention may be applied to substantially any appliance for items treatment, e.g. laundry treatment appliance - such as washer/dryer, washing machine, dryer (as exemplarily illustrated in the figure, and to which reference will be made in the following by way of a nonlimiting example only) - either of the front loading type (as exemplarily depicted in the figure) or of the top loading type, as well as dishwasher, refrigerator, oven and substantially any other appliance generally provided with heat exchanger assembly for performing refrigerating, conditioning and/or heating functions.
The appliance 100 comprises a substantially parallepiped-shaped cabinet 105, which encloses an inner compartment comprising a drying chamber 110 (e.g., drum, tumbler, and the like) for housing a laundry load to be treated (e.g., washed and/or dried), and an access door 115 (shown in a closed configuration) provided on a front wall of the cabinet 105 for accessing the drying chamber 110 thereby allowing loading/unloading operations of the laundry by a user. As usual for a laundry dryer, the drying chamber 110 is configured for causing drying air (usually, properly heated cool, dry, ambient air) circulating therethrough to enable evaporation of moisture from the laundry load.
As partly visible from the figure, the appliance 100 comprises a heat pump device 120 that, by means of a refrigerant circuit, is configured for effectively transferring thermal energy from a first side at a lower temperature (also referred to as cool side, not visible) to a second side at a higher temperature (also referred to as hot side, not visible) thereby allowing recycling/recovering of at least part of the cool, moisture-laden air coming from the drying chamber -hereinafter, referred to also as dump air.
With reference now to Figure 2 , it schematically shows a perspective exploded view with removed parts of the heat pump device 120. As discussed in the introductory part of the present description, the heat pump device 120 may comprise various components for operation thereof, such as electric/electromechanical/electro-hydraulic components, e.g. compressor, pressure-lowering device (e.g., expansion valve), air circulation fan and related motor- not shown, as not limiting for the present invention - and a heat exchanger assembly 300 (to which the solution according to one or more embodiments of the present invention may be applied) for allowing heat exchange between an operative fluid (e.g., the dump air coming from the drying chamber) and a reference fluid (e.g., a condensing and evaporating fluid known as refrigerant fluid or refrigerant). In this respect, such figure will be discussed together with Figure 3A , which schematically shows a perspective view of the heat exchanger assembly 300 and a close-up view of a part thereof, and to Figure 3B , which schematically shows a rear view of part of the heat exchanger assembly 300.
As visible in Figure 2 , the heat pump device 120 comprises a base 205 for supporting the heat exchanger assembly 300 and the other components. According to a known, not limiting configuration, the base 205 is provided with a lower shell 205_L mainly comprising a housing 210 for accommodating the heat exchanger assembly 300, another housing 215 for accommodating the fan motor (not shown) and a further housing 220 for accommodating the compressor (not shown), and an upper shell 205_U adapted to be coupled to the lower shell 205_L for properly enclosing the heat exchanger assembly 300 therebetween (and forming a corresponding process channel for the dump air). The upper shell 205_U comprises vertical slots, e.g. four vertical slots 225, so that piping end portions of the heat exchanger assembly 300 are allowed to pass therethrough for proper connection to the components of the heat pump device 120 (e.g., the compressor) when the upper shell 205_U is mounted on the lower shell 205_L. As best visible in Figure 3A , the heat exchanger assembly 300 comprises a e.g. copper, piping 305 (e.g., of the coiled type, i.e comprising both straight pipe portions and bent, such as elbow-bent, pipe portions for connecting adjacent straight pipe portions) inside which the refrigerant is made to flow, and one or more (e.g., two, as exemplarily illustrated) heat-radiating members, such as the heat-radiating members 310₁ and 310₂, which are configured for radiating heat between the dump air flowing therethrough along a main flow, or operative, direction x and the refrigerant circulating within the piping 305. In this respect, each heat-radiating member 310₁,310₂ comprises one or more, e.g., a plurality of elongated fitting seats or seats 315 for fitting (respective sections of) the piping 305 thereinto along a piping fitting direction y, typically different from (e.g., substantially orthogonal to) the operative direction x.
Thus, the heat-radiating member 310₁ (with the respective piping section) forms as a whole an evaporator member or evaporator 300₁ (i.e., the cool side of the heat pump device), at which the refrigerant is vaporized by absorbing heat from the cool, humid dump air leaving the drying chamber with decreased temperature and increased humidity (with respect to the incoming hot air), whereas the heat-radiating member 310₂ (with the respective piping section) forms as a whole a condensation member or condenser 300₂ (i.e., the hot side of the heat pump device), at which the refrigerant condenses thereby releasing heat which reheats the cool, dehydrated dump air (from the evaporator 300₁) that generates the hot air to be fed inside the drying chamber for evaporating moisture from the laundry load housed therein.
By way of example only, the illustrated heat exchanger assembly 300 (e.g., both the evaporator 300₁ and the condenser 300₂) is of the finned-pack type, i.e. each heat-radiating member 310₁,310₂ thereof comprises, as visible in the figure, a plurality of facing, parallel heat-conducting (e.g., metal) fins for allowing even and rapid heat distribution (thus promoting heat exchange between the dump air and the refrigerant), said fins being mechanically separated from each other (by a proper gap, through which the dump air is thus allowed to flow along the operative direction x) upon fitting/insertion of the piping 305 into the seats 315. In a known manner, each fin of the heat exchanger assembly 300 is provided with one or more, e.g. a plurality of elongated through-openings, which define, together with corresponding through-openings of all the other fins (of the same finned-pack heat-radiating member 310₁,310₂), the respective seats 315 extending between opposite side through-openings (i.e., between the through-openings of opposite end fins 320_F1,320_L1 and 320_F2,320_L2 of the evaporator 300₁ and the condenser 300₂, respectively).
Referring back to Figure 2, when the upper shell 250_U is mounted on the lower shell 205_L (configuration not shown), the heat exchanger assembly 300 is enclosed by the base 205 such that, by fan action, the dump air is allowed to enter the evaporator 300₁ and the hot drying air to exit the condenser 300₂ (theoretically, only) along the operative direction x. The drying air is then fed by fan action into the drying chamber (not shown) - typically arranged on or above the upper shell 205_U -for performing the intended drying operation, and the dump air exiting the drying chamber is again fed into the heat exchanger assembly for a new cycle. However, as briefly discussed in the introductory part of the present description, in modern application the piping 305 is monolithic, i.e. the elbow-bent pipe portions thereof are conveniently provided already welded to the straight pipe portions before fitting operation (the straight pipe portions being only partly visible in the bottom drawing Figure 3A as fitted into the seats 315), thus allowing the piping 305 to be inserted into the heat radiating members 310₁,310₂ easily and by a single operation. Moreover, due to piping volume occupation issues, the elbow-bent pipe portions protruding from opposite end fins are typically arranged according to reciprocal different orientations, so that the elongated through-openings of all the fins (both the end fins and the corresponding fins therebetween, hereinafter intermediate fins) of the finned-pack are arranged according to a "universal" grid.
Hence, as best visible in Figure 3A for the end fins 320_F1 and 320_F2 (upper drawing) and in the close-up view (lower drawing), after finned-pack/piping assembling/fitting, the seats 315 result to be only partially filled/occupied by piping 305 (with each elbow-bent pipe portion that is arranged between adjacent fitting seats). More particularly, each elbow-bent pipe portion is arranged between edge portions 315a,315b (of adjacent seats 315) that actually friction/engage the piping 305, thereby leaving a central portion 315c (between the edge portions 315a,315b) of each seat 315 unfilled/unoccupied.
As discussed in the introductory part of the present description, this causes a certain percentage of dump air flowing in the main flow direction x to laterally escape outside the heat exchanger assembly 300 by the through-openings of the end fins. This causes air vortices, whirling motions, turbulences, and air stagnation in the free space between the end fins the inner walls of the base 205 enclosing the heat exchanger assembly 300. If follows that the drying air output the heat exchanger assembly 300 available for performing drying operations is decreased in speed and temperature with respect to the incoming dump air, which involves low efficiency in terms of drying operation and electric energy wasting.
Moreover, a certain percentage of stagnating air (and hence of dump air flowing in the main flow direction x) may laterally leak (along the fitting direction y) outside the heat exchanger assembly 300 by the through-openings of the end fins and the vertical slots 225 of the upper shell 205_U of the base 205. This further reduces efficiency of the heat exchanger assembly 300, as the amount of air available for flowing therethrough decreases at each cycle, thereby decreeing electric energy issues (as the appliance employs more time for drying operations) and reliability issues (as the various components of the appliance, e.g., electronic boards, compressor and the like, when reached by leakage humid air - i.e., the partially dehydrated dump air through the evaporator 300₁ - and by leakage hot air - i.e. the partially heated up cooled, dehydrated dump air through the condenser 300₂ - may be damaged even after a relatively low period of use).
As should be readily understood, the seats 315 at end fins 320_L1 and 320_L2 side are partially filled/occupied by piping 305 as well, however, this concurs less to air leakage. In fact, as visible in Figure 3B for the end fin 320_L1 only, each elbow-bent pipe portion protrudes from a corresponding one of the through openings (i.e. it frictions/engage both the edge portions 315a,315b of a single seat 315), thus the central portions 315c, although not occupied, are partly covered by the elbow-bent pipe portions protruding therefrom. Moreover, no piping connection is required at the end fins 320_L1,320_L2 side, so that a small free space between the base walls and the end fins 320_L1,320_L2 is available for stagnating air.
Referring now to Figures 4A-4B , they schematically show perspective views of a heat exchanger assembly 400 in a partly-assembled configuration and in an assembled configuration, respectively, according to an embodiment of the present invention.
The heat exchanger assembly 400 is structurally equivalent to that above described. With respect to the latter, the heat exchanger assembly 400 further comprises, on at least one free surface thereof along the fitting direction y - i.e., the exposed surface of the end fin 320_F1,320_F2 and/or of the end fin 320_L1,320_L2 of the corresponding heat radiating member 310₁,310₂ - one or more covering members or covers (e.g., made of aluminum and/or plastic material and/or a combination thereof) generally configured for covering portions of the seats 315 (i.e., the central portions thereof) not occupied by the piping 305, such as the covers 405₁,405₂ on the exposed surface of each end fin 320_F1,320_F2 of both the heat radiating members 310₁ and 310₂. Thus, in the illustrated embodiment, the covers 405₁,405₂ cover the portions of the seats 315 not occupied by the piping 305 by plugging the central portions of the through-openings of the end fins 320_F1,320_F2.
In the exemplarily disclosed and illustrated implementation, each cover 405₁,405₂ comprises one ore more (e.g., a plurality of) through-slots 410 arranged for substantially matching the elbow-bent pipe portions, so that each elbow-bent pipe portions is allowed to pass therethrough thereby allowing the cover 405₁,405₂ to be fixed (by any proper fixing technique, e.g., engagement by friction, or interference, or fitting - e.g., snap-fitting) to the respective heat exchanger surface (in the example at issue, the exposed surface of the end fins 320_F1 and 320_F2 of both the heat radiating members 310₁ and 310₂, respectively).
In order to achieve that, part, or each one, of the through-slots 410 may be advantageously shaped such as to substantially define the orthogonal projection of the corresponding elbow-bent pipe portions on the exposed surface; thus, in the particular, not limiting considered configuration, the through-slots 410 have an elongated shape, and are oriented according to the orientation of the elbow-bent pipe portions.
Although the covers 405₁,405₂ have been described as covering the portions of the seats 315 not occupied by the piping 305 by plugging the central portions of the through-openings of the end fins 320_F1,320_F2, this is not to be construed limitatively.
In fact, additionally or alternatively, in embodiments of the present invention, not shown, the covers 405₁,405₂, or other covers similar thereto, may be fixed to the surfaces of the intermediate fins (i.e., the fins between the end fins 320_F1,320_L1 and 320_F2,320_L2) for achieving different purposes (e.g., for obtaining specific canalizations of the dump air).
Moreover, as should be readily understood, the covers may take any shape and/or size without departing from the scope of the invention. In this respect, an embodiment of the present invention, not shown, may also provide, additionally or alternatively to the covers of above, further covers, not shown, e.g. on the exposed surface of the end fin 320_L1,320_L2 of one or both the heat radiating members 310₁ and 310₂. By way of example only, such further covers may comprise a comb-shaped cover for covering/plugging the (central) through-openings portions of the end fin 320_L1,320_L2 that by construction are left unfilled/uncovered by the elbow-bent pipe portions (as shown in Figure 3B ). For example, such comb-shaped cover (not shown) may comprise one or more strip or finger portions each one configured for being fitted between (i.e. passing under) adjacent elbow-bent pipe portions along the main flow direction x.
Although the present invention has been described by making explicit reference to a finned-pack heat exchanger assembly, this is not limiting for the present invention, as the principles of the present invention may be applied to any heat exchanger assembly and to any implementation and/or configuration thereof.
In this respect, it should be noted that each through-opening in Figure 3B has been shown as comprising engaging portions generally configured for improving piping engagement upon fitting thereof. Such feature, although not necessary for the principles of the present invention, may implement a preferred embodiment thereof. In such embodiment, each engaging portion (e.g., made of the same material as the fin, e.g., aluminum and/or plastic material, or different from it) has, at a premounting phase (configuration not illustrated), a diameter lower than the diameter of the piping; in this way, the engaging portion is configured for at least partially bending, along the fitting direction, upon friction with the piping. Thus, each bent engaging portion acts as a collar adapted to substantially encircle a predefined outer surface part of the piping (in the exemplary disclosed embodiment, a first collar 325a is provided at the first edge portion 315a of each through-opening and a second collar 325b is provided at the second edge portion 315b of the through-opening); this, apart from securing engagement between the piping and the fins, thus making assembly operation simple, effective and reversible, also provides good heat exchange between the piping and the fins.
Moreover, as should be readily understood, the finned-pack heat radiating members may be equipped with many other solutions intended to improve efficiency thereof, without departing from the scope of the present invention. Incidentally, the covers of the present invention may also be applied to the heat radiating member comprising the features illustrated in Figures 5A and 5B . As will be readily understood, such features, although discussed in the following as (a basis for) further, advantageous or best embodiments all falling within the claimed scope, may also represent a different and separated aspect of the present invention.
With reference to Figure 5A , it schematically shows a perspective rear view of a part of a heat exchanger assembly 500 according to another embodiment of the present invention (shown without any cover). For the sake of exposition ease, such figure will be discussed together with Figure 5B , the latter schematically showing a close-up view of the heat exchanger assembly 500 in two different configurations (i.e., before and after the piping fitting - the piping being not shown for the sake of illustration ease).
The heat exchanger assembly 500 is similar to that above described, i.e., each through-opening thereof comprises first and second engaging portions, but, with respect to the latter, a first slit 530a is provided in the first engaging portion and a second slit 530b is provided in the second engaging portion, the first and second slits 530a,530b being arranged substantially centrally with respect to the first and second engaging portions, respectively (as shown in Figure 5B ). As before, each engaging portion is configured for at least partially bending (from the unbent condition before the piping fitting, shown in the left drawing of Figure 5B ) upon friction with the piping 305, thus forming a corresponding collar 525a,525b as illustrated in Figure 5A (with the piping 305) and on the right drawing of Figure 5B (without the piping).
Such solution is particularly advantageous as the provision of the slits 530a,530b makes the bending of the engaging portion easier and effective. In fact, bending improvement given by the slits 530a,530b increases an height of the collars 525a,525b and an adhesion surface thereof to the piping 305. Of-fact, each collar 525a,525b is split into two sub-collars, thereby greatly improving heat exchange between the fins and the piping 305. Moreover, such solution makes the bending of the collars 525a,525b at least partially controllable according to a length of the slits 530a,530b.
Without losing of generality, although friction-bendable collars have been herein described for the particular case of a finned-pack heat-exchanger assembly as advantageous features of the present invention or as a different aspect thereof, it should be readily understood that the same solution may also be applied to the covers (implementation not illustrated in any figure). In this respect, the through-slots of the covers may be equipped with one or more engaging portions (e.g., made of the same material as the cover, e.g., aluminum and/or plastic material, or different from it) configured, as above, for at least partially bending by friction with, thus engaging, the piping, and possibly provided with the described slits for making such bending easier and effective.
Naturally, in order to satisfy local and specific requirements, a person skilled in the art may apply to the solution described above many logical and/or physical modifications and alterations. More specifically, although the present invention has been described with a certain degree of particularity with reference to preferred embodiments thereof, it should be understood that various omissions, substitutions and changes in the form and details as well as other embodiments are possible. In particular, different embodiments of the invention may even be practiced without the specific details (such as the numeric examples) set forth in the preceding description for providing a more thorough understanding thereof; on the contrary, well known features may have been omitted or simplified in order not to obscure the description with unnecessary particulars. Moreover, it is expressly intended that specific elements and/or method steps described in connection with any disclosed embodiment of the invention may be incorporated in any other embodiment as a matter of general design choice.
For example, analogous considerations apply if the appliance has a different structure or includes equivalent components, or it has other operating features. In any case, any component thereof may be separated into several elements, or two or more components may be combined into a single element; in addition, each component may be replicated for supporting the execution of the corresponding operations in parallel. It should also be noted that any interaction between different components generally does not need to be continuous (unless otherwise indicated), and it may be both direct and indirect through one or more intermediaries.
Moreover, although in the present description explicit reference has been made to an electric appliance whose drying operation is carried out by means of a heat exchanger comprising an evaporator/condenser assembly, the principles of the present invention may also apply to any moisture condensing unit generally intended to dehydrate the dump air coming from the drying chamber without using the refrigerant circuit. In this respect, the moisture condensing unit may be a condenser configured for condensing the moisture of the dump air, and for properly collecting the liquid moisture for subsequent manual (or automatic) removal thereof outside the laundry dryer. In such case, the laundry dryer may also be unprovided with any air recovering system, as the dehydrated dump air/drying air may be exhausted/introduced from/to the surrounding environment by corresponding exhaust/inlet holes of the laundry dryer (with the incoming drying air that can be properly heated up, e.g. by an electric resistor before getting into the drying chamber).
Moreover, the principles of the present invention equivalently apply to an electric appliance whose refrigerant fluid is not subject to phase change. By way of example only, the refrigerant fluid may consist of (or comprise) gaseous CO₂ whose pressure is equal or higher than the critical pressure thereof. In this respect, the heat exchanger assembly of the present invention may comprise a gas cooling member (instead of the condenser) and a gas heating member (instead of the evaporator).

Claims

Electric appliance (100) comprising a heat exchanger assembly (300,300₁,300₂) for the exchange of heat between an operative fluid and a refrigerant fluid, the heat exchanger assembly comprising:
a piping (305) for containing the refrigerant fluid, and

at least one heat-radiating member (310₁,310₂) configured for being flown by the operative fluid along an operative direction (x) and comprising fitting seats (315) for fitting the piping (305) thereinto along a piping fitting direction (y) different from the operative direction,

wherein the piping comprises elbow-bent pipe portions protruding beyond at least one surface of the at least one heat-radiating member along the fitting direction, said fitting seats being elongated-shaped for allowing the elbow-bent pipe portions to pass therethrough upon fitting of the piping and comprising filled portions filled by the piping and free portions free from the piping,
characterized in that
the heat exchanger assembly further comprises at least one covering member (405₁,405₂ ) associated with the at least one free surface of the at least one heat-radiating member and configured for covering said free portions of the fitting seats.
Electric appliance according to Claim 1, wherein said at least one surface comprises a first surface, each elbow-bent pipe portion protruding beyond the first surface being fitted between engaging portions of a pair of adjacent fitting seats, and wherein the at least one covering member comprises a first covering member (405₁,405₂) associated with the first surface, the first covering member comprising at least one through-slot (410) arranged for matching a corresponding elbow-bent pipe portion thereby allowing it to pass therethrough for fixing the first covering member to the first surface.
Electric appliance according to Claim 2, wherein the at least one through-slot is shaped so as to substantially define the orthogonal projection of the corresponding elbow-bent pipe portion on the first surface.
Electric appliance according to Claim 2 or 3, wherein said at least one surface comprises a second surface opposite the first surface, each elbow-bent pipe portion protruding beyond the second surface being fitted between engaging portions of a respective same fitting seat, and wherein the at least one covering member comprises a second covering member associated with the second surface, the second covering member comprising finger portions arranged for passing under the elbow-bent pipe portions protruding beyond the second surface.
Electric appliance according to Claim 4, wherein each heat-radiating member comprises a plurality of parallel heat-conducting fins extending in packed arrangement from an end fin (320_F1,320_F2) to a further end fin (320_L1,320_L2) opposite to said end fin (320_F1,320_F2) along the fitting direction, said fins being spaced apart from one another for allowing the operative fluid to flow therethrough, an exposed surface of said end fin and of said further end fin defining the first surface and the second surface, respectively, of the at least one heat radiating member.
Electric appliance according to Claim 5, wherein each fin comprises elongated through openings defining, together with corresponding elongated through openings of the other fins of the respective heat-radiating member, said fitting seats.
Electric appliance according to Claim 6, wherein each through opening comprises at least one collar member (325a,325b,525a,525b) each one adapted to substantially encircle a predefined outer surface part of the piping upon fitting thereof.
Electric appliance according to Claim 7, wherein each collar member further comprises at least one slit (530a,530b) for improving an adhesion surface thereof with the piping.
Electric appliance according to Claim 7 or 8, wherein the at least covering member and/or the at least one collar member are made of aluminum and/or plastic material and/or a combination thereof.
Electric appliance according to any of the preceding Claims, wherein the electric appliance comprises a laundry dryer.
Electric appliance according to Claim 10, wherein the heat exchanger assembly comprises a heating member (300₁) at which the refrigerant fluid is evaporated thereby absorbing heat from the operative fluid, and a cooling member (300₂) at which the refrigerant fluid is condensed thereby releasing heat to the operative fluid.
Electric appliance according to Claim 11, wherein the appliance further comprises a drying chamber (110) for housing a laundry load to be dried, the operative fluid input the heat exchanger assembly comprising dump air coming from the drying chamber, and the operative fluid output the heat exchanger assembly comprising drying air to be fed into the drying chamber for enabling moisture evaporation from the laundry load therewithin.
Electric appliance according to Claim 12, wherein the appliance further comprises a base (205,205_L,205_U) having
a lower shell (205_L) comprising a housing (210) for accommodating the heat exchanger assembly, and
an upper shell (205_U) adapted to be coupled to the lower shell 205_L for properly enclosing the heat exchanger assembly therebetween, the base forming a corresponding process channel for the dump air when the upper shell is coupled to the lower shell.
Electric appliance according to Claim 13, wherein the lower shell comprises at least one further housing (215,220) for housing operative components configured for operating the heat exchanger assembly, and wherein the upper shell comprises at least one vertical slot (225) for allowing piping end portions to pass therethrough for proper connection to one or more of said operative components when the upper shell is mounted on the lower shell.