Acoustic panel, electric appliance and method of assembling an electric appliance

Abstract

An acoustic panel (1) for an electric appliance (2) with a tank (21) is specified, wherein the acoustic panel (1) comprises an inner plate (11) facing the tank (21) and an outer plate (22) facing away from the tank (21), a volume (13) between the inner plate (11) and the outer plate (12) is subdivided into a plurality of chambers (16), the acoustic panel (1) is configured to be mounted to at least one reinforcement bar (22) on an outer wall (210) of the tank (21) wherein the inner plate (21) of the acoustic panel (1) is located closer to the outer wall (210) of the tank (21) than a surface (220) of the reinforcement bar (22) that faces away from the tank (21). Further, an electric appliance (2) and a method of assembling an electric appliance (2) are specified.

Description

[0001]P2024,0669 WO N / P240067WO01 September22,2025 -1 - DescriptionAcoustic panel, electric appliance and method of as semblingan electricapplianceThe present disclosure relates to an acoustic panel , anelectric appliance, and to a method of assembling a n electricappliance.Electric appliances such as those used in energy di stributionnetworksmayproduce noise during operation.Embodiments of the disclosure relate to a way to da mpen noiseduring operation ofan electricappliance.According to an embodiment of an acoustic panel, th e acousticpanelisconfigured foran electricappliance with a tank,wherein the acoustic panel comprises an inner plate facingthe tank and an outer plate facing away from the ta nk. Avolume between the innerplate and the outerplate issubdivided into a plurality of chambers. The acoust ic panelis configured to be mounted to at least one reinfor cement baron an outer wall of the tank wherein the inner plat e of theacousticpanelislocated closerto the outerwall ofthetank than a surface of the reinforcement bar that f aces awayfrom the tank.In particular,atleastsome ofthe chambers are air-tight.Thus, the acoustic panel is configured such that th ereinforcement bars of the tank may be used to mount theacoustic panel. In contrast to conventional solutio ns, anadditional supporting construction spaced apart fro m the tankcan be dispensed with. P2024,0669 WO N / P240067WO01 September22,2025 -2 -Further, the addition of the acoustic panel does no t or atleast not significantly increase the overall dimens ions ofthe electricappliance.Further, access to the electric appliance, for inst ance formaintenance purposes is facilitated compared to sol utionswhere a supporting structure is mounted to the tank or / andto the ground and extends around the tank at a dist ance fromthe tank.The noise reduction may result from the dissipation ofacoustic energy in the volume subdivided into the c hambers.In particular, vibrations of the acoustic panel may be causedby an acoustic pressure in the chambers. The chambe rstructure maybe configured such thatan efficient noisereduction can be obtained. For example, the acousti c panelmay have an increased stiffness on account of the c hamberstructure, which minimizes vibrations of the low or derfrequencieson the outerplate.In particular, a highly efficient and durable noise reductionmay be obtained by means of air-tight chambers. For example,the ingress of dust that might negatively affect th e dampingpropertiesofthe chambersmaybe prevented.A solid filling material in the chambers is not req uired fora noise reduction but may be additionally provided. Thus, theacoustic panel may have a low weight compared to co nventionalsolutions. P2024,0669 WO N / P240067WO01 September22,2025 -3 - Forexample,the acousticpanelcomprisesatleast twochambers and / or at most 200 chambers or at most 100 chambersoratmost50 chambers.For example, the electric appliance comprises a liq uid-immersed, in particular an oil-immersed power devic e. Thus,the tankreceivesthe powerdevice and the liquid.For example, the power device comprises at least on e of: atransformer, a phase shifter, a reactor, an inducto r.For example, the electric appliance is configured t o be usedin an energydistribution network.For example, the inner plate and the outer plate of theacousticpanelextend in parallelorsubstantially in parallelto one another.Forexample,the acoustic panelcomprises side walls extending obliquely or perpend icularlywith respect to the inner plate and / or to the outer plate.The inner plate, the outer plate and the side walls takentogether may define the volume.For example, the inner plate and / or the outer plate comprisesor consists of a metal such as carbon steel, stainl ess steelor aluminum. Alternatively or in addition, at least one ofthe innerplate orthe outerplate maycomprise or consistof a plasticsmaterial.The reinforcement bars are not limited with respect to theircross-section.Forexample,the reinforcementbars mayhave aU-shaped, C-shaped, L-shaped, I-shaped, T-shaped or arectangularcross-section. P2024,0669 WO N / P240067WO01 September22,2025 -4 -Further, the electric appliance may comprise reinfo rcementbars that differ from one another with respect to a shapeand / or the dimensions of the cross-section. For exa mple, atleast some of the reinforcement bars are arranged v erticallyor at least substantially vertically in space. Alte rnativelyor in addition, horizontal reinforcement bars may b eprovided. Alternatively or in addition, oblique rei nforcementbars may be provided, for instance diagonal reinfor cementbars.For example, the acoustic panel is configured to be mountedbetween reinforcementbarsofthe tankarranged on the outerwall of the tank, in particular between two directl y adjacentreinforcementbars.Thus,a gap between adjacentreinforcement bars may be at least partly filled wi th theacousticpanel.Alternatively, the acoustic panel may be mounted on ly on oneside ofthe acousticpanelto a reinforcementbar. Forexample, this may apply at an edge or a corner of t he tank.In this case, an additional construction may be use d to mountthe acousticpanelon the otherside.According to a further embodiment of the acoustic p anel,sub-volumesofthe chambersare selected such that theacoustic panel comprises a specific acoustic dampen ingfrequency band. For example, the size of the chambe rs and / orthe number of the chambers may be selected such tha t theacoustic panel dampens a specific acoustic frequenc y band ofa particular electric appliance. In particular, the vibrationmodes maybe changed in a targeted mannerbymeans ofthechambers, so that the acoustic panel has the highes t noisereduction in a predetermined frequency range. Thus, during P2024,0669 WO N / P240067WO01 September22,2025 -5 -its production the acoustic panel may be specifical ly adaptedby means of the chamber structure to efficiently da mpen noisein a frequency band where the noise emission of the electricappliance during operation is particularly high. Fo r example,typical dominant noise frequencies are around 100 H z, 120 Hz,300 Hz,or400 Hz. Further,parametersaffecting the stiffnessofthe acousticpanel and / or parameters of the filling material may be usedto appropriately tune the dampening properties of t heacousticpanel.According to a further embodiment of the acoustic p anel, atleast some of the chambers or all chambers are air- tight. Inthis context, air-tight means that there is no or a t least nosignificant exchange of air between the chamber and anadjacentchamber.According to a further embodiment of the acoustic p anel, thechambers have a thickness in a range from 5 mm to 3 00 mm. Thethicknessrefersto an extentofthe chambersin a directionperpendicular to the outer plate of the acoustic pa nel. Inparticular, the thickness of the chambers may be us ed toadaptthe efficiencyofnoise dampening and / orthe spectral response ofthe acousticpanel.According to a further embodiment of the acoustic p anel, theacoustic panel comprises a rib structure that exten ds atleastin regionsfrom the outerplate to the inner plate.Forexample, the inner plate and the outer plate are me chanicallyconnected to one another via the rib structure. Thi s maysignificantly increase the stiffness of the acousti c panel. P2024,0669 WO N / P240067WO01 September22,2025 -6 -It has been found that the stiffness of the acousti c panelsignificantly affects the acoustic dampening proper ties.In particular, the rib structure may be used to inc rease thestiffness of the acoustic panel without having to i ncreasethe thickness of the inner plate and / or the outer p late. Thishelps to keep the weight of the acoustic panel low.The rib structure may subdivide the volume into the pluralityof chambers. The rib structure may comprise one rib or apluralityofribsthatextendshorizontallyand / or one rib ora plurality of ribs that extends vertically in spac e when theacousticpanelismounted to the tank.The rib structure may be formed from the same mater ial as theinner plate and / or the outer plate. The rib structu re maycomprise a metal, for instance. Alternatively, a ma terial ofthe rib structure maybe differentfrom a material oftheinner plate or the outer plate. The rib structure m aycomprise a plasticsmaterial,forinstance.According to a further embodiment of the acoustic p anel, atleastsome ofthe chambersare free from a filling material.In particular, all of the chambers may be free from a fillingmaterial. This helps to reduce the weight of the ac ousticpanel.According to a further embodiment of the acoustic p anel, atleast some of the chambers are filled with a fillin gmaterial. An additional noise damping may be obtain ed by thefilling material located in some or all of the cham bers. P2024,0669 WO N / P240067WO01 September22,2025 -7 -For example, a density of the filling material is i n a rangefrom 5 kg / m³ to 500 kg / m³. For example, mineral woo ltypically has a density in a range from 30 to 200 k g / m³.Alternatively or in addition the filling material m aycomprise an acoustic foam. A filling material havin g a lowdensity helps to keep the weight of the acoustic pa nel low.According to a further embodiment of the acoustic p anel, thefilling materialhasa densityin a range from 0.5 g / cm³to5 g / cm³. Thus, the filling material has a comparabl y highdensity. For example, the filling material may comp rise aplastics material such as polyvinyl chloride (PVC).Alternativelyorin addition,the filling material maycomprise a granular rubber material such as granula r EPDM(ethylene propylene diene monomer). It has turned o ut that afilling materialhaving a comparablyhigh density, inparticular granular rubber, is suitable to efficien tly dampennoise with frequencies occurring during operation o f electricapplianceswith a powerdevice immersed in a tank.According to a further embodiment of the acoustic p anel, agrain size of the filling material is in a range fr om 0.1 mmto 5 mm. Granular material with a grain size in thi s rangehas been proven to be particularly efficient for da mpeningnoise in typical emission frequency bands of electr icappliances.However,non-granularfilling material mayalso be used.According to a further embodiment of the acoustic p anel, theacoustic panel comprises a mounting region for moun ting theacousticpanel.In particular,the mounting region laterallyprojects beyond the inner plate. For example, the a coustic P2024,0669 WO N / P240067WO01 September22,2025 -8 -panel comprises two mounting regions extending alon g twoopposite edgesofthe acousticpanel.Forexample, themounting region is configured to receive a mechanic alconnectorsuch asa screw ora boltora clamp.For example, the mounting region is formed by a par t of theouter plate that laterally projects beyond the inne r plate.Alternatively or in addition, the mounting region m ay beformed by an extension attached to the outer plate.According to a further embodiment of the acoustic p anel, theacoustic panel is configured to dampen a specific a cousticfrequency band of the electric appliance. Thus, the acousticpanel may be specifically designed to efficiently d ampennoise in a frequencyband where the noise emission oftheelectric appliance during operation is particularly high. Forexample, the chambers and / or parameters affecting t hestiffness of the acoustic panel and / or parameters o f thefilling materialmaybe used to appropriatelytune the dampening propertiesofthe acousticpanel.According to a further embodiment of the acoustic p anel, atleast one of the inner plate or the outer plate has athickness in a range from 2 mm to 6 mm. It has turn ed outthat an efficient noise reduction can be obtained w hile theweight of the acoustic panel can be kept low at the sametime.According to a further embodiment of the acoustic p anel, athicknessofthe acousticpanelisin a range from 10 mm to300 mm. The thickness refers to the extent of the a cousticpanel in a direction perpendicular to the outer pla te of theacoustic panel. In particular, the thickness of the acoustic P2024,0669 WO N / P240067WO01 September22,2025 -9 - panelmaybe used to adaptthe efficiencyofnoise dampeningand / or the spectral response of the acoustic panel.Further, an electric appliance is specified. In par ticular,the electric appliance comprises at least one acous tic panelasdescribed above and a tank.According to an embodiment of the electric applianc e, thetank comprises a plurality of reinforcement bars ar ranged onan outer wall of the tank wherein the acoustic pane l ismounted to at least one of the reinforcement bars w herein theinner plate of the acoustic panel is located closer to theouter wall of the tank than a surface of the reinfo rcementbarthatfacesawayfrom the tank.For example, the acoustic panel may be mounted betw een tworeinforcement bars of the plurality of reinforcemen t bars, inparticular between two directly adjacent reinforcem ent bars.Forexample,the acousticpanelextendsinto a gap betweentwo directly adjacent reinforcement bars in a top v iew ontothe electric appliance. Alternatively or in additio n, anacoustic panel of the electric appliance may be mou nted toonly one of the reinforcement bars as described abo ve.According to a further embodiment of the electric a ppliance,the inner plate is arranged completely within a gap betweentwo adjacentreinforcementbarsin a top view onto theelectric appliance. Thus, the space between the rei nforcementbars can be used, at least in part, for the acousti c panel.For example, all gaps between two adjacent reinforc ement barsare at least partly filled with one acoustic panel. P2024,0669 WO N / P240067WO01 September22,2025 -10 -According to at least one embodiment of the electri cappliance,the acousticpanelcomprisesa mounting regionthat overlaps with one of the reinforcement bars. I nparticular, a sealing and / or damping material may b e arrangedbetween the mounting region and the reinforcement b ar. Thesealing and / or damping material may be used to redu ce atransfer of vibrations of the outer wall of the tan k to theacoustic panel via the mounting region, and / or to s eal aclosed area created between the acoustic panels, th ereinforcement bars, and the outer wall of the tank.For example, the sealing and / or damping material co mprises arubber material or cork rubber. In this area also o therdamping systemscan be used,forexample single or stacked spring washers.According to at least one embodiment of the electri cappliance, a distance between a support structure o f theacoustic panel and the tank is sealed using a seali ng system.For example, the sealing system comprises cork, rub ber oranothersealing material.Forexample,a thickness ofthe sealing system isin a range from 1 mm to 500 mm.According to at least one embodiment of the electri cappliance, a distance between the inner plate of th e acousticpaneland the outerwallofthe tankisin a range from 0 mmto 500 mm. Thus, the inner plate may directly adjoi n theouter wall of the tank. Alternatively, the inner pl ate may bespaced apart from the outer wall of the tank. For e xample,the distance between the inner plate of the acousti c paneland the outerwallofthe tankisatleast1 mm or atleast 5 mm oratleast10 mm. P2024,0669 WO N / P240067WO01 September22,2025 -11 -Further, a method of assembling an electric applian ce isspecified.According to an embodiment of the method, the metho dcomprisesthe stepsofproviding an electricpower device, the step offorming a tankthatextendsaround the electricpower device wherein the tank comprises a plurality ofreinforcement bars arranged on an outer wall of the tank andthe step ofmounting an acousticpanelto atleast one oftheplurality of reinforcement bars wherein the inner p late ofthe acoustic panel is located closer to the outer w all of thetank than a surface of the reinforcement bar that f aces awayfrom the tank. The method steps can be performed in theindicated order.However,thisisnotnecessary.According to a further embodiment of the method, th e step ofmounting the acoustic panel is performed prior to t he step offorming the tank. Thus, the acoustic panel can be p rovided ina pre-assembled mannertogetherwith a partofthe tank.Inconventional approaches, in contrast, the tank is f ormedfirst and the sound panels are attached to a suppor tingstructure thatextendsaround the finished tankat a minimumdistance from the tank which is typically about 500 mm.The method is particularly suitable for the electri cappliance described above.Featuresand advantages describedin connection with the acoustic panel or the electr icappliance can therefore be used forthe method and vice versa. P2024,0669 WO N / P240067WO01 September22,2025 -12 - Featuresdescribed in connection with atleastone embodimentmay be combined with other features described in co nnectionwith other embodiments unless they are contradictor y.The accompanying figuresare included to provide a furtherunderstanding. In the figures, elements of the same structureand / orfunctionalitymaybe referenced bythe same reference signs.Itisto be understood thatthe embodiments shown inthe figures are illustrative representations and ar e notnecessarilydrawn to scale. In the Figures:Figure 1A shows a schematic sectional view of an el ectricappliance with acoustic panels according to an embo diment,Figure 1B shows a schematic side view of an electri cappliance with acoustic panels according to an embo diment,Figure 2 shows a perspective sectional view of a de tail of anelectric appliance with an acoustic panel according to anembodiment,Figure 3A shows a perspective view of a detail of a n electricappliance with an acoustic panel according to an em bodiment,Figure 3B showsa sectionalview ofa detailofan electricappliance with an acoustic panel according to an em bodiment,Figure 4A shows a perspective view of a detail of a n electricappliance with an acoustic panel according to an em bodiment,Figure 4B shows a perspective view of a detail of a n electricappliance with an acoustic panel according to an em bodiment,Figure 5A shows a schematic side view of an electri cappliance with acoustic panels according to an embo diment, P2024,0669 WO N / P240067WO01 September22,2025 -13 -Figure 5B shows a further schematic side view of an electricappliance with acoustic panels according to an embo diment,Figure 6 shows a schematic representation of a meth odaccording to an embodiment,Figures 7A and 7B show simulation results of a disp lacementofan embodimentofan acousticpanelin a contour plot(Figure 7A) and as a function of the frequency (Fig ure 7B),andFigures 8A and 8B show simulation results of a resp onse of anembodiment of an acoustic panel in a contour plot ( Figure 8A)and asa function ofthe frequency(Figure 8B).While the disclosure is amendable to various modifi cationsand alternative forms,specificsthereofhave been shown byway of example in the figures and will be described indetail.Itshould be understood,however,thatthe intentionis not to limit the disclosure to the particular em bodimentsdescribed. On the contrary, the intention is to cov er allmodifications, equivalents, and alternatives fallin g withinthe scope of the disclosure defined by the appended claims.In the embodiment shown in Figures 1A and 1B, an ac ousticpanel 1 is configured for an electric appliance 2 w ith a tank21. The acoustic panel 1 comprises an inner plate 1 1 facingthe tank21 and an outerplate 12 facing awayfrom the tank 21.A volume 13 between the innerplate 11 and the outerplate 12 is subdivided in a plurality of chambers 1 6. Theacousticpanel1 isconfigured to be mounted to at leastonereinforcement bar 22 on an outer wall 210 of the ta nk 21. Theinner plate 11 of the acoustic panel 1 is located c loser tothe outer wall 210 of the tank 21 than a surface of thereinforcementbar22 thatfacesawayfrom the tank 21. P2024,0669 WO N / P240067WO01 September22,2025 -14 - The chambers16 are separated from one anothervia a ribstructure 17. The rib structure 17 extends from the outerplate 12 to the inner plate 11. The mechanical conn ectionbetween in the inner plate 11 and the outer plate 1 2 via therib structure 17 increases the stiffness of the aco usticpanel 1. This may result in minimized low frequencyvibrations of the outer plate 12. The rib structure 17 may beformed from the same material as the inner plate 11 and / orthe outerplate 12 orfrom a differentmaterial.Figures 1A and 1B exemplarily illustrate three diff erentconfigurations for the rib structure 17. The acoust ic panel 1depicted on the left comprises three chambers 16 th at arearranged one above the other in the vertical direct ion. Theribs17 extend horizontally. The acousticpanel1 in the middle comprisesa rib structure17 with an additional horizontal rib, so that the v olume 13is subdivided both horizontally and vertically in s pace.The acousticpanel1 in the middle comprisesa rib structure17 with a plurality of horizontal and a plurality o f verticalribs. Exemplarily, the volume 13 is subdivided into 18chambers.The number of chambers 16 may be varied in wide ran ges.In the embodiment shown in Figures 1A and 1B, the a cousticpanels1 are each mounted in a gap 221 between two adjacentreinforcement bars 22. Thus, the gap 221 is at leas t partlyfilled with the acoustic panel 1 so that this space can beused fornoise dampening. P2024,0669 WO N / P240067WO01 September22,2025 -15 -Different ways for mounting the acoustic panel 1 to thereinforcement bars 22 will be described in connecti on withFigures3A,3B,4A,and 4B. Unlike the schematicrepresentationsofFigures1A and 1B,the acoustic panel 1 can also be mounted to only on ereinforcementbar22.Forexample,thismaybe the case atanedge or a corner of the tank 2. Here, the side of t heacoustic panel opposite to the reinforcement bar 22 may beconnected to the tank 2 or to another acoustic pane l 1 bymeans ofa dedicated supportstructure.During operation of the electric appliance 2, the a cousticpanels 1 dampen the noise in an electric power devi ce 20 ofthe electric appliance 2. For example, the electron ic powerdevice 20 may comprise or consist of a transformer, a phaseshifter,a reactororan inductor. In particular,almostthe complete outerwalls210 ofthe tank21 maybe covered byacousticpanels1.The noise reduction may result from the dissipation ofacoustic energy in the volume 13 subdivided into th e chambers16.The vibration ofthe innerplate 11 and / orthe outer plate 12 mayresultfrom pressure wavesin the air betweenthe outer wall 210 of the tank and the acoustic pan el 1.In particular, vibrations of the acoustic panel 1 m ay becaused byan acousticpressure in the chambers16. Thechamber structure 16 may be configured such that an efficientnoise reduction can be obtained in a particular aco usticfrequencyband. P2024,0669 WO N / P240067WO01 September22,2025 -16 -For example, the acoustic panel 1 may have an incre asedstiffness on account of the chamber structure 16, w hichminimizes vibrations of the low order frequencies o n theouterplate 12.For example, the chambers may have a thickness in a rangefrom 5 mm to 300 mm.The acoustic panel 1 can be specifically designed s uch thatthe noise reduction is tuned to a particular freque ncy bandof the noise emitted by the electric appliance 2 du ringoperation,in particularbymeansofthe design of thechambers 16 and / or the rib structure 17. The acoust icfrequency bands are specific to the electric applia nce 2. Inparticular, these frequencies may also depend on th e netfrequencyofthe energydistribution network.For example, typical dominant noise frequencies are around100 Hz,120 Hz,300 Hz,or400 Hz.Optionally, the chambers 16 may be filled with a fi llingmaterial 14. The filling material 14 may help to ob tain afurther noise reduction. The filling material 14 ma y have acomparably low density. For example, the density of thefilling materialisin a range from 5 kg / m³to 500 kg / m³.For example,a mineralwooloran acousticfoam maybe used.The inner plate 11 and / or the outer plate 12 may ha ve athickness in a range from 2 mm to 6 mm. As the thic kness ofthe inner plate 11 and the outer plate 12 affects t hestiffness of the acoustic panel 1, the thickness of the inner P2024,0669 WO N / P240067WO01 September22,2025 -17 -plate 11 and / or the outer plate 12 may also be used to tunethe acousticfrequencyresponse.A thickness of the acoustic panel 1 may be in a ran ge from10 mm to 300 mm,forexample.In the embodiment of Figures 1A and 1B, the inner p late 11 ofthe acoustic panel 1 is spaced apart from the outer wall 210of the tank 21. However, the inner plate 11 may als o directlyadjoin the tank 21. For example, the distance betwe en theinner plate 11 of the acoustic panel 1 and the oute r plate210 of the tank 21 is in a range from 0 mm to 500 m m.For example, the inner plate 11 and / or the outer pl ate 12comprises a metal such as carbon steel, stainless s teel oraluminum ora plasticsmaterial.A distance between a support structure of the acous tic panel1 and the tank 21 may be sealed using a sealing sys tem. Forexample,the sealing system comprisescork,rubber oranothersealing material. For example, a thickness of the s ealingsystem is in a range from 1 mm to 500 mm.The impact of the chamber structure on the frequenc y responsefunction of the acoustic panel is illustrated in Fi gures 7A,7B, 8A, and 8B. The simulations of Figures 7A and 7 B arebased on an acoustic panel subdivided in six chambe rs havingwidth of 250 mm, a length of 400 mm and a thickness of 10 mmwhere a constant pressure of 1 Pa is applied to the middle ofthe inner plate. Figure 7B illustrates the displace ment d intwo chosen pointsasa function offrequency. P2024,0669 WO N / P240067WO01 September22,2025 -18 -For comparison, the simulations of Figures 8A and 8 B arebased on an acoustic panel having the same size and the samethickness, but being subdivided in only three chamb ers with awidth of 500 mm. As Figure 8B illustrates, this str uctureresults in a pronounced peak of the frequency respo nsefunction near125 Hz.These simulations confirm that frequency response o f theacoustic panel 1 can be tuned to specific frequenci es byappropriately setting the parameters of the acousti c panel.Figure 2 illustrates details of an embodiment of an acousticpanel 1 to be mounted to reinforcement bars 22 on a n outerwall210 ofthe electricappliance 2.The acoustic panel1comprises an inner plate 11 and an outer plate 12 e xtendingin parallel to one another. A sidewall 19 is arrang ed betweenthe inner plate 11 and the outer plate 12. A volume 13between the inner plate 11 and the outer plate 12 i ssubdivided into a pluralityofchambers16.The acoustic panel 1 comprises a mounting region 15 . Themounting region 15 laterally extends beyond the inn er plate11 and is configured to overlap with the reinforcem ent bar 22when mounted to the outerwall210 ofthe tank21. In theembodiment of Figure 2 the mounting region 15 is fo rmed by apart of the outer plate 12. Alternatively, the moun tingregion 15 mayalso be formed bya separate element attached to the outerplate 12 asillustrated in Figure 4A, for instance.The mounting region 15 and means for mechanically m ountingthe acoustic panel 1 to the reinforcement bars 22 m ay beadapted to the cross-section of the reinforcement b ars 22. In P2024,0669 WO N / P240067WO01 September22,2025 -19 -Figure 2, the reinforcement bars 22 have a T-shaped cross-section. However, other geometries may also be used for thereinforcement bars, for example a U-shaped or subst antiallyrectangular cross-section of the reinforcement bars 22. Othercross-sections such as C-shaped, L-shaped, or I-sha ped mayalso be used.Figures 3A and 3B illustrate an embodiment of an ac ousticpanel 1 mounted to a T-shaped reinforcement bar 22. Asdescribed in connection with Figure 2, the mounting region 15overlaps with the reinforcement bar 22. The chamber s 16 andthe rib structure 17 are not explicitly depicted in Figures3A and 3B and may be configured as described in con nectionwith Figures 1A, 1B, or 2. The mechanical connectio n betweenthe acoustic panel 1 and the reinforcement bar 22 i s obtainedvia a clamp 31 that directly adjoins the reinforcem ent bar 22and is secured to the acoustic panel 1 via a washer 33 and anut32.A sealing and / or damping material 222 is arranged b etween themounting region 15 of the acoustic panel and the su rface 220of the reinforcement bar 22, for example the sealin g and / ordamping materialcomprisesa rubber.In the embodiments of Figures 4A and 4B, the reinfo rcementbars 22 have a U-shaped cross-section. The chambers 16 andthe rib structure 17 are not explicitly depicted in Figures4A and 4B and may be configured as described in con nectionwith Figures1A,1B,or2.In the embodiment of Figure 4A, the mounting region 15 isformed by an extension 151 attached to the outer pl ate 12 ofthe acoustic panel. The extension 151 has a hole or a cutout P2024,0669 WO N / P240067WO01 September22,2025 -20 -to receive a screw 34 extending into a blind bushin g 225 ofthe reinforcementbar22.The embodiment of Figure 4B substantially correspon ds to theembodiment of Figure 4A. However, the mounting regi on 15 isformed by a portion of the outer plate 12 that over laps withthe reinforcementbar22.Figures 5A and 5B illustrate two side views of an e lectricappliance 2 with a tank 21 and a plurality of acous tic panels1 that may be configured as described in the previo usfigures. Figure 5B further schematically illustrate s theelectric power device 20 immersed in a liquid withi n tank 21.Figures 5A and 5B illustrate that almost the entire surfaceof the outer wall 210 of the tank 21 may be covered withacoustic panels 1 so that an efficient noise reduct ion can beobtained. Compared to conventional solutions, the a cousticpanels1 do notsignificantlyincrease the size of theelectric appliance 2. Further, access to the tank 2 1 isfacilitated.Figure 6 illustrates an embodiment of a method of a ssemblingan electric appliance. For better understanding, st ructuralfeaturesdescribed in connection with the previous figuresare used even though these elements are not explici tly shownin Figure 6.In a step S1, an electric power device 20 is provid ed. In astep S2, a tank is formed that extends around the e lectricpowerdevice.The tank21 comprisesa pluralityofreinforcement bars 22 arranged on an outer wall 210 of thetank 21. In a step S3, an acoustic panel 1 is mount ed to at P2024,0669 WO N / P240067WO01 September22,2025 -21 -least one of the plurality of reinforcement bars 22 whereinthe innerplate ofthe acousticpanel1 islocated closertothe outer wall of the tank 21 than a surface 220 of thereinforcement bar 22 that faces away from the tank.The method can be performed in the indicated order.However,thisisnotnecessarilyrequired.Rather, atleast partofstep S3 maybe performed priorto step S2. Forexample, at least one acoustic panel 1 may be preas sembled toa partofthe tank.Thus,partsofthe tankmaybe provided with an acousticpanelbefore the tank21 hasbeen completed. Thismayhelp to facilitate the assembling process ofthe electricappliance.In particular, the method can be used to assemble a n electricappliance configured as described in connection wit h thepreviousfigures.The embodiments shown in the Figures 1A to 8B as st atedrepresent exemplary embodiments of the acoustic pan el, of theelectric appliance, and of the method; therefore, t hey do notconstitute a complete list of all embodiments accor ding tothe acoustic panel, the electric appliance, and the method.Actualacousticpanelsand electricappliancesand methodsmay vary from the embodiments shown in terms of spa tialarrangements, components, and materials, for exampl e. P2024,0669 WO N / P240067WO01 September22,2025 -22 - Reference Signs 1 acousticpanel 11 innerplate 12 outerplate 13 volume 14 filling material 15 mounting region 151 extension 16 chamber 17 rib structure 19 side wall 2 electricappliance 20 electricpowerdevice 21 tank 210 outerwall 22 reinforcementbar 220 surface ofreinforcementbar 221 gap 222 sealing and / ordamping material 225 blind bushing 31 clamp 32 nut 33 washer 34 screw S1 step S2 stepS3 step

Claims

1. P2024,0669 WO N / P240067WO01 September22,2025 -23 - Claims 1.An acousticpanel(1)foran electricappliance (2)with a tank(21),wherein- the acoustic panel (1) comprises an inner plate ( 11) facingthe tank (21) and an outer plate (22) facing away f rom thetank(21),- a volume (13) between the inner plate (11) and th e outerplate (12) is subdivided into a plurality of chambe rs (16),- the acoustic panel (1) is configured to be mounte d to atleast one reinforcement bar (22) on an outer wall ( 210) ofthe tank (21) wherein the inner plate (21) of the a cousticpanel (1) is located closer to the outer wall (210) of thetank (21) than a surface (220) of the reinforcement bar (22)thatfacesawayfrom the tank(21),and- at least some of the chambers (16) are air-tight.2.The acousticpanelaccording to claim 1,wherein sub-volumes of the chambers (16) are select ed suchthat the acoustic panel comprises a specific acoust icdampening frequencyband.

3. The acoustic panel according to any one of the p recedingclaims,wherein the chambers (16) have a thickness in a ran ge from5 mm to 300 mm.

4. The acoustic panel according to any one of the p recedingclaims,wherein the acoustic panel (1) comprises a rib stru cture (17)that extends at least in regions from the outer pla te (12) tothe innerplate (11). P2024,0669 WO N / P240067WO01 September22,2025 -24 -5. The acoustic panel according to claim 4, wherein th e ribstructure (17)subdividesthe volume (13)into the pluralityof chambers, wherein the rib structure (17) extends from theouterplate (12)to the innerplate (11).

6. The acoustic panel according to any one of the p recedingclaims,wherein at least some of the chambers (16) are free from afilling material.7.The acousticpanelaccording to claim 1 or2,wherein at least some of the chambers (16) are fill ed with afilling material (14), wherein a density of the fil lingmaterial (14) is in a range from 5 kg / m³ to 500 kg / m³.

8. The acoustic panel according to any one of the p recedingclaims,wherein the acoustic panel (1) comprises a mounting region(15) for mounting the acoustic panel (1), wherein t hemounting region (15)laterallyprojectsbeyond the inner plate (11).

9. An electric appliance comprising an acoustic pan el (1)according to anyone ofthe preceding claimsand a tank(21),wherein the tank (21) comprises a plurality of rein forcementbars (22) arranged on an outer wall of the tank (21 ) andwherein the acoustic panel (1) is mounted to at lea st one ofthe reinforcement bars (22) wherein the inner plate of theacoustic panel (1) is located closer to the outer w all (210)of the tank (21) than a surface of the reinforcemen t bar (22)thatfacesawayfrom the tank(21). 10.The electricappliance according to claim 9, P2024,0669 WO N / P240067WO01 September22,2025 -25 -wherein the acoustic panel (1) comprises a mounting region(15) that overlaps with one of the reinforcement ba rs (22),wherein a sealing and / ordamping material(222)is arrangedbetween the mounting region (15) and the reinforcem ent bar(22). 11.The electricappliance according to claim 9 or 10, wherein a distance between the innerplate (11)of the acousticpanel(1)and the outerwall(210)ofthe tank(21) isin a range from 0 mm to 500 mm.

12. A method of assembling an electric appliance (2 ),comprising the steps of:a)providing an electricpowerdevice (20);b) forming a tank (21) that extends around the elec tric powerdevice (20), wherein the tank (21) comprises a plur ality ofreinforcement bars (22) arranged on an outer wall ( 210) ofthe tank(21);and c)mounting an acousticpanel(1)according to any one of claims1 to 8 to atleastone ofthe pluralityofreinforcement bars (22) wherein the inner plate (21 ) of theacoustic panel (1) is located closer to the outer w all (210)of the tank (21) than a surface (220) of the reinfo rcementbar(22)thatfacesawayfrom the tank(21). 13.The method according to claim 12, wherein step c)isperformed priorto step b). 14.The method according to claim 12 or13, wherein an electricappliance (2)according to any one of claims9 to 11 isproduced.

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