DK172125B1

DK172125B1 - Turbocharged internal combustion engine

Info

Publication number: DK172125B1
Application number: DK025494A
Authority: DK
Inventors: Per Roennedal; Jens Hoejgaard
Original assignee: Man B & W Diesel Gmbh
Priority date: 1994-03-04
Filing date: 1994-03-04
Publication date: 1997-11-17
Also published as: KR100369508B1; KR950033000A; DK25494A; JP3448124B2; JPH07259672A

Description

i DK 172125 B1in DK 172125 B1

Opfindelsen angår en turboladet forbrændingsmotor, navnlig en stor totakts krydshovedmotor, med en af udstødsgas drevet turbolader, hvis kompressor er forbundet med cylindrenes indsugningsside via et rør, 5 som udmunder i et gennemstrømningskammer, såsom en ladeluftkøler eller en ladeluftreceiver.The invention relates to a turbocharged internal combustion engine, in particular a large two-stroke cross-head motor, with an exhaust gas turbocharger, the compressor of which is connected to the inlet side of the cylinders via a pipe, which opens into a flow chamber, such as a charge air cooler or a charge air receiver.

Støjniveauet genereret ved motorens drift er af betydning for arbejdsforholdene i maskinrummet omkring motoren. Det er naturligvis ønskeligt, at støjniveauet 10 er så lavt som muligt, men en række motorkomponenter fremkalder støj. Turboladeren er en særlig kraftig støjkilde. Når kompressorhjulets skovle passerer forbi randen af udløbsåbningen klippes den udstrømmende luftmængde over, hvilket fremkalder tryksvingninger i 15 luften på kompressorens leveringsside. Disse tryksvingninger sætter den omgivende konstruktion i svingninger, hvilket fremkalder støj. Nyere turboladere har højere virkningsgrad og større trykforhold over kompressoren, hvilket fremkalder væsentlig højere støjniveau end 20 tidligere.The noise level generated by the engine operation is important for the working conditions in the engine room around the engine. Of course, it is desirable that the noise level 10 is as low as possible, but a number of engine components produce noise. The turbocharger is a particularly powerful source of noise. As the blades of the compressor wheel pass past the edge of the outlet opening, the outflow of air is cut, causing pressure fluctuations in the air on the delivery side of the compressor. These pressure oscillations put the surrounding structure into oscillations, causing noise. Newer turbochargers have higher efficiency and greater pressure ratios over the compressor, causing significantly higher noise levels than 20 before.

Støjen udstråles enten direkte fra turboladeren eller indirekte ved, at tryksvingningerne fra kompressoren transmitteres videre til de tilknyttede dele af motoren, som så udstråler støj. Støjdæmpning af et 25 motorelement kan principielt ske på to forskellige måder. Den primære, støjabsorberende metode består i at reducere niveauet for tryksvingninger inden i elementet, så elementet som helhed udstråler mindre støj, og den sekundære, støj isolerende metode består i at pakke 30 elementet ind i støjisolerende materiale.The noise is either radiated directly from the turbocharger or indirectly by the pressure fluctuations from the compressor being transmitted to the associated parts of the engine which then emit noise. Noise cancellation of a 25 engine element can in principle be done in two different ways. The primary noise absorbing method consists in reducing the level of pressure fluctuations within the element so that the element as a whole radiates less noise and the secondary noise insulating method consists of wrapping the element into noise insulating material.

Det rør, som forbinder kompressorens luftafgang med gennemstrømningskammeret, er normalt støjisoleret, men kan også være beklædt indvendigt med støjabsorberende materiale i tillæg til støjreduktionen ved hjælp 35 af den udvendige, støjisolerende indpakning af røret.The tube connecting the air outlet of the compressor to the flow chamber is normally noise insulated, but may also be lined internally with noise absorbing material in addition to the noise reduction by means of the outer, noise insulating package of the tube.

DK 172125 B1 2DK 172125 B1 2

Den primære støjreduktion i røret har også virkning i de mellem røret og motorens cylindre beliggende strømningselementer .The primary noise reduction in the pipe also has effect in the flow elements located between the pipe and the engine cylinders.

Opfindelsen har til formål at mindske støjen 5 udstrålet fra motorens indsugningssystem.The invention aims to reduce the noise 5 emitted from the engine intake system.

Med henblik herpå er ovennævnte motor ifølge opfindelsen ejendommelig ved, at et lyddæmpende legeme er beliggende ud for rørudmundingen og strækker sig således på tværs forbi denne, at legemet sammen med den 10 modstående omkring rørudmundingen beliggende kammervæg afgrænser en ringformet udløbsåbning.To this end, the aforementioned engine according to the invention is characterized in that a sound attenuating body is located adjacent to the pipe opening and extends transversely beyond it, that the body, together with the chamber wall located around the pipe opening, defines an annular outlet opening.

Når luften strømmer ud gennem rørudmundingen træffer den legemet, som blokerer for luftens bevægelse i rørets længderetning og afbøjer luftstrømningen ud 15 gennem den ringformede udløbsåbning. Når tryksvingningerne i røret træffer legemet, vil de i væsentlig grad reflekteres tilbage i røret i stedet for at udbredes videre ud i indsugningssytemets gennemstrømningskammer. Gennemstrømningskammeret har ofte så stort 20 volumen, at det vanskeligt kan pakkes ind med støjisolerende materiale på ydersiden. Det lyddæmpende legemes primære reduktion af tryksvingningerne i gennemstrømningskammeret er derfor særlig virkningsfuldt ved sådanne store motorelementer. Ved at begrænse tryksving-25 ningernes udbredelse til røret kan støjniveauet ud for indsugningssystemet mindskes til omkring halvdelen af den oprindelige lydstyrke. Denne store virkning opnås bl.a. i og med, at tryksvingningernes udbredelse til store motorelementer begrænses.As the air flows out through the pipe outlet, it engages the body which blocks the movement of the air in the longitudinal direction of the pipe and deflects the air flow out through the annular outlet opening. When the pressure fluctuations in the tube hit the body, they will be substantially reflected back into the tube rather than spreading further out into the intake chamber's flow chamber. The flow chamber is often so large that it can be difficult to wrap it with noise-insulating material on the outside. Therefore, the primary attenuation of the sound attenuation of the pressure fluctuations in the flow chamber is particularly effective in such large motor elements. By limiting the distribution of pressure fluctuations to the tube, the noise level next to the intake system can be reduced to about half of the original volume. This great effect is achieved, among other things. as the distribution of pressure fluctuations to large engine elements is limited.

30 I en foretrukken udførelsesform ligger legemet i en sådan afstand fra rørudmundingen, at den ringformede udløbsåbning har et gennemstrømningsareal af mindst samme størrelse som rørudmundingen. Ved at undgå en formindskelse af strømningsarealet umiddelbart efter 35 rørudmundingen begrænses ladeluftens trykfald ved 3 DK 172125 B1 passagen af det lyddæmpende legeme til et minimum. Med det lille trykfald undgås at sætte kompressorens trykforhold op. Som nævnt ovenfor ville et sådant øget trykforhold ellers føre til større støjudstråling fra 5 selve kompressoren.In a preferred embodiment, the body is at such a distance from the pipe opening that the annular outlet opening has a flow area of at least the same size as the pipe opening. By avoiding a reduction in the flow area immediately after the pipe opening, the charge drop pressure at the passage of the sound attenuating body is minimized. The small pressure drop prevents the compressor pressure ratio from being set up. As mentioned above, such an increased pressure ratio would otherwise lead to greater noise emission from the compressor itself.

I en særlig enkel udførelsesform er legemet et pladestykke, der holdes i afstand fra kammervæggen omkring rørudmundingen af flere stavformede afstandsstykker, der ligger fordelt langs pladens periferi.In a particularly simple embodiment, the body is a plate piece which is spaced from the chamber wall around the pipe opening by several rod-shaped spacers distributed along the plate periphery.

10 Afstandsstykkerne holder pladen fast uden nævneværdig forstyrrelse af luftstrømningen ud igennem den ringformede udløbsåbning. Det lyddæmpende legeme er enkelt at fremstille og meget lidt pladskrævende.10 The spacers hold the plate firmly without significant interference with the air flow through the annular outlet opening. The sound attenuating body is simple to manufacture and very little space consuming.

Legemet kan hensigtsmæssigt bære lydabsorberende 15 materiale på den side, der vender hen mod rørudmundingen. Når luftstrømmen rammer det lyddæmpende legeme, vil der i tillæg til reflektionen af tryksvingningerne tilbage i røret ske en lydabsorption, idet en del af tryksvingningerne opfanges i det absorberende materiale.Conveniently, the body may carry sound-absorbing material on the side facing the pipe outlet. When the airflow strikes the sound attenuating body, in addition to the reflection of the pressure fluctuations back into the tube, a sound absorption occurs, with a portion of the pressure fluctuations being trapped in the absorbent material.

20 Den lyddæmpende virkning ved denne absorption er optimal, fordi tryksvingningerne rammer stort set vinkelret ind i overfladen af det lydabsorberende materiale. En sådan effektiv absorption er ikke mulig ved hjælp af det lydabsorberende materiale på rørets 25 inderside, idet tryksvingningerne her udbredes i rørets længderetning parallelt med materialets overflade.The sound-attenuating effect of this absorption is optimal because the pressure fluctuations strike substantially perpendicularly to the surface of the sound-absorbing material. Such effective absorption is not possible by means of the sound-absorbing material on the inside of the pipe 25, since the pressure fluctuations are propagated here in the longitudinal direction of the pipe parallel to the surface of the material.

Den indbyrdes placering af turboladeren og de øvrige komponenterne i motorens indsugningssystem er afgørende for forløbet af røret. I de tilfælde, hvor 30 rørets længdeakse forløber skråt i forhold til rørudmundingens plan, kan det af pladshensyn være fordelagtigt, at det lyddæmpende legeme forløber parallelt med rørudmundingens plan. For at opnå effektiv lyddæmpning foretrækkes, at legemet i dette tilfælde ligger således 35 excentrisk i forhold til rørudmundingen, at en frem- DK 172125 B1 4 bringer for rørfladen kan aftegne en lukket kurve på legemet. Frembringeren repræsenterer en fiktiv forlængelse af rørets sidevæg ud på den anden side af rørudmundingen. Når luften træder ud af røret, vil den 5 umiddelbart fortsætte med samme strømningsretning som inden i røret. Når en frembringer for rørf laden kan aftegne en lukket kurve på legemet, tvinger dette luften til at ændre retning over hele strømningstværsnittet, så det undgås, at tryksvingningerne visse steder kan 10 passere forbi det lyddæmpende legeme. Strømningen gennem den ringformede udløbsåbning bliver mere ensartet, hvis rørets længdeakse i det væsentlige skærer legemets arealtyngdepunkt.The mutual positioning of the turbocharger and the other components of the engine intake system is crucial for the course of the pipe. In cases where the longitudinal axis of the pipe extends obliquely with respect to the plane of the pipe opening, it may be advantageous for space reasons that the sound attenuating body extend parallel to the plane of the pipe opening. In order to achieve effective sound attenuation, it is preferred that in this case the body is so eccentric with respect to the pipe opening that a forward curve for the pipe surface can mark a closed curve on the body. The generator represents a fictitious extension of the side wall of the tube to the other side of the tube opening. As the air exits from the tube, it will immediately proceed with the same flow direction as inside the tube. When a platen bar can produce a closed curve on the body, this forces the air to change direction over the entire flow cross-section, so that the pressure fluctuations in certain places cannot pass past the sound attenuating body. The flow through the annular outlet opening becomes more uniform if the longitudinal axis of the tube substantially intersects the area of gravity of the body.

Hvis pladsforholdene omkring rørudmundingen er 15 snævre, foretrækkes, at legemet er en plan plade, der ligger parallelt med og i afstand fra rørudmundingen.If the space conditions around the pipe opening are 15 narrow, it is preferred that the body is a flat plate which is parallel to and spaced from the pipe opening.

Et sådant legeme er meget lidt pladskrævende og kan som oftest indbygges ved rørets tilslutningsflange uden øvrige ændringer i den omgivende konstruktion.Such a body is very little space consuming and can usually be built into the pipe connection flange without any other changes in the surrounding structure.

20 Det foretrækkes, at det lyddæmpende legeme ligger så tæt på kompressoren som praktisk muligt, hvilket hensigtsmæssigt kan ske ved, at det lyddæmpende legeme er beliggende ved ladeluftkølerens luftindløb ud for røret, som forbinder kompressorens luftafgang med 25 ladeluftkølerens lufttilgang.It is preferred that the sound attenuating body be as close to the compressor as practicable, which may be convenient in that the sound attenuating body is located at the air inlet of the charge cooler outside the pipe connecting the air outlet of the compressor with the air inlet of the charge cooler.

Eksempler på udførelsesformer for opfindelsen forklares herefter nærmere med henvisning til den skematiske tegning, hvor fig. 1 og 2 viser en stor totakts turboladet 30 krydshovedmotor i henholdsvis endebillede og opstalt, fig. 3 en første udførelsesform for det lyddæmpende legeme ifølge opfindelsen, i sidebillede, fig. 4 i større skala et udsnit af legemet i fig.Examples of embodiments of the invention will now be explained in more detail with reference to the schematic drawing, in which fig. 1 and 2 show a large two-stroke turbocharged 30 cross-head motor in end view and elevation respectively; 3 is a side view of a first embodiment of the sound attenuating body according to the invention; FIG. 4 shows on a larger scale a section of the body of FIG.

3' 5 DK 172125 B1 fig. 5 en anden udførelsesform for det lyddæmpende legeme ifølge opfindelsen, set fra linien V-V i fig. 6, °g fig. 6 et planbillede visende beliggenheden af 5 rørudmundingen i forhold til legemet i fig. 5.3 '5 DK 172125 B1 fig. 5 shows another embodiment of the sound attenuating body according to the invention, seen from line V-V in FIG. 6, g FIG. 6 is a plan view showing the location of the pipe opening relative to the body of FIG. 5th

En stor totakts forbrændingsmotor 1 af krydshovedtypen kan anvendes som fremdrivningsmotor i et skib eller som stationær kraftproducerende motor. Motorens cylindre 2 afleverer gennem en udstødspassage 3 ud-10 stødsluften til en udstødsreceiver 4, der udligner tryksvingninger fra de enkelte cylindre og leder luften til et turbineindløb 5 på en turbolader 6. Motoren kan have én eller flere turboladere, alt efter motoreffekten og antallet af cylindre. I den viste motor med seks 15 cylindre er der to turboladere. Fra turbinen bortledes udstødsgassen gennem en ikke-vist udstødsledning.A large two-stroke internal combustion engine 1 of the crosshead type can be used as a propulsion engine in a ship or as a stationary power producing engine. The engine cylinders 2 deliver an exhaust air through an exhaust passage 3 to an exhaust receiver 4 which equalizes pressure fluctuations from the individual cylinders and directs the air to a turbine inlet 5 on a turbocharger 6. The engine can have one or more turbochargers, depending on the engine power and the number of cylinders. In the engine shown with six 15 cylinders there are two turbochargers. The exhaust gas is discharged from the turbine through an exhaust pipe not shown.

Turbinen driver en kompressor, som komprimerer motorens indsugningsluft til det ønskede tryk. Indsugningsluften virker både som skylle- og ladeluft, og 20 benævnes for nemheds skyld herefter som ladeluft. Fra et kompressorudløb 7 sendes luften gennem et rør 8 (se fig. 2), som leder luften til et gennemstrømningskammer, der som vist kan være en ladeluftkøler 9. Køleren afleverer luften til et andet gennemstrømningskammer i 25 form af en ladeluftreceiver 10, hvorfra luften gennem et ikke-vist rør passerer ind i et gennemstrømningskammer i motorstativets cylinderparti 11, hvorfra luften gennem skylleluft-slidser i cylinderforingens sidevæg kan strømme ind i cylinderen. Hvis der i stedet for en 30 længdeskyllet totakts motor anvendes en firtakts motor, styres luftindstrømningen ved cylindrenes indsugningsside af indsugningsventiler.The turbine operates a compressor which compresses the intake air of the engine to the desired pressure. The intake air acts both as flushing and charging air, and 20 is hereafter referred to as charging air for convenience. From a compressor outlet 7, the air is passed through a pipe 8 (see Fig. 2) which conducts the air to a flow chamber, which as shown may be a charge air cooler 9. The cooler delivers the air to another flow chamber in the form of a charge air receiver 10, from which the air passing through a pipe (not shown) into a flow chamber in the cylinder portion 11 of the engine rack, from which the air can flow into the cylinder through the flushing air slots in the side wall of the cylinder liner. If a four stroke engine is used instead of a 30 length rinsed two stroke engine, the air inflow at the intake side of the cylinders is controlled by intake valves.

Det ses, at motoren på indsugningssiden omfatter flere gennemstrømningskamre, der er strømningsmæssigt 35 forbundet ved hjælp af rør. I fig. 3 ses et lyddæmpende 6 DK 172125 B1 legeme 12, der ligger ud for udmundingen af røret 8, som forbinder kompressorens luftafgang med lufttilgangen på ladeluftkøleren 9. Det er naturligvis muligt at anbringe et tilsvarende lyddæmpende legeme ud for de efter-5 følgende rørudmundinger, hvis der Ønskes yderligere støjdæmpning. For at begrænse trykfaldet i indsugningssystemet foretrækkes, at der kun findes ét lyddæmpende legeme 12 ud for udmundingen af røret fra kompressoren.It can be seen that the motor on the intake side comprises several flow chambers which are connected in flow by means of pipes. In FIG. 3, a sound attenuating 6 is seen, which corresponds to the outlet of the pipe 8, which connects the air outlet of the compressor with the air inlet of the charge air cooler 9. It is of course possible to place a corresponding sound attenuating body next to the subsequent pipe openings if additional noise reduction is required. In order to limit the pressure drop in the intake system, it is preferred that there is only one sound attenuating body 12 next to the outlet of the pipe from the compressor.

Med denne beliggenhed foretages lyddæmpningen tæt på 10 kompressoren. Det lyddæmpende legeme kan også ligge ud for kompressorudløbet, men med den viste placering ud for røret 8 kan opnås den særlige fordel, at en lydabsorberende isolering 13 på indersiden af røret 8 dæmper tryksvingningerne i røret og dermed også tryks-15 vingningerne reflekteret fra legemet 12. Hvis motoren ikke har en ladeluftkøler, kan det lyddæmpende legeme være beliggende ved luftindløbet til ladeluftreceiveren eller ved luftindløbet til cylinderpartiet.With this location the sound attenuation is made close to the 10 compressor. The sound attenuating body may also lie on the compressor outlet, but with the shown location next to the tube 8, the particular advantage can be obtained that a sound-absorbing insulation 13 on the inside of the tube 8 dampens the pressure fluctuations in the tube and thus also the pressure fluctuations reflected from the body 12 If the engine does not have a charge air cooler, the sound attenuating body may be located at the air inlet to the charge air receiver or at the air inlet to the cylinder portion.

I fig. 3 ses kun et udsnit af ladeluf tkølerens øvre 20 kammervæg 14, der på indersiden er beklædt med lydabsorberende materiale 15. Materialet 15 ligger beskyttet af en ringformet krave 16 omkring rørudmundingen.In FIG. 3, only a section of the upper air chamber cooler 14 of the charging air cooler 14, which is coated on the inside with sound absorbing material 15. The material 15 is protected by an annular collar 16 around the pipe opening.

Det lyddæmpende legeme 12 er ved hjælp af afstandsstykker 17 fikseret til kammervæggen 14 i en sådan 25 afstand A fra kraven 16, at gennemstrømningsarealet af en ringformet udløbsåbning 18 i det væsentlige svarer til gennemstrømningsarealet ved rørudmundingen. Arealet af den ringformede udløbsåbning kan groft taget beregnes som friafstanden A mellem legemet 12 og indersiden af 30 isoleringen på kammervæggen 14 multipliceret med periferilængden af rørudmundingen. I praksis kan arealet være lidt mindre som følge af, at den ringformede udløbsåbning er brudt ved holdere eller afstandsstykker. Udløbsåbningen kan udformes med større areal, hvis 35 pladsforholdene i kammeret tillader dette.The sound attenuating body 12 is fixed by means of spacers 17 to the chamber wall 14 at such a distance A from the collar 16 that the flow area of an annular outlet opening 18 corresponds substantially to the flow area at the pipe opening. The area of the annular outlet opening can roughly be calculated as the clearance distance A between the body 12 and the inside of the insulation on the chamber wall 14 multiplied by the peripheral length of the pipe opening. In practice, the area may be slightly smaller due to the annular outlet opening being broken by holders or spacers. The outlet opening can be designed with a larger area if the 35 room conditions in the chamber allow this.

7 DK 172125 B17 DK 172125 B1

Afstandsstykkerne 17 omfatter en gevindstang, som indskrues i et gevindhul i kammervæggen 14, hvorefter et afstandsdannende rør s tykke skubbes ind på gevindstangen, som derefter føres gennem et hul i legemet 12.The spacers 17 comprise a threaded rod which is screwed into a threaded hole in the chamber wall 14, after which a spacer tube thick is pushed into the threaded rod which is then passed through a hole in the body 12.

5 Legemet 12 spændes ind mod enden af rørstykket ved hjælp af et par møtrikker 19. Alternativt kan kammervæggen omkring rørudmundingen være forsynet med påsvejste bæreflanger, hvortil det lyddæmpende legeme 12 fikseres.The body 12 is clamped to the end of the pipe piece by a pair of nuts 19. Alternatively, the chamber wall around the pipe opening may be provided with welded support flanges to which the sound-damping body 12 is fixed.

Det lyddæmpende legeme 12 er opbygget af et 10 pladestykke 20, der på siden hen mod rørudmundingen er forsynet med et varmebestandigt lydabsorberende materiale 21, såsom glasuld, Rockwool (VM), opskummet plast eller et svampmateriale. Da indsugningsluften ved tilgangen til køleren er varm, beskyttes materialet 15 gennem indpakning i glasfibervæv 22, og den mekaniske styrke af det lydabsorberende materiale sikres ved hjælp af et rustfrit stålnet 23 anbragt omkring glasfibervævet. Nærmest rørudmundingen er der en perforeret plade 24, som beskytter det underliggende materiale.The sound attenuating body 12 is made up of a sheet plate 20, which is provided with a heat-resistant sound-absorbing material 21, such as glass wool, Rockwool (VM), foamed plastic or a sponge material, on the side towards the pipe opening. Since the suction air at the access to the cooler is hot, the material 15 is protected by wrapping in fiberglass tissue 22 and the mechanical strength of the sound absorbing material is ensured by means of a stainless steel mesh 23 arranged around the fiberglass fabric. Closest to the pipe opening is a perforated plate 24 which protects the underlying material.

20 Inden i røret 8 strømmer luften i en hvirvlende bevægelse hen mod rørudmundingen ved kraven 16. Efter passage af kraven 16 rammer luftstrømningen det lyddæmpende legeme 12, som tvinger luften til at ændre strømningsretning ud gennem udløbsåbningen 18, hvorfra 25 luften fortsætter ind i ladeluftkølerens indre. Når tryksvingningerne i luften rammer det lyddæmpende legeme, absorberes en del af svingningerne i det lydabsorberende materiale 21 på pladestykket 20, mens en anden del af tryksvingningen reflekteres tilbage i 30 røret 8.20 Inside the pipe 8, the air flows in a swirling motion towards the pipe outlet at the collar 16. After passage of the collar 16, the air flow impacts the sound attenuating body 12, which forces the air to change flow direction through the outlet opening 18, from which the air continues into the interior of the charge air cooler. . When the pressure fluctuations in the air hit the sound attenuating body, part of the fluctuations in the sound-absorbing material 21 is absorbed on the plate piece 20, while another part of the pressure fluctuation is reflected back into the tube 8.

I stedet for en plan plade 20 kan der benyttes en hvælvet plade, der set fra rørudmundingen kan være konkav for at koncentrere de reflekterede trykbølger i røret eller konveks for at lede den indstrømmende luft 35 skråt ind i det efterstillede kammer.Instead of a flat plate 20, a vaulted plate may be used which, viewed from the pipe opening, may be concave to concentrate the reflected pressure waves in the tube or convex to guide the inflowing air 35 obliquely into the subordinate chamber.

8 DK 172125 B1 I den efterfølgende beskrivelse af en anden udførelsesform anvendes sammen henvisningstal som ovenfor for elementer med samme funktion som i den første udførelsesform.In the following description of a second embodiment, reference numerals as above are used for elements having the same function as in the first embodiment.

5 Røret 8 er også i dette tilfælde fastgjort til den øvre kammervæg 14. Kammervæggen 14 er på ydersiden forbundet med en stiver 30, der sammen med andre holdere bærer køleren. Omkring rørudmundingen 31, hvis periferi er vist i fuld streg i fig. 6, er kammervæggen trinfor-10 met ved hjælp af et vægafsnit 14' . Kompressorudløbet har en sådan beliggenhed i forhold til ladeluftkølerens indløb, at røret forløber skråt hen mod kammervæggen 14.In this case, the tube 8 is also attached to the upper chamber wall 14. The chamber wall 14 is connected on the outside to a strut 30 which, together with other holders, carries the cooler. Around the pipe opening 31, the periphery of which is shown in full line in FIG. 6, the chamber wall is step-shaped by means of a wall section 14 '. The compressor outlet has such a position relative to the charge air cooler inlet that the pipe extends obliquely towards the chamber wall 14.

Rørets skrå forløb bevirker, at tryksvingningerne i luften efter passagen af rørudmund!ngen 31 udbredes 15 parallelt med rørets længdeakse 32. Det lyddæmpende legeme 12 har derfor en sådan størrelse og beliggenhed, at en frembringer for rørvæggen overalt vil træffe legemet 12. Den heraf følgende excentriske beliggenhed af legemet 12 i forhold til rørudmundingen 31 ses bedst 20 af fig. 6, hvor areal tyngdepunktet for rørudmundingen er markeret ved 33 og arealtyngdepunktet for legemet 12 ved 34. Det ses, at legemet 12 er cirkulært, men andre faconer kan naturligvis også anvendes, såsom en flerkantet facon. Beliggenheden af legemet 12 er valgt således, 25 at rørets længdeakse 32 skærer gennem arealtyngdepunktet 34.The sloping course of the pipe causes the pressure fluctuations in the air after the passage of the pipe opening 31 to be propagated 15 parallel to the longitudinal axis of the pipe 32. The sound-damping body 12 therefore has such a size and location that a generator for the pipe wall will take the body everywhere 12. eccentric location of the body 12 relative to the pipe opening 31 is best seen 20 of FIG. 6, where the area of gravity of the pipe opening is marked at 33 and the area of gravity of the body 12 at 34. It is seen that the body 12 is circular, but other shapes can of course also be used, such as a multilayered shape. The location of the body 12 is chosen such that the longitudinal axis 32 of the pipe intersects with the area of center of gravity 34.

I ovennævnte beskrivelse skal med rør blot forstås en strømningspassage, som leder hen til en udmunding, hvor luften strømmer ind i et kammer. Det støjdæmpende 30 legeme kan således også være anbragt ud for en udmunding i ladelu ft receiveren i tilfælde af, at køler og receiver er sammenbygget til en enhed uden egentlig mellemliggende rørforbindelse.In the above description, by pipe is meant only a flow passage leading to an outlet where the air flows into a chamber. Thus, the noise attenuating body 30 may also be disposed adjacent to an outlet in the charge-air receiver in the event that the cooler and receiver are assembled into a unit with no actual intermediate pipe connection.

Claims

9 DK 172125 B1

A turbocharged internal combustion engine (1), in particular a large two-stroke cross-head engine, with a turbocharger (6) powered by an exhaust gas, the compressor of which is connected to the 5-cylinder intake side via a pipe (8), which opens into a flow chamber such as a charge air cooler (9) or a charge air receiver (10), characterized in that a sound attenuating body (12) is located adjacent to the pipe opening (31) and extends transversely 10 thereof, so that the body, together with the opposing chamber wall (14), is delimited. an annular outlet opening (18).

Combustion engine according to claim 1, characterized in that the body (12) is at such a distance from the pipe opening that the annular outlet opening (18) has a flow area of at least the size of the pipe opening.

An internal combustion engine according to claim 1 or 2, characterized in that the body (12) is a plate piece 20 (20) spaced from the chamber wall (14) around the pipe opening of several rod-shaped spacers (17) distributed along plate periphery.

Combustion engine according to one of claims 1 to 3, characterized in that the body (12) carries 25 sound-absorbing material (21, 24) on the side facing the pipe outlet.

An internal combustion engine according to any one of claims 1-4, characterized in that the longitudinal axis (32) of the pipe extends obliquely to the plane of the pipe opening (33), and that the body (12) is so eccentric to the pipe opening that one produces for the pipe surface. can draw a closed curve on the body. 10 DK 172125 B1

Combustion engine according to claim 5, characterized in that the longitudinal axis (32) of the pipe substantially intersects the area's center of gravity (34).

Combustion engine according to one of the preceding claims, characterized in that the body is a flat plate which is parallel to and spaced from the pipe outlet.

Combustion engine according to one of the preceding claims, characterized in that the pipe (8) connects the air outlet of the compressor with the air inlet of the charge air cooler (9) and that the sound-damping body (12) is located at the air inlet of the charge air cooler.