Abstract:
A baffle arrangement for a genset enclosure is disclosed. The genset enclosure may include an opening in a side of the enclosure and a plurality of baffles internally supported in the enclosure between the opening and a radiator portion. The baffles may be positioned in a sound path to reflect a sound transmitted along the sound path. A method for reducing sound in a genset enclosure is also disclosed. The method may include arranging a plurality of baffles within the enclosure between an opening and a radiator portion, the baffles being positioned in a sound path to reflect a sound transmitted along the sound path.

Description:
PRIORITY 
     This is a U.S. National Stage Application under 35 U.S.C. §371 based on International Application No. PCT/EP2008/066302, filed Nov. 27, 2008, which is incorporated herein by reference in its entirety and for which priority is claimed. 
     TECHNICAL FIELD 
     This disclosure relates generally to enclosures for an engine-generator set. More particularly, the disclosure relates to the attenuation of sound emitted from the enclosure during operation of an engine-generator set. 
     BACKGROUND 
     An engine-generator or a genset may be a combination of an engine and a generator. Both components may be mounted together to form a single machine. A genset may provide electricity at various locations such as construction sites or emergency response sites. Generally, a genset may provide electricity for apartments, office buildings, hotels and hospitals. 
     A genset may be a small person-portable device or a larger device that may be mounted on a skid or a trailer, depending on the requirements and location, and the amount of power that is needed for a particular use. Often, a genset may be mounted within an enclosure, such as a removable shroud or cover. 
     Within the enclosure, adequate ventilation and cooling may be required to dissipate heat generated by the genset components for reliable operation of the genset. Generally, heat, from a genset, may be dissipated by natural convection. For instance, heat may be dissipated from an engine mounted radiator which may be cooled by air flowing through a compartment in the enclosure. An air flow may be usually produced by a radiator fan. 
     Besides heat, noise or sound may be also generated by the engine, by the generator and by the exhaust, and it is obviously desirable to keep such sound emissions as low as possible. Local authorities may also set sound regulations, which may include limits on maximum sound emissions. Hence, the sound emission from the genset enclosure may need to be within the maximum sound limits in order to operate legally. The enclosure may block or attenuate sound emanating from the engine or other genset components. 
     In order to provide adequate cooling within the genset enclosure, it may be necessary to provide openings within the enclosure for ventilation. Hence, sound may be emitted through the openings. In some genset enclosures, the radiator may be located near an opening to facilitate airflow through the enclosure. 
     To reduce sound emission through the openings, the number or size of openings in the compartment may be decreased. However, the air flow may decrease to a level where the cooling effect may be also reduced, resulting in an increase in temperature within the enclosure. This may adversely affect temperature sensitive components, such as an alternator, a fuel injection system, and various electronic components, such as microprocessors. A solution may be to increase the air flow by providing a fan which has a high rotational speed. However, the increase in fan speed may result in more noise being produced from the engine compartment. 
     Sound may also be reduced by lowering the fan speed or lowering engine output. However, such actions may decrease the overall efficiency of the machine. Sound dampers may be used to reduce or avoid the transmission of sound. The genset enclosure may be lined with sound dampers, which may either absorb or reflect the noise. 
     It is desirable to provide adequate ventilation through a genset enclosure with a minimal emission of sound from the genset enclosure. The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of the prior art system. 
     BRIEF SUMMARY OF THE INVENTION 
     In a first aspect, the present disclosure describes a baffle arrangement for a genset enclosure comprising: an opening in a side of the enclosure; and a plurality of baffles internally supported in the enclosure between the opening and a radiator portion, the baffles positioned in a sound path to reflect sound transmitted along the sound path. 
     In a second aspect, the present disclosure describes a method for reducing sound in a genset enclosure comprising: arranging a plurality of baffles within the enclosure between an opening and a radiator portion, the baffles being positioned in a sound path to reflect a sound transmitted along the sound path. 
     Other features and advantages of the present disclosure will be apparent from the following description of various embodiments, when read together with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features and advantages of the present disclosure will be more fully understood from the following description of various embodiments, when read together with the accompanying drawings, in which: 
         FIG. 1  is an isometric view of a partially assembled genset enclosure including a baffle arrangement according to the present disclosure; 
         FIG. 2  is a side view of a partially assembled genset enclosure including a baffle arrangement according to the present disclosure; and 
         FIG. 3  is a schematic representation of genset components and a baffle arrangement in a genset enclosure, according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure generally relates to a baffle arrangement for a genset enclosure. The baffle arrangement may allow ventilation or air flow through the enclosure and minimize sound emission from genset components. 
     With reference to  FIG. 1 , a genset enclosure  10  may comprise an embodiment of a baffle arrangement  12 . The enclosure  10  may be bound by walls  14 . The walls  14  may be of any suitable material and shape as required to contain the genset. 
     Walls  14  may have at least two openings to permit an airflow through the enclosure  10 . A first opening may be an inlet and a second opening may be an outlet  18 . The inlet and outlet  18  may allow the interior of the enclosure  10  to communicate with air space external thereto. The openings may allow passage of air into and out of the enclosure  10 . The openings may be formed on any wall  14  or may be in any suitable position on the walls  14  of enclosure  10 . The openings may include a matrix or a grid of holes to prevent passage of objects larger than the size of the holes. 
     In one embodiment, the inlet and the outlet  18  may be formed on multiple adjacent walls  14 , for instance an outlet  18  may be formed in a corner of the enclosure, which may be a junction of three walls  14 . The outlet  18  formed on a wall  14  may define a single plane. An outlet  18  formed on multiple adjacent walls  14  may define multiple planes, each plane corresponding to a wall  14 . 
     An air passage  20  may be formed within the interior of the enclosure  10  and may be enclosed by walls  14 . Ambient air external the enclosure  10  may enter through the inlet flow through the interior of the enclosure  10  along the air passage  20  and may exit through outlet  18 . 
     The enclosure  10  may be divided into portions or sections to receive the genset or components of a genset. The sections or portions may be within the air passage  20  such that air flowing through the air passage  20  flows over the genset positioned within the sections or portions. The genset may comprise a radiator for transfer of heat to the air flowing through the air passage  20 . The genset may comprise a fan wherein rotation of the fan draws air in through the inlet and forces air out of through the outlet  18  thereby driving circulation of the air through the air passage  20 . 
     In one embodiment, the section or portion  21  of the enclosure  10  which receives the radiator may be adjacent to the outlet  18  or the plane of the outlet  18 . In another embodiment the radiator section or portion  21  which receives the radiator may be normal to the outlet  18  or the plane of the outlet  18 . In the embodiment where the outlet  18  may be formed on multiple adjacent walls  14 , the radiator section or portion  21  may be normal to at least one plane of the outlet  18 . 
     With reference to  FIGS. 1 and 2 , one embodiment of a baffle  22  of the baffle arrangement  12  may comprise a body portion  24  and coupling portion  28 . Baffle  22  may further comprise an incline portion  26 . 
     Body portion  24  may be a panel, and an edge of the body portion  24  may be positioned transverse to the opening  18 . Body portion  24  may be of a suitable length to extend across the outlet  18 . 
     At both ends, body portion  24  may be connected to coupling portions  28 . Body portion  24  may have a rigid connection to the coupling portions  28 . Coupling portions  28  may have a triangular shape. In one embodiment, the coupling portions may comprise at least a connection edge  30  and a mounting edge  32 . 
     Mounting edge  32  may be mounted to a support within the air passage  20 . The support may be a wall  14 , or a flange or bracket projecting from a wall  14 . Mounting edge  32  may be mounted directly or indirectly through a flange or bracket to the wall  14  having the outlet  18  or to an adjacent wall  14 . Mounting edge  32  may be fixedly or removably mounted to the support. 
     Body portion  24  of baffle  22  may be oblique to the plane of outlet  18  and may form an angle α relative to the plane of outlet  18 . In one embodiment the angle α may range from 40° to 80°. In another embodiment the angle α may range from 50° to 70°. In a further embodiment the angle α may be 60°. In an assembled genset enclosure, the body portion  24  may incline away from the radiator portion  21 . 
     Body portion  24  may be configured to be rotatable relative to coupling portions  28 . Body portion  24  may have an angle α ranging from 0° to 90° relative to the plane of outlet  18 . In another embodiment angle α may range from 50° to 70°. 
     Body portion  24  may be formed as a series of vanes which may be fixed or rotatable. Each vane may have an angle α ranging from 0° to 90° relative to the plane of outlet  18 . In another embodiment angle α of the vanes may range from 50° to 70°. Connection edge  30  may connect to the body portion  24 . Connection edge  30  may have an angle relative the plane of the opening which corresponds to an angle α. 
     Incline portion  26  may be rigidly connected to an edge of body portion  24 . In an assembled genset enclosure, the incline portion  26  may incline toward the radiator portion  21 . Incline portion  26  may be oblique to the body portion  24  and may form an angle β relative thereto. In one embodiment, the angle β may range from 90° to 140°. In another embodiment, the angle β may range from 100° to 130°. In a further embodiment, the angle β may be 120°. 
     Incline portion  26  may be pivotably connected to an edge of body portion  24 . The incline portion  26  may form an angle β relative thereto. In one embodiment the angle β may range from 80° to 140°. In another embodiment the angle β may range from 100° to 130°. Baffle  22  may be mounted within air passage  20  such that air flowing through the air passage  20  may flow over the baffle  22  prior to exit through the outlet  18 . 
     Baffle  22  may be composed of suitable materials for instance, galvanised steel, stainless steel or aluminium. Baffle  22  may be lined with a sound absorbent material, for instance foam. In one embodiment, baffle  22  may have 30 mm of foam. The sound absorbent material may be on the sides of body portion  24  and the incline portion  26  that face the radiator portion  21  of the enclosure  10 . 
     The baffle arrangement  12  may comprise a plurality of baffles  22 . The baffles  22  may be mounted to the support, through mounting edge  32 , within the air passage  20 . Each baffle  22  may be parallel to the adjacent baffle  22 . The plurality of baffles  22  across the outlet  18  may form a series of inclined channels between the baffles  22 . The channels direct the flow of air from the air passage  20  to the outlet  18 . 
     In one embodiment, the baffle arrangement  12  may comprise from 2 to 10 baffles  22 . In another embodiment, the baffle arrangement  12  may comprise from 4 to 8 baffles  22 . The number of baffles  22  may be a function of the angle α. In the embodiment where angle α or the angle of the vanes is 60°, the baffle arrangement  12  may have 4 baffles  22 . 
     The baffle arrangement  12  may have an even spacing between baffles  22  along the outlet  18 . In one embodiment, baffle arrangement  12  may have a varying spacing between baffles  22  along the outlet  18 . The spacing between the baffles  12  may increase between each consecutive pair of baffles  22 . In another embodiment, the spacing between each consecutive pair of baffles  22  may increase as the distance of the baffles  22  from the radiator portion  21  increases. In yet another embodiment, the spacing between each consecutive pair of baffles  22  may increase in proportion relatively to the increase in distance of the baffles  22  from the radiator portion  21 . 
     In the baffle arrangement  12 , a baffle  22  may extend over or overlap a portion of an adjacent baffle  22  in the direction of inclination of body portion  24 . The degree of overlap between adjacent baffles  22  may be a function of the spacing between the baffles  22  and the angle of inclination of body portion  24 . The series of overlapping baffles  22  in a baffle arrangement  12  may screen a part of the interior of the enclosure  10  from the outlet  18  of the enclosure  10 . In one embodiment, the baffle arrangement  12  may form a screen between the outlet  18  and the radiator portion  21 . 
     Baffles  22  may be connected together to pre-form the baffle arrangement  12 . The pre-formed baffle arrangement  12  may be connected, by any suitable means, to the outlet  18 . In one embodiment, the pre-formed baffle arrangement  12  may be removably coupled to a wall  14  or to a flange or bracket projecting from a wall  14 , at the outlet  18 . In another embodiment, the pre-formed baffle arrangement  12  may be fixedly mounted to a wall  14  or bracket projecting from a wall  14 , at the outlet  18 . 
     With reference to  FIG. 3 , a source of sound or noise in a genset  34  may be components of the genset, for instance the radiator  38 , more particularly the radiator fan  36 . Sound produced by the fan  36  may be transmitted from the radiator portion  21  along a sound path towards the outlet  18  and out to the area external the enclosure  10 . The sound path may be a route of sound from the source, for instance the fan  36 , to a destination, for instance the outlet  18 . The route of sound may be a straight-line route between the source and the outlet  18 . 
     A baffle  22  or a baffle arrangement  12  may be positioned in a sound path between the outlet  18  and the radiator portion  21 . The placement of the baffle  22  or the baffle arrangement  12  in the sound path is such that sound travelling along the sound path may be reflected. The baffle  22  or baffle arrangement  12  may prevent a direct transmission of sound from the source to the outlet  18 . In one embodiment, baffle  22  or baffle arrangement  12  may reflect the sound travelling in the sound path into the enclosure  10 . 
     The position of the baffle  22  or the baffle arrangement  12  relative to outlet  18  may determine the rate of air flow and the level of sound emission. In one embodiment, the baffle  22  or baffle arrangement  12  may be positioned in proximity to the outlet  18 . In a further embodiment, the baffle  22  or the baffle arrangement  12  may be positioned at the outlet  18 . 
     In operation, fan  36  circulates air through the air passage  20 . Air flowing through the air passage  20  may convey heat absorbed from the radiator  38  through the outlet  18  and out from the enclosure  10 . 
     A baffle arrangement  12  may be positioned in the air passage  20  between the outlet  18  and the radiator portion  21  of the enclosure  10 . Baffle arrangement  12  may permit the flow of heated air through the channels formed between the baffles  22 . The baffle arrangement  12  may reflect sound produced by the genset components, for instance the radiator fan  36 , and thereby restrict the level of sound emitted, through the outlet  18 , from the genset during operation thereof. 
     The skilled person would realise that foregoing embodiments may be modified or combined to obtain the baffle  22  or the baffle arrangement  12  of the present disclosure 
     Industrial Applicability 
     This disclosure describes baffles  22  and baffle arrangements  12  for controlling sound transmission from a sound source to areas external to the genset enclosure  10 . The baffle arrangement  12  according to the present disclosure may reflect sound from a source away from an outlet  18  of an enclosure  10 . The baffle arrangement  12  may reflect sound travelling a transmission sound path from the sound source to the outlet  18  and may allow ventilation of the enclosure  10  and cooling of the radiator  38  by the air flow through air passage  20 . 
     The incline portion  26  may be provided as an aerodynamic leading edge to the baffle  22  to minimize restriction to airflow. In an embodiment, incline portion  26  may be provided as an aerodynamic leading edge to the baffle  22  to minimize restriction to airflow when the sound absorbent foam is attached to body portion  24 . 
     The baffle arrangement  12  according to the present disclosure may be suitable for genset enclosures. The industrial applicability of the baffle arrangement  12  as described herein will have been readily appreciated from the foregoing discussion. 
     Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein. 
     One skilled in the art will realise the disclosure may be embodied in other specific forms without departing from the disclosure or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the disclosure described herein. Scope of the invention is thus indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalence of the claims are therefore intended to be embraced therein.