Classifications

• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
  • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B63/00—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices
  • F02B63/04—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices for electric generators
  • F02B63/044—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices for electric generators the engine-generator unit being placed on a frame or in an housing
  • F02B2063/045—Frames for generator-engine sets

Definitions

• the present invention relates to a generator set comprising an internal combustion piston engine, an electric generator mechanically coupled with the internal combustion piston engine so as to receive power to rotate the electric generator and a common base frame which the internal combustion piston en- gine and the electric generator are supported on and attached to according to the preamble of claim 1 .
• An object of the invention is to provide a generator set in which attenua- tion of noise to the surrounding air is considerably improved compared to the prior art solutions. Disclosure of the Invention
• a generator set comprising an internal combustion piston engine, an electric generator mechanically coupled with the internal combustion piston engine, is provided with a common base frame, which is provided with plurality of resonator units comprising a bordered resonator space, which resonator space is provided with at least one communi- cation port so as to allow communication between the resonator space and its surroundings.
• the resonator units are integrated or attached to the source of noise. Even the large generator set is in a building the walls of which may attenuate the noise to some extent, by means of the pre- sent invention it is possible to decrease the noise level already in the building. Also, this way the resonator units effect to the direct noise wave from the source and not so much to noise reflected from the walls of the building.
• the resonator unit is a Helm- holtz resonator in which the resonator space is arranged in communication with the surroundings via at least one neck as a communication port.
• the resonator space corn- prises an air filled resonator space.
• the resonator space is at least partially formed by the structure of the base frame. This provides a further effect of inter alia material savings and results in a compact structure.
• the resonator unit is prefab- ricated resonator unit, separate to, and removably attached to the base frame. This provides a further effect of making it possible to assemble the resonator units into existing generator sets.
• the resonator unit is a per- forated wall noise absorber in which the resonator space is arranged in commu- nication with the surroundings via a perforation in at least one wall of the resona- tor unit.
• the generator set comprises more than two resonator units, each tuned to attenuate a same frequency.
• the generator set comprises a first set of resonator units tuned to attenuate a first frequency, and a second set of resonator units tuned to attenuate a second frequency.
• the resonator unit advanta- geously is tuned to attenuate a frequency corresponding to the firing frequency of the internal combustion piston engine.
• the generator set comprises a computer controller unit configured to run the engine at constant speed (RPM), and internal combustion piston engine is a four-stroke engine and the resonator unit is tuned to attenuate a first frequency
• RPM is the constant speed in revolutions per minute
• C is the number of cylinders.
• the generator set corn- prises a computer controller unit configured to run the engine at constant speed (RPM), and that internal combustion piston engine is a four-stroke engine and the resonator unit is tuned to attenuate
• F1 is the first frequency
• F2 is the second frequency
• RPM is the constant speed in revolutions per minute
• C is the number of cylinders.
• Figure 1 illustrates a side view of a generator set provided with a base frame according to an embodiment of the invention
• Figure 2 illustrates a front view of a generator set provided with a base frame according to an embodiment of the invention
• Figure 3 illustrates a detail of a base frame according to an embodiment of the invention
• Figure 4 illustrates a detail of a base frame according to another embodiment of the invention
• FIG. 5 illustrates a front view of a generator set provided with a base frame according to another embodiment of the invention.
• Figures 1 and 2 depict schematically an internal combustion piston en- gine 10 which is coupled with an electric generator 12 together forming a gener- ator set 14.
• Figure 1 shows a side view of the generator set 14 and an end view II of the generator set in the direction of the arrow in the left margin of the Figure 1 is shown in the Figure 2.
• the internal combustion piston engine 10 and the electric generator 12 of the generator set 14 are mechanically coupled with each other via drive shafts using a suitable coupling so as to transmit power from the engine to rotate the electric generator 12.
• the generator set has a common base frame 16 on which the internal combustion piston engine 10 and the electric gen- erator 12 are supported, and also releasably attached to the base frame 16.
• the base frame 16 is constructed of suitable steel such that it comprises at least two parallel longitudinal beams 18.1 , 18.2 substantially parallel with the longitudinal direction of the engine 10.
• the longitudinal beams 18.1 and 18.2 are coupled with each other e.g. by means of cross-beams 18.3 at least at the ends of the longitudinal beams 18.1 , 18.2 of suitable length providing suitable distance between the longitudinal beams for rigidly supporting the engine 10 and the gen- erator 12 as desired.
• the base frame 16 of the generator set 14 is provided with plurality of resonator units 20 configured to attenuate noise generated by the generator set when in use.
• the resonator unit are tuned to attenuate low frequency noise having frequency below 200 Hz.
• the engine is configured to run at constant speed when in use, and therefore the noise emitted from the gener- ator set 14 a substantially constant frequency spectrum.
• the resonator units are configured, or tuned, to attenuate noise at certain frequency, which ef- fectively attenuates the noise right where it is generated, that is in close proximity to the engine 10 of the generator set 14.
• the resonator unit 20 comprises a bor- dered resonator space 22, which may be referred to as a resonator cavity as well, which is filled only with the air, thus being a reactive noise absorber.
• Each reso- nator space is provided with at least one communication port 24 so as to allow communication between the resonator space and its surrounding air.
• the longitudinal beams 18.1 , 18.2 form a vertical wall of the base frame at its sides, and is therefore called as a side wall.
• the side wall is otherwise solid, except that there is the at least one communication port 24 arranged to the wall.
• the resonator space 22 is inside the longitudinal beam 18.1 , 18.2, 18.3, under the engine 10 and the electric generator 12. In the embodiments of the Figures 1 to 3 the resonator space 22 is at least partially formed and bordered by the structure of the base frame 16.
• the base frame 16 is provided with intermediate walls 26 and an end wall 28 which border the number of resonator cavities 22 in the base frame 16.
• the intermediate walls 26 are substantially perpendicular to the vertical side wall of the longitudinal beams 18.1 , 18.2 and the end wall 28 is parallel to the vertical side wall of the longitudinal beams 18.1 , 18.2.
• Advanta- geously the number of separate resonator units 20 in the base frame 16 is at least twenty units 20. This way an effective combined attenuation effect of the noise can be obtained practically without consuming extra space for the purpose.
• the base frame 16 is provided with a plurality of separate resonator units 20.
• the resonator unit 20 shown in the Figures 1 to 3 is a Helmholtz resonator in which the resonator space 22 is ar- ranged in communication with the surrounding air via at least one neck 32 as a communication port 24.
• the neck 32 may be a tube or a channel of other suitable cross sectional area, such a square or quadrangle, or alike.
• the dimensioning of a Helmholtz resonator to attenuate a selected frequency is known as such for a skilled person in the art.
• the resonator units are tuned to attenuate noise at a same frequency.
• the resonator units are tuned to attenuate a firing frequency of the internal combus- tion piston engine.
• the generator set 14 comprises a first set of resonator units 20.1 tuned to attenuate a first fre- quency, and a second set of resonator units 20.2 tuned to attenuate a second frequency.
• the first and the second frequency are different frequencies.
• the first frequency is a firing frequency of the internal com- bustion piston engine and the second frequency is a second order harmonics of the firing frequency.
• the generator set comprises a computer controller unit which is configured to run the engine at constant speed (RPM), and the internal combustion piston engine is a four-stroke engine and the resonator unit is tuned to attenuate a first frequency
• F1 is the first frequency
• RPM is the constant speed in revolutions per minute
• C is the number of cylinders.
• the first frequency is
• F1 is the first frequency
• F2 is the second frequency
• RPM is the constant speed in revolutions per minute
• C is the number of cylinders [0030] For example, when a four stroke engine having 18 cylinders runs at 750
• the resonator unit is a perforated wall noise absorber in which the reso- nator space is arranged in communication with the surroundings via a perforation in at least one wall of the resonator unit 20.
• the resonator unit is a separate prefabricated resonator unit 20’. This embodiment is disclosed in the Figure 4.
• the prefabricated resonator unit 20’ is an individual entity which has a body with the resonator space and one or more a communication ports 24. Such a prefab- ricated resonator unit 20’ is removably attached to the base frame 16. As can be seen from the Figure 4 when using prefabricated resonator unit 20’ the commu- nication port may open into a space under the engine 10 and the electric gener- ator 12.
• Figure 4 also illustrates the aspect of the invention according to which the generator set 14 comprises a first set of resonator units 20. T tuned to atten- uate a first frequency, and a second set of resonator units 20.2’ tuned to attenu- ate a second frequency. The first and the second frequency are different frequen- cies. Even if not shown, also in this embodiment the base frame may be provided with openings through which the communication ports 24 are in connection with the surrounding air.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Multimedia (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

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Publications (2)

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• 2018
  • 2018-10-10 EP EP18789024.9A patent/EP3864648B1/de active Active
  • 2018-10-10 WO PCT/EP2018/077543 patent/WO2020074074A1/en active Search and Examination

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