NL2024674B1

NL2024674B1 - Noise insulated portable generator

Info

Publication number: NL2024674B1
Application number: NL2024674A
Authority: NL
Inventors: Arnoldus Antonius Wevers Bart; Elbertus De Graaf Dirkjan
Original assignee: Bredenoord Holding B V
Priority date: 2020-01-14
Filing date: 2020-01-14
Publication date: 2021-09-08

Abstract

Portable generators comprise an internal combustion engine for generating electricity. Such an engine then generates sound and heat. The sound is often undesired, and as such an insulated housing is provided around the engine. However, such an insulated housing makes it difficult to get rid of the heat, Which may cause overheating of the generator. The present invention provides a portable generator With two separate compartments, of Which one is arranged to be sound insulated, and the other compartment is a heat exchange compartment arranged to expel heat from the generator. The engine is provided in the sound insulated compartment, and a cooling unit is provided in the heat exchange compartment. Thermal energy is transferred using a fluid flow from the engine to the cooling unit, and via the cooling unit out of the generator such that overheating may be prevented.

Description

P121487NL00 Title: Noise insulated portable generator

FIELD OF THE INVENTION The invention relates to a portable generator.

BACKGROUND Portable generators are used to provide electric power at locations where no or insufficient power can be supplied by the main power grid.

These generators comprise a combustion engine arranged to covert chemical energy from a fuel such as diesel to rotational energy, and a generator for converting this rotational energy to electrical energy.

The internal combustion engine and generator are provided in a generator housing, which may be provided with sound insulation to reduce unwanted noise from leaking out of the housing into the environment.

SUMMARY In a portable generator, the combustion engine generates thermal energy and sound waves when the combustion engine is in use. There may be other components in the portable generator which generate one or both of thermal energy and sound waves, however the engine may be considered the main source of thermal energy and sound waves.

Sound insulation of a housing of a generator may be achieved by limiting air flow passages between the inside of the housing and the outside, as sound waves may travel through these air flow passages. However, some air flow into the housing is required for providing oxygen to the combustion engine. Air flow out of the housing may be beneficial for removing thermal energy from the housing as the air flow may carry thermal energy out of the housing. Air flow in and out of the housing may thus be advantageous for heat exchange but disadvantageous for sound insulation, and designers of generator housings for portable generators have to make a trade-off between the two.

Sound may be transmitted by different mediums, such as air, but also by solid material, for example the material of which parts of the housing are made of. A person skilled in the art will appreciate that perfect sound insulation, i.e. no sound waves propagating from the inside of the housing to the outside housing, may be nearly impossible to achieve. However, any additional damping of said sound waves of all or certain frequencies of sound may be regarded as an advantage for a portable generator.

The present invention aims to provide a portable generator with amongst others improved sound insulation and/or improved heat exchanging properties. Aspects of the present invention may also be applied in non-portable generators, such as power plants.

A first aspect provides a portable generator, comprising a generator housing comprising a sound insulated compartment, a heat exchange compartment provided adjacent to the sound insulated compartment, and a sound insulated partition separating the sound insulated compartment from the heat exchange compartment, a combustion engine and an electrical generator provided in the sound insulated compartment, a heat transfer module arranged to transfer thermal energy generated by the combustion engine from the sound insulated compartment to the heat exchange compartment by means of a fluid, and a cooling unit provided in the heat exchange compartment for transferring thermal energy from the heat exchange compartment outside of the generator housing by means of a fluid.

The term portable generator refers to a combination of a combustion engine and an electrical generator both provided in the same housing to be transported as a single unit. The housing may be arranged as a container, for example a conventional shipping container. Note that portable need not imply that the generator is carryable by a man; instead a fork-lift truck or crane may be required for transporting the portable generator. The portable generator may be provided with a fuel tank for storing fuel that is to be supplied to the combustion engine.

The electrical generator as a part of the portable generator is used for converting kinetic energy from the combustion engine into electrical energy. In an alternative embodiment of the portable generator, the electrical generator may be provided in the heat exchange compartment. In such an embodiment, an axle as an example of a kinetic energy transfer unit may be provided between the sound insulated compartment where the combustion engine is located and the heat exchange compartment where the electrical generator is provided.

The sound insulated compartment, arranged for housing the combustion engine and the electrical generator, is arranged to substantially prevent sound waves generated by the combustion engine to propagate through the sound insulated compartment to the outside of the housing.

The sound insulated compartment may be sound insulated by virtue of the use of sound absorbing materials and/or sound damping materials such as foams or other porous absorbers, resonant absorbers, any other sound insulating material, or a combination thereof. Additionally or alternatively, sound insulating construction elements may be used, such as vibration dampers, acoustic decoupling elements, sound traps which may be tuned to certain ranges of frequencies, any other sound insulating construction element, or any combination thereof.

The sound insulated compartment may comprise one or more doors to allow access to the components inside the sound insulated compartment.

Because the sound insulated compartment is arranged for housing the combustion engine, it requires some input of oxygen for the combustion process in the engine. Furthermore, since the combustion engine produces thermal energy when used, the sound insulated compartment requires some output of thermal energy to prevent overheating the sound insulated compartment.

The heat exchange compartment comprises one or more heat exchange channels, such as ventilation shafts, for facilitating an air flow between the generator housing and the outside of the generator. The heat exchange compartment may be at least partially sound insulated as well. More specifically may the sound insulating compartment and heat exchange compartment be sound insulated for different specific ranges of sound frequencies, for example tuned to the different sound producing components in the different compartments.

The sound insulated partition separating the sound msulated compartment from the heat exchange compartment forms a sound wave dampening barrier between the combustion engine and the heat exchange compartment such that sound waves are substantially prevented from propagating via the sound insulated partition and through the heat exchange compartment to the outside of the housing.

The combustion engine is likely to, in use, be the main source of sound inside the generator housing. Therefore, the combustion engine is provided in the sound insulated compartment. The combustion engine is, in use, further likely to be the main source of thermal energy inside the generator housing. To prevent overheating, the combustion engine and/or other components in the sound insulated compartment, thermal energy needs to be transferred out of the sound insulated compartment.

The heat transfer module is arranged to transfer thermal energy from the sound insulated compartment to the heat exchange compartment. At least part of this transfer of thermal energy is done by means of a fluid, which may be a gas, a liquid, or a combination thereof. As such, the fluid functions as a carrier for thermal energy. By transferring the fluid, the thermal energy carried in the fluid may be transferred as well.

Thermal energy may be transferred by means of convection, conduction, radiation, or a combination thereof.

A hot fluid refers to a fluid which has had its thermal energy increased inside the portable generator.

A cooled fluid refers to a fluid from which thermal energy has been extracted 5 inside the portable generator.

A cool fluid furthermore refers to a fluid to which thermal energy may be added; for example considered as a cool fluid is ambient air from outside the housing.

The cooling unit is arranged for extracting thermal energy from a fluid provided to the cooling unit for example by the heat transfer module.

Extracting thermal energy from a fluid is referred to as cooling, and may be done by transferring the thermal energy to another medium via radiation, conduction and/or convection.

Cooling may be performed using a medium with a lower temperature than the medium that is to be cooled, or by using a refrigeration device arranged to transfer thermal energy from a medium with a lower temperature to a medium with a higher temperature.

Such a refrigeration device requires external work to function, which may be provided for example by a compressor.

At least part of the thermal energy generated in the sound insulated compartment by for example the combustion engine is thus first transferred to the heat exchange compartment by virtue of the heat exchange module, and next transferred at least partially out of the heat exchange compartment by virtue of the cooling unit to the outside surroundings of the portable generator.

The heat exchange compartment may be provided with sound insulation as well, to further prevent sound waves from leaving the generator housing.

The sound insulation of the heat exchange compartment may be tuned to dampen different frequencies of sound than the sound insulation of the sound insulated compartment, since the sound producing components inside the heat exchange compartment may produce sound with different dominant frequencies than the components inside the sound insulated compartment. For example may the combustion engine produce sounds at lower frequencies than a whirring fan inside the heat exchange compartment.

As such, the sound insulated compartment may be arranged to dampen sound waves in a first range of frequencies, and the heat exchange compartment may be arranged to dampen sound waves in a second range of frequencies.

The first range of frequencies is predominantly low-frequent, for example predominantly comprising frequencies below 600 Hz. The second range of frequencies may be predominantly high-frequent, for example predominantly comprising frequencies above 400 Hz. As such, the first range of frequencies and the second range of frequencies may substantially not overlap.

Depending on which components generate sound waves, in different embodiments the first range of frequencies may predominantly comprise frequencies below 200 Hz, below 400 Hz, below 600 Hz, below 800 Hz or below 1 kHz, and the second range of frequencies may predominantly comprise frequencies above 300 Hz, above 500 Hz, above 80 Hz or above 1 kHz.

For dampening sound waves in the first range of frequencies — i.e. relatively low-frequent sound — materials or components with high density, high mass, and/or high stiffness may be used in the construction of the insulation. For dampening sound waves in the second range of frequencies — i.e. relatively high-frequent sound — materials which absorb these short waves may be used in the construction of the insulation.

For damping sound waves of particular frequencies, materials may be used according to their material properties, such as their density, stiffness, porosity, flow resistivity, cell size, tortuosity, any other property of any combination thereof. Combinations of materials in specific configuration may be used as well.

When the sound insulated compartment is arranged to dampen sound waves in a first range of frequencies, and the heat exchange compartment is arranged to dampen sound waves in a second range of frequencies, thus, different materials, components and/or configurations may be used for constructing the two different compartments. As such, different damping levels may be obtained for different frequencies of sound for both compartments.

In embodiments, the partition which at least partially separates the sound insulated compartment from the heat exchange compartment may be arranged to dampen sound waves in the first range of frequencies, in the second range of frequencies, or in at least parts of both ranges.

The heat transfer module may comprise a ventilation module arranged to allow a flow of air from the heat exchange compartment to the sound insulated compartment such that cool air from the heat exchange compartment may flow into the sound insulated compartment. Optionally, the ventilation module may be arranged to allow a flow of air from the sound insulated compartment to the heat exchange compartment.

The ventilation module may be arranged as one or more through holes in the sound insulated partition which provide a fluid connection between the sound insulated compartment and the heat exchange compartment. The through holes may be provided with one or more valves, which may be arranged as one- or two-way valves. Such valves may be arranged to allow or at least partially block the air flow through the through hole provided with the valve depending on one or more conditions. Examples of conditions are the air pressure in the sound insulated compartment or the heat exchange compartment, the air temperature in the sound insulated compartment or the heat exchange compartment, or any other condition, or any combination thereof. The valves may be controllable by a valve controller arranged to open and close the valves according to any of the conditions.

The through holes in the sound insulated partition may be spread around over the sound insulated partition, and may as such be provided at different horizontal and/or vertical positions.

If the temperature of the air in the sound insulated compartment is higher than the temperature of air in the heat exchange compartment, an air flow of the warmer air into the heat exchange compartment and an air flow of the colder air into the sound insulated compartment by virtue of the ventilation module results in a transfer of thermal energy from the heat exchange compartment to the sound insulated compartment.

The air flow arranged by or made possible by the ventilation module may be the result of the difference in densities between air of different temperatures and/or a pressure difference between the two adjacent compartments. Alternatively or additionally, the ventilation module may comprise one or more air forcing modules for creating a forced air flow from the heat exchange compartment to the sound insulated compartment and/or from the sound insulated compartment to the heat exchange compartment. Such an air forcing module may be arranged as one or more fans, which may be operated by an air forcing module controller arranged to for example control the air flow dependent of the air temperature in the sound insulated compartment.

The sound insulated compartment may be provided with a sound insulated exhaust channel, arranged to provide a flow path for exhaust gasses produced by the internal combustion engine out of the sound insulated compartment and out of the generator housing. The exhaust channel may be sound insulated to substantially prevent or limit noise from the internal combustion engine from exiting the generator.

To provide the sound insulating properties of the sound insulated exhaust channel, the exhaust channel may be provided with and/or at least partially run through an acoustic damping element such as an acoustic trap,

a bass trap, any other acoustically absorptive device, any other damping element or any combination thereof.

A turbocharger may be provided in the sound insulated compartment, and the turbocharger may optionally be regarded as part of the internal combustion engine, for example when considering that the turbocharger in use may generate sound and/or thermal energy.

In embodiments of the portable generator comprising the turbocharger, the cooling unit may comprise an intercooler arranged to receive, from the heat transfer module, a hot flow of air compressed by the turbocharger, and arranged to cool this flow of compressed air. The combustion engine may be arranged to receive the cooled flow of air compressed by the turbocharger.

Such a turbocharger comprises a turbine connected to a compressor. The turbine is drivable by exhaust gasses from the combustion engine, and drives the compressor which compresses an air flow to be forced into a combustion chamber of the combustion engine. The power output of the combustion engine may be increased by virtue of the compressed air flow as now more oxygen can be provided to the combustion engine, and thus more fuel can be combusted in the combustion engine.

When the air flow is compressed, the temperature of the air flow increases by virtue of the ratio of the pressure and temperature for a given mass of a gas being a constant. It may be advantageous to cool the compressed air flow before it enters the combustion engine to even further increase the amount of oxygen available to the combustion engine from the air flow.

To cool the air flow compressed by the turbocharger, the cooling unit may comprise an intercooler arranged to receive, from the heat transfer module, a hot flow of air compressed by the turbocharger, and arranged to cool the flow of compressed air.

For transferring the hot flow of compressed air and the thermal energy in the compressed air, the heat transfer module may comprise one or more pipes, tubes, hoses, any other gas transport component, or a combination thereof as compressed air piping. This piping may extend through the sound insulated partition and/or may extend partially outside of the generator housing.

The cooling unit may comprise a fluid cooler, arranged to cool a hot fluid received from the heat transfer module. Such a hot fluid may be a cooling fluid such as oil or water, which may be used to cool the combustion engine. The fluid cooler may be arranged as a fluid to air cooler, wherein a cold flow of air is provided over the hot fluid in order to transfer thermal energy from the hot fluid into the flow of air, in an attempt to lower the temperature of the hot fluid.

The cooling unit may comprise a radiator and a fan arranged to provide a forced air flow to the radiator, wherein the radiator is arranged to receive a hot fluid from the heat transfer module. The hot fluid may be provided to the radiator through radiator piping comprised by the heat transfer module. The hot fluid may be any of cooling water, oil, any other cooling liquid, but may also be a flow of gas, such a flow of air, or may be any combination thereof.

The forced air flow may be used to extract thermal energy from the radiator, and as such thermal energy may be extracted from the fluid flowing through the radiator.

The fan of the cooling unit may be mounted on a arm which is swivebaly mounted to the housing to be swivelled between an inner position in which the fan is provided inside the housing and an outer position in which the fan is provided substantially outside of the housing.

In the inner position, the fan may block access to other components in the heat exchange compartment or at least make the access harder. In the outer position, the access may be easier because at least part of the fan is now provided outside the housing.

The fan may be provided with a motor for driving the fan, and a motor controller for controlling a rotational speed of the fan. The rotational speed may as such be independent from a rotational speed of the combustion engine. Alternatively, the fan may be rotatably connected to the combustion engine, and as such the rotational speed of the fan would be dependent on the rotational speed of the combustion engine.

The heat exchange module is thus a collective name for components of the portable generator arranged to transfer thermal energy generated in the sound insulated compartment, for example by the combustion engine, from the sound insulated compartment to the heat exchange compartment by means of one or more gasses or gas flows and/or fluids or fluid flows.

The cooling unit is thus a collective name for components of the portable generator arranged to transfer thermal energy from the heat exchange compartment out of the generator housing. This may reduce the amount of thermal energy comprised by the portable generator and the air inside the portable generator, and may as such reduce the temperature of some or all components of the portable generator. A reduced temperature may be beneficial for operation of components such as the combustion engine.

BRIEF DESCRIPTION OF THE FIGURES The various aspects and embodiments thereof will now be discussed in conjunction with figures. In the figures, Fig. 1A shows a schematic overview an embodiment of a portable generator; Fig. 1B shows a schematic overview another embodiment of a portable generator;

Fig. 2A shows a schematic side view of another embodiment of the portable generator; Fig. 2B shows the embodiment of the portable generator as shown in Fig. 2A, with the fan swivelled to an outer position.

DETAILED DESCRIPTION OF THE EMBODIMENTS Fig. 1A shows a schematic overview an embodiment of a portable generator 100, comprising a generator housing 102. The generator housing 102 comprises a sound insulated compartment 104, and a heat exchange compartment 106 provided adjacent to the sound insulated compartment

104. At least partially separating the sound insulated compartment 104 from the heat exchange compartment 106 is a partition 108 which may be an at least partially sound insulating partition 108.

The partition 108 may be at least partially sound insulating by virtue of a material or materials comprised by the partition 108, and/or by virtue of the construction of the partition 108. The materials may be a sound absorbing material such as fiberglass insulation material, foam, have a high density because when more mass needs to be moved by the sound energy, it will be harder for sound to propagate through the partition 106, other materials or a combination thereof.

The partition 108 may be formed as a sandwich panel comprising layers made out of different materials. The outer wall of the sound insulated compartment 104 may comprise the same material or combination of materials, as may the roof, ceiling, floor and/or bottom of the sound insulated compartment 104.

The partition 108 may at least partially acoustically decouple the part of the generator housing 102 surrounding the sound insulated compartment 104 from the part of the generator housing 102 surrounding the heat exchange compartment 106.

Provided at least partially inside the sound insulated compartment 104 is an internal combustion engine 110 connected to an electrical generator 112 such that rotational energy generated in the internal combustion engine 110 can be transferred to the generator 112 and can be converted to electrical energy by the generator 112. In the embodiments discussed and shown here, the generator 112 is place in the sound insulated compartment. In other embodiment, the generator 112 may also be placed in the heat exchange compartment 106 of another compartment comprised by the generator housing 102.

The portable generator 100 further comprises a heat transfer module 114 arranged to transfer thermal energy generated inside the sound insulated compartment 104, e.g. by the combustion engine 110 or the generator 112, from the sound insulated compartment 104 to the heat exchange compartment 106. The transfer of thermal energy is at least partially done by means of a fluid.

The thermal energy may be transferred directly by the heat transfer module 114, or by using a heat exchanger. In such a heat exchanger, thermal energy is transferred between two fluid flows and two liquid flows more in particular. A first fluid flow may be a fluid flow of the sound insulated compartment 104, and a second fluid flow may be a fluid flow of the heat exchange compartment 106. In different embodiments, different numbers of fluid flows may be used, including more than two. Some thermal energy may also be transferred through the partition 108 by means of conduction and/or radiation.

Provided in the heat exchange compartment 106 is a cooling unit 116 arranged for transferring thermal energy from the heat exchange compartment 106 out of the generator housing by means of a fluid flow.

Thermal energy may follow the following path by means of radiation, convection and/or conduction inside the generator 100: thermal energy is generated by the combustion process inside the combustion engine

110. The thermal energy may flow via path 118a to the heat transfer module

108. If the combustion engine is liquid cooled, the path 118a may be a conduit carrying coolant. If the combustion engine 110 is air cooled, the path 118 may be an open air path or a duct carrying air heated by the combustion engine 110 or liquid heated by the heated air. Via the heat transfer module 108, the thermal energy flows through the partition 108, or alternatively at least partially outside the housing, via path 118b to the cooling unit 116. In the cooling unit 116, or by virtue of one or more components of the cooling unit 116, the thermal energy follows a path 118c out of the housing 102 and thus out of the generator 100.

Next to a flow path for thermal energy, in Fig. 1A there is also indicated a flow path for air, which air may be required by the combustion engine 110 for providing oxygen to the combustion process. Air may enter the generator 100 through the housing 102 at the heat exchange compartment through path 120a. There may be a single point of entry for air in the heat exchange compartment 106, or a plurality of points of entry for air. Next, air may flow via path 120b to ventilation module 122, which is arranged to allow a flow of air from the heat exchange compartment 106 to the sound insulated compartment 104. Finally, via path 120c may the air with the required oxygen reach the combustion engine 110, either directly via for example a tube or indirectly, wherein the air is provided to the sound insulated compartment 104, and the engine 110 retrieves the air from the sound insulated compartment 104.

An advantage of not directly receiving air in the sound insulated compartment 104 1s that less possible acoustic leaks have to be made in the housing 102 part which surrounds the sound insulated compartment 104.

Provided in the part of the housing 102 surrounding the sound insulating compartment 104 may be an exhaust channel 124, arranged for receiving a flow of hot exhaust gasses 126a and for guiding the flow of hot exhaust gasses 126b out of the generator housing 102. The exhaust channel

124 may comprise sound absorbing or sound damping elements, including, but not limited to baffles, foam, other, or a combination thereof to attenuate, dampen or otherwise decrease the acoustic features in the exhaust gases.

Fig. 1B shows a schematic overview an embodiment of the portable generator 100, further comprising a turbocharger 128 comprising a turbine 130, arranged to be driven by the flow of exhaust gasses 126a from the combustion engine 110. The turbocharger 128 further comprises a compressor 132 arranged to receive at least part of the flow of air 120c' from the heat exchange compartment 106 and/or an optional flow of air from outside the housing 102 entering the housing 102 at the sound insulated compartment 104. Because the compressor 132 is driveable by the turbine 130, the flow of exhaust gasses 126a may be used to compress the air flow flowing through the compressor side 132 of the turbocharger.

The turbocharger 128 may be provided in the sound insulated compartment 104, or may alternatively be at least partially provided in the heat exchange compartment 106. For example may the turbine 130 be provided in the sound insulated compartment 104, and the compressor 132 may be provided in the heat exchange compartment 106. The flow paths for air to and from the compressor 132 may in such embodiments be adapted accordingly.

Due to the compression of the air by the compressor 132, the temperature of that air may rise by virtue of the ideal gas law. The compressed air, now as a relatively hot fluid, may thus require cooling. Therefore, a compressed air flow path 134a may be provided to the heat transfer module 114, in order to be able to transport the hot compressed air to the heat exchange compartment 106 where heat can be removed from the flow of hot compressed air 134a.

From the heat transfer module 114, a further hot compressed air flow path 134b is provided from the heat transfer module 114 to an intercooler 136 comprised by the cooling unit 116. The intercooler 136 1s arranged to receive the flow of hot compressed air 134b and to extract thermal energy from that flow by virtue of another flow of air or fluid provided to the intercooler 136. As such, thermal energy is transferred from the flow of hot compressed air 134b to the another flow of air or fluid.

After having passed through the intercooler 136, the flow of compressed air is now a flow of cooled compressed air 134c and may be transferred back to the sound insulated compartment 104 to be provided to the engine 110 or optionally to a second or further turbocharger stage. When the engine 110 is provided by a flow of air from the turbocharger 128, there may still be some flow of air provided to the engine 110 which has not passed through the turbocharger 128.

For providing cooling to the engine 110, in the embodiment of the generator 100 as shown in Fig. 1B the cooling unit 116 comprises a fluid cooler 138, arranged to cool a flow of hot fluid 118b' received from the heat transfer module 114. The flow of hot fluid 118b' is provided to the heat exchange compartment 106 via the heat transfer module 114, and is provided to the heat transfer module 114 via path 118a'. The fluid flowing to path 118a' has been in such proximity to the engine 110 as an example of a heat generating element within the sound insulated compartment that thermal energy is transferred from the engine to the fluid flowing to path 118a’.

For cooling the flow of hot fluid 118b', the fluid cooler 138 is arranged to receive the flow of hot fluid 118b' and to extract thermal energy from it. To that end, a second flow of cool fluid and/or air may be provided to the cooling unit 116, such that thermal energy may be transferred by the cooling unit 116 from the flow of hot fluid 118b' to the second flow of cool fluid and/or air. After having passed through the fluid cooler 138, the flow of fluid has become a cool flow of fluid 118¢', which is allowed to flow back towards the engine 110 via path 118c' in order to once again extract thermal energy from the engine 110.

Additionally or alternatively to a flow of hot fluid, such as flows 118a' and 118b', passing through the heat transfer module 114, the flows 118a' and 118b' may be separate flows. As such, the heat transfer module 114 may comprise one or more heat exchangers, arranged to receive a first fluid flow and a second fluid flow, wherein a temperature difference between the fluid in the first fluid flow and the fluid in the second fluid flow constitutes in a flow of thermal energy through the heat transfer module 114 from the sound insulated compartment 104 to the heat exchange compartment 106.

A flow path may be interpreted as any path over which a flow may be constituted, and a flow path may be delimited by tubing, one or more conducts, pipes, or through an open space such as at least part of the housing 102, or any combination thereof, and a flow path may be completely inside the housing 102, or may be at least partially provided outside the housing 102. The flow path being fully inside the housing 102, or even fully inside the sound insulated compartment104, may be preferred to decrease the amount of sound from exiting the housing 102.

The heat transfer module 114 may, in any of the embodiments of the generator 100, comprises one or more devices for forcing a fluid flow, such a pump, fan, any other device for increasing a flow energy or kinetic energy of a fluid flow, or any combination thereof.

For example, the generator 100 comprises a fan 140 as an air forcing module for creating a forced air flow from the heat exchange compartment 106 to the sound insulated compartment 104, as shown in Fig.

1A as from flow path 120b to flow path 120c'. With a forced air flow, more volume of air may be transferred from the heat exchange compartment to the sound insulated compartment, which may in turn increase the volume of oxygen available for the combustion engine 110 over time.

Alternatively, or additionally to the air flow path as indicated by 1204, 120b and 120c, an air flow path may be provided from the outside of the generator housing 102 directly into the sound insulated compartment. Such an air flow path may be provided directly to the combustion engine 110 and/or the compressor 132 of the turbocharger 128. The cooling unit 106 may in embodiments of the generator 100 comprise a cooling unit fan 142 and a radiator 146. The cooling unit fan 142 is arranged to force a flow of ambient air 144a to the radiator 146 in a forced air flow 144b. The radiator 146 may be a separate component of the coolant unit 116, or may be a component of the fluid cooler 138. The radiator 146 is preferably thermally conductively coupled to the fluid cooler 138 and/or the intercooler 136. This may be established by means of heat exchange between two coupled fluid circuits or by leading heated fluid from the fluid cooler 138 and/or the intercooler 136 through the radiator 146 for radiating heat, i.e. losing thermal energy.

Fig. 2A shows a schematic side view of another embodiment of the portable generator 100, with a top side 202 and bottom side 204 of the generator indicated. The cooling unit fan 142 is mounted on an arm 206, which is swivebaly mounted to the housing 102. The arm 206 is arranged to swivel around a hinging point 208, which may be provided substantially at the bottom side 204 of the generator 100. Alternatively may the hinging point 208 be provided anywhere between the bottom side 204 and the top side 202 of the generator 100.

Fig. 2A shows the arm 206, and thus also the fan 142 mounted on the arm 206, in an inner position in which the fan 142 is provided inside the housing 102. Fig. 2B shows the same embodiment of the portable generator 100, where now the arm, and thus also the fan 142 mounted on the arm 206, is In an outer position in which the fan 142 is provided substantially outside the housing 206.

In the inner position as shown in Fig. 2A, the fan 142 is substantially aligned with at least part of the cooling unit 116 such that the fan 142 may provide a flow of air to the at least part of the cooling unit 116.

In the outer position as shown in Fig. 2B, the fan 142 is substantially not aligned with the cooling unit 116. This position may be used for example when maintenance 1s due for parts of the generator 100 to which access is blocked or restricted by the fan 142, such as for example the cooling unit

116. Other methods of moving the fan 142 from an inner position to an outer position are envisioned as well, using for example a sliding motion, a rotating motion, a hinging motion, any other motion of the fan 142 relative to the housing 102, or any combination thereof.

The fan 142 is provided with a motor 210 for rotating the fan 142, which may be an electric motor. For controlling a rotational speed of the fan 142, the fan 142 is provided with a motor controller 212. Compared to a more conventional way of driving the fan 142 using a rotational connection to the combustion engine 110, having a separate motor 210 for driving the fan 142 allows the fan speed to be controlled independently of the engine speed. This in turn allows the amount of cooling by the flow of air generated by the fan 142 to the cooling unit 116 to be controlled independently of the engine speed.

The motor controller 212 may for example be provided with sensors for detecting a temperature in one or both of the sound insulated compartment 104 and the heat exchange compartment 106, sensors for detecting a sound level, any other sensor, or any combination thereof. The motor controller 212 may then be arranged to control the rotational speed of the motor 210 dependent on received sensor signals from those sensors.

In summary, portable generators comprise an internal combustion engine for generating electricity. Such an engine then generates sound and heat. The sound is often undesired, and as such an insulated housing is provided around the engine. However, such an insulated housing makes it difficult to get rid of the heat, which may cause overheating of the generator. The present invention provides a portable generator with two separate compartments, of which one is arranged to be sound insulated, and the other compartment is a heat exchange compartment arranged to expel heat from the generator. The engine is provided in the sound insulated compartment, and a cooling unit is provided in the heat exchange compartment. Thermal energy is transferred using a fluid flow from the engine to the cooling unit, and via the cooling unit out of the generator such that overheating may be prevented. The various aspects and embodiments thereof may be summarised, in a non-limitative way, by means of the following numbered embodiments:

1. A portable generator, comprising: - a generator housing comprising a sound insulated compartment, a heat exchange compartment provided adjacent to the sound insulated compartment, and a sound insulated partition separating the sound insulated compartment from the heat exchange compartment; - a combustion engine provided in the sound insulated compartment; - a heat transfer module arranged to transfer thermal energy generated by the combustion engine from the sound insulated compartment to the heat exchange compartment by means of a fluid; - an electrical generator mechanically coupled to the combustion engine for being driven by the combustion engine; and - a cooling unit provided in the heat exchange compartment for transferring thermal energy from the heat exchange compartment out of the generator housing.

2. Portable generator according to embodiment 1, wherein the heat transfer module comprises a ventilation module arranged to allow a flow of air from the heat exchange compartment to the sound insulated compartment such that cool air from the heat exchange compartment may flow into the sound insulated compartment.

3. Portably generator according to embodiment 2, wherein the ventilation module comprises an air forcing module for creating a forced air flow from the heat exchange compartment to the sound insulated compartment.

4 Portable generator according to any of the preceding embodiments, wherein the sound insulated compartment is provided with a sound insulated exhaust channel, arranged to provide a flow path for exhaust gasses produced by the internal combustion engine out of the sound insulated compartment and out of the generator housing.

5. Portable generator according to any of the preceding embodiments, comprising a turbocharger provided in the sound insulated compartment, wherein: - the cooling unit comprises an intercooler; - the intercooler is arranged to receive, from the heat transfer module, a hot flow of air compressed by the turbocharger; - the intercooler is arranged to cool the flow of compressed air; and - the combustion engine is arranged to receive the cooled flow of air.

6. Portable generator according to any of the preceding embodiments, wherein the cooling unit comprises a fluid cooler, arranged to cool a hot fluid received from the heat transfer module.

7. Portable generator according to any of the preceding embodiments, wherein the cooling unit comprises a radiator and a fan arranged to provide a forced air flow to the radiator, wherein the radiator is arranged to receive a hot fluid from the heat transfer module.

8. Portable generator according to embodiment 7, wherein the fan is mounted on an arm which is swivebaly mounted to the housing to be swivelled between an inner position in which the fan is provided inside the housing and an outer position in which the fan is provided substantially outside of the housing.

9. Portable generator according to embodiment 7 or 8, wherein the fan is provided with a motor for driving the fan, and a motor controller for controlling a rotational speed of the fan.

10. Portable generator according to any of the preceding embodiments, wherein the heat transfer module comprises one or more heat exchangers, arranged for receiving a first fluid flow and a second fluid flow, wherein a temperature difference between the fluid in the first fluid flow and the fluid in the second fluid flow constitutes in a flow of thermal energy through the heat transfer module between the sound insulated compartment and the heat exchange compartment.

11. Portable generator according to any of the preceding embodiments, wherein the sound insulated compartment is arranged to dampen sound waves in a first range of frequencies, and the heat exchange compartment is arrange to dampen sound waves in a second range of frequencies.

12. Portable generator according to embodiment 11, wherein the first range of frequencies is predominantly low-frequent.

13. Portable generator according to embodiment 11 or 12, wherein the second range of frequencies is predominantly high-frequent.

14. Portable generator according to any of the embodiments 11-13, wherein the first range of frequencies and the second range of frequencies substantially do not overlap.

Claims

Conclusions

A transportable unit, comprising: - a unit housing comprising a sound-insulated compartment, a heat-exchange compartment provided adjacent to the sound-insulated compartment, and a sound-insulated partition separating the sound-insulated compartment from the heat-exchange compartment; - a combustion engine and an electric generator provided in the sound-insulated compartment; - a heat transfer module adapted to transfer heat energy generated by the combustion engine from the sound-insulated compartment to the heat exchange compartment by means of a liquid; and - a cooling unit provided in the heat exchange compartment for transferring heat energy from the heat exchange compartment out of the aggregate housing.

Transportable aggregate according to claim 1, wherein the heat transfer module comprises a ventilation module arranged to allow airflow from the heat exchange compartment to the sound-insulated compartment so that cool air from the heat exchange compartment can flow into the sound-insulated compartment.

Transportable aggregate according to claim 2, wherein the ventilation module comprises an air forcing module for creating a forced air flow from the heat exchange compartment to the sound-insulated compartment.

Transportable aggregate as claimed in any of the foregoing claims, wherein the sound-insulated compartment is provided with a sound-insulated exhaust duct.

Transportable aggregate according to any one of the preceding claims, comprising a turbocharger provided in the sound-insulated compartment, wherein: - the cooling unit comprises an intercooler; the intercooler is arranged to receive, from the heat transfer module, a warm stream of air compressed by the turbocharger; - the intercooler is arranged to cool the flow of compressed air; and - the combustion engine is arranged to receive the cooled airflow.

Transportable aggregate according to any one of the preceding claims, wherein the cooling unit comprises a liquid cooler adapted to cool a warm liquid received by the heat transfer module.

Transportable aggregate according to any one of the preceding claims, wherein the cooling unit comprises a radiator and a fan arranged to provide a forced air flow to the radiator, wherein the radiator is adapted to receive a hot liquid from the heat transfer module.

The transportable unit of claim 7, wherein the fan is mounted on an arm pivotally mounted to the housing to be pivoted between an inner position in which the fan is provided within the housing, and an outer position in which the fan is substantially outside the housing. housing is provided.

Transportable aggregate according to claim 7 or 8, wherein the fan comprises a motor for driving the fan, and a motor controller for controlling a rotational speed of the fan.

Transportable aggregate according to any one of the preceding claims, wherein the heat transfer module comprises one or more heat exchangers adapted to receive a first liquid flow and a second liquid flow, wherein a temperature difference between the liquid in the first liquid flow and the liquid and the second liquid flow a flow of heat energy caused by the heat transfer module between the sound-insulated compartment and the heat exchange compartment.

Transportable aggregate according to any one of the preceding claims, wherein the sound-insulated compartment is arranged to attenuate sound waves in a first range of frequencies, and the heat exchange compartment is adapted to attenuate sound waves in a second range of frequencies.

The transportable aggregate of claim 11, wherein the first range of frequencies is substantially low frequency 1s.

The transportable aggregate of claim 11 or 12, wherein the second range of frequencies is substantially radio frequency.

Transportable aggregate according to any one of claims 11-13, wherein the first range of frequencies and the second range of frequencies do not substantially overlap.