Electric movable compressor

Abstract

According to one embodiment, disclosed is a mobile compressor (100) for providing compressed gas by drawing in ambient air, comprising: a battery pack (201) configured to provide power for an electric motor; and a cooling system (203) configured to cool the battery pack (201), the cooling system comprising a set of conduits (204) comprising a coolant for absorbing heat from the battery pack (201), a pump for circulating the coolant through the conduits (204), and a heat exchanger (112, 202) for releasing the absorbed heat into the environment, where the heat exchanger (112, 202) is configured to heat the battery pack (201). The heat exchanger (112, 202) is arranged such that ambient air flows through the heat exchanger (112, 202) when inhaled. According to the invention, greater autonomy of the electric movable compressor can be realized.

Description

Technical Field

[0001] The utility model relates to an electric mobile compressor powered by a battery pack, and more particularly to a cooling system for cooling the battery pack. Background Art

[0002] A compressor is a machine designed to produce compressed gas, such as compressed air. The compressed gas at a certain working pressure is then used in a range of applications, such as driving other machines, such as pneumatic hammers and drills.

[0003] Such jackhammers and drills are often used in places where there is no permanent compressed air network, such as construction sites. Usually, mobile compressors are used at these locations. The term "mobile" is therefore understood to mean that such compressors can be moved with or without the aid of transport devices and / or lifting devices. In other words, a mobile compressor is a compressor that is not designed to be used stationarily in a fixed location.

[0004] Mobile compressors can be powered by diesel engines so that they can be operated independently. However, since they emit combustion gases and are noisy, there is a trend to replace these diesel engines with electric motors. The mobile compressors can then be powered, for example, by a battery pack integrated therein. In other words, the electricity used to power the compressor is provided by the battery pack.

[0005] To charge the batteries of the battery pack, the grid may be used if available, and / or the batteries may be charged at a location other than the location where the mobile compressor is used.

[0006] Such an electric mobile compressor is disclosed in BE1024040A1. As already mentioned, the energy supply from the grid can be supplemented by a battery pack. When the mobile compressor is not started but connected to the grid, the batteries of the battery pack can then be charged. In the absence of a grid, the mobile compressor can then be powered by electricity drawn from the charged batteries.

[0007] However, when power is drawn from the battery, it will heat up due to internal losses. This generated heat must be efficiently and safely discharged to the environment to ensure the proper operation of the mobile compressor.

[0008] The first difficulty is the limited space available to provide the cooling system. The reason for this is the desire to keep the mobile compressor as compact as possible. The second difficulty is that the cooling system itself must be powered, which reduces the autonomy of the compressor itself in its operation and uses only batteries.

[0009] Therefore, the object of the present invention is to provide a cooling system for an electric mobile compressor which overcomes one or more of the described drawbacks and difficulties of prior art solutions. More specifically, the object of the present invention is to provide a cooling system which leads to greater autonomy of the electric mobile compressor. Utility Model Content

[0010] According to the utility model, the above-mentioned purpose is achieved by providing an electric mobile compressor, which includes an electric motor for driving a compressor element, and the compressor element is used to supply compressed gas at a predetermined pressure and / or flow rate by inhaling ambient air. The compressor also includes a battery pack and a cooling system, the battery pack is configured to provide power to the electric motor, the cooling system is configured to cool the battery pack, the cooling system includes a group of pipes, a pump and a heat exchanger, the group of pipes includes a coolant configured to absorb heat from the battery pack, the pump is configured to circulate the coolant through the pipes, and the heat exchanger is configured to release the heat absorbed by the coolant to the environment, characterized in that the heat exchanger is arranged so that when inhaled, ambient air flows through the heat exchanger.

[0011] The electric mobile compressor is configured to provide compressed air at locations where a compressed air network is not normally present, such as at a construction site. On the other hand, there may be an electrical grid that can be used to power the compressor. Such a potentially existing electrical grid is, for example, a low-voltage electrical grid at a certain voltage, such as 400V, which is common in Europe, or 480V, which is common in the United States. Therefore, it should be understood that the voltage value to which the mobile compressor can be connected is not restrictive, but can be adapted to the area where the compressor will be used.

[0012] The compressor is equipped with an electric motor to drive the compressor element. For example, when the compressor is a screw compressor type, the compressor element is a screw. Here, it should also be understood that the type of compressor element is not restrictive and other compressor elements can be used to supply compressed gas at a predetermined pressure. The value of this pressure also depends on the intended application and may also be adjustable.

[0013] Furthermore, there may be a mechanical coupling, such as a gearbox, between the electric motor and the driven compressor element. In other words, the drive of the compressor element does not have to be directly driven by the electric motor, but a mechanical coupling may also be provided between them. This converts the rotational speed of the electric motor into a rotational speed suitable for the compressor element.

[0014] Furthermore, the type of motor is also not limited to the disclosed utility model. This can be a three-phase asynchronous motor or a three-phase permanent magnet synchronous motor. In these cases, a frequency converter will be present between the power distribution device and the motor. The frequency converter, also known as a frequency controller, inverter or variable speed drive VSD, then converts the DC voltage from the power distribution device into an AC voltage with a specific frequency suitable for the three-phase motor. In addition, both the frequency and the AC voltage can be changed in order to provide a specific torque to the compressor element depending on the required pressure of the compressed gas.

[0015] Alternatively, the motor may be of the DC motor type. In this case, the DC motor may be connected directly to the power distribution device, but typically a DC / DC converter will be present between the power distribution device and the DC motor to be able to apply a terminal voltage suitable therefor.

[0016] Furthermore, there may also be a plurality of electric motors, each of which drives a compressor element individually. In this case, a frequency controller may be provided for each electric motor. Another possible configuration is that a single electric motor drives two or more compressor elements. When referring to the current for the electric motor, this also refers to the total current required to drive the electric motor or motors.

[0017] The provision of compressed gas is further achieved by sucking in ambient air. The term ambient air is therefore to be understood as meaning the air around and in the vicinity of the compressor, and thus in the environment of the compressor. This ambient air, or simply air, is sucked in by the compressor in order to compress it, wherein the ambient air will generally first be filtered, among other things, to avoid damage to the compressor elements and to ensure the quality of the supplied compressed gas.

[0018] The mobile compressor further comprises a battery pack configured to provide power to the electric motor. The battery pack then comprises one or more batteries. According to a preferred embodiment, the batteries are rechargeable batteries and the compressor further comprises an electrical connection for an electrical grid. The compressor then further comprises a power distribution device connected to the electric motor. The power distribution device then further comprises an onboard charger configured to provide power from the electrical grid to the power distribution device, a battery management system between the power distribution device and the battery pack, and a controller configured to coordinate the exchange of power between the electrical grid, the battery pack and the electric motor.

[0019] The power distribution device is a voltage rail, also called a busbar, to distribute power between various connected devices. The first device is a motor as described above. The consuming current then flows from the power distribution device to the motor. The second device connected to the power distribution device is an onboard charger as described above. The onboard charger is configured to convert the power from the power grid into a suitable value and make it available to the power distribution device. Typically, the alternating current from the power grid will be converted into direct current. Here, the current will flow from the power grid through the onboard charger to the power distribution device to provide the power to various power consuming devices connected to the power distribution device. Another device connected to the power distribution system is a battery management system. The battery management system is configured to support the exchange of power between the power distribution device and the assembly of one or more rechargeable batteries by monitoring the state of charge of the battery pack. To support this, the current, voltage and temperature of one or more batteries are measured and data is exchanged with the controller based on this. The controller then calculates the set point of the onboard charger and sends the result to the onboard charger. This allows the power exchange to be carried out in an optimal way. The battery management system will also include safety functions to protect the battery by not discharging the battery too deeply. For example, when no power grid is available, when another electrical consumer connected to the power distribution device (e.g. an electric motor for driving a compressor element) consumes power (i.e. when the compressor is working autonomously), the discharge occurs. In other words, a battery management system is a system known in the prior art. This will therefore ensure that the cells of the battery pack are kept in a safe and reliable state. This is done in particular by monitoring the state of charge and ensuring that the battery is not discharged too deeply.

[0020] Furthermore, the compressor comprises a cooling system to cool the battery pack. The cooling system comprises groups of pipes configured to absorb heat originating from the battery pack. Thus, the pipes are positioned so that the heat generated by the battery can be effectively and safely absorbed by the coolant present in these pipes. It should also be understood that the group of pipes may comprise a single pipe wound between and on the batteries. Alternatively, the group of pipes may be composed of several groups of pipes arranged in parallel. In the following, the term "group of pipes" is understood to mean a single pipe, or a plurality of pipes arranged in parallel and connected to each other to allow a coolant to flow through. The coolant is preferably a liquid, but may also be a gas, and is therefore a cooling medium as known in the prior art.

[0021] The cooling system also includes a pump for circulating a coolant through the set of pipes, and a heat exchanger configured to release the absorbed heat from the battery pack to the environment in which the compressor is arranged. The heat exchanger then has as a first medium a coolant, which includes the heat from the battery pack. The second medium of the heat exchanger is then ambient air, as will be explained further. In other words, the heat from the battery pack is released to the environment using the ambient air.

[0022] In order for this to happen efficiently, a heat exchanger is positioned in the compressor section of the battery-powered mobile compressor so that ambient air can flow past and / or through the heat exchanger. This can be done naturally or forced with the aid of a fan, as will be explained further. Ambient air is drawn in to cool the oil, coolant and compressed air of the mobile compressor.

[0023] The advantage is that there is no need to provide facilities (also called compartments) in the battery pack to allow an air flow to flow through it to cool the battery pack. This allows the battery pack to be constructed more compactly, since the group of ducts can be integrated into the battery pack. In addition, since there is more control over the heat dissipation when using grouped ducts compared to air flow, the heat dissipation can also be carried out more effectively. For example, during the air flow, undesirable turbulence may occur, with the result that the air flow is not optimal for the heat dissipation of the battery pack. In addition, it is not necessary to provide an additional fan to generate this forced air flow, which in turn must be provided with the necessary power. By using the air flow to draw in the surrounding air, space and power are saved. In other words, no additional air flow and fan are required to cool the battery pack.

[0024] Furthermore, the pump will circulate the coolant through the set of pipes and heat exchangers, whereby, according to this embodiment, the battery pack can then be cooled to ambient temperature according to the limit value. In a practical implementation, this will be slightly higher than the ambient temperature, as there are inevitably losses. In this case, the coolant is a passive coolant.

[0025] When absorbing heat, the coolant can also change phase. According to a preferred embodiment, the cooling system also includes a cooler, wherein the heat exchanger of the cooling system then corresponds to the condenser of the cooler. The advantage of the cooler is that it can be cooled below the ambient temperature. The cooler then comprises a pump or compressor, a condenser, an expansion member, an evaporator and a coolant. In this case, the coolant is an active coolant.

[0026] According to an embodiment, the mobile compressor further includes a beam-shaped container arranged at a bottom side of the mobile compressor and configured to accommodate the battery pack and the cooling system, and the heat exchanger is arranged outside the beam-shaped container.

[0027] The holder is used to protect the battery pack. In addition, a cooling system is also housed here, wherein the heat exchanger is located outside the beam-shaped container. Preferably, the heat exchanger comprises a rectangular cooling body, which is positioned perpendicular to the beam-shaped holder at the top side of the heat exchanger.

[0028] The term top side is to be understood as the top side when the compressor is normally placed on a surface for its operation. The term "bottom side" therefore refers to the side facing and / or closest to this surface. Note that the compressor may also comprise a set of wheels to make it movable, which means that the holder should not be placed on a surface. With the help of these wheels, the compressor is towed by a vehicle. Furthermore, the longitudinal direction of the beam-shaped holder will therefore correspond to the normal direction of travel when the compressor is towed by a vehicle.

[0029] By positioning the cooling body outside the holder, and preferably at its top side, the heat generated can be dissipated in an even more efficient manner. Since the specific gravity of the coolant decreases with increasing temperature, the coolant will move to the heat exchanger in a partially natural manner. Thus, less electricity has to be provided and used to control the pump in order to circulate the coolant. In addition, as will be explained further, ambient air can then be allowed to flow through the heat exchanger.

[0030] The compressor may also include a housing that is arranged on the beam-shaped retainer as described above at the top side of the compressor. The housing is used to shield and protect the compressor elements. It should also be understood that such shielding and protection is also used for peripheral equipment to support the operation of the compressor, motor, buffer tank (if present) and / or other equipment (if present). The retainer is securely and snugly fitted to the retainer.

[0031] The housing also includes recesses on its respective opposite sides. The opposite sides are, for example and preferably, the sides when viewed in the longitudinal direction of the beam-shaped holder as described above. Alternatively, the recesses may also be located on the respective opposite sides according to the transverse direction of the beam-shaped holder. These recesses are configured so that there are one or more flow paths between them. The term flow path should be understood as a path or trajectory that the airflow can follow between and within the housing. The trajectory may be a straight line, but will typically follow a curved and winding trajectory. In addition, the path that the airflow will follow cannot be defined a priori, but depends on various factors, such as flow, temperature, humidity and / or air velocity.

[0032] In this case, the heat exchanger is arranged so that it intersects the one or more flow paths. This will therefore cause the inhaled air to flow through the heat exchanger to cool the heat exchanger. When the heat exchanger comprises a rectangular cooling body, the rectangular cooling body is preferably arranged transversely to the direction of the flow path so that the cooling surface intersects the flow path to the greatest extent for effective cooling.

[0033] According to one embodiment, the compressor further comprises a fan configured to force ambient air to flow along the flow path. This can be achieved by suction and / or by having the fan blow air in the direction of the flow path. The fan is then located above the battery pack and is also protected by the holder.

[0034] The heat exchanger further comprises a rectangular radiator, which is arranged perpendicular to the retainer at the top side of the retainer.

[0035] Wherein, the coolant includes cooling liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described with reference to the accompanying drawings, wherein

[0037] Figure 1A An electric mobile compressor according to an embodiment of the utility model is shown; and

[0038] Figure 1B Shown according to Figure 1A An electrically powered portable compressor having no housing or shielding; and

[0039] Figure 2A A first view showing a beam-shaped container for accommodating a battery pack according to an embodiment of the present invention; and

[0040] Figure 2B Shown according to Figure 2A Second view of the beam container. DETAILED DESCRIPTION

[0041] The present invention will be described with reference to certain embodiments and with reference to certain drawings, but the invention is not limited thereto but only by the claims. The drawings described are only schematic and non-restrictive. In the drawings, for the purpose of illustration, the size of some elements may be exaggerated and not drawn to scale. The sizes and relative sizes do not necessarily correspond to the actual practical embodiments of the present invention.

[0042] In addition, the terms first, second, third, etc. are used in the description and claims to distinguish similar elements without necessarily describing a sequential or chronological order. These terms are interchangeable under appropriate circumstances, and the embodiments of the present invention can be implemented in a sequence different from that described or illustrated herein.

[0043] In addition, the terms upper, lower, above, below, etc. in the specification and claims are used for illustrative purposes and do not necessarily describe relative positions. The terms used in this way are interchangeable under appropriate circumstances, and the embodiments of the utility model described herein can be used in orientations other than those described or shown herein.

[0044] Furthermore, although referred to as "preferred embodiments," the various embodiments should be interpreted as exemplary means of implementing the invention, rather than limiting the scope of the invention.

[0045] The term "comprising" used in the claims should not be interpreted as being limited to the means or steps set forth below; the term does not exclude other elements or steps. The term should be interpreted as specifying the presence of the features, elements, steps or components mentioned, but does not exclude the presence or addition of one or more other features, elements, steps or components or a combination thereof. Therefore, the scope of the expression "a device comprising means A and B" should not be limited to a device consisting only of components A and B. The meaning is that, for the present utility model, only components A and B of the device are listed, and the claims are also interpreted as also including the equivalents of these components.

[0046] Figure 1A An electric mobile compressor 100 is shown. The mobile compressor 100 comprises a set of wheels 105 and a tow bar 106 for moving the compressor 100 using a suitable vehicle. The compressor 100 also comprises a beam-shaped holder (also referred to as a container 101) on the bottom side of the compressor 100, a frame 102 and a housing 103. It should also be noted that the wheels 105 and the tow bar 106 are connected to the container 101.

[0047] like Figure 2A and 2B As further shown, the beam-shaped container 101 is configured to accommodate a battery pack.

[0048] The frame 102 is configured to permanently support the components of the compressor 100. Figure 1B , which shows that Figure 1A The same compressor 100 in which the housing 103 has been removed 111 , these components are visible.

[0049] The first component is a compressor element combined with an electric motor 114. The electric motor is configured to drive the compressor element to provide compressed gas. Ambient air is used for this purpose, and the compressed gas is supplied at a predetermined pressure and / or flow rate. The electric motor is, for example, a three-phase asynchronous motor, but can also be another type, for example a DC motor, as already explained above.

[0050] Although not shown, there may also be a mechanical coupling between the electric motor and the compressor element 114. This coupling is, for example, a gearbox and ensures that the speed of the electric motor is converted into a speed suitable for driving the compressor element 114.

[0051] Furthermore, the compressor 100 is provided with a fan 116, which is located near the heat exchanger 113 of the oil cooler for cooling the compressor element 114. Furthermore, there is a reservoir or buffer tank 118 as a buffer for storing compressed gas.

[0052] It should also be understood that there are other components and devices known to those skilled in the art to support the normal operation of the compressor 100.

[0053] A lifting arm 117 is also connected to the frame 102, which can lift the frame 102 together with the components described above and other components. The frame 102 with these components can be separated from the beam-shaped container 101.

[0054] Reference again Figure 1A As already mentioned, the housing 103 serves to protect components of the compressor 100. The housing 103 may be connected to the frame 102 by means of a clamp, such as the clamp 110, whereby the housing 103 may then be removed by releasing the clamp 110, for example for maintenance.

[0055] The housing 103 has further recesses 104, 107 on its opposite sides. Ambient air can then flow through the housing 103 and thus through the components via these recesses 104, 107. A fan 116 can further force the flow of ambient air by sucking in or blowing out air.

[0056] exist Figure 2A In the figure, a beam-shaped container 101, 200 is further shown located on the bottom side of the mobile compressor 100. This illustration 200 corresponds to the case where the frame 102 and the housing 103 with the associated devices permanently attached thereto are detached from the container 101, 200.

[0057] The beam container 101, 200 comprises a battery pack including a set of rechargeable batteries 201 adapted to provide power to an electric motor for driving the compressor element 116. Although not shown, a power distribution device is provided for this purpose to connect the various devices together so that power can be exchanged.

[0058] In addition, the container 101, 200 includes a battery management system 205 and a controller. The controller is configured to communicate with the onboard charger and may also communicate with the inverter and the battery management system 205. If there is no inverter, then when the motor 114 is a DC motor type, it is directly connected to the power distribution device. The controller may also be located in the container 101, 200.

[0059] Using the battery management system 205, the controller will also be able to determine what the maximum charging current is to charge the components of the battery 201. The battery management system 205 monitors the charging state of the battery 201 and communicates to the controller what the maximum charging current is. The controller will then control the onboard charger based on this so that current can be drawn from the grid for charging.

[0060] Furthermore, the battery pack includes a cooling system 203 for cooling the group of rechargeable batteries 201. The cooling system 203 includes a group of pipes 204, which contain a coolant and circulate with the help of a pump. Furthermore, the heat exchanger 202 is located outside the container 101 and perpendicular to it. Again referring to Figure 1A and 1B The heat exchanger 202 corresponds to reference numeral 112 and is therefore not part of a component permanently connected to the frame 102 , but is part of a cooling system for the battery pack accommodated in the container 101 , 200 .

[0061] The heat exchanger 202 is then located in the air flow, which may flow between the recesses 104 and 107, whether or not forced by the fan 116. As a result, the drawn air will then flow through the heat exchanger 112, 202 to cool it. The heat exchanger 112, 202 also comprises a rectangular cooling body and is arranged transversely to the direction of these flow paths so that the cooling surface intersects the flow paths to the greatest extent for effective cooling.

[0062] Furthermore, the beam-shaped container 101 can be completely disconnected from the frame 102. This means that the battery pack and the associated appliances can be completely disconnected from the other components of the compressor carried by the frame 102. However, in order to connect the frame 102 to the container 101, a holder is provided at the top side of the container 101.

[0063] Such a retainer is, for example, a curved edge at the top side, as indicated by reference numerals 210 and 211. In addition, drilled holes are provided for inserting bolts. The frame 102 then also has holes arranged at corresponding positions, through which the frame 102 can be connected to the container 101 by means of bolts through a combination of such holes and nuts. The retainers with holes are then distributed on the outer edge of the container at the top of the container 101. The forces originating from the frame 102 are then distributed on the edge of the container 101 and on the retainers. In addition, by means of a bolt-nut connection, both 101 and 102 are then permanently but reversibly connected to each other.

Claims

1. An electric mobile compressor (100), comprising an electric motor for driving a compressor element, the compressor element for supplying compressed gas at a predetermined pressure and / or flow rate by sucking in ambient air, the compressor (100) further comprising a battery pack (201) and a cooling system (203), the battery pack being configured to provide power to the electric motor, the cooling system being configured to cool the battery pack (201), the cooling system comprising: a set of tubes (204), the set of tubes comprising a coolant configured to absorb heat from the battery pack (201); a pump configured to circulate the coolant through the set of tubes (204); a heat exchanger (112, 202) configured to release heat absorbed by the coolant to an environment; Characterized in that the heat exchanger (112, 202) is arranged such that the ambient air flows through the heat exchanger (112, 202) when the ambient air is drawn in.

2. The electric portable compressor (100) according to claim 1, characterized in that: Also included is a beam-shaped container (101) as a holder, the beam-shaped container being arranged at the bottom side and configured to accommodate the battery pack (201) and the cooling system (203), and wherein the heat exchanger (112, 202) is also arranged outside the holder.

3. The electric portable compressor (100) according to claim 2, characterized in that: The heat exchanger (112, 202) further includes a rectangular heat sink arranged perpendicular to the holder at the top side of the holder.

4. The electric portable compressor (100) according to claim 2 or 3, characterized in that: Also included is a housing arranged on the retainer for protecting the compressor element, the housing including recesses (104, 107) located on respective opposite sides thereof, the recesses being configured to provide one or more flow paths between the recesses to allow ambient air to flow along the recesses, and wherein the heat exchanger (112, 202) is also arranged to intersect one or more of the one or more flow paths.

5. The electric portable compressor (100) according to claim 4, characterized in that: Also included is a fan configured to force ambient air along the flow path.

6. The electric portable compressor (100) according to any one of the preceding claims 1 to 3, characterized in that: The cooling system (203) further comprises a cooler, and wherein the heat exchanger (112, 202) corresponds to a condenser of the cooler.

7. The electric portable compressor (100) according to any one of the preceding claims 1 to 3, characterized in that: The coolant includes a cooling liquid.

8. The electric portable compressor (100) according to any one of the preceding claims 1 to 3, characterized in that: The battery pack (201) comprises one or more rechargeable batteries, the compressor (100) further comprises an electrical connection for an electrical grid, and wherein the electric motor (114) is connected to an electrical distribution device, the electrical distribution device comprising: an onboard charger configured to provide power from the power grid to the power distribution device; and A battery management system (205) configured to support power exchange between the power distribution device and the battery pack (201); and A controller is configured to coordinate the exchange of power between the grid, the battery pack (201), and the electric motor (114).

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