Filter element, cooling system, vehicle comprising said filter and method of manufacturing said filter

Abstract

A filter element for a vehicle for filtering ambient air comprises a surface for receiving unpurified air on an upstream side and an opposing surface for releasing filtered air on a downstream side wherein an air permeability is in a range from 800 L / m2 to 7000 L / m2. A method for producing a filter element, comprising: defining boundary conditions, including element geometry boundary conditions and filter media boundary conditions; calculating a pressure loss selected from a plurality of different virtual filter elements within the boundary condition; selecting a subset of the plurality of virtual filter elements for which the pressure loss is within a predetermined speed range or within variables derivable therefrom, where each filter element has a set of filter parameters including an element geometry parameter, a filter media parameter and a pressure loss; selecting a virtual filter element of the subset, retrieving a property of the virtual filter element, and selecting a filter medium having the property of the virtual filter element; and producing a filter element having the geometry of the one dummy filter element.

Description

[0001] This patent application claims priority to European patent application number EP22197110.4 filed with the European Patent Office on September 22, 2022, the subject matter of which is hereby incorporated by reference. Technical Field

[0002] The invention relates to a filter element for a vehicle for purifying ambient air, an ambient air treatment system, a cooling system for a vehicle comprising said filter element, a vehicle comprising such a filter element, and a method for producing said filter element. Background Art

[0003] Due to progressive urbanization, the PM limit values ​​in ambient air may be exceeded several times, especially under certain weather conditions, such as absence of rain, temperature inversions, low wind speeds, no air exchange between altitudes, or due to industrial exhaust fumes, road traffic and private fireplaces.

[0004] The problem of transport-related emissions has worsened in recent times, with some calling for bans on certain categories of vehicles, particularly diesel cars, in areas where air pollution is particularly severe due to their emissions of particulate matter.

[0005] In order to compensate for vehicle emissions, patent application WO 2019 / 110223 A1 discloses a motor vehicle having an air inlet opening in the front area, behind which an ambient air purification device is arranged, which is designed to remove pollutants from the ambient air.

[0006] The selection of filter type and media is usually done using reference values ​​and based on the designer’s experience, which can be time consuming as different applications may require different characteristics of the filter which still have to be highly efficient.

[0007] Therefore, the problem of providing an improved air filter element and an improved method of production persists. Summary of the invention

[0008] One aspect of the present disclosure relates to a filter element comprising a surface for receiving unpurified air on an upstream side and an opposing surface for releasing filtered air on a downstream side. The filter element may be configured to generate a pressure loss on the downstream side relative to the air pressure at the upstream side when air pressure is applied to the upstream side. The air permeability is from 800 L / m 2 s to 7000L / m 2 s. The air permeability k can be determined using the flat medium of the filter element. The filter element can be replaceable.

[0009] One aspect of the present disclosure relates to an ambient air treatment system for a vehicle, the system comprising: a flow channel for allowing air to flow in a direction from a first position to a second position of the vehicle (e.g., from front to back), each of the first and second positions being flow-coupled to an external environment; and a filter element. The filter element may be replaceable. The filter element may include a surface for receiving unpurified air on an upstream side and an opposing surface for releasing filtered air on a downstream side, and when air pressure is applied to the upstream side, the filter element produces a pressure loss on the downstream side relative to the air pressure at the upstream side. The air permeability is from 800 L / m 2 s to 7000L / m 2 The air permeability k can be determined using the flat medium of the filter element.

[0010] One aspect of the present disclosure relates to a cooling system for a vehicle, the system comprising an ambient air treatment system according to various embodiments. The cooling system may further comprise a heat exchanger configured to exchange heat with air from the air flow, the heat exchanger optionally being positioned downstream of the filter element.

[0011] According to various embodiments, the cooling system may further include a blower for generating an air flow, for example, when the vehicle has a speed low but greater than zero, is in reverse, is charging, or is stationary.

[0012] One aspect of the present disclosure relates to a vehicle including a filter element according to various embodiments.

[0013] One aspect of the present disclosure relates to a vehicle including a cooling system according to various embodiments.

[0014] One aspect of the present disclosure relates to a vehicle including an ambient air treatment system according to various embodiments. As used herein and according to various embodiments, processing external air refers to inhaling external air from the external environment, processing the external air, and discharging the processed air to the external environment, the air can be cooling air, wherein the corresponding air flow helps cool the components of the vehicle (e.g., radiator), and the corresponding air flow can exclude the use of cabin air, or in a fuel cell, or in an internal combustion engine process. For embodiments including an internal combustion engine or a fuel cell, ambient air is air outside the vehicle that passes through the air treatment system in a flow that can avoid (i.e., separate) the internal combustion engine or fuel cell air flow. Therefore, the air treatment system can be used to treat external air that is separated from other systems that directly process the pollution generated on the vehicle (such as exhaust treatment). In addition, the air treatment system releases the processed air into the environment and does not use it as an inlet for combustion or fuel cell reactions.

[0015] One aspect of the present disclosure relates to a method for producing a filter element for a vehicle (e.g., for use in a vehicle) for filtering ambient air or for use in an ambient air treatment system. The method may include: defining boundary conditions, including element geometry boundary conditions and filter medium boundary conditions; calculating the pressure loss of a plurality of different virtual filter elements selected from within the boundary conditions; and selecting a subset of the plurality of virtual filter elements, for which the pressure loss is within a predetermined range. Each virtual filter element may be characterized by a set of filter parameters including element geometry parameters, filter medium parameters, and pressure loss. The method may also include selecting one virtual filter element of the subset, retrieving properties of the one virtual filter element, and selecting a filter medium having properties that approximate the one virtual filter element. The method may further include producing a filter element having a geometry that approximates the one virtual filter element. The method may also include inserting the filter element into a vehicle.

[0016] According to various embodiments, the method may further comprise, before the virtual filter element selection step, restricting the subset to a desired energy efficiency range, for example limiting pressure energy losses that do not contribute to filtering, for example in the form of Euler number restriction.

[0017] As used herein and in accordance with various embodiments, unless explicitly mentioned otherwise, total pressure loss is referred to simply as pressure loss. The total pressure loss may be denoted as Δp. The total pressure loss may be the sum of pleat-related pressure loss and filtration-related pressure loss, the filtration-related pressure loss being attributable to the filtration characteristics of the filter medium. As used herein and in accordance with various embodiments, pleat-related pressure loss may have the meaning of pressure loss that is not attributable to the filtration characteristics of the filter medium and may be attributable to the geometric properties of the pleats. The pleat-related pressure loss is also referred to herein as Δp dissipation The pressure loss attributable to filtration (i.e., the loss that does not contribute to filtration) is also referred to herein as filter media pressure loss or simply media pressure loss, and may be expressed as Δp medium .

[0018] According to various embodiments, optionally, before the selection step, the method may also include: providing a graphical representation of the filter parameter set of the available filter. In a non-limiting example, the available filter may be a plurality of virtual filters, a subset, a further selection of a subset. The graphical representation includes a delimiter representing the parameter limits. The method may also include receiving user input via a user interface, the user interface being configured to allow the user to graphically move the delimiter, thereby constraining the limits of the parameter, and limiting the available virtual filter element to the subset according to the constrained limits.

[0019] According to various embodiments, when in an unloaded state and the airspeed at the upstream side is 4.63 ms -1When , the filter element produces a pressure loss less than or equal to 120 Pa. As used herein and according to various embodiments, the upstream space velocity may also be referred to as the surface velocity.

[0020] According to different embodiments, the air permeability can be from 800L / m 2 s to 7000L / m 2 s, optional 800L / m 2 s to 6000L / m 2 s, optional 800L / m 2 s to 4500L / m 2 s.

[0021] As used herein and according to various embodiments, air permeability may be determined utilizing flat media of an air filter, for example, the media used to make the filter (eg, prior to pleating) or a flat portion of the media selected between pleat folds.

[0022] According to various embodiments, the filter element is configured such that the pleat-related pressure loss of the filter element has a rate of change with increasing airspeed that is less than or equal to 1.8 times the air density (ρ). In other words, the pleat-related pressure loss is at most 10% lower than the pressure potential and therefore has an Euler number less than or equal to 0.9. Exemplary Euler numbers are further described below.

[0023] According to various embodiments, the upstream airspeed is 4.63 ms -1 The no-load pressure loss can be equal to or greater than 50Pa.

[0024] According to various embodiments, the filter media is pleated, and wherein the pleat height (h) is from 0.025 m to 0.060 m, optionally from 0.025 m to 0.051 m. The pleat height and pleat distance may be substantially consistent across the filter element. Although pleating increases the surface area of ​​the filter, due to the geometry of the pleat folds, pleat-related pressure losses are introduced, which reduces the pressure differential across the filter media available for filtration.

[0025] According to various embodiments, the pleat ratio (ratio of pleat height to pleat distance) is from 3 to 7, optionally between 3 and 6.8. The pleat ratio may be substantially uniform across the filter element.

[0026] According to various embodiments, the filter media thickness is from 0.4 mm to 1.5 mm. At least prior to pleating, the filter media thickness may be substantially uniform, with small variations (eg, less than 5% of area) attributable to the production of the filter element.

[0027] According to various embodiments, the filter element is a particulate filter for filtering particles suspended in the air, for example, filtering out (not letting through) PM10 particles and above, PM2.5 particles and above, or PM1 particles and above. The filter may be a fine dust filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings show:

[0029] - Figure 1A An exemplary filter element 110 is shown including an area defined by a length L and a width L';

[0030] - Figure 1B shows a cross section of an exemplary ambient air treatment system 200, the system including a flow channel 210, which may be defined, for example, by a wall or a conduit, and a filter element 110 located in the flow channel 210, the filter element 110 being shown in cross section along a width L';

[0031] - Figure 2 An exemplary vehicle 1 including an ambient air treatment system 200 is shown, as well as the location of the ambient air treatment system 200 when installed in the vehicle 1;

[0032] - Figure 3 shows a cross section of an exemplary cooling system 300 including an ambient air handling system 200 and a heat exchanger 150 according to various embodiments;

[0033] - Figure 4A shows a flow chart of a method 400 for producing a filter element 110 for a vehicle for filtering ambient air;

[0034] - Figure 4B Further steps of method 400 are shown;

[0035] - Figure 5A and Figure 5B A graphical representation 500 is shown according to various embodiments;

[0036] - Figure 6 , 7 8 show graphs of virtual filters, each filter being represented by a set of parameters. Figure 6 In , all virtual filters are shown. Figure 7 In , the subset filtered to the maximum Δp is shown, and in Figure 8 In , the subset filtered to the maximum Euler number is shown.

[0037] - Fig. 9A and Figure 8The same except that two virtual filters are emphasized, namely a first virtual filter SIM1 shown with a dashed line and a second virtual filter SIM2 shown with a dash-dot line.

[0038] - Fig. 9B The parameter sets for each virtual filter shown in the table are shown, the parameters being the same as for the graphs and having the same units;

[0039] - Fig.10 shows the evolution of Δp for different space velocities, where it can be seen that the simulations (SIM1, SIM2) are able to accurately predict the Δp of the produced filter elements; and

[0040] - Fig.11 Δp and its component Δpmedium are shown as a function of airspeed; DETAILED DESCRIPTION

[0041] The following detailed description refers to the accompanying drawings to facilitate understanding of the present disclosure, but the present disclosure is not limited to the accompanying drawings or embodiments. Elements of an accompanying drawing or embodiment may be combined with elements of another accompanying drawing or embodiment.

[0042] Figure 1A An exemplary filter element 110 including an area defined by a length L and a width L' is shown. The filter element 110 includes a pleated filter medium 111, which is made by pleating the filter medium 111 into pleats with a height of h and a pleat distance of w. The filter medium 111 includes a thickness d. The ratio R is given by the pleat height divided by the pleat distance (R=h / w). The non-effective area of ​​the filter element 110 (such as the glued area or the area in the frame) is ignored in the calculation herein. As used herein and according to various embodiments, the geometric parameters of the filter element refer to the effective area of ​​the filter element. Therefore, for the filter element area that does not contribute to filtering (for example, the filter element area blocked by the frame or used for gluing), the length, width and effective area of ​​the filter element can be ignored.

[0043] The filter element may include at least one filter medium which may be folded (pleated) into at least one filter corrugated element. The filter element may include a plurality of fold stabilizing means for supporting the filter corrugated element. It may be provided that the filter medium has a tensile strength of at least 1 Nm 2 , for example at least 2Nm 2 The inherent bending stiffness of the filter medium. This refers to the inherent bending stiffness of the filter medium, ie in the raw / unfolded state. The filter may include pleat stabilization means. The system may include water separation means.

[0044] In one embodiment, the size of the effective surface (also called filtration area) of the filter element may be, for example, 2800 cm 2For a typical mid-sized passenger car, the filter element dimensions are 45 cm (width) x 65 cm (length). However, depending on the size of the vehicle, the filter element dimensions may deviate significantly from this, so that in principle a size range from 20 cm long to 120 cm long and from 15 cm wide to 100 cm wide is possible.

[0045] The filter element may include a filter frame, such as an at least partially circumferential frame, in which the filter element (e.g., filter corrugated member) is accommodated. In one example, it may be provided that the frame has an L-shaped cross-sectional form, such as a leg of the L-shaped cross-section of the frame engages behind the filter corrugated member of the filter element, and thus supports the filter element against the effects of pressure. The filter element may include two or more sub-filter elements, and the sub-filter elements may be arranged in (e.g., fixed to) a single filter frame, or alternatively, each sub-filter element may be arranged in a separate frame element of the filter frame.

[0046] The filter element can in particular comprise or be a plastic molded filter element, wherein the at least partially circumferential frame can be connected to the filter medium by a material-to-material bond. However, the invention is not limited to a material connection; as an alternative to a material connection of the filter medium to the frame, it can also be provided that the filter element is merely inserted into the frame so that it is supported in a form-fitting manner, for example, on the rear legs of the L-shaped profile.

[0047] The filter can be arranged (and can be arranged) in a receptacle of an ambient air treatment system, a cooling system or a vehicle. The receptacle can correspond to a frame of the filter, in which the filter is optionally held by a detachable fastening device (e.g., a clip connection). The receptacle can also be configured to serve as a mounting shaft, into which the at least one filter element can be inserted linearly. This makes it easy to replace the filter element, for example, from the upper side of the lock bracket of the front engine hood or from an easily accessible underbody side (e.g., during maintenance on a lifting platform). The filter element can be flexible to allow insertion, wherein the filter element must be bent during insertion and / or in the use position.

[0048] Some embodiments relate to a cooling system for a vehicle, the system comprising an ambient air treatment system according to various embodiments. The cooling system may also include a heat exchanger configured to exchange heat with air from the air flow, the heat exchanger optionally positioned downstream of the filter element. According to various embodiments, the cooling system may further include a blower for generating the air flow, for example when the vehicle has a low speed but greater than zero, is in reverse, is charging, or is stationary.

[0049] In some embodiments, it can be further provided that the filter is arranged relative to the heat exchanger of the cooling system in such a way that it covers no more than a portion (e.g., no more than 75%) of the incident flow surface of the heat exchanger, so that there may be sufficient residual heat dissipation even when the filter element is loaded. In order to achieve this, the filter element can be arranged to deviate from the heat exchanger in the vertical and / or lateral direction around the vehicle. The uncovered part of the radiator can form a bypass that can be opened and closed. In other embodiments, the bypass can be an air passage that can be opened / closed independently of the heat exchanger surface, and the filter and the heat exchanger can be separated from each other by a sufficiently large distance to allow air to flow through the heat exchanger when the bypass is open and even when the filter is loaded.

[0050] Figure 1B A cross section of an exemplary ambient air treatment system 200 is shown, the system including a flow channel 210 and a filter element 110 located in the flow channel 210, the flow channel 210 may be defined, for example, by a wall or a conduit, the filter element 110 being shown along a cross section of width L'. The arrows show an exemplary direction of airflow, wherein a surface 112 of the filter element 110 for receiving unpurified air is positioned facing the upstream side of the airflow, and an opposing surface 114 of the filter element 110 for releasing filtered air is positioned facing the downstream side of the airflow. The airflow through the filter element 110 results in an air pressure loss Δp between the upstream and downstream sides of the filter element 110.

[0051] The filter element according to various embodiments comprises at least one filter medium, and this filter medium is pleated, and can comprise frame or can be frameless.As used herein and according to various embodiments, surface and relative surface refer to the main surface of filter element.The filter medium can be a single layer or multilayer filter medium, and it can be waterproof.It can be a multilayer medium including at least one drainage layer and / or a pre-separator layer.Alternately or additionally, the filter medium can include or be composed of glass fiber and / or plastic fiber, particularly polyester and / or polyethylene.It can also be provided that the filter medium has a porosity gradient in the thickness direction, for example, in such a way that the pore size is reduced in the air flow direction.

[0052] Various embodiments relate to a filter element 110 that includes a surface 112 for receiving unpurified air on an upstream side 102, and an opposing surface 114 for releasing filtered air on a downstream side 104. The filter element 110 can be configured to generate a pressure loss (Δp) on the downstream side 104 relative to the air pressure at the upstream side 102 when air pressure is applied to the upstream side 102. The air permeability is from 800 L / m 2 s to 7000L / m 2 s, optionally from 800L / m2 s to 6000L / m 2 s, optionally from 800L / m 2 s to 4500L / m 2 The air permeability k can be determined using the flat medium of the filter element 110 .

[0053] As used herein and according to various embodiments, pressure loss (Δp) may be measured under defined conditions and in accordance with ISO 16890-2:2016, with an environment controlled in accordance with ISO 16890-2:2016 7.1.4.2.

[0054] As used herein and according to various embodiments, the air permeability of a filter media is determined according to ISO 9237:1995, "Determination of the air permeability of fabrics to air". Standard atmospheric conditions are according to ISO 139. The circular test area of ​​the filter media sample is 20 cm 2 , and the sample size is 100mm×100mm. The pressure used for the test is 200Pa.

[0055] As used herein and in accordance with various embodiments, all references to pressure loss refer to the filter element in an unloaded state unless expressly stated otherwise.

[0056] Various embodiments relate to an ambient air treatment system 200 for a vehicle, the system comprising: a flow channel 210 for allowing air to flow in a direction from a first position to a second position of the vehicle (e.g., from front to back), each of the first and second positions being flow-coupled to an external environment; and a filter element 110. The filter element 110 may be replaceable. The filter element 110 may include a surface 112 for receiving unpurified air on an upstream side 102, and an opposing surface 114 for releasing filtered air on a downstream side 104, when air pressure is applied to the upstream side 102, the filter element 110 produces a pressure loss (Δp) on the downstream side 104 relative to the air pressure at the upstream side 102. The air permeability may be from 800 L / m 2 s to 7000L / m 2 s, optionally from 800L / m 2 s to 6000L / m 2 s, optionally from 800L / m 2 s to 4500L / m 2 The air permeability k can be determined using the flat medium of the filter element 110 .

[0057] Various embodiments are directed to a cooling system 300 for a vehicle that includes an ambient air treatment system 200 according to various embodiments. The cooling system 300 may also include a heat exchanger 150 configured to exchange heat with air from the air flow, the heat exchanger 150 optionally being positioned downstream of the filter element 110.

[0058] According to various embodiments, the cooling system 300 may further include a blower for generating air flow, for example, when the vehicle has a low speed but greater than zero, is in reverse, is charging, or is stationary.

[0059] According to various embodiments, when in an unloaded state and the airspeed at the upstream side is 4.63 ms -1 When , the filter element 110 generates a pressure loss less than or equal to 120Pa.

[0060] According to various embodiments, the air permeability (k) is from 800 L / m 2 s to 7000L / m 2 s, optionally from 800L / m 2 s to 6000L / m 2 s, or from 800L / m 2 s to 4500L / m 2 The air permeability k can be determined using the flat media of the filter element 110 .

[0061] According to various embodiments, the filter element 110 is configured such that the pleat-related pressure loss of the filter element 110 has a rate of change with increasing airspeed less than or equal to 1.8 times the air density (ρ). In other words, the pleat-related pressure loss is lower than or at most equal to a pressure 10% lower than the dynamic pressure potential, and therefore has an Euler number less than or equal to 0.9.

[0062] According to various embodiments, the no-load pressure loss (Δp) is equal to or greater than 50 Pa.

[0063] The pleat height (h) of the filter element may be less than 0.15 m, for example less than 0.11 m. According to various embodiments, the pleat height (h) may be selected from 0.025 m to 0.060 m, optionally selected from 0.025 m to 0.051 m. The pleat height (h) and the pleat distance (w) may be substantially uniform over the entire filter element 110.

[0064] According to various embodiments, the pleat ratio (R=h / w) is from 3 to 7, optionally between 3 and 6.8. The pleat ratio may be substantially uniform throughout the filter element 110 .

[0065] According to various embodiments, the filter media thickness (d) is from 0.4 mm to 1.5 mm. At least before pleating, the filter media thickness may be substantially uniform, while small variations (e.g., less than 5%) may be due to the production of the filter element. The thickness is measured according to EN ISO 9073-2:1996.

[0066] According to various embodiments, the filter element is a particulate filter for filtering out particles suspended in the air, for example, filtering out (not letting through) PM10 particles and above, PM2.5 particles and above, or PM1 particles and above. The filter may be a fine dust filter.

[0067] Figure 2 An exemplary vehicle 1 including an ambient air treatment system 200 is shown, as well as the position of the ambient air treatment system 200 when installed in the vehicle 1. The flow channel 210 is configured to allow air to flow in a direction from a first position to a second position of the vehicle (e.g., from front to back). In this example, the ambient air treatment system 200 is installed so that the surface 112 of the filter element 110 faces toward the front 2 of the vehicle 1, and the opposing surface 114 of the filter element 110 faces toward the rear 3 of the vehicle 1. This allows, for example, forward movement of the vehicle (e.g., at a speed S v The airflow relative to the vehicle (ie, the forward movement of the vehicle) flows in the direction indicated by the arrow "airflow". Alternatively or additionally, the airflow may be generated by a blower. In some examples, when the airspeed on the upstream side of the airflow is determined by the vehicle speed S v Dominated or only by vehicle speed S v When the airspeed on the upstream side of the airflow is dominant, it can be a fraction of the vehicle speed, less than 1. This fraction can be measured and can be, for example, for a vehicle at speed S v Vehicles, usually at speed S v In the range of 1 / 2 to 1 / 4, for example, the vehicle speed S v = 13.89ms-1 The fraction of 1 / 3 results in 13.89 / 3 = 4.63ms -1 The upstream airspeed.

[0068] Various embodiments relate to a vehicle 1 including a filter element 110 , an ambient air treatment system 200 , and / or a cooling system 300 according to various embodiments.

[0069] According to various embodiments, the vehicle can be a self-propelled motor powered vehicle, for example, with 2, 3, 4 or more wheels. The example of the vehicle is a passenger car, a truck, a bus, a van or a rail vehicle, such as a locomotive. The vehicle may include an air inlet opening in the front region upstream of the filter element for allowing air to enter, and an air outlet downstream of the filter element for allowing air to be discharged. The air inlet opening of the ambient air treatment device present behind it can be particularly a cooling air air inlet opening, and can be covered by a radiator grille, for example. For example, relative to the vertical axis of the vehicle, this can be at the same level as the headlights, or can be positioned below or above them. The cross-sectional area of ​​the air inlet opening can be as large as possible, so that the largest possible air volume can be supplied. In some embodiments, the vehicle can be an electric vehicle or a hybrid (internal combustion engine and electric) vehicle. In some embodiments, the vehicle can be an internal combustion engine (ICE) vehicle (i.e., non-hybrid vehicle). For example, this battery of an ICE vehicle can have a relatively large capacity, and even if it is not charged by an alternator, the fan can be operated for a long time (e.g., 1 hour) without significant consumption. In some embodiments, the vehicle includes an internal combustion engine, and the cooling fluid temperature (from the hot side) can be used as an indication of the engine temperature. In some embodiments, the vehicle includes a fuel cell, and the cooling fluid temperature (from the hot side) can be used as an indication of the fuel cell temperature.

[0070] Figure 3 A cross section of an exemplary cooling system 300 is shown that includes the ambient air treatment system 200 and the heat exchanger 150 according to various embodiments. The heat exchanger 150 is configured to exchange heat with air from the air flow and is optionally positioned downstream of the filter element 110. In one example, the heat exchanger is a radiator of a vehicle, such as a radiator of an internal combustion engine vehicle.

[0071] Various embodiments relate to a method for producing a filter element for a vehicle, the filter element being used to filter ambient air. The method may include selecting a virtual filter element of a subset. For example, a user may select a curve representing parameters of a virtual filter element on a graphical user interface (e.g., by clicking with a mouse). The method may include retrieving the parameters of the one virtual filter element, such as displaying the parameters in a human-readable form, such as a numerical format such as in a table, and / or sending the parameters of the one virtual filter element to a production plant. The method may include, for example, selecting a filter medium at the production plant. In an example, the selection of the filter medium may include selecting a filter medium having a thickness and air permeability that is closest to or substantially the same as the selected virtual filter. For example, the deviation between the parameters of the filter medium and the medium of the virtual filter element may be within a tolerance range of the filter medium parameters.

[0072] The method may also include producing a filter element using the selected filter media, the filter element having a geometry (eg, pleat height) and ratios approximating the one virtual filter element.

[0073] If desired, the method may include a further selection step of a plurality of virtual filter elements (or a subset thereof). For example, the selection may include limiting by efficiency, by Euler number or by a second derivative of a graph or a fit of equation 1.

[0074] Figure 4A A flow chart of a method 400 for producing a filter element 110 for a vehicle for filtering ambient air is shown. The method 400 may include defining 410 boundary conditions, which may include element geometry boundary conditions and filter media boundary conditions; and calculating 420 pressure losses (Δp) of a plurality of different virtual filter elements selected from within the boundary conditions. The method 400 may further include selecting 422 a subset of the plurality of virtual filter elements for which the pressure losses are within a predetermined range. Each virtual filter element may be characterized by a filter parameter set including element geometry parameters, filter media parameters, media pressure losses, and pleat-related pressure losses. The method 400 may further include selecting 432 one virtual filter element of the subset, retrieving properties of the one virtual filter element, and selecting 434 a filter media having properties that approximate the one virtual filter element. The method 400 may further include producing 450 a filter element having a geometry that approximates the one virtual filter element.

[0075] As used herein and according to various embodiments, the boundary conditions may include one or more of the pleat distance (w) and the pleat height (h), or a combination thereof, such as, for example, using a pleat ratio instead of the pleat distance (w) or the pleat height (h). The boundary conditions may further include one or more of the media thickness (d), the media air permeability (k). However, the boundary conditions are not limited to the above. The boundary conditions may be in the form of a range, for example, a filter parameter set includes a height (h) from 25 mm to 50 mm, a media thickness (d) from 0.4 mm to 1.5 mm, a media air permeability (k) from 800 L / m 2 s to 7000L / m 2 s air permeability (k), and / or a pleat ratio (R=h / w) from 3 to 7. The above ranges are from experiments performed and were found to provide a feasible and optimized initial design space, however, if desired, the range can be wider to provide a larger design space.

[0076] As used herein and according to various embodiments, calculating the pressure loss (Δp) may mean, for a plurality of data points within the boundary conditions, generating a plurality of virtual filter elements by using the simulation model. The data points may be generated using known methods, such as latin hypercube sampling. Other known methods may be used to generate parameter values, wherein, preferably, the distribution of the results is random. Exemplary simulations are from: Fu, H. M., Fu, Y., Xu, F., 2014., Experiment and Simulation on Pressure Drop of Pleated Air Filters, AMR, https: / / doi.org / 10.4028 / www.scientific.net / amr.960-961.568; Hettkamp, ​​P. and Kasper, G. and Meyer, J., 2012., Simulation of pressure drop and capacity for pleated air filters loaded with dust, Filtration v. 12, Numbers 3, 1479-0602; Keller, F., Riesterer, D., Lehmann, M. J. (2016): Modelling the flow transition at the porous-fluid interface of pleated filterelements (Modeling Flow Transitions at Porous Fluid Interfaces in Pleated Filter Elements), Proceedings of the 2016 International Conference and Exhibition on Filtration and Separation Technologies: 2016; 11-13, Cologne, Germany (Keller et al.). It was found that different simulation models led to comparable results.

[0077] As used herein and according to various embodiments, selecting a subset of a plurality of virtual filter elements having a pressure loss (Δp) within a predetermined range may include receiving a sub-range of pressure losses (e.g., from a computer memory, a communication interface, and / or from an input device) and discarding all virtual filter elements that are not within the predetermined range. As previously described, the pressure loss occurs at an upstream airspeed of 4.63 ms. -1 hour.

[0078] In a further embodiment, the method 400 for producing a filter element 110 for filtering ambient air for a vehicle may further include: Figure 4BThe method 400 may include providing 423 a graphical representation 500 (eg, of filter parameter sets P1, P2, P3, and P4) of a plurality of filters (eg, filters 501 and 502). Figure 5A and 5B ). The graphical representation 500 may include delimiters, such as 511 and 512, indicating the limits of the parameters P1, P2, P3, and P4. The method 400 may include receiving 424 user input via a user interface, the user interface being configured to allow a user to graphically move the delimiters 511 and 512, thereby constraining the limits of the parameters and limiting the available virtual filter elements 501 and 502 to the subset 501 according to the constrained limits. Figure 5B In the embodiment, the mouse pointer is used to symbolically represent that the user interface may be a computer mouse. These steps may be optionally performed before the virtual filter element selection step 434.

[0079] Various embodiments relate to a method 400 of producing a filter element 110 for a vehicle (e.g., for use in a vehicle) for filtering ambient air or for use in an ambient air treatment system 200. The method may include defining 410 boundary conditions, including element geometry boundary conditions and filter media boundary conditions; calculating 420 pressure losses (Δp) for a plurality of different virtual filter elements selected from within the boundary conditions; and selecting 422 a subset of the plurality of virtual filter elements for which the pressure losses are within a predetermined range. Each filter element may be characterized by a set of filter parameters, including element geometry parameters, filter media parameters, and pressure losses. The method 400 may also include selecting 432 one virtual filter element of the subset, retrieving properties of the one virtual filter element, and selecting 434 a filter media having properties that approximate the one virtual filter element. The method 400 may further include producing 450 a filter element having a geometry that approximates the one virtual filter element. The method 400 may further include inserting the filter element 110 into the vehicle.

[0080] According to various embodiments, the method may further include, prior to the virtual filter element selection step 434 , limiting 425 the subset to a desired energy efficiency range, such as limiting pleat-related media pressure losses, for example in the form of Euler number limitations.

[0081] According to various embodiments, optionally before the selection step 430, the method may further include: providing 423 a graphical representation 500 of a set of filter parameters for a plurality of filters (501, 502), wherein the graphical representation 500 includes delimiters (511, 512) representing limits of the parameters. The method may further include receiving 424 a user input via a user interface, the user interface being configured to allow a user to graphically move the delimiters (511, 512) to constrain the limits of the parameters, and limiting the available virtual filter elements (501, 502) to the subset 501 according to the constrained limits.

[0082] Figure 5A and Figure 5B An exemplary graphical representation 500 of a filter parameter set including parameters P1, P2, P3, and P4 is shown. For illustrative purposes, parameters P1-P4 are shown, however, there may be more or fewer parameters, in one example, the filter parameter set includes h, t, k, R, Δp, Eu. Some of the parameters P1-P4 have been determined, for example, by numerically solving equations involving these parameters, and other parameters in P1-P4 are boundary conditions. The graphical representation shows the parameter values ​​associated with the virtual filter as positions on a graphical reference for the eye, such as but not limited to a bar or line. A disk is used to represent delimiters 511 and 512, however any other symbolic representation may be used, such as but not limited to: square, rectangle, bar, star, circle. Different colors may also be used to distinguish filters from each other. The points (parameter values) corresponding to each virtual filter may be linked by lines to help the user identify the parameter values ​​associated with the filter. Other forms of representation may be used, such as, but not limited to, polylines, dots, specific colors and / or line styles, such as a blue line for the selected filter to distinguish it from the remaining filters which are black. Figure 5A Parameters are shown for a first filter 501 and a second filter 502. As can be seen, both filters 501 and 502 have parameters within a range 514 defined by delimiters 511 and 512.

[0083] Steering Figure 5B, the user can use a user input interface (such as a computer mouse) in conjunction with an output user interface (such as a computer monitor) that displays the graphical representation 500. The user can use the mouse pointer to select the position of the delimiter 501, for example, to move the delimiter 501 upwards, and thereby limit the limits of the parameters, and by excluding 502 with parameter P2 outside the new range 515, the available virtual filter elements are limited to 502, so that the filters with parameters in the excluded range 516 can not be displayed. With this method, the user can exclude all parameters (whether output or boundary conditions) that are not needed for the filter in a simplified manner, and read the resulting filter subset, and obtain the technical details necessary to manufacture the filter. This reduces the multiple virtual filter elements to a subset from which parameters can be selected to generate the filter element 110. Note that the user input interface is not limited to a computer mouse, and can be, for example, but not limited to, a touch screen, a scroll wheel, a knob, a button.

[0084] Figure 6 and 7 A graph of virtual filters is shown, each filter being represented by geometric parameters: pleat height h, ratio of pleat height to pleat distance R (R = h / w); filter media parameters: media thickness d, media air permeability k; pressure loss Δp; and c2h in this form or an equivalent form (e.g., Euler number). The parameters of each virtual filter are connected by curves to facilitate graphical reading of the data. The boundary conditions for the complete data set used in the example are thickness 0.5 mm ≤ d ≤ 1.5 mm, and air permeability 250 Lm -2 s -1 ≤k≤7000Lm -2 s -1 .

[0085] exist Figure 6 All results are shown in , and it can be seen that some virtual filters have very high pressure losses Δp, making them unsuitable for certain applications requiring minimum air flow at a predetermined applied pressure range below the pressure loss Δp. In this example, this set of virtual filters can be limited by limiting the pressure loss Δp to values ​​below 120Pa (see circle), which is a suitable upper range of Δp for vehicles (e.g. buses). The resulting subset of virtual filters can be found in Figure 7 Surprisingly, no parameter combination from the original set of virtual filters has a value less than 900 Lm -2 s -1 The air permeability k. Figure 7In the figure, it can still be seen that there is a series of virtual filters with different pressure losses that can be attributed to the geometry of the filter element but do not contribute to the filtration (parameter Eu, see circle). This parameter Euler is constrained to 0.9, and the remaining virtual filters are as follows Figure 8 shown.

[0086] Fig. 9A and Figure 8 The same except that two virtual filters are emphasized, namely a first virtual filter SIM1 shown with a dashed line and a second virtual filter SIM2 shown with a dash-dot line. Fig. 9B The parameter set for each virtual filter is shown in the table. The parameters are the same as in the graph and have the same units. It can be seen that SIM1 and SIM2 have the same resolution at 4.63ms. -1 The Δp at the time is 118.7Pa and 177.9Pa respectively. The first filter element EXP1 and the second filter element EXP2 are produced with the same specifications as the virtual filters SIM1 and SIM2, i.e. the same geometry, media thickness and media permeability. For EXP1 and EXP2, 4.63ms -1 The Δp at φ and Δp at φ are 118.0 Pa and 187.0 Pa, respectively, which have very good matches with the simulation data.

[0087] Fig.10 The evolution of Δp at different space velocities is shown, where it can be seen that the simulated virtual filters (SIM1, SIM2) are able to accurately predict the Δp of the produced filter elements.

[0088] In one non-limiting example, the following model may be used to calculate the pressure differential (also known as pressure loss) for fluid flow across a filter element.

[0089] The pressure difference (ΔP) of the air flow across the pleated filter element total or Δp ​​for short) is usually a superlinear function of the cross-sectional airspeed, such as Fig.10 As shown, Fig.10 is Δp as the airspeed (V F ). Two separate contributions to the total pressure drop Δp have been distinguished: the media pressure loss, which is the pressure loss across the porous filter medium Δp medium , which is consistent with the pressure potential available for the actual filtration process; and the pleat-related pressure loss, i.e., the pressure loss of the viscous fluid flow in the pleat channel, Δp dissipation This is not directly attributable to the pressure loss potential of filtration.

[0090] For a given filter element, the total pressure taking into account these two effects can be modeled using the Darcy-Forchheimer equation: Wherein, h is the thickness of the filter element (i.e., pleat height), ρ and μ are the fluid density and dynamic viscosity, and v is the air velocity. C1 and C2 are model coefficients obtained by fitting experimental or simulated data, such as according to the simulation of Keller et al. C1 is also called the viscous drag coefficient, which is the inverse of the permeability k, i.e., C1 = 1 / k.

[0091] Breaking down the above equation into the individual pressure loss contributions yields two separate expressions: Δp medium = C1·d·μv, which is essentially Darcy's law applied to porous filter media; and Fig.11 shows Δp and its components Δp as a function of airspeed medium and Δp dissipation .

[0092] Targeting a filter element that results in a preferably low overall pressure differential, it is desirable to minimize Δp dissipation In order to introduce a nominal value measurement of this property that is independent of airspeed, the above equation is divided by ρv 2 , so rearrange to:

[0093]

[0094] Here, Eu is the Euler number, which relates pressure to the inertial force generated in the flow phenomenon. The inertial force is related to the dynamic pressure potential of the air flow. According to various embodiments, Eu used herein can be expressed as

[0095] The requirement that the pleat-related pressure loss of the filter element should not exceed the medium pressure loss is that the pleat-related pressure loss should be lower than or at most equal to a pressure 10% lower than the dynamic pressure potential. Therefore, Eu<0.9. This standard can be used to identify the range of filter media properties to achieve the best energy efficiency.

Claims

1. An ambient air treatment system (200) for a vehicle, comprising: a flow channel (210) for allowing air to flow in a direction from a first position to a second position of the vehicle, such as from front to rear, each of the first and second positions being capable of fluid coupling with an external environment; and a filter element (110) comprising a surface (112) for receiving unpurified air on an upstream side (102) and an opposing surface (114) for releasing filtered air on a downstream side (104), When air pressure is applied to the upstream side (102), the filter element (110) generates a pressure loss (Δp) on the downstream side (104) relative to the air pressure at the upstream side (102), and in, The air permeability of the filter medium of the filter element (110) is between 800 L / m 2 s to 7000L / m 2 within the range of s.

2. The ambient air treatment system (200) according to claim 1, wherein: In no-load state and at 4.63ms -1 At the upstream air velocity of , the pressure loss is less than 120Pa.

3. The ambient air treatment system (200) according to claim 1 or claim 2, wherein: The air permeability (k) of the filter medium of the filter element (110) is between 800 L / m 2 s to 7000L / m 2 s, optionally from 800L / m 2 s to 6000L / m 2 s, and optionally from 800 L / m 2 s to 4500L / m 2 within the range of s.

4. The ambient air treatment system (200) according to claim 3, wherein: The air permeability (k) of the filter medium is determined according to ISO 9237:1995, based on standard atmospheric conditions according to ISO 139 and at a pressure of 200 Pa, and wherein the circular test area of ​​the filter medium sample is 20 cm 2 , and the sample size of the filter medium is 100 mm×100 mm.

5. The ambient air treatment system (200) according to claim 3 or claim 4, wherein: The air permeability (k) is determined using a flat filter medium of the filter element (110).

6. The ambient air treatment system (200) according to any one of the preceding claims, wherein: The pressure loss associated with the pleats of the filter element (110) is smaller than the pressure loss of the filter medium of the filter element (110).

7. The ambient air treatment system (200) according to claim 4, wherein: The pleat-related pressure loss of the filter element (110) has an Euler number less than or equal to 0.

9.

8. The ambient air treatment system (200) according to any one of the preceding claims, wherein: At 4.63ms -1 At the upstream air velocity, the no-load pressure loss (Δp) is equal to or greater than 50Pa.

9. The ambient air treatment system (200) according to any one of the preceding claims, wherein: The filter medium (111) is pleated, and wherein the pleat height (h) is from 0.025m to 0.060m.

10. The ambient air treatment system (200) according to any one of the preceding claims, wherein: The pleat ratio (R) is from 3 to 7, optionally between 3 and 6.

8.

11. The ambient air treatment system (200) according to any one of the preceding claims, wherein: The filter medium (111) has a thickness (d) of from 0.4 mm to 1.5 mm, wherein the thickness (d) is measured according to EN ISO 9073-2:1996.

12. The ambient air treatment system (200) according to any one of the preceding claims, wherein: The filter element (110) is a particle filter, such as PM10, PM2.5 or PM1.

13. A cooling system (300) for a vehicle, comprising: The ambient air treatment system (200) according to any one of the preceding claims, A heat exchanger (150) configured to exchange heat with air from the air stream, the heat exchanger (150) being in the stream of the filter element (110), optionally downstream of the filter element (110).

14. The cooling system (300) according to claim 13, wherein: The cooling system (300) also includes a blower for generating air flow, for example, when the vehicle has a low speed but greater than zero, is in reverse, is charging, or is stationary.

15. A vehicle (1) comprising a cooling system (300) according to claim 13 or 14.

16. A method (400) for producing a filter element (110) for a vehicle according to claim 15 for filtering ambient air, the method comprising: - defining (410) boundary conditions, including element geometry boundary conditions and filter medium boundary conditions; - calculating (420) the pressure loss (Δp) of a plurality of different virtual filter elements selected within the boundary conditions; - selecting (422) a subset of the plurality of virtual filter elements for which the pressure loss is within a predetermined range, Wherein, each virtual filter element is characterized by a filter parameter set including element geometric parameters, filter medium parameters, and pressure loss; - selecting (432) a virtual filter element of the subset, retrieving properties of the one virtual filter element, and selecting (434) a filter medium having properties that approximate the one virtual filter element; and - producing (450) a filter element (110) having a geometry approximating said one virtual filter element.

17. The method of claim 16, further comprising, prior to the virtual filter element selecting step (434), limiting (425) the subset to a desired range of pleat-related pressure losses.

18. The method of claim 16, further comprising, optionally before the selecting step (432), providing (423) a graphical representation (500) of a set of filter parameters of available virtual filter elements (501, 502), in, The graphical representation (500) includes delimiters (511, 512) indicating parameter limits, and User input is received (424) via a user interface configured to allow a user to graphically move the delimiters (511, 512), thereby constraining the limits of the parameters and limiting the available virtual filter elements (501, 502) to a subset (501) according to the constrained limits.

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