Air-cooled pressurizing device

Abstract

An air-cooled pressurization device (1), in which two or more heat exchangers (16, 17, 23) are arranged near each other or overlapping each other or both in a cross section (24, 49) of the air channel (13) such that a total air flow (15) through the air channel (13) is divided into a plurality of air flows (25-27), and one or more guide elements (28) are provided in the air channel (13) for dividing the air flow (15) and guiding the air to one or more of the heat exchangers (16, 17, 23) or to parts of such heat exchangers (16, 17, 23).

Description

[Technical field]

[0001] The present invention relates to a pressurization device, typically a compressor, for compressing or pressurizing a fluid, typically a gaseous fluid, such as air or other gases, such as oxygen, carbon dioxide, nitrogen, argon, helium or hydrogen, etc. However, the invention does not exclude that the pressurization device is used to compress or pressurize denser fluids, such as water vapour.

[0002] Furthermore, the pressurizing device of the present invention comprises a housing, a fluid duct for guiding a fluid through the pressurizing device from a fluid duct inlet to a fluid duct outlet, and one or more pressurizing stages each comprising a pressurizing element for pressurizing the fluid, the pressurizing stages being contained in and forming part of the fluid duct.

[0003] These pressure application elements are typically connected in series, although the invention does not exclude other configurations.

[0004] Typically, uncompressed ambient air is taken in at a fluid duct inlet, converted through various pressurization stages in the pressurization device into compressed air, and this compressed air is supplied at a fluid duct outlet for use by a user of the compressed air or pressurized air (or, in the more general case, pressurized fluid).

[0005] More specifically, the invention relates to a pressurizing device of this kind comprising means for cooling, which are at least in part air cooling means.To this end, the pressurizing device to which the invention relates comprises one or more devices for forcing an air flow in an air channel passing through the housing from an air channel inlet to an air channel outlet.

[0006] Furthermore, the pressurization device according to the invention comprises at least two, and possibly more than two, heat exchangers positioned in the air channel, for transferring heat from the heat exchanger to the air forced through the air channel by one or more devices for forcing the air flow. Typically, these heat exchangers are intended to cool the pressurized fluid and to transfer the heat stored in it during compression to the ambient air flowing through said heat exchanger. Hot pressurized fluid is not suitable for supply to a pressurized fluid consumer, not only because it is hot, but also because, for example, excessive moisture will accumulate in it. Often, after each pressurization stage in the pressurization device, a heat exchanger is provided in order to cool the fluid before providing it to the next pressurization stage or to a pressurized fluid consumer.

[0007] Also, the invention does not exclude heat exchangers being positioned in the air channels for purposes other than cooling the pressurized fluid. In one possible embodiment, for example, an oil-to-air heat exchanger or cooler may be positioned in the air channel through which oil flows to lubricate or cool compressor components, such as bearings and gearing. [Background technology]

[0008] Compressing air or another fluid converts energy into heat, resulting in hot compressed or pressurized air or fluid that needs to be cooled to be useful to a user. In addition, the oil circulating in the oil circulation system of the pressurization device to lubricate or cool the components of the pressurization device also needs to be cooled. In yet another example, the pressurization device includes a liquid cooling circuit, for example to recover energy stored in the pressurized fluid during the compression process. In many cases, the liquid cooling circuit further includes a liquid-to-air heat exchanger to cool the residual heat that is not consumed by the consumers of this recovered energy and remains in the liquid cooling circuit.

[0009] In summary, in many applications using pressurizing devices, there is a need to cool two or more heat exchangers in an air flow of ambient air drawn in from the surrounding environment by a device for forcing an air flow in an air channel provided in the housing of the pressurizing device.

[0010] Generally, several difficulties or problems arise when several heat exchangers have to be cooled by the same air flow generated in the air channel. In practice, a single device for forcing the air flow is usually used, and sometimes one or more such devices for forcing the air flow through the air channel provided in the housing of the pressurizing device. Several heat exchangers in this air channel are exposed to the air flow generated by the device for forcing the air flow through the air channel. That is to say, this forcing air flow is divided in the air channel into different heat exchangers or coolers. There is no separate device for forcing the air flow for each heat exchanger.

[0011] However, said heat exchangers may vary widely in size, shape and characteristics and may be made from different materials depending on their purpose, and may be used to cool very different media, and furthermore the cooling requirements in terms of cooling rate, input and output temperatures of the media to be cooled, and flow rate of the media flowing through said heat exchanger may vary widely depending on the application.

[0012] An important characteristic in this context is, for example, the flow resistance of the heat exchanger mentioned above. Air-air, fluid-air or liquid-air heat exchangers in the form of coolers are essentially cooling devices with one or more ducts. These ducts are some kind of narrow channels or passages, typically formed as tubular elements with a rectangular cross section, in which the air, fluid or liquid (medium) to be cooled by the cooling air flows. These ducts are somewhat spaced apart from each other to allow the cooling air to flow through the open spaces between the ducts. Internal fins are provided in these ducts or in the narrow channels to increase the contact surface area with the air, fluid or liquid (medium) to be cooled flowing in the ducts. These fins, also called turbulators, introduce turbulence into the flow, increasing the efficiency of the heat transfer process.

[0013] Additionally, external fins are further provided on the exterior of the ducts to increase the contact surface area with the cooling air flowing in the open spaces between the ducts, improving heat transfer between the cooling air and the fluid, air, or liquid being cooled.

[0014] Clearly, depending on the amount of open space between the ducts, the width of the ducts, and the shape of the external fins, etc., the airflow to the heat exchanger will encounter more or less resistance as it flows through the spaces between the ducts.

[0015] It is easily understood that this air flow will tend to flow more smoothly in a heat exchanger with a lower flow resistance than in a heat exchanger with a higher flow resistance. As a result, if two heat exchangers of the same size but with different flow resistances are subjected to the same biased air flow flowing uniformly through the air channels, the heat exchanger with the lower flow resistance will experience a relatively higher flow rate of cooling air than the heat exchanger with the higher flow resistance, and therefore a higher cooling capacity.

[0016] However, these cooling requirements are often such that the cooling air flow rate passing through both heat exchangers is split more or less evenly. In other instances, or more commonly, the cooling air flow rate passing through each heat exchanger in the air channel does not match the cooling air flow rate required to meet the cooling capacity required for the aforementioned heat exchanger.

[0017] Further parameters play an important role and can complicate things considerably. Indeed, consider two identical heat exchangers, completely identical in shape and size, flow resistance and other external characteristics, and made of the same material, placed in the air channel of a pressurized device. If such a type of heat exchanger is positioned in a uniform air flow in the air channel, it is expected that the air flow passing through this heat exchanger will also be identical.

[0018] Moreover, it is assumed that both identical heat exchangers are intended to cool different media having quite different specific heat capacities, while these media are pumped at the same flow rate through them. For example, it is assumed that a first heat exchanger is intended to cool a medium with a low specific heat capacity, such as air, and a second heat exchanger is intended to cool a medium in liquid form with a(n) higher specific heat capacity, such as lubricating oil.

[0019] It is clear that in order to cool the medium with the lower specific heat capacity (air) by 1°C in this first heat exchanger, a certain flow rate of cooling air is required for the previous heat exchanger, which is much lower than the flow rate of cooling air required to cool the medium with the higher specific heat capacity (oil) by 1°C in the second heat exchanger.

[0020] Thus, if the objective is to cool both different media in these two equivalent heat exchangers or to reduce the temperature of these media at the same rate, the first heat exchanger should be subjected to a lower air flow rate than the second heat exchanger. This is not the case if the aforementioned media flow through the equivalent heat exchangers of the same size at the same flow rate and if these heat exchangers are subjected to the same uniform air flow of cooling air in the air channels. Moreover, this shows that it is by no means obvious to meet a specific cooling capacity requirement in two or more heat exchangers simultaneously exposed to the same cooling air flow, even when only the medium to be cooled is taken into account, let alone when other factors are taken into account.

[0021] Of course, further parameters may play an additional or alternative role, for example the media in these heat exchangers may have different approach temperatures, which have a large influence on the efficiency of heat transfer between the media flowing in the heat exchanger to be cooled and the cooling air.

[0022] Indeed, it is assumed for example that the first and second heat exchangers are identical and intended to cool the same medium, that these media flow at the same flow rates through said heat exchangers, as well as that the cooling air flows to these heat exchangers are the same, and furthermore that the temperature of the medium to be cooled at the inlet of the first heat exchanger is relatively higher than the temperature of the medium at the inlet of the second heat exchanger.

[0023] It is clear that the heat of the medium in this first heat exchanger is transferred more effectively to the cooling air than in the second heat exchanger, since the temperature difference between the medium to be cooled and the cooling air is higher in the first heat exchanger than in the second heat exchanger. Meanwhile, the flow rates of the medium to be cooled and the cooling air are still identical. The first heat exchanger therefore has a higher cooling capacity than the second heat exchanger. Hence, also from this point of view, it does not seem clear to meet certain cooling requirements for two or more heat exchangers subjected to a common uniform air flow in the air channel.

[0024] From the above, it also becomes clear that the flow rate of the medium to be cooled in said heat exchanger plays a role: indeed, the higher the flow rate of the medium to be cooled, the more the amount of medium that has to be cooled by the cooling air at a certain fixed air flow rate in a certain time interval, and the weaker the temperature drop of the medium to be cooled after passing through said heat exchanger.

[0025] And finally, the design of the pressurizing device itself, the operating conditions of the pressurizing device, and the desired requirements by the consumers of the pressurized fluid (e.g., output flow rate, output pressure, output fluid temperature, etc.) significantly constrain the freedom to randomly select or set the aforementioned parameters and essentially determine the cooling needs in the air channels, which typically vary significantly for the various heat exchangers mentioned above.

[0026] For example, typically, a pressurizing device includes an oil lubrication system, where the temperature of the oil increases to a certain higher oil temperature after passing through the lubrication circuit. An oil-air cooler may be placed in the air channel to cool the oil to a required lower oil temperature. The oil flows through the oil lubrication circuit at a certain flow rate. These higher and lower oil temperatures, as well as the required oil flow rate, depend on the type of oil used, as well as the design, operating conditions, and constraints of the components of the pressurizing device.

[0027] Likewise, such a pressurization device usually comprises two or more compression stages. A fluid is, for example, compressed in a first stage and further compressed in a second stage, each time being heated during the compression process. The fluid is cooled after each stage in a first fluid-air cooler and a second fluid-air cooler, respectively. The fluid flow rate after each compression stage is usually different, as is the fluid temperature reached by the compressed fluid during compression and the required fluid temperature after cooling. These parameters are usually determined by the design and operating conditions of the pressurization device and by the requirements stipulated by the consumers of the pressurized fluid.

[0028] It is clear that the parameters of the oil-air cooler and the two fluid-air coolers cannot be selected randomly, so that several heat exchangers with very different cooling air requirements are positioned together and provided in the air channel, simultaneously subject to the same cooling air flow. In general, the cooling air flow conditions will not be suitable for all the aforementioned heat exchangers or coolers with very different requirements.

[0029] One possible method known from the state of the art to address the issue of cooling air flow and cooling capacity of multiple heat exchangers in an air channel consists of redesigning the heat exchanger so that it has an outer shape, flow resistance, size, tube inner diameter, etc., such that the required part of the total amount of cooling air flows through said heat exchanger corresponding to the required cooling capacity (possibly adapted).

[0030] One major drawback of this solution is that designing and manufacturing a heat exchanger or set of heat exchangers suitable for each particular application or even combination of applications is very time-consuming, difficult and costly.

[0031] Moreover, such a method is disadvantageous for the standardization and reuse of the components of the pressure device, in particular the heat exchangers or cooling elements provided in such a pressure device.

[0032] Furthermore, a pressurizing device of a particular type, and even a single pressurizing device of a particular type, is often used in situations where the required output pressure of the pressurized fluid or the required output flow rate of the pressurized fluid is subject to varying conditions.

[0033] Therefore, in practice, it is not feasible to tailor the design to each situation, and as a result, heat exchangers often do not function at optimum conditions.

[0034] Another possibility for solving the airflow problem in applications with multiple heat exchangers consists of regulating the flow rate of the cooling air by means of a device for forcing the airflow through the air channels.

[0035] In fact, by increasing the flow rate of cooling air provided by the device for energizing the air flow to a sufficiently high level, it is often possible to ensure that each of the aforementioned heat exchangers achieves at least its minimum required cooling capacity. However, this solution usually requires that an excessively high flow rate of cooling air is provided, which is not cost-effective in the first place. Moreover, it is generally not possible to provide an adapted cooling air flow for each of the aforementioned heat exchangers or coolers, so that over- or under-cooling situations are not eliminated.

[0036] Yet another problem existing with known pressurization devices is the high level of noise caused by the cooling air flow in the air channel and through the cooler or heat exchanger, and the fan or device for forcing the air flow in the air channel. Summary of the Invention [Problem to be solved by the invention]

[0037] It is an object of the present invention to overcome one or more of the above-mentioned problems and / or possibly further problems.

[0038] In particular, one object of the invention is to provide an improved air-cooled pressurization device, which comprises two or more heat exchangers in the air channel of the pressurization device, making it possible to better supply the required cooling air flow to at least one, and preferably to each, of said heat exchangers, in which the supplied cooling air flow is better adapted to the required cooling capacity of said heat exchangers than is the case with similar pressurization devices known from the state of the art.

[0039] Yet another object of the present invention is to provide an air-cooled pressurization device in which the total power required to force the refrigerant air through the refrigerant air channels is minimized or at least reduced compared to similar pressurization devices known from the state of the art.

[0040] Additionally, it is an object of the present invention to reduce the noise generated and acoustic energy dissipated by elements of the air cooling system of a pressurized device as compared to similar pressurized devices currently known.

[0041] A further object of the present invention is to provide a method for easily adapting existing known pressure devices with minimal additional elements and without the need for significant modifications to the components of such existing known pressure devices.

[0042] Finally, it is a further object of the present invention to develop an air-cooled pressurization device that is size limited, reliable and cost effective. [Means for solving the problem]

[0043] To this end, the invention relates to an air-cooled pressurization device comprising a housing, a fluid duct for guiding a fluid through the pressurization device from a fluid duct inlet to a fluid duct outlet, one or more pressurization stages in the fluid duct each comprising a pressurization element, a device for biasing an air flow in an air channel passing through the housing, and two or more heat exchangers positioned in the air channel for transferring heat from the heat exchanger to air biased through the air channel by the device for biasing the air flow. These two or more heat exchangers are arranged near each other or overlapping each other, or both, in the cross-section of the air channel, such that the total air flow through the channel is divided into multiple air flows, each air flow passing through a corresponding one of these two or more heat exchangers, which allocate the total air flow to the two or more heat exchangers in the cross-section, and one or more sheet-like or plate-like guide elements are provided in the air channel to divide the air flow and guide the air to one or more of the two or more heat exchangers or parts of such one or more heat exchangers.

[0044] One great advantage of such a pressurization device according to the invention is that the airflow of cooling air is distributed to the multiple heat exchangers by means of sheet-like or plate-like guiding elements provided in the air channel and can be guided or directed towards one or more of the heat exchangers or, conversely, away from one or more of the heat exchangers, with the intention of dividing the total airflow into different airflows better adapted to the needs of the different heat exchangers.

[0045] In this way, it is possible to control the amount of refrigerant airflow passing through at least one of these heat exchangers or coolers, which can be advantageously used to increase the cooling power of one particular cooler by decreasing the cooling power of another cooler in the airflow.

[0046] Another advantage of such a pressurization device according to the invention is that in many cases the total power required to move the refrigerant air over the entire air channel can be minimized. Indeed, if the air flow is partially guided towards a heat exchanger with a higher air flow resistance, for example by a sheet-like or plate-like guide element, a higher air flow rate will flow through the heat exchanger than if no sheet-like or plate-like guide element was arranged in the air channel. This means that the required air flow in said heat exchanger can be achieved with a lower total air flow provided by the device for biasing the air flow. Moreover, this also makes it possible to reduce the energy consumption of the device for biasing the air flow.

[0047] Thus, in one possible embodiment of the air-cooled pressurization device according to the invention, heat exchangers with different flow resistances are provided in the air channel, and one or more guide elements are oriented and positioned in the air channel to restrict, guide or divide the air flow in the air channel, so that a relatively large part of the air flow is guided towards the heat exchanger with the higher flow resistance, and the part of the air flow going towards the heat exchanger with the lower flow resistance is partially guided away from the heat exchanger or is somewhat restricted. The word "relatively" is used to express that the part of the air flow guided towards said heat exchanger with the higher flow resistance is not necessarily larger in an absolute sense than the part of the air flow going towards the heat exchanger with the lower flow resistance, but is larger in a relative sense compared to the case where there are no guide elements in the air channel.

[0048] In contrast, if the air flow through the heat exchanger with the lower airflow resistance is not sufficient to achieve the required cooling capacity and the heat exchanger with the higher airflow resistance has excess cooling capacity, it may be advantageous to partially guide the air flow towards the heat exchanger with the lower airflow resistance by means of sheet-like or plate-like guide elements.

[0049] Therefore, in another possible embodiment of the air-cooled pressurization device according to the invention, one or more guide elements are oriented and positioned in the air channel to restrict, guide or divide the air flow within the air channel so that a relatively large portion of the air flow is guided towards the heat exchanger with the lower flow resistance and the portion of the air flow heading towards the heat exchanger with the higher flow resistance is partially guided away from the heat exchanger or is somewhat restricted.

[0050] In another preferred embodiment of the air-cooled pressurization device according to the invention, one or more guide elements are positioned and oriented in the air channel such that the air flow passing through said heat exchanger having different air flow resistance is more evenly distributed over said heat exchanger than in the absence of such one or more guide elements.

[0051] One advantage of such an embodiment of the pressurization device according to the invention is that the total air flow is distributed more evenly between the different heat exchangers or coolers, i.e. those with higher air flow resistances fed by a larger portion of the total air flow and those with lower air flow resistances fed by a smaller portion of the total air flow, compared to the case where there are no guiding elements in the air channels. Such an arrangement is suitable when said heat exchangers or coolers require more or less the same flow rate of cooling air to meet their cooling needs.

[0052] In other examples, of course, the present invention does not preclude directing a larger portion of the total airflow towards heat exchangers or coolers requiring higher cooling capacity, and / or restricting the airflow somewhat towards heat exchangers or coolers requiring lower cooling capacity, even in situations where all heat exchangers or coolers are performed in the same way.

[0053] In yet another preferred embodiment of the air-cooled pressurization device according to the present invention, one or more guide elements are oriented and positioned in the air channel to restrict, guide or divide the air flow within the air channel in a manner that improves the overall flow through the air channel by reducing friction losses, thereby reducing the pressure drop across the air channel compared to without the one or more guide elements.

[0054] Such an embodiment of the pressure device according to the invention has the advantage that less energy is consumed by the device to force an air flow in the air channel.

[0055] In another possible embodiment of the air-cooled pressurization device according to the invention, the guide element forms a baffle which is at least partially covered on one or both sides by a noise-absorbing acoustic foam or is made entirely from a foam or porous material with very high flow resistance.

[0056] One advantage of such an embodiment of the pressure device according to the present invention is that the noise absorbing acoustic material or foam absorbs sound energy, thereby significantly reducing the noise generated by cooling of the pressure device.

[0057] The invention will now be further described with reference to the drawings. [Brief description of the drawings]

[0058] [Figure 1] 1 is a schematic cross-sectional view of one possible embodiment of a pressure device according to the invention; [Diagram 2] FIG. 2 is a schematic cross-sectional view showing another possible embodiment of a pressure device according to the present invention in a more simplified manner. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing another possible embodiment of a pressure device according to the present invention in a more simplified manner. [Figure 4] FIG. 2 is a schematic cross-sectional view showing another possible embodiment of a pressure device according to the present invention in a more simplified manner. [Diagram 5] FIG. 2 is a schematic cross-sectional view showing another possible embodiment of a pressure device according to the present invention in a more simplified manner. [Figure 6] FIG. 6 is a front view of a heat exchanger of a pressurizing device according to the invention, as indicated by arrow F6 in FIG. 5; [Figure 7] FIG. 3 is a front view of a heat exchanger of a pressurizing device according to the invention, as indicated by arrow F7 in FIG. 2; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] 1 shows a first possible embodiment of an air-cooled pressurization device 1 according to the invention, intended to compress or pressurize a fluid 2. In this example, this fluid 2 is air 2 taken from the surrounding environment 3 of the pressurization device 1.

[0060] The pressurization device 1 comprises a housing 4 and a fluid duct 5 for guiding a fluid 2 through the pressurization device 1 from a fluid duct inlet 6 to a fluid duct outlet 7. The fluid 2 taken in at the fluid duct inlet 6 is pressurized or compressed in the pressurization device 1 by one or more pressurization stages, in this example two pressurization stages 8 and 9. These pressurization stages 8 and 9 form part of the fluid duct 5 and each comprise a pressurization element, namely pressurization element 10 and pressurization element 11 in this example.

[0061] In the example of this figure, the pressurizing elements 10 and 11 are compressors 10 and 11, but the invention does not exclude the use of other types of pressurizing elements, such as pumps, etc. Each of the pressurizing elements 10 and 11 is driven by a motor, such as an electric motor, not shown in FIG.

[0062] The pressurized fluid (air) 12 leaves the pressurization device 1 at a fluid duct outlet 7 and is supplied to a consumer or network of pressurized fluid 12, for example via a pipe or piping network (not shown).

[0063] In the example of FIG. 1, the fluid 2 to be pressurized is air, but it could also be any other gaseous or denser fluid, for example oxygen, carbon dioxide, nitrogen, argon, helium, hydrogen or water vapor.

[0064] An air channel 13 is provided in the housing 4, and a device 14 for forcing an air flow 15 in the air channel 13 ensures the supply of an air flow 15 through the air channel 13. The device 14 for forcing the air flow 15 is typically a fan 14 or a ventilator. The illustrated device 14 for forcing the air flow 15 is only one of many possibilities, in other embodiments several such devices 14 for forcing the air flow 15 may be provided, these devices 14 being mounted, for example, in a parallel or series configuration or even in other configurations. The device 14 for forcing the air flow 15 can also consist of several fans or ventilators or just a single fan or ventilator.

[0065] In each stage 8 or 9, the pressurized fluid 2, after passing through the aforementioned pressurizing element 10 or 11, is cooled in a corresponding heat exchanger or cooler, namely cooler 16 and cooler 17, respectively, which are positioned in the air channel 13 for transferring heat from the heat exchanger or cooler 16 or 17 to the cooling air 15. This cooling air 15 is ambient air drawn from the surrounding environment 3 of the pressurizing device 1 and forced through the air channel 13 by a device 14 for forcing the air flow.

[0066] The first cooler 16 cools the fluid 2 compressed in the compression element 10 of the first stage 8, i.e. the first compression element 10, and constitutes an intercooler 16 positioned downstream (in the fluid flow 2) of the first compression element 10 and upstream (in the fluid flow 2) of the second compression element 11.

[0067] The second cooler 17 cools the fluid 2 compressed in the compression element 11 of the second or final stage 8, i.e. the second compression element 11, and constitutes a final cooler 17 positioned downstream (in the fluid flow 2) of the second compression element 11.

[0068] The pressurizing device 1 further comprises an oil lubrication and / or cooling system comprising an oil reservoir or oil sump 18 having oil 19. A closed-loop oil circuit 20 consisting of oil tubes 21 connects the oil reservoir 18 to components of the pressurizing device 1 that require lubrication or cooling, such as the rotors, bearings, gearing and drive motors of the pressurizing elements 10 and 11 (not shown in Figure 1). Furthermore, oil 19 is returned from said components to the oil reservoir 18 through the oil circuit 20.

[0069] An oil pump 22 is provided in the oil circuit 20 upstream of the oil reservoir 18 for circulating the oil 19 around the oil circuit 20 .

[0070] In the example of Fig. 1, the oil circuit 20 comprises two loops: a first loop runs from the oil reservoir 18 towards the first pressurizing element 10 and back to the oil reservoir 18. A second loop runs from the oil reservoir 18 towards the second pressurizing element 11 and back to the oil reservoir 18.

[0071] An oil cooler 23 is provided in the oil circuit 20. This oil cooler 23 is also positioned in the air channel 13 for cooling the oil 19 circulating in the oil circuit 20 by the cooling air flow 15 flowing through the air channel 13.

[0072] Generally, according to the present invention, at least two, and possibly more, heat exchangers are arranged in the cross section 24 of the air channel 13 near each other or overlapping each other, or both, such that the total air flow 15 through the channel 13 is divided into multiple air flows.

[0073] In the example of FIG. 1, there are three such heat exchangers or coolers, namely an intercooler 16, an aftercooler 17 and an oil cooler 23, and these three heat exchangers or coolers 16, 17 and 23 are stacked so as to overlap one another in the cross section 24 of the air channel 13.

[0074] The oil cooler 23 is positioned between the aftercooler 17 and the intercooler 16 , the intercooler 16 is located above the oil cooler 23 , and the oil cooler 23 is located above the aftercooler 17 .

[0075] Since there are no other openings in the cross section 24 other than those in the coolers 16, 17, 23, the total air flow 15 is divided into a number of air flows 25, 26, and 27 (indicated by arrows in FIG. 1).

[0076] Each of the air flows 25, 26, and 27 flows through an opening in one corresponding heat exchanger or cooler, namely the intercooler 16, the oil cooler 23, and the aftercooler 17. The air flows 25, 26, and 27 divide the total air flow 15 at the cross section 24 for the aforementioned coolers 16, 17, and 23.

[0077] Furthermore, according to the invention, one or more sheet-like or plate-like guide elements 28 are provided in the air channel 13 for dividing the air flow 15 and guiding the air to one or more of two or more heat exchangers or coolers or to parts of such one or more heat exchangers or coolers.

[0078] 1, the air channel 13 comprises only one such sheet- or plate-like guide element 28. In this example, this guide element 28 is positioned upstream (in the air flow) of the heat exchangers or coolers 16, 17 and 23 or upstream of said cross section 24 in the air channel 13.

[0079] The air channel 13 extends from an air channel inlet 29 to an air channel outlet 30 and, in this example, the device for biasing air flow 14 is attached to the air channel outlet side 30 .

[0080] However, the present invention does not exclude mounting a device 14 for biasing air flow on the air channel inlet side 29, or mounting such a device 14 for biasing air flow on both the inlet side 29 and the outlet side 30 of the air channel 13.

[0081] 1, the air channels 13 extend mainly in a vertical direction AA′ through the pressure device 1. Preferably, the device 14 for biasing the air flow is positioned in the upper part 31 of the pressure device 1 or on the top of the pressure device 1.

[0082] An air channel inlet 29 and an air channel outlet 30 are also provided at the top 31 of the pressurization device 1, and the air 15 in the air channel 13 flows downward from the air channel inlet 29 to the heat exchangers or coolers 16, 17, and 23 in the air channel 13, and flows upward from the heat exchangers or coolers 16, 17, and 23 to the air channel outlet 30.

[0083] The air channel 13 is mainly U-shaped or V-shaped, and the heat exchangers or coolers 16, 17 and 23 are positioned one above the other in a mainly vertical plane of a cross section 24. This cross section 24 essentially divides the air channel 13 into a portion for a downward air flow 32 and a portion for an upward air flow 33.

[0084] 1, the guide element 28 is provided upstream (in the air flow 15) of the heat exchangers or coolers 16, 17 and 23. The guide element 28 has a lower part 34 with a flat surface oriented parallel to the vertical plane of the heat exchangers or coolers 16, 17 and 23 and an upper part 35 with a flat surface inclined in an oblique direction BB′ relative to the lower part 34 towards the air channel inlet 29 provided in the side wall 36 of the housing 4 of the pressurizing device 1.

[0085] In the embodiment of Fig. 1 discussed here, it is clear that the heat exchangers or coolers 16, 17 and 23 have different sizes. More generally, the heat exchangers or coolers 16, 17 and 23 arranged in the air channel have different air flow resistances. In particular, for example the oil cooler 23 may have very different characteristics in terms of shape, air flow resistance, cooling capacity, and inlet and outlet temperature of the oil 19 to be cooled compared to the characteristics of the corresponding intercooler 16 and aftercooler 17. Furthermore, the specific heat capacity of the oil 19 is significantly different from the specific heat capacity of the pressurized fluid 2 (typically air) to be cooled in the intercooler 16 and aftercooler 17.

[0086] If guide element 28 is not installed in air channel 13, total air flow 15 will be divided among coolers 16, 17, and 23 in a manner determined by air flow resistance, but the respective air flows resulting from this division will generally not match the required flow rate of cooling air required by each cooler 16, 17, or 23 to achieve the desired cooling capacity.

[0087] Generally, the cooler with the lowest airflow resistance will have a higher flow rate of cooling air and the cooler with the highest airflow resistance will have a lower flow rate of cooling air.

[0088] If there is not enough airflow through the heat exchanger or cooler with high flow resistance, it is possible to remedy this by increasing the total airflow 15, for example by increasing the rotational speed of the device 14 or devices 14. However, one drawback of this solution is that more energy is consumed and possibly an excessively high proportion of cooling air airflow to the heat exchanger or cooler with lower air resistance may occur, resulting in overcooling in said cooler.

[0089] The installation of the guide element 28 within the air channel 13 allows the total air flow 15 to be divided and guided towards one or more heat exchangers or coolers 16, 17, or 23 that require a relatively larger portion 25, 26, or 27 of the total air flow 15 than would be the case without the guide element 28. Additionally, a portion of the total air flow 15 can be guided away from one or more heat exchangers or coolers 16, 17, or 23 that require a relatively smaller portion 25, 26, or 27 of the total air flow 15 than would be the case without the guide element 28.

[0090] The air-cooled pressurization device according to claim 2 or 3 is characterized in that one or more guide elements are positioned and oriented in the air channel such that the air flow passing through said heat exchanger is distributed more evenly over said heat exchanger than would be the case without said one or more guide elements.

[0091] Another criterion that can be used to define the positioning and orientation of the guide elements 28 within the air channel 13 consists of searching for a positioning or orientation such that the overall air flow 15 through the air channel 13 is improved by reducing friction losses, thereby reducing the pressure drop across the air channel 13 compared to when one or more guide elements 28 are not used.

[0092] The situation shown in Figure 1 can be considered as a rather schematic illustration of a pressure device 1 of the present invention. Figures 2 to 5 are even more schematic views that are only intended to illustrate some principles of the present invention that can be applied in an actual pressure device 1 of the present invention.

[0093] 2 shows very diagrammatically an air channel 13 of a pressurization device 1 according to the invention. In a cross section 24 of the air channel 13 there are two coolers 16 and 17 mounted one on top of the other in a vertical cross section 24 of the air channel 13. For example, the coolers 16 and 17 can be an intercooler 16 and an aftercooler 17 etc. for cooling the pressurized fluid 2, similar to the previous example of FIG.

[0094] 6 is a front view of the cross section 24. At the position of the cross section 24, it is clear that the total air flow 15 through the channel 13 is divided into air flows 25 and 26 between the two coolers 16 and 17. The coolers 16 and 17 are mounted in a frame 37, which consists of side strips 38 and 39, an upper strip 40 and a lower strip 41. In the middle of the frame, a middle strip 42 separates the upper cooler 16 from the lower cooler 17. There are no openings in the cross section 24 other than those provided in the coolers 16 and 17. Naturally, the invention does not exclude the application of any kind of other configurations with a larger number of coolers or heat exchangers, regardless of their mounting position relative to each other.

[0095] In Figure 2, the air channels 13 extend horizontally, although in practice this is not necessarily the case. The arrows at the top of Figure 2 indicate the direction of cooling air flow through the channels 13.

[0096] A guide element 28 in the form of a sheet- or plate-like element 28 is attached to the coolers 16 and 17 and to the upstream side (in the cooling air flow 15) of the cross section 24. The guide element 28 inclines downwards along the direction BB' towards the centre of the air channel 13, i.e. towards the middle strip 42 of the frame 37 separating the upper cooler 16 from the lower cooler 17.

[0097] Naturally, the guide elements 28 guide the air flow 15 towards the undercooler or aftercooler 17 and somewhat impede the cooling air flow towards the topcooler or intercooler 16. This is also very clear from the front view shown in FIG.

[0098] As a result, a larger portion of the total air flow 15 flowing through the air channel 13 forms an air flow 26 towards the aftercooler 17, thus increasing the cooling capacity of this aftercooler 17 compared to the case where the guide element 28 is not installed in the air channel 13.

[0099] On the other hand, a smaller portion of the total air flow 15 forced through the air channel 13 forms an air flow 25 toward the intercooler 16, which has a reduced cooling capacity compared to when the guide element 28 is not installed in the air channel 13.

[0100] Of course, this is only one possible configuration and, for example, the positions of the intercooler 16 and the aftercooler 17 could be swapped.

[0101] FIG. 3 shows an arrangement which is entirely identical to that shown in FIG. 2, except that now the guide element 28 forms a baffle which is covered on one side by a noise absorbing acoustic foam 43.

[0102] Naturally, this contributes to a reduction in the noise level generated by the air cooling of the pressure device 1 .

[0103] In the example of FIG. 3, a layer of noise absorbing acoustic foam 43 is applied to the entire side of the guide element 28 facing the lower part of the air channel 13, ie the side exposed to the air flow 26 with the highest flow rate.

[0104] In other embodiments, it is not excluded to provide the guide element 28 with a noise-absorbing acoustic foam 43 on both sides or only on the side facing towards the top of the air channel 13. Furthermore, it is also possible to cover only a part of the side of the guide element 28 with such a noise-absorbing acoustic foam 43.

[0105] In the embodiment of the pressure device 1 shown in Fig. 4, the pressure device 1 has a substantially T-shaped air channel 13. This air channel 13 has an air channel main section 44 which in the example of Fig. 4 extends along a horizontal direction and has an air channel side branch 45 pointing upwards.

[0106] Two coolers 46 and 47 are provided in the cross section 24 of the air channel main section 44 in a manner equivalent to that in the previous example of FIGS.

[0107] A third cooler 48 is mounted within a cross section 49 of the air channel side branch 45 .

[0108] In this example, the air channel 13 has a single air channel inlet 29 and two air channel outlets 50 and 51, namely, the air channel outlet 50 for air flowing through the air channel main section 44 and the air channel outlet 51 for air flowing through the air channel side branch 45.

[0109] A fan 14 or other device or devices for forcing air flow through the air channel 13 may be installed at the air channel inlet 29. Further, alternatively or additionally, such a fan 14 or other device for forcing air flow through the air channel 13 may be installed at each of the air channel outlets 50 and 51. Air may exit the air channel 13 only by passing through one of the coolers 46, 47, and 48. No other openings are provided in the cross sections 24 and 49. The total air flow 15 is divided into three air flows 25, 26, and 27. These air flows correspond to the air flowing through the coolers 46 and 47 in the air channel main section 44 and the cooler 48 installed at the inlet of the air channel side branch 45, respectively.

[0110] Furthermore, according to the invention, upstream of the coolers 46 , 47 and 48 (in the cooling air flow 15 ), a guide element 28 in the form of a sheet-like or plate-like element 28 is mounted in the air channel main section 44 .

[0111] In this case, the guide element 28 is inclined upward along the direction CC' towards the centre of the air channel main section 44, i.e. towards the intermediate strip 42 separating the cooler 47 at the top of the air channel main section 44 from the cooler 46 at the bottom of the air channel main section 44.

[0112] In this way, a larger portion of the total air flow 15 is pushed towards the coolers 47 and 48. The air flows 26 and 27 are therefore relatively larger than if such guide elements 28 were not mounted in the air channel main section 44, resulting in a relatively higher cooling capacity of the corresponding coolers 47 and 48.

[0113] On the other hand, the cooler 46 in the lower part of the air channel main section 44 receives a relatively smaller portion of the total air flow compared to the case without the guide element 28, and therefore its cooling capacity is also relatively lower.

[0114] Of course, depending on the cooling needs of the coolers 46, 47, and 48, the air flows 25, 26, and 27 can be adapted in any other way, such as by using a larger number of guide elements, by changing the orientation or position of such guide elements 28, etc.

[0115] Finally, FIG. 5 shows that it is possible to obtain results similar to those in the examples of FIGS. 2 and 3 by using a guide element 28, now positioned downstream (in the air flow) of the coolers or heat exchangers 16 and 17 in the cross section 24 of the air channel 13.

[0116] In the example of FIG. 5, the guide element 28 is inclined upwards along the direction DD′, away from the center of the air channel 13 or the intermediate strip 42 between the coolers 16 and 17 .

[0117] Moreover, such an arrangement of guide elements 28 may have a similar effect on the total air flow 15 to stimulate flow to certain coolers or conversely reduce flow to certain coolers.

[0118] The present invention is in no way limited to the embodiment of the air-cooled pressure device 1 described above, which can be applied and implemented in many different ways without departing from the scope of the present invention. [Explanation of symbols]

[0119] 1 Air-cooled pressurized device 2 Fluid, air, pressurized fluid, fluid flow 3. Surrounding environment 4. Housing 5 Fluid Duct 6 Fluid Duct Inlet 7 Fluid duct outlet 8 Pressurization stage, first stage 9 Pressurization Stage 10 Pressurizing element, compressor, first compression element, first pressurizing element 11 Pressurizing element, compressor, second compression element, second pressurizing element 12 Pressurized fluid, air 13 Air Channel 14 Devices, Fans 15 Air flow, cooling air, cooling air flow, total air flow 16 Cooler, first cooler, intermediate cooler, upper cooler, heat exchanger 17 Cooler, second cooler, final cooler, bottom cooler, heat exchanger 18 Oil reservoir, oil sump 19 Oil 20 Closed Loop Oil Circuit 21 Oil tube 22 Oil pump 23 Oil Cooler 24 Section 25 Air flow, part 26 Air flow, part 27 Air flow, part 28 Guide Elements 29 Air channel inlet, air channel inlet side 30 Air channel outlet, air channel outlet side 31 Top 32 Downward Air Flow 33 Upward Air Flow 34 Lower 35 Top 36 Side wall 37 Frames 38 Side Strips 40 Top Strip 41 Bottom Strip 42 Middle Strip 43 Noise Absorbing Acoustic Foam 44 Air Channel Main Section 45 Air Channel Side Branch 46 Cooler 47 Cooler 48 Cooler 49 Section 50 Air Channel Outlet 51 Air channel outlet

Claims

1. An air-cooled pressurizing device (1), comprising: A housing (4); a fluid duct (5) for guiding fluid through said air-cooled pressurizing device (1) from a fluid duct inlet (6) to a fluid duct outlet (7); one or more pressurization stages (8, 9) arranged inside said fluid duct (5), each of said pressurization stages (8, 9) comprising a pressurization element (10, 11); one or more devices (14) for forcing an air flow (15) inside air channels (13, 44, 45) passing through said housing (4); two or more heat exchangers (16, 17, 23, 46-48) positioned inside said air channel (13, 44, 45), for transferring heat from said heat exchangers (16, 17, 23, 46-48) to air forced through said air channel (13, 44, 45) by said device (14) for forcing an air flow; In the air-cooled pressurizing device (1), The two or more heat exchangers (16, 17, 23, 46-48) are arranged adjacent to each other or overlapping or adjacent to each other and overlapping in a cross section (24, 49) of the air channel (13, 44, 45) such that a total amount of the air flow (15) passing through the air channel (13, 44, 45) is divided into a plurality of air flows (25-27), and each of the air flows (25-27) flows through a corresponding one of the two or more heat exchangers (16, 17, 23, 46-48) and the air flows (25-27) are divided into a plurality of air flows (25-27). to 27) distributes the total amount of the air flow (15) in said cross section (24, 49) among two or more of the heat exchangers (16, 17, 23, 46-48), characterized in that one or more sheet-like or plate-like guide elements (28) are provided inside the air channels (13, 44, 45) for dividing the air flow (15) and for guiding the air to one or more of the two or more heat exchangers (16, 17, 23, 46-48) or to parts of one or more of the heat exchangers (16, 17, 23, 46-48).

2. 2. Air-cooled pressurization device (1) according to claim 1, characterized in that the heat exchangers (16, 17, 23, 46-48) with different flow resistances are arranged inside the air channel (13, 44, 45).

3. 3. An air-cooled pressurization device (1) according to claim 2, characterized in that one or more guide elements (28) are oriented and positioned in the air channel (13, 44, 45) to restrict, guide or divide the air flow (15) in the air channel (13, 44, 45) such that a relatively large portion of the air flow (15) is guided towards a heat exchanger (16, 17, 23, 46-48) having a higher flow resistance and a portion of the air flow (15) heading towards a heat exchanger (16, 17, 23, 46-48) having a lower flow resistance is partially guided away from the heat exchanger (16, 17, 23, 46-48) or is somewhat restricted.

4. 3. An air-cooled pressurization device (1) according to claim 2, characterized in that one or more guide elements (28) are oriented and positioned in the air channel (13, 44, 45) to restrict, guide or divide the air flow (15) in the air channel (13, 44, 45) such that a relatively large portion of the air flow (15) is guided towards a heat exchanger (16, 17, 23, 46-48) having a lower flow resistance and a portion of the air flow (15) heading towards a heat exchanger (16, 17, 23, 46-48) having a higher flow resistance is partially guided away from the heat exchanger (16, 17, 23, 46-48) or is somewhat restricted.

5. 5. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that one or more guide elements (28) are positioned and oriented in the air channel (13, 44, 45) such that the air flow (15) passing through the heat exchanger (16, 17, 23, 46-48) is more evenly distributed over the heat exchanger (16, 17, 23, 46-48) than would be the case without the one or more guide elements (28).

6. 6. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that one or more guide elements (28) are oriented and positioned in the air channel (13, 44, 45) to restrict, guide or divide the air flow (15) within the air channel (13, 44, 45) in such a way that the overall air flow (15) through the air channel (13, 44, 45) is improved by reducing friction losses, thereby reducing the pressure drop across the air channel (13, 44, 45) compared to without the one or more guide elements (28).

7. 7. An air-cooled pressurization device (1) according to any one or more of claims 1 to 6, characterized in that at least one of the heat exchangers (16, 17, 23, 46-48) forms an air cooler (16, 17, 23, 46-48) for cooling the pressurized fluid (2, 12) in the fluid duct (5) downstream (in the fluid flow) of the pressurization element (10, 11).

8. 8. An air-cooled pressurization device (1) according to any one or more of claims 1 to 7, characterized in that it comprises at least two pressurization stages (8, 9) having a first pressurization element (10) in the form of a first compressor (10) and a second pressurization element (11) in the form of a second compressor (11), and two heat exchangers (16, 17) for cooling the pressurized fluid (2, 12) in the fluid duct (5), the two heat exchangers (16, 17) being air coolers (16, 17), i.e. a first air cooler (16) which is an intercooler (16) positioned downstream (in the fluid flow) of the first compressor (10) and upstream (in the fluid flow) of the second compressor (11), and a second air cooler (17) which is an aftercooler (17) positioned downstream (in the fluid flow) of the second compressor (11).

9. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that one of the two or more heat exchangers (16, 17, 23, 46-48) is an air-cooled oil cooler (23).

10. 10. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that the air channels (13, 44, 45) extend from an air channel inlet (29) to one or more air channel outlets (30, 50, 51) and the device (14) for forcing an air flow is attached at the air channel outlet side (30, 50, 51).

11. 11. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that the air channels (13, 44, 45) extend from an air channel inlet (29) to one or more air channel outlets (30, 50, 51) and the device (14) for forcing an air flow is attached to the air channel inlet side (29).

12. The air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that a guide element (28) is positioned upstream (in the air flow (15)) of two or more of the heat exchangers (16, 17, 23, 46-48).

13. The air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that a guide element (28) is positioned downstream (in the air flow (15)) of two or more of the heat exchangers (16, 17, 23, 46-48).

14. 14. An air-cooled pressurizing device (1) according to any one or more of the preceding claims, characterized in that the air channels (13, 44, 45) extend mainly in a vertical direction (AA') through the air-cooled pressurizing device (1) and the device (14) for forcing an air flow (15) is positioned in the upper part of the air-cooled pressurizing device or on the top of the air-cooled pressurizing device.

15. 15. The air-cooled pressurization device (1) of claim 14, characterized in that an air channel inlet and an air channel outlet are provided at an upper portion (31) of the air-cooled pressurization device (1), and the air in the air channels (13, 44, 45) flows downward from the air channel inlet (29) towards two or more of the heat exchangers (16, 17, 23, 46-48) and upward from the two or more of the heat exchangers (16, 17, 23, 46-48) towards the air channel outlet (30).

16. 16. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that two or more of the heat exchangers (16, 17, 23, 46-48) are positioned one above the other in a mainly vertical plane, the mainly vertical plane dividing the mainly U-shaped or V-shaped air channel (13) into a part for a downward air flow (32) and a part for an upper air flow (33).

17. 17. The air-cooled pressurization device (1) according to claim 16, characterized in that a guide element (28) is provided upstream (in the air flow (15)) of two or more of the heat exchangers (16, 17, 23, 46-48), the guide element (28) having a lower part (34) with a flat surface oriented parallel to the vertical plane of the heat exchangers (16, 17, 23, 46-48) and an upper part (35) with a flat surface inclined in an oblique direction (BB') relative to the lower part (34) towards an air channel inlet (29) provided in a side wall (36) of the air-cooled pressurization device (1).

18. 18. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that the guide element (28) forms a baffle, which is at least partially covered on one or both sides by a noise-absorbing acoustic foam (43).

19. The fluid (2) to be pressurized is a gaseous fluid or a fluid of higher density, air, oxygen, carbon dioxide, nitrogen, argon, helium, Hydrogen, or water vapor 19. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that it is one of the following:

20. 20. An air-cooled pressurization device (1) according to any one or more of the preceding claims, characterized in that the pressurization element (10, 11) is a compressor (10, 11) and the device (14) or devices (14) for forcing an air flow (15) in the air channel (13) is a fan or a ventilator (14).

Images