Air-cooled pressurizing device with energy recovery for compressing or pressurizing fluids and allowing improved cooling - Patent Application 20070122997

Abstract

A pressurizing device (1) for compressing a fluid (2) comprises a housing (4), a fluid duct (5), one or more pressurizing stages (38, 39) each comprising a pressurizing element (40, 41), a device for feeding an air flow (24) into an air passage (19) passing through the housing (4), and a liquid cooling circuit (25), the liquid cooling circuit (25) comprising at least a pump (26) for circulating the liquid (27); a liquid-fluid heat exchanger (42, 43) downstream of each pressurization element (40, 41); a liquid-liquid heat exchanger (30) for recovering energy; a liquid-air heat exchanger (33) arranged in the air flow path (19); At the fluid duct outlet (36), a fluid-air heat exchanger (35) is provided in the air flow path (19).

Description

[Technical Field]

[0001] The present invention relates to a compression device, generally a compressor, for compressing or pressurizing a fluid, generally a gaseous fluid such as air, or other gases such as carbon dioxide, nitrogen, argon, helium, hydrogen, etc. However, it is not excluded from the invention that the compression device be used to compress or pressurize a fluid of higher density, such as water vapor, etc.

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

[0003] Typically, the pressure elements are connected in series, although other configurations are not excluded from the invention.

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

[0005] More particularly, the present invention relates to a type of pressurizing device that includes cooling means that are at least partially air-cooled. To that end, the pressurizing device to which the present invention relates includes a device for forcing air flow in an air passage through the housing from an air passage inlet to an air passage outlet. Air-cooled pressurizing devices are typically used when an external cooling system for cooling the pressurizing device is not available.

[0006] Pressurizing devices of the type to which the present invention relates also comprise elements for recovering energy, in particular heat stored in the fluid pressurized or compressed during operation of the pressurizing device. [Background technology]

[0007] When air or other fluids are compressed, energy is converted into heat, resulting in a hot compressed or pressurized fluid. This heat can be recovered by cooling the pressurized or compressed fluid with a liquid such as water. In this way, a hot liquid, typically hot water, becomes available that can be used for other processes (such as general heating), and the energy of the compression and pressurization process has been at least partially recovered. This is called a compression device or compressor with energy recovery (ER).

[0008] Generally, water- or liquid-cooled pressurizing devices use a liquid coolant from an external unit to cool the compressed or pressurized fluid and any other materials present during the compression process (such as oil for lubricating bearings, pumps, gearing, and other parts of the pressurizing device). Such water- or liquid-cooled pressurizing devices are also obviously well suited for use in energy recovery, since they have access to a liquid that can temporarily store heat, from which the heat can be easily transferred to heat consumers.

[0009] In pressurized equipment applications where such external coolant systems are not available on-site, cooling must be obtained by other means. In such cases, air cooling is commonly applied, and the heat transferred to the air is typically lost to the atmosphere. However, even in such applications where air cooling is used, some degree of energy recovery is often desired.

[0010] While there are similarities between refrigeration systems and energy recovery systems in that they both absorb some energy from a pressurized device and / or pressurized or compressed fluid and transfer this heat to another location, it is important to note that there are also some significant differences between refrigeration systems and energy recovery systems.

[0011] For example, a cooling system must provide sufficient cooling to the pressurizing device under all circumstances, e.g., to avoid failure of the pressurizing device. Furthermore, the cooling system must typically ensure that a sufficiently low temperature is reached in a particular part of the system, no matter how high the temperature elsewhere. These temperatures depend, for example, on the flow rate through the pressurizing device or the required outlet pressure of the pressurized fluid supplied from the pressurizing device. In other words, the relevant temperature of the pressurizing device can vary significantly depending on the operating conditions of the pressurizing device.

[0012] Energy recovery systems, on the other hand, supply energy to external energy or heat consumers. Such heat consumers typically require a liquid with a sufficiently high temperature at the inlet to be useful for practical applications such as central heating systems. Energy recovery systems are also often not used continuously or are independent of the operation of the pressurizing device, and have fluctuating energy consumption that is not directly linked to the safe and efficient functioning of the pressurizing device. In energy recovery systems, the fluctuations in energy consumption depend entirely on the requirements and demands from the energy or heat consumers.

[0013] According to the prior art, an air-cooled pressurized device with energy recovery can be obtained by incorporating a closed-loop liquid cooling circuit into the pressurized device. To circulate a liquid in the closed-loop liquid cooling circuit, the liquid cooling circuit comprises a device for pumping a liquid flow, typically a water pump. The liquid in the liquid cooling circuit is a heat transfer liquid, typically water, although the use of other heat transfer liquids in the liquid cooling circuit, such as oil, synthetic hydrocarbon or silicone-based fluids, molten salt or molten metal, or any other suitable liquid, is not excluded from the present invention. It is also possible to use other corresponding suitable devices for pumping a liquid flow in the liquid cooling circuit, not necessarily a water pump.

[0014] On the other hand, energy recovery is achieved by temporarily storing the heat stored in the pressurized fluid during compression or compression in a liquid in a liquid cooling circuit and transferring this heat to a heat consumer.

[0015] The heat stored in the pressurized fluid during compression is captured in the liquid of the liquid cooling circuit by a liquid-to-fluid heat exchanger included in the liquid cooling circuit. Typically, the liquid cooling circuit includes a number of liquid-to-fluid heat exchangers corresponding to the number of pressurization stages of the pressurization device. These liquid-to-fluid heat exchangers are arranged in a portion of the fluid duct downstream (in the fluid flow) of each pressurization element. In this way, heat from the pressurized fluid in that portion of the fluid duct is transferred to the liquid in the corresponding portion of the liquid cooling circuit. Typically, the liquid-to-fluid heat exchangers are connected in series, and the liquid flow in the liquid cooling circuit is preferably countercurrent to the fluid flow in the fluid duct.

[0016] A liquid-liquid heat exchanger is also included in the liquid cooling circuit to supply the recovered heat temporarily stored in the liquid of the liquid cooling circuit to a heat consumer. This liquid-liquid heat exchanger is intended to transfer heat from the liquid in the liquid cooling circuit to another liquid circuit (typically a water circuit) of the heat consumer. For example, such a heat consumer can be a heating system for heating radiators in a factory office, for heating substances in a production process, or any other type of heat consumer. This liquid-liquid heat exchanger is located upstream (in the liquid flow) of the series of liquid-fluid heat exchangers.

[0017] On the other hand, the required cooling capacity is guaranteed in all circumstances by air cooling, which consists of a large liquid-to-air heat exchanger that is also included in the liquid cooling circuit.

[0018] An air flow path is provided in the housing of the pressurizing device, and an airflow-injecting device, typically a fan or ventilator, is installed in the air flow path. In this manner, airflow can be generated by the housing from the air flow path inlet to the air flow path outlet. A liquid-to-air heat exchanger is disposed in the air flow path for heat transfer from the liquid in the liquid cooling circuit to air pumped through the air flow path by the airflow-injecting device.

[0019] The liquid-to-air heat exchanger is positioned downstream (in the liquid flow) of the above-mentioned liquid-to-liquid heat exchanger for energy recovery and is intended as an additional liquid cooler to additionally cool the liquid in the closed-loop liquid cooling circuit before returning it to the liquid-to-fluid heat exchanger behind the pressurizing element for further absorption of heat from the pressurized fluid.

[0020] Indeed, for efficient heat transfer in a liquid-to-fluid heat exchanger, the difference between the temperature of the pressurized fluid in the fluid duct and the temperature of the liquid in the liquid cooling circuit must be sufficiently large.

[0021] Furthermore, any excess heat not released by transfer to the heat consumers, for example due to insufficient heat consumption by the heat consumers, is released into the air flow path by the liquid-air heat exchanger in any circumstances, thus ensuring safe functioning of the pressurization device and optimizing the transfer of heat from the pressurized or compressed fluid to the liquid in the liquid cooling circuit.

[0022] However, known configurations of air-cooled pressurization devices with energy recovery have several drawbacks.

[0023] An important drawback of such known configurations of air-cooled pressurizing units with energy recovery is that the outlet temperature of the pressurizing unit is still high compared to the outlet temperature of an air-cooled compressor that does not have energy recovery means and therefore does not have an integrated liquid cooling circuit for heat exchange with an external heat consumer.

[0024] The reason is that the efficiency of the liquid-to-fluid heat exchangers used in air-cooled pressurized systems with energy recovery is low or very low because the flow rate of liquid through the liquid cooling circuit must be kept low to obtain a high enough liquid temperature to be useful to the heat consumer. Energy recovery is only practical if it can provide a useful heat source for the heat consumer.

[0025] At low liquid cooling circuit flow rates, the liquid remains in the liquid-to-fluid heat exchanger for a relatively long time, allowing time for the temperature to rise to a sufficiently high level. On the other hand, for a given flow rate of fluid through the fluid ducts of a pressurizing device, a particular volume of fluid will transfer less heat to the liquid in the liquid cooling circuit at low liquid flow rates than at high liquid flow rates. Indeed, the amount of liquid that such a volume of fluid is exposed to while flowing through a given liquid-to-fluid heat exchanger will be relatively smaller and will be cooled less at low liquid flow rates than at high liquid flow rates.

[0026] As a result, the temperature of the fluid at the outlet of the pressurization device (after the relevant heat exchanger) is relatively high, and the approach temperature, which is the difference between the water / liquid temperature at the inlet of the water / liquid side of the heat exchanger and the temperature of the fluid at the outlet of the fluid side of the heat exchanger, is relatively high.

[0027] Furthermore, in this known configuration of an air-cooled pressurizing device with energy recovery, two heat exchanges actually take place. The first heat exchange takes place in a liquid-air heat exchanger installed in the air flow path, which uses ambient air to cool the coolant in the liquid cooling circuit. The second heat exchange then takes place in the aforementioned liquid-fluid heat exchanger, where the coolant in the liquid cooling circuit absorbs heat from the compressed fluid in the fluid duct of the pressurizing device. As a result, the difference between the ambient air temperature (cooled air) and the compressed or compressed fluid at the outlet of the fluid duct of the pressurizing device becomes large. In fact, the total approach temperature is the sum of the approach temperatures of the two heat exchanges mentioned above.

[0028] A drawback of a high temperature of the compressed or pressurized fluid at the fluid duct outlet of the pressurizing device is that the compressed or pressurized fluid has a high humidity load. Typically, compressed or pressurized fluids with a high humidity content are not acceptable to most consumers of the compressed or pressurized fluid, for example due to their corrosive properties.

[0029] A further negative consequence of the high temperature of the compressed or pressurized fluid at the fluid duct outlet and its high humidity therefore requires that additional measures be taken to dry the compressed or pressurized fluid.

[0030] A possible solution to reduce the high moisture content in the delivered compressed or pressurized fluid is to add an additional external aftercooler after the pressurization device, combined with an external water separator or external dryer specially designed for this purpose. The drawback of such a solution is that the size required for the complete installation increases significantly. For example, a dryer suitable for removing excess moisture would be much larger than the standard dryers usually applied in similar known pressurization devices. Another drawback of this type of solution is that it would be very costly. Summary of the Invention [Problem to be solved by the invention]

[0031] It is an object of the present invention to solve one or more of the problems mentioned above, and / or possibly further problems.

[0032] In particular, it is an object of the present invention to provide an air-cooled pressurization device with energy recovery, in which the fluid temperature of the fluid being compressed or pressurized in the pressurization device, measured at the fluid duct outlet of the pressurization device, is improved, i.e. reduced, compared to the outlet fluid temperature measured in similar pressurization devices known in the prior art.

[0033] It is yet another object of the present invention to provide an air-cooled pressurization device with energy recovery, wherein the compressed or pressurized fluid at the fluid duct outlet of the pressurization device has a very reduced humidity content.

[0034] An object of the present invention is to increase the controllability of fluid outlet temperature in a flexible manner.

[0035] It is a further object of the present invention to achieve the above-mentioned objectives of low fluid outlet temperature and low humidity content of the exiting pressurized or compressed fluid by adding only limited additional means compared to known pressurizing devices that are integrated into the pressurizing device and / or by applying only relatively compact modifications to known pressurizing devices of a similar type. In particular, it is an object of the present invention to achieve the above-mentioned objectives without the need for adding external devices to the pressurizing device.

[0036] Finally, it is also an object of the present invention to develop an efficient air-cooled pressurization device with energy recovery that is limited in size, reliable, cost-effective. [Means for solving the problem]

[0037] To this end, the present invention relates to an air-cooled pressurizing device with energy recovery for compressing or pressurizing a fluid, the air-cooled pressurizing device comprising a housing, a fluid duct for directing the fluid through the pressurizing device from a fluid duct inlet to a fluid duct outlet, one or more pressurization stages of the fluid duct each comprising a pressurizing element, a device for forcing an air flow into an air passage passing through the housing, and a closed-loop liquid cooling circuit, The liquid cooling circuit includes at least: a device for pumping a liquid flow to circulate the liquid in a closed-loop liquid cooling circuit; a liquid-fluid heat exchanger downstream (in the liquid flow) of each of the pressurizing elements; a liquid-liquid heat exchanger for energy recovery; a liquid-to-air heat exchanger disposed in the air flow path; Equipped with A fluid-to-air heat exchanger is provided in the air flow path at the fluid duct outlet for heat transfer from the pressurized fluid in the fluid duct to the air in the air flow path.

[0038] A major advantage of such an air-cooled pressurization device with energy recovery according to the invention is that it comprises an additional aftercooler for cooling the compressed or pressurized fluid in the form of a separate fluid-to-air heat exchanger, which is not part of the liquid cooling circuit that also functions as the energy recovery system, but is an independent part of the air cooling of the pressurization device installed in the air flow path.

[0039] This separate fluid-to-air heat exchanger allows the compressed or pressurized fluid to be cooled directly by the airflow pumped through the airflow path, with the cooling being largely unaffected by the energy recovery portion of the liquid-cooled circuit. The cooling is also more effective because only one heat exchange occurs, rather than indirect cooling, which involves at least two heat exchanges as in a closed-loop liquid-cooled circuit. In practice, in a liquid-to-fluid heat exchanger, a first heat exchange occurs to absorb heat from the compressed or pressurized fluid into the liquid coolant, and at least a second heat exchange occurs in a liquid-to-air heat exchanger in the airflow path to reject the remaining excess heat from the liquid to the air, thereby cooling the liquid, independent of the energy recovery.

[0040] Air cooling of the compressed or pressurized fluid can also be controlled within certain limits in a more direct manner by increasing or decreasing the airflow through the airflow path by a device that forces airflow through the airflow path.

[0041] In this way, the above-mentioned problems currently encountered with known air-cooled pressurization devices with energy recovery are solved. First, the pressurized or compressed fluid can be supplied to the fluid duct outlet of the pressurization device and has a fluid temperature that is low enough to be suitable for supplying the pressurized or compressed fluid to consumers. Furthermore, the cooled pressurized or compressed fluid cannot contain high humidity because saturation humidity is much lower at low temperatures.

[0042] Another advantage of such an air-cooled pressure device with energy recovery according to the invention is that the pressure device remains very compact, since all components are primarily integrated in a housing that does not substantially differ from the housing of known similar pressure devices.

[0043] Yet another important advantage of such an air-cooled pressurization device with energy recovery according to the invention is that the additional aftercooler of the compressed or pressurized fluid in the form of a fluid-to-air heat exchanger uses the same cooling air flow as the liquid-to-air heat exchanger of the liquid cooling circuit, which acts as a kind of backup heat exchanger in case the heat consumers in the energy recovery part of the liquid cooling circuit do not carry away enough heat.

[0044] In this manner, cooling airflow can be supplied to both heat exchangers by a single airflow path pumping device, which may comprise, for example, a large fan supplying flow to both an additional aftercooler for cooling the compressed or pressurized fluid and the liquid-to-air backup heat exchanger of the liquid cooling circuit.

[0045] Another advantage of the air-cooled pressurization device with energy recovery according to the present invention is that a single air channel with an air channel inlet and an air channel outlet can be applied to supply cooling air to both heat exchangers of the air-cooled section of the pressurization device.

[0046] Furthermore, the air flow path for the cooling air flow is advantageously part of the design of the pressurizing device, making installation of such a pressurizing device very simple as no additional on-site measures need to be taken for additional fluid cooling or fluid drying, etc.

[0047] In a preferred embodiment of the air-cooled pressurizing device according to the invention, the pressurizing device is a compressor device comprising one or more pressurizing elements which are compressor elements.

[0048] A compressor or a pressurizing device implemented as a compressor unit is of course the most obvious choice for compressing or pressurizing a fluid.

[0049] In another preferred embodiment of the air-cooled pressurization device according to the present invention, the device for supplying air flow is a single fan or ventilator, the liquid in the liquid cooling circuit is water, and the device for supplying liquid flow for circulating the liquid in the closed-loop liquid cooling circuit is a water pump.

[0050] Also, while the choices made to realize this embodiment of the air-cooled pressurization device are of a practical, relatively inexpensive, and universally applicable kind, other choices can, of course, be made in function of particular needs without departing from the invention.

[0051] In yet another preferred embodiment of the air-cooled pressurizing device according to the invention, the housing of the pressurizing device mainly comprises two compartments: a first compartment in which the pressurizing element, the liquid-fluid heat exchanger(s) and the liquid-liquid heat exchanger are integrated, and a second compartment forming the air flow path in which the liquid-air heat exchanger and the fluid-air heat exchanger are installed.

[0052] A great advantage of such an embodiment of the pressure application device according to the invention is that the air-cooled components of the device, which exchange heat with the air coming from around the device, are grouped together in a second compartment of the housing that is clearly separated from the first compartment of the housing, resulting in a very structured design and the size of the pressure application device still being kept compact even when it includes many different components.

[0053] In a possible embodiment of the air-cooled pressurization device with energy recovery of the present invention, the first compartment incorporates a dryer for drying the pressurized fluid, which dries the pressurized fluid in a portion of the fluid duct outlet section downstream (in the fluid flow) of the fluid-air heat exchanger.

[0054] Such an embodiment of the pressurizing device according to the invention allows for very high quality compressed or pressurized fluid to be provided to external consumers, whereby the high pressure requirements, low outlet temperature and very low humidity content of the compressed or pressurized fluid are easily met, and all the necessary components are integrated into a single pressurizing device.

[0055] The invention will be further explained below with reference to the drawings. [Brief explanation of the drawings]

[0056] [Figure 1] 1 is a schematic diagram of a pressure device according to the present invention; [Figure 2] Similar to FIG. 1, another embodiment of the pressure device according to the present invention is shown. [Figure 3] Similar to FIG. 1, another embodiment of the pressure device according to the present invention is shown. [Figure 4] Similar to FIG. 1, another embodiment of the pressure device according to the present invention is shown. [Figure 5] Similar to FIG. 1, another embodiment of the pressure device according to the present invention is shown. [Figure 6] Similar to FIG. 1, another embodiment of the pressure device according to the present invention is shown. [Figure 7] Similar to FIG. 1, another embodiment of the pressure device according to the present invention is shown. [Figure 8] Similar to FIG. 1, another embodiment of the pressure device according to the present invention is shown. DETAILED DESCRIPTION OF THE INVENTION

[0057] FIG. 1 shows a first possible embodiment of an air-cooled pressurizing device 1 with energy recovery according to the invention, intended to compress or pressurize a fluid 2, which in this case is air taken from the surroundings 3 of the pressurizing device 1.

[0058] The pressure applying device 1 comprises a housing 4, to which a fluid duct 5 is attached for conducting the fluid 2 through the pressure applying device 1. The housing is substantially box-shaped. The fluid duct 5 extends from a fluid duct inlet 6, which in the example of FIG. 1 is located in a first side wall 7 of the housing 4, to a fluid duct outlet 8, which in the example of FIG. 1 is located in a second side wall 9 of the housing 4, which in this case is opposite the first side wall 7 of the housing 4. Of course, in other embodiments, the fluid duct 5 can be designed in a completely different way, having a completely different configuration, and the fluid duct inlet 6 and / or the fluid duct outlet 8 can be located in parts of the pressure applying device 1 completely different from those shown in FIG. 1. In a preferred embodiment of the pressure applying device 1 of the present invention, the fluid duct 5 extends in a substantially horizontal direction AA'.

[0059] The fluid duct outlet 8 is preferably connected to a consumer 10 of the compressed or pressurized fluid 2, or to a number of such consumers 10, for example by means of a piping network (not shown in FIG. 1, dashed line).

[0060] This first embodiment of a pressure device 1 according to the invention shown in FIG. 1 can be considered as a simple or simplest version of this pressure device 1.

[0061] 1 comprises only a single pressurization stage 11, which comprises a pressurization element 12 for pressurizing the fluid. In this case, the pressurization device 1 is a compressor device 1 and the pressurization element 12 is a compressor element 11. The compressor element 12 is contained in the fluid duct 5 and essentially forms part of the fluid duct 5.

[0062] The interior space 13 of the housing 4, defined by the outer wall 14 of the housing 4, is divided in the case of Figure 1 into two separate compartments 15 and 16 by an intermediate wall 17. In Figure 1, this intermediate wall 17 is represented by a dashed line, but in reality it should be considered to be an intermediate wall 17 that does not allow air flow between the first compartment 15 and the second compartment 16 within the housing 4.

[0063] The fluid duct 5 passes through both compartments 15, 16. The compressor element 12 is contained in the part of the fluid duct 5 located in the first compartment 15 of the housing 4.

[0064] The pressurizing device 1 is provided with an air cooling device 18. To that end, the pressurizing device 1 is provided with an air passage or air duct 19 which extends through the housing 4 from an air passage inlet 20 to an air passage outlet 21.

[0065] 1, the air flow path 19 is essentially formed by the second section 16 of the interior space 13 of the housing 4, although in other embodiments this is not required. In this case, the air flow path inlet 20 is provided in the outer top wall 22 of the housing 4, and the air flow path outlet 21 is provided in the outer bottom wall 23 of the housing 4. As a result, the air flow path 19 extends substantially along a vertical direction BB', i.e., a direction BB' transverse to the horizontal direction AA' of the fluid duct 5.

[0066] The air cooling device 18 also comprises a device 24 for forcing an air flow through the air passage 19, which passes through the housing 4 from the air passage inlet 20 to the air passage outlet 21. Typically, this air passage device 24 is located at the air passage inlet 20 and is formed by a fan or ventilator, but in other cases the device 24 may be made up of different components, such as multiple fans or ventilators or even other elements, which may be located at other locations for forcing the air flow through the air passage 19.

[0067] The air-cooled pressurizing device 1 also includes elements for recovering the energy or heat stored in the compressed or pressurized fluid 2 during operation of the pressurizing device.

[0068] These elements form part of a separate closed-loop liquid cooling circuit 25 integrated into the pressurization device 1. This closed-loop liquid cooling circuit 25 is provided with a liquid flow pump 26, the purpose of which is to circulate a liquid 27 within the liquid cooling circuit 25. The liquid 27 is a heat transfer liquid, typically water, although other liquids can be used in the present invention. In the case of Figure 1, the liquid 27 is water and therefore the liquid flow pump 26 is a water pump 26.

[0069] According to the invention, the liquid cooling circuit 25 includes a number of liquid-to-fluid heat exchangers corresponding to the number of pressurization stages. In the simple case of Figure 1, there is only a single pressurization stage 11, so in this case the closed-loop liquid cooling circuit 25 includes only a single liquid-to-fluid heat exchanger 28, which is located in or interacts with a portion of the fluid duct 5 downstream (in the fluid flow) of the single pressurization element 12. This single liquid-to-fluid heat exchanger 28 forms a first aftercooler 29 in which heat from the pressurized fluid 2 in that portion of the fluid duct 5 is transferred to the liquid 27 in that portion of the liquid cooling circuit 25. Since the fluid 2 is air and the liquid 27 is water, in this case the liquid-to-fluid heat exchanger 28 is a water-to-air heat exchanger 28.

[0070] The liquid cooling circuit 25 (in this case the water cooling circuit 25) also includes a liquid-liquid heat exchanger 30 for transferring heat from the liquid cooling circuit 25 to a liquid circuit 31 of a heat consumer 32 for energy recovery. For example, the liquid circuit 31 is a heating system in which hot water is conveyed to a radiator. In that case, the liquid-liquid heat exchanger 30 is a water-water heat exchanger 30.

[0071] In fact, the liquid-to-fluid heat exchanger 28 and the liquid-to-liquid heat exchanger 30 are the primary elements by which energy recovery is realized.

[0072] Upstream (in the liquid flow) of the liquid-fluid heat exchanger 28 of the liquid cooling circuit 25, a device 26 for feeding the liquid flow or a water pump 26 is installed.

[0073] The pressurizing element 12 , the liquid-fluid heat exchanger 28 , the liquid-liquid heat exchanger 30 and the device for pumping the liquid flow 26 or water pump 26 are all located together in the first compartment 15 of the housing 4 .

[0074] Furthermore, the liquid cooling circuit 25, which forms part of the air cooling device 18 of the pressurization device 1, includes a liquid-to-air heat exchanger 33. This liquid-to-air heat exchanger 33 is arranged in the air flow path 19 and is intended to transfer heat from the liquid cooling circuit 25 to air 34 flowing through the air flow path 19 under the force of the air flow pumping device 24. Since the liquid 27 in the liquid cooling circuit 25 is water 27, in this case the liquid-to-air heat exchanger 33 is a water-to-air heat exchanger 33.

[0075] Thus, the liquid-to-air heat exchanger 33 is installed in the second compartment 16 of the housing 4 forming an air flow path 19, and a closed-loop liquid cooling circuit 25 passes partly through the first compartment 15 and partly through the second compartment 16.

[0076] Finally, the pressurization device 1 comprises a fluid-to-air heat exchanger 35, which forms another part of the air cooling device 18 and is therefore arranged in the air flow path 19. This fluid-to-air heat exchanger 35 has the purpose of transferring the heat stored in the pressurized or compressed fluid 2 in the fluid duct 5 to the air 34 in the air flow path 19. Since the fluid 2 in the fluid duct 5 is air 2, in this case the fluid-to-air heat exchanger 35 is an air-to-air heat exchanger 35.

[0077] This fluid-to-air or air-to-air heat exchanger 35 is arranged in a fluid duct outlet 36, which is the portion of the fluid duct 5 downstream (in the fluid flow) of the most downstream pressurizing element (in this case, the single pressurizing element 12). According to the invention, this fluid duct outlet 36 passes at least partially through the air flow path 19. In the example of FIG. 1, the fluid duct outlet 36 is arranged entirely within the air flow path 19, but this is not required in other embodiments, as will be explained further herein. Furthermore, the fluid-to-air heat exchanger 35 is arranged in a portion 36 of the fluid duct 5 downstream (in the fluid flow) of the liquid-to-fluid heat exchanger 28, which is the first aftercooler 29, and therefore forms an additional aftercooler 37.

[0078] It is clear that the elements that primarily form the air cooling device 18, namely the liquid-to-air heat exchanger 33 or the water-to-air heat exchanger 33 and the fluid-to-air heat exchanger 35 or the air-to-air heat exchanger 35, are installed together in the second section 16 of the housing, which forms the air flow path 19.

[0079] In an air-cooled pressurizing device 1, there is usually also a separate circuit for cooling the lubricant (oil), but this is not shown in the figures as it is not an essential part of the invention. The lubricant or oil circulates through such a circuit from the parts requiring lubrication, over a filter and a heat exchanger, and back to the parts to be lubricated. In an air-cooled pressurizing device 1, this heat exchanger is generally an oil-air heat exchanger and can be installed, for example, as an additional cooler in the air flow path 19.

[0080] The energy recovery function of the air-cooled pressurizing device 1 is very simple and is as follows:

[0081] Air 2 or another fluid 2 is drawn in at the fluid duct inlet 6 and directed through the fluid duct 5 to the compression or compressor element 12, where it is compressed or pressurized. During this process, heat is accumulated in the fluid 2, some of which is released in a first aftercooler 29, which is a liquid-to-fluid heat exchanger 28. The compressed or compressed fluid 2 is further directed through the fluid duct 5 to a second section, which forms the air flow path 19, in which the air flow 34 is produced by the fan 24. At the fluid duct outlet 36, the compressed or compressed fluid 2 passes through a second aftercooler 37 for further cooling, which in turn is a fluid-to-air heat exchanger 35. The cooled compressed or pressurized fluid 2 is sent at the fluid duct outlet 8 to the compressed or compressed fluid consumer 10.

[0082] A portion of the heat absorbed by the liquid (water) 27 in the first aftercooler 29 can be recovered. A water pump 26 in the water cooling circuit 25 sends the water 27 from the first aftercooler 29 to a liquid-liquid heat exchanger 30 or a water-water heat exchanger 30, where the heat is rejected to a heat consumer 32. The water 27 is then sent from the liquid-liquid heat exchanger 30 through the water cooling circuit 25 to the second section 16, where the excess heat remaining in the water 27 is rejected in a liquid-air heat exchanger 33 or a water-air heat exchanger 33 to the air 34 flowing through the air flow path 19. The cooled water 27 is then returned to the inlet of the first aftercooler 29, where it can again absorb heat from the pressurized or compressed fluid 2.

[0083] It is clear that such a pressure device 1 according to the invention achieves the objectives set out at the outset.

[0084] Figure 2 shows another embodiment of an air-cooled pressurization device 1 with energy recovery according to the invention. This embodiment differs from the embodiment of Figure 1 described above in that the pressurization device 1 in this case comprises two pressurization stages 38 and 39. The first pressurization stage 38 is closer to the fluid duct inlet 6 and is a low-pressure stage 38 and comprises a low-pressure stage pressurization element 40. The second pressurization stage 39 is closer to the fluid duct outlet 8 and is a high-pressure stage 39 and comprises a high-pressure stage pressurization element 41. These pressurization elements 40 and 41 are arranged in series within the fluid duct 5.

[0085] As in the above-described embodiments, the liquid cooling circuit 25 is integrated into the housing 4 of the pressurization device 1. Since the embodiment of the pressurization device 1 according to the invention shown in Figure 2 comprises two pressurization stages 38 and 39, in this case the liquid cooling circuit 25 comprises two liquid-to-fluid heat exchangers 42 and 43, each of which is arranged in or interacts with a part of the fluid duct 5 downstream (in the fluid flow) of each of the corresponding pressurization elements 40 and 41. Both of these liquid-to-fluid heat exchangers 42, 43 have the purpose of transferring heat from the pressurized fluid 2 in the corresponding part of the fluid duct 5 to the liquid 27 in the corresponding part of the liquid cooling circuit 25.

[0086] The first liquid-fluid heat exchanger 42 is included in the closed-loop liquid cooling circuit 25 in the portion of the fluid duct 5 between the low-pressure stage pressurizing element 38 and the high-pressure stage pressurizing element 39 and can therefore be considered to form an intercooler 44.

[0087] The second liquid-fluid heat exchanger 43 is included in the portion of the fluid duct 5 downstream (in terms of fluid flow) of the high-pressure stage pressurizing element 39, which is the most downstream (in terms of fluid flow) pressurizing element in the closed-loop liquid cooling circuit 25, and can therefore be considered to form the first aftercooler 29.

[0088] The liquid 27 in the liquid cooling circuit 25 flows countercurrently to the fluid 2 in the fluid duct 5 .

[0089] The first liquid-fluid heat exchanger 42 and the second liquid-fluid heat exchanger 43 are connected in series below (in the liquid flow) the device 26 that pumps the liquid flow (typically a water pump 26 when the liquid 27 is water).

[0090] The remainder of the closed-loop liquid cooling circuit 25 is essentially the same as in the first embodiment of Fig. 1. Downstream (in the liquid flow) of the series of liquid-fluid heat exchangers 42 and 43 there is first a liquid-liquid heat exchanger 30 for exchanging heat with an energy or heat consumer 30. Further downstream in the liquid cooling circuit 25 there is a liquid-air heat exchanger 33, which is arranged in the second compartment 16 of the housing 4 forming the air flow path 19. This liquid-air heat exchanger 33 has the same function of cooling the liquid 27 in the liquid cooling circuit 25 before it is again provided to the liquid flow feeding device 26 or the water pump 26.

[0091] 2 also comprises, as in FIG. 1, a fluid-to-air heat exchanger 35, which is arranged in a portion 36 of the fluid duct 5 downstream (in the fluid flow) of the first aftercooler 29, thus likewise forming an additional aftercooler 37.

[0092] Other than the two-stage design, the function of the second embodiment of the pressure device 1 according to the invention is essentially the same as that of the first embodiment of FIG.

[0093] FIG. 3 shows yet another embodiment of a pressure device 1 according to the invention, which has many similarities to the embodiment of FIG. 2 described above, since it also comprises two pressure stages 38 and 39.

[0094] However, in this third embodiment, the pressurization device 1 includes only a single aftercooler 45, which is a composite aftercooler 45. The composite aftercooler 45 includes a first portion 46, which forms the first aftercooler 29 and is a liquid-to-fluid heat exchanger 43 located in the first section 15 of the housing 4. The composite aftercooler 45 also includes a second portion 47, which forms the additional aftercooler 37 and is a fluid-to-air heat exchanger 35 located in the air flow path 19 formed by the second section 16 of the housing 4. The first and second portions 46 and 47 of the composite aftercooler 45 are separated from each other by or at the intermediate wall 17 of the housing 4, and therefore the third embodiment can be considered a slightly special case of the second embodiment in which the liquid-to-fluid heat exchanger 43 and the fluid-to-air heat exchanger 35 are combined into a single aftercooler 45.

[0095] Figure 4 shows a fourth embodiment of an air-cooled pressurization device 1 according to the invention, which is likewise based on the second embodiment of Figure 2, and which comprises all the elements present in the second embodiment, as well as additional elements for drying the pressurized or compressed fluid 2.

[0096] In this fourth embodiment, the housing 4 comprises a first compartment 15 enclosing the pressurizing or compressor elements 40 and 41, the liquid-fluid heat exchangers 42 and 43, the liquid-liquid heat exchanger 30, and the device 26 for feeding the liquid flow. To achieve the envisaged purpose, a dryer 48 for drying the pressurized fluid 2 is integrated into this first compartment 15. This dryer 48 dries the pressurized fluid 2 in the part of the fluid duct outlet 36 downstream (in the fluid flow) of the fluid-air heat exchanger 35, forming an additional aftercooler 37. The fluid duct outlet 36 of the fluid duct 5 thus has a first section 49, which passes through the air passage 19 formed by the second compartment 16, in which the fluid-air heat exchanger 35 is arranged. This first section 49 returns to the first compartment 15 and to an intermediate section 50 of the fluid duct outlet 36, in which the dryer 48 is included. Finally, this intermediate section 50 returns to the air flow path 19 where it connects to a final section 51 of the fluid duct outlet 36 which traverses the entire air flow path 19 and exits the housing 4 at the fluid duct outlet 8 .

[0097] In the embodiment shown in Figure 4, the dryer 48 is a rotary drum dryer 48 that includes a rotary drum 52 and dries the fluid 2 by absorption in an absorbing means 53. The absorbing means 53 rotates through a drying section 54 for drying the pressurized fluid 2 by absorption of water from the pressurized fluid 2 into the absorbing means 53, and a regeneration section 55 in which the absorbing means 53 is regenerated by desorption of water from the absorbing means 53.

[0098] In order to regenerate the absorption means 53 in the regeneration section 55 of the rotary dryer 48, it is necessary to supply this regeneration section 55 with an unsaturated high-temperature fluid 2. Water accumulated in the regeneration section 55 during drying can be easily absorbed by the passing unsaturated high-temperature fluid 2. For this purpose, the pressurizing device 1 is provided with an inlet fluid duct branch 56, which is connected to the fluid duct 5 in the section between the most downstream (in the fluid flow) pressurizing element 41 and the corresponding first aftercooler 43. This inlet fluid duct branch 56 extends between the fluid duct 5 and the regeneration section 55 of the rotary drum dryer 48 to supply the unsaturated high-temperature fluid 2.

[0099] The inlet fluid duct branch 56 includes a throttle valve 57 for adjusting the flow rate of the unsaturated hot fluid 2 supplied to the regeneration section 55 of the rotary drum dryer 48 .

[0100] After absorbing water from the absorption means 53 in the regeneration section 55 of the rotary drum dryer 48, the incoming unsaturated high temperature fluid 2 is converted into saturated high temperature fluid 2 and exits the regeneration section 55 of the rotary drum dryer 48 through the fluid duct branch 58.

[0101] An additional liquid-fluid heat exchanger 59 is incorporated into the closed-loop liquid cooling circuit 25 upstream (in the liquid flow) of the first aftercooler 29 or 43 to cool the saturated high-temperature fluid 2 exiting the regeneration section 55 of the rotary drum dryer 48. In the example of FIG. 4, all liquid-fluid heat exchangers 42, 43, 49 are connected in series one after the other. The additional liquid-fluid heat exchanger 59 interacts with a portion of the outlet fluid duct branch 58 to form a regenerative cooler 59 for heat transfer from the fluid 2 exiting the regeneration section 55 of the rotary drum dryer 48, i.e., the saturated high-temperature fluid 2, to the liquid 27 in the corresponding portion of the liquid cooling circuit 25. After passing through the regenerative cooler 59, the fluid 2 continues to flow through the outlet fluid duct branch 58 as a low-temperature saturated fluid 2 to be dried in the drying section 54 of the rotary drum dryer 48.

[0102] For this purpose, the flow of cooled saturated fluid 2 coming from the regeneration section 55 of the rotary drum dryer 48 through the outlet fluid duct branch 58 and the flow of compressed or compressed fluid 2 leaving the fluid-air heat exchanger 35 of the air flow path 19 forming the additional aftercooler 37 are mixed and supplied to the drying section 54 of the rotary drum dryer 48 through part of the intermediate section 50 of the fluid duct outlet 36.

[0103] To mix these streams, a mixing valve 60 is provided at the T-junction of the intermediate section 50 of the fluid duct outlet 36 and the outlet fluid duct branch 58. The flow through the drying section 54 of the rotary drum dryer 48 is countercurrent to the flow of fluid 2 through the regeneration section 55 of the rotary drum dryer 48. The dried and cooled pressurized fluid 2 exits the rotary drum dryer 48 through the intermediate section 50 and final section 51 of the fluid duct outlet 36 and is supplied to the consumer 10 of the pressurized or compressed fluid 2.

[0104] 5 shows a fifth embodiment of the pressurizing device 1 according to the present invention, which is a modification of the fourth embodiment. In this fifth embodiment, the pressurizing device 1 includes a bypass pipe 61 that short-circuits a portion of the liquid cooling circuit 25. In detail, the bypass pipe 61 extends between the portion of the liquid cooling circuit 25 between the liquid-liquid heat exchanger 30 for energy recovery and the liquid-air heat exchanger 33 arranged in the air flow path 19, and the portion of the liquid cooling circuit 25 between the regenerative cooler 59 and the liquid-fluid heat exchanger 43 that forms the first aftercooler 29.

[0105] 5, a bypass valve 62 is provided in the portion of the liquid cooling circuit 25 between the regenerative cooler 59 and the liquid-to-fluid heat exchanger 43 forming the first aftercooler 29. In this fifth embodiment, at least a portion of the liquid flow, after leaving the regenerative cooler 59, is permanently returned to the air flow path 19 to be cooled in the liquid-to-air heat exchanger 33. The more the bypass valve 62 is closed, the greater the proportion of the liquid flow is returned to the air flow path 19 through the bypass pipe 61 for cooling, and the smaller the proportion of the liquid flow following the liquid-to-fluid heat exchangers 43, 42 in the cooling-liquid circuit 25.

[0106] 6 shows a sixth embodiment of the pressurization device 1, which is yet another modification of the fourth embodiment (or the fifth embodiment) according to the present invention. The only difference from the fifth embodiment is that in the embodiment of FIG. 6, a bypass valve 62 is provided in the bypass pipe 61. This means that when the bypass valve 62 is fully closed, all the liquid flow continues to flow towards the liquid-to-fluid heat exchangers 43, 42 after passing through the regenerative cooler 59, which is completely equivalent to the situation shown in FIG. 4. The more the bypass valve 62 is opened, the greater the proportion of the liquid flow is returned to the air flow path 19 for cooling in the liquid-to-air heat exchanger 33.

[0107] 7 shows a seventh embodiment of the pressurization device 1 according to the invention, which differs from the other embodiments with the rotary drum dryer 48, i.e., the embodiment shown in FIGS. 4-6, in that a regenerative cooler 59 is mounted in parallel with the most downstream (in the fluid flow) liquid-to-fluid heat exchanger 43 forming the first aftercooler 29. The liquid cooling circuit 25 therefore comprises a parallel liquid flow branch 63 connected in parallel with the part of the liquid cooling circuit 25 including the first aftercooler 29. The regenerative cooler 59 is included in this parallel liquid flow branch 63.

[0108] Finally, Figure 8 shows an eighth embodiment of the pressurization device 1 according to the invention, which comprises the same elements as the fifth embodiment of the pressurization device shown in Figure 5, but in which an additional regenerative cooler 64 is provided in the outlet fluid duct branch 58 leading from the regenerative section 55 of the rotary drum dryer 48. This additional regenerative cooler 64 is located downstream (in the fluid flow) of the first regenerative cooler 59, which is a fluid-to-air heat exchanger 64 located in the air flow path 19 to be cooled by air forced through this air flow path 19 by the fan or ventilator 24.

[0109] The present invention is not limited to the embodiment of the air-cooled pressure device 1 described above, and such a pressure device 1 can be applied and implemented in many different ways without departing from the scope of the present invention. [Explanation of symbols]

[0110] 1. Air-cooled pressure device 2 fluid 4. Housing 5 Fluid Duct 19 Air flow path 24 Airflow 25 Liquid cooling circuit 27 liquid 26 Pump 30 Liquid-Liquid Heat Exchanger 33 Liquid-to-air heat exchanger 36 Fluid duct outlet 35 Fluid-Air Heat Exchanger 38, 39 Pressure stage 40, 41 Pressurizing element 42, 43 Liquid-fluid heat exchanger

Claims

1. 1. An air-cooled pressure device (1) with energy recovery for compressing or pressurizing a fluid (2), comprising a housing (4), a fluid duct (5) for conducting the fluid (2) through the pressure device (1) from a fluid duct inlet (6) to a fluid duct outlet (8), one or more pressure stages (11, 38, 39) of the fluid duct (5) each comprising a pressure element (12, 40, 41), a device (24) for forcing an air flow into an air passage (19) passing through the housing (4), and a closed-loop liquid cooling circuit (25), The closed loop liquid cooling circuit (25) includes at least: a liquid flow pump (26) for circulating a liquid (27) in said closed-loop liquid cooling circuit (25); a liquid-fluid heat exchanger (28, 42, 43) downstream (in the fluid flow) of each of said pressurizing elements (12, 40, 41); a liquid-liquid heat exchanger (30) for energy recovery; a liquid-to-air heat exchanger (33) arranged in said air flow path (19); Equipped with a fluid-to-air heat exchanger (35) is provided in the air flow path (19) at the fluid duct outlet (36) of the fluid duct (5) for heat transfer from the pressurized fluid (2) in the fluid duct (5) to the air (34) in the air flow path (19); The housing (4) mainly comprises two compartments (15, 16), the first compartment (15) incorporating the pressurizing elements (12, 40, 41), the liquid-fluid heat exchangers (28, 42, 43) and the liquid-liquid heat exchanger (30), and the second compartment (16) forming the air flow path (19) in which the liquid-air heat exchanger (33) and the fluid-air heat exchanger (35) are installed. Air-cooled pressure device (1).

2. A compressor device (1) comprising one or more pressurizing elements (12, 40, 41) that are compressor elements (12, 40, 41), An air-cooled pressure device (1) according to claim 1.

3. The device (24) for supplying air flow is a single fan or ventilator (24), the liquid (27) in the closed-loop liquid cooling circuit (25) is water (27), and the device (26) for supplying liquid flow for circulating the liquid (27) in the closed-loop liquid cooling circuit (25) is a water pump (26). An air-cooled pressure device (1) according to claim 1 or 2.

4. the pressurization device (1) comprises only a single pressurization stage (11); the pressurization device (1) comprises a single liquid-to-fluid heat exchanger (28) in the closed-loop liquid cooling circuit (25); the single liquid-to-fluid heat exchanger (28) is arranged in a portion of the fluid duct (5) downstream (in the fluid flow) of the single pressurization stage (11) or interacts with a portion of the fluid duct (5) to form a first aftercooler (29); and the fluid-to-air heat exchanger (35) is arranged in a portion of the fluid duct (5) downstream (in the fluid flow) of the first aftercooler (29) to form an additional aftercooler (37). An air-cooled pressure device (1) according to claim 1.

5. the pressurizing device comprises two pressurizing stages (38, 39), respectively a low-pressure stage (38) having a low-pressure stage pressurizing element (40) and a high-pressure stage (39) having a high-pressure stage pressurizing element (41), the pressurizing device being arranged in or interacting with a portion of the fluid duct (5) between the low-pressure stage pressurizing element (40) and the high-pressure stage pressurizing element (41), a first liquid-to-fluid heat exchanger (42) of the closed-loop liquid cooling circuit (25) forming an intercooler (44); a second liquid-to-fluid heat exchanger (43) of the closed-loop liquid cooling circuit (25) arranged in or interacting with a portion of the fluid duct (5) downstream (in the fluid flow) of the high-pressure stage pressurizing element (41) and forming a first aftercooler (29); and the fluid-to-air heat exchanger (35) arranged in a portion (36) of the fluid duct (5) downstream (in the fluid flow) of the first aftercooler (29) and forming an additional aftercooler (37). An air-cooled pressure device (1) according to claim 1.

6. The pressurization device (1) comprises a single aftercooler, which is a compound aftercooler (45), which comprises a first part (46) which is a liquid-to-fluid heat exchanger (43) arranged in the first section (15) of the housing (4) forming the first aftercooler (29), and a second part (47) which is a fluid-to-air heat exchanger (35) arranged in the air flow path (19) formed by the second section of the housing (16) forming the additional aftercooler (37). An air-cooled pressurizing device (1) according to claim 4.

7. the housing comprises a first compartment (15), in which the pressurizing elements (40, 41), the liquid-fluid heat exchangers (42, 43), and the liquid-liquid heat exchanger (30) are incorporated, and the first compartment (15) incorporates a dryer (48) for drying the pressurized fluid (2), the dryer (48) dries the pressurized fluid (2) at a portion (50) of the fluid duct outlet (36) downstream (in the fluid flow) of the fluid-air heat exchanger (35); An air-cooled pressure device (1) according to claim 1.

8. The dryer (48) is a rotary drum dryer (48) configured to dry the fluid (2) by absorption in an absorbing means (53), and the absorbing means (53) is configured to rotate through a drying section (54) for drying the pressurized fluid (2) by absorption of water from the pressurized fluid (2) into the absorbing means (53), and a regeneration section (55) for regenerating the absorbing means (53) by desorption of water from the absorbing means (53). An air-cooled pressure device (1) according to claim 7.

9. the pressurizing device (1) is connected to the fluid duct (5) at a portion between the most downstream (in the fluid flow) pressurizing element (41) and the corresponding first aftercooler (29), and comprises an inlet fluid duct branch (56) extending between the fluid duct (5) and the regeneration section (55) of the rotary drum dryer (48) for supplying the unsaturated high-temperature fluid (2) to the regeneration section (55); An air-cooled pressurizing device (1) according to claim 8.

10. an additional liquid-fluid heat exchanger (59) is incorporated in the closed-loop liquid cooling circuit (25) upstream (in the liquid flow) of the first aftercooler (29), the additional liquid-fluid heat exchanger (59) forming a regenerative cooler (59) for heat transfer from the fluid (2) leaving the regenerative section (55) of the rotary drum dryer (48) to the liquid (27) in the corresponding part of the liquid cooling circuit (25); An air-cooled pressurizing device (1) according to claim 9.

11. a flow of cooled fluid (2) from the regeneration section (55) of the rotary drum dryer (48) flowing through an outlet fluid duct branch (58) and a flow of fluid (2) from the fluid-air heat exchanger (35) of the air flow path (19) flowing through a first section (49) of a fluid duct outlet (36) forming an additional aftercooler (37) are mixed at a T-junction between the outlet fluid duct branch (58) and a section (50) of the fluid duct outlet (36) and are supplied to a drying section (54) of the rotary drum dryer (48) in countercurrent to the flow of fluid (2) through the regeneration section (55) of the rotary drum dryer (48); An air-cooled pressure device (1) according to claim 10.

12. The pressurizing device (1) includes a bypass pipe (61) for short-circuiting a part of the liquid-cooled circuit (25), the bypass pipe (61) extending between a part of the liquid-cooled circuit (25) between the liquid-liquid heat exchanger (30) for energy recovery and the liquid-air heat exchanger (33) arranged in the air flow path (19), and a part of the liquid-cooled circuit (25) between the regenerative cooler (59) and the liquid-fluid heat exchanger (43) forming a first aftercooler (29). An air-cooled pressure device (1) according to claim 10 or 11.

13. a bypass valve (62) is provided in the bypass pipe (61) or in a portion of the liquid cooling circuit (25) between the regenerative cooler (59) and the liquid-to-fluid heat exchanger (43) forming the first aftercooler (29); An air-cooled pressurizing device (1) according to claim 12.

14. the liquid cooling circuit (25) comprises a parallel liquid flow branch (63) connected in parallel with a portion of the liquid cooling circuit (25) including the first aftercooler (29), and the regenerative cooler (59) is included in the parallel liquid flow branch (63). An air-cooled pressure device (1) according to claim 10.

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