SE1650975A1 - Ventilation device for venting a space, in particular an engine room of a vehicle - Google Patents

Abstract

The invention relates to a ventilation device for a first space (7), in particular an engine room of a vehicle (1), comprising a chimney (9) extending from said first space (7), the chimney (9) comprising an inlet (11 ) and an outlet (13), wherein the inlet (11) is arranged in fluid communication with the first space (7) and the outlet (13) is in fluid communication with a surrounding atmosphere. The ventilation device (3) further comprises an auxiliary second space (15), the second space (15) being arranged adjacent the chimney (9) and being in fluid communication with the chimney (9) by means of at least one opening (17), wherein an airflow flowing from the auxiliary second space (15) to the surrounding atmosphere via the chimney (9) causes an ejector effect in the chimney (9) which vents air from the first space (7). The invention also relates to a vehicle (1) comprising a ventilation device (3) and a method for venting a first space (7) by using a ventilation device (3).

Description

EJECTOR EFFECT FOR CHII\/INEY WITH FAN VENTILATION DEVICE FOR VENTING A SPACE, IN PARTICULAR AN ENGINEROOIVI OF A VEHICLE TECHNICAL FIELDThe present invention relates to a ventilation device, a vehicle with such a device,and a method for venting a space in which heat is generated, in particular an engine room of a vehicle.

BACKGROUND AND PRIOR ARTThe present invention relates to a ventilation device, a vehicle with such a device,and a method for venting a space in which heat is generated according to the appended claims.

As a lot of different types of machinery and/or devices generate heat as a by-productof the work they perform venting said heat is a common problem within severalfields, such as industrial processes, other machinery, or vehicles. Dissipating heatmay be done in various ways, for example using fans, heat sinks, water cooling orother. For vehicles in particular, build-up of heat needs to be avoided as the engines,batteries and other equipment may take harm if being subjected to overexposure ofheat. An engine, and especially an internal combustion engine, which is well cooled works better and has a longer lifespan than a sub-par cooled engine for example.

For heavy vehicles such as buses, this is a very important issue as a bus often isused over long periods of time, the weight the engine supports is large, and thedesign of buses is separate from that of a, for example, a car. Buses are commonlybuilt with the engine at the back of the bus, which makes it more difficult to use thewind hitting the front of the bus as cooling medium. Furthermore, as heat risesupwards and said type of engine is covered on top by the seats and body of the bus, the heat generated by the engine of a bus might require special attention comparedto that of a normal car.

D1 - DE102015008248 A1 describes a ventilation system for a bus comprising achimney. Said chimney is arranged in fluid communication with the engine roomwherein heat generated by the engine may rise up through the chimney and bevented to the surrounding atmosphere above the roof of the bus. The engine roomfurther comprises an air inlet arranged to have cold outside air flow in through saidinlet to the engine room. Thereby a continuous air flow going in through said inlet,cooling the engine, and transports heat from the engine via the chimney to theoutside of the bus is provided.

There is however drawbacks with the above described ventilation system. As the airflowing into the engine room might be subjected to high air resistance, and alsocause an increased air pressure in the inlet, the air of the system might not flow asintended and sub-par ventilation might be the result. Additional fans might berequired to guarantee that the system provides the intended venting effect withoutrelying on the airflow being sucked in via the air inlet. Having additional fans installedin an engine room is often not desired as the environment therein is exposed to a lotof contamination in the form of oil, dirt or similar, which may impede the function of said fans and/or lead to a malfunction of said fans.

SUMMARY OF THE INVENTION Despite prior art there is therefore a need to develop a ventilation device, which canimprove the ventilation of a first space in which heat is generated, in particular anengine room of a vehicle. There is also a need to develop a ventilation device whichfunctions without the need to install additional fans inside of said first space.Furthermore, there is a need to develop a ventilation device which reduces the riskof pressure build-up within said ventilation device to provide a consistent and reliableventing of said first space.

An object of the present invention is thus to provide a ventilation device, which canimprove the ventilation of a first space in which heat is generated, in particular an engine room of a vehicle. Another object is to provide a ventilation device which functions without the need to install additional fans inside of said first space. Anotherfurther object of the invention is to provide a ventilation device which reduces the riskof pressure build-up within said ventilation device to provide a consistent and reliable venting of a first space.

The herein mentioned objects are achieved by a ventilation device, a vehicle withsuch a ventilation device, and a method for venting a space according to the independent claims.

According to an aspect of the invention the ventilation device for a first space, inparticular an engine room of a vehicle, comprises a chimney extending from said firstspace. The chimney comprises an inlet and an outlet, wherein the inlet is arranged influid communication with the first space and the outlet is in fluid communication witha surrounding atmosphere. The device further comprises an auxiliary second space,the second space being arranged adjacent the chimney and being in fluidcommunication with the chimney by means of at least one opening, wherein anairflow flowing from the auxiliary second space to the surrounding atmosphere viathe chimney causes an ejector effect in the chimney which vents air from the first space.

This has the advantage that a cooling airflow may be guided via said auxiliarysecond space to effectively vent the engine room via the chimney. Thereby a deviceis provided which can vent the heat generated in a first space without altering thedesign of said first space. This is beneficial as the auxiliary second space may bedesigned for an effective airflow only and no consideration is needed to provide saidairflow in the first space by default. Thereby the first space can be manufactured in asimple and effective way where only the needs of the engine or the like needs to be taken into account.

According to another aspect of the invention at least one fan is arranged in an outerwall of the auxiliary space, which at least one fan guides air from the surrounding atmosphere to the chimney via the auxiliary space.

This has the advantage that the benefits of a guided airflow provided by a fan areprovided without installing said at least one fan in the first space itself. This isbeneficial as the airflow may be guided more effectively by means of at least one fanwhile said at least one fan will not be subjected to the potentially contaminatedenvironment in the first space. This has the advantage that the at least one fan canoperate under better working conditions and a longer operating lifespan is thereby ensured.

According to yet another aspect of the invention the first space is an engine roomwith an engine, and the at least one fan is part of a heat exchanger unit of the engine.

This has the advantage that the fans of the heat exchanger unit may be operated inthe cleaner working environment of the auxiliary second space whilst still perform theheat exchange from the engine. A further advantage with this is that the fan of theheat exchanger unit may at the same time operate as a driving force for the airflow flowing in the chimney and hence drive the ejector effect.

According to a further aspect of the invention the at least one opening of the chimneyis provided with angled guide vanes, which vanes directs airflow from the axillary space towards the outlet of the chimney.

This has the advantage that the airflow is more effectively guided in the rightdirection within the chimney in regards of venting the first space. This is beneficial asthe risk of the airflow moving from the auxiliary second space towards the first spaceis reduced.

According to an even further aspect of the invention the auxiliary second spacefurther comprises at least one baffle plate which can move between a closed stateand an open state, wherein the open state provides fluid communication with thesurrounding atmosphere, and the at least one baffle plate moves to the open statewhen the pressure within the auxiliary second space reaches a predetermined value.

This has the advantage that a build-up of high pressure is avoided in the auxiliarysecond space and the chimney. lf the air within the chimney would reach a too highpressure the flow within the chimney could potentially risk flowing backwards,towards the first space or the auxiliary second space. The at least one baffle plate inan open state prevents this by letting air flow outside to the surrounding atmosphereand relieve such pressure build-up.

According to an aspect of the invention the at least one baffle plate is spring-loadedwith a spring, and biased to be in the closed state by means of a spring force of thespring, and move to the open state when the pressure of the auxiliary second spacereaches the predetermined value, which overcomes the spring force.

This has the advantage that the pressure within the auxiliary second space andthereby also the chimney may be controlled automatically by means of said springforce. This is beneficial as the internal pressure within the system is not reliant onadditional devices or functions and/or control of such devices or functions. Hence, aneffective pressure relieving system is provided which is easy and cost effective to manufacture.

According to another aspect of the invention the at least one baffle plate is moved between the closed state and the open state by means of an actuating device.

This has the advantage that a customizable device is provided, wherein theactuating device may be designed to work with a variety of predetermined pressures,which predetermined pressures may be initially set and later on changed by meansof changing the operating parameters of the actuating device.

According to yet another aspect of the invention the device further comprises asensor arranged to determine the pressure of the auxiliary second space wherein theactuating device can move the at least one baffle plate to the open state based onthe determined pressure.

This has the advantage that the pressure of the auxiliary second space may becontinuously monitored in a non-complex manner, wherein said monitoring provides a reliable ventilation device in which pressure build-up is continuously alleviated.

According to a further aspect of the invention a vehicle is provided, which vehicle comprises a ventilation device according to the present invention.

This has the advantage that a vehicle with a ventilation device is provided, whichventilation device effectively cools the engine of said vehicle in a simple and reliablemanner. Thereby the engine of the vehicle will operate under better workingconditions and longevity of the engine may be increased.

According to yet a further aspect of the invention a method for venting a first spaceby using a ventilation device is provided. The ventilation device comprises a chimneyextending from the first space, the chimney comprising an inlet and an outlet,wherein the inlet is arranged in fluid communication with the first space and theoutlet is in fluid communication with a surrounding atmosphere. The device furthercomprises an auxiliary second space, the second space being arranged adjacent thechimney and being in fluid communication with the chimney by means of at least oneopening, the method comprising the step of: a) guiding an airflow from the auxiliary second space to the surrounding atmospherevia the chimney so as to cause an ejector effect in the chimney which vents the air inthe first space.

This has the advantage that a method is provided, which method can vent a first space without the need for additional fans or similar within said first space. This isbeneficial as the working environment in the first space might not be beneficial forsuch fans, if the need to vent said first space comes from, for example an engine which generally also generates contamination for said first space.

According to another aspect of the invention the auxiliary second space furthercomprises at least one baffle plate which can move between a closed state and anopen state, wherein the open state provides fluid communication with thesurrounding atmosphere, and wherein the method further comprises the step of: b) opening the at least one baffle plate to equalize the pressure within the auxiliarysecond space.

This has the advantage that a method is provided which can vent a first space and atthe same time a||eviate the risk of pressure build-up with the ventilation device beingused.

According to yet another aspect of the invention the auxiliary second space furthercomprises a sensor, arranged to determine the pressure of the auxiliary secondspace, and wherein the method further comprises the step of: c) after a) and beforeb) determining the pressure within the auxiliary second space by means of the SGHSOI' This has the advantage that the pressure within the auxiliary second space may beconstantly monitored wherein the measured pressure may be used to know whenthe baffle plates are to be moved to the open state, which in turn provides a reliableworking environment of the at least one fan of the ventilation device as the risk ofpressure build-up is securely avoided.

BRIEF DESCRIPTION OF THE DRAWINGSBelow is a description of, as examples, preferred embodiments of the invention withreference to the enclosed drawings, in which: Figure 1 schematically illustrates a vehicle provided with a ventilation device according to the invention, Figure 2 schematically illustrates a perspective view of an auxiliary second space of a ventilation device according to the invention, Figure 3 schematically illustrates a perspective view of an auxiliary second space ofa ventilation device, comprising baffle plates, according to the invention, Figure 4 schematically illustrates a cross-sectional side view of a ventilation deviceaccording to the invention, and Figure 5 shows a flowchart of a method for venting a first space according to the invenfion.

DETAILED DESCRIPTION OF PREFERRED El\/lBODll\/IENTS OF THE INVENTIONFigure 1 schematically illustrates a vehicle 1 provided with a ventilation device 3according to the invention. The vehicle 1 comprises an engine 5, situated within afirst space 7 of the vehicle 1, a chimney 9 extending from said first space 7, thechimney 9 comprising an inlet 11 and an outlet 13, wherein the inlet 11 is arranged influid communication with the first space 7 and the outlet 13 is in fluid communicationwith a surrounding atmosphere outside of the vehicle 1. The ventilation device 3further comprises a second auxiliary space 15, said space 15 being arrangedadjacent the chimney 9 and being in fluid communication with the chimney 9 bymeans of a plurality of openings 17, wherein an airflow flowing from the auxiliarysecond space 15 to the surrounding atmosphere via the chimney 9 causes anejector effect in the chimney 9 which vents the air in the first space 7. The engine 5may be an internal combustion engine and/or an electrical machine and the heatgenerated from the engine 5 may be vented from the first space 7 by means of saidejector effect without the need to place fans for this object within the first space 7.The first space 7 comprises at least one air intake opening 19 for outside air whichwill flow through the first space 7 and cool the engine 5. Said air will then be ventedback to the surrounding atmosphere outside of the vehicle 1 via the chimney 9 of theventilation device 3. The at least one air intake opening 19 of the first space 7 maybe by means of air ducts or similar, or being incorporated in existing mechanicalstructures of the vehicle 1, such as using the propeller shaft tunnel of the vehicle 1as an air intake opening 19. The auxiliary second space 15 further comprises at leastone fan 21 being arranged in an outer wall of the auxiliary second space 15, which atleast one fan 21 guides the air from the surrounding atmosphere to the chimney 9via the auxiliary second space 15. The at least one fan 21 may however be placedanywhere within the auxiliary second space 15, wherein additional openings forintake of air may be arranged to the auxiliary second space 15 for intake of air from the surrounding atmosphere.

The principle of an ejector effect is a way of creating a suction effect in the vicinity ofa nozzle in which nozzle a motive fluid is guided and directed. By locally increasingthe pressure of the motive fluid within the nozzle, the velocity of said fluid will then beincreased when discharged from said nozzle, and the pressure locally decreased atthe same time. By guiding the direction of a motive fluid in a specific direction saidmotive fluid will then cause a suction effect in the vicinity of said nozzle due to thelocally lowered pressure. When a fluid intake opening, through which a secondaryfluid which is to be vented is flowing, is arranged in fluid communication with thesuction effect, said fluid which is to be vented will be sucked in by the suction effectand led away from the intake opening and transported through adjacent fluidtransportation means, usually called a diffuser. lt is to be understood that theopenings 17 of the ventilation device 3 may be compared to nozzles as describedabove, wherein the airflow flowing from the auxiliary second space 15 may becompared to the motive fluid when guided via said openings 17 to the chimney 9which may be compared to a diffuser, discharging the airflow to the surroundingatmosphere via said chimney 9. The suction effect caused by the ejector effect willthus be generated in, or in the vicinity of, the intake 11 of the chimney 9, wherein aventing of the first space 7 is provided by the ventilation device 3. lt should be noted that the term chimney 9 used for the ventilation device 3 of theinvention is to be seen as a ventilation duct, mainly or purely for venting the firstspace 7 by means of guiding an airflow through the second space 15. When theventilation device 3 is used for a vehicle 1, as described in accordance with figure 1,the chimney 9 of the ventilation device 3 is not to be viewed as the exhaust systemof the engine 5 of the vehicle 1. The exhaust system for the engine 5 may beincorporated with the chimney 9, but it may also be a regular exhaust pipetransporting produced exhaust gases away from the engine to any suitableplacement of said exhaust pipe. Such an exhaust pipe may further also be formed asa chimney, leading the exhaust gases upwards if so is desired. lt should therefore beemphasized that the term chimney, when used in the description for the inventionrelates to a chimney 9 of a ventilation device 3.

Figure 2 schematically illustrates a perspective view of an auxiliary second space 15of a ventilation device 3 according to the invention. The auxiliary second space 15 shown in figure 2 should be viewed as part of a ventilation device 3 which isarranged to a first space 7 under the auxiliary second space 15. ln this example, theauxiliary second space 15 comprises a chimney 9 with an inlet 11 and an outlet 13,wherein the inlet 11 is designed to be arranged in fluid communication with the firstspace 7 for which the ventilation device 3 is meant to be used, wherein an airflowgoing through the auxiliary second space 15 and into the chimney 9 creates anejector effect which drags air and thereby heat from said first space 7. The airflowguided by means of the ventilation device 3 is illustrated with arrows with solid lines23 and the airflow flowing as a result of the ejector effect is illustrated with arrowswith dotted lines 25. The chimney 9 of this example has a rectangular cross-sectional shape, but other shapes are also possible without deviating from theinventive concept of the invention. lt should also be understood that the chimney 9 ofthis example is only shown extending in length along the auxiliary second space 15,but may extend further upwards positioning the outlet 13 higher, and may alsoextend downwards if the first space 7 is placed at a distance from the auxiliarysecond space 15. Generally the first space 7 is arranged directly under the auxiliarysecond space 15, to increase the effectiveness of the ejector effect provided by theventilation device 3. The auxiliary second space 15 shown in this example furthercomprises a heat exchanger 27, which extends down into the first space 7. The heatexchanger 27 may further be part of a heat exchanger unit arranged to a devicewithin the first space 7, wherein the heat exchanger 27 may be coupled to said heatexchanger unit by means of hoses or tubes or similar, as a way of transporting heatto the heat exchanger 27. The extension of the heat exchanger 27 down into the firstspace 7 are thus to be viewed merely as an illustration of heat being transferred fromthe first space 7 to the auxiliary second space 15. Thereby part of heat generated inthe first space 7 is being removed by means of the heat exchanger 27 while at thesame time more heat is being removed by means of the ejector effect provided bythe ventilation device 3. Furthermore, the auxiliary second space 15 of figure 2comprises four fans 21, which fans 21 are arranged in an outer wall 29 of theauxiliary second space 15. The fans 21 sucks in air from a surrounding atmosphere,guiding said air through the auxiliary second space 15 and into the chimney 9 via aplurality of openings 17 arranged in a dividing wall 31 situated between the auxiliarysecond space 15 and the chimney 9. lt should be realized that the number of fans 21and the number of openings 17 may vary in different embodiments of the ventilation 11 device 3, and may be chosen depending on factors such as the size of theventilation device 3. Furthermore, the fans 21 may also be placed anywhere withinthe auxiliary second space 15, wherein additional openings for intake of air may bearranged to the auxiliary second space 15 for intake of air from the surroundingatmosphere. The openings 17 arranged in the dividing wall 31 shown in figure 2further comprises angled guide vanes 33, arranged at the bottom of each opening 17and extending into the chimney 9 at an angle. The angled guide vanes 33 therebyguide the airflow upwards as it is passing through the openings 17. This provides anairflow which is guided in the right direction more effectively and lowers the risk of airpassing through the openings 17 and going down towards the first space 7, whichwould be counter-effective in regards of the ejector effect. The angled guide vanes33 may further have an end portion directed upwards the outlet of the chimney 9further guiding the airflow upwards. Other shapes are also possible for the guidevanes 33, such as rounded shapes to guide the airflow along a curve of roundedguide vane 33. lt should furthermore also be noted that the auxiliary second space15 shown in figure 2 further comprises a ceiling and another outer wall, which are notshown in figure 2. The auxiliary second space 15 according to this embodiment ofthe auxiliary second space 15 is hence meant to be seen as a closed space notbeing in fluid communication with the environment except for the described openings17 and fans 21. As should be realized, the ceiling and other outer wall are not being depicted to help the understanding of the perspective figure. lf the example of the auxiliary second space shown in figure 2 would to be used for avehicle 1 as shown in figure 1, the heat exchanger 27 and the fans 21 may be part ofa heat exchanger unit of the engine 5 of the vehicle 1. Thereby the heat exchangingprovided by the heat exchanger unit which is commonly used for engines is providedwhile at the same time moving the fans of said heat exchanger unit to the auxiliarysecond space 15 which provides a better working environment for said fans. As thefans will operate in a non-engine room environment the working life of the fans maybe extended and an efficient cooling is provided. However, it should be realized thatthe ventilation device 3 according to the invention may also be used to vent othertypes of first spaces 7 which may not be engine rooms, wherein fans 21 may still beprovided to the auxiliary second space 15 to guide an airflow within said second space 15 and suck in cool air from a surrounding environment. Another example of 12 first spaces 7 with ventilation needs may be a first space 7 containing hazardouschemicals, wherein fumes of said chemicals could have a negative impact of thefans 21 of the ventilation device 3. Thereby the ventilation device 3, by means ofventing a first space 7 using an ejector effect, may provide an effective venting ofsaid first space 7 using fans 21 but placing said fans 21 in a better workingenvironment. For such an example the heat exchanger 27 shown in figure 2 may notbe needed or desired and may simply not be present if heat is a non-issue for the ventilation device 3.

Figure 3 schematically illustrates a perspective view of an auxiliary second space 15of a ventilation device 3, further comprising baffle plates 35, according to theinvention. The auxiliary second space 15 shown in figure 3 can be viewed as similarto the auxiliary second space 15 shown in figure 2, further comprising another outerwall 29, in which a plurality of baffle plates 35 are arranged. The baffle plates 35 arearranged to be able to move between a closed state and an open state. The closedstate prevents air from passing through outer wall openings 37 to which the baffleplates 35 are mounted. The open state, which is shown in figure 3, provides fluidcommunication with the surrounding atmosphere and the auxiliary second space 15.The baffle plates 35 are arranged to move to the open state when the pressurewithin the auxiliary second space 15 reaches a predetermined value. Saidpredetermined value is based on an acceptable pressure for the airflow within theventilation device 3 affecting the fans 21 guiding said airflow. lf a too high pressure isreached within the auxiliary second space 15 and/or the chimney 9, the desiredejector effect might be negatively affected or in worst case negated. Further, if theventilation device 3 comprises a heat exchanger as depicted in the example of figure2, the heat exchange within said heat exchanger 27 may also be negatively affectedby the reduced flow of air due to a too high pressure within the auxiliary secondspace 15. Furthermore, depending on the type of fan 21, or fans 21, used in theventilation device 3, said fan 21, or fans 21, might also be subjected to an increasedware and hence a lesser working lifespan if the pressure within the ventilation device3 reaches too high values. The baffle plates 35 are arranged in the outer wall 29 toalleviate such a situation from arising. The baffle plates 35 shown in figure 3 arespring-loaded by means of springs 39 arranged to bias the baffle plates 35 to be in the closed state when acceptable pressure levels are present within the auxiliary 13 second space 15 and in the chimney 9. Said springs 39 have specific spring forcesholding the baffle plates 35 closed based on the design parameters of said springs39. When/if a too high pressure is reached within the auxiliary second space 15, theforce based on said pressure will overcome the spring forces of the springs 39release the bias towards the closed state which will automatically move the baffleplates 35 to the open state. ln such a situation the pressure will be equalized with thepressure of the outside atmosphere which in turn alleviates the build-up of pressurewithin the ventilation device 3. Additional baffle plates 35 may also be placed in anouter wall of the chimney if it is desired to equalize a build-up of pressure within thechimney 9 directly. The baffles plates 35 may also be mounted with an actuatingdevice (not shown), which actuating device moves the baffle plates 35 between theopen and closed state. The actuating device may be any known type of actuatingdevice such as a motorized piston or similar. The actuating device may then becontrolled by a driver of the vehicle directly or be operated on basis of a measuredpressure value. The baffle plates 35 may be mounted with springs 39, or withactuating devices, or a combination of both, if desired. Thereby a versatile ventilationdevice 3 is provided, wherein the pressure can be equalized both by automaticmeans and by user controlled means. Furthermore, the baffle plates 35 of theventilation device 3 may be designed to be fixed in the open state wherein thepressure within the auxiliary second space 15 instead is controlled by the operationof the fans 21.

Figure 4 schematically illustrates a cross-sectional side view of a ventilation device 3according to the invention. This schematic illustration of a ventilation device 3comprises a first space 7, preferably being viewed as an engine room of a vehicle 1with an engine 5 situated therein. The engine 5 generates heat when operated givingrise to a need to vent said heat from said first space 7. The first space 7 comprisesan air intake opening 19, wherein air is sucked into the first space 7 by means of apressure difference between said first space 7 and a surrounding atmosphere,outside of the vehicle 1. The air intake opening 19 may be placed anywhere in anouter wall 29 of the first space 7. The placement of the air intake opening 19depicted in figure 4 is merely placed at its location as a convenience in regards toviewing the figure in an easy way. Preferably the placement of the air intake opening19 is situated in, or in the proximity to, the opposite corner of the first space 7 in 14 regards to the chimney 9 so as to achieve maximum cooling on the engine 5 bymeans of the airflow flowing through the first space 7. The first space 7 may furthercomprise a plurality of air intake openings 19, and the example depicted in figure 4should not be viewed as a restriction of the invention. The engine 5 in the first space7 further comprises a heat exchanger unit 41 with a heat exchanger 27 whichextends up into the auxiliary second space 15, situated directly on top of the firstspace 7. The ventilation device 3 may however comprise a plurality of heatexchangers 27 and/or heat exchanger units 27 without deviating from the inventiveconcept of the invention. The heat exchanger unit 41 further comprises a fan 21which cools the engine by means of cooling a coolant which circulating within theheat exchanger 27 and the engine 5 as well as guiding cool intake air from asurrounding atmosphere into the auxiliary second space 15. Said fan 21 then guidesthe intake air through the auxiliary second space 15 and into the chimney 9,arranged adjacent the auxiliary second space 15, via a plurality of openings 17provided with angled guide vanes 33 to guide the airflow in a direction towards theoutlet 13 of the chimney 9. Thereby the airflow creates an ejector effect in the inlet11 of the chimney 9 by means of the pressure difference created by the directed airguided away from the first space 7. The example of the ventilation device 3 shown infigure 4 further comprises a sensor 43, arranged to determine the pressure within theauxiliary second space 15. Said sensor 43 can be viewed as any type of pressuresensor known in the art. Said sensor 43 can measure the pressure within theauxiliary second space 15 to determine if baffles plates (not shown in figure 4)should be moved to an open state by means of an actuating device (as describedwith reference to figure 3) and/or as a means to monitor the internal pressure of theventilation device 3. Additional sensors may also be arranged in the chimney 9and/or the first space 7 as a means of closely monitoring the internal pressures ofeach individual space 7, 9, 15 of the ventilation device 3, wherein baffles plates 35 may be opened or closed to control said internal pressures.

Figure 5 shows a flowchart of a method for venting a first space 7 according to theinvention. The method is performed by using a ventilation device 3 according to thedescription accompanying figure 4. Wherein the ventilation device 3 comprises achimney 9 extending from the first space 7, the chimney 9 comprising an inlet 11 andan outlet 13, wherein the inlet 11 is arranged in fluid communication with the first space 7 and the outlet 13 is in fluid communication with a surrounding atmosphere.The ventilation device 3 further comprises an auxiliary second space 15, the secondspace 15 being arranged adjacent the chimney 9 and being in fluid communicationwith the chimney 9 by means of at least one opening 17. The method shown in theflowchart in figure 5 comprises the steps of: a) guiding an airflow from the auxiliarysecond space 15 to the surrounding atmosphere via the chimney 9 so as to causean ejector effect in the chimney 9 which vents the air in the first space 7, b) openingat least one baffle plate 35 to equalize the pressure within the auxiliary second space15, and c) which is performed after a) and before b) determining the pressure of theauxiliary second space 15 by means of the sensor 43. According to differentembodiments of the invention, the method may be performed in different ways. Themethod described above in accordance with figure 5 describes a method wherein afirst space 7 is vented by means of step a), and where the risk of a build-up ofpressure is monitored by means of step c) and alleviated by means of step b).However, another embodiment of the method may be performed by using anembodiment of a ventilation device 3 as shown in figure 2, wherein only step a) isperformed so as to purely vent a first space 7 by means of creating an ejector effectin a chimney 9 arranged in fluid communication with said first space 7. Furthermore,yet another embodiment of the method may be performed by using an embodimentof a ventilation device 3 as shown in figure 3, wherein step a) and b) are performedto vent a first space 7 and automatically open baffles plates 35 which are spring-loaded with a specific force, corresponding to a predetermined allowed pressurewithin the embodiment of the ventilation device 3.

As should be realized, the components and features specified above may within theframework of the invention be combined between the different embodiments specified.

Claims (12)

16 CLAIIVIS 1 _

1. A ventilation device for a first space (7), in particular an engine room of avehicle (1), comprising a chimney (9) extending from said first space (7), thechimney (9) comprising an inlet (11) and an outlet (13), wherein the inlet (11)is arranged in fluid communication with the first space (7) and the outlet (13)is in fluid communication with a surrounding atmosphere, characterized in that the ventilation device (3) further comprises an auxiliary second space (15),the second space (15) being arranged adjacent the chimney (9) and being influid communication with the chimney (9) by means of at least one opening(17), wherein an airflow flowing from the auxiliary second space (15) to thesurrounding atmosphere via the chimney (9) causes an ejector effect in thechimney (9) which vents air from the first space (7).

2. The ventilation device according to claim 1, wherein at least one fan (21) isarranged in an outer wall (29) of the auxiliary second space (15), which atleast one fan (21) guides air from the surrounding atmosphere to the chimney(9) via the auxiliary second space (15).

3. The ventilation device according to claim 2, wherein the first space is anengine room with an engine, and the at least one fan is part of a heat exchanger unit of the engine.

4. The ventilation device according to any of the preceding claims, wherein theat least one opening (17) of the chimney (9) is provided with angled guidevanes (33), which guide vanes (33) directs airflow from the axillary space (15)towards the outlet (13) of the chimney (9).

5. The ventilation device according to any of the preceding claims, wherein theauxiliary second space (15) further comprises at least one baffle plate (35)which can move between a closed state and an open state, wherein the openstate provides fluid communication with the surrounding atmosphere, and theat least one baffle plate (35) moves to the open state when the pressure 17 within the auxiliary second space (15) reaches a predetermined value.

6. The ventilation device according to claim 5, wherein the at least one baffleplate (35) is spring-Ioaded with a spring (39), and biased to be in the closedstate by means of a spring force of the spring (39), and move to the openstate when the pressure of the auxiliary second space (15) reaches thepredetermined value, which overcomes the spring force.

7. The ventilation device according to claim 5, wherein the at least one baffleplate (35) is moved between the closed state and the open state by means of an actuating device.

8. The ventilation device according to claim 7, further comprising a sensor (43)arranged to determine the pressure of the auxiliary second space (15)wherein the actuating device can move the at least one baffle plate (35) to theopen state based on the determined pressure.

9. A vehicle (1), characterized in that it comprises a ventilation device (3)according to any of the preceding claims.

10.A method for venting a first space (7) by using a ventilation device (3)comprising a chimney (9) extending from the first space (7), the chimney (9)comprising an inlet (11) and an outlet (13), wherein the inlet (11) is arrangedin fluid communication with the first space (7) and the outlet (13) is in fluidcommunication with a surrounding atmosphere,characterized in thatthe ventilation device (3) further comprises an auxiliary second space (15),the second space (15) being arranged adjacent the chimney (9) and being influid communication with the chimney (9) by means of at least one opening(17), the method comprising the step of: a) guiding an airflow from the auxiliary second space (15) to the surroundingatmosphere via the chimney (9) so as to cause an ejector effect in the chimney (9) which vents the air in the first space (7). 18

11.The method according to claim 10, wherein the auxiliary second space (15)further comprises at least one baffle plate (35) which can move between aclosed state and an open state, wherein the open state provides fluidcommunication between the auxiliary second space (15) and the surroundingatmosphere, and wherein the method further comprises the step of: b) opening the at least one baffle plate (35) to equalize the pressure within theauxiliary second space (15).

12.The method according to claim 11, wherein the auxiliary second space (15)further comprises a sensor (43), arranged to determine the pressure of theauxiliary second space (15), and wherein the method further comprises thestep of: c) after a) and before b) determining the pressure within the auxiliary secondspace (15) by means of the sensor.