Improved jet pump for an aircraft climatization system

Abstract

A jet pump (11) for air conditioning system of an aircraft, comprising a first duct (2) extending along a longitudinal axis (A) defining a first and a second opening (2a, 2b) respectively fluidly connectable to an outside air intake and to a portion of the aircraft to be conditioned, a second duct (3) defining a first and a second opening (3a, 3b), the first opening (3a) being fluidly connectable to an engine system of the aircraft and the second opening (3b) being placed inside the first duct (2) between the first and the second opening (2a, 2b), the second duct (3) defining at least one intermediate opening (7) made between the first and second opening (3a, 3b), the intermediate opening (7) having an axis (B) inclined with respect to the longitudinal axis (A).

Description

[0001] "IMPROVED JET PUMP FOR AN AIRCRAFT CLIMATIZATION SYSTEM"

[0002] Cross-Reference to Related Applications

[0003] This Patent Application claims priority from Italian Patent Application No. 102024000009505 filed on April 24, 2024, the entire disclosure of which is incorporated herein by reference.

[0004] Technical Field

[0005] The present invention relates to a jet pump, in particular to a jet pump for an aircraft.

[0006] The present invention finds a preferred, although not exclusive, application in an air conditioning system for an aircraft such as a helicopter. Said application will be referred to in the following by way of example.

[0007] State of the Known Art

[0008] Aircraft, such as helicopters, need to heat select aircraft compartments such as, for example, the cabin.

[0009] It is known to use jet pump systems (so-called "jet pumps") that draw hot air from the aircraft engine system and inject the same into a flow of cold air drawn from the outside environment to obtain air at a given temperature to be injected into the compartment to be heated.

[0010] An example of said system is illustrated in US 2016 / 0288913 Al or US8303384B2.

[0011] However, known jet pump systems are particularly energy- intensive and poorly efficient. Furthermore, said systems are sized to provide heated air within specific temperature ranges. When used at high altitudes or in particularly cold weather conditions , known systems may not be ef fective or require an increase in the load of compressed air drawn from the engine , thus increasing consumption and reducing the autonomy and performance of the aircraft .

[0012] There is therefore a need to reduce the energy consumption of j et pumps for air conditioning systems of aircrafts .

[0013] There is also a need to provide ef ficient j et pumps whose performance can be maximi zed in various atmospheric contexts and at various altitudes .

[0014] In addition, it is necessary to provide the aforementioned purposes while maintaining, i f not improving, the performance of known air conditioning systems .

[0015] The obj ect of the present invention is to meet the above- mentioned needs in an optimi zed and inexpensive manner .

[0016] Summary of the Invention

[0017] The aforementioned obj ect is achieved by a j et pump, an air conditioning system, an aircraft , and a control method thereof as claimed in the attached claims forming an integral part of the present description .

[0018] Brief Description of the Drawings

[0019] For a better understanding of the present invention, a preferred embodiment is described in the following, by way of non-limiting example and with reference to the attached drawings wherein :

[0020] • Figure 1 is a schematic sectional view of a j et pump for an air conditioning system according to the invention;

[0021] • Figures from 2 to 4 are perspective views of a portion of the j et pump of Figure 1 in di f ferent operating configurations . Detailed Description of the Invention

[0022] Figure 1 schematically illustrates a jet pump 1 forming part of an air conditioning system (not illustrated) for an aircraft (not illustrated) . For example, the jet pump 1 can be used for an air conditioning system of a passenger and / or pilot cabin of a helicopter.

[0023] The jet pump 1 essentially comprises a first duct 2, or main duct, extending along a longitudinal axis A. The main duct 2 defines a first opening 2a and a second opening 2b, respectively fluidically connected, for example by conduits not shown, to an outside air intake outside the aircraft and to the compartment of the vehicle to be heated.

[0024] In detail, the main duct 2 is coaxial with the longitudinal axis A and comprises a first end portion 2' , a second end portion 2' ’ and an intermediate portion 2’ ’ ’ longitudinally comprised between said first and second end portions 2’ , 2’ ’ . Advantageously, the main duct 2 is made in a single piece.

[0025] In particular, the first end portion 2’ defines the first opening 2a whereas the second end portion 2’ ’ defines the second opening 2b.

[0026] Advantageously, the main duct 2 has a variable section along the longitudinal axis A. Preferably the first end portion 2’ has a constant section that is greater than the third end portion 2’ ’ ’ connected to the same. Similarly, the second end portion 2’ ’ has a variable section starting from a minimum value, coinciding with the section of the intermediate portion 2’ ’ ’ to a maximum value advantageously equal to the section of the first end portion 2 ’ .

[0027] The jet pump 1 further comprises a second duct 3, injector duct, defining a first opening 3a and a second opening 3b. The inj ector duct 3 defines a first opening 3a and a second opening 3b, respectively fluidically connected, for example by pipes not shown, to a heated and high-pressure air intake coming from an engine system (not shown) , in particular from the first compression stage of a turboshaft engine , and inside the main duct 2 .

[0028] In detail , the f irst opening 3a is coaxial with an auxiliary axis A' , preferably parallel to the longitudinal axis A, whereas the second opening 3b faces along the longitudinal axis A, advantageously parallel to and better yet , coaxial with the same .

[0029] In detail , the auxiliary duct 3 comprises a first end portion 3 ' , a second end portion 3 ' ’ and an intermediate portion 3 ' ’ ’ comprised between said first and second end portions 3 ' , 3 ' ’ . Advantageously, the auxiliary duct 3 is made in a s ingle piece , in greater detail in a material resistant to high pressures and temperatures .

[0030] In particular, the first end portion 3 ' defines the first opening 3a whereas the second end portion 3 ' ' defines the second opening 3b . The intermediate portion 3 ' ’ ’ is advantageously perpendicular to the first and second end portions 3 ’ , 3 ’ ’ that is , it extends along a vertical axis B, inclined and preferably perpendicular to the longitudinal axis A.

[0031] Advantageously, the auxiliary duct 3 has a variable section along its extension along the axes A' , B, A.

[0032] Preferably the intermediate portion 3 ’ ’ ’ has a substantially constant section, the first end portion 3 ’ has a variable section narrowing from a maximum section, at the first opening 3a, to a minimum section equal to that of the intermediate portion . Similarly, in its simplest form, the second end portion 3 ' has a variable section narrowing from a minimum section, at the second opening 3b, to a maximum section equal to that of the intermediate portion .

[0033] Clearly, the main and auxiliary ducts 2 , 3 have an axisymmetric shape along their respective axes , however they could have a polygonal-section shape or any shape according to process needs .

[0034] The variable sections mentioned above are advantageously linear between the minimum and maximum sections described above ; in particular they define a Venturi type system . Advantageously, the main ducts 2 , 3 are made of composite materials or metallic materials , preferably light ; the second of metallic material , such as steel .

[0035] In detail , there fore , the auxiliary duct 3 is housed within an intermediate opening 2c of the axi s B, that is , pas sing the main duct 2 transversally with respect to the longitudinal axis A longitudinally comprised between the first and second openings 2a, 2b of the main duct 2 , advantageously made in the first end portion 2 ’ .

[0036] The opening 2c advantageously houses a support 4 configured to house part of the intermediate portion 3 ' ’ ’ of the auxiliary duct 3 . Advantageously, said support is cup-shaped and si zed to fit into the opening 2c .

[0037] In particular, the support 4 also defines an opening 4a suitable for allowing the passage of the intermediate portion 3 ' ’ ’ of the auxiliary duct 3 . The latter comprises a radial flange 6 extending from the intermediate portion 3 ' ’ ’ and configured to cooperate in contact with the support 4 to prevent movement of the auxiliary duct 3 with respect to said support 4 . In particular, the j et pump 1 comprises insulation means 5 interposed between the flange 6 and the support 4 and configured to prevent direct thermal transmission between the main and auxiliary ducts 2 , 3 and fluidically isolate the opening 4a of the support 4 .

[0038] Advantageously, therefore , the insulation means 5 comprise an annular element made of a polymeric material / a sealing ring .

[0039] Preferably, the second end portion of the auxiliary duct 3 defines at least one intermediate opening 7 with an axis along the vertical axis B .

[0040] Preferably said axis is inclined, in particular incident and more preferably perpendicular to the longitudinal axis A.

[0041] In the embodiment described, two intermediate openings 7 are provided, advantageously coaxial with one another .

[0042] As better shown in Figure 3 , advantageously, the j et pump 1 comprises a regulation system 8 configured to vary the passage section of at least one intermediate opening 7 .

[0043] In particular, the regulation system 8 comprises a shutter element 9 configured to assume a position between a maximum opening position in which it allows the free pas sage of fluid through the at least one intermediate opening 7 , a minimum opening position in which it prevents the passage of fluid through the at least one opening 7 or any intermediate position between the latter .

[0044] The regulation system 8 comprises , furthermore , actuator means (not illustrated) configured to control the shutter element 9 between the aforementioned positions . In the illustrated embodiment , the shutter element 9 is a ring fitted on the second portion 3 ' ’ so as to rotate around the same and provided with a respective opening 9a that can totally or partially overlap or block the intermediate opening ( or intermediate openings ) 7 .

[0045] Clearly, depending on the number of intermediate openings 7 , an equal number of openings 9a can be provided on the ring 9 .

[0046] Advantageously, the heating system or the aircraft comprise sensor means conf igured to detect a physical quantity indicative of a physical state of the fluid exiting from the second opening 2b of the main duct 2 and an electronic unit comprising processing means suitable for processing the physical quantity detected by the aforementioned sensor means and providing a control signal to the actuator means to control the passage of the shutter element between the aforementioned positions .

[0047] Advantageously, the sensor means are temperature sensors , pressure sensors and / or flow meters . Optionally, the first opening 3a of the auxiliary duct 3 and / or the first opening 2a of the main duct 2 may also be provided to check the physical state of the incoming fluid .

[0048] The electronic unit is also electronically connected to input means , such as a display or a control knob / button, configured to receive an input signal indicative of a desired temperature in the portion of the aircraft to be air-conditioned and / or the temperature and / or pressure detected by the sensor means designed to check the physical state of the fluid entering the cabin from the section 2b and / or the temperatures of the fluid entering from the section 2a, and / or (where applicable ) the temperature measured in the cabin . The electronic unit is also connected to the engine system or other thermal energy source of the aircraft to acquire operating data .

[0049] The processing means of the electronic unit are configured to process the indicative input signal received from the input means , the sensor means and, where applicable , the engine system to control , for example by a closed-loop system, the actuator means as described above .

[0050] The operation of the embodiment of the j et pump, of the air conditioning system, and of the aircraft according to the invention described above is as follows .

[0051] The j et pump 1 receives as input , through the first opening 3a of the auxiliary duct 3 , a first inlet flow Fb at a pressure higher than the outside air pres sure and at a high temperature from an engine system of the aircraft . Said first flow exits from the second opening 3b providing a first internal flow Fc . Said inj ection of fluid into the main duct 2 draws , from the first opening 2a of the latter, a second inlet flow Fa from the outside environment which therefore tends to mix with the first internal flow Fc to provide an outlet flow Fe towards the compartment to be air conditioned .

[0052] I f one or more intermediate openings 7 are provided in the second end portion 3 ' ’ of the auxiliary duct 3 , part of the first inlet flow Fb exits from the same , perpendicular to the first portion, as a second internal flow Fd inside the main duct 2 upstream of the second opening 3b of the auxiliary duct 3 . In this way, the mixing of the first and second inlet flows Fb, Fa is signi ficantly increased without increasing the drag ef fect on the flow entering from the section 2a and therefore without increasing the flow rate of cold air aspirated, thus providing a mixed outlet flow Fe with practically the same flow rate but at a signi ficantly higher temperature .

[0053] I f one or more intermediate openings 7 provided with a regulation system 8 are provided, the operation is similar to that described above , in particular it is possible to vary the value of the second internal f low Fd between a zero value and a maximum value corresponding to a complete blockage or opening of one or more intermediate openings 7 .

[0054] I f the regulation system is provided, the electronic unit comprises processing means to process the data acquired by the engine system, the input means , the sensor means to control the regulation system 8 . The processing clearly uses thermodynamic laws that link the need for air conditioning o f the vehicle portion with the physical characteristics of the fluids entering the j et pump and therefore not disclosed for the sake of brevity, being able to vary depending on the speci fic use and aircraft needs .

[0055] According to the above , the invention is therefore also related to a method for controlling a j et pump 1 in an aircraft as described above , comprising the steps of : i ) acquiring data from the sensor means , the input means , and the engine system; ii ) processing a control signal based on the data acquired in point ii ) to control the regulation system to define a percentage of blockage of the at least one intermediate opening ( 7 ) .

[0056] The method described above can be performed continuously or at given intervals , i f air conditioning of the aircraft compartment is required .

[0057] From the foregoing, the advantages of a j et pump, of an air conditioning system, of an aircraft and of a control method thereof according to the invention are clear . Thanks to the intermediate openings provided on the auxiliary duct 3 , it is possible to signi ficantly increase the mixing between the fluids entering the j et pump, providing a fluid at a more homogeneous temperature at the outlet .

[0058] The aforementioned mixing, moreover, allows to signi ficantly increase the temperature of the fluid at the outlet , in particular by 50- 100% compared to the systems of the prior art .

[0059] The higher outlet temperature allows to have to draw less fluid or fluid at a lower temperature from the engine system, allowing a substantial energy saving . Furthermore , this makes the j et pump ef fective in conditions where , in the absence of the system described here , it could not guarantee the flow rates of hot air required by the aircraft heating system .

[0060] Furthermore , it is clearly possible to use said j et pump in various atmospheric conditions or altitude variations , given the greater thermal power that can be supplied to the output fluid .

[0061] Thanks to the regulation system, it is also possible to regulate the functionality of the aforementioned openings between a minimum and a maximum value , achieving further energy savings depending on the vehicle needs and external atmospheric conditions .

[0062] In particular, the suggested shutter system is particularly compact and has minimal influence on the internal fluid dynamics of the duct 2 . Furthermore , the supplied shutter system is particularly inexpensive and easy to produce .

[0063] Finally, it is clear that changes and alternatives can be made to the j et pump, to the air conditioning system, to the aircraft and to a control method thereof according to the present invention which, however, do not go beyond the scope of protection defined by the claims.

[0064] Clearly the shape of the ducts can vary, as well as their mutual assembly.

[0065] For example, the second end portion 3' can have convergent- divergent shapes (so-called De Lavall nozzle) . Again, different shapes and numbers of intermediate openings could be foreseen.

[0066] Furthermore, the shutter system, as mentioned, can be omitted or can be made differently than described.

Claims

CLAIMS1.- A jet pump (1) for an air conditioning system of an aircraft, comprising a first duct (2) extending along a longitudinal axis(A) defining a first and a second opening (2a, 2b) respectively fluidly connectable to an outside air intake and to a portion of said aircraft to be conditioned, a second duct (3) defining a first and a second opening (3a, 3b) , said first opening (3a) being fluidly connectable to an engine system of said aircraft and said second opening (3b) being placed inside said first duct (2) between said first and second opening (2a, 2b) , said second duct (3) defining at least one intermediate opening (7) made between said first and second opening (3a, 3b) inside said first duct ( 2 ) , wherein said intermediate opening (7) is centred on a first axis(B) inclined with respect to said longitudinal axis (A) and wherein said first opening (3a) of said second duct (3) is centred on a second axis (A' ) parallel to said longitudinal axis (A) and spaced from the latter along said first axis (B) .2.- The jet pump according to claim 1, wherein said first axis (B) is incident with respect to said longitudinal axis (A) .3.- The jet pump according to claim 1 or 2, wherein said first axis (B) is perpendicular with respect to said longitudinal axis(A) .4.- The jet pump according to one of the preceding claims, comprising several intermediate openings (7) .5.- The jet pump according to claim 4, wherein said intermediate openings (7) are coaxial with one another.6.- The jet pump according to one of the preceding claims, wherein said second axis (A' ) is coaxial with said longitudinal axis (A) .7.- The jet pump according to one of the preceding claims, wherein said first duct (2) has a variable section along said longitudinal axis (A) .8.- The jet pump according to one of the preceding claims, wherein said second duct (3) extends partly along said first axis (B) , said first and second openings (3a, 3b) being centred on respective axes parallel to said longitudinal axis (A) .9.- The jet pump according to one of the preceding claims, comprising insulating means (6) operationally interposed between said first and second duct (2, 3) .10.- The jet pump according to any of the preceding claims, comprising a regulation system (8) configured to regulate the passage of fluid through said at least one intermediate opening (7) .11.- The jet pump according to claim 10, wherein said regulation system (8) comprises a shutter element (9) and actuator means configured to bring said shutter element (9) between a maximum opening position in which it allows the free passage of fluid through the at least one intermediate opening (7) , a minimum opening position in which it prevents the passage of fluid through the at least one opening (7) or an intermediate position between the latter.12.- An air conditioning system for an aircraft comprising a jet pump (1) according to one of the preceding claims.13.- An aircraft comprising an air conditioning system according to claim 12 for conditioning a portion of said aircraft.14.- The aircraft according to claim 13 when dependent on oneof claims 10 or 11, comprising an engine system, an electronic unit and sensor means suitable for detecting a physical quantity indicative of a physical state of the fluid supplied by said jet pump (1) , said aircraft comprising input means suitable for receiving a required temperature data of said portion, said electronic unit being electrically connected to said engine system, said input means, said sensor means and said regulation system (8) , said electronic unit comprising processing means for processing the data acquired by said engine system, said input means, said sensor means for controlling said regulation system (8) .15.- A method for controlling a jet pump (1) in an aircraft according to claim 14 comprising the steps of: i) acquiring data from said sensor means, said input means, said engine system; ii) processing a control signal based on the data acquired in point ii) to control said regulation system to define a percentage of blockage of said at least one intermediate opening (7) .

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