PRESSURE RELIEF DOOR ASSEMBLY
20200095806 ยท 2020-03-26
Inventors
Cpc classification
E05B51/023
FIXED CONSTRUCTIONS
E05C19/02
FIXED CONSTRUCTIONS
International classification
E05B51/00
FIXED CONSTRUCTIONS
B64D29/06
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A pressure relief door assembly that includes a relief door arranged in an opening of a compartment, wherein the relief door has a closed position in which the opening is closed and an opened position in which the opening is open, and a locking and release mechanism that is configured to keep the relief door in the closed position if the pressure inside the compartment is below a predetermined threshold pressure and that is configured to move or allow the relief door into the opened position if the predetermined threshold pressure is reached inside the compartment. The locking and release mechanism is further configured to move or allow the relief door into the opened position if a predetermined temperature is reached inside the compartment.
Claims
1. A pressure relief door assembly, comprising: a relief door arranged in an opening of a compartment, wherein the relief door has a closed position in which the opening is closed and an opened position in which the opening is open, a locking and release mechanism that is configured to keep the relief door in the closed position if the pressure inside the compartment is below a predetermined threshold pressure and that is configured to move or allow the relief door into the opened position if the predetermined threshold pressure is reached inside the compartment, wherein the locking and release mechanism is further configured to move or allow the relief door into the opened position if a predetermined temperature is reached inside the compartment.
2. The pressure relief door assembly of claim 1, wherein the locking and release mechanism comprises a movable locking member, the locking member having a first position in which the relief door is closed and a second position in which the relief door can be opened, wherein the locking and release mechanism is configured to move the locking member in the second position if the predetermined threshold pressure or the predetermined temperature is reached inside the compartment.
3. The pressure relief door assembly of claim 1, wherein the locking member is moved into the second position depending on the position and/or force of a spring that loads the locking member or a release component interacting with the locking member.
4. The pressure relief door assembly of claim 2, wherein the locking and release mechanism comprises a SMA wire or other SMA element that assumes a specific high-temperature form when the predetermined temperature is reached, wherein the high-temperature form directly or indirectly causes the locking member to move into the second position.
5. The pressure relief door assembly of claim 4, wherein the spring is a compression spring, wherein the high-temperature form of the SMA wire causes the compression spring to get shorter, such reduction in length removing load from the locking member or from the release component interacting with the locking member.
6. The pressure relief door assembly of claim 5, wherein the shape memory alloy wire is combined with a compression spring, wherein the wire is connected to the compression spring and acts as a switch, switching the spring between two different lengths depending on the temperature.
7. The pressure relief door assembly of claim 2, wherein the locking and release mechanism comprises an element that shrinks when thermally activated, thermal activation occurring at the predetermined temperature, wherein thermal activation directly or indirectly causes the locking member to move into the second position.
8. The pressure relief door assembly of claim 7, wherein the spring is a compression spring, wherein thermal activation of said element causes the compression spring to get longer, such increase in length decreasing the spring force, thereby removing load from the locking member or from the release component interacting with the locking member.
9. The pressure relief door assembly of claim 7, wherein the element that shrinks when thermally activated is made of a polymer or a lower melting temperature metal.
10. The pressure relief door assembly of claim 2, wherein the locking and release mechanism comprises a bimetallic strip that, when reaching the predetermined temperature, is bent to an extent that it directly or indirectly causes the locking member to move into the second position.
11. The pressure relief door assembly of claim 10, wherein the bimetallic strip in its bent shape that is reached at the predetermined temperature exerts a force on the locking member or a component connected to or interacting with the locking member, thereby increasing the force causing the locking member to move into the second position.
12. The pressure relief door assembly of claim 2, wherein the locking and release mechanism comprises a phase-change element that expands when thermally activated, thermal activation occurring at the predetermined temperature, wherein expansion of the phase-change element directly or indirectly causes the locking member to move into the second position.
13. The pressure relief door assembly of claim 12, wherein the phase-change element when thermally activated exerts a force on the locking member or a component connected to or interacting with the locking member, thereby increasing the force causing the locking member to move into the second position.
14. The pressure relief door assembly of claim 12, wherein the phase-change element is a wax or a low melting temperature metal that expands when changing its aggregate state.
15. The pressure relief door assembly of claim 1, wherein the locking and release mechanism comprises a fixed locking arrangement, the fixed locking arrangement comprising two fixed locking members connected to each other with a predetermined looking pressure, wherein the locking members or a connecting member connecting the two locking members consist of a material that changes material properties when the predetermined temperature is reached, wherein the change in material properties reduces the locking pressure between the locking members.
16. The pressure relief door assembly of claim 15, wherein the two fixed locking members are magnets, wherein the magnetic properties of the magnets are such that the magnetic force decreases when the predetermined temperature is reached.
17. The pressure relief door assembly of claim 16, wherein the magnets are made of or comprise neodymium.
18. The pressure relief door assembly of claim 15, wherein the two fixed locking members are connected by a connecting member that becomes liquid when the predetermined temperature is reached.
19. The pressure relief door assembly of claim 18, wherein the connecting material is made of a bismuth-tin alloy or indium or an indium alloy.
20. The pressure relief door assembly of claim 1, wherein the locking and release mechanism comprises a pressure driven release mechanism and a temperature driven release mechanism, wherein the temperature driven release mechanism interacts with the pressure driven release mechanism in that forces applied by the pressure driven release mechanism are changed by the temperature driven release mechanism when the predetermined temperature is reached.
Description
[0028] The invention will be explained in more detail on the basis of exemplary embodiments with reference to the accompanying drawings in which:
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
[0040] The medium-pressure compressor 111 and the high-pressure compressor 112 respectively have a plurality of compressor stages that respectively comprise a rotor stage and a stator stage. The turbofan engine 100 of
[0041] The turbofan engine 100 has an engine nacelle 101 that comprises an inlet lip 102 and forms an engine inlet 103 at the inner side, supplying inflowing air to the fan 104. The fan 104 has a plurality of fan blades 107 that are connected to a fan disc 106. The annulus of the fan disc 106 forms the radially inner boundary of the flow path through the fan 104. Radially outside, the flow path is delimited by the fan housing 108. Upstream of the fan-disc 106, a nose cone 105 is arranged.
[0042] Behind the fan 104, the turbofan engine 100 forms a secondary flow channel 109 and a primary flow channel 110. The primary flow channel 110 leads through the core engine (gas turbine) that comprises the medium-pressure compressor 111, the high-pressure compressor 112, the combustion chamber 113, the high-pressure turbine 114, the medium-pressure turbine 115, and the low-pressure turbine 116. At that, the medium-pressure compressor 111 and the high-pressure compressor 112 are surrounded by a circumferential housing 117 which forms an annulus surface at the internal side, delimitating the primary flow channel 110 radially outside.
[0043] During operation of the turbofan engine 100, a primary flow flows through the primary flow channel 110, which is also referred to as the main flow channel, and a secondary flow flows through the secondary flow channel 109, which is also referred to as bypass channel, wherein the secondary flow bypasses the core engine.
[0044] The described components have a common rotational or machine axis 200. The rotational axis 200 defines an axial direction of the turbofan engine. A radial direction of the turbofan engine extends perpendicularly to the axial direction.
[0045] In the context of the present invention a compartment 2 within the nacelle 101 having a pressure relief door 3 his considered, as is schematically depicted in
[0046]
[0047] In the lower depiction of
[0048]
[0049] To implement an opening of the relief door 3 depending on temperature, a locking and release mechanism is provided that is configured to open the relief door 3 if a predetermined temperature is reached inside the compartment 2.
[0050] It is pointed out that the compartment 2 may be any construction in which there is an internal pressure that may be increased due to specific circumstances such as the burst of a duct that runs through our is located inside the compartment.
[0051]
[0052]
[0053] A locking and release mechanism 4 is provided which determines if the relief door 3 is in the closed position or in the open position. The locking and release mechanism 4 connects the door 3 to wall section 22. In the embodiment of
[0054] As is schematically shown, both pressure P and temperature T influence the functioning of the locking mechanism 41. The locking mechanism 41 is configured to move the locking member 410 into the locked position if the pressure and temperature inside the compartment 2 are below a predefined threshold pressure and threshold temperature. On the other hand, the locking mechanism 41 is configured to move the locking member 410 into the unlocked positionsuch that the relief door 3 opensif the pressure inside the compartment 2 is at or above the threshold pressure or if the temperature inside the compartment 2 is at or above the threshold temperature.
[0055]
[0056] As in the other embodiments, a relief door 3 is located between wall sections 21, 22 in a wall of a compartment. A console 46 is attached to the wall section 21. The movable locking member 410 is formed by a lever which is rotatable about an axis 411. In
[0057] When the pressure increases inside the compartment, the pressure on relief door 3 tends to rotate the lever 410 into the unlocked position. This force, however, is compensated at least at the beginning by the force exerted by spring 42 via roller 44 on the profile 48 of the lever 210. When the pressure in the compartment has reached a sufficient level, a small rotation of the lever 410 about rotational axis 411 causes the roller 44 to move towards a nose 45 of the profile 48, thereby compressing spring 42. With the pressure inside the compartment and the force on the lever 410 further rising, the roller 44 is displaced by going beyond nose 45. The lever 410 is now not anymore retained in the closed position and can rotate into the opened position to open relief door 3. By adjusting the force of compression spring 42, the threshold pressure at which the relief door 3 is opened can be adjusted.
[0058] In the context of the present invention, the relevant feature of this mechanism are the locking member/lever 410 that can be moved between a locked position and an unlocked position, the roller 44 which is a release component interacting with the locking member 410 and the spring 42 which spring loads the release component/roller 44. When the spring force of the compression spring 42 is increased, a higher torque needs to act on lever 410 to rotate the lever 410 into the unlocked position, as there is a stronger force acting on roller 44.
[0059] According to the embodiment of
[0060] The SMA wire 401 has the property that while exposed to a specific tension load at a higher temperature than the threshold temperature, it decreases in length. SMA wires which change length depending on temperature are known in the art. Under a specified temperature (the threshold temperature), the SMA wire has a first length and above the specified temperature the SMA wire has a second length. In this aspect, the SMA wire is a switch switching between two states depending on temperature.
[0061]
[0062]
[0063] SMA wire 401, accordingly, acts as a switch and unlocks the locking mechanism and allows pressure relief door 3 to rotate into the open position (if the pressure inside the compartment is larger than the outside pressure, which typically is the case if a duct is partially burst even if the pressure is not sufficient to trigger the opening of the lever 410 by pressure only). Further, other embodiments may provide for a controlled opening of the relief door 3 independent of the pressure inside the compartment, i.e., by means of a piston arrangement.
[0064] It is pointed out that in
[0065] In the embodiment of
[0066] As shown in
[0067]
[0068] The bimetallic strip 5 is schematically shown in
[0069] The bimetallic strip 5 is located at the inside of wall section 22 and abuts the end 412 of lever 410. When thermally activated at the threshold temperature, it flexes and, accordingly, exerts a force on end 412 of lever 410, this force rotating lever 410 into the unlocked position.
[0070]
[0071] Generally, a phase-change wax may be used which has a threshold melting temperature in the range of 140 C. to 190 C., with a higher density in solid phase than liquid phase. As phase-change wax could be used, e.g., [0072] i. 4-Aminobenzoic acid or [C.sub.7H.sub.7NO.sub.2] which has a melting point of 187 C.; [0073] ii. 2-Aminopyridine [C.sub.5H.sub.6N.sub.2] which has a melting point of 159 C.; [0074] iii. Citric acid [C.sub.6H.sub.8O.sub.7] which has a melting point of 153 C.; or [0075] iv. Pyrene [C.sub.6H.sub.10] which has a melting point of 148 C.
[0076] Alternatively, a low melting temperature metal that expands when changing its aggregate state could be used as element 6, with a density in solid phase that is higher than the density in liquid phase. As low melting temperature metal could be used, e.g., [0077] i. Different alloys of In (Indium) and Ag (Silver) that have melting points around 143 C.; [0078] ii. Indium (In) which has a melting point of 157 C. with a density of 7,3 kg/m3 in solid phase (at 20 deg C) and 7,026 kg/m3 in liquid phase (at 164 C.); or [0079] iii. Different alloys of Sn, In, Ag which have melting points around 175 C. to 187 C.
[0080]
[0081] One of the locking members 71 is firmly attached to the inside of relief door 3. The other locking members 72 is firmly attached to a collar 32 that is attached to the inside of wall section 22. This way, the connection of the locking members 71, 72 keeps pressure relief door 3 closed. On the other hand, if the connection between the locking members 71, 72 is released, the relief door 3 can be opened (typically by an increased pressure inside the compartment 2 that is present even if the increased pressure does not reach the threshold pressure).
[0082] The two locking members 71, 72 consist of a material that changes material properties if the predetermined threshold temperature is reached, this change in material properties leading to a reduction in the force or locking pressure between the two locking members 71, 72.
[0083] An example of such locking members 71, 72 are permanent magnets, wherein the magnetic force of the magnets decreases at the predetermined threshold temperature. Such magnets are well known. More particularly, it is known that permanent magnets have a characteristic curve when plotting the magnetic B-field against the magnetic H-field that shows a knee in which the magnetic force rapidly changes. At the same time, this characteristic curve is dependent on temperature.
[0084] Accordingly, when magnets are chosen such that the knee area lies at the threshold temperature, a fast change in magnetic force takes place at the threshold temperature. In particular, it is provided that the magnetic force decreases in a relatively sudden manner when the predetermined temperature is reached. This way, the connection between the locking members 71, 72 is released.
[0085] In addition, of course, the connection between the locking members 71, 72 is released if the pressure inside the compartment reaches a predetermined threshold pressure, wherein the locking pressure discussed above connecting the locking members 71, 72 with each other is chosen such that it is identical to the threshold pressure.
[0086] Accordingly, the locking and release mechanism 4 of
[0087] In a further embodiment (not shown), the locking members 71, 72 are connected to each other by a connecting member, as mentioned above. The connecting member may be chosen such that it becomes liquid when the predetermined temperature is reached. The connecting material is made of a bismuth-tin alloy or indium or an indium alloy. When becoming liquid at the threshold temperature, the connection between the locking members 71, 72 is released and the pressure relief door 3 opens.
[0088] From the embodiments discussed above it is clear that the change in material properties at the threshold temperature that leads to an opening of the pressure relief door may take place in a linear or nonlinear manner. For example, in the embodiments of
[0089] It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present disclosure in any way. Also, those skilled in the art will appreciate that other aspects of the disclosure can be obtained from a study of the drawings, the disclosure and the appended claims. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. Various features of the various embodiments disclosed herein can be combined in different combinations to create new embodiments within the scope of the present disclosure. Any ranges given herein include any and all specific values within the range and any and all sub-ranges within the given range.