This application claims priority to German Application No. 10 2017 115 671.2 filed Jul. 12, 2017, which application is incorporated by reference herein.
The invention relates to a valve system for a fluid line system in an aircraft engine having the features of claim 1, and to a method for operating a valve system for a fluid line system in an aircraft engine having the features of claim 11.
In an aircraft engine, a multiplicity of fluids (for example hydraulic fluid, oil, air) is conducted through fluid line systems. One example for such a fluid line system is the so-called secondary air system, which comprises all the air guides in the aircraft engine which do not contribute directly to the thrust of the aircraft engine. The secondary air system conducts for example cooling air or sealing air and/or into those regions of the aircraft engine in which the air is required.
Cooling air is typically used for cooling turbine blades, turbine discs and/or the turbine casing (for example during a tip clearance control).
Sealing air serves for example for the fluid dynamic sealing of spaces in the turbine region, for example with respect to the penetration of hot gases.
The object is thus to efficiently conduct or control fluids within the aircraft engine, and to provide fluid line systems which are in particular also robust with respect to failure of a fluid line.
The object is achieved by a valve system having the features of claim 1.
In this case, in the valve system, the valve position of an actuator in the at least one check valve is changeable, in particular automatically changeable, in dependence on the pressure ratios in each case acting on the at least one check valve; and a monitoring means records the respective valve position, in particular an open position and/or a closed position of the actuator, in dependence on at least one measurement value, wherein a signal is output in dependence on the recorded valve position. Through the use of measurement value monitoring, efficient and non-invasive monitoring of the valve positions is possible. It is thus possible, for example, to respond efficiently to possible failure of fluid lines, in particular air lines. A means, for example the monitoring means, is used to achieve a setting of a minimum required sealing-air stream. It is thus possible to prevent the pressure from dropping by too great an extent locally.
In one embodiment, the at least one measurement value is a temperature value, a pressure value and/or a flow speed value. It is in particular also possible for multiple, different measurement values to be used and for correlations between the measurement values to be utilized.
In one embodiment, a sensor, in particular at least one temperature sensor, at least one pressure sensor and/or at least one flow speed sensor, are/is arranged upstream and/or downstream of the at least one check valve.
Also, in one embodiment of the valve system, when processing the measurement values, a difference of the measurement values from given and/or determined reference measurement values is determined by the monitoring means. It is thus not necessary for absolute measurement values to be used for monitoring, but rather suitably scaled values can be used.
Furthermore, it is possible in one embodiment for the signal for the valve position to be able to be indicated in a magnetic, optical, haptic and/or mechanical manner. The signal may be conducted for example via the flight data processing system of the aircraft engine, with the result that a corresponding valve position is able to be indicated in the maintenance recorder or also in the cockpit.
Embodiments of the valve system may have at least one check valve with a double flap, a rotary flap and/or a ball as an actuator for the fluid. Said actuators allow efficient opening and closing of the fluid line to be achieved.
Here, in one embodiment, air, in particular cooling air and/or sealing air, may be the fluid which flows through the fluid line.
Here, in one embodiment, the fluid line may conduct air from a compressor stage to a turbine stage, in particular to a high-pressure turbine of the aircraft engine. High temperatures prevail precisely in the region of the high-pressure turbine, and so an efficient supply of cooling air is expedient. In a further embodiment, the at least one check valve is arranged in the spatial vicinity of a turbine stage.
The object is also achieved by a method for operating a valve system for a fluid line system in an aircraft engine.
In this case, the valve position of an actuator in the at least one check valve is changed, in particular automatically changed, in dependence on the pressure ratios in each case acting on the at least one check valve, and the respective valve position, in particular the open position and/or the closed position of the actuator, is monitored by a monitoring means in dependence on at least one measurement value, wherein a signal is then output in dependence on the recorded valve position and a minimum required sealing-air stream is set.
The measurement value may be for example a temperature value, a pressure value and/or a flow speed value.
Here, it is possible for example for at least one measurement value to be measured upstream and/or downstream of the at least one check valve.
Also, in one embodiment, when processing the measurement values, a difference of the measurement values from given and/or determined reference measurement values can be determined by the monitoring means. Said determination of the difference is a relatively simple measure.
Also, the signal for the valve position may be indicated for example in a magnetic, optical, haptic and/or mechanical manner.
In one embodiment of the method, the fluid is air, in particular cooling air and/or sealing air. Said media are required in aircraft engines.
The invention will be discussed in connection with the exemplary embodiments illustrated in the figures. In the figures:
Also, part of the air stream L is conducted further into the interior of the aircraft engine, specifically in a space for sealing air. It is thus possible, for example, for bearings to be protected against the entry of hot gases.
Upstream of the entry into the region of the turbine stage 12, specifically upstream of the entry of the air into the space around one of the turbine discs and into the space for sealing air, a check valve 1 is arranged as a part of a valve system.
The illustration in
In the embodiment in
In principle, the fluid line may, in another embodiment of the valve system, also conduct liquid media, such as for example hydraulic fluid or oil.
The function of the check valve 1 within the embodiments of the valve system is described more precisely below.
Examples for check valves 1 within the context of the following embodiments are shut-off valves, quick-acting valves, non-return valves or also closure valves, which can allow or prevent a fluid flow, wherein here the check valves 1 are able to be controlled in dependence on pressure ratios prevailing at the check valve 1, in particular automatically.
In
Here, the fluid line system has a fluid line 10 through which—as in the exemplary embodiment in
Here, a check valve 1 in the form of a butterfly valve with an actuator 2 is arranged in the fluid line 10. The two valve positions (S1, S2) of the butterfly valve are illustrated in
In alternative embodiments, use is made for example of a non-return valve in the form of a flap instead of the butterfly valve.
Upstream of the check valve 1, the temperature T1, the pressure P1 and the flow speed v1 prevail; downstream, the temperature T2, the pressure P2 and the flow speed v2 prevail. The sensors 21 for said measurement values M, that is to say the pressures, temperatures and/or flow speeds, are not illustrated in
Here, the valve position S1, S2 of the actuator 2 in the check valve 1 is changeable in dependence on the pressure ratios P1, P2 in each case acting at the check valve 1. If, for example, owing to a break or a leak, a pressure difference (|P1−P2|) of a specific size prevails, then the check valve 1 is automatically closed.
The illustration in
If, for example, hot gas were to flow out the fluid line 10 through the leak in the fluid line 10, then the surrounding region of the fluidline 10 would be protected from the hot gas from the spaces in the turbine space.
It is of interest, inter alia for operational safety, to monitor the valve position S1, S2 (open, closed) in a robust manner.
In the illustrated embodiment, use is made of a sensor 21 to measure at least a temperature T, a pressure P and/or a speed v in the fluid line 10 in the vicinity of the check valve 1 (upstream and/or downstream).
Said measured measurement value M (that is to say the absolute value) will be different in each case for the case of a closed and of an open check valve 1, and so monitoring of the valve position S1, S2 is possible.
The measurement values M are transmitted to a monitoring means 20, for example a microcomputer, which is able to process and/or save the measurement values M. The state of the valve position S1, S2 can then be transmitted in the form of a signal Sig to an optical, mechanical, haptic and/or acoustic reproduction device (not illustrated here).
The monitoring of the valve positions S1, S2 may in this case also be realized in dependence on a difference of the measurement values M from a reference measurement value Mr. The reference measurement value Mr may for example be a target value, or an averaged value which has been measured by the monitoring means 20 over a specific period of time. The change in the value can in some cases be recorded more accurately by subtracting a, for example numerically relatively large, target value (that is to say by scaling) (|x−xr|).
The monitoring means 20 may also be used for ensuring the minimum supply of sealing air if a fluid line 10 is closed by the check valve 1 (that is to say a corresponding signal Sig is present). This may be realized for example in that, via other fluid lines, correspondingly more air is delivered into the spaces around the turbine stage.
Number | Date | Country | Kind |
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10 2017 115 671.2 | Jul 2017 | DE | national |