Systems and methods for detecting excess flow in fluid systems

Abstract

A system and method for detecting excessive flow in an engine fluid system are provided. The method includes: sensing the temperature of a fluid flowing in a fluid line of the fluid system, the fluid line being downstream of a fluid restrictor configured to receive fluid from an upstream source and allow fluid to flow from the source into the downstream fluid line; comparing the temperature with a temperature threshold; and detecting excessive flow of fluid in the fluid line and outputting an excessive flow indication accordingly when the temperature exceeds the temperature threshold.

Description

Technical Field

[0001] This application relates generally to engine fluid systems, and more specifically to detecting excessive flow in engine fluid systems. Background Technology

[0002] In engine fluid systems, excessive flow in fluid lines can be caused by disconnected or loose fluid connections, possibly due to missed maintenance or assembly operations. Excessive fluid flow can also be caused by ruptures in fluid lines (e.g., a broken pipe in the engine's pneumatic system), which can be a serious failure mode. Therefore, it is desirable to detect these failures effectively. However, existing methods for monitoring fluid flow in engine fluid systems can prove complex. Therefore, there is room for improvement. Summary of the Invention

[0003] In one aspect, a method for detecting excessive flow in an engine fluid system is provided, the method comprising sensing the temperature of a fluid flowing in a fluid line of the fluid system downstream of a fluid restrictor configured to receive fluid from an upstream source and allow fluid to flow from the source into the downstream fluid line, comparing the temperature to a temperature threshold, and detecting excessive flow of fluid in the fluid line and outputting an excessive flow indication accordingly when the temperature exceeds the temperature threshold.

[0004] In some embodiments, when an excess fluid flow is supplied to the fluid line, the fluid restrictor is configured to create choked flow and cause a temperature drop downstream of the fluid restrictor.

[0005] In some embodiments, the fluid restrictor is a venturi nozzle.

[0006] In some embodiments, sensing the temperature includes sensing a decrease in temperature downstream of the fluid restrictor.

[0007] In some embodiments, sensing the temperature includes obtaining a temperature measurement from a temperature sensor located downstream of the fluid restrictor.

[0008] In some embodiments, sensing the temperature includes sensing the temperature of the fluid flowing in the main fluid line of the fluid system.

[0009] In some embodiments, sensing the temperature includes sensing the temperature of fluid flowing in an auxiliary bypass fluid line of the fluid system, the auxiliary bypass fluid line being parallel to the main fluid line of the fluid system.

[0010] In some embodiments, sensing the temperature includes sensing the temperature of the fluid flowing in the fluid lines of the buffer air cooler.

[0011] In some embodiments, the output excess flow indication includes outputting a message to the engine monitoring system, the message including instructions to cause at least one corrective action to be performed.

[0012] In some embodiments, the method further includes activating a timer when the temperature exceeds a temperature threshold, and detecting excessive flow of fluid in the fluid pipeline when the timer exceeds a predetermined time period.

[0013] On the other hand, a system for detecting excessive fluid flow in an engine fluid system is provided. The system includes a fluid restrictor, a temperature sensor, and a processing unit. The fluid restrictor is located upstream of a fluid line in the fluid system and downstream of a source in the fluid system. The fluid restrictor is configured to receive fluid from the source and allow fluid to flow from the source into the fluid line. The temperature sensor is located downstream of the fluid restrictor and is configured to sense the temperature of the fluid flowing into the fluid line. The processing unit is configured to receive the temperature sensed by the temperature sensor, compare the temperature with a temperature threshold, and when the temperature exceeds the temperature threshold, detect excessive fluid flow in the fluid line and output an excessive flow indication accordingly.

[0014] In some embodiments, when an excess fluid flow is supplied to the fluid line, the fluid restrictor is configured to create a flow obstruction and cause a temperature drop downstream of the fluid restrictor.

[0015] In some embodiments, the fluid restrictor is a venturi nozzle.

[0016] In some embodiments, the processing unit is configured to sense a decrease in temperature downstream of the fluid restrictor.

[0017] In some embodiments, the fluid restrictor is located upstream of the main fluid line of the fluid system.

[0018] In some embodiments, the fluid restrictor is positioned upstream of an auxiliary bypass fluid line of the fluid system, which is parallel to the main fluid line of the fluid system.

[0019] In some embodiments, the fluid restrictor is located upstream of the fluid line of the buffer air cooler.

[0020] In some embodiments, the processing unit is configured to output an excessive flow indication, including an output message to an engine monitoring system, the message including instructions for causing at least one corrective action to be performed.

[0021] In some embodiments, the processing unit is configured to start a timer when the temperature exceeds a temperature threshold, and to detect excessive fluid flow in the fluid line when the timer exceeds a predetermined time period.

[0022] On the other hand, a system for detecting excessive fluid flow in an engine fluid system is provided. The system includes a processing unit and a non-transitory memory communicatively coupled to the processing unit and including computer-readable program instructions executable by the processing unit for sensing the temperature of fluid flowing in a fluid line downstream of a fluid restrictor configured to receive fluid from an upstream source and allow fluid to flow from the source into the downstream fluid line, comparing the temperature to a temperature threshold, and detecting excessive flow of fluid in the fluid line when the temperature exceeds the temperature threshold and outputting an excessive flow indication accordingly. Attached Figure Description

[0023] Now refer to the attached diagram, in which:

[0024] Figure 1 This is a schematic cross-sectional view of an exemplary gas turbine engine;

[0025] Figure 2A This is a schematic diagram of an example system for detecting excess flow in a fluid system according to one embodiment;

[0026] Figure 2B This is a schematic diagram of an example system for detecting excess flow in a fluid system according to another embodiment;

[0027] Figure 2C According to another embodiment, it is used for... Figure 2B A schematic diagram of the entry points used in the example system;

[0028] Figure 3 yes Figure 2A , Figure 2B and Figure 2C The fluid limiter along Figure 2A , Figure 2B and Figure 2C A cross-sectional view taken from line II-II;

[0029] Figure 4 This illustrates an embodiment. Figure 2A , Figure 2B and Figure 2C A schematic diagram of the excessive flow detection unit;

[0030] Figure 5 This is for implementation according to the embodiments. Figure 4 A block diagram of an exemplary computing system for an excessive current detection unit; and

[0031] Figure 6 This is a flowchart of a method for detecting excessive flow in a fluid system according to one embodiment. Detailed Implementation

[0032] Figure 1 A gas turbine engine 10, preferably configured for subsonic flight, is shown. It typically includes a fan 12 in series flow communication through which ambient air is propelled, a compressor section 14 for pressurizing air, a combustor 16 in which the compressed air is mixed with fuel and ignited to generate an annular flow of hot combustion gases, and a turbine section 18 for extracting energy from the combustion gases. The high-pressure rotor 20 of the turbine section 18 is drivenly engaged with the high-pressure rotor 22 of the compressor section 14 via a high-pressure shaft 24. The low-pressure rotor 26 of the turbine section 18 is drivenly engaged with the fan rotor 12 and other low-pressure rotors (not shown) of the compressor section 14 via a low-pressure shaft 28 extending within and rotating independently of the high-pressure shaft 24.

[0033] Although shown as a turbofan engine, the gas turbine engine 10 can alternatively be another type of engine, such as a turboshaft engine, which typically also includes a compressor section, a combustor and turbine section in series flow communication, and a fan through which ambient air is propelled. Other types of aircraft engines and any other suitable types of engines (e.g., industrial engines, automotive engines, etc.) can also be applied. Other examples of engines include, but are not limited to, auxiliary power units (APUs), rotary engines, electric motors, and hybrid electric propulsion systems with thrusters driven in a hybrid architecture (series, parallel, or series / parallel) or a turbine-electric architecture (turbine-electric or partially turbine-electric). Engine 10 can be used in flight applications, industrial applications, etc.

[0034] refer to Figure 2A The method for detecting fluid systems (e.g., such as) will now be described according to one embodiment. Figure 1This is an example system 200 of excess flow in the fluid system of engine 10. As used herein, the term excess (or excess) fluid flow refers to a fluid flow that exceeds the normal fluid flow that occurs under normal operating conditions. As used herein, the term excess (or excess) fluid flow can therefore refer to a fluid leak (e.g., in the monitored engine fluid system). While system 200 is described and illustrated herein with reference to engine 10, it should be understood that this is for illustrative purposes only, and as discussed above, any other suitable engine may be applied. Therefore, any suitable fluid system, including but not limited to aircraft or engine aerodynamic systems, may be applied. In one embodiment, the systems and methods described herein may be applied to aircraft engines, such as on the wings of engine 10, and on the ground for maintenance, assembly, or testing units. Other embodiments may be applied.

[0035] In one embodiment, the systems and methods described herein can be applied to the fluid lines of a buffer air cooler (BAC) (not shown). The BAC is an air-to-air heat exchanger located in a turbofan gas turbine engine (such as...) Figure 1 The bypass air duct (not shown) of engine 10 is located downstream of the fan assembly and upstream of one of the top dead center (TDC) cowlings (not shown) of engine 10. The BAC is in fluid communication with a compressor air source (not shown) to direct compressor airflow through the BAC, wherein the compressor airflow is cooled by a relatively cool bypass airflow passing through an annular bypass air duct. The cooled compressor airflow can then be delivered to various locations (not shown) within engine 10, such as bearing cavities or other hot turbine components, for cooling purposes. As will be further described below, existing buffer air cooler temperature (BACT) sensors (not shown) can be used to detect the air temperature downstream of the BAC and, accordingly, detect faults in the BAC line that delivers pressurized air to the bearing seals of the BAC (e.g., breaks, disconnections, or loose fluid fittings in the line). A disconnection in the BAC line would be practically undesirable, as it would result in insufficient air pressure at the bearing seals, leading to fluid leakage from the BAC. However, it should be understood that the systems and methods described herein can be applied to fluid systems outside the BAC. Therefore, temperature sensors can be used, as proposed in this paper, to detect faults in any disconnected fluid connections or broken engine fluid lines.

[0036] exist Figure 2AIn the illustrated embodiment, system 200 includes a fluid line 202 of an engine fluid system, a fluid restrictor 204, a temperature sensor 206 (e.g., a BACT sensor), and a detection unit 208. In the illustrated embodiment, fluid F flows from a source 210 located upstream of and in fluid communication with the restrictor 204 into an upstream portion 212 of the fluid line 202. It should be noted that the fluid restrictor 204 may be an integral part of the fluid line 212. As used herein, the terms “upstream” and “downstream” are defined relative to the normal flow direction of fluid F. Fluid F may be engine exhaust air or any suitable compressible mixture. In one embodiment, source 210 is an engine-side pressure source of the aircraft’s exhaust system. Temperature sensor 206 may be part of an existing sensor of engine 10, or may be added to engine 10 to obtain measurements of downstream temperature. Thus, temperature sensor 206 may be provided as part of the fluid system or may be external to the fluid system. In some embodiments, detection unit 208 may be provided as part of engine 10; in other embodiments, detection unit 208 may be external to engine 10. The detection unit 208 may be part of an electronic engine control (EEC, not shown), which may be part of a full authority digital engine control (FADEC, not shown) for controlling the overall operation and performance of the engine 10.

[0037] The flow restrictor 204 can be installed at an easily accessible location along the fluid line 202 for visual inspection and maintenance of the fluid line 202. In this embodiment, the fluid line 202 is typically located as close as possible to the source 210. Figure 2A In one embodiment, the upstream portion 212 of the fluid line 202 may be located between the source 210 and the flow restrictor 204, which is upstream of the rest of the fluid line 202, where a potential fault will not be directly detected. The input or inlet (not shown) of the flow restrictor 204 is then fluidly connected to the upstream portion 212 of the fluid line 202, allowing fluid F to flow into the inlet of the flow restrictor 204. However, it should be understood that in some embodiments, fluid F may flow directly from the source 210 into the inlet of the flow restrictor 204. Fluid F then flows downstream of the flow restrictor 204 and exits from the output or outlet (not shown) of the flow restrictor 204, entering the downstream portion 214 of the fluid line 202 to which the outlet of the flow restrictor 204 is fluidly connected. In other words, the flow restrictor 204 is fluidly connected to the fluid line 202 (i.e., to its upstream portion 212 and downstream portion 214) and is thus positioned along the flow path of fluid F.

[0038] It should be understood that the location of the fluid restrictor 204 can depend on a variety of factors, including but not limited to the length of the fluid line 202, the construction of the fluid line support, the location of the weld line along the fluid line 202, the pressure and associated losses of the fluid F, and maintenance access. In one embodiment, the location of the fluid restrictor 204 can be selected based on these factors, and the fluid restrictor 204 can therefore be located at any suitable location along the length of the fluid line 202. The systems and methods described herein allow for the detection of faults in the downstream portion 214 of the fluid line 202 (i.e., faults that may not be detected in the upstream portion 212 of the fluid line 202). Therefore, the fluid restrictor 204 can be located as close as possible to the source 210. However, as discussed above, it should be understood that the fluid restrictor 204 may not always be placed directly at the outlet of the source 210. In some embodiments, if the area of ​​concern (i.e., the area in the fluid line 202 where a break may occur) is far from the source 210, the fluid restrictor 204 can be located further away from the source 210.

[0039] Temperature sensor 206 is located downstream of fluid restrictor 204 and connected to the downstream portion 214 of fluid line 202. Temperature sensor 206 is configured to measure the temperature (referred to herein as “downstream temperature”) of fluid flowing into fluid line 202 downstream of fluid restrictor 204 (e.g., air in the case of a BACT sensor). Temperature sensor 206 then generates one or more sensor signals indicating the downstream temperature measurement. The sensor signals can be electrical, digital or analog, DC or AC, or any other suitable type of signal, and are transmitted to or otherwise received by detection unit 208. Detection unit 208 is further configured to detect excess fluid flow (or leakage) in the engine's fluid system in a manner further described below. As will be discussed further below, in the event of a downstream fault (i.e., excess fluid flow) in fluid line 202, fluid restrictor 204, located upstream of temperature sensor 206, is configured to generate a temperature change in the downstream portion 214 of fluid line 202. The temperature change can then be detected by temperature sensor 206 to detect excessive flow in fluid line 202, which in turn indicates an abnormality in the operation of the fluid system (i.e., a potential failure of fluid line 202).

[0040] although Figure 2A An embodiment is shown in which the fluid restrictor 204 and temperature sensor 206 are disposed in the main fluid line 202; however, it should be understood that, depending on the application and engine configuration, the fluid restrictor 204 and temperature sensor 206 may be disposed in different locations. In practice, the fluid restrictor 204 and temperature sensor 206 may be provided to allow the main fluid line to operate in a typical manner. Figure 2BAn example system 200' for detecting excess flow in a fluid system according to this alternative embodiment is shown.

[0041] Figure 2B System 200' includes a first fluid line 202 and a second fluid line 202' parallel to the first fluid line 202. The first fluid line 202 (referred to herein as the "main" fluid line) is illustratively sized according to system requirements and may have a diameter d1 greater than the diameter d2 of the second fluid line 202 (referred herein as the "auxiliary" or "bypass" fluid line). In one embodiment, diameter d1 is also smaller than the diameter d3 at the end 216 of fluid line 202. Figure 2B In one embodiment shown, fluid can be supplied to the main and auxiliary fluid lines 202, 202' through a common fluid inlet 218, which has a diameter d3 substantially equal to the diameter of the end 216. Figure 2C In another embodiment shown, fluid can be supplied to fluid lines 202, 202' through two separate inlets 220, 222 having diameters d1 and d2 respectively.

[0042] Return to reference Figure 2B A fluid restrictor 204 and a temperature sensor 206 are positioned in the auxiliary fluid line 202'. A first fluid flow F1 (from source 210) flows into the main fluid line 202, and a second (or parallel) fluid flow F2 flows into the fluid restrictor 204 and downstream of the fluid restrictor 204 into the auxiliary fluid line 202'. The main fluid line 202 is used for normal operation and is configured to receive the first (or "main") fluid flow F1, while the auxiliary fluid line 202' is used for fluid leak detection (i.e., detecting leaks caused by the second fluid flow F2). For this purpose, the temperature sensor 206, positioned downstream of the fluid restrictor 204, measures the temperature of the fluid flow F2 flowing into the auxiliary fluid line 202', which is positioned downstream of the fluid restrictor 204. The temperature sensor 206 then provides the temperature measurement to a detection unit 208, which is configured to detect faults (i.e., excessive fluid flow) in the engine's fluid system in a manner further described below.

[0043] In some embodiments, a flow control device, such as a valve (not shown), may be employed in the fluid system. Upon startup, the flow control device can block fluid flow in the main fluid line 202 in the event of a fault in the main fluid line 202, thereby increasing fluid flow in the auxiliary fluid line 202'. The valve can be any suitable valve or other flow control device, including but not limited to check valves, ball valves, and spring-actuated valves.

[0044] Now for reference Figure 3In one embodiment, the fluid restrictor 204 is a nozzle (e.g., a venturi nozzle). However, it should be understood that any suitable mechanism for restricting fluid (e.g., one or more orifices, etc.) can be applied in addition to a nozzle. In this embodiment, the fluid restrictor 204 has an interior extending between an inlet 302a connected to the source 210 and an outlet 302b connected to the fluid line 202. The interior of the fluid restrictor 204 is surrounded by an outer peripheral wall 302c. At the inlet and outlet, the outer peripheral wall 302c defines an inner diameter corresponding to the inner diameter of the fluid line 202. The outer peripheral wall 302c is shaped to define a contraction section (i.e., a contraction portion 304), an expansion section (i.e., a diffuser 306), and a throat 308 of the fluid restrictor 204 between the contraction portion 304 and the diffuser 306. The contraction portion 304 has an upstream end 304a adjacent to the inlet 302a and a downstream end 304b spaced apart therefrom. The constriction portion 304 narrows as it extends from its upstream end 304a to its downstream end 304b. The diffuser 306 has a downstream end 306b near the outlet 302b and an upstream end 306a spaced apart therefrom. The diffuser 306 widens as it extends from its upstream end 306a to its downstream end 306b. In this embodiment, both the constriction portion 304 and the diffuser 306 have a continuous tapered shape, although with different taper angles. In other embodiments, the constriction portion 304 and the diffuser 306 may each be formed from multiple portions tapering at different taper angles.

[0045] The throat 308 serves as the interface between the constriction portion 304 and the diffuser 306, defining a flow-blocking orifice, i.e., an orifice with a minimum diameter formed by the outer peripheral wall 302c. In this embodiment, the constriction portion 304 and the diffuser 306 are spaced apart from each other, such that the throat 308 has a straight cylindrical shape. The throat 308 thus has an upstream end 308a adjacent to the downstream end 304b of the constriction portion 304, and a downstream end 308b adjacent to the upstream end 306a of the diffuser 306. In other embodiments, the throat 308 may otherwise form a continuously curved transition between the constriction portion 304 and the diffuser 306, such that the outer peripheral wall 302c has an hourglass shape.

[0046] In operation, source 210 is configured to provide a pressurized fluid flow via fluid line 202. The fluid restrictor 204 is as follows: Figure 2BIn the illustrated embodiment of the Venturi tube, within the fluid restrictor 204, the flow can be described as a Venturi flow 310 having a Venturi velocity (not shown) and a Venturi pressure (not shown) that can vary along the length of the fluid restrictor 204. As mentioned above, in one embodiment, the fluid restrictor 204 may be positioned downstream of, but close to, the fluid source 210, such that the flow upstream of the fluid restrictor 204 can be described as source flow 312. Conversely, the flow downstream of the fluid restrictor 204 (i.e., into the downstream portion 214 of the fluid line 202) can be described as line flow 314. The fluid restrictor 204 is configured to impart certain property values ​​to the line flow 314, which can vary based on the property values ​​of the source flow 312 received by the fluid restrictor 204.

[0047] For example, when there is no excess flow in fluid line 202 (i.e., under normal operating conditions), source flow 312 can be described as nominal source flow (i.e., flow with properties corresponding to nominal flow), and Venturi flow 310 can be described as nominal Venturi flow. Under normal operating conditions, fluid restrictor 204 is configured such that upon receiving nominal source flow, the Venturi velocity accelerates from a nominal velocity value to a first value in contraction section 304 and decelerates back to the nominal velocity value in diffuser 306, such that the nominal line flow downstream of fluid restrictor 204 has a nominal line velocity and nominal line pressure corresponding to the nominal line velocity and nominal line pressure upstream of fluid restrictor 204. In fluid restrictor 204, the Venturi pressure decreases to a reduced pressure value less than the nominal pressure value in contraction section 304 and increases in diffuser 306 to restore the nominal pressure value.

[0048] On the other hand, when excess fluid is supplied from source 210 to the downstream portion 214 of fluid line 202, fluid restrictor 204 has a different effect on the fluid transported therein. In this case, fluid restrictor 204 is configured to produce a pressure drop downstream of fluid restrictor 204. This pressure drop, illustratively due to a break in fluid line 202, causes the higher-pressure fluid in fluid line 202 to flow to a lower-pressure area outside fluid line 202. Specifically, in fluid restrictor 204, the Venturi pressure decreases in contraction section 304 (e.g., from the nominal pressure value) and further decreases in diffuser 306. Therefore, the pressure in fluid line 202 decreases from the nominal pressure value to the reduced pressure value. The high-pressure fluid F is then forced to flow to the low-pressure area (not shown), creating flow obstruction at fluid restrictor 204 and causing a temperature drop downstream of fluid restrictor 204. The temperature drop can then be detected by temperature sensor 206 and used by detection unit 208 to detect abnormal operation of the engine's fluid system (i.e., excessive fluid flow).

[0049] Now for reference Figure 4 In one embodiment, the detection unit 208 includes an input unit 402, an overflow detection unit 404, and an output unit 406. The input unit 402 is configured to receive one or more sensor signals from the temperature sensor 206 indicating a downstream temperature measurement. The input unit 402 is also configured to send the downstream temperature measurement to the overflow detection unit 404. The temperature sensor 206 provides a temperature that is compared at the overflow detection unit 404 to a temperature threshold. The temperature threshold may be specific to engine operating conditions and / or a setpoint. For example, the fluid temperature may differ between ground idling and cruising, and a temperature threshold may be determined accordingly. In some embodiments, the overflow detection unit 404 may obtain the temperature threshold by querying one or more lookup tables based on the engine setpoint. However, it should be understood that the temperature threshold can be obtained without the aid of one or more lookup tables. In one embodiment, if the overflow detection unit 404 determines that the downstream temperature exceeds the temperature threshold for a specified amount of time (e.g., ten (10) seconds or longer), a fault is triggered, and the overflow detection unit 404 outputs one or more corresponding fault signals.

[0050] As previously mentioned, due to the fluid restrictor 204, the temperature downstream of the fluid restrictor 204 will decrease, and the temperature sensor 206 will sense the temperature change. To determine whether the fault is indeed a break in the fluid line 202, the excess flow detection unit 404 triggers a fault when the downstream temperature exceeds the lower limit. It should be understood that, in one embodiment, a comparison of the downstream temperature with the upper temperature limit (rather than the lower limit) can indicate a fault in the BAC. If the downstream temperature is below the threshold (i.e., below the lower limit, within a predetermined tolerance that will vary depending on the engine configuration), the downstream temperature is considered to exceed the threshold and a fault is triggered. Therefore, in one embodiment, the term "exceeds" as used herein refers to a downstream temperature below the lower limit or the threshold within a predetermined tolerance. However, it should be understood that in some embodiments, the temperature threshold may be a range having both a lower limit and an upper limit. In this case, the term "exceeds" as used herein refers to a downstream temperature falling outside the temperature range, i.e., below the lower limit or above the upper limit (within a predetermined tolerance).

[0051] In some embodiments, upon triggering a fault and receiving a fault signal from the overflow detection unit 404, the output unit 406 generates an output message (e.g., an alarm or overflow indication) indicating a fault (i.e., overflow in the engine's fluid system). The output message may include instructions to cause (e.g., via a ground maintenance team) one or more corrective actions (e.g., inspecting and verifying fluid line 202 using another aircraft fault detection system). The output message may be transmitted (using any suitable transmission device) to the engine and / or aircraft monitoring system, whose display elements may be located in the aircraft's cockpit. The output message may then be presented via a suitable output device, such as a display element, to bring the fluid system fault to the attention of aircraft personnel and allow for timely initiation of corrective actions.

[0052] In some embodiments, the overflow detection unit 304 may be configured to use a timer to distinguish overflow conditions from transient conditions. For this purpose, the overflow detection unit 304 may start a timer when the temperature exceeds a temperature threshold. Then, when the timer exceeds a predetermined time period, the overflow detection unit 304 may detect an overflow condition. If the temperature drops below the temperature threshold before the timer exceeds the predetermined time period, the timer will be reset.

[0053] Figure 5 It is used to implement the above reference Figure 4 An example embodiment of a computing device 500 with a described detection unit 208. The computing device 500 includes a processing unit 502 and a memory 504 storing computer-executable instructions 506 therein. The processing unit 502 may include any suitable means configured to cause a series of steps to be performed, such that the instructions 506, when executed by the computing device 500 or other programmable device, can cause the functions / actions / steps specified in the methods described herein to be performed. The processing unit 502 may include, for example, any type of general-purpose microprocessor or microcontroller, digital signal processing (DSP) processor, CPU, integrated circuit, field-programmable gate array (FPGA), reconfigurable processor, other appropriately programmable or programmable logic circuitry, or any combination thereof.

[0054] Memory 504 may include any suitable known or other machine-readable storage medium. Memory 504 may include non-transitory computer-readable storage media, such as, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses, or any suitable combination thereof. Memory 504 may include any suitable combination of computer memories, whether internal or external to the device, such as random access memory (RAM), read-only memory (ROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), ferroelectric RAM (FRAM), etc. Memory 504 may include any storage device (e.g., apparatus) suitable for retrievably storing machine-readable instructions 506 executable by processing unit 502.

[0055] refer to Figure 6 An example method 600 for detecting excess flow in a fluid system, such as..., will now be described. Figure 1 The fluid system of engine 10. Although method 600 is referenced here. Figure 1 The method 600 is described using engine 10, but this is for illustrative purposes only. Method 600 can be applied to any suitable engine and / or any suitable fluid system. Method 600 can be manufactured by... Figure 5 The computing device 500 is implemented.

[0056] At step 602, a temperature measurement is obtained, for example, using a temperature sensor located downstream of the flow restrictor, of the temperature downstream of the flow restrictor (e.g., a nozzle) in the main or auxiliary bypass fluid line of the fluid system. The next step 604 then obtains a temperature threshold for detecting excessive fluid flow in the fluid system. In one embodiment, as described above, the temperature threshold is obtained using one or more lookup tables based on the engine setpoint. The temperature downstream of the flow restrictor is then compared to the temperature threshold at step 606. The next step 608 then determines whether the downstream temperature exceeds (e.g., is below) the temperature threshold. If so, an abnormal operation of the fluid system (i.e., excessive fluid flow in the main or auxiliary bypass fluid line) is detected, and a fault is triggered accordingly (step 610). At step 610, an excessive flow indication (e.g., an output message indicating excessive flow in the fluid line) is also schematically output. The excessive flow indication can be output to an appropriate output device (e.g., a display element of the engine and / or aircraft monitoring system) to enable appropriate corrective action. Otherwise, if the downstream temperature does not exceed the temperature threshold, the fluid system is considered to be operating normally and no fault is triggered (step 612).

[0057] In some embodiments, the systems and methods described herein can provide effective detection of maintenance errors and component failures. The systems and methods described herein can effectively enable the use of existing temperature sensors in conjunction with fluid flow limiters to achieve a dual function of the temperature sensor (i.e., temperature measurement and excessive flow detection). This provides a less complex and more cost-effective solution compared to adding pressure sensors to a fluid system for monitoring fluid flow and detecting abnormal operation of the fluid system.

[0058] The embodiments described in this document provide non-limiting examples of possible implementations of the technology. Upon reading this disclosure, those skilled in the art will recognize that changes can be made to the embodiments described herein without departing from the scope of the technology. Further modifications can be made by those skilled in the art based on this disclosure, and these modifications will be within the scope of the technology.

Claims

1. A method for detecting excess flow in an engine fluid system, the method comprising: sensing a temperature of a fluid flowing in a fluid line of the fluid system, the fluid line being downstream of a fluid flow restrictor configured to receive the fluid from a source upstream thereof and flow the fluid from the source into the fluid line downstream thereof, wherein, when an excess fluid flow is supplied into the fluid line, the fluid flow restrictor is configured to create a choke thereat and cause a temperature drop downstream of the fluid flow restrictor; comparing the temperature to a temperature threshold; and detecting an excess flow of the fluid in the fluid line when the temperature exceeds the temperature threshold and outputting an excess flow indication accordingly.

2. The method of claim 1, wherein the fluid flow restrictor is a venturi nozzle.

3. The method of claim 1, wherein sensing the temperature comprises sensing the drop in the temperature downstream of the fluid flow restrictor.

4. The method of claim 1, wherein sensing the temperature comprises obtaining a measurement of the temperature from a temperature sensor positioned downstream of the fluid flow restrictor.

5. The method of claim 1, wherein, sensing the temperature comprises sensing a temperature of a fluid flowing in a primary fluid line of the fluid system.

6. The method of claim 1, wherein, sensing the temperature comprises sensing a temperature of the fluid flowing in an auxiliary bypass fluid line of the fluid system, the auxiliary bypass fluid line being parallel to a primary fluid line of the fluid system.

7. The method of claim 1, wherein sensing the temperature comprises sensing the temperature of the fluid flowing in the fluid line of a buffer air cooler.

8. The method of any one of claims 1 to 7, wherein, outputting the excess flow indication comprises outputting a message to an engine monitoring system, the message including instructions causing at least one corrective action to be performed.

9. The method of any one of claims 1 to 8, further comprising starting a timer when the temperature exceeds the temperature threshold and detecting an excess flow of fluid in the fluid line when the timer exceeds a predetermined time period.

10. A system for detecting excess fluid flow in an engine fluid system, the system comprising: a fluid flow restrictor positioned upstream of a fluid line of the fluid system and downstream of a source of the fluid system, the fluid flow restrictor configured to receive fluid from the source and flow the fluid from the source into the fluid line; a temperature sensor positioned downstream of the fluid flow restrictor, the temperature sensor configured to sense a temperature of the fluid flowing into the fluid line; and a processing unit configured to: receive the temperature sensed by the temperature sensor; compare the temperature to a temperature threshold; and detect an excess flow of fluid in the fluid line when the temperature exceeds the temperature threshold and output an excess flow indication accordingly, and wherein, when an excess fluid flow is supplied into the fluid line, the fluid flow restrictor is configured to create a choke thereat and cause a temperature drop downstream of the fluid flow restrictor.

11. The system of claim 10, wherein the fluid restrictor is a venturi nozzle.

12. The system of claim 10, wherein the processing unit is structured to sense a decrease in the temperature downstream of the fluid restrictor.

13. The system of claim 10, wherein, the fluid restrictor is positioned upstream of a main fluid line of the fluid system.

14. The system of claim 10, wherein, the fluid restrictor is positioned upstream of an auxiliary bypass fluid line of the fluid system, the auxiliary bypass fluid line being parallel to a main fluid line of the fluid system.

15. The system of claim 10, wherein, the fluid restrictor is positioned upstream of a fluid line of a buffer air cooler.

16. The system of any one of claims 10 to 15, wherein, the processing unit is structured to output the excess flow indication, outputting the excess flow indication including outputting a message to an engine monitoring system, the message including instructions for causing at least one corrective action to be performed.

17. The system of any one of claims 10 to 16, wherein, the processing unit is structured to start a timer when the temperature exceeds the temperature threshold, and to detect an excess fluid flow in the fluid line when the timer exceeds a predetermined time period.

18. A system for detecting an excess fluid flow in an engine fluid system, the system comprising: a processing unit; and a non-transitory memory communicatively coupled to the processing unit and including computer readable program instructions executable by the processing unit for: sensing a temperature of a fluid flowing in a fluid line of the fluid system, the fluid line being downstream of a fluid restrictor structured to receive the fluid from a source upstream thereof and to cause the fluid to flow from the source into the fluid line downstream thereof, wherein, upon an excess fluid flow being supplied into the fluid line, the fluid restrictor is structured to create a choke thereat and to cause a decrease in temperature downstream of the fluid restrictor; comparing the temperature to a temperature threshold; and detecting an excess flow of the fluid in the fluid line when the temperature exceeds the temperature threshold, and outputting an excess flow indication accordingly.

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