CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is related to and claims priority benefits from U.S.

Provisional Application Serial No. 62/829,477, filed on April 4, 2019, entitled“Aircraft Leak Detection Unit,” the entire contents of which is hereby incorporated by this reference.

FIELD OF THE INVENTION

[0002] The field of this disclosure relates to water leak detection to protect flight critical equipment from failed water distribution lines. The system uses a reference sensor and an additional sensor in order to measure voltage across a circuit when both sensors are in contact with a conductive fluid. The system also provides a water shut off protocol that can protect the equipment from a leak during flight, while allowing unaffected galleys and lavatories to remain functional.

BACKGROUND

[0003] Many vehicles such as passenger aircraft, buses, trains, ships, automobiles, and the like include water lines that deliver water to various locations on the vehicle. It is important to be able to detect when a leak may occur in a water line.

[0004] Various solutions for detecting leaks have included use of leak sensors or alarms. If a leak is detected, there may be a control interface that can shut off the equipment that is leaking. Other solutions have included use of a shroud around certain water lines, such that if a leak were to occur in the line, the shroud would capture/contain any accumulated water and prevent spraying of the water due to pressurized water lines. However, use of a shroud around a water line does not necessarily allow leak detection, it can simply prevent water from dripping or spraying out of the water line. Improvements to leak detection and leak management are thus desirable.

SUMMARY

[0005] The present inventors have identified a leak detection system that can detect a leak and isolate water lines that are subject to the leak, while leaving remaining water lines accessible.

[0006] The terms “invention,” “the invention,” “this invention” “the present invention,”“disclosure,”“the disclosure,” and“the present disclosure,” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings and each claim.

[0007] According to certain embodiments of this disclosure, there is provided a leak detection system, comprising: a leak detection unit positioned at a drain port of a water line shroud, the leak detection unit comprising a reservoir; a reference sensor positioned at a lower portion of the reservoir; at least one additional sensor positioned above the reference sensor; and an isolation valve associated with a water line running above an electronic and equipment bay; and a communication system that receives information about a water leak from the leak detection unit and the closes the isolation valve. There may be provided a second additional sensor for redundancy with the at least one additional sensor. The leak detection unit may also have an overflow port.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 shows a schematic of an aircraft with a water line running above equipment and electronic bays.

[0009] Figure 2 shows a side plan view of a leak detection unit.

[0010] Figure 3 shows a side perspective view of the leak detection unit of Figure 2.

[0011] Figure 4 shows a communication protocol of a leak detection unit for activating an isolation valve.

[0012] Figure 5 shows a leak detection unit and activation of an isolation valve.

[0013] Figure 6A shows one embodiment of a leak detection unit with a sensor housing.

[0014] Figure 6B shows a close-up view of one embodiment of a sensor housing.

DETAILED DESCRIPTION

[0015] This disclosure provides water leak detection, and finds particular use in connection with pressurized water lines, such as those on board aircraft. Typically, water lines are run below aircraft equipment areas. Although any leak that may occur creates a myriad of problems, affecting the electronic equipment is typically not one of them because the water lines are below the equipment. However, a new aircraft design has proposed running a water line over one or more electronic and equipment (EE) bays. For this design, a water leak in one of the lines running over the EE bay could be catastrophic to flight critical electronic equipment.

[0016] This disclosure thus provides a leak detection system 10 that incorporates more than one water sensor in a leak detection unit 14. Specifically, Figure 1 shows an aircraft 16 with multiple EE bays 18. In this example, there is a forward EE bay 18a and an aft EE bay 18b, but it should be understood that any number of EE bays 18 may be on board. A water line 20 runs over the EE bays 18a, 18b. This is a configuration in which a water leak would cause damage to flight critical equipment, potentially putting passengers and crew in danger.

[0017] The disclosed water leak detection system 10 thus provides a protective shroud over the water line 20. The shroud is intended to protect the flight critical electrical equipment in the EE bay 18 from water spray or dripping caused by a failed water distribution line 20. In one example, the shroud may be a flexible silicone hose that may be installed over the water line. The shroud also redirects and delivers any captured water to a safe area to drain, one example of which is an aircraft bilge. However, during this redirection, use of a shroud alone does not provide detection of the occurrence of the water leak. For example, when an aircraft lands on ground, a bilge drain opens when the bilge is depressurized, and any collected water can be drained. An undetected water leak could cause the aircraft to quickly lose remaining water during the flight and disable part of galley and lavatory functions. Also, the aircraft could be dispatched again to its next destination without the ground crew knowing of the water leak in the system and making proper repairs.

[0018] Figures 2 and 3 illustrate a unit 14 with a plurality of sensors that provide the necessary leak detection. The unit 14 may be positioned at the end of the shroud drain port 22. Any water that is collected and routed by the shroud will be delivered to the reservoir 24 within the unit 14. A reference sensor 26 is positioned a lower portion of the unit 14. If any water is delivered into the reservoir 24 from the shroud, this is the first sensor 26 that will detect its presence. Two additional sensors 28, 30 are also provided. The presence of two sensors 28, 30 is for redundancy only. It is possible for the system to function with only the reference sensor 26 and only one of the additional sensors 28, 30. Sensors 28, 30 are positioned a distance above the reference sensor 26. If the water in the reservoir 24 reaches the height of one of the additional sensors 28, 30, the system will detect that both sensors (reference sensor 26 and one of 28 or 30) are submerged and that a leak is present.

[0019] The sensors 26, 28, 30 and the related circuit (described below) may be powered via aircraft power, and the unit may be provided with an AC connector 32. The unit may also be provided with an overflow port 34, which will allow fluid accumulated within the reservoir 24 to drain once/if it reaches the height of the overflow port 34. The unit 14 may also be provided with a condensation drain 36 which can help prevent a false signal. The unit 14 may be positioned over a bilge drain such that any overflow fluid or condensation can be safely drained from the aircraft. An optional mounting bracket 38 may be provided for safe securement of the unit 14 in place.

[0020] Data Process and Control:

[0021] An oscillator circuit may be connected to sensor 28, sensor 30, and the reference sensor 26. Voltage can be measured across the circuit. The voltage remains constant when no leak is present, but it drops when one of the sensors 28, 30 and the reference sensor 26 are both touching a conductive fluid, which then completes the circuit. By measuring the drop in voltage, the conductivity of the fluid can be calculated. The unit 14 can be programmed to send a fluid detection signal based on the conductivity of the fluid. In a specific example, the unit 14 will trigger the detection if any fluid touches sensor 28 or 30 and the reference sensor 26. An integrated printed circuit board (PCB) can allow data processing and communication logic to the Integrated Modular Avionics (IMA) system via CAN bus or discrete signal. One example of this leak detection sensor controller communication logic in outlined in Figure 4.

[0022] Isolation:

[0023] One benefit of the disclosed leak detection unit 14 is that the sensor(s) will send a signal to the water and waste systems controller (WWSC) Integrated Modular Avionics (IMA) partition, and the WWSC can automatically isolate the leaked section from the main public water system (PWS). This may be referred to as a communication system that receives information about a water leak from the leak detection unit and that closes an isolation valve. [0024] The system can also send a signal to the flight crew and alert them about the water leak event by an indication light or visual fault message. Having the capability of early detection of the water leak, as well as isolation of the leak once detected, can help prevent a large amount of water leakage in the bilge, which can damage the aircraft structure or other system functions (e.g., by freezing or flooding).

[0025] In order to achieve the leak detection and isolation functions, it is desirable to install a leak detection unit 14 and an isolation valve 40 adjacent to each EE bay area. One example is illustrated by Figure 5. In a specific example, the leak detection unit 14 may be located in a forward location of the aircraft (generally referred to as area 42 in Figure 5), downstream of a shroud drain line, near the bilge area. If the forward unit 14 detects a positive water leak by collecting water from the shroud drain line that reaches both reference sensor 26 and one of sensors 28, 30, the unit 14 sends a signal via an appropriate communication system that a positive leak event has occurred in a forward portion 42 of the aircraft. The communication system sends a signal to close the forward isolation valve 40. Accordingly, installed forward sections of the main water distribution line 20 above the EE bay area 18a are closed automatically by WWSC commands. Once the leak section is isolated, the potable water systems will remain functional in the aft section of the aircraft. Forward passengers may safely access mid and aft laboratories. In either instance, the aircraft can continue its journey to the original destination, albeit with limited access to the forward galleys and lavatories. Similarly, an aft leak would isolate the aft section of the aircraft.

[0026] Leak Sensor Assembly:

[0027] As described above, the leak detection unit 14 has three individual sensors, 26,

28, 30. Each sensor may be mounted in different location of the unit 14. In a specific example, a sensor housing 44 may have three separate internal chambers 46, one for each sensor interface. This can eliminate any false reading that may otherwise occur via the water bridge by condensation. The sensor housing 44 may be an injection molded with Nylon 6/6 or Ultem 1000 material. One example is shown by Figures 6A and 6B. These sensor designs are described more fully in co-owned U.S. Patent No. 10,308,361 titled“Disposable Modular Reservoir” and U.S. Patent No. 9,718,549, titled“Grey Water Interface Valve Liquid Level Sensor System.” [0028] The subject matter of certain embodiments of this disclosure is described with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.

[0029] It should be understood that different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and sub-combinations are useful and may be employed without reference to other features and sub-combinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications may be made without departing from the scope of the claims below.