Thermal expansion coupler

Abstract

This invention relates to a thermal expansion coupler for connecting piping within a system that distributes temperature and pressure-controlled airflow. [Solution] A thermal expansion absorbing coupler configured to join individual pipes includes a multi-segment retaining shell having a V-shaped inner cross-sectional surface configured to pull adjacent pipe ends together. The coupler also includes a sealing ring of a high-temperature material configured to be positioned between the retaining shell and the outer diameter of adjacent pipes, and configured to block airflow leakage between adjacent pipe ends. A test stand configured to house an air cycling machine (ACM) having a compressor and a turbine may employ such a thermal expansion absorbing coupler.

Description

Technical Field

[0001]

[0001] The present disclosure relates to a thermal expansion coupler for connecting pipes within a system that distributes a temperature- and pressure-controlled air flow and can be used in a test stand.

Background Art

[0002]

[0002] A test system is a resource used for the development, characterization, and testing of components, systems, and machines. A test system can use a working fluid and / or electric power to operate various devices and perform specific operations. A test system can also use a controller that interacts with a data collection device and actuators (such as valves and transducers) to manage the control parameters of the system and the operation of the test machine.

[0003]

[0003] A test stand can be integrated into a test system, attached to a test system, and designed to operate a specific machine. A test stand enables a machine to be evaluated in different operating regimes and provides measurements of some physical variables associated with the target operation. A test stand can be used in a research and development institute of an original equipment manufacturer (OEM). A test stand can also be used in a service center for tuning and evaluating an in-use machine or at the end of a production line in a manufacturing facility.

Summary of the Invention

[0004]

[0004] One embodiment of the present disclosure is a test setup comprising an air heating and distribution system (AHRS) configured to receive and transport an airflow. The AHRS includes a three-stage pressure regulating subsystem configured to regulate the pressure of the transported air. The AHRS system also includes an air heater configured to regulate the temperature of the transported air, and piping configured to fluidly connect the air heater and the three-stage pressure regulating subsystem and transport the airflow. The test setup also includes a pressure transducer configured to detect the pressure of the transported air, and an electronic controller operably communicating with the air heater, the three-stage pressure regulating subsystem, and the pressure transducer. The electronic controller is configured to regulate the air heater and the three-stage pressure regulating subsystem using the pressure of the transported air detected by the pressure transducer to output pressure and temperature regulated air through the AHRS piping.

[0005]

[0005] The test setup may further include an actuation sensor configured to detect airflow and, when airflow is detected, enable the operation of the air heater via an electronic controller.

[0006]

[0006] The three-stage pressure regulation subsystem may include a first stage having a dome-loaded pressure reducing first valve having a first valve outlet pressure sensor and a pressure-maintaining feedback loop. The three-stage pressure regulation subsystem may also include a second stage having three pressure regulating valves. The three pressure regulating valves specifically include second, third, and fourth valves arranged in parallel. One of the three valves may be selected to regulate the pressure of the air being transported based on the required outlet pressure of the AHRS.

[0007]

[0007] The three-stage pressure regulation subsystem may further include a third stage having a fifth pressure regulation valve operated by an electronic controller, the fifth pressure regulation valve being positioned along the flow of air being transported in the AHRS piping. The fifth pressure regulation valve is configured to control the pressure of the air being transported at the outlet of the AHRS defined by the AHRS piping.

[0008]

[0008] The dome-loaded pressure reducing valve first may be configured to reduce the pressure of the air being transported from 700 to 150 Psig.

[0009]

[0009] In the second stage, the target selection valve can be tuned for fine-tuning pressure control so as to reduce the pressure from 150 Psig to a preset pressure value selected and maintain the target pressure at + / - 0.5 Psig.

[0010]

[0010] In the third stage, when the difference between the detected pressure at the outlet of the AHRS and the preset pressure value exceeds the preset deviation, a fifth pressure regulating valve may be adjusted by an electronic controller in the active pressure control loop to activate the second stage.

[0011]

[0011] The preset deviation is + / -0.015 Psig.

[0012]

[0012] The test setup may further include a test stand operably connected to the AHRS, and configured to position an air cycle machine (ACM) having a compressor and a turbine on the test stand. The test stand includes a support structure and a plurality of wheels attached to the support structure and configured to facilitate the movement of the test stand.

[0013]

[0013] The test stand also includes a support structure and a movably mounted duct assembly configured to receive pressure and temperature-controlled air from the outlet of the AHRS, supply the pressure and temperature-controlled air to the compressor inlet of the ACM, and exhaust the air to the atmosphere from the turbine outlet of the ACM.

[0014]

[0014] The test stand is a heat exchanger in fluid communication with the ACM via a duct assembly, and further includes a heat exchanger configured to lower the temperature of the air received from the compressor outlet and to circulate the cooled air to the turbine inlet.

[0015]

[0015] The test stand further includes at least one sensor configured to detect the temperature of the air in the duct assembly and to communicate the detected temperature to an electronic controller.

[0016]

[0016] The ACM may include at least one thermocouple configured to detect the temperature of the ACM bearing and communicate the detected temperature of the ACM bearing to an electronic controller for evaluation of the health of the ACM.

[0017]

[0017] The pressure transducer may be placed on a test stand and configured to detect the pressure of the air being transported at the inlet to the compressor of the air cycling machine.

[0018]

[0018] The electronic controller can be programmed with a preset pressure value. In one such embodiment, the electronic controller may be further configured to adjust the pressure of the air being delivered in order to output pressure- and temperature-controlled air at the outlet of the AHRS by comparing the detected pressure with a preset pressure value.

[0019]

[0019] The test setup may further include at least one pneumatic connector configured to fluidly link the test stand to the AHRS piping.

[0020]

[0020] The duct assembly may include flexible pipes, expansion joints, and hangers configured to keep the duct assembly adaptable to the support structure.

[0021]

[0021] The duct assembly may further include a plurality of discrete pipes on rollers configured to facilitate the movement of each pipe relative to the support structure due to thermal expansion and contraction.

[0022]

[0022] The test stand may further include at least one coupler configured to connect the air cycling machine to the duct assembly. Such a coupler can also join the individual pipes of the duct assembly and absorb the thermal expansion or contraction of the duct assembly.

[0023]

[0023] Each coupler may include a multi-segment retaining shell having an inner surface with a V-shaped cross-section configured to draw together adjacent pipe ends.

[0024]

[0024] Each coupler may include a band having a clamp configured to draw together segments of the retaining shell and hold the shell in a compressed state.

[0025]

[0025] The joined individual pipes may include adjacent pipe ends having retaining ridges configured to interact with the inner surface of the retaining shell and oppose separation of the joined pipes.

[0026]

[0026] The coupler may include a seal ring of a high-temperature material (such as silicone) disposed on the outer diameter of the adjacent pipes and configured to block airflow leakage between the adjacent pipe ends.

[0027] [[ID=I9]]

[0027] The retaining shell may be sized to create a gap between adjacent pipe ends configured to absorb the expansion and / or contraction of the adjacent pipes of the duct assembly. Each coupler may be configured to absorb thermal expansion or contraction between adjacent pipe ends without leakage up to a maximum of 0.4 inches.

[0028]

[0028] The test stand may further include an optical fiber velocity sensor disposed within the duct assembly proximate to the ACM. The optical fiber velocity sensor may be configured to detect the rotational speed of the ACM and transmit a signal indicative of the detected rotational speed to an electronic controller.

[0029]

[0029] The pipes to which the speed sensors are attached can be firmly connected to each of the adjacent pipes and the ACM via respective couplers. In such an embodiment, each coupler can facilitate removal and replacement of the ACM and installation of the pipes having speed sensors to the ACM.

[0030]

[0030] The test arrangement can further include a filter disposed in fluid communication with the duct assembly, the filter being configured to remove contaminants from the air supplied to the air cycling machine.

[0031]

[0031] A further embodiment of the present disclosure is a test method that employs the test arrangement described above.

[0032]

[0032] The above-described features and advantages of the present disclosure, as well as other features and advantages, will become immediately apparent when the following detailed description of one or more embodiments and one or more modes for carrying out the present disclosure is combined with the accompanying drawings and the appended claims.

Brief Description of the Drawings

[0033] [Figure 1A]

[0033] It is a schematic diagram of a system layout of an air heating and distribution system (AHRS) included in a test arrangement according to the present disclosure. [Figure 1B]

[0034] It is a schematic diagram of a test stand operably communicating with the AHRS shown in FIG. 1A, which includes an air cycling machine (AMC) disposed on the test stand and is included in the test arrangement according to the present disclosure. [Figure 2]

[0035] It is a schematic perspective view of the test stand shown in FIG. 1B according to the present disclosure. [Figure 3]

[0036] It is a schematic partial cross-sectional view of a duct assembly connected to an ACM disposed on the test stand shown in FIG. 1B, specifically showing a plurality of couplers and an optical fiber speed sensor according to the present disclosure. [Figure 4]

[0037] Figure 3 is a schematic perspective exploded view of the coupler, showing the individual components of the coupler. [Figure 5]

[0038] Figure 3 shows a schematic perspective view of an optical fiber velocity sensor, as disclosed herein, mounted on a pipe for fixation within a duct assembly via a typical coupler. [Figure 6]

[0039] Figures 1 to 5 are flowcharts showing the test method using AHRS. [Modes for carrying out the invention]

[0034]

[0040] The embodiments of the Disclosure described herein are intended to serve as multiple examples. Other embodiments may take various and alternative forms. Furthermore, the drawings are generally schematic and not necessarily to scale. Some features are exaggerated or minimized to illustrate details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but rather as representative principles to teach those skilled in the art how to utilize the Disclosure in various ways.

[0035]

[0041] In the following explanation, certain terms may be used for reference purposes only and are therefore not intended to be limiting. For example, terms such as “above” and “below” refer to the direction in the referenced drawing. Terms such as “front,” “back,” “fore,” “aft,” “left,” “right,” “side,” “rear,” and “side” describe the orientation and / or position of a component or part of an element within a consistent but arbitrary frame of reference, which will be clarified by referring to the text and related drawings describing the component or element in the explanation.

[0036]

[0042] Furthermore, terms such as “first,” “second,” and “third” may be used to describe separate components. Such terms may include the words specifically mentioned above, their derivatives, and words with similar meanings, and are used descriptively for the sake of illustration and do not represent a limitation on the scope of this disclosure as defined by the appended claims. Furthermore, teachings may be described herein with respect to constituent elements of functional and / or logical blocks and / or various processing steps. It should be understood that such block components may include any number of hardware, software, and / or firmware configured to perform a specified function.

[0037]

[0043] Referring to drawings in which similar elements are identified by the same numbers throughout, Figures 1A and 1B show the test setup 10. The test setup 10 is configured as a system of operable connected and interacting subsystems and components designed and built to facilitate the performance evaluation and development of a machine operated using pressure and temperature controlled airflow. The test setup 10 includes an air heating and distribution system (AHRS) 12 (shown in Figure 1A) configured to receive and transport an airflow 14. The AHRS 12 includes a three-stage pressure adjustment subsystem 16 configured to adjust the pressure of the received and transported air 14. The AHRS 12 also includes an air heater 18 configured to adjust the temperature of the transported air 14. The air heater 18 may be electrically operated. The treated, pressure and temperature controlled airflow is shown in the drawings by the number 14A. The AHRS12 further includes AHRS piping 20 having various pipes configured to fluidly connect the air heater 18 and the three-stage pressure adjustment subsystem 16 and to transport the airflow 14.

[0038]

[0044] The AHRS piping 20 also defines an inlet 20A for receiving the air to be transported 14 and at least one outlet, illustrated as AHRS outlets 20B, 20C, 20D, 20E, and 20F, for releasing the pressure- and temperature-controlled air 14A. The test setup 10 may also include pneumatic connectors 20-1 located on the AHRS piping 20 at each outlet 20B, 20C, 20D, 20E, 20F (shown in Figure 1A). Each pneumatic connector 20-1 is configured to fluidly link the AHRS piping 20 to a test stand, such as a test stand for an air cycling machine (ACM), which will be described in detail below. The test setup 10 also includes a pressure transducer 22 (located on a test stand, which will be described in detail below) configured to detect the pressure of the air to be transported, pressure- and temperature-controlled air 14A. The test setup 10 further includes an electronic controller 24 (shown in Figures 1A and 1B) configured as a control and measurement system that operably communicates with the air heater 18, the three-stage pressure adjustment subsystem 16, and the pressure transducer 22.

[0039]

[0045] The electronic controller 24 includes a tangible, non-transient memory 24A. The memory 24A may be a recordable medium that provides computer-readable data or process instructions. Such a medium can take many forms, but is not limited to, non-volatile and volatile media. Non-volatile media used by the electronic controller 24 may include, for example, optical or magnetic disks and other persistent memory. Each volatile medium in the controller's memory 24A may include, for example, dynamic random-access memory (DRAM) that may constitute main memory. Such instructions may be transmitted by one or more transmission media, including coaxial cables, copper wires, and optical fibers, including wires with a system bus coupled to the vehicle system.

[0040]

[0046] The memory 24A of the electronic controller 24 may also include flexible disks, hard disks, magnetic tapes, other magnetic media, CD-ROMs, DVDs, other optical media, etc. The electronic controller 24 may be equipped with a high-speed primary clock, necessary analog / digital (A / D) circuits and / or digital / analog (D / A) circuits, input / output circuits and devices (I / O), and appropriate signal conditioning and / or buffer circuits. Algorithms required by or accessed by the electronic controller 24 (generally indicated by the number 26) are stored in the memory 24A and executed automatically to provide the functions necessary to facilitate the operation and performance evaluation and development of the machine in the context of the test setup 10.

[0041]

[0047] As part of the test setup 10, the electronic controller 24 is configured, i.e., built and programmed, to adjust the heater 18 and the three-stage pressure adjustment subsystem 16 using the pressure of the delivered air detected by the pressure transducer 22 in order to output pressure- and temperature-controlled air 14A via the AHRS piping 20. The electronic controller 24 adjusts the delivered air 14 to adjust the parameters of the output airflow 14A using the three-stage pressure adjustment subsystem 16 by comparing the pressure detected by the pressure transducer 22 with the programmed preset pressure value 28. The electronic controller 24 can adjust the pressure of the output airflow 14A to within a pressure deviation 29 (e.g., + / - 0.015 Psig) of the preset pressure value 28.

[0042]

[0048] As shown in Figure 1A, the three-stage pressure adjustment subsystem 16 may include a first stage 16-1 having a dome-loaded pressure reducing first valve 30. The first valve 30 may have a first valve outlet pressure sensor 30-1 and a pressure maintenance feedback loop 30-2. For example, the first valve 30 may be configured to reduce the pressure of the conveyed air 14 from 700 to 150 Psig. The three-stage pressure adjustment subsystem 16 may further include a second stage 16-2 having several pressure regulating valves, specifically illustrated as three pressure regulating valves (a second valve 32, a third valve 34, and a fourth valve 36). The second, third, and fourth valves 32, 34, and 36 may be arranged in parallel. In this case, one of the three valves is selected to regulate the pressure of the conveyed air 14 based on the required outlet pressure of the AHRS 12. The target selection valves 32, 34, or 36 can be tuned for fine-tuning pressure control to reduce the pressure from 150 Psig to a selected preset pressure value and maintain such a pressure at + / - 0.5 Psig.

[0043]

[0049] The three-stage pressure regulation subsystem 16 may further include a third stage 16-3 having a reduced-diameter pipe (compared to the pipes of the preceding stages 16-1 and 16-2) that connects the 150 Psig outlet of the first stage 16-1 to the outlet of the second stage 16-2. The third stage 16-3 is configured to control the air 14 being transported via a fifth pressure regulating valve 38 operated by an electronic controller 24. The fifth pressure regulating valve 38 may be positioned along the flow of the transported air 14 in the AHRS piping 20. The fifth pressure regulating valve 38 is configured in particular to control the pressure of the transported air 14 at the outlet of the AHRS 12 and may provide a final outlet pressure with an accuracy of 0.01%. Thereafter, with an input pressure of 150 Psig, the resulting accuracy may be approximately 0.015 Psi. The electronic controller 24 may be specifically configured to operate the fifth pressure regulating valve 38. The fifth pressure regulating valve 38 can be set to a 50% open starting position to target the required outlet pressure of the regulated air 14A.

[0044]

[0050] Continuing with the reference to Figure 1A, the AHRS piping 20 can receive ambient temperature inlet air 14 at a flow rate of 230 lbs / min and a maximum of 700 Psig from the equipment's air source through a 4-inch inlet pipe 20A. The equipment source should generally be configured to maintain such inlet conditions for a duration sufficient to perform at least the specific test procedure of each test unit, such as 30 minutes. As can be seen in Figure 1A, from inlet 20A, the airflow 14 travels through the AHRS pipe 20-1, crossing a manual inline valve 40 and a ball valve 42 to junction J1. Valve 40 can be used to isolate the AHRS 12 from the equipment source when the system is not in use or for maintenance. The ball valve 42 is set to an on or off position by the electronic controller 24 to isolate the remainder of the AHRS 12 or to supply airflow 14 to the system.

[0045]

[0051] The airflow 14 travels from junction J1 through pipe 20-2 and ball valve 44 into the first stage 16-1 of the three-stage pressure adjustment subsystem 16 for pressure adjustment via dome-loaded first valve 30. In the first stage 16-1, the pressure reducing valve 30 can adjust the pressure downstream of the pressure reducing valve 30 to a setpoint up to 150 Psig using direct input from pressure transducer 30-1. To adjust the pressure at the top of the dome inside the valve 30, pressure compensation is sent from pressure transducer 30-1 to regulator 30-2 via a pneumatic control loop. The setpoint of the control loop is set by the electronic controller 24. The orifice plate 30-3 allows a small amount of air 14 to leak through the valve 30 while the AHRS 12 is not operating, in order to prevent the pressure either upstream or downstream of the valve 30 from being trapped.

[0046]

[0052] As shown in Figure 1A, after the first stage 16-1, the airflow 14 moves into the second, third, or fourth valves 32, 34, 36, which are regulated by individual electronic controllers 24 within the respective pressure control branches and control loops of the second stage 16-2. The airflow 14 is controlled via the respective ball valves 46, 48, and 50. The ball valves 46, 48, and 50 perform on / off operations to regulate which pressure control branch of the second stage 16-2 the air 14 flows into. This causes the air 14 to flow into one of the valves 32, 34, and 36 configured to regulate the air pressure in the corresponding branch. Ball valve 46 can control the pressure of the airflow in the range of 0 to 50 Psig. Ball valve 48 can control the pressure of the airflow in the range of 50 to 100 Psig. Meanwhile, ball valve 50 can control the pressure of the airflow in the range of 110 to 125 Psig. The pressure setpoint of the airflow 14 can be adjusted to within + / - 0.5 Psi in the second stage 16-2 via ball valves 46, 48, 50, which activate individual valves 32, 34, 36 based on the pressure required by specific test stands such as air cycling machines, which are described in detail below.

[0047]

[0053] The pressure setpoint is set by the controller 24. Pressure compensation when the output pressure of the second stage 16-2 deviates from the setpoint is performed according to the following procedure. The second pressure regulating valve 32 can regulate the pressure downstream of it using a direct input from the pressure transducer 32-1. To adjust the output of the second valve 32, pressure compensation is sent from the pressure transducer 32-1 to the regulator 32-2 via the pneumatic control loop. Similarly, the third pressure regulating valve 34 can regulate the pressure downstream of it using a direct input from the pressure transducer 34-1. To adjust the output of the third valve 34, pressure compensation is sent from the pressure transducer 34-1 to the regulator 34-2 via the pneumatic control loop. The fourth pressure regulating valve 36 can similarly regulate the pressure downstream of it using a direct input from the pressure transducer 36-1. To adjust the output of the fourth valve 36, pressure compensation is sent from the pressure transducer 36-1 to the regulator 36-2 via the pneumatic control loop.

[0048]

[0054] The output air 14 from the individual second, third, and fourth pressure regulating valves 32, 34, and 36 is directed to their respective check valves 32-3, 34-3, and 36-3 to prevent backflow of the regulated air 14. After the second stage 16-2, the airflow 14 exiting from one of the second, third, and fourth pressure regulating valves 32, 34, and 36 is directed into the third stage 16-3. In the third stage 16-3, when the difference between the detected outlet pressure (at outlet 20F, for example) and the preset pressure value 28 exceeds the preset deviation 29, the fifth pressure regulating valve 38 operates in the active pressure control loop to alter the airflow 14 upstream of the second stage 16-2. For example, in the third stage 16-3, by applying a limiting amount of airflow and pressure through a relatively small (e.g., 0.25 inch) diameter pipe 38-1, the airflow 14 can be controlled to an accuracy of 0.5 Psi or less via the fifth pressure regulating valve 38.

[0049]

[0055] As a result of changing the airflow into the second stage 16-2, the fifth pressure regulating valve 38 can be adjusted by the electronic controller 24 to precisely maintain the outlet pressure of the AHRS to a preset deviation 29 of + / - 0.015 Psig of the preset pressure value 28. In other words, in the event that the electronic controller 24 detects an outlet pressure deviation of more than 0.5 Psig, the appropriate pressure regulating valve 32, 34, or 36 of the second stage 16-2 may be activated. If higher precision is required, the fifth pressure regulating valve 38 may be activated from an initial setting point up to 50% open or from a fully closed state to increase or decrease a relatively small amount of airflow between the first pressure regulating stage 16-1 and the second pressure regulating stage 16-2. Thus, the fifth pressure regulating valve 38 operates up to 150 Psig to achieve the desired pressure setpoint downstream of the regulating valve of the three-stage pressure regulating subsystem 16.

[0050]

[0056] The fifth pressure regulating valve 38 is deactivated or returned to its initial position when a pressure deviation exceeding 0.5 Psi is detected. Air generally flows forward through the three-stage pressure regulating subsystem 16 of the AHRS 12, because the upstream pressure in the system is higher than the downstream pressure, and check valves are in place to prevent backflow. Dealing with deviations of 0.5 Psi or more is controlled by the electronic controller 24 using the appropriate pressure regulating valves 32, 34, or 36. Once the operation of the AHRS 12 stabilizes and the outlet pressure is within 0.5 Psi, the fifth pressure regulating valve 38 is activated. This approach prevents the two separate pressure control loops of the second and third stages 16-2 and 16-3 from competing with each other, and prevents the outlet pressure of the AHRS 12 from overshooting its required value. It is also conceivable that the two separate pressure loops of stages 16-2 and 16-3 may be active simultaneously.

[0051]

[0057] Following the fine pressure adjustment in the third stage 16-3, the airflow 14 is led to an air heater 18 through a pressure sensor 52 and a flow meter 54. The pressure sensor 52 is a sensor tap in a corresponding pipe configured to act as an auxiliary or backup pressure sensor. The pressure sensor 52 and the flow meter 54 communicate their respective data to an electronic controller 24. The air heater 18 is adjusted via the electronic controller 24 to increase the temperature of the pressure-regulated airflow to a value required by a particular test stand from which pressure- and temperature-regulated air 14A is supplied. After the temperature of the pressure-regulated airflow has increased, the pressure- and temperature-regulated air 14A is led to one of the outlets 20D, 20E, and 20F of the AHRS. Specifically, the airflow can move to junction J2, from which the air can be released into the atmosphere through an emergency release ball valve 56 via outlet 20D of the AHRS. Alternatively, the airflow may be directed to the outlet 20E of the AHRS via a manual valve 58 and a ball valve 60 (regulated by the controller 24), or to the outlet 20F of the AHRS via a manual valve 62 and a ball valve 64 (regulated by the controller 24). A pressure sensor 66 communicates the pressure of the regulated air 14A provided at the outlet 20F of the AHRS to the electronic controller 24, and a temperature sensor 68 communicates the temperature.

[0052]

[0058] Continuing with the reference in Figure 1A, from junction J1, the airflow 14 also moves to outlets 20B and 20C via pipes 20-3. Specifically, the airflow 14 may move through junction J3 and be led to a pressure regulating valve 70. The pressure regulating valve 70 controls its inlet pressure of 700 Psig to an outlet pressure in the range of 0 to 40 Psig. From the pressure regulating valve 70, the airflow 14 moves to junction J4. Junction J4 branches to a pressure relief valve 72 configured to allow air to flow to the atmosphere when the line pressure exceeds 40 Psig. When the pressure relief valve 72 is closed, the airflow 14 moves from junction J4 to a flow meter 74 (such as a visual inspection gauge used to adjust the pressure regulating valve 70) to achieve an airflow of 0.5 to 5 SCFM. After the flow meter 74, the airflow is led to an actuation sensor 76 configured as an airflow detection switch. The operating sensor 76 may be located in the heater 18 and configured to enable the heater to operate only when an airflow 14 is detected.

[0053]

[0059] The airflow 14 also passes through junctions J3 and J5 to an electromagnetically operated valve 78. The valve 78 is controlled by an electronic controller 24 and is configured to release pressure from the AHRS piping 20 line upstream of the outlet 20B. The airflow 14 also passes through junction J5 and passes through a manually operated throttle valve 80 to an electromagnetically operated valve 82. The electronic controller 24 is configured to open the valve 82 when each test stand (such as the air cycling machine test stand described in detail below) is connected and in use. From the electromagnetically operated valve 82, the airflow 14 is led to a pressure regulating valve 84 operated by the electronic controller 24. The pressure regulating valve 84 controls the pressure of the airflow to drop from an inlet of 700 Psig to 0-300 Psig. From the pressure regulating valve 84, the airflow 14 passes through junction J6. Junction J6 branches off to a pressure relief valve 86 configured to allow air to flow to the atmosphere when the line pressure exceeds 150 Psig. When the pressure relief valve 86 is closed, the airflow 14 moves from junction J6 to a flow meter 88 and then to outlet 20B. Alternatively, from junction J1, the airflow 14 is directed to a manually operated on / off valve 90 and then through a ball valve 92 to outlet 20C.

[0054]

[0060] As shown in Figures 1B and 2, the test setup 10 may further include a test stand 100 configured to operably connect to the AHRS 12 and to position a test unit, such as an air cycling machine (ACM) 102, on the test stand. The ACM 102 is configured to change the pressure (and temperature) of the air conveyed through the ACM 102. As shown, the ACM 102 has a compressor 102-1 (having inlets 102-1A and outlets 102-1B) and a turbine 102-2 (having inlets 102-2A and outlets 102-2B), each having a bladed wheel mounted on a common shaft. The test stand 100 includes a support structure 104 and a plurality of wheels 106 (as shown in Figure 2) mounted on the support structure and configured to facilitate the movement of the test stand. The test stand 100 also includes a duct assembly 108 that is movably mounted to the support structure 104. The duct assembly 108 is configured to receive pressure and temperature-controlled air 14A from the outlet of the AHRS 10 and supply the target air to the ACM compressor inlet 102-1A. The test stand 100 further includes a heat exchanger 110 configured to fluidize the ACM via the duct assembly 108, cool the airflow 14A received from the ACM compressor outlet 102-1B, and circulate the cooled air to the ACM turbine inlet 102-2A. The duct assembly 108 is further configured to exhaust the cooled air to the atmosphere or through the cold side of the attached heat exchanger 110. The heat exchanger 110 will not operate if the air supplied by the ACM turbine outlet 102-2B is not flowing through the cold side. A specific heat exchanger 110 may be selected to replicate the actual conditions experienced by the system using the ACM 102 during operation, such as in aircraft applications.

[0055]

[0061] Each pneumatic connector 20-1 (shown in Figures 1A, 1B, and 2) fluidly connects the AHRS piping at a specific outlet 20F to the duct assembly 108 of the air cycling machine (ACM) test stand. As shown in Figure 2, the duct assembly 108 may include flexible pipes 112, expansion joints 114, and hangers 116 configured to capture the movement of the ACM 102 in the X-Y-Z plane and maintain the duct assembly in a position adaptable to the support structure 104. The duct assembly 108 may further include a plurality of discrete pipes 118 on rollers 120 configured to facilitate the movement of each rigid pipe relative to the support structure 104 by a technician during the setup and dismantling of the ACM 102. The flexible pipes 112 suspended by the hangers 116 provide the system operator with the ability to connect the ACM 102 to the target pipe and to allow thermal expansion within the system. In relation to these, the expansion joint 114 and roller 120 provide further capacity for thermal expansion. The test stand 100 may also include a filter 122 positioned in fluid communication with a duct assembly 108 to remove contaminants from the pressure and temperature-controlled air 14A supplied to the ACM 102.

[0056]

[0062] As shown in Figures 2 to 4, the test stand 100 may further include at least one coupler 124 configured to connect the ACM 102 to the duct assembly 108 and to join individual adjacent pipes 118, thereby creating individual thermal expansion joints. Specifically, the coupler 124 includes a multi-segment retaining shell 124-1 having an inner surface with a generally V-shaped cross section 124-1A (shown in Figure 4) configured to pull together the ends of adjacent (neighboring or adjacent) pipes 118. The coupler 124 also includes a band 124-2 configured to pull together the segments of the retaining shell 124-1 via a fastener 124-3 and hold the shell in a compressed state. Furthermore, as shown in Figure 3, the V-shaped cross section 124-1A may be sized to create a gap 124-4 between the ends of adjacent pipes 118. The gap 124-4 is beneficial for absorbing the expansion and / or contraction of the adjacent pipe 118 within the duct assembly 108.

[0057]

[0063] The coupler 124 may further include a seal ring 124-5 of a high-temperature material (e.g., silicon) positioned on the outer diameter of an adjacent pipe 118 (shown in Figure 3). The seal ring (124-5) is positioned between the inner surface of the V-shaped cross section 124-1A of the retaining shell 124-1 and the outer diameters of the two adjacent pipes 118. The seal ring 124-5 is configured to block the leakage of pressure- and temperature-controlled air 14A from between the adjacent pipe ends. As shown in Figure 3, the ends of the adjacent pipes 118 may include adjacent ridges 118-1. The inner surface of the V-shaped cross section 124-1A is configured to apply a throttling force to the adjacent retaining ridge 118-1 on the outer diameter of the ridge. The multi-segment retaining shell 124-1 applies a throttling force via the corresponding seal ring 124-5, thereby pulling the adjacent pipe ends together and counteracting the tendency for the joined pipes to separate. The coupler shell 124-1 is sized to prevent adjacent pipes 118 from coming into contact with each other, as determined by how and where the shell engages with the ridge 118-1 via the seal ring 124-5.

[0058]

[0064] Overall, the coupler 124 allows the pipes 118 of the test stand 100 to be joined using an airtight, detachable connector that absorbs thermal expansion or contraction of the duct assembly 108, thereby protecting the pipes from cracking or breaking at their attachment points. In other words, the coupler 124 enables the construction of a thermal expansion and contraction absorbing joint within the context of the AHRS 12. The construction of the coupler 124 can allow thermal expansion and contraction of up to 0.4 inches to be absorbed between adjacent pipe ends (in each coupler) without leakage. The coupler 124 also allows one test unit (e.g., ACM 102) to be removed and replaced with another test unit, and allows an operator to install a speed sensor (as described below) inside the ACM 102.

[0059]

[0065] As shown in Figure 1B, the test stand 100 may further include an optical velocity sensor 126 configured to detect the rotational speed of the ACM 102. The optical velocity sensor 126 is located inside one of the pipes 118 downstream of the ACM turbine outlet 102-2B (thereby forming a velocity sensor assembly). The velocity sensor 126 of the velocity sensor assembly is configured to withstand extreme temperatures that the turbine 102-2 may encounter during operation (e.g., in the range of -63°F to +388°F). The velocity sensor 126 may be located inside a particular pipe 118 along the airflow 14A. As will be understood by those skilled in the art, the ACM turbine 102-2 has multiple turbine blades. The velocity sensor 126 is positioned in close proximity to and opposite the rotating blades of the ACM turbine 102-2 wheel and is thereby configured to detect the movement of individual blades. The target pipe 118 defines an opening 118-2 (shown in Figures 3 and 5) for the optical fiber cable 128. The optical fiber cable 128 provides communication between the speed sensor 126 and the electronic controller 24.

[0060]

[0066] The speed sensor 126 may also include an adapter or tube 130 that routes the optical fiber cable 128 through the adapter or tube 130, defining a threaded end 130-1 configured to receive a sensor tip 126-1 (variant configurations of which are shown in Figures 3 and 5). The adapter 130 may pass through the opening 118-2 with the opening sealed on the outer circumference of the adapter to prevent air leakage. The speed sensor 126-1 may be axially adjustable via the threaded end 130-1 to facilitate precise positioning of the optical fiber cable 128 relative to its mounting pipe 118. The speed sensor 126 may further include a set screw 126-2 configured to fix the position of the tip 126-1 relative to the threaded end 130-1. The adapter 130 may also define a distal end configured to interact with a specific pipe 118 and to be fixedly attached to that pipe 118 via a fin 130-2 (shown in Figures 3 and 5). As shown in Figure 3, the fin 130-2 may be positioned and welded within a slot 118-3 defined by the pipe 118 to precisely position an optical velocity sensor 126 relative to the ACM turbine outlet 102-2B.

[0061]

[0067] As shown in Figure 3, the velocity sensor 126 further includes an LED transmitter / receiver 132 and an amplifier 134 (which operably connects the optical cable to the electronic controller 24), as well as two couplers 124 that connect a pipe 118 containing the velocity sensor assembly to the ACM 102 and duct assembly 108 of the test stand 100. One coupler 124 is configured to firmly connect the velocity sensor 126 to the ACM 102 in order to maintain a consistent distance between the end of the optical fiber cable 128 and the blades of the ACM turbine 102-2. Once the velocity sensor 126 assembly is connected to the ACM 102, the position of the optical fiber cable 128 can be adjusted and fixed via a threaded end 130-1 and a set screw 126-2 to facilitate precise positioning of the cable end relative to the rotating blades of the ACM turbine 102-2. The electronic controller 24 uses the speed sensor 126 signal as a data point to adjust the main line pressure at outlet 20F, thereby adjusting the speed of the ACM turbine 102-2 during testing.

[0062]

[0068] The electronic controller 24 may be configured to use a signal 140 received from the speed sensor 126 via the fiber optic cable 128 to determine the instantaneous or current rotational speed 142 of the ACM 102 and output the determined rotational speed to a monitoring device / display 144. As described in detail below, the test stand 100 may further include a plurality of temperature sensors or thermocouples configured to detect the temperature of the air 14A and its components, as well as pressure transducers for detecting the air pressure at discrete locations within the duct assembly 108, the test stand 100, and the ACM 102 test unit. These sensors are used to communicate the detected data to the electronic controller 24 for evaluation. The evaluation of the subject may be automated, for example, via a controller algorithm 26 configured to display the pass or fail status of the unit under test and the recorded detailed data. As shown in Figure 1B, the pressure transducer 22 may be located on the test stand 100 within the duct assembly 108 and configured to detect the pressure of the air 14A upstream of or at the ACM compressor inlet 102-1A. The electronic controller 24 then compares the detected pressure to the pressure of the air being transported at the AHRS line outlet 20F by comparing it to a preset pressure value 28 programmed within the electronic controller 24.

[0063]

[0069] Referring to Figure 1B, the test stand 100 can receive pressure and temperature-controlled air 14A from the AHRS 12 via outlet 20F. The parameters of the inlet airflow 14A to the test stand 100 can reach 580 degrees Fahrenheit and 80 Psig at 220 lbs / min. As illustrated, the airflow 14A first passes through filter 122 to ensure that no foreign matter or debris reaches the ACM 102. The inlet pressure and temperature of the airflow 14A are measured by pressure transducer 22 and temperature sensor (such as a resistance detector) 152, respectively, and communicated to the electronic controller 24. The inlet airflow 14A is then led through duct assembly 108 to the ACM compressor inlet 102-1A, where its pressure and temperature increase. Temperature sensor 154 measures the temperature of the airflow at the compressor outlet 102-1B and communicates the corresponding data to the electronic controller 24. Next, the airflow moves through the high-temperature side of the heat exchanger 110, causing the temperature and pressure to decrease.

[0064]

[0070] After being cooled through the heat exchanger 110, the airflow is directed into a butterfly valve 156, which is actuated by an electronic controller 24. The butterfly valve 156 is configured to generate the required test pressure difference (programmed in the electronic controller 24) between the compressor outlet 102-1B and the turbine inlet 102-2A. A temperature sensor 158 measures the temperature of the airflow at the turbine inlet 102-2A and communicates the corresponding data to the electronic controller 24. A pressure transducer 160 measures the actual pressure difference between the compressor outlet 102-1B and the turbine inlet 102-2A and communicates such data to the electronic controller 24 in order to actuate the butterfly valve 156. A pressure transducer 162 measures the pressure of the airflow at the turbine inlet 102-2A and communicates the corresponding data to the electronic controller 24. The airflow then travels through the turbine 102-2, where its temperature and pressure decrease further.

[0065]

[0071] As shown in Figure 1B, the ACM102 test unit may further include thermocouples 164 and 166 configured to detect the temperature of bearings (not shown) adjacent to the respective ACM compressors 102-1 and turbines 102-2. Thermocouples 164 and 166 also communicate the detected ACM assembly temperatures to the electronic controller 24 for assessment of the integrity of the ACM102 test unit. An optical velocity sensor 126 is located within the duct assembly 108 to measure the rotational speed of the turbine 102-2 wheel. As described above, the optical velocity sensor 126 communicates the measured rotational speed of the turbine 102-2 wheel to the electronic controller 24.

[0066]

[0072] Upon exiting turbine 102-2, a pressure transducer 168 measures the pressure of the airflow at turbine outlet 102-2B, and a temperature sensor 170 measures the temperature, communicating the corresponding data to the electronic controller 24. After pressure and temperature measurements, the airflow is directed to a ball valve 172, which is operated by the electronic controller 24 to regulate the back pressure of the entire test stand 100. After junction J7, the airflow moves into ball valves 174 and 176, which are regulated by the electronic controller 24 to achieve a desired temperature drop in the airflow between compressor outlet 102-1B and turbine inlet 102-2A, as programmed in the controller. Specifically, the desired temperature drop can be achieved by passing the relatively cool turbine outlet 102-2B air over projections or fins positioned on the outer surface of the heat exchanger 110 tubes through which the compressor's hot air flows. Thus, in such a configuration, the hot and cold air will not be physically mixed. Furthermore, if cooling is not required, the air may be routed to the atmosphere, bypassing the low-temperature side of the heat exchanger 110. After adjusting the temperature drop between the compressor outlet 102-1B and the turbine inlet 102-2A, the airflow is exhausted to the atmosphere at outlet 178.

[0067]

[0073] Figure 6 shows test method 200. Method 200 employs a test setup 10 including an air heating and distribution system (AHRS) 12, as described above with respect to Figures 1 to 5. Method 200 can be used to facilitate the performance evaluation and development of machines such as an ACM 100 operated using a pressure and temperature-controlled airflow 14A generated by the AHRS 12. Method 200 begins in block 202. In block 202, Method 200 includes receiving an airflow 14 through the piping 20 of the air heating and distribution system (AHRS) 12. After block 202, the method proceeds to block 204. In block 204, Method 200 includes detecting the pressure of the air 14 being transported via a pressure transducer 22. For example, the pressure transducer 22 is located on the test stand 100, as described above with respect to Figures 1A and 1B, and the air pressure may be detected in particular at the ACM compressor inlet 102-1A.

[0068]

[0074] Following the detection of the pressure of the conveyed air 14 in block 204, method 200 proceeds to block 206. In block 206, method 200 includes adjusting the pressure of the conveyed air 14 via a three-stage pressure adjustment subsystem 16 using the pressure detected by the pressure transducer 22. As described above with respect to Figures 1 to 5, the electronic controller 24 may adjust the pressure of the conveyed air 14 at the outlet of the AHRS 12 by having a preset pressure value 28 programmed into it and comparing the pressure detected by the transducer 22 with the preset pressure value. In block 206, the method may particularly include reducing and maintaining the pressure of the conveyed air 14 via the first valve 30.

[0069]

[0075] In block 206, after the reduction of the air pressure through the first valve 30, the method may further include regulating the pressure of the transported air 14 based on the required outlet pressure of the AHRS 12 via one of the second, third, and fourth valves 32, 34, and 36. After the pressure of the transported air 14 has been regulated in the second stage 16-2, the method may include controlling the pressure of the transported air 14 at the outlet of the AHRS 12 (e.g., outlet 20E) via a fifth pressure regulating valve 38 by the electronic controller 24. For example, if the pressure detected by the transducer 22 deviates from the preset pressure value 28 by more than 0.5 Psi, one of the pressure regulating valves 32, 34, and 36 of the second pressure stage 16-2 may be activated by an input from the aforementioned active control loop using the fifth pressure regulating valve 38 for further pressure adjustment.

[0070]

[0076] After block 206, method 200 proceeds to block 208. In block 208, method 200 includes regulating the temperature of air 14 being delivered through air heater 18. Method 200 proceeds from block 208 to block 210. In block 210, method includes outputting pressure and temperature-controlled air 14A through AHRS piping 20 at outlet 20F, etc. Method 200 may loop back from block 210 to block 202 to continue receiving the airflow 14. Method 200 may proceed from block 210 to block 212. In block 212, method includes receiving pressure and temperature-controlled air 14A from outlet 20F of AHRS 12 via test stand 100 configured to circulate ACM 102. Method 200 may then proceed to block 214. Block 214 includes supplying pressure and temperature-controlled air 14A to the ACM compressor inlet 102-1A in order to increase the temperature and pressure of the airflow.

[0071]

[0077] From block 214, the method may proceed to block 216. In block 216, the method includes reducing the temperature of the air received from the ACM compressor outlet 102-1B and circulated to the turbine inlet 102-2A via the heat exchanger 110. Through blocks 212 to 216, the method may include detecting the temperature and pressure of the air at discrete locations within the duct assembly 108 via appropriate sensors and communicating the detected temperatures to the electronic controller 24. After block 216, the method may proceed to block 218. In block 218, the method includes detecting the rotational speed of the ACM 102 (for example, at turbine 102-2) via an optical fiber velocity sensor 126 and communicating the detected ACM speed to the electronic controller 24. In block 218, the method may further include outputting the specified rotational speed to a monitoring device / display 144 via the electronic controller 24. In block 218, method 200 may also employ a controller algorithm 26 for recording detected data, providing the system with a pass / fail status for the ACM102 test unit, and recording and displaying the received data values.

[0072]

[0078] After block 218, method 200 may proceed to block 220. In block 220, the method includes exhausting air from the ACM turbine outlets 102-2B to the atmosphere via outlet 178. Blocks 218-220 may also include detecting and controlling the pressure and temperature of the exhaust air. After block 220, the method may loop back to block 212 to continue receiving pressure and temperature-controlled air 14A from each outlet of the AHRS 12. Alternatively, once appropriate test procedures (such as performance evaluation of the ACM 102) are completed, method 200 may terminate in block 222.

[0073]

[0079] Detailed descriptions and drawings or figures support and illustrate this disclosure, but the scope of this disclosure is defined solely by the claims. While some of the best modes and other embodiments for carrying out this disclosure have been described in detail, there are various alternative designs and embodiments for carrying out this disclosure as defined in the appended claims. Furthermore, features of embodiments shown in the drawings or various embodiments described in this description do not necessarily have to be understood as unrelated embodiments. Rather, each feature described in one of several embodiments of a single embodiment may be combined with one or more other desired features from other embodiments, making it possible to obtain other embodiments not described in words or by reference to the drawings. Thus, such other embodiments are included within the framework of the appended claims.

Claims

1. A thermal expansion absorbing joint, A duct assembly (108) having a plurality of pipes (118) configured to transport pressure and temperature controlled air (14A), and A thermal expansion absorbing joint comprising at least one coupler (124) configured to join individual pipes within the duct assembly (and / or connect the ACM to the duct assembly) and to absorb the thermal expansion of the duct assembly.

2. The thermal expansion absorbing joint according to claim 1, wherein each coupler includes a multi-segment retaining shell (124-1) having a V-shaped cross-section (124-1A) on its inner surface, configured to pull adjacent pipe ends together.

3. The thermal expansion absorbing joint according to claim 2, wherein each coupler includes a band (124-2) having a fastener (124-3) configured to pull together the segments of the retaining shell and to hold the shell in a compressed state.

4. The thermal expansion absorbing joint according to claim 2, wherein the joined individual pipes include the adjacent pipe ends having retaining ridges (118-1), and the inner surface of the V-shaped cross section is configured to apply a thoracic force to the adjacent retaining ridges, thereby pulling the adjacent pipe ends together and resisting separation of the joined pipes.

5. The thermal expansion absorbing joint according to claim 2, wherein each coupler further includes a seal ring (124-5) of a high-temperature material disposed on the outer diameter of the retaining ridge, configured to block airflow leakage between adjacent pipe ends.

6. The thermal expansion absorbing joint according to claim 5, wherein the high-temperature material of the seal ring is silicone.

7. The thermal expansion joint according to claim 2, wherein the retaining shell is sized to create a gap (124-4) between adjacent pipe ends in order to absorb the thermal expansion of the duct assembly without leakage.

8. The thermal expansion joint according to claim 1, further comprising an optical fiber velocity sensor (126) disposed within a pipe (118) of the duct assembly and configured to detect the rotational speed of an air cycling machine (ACM) (102), wherein the pipe having the velocity sensor is rigidly connected to an adjacent pipe and to each of the ACMs via their respective couplers.

9. The thermal expansion joint according to claim 1, wherein at least one of the couplers facilitates the removal and replacement of the ACM and the installation of the pipe having the speed sensor relative to the ACM.

10. The test stand (100) is configured to accommodate an air cycling machine (ACM) (102) having a compressor (102-1) and a turbine (102-2), support structure (104); A duct assembly (108) movably mounted on the support structure, configured to receive pressure and temperature-controlled air (14A) from an external source, supply the pressure and temperature-controlled air to the compressor inlet (102-1A) of the ACM, and exhaust the air to the atmosphere from the turbine outlet (102-2B) of the ACM, and A test stand comprising at least one coupler (124) configured to connect the ACM to the duct assembly and / or to join the individual pipes of the duct assembly and to absorb the thermal expansion of the duct assembly.

11. The test stand according to claim 10, wherein each coupler includes a multi-segment retaining shell (124-1) having an inner surface with a V-shaped cross-section (124-1A) configured to pull adjacent pipe ends together.

12. The test stand according to claim 11, wherein each coupler includes a band (124-2) having a fastener (124-3) configured to pull together the segments of the retaining shell and to hold the shell in a compressed state.

13. The test stand according to claim 11, wherein the joined individual pipes include the adjacent pipe ends having retaining ridges (118-1), and the inner surface of the V-shaped cross section is configured to apply a thoracic force to the adjacent retaining ridges, thereby pulling the adjacent pipe ends together and preventing the joined pipes from separating.

14. The test stand according to claim 11, wherein each coupler further comprises a sealing ring (124-5) of a high-temperature material positioned on the outer diameter of the retaining ridge, and configured to block airflow leakage between adjacent pipe ends.

15. The test stand according to claim 11, wherein the retaining shell is sized to create a gap (124-4) between adjacent pipe ends in order to absorb the thermal expansion of the duct assembly.

16. The duct assembly further comprises an optical fiber velocity sensor (126) positioned within the pipe (118) of the duct assembly adjacent to the ACM and configured to detect the rotational speed of the ACM, The pipe having the speed sensor is firmly connected to the adjacent pipe and to each of the ACMs via their respective couplers. The test stand according to claim 10, wherein at least one of the couplers facilitates the removal and replacement of the ACM and the installation of the pipe having the speed sensor relative to the ACM.

17. A thermal expansion absorbing coupler (124) configured to join individual pipes, A multi-segment retaining shell (124-1) having an inner surface with a V-shaped cross-section (124-1A) configured to pull adjacent pipe ends together, and A thermal expansion absorbing coupler comprising a high-temperature material sealing ring (124-5) positioned between the retaining shell and the outer diameter of the adjacent pipe, configured to block airflow leakage between the adjacent pipe ends.

18. The thermal expansion absorbing coupler according to claim 17, wherein each coupler includes a band (124-2) having a fastener (124-3) configured to pull together the segments of the retaining shell and to hold the shell in a compressed state.

19. The thermal expansion absorbing coupler according to claim 17, wherein the high-temperature material of the seal ring is silicone.

20. The thermal expansion absorbing coupler according to claim 17, wherein the retaining shell is sized to create a gap between the adjacent pipe ends in order to absorb a maximum thermal expansion of 0.4 inches between the adjacent pipe ends without leakage.

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