System and method for detecting hydrogen leaks in turbomachinery enclosures

Abstract

This specification describes a turbomachinery system comprising a turbomachinery and an enclosure surrounding the turbomachinery, including at least one duct, the at least one duct being adapted to contain a flammable gas. An ultrasonic gas leak detector configuration housed within the enclosure is adapted to detect a flammable gas leak within the enclosure. This specification also discloses a method for detecting a gas leak within an enclosure housing a turbomachinery.

Description

[Technical Field]

[0001] The present disclosure relates to turbomachinery. Embodiments disclosed herein relate to safety means adapted to improve operational safety of turbomachinery involving flammable gas, particularly gas turbine engines supplied with gaseous fuel. [Background Art]

[0002] In view of growing concerns about climate change, the general trend toward reduction of carbon dioxide emissions characterizes recent research in the field of power generation equipment and devices. In particular, gas turbine manufacturers are striving to reduce CO₂ emissions from gas turbine engines. One approach is to use hydrogen as an alternative to natural gas (primarily methane) as a fuel for gas turbine engines. Combustion of hydrogen produces water and does not produce carbon dioxide.

[0003] The introduction of hydrogen as a fuel for gas turbines requires assessment of the safety of the entire gas turbine package, which consists of auxiliary systems, instruments, and other equipment necessary for its function.

[0004] Portions of the gas turbine and auxiliary systems are typically installed inside an acoustic enclosure. Among the auxiliary systems housed within the enclosure, it is worth mentioning the fuel gas line supplying the gas turbine combustor and the connections thereof, which may be potential leak sources. This gives rise to additional issues that need to be assessed from a safety perspective.

[0005] To dilute possible fuel gas leaks, a ventilation system is one of the essential auxiliary systems provided in a gas turbine package. In addition to ventilation, gas sensors and detectors are required to detect the presence of unexpected leaks.

[0006] Gas leaks can occur from flanged or threatened connections. In such cases, the response time of the detection system is crucial to limit the potential risk of flammable mixtures being present within the gas turbine enclosure.

[0007] Today, the most commonly used gas detectors are based on infrared (IR) technology. These can be installed at both the ventilation outlets of a gas turbine enclosure, enabling monitoring of any leaks inside the enclosure. Alternatively, or in combination, detectors can be housed inside the enclosure, closer to potential leak sources, to predict detection. Infrared detectors cannot detect hydrogen; the most common alternative to infrared gas detectors in the oil and gas sectors is the so-called catalytic detector, adapted to detect any percentage of hydrogen. However, catalytic detectors have a much longer response time compared to infrared detectors.

[0008] Therefore, more efficient and safer detection configurations for hydrogen fuel gas turbine engines would be welcomed in the field of technology. [Overview of the project]

[0009] To mitigate the shortcomings of conventional gas leak detection systems, the present disclosure provides a gas turbine engine system comprising an ultrasonic gas leak detector configuration adapted to detect hydrogen leaks. The ultrasonic gas leak detector configuration is housed within the enclosure of the gas turbine engine.

[0010] Ultrasonic gas leak detectors are based on microphone sensing elements and are typically used to detect outdoor leaks by sensing the distinct high-frequency ultrasonic waves (20kHz-100kHz) emitted by all high-pressure gas leaks (natural gas and H2). They respond almost instantaneously within 1-3 seconds and are less susceptible to malfunctions due to environmental factors such as wind. Furthermore, they do not require physical contact with the gas leak and do not require routine calibration.

[0011] Ultrasonic gas leak detectors cannot detect gas concentration and are sensitive to background noise, such as that generated by a gas turbine engine during operation.

[0012] Tests conducted on a gas turbine engine system, including an enclosure housing an ultrasonic gas leak detector (as reported in more detail below), surprisingly demonstrated that, despite its sensitivity to background noise, the ultrasonic gas leak detector could distinguish the ultrasound generated by hydrogen leaks in highly noisy environments such as gas turbine enclosures, thus providing a safe and efficient alternative to state-of-the-art detectors for the safe and rapid detection of hydrogen leaks in turbine enclosures.

[0013] The currently preferred embodiment is based on an ultrasonic gas leak detector, typically adapted to provide signals at frequencies in the range of above 10 kHz, above 20 Hz, or above 25 kHz, and preferably below 100 kHz, or below 70 kHz. Tests performed on gas turbine systems, including enclosures housing gas turbine engines, demonstrate that ultrasonic gas leak detectors operating in the aforementioned frequency ranges can generate useful signals in the case of hydrogen leaks despite high background noise generated by the turbomachinery within the enclosure. Sound waves at frequencies below 20 kHz are typically unaffected by hydrogen leaks, but at higher ultrasonic frequencies, the contribution of hydrogen leaks to the detected total sound pressure level is significant and can be distinguished from background noise, thus providing useful information that can trigger a rapid alarm with a potentially short reaction time of about 2 seconds in the case of gas leak detection.

[0014] More generally, this specification discloses a system comprising a rotary turbomachinery, specifically a gas turbine engine, housed within an enclosure, the enclosure comprising at least one duct containing gaseous fuel supplied to the gas turbine engine. The system further comprises an ultrasonic gas leak detection configuration within the enclosure, adapted in particular to detect gaseous fuel leaks inside the enclosure, for example, while the gas turbine engine is operating.

[0015] While the use of ultrasonic gas leak detectors adapted to detect hydrogen leaks in gas turbine engine systems is particularly advantageous over current technologies for the reasons outlined above, the novel systems described herein can also offer some advantages in applications where the flammable gas is not hydrogen or a hydrogen-containing blend. For example, an ultrasonic gas leak detector configuration can be used to detect natural gas leaks in enclosures housing rotating turbomachinery such as gas turbine engines.

[0016] Furthermore, the use of ultrasonic gas leak detectors is particularly beneficial in combination with gas turbine engines where the flammable gas is (part of) the fuel delivered to the turbine compressor. In other embodiments, the novel features disclosed herein can be used in combination with different turbomachinery, such as compressors, including dynamic compressors that process other flammable gases, such as hydrogen or hydrogen-containing blends, or methane. The flammable gas can be contained in a duct and processed by the turbomachinery, such as methane, or hydrogen compressed by the compressor. In some embodiments, the flammable gas can be contained in, for example, the compressor's intake duct, a flow path inside the turbomachinery, or a delivery duct and flow through it during the compressor's operation. The flammable gas may also be contained in other ducts of the turbomachinery, such as a duct that delivers dry gas to the turbomachinery's dry gas seal. This may be the case, for example, when the flammable process gas processed by the compressor is also used as the dry gas for the dry gas seal. [Brief explanation of the drawing]

[0017] Here, we will briefly refer to the attached diagram. [Figure 1] This is a schematic diagram showing a gas turbine system with an associated enclosure. [Figure 2] This diagram illustrates data collected during the operation of an ultrasonic gas leak detector under various operating conditions of a gas turbine engine. [Figure 3] This diagram illustrates data collected during the operation of an ultrasonic gas leak detector under various operating conditions of a gas turbine engine. [Figure 4] This diagram illustrates further data collected during the operation of a detector under variable conditions in a gas turbine engine. [Figure 5A] This diagram illustrates further data collected during the operation of a detector under variable conditions in a gas turbine engine. [Figure 5B] This diagram illustrates further data collected during the operation of a detector under variable conditions in a gas turbine engine. [Figure 5C] This diagram illustrates further data collected during the operation of a detector under variable conditions in a gas turbine engine. [Figure 6] This diagram illustrates further data collected during the operation of a detector under variable conditions in a gas turbine engine. [Figure 7A] This diagram illustrates further data collected during the operation of a detector under variable conditions in a gas turbine engine. [Figure 7B] This diagram illustrates further data collected during the operation of a detector under variable conditions in a gas turbine engine. [Modes for carrying out the invention]

[0018] The following detailed description specifically relates to the application of the novel features disclosed herein to systems including a gas turbine engine that is fueled by hydrogen or a hydrogen-containing gaseous blend and housed in an enclosure.

[0019] Fig. 1 schematically shows a gas turbine engine system 1 comprising an enclosure 3 that houses a gas turbine engine 5. The enclosure 3 includes a combustion air inlet 7 and a flue gas outlet 9. The enclosure further includes a ventilation air inlet 8 and a ventilation air outlet 10.

[0020] The gas turbine engine 5 comprises a compressor section 5.1, a combustor 5.2, and a turbine section 5.3. The turbine is drivingly coupled via a shaft line 13 to a load 11, for example a compressor or an electric generator.

[0021] Fuel is injected into the gas turbine engine 5 via a fuel line 15. The fuel may be hydrogen, or a blend containing hydrogen, for example hydrogen and natural gas.

[0022] According to embodiments disclosed in the present specification, an ultrasonic gas leak detector arrangement 17 is housed inside an enclosure 3. In some embodiments, the ultrasonic gas leak detector arrangement 17 comprises a plurality of ultrasonic gas leak detectors 17.1, 17.2 arranged around axis A-A of the gas turbine engine 5 at one or more positions along the axial extension of the gas turbine engine. As will be described in more detail below, in some embodiments, the detectors are positioned at a substantially intermediate height along the vertical extension of the gas turbine engine, i.e., on or near a central vertical plane containing the axis of rotation A-A of the turbomachine, preferably on opposite sides of the turbomachine, i.e., on opposite sides of the central vertical plane containing the axis A-A of the gas turbine engine. The option of arranging one or more detectors in different positions, for example below the gas turbine engine or above the gas turbine engine, depending on aerodynamic conditions, noise reflections and temperature distribution within the enclosure, is not excluded. Additionally, while it may be more appropriate to position the detectors at or near the front end of the gas turbine engine, i.e., in the area around the compressor section where temperatures are lower than around the combustor or the rearmost section of the gas turbine engine, i.e., the turbine section, the option of positioning the detectors closer to the combustor or the rear end of the gas turbine engine is not excluded. Selection of the most suitable position may depend on ultrasonic detection efficiency, temperature distribution inside the enclosure, and the geometry of the turbine and the enclosure.

[0023] The ultrasonic gas leak detectors can be operatively connected to a controller 18 configured to receive and process signals from the detectors and to trigger an alarm or optionally shut down the turbomachine if a hydrogen leak is detected.

[0024] In some embodiments, at least one ultrasonic gas leak detector can be provided on each side of the central vertical plane including the rotation axis AA of the gas turbine engine. In the current preferred embodiment, the ultrasonic gas leak detector is placed at an intermediate height, i.e., substantially horizontal plane including the rotation axis AA of the gas turbine engine. This position provides a good compromise between the need to protect the detector from excessive thermal load and the need to place the detector in a position where it can detect ultrasonic waves generated at any angular position around the rotation axis AA of the gas turbine engine.

[0025] In Figure 1, only the ultrasonic gas leak detector on one side of the gas turbine engine is shown; the other side is not visible in the side view.

[0026] To prevent adverse temperature effects on the ultrasonic gas leak detector, the ultrasonic gas leak detector can be positioned toward the cooler side of the gas turbine engine 5, i.e., around its compressor section 5.1. This position is still close enough to the combustor section where most of the fuel duct is located, but far enough away to avoid overheating of the detector.

[0027] During operation, the gas turbine engine 3, ventilation, and other auxiliary systems generate sound vibrations in the audible and ultrasonic ranges. Simulation tests were performed on the gas turbine engine and associated enclosure to check whether leaks of low molecular weight gases such as hydrogen could be detected by an ultrasonic gas leak detector despite a very noisy background, and whether the detection was fast enough (e.g., with a reaction time of less than 4 seconds) as required for safety reasons in the case of highly flammable gases such as hydrogen.

[0028] The technical characteristics of these gas detectors must be analyzed in actual operating environments to evaluate the performance of this technology. Special attention is paid to filtering background noise and its reflections in indoor environments to isolate H2 leakage signals from gas turbine noise radiation. A test campaign was conducted, during which the sound pressure level (SPL) of the gas turbine and auxiliary systems in the ultrasonic frequency range was measured. It is important to note that this characterization process of background noise in ultrasonic frequencies must be repeated for each model of gas turbine, as different engines may have different spectra.

[0029] The tests were conducted with the NovaLT12 turbine package, available from Nuovo Pignone spa, Florence, Italy. The gas turbine engine is housed within an acoustic enclosure, which is a parallelepiped box containing the gas turbine engine and receiving the auxiliary skids necessary for proper operation. During the tests, the gas turbine engine drives a generator, and its power is dissipated by the cooling resistor.

[0030] To evaluate which ultrasonic gas leak detectors are best suited for gas turbine environments, different manufacturers of the same technology were tested to compare their performance. The detectors differ primarily in shape, ambient temperature range, certification, response time, and sensitivity. Two models were selected as Devices Under Test (DUT) for further testing.

[0031] The first model provides a signal proportional to the average SPL% over time, while the second model provides a signal showing the frequency spectrum of the detected sound wave received in real time at audible and ultrasonic frequencies. Two units of each detector model were installed in an enclosure, one on each side (left and right) of the central vertical plane containing the rotation axis of the gas turbine engine.

[0032] For safety reasons, helium (He2) was used as a substitute for hydrogen in the test bench. Helium has a molecular weight of 4 g / mol and, like hydrogen, is lighter than air. Although helium is not as light as hydrogen, it is safer than highly flammable hydrogen because it is inert and non-flammable. The ultrasonic spectrum produced by a helium leak is very similar to the spectrum produced by a hydrogen leak.

[0033] Leakage in the gas turbine enclosure was simulated by using helium contained in tanks connected to piping terminated with orifices of different sizes. During testing, the gas pressure and orifice size were varied to evaluate the response of ultrasonic gas leak detectors with different flow leaks in terms of amplitude and frequency values. The test bench was adapted to achieve the mass flow values ​​shown in Table 1 at the minimum and maximum design pressure values. Typical operating pressures of the fuel gas system varied from 10 bar to 30 bar, which ensured the emission of ultrasonic spectra in the case of choke flow.

[0034] [Table 1]

[0035] Gas leaks are simulated on the gas turbine baseplate, which is close to the fuel skid gas, because this is an area with numerous fuel gas connections.

[0036] The examination was divided into the following three stages, summarized in Table 2. Stage a: During this initial stage, at the start of the test, both the gas turbine engine and auxiliary systems (ventilation, lubrication, etc.) were switched off to prevent helium leakage. Stage b: During the second stage, the auxiliary system was started, but the gas turbine engine was kept in a non-operating state. In the first stage of this second step, the response of the ultrasonic gas detector was evaluated in a leak-free state, and the spectrum of sound emitted by the auxiliary system without engine rotation was analyzed to distinguish and separate it from the sound generated by the leak. Stage c: During the third test stage, the gas turbine engine was started and accelerated to full speed full load (FSFL) conditions. In this third stage of the test, the contribution to the sound pressure level came from the auxiliary systems and the gas turbine engine. Detector signals were recorded with and without gas leak simulation (helium leak).

[0037] [Table 2]

[0038] The test results are summarized below and shown in Figures 2A, 2B, 2C, 3A, 3B, and 3C. Figures 2A, 2B, and 2C relate to steps a and b. Figures 3A, 3B, and 3C relate to step c.

[0039] In Figures 2A and 3A, the intensity of the sound waves detected by the first model ultrasonic gas leak detector is plotted on the y-axis against time. The acquisition scan time was 1 second. The acquired signal is proportional to the intensity received from the ultrasonic gas leak detector during the test and correlates with the gas turbine engine test parameters.

[0040] In Figures 2B, 2C, 3B, and 3C, the signals from the second model ultrasonic gas leak detector are plotted as a function of frequency.

[0041] Figures 2A, 2B, and 2C show the measurements taken between stages a and b outlined above, with the gas turbine engine stopped and the auxiliary systems off (stage a) and on (stage b), respectively. The purpose of stage b is to evaluate the background noise generated by the auxiliary equipment.

[0042] Figure 2A shows the average SPL over time for the first ultrasonic gas leak detector model. The two detectors in this model are installed on each side (left and right) of the central vertical plane containing the rotation axis AA of the gas turbine engine. Curves C1 and C2 represent the signals from the left and right ultrasonic gas leak detectors of the first model. C3 is the ventilation signal.

[0043] Figures 2B and 2C show spectra captured at different time frames. Specifically, Figure 2B shows data collected with ventilation off (stage a), and Figure 2C shows data collected with ventilation on.

[0044] The window W plotted in Figures 2B and 2C represents the ultrasonic frequency (frequency above 20 kHz) on the x-axis and the alarm threshold set to SPL on the y-axis.

[0045] When the gas turbine engine is not running and ventilation is off, the SPL (providing the average value of SPL% over time) of the first model ultrasonic gas leak detector is constant and equal to 20.8%, which is the minimum full-scale value of the instrument (see Figure 2A).

[0046] In Figure 2B, the sound pressure level versus frequency on the x-axis shows a small variation of 16% to 20.6%. This indicates that when the ventilation system is off and the gas turbine engine is stopped, background noise is negligible and no false alarms are detected.

[0047] When the gas turbine engine is not running and the ventilation system is on, the ventilation signal is activated (curve C3 in Figure 2A), and the signal intensity increases by 22.55% or 25% for the left (curve C1) and right (curve C2) detectors of the first model. This means that both detectors detect the noise generated by the operating ventilation system, but the left detector (curve C1) "hears" higher frequencies than the right detector because it is closer to the simulated He leak. In Figure 2C, the sound pressure level rises to 37% at audible frequencies and to 26% at ultrasonic frequencies (above 20 kHz). Therefore, the background noise generated by the operation of the ventilation system mainly affects the audible spectrum.

[0048] Figures 3A, 3B, and 3C illustrate the measurement results during stage c when the auxiliary system is on and the gas turbine engine is running to FSFL. Measurements with and without helium leakage are plotted in all figures.

[0049] In detail, Figure 3A shows the average SPL over time for the first model of the ultrasonic gas leak detector, while Figures 3B and 3C show spectra captured at different time frames by the second model of the ultrasonic gas leak detector (no He leak in Figure 3B, and He leak in Figure 3C).

[0050] Specifically, when the gas turbine engine is operating and there is no helium leak (left side of Figure 3A and Figure 3B), the sound pressure level achieves a higher value compared to Figures 2A and 2B because the noise contribution generated by the rotation of the gas turbine engine is added. In particular, in Figure 3B, it can be noticed that the intensity increases uniformly across all frequencies, but contributes significantly to the audible frequency range.

[0051] He leaks were simulated by operating different lines with orifices while the gas turbine engine was running. Refer to the second dot area in Figures 3A and 3C. In Figure 3A, the signal from one ultrasonic gas leak detector (curve C1) increases following the opening of the helium release orifice. The SPL rises from 45% to 97% of the background noise. Once the ultrasonic gas leak detector reaches the alarm threshold, its output signal is maintained at full scale until the alarm condition is present. It is interesting to note that the ultrasonic gas leak detector on the other side of the gas turbine engine (curve C2) does not hear any He leaks, and its signal remains constant at a background noise level of 45%. This difference between the signals received by the left and right detectors is due to the presence of the gas turbine engine, which interferes with the propagation of ultrasound.

[0052] Referring to Figure 3C, it is noted that the main contribution of the blockage leak is within the ultrasonic frequency range, as ultrasonic frequencies increase above the audible frequency range. In particular, an alarm is sent to the control system because many bands exceed the alarm threshold set at 52.1%. Background noise is present and can be measured, but it does not affect the gas leak detection.

[0053] Several test points were run with varying He leakage, orifice size, and gas pressure to evaluate the effects on SPL intensity and frequency. All ultrasonic gas leak detectors detect gas leaks at the maximum pressure and maximum orifice size. Conversely, at minimum pressure and minimum orifice size, a detector positioned opposite the leak orifice will only hear background noise and not the sound emitted by the leak. Therefore, ultrasonic gas leak detector models that measure the average SPL will show differences in detection between devices installed on the right side of the engine and other devices installed on the left side.

[0054] In summary, tests conducted on the NovaLT12 turbine package demonstrate that ultrasonic gas leak detectors can detect sound waves generated by low molecular weight gas leaks, particularly H2 leaks, in gas turbine enclosures during turbine operation, despite the presence of high levels of noise. Therefore, ultrasonic gas leak detection technology is a promising new method for safe and rapid gas leak detection, meeting the safety requirements for hydrogen leak detection in gas turbine engines.

[0055] Since ultrasonic gas leak detectors are placed inside the enclosure surrounding a gas turbine engine, it may be necessary to find the most suitable location for the detector within the enclosure, where it can detect hydrogen leaks despite strong background noise, and where temperature conditions do not adversely affect detection or damage the detector.

[0056] Generally speaking, setting up an enclosure with an ultrasonic gas leak detector configuration for detecting fuel leaks from a gas turbine engine may require a preliminary step of finding the most appropriate location for one or more detectors inside the enclosure. The most appropriate location may depend, among other things, on the characteristics of the enclosure and the gas turbine engine, which affect the sound wave distribution inside the enclosure under different operating conditions of the turbomachinery.

[0057] Therefore, a setup method for setting up a system including an enclosure and a turbomachinery housed within the enclosure may include the following steps: Once a set of ultrasonic gas leak detectors is placed in a temporary position inside the enclosure, audible and ultrasonic measurements are taken through the detectors: -Under the conditions that auxiliary devices are on, the gas turbine is off, and there are no gas leaks, - Auxiliary device ON, gas turbine OFF, gas leak simulation conditions, -Under the conditions that auxiliary devices are on, the gas turbine is on, and there are no gas leaks, -This is performed under conditions where auxiliary devices are on, the gas turbine is on, and gas leak simulation is being conducted.

[0058] The same step can be repeated several times at different detector positions within the enclosure until the optimal detector location is found where the ultrasonic signal generated by the simulated gas leak is stronger and best distinguishable from background noise. This location is then adopted as the final detector position within the enclosure.

[0059] Figures 4 to 7(C) illustrate further data collected from ultrasonic gas leak detectors under various operating conditions of a gas turbine engine.

[0060] More specifically, Figure 4 illustrates signals collected using a non-operating gas turbine engine and operating operational auxiliary components, specifically using ventilation and lubrication circuits under operating conditions. The horizontal axis represents time, and the vertical axis represents the sound pressure level (percentage) detected by the two detectors. Curves C10 and C11 are signals from two ultrasonic gas leak detectors operating in the time domain and positioned symmetrically on two opposing sides of the gas turbine engine. In the illustration of Figure 4, three time intervals are highlighted, during which He leaks through each of the variable-size orifices, occurring under different He pressure conditions to simulate fuel leaks. The time intervals are labeled P2, P3, and P4. The orifice diameters and helium pressures used in each leak simulation are as follows:

[0061] [Table 3]

[0062] As shown in Figure 4, both detectors detect the gas leak, regardless of whether the detectors are positioned on the leak side or the opposite side.

[0063] Figures 5(A) to 5(C) illustrate three diagrams showing signals generated by an ultrasonic gas leak detector operating in the frequency domain. In each diagram, frequency is plotted on the horizontal axis, and the sound pressure level (percentage) detected by the detector is plotted on the vertical axis. The series of diagrams in Figures 5(A), 5(B), and 5(C) correspond to leak conditions P2, P3, and P4 listed in Table 3 above. Each diagram shows the signal increase at frequencies above 10–15 kHz caused by the detected leak. The frequency response depends on the leak condition with respect to pressure and flow rate.

[0064] The same measurements were repeated with the gas turbine engine operating at full load and full speed. In Figure 6, time is plotted on the horizontal axis. Curves C15 and C16 represent signals from two ultrasonic gas leak detectors positioned on the same side and opposite side of the leak orifice relative to the turbine body, respectively. The leak conditions summarized in Table 4 were tested.

[0065] [Table 4]

[0066] The illustration in Figure 6 illustrates the time-domain detector signals for leak simulations P27, P28, and P32 (see Table 4). The results show that, despite background noise generated by the gas turbine engine, an ultrasonic gas leak detector positioned on the same side as the turbine leak orifice can detect both large and small leaks. A detector positioned on the opposite side of the leak orifice can only detect larger leaks due to background noise.

[0067] Figures 7(A) and 7(B) illustrate the sound pressure signals generated by detectors operating in the frequency domain and corresponding to conditions P31 and P32 (see Table 4). Each figure shows the detector signal (sound pressure level expressed as a percentage) on the vertical axis as a function of frequency plotted on the horizontal axis. The illustrations in Figures 7(A) and 7(B) illustrate that the frequency domain detector measures different sound pressure levels for different leakage rates.

[0068] In summary, the above tests provide evidence that ultrasonic gas leak detectors can detect helium (as a substitute for hydrogen) leaks inside the gas turbine enclosure when auxiliary systems (ventilation and lubrication systems) are operating and the gas turbine engine is stopped. In this case, the ultrasonic gas leak detector can detect the presence of the leak despite the background noise generated by the ventilation and lubrication systems during operation. The ultrasonic gas leak detector can detect different sound pressures generated by variable leak mass flow rates, regardless of its location. Both the time-domain signal and the frequency-domain system provide different sound pressure level intensity values ​​as the leak rate changes. The pressure upstream of the orifice affects the sound pressure level system as well as the leak rate.

[0069] The same results are achieved with gas turbine engines operating at full speed and full load. Ultrasonic gas leak detectors can detect leaks in most cases. However, once a gas leak is detected, the sound pressure signal saturates against the high background noise generated by the operating gas turbine engine, so the detector cannot detect different sound pressure levels with variable leak mass flow rates in the time domain. On the other hand, ultrasonic gas leak detectors operating in the frequency domain can detect different leak rates because the spectrum of the signal in the frequency domain, typically at high frequencies above 10 kHz, changes as a function of the leak flow rate.

[0070] These results, surprisingly, demonstrate that ultrasonic gas leak detectors can be used as reliable detectors within gas turbine engine enclosures, despite the significant noise generated inside the enclosure by the gas turbine engine.

[0071] Exemplary embodiments are disclosed above and illustrated in the accompanying drawings. Those skilled in the art will understand that various modifications, omissions, and additions can be made to what is specifically disclosed herein without departing from the scope of the invention as defined in the following claims.

Claims

1. It is a turbomachinery system, Gas turbine engine and An enclosure surrounding the gas turbine engine, including at least one fuel delivery duct, wherein the at least one fuel delivery duct is adapted to supply gaseous fuel to the gas turbine engine, A turbomachinery system comprising: an ultrasonic gas leak detector configuration housed within the enclosure and adapted to detect leakage of the gaseous fuel supplied to the gas turbine engine during operation of the gas turbine engine within the enclosure.

2. The system according to claim 1, wherein the gaseous fuel includes hydrogen.

3. The system according to claim 1 or 2, wherein the ultrasonic gas leak detector configuration comprises a plurality of ultrasonic gas leak detectors arranged around the shaft of the gas turbine engine.

4. The system according to any one of claims 1 to 3, wherein the ultrasonic gas leak detector configuration is adapted to detect ultrasonic waves near the detection frequency included in 20 kHz to 100 kHz, preferably 25 kHz to 70 kHz.

5. A method for detecting a flammable gas leak in an enclosure housing a gas turbine engine, The steps include supplying gaseous fuel to the gas turbine engine, A method comprising the step of detecting a leak of the gaseous fuel in the enclosure during operation of the gas turbine engine via an ultrasonic gas leak detection configuration.

6. The method according to claim 5, wherein the gaseous fuel contains hydrogen.

7. The method according to claim 5 or 6, wherein the ultrasonic gas leak detector configuration comprises a plurality of ultrasonic gas leak detectors arranged around the shaft of the gas turbine engine.

8. The method according to any one of claims 5 to 7, wherein the ultrasonic gas leak detector configuration is adapted to detect ultrasonic waves near detection frequencies included in 10 kHz to 100 kHz, preferably 20 kHz to 70 kHz, and more preferably 25 kHz to 70 kHz.

9. A method for setting up a system comprising an enclosure, a gas turbine engine housed within the enclosure, and at least one duct adapted for delivering gaseous fuel into the enclosure, a) The step of positioning the set of ultrasonic gas leak detectors inside the enclosure, b) The signal from the ultrasonic gas leak detector, - Under the conditions that the auxiliary device of the gas turbine engine is ON, the gas turbine engine is OFF, and there is no gas leak, - Under the conditions that the auxiliary device of the gas turbine engine is ON, the gas turbine engine is OFF, and a gas leak simulation is performed, - Under the conditions that the auxiliary device of the gas turbine engine is ON, the gas turbine engine is ON, and there is no gas leak, - Under the conditions that the auxiliary device of the gas turbine engine is ON, the gas turbine engine is ON, and a gas leak simulation is being performed, the steps are to collect data. c) Repeating steps (a) and (b) for different positions of the ultrasonic gas leak detector, d) A method comprising the step of selecting a detector position that provides the strongest leakage signal as the final position of the detector within the enclosure.

10. The method according to claim 9, wherein the gaseous fuel includes hydrogen.

Images