Mass spectrum ionization source for online detection of gas components at outlet of combustion chamber of aero-engine

Abstract

The invention belongs to the technical field of mass spectrum ionization sources, provides an online detection mass spectrum ionization source for gas components at an outlet of a combustion chamber of an aero-engine, and solves the problem that an existing ionization source is difficult to be applied to a field test for measuring the concentration of components at the outlet of a combustion chamber of a real aero-engine. According to the technical scheme, the device comprises an ionization source cavity and a radio frequency windowless discharge lamp, a plate electrode, a taper hole electrode, a lamp holder electrode, a direct current transmission electrode, a radio frequency transmission electrode and a differential electrode are sequentially arranged in the ionization source cavity in the axis direction, and a discharge gas inlet is formed in the ionization source cavity. One end of the radio frequency windowless discharge lamp is connected to the discharge gas inlet, and the other end of the radio frequency windowless discharge lamp extends into the lamp holder electrode; the taper hole electrode enables fuel gas to be fed in a molecular beam mode, efficient transmission of stable components and active components in the fuel gas is guaranteed, efficient transmission of ions is achieved in the mode that the direct-current transmission electrode and the radio-frequency transmission electrode are combined, and full-spectrum online analysis of the components of the fuel gas at the outlet of a combustion chamber of an aero-engine can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of mass spectrometry ionization sources, and in particular relates to a mass spectrometry ionization source for online detection of fuel gas components at an outlet of an aircraft engine combustion chamber. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] As one of the indicators of the combustion chamber, the flow field parameters at the outlet of the aircraft engine combustion chamber directly reflect the quality of the combustion in the combustion chamber. Due to the increase in thrust-to-weight ratio, the outlet flow field of the combustion chamber of a modern aircraft engine has the characteristics of high temperature, high pressure and high turbulence. Under the design requirements of advanced combustion chambers, the temperature at the outlet of the combustion chamber increases, the air intake at the head increases, and the amount of mixed air decreases sharply, making the outlet flow field environment even worse. In order to break through the design of the combustion chamber of a new generation of high-performance aircraft engines, it is required to be able to measure and obtain combustion performance parameters such as combustion efficiency, oil-gas ratio, and pollutant emission parameters. Therefore, it is necessary to perform high-precision measurement and analysis of the component concentration at the outlet of the combustion chamber.

[0004] Aviation engines use aviation kerosene as fuel. The gas component concentrations produced under different operating conditions are different, but they all produce a variety of combustion products such as O2, CO, CO2, H2O, NOx, and UHC. The physical and chemical properties of the gas components vary greatly, so it is necessary to choose a reasonable detection technology. The gas analysis method is a method that directly measures the concentration of the components at the combustion chamber outlet by continuously measuring the gas composition at the combustion chamber outlet, and indirectly calculates performance parameters such as the oil-gas ratio, combustion efficiency, and gas temperature.

[0005] The current assembled gas analysis cabinets detect UHC, CO / CO2, O2, and NOx in gas, which are large in size and difficult to maintain. In addition, the existing gas analysis systems do not implement the standards well enough, such as the pipe insulation does not meet the standard requirements, the conversion efficiency of the NOx analyzer converter does not meet the standard requirements, and the calibration and inspection of the gas composition analyzer are not carried out according to the standard requirements, etc.

[0006] Mass spectrometry uses an ionization source to ionize gas samples to obtain gas-phase ions, and then uses a mass analyzer to separate and analyze the mass-to-charge ratio of gas-phase ions. Therefore, it is possible to detect the gas components at the outlet of the combustion chamber of an aircraft engine. The ionization source is one of the core components of the mass spectrometer and is closely related to the detection performance of the mass spectrometer.

[0007] The current mass spectrometry ionization sources have the following technical defects:

[0008] 1. The current mass spectrometry ionization source has difficulty in detecting samples with high ionization energy. For example, the publication number is "CN102479661B", and the invention name is "composite ionization source of vacuum ultraviolet photoionization and chemical ionization for mass spectrometry analysis". It can detect acetonitrile (12.2eV), chloroform (11.37eV) and acetic acid (11.65eV) with ionization energy higher than the photon energy of vacuum ultraviolet light (10.6eV). However, CO and CO2 in aircraft engine fuel gas have higher ionization energy, so this ionization source is not applicable.

[0009] 2. The current use of molecular beam ionization sources combined with synchrotron radiation sources has been used to conduct combustion kinetics experiments and model studies on single-chain aromatic hydrocarbons, aromatic hydrocarbons, butanol, cyclohexane and its monoalkyl derivatives, typical alkanes and cycloalkanes, which can achieve efficient ionization of components at the outlet of the combustion chamber of an aircraft engine. However, considering that the cost of synchrotron radiation sources is very high and the measurement environment requirements are very demanding, the current work is mainly focused on the study of the components of enol combustion intermediates and some important free radicals in low-pressure, laminar premixed flames in laboratory environments, which is still far from the test requirements under actual engine operating conditions.

[0010] 3. At present, an ionization source combining hard electron ionization and soft single photon ionization has been developed, and mineral diesel samples have been studied. For hard electron ionization, electrons with a kinetic energy of 70eV are emitted from the luminous tungsten filament, which can achieve the ionization of inorganic components with high ionization energy, but it will also cause organic matter with lower ionization energy to produce fragment ions, affecting the subsequent spectrum analysis. Secondly, hard electron ionization requires the use of long capillaries to limit the injection volume, so highly active species such as free radicals cannot be detected; for soft single photon ionization, 9.8eV soft photons are used to achieve the analysis of organic components. At the same time, complex timing control is required for the switching of hard electron ionization and soft single photon ionization during detection, and the single detection time is long and the efficiency is low. Summary of the invention

[0011] In order to solve at least one technical problem existing in the above-mentioned background technology, the present invention provides a mass spectrometry ionization source for online detection of the gas composition at the outlet of an aircraft engine combustion chamber, which injects samples in the form of a molecular beam, ensures the efficient transmission of stable components and active components in the gas, and realizes the efficient transmission of ions by combining a DC transmission electrode with a RF transmission electrode, thereby realizing full-spectrum online analysis of the gas composition at the outlet of an aircraft engine combustion chamber.

[0012] In order to achieve the above object, the present invention adopts the following technical solution:

[0013] A mass spectrometer ionization source for online detection of gas components at the outlet of an aircraft engine combustion chamber comprises an ionization source cavity and a radio frequency windowless discharge lamp, wherein a flat plate electrode, a cone hole electrode, a lamp holder electrode, a DC transmission electrode, a radio frequency transmission electrode and a differential electrode are sequentially arranged inside the ionization source cavity along the axial direction, and the multiple electrodes are parallel to each other and the central through hole is coaxially arranged;

[0014] A discharge gas inlet is provided on the ionization source cavity, one end of the radio frequency windowless discharge lamp is connected to the discharge gas inlet, and the other end extends into the interior of the lamp cap electrode;

[0015] The flat electrode, cone electrode, lamp cap electrode, DC transmission electrode, radio frequency transmission electrode and differential electrode are sequentially loaded with different voltages in the order of absolute voltage from high to low, forming an ion transmission channel in the axial direction.

[0016] As an implementation mode, the flat plate electrode, the conical hole electrode and the differential electrode are all plate-type electrodes with a conical protrusion at the center, and a through hole for ion transmission is processed in the transverse direction at the tip of the cone;

[0017] The lamp cap electrode is a cylindrical structure with a through hole at the center;

[0018] The DC transmission electrode and the RF transmission electrode are both plate-type structures with a central opening.

[0019] As an implementation mode, the through hole diameter of the flat electrode is 0.3-0.5 mm, the through hole diameter of the conical hole electrode is 1-2 mm, the through hole diameter of the differential electrode is 0.6-1.5 mm, and the conical hole angle is 40-50°.

[0020] As an embodiment, the ionization source also includes a discharge gas storage and a mass flow controller, the air inlet end of the radio frequency windowless discharge lamp is connected to the air outlet end of the mass flow controller, and the air inlet end of the mass flow controller is connected to the discharge gas storage.

[0021] As an implementation manner, the discharge gas stored in the discharge gas storage device is helium, neon or argon.

[0022] As an implementation mode, the area between the flat plate electrode and the conical hole electrode constitutes a gas buffer zone; the area between the conical hole electrode and the DC transmission electrode constitutes a gas component ionization zone.

[0023] As an embodiment, the ionization source further includes a vacuum pump group, the vacuum pump group includes an oil pump and a dry pump, the oil pump is connected to the gas buffer zone, and the dry pump is connected to the gas component ionization zone.

[0024] As an implementation mode, the discharge tube in the radio frequency windowless discharge lamp is made of quartz material, a high-frequency coil is wound around the discharge tube, a high-frequency voltage is applied to the high-frequency coil, and the discharge gas discharges in the discharge tube to generate photons and metastable atoms / molecules.

[0025] As an implementation mode, the RF transmission electrode adopts a segmented quadrupole, which is composed of a plurality of segmented electrode rings, which are fixed on four insulating rods placed equidistantly, and each electrode ring is isolated by insulating rings of the same size. A DC voltage is applied to the electrode ring of each pole through a voltage-dividing resistor to form a DC electric field along the axial direction, and capacitors of the same capacitance are connected to apply RF voltage.

[0026] As an implementation manner, an ion outlet is provided on the differential electrode, and the ion outlet is connected to a mass spectrometer.

[0027] The beneficial effects of the present invention are:

[0028] 1. The conical hole electrode of the present invention allows the gas to be sampled in the form of a molecular beam, ensuring the efficient transmission of stable components and active components in the gas, and realizes efficient transmission of ions by combining a DC transmission electrode with a radio frequency transmission electrode, which can realize full-spectrum online analysis of the gas components at the outlet of the aircraft engine combustion chamber.

[0029] 2. The present invention changes the sampling mode of online mass spectrometry from the commonly used capillary sampling to molecular beam sampling. The molecular beam sampling form can prevent the active components in the high-temperature fuel gas from further reacting. Therefore, it can not only detect stable inorganic components in the fuel gas, but also realize the detection of various free radicals, intermediates and other highly reactive species. It can be applied to the detection of real aircraft engine combustion chamber outlet fuel gas, expanding the application range of mass spectrometers.

[0030] 3. The present invention uses a radio frequency windowless lamp as a light source. The design of the radio frequency windowless discharge lamp without light window is not affected by the harsh environment of the aircraft engine combustion chamber, and there is no light window pollution problem, so it can be used for a long time. Helium is used as the discharge gas to generate photons with energy of 21.2eV and metastable atoms / molecules of helium, and a double ionization process of VUV photoionization + Penning ionization is generated inside the ionization source, thereby realizing the full spectrum online analysis of inorganic and organic components in the fuel gas at the outlet of the aircraft engine combustion chamber.

[0031] 4. The windowless radio frequency lamp of the present invention is relatively small in size and can be placed inside the ionization source cavity, which not only integrates the ionization source but also obtains a higher luminous flux.

[0032] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 It is a schematic diagram of the structure of an online mass spectrometer ionization source for combustion chamber outlet gas of an aircraft engine provided by an embodiment of the present invention;

[0035] Figure 2 This is a mass spectrum of CO detected by an online mass spectrometer ionization source of the combustion chamber outlet gas of an aircraft engine provided by an embodiment of the present invention;

[0036] Figure 3 It is a mass spectrum of CO2 detected by an online mass spectrometer ionization source of the combustion chamber outlet gas of an aircraft engine provided by an embodiment of the present invention;

[0037] Figure 4 This is a mass spectrum of H2O detected by an online mass spectrometer ionization source of the combustion chamber outlet gas of an aircraft engine provided by an embodiment of the present invention;

[0038] Figure 5 It is a mass spectrum of NO detected by online mass spectrometry ionization source of combustion gas at the outlet of an aircraft engine combustion chamber provided by an embodiment of the present invention;

[0039] Figure 6 It is a mass spectrum of NO2 detected by an online mass spectrometry ionization source of the combustion chamber outlet gas of an aircraft engine provided by an embodiment of the present invention;

[0040] Figure 7 This is a mass spectrum of O2 detected by an online mass spectrometer ionization source of the combustion chamber outlet gas of an aircraft engine provided by an embodiment of the present invention.

[0041] Figure 8 It is a mass spectrum of UHC detected by online mass spectrometry ionization source of combustion gas at the outlet of an aircraft engine combustion chamber provided by an embodiment of the present invention.

[0042] Among them, 1. Flat plate electrode; 2. Conical hole electrode; 3. Lamp holder electrode; 4. DC transmission electrode; 5. RF transmission electrode; 6. Differential electrode; 7. Oil pump; 8. RF windowless discharge lamp; 9. Mass flow controller 9; 10. Discharge gas storage; 11. Dry pump. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0044] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0045] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0046] In the present invention, terms such as "connected" and "connection" should be understood in a broad sense, indicating that the connection can be fixed, integral or detachable; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meaning of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0047] As introduced in the background technology, the current flow field environment at the outlet of the aircraft engine combustion chamber is harsh. In order to accurately measure the concentration of the components at the outlet of the combustion chamber, it is of great significance to develop new measurement technologies. The existing gas analysis technology uses multiple imported instruments to detect the concentration of gas components, and the source of error between different technologies is difficult to trace; although the online mass spectrometry ionization source based on the synchrotron radiation light source and the ionization source combining hard electron ionization and soft single photon ionization can realize the measurement of the concentration of gas components at the outlet of the aircraft engine combustion chamber, it is difficult to apply it to the field test of the measurement of the concentration of components at the outlet of the actual aircraft engine combustion chamber. In order to solve the above technical problems, the present invention proposes an online detection mass spectrometry ionization source for the composition of the combustion chamber outlet of an aircraft engine, comprising an ionization source cavity and a radio frequency windowless discharge lamp, wherein a flat electrode, a conical hole electrode, a lamp holder electrode, a DC transmission electrode, a radio frequency transmission electrode and a differential electrode are sequentially arranged inside the ionization source cavity along the axial direction, and a discharge gas inlet is arranged on the ionization source cavity, one end of the radio frequency windowless discharge lamp is connected to the discharge gas inlet, and the other end extends into the lamp holder electrode; the conical hole electrode enables the fuel gas to be sampled in the form of a molecular beam, thereby ensuring the efficient transmission of stable components and active components in the fuel gas, and realizing the efficient transmission of ions by combining the DC transmission electrode with the radio frequency transmission electrode, thereby realizing the full spectrum online analysis of the fuel gas composition at the combustion chamber outlet of an aircraft engine.

[0048] like Figure 1 As shown, this embodiment provides an online mass spectrometry ionization source for full spectrum analysis of combustion gas components at the outlet of an aircraft engine combustion chamber, comprising an ionization source cavity and a radio frequency windowless discharge lamp 8;

[0049] A flat plate electrode 1, a cone hole electrode 2, a lamp holder electrode 3, a DC transmission electrode 4, a radio frequency transmission electrode 5 and a differential electrode 6 are sequentially arranged inside the ionization source cavity along the axial direction, and the flat plate electrode 1, the cone hole electrode 2, the lamp holder electrode 3, the DC transmission electrode 4, the radio frequency transmission electrode 5 and the differential electrode 6 are parallel to each other, and the central through hole is coaxially arranged;

[0050] A discharge gas inlet is provided on the ionization source cavity, one end of the radio frequency windowless discharge lamp 8 is connected to the discharge gas inlet, and the other end extends into the interior of the lamp cap electrode 3;

[0051] The flat electrode 1, the conical hole electrode 2, the lamp holder electrode 3, the DC transmission electrode 4, the RF transmission electrode 5 and the differential electrode 6 are loaded with different voltages in order from high to low absolute values ​​of the voltages, forming an ion transmission channel in the axial direction.

[0052] The present invention changes the sampling mode of online mass spectrometry from the commonly used capillary sampling to molecular beam sampling. The molecular beam sampling form can prevent the active components in the high-temperature fuel gas from further reacting, and can only detect the stable inorganic components in the fuel gas. It can also realize the detection of highly reactive species such as various free radicals and intermediates, and can be applied to the detection of fuel gas at the outlet of a real aircraft engine combustion chamber. The efficient transmission of ions is realized by combining a DC transmission electrode with a radio frequency transmission electrode, and the full-spectrum online analysis of the fuel gas components at the outlet of the aircraft engine combustion chamber can be realized, thereby expanding the application scope of the mass spectrometer.

[0053] In this embodiment, the flat plate electrode 1, the conical hole electrode 2, and the differential electrode 6 are all plate structures with ion holes, and the shape of the ion holes is a truncated cone; the DC transmission electrode 4 and the RF transmission electrode 5 are both plate structures with a central opening; the lamp holder electrode 3 is a cylindrical structure with a central opening.

[0054] Furthermore, the flat electrode 1, the conical hole electrode 2, and the differential electrode 6 are plate-type electrodes with a conical protrusion at the center, and the tip of the cone is processed with a through hole for ion transmission in the transverse direction. Preferably, the through hole diameter of the flat electrode 1 is 0.3-0.5 mm, the through hole diameter of the conical hole electrode 2 is 1-2 mm, the through hole diameter of the differential electrode 6 is 0.6-1.5 mm, and the angle of the conical hole is 40-50°.

[0055] The DC transmission electrode 4 is a circular plate structure with a through hole at the center, and the diameter of the through hole is preferably 6-8 mm;

[0056] The lamp cap electrode 3 is a cylindrical structure with a through hole at the center, and the diameter of the through hole is preferably 10-15 mm; the lamp cap electrode ring surface is processed with a through hole to allow the discharge lamp to extend into, and the diameter of the through hole is preferably 6-8 mm.

[0057] The radio frequency windowless discharge lamp 8 is placed inside the ionization source cavity, perpendicular to the axis direction of the injection port, and the discharge lamp tube of the radio frequency windowless discharge lamp 8 extends into the lamp holder electrode 3.

[0058] The present invention uses a radio frequency windowless lamp as a light source. The radio frequency windowless discharge lamp is not affected by the harsh environment of the aircraft engine combustion chamber, and has no light window pollution problem, so it can be used for a long time. At the same time, the volume of the radio frequency windowless discharge lamp is reduced and integrated inside the ionization source cavity, so that the ionization source is integrated and a higher light flux is obtained.

[0059] Furthermore, the ionization source further includes a discharge gas storage 10 and a mass flow controller 9, the air inlet end of the radio frequency windowless discharge lamp 8 is connected to the air outlet end of the mass flow controller 9, and the air inlet end of the mass flow controller 9 is connected to the discharge gas storage 10. The discharge gas storage 10 provides discharge gas for the radio frequency windowless discharge lamp 8, and the mass flow meter 9 controls the flow of the discharge gas.

[0060] In this embodiment, the discharge gas stored in the discharge gas storage 10 is helium, neon or argon, etc., and the preferred flow rate is 10-100 mL / min.

[0061] For example, the present invention uses a radio frequency windowless lamp as the light source of an online mass spectrometer ionization source and adopts helium as the discharge gas to generate photons with an energy of 21.2 eV and metastable atoms / molecules of helium. Therefore, a double ionization process of VUV photoionization + Penning ionization is generated inside the ionization source, which can completely ionize the gas components at the outlet of the aircraft engine combustion chamber.

[0062] In this embodiment, the area between the flat electrode 1 and the conical electrode 2 constitutes a gas buffer zone; the area between the conical electrode 2 and the DC transmission electrode 4 constitutes a gas component ionization zone.

[0063] The ionization source further includes a vacuum pump group, which includes an oil pump 7 and a dry pump 11. The oil pump 7 is connected to the gas buffer zone, and the dry pump 11 is connected to the gas component ionization zone.

[0064] The gas buffer area is maintained in vacuum by an oil pump 7, and the gas component ionization area is maintained in vacuum by a dry pump 11;

[0065] Preferably, the pumping speed of the oil pump is 7.6 L / s, the pumping speed of the dry pump is 3.5 L / s, the vacuum degree of the gas buffer zone is 800-2000 Pa, and the vacuum degree of the gas component ionization zone is 50-200 Pa.

[0066] In this embodiment, the discharge tube of the radio frequency windowless discharge lamp is made of quartz, and a high-frequency coil is wound around the discharge tube. A high-frequency voltage is applied to the high-frequency coil, and the discharge gas discharges in the discharge tube to generate photons and metastable atoms / molecules. The preferred radio frequency frequency is 133MHz, and the peak-to-peak value of the radio frequency voltage is 35V.

[0067] The differential electrode 6 is provided with an ion outlet, and the ion outlet is connected to the mass spectrometer. Specifically, the ion outlet is connected to the mass spectrometer, that is, the ions obtained by ionizing the gas sample in the ionization source cavity are directly introduced into the mass spectrometer through the ion outlet on the differential electrode 6;

[0068] The RF transmission electrode 5 is a segmented quadrupole, which is composed of a plurality of segmented electrode rings, which are fixed on four insulating rods placed equidistantly, and each electrode ring is isolated by insulating rings of the same size. A DC voltage is applied to the electrode ring of each pole through a voltage-dividing resistor to form a DC electric field along the axial direction, and capacitors of the same capacitance are connected to apply RF voltage.

[0069] Preferably, the insulating rod is made of polyetheretherketone or ceramic.

[0070] Preferably, the dimensions of the segment quadrupole ring are: inner diameter 6 mm, outer diameter 11.5 mm, height 8.5 mm, and the dimensions of the polyetheretherketone ring are: inner diameter 6 mm, outer diameter 11.5 mm, height 0.5 mm.

[0071] Preferably, the resistance of the voltage divider resistor is 10MΩ; the capacitance is 100nF, the frequency of the radio frequency voltage is 1.8MHz, and the peak-to-peak value is 300V.

[0072] In this embodiment, the mass spectrometer is a time-of-flight mass spectrometer, and a single detection is at the microsecond level, so the transient change process inside the combustion chamber of the aircraft engine can be observed.

[0073] Standard gas analysis is performed on the combustion chamber outlet gas components O2, CO, CO2, H2O, NOx, and UHC of aircraft engines. Figure 2-Figure 8 The mass spectra of CO, CO2, H2O, NO, NO2, O2, and UHC obtained by the online mass spectrometry ionization source described in this embodiment. Among them, the characteristic peaks of CO and H2O are [M+H] + The characteristic peaks of the other gas products are all molecular ion peaks [M] + .

[0074] The existing composite ionization source of vacuum ultraviolet photoionization and chemical ionization relies on vacuum ultraviolet light to obtain high-concentration reagent ions. The sample and the reagent ions undergo a chemical reaction in the reaction zone and are ionized. When O2 is used as the reagent gas, only substances with a maximum of 12.07eV can be detected. The components of the combustion gas at the outlet of the aircraft engine combustion chamber are complex, and the ionization energies of CO (14.01eV) and CO2 (13.78eV) are higher than 12.07eV. Samples with higher ionization energies such as CO (14.01eV) and CO2 (13.78eV) cannot be detected. Therefore, this ionization source cannot complete the detection of the above-mentioned high ionization energy substances and is not suitable for the detection of the components of the combustion gas at the outlet of the aircraft engine combustion chamber of the present invention.

[0075] In the on-line mass spectrometry ionization source for the combustion chamber outlet gas of an aircraft engine of the present invention, the combustion chamber outlet gas is sampled in the form of a molecular beam, thereby ensuring efficient transmission of stable components and active components in the combustion chamber gas; helium is used as the discharge gas to generate photons with an energy of 21.2 eV and metastable atoms / molecules of helium, and a double ionization process of VUV photoionization + Penning ionization is generated inside the ionization source, thereby achieving complete ionization of the combustion chamber outlet gas components of the aircraft engine, and has good practical application value when used in conjunction with a mass spectrometer.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mass spectrometer ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber, characterized in that: It comprises an ionization source cavity and a radio frequency windowless discharge lamp (8), wherein a flat plate electrode (1), a cone hole electrode (2), a lamp holder electrode (3), a DC transmission electrode (4), a radio frequency transmission electrode (5) and a differential electrode (6) are sequentially arranged inside the ionization source cavity along the axial direction, and the plurality of electrodes are parallel to each other and the central through hole is coaxially arranged; A discharge gas inlet is provided on the ionization source cavity, one end of the radio frequency windowless discharge lamp (8) is connected to the discharge gas inlet, and the other end extends into the interior of the lamp cap electrode (3); The flat plate electrode (1), the conical hole electrode (2), the lamp cap electrode (3), the DC transmission electrode (4), the radio frequency transmission electrode (5) and the differential electrode (6) are sequentially loaded with different voltages in the order of the absolute value of the voltage from high to low, thereby forming an ion transmission channel in the axial direction.

2. A mass spectrometry ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber as claimed in claim 1, characterized in that: The flat plate electrode (1), the conical hole electrode (2) and the differential electrode (6) are all plate-type electrodes with a conical protrusion at the center, and a through hole for ion transmission is processed along the lateral direction at the tip of the cone; The lamp cap electrode (3) is a cylindrical structure with a through hole at the center; The DC transmission electrode (4) and the radio frequency transmission electrode (5) are both plate-type structures with a central opening.

3. A mass spectrometry ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber as claimed in claim 2, characterized in that: The through hole diameter of the flat electrode (1) is 0.3-0.5 mm, the through hole diameter of the conical hole electrode (2) is 1-2 mm, the through hole diameter of the differential electrode (6) is 0.6-1.5 mm, and the conical hole angle is 40-50°.

4. A mass spectrometry ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber as claimed in claim 1, characterized in that: The ionization source further comprises a discharge gas storage (10) and a mass flow controller (9), the air inlet end of the radio frequency windowless discharge lamp (8) is connected to the air outlet end of the mass flow controller (9), and the air inlet end of the mass flow controller (9) is connected to the discharge gas storage (10).

5. A mass spectrometry ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber as claimed in claim 3, characterized in that: The discharge gas stored in the discharge gas storage (10) is helium, neon or argon.

6. A mass spectrometry ionization source for online detection of combustion gas components at the outlet of an aircraft engine combustion chamber as claimed in claim 1, characterized in that: The area between the flat plate electrode (1) and the conical hole electrode (2) constitutes a gas buffer zone; the area between the conical hole electrode (2) and the direct current transmission electrode (4) constitutes a gas component ionization zone.

7. A mass spectrometry ionization source for online detection of combustion gas components at the outlet of an aircraft engine combustion chamber as claimed in claim 6, characterized in that: The ionization source further comprises a vacuum pump group, the vacuum pump group comprises an oil pump (7) and a dry pump (11), the oil pump (7) is connected to the gas buffer zone, and the dry pump (11) is connected to the gas component ionization zone.

8. The mass spectrometry ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber as claimed in claim 1, characterized in that: The discharge tube in the radio frequency windowless discharge lamp (8) is made of quartz material, and a high-frequency coil is wound around the discharge tube. A high-frequency voltage is applied to the high-frequency coil, and the discharge gas discharges in the discharge tube to generate photons and metastable atoms / molecules.

9. A mass spectrometry ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber as claimed in claim 1, characterized in that: An ion outlet is arranged on the differential electrode (6), and the ion outlet is connected to a mass spectrometer.

10. The mass spectrometry ionization source for online detection of gas composition at the outlet of an aircraft engine combustion chamber as claimed in claim 1, characterized in that: The radio frequency transmission electrode (5) adopts a segment quadrupole, which is composed of a plurality of segment electrode rings, the electrode rings are fixed on four insulating rods placed at equal distances, and each electrode ring is isolated by insulating rings of the same size. A DC voltage is applied to the electrode ring of each pole through a voltage-dividing resistor to form a DC electric field along the axis direction, and capacitors of the same capacitance are connected to apply a radio frequency voltage.

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