Aero-engine combustion chamber outlet fuel gas temperature mass spectrum measurement system and method

Abstract

The invention belongs to the field of gas temperature measurement, provides a mass spectrum measurement system and method for gas temperature at an outlet of a combustion chamber of an aero-engine, solves the problem of inaccurate temperature measurement in the prior art, and adopts the technical scheme that the mass spectrum measurement system comprises a molecular beam ionization source, a mass spectrometer and a temperature calculation module; the molecular beam ionization source comprises a molecular beam ionization source cavity, a plate electrode, a taper hole electrode, a transmission electrode set and a differential electrode set are arranged in the molecular beam ionization source cavity, a fuel gas molecular beam forming area is formed between the plate electrode and the taper hole electrode, and an ionization area is formed between the taper hole electrode and the transmission electrode set. A transmission area is formed between the transmission electrode group and the differential electrode group, and the fuel gas molecular beam forming area, the ionization area and the transmission area are communicated and then connected to a mass spectrometer to measure and obtain the concentration of each stable component and active component of the outlet fuel gas; the temperature calculation module is connected with the mass spectrometer and is configured to calculate the temperature of the outlet gas according to the concentration of each stable component and active component of the outlet gas; and the precision of temperature back calculation is improved.

Description

Technical Field

[0001] The invention belongs to the field of gas temperature measurement, and in particular relates to a mass spectrometry measurement system and method for gas temperature 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 combustion chamber outlet flow field parameters directly reflect the quality of the combustion organization in the combustion chamber. By analyzing the combustion chamber outlet flow field, the flow and combustion conditions in the combustion chamber can be inferred and verified, thereby further deepening the understanding of the combustion flow mechanism in the combustion chamber. The distribution of the combustion chamber outlet temperature field plays a decisive role in the durability and life of the turbine. The uneven outlet temperature distribution will cause differences in the thermal load borne by the turbine blades, which will lead to the generation of thermal stress and reduce the service life of the turbine.

[0004] Thermocouple technology developed earlier and is relatively mature, and is widely used in the field of high-temperature measurement. At present, the long-term use temperature of the mature double platinum-rhodium thermocouple is 1600°C, and the short-term use temperature is 1800°C, which can no longer meet the needs of ultra-high temperature measurement.

[0005] Gas analysis technology requires the use of multiple component measuring instruments to analyze and measure the gas composition at the combustion chamber outlet, and calculate the gas temperature based on the gas component concentration. The measurement errors between multiple measuring instruments are large, the overall size of the instrument is large, and the price and maintenance costs are high. The interior of the combustion chamber is a high-pressure system, and a complex pretreatment system is required for the gas to reach the gas analyzer from the interior of the combustion chamber, including pressure reduction, gas extraction, and other treatments. In addition, due to its long gas transmission pipeline, the gas analysis system can only detect stable species in the gas, and the time resolution is high (20-30s), so it is impossible to obtain the component concentration information of highly active species, which makes the average relative error of the temperature calculated by the gas analysis method at ultra-high temperatures (above 1800K) about 10%. Summary of the invention

[0006] In order to solve at least one technical problem existing in the above-mentioned background technology, the first aspect of the present invention provides a mass spectrometry measurement system for the temperature of the combustion chamber outlet gas of an aircraft engine, which allows the high-temperature fuel gas to be sampled in the form of a molecular beam to prevent the active components in the fuel gas from further reacting. On this basis, the principle of conservation of energy is adopted to invert the temperature of the fuel gas according to the concentration of each component in the fuel gas, thereby improving the accuracy of temperature inversion. When connected to a mass spectrometer, the single detection time can reach the microsecond level, and the instantaneous changes inside the combustion chamber of the aircraft engine can be obtained, thereby expanding the application scope of the mass spectrometer and having good practical application value for the development of aircraft engines.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A mass spectrometry system for measuring the temperature of combustion gas at the outlet of an aircraft engine combustion chamber, comprising a molecular beam ionization source, a mass spectrometer and a temperature calculation module;

[0009] The molecular beam ionization source comprises a molecular beam ionization source cavity, in which a flat plate electrode, a conical hole electrode, a transmission electrode group and a differential electrode group are arranged, a gas molecular beam forming region is formed between the flat plate electrode and the conical hole electrode, an ionization region is formed between the conical hole electrode and the transmission electrode group, and a transmission region is formed between the transmission electrode group and the differential electrode group. The gas molecular beam forming region, the ionization region and the transmission region are connected to a mass spectrometer to measure the concentrations of various stable components and active components of the outlet gas;

[0010] The temperature calculation module is connected to the mass spectrometer and is configured to calculate the temperature of the outlet gas according to the concentrations of the stable components and active components of the outlet gas.

[0011] As an embodiment, a radio frequency windowless discharge lamp and a lamp holder electrode are also provided in the molecular beam ionization source chamber, a discharge lamp tube is provided in the radio frequency windowless discharge lamp, a gas inlet is provided on the molecular beam ionization source chamber, one end of the discharge lamp tube is connected to the gas inlet, and the other end extends into the interior of the lamp holder electrode.

[0012] As an embodiment, the system further includes a discharge gas storage device and a mass flow controller, the air inlet end of the RF 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 device.

[0013] As an embodiment, the transmission electrode group includes a DC transmission electrode and a RF transmission electrode, the differential electrode group includes a first differential electrode and a second differential electrode, an ionization zone is formed between the conical hole electrode and the DC transmission electrode, and a transmission zone is formed between the DC transmission electrode, the RF transmission electrode, the first differential electrode and the second differential electrode.

[0014] As an implementation mode, the flat plate electrode, the conical hole electrode, the lamp holder electrode, the DC transmission electrode, the RF transmission electrode, the first differential electrode and the second differential electrode are parallel to each other, and the through holes are coaxial.

[0015] As an implementation mode, the DC transmission electrode and the RF transmission electrode are both plate-type structures with a central opening.

[0016] As an implementation mode, the vacuum degrees of the fuel gas molecular beam forming region, the ionization region and the transmission region decrease in sequence.

[0017] As an implementation mode, a slit is further provided in the molecular beam ionization source cavity, a shaping region is formed between the slit and the second differential electrode, and a mass spectrometer is provided at the exit of the shaping region.

[0018] As an embodiment, the measurement system includes an oil pump, a dry pump and multiple molecular pumps, the oil pump is connected to the gas molecular beam forming area, the dry pump is connected to the ionization area, the molecular pumps include a first molecular pump, a second molecular pump and a third molecular pump, the dry pump also serves as a pre-pump for multiple molecular pumps, the first molecular pump is connected to the transmission area, the second molecular pump is connected to the shaping area, and the third molecular pump is connected to a mass spectrometer.

[0019] In order to solve the above problems, the second aspect of the present invention provides a mass spectrometry method for measuring the temperature of the combustion chamber outlet gas of an aircraft engine, which allows the high-temperature fuel gas to be sampled in the form of a molecular beam to prevent the active components in the fuel gas from further reacting. On this basis, the principle of conservation of energy is adopted to invert the temperature of the fuel gas according to the concentration of each component in the fuel gas, thereby improving the accuracy of temperature inversion. When connected to a mass spectrometer, the single detection time can reach microseconds, and the instantaneous changes inside the combustion chamber of the aircraft engine can be obtained, thereby expanding the application range of the mass spectrometer and having good practical application value for the development of aircraft engines.

[0020] In order to achieve the above object, the present invention adopts the following technical solution:

[0021] A method for measuring the gas temperature at the outlet of an aircraft engine combustion chamber, based on the mass spectrometry measurement system for the gas temperature at the outlet of an aircraft engine combustion chamber described in the first aspect, comprises the following steps:

[0022] Receive various stable and active components of the fuel gas at the outlet of the combustion chamber of the aviation gas engine;

[0023] Substituting the signal intensities of various stable components and active components obtained by transformation into the quantitative curve to obtain the concentrations of various stable components and active components; wherein the quantitative curve is drawn according to the signal intensities of various stable components and active components at different concentrations of the combustion chamber outlet gas of the aircraft engine;

[0024] Fitting the enthalpy-temperature curves of various stable and active components at the inlet and outlet of the aviation gas engine combustion chamber;

[0025] Based on the law of conservation of energy, the temperature of the outlet gas is calculated by combining the concentrations of various stable and active components and the enthalpy-temperature curve.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention adopts a molecular beam ionization source to inject the fuel gas in the form of a molecular beam, thereby ensuring the efficient transmission of stable components and active components in the fuel gas; the stable components and active components in the fuel gas are efficiently ionized and transmitted to the mass analyzer for detection, and the energy conservation principle is adopted to invert the temperature of the fuel gas according to the concentration of each component in the fuel gas, thereby improving the accuracy of temperature backcalculation.

[0028] 2. The present invention adopts a radio frequency windowless discharge 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. In addition, the radio frequency windowless discharge lamp can obtain high-energy photons and metastable molecular atoms, so as to achieve full ionization of the gas components at the outlet of the aircraft engine combustion chamber.

[0029] 3. The present invention introduces online mass spectrometry technology into the field of measuring the temperature of the gas at the outlet of the combustion chamber of an aircraft engine, and applies the temperature calculation method of the gas analysis method to the online mass spectrometry system, thereby broadening the application field of the online mass spectrometry. The present invention uses an online mass spectrometer to detect the concentration of the gas components, with a small relative error and without the need for a complicated concentration correction process.

[0030] 4. The present invention adopts a time-of-flight mass spectrometer as a gas detection instrument. A single instrument can complete the detection of stable species and active species in the fuel gas at the outlet of the aircraft engine combustion chamber. When calculating the fuel gas temperature based on the fuel gas component concentration, in addition to considering free radicals such as N, O, H, OH, etc., the concentration of hydrocarbon free radicals in UHC is also brought into the calculation formula, thereby improving the accuracy of the fuel gas temperature calculation.

[0031] 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

[0032] 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.

[0033] Figure 1 It is a schematic diagram of the structure of a mass spectrometer measurement system for combustion chamber outlet gas temperature of an aircraft engine provided by an embodiment of the present invention;

[0034] Figure 2 The present invention is a flowchart of a method for measuring the combustion chamber outlet gas temperature of an aircraft engine provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0036] 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.

[0037] 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.

[0038] As introduced in the background technology, the hot spot temperature of the current aircraft engine combustion chamber has reached 2300K. In order to break through the design of the new generation of high-performance aircraft engine combustion chambers, it is of great significance to develop new high-temperature measurement technology. The existing thermocouple technology can no longer meet the test requirements under the high temperature condition of 2300K; the gas analysis technology cannot detect highly active substances in the gas, and the reverse temperature has a deviation of about 10%. In order to solve the above technical problems, the present invention proposes a mass spectrometry measurement system and method for the gas temperature at the outlet of the aircraft engine combustion chamber, including a molecular beam ionization source and a mass spectrometer. The molecular beam ionization source injects the gas at the outlet of the aircraft engine combustion chamber in the form of a molecular beam, ensuring the efficient transmission of stable components and active components in the gas; the mass spectrometer adopts the principle of energy conservation to invert the temperature of the gas according to the concentration of each component in the gas. The present invention can realize the online detection of the concentration of the gas component at the outlet of the aircraft engine combustion chamber, and can invert the temperature of the gas according to the component concentration value. The inversion temperature has a higher accuracy and has good practical application value.

[0039] Embodiment 1

[0040] like Figure 1 As shown, this embodiment provides a mass spectrometry system for measuring the temperature of combustion chamber outlet gas of an aircraft engine, including a molecular beam ionization source, a mass spectrometer and a temperature calculation module;

[0041] The molecular beam ionization source comprises a molecular beam ionization source cavity, wherein the molecular beam ionization source cavity is provided with a flat plate electrode 1, a conical hole electrode 2, a transmission electrode group and a differential electrode group, a gas molecular beam forming region is formed between the flat plate electrode 1 and the conical hole electrode, an ionization region is formed between the conical hole electrode 2 and the transmission electrode group, and a transmission region is formed between the transmission electrode group and the differential electrode group, and the gas molecular beam forming region, the ionization region and the transmission region are connected to a mass spectrometer to measure the concentrations of various stable components and active components of the outlet gas;

[0042] The temperature calculation module is connected to the mass spectrometer and is configured to calculate the temperature of the outlet gas according to the concentration of each stable component and active component of the outlet gas. Through the above scheme, the molecular beam ionization source can inject high-temperature gas in the form of a molecular beam to prevent the active components in the gas from further reacting. It can not only realize the efficient detection of stable inorganic components in the gas, but also realize the detection of various free radicals, intermediates and other highly reactive species, expanding the application range of the mass spectrometer.

[0043] A radio frequency windowless discharge lamp 8 and a lamp holder electrode 3 are also arranged in the molecular beam ionization source chamber. A discharge lamp tube is arranged in the radio frequency windowless discharge lamp 8. A gas inlet is arranged on the molecular beam ionization source chamber. One end of the discharge lamp tube is connected to the gas inlet, and the other end extends into the lamp holder electrode 3.

[0044] The radio frequency windowless discharge lamp is used as the 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. In addition, the radio frequency windowless discharge lamp can obtain high-energy photons and metastable molecular atoms, so as to achieve full ionization of the gas components at the outlet of the aircraft engine combustion chamber.

[0045] The transmission electrode group includes a DC transmission electrode 4 and a RF transmission electrode 5, and the differential electrode group includes a first differential electrode 6 and a second differential electrode 11;

[0046] In this embodiment, the DC transmission electrode 4 and the RF transmission electrode 5 are both plate-type structures with a central opening.

[0047] In this embodiment, the molecular beam ionization source cavity is a closed hollow chamber, and the flat plate electrode 1, the conical hole electrode 2, the lamp holder electrode 3, the DC transmission electrode 4, the radio frequency transmission electrode 5, the first differential electrode 6 and the second differential electrode 11 are sequentially arranged in the molecular beam ionization source cavity, and the multiple electrodes are parallel to each other and the central through hole is coaxially arranged;

[0048] Furthermore, a radio frequency windowless discharge lamp 8 and a lamp holder electrode 3 are also arranged in the molecular beam ionization source chamber. The radio frequency windowless discharge lamp 8 is perpendicular to the axis direction of the injection port and has a built-in discharge lamp tube. A gas injection port is arranged on the molecular beam ionization source chamber. One end of the discharge lamp tube is connected to the gas injection port, and the other end extends into the lamp holder electrode 3.

[0049] The system further includes a discharge gas storage 10 and a mass flow controller 9, wherein the gas inlet end of the radio frequency windowless discharge lamp 8 is connected to the gas outlet end of the mass flow controller 9, and the gas 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 controller 9 controls the flow rate of the discharge gas.

[0050] In this embodiment, the discharge gas in the discharge gas storage 10 is helium, neon, argon, etc., and the flow rate is controlled by a mass flow controller 9, and the preferred flow rate is 10-100 mL / min.

[0051] The system forms a five-stage vacuum differential, including a buffer zone, an ionization zone, a transmission zone, a shaping zone, and a mass analyzer zone.

[0052] The buffer zone is the area between the flat electrode 1 and the conical electrode 2; the ionization zone is the area between the conical electrode 2 and the DC transmission electrode 4; the transmission zone is the area 11 between the DC transmission electrode 4 and the second differential electrode; the second differential electrode 11 is arranged between the shaping zone and the transmission zone, a slit 12 is arranged behind the shaping zone, and the mass analyzer zone is arranged behind the shaping zone.

[0053] The vacuum degrees of the buffer zone, ionization zone, transmission zone, shaping zone, and mass analyzer zone decrease in sequence; preferably, the vacuum degree of the buffer zone is 800-3000Pa, the vacuum degree of the ionization zone is 50-200Pa, the vacuum degree of the transmission zone is 0.1-10Pa, the vacuum degree of the shaping zone is 10 -3 Pa, the vacuum degree of the mass analyzer area is 10 -5 Pa.

[0054] The buffer area is maintained in vacuum by an oil pump, the ionization area is maintained in vacuum by a dry pump, and the transmission area, shaping area, and mass analyzer area are maintained in vacuum by a plurality of molecular pumps with different pumping speeds;

[0055] The molecular pump comprises a first molecular pump 14, a second molecular pump 15 and a third molecular pump 16. The dry pump 13 simultaneously serves as a pre-stage pump for a plurality of molecular pumps. The first molecular pump (14) is connected to a transmission area, the second molecular pump (15) is connected to a shaping area, and the third molecular pump (16) is connected to a mass spectrometer.

[0056] The dry pump also serves as the front pump of the molecular pump. Preferably, the pumping speed of the oil pump is 7.6L / s, the pumping speed of the dry pump is 3.5L / s, the pumping speed of the first molecular pump is 40L / s, the pumping speed of the second molecular pump is 200L / s, and the pumping speed of the second molecular pump is 250L / s.

[0057] In this embodiment, the mass spectrometer is a time-of-flight mass spectrometer, specifically including a time-of-flight mass analyzer; ions of each component will generate voltage after reaching the detector, and the data acquisition card will convert this voltage signal into signal intensity.

[0058] Connected to a time-of-flight mass spectrometer, the single detection time can reach microseconds, which can obtain the instantaneous changes inside the combustion chamber of an aircraft engine, expanding the application range of the mass spectrometer and having good practical application value for the development of aircraft engines.

[0059] The specific temperature measurement principle is:

[0060] Receive various stable and active components of the fuel gas at the outlet of the combustion chamber of the aviation gas engine;

[0061] Substituting the signal intensities of various stable components and active components obtained by transformation into the quantitative curve to obtain the concentrations of various stable components and active components; wherein the quantitative curve is drawn according to the signal intensities of various stable components and active components at different concentrations of the combustion chamber outlet gas of the aircraft engine;

[0062] Fitting the enthalpy-temperature curves of various stable and active components at the inlet and outlet of the aviation gas engine combustion chamber;

[0063] Based on the law of conservation of energy, the temperature of the outlet gas is calculated by combining the concentrations of various stable and active components and the enthalpy-temperature curve.

[0064] The present invention introduces online mass spectrometry technology into the field of measuring the temperature of the combustion chamber outlet of an aircraft engine, applies the temperature calculation method of the gas analysis method to the online mass spectrometry system, and broadens the application field of the online mass spectrometry; the present invention uses an online mass spectrometer to detect the concentration of the gas components, with a small relative error and without the need for a complicated concentration correction process.

[0065] Embodiment 2

[0066] like Figure 2 As shown, this embodiment provides a method for measuring the gas temperature at the outlet of an aircraft engine combustion chamber by mass spectrometry, based on the gas temperature at the outlet of an aircraft engine combustion chamber mass spectrometry system of Embodiment 1, comprising the following steps:

[0067] Step 1: receiving various stable components and active components of the fuel gas at the outlet of the combustion chamber of the aviation gas engine;

[0068] Among them, stable components such as CO, CO 2 , NOx and unburned hydrocarbons, active components such as CH 3 , C 3 H 3 and C 3 H 4 Hydrocarbon free radicals.

[0069] Step 2: Substituting the signal intensities of various stable components and active components obtained by transformation into the quantitative curve to obtain the concentrations of various stable components and active components;

[0070] Among them, the ions of each component will generate voltage after reaching the detector, and the data acquisition card will convert this voltage signal into signal intensity; among them, the quantitative curve is drawn based on the signal intensity of various stable components and active components at different concentrations of the historical aircraft engine combustion chamber outlet gas;

[0071] Step 3: Fitting the enthalpy-temperature curves of various stable components and active components at the inlet and outlet of the aviation gas engine combustion chamber;

[0072] The enthalpy of the gas is a function related to temperature, so the enthalpy-temperature curve of the gas is first fitted, and then the temperature of the gas is obtained based on the calculated enthalpy of the gas combined with the enthalpy-temperature curve of the gas.

[0073] It should be noted that the enthalpy of the gas can be obtained by fitting it according to the thermodynamic database;

[0074] Step 4: Based on the law of conservation of energy, the temperature of the outlet gas is calculated by combining the concentrations of various stable components and active components and the enthalpy-temperature curve.

[0075] In this embodiment, if the temperature is to be solved, it needs to be solved based on the constant relationship that the sum of the inlet air enthalpy and the fuel calorific value is equal to the outlet gas enthalpy. The specific formula is:

[0076]

[0077] Among them, H f is the calorific value of the fuel, and the enthalpy values ​​of the air component and the gas component are H i and H j , N a is the number of components in the air, N g is the number of components in the fuel gas.

[0078] At this time, we need to assume a temperature. When both sides of the equation are equal, the assumed temperature is the problem we are looking for.

[0079] Among them, "the constant relationship that the sum of the inlet air enthalpy and the fuel calorific value is equal to the outlet gas enthalpy" requires the calculation of the inlet air enthalpy and the outlet gas enthalpy in this equation;

[0080] According to step 3, the enthalpy-temperature curve of the outlet gas is obtained. At this time, the concentration of the outlet gas needs to be obtained. The inlet air concentration is known because the inlet enthalpy = concentration x enthalpy at a given temperature.

[0081] According to steps 1 and 2, the concentrations of CO, CO2, NOX, and UHC gas components can be obtained. Among them, UHC includes stable hydrocarbon components and hydrocarbon free radicals, so there are still 8 gas component concentrations that need to be calculated. Therefore, according to the conservation of components and the chemical equilibrium equation, a series of formulas are obtained to construct a nonlinear equation group, and the iterative solution is obtained to obtain the concentrations of 8 gas components and the unknown quantities T and n in the calculation. a 、n g , P.

[0082] The specific solution process is as follows:

[0083] Assume that the molecular formula of the fuel used in the combustion chamber of an aircraft engine is CHa, which burns with air at high temperature to produce CO 2 , CO, H 2 O, O 2 、N 2 , H 2 , NOx, OH, H, O, N, UHC. The combustion chemical reaction equation is as follows:

[0084]

[0085] Among them, n a is the amount of air consumed by burning 1 mole of fuel, n g is the amount of fuel gas obtained by the combustion of 1 mole of fuel and air, x a,i is the concentration of component i in the inlet air, x g,j is the concentration of component j in the fuel gas.

[0086] According to the conservation of elements, the C balance, H balance, O balance and N balance equations and the component equation ∑x g,j =1;

[0087] For the reaction system including 4 elements and 12 gas components discussed in this embodiment, 7 independent chemical equilibrium reaction equations can be listed accordingly:

[0088] CO 2 +H 2 =CO+H 2 O, the corresponding equilibrium constant is: Kp 1 =(x g,CO )(x g,H2O ) / (x g,CO2 )(x g,H2 ),

[0089] CO 2 =CO + 0.5O 2 , the corresponding equilibrium constant is: Kp 2 / (P / P 0 )0.5 =(x g,CO )(x g,O2 ) 0.5 / (x g,CO2 ),

[0090] H 2 O=OH+0.5H 2 , the corresponding equilibrium constant is: Kp 3 / (P / P 0 ) 0.5 =(x g,OH )(x g,H2 ) 0.5 / (x g,H2O ),

[0091] N 2 +O 2 =2NO, the corresponding equilibrium constant is: Kp 4 =(x g,NO ) 2 / (x g,N2 )(x g,O2 ),

[0092] H 2 =H+H, the corresponding equilibrium constant is: Kp 5 / (P / P 0 )=(x g,H ) 2 / (x g,H2 ),

[0093] O 2 =O+O, the corresponding equilibrium constant is: Kp 6 / (P / P 0 )=(x g,O ) 2 / (x g,O2 ),

[0094] N 2 =N+N; the corresponding equilibrium constant is: Kp 7 / (P / P 0 )=(x g,N ) 2 / (x g,N2 ),

[0095] And InKp=-ΔG T / RT=ΔS T / R-ΔH T / RT;

[0096] Among them, Kp 1 -Kp 7 is the equilibrium constant corresponding to each chemical equilibrium equation, P is the combustion chamber outlet pressure, P0 is the atmospheric pressure, R is the molar gas constant, T is the combustion chamber outlet temperature, ΔG T is the reaction Gibbs function ΔS at the combustion chamber outlet temperature T is the reaction entropy at the combustion chamber outlet temperature, ΔH T is the molar reaction enthalpy at the combustion chamber outlet temperature;

[0097] Through step 2, online mass spectrometry can be used to measure CO and CO 2 , NOx, UHC and other components, and the unknowns are the combustion chamber outlet gas temperature T, n a 、n g , P and the remaining 8 component concentrations were solved by combining the above 13 equations and using Newton's method through an iterative approach.

[0098] Through the above scheme, the stable species and active species in the combustion chamber outlet gas of the aircraft engine can be detected; the concentration of active species introduced in the back-calculation process of temperature can improve the accuracy of the gas temperature calculation.

[0099] 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 spectrometry system for measuring the temperature of gas at the outlet of an aircraft engine combustion chamber, characterized in that: Includes molecular beam ionization source, mass spectrometer and temperature calculation module; The molecular beam ionization source comprises a molecular beam ionization source cavity, in which a flat plate electrode (1), a conical hole electrode (2), a transmission electrode group and a differential electrode group are arranged, a gas molecular beam forming region is formed between the flat plate electrode (1) and the conical hole electrode (2), an ionization region is formed between the conical hole electrode (2) and the transmission electrode group, and a transmission region is formed between the transmission electrode group and the differential electrode group, and the gas molecular beam forming region, the ionization region and the transmission region are connected to a mass spectrometer to measure the concentrations of various stable components and active components of the outlet gas; The temperature calculation module is connected to the mass spectrometer and is configured to calculate the temperature of the outlet gas according to the concentrations of the stable components and active components of the outlet gas.

2. The mass spectrometry system for measuring the temperature of the combustion chamber outlet gas of an aircraft engine according to claim 1, characterized in that: A radio frequency windowless discharge lamp (8) and a lamp holder electrode (3) are also arranged in the molecular beam ionization source chamber. A discharge lamp tube is arranged in the radio frequency windowless discharge lamp (8). A gas injection port is arranged on the molecular beam ionization source chamber. One end of the discharge lamp tube is connected to the gas injection port, and the other end extends into the interior of the lamp holder electrode (3).

3. The mass spectrometry system for measuring the temperature of the combustion chamber outlet gas of an aircraft engine according to claim 2, characterized in that: The system further comprises a discharge gas storage (10) and a mass flow controller (9), wherein 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).

4. The mass spectrometry system for measuring the temperature of the combustion chamber outlet gas of an aircraft engine according to claim 1, characterized in that: The transmission electrode group comprises a DC transmission electrode (4) and a radio frequency transmission electrode (5); the differential electrode group comprises a first differential electrode (6) and a second differential electrode (11); an ionization zone is formed between the cone electrode (2) and the DC transmission electrode (4); and a transmission zone is formed between the DC transmission electrode (4), the radio frequency transmission electrode (5), the first differential electrode (6) and the second differential electrode (11).

5. The mass spectrometry system for measuring the temperature of the combustion chamber outlet gas of an aircraft engine as claimed in claim 4, characterized in that: 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), the first differential electrode (6) and the second differential electrode (11) are parallel to each other, and the through holes are coaxial.

6. The mass spectrometry system for measuring the temperature of the combustion chamber outlet gas of an aircraft engine as claimed in claim 4, characterized in that: The DC transmission electrode (4) and the radio frequency transmission electrode (5) are both plate-type structures with a central opening.

7. The mass spectrometry system for measuring the temperature of combustion chamber outlet gas of an aircraft engine as claimed in claim 1, characterized in that: The vacuum degrees of the fuel gas molecular beam forming region, the ionization region and the transmission region decrease in sequence.

8. The mass spectrometry system for measuring the temperature of combustion chamber outlet gas of an aircraft engine as claimed in claim 1, characterized in that: A slit (12) is also arranged in the molecular beam ionization source cavity, a shaping region is formed between the slit (12) and the second differential electrode (11), and a mass spectrometer is arranged at the outlet of the shaping region.

9. The mass spectrometry system for measuring the temperature of the combustion chamber outlet gas of an aircraft engine according to claim 8, characterized in that: The measuring system comprises an oil pump (7), a dry pump (13) and a plurality of molecular pumps, wherein the oil pump (7) is connected to a fuel gas molecular beam forming region, the dry pump (13) is connected to an ionization region, the molecular pumps comprise a first molecular pump (14), a second molecular pump (15) and a third molecular pump (16), the dry pump (13) simultaneously serves as a pre-stage pump for the plurality of molecular pumps, the first molecular pump (14) is connected to a transmission region, the second molecular pump (15) is connected to a shaping region, and the third molecular pump (16) is connected to a mass spectrometer.

10. A method for measuring the gas temperature at the outlet of an aircraft engine combustion chamber, characterized in that: A mass spectrometry system for measuring the temperature of combustion chamber gas at the outlet of an aircraft engine according to any one of claims 1 to 9 comprises the following steps: Receive various stable and active components of the fuel gas at the outlet of the combustion chamber of the aviation gas engine; Substituting the signal intensities of various stable components and active components obtained by transformation into the quantitative curve to obtain the concentrations of various stable components and active components; wherein the quantitative curve is drawn according to the signal intensities of various stable components and active components at different concentrations of the combustion chamber outlet gas of the aircraft engine; Fitting the enthalpy-temperature curves of various stable and active components at the inlet and outlet of the aviation gas engine combustion chamber; Based on the law of conservation of energy, the temperature of the outlet gas is calculated by combining the concentrations of various stable and active components and the enthalpy-temperature curve.

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