Fuel component applicability evaluation method based on delay time

Abstract

The invention discloses a delay time-based fuel component applicability evaluation method, and belongs to the technical field of gas turbines. According to the method, whether the calorific value meets the requirement or not is judged, the delay time is introduced as a criterion, and the oscillation performance change of the combustion chamber under new fuel is further pre-judged; and according to the delay time, the equivalence ratio and the geometric structure of the combustor are improved, and the method can be well applied to judgment of the applicability of new fuel.

Description

Technical Field

[0001] The invention belongs to the technical field of combustion engines, and in particular relates to a method for evaluating the suitability of fuel components based on hysteresis time. Background Art

[0002] For an existing gas engine, it has a certain design fuel. If it needs to burn other fuels, it is usually necessary to confirm through tests whether the combustion chamber of this type of gas engine can burn the new fuel to evaluate the combustion performance, with a focus on flashback and oscillation performance.

[0003] This method has a long cycle, high cost and many iterations. Therefore, a fuel applicability prediction method is designed to preliminarily determine whether the combustion chamber of the gas turbine can burn a certain type of new fuel before the test, so as to reduce the test cost and shorten the verification cycle.

[0004] The commonly used method at present is to judge the fuel by calculating the calorific value of the fuel through the components, but this method cannot evaluate the oscillation performance of the combustion and is prone to misjudgment. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a fuel component applicability evaluation method based on hysteresis time. In addition to judging whether the calorific value meets the requirements, the hysteresis time is introduced as a criterion to further predict the changes in the oscillation performance of the combustion chamber under new fuel; and according to the hysteresis time, the equivalence ratio and the geometric structure of the burner are improved, which can be well applied to the judgment of the applicability of new fuels.

[0006] The present invention provides a method for evaluating the suitability of fuel components based on hysteresis time, comprising the following steps: Determine the composition and molar calorific value of the new fuel; The calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirements, the new fuel is considered to be unsuitable for this gas engine. If the calorific value of the new fuel meets the design fuel calorific value requirements, the oscillation performance of the new fuel is predicted based on the hysteresis time. If the oscillation amplitude is less than or equal to the allowable oscillation amplitude, the oscillation risk of the new fuel is considered to be small and can be used for this gas engine. If the oscillation amplitude is greater than the allowable oscillation amplitude, the new fuel is considered to be unsuitable for this gas engine.

[0007] Preferably, the calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirement, it is considered that the new fuel is not suitable for the gas engine and the evaluation is terminated. If the calorific value of the new fuel meets the design fuel calorific value requirement, the oscillation performance prediction of the new fuel based on the hysteresis time specifically includes: According to the mole fraction and calorific value of each component in the new fuel, the mixed calorific value of the new fuel is calculated; The mixed calorific value of the new fuel is compared with the design fuel calorific value requirement. If the calorific value deviation is within the preset range, it is considered that the new fuel can meet the combustion requirements, and the oscillation performance of the new fuel is predicted based on the hysteresis time; if the calorific value deviation exceeds the preset range, it is considered that the new fuel is not suitable for this gas engine.

[0008] Preferably, predicting the oscillation performance of the new fuel based on the hysteresis time includes the following steps: The relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is obtained through experimental data and operation data; The relationship curve between the hysteresis time and the oscillation amplitude is corrected by using the influence of the hydrogen content and the carbon monoxide content on the hysteresis time, so as to obtain the corrected relationship curve between the hysteresis time and the oscillation amplitude; The oscillation amplitude A' at the designed hysteresis time point after using the new fuel is determined based on the relationship curve between the corrected hysteresis time and the oscillation amplitude.

[0009] Preferably, the relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is fitted into a trigonometric function relationship curve, which is defined as A=asin(wt D +b)+c, where a, w, b, and c are constant coefficients obtained by fitting the experimental data and the operating data.

[0010] Preferably, the relationship curve between the modified hysteresis time and the oscillation amplitude is A'=asin(wt'+b)+c; Where t'=t(1-r H2 +r CO ); r H2 is the hydrogen correction factor, defined as ; r CO is the carbon monoxide correction factor, defined as ; Among them, k1, k2, t D ,t CO and t H2 is a given constant, m H2 is the mole fraction of hydrogen, m CO is the mole fraction of carbon monoxide.

[0011] Preferably, it also includes, if the oscillation amplitude is greater than the allowed oscillation amplitude, it is considered that the new fuel is not suitable for the present combustion engine, and the equivalence ratio and the structure of the burner are improved according to the hydrogen correction factor and the carbon monoxide correction factor.

[0012] Preferably, if 1-r H2 +r CO If it is less than 1, it means that the delay time is shortened, the length of the premixing section of the burner is increased, or the equivalence ratio of the combustion area is reduced; If 1-r H2 +r CO If it is greater than 1, it means that the delay time increases, the length of the burner premixing section is reduced, or the equivalence ratio of the combustion area is increased.

[0013] Preferably, the delay time t of the fuel is obtained by obtaining a heat release signal through a fire detector or a camera, and then the heat release signal is compared with the pressure pulsation signal to obtain the heat release signal.

[0014] Preferably, the oscillation amplitude A is obtained through a pressure pulsation signal.

[0015] Preferably, the calorific value is calculated according to GB / T 11062 specification, and the preset range of the calorific value is obtained from the fuel gas specification of the combustion engine.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In addition to judging whether the calorific value meets the requirements, the present invention introduces the hysteresis time as a criterion to further predict the change of the oscillation performance of the combustion chamber under the new fuel; and according to the hysteresis time, the equivalence ratio and the geometric structure of the burner are improved, which can be well applied to the judgment of the applicability of the new fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a curve showing the relationship between the hysteresis time and the oscillation amplitude of an embodiment of the present invention, wherein A is the vibration amplitude before correction, and the corresponding hysteresis time is , A' is the corrected vibration amplitude, and the corresponding hysteresis time is , A D is the experience value; Figure 2 The present invention is a flowchart of a method for evaluating the suitability of fuel components based on hysteresis time according to an embodiment of the present invention.

[0018] Figure 3 The present invention is a flowchart of a method for evaluating the suitability of fuel components based on hysteresis time according to another embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The present invention provides a method for evaluating the suitability of fuel components based on hysteresis time, comprising the following steps: Determine the composition and molar calorific value of the new fuel; The calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirements, the new fuel is considered to be unsuitable for this gas engine. If the calorific value of the new fuel meets the design fuel calorific value requirements, the oscillation performance of the new fuel is predicted based on the hysteresis time. If the oscillation amplitude is less than or equal to the allowable oscillation amplitude, the oscillation risk of the new fuel is considered to be small and can be used for this gas engine. If the oscillation amplitude is greater than the allowable oscillation amplitude, the new fuel is considered to be unsuitable for this gas engine.

[0021] According to a specific embodiment of the present invention, the calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirement, it is considered that the new fuel is not suitable for the gas engine and the evaluation is terminated; if the calorific value of the new fuel meets the design fuel calorific value requirement, the oscillation performance prediction of the new fuel based on the hysteresis time specifically includes: According to the mole fraction and calorific value of each component in the new fuel, the mixed calorific value of the new fuel is calculated; The mixed calorific value of the new fuel is compared with the design fuel calorific value requirement. If the calorific value deviation is within the preset range, it is considered that the new fuel can meet the combustion requirements, and the oscillation performance of the new fuel is predicted based on the hysteresis time; if the calorific value deviation exceeds the preset range, it is considered that the new fuel is not suitable for this gas engine.

[0022] According to a specific embodiment of the present invention, the oscillation performance prediction of the new fuel based on the hysteresis time includes the following steps: The relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is obtained through experimental data and operation data; The relationship curve between the hysteresis time and the oscillation amplitude is corrected by using the influence of the hydrogen content and the carbon monoxide content on the hysteresis time, so as to obtain the corrected relationship curve between the hysteresis time and the oscillation amplitude; The oscillation amplitude A' at the designed hysteresis time point after using the new fuel is determined based on the relationship curve between the corrected hysteresis time and the oscillation amplitude.

[0023] According to a specific embodiment of the present invention, the relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is fitted into a trigonometric function relationship curve, defined as A=asin(wt D +b)+c, where a, w, b, and c are constant coefficients obtained by fitting the experimental data and the operating data.

[0024] According to a specific embodiment of the present invention, the relationship curve between the modified hysteresis time and the oscillation amplitude is A'=asin(wt'+b)+c; Where t'=t(1-r H2 +r CO ); r H2 is the hydrogen correction factor, defined as ; r CO is the carbon monoxide correction factor, defined as ; Among them, k1, k2, t D ,t CO and t H2 is a given constant, m H2 is the mole fraction of hydrogen, m CO is the mole fraction of carbon monoxide.

[0025] According to a specific embodiment of the present invention, if the oscillation amplitude is greater than the allowed oscillation amplitude, it is considered that the new fuel is not suitable for the present combustion engine, and the equivalence ratio and the structure of the burner are improved according to the hydrogen correction factor and the carbon monoxide correction factor.

[0026] According to a specific embodiment of the present invention, if 1-r H2 +r CO If it is less than 1, it means that the delay time is shortened, the length of the premixing section of the burner is increased, or the equivalence ratio of the combustion area is reduced; If 1-r H2 +r CO If it is greater than 1, it means that the delay time increases, the length of the burner premixing section is reduced, or the equivalence ratio of the combustion area is increased.

[0027] According to a specific embodiment of the present invention, the delay time t of the fuel is obtained by obtaining a heat release signal through a fire detector or a camera, and then the heat release signal is compared with the pressure pulsation signal to obtain it.

[0028] According to a specific embodiment of the present invention, the oscillation amplitude A is obtained through a pressure pulsation signal.

[0029] According to a specific embodiment of the present invention, the calorific value is calculated according to the GB / T 11062 specification, and the preset range of the calorific value is obtained from the fuel gas specification of the combustion engine.

[0030] Example 1 like Figure 2 As shown, the present invention provides a fuel component suitability evaluation method based on hysteresis time, comprising the following steps: Determine the composition and molar calorific value of the new fuel; The calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirements, the new fuel is considered to be unsuitable for this gas engine. If the calorific value of the new fuel meets the design fuel calorific value requirements, the oscillation performance of the new fuel is predicted based on the hysteresis time. If the oscillation amplitude is less than or equal to the allowable oscillation amplitude, the oscillation risk of the new fuel is considered to be small and can be used for this gas engine. If the oscillation amplitude is greater than the allowable oscillation amplitude, the new fuel is considered to be unsuitable for this gas engine.

[0031] Example 2 like Figure 3 As shown, the present invention provides a fuel component suitability evaluation method based on hysteresis time, comprising the following steps: Determine the composition and molar calorific value of the new fuel; The calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirements, the new fuel is considered unsuitable for this engine. If the calorific value of the new fuel meets the design fuel calorific value requirements, the oscillation performance of the new fuel is predicted based on the hysteresis time. If the oscillation amplitude is less than or equal to the allowable oscillation amplitude, the oscillation risk of the new fuel is considered to be small and can be used for this engine. If the oscillation amplitude is greater than the allowable oscillation amplitude, the new fuel is considered unsuitable for this engine. The calorific value is calculated according to GB / T 11062.

[0032] Furthermore, the calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirement, it is considered that the new fuel is not suitable for the gas engine and the evaluation is terminated. If the calorific value of the new fuel meets the design fuel calorific value requirement, the oscillation performance prediction of the new fuel based on the hysteresis time specifically includes: According to the mole fraction and calorific value of each component in the new fuel, the mixed calorific value of the new fuel is calculated; Compare the mixed calorific value of the new fuel with the calorific value requirement of the designed fuel. If the calorific value deviation is within the preset range, it is considered that the new fuel can meet the combustion requirements, and the oscillation performance of the new fuel is predicted based on the hysteresis time; if the calorific value deviation exceeds the preset range, it is considered that the new fuel is not suitable for this gas engine. The preset range of calorific value is obtained from the fuel gas specification of the gas engine.

[0033] The oscillation performance prediction of the new fuel based on the hysteresis time includes the following steps: The heat release signal is obtained through fire detection or camera, and then the heat release signal is compared with the pressure pulsation signal to obtain the fuel hysteresis time t, and the oscillation amplitude A is obtained through the pressure pulsation signal. Then, the relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is obtained through regression calculation. The relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is fitted into a trigonometric function relationship curve, such as Figure 1 As shown, it is the absolute value curve of the relationship curve, where A D is an empirical value, defined as A=asin(wt D +b)+c, where a, w, b, and c are constant coefficients obtained by fitting the experimental data and the operating data.

[0034] The flame propagation speed of hydrogen is fast. Under the condition that the burner structure remains unchanged, the increase of hydrogen content will reduce the fuel lag time t; the flame propagation speed of carbon monoxide is slow. The increase of carbon monoxide content will increase the fuel lag time t. By using the influence of hydrogen content and carbon monoxide content on the lag time t, the relationship curve between the lag time and the oscillation amplitude is corrected to obtain the relationship curve between the corrected lag time and the oscillation amplitude; the relationship curve between the corrected lag time and the oscillation amplitude is A'=asin(wt'+b)+c; Where t'=t(1-r H2 +r CO ); r H2 is the hydrogen correction factor, defined as ; r CO is the carbon monoxide correction factor, defined as ; Among them, k1, k2, t D ,t CO and t H2 is a given constant, m H2 is the mole fraction of hydrogen, m CO is the mole fraction of carbon monoxide; According to the relationship curve between the modified hysteresis time and the oscillation amplitude, the oscillation amplitude A' at the designed hysteresis time point after using the new fuel is determined; It also includes that if the oscillation amplitude is greater than the allowed oscillation amplitude, the new fuel is considered unsuitable for the present combustion engine. At this time, the equivalence ratio and the structure of the burner are improved according to the hydrogen correction factor and the carbon monoxide correction factor.

[0035] Among them, if 1-r H2 +r CO If it is less than 1, it means that the delay time is shortened, the length of the premixing section of the burner is increased, or the equivalence ratio of the combustion area is reduced; If 1-r H2 +r CO If it is greater than 1, it means that the delay time increases, the length of the burner premixing section is reduced, or the equivalence ratio of the combustion area is increased.

[0036] 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 are included in the protection scope of the present invention.

Claims

1. A method for evaluating the suitability of fuel components based on hysteresis time, characterized in that: The steps include: Determine the composition and molar calorific value of the new fuel; The calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirements, the new fuel is considered to be unsuitable for this gas engine. If the calorific value of the new fuel meets the design fuel calorific value requirements, the oscillation performance of the new fuel is predicted based on the hysteresis time. If the oscillation amplitude is less than or equal to the allowable oscillation amplitude, the oscillation risk of the new fuel is considered to be small and can be used for this gas engine. If the oscillation amplitude is greater than the allowable oscillation amplitude, the new fuel is considered to be unsuitable for this gas engine.

2. The fuel composition suitability evaluation method based on hysteresis time according to claim 1, characterized in that: The calorific value of the new fuel is determined. If the calorific value of the new fuel does not meet the design fuel calorific value requirement, the new fuel is considered unsuitable for the engine and the evaluation is terminated. If the calorific value of the new fuel meets the design fuel calorific value requirement, the oscillation performance of the new fuel is predicted based on the hysteresis time. Specifically, the following steps are performed: According to the mole fraction and calorific value of each component in the new fuel, the mixed calorific value of the new fuel is calculated; The mixed calorific value of the new fuel is compared with the design fuel calorific value requirement. If the calorific value deviation is within the preset range, it is considered that the new fuel can meet the combustion requirements, and the oscillation performance of the new fuel is predicted based on the hysteresis time; if the calorific value deviation exceeds the preset range, it is considered that the new fuel is not suitable for this gas engine.

3. The fuel composition suitability evaluation method based on hysteresis time according to claim 1, characterized in that: Predicting the oscillation performance of new fuel based on the hysteresis time includes the following steps: The relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is obtained through experimental data and operation data; The relationship curve between the hysteresis time and the oscillation amplitude is corrected by using the influence of the hydrogen content and the carbon monoxide content on the hysteresis time, so as to obtain the corrected relationship curve between the hysteresis time and the oscillation amplitude; The oscillation amplitude A' at the designed hysteresis time point after using the new fuel is determined based on the relationship curve between the corrected hysteresis time and the oscillation amplitude.

4. The method for evaluating the suitability of fuel components based on hysteresis time according to claim 3, characterized in that: The relationship curve between the hysteresis time t and the oscillation amplitude A of the designed fuel is fitted into a trigonometric function relationship curve, defined as A=asin(wt D +b)+c, where a, w, b, and c are constant coefficients obtained by fitting the experimental data and the operating data.

5. The method for evaluating the suitability of fuel components based on hysteresis time according to claim 4, characterized in that: The relationship curve between the corrected hysteresis time and the oscillation amplitude is A'=asin(wt'+b)+c; Where t'=t(1-r H2 +r CO ); r H2 is the hydrogen correction factor, defined as ; r CO is the carbon monoxide correction factor, defined as ; Among them, k1, k2, t D ,t CO and t H2 is a given constant, m H2 is the mole fraction of hydrogen, m CO is the mole fraction of carbon monoxide.

6. The method for evaluating the suitability of fuel components based on hysteresis time according to claim 5, characterized in that: It also includes that if the oscillation amplitude is greater than the allowed oscillation amplitude, the new fuel is considered unsuitable for the present combustion engine, and the equivalence ratio and the structure of the burner are improved according to the hydrogen correction factor and the carbon monoxide correction factor.

7. The method for evaluating the suitability of fuel components based on hysteresis time according to claim 6, characterized in that: If 1-r H2 +r CO If it is less than 1, it means that the delay time is shortened, the length of the premixing section of the burner is increased, or the equivalence ratio of the combustion area is reduced; If 1-r H2 +r CO If it is greater than 1, it means that the delay time increases, the length of the burner premixing section is reduced, or the equivalence ratio of the combustion area is increased.

8. The method for evaluating the suitability of fuel components based on hysteresis time according to claim 3, characterized in that: The fuel delay time t is obtained by obtaining a heat release signal through a fire detector or a camera, and then the heat release signal is compared with the pressure pulsation signal.

9. The method for evaluating the suitability of fuel components based on hysteresis time according to claim 1, characterized in that: The oscillation amplitude A is obtained through the pressure pulsation signal.

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