阅读说明：本技术 一种加力总燃油流量控制规律确定方法 (Method for determining flow control rule of boosting total fuel oil ) 是由 袁继来 姜繁生 张志成 陈泽华 张志舒 于 2019-10-08 设计创作，主要内容包括：本申请属于航空发动机状态检测技术领域,具体涉及一种加力总燃油流量控制规律确定方法。所述方法包括进行全加力状态性能计算,获取不同发动机进口总温偏差以及不同发动机进口总温下的加力燃烧室油气比；获取飞机高度并计算对应的标准大气条件下的环境温度；获取飞机马赫数并计算对应的进气道进口总温；确定发动机进口总温偏差；插值计算加力燃烧室油气比,从而获得加力总燃油流量控制规律,本申请考虑了非标准天条件下的加力总燃油流量控制规律,能够有效解决现有规律存在的非标准天条件下适用性差问题,可以有效提升发动机非标准天的性能表现、工作安全性等。(The application belongs to the technical field of aero-engine state detection, and particularly relates to a method for determining a stress application total fuel flow control rule. The method comprises the steps of calculating the performance of a full stress state, and obtaining the total temperature deviation of inlets of different engines and the oil-gas ratio of a afterburner at the total temperature of the inlets of the different engines; acquiring the height of the airplane and calculating the corresponding ambient temperature under the standard atmospheric condition; acquiring the Mach number of the airplane and calculating the corresponding total inlet temperature of the air inlet; determining the total temperature deviation of an inlet of the engine; the method has the advantages that the afterburner oil-gas ratio is calculated through interpolation, so that an afterburner total fuel flow control rule is obtained, the afterburner total fuel flow control rule under the condition of a non-standard day is considered, the problem of poor applicability of the existing rule under the condition of the non-standard day can be effectively solved, and performance, working safety and the like of the engine on the non-standard day can be effectively improved.)

1. A method for determining a flow control rule of a boosting total fuel oil is characterized by comprising the following steps:

step S1, performing full stress state performance calculation to obtain total temperature deviation DT of the inlet of different engines and the oil-gas ratio of the afterburner at the total temperature of the inlet of different engines, wherein the total temperature deviation DT of the inlet of the engine is the difference between the actual measured total temperature of the inlet of the engine and the total temperature of the inlet of the engine under the standard atmospheric environment;

s2, acquiring the altitude of the airplane, and calculating the corresponding ambient temperature under the standard atmospheric condition;

s3, acquiring the Mach number of the airplane, calculating the total temperature of an inlet of the air inlet channel under the corresponding standard atmospheric condition, and equating the total temperature of the inlet of the air inlet channel to be the total temperature of an inlet of an engine;

step S4, determining the deviation of the total temperature of the engine inlet according to the measured total temperature of the engine inlet and the total temperature of the engine inlet calculated in the step S3;

and step S5, calculating the fuel-air ratio of the afterburner by interpolation, thereby obtaining an afterburner total fuel flow control rule.

2. The boosted total fuel flow control law determination method according to claim 1, characterized in that said step S2 includes:

step S21, obtaining a relation table between the environmental temperature and the altitude under the standard atmospheric condition;

and step S22, obtaining the environment temperature corresponding to the aircraft altitude through interpolation.

3. The boosted total fuel flow control law determination method according to claim 1, characterized in that after said step S5, it comprises:

step S61, obtaining a total pressure measurement value of an outlet of the compressor, and equivalently obtaining the total pressure measurement value as an air flow;

and S62, calculating the engine boosting total fuel flow according to the oil-gas ratio determined in the S5 and the air flow determined in the S61.

4. The method for determining the boosted total fuel flow control law according to claim 3, wherein after the step S5, when calculating the fuel flow of the high altitude small gauge speed area or the low altitude large gauge speed area, the method comprises the following steps:

step S63, obtaining an engine inlet pressure measured value, and enabling the measured value to be equivalent to an air flow;

and S64, calculating the engine boosting total fuel flow according to the oil-gas ratio determined in the S5 and the air flow determined in the S63.

5. The method for determining the boost total fuel flow control law according to claim 4, wherein the method for determining the high altitude small meter speed area or the low altitude large meter speed area comprises the following steps:

determining an engine inlet total temperature equipotential line in a two-dimensional plane with the height as a vertical coordinate and the Mach number as a horizontal coordinate;

determining the upper and lower boundaries of the engine inlet total temperature equipotential line;

the area beyond the upper boundary is set as a high altitude small gauge speed area, and the area below the lower boundary is set as a low altitude large gauge speed area.

6. The method for determining the boosted total fuel flow control law of claim 1, characterized in that in step S3, the total inlet temperature of the intake passage is T₀*(1+0.2*M²) Wherein, T₀Is a labelThe environment temperature under the quasi-atmospheric condition, M is Mach number.

Technical Field

The application belongs to the technical field of fuel control of aero-engines, and particularly relates to a method for determining a stress application total fuel flow control rule.

Background

Boost total fuel flow controlThe rule generally means according to the total temperature T of the inlet of the engine_t2Making a corresponding oil-gas ratio W_fab/P_t3。

With the development of aviation science and technology, military aircrafts are required to have the capability of suddenly increasing the flying speed during taking off, climbing or executing tasks such as interception, and gas turbine engines with afterburners are produced at the same time. The afterburner is supplied with fuel oil by an afterburner fuel oil control system, and the fuel oil and oxygen contained in the airflow at the outlet of the turbine and the outer culvert are mixed and combusted again, so that the aim of further improving the thrust of the engine is fulfilled. At present, the general design process of the boosting total fuel flow rule of the domestic turbofan engine is as follows: and obtaining the total forced fuel oil flow under the full-forced state based on the calculation result of the intermediate state height speed characteristic under the standard day condition and based on the principle of the residual gas coefficient of the forced combustion chamber in the full-envelope (ensuring that the full-forced thrust meets the requirement). Since the afterburner inlet air flow cannot be directly measured, the compressor outlet pressure P is used_t3Indirectly replacing the air flow to obtain W_fab/P_t3～T_t2And controlling a regular form.

The existing turbofan engine adopts W in a full-stress state_fab/P_t3～T_t2The regular pattern (see fig. 1 in particular) is obtained from the calculation under standard day conditions. In the actual use process, the problem of poor applicability of the control law under the condition of non-standard days mainly shows that the stress application oil-gas ratio is not appropriate:

1) envelope left border region (T)_t2≤T₀)

At any working point in the left boundary area of the envelope, according to the control law of the engine main machine, the outlet pressure P of the cold and hot natural gas compressor_t3Basically, the engine oil-gas ratio of the afterburner is not changed (the control result of the existing host control law), but the oil-gas ratio of the afterburner deviates according to the existing afterburning oil supply control law: the gas-oil ratio is low in hot days, the flow of the boost fuel oil is reduced, and the boost thrust is reduced; the oil-gas ratio is higher in cold days, the flow of the boosting fuel oil is increased, and the boosting thrust is increased. Especially in the high altitude small surface velocity region (the combustion efficiency of the afterburning oil is reduced), the afterburning is unstable due to the lean oil, and the afterburning is unstable due to the rich oilThe problem of flameout and even surge of the Lifu oil occurs.

2) Envelope right border region (T)_t2＞T₀)

At any working point in the right boundary area of the envelope, the outlet pressure P of the compressor is limited by the exhaust temperature of the main engine_t3Reduction, air flow reduction, and cold weather compressor outlet pressure P_t3The air flow rate increases. According to the existing boosting fuel supply control law, the flow of boosting fuel in hot days is reduced, and the flow of boosting fuel in cold days is increased. The oil-gas ratio of the afterburner can deviate under the comprehensive influence: the oil-gas ratio is larger in hot days, and the stress application outlet temperature is higher, so that the stress application ablation problem can be caused; the oil-gas ratio is smaller in cold days, and the thrust is reduced due to the lower temperature of a thrust application outlet. Especially in the low altitude high gauge speed region (compressor outlet pressure P)_t3Limited), when the engine is working in cold weather, the existing boost fuel control law will result in W_fab/P_t3Reduced, and compressor outlet pressure P_t3And the full thrust augmentation of the engine can be greatly reduced without change, so that the use of the airplane in the area is influenced.

Disclosure of Invention

In order to solve at least one of the technical problems, the application provides a method for determining a boost total fuel flow control rule, which solves the problem of poor applicability of the existing control rule in a non-standard day, improves the performance of an engine in the non-standard day, and improves the working safety of the engine, and the method comprises the following steps:

step S1, performing full stress state performance calculation to obtain total temperature deviation DT of the inlet of different engines and the oil-gas ratio of the afterburner at the total temperature of the inlet of different engines, wherein the total temperature deviation DT of the inlet of the engine is the difference between the actual measured total temperature of the inlet of the engine and the total temperature of the inlet of the engine under the standard atmospheric environment;

s2, acquiring the altitude of the airplane, and calculating the corresponding ambient temperature under the standard atmospheric condition;

s3, acquiring the Mach number of the airplane, calculating the total temperature of an inlet of the air inlet channel under the corresponding standard atmospheric condition, and equating the total temperature of the inlet of the air inlet channel to be the total temperature of an inlet of an engine;

step S4, determining the deviation of the total temperature of the engine inlet according to the measured total temperature of the engine inlet and the total temperature of the engine inlet calculated in the step S3;

and step S5, calculating the fuel-air ratio of the afterburner by interpolation, thereby obtaining an afterburner total fuel flow control rule.

Preferably, the step S2 includes:

step S21, obtaining a relation table between the environmental temperature and the altitude under the standard atmospheric condition;

and step S22, obtaining the environment temperature corresponding to the aircraft altitude through interpolation.

Preferably, after the step S5, the method includes:

step S61, obtaining a total pressure measurement value of an outlet of the compressor, and equivalently obtaining the total pressure measurement value as an air flow;

and S62, calculating the engine boosting total fuel flow according to the oil-gas ratio determined in the S5 and the air flow determined in the S61.

Preferably, after the step S5, when calculating the fuel flow rate in the high altitude low gauge speed region or the low altitude high gauge speed region, the method includes:

step S63, obtaining an engine inlet pressure measured value, and enabling the measured value to be equivalent to an air flow;

and S64, calculating the engine boosting total fuel flow according to the oil-gas ratio determined in the S5 and the air flow determined in the S63.

Preferably, the method for determining the high altitude small gauge speed area or the low altitude large gauge speed area includes:

determining an engine inlet total temperature equipotential line in a two-dimensional plane with the height as a vertical coordinate and the Mach number as a horizontal coordinate;

determining the upper and lower boundaries of the engine inlet total temperature equipotential line;

the area beyond the upper boundary is set as a high altitude small gauge speed area, and the area below the lower boundary is set as a low altitude large gauge speed area.

Preferably, in step S3, the total inlet temperature of the intake passage is T₀*(1+0.2*M²) Wherein, T₀Is a labelThe environment temperature under the quasi-atmospheric condition, M is Mach number.

The method comprises the steps of obtaining stress application fuel oil flow under any state point and any temperature condition in a full envelope according to total temperature deviation (actual temperature and standard day temperature) of an inlet of an engine, inlet temperature and total pressure measurement value of an outlet of a compressor, wherein the fuel oil flow meets performance requirements and stress application working stability requirements;

the application considers a method for correcting the actual working conditions of high altitude small gauge speed and low altitude large Mach number. And obtaining a fuel flow correction coefficient in a full-stress state in a high-altitude small surface speed area and a low-altitude large Mach number area based on the inlet pressure and the inlet total temperature deviation of the engine.

Drawings

FIG. 1 shows a conventional W_fab/P_t3And (5) a control rule schematic diagram.

Fig. 2 is a flowchart of an embodiment of a method for determining a boost total fuel flow control law according to the present application.

FIG. 3 is a schematic diagram of the high altitude low gauge speed and low altitude high gauge speed regions of the present application.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application, and should not be construed as limiting the present application. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the embodiments in the present application are within the scope of protection of the present application. Embodiments of the present application will be described in detail below with reference to the drawings.

As shown in fig. 2, the present application provides a method for determining a law of boosted total fuel flow control, including:

step S1, performing full stress state performance calculation to obtain total temperature deviation DT of the inlet of different engines and the oil-gas ratio of the afterburner at the total temperature of the inlet of different engines, wherein the total temperature deviation DT of the inlet of the engine is the difference between the actual measured total temperature of the inlet of the engine and the total temperature of the inlet of the engine under the standard atmospheric environment;

s2, acquiring the altitude of the airplane, and calculating the corresponding ambient temperature under the standard atmospheric condition;

s3, acquiring the Mach number of the airplane, calculating the total temperature of an inlet of the air inlet channel under the corresponding standard atmospheric condition, and equating the total temperature of the inlet of the air inlet channel to be the total temperature of an inlet of an engine;

step S4, determining the deviation of the total temperature of the engine inlet according to the measured total temperature of the engine inlet and the total temperature of the engine inlet calculated in the step S3;

and step S5, calculating the fuel-air ratio of the afterburner by interpolation, thereby obtaining an afterburner total fuel flow control rule.

It can be understood that the existing control law is W_fab/P_t3～T_t2The application considers that the control law only passes through the total temperature T of the inlet of the engine_t2To design the oil-gas ratio W_fab/P_t3The method has the defect that the engine inlet total temperature deviation DT is added, and the engine inlet total temperature deviation DT is related to the current atmospheric environment, so that the parameters related to the atmospheric environment are introduced, and the accurate control of the boosted total fuel flow is realized.

The invention provides a afterburning total fuel flow control rule considering nonstandard day conditions, and the afterburning total fuel flow meeting the performance and stable working requirements is obtained from a characteristic parameter of afterburning, namely a residual gas coefficient, and the method specifically comprises the following steps:

a) considering the performance requirements of the engines on the standard days and the nonstandard days, the structural integrity of the afterburner and the limitation of afterburner working stability, and developing the total temperature deviation DT (T) of all heights and Mach numbers and different engine inlets in the full envelope range_t2-T_{t2, Standard day}) Calculating the performance of the full stress state under the condition to obtain the total temperature deviation DT of the inlet of the engine and the total temperature of the inlet of the engineT_t2And W_fab/P_t3Corresponding relation, i.e. W_fab/P_t3＝f(DT、T_t2) The specific data format is shown in table 1;

TABLE 1 Total Inlet temperature deviation DT of Engine_t2And W_fab/P_t3Corresponding relation

Wherein xx is used only to illustrate W_fab/P_t3(kg/s/kPa), and the specific calculation result can be obtained through experiments or simulation.

b) Obtaining the ambient temperature T under the standard atmospheric conditions by interpolation according to the aircraft altitude signal H and according to the table 2₀；

TABLE 2 ambient temperature T under Standard atmospheric conditions₀

c) According to the Mach number signal M of the airplane, the total temperature T of the inlet of the air inlet of the airplane under the standard day condition is calculated through a pneumatic formula_{t1, calculation}The calculation formula is T_{t1, calculation}＝T₀*(1+0.2*M²) And after the air passes through the air inlet channel, the total temperature of the air inlet of the engine is basically unchanged, and the total temperature T of the air inlet of the engine is measured under the condition of a standard day_{t2, calculation}Equal to total inlet temperature T of airplane_{t1, calculation}；

d) By measurement of total engine inlet temperature T_{t2, measurement}And standard day T_{t2, calculation}Calculating to obtain the inlet total temperature deviation DT, and then measuring the total pressure of the outlet of the compressor according to the inlet total temperature deviation DT_t3And total inlet temperature T_{t2, measurement}Based on W_fab/P_t3＝f(DT、T_t2) The relational expression (see table 1 specifically) is used for obtaining the full-stress-state stress fuel oil flow required by the current height H and M under the non-standard day condition through interpolation;

e) considering the thrust application working stability of the high altitude small gauge speed area and the thrust requirement of the low altitude large gauge speed area, the requirements are metCorrecting the boosted fuel flow obtained by interpolation of the d) strips by using the inlet pressure P of the engine_t2To represent the above region (see in particular fig. 3), the boosted fuel flow correction factor is the engine inlet pressure P_t2And the inlet total temperature deviation DT, see Table 3.

TABLE 3 correction coefficient of fuel flow in full-stress state

Description of the drawings: xx represents an uncorrected value (1.0), yy represents a correction value for a high altitude small gauge speed region, and zz represents a correction value for a low altitude large gauge speed region.

As shown in fig. 3, the method for determining the high altitude small gauge speed area or the low altitude large gauge speed area includes: determining an engine inlet total temperature equipotential line in a two-dimensional plane with the height as a vertical coordinate and the Mach number as a horizontal coordinate; determining the upper and lower boundaries of the engine inlet total temperature equipotential line; the area beyond the upper boundary is set as a high altitude small gauge speed area, and the area below the lower boundary is set as a low altitude large gauge speed area.

f) The calculation formula of the stress application total fuel flow considering the non-standard day condition is as follows: w_fab＝K*P_t3*f(DT、T_t2) Wherein f (DT, T)_t2) The values are shown in Table 1, the K values are shown in Table 3, P_t3The total pressure measurement value of the outlet of the compressor is obtained;

g) if the aircraft altitude signal H or Mach number signal M is abnormal and can not be used, the fuel flow control rule in the backup full-stress state is used to ensure the safety of the engine, for example, the existing W signal is adopted_fab/P_t3～T_t2In a regular fashion.

And (3) carrying out the cumulative test verification (ground platform, high-altitude platform and flight test) in the full envelope range on the basis of the parameters in the tables 1 and 3, and correcting the control rule numerical value according to the test result.

The invention considers the law of control of the flow of the stress application total fuel under the condition of a non-standard day, can effectively solve the problem of poor applicability of the existing law under the condition of the non-standard day, and can effectively improve the performance, the working safety and the like of the engine on the non-standard day.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.