A method for simulating the performance of a hydrogen turbine engine based on the physical property changes of hydrogen fuel

Abstract

The present invention discloses a method for simulating the performance of a hydrogen turbine engine based on the change of the physical properties of hydrogen fuel, including: clarifying the working environment of the engine, determining its flight altitude and flight Mach number; simulating the working process of the compressor components doing work on the airflow and compressing the airflow, and calculating the flow rate, enthalpy value, temperature and pressure of the compressor outlet airflow; simulating the heat release process of the hydrogen fuel combustion in the engine combustion chamber; simulating the working process of the gas doing work on the turbine according to various parameters of the combustion chamber outlet gas; simulating the process of the airflow accelerating and expanding in the tail nozzle according to various parameters of the turbine outlet airflow; after the performance simulation, the engine needs to meet the balance conditions of flow balance and power balance, and the method for simulating the performance of a hydrogen turbine engine based on the change of the physical properties of hydrogen fuel is completed. The present invention shows the performance advantages and disadvantages of hydrogen fuel applied to aviation turbine engines through performance simulation, and provides a certain reference value for the practical application of hydrogen turbine engines.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen power, and relates to a method for simulating the performance of a hydrogen turbine engine based on changes in the physical properties of hydrogen fuel. Background Art

[0002] The large amount of carbon dioxide emissions from the aviation industry has brought increasingly severe environmental challenges to the development of the aviation industry, and traditional fuel aircraft cannot meet the future green development needs of the aviation industry due to the inherent disadvantages of the fuel. Hydrogen fuel, as a new type of energy, is clean and renewable. Its combustion products theoretically contain only H2O and NO x , will not produce CO2 and other pollutants. If NO x As for the emission problem, the impact of hydrogen combustion on the environment will be minimal, so hydrogen fuel is one of the important solutions to achieve the energy conservation and emission reduction needs of the aviation industry. Among them, hydrogen turbine aviation engines are a highly valued application of hydrogen fuel.

[0003] Since the development of hydrogen power technology is still immature, the high calorific value, flammability and explosion of hydrogen fuel have limited the development of hydrogen turbine engines and have few practical applications. Therefore, numerical simulation plays a vital role in the research of hydrogen turbine engines. Compared with traditional engines, hydrogen turbine engines have different fuel combustion products in addition to the different calorific value of fuel. This causes the physical parameters of the airflow in the hydrogen turbine engine to change, which has a certain impact on the engine performance. Therefore, when simulating the performance of hydrogen turbine engines, it is necessary to consider the impact of changes in the physical parameters of the airflow and show the characteristics of hydrogen fuel in aviation engine applications. Summary of the invention

[0004] The purpose of the present invention is to provide a hydrogen turbine engine performance simulation method based on the physical property changes of hydrogen fuel, to show the performance advantages and disadvantages of hydrogen fuel applied to aviation turbine engines through performance simulation, and to provide a certain reference value for the practical application of hydrogen turbine engines.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A method for simulating the performance of a hydrogen turbine engine based on the change of hydrogen fuel properties, characterized by comprising the following steps:

[0007] 1) Clarify the working environment of the engine, determine its flight altitude and flight Mach number, calculate the flow rate, enthalpy, temperature and pressure of the engine inlet airflow, simulate the working characteristics of the engine inlet, and calculate the flow rate, enthalpy, temperature and pressure of the inlet airflow outlet. In addition, since the inlet parts are not affected by hydrogen fuel, the traditional air property parameter calculation method can be used for calculation.

[0008] 2) According to the parameters of the airflow at the inlet duct outlet, the working process of the compressor components doing work on the airflow and compressing the airflow is simulated, and the flow rate, enthalpy, temperature and pressure of the airflow at the compressor outlet are calculated. In addition, since the inlet duct components are not affected by hydrogen fuel, the traditional air physical parameter calculation method can be used for calculation.

[0009] 3) According to the various parameters of the compressor outlet airflow, the hydrogen fuel flow rate input to the combustion chamber components, and the calorific value of the hydrogen fuel, the heat release process of the hydrogen fuel combustion in the engine combustion chamber is simulated, and the flow rate, enthalpy value, temperature and pressure of the combustion chamber outlet gas are calculated.

[0010] Since the operation of the combustion chamber components is affected by hydrogen fuel, the changes in the physical parameters of the airflow need to be considered. In the engine, the influence of the physical parameters is mainly reflected in the constant pressure specific heat capacity of the airflow c p The change of the value affects the conversion between air flow temperature and enthalpy, as shown in the following formula.

[0011] h=c p T

[0012] Where h is the enthalpy of the airflow, and T is the temperature of the airflow.

[0013] The high-temperature combustion gas produced by hydrogen fuel combustion is mainly composed of incompletely burned hydrogen fuel H2, oxygen O2, nitrogen N2 and combustion product water H2O. Therefore, before correcting the physical property parameters, it is necessary to calculate the c of these gases. p value, and the c p The value changes with the gas temperature. The specific calculation formula is as follows.

[0014] c p =C0+C1θ+C2θ 2 +C3θ 3 ,θ=T / 1000

[0015] In the formula, T represents the gas temperature; C0, C1, C2, and C3 are all constant values ​​that can be obtained from reference materials. The specific values ​​depend on the type of gas. The C0, C1, C2, and C3 values ​​corresponding to different gases are different. The above formula is applicable to H2, O2, N2, and H2O.

[0016] Based on the hydrogen fuel consumption and air mass flow rate of the engine, the mass fraction of each component of the high-temperature combustion gas produced in the engine combustion chamber can be calculated. p The c value of the high temperature fuel gas composed of H2, O2, N2 and H2O can be calculated by the weighted average method of mass fraction. p The specific calculation formula is as follows.

[0017]

[0018] In the formula, c p,i Indicates the c of one gas in a mixed gas p Value, y i Indicates the mass fraction of the gas.

[0019] Applying the above-mentioned physical property parameter calculation method to the calculation of combustion chamber components can realize the performance simulation of hydrogen turbine engine combustion chamber components.

[0020] 4) According to the various parameters of the combustion chamber outlet gas, simulate the working process of the gas on the turbine, and calculate the flow rate, enthalpy, temperature and pressure of the turbine component outlet airflow. Since the airflow passing through the turbine component is the gas generated after the combustion of hydrogen fuel, the influence of the change of physical parameters must also be considered. By applying the physical parameter calculation method described in step 3 to the simulation process of the turbine component, the performance simulation of the turbine component of the hydrogen turbine engine can be realized.

[0021] 5) According to the various parameters of the turbine outlet airflow, simulate the process of airflow acceleration and expansion in the tail nozzle, and calculate the flow rate, enthalpy, temperature and pressure of the tail nozzle outlet airflow. Since the airflow passing through the tail nozzle component is the fuel gas generated after the combustion of hydrogen fuel, the influence of the change of physical parameters must also be considered. By applying the physical parameter calculation method described in step 3 to the simulation process of the tail nozzle component, the performance simulation of the tail nozzle component of the hydrogen turbine engine can be realized.

[0022] 6) After the performance simulation of the engine inlet, compressor, combustion chamber, turbine and tail nozzle components, the engine must meet the balance conditions of flow balance and power balance. The specific formula is shown below.

[0023] The gas flow through the turbine and the air flow through the compressor in the engine remain continuous:

[0024] q mg =q ma -q ma,col +q mf

[0025] In the formula, q mg is the gas flow rate through the turbine in the engine, q ma represents the air flow entering the engine, q ma,col represents the amount of cooling air drawn from the compressor, q mf Indicates the fuel flow entering the combustion chamber.

[0026] Compressor and turbine power balance in the engine:

[0027] q ma W c =qmg W t η m

[0028] Where W c Indicates the output power of the compressor, W t represents the turbine power, η m It indicates the energy transfer efficiency when the turbine drives the compressor to rotate.

[0029] At this point, the performance simulation method of a hydrogen turbine engine based on changes in the physical properties of hydrogen fuel has been completed.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1) A hydrogen turbine engine performance simulation method is provided. In the absence of practical applications of hydrogen turbine engines, the performance advantages and disadvantages of hydrogen fuel applied to aviation turbine engines are demonstrated through performance simulation, which provides a certain reference value for the practical application of hydrogen turbine engines.

[0032] 2) A method for correcting the physical properties of hydrogen fuel is provided, which fully reflects the difference between hydrogen fuel and traditional engine fuel, improves the reliability of the performance simulation results of hydrogen turbine engines, and has certain guiding significance for the design of hydrogen turbine engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A flow chart of a method for simulating the performance of a hydrogen turbine engine based on the physical property changes of hydrogen fuel.

[0034] Figure 2 Schematic diagram of the structure of a certain type of hydrogen turbofan engine. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution in the present invention is clearly and completely described in conjunction with the drawings in the present invention. The specific examples described here are only used to explain the present invention and are not used to limit the present invention.

[0036] Take a certain type of turbofan engine as an example, its structure is as follows Figure 2 As shown in the figure, the turbofan engine includes a fan 1, a compressor 2, a combustion chamber 3, a turbine 4 and a tail nozzle 5; the gray line represents the air flow, and the red line represents the gas flow; the combustion chamber, the turbine and the tail nozzle are affected by the change of the physical properties of the hydrogen fuel.

[0037] according to Figure 1The performance simulation method of the hydrogen turbine engine shown in the figure simulates the performance of the fan, compressor, combustion chamber, turbine and nozzle components in the engine respectively. The simulation method of the fan component is similar to that of the compressor. In addition, the performance simulation of the hydrogen turbine engine needs to meet the conditions of flow balance and power balance.

[0038] A method for simulating the performance of a hydrogen turbine engine based on the change of hydrogen fuel properties comprises the following steps:

[0039] 1) Clarify the working environment of the engine, determine its flight altitude and flight Mach number, calculate the flow rate, enthalpy, temperature and pressure of the engine inlet airflow, simulate the working characteristics of the engine inlet, and calculate the flow rate, enthalpy, temperature and pressure of the inlet airflow outlet. In addition, since the inlet parts are not affected by hydrogen fuel, the traditional air property parameter calculation method can be used for calculation.

[0040] 2) According to the parameters of the airflow at the inlet duct outlet, the working process of the compressor components doing work on the airflow and compressing the airflow is simulated, and the flow rate, enthalpy, temperature and pressure of the airflow at the compressor outlet are calculated. In addition, since the inlet duct components are not affected by hydrogen fuel, the traditional air physical parameter calculation method can be used for calculation.

[0041] 3) According to the various parameters of the compressor outlet airflow, the hydrogen fuel flow rate input to the combustion chamber components, and the calorific value of the hydrogen fuel, the heat release process of the hydrogen fuel combustion in the engine combustion chamber is simulated, and the flow rate, enthalpy value, temperature and pressure of the combustion chamber outlet gas are calculated.

[0042] Since the operation of the combustion chamber components is affected by hydrogen fuel, the changes in the physical parameters of the airflow need to be considered. In the engine, the influence of the physical parameters is mainly reflected in the constant pressure specific heat capacity of the airflow c p The change of the value affects the conversion between air flow temperature and enthalpy, as shown in the following formula.

[0043] h=c p T

[0044] Where h is the enthalpy of the airflow, and T is the temperature of the airflow.

[0045] The high-temperature combustion gas produced by hydrogen fuel combustion is mainly composed of incompletely burned hydrogen fuel H2, oxygen O2, nitrogen N2 and combustion product water H2O. Therefore, before correcting the physical property parameters, it is necessary to calculate the c of these gases. p value, and the c p The value changes with the gas temperature. The specific calculation formula is as follows.

[0046] c p =C0+C1θ+C2θ 2 +C3θ3 ,θ=T / 1000

[0047] In the formula, T represents the gas temperature; C0, C1, C2, and C3 are all constant values ​​that can be obtained from reference materials. The specific values ​​depend on the type of gas. The C0, C1, C2, and C3 values ​​corresponding to different gases are different. The above formula is applicable to H2, O2, N2, and H2O.

[0048] Based on the hydrogen fuel consumption and air mass flow rate of the engine, the mass fraction of each component of the high-temperature combustion gas produced in the engine combustion chamber can be calculated. p The c value of the high temperature fuel gas composed of H2, O2, N2 and H2O can be calculated by the weighted average method of mass fraction. p The specific calculation formula is as follows.

[0049]

[0050] In the formula, c p,i Indicates the c of one gas in a mixed gas p Value, y i Indicates the mass fraction of the gas.

[0051] Applying the above-mentioned physical property parameter calculation method to the calculation of combustion chamber components can realize the performance simulation of hydrogen turbine engine combustion chamber components.

[0052] 4) According to the various parameters of the combustion chamber outlet gas, simulate the working process of the gas on the turbine, and calculate the flow rate, enthalpy, temperature and pressure of the turbine component outlet airflow. Since the airflow passing through the turbine component is the gas generated after the combustion of hydrogen fuel, the influence of the change of physical parameters must also be considered. By applying the physical parameter calculation method described in step 3 to the simulation process of the turbine component, the performance simulation of the turbine component of the hydrogen turbine engine can be realized.

[0053] 5) According to the various parameters of the turbine outlet airflow, simulate the process of airflow acceleration and expansion in the tail nozzle, and calculate the flow rate, enthalpy, temperature and pressure of the tail nozzle outlet airflow. Since the airflow passing through the tail nozzle component is the fuel gas generated after the combustion of hydrogen fuel, the influence of the change of physical parameters must also be considered. By applying the physical parameter calculation method described in step 3 to the simulation process of the tail nozzle component, the performance simulation of the tail nozzle component of the hydrogen turbine engine can be realized.

[0054] 6) After the performance simulation of the engine inlet, compressor, combustion chamber, turbine and tail nozzle components, the engine must meet the balance conditions of flow balance and power balance. The specific formula is shown below.

[0055] The gas flow through the turbine and the air flow through the compressor in the engine remain continuous:

[0056] q mg =q ma -q ma,col +q mf

[0057] In the formula, q mg is the gas flow rate through the turbine in the engine, q ma represents the air flow entering the engine, q ma,col represents the amount of cooling air drawn from the compressor, q mf Indicates the fuel flow entering the combustion chamber.

[0058] Compressor and turbine power balance in the engine:

[0059] q ma W c =q mg W t η m

[0060] Where W c Indicates the output power of the compressor, W t represents the turbine power, η m It indicates the energy transfer efficiency when the turbine drives the compressor to rotate.

[0061] Since the combustion chamber, turbine and nozzle components in the engine are affected by the physical property changes of hydrogen fuel, the physical property parameter calculation method described in the present invention needs to be applied in the performance simulation process. The specific method is as follows: calculate the mass fraction of each component gas in the high-temperature fuel gas at the outlet of the engine combustion chamber, and calculate the c p The c value of the mixed gas is calculated by the weighted average method of mass fraction. p The calculated c p The value is closely related to the mixture composition and mixture temperature, realizing the flexible change of physical parameters under different engine operating conditions.

[0062] At this point, a performance simulation scheme for a certain type of hydrogen-powered turbofan engine is formed. Under the engine cruising condition, the temperature before the engine turbine is kept constant, and the performance parameters of the traditional engine and the hydrogen-powered turbine engine are calculated respectively. Table 1 shows the performance of the traditional engine and the hydrogen-powered turbine engine in c after the physical property parameters are corrected. p Table 2 shows the impact of changes in physical parameters on engine performance.

[0063] Table 1 Comparison of physical properties between conventional engines and hydrogen turbine engines

[0064] <![CDATA[c p [kJ / (kg*K)]]]> Conventional engine Hydrogen turbine engine Increment High pressure turbine inlet 1.086 1.138 4.79％ Low pressure turbine inlet 1.056 1.108 4.92％

[0065] Table 2 Performance comparison between conventional engine and hydrogen turbine engine

[0066] Performance parameters Conventional engine Hydrogen turbine engine Increment Turbine inlet temperature (K) 1213 1213 0％ Engine thrust (kN) 41.66 50.53 21.3％ Fuel consumption rate [kg / (N*h)] 0.0561 0.01633 -70.9％ Energy consumption rate [kJ / (N*h)] 2399 2325 3.08％

[0067] It can be seen from Table 1 that when the temperature before the engine turbine remains unchanged, the use of hydrogen fuel makes the engine high-pressure vortex and low-pressure turbine inlet airflow c p As shown in Table 2, when the temperature before the engine turbine remains unchanged, the engine thrust is improved due to the change in the physical properties of hydrogen fuel, while its fuel consumption rate and energy consumption rate are reduced, which improves the engine performance.

Claims

1. A method for simulating the performance of a hydrogen turbine engine based on the physical property changes of hydrogen fuel, characterized in that: The following steps are involved: 1) Clarify the working environment of the engine, determine its flight altitude and flight Mach number, calculate the flow rate, enthalpy, temperature and pressure of the engine inlet airflow, simulate the working characteristics of the engine inlet, and calculate the flow rate, enthalpy, temperature and pressure of the inlet airflow outlet; 2) According to the various parameters of the airflow at the inlet duct outlet, simulate the working process of the compressor components doing work on the airflow and compressing the airflow, and calculate the flow rate, enthalpy value, temperature and pressure of the airflow at the compressor outlet; 3) According to the parameters of the compressor outlet airflow, the hydrogen fuel flow rate input to the combustion chamber components, and the calorific value of the hydrogen fuel, the heat release process of the hydrogen fuel combustion in the engine combustion chamber is simulated, and the flow rate, enthalpy value, temperature and pressure of the combustion chamber outlet gas are calculated; 4) According to the various parameters of the combustion chamber outlet gas, simulate the working process of the gas on the turbine, and calculate the flow rate, enthalpy, temperature and pressure of the turbine component outlet airflow; 5) According to the various parameters of the turbine outlet airflow, simulate the process of airflow acceleration and expansion in the tail nozzle, and calculate the flow rate, enthalpy, temperature and pressure of the tail nozzle outlet airflow; 6) After the performance simulation of the engine inlet, compressor, combustion chamber, turbine and tail nozzle components, the engine must meet the balance conditions of flow balance and power balance. The specific formula is as follows: The gas flow through the turbine and the air flow through the compressor in the engine remain continuous: q mg =q ma -q ma，col +q mf In the formula, q mg is the gas flow rate through the turbine in the engine, q ma represents the air flow rate entering the engine, qma, and col represents the cooling air volume drawn from the compressor, qm f Indicates the fuel flow rate entering the combustion chamber; Compressor and turbine power balance in the engine: q ma W c =q mg W t η m Where W c Indicates the output power of the compressor, W t represents the turbine power, η m It indicates the energy transfer efficiency when the turbine drives the compressor to rotate; Complete the performance simulation method of hydrogen turbine engines based on changes in the physical properties of hydrogen fuel.

2. The method for simulating the performance of a hydrogen turbine engine based on the change of hydrogen fuel properties according to claim 1, characterized in that: In step 3), the operation of the combustion chamber components is affected by the hydrogen fuel. Considering the changes in the physical parameters of the airflow, in the engine, the influence of the physical parameters is reflected in the constant pressure specific heat capacity c of the airflow. p The change of the value affects the conversion between air flow temperature and enthalpy value, as shown in the following formula: h=c p T In the formula, h represents the enthalpy of the airflow, and T represents the temperature of the airflow; The high-temperature combustion gas produced by hydrogen fuel combustion consists of incompletely burned hydrogen fuel H2, oxygen O2, nitrogen N2 and combustion product water H2O. Before correcting the physical property parameters, the gas c p value, and the c p The value changes with the gas temperature. The specific calculation formula is as follows: c p =C0+C1θ+C2θ 2 +C3θ 3 ,θ=T / 1000 Where, T represents the gas temperature; C0, C1, C2, and C3 are all constant values. The specific values ​​depend on the type of gas. The C0, C1, C2, and C3 values ​​corresponding to different gases are different. The above formula is applicable to H2, O2, N2, and H2O. According to the hydrogen fuel consumption and air mass flow of the engine, the mass fraction of each component of the high-temperature combustion gas produced in the engine combustion chamber is calculated; combined with the c of each component gas in the above calculation p The c value of the high temperature fuel gas composed of H2, O2, N2 and H2O is calculated by the weighted average method of mass fraction. p The specific calculation formula is as follows: In the formula, c p，i Indicates the c of one gas in a mixed gas p Value, y i Indicates the mass fraction of the gas.

3. The method for simulating the performance of a hydrogen turbine engine based on the change of hydrogen fuel properties according to claim 1, characterized in that: In step 4), the airflow passing through the turbine component is the combustion gas produced by the combustion of hydrogen fuel. Considering the influence of the change of physical parameters, the physical parameter calculation method described in step 3) is applied to the simulation process of the turbine component to realize the performance simulation of the turbine component of the hydrogen turbine engine.

4. The method for simulating the performance of a hydrogen turbine engine based on the change of hydrogen fuel properties according to claim 1, characterized in that: In step 5), the airflow passing through the tail nozzle component is the combustion gas produced after the combustion of hydrogen fuel, and the influence of the change of physical parameters needs to be considered. The physical parameter calculation method described in step 3) is applied to the simulation process of the tail nozzle component to realize the performance simulation of the tail nozzle component of the hydrogen turbine engine.

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