A method and system for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber

Abstract

The present invention relates to the field of gas turbine technology, and more particularly to a method and system for optimizing and adjusting the combustion chamber outlet temperature of a gas turbine. The method comprises establishing a three-dimensional combustion calculation numerical model for the combustion chamber, calculating the combustion chamber flow field characteristic parameters under typical load conditions; obtaining the gas specific heat ratio at the combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under typical load conditions; fitting a calculation formula for the gas specific heat ratio and the total pressure loss coefficient of the combustion chamber; establishing a turbine inlet temperature calculation formula to calculate the turbine inlet temperature; and feeding the calculated turbine inlet temperature and combustion pressure pulsation data obtained from the operating data of the gas turbine generator set back to the gas turbine control system to adjust the IGV opening and fuel flow rate. The present invention can improve the thermal efficiency of the gas turbine cycle and the operational safety of the gas turbine by accurately adjusting the combustion chamber outlet temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines, and in particular to a method and system for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber. Background Art

[0002] A gas turbine is a highly efficient thermal energy conversion device. It burns fuel to generate high-temperature, high-pressure gas, which in turn drives the turbine and converts it into mechanical energy. Combustion chamber outlet temperature is a critical parameter in gas turbine operation, significantly impacting overall system efficiency, safety, lifespan, and pollutant emissions. In terms of efficiency, higher combustion chamber outlet temperatures mean more thermal energy can be converted into mechanical energy, thereby improving overall system efficiency. However, this process is not unlimited, as excessively high combustion chamber outlet temperatures can increase thermal stress in materials, impacting the lifespan of the gas turbine. For safety and longevity, the combustion chamber and turbine sections of a gas turbine require materials that can withstand high temperatures, such as nickel-based alloys. Controlling combustion chamber outlet temperature is crucial to ensuring these high-temperature components do not exceed their material limits. Furthermore, a uniform combustion chamber outlet temperature distribution reduces thermal stress and extends component life. Regarding emissions control, while higher combustion chamber outlet temperatures promote more complete combustion and reduce unburned hydrocarbons and carbon dioxide emissions, they can also increase nitrogen oxide (NOx) emissions. This is because high temperatures promote the reaction between nitrogen and oxygen in the air, producing more NOx.

[0003] In summary, controlling the combustor outlet temperature of a gas turbine is crucial for ensuring high efficiency, safety, environmental friendliness, and economic efficiency of the entire system. Precise control of combustor outlet temperature is crucial for ensuring safe operation of the gas turbine. This precise control not only ensures safe operation but also effectively extends the maintenance cycle and service life of the gas turbine, reducing maintenance costs and improving the economic benefits of the gas turbine. Summary of the Invention

[0004] In view of the above problems in the prior art, the present invention is proposed.

[0005] Therefore, the present invention provides a method for optimizing and adjusting the combustion chamber outlet temperature of a gas turbine, which can solve the problem that traditional gas turbines cannot accurately control the combustion chamber outlet temperature.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solutions: a method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber, comprising: establishing a three-dimensional combustion calculation numerical model of the combustion chamber, calculating the flow field characteristic parameters of the combustion chamber under typical load conditions; obtaining the gas specific heat ratio at the combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under typical load conditions; fitting to obtain calculation formulas for the gas specific heat ratio and the total pressure loss coefficient of the combustion chamber; establishing a turbine inlet temperature calculation formula, and calculating the turbine inlet temperature; feeding back the calculated turbine inlet temperature and the combustion pressure pulsation data obtained from the gas turbine generator set operating data to the gas turbine control system to adjust the IGV opening and fuel flow rate.

[0007] As a preferred embodiment of the method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to the present invention, the method further comprises: establishing a three-dimensional combustion calculation numerical model for the combustor, using Thermoflow power plant heat balance analysis software to establish a Thermoflow gas turbine heat balance calculation model for the gas turbine model used in the gas power plant; setting boundary parameters of the calculation model according to historical operating data of the gas turbine; verifying the accuracy of the calculation model using the historical operating data of the gas turbine; using the verified Thermoflow gas turbine heat balance calculation model to calculate the inlet and outlet boundary parameters of the combustor from startup to full load operation of the gas turbine; and then using fluid numerical simulation software to establish a three-dimensional combustion numerical model for the combustor; and setting the inlet and outlet boundary conditions of the combustion numerical model according to the boundary parameters calculated using the Thermoflow gas turbine heat balance calculation model.

[0008] The calculation of the combustion chamber flow field characteristic parameters under typical load conditions includes respectively calculating the gas pressure field, temperature field, and velocity field in the gas turbine combustion chamber under 50%, 60%, 70%, 80%, 90%, and 100% typical loads.

[0009] As a preferred embodiment of the method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to the present invention, the total pressure loss coefficient of the combustor is expressed as follows: the total pressure loss coefficient of the combustor at the inlet of the gas turbine combustor under typical loads of 50%, 60%, 70%, 80%, 90% and 100% is obtained by analysis. * 2. Total pressure P at the combustion chamber outlet * 3, expressed as,

[0010]

[0011] Among them, σ c Expressed as the total pressure loss coefficient of the combustion chamber.

[0012] As a preferred embodiment of the method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to the present invention, the calculation formula for obtaining the gas specific heat ratio and the combustor total pressure loss coefficient by fitting includes adopting a curve fitting method, using the calculated combustor total pressure loss coefficient and the combustor outlet gas specific heat ratio, and taking relative load as an independent variable, respectively fitting the calculation formulas for obtaining the combustor total pressure loss coefficient and the combustor outlet gas specific heat ratio.

[0013] σ c =f(w)

[0014] γ=g(w)

[0015] Where w is the relative load of the independent variable, f(w) is the calculation function of the total pressure loss coefficient of the combustion chamber obtained by fitting, and g(w) is the calculation function of the specific heat ratio of the combustion chamber outlet gas obtained by fitting.

[0016] As a preferred embodiment of the method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to the present invention, the formula for calculating the turbine inlet temperature includes utilizing the energy variation characteristics of the high-temperature and high-pressure gas as it expands and performs work in the turbine to establish a formula for calculating the turbine inlet temperature T3, which is expressed as follows:

[0017]

[0018] Wherein, T4 is the gas turbine exhaust temperature; P2 is the gas turbine compressor exhaust pressure; P4 is the gas turbine exhaust pressure;

[0019] The gas turbine exhaust temperature T4, gas turbine compressor exhaust pressure P2, and gas turbine exhaust pressure P4 are obtained from the gas turbine generator set operation data, combined with the combustion chamber total pressure loss coefficient σ c The turbine inlet temperature T3 is calculated using the calculation formula for the combustion chamber outlet gas specific heat ratio γ and the calculation formula for the turbine inlet temperature.

[0020] As a preferred embodiment of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to the present invention, the calculated turbine inlet temperature T3 and the combustion pressure pulsation data obtained from the operating data of the gas turbine generator set are fed back to the gas turbine control system, and the gas turbine control system determines: when T 3r -T3≥α, and the combustion pressure pulsation value is less than the alarm value, the IGV opening is output to reduce by 1%; when T 3r -T3≥α, but the combustion pressure pulsation value is greater than the alarm value, the output fuel flow rate increase instruction 0.5%; when T 3r -T3<0, then the output is the instruction to increase the IGV opening by 1%;

[0021] Among them, T3r is the turbine inlet temperature limit set in the gas turbine control system, and α is the turbine inlet temperature safety threshold set in the gas turbine control system.

[0022] As a preferred embodiment of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to the present invention, the adjustment of the IGV opening and the fuel flow rate includes real-time calculation of the turbine inlet temperature and, in combination with the changes in the combustion pressure pulsation data, immediate generation of new IGV and fuel flow rate control instructions until the turbine inlet temperature T3 is higher than T 3r -α value, so that the turbine inlet temperature T3 is close to the turbine inlet temperature limit T under safe conditions 3r , improve the thermal efficiency of gas turbine power generation.

[0023] Another object of the present invention is to provide a gas turbine combustion chamber outlet temperature optimization and adjustment system to improve combustion efficiency, optimize combustion chamber design, ensure accurate understanding of the flow conditions in the combustion chamber, adjust the fuel ratio, reduce pressure loss, improve energy utilization efficiency, realize the prediction and optimization of gas turbine operating parameters, enhance system stability, ensure reasonable turbine inlet temperature, and realize efficient and stable operation of the gas turbine.

[0024] As a preferred embodiment of the gas turbine combustor outlet temperature optimization and adjustment system described in the present invention, the system comprises: a combustion model establishment module, a flow parameter calculation module, a gas specific heat ratio and combustor pressure loss calculation module, a gas specific heat ratio and combustor pressure loss fitting module, a turbine inlet temperature calculation module, and a data feedback and adjustment module;

[0025] The combustion model establishment module establishes a three-dimensional combustion calculation numerical model of the combustion chamber;

[0026] The flow parameter calculation module calculates the flow field characteristic parameters of the combustion chamber under typical load conditions;

[0027] The gas specific heat ratio and combustion chamber pressure loss calculation module obtains the gas specific heat ratio at the combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under typical load conditions;

[0028] The gas specific heat ratio and combustion chamber pressure loss fitting module is used to obtain the calculation formula of the gas specific heat ratio and the combustion chamber total pressure loss coefficient by fitting;

[0029] The turbine inlet temperature calculation module establishes a turbine inlet temperature calculation formula to calculate the turbine inlet temperature;

[0030] The data feedback and adjustment module feeds back the calculated turbine inlet temperature and the combustion pressure pulsation data obtained from the gas turbine generator set operation data to the gas turbine control system; and adjusts the IGV opening and fuel flow.

[0031] A computer device includes a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of any one of the methods for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber are implemented.

[0032] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of any one of the methods for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber are implemented.

[0033] The beneficial effects of the present invention are as follows: the cycle thermal efficiency of a gas turbine is generally positively correlated with the turbine inlet temperature. Increasing the turbine inlet temperature can improve the cycle thermal efficiency. However, due to the high turbine inlet temperature of a gas turbine, it cannot be directly measured. This solution calculates the turbine inlet temperature based on the turbine exhaust temperature, compares and analyzes the distance between the calculated turbine inlet temperature and the turbine inlet temperature limit, and reduces or increases the IGV opening in real time, thereby controlling the air flow entering the gas turbine. When the IGV opening is reduced, the air flow entering the gas turbine decreases, and the turbine inlet temperature will increase, thereby improving the cycle thermal efficiency of the gas turbine; when the IGV opening is increased, the air flow entering the gas turbine will increase, and the turbine inlet temperature will decrease, thereby preventing the turbine blades from being burned and improving the operating safety of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A flow chart of a method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber provided in one embodiment of the present invention.

[0036] Figure 2 A three-dimensional solid model of a combustion chamber of a gas turbine combustion chamber outlet temperature optimization adjustment method provided in one embodiment of the present invention.

[0037] Figure 3 A three-dimensional numerical model of a combustion chamber of a gas turbine combustion chamber outlet temperature optimization adjustment method is provided in accordance with one embodiment of the present invention.

[0038] Figure 4 The present invention provides a method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber, and provides a result of heat balance calculation of a thermoflow gas turbine under 100% typical load.

[0039] Figure 5 The present invention provides a method for optimizing and adjusting the outlet temperature of a gas turbine combustor, according to one embodiment of the present invention, and shows the pressure field result of the central cross section of the combustor under 100% typical load.

[0040] Figure 6 The present invention provides a method for optimizing and adjusting the outlet temperature of a gas turbine combustor, according to one embodiment of the present invention, and shows the temperature field result of the central cross section of the combustor under 100% typical load.

[0041] Figure 7 The present invention provides a method for optimizing and adjusting the outlet temperature of a gas turbine combustor, according to one embodiment of the present invention, and shows the velocity field result of the central cross section of the combustor under 100% typical load. DETAILED DESCRIPTION

[0042] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0043] Example 1, reference Figure 1 , which is the first embodiment of the present invention, provides a method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber, including: this scheme uses the combustion chamber inlet pressure P2 and combines it with the combustion chamber pressure loss coefficient to calculate the turbine inlet pressure, and then calculates the turbine inlet temperature T3. The method is simple, feasible, and has high implementation efficiency.

[0044] This scheme does not require experiments. By simply establishing a gas turbine heat balance calculation model and a gas turbine combustion chamber numerical model and using a curve fitting method, the total pressure loss coefficient σ of the gas turbine combustion chamber under different loads can be obtained. c and the specific heat ratio γ of the combustion chamber outlet gas, which improves the calculation accuracy of the turbine inlet temperature.

[0045] This solution can calculate the turbine inlet temperature in real time by retrieving operating parameters such as the combustion chamber inlet pressure P2, turbine exhaust pressure P4, and turbine exhaust temperature T4 from the real-time database of the gas turbine generator set, and compare it with the turbine inlet temperature limit of the gas turbine in real time. According to the distance between the comparison result and the turbine inlet temperature safety threshold α, the IGV opening and fuel flow rate are adjusted in real time to increase the turbine inlet temperature of the gas turbine under partial load, thereby improving the thermal efficiency of the gas turbine cycle.

[0046] This solution makes up for the defect that the turbine inlet temperature of the gas turbine cannot be directly measured, making the turbine inlet temperature control of the gas turbine more accurate. It can improve the thermal efficiency of the gas turbine cycle under low load, and increase the IGV opening under high load, increase the air flow entering the gas turbine, reduce the turbine inlet temperature, prevent turbine blade burning, and improve the safety of gas turbine operation.

[0047] 1) Establish a three-dimensional combustion calculation numerical model for the gas turbine combustor.

[0048] 2) Due to the high temperature of the gas at the combustor outlet of a gas turbine, there are generally no measurement points to directly measure the pressure and temperature of the gas at the combustor outlet. To obtain the combustor inlet and outlet boundary parameters required for the three-dimensional combustion numerical model analysis of the gas turbine combustor, a Thermoflow gas turbine heat balance calculation model was developed using the Thermoflow power plant heat balance analysis software, specifically for the gas turbine model used in gas-fired power plants. The model boundary parameters were set based on historical gas turbine operating data, and the accuracy of the calculation model was verified using historical gas turbine operating data. The verified Thermoflow gas turbine heat balance calculation model was used to calculate the combustor inlet and outlet boundary parameters for the gas turbine from startup to full load operation. Considering that gas turbine pollutant emissions can exceed standards when operating at low load, gas turbine generator sets generally operate between 50% and 100% load. Therefore, the above method is used to calculate the boundary parameters such as the air and fuel mass flow rate, temperature, and combustor outlet pressure at the gas turbine combustor under typical loads of 50%, 60%, 70%, 80%, 90%, and 100%. The typical load can be selected and determined based on the regular operating load point of the gas turbine power plant. In the three-dimensional combustion calculation numerical model of the gas turbine combustor established in step 1, the combustor inlet and outlet boundary parameters calculated in step 2 are set to calculate the gas pressure field, temperature field, and velocity field of the gas in the gas turbine combustor under typical loads of 50%, 60%, 70%, 80%, 90%, and 100%.

[0049] 3) According to the calculation results of step 2, the total pressure P2* at the inlet of the gas turbine combustor, the total pressure P3* at the outlet of the combustor and the specific heat ratio γ of the gas at the outlet of the combustor are analyzed and obtained under typical loads such as 50%, 60%, 70%, 80%, 90% and 100%. Calculate the total pressure loss coefficient σ of the combustion chamber c .

[0050] 4) Using the curve fitting method, the total pressure loss coefficient σ of the combustion chamber obtained by step 3 is used c and the specific heat ratio of the combustion chamber outlet gas γ, and the relative load as the independent variable, respectively, to obtain the total pressure loss coefficient σ of the combustion chamber cAnd the calculation formula for the specific heat ratio γ of the combustion chamber outlet gas.

[0051] σ c =f(w)

[0052] γ=g(w) (1)

[0053] Where w is the relative load of the independent variable, f(w) is the calculation function of the total pressure loss coefficient of the combustion chamber obtained by fitting, and g(w) is the calculation function of the specific heat ratio of the combustion chamber outlet gas obtained by fitting.

[0054] 5) Using the energy variation characteristics of high-temperature and high-pressure gas expanding and working in the turbine, the calculation formula for the turbine inlet temperature T3 (i.e., the combustion chamber outlet temperature) is established:

[0055]

[0056] Where T4 is the gas turbine exhaust temperature; P2 is the gas turbine compressor exhaust pressure; and P4 is the gas turbine exhaust pressure.

[0057] 6) Obtain the gas turbine exhaust temperature T4, gas turbine compressor exhaust pressure P2, and gas turbine exhaust pressure P4 from the gas turbine generator set operating data, and calculate the turbine inlet temperature T3 by combining formula (1) and formula (2).

[0058] 7) Feedback the calculated turbine inlet temperature T3 and the combustion pressure pulsation data obtained from the gas turbine generator set operation data to the gas turbine control system, and the gas turbine control system makes the following judgments: 1. When T 3r -T3≥α(T 3r is the turbine inlet temperature limit set in the gas turbine control system, α is the turbine inlet temperature safety threshold set in the gas turbine control system), and the combustion pressure pulsation value is less than the alarm value, then the IGV opening is output to reduce by 1%; 2. When T 3r -T3≥α, but the combustion pressure pulsation value is greater than the alarm value, the output is a command to increase the fuel flow by 0.5%; 3. When T 3r -T3<0, then the output is a command to increase the IGV opening by 1%.

[0059] 8) After executing the control command issued by the gas turbine control system in step 7, the turbine inlet temperature is calculated in real time, and combined with the changes in the combustion pressure pulsation data, new IGV and fuel flow control commands are generated immediately until the turbine inlet temperature T3 is higher than T 3r -α value, so that the turbine inlet temperature T3 is as close as possible to the turbine inlet temperature limit T under safe conditions 3r , improve the thermal efficiency of gas turbine power generation.

[0060] The above is a schematic diagram of a method for optimizing and adjusting the combustor outlet temperature of a gas turbine according to this embodiment. It should be noted that the system technical solution of this method for optimizing and adjusting the combustor outlet temperature of a gas turbine is based on the same concept as the technical solution of the aforementioned method for optimizing and adjusting the combustor outlet temperature of a gas turbine. For details not described in detail in the system technical solution of the method for optimizing and adjusting the combustor outlet temperature of a gas turbine according to this embodiment, reference can be made to the description of the technical solution of the aforementioned method for optimizing and adjusting the combustor outlet temperature of a gas turbine.

[0061] The gas turbine combustor outlet temperature optimization and adjustment system of this embodiment includes a combustion model establishment module, a flow parameter calculation module, a gas specific heat ratio and combustor pressure loss calculation module, a gas specific heat ratio and combustor pressure loss fitting module, a turbine inlet temperature calculation module, and a data feedback and adjustment module.

[0062] The combustion model establishment module establishes a three-dimensional combustion calculation numerical model of the combustion chamber;

[0063] The flow parameter calculation module calculates the flow field characteristic parameters of the combustion chamber under typical load conditions;

[0064] The gas specific heat ratio and combustion chamber pressure loss calculation module obtains the gas specific heat ratio at the combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under typical load conditions;

[0065] The gas specific heat ratio and combustion chamber pressure loss fitting module is used to obtain the calculation formula of the gas specific heat ratio and the combustion chamber total pressure loss coefficient by fitting;

[0066] The turbine inlet temperature calculation module establishes a turbine inlet temperature calculation formula to calculate the turbine inlet temperature;

[0067] The data feedback and adjustment module feeds back the calculated turbine inlet temperature and the combustion pressure pulsation data obtained from the gas turbine generator set operation data to the gas turbine control system; and adjusts the IGV opening and fuel flow.

[0068] This embodiment further provides a computing device applicable to a method for optimizing and adjusting the outlet temperature of a gas turbine combustor, including:

[0069] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0070] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0071] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0072] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0073] Example 2, reference Figure 2-Figure 7 , which is the second embodiment of the present invention, provides a method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0074] 1) A gas power plant uses a 9FA gas turbine and uses UG modeling software to build a three-dimensional solid model of the gas turbine combustion chamber. Figure 2 , the solid model established by UG was meshed using ANSYS commercial software, and a three-dimensional numerical model of the combustion chamber was constructed. Figure 3 .

[0075] 2) Using Thermoflow power plant heat balance analysis professional software, a 9FA gas turbine heat balance calculation model was established. According to the historical operation data of the gas turbine, the calculation model inlet atmospheric pressure was set to 1.001 bar, the atmospheric temperature was set to 21.49 ° C, the relative humidity was set to 79%, and the load was set to 100%. The calculation results are shown in Figure 4The power plant's gas turbine operating data indicates that the combustor inlet air pressure is 15.5 bar and the temperature is 400°C. The pressure and temperature calculated by Thermoflow are 15.46 bar and 399.8°C, respectively, verifying the accuracy of the established Thermoflow gas turbine heat balance calculation model. Given that the gas turbines of a certain gas-fired power plant typically operate at loads of 50%, 65%, 80%, 95%, and 100%, these loads were used as typical loads. The verified Thermoflow gas turbine heat balance calculation model was used to calculate the combustor inlet and outlet boundary parameters under these typical loads. At 50% load, the combustor inlet air temperature is 358°C, the flow rate is 341.6 kg / s, the combustor inlet fuel temperature is 185°C, the flow rate is 9.054 kg / s, and the combustor outlet pressure is 10.12 bar. At 65% load, the air temperature at the combustor inlet was 374°C, the flow rate was 385 kg / s, the fuel temperature at the combustor inlet was 185°C, the flow rate was 10.674 kg / s, and the combustor outlet pressure was 11.59 bar. At 80% load, the air temperature at the combustor inlet was 385°C, the flow rate was 436.4 kg / s, the fuel temperature at the combustor inlet was 185°C, the flow rate was 12.168 kg / s, and the combustor outlet pressure was 13.18 bar. At 95% load, the air temperature at the combustor inlet was 392°C, the flow rate was 490.4 kg / s, the fuel temperature at the combustor inlet was 185°C, the flow rate was 13.608 kg / s, and the combustor outlet pressure was 14.79 bar. At 100% load, the combustion chamber inlet air temperature is 399.8°C, the flow rate is 493 kg / s, the combustion chamber inlet fuel temperature is 185°C, the flow rate is 13.77 kg / s, and the combustion chamber outlet pressure is 14.88 bar.

[0076] 3) Based on the combustion chamber inlet and outlet boundary parameters calculated in step 2, the three-dimensional numerical model of the combustion chamber established in step 1 is used to calculate the flow field parameters such as pressure, temperature, and velocity of the gas turbine combustion chamber under typical loads of 50%, 65%, 80%, 95%, and 100%. Some of the results are shown in Figures 5 to 7 , read the combustion chamber inlet total pressure P2* and combustion chamber outlet total pressure P3* from the numerical calculation results, and use the formula The total pressure loss coefficient σ of the combustion chamber under typical loads such as 50%, 65%, 80%, 95% and 100% is calculated respectively. c The specific heat ratio γ of the combustion chamber outlet gas under typical loads of 50%, 65%, 80%, 95% and 100% are 1.33087, 1.31899, 1.28342, 1.28386 and 1.28393 respectively.

[0077] 4) Using the curve fitting method, the total pressure loss coefficient σ of the combustion chamber obtained by step 3 is used c and the specific heat ratio of the combustion chamber outlet gas γ, and the relative load as the independent variable, respectively, to obtain the total pressure loss coefficient σ of the combustion chamber c And the calculation formula for the specific heat ratio γ of the combustion chamber outlet gas.

[0078] σ c =0.004w+0.036 0.5≤w≤1.0 (3)

[0079]

[0080] Where w is the relative load of the independent variable.

[0081] 5) Establish the calculation formula for turbine inlet temperature T3 (i.e. combustion chamber outlet temperature):

[0082]

[0083] Among them, T4 is the gas turbine exhaust temperature; P2 is the gas turbine compressor exhaust pressure; P4 is the gas turbine exhaust pressure.

[0084] 6) From the real-time database of a power plant's F-class gas turbine generator set, it is obtained that when the generator set power is 90% load, the combustion chamber inlet pressure P2 is 1.56MPa, the turbine exhaust pressure P4 is 0.105357MPa, and the turbine exhaust temperature T4 is 860K. The total pressure loss coefficient σ of the combustion chamber is calculated using formula (3) and formula (4) respectively. c The specific heat ratio of the combustion chamber outlet gas is 0.0396, and the specific heat ratio γ is 1.283698. Then, the turbine inlet temperature T3 is calculated to be 1546.3K using formula (5).

[0085] 7) The maximum amplitude of the combustion pressure pulsation at this time is 0.67 kPa obtained from the real-time database of a class F gas turbine generator set in a power plant. The gas turbine inlet temperature limit T is obtained by analyzing the gas turbine control system. 3r The turbine inlet temperature (T3) is set to 1620K, the turbine inlet temperature safety threshold α is set to 10K, and the pressure pulsation alarm value is set to 2.5kPa. The calculated turbine inlet temperature T3 and combustion pressure pulsation data obtained from the gas turbine generator set operating data are fed back to the gas turbine control system. The gas turbine control system calculates in real time: 1620 - 1546.3 = 73.7 > α, and if the combustion pressure pulsation value is less than the alarm value, it outputs a command to reduce the IGV opening by 1%.

[0086] 8) After executing the control command issued by the gas turbine control system in step 7, the real-time calculation shows that the turbine inlet temperature T3 is 1568.2K and the maximum amplitude of the combustion pressure pulsation is 0.65kPa. The gas turbine control system continues to output the command to reduce the IGV opening by 1%. After adjustment, the turbine inlet temperature T3 is calculated again to be 1612.2K and the maximum amplitude of the combustion pressure pulsation is 0.66kPa. The gas turbine control system calculates and determines in real time that: 1620-1612.2=7.8<α, and the turbine inlet temperature T3 is higher than T3 for the first time. 3r -α value, indicating that the turbine inlet temperature has reached the optimal value.

Claims

1. A method for optimizing and adjusting the outlet temperature of a gas turbine combustor, characterized by: include, Establish a three-dimensional combustion calculation numerical model for the combustion chamber and calculate the flow field characteristic parameters of the combustion chamber under typical load conditions; Obtain the specific heat ratio of the gas at the combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under typical load conditions; The calculation formulas of gas specific heat ratio and combustion chamber total pressure loss coefficient are obtained by fitting; Establish the turbine inlet temperature calculation formula to calculate the turbine inlet temperature; The calculated turbine inlet temperature and combustion pressure pulsation data obtained from the gas turbine generator set operating data are fed back to the gas turbine control system to adjust the IGV opening and fuel flow; The calculation formula for obtaining the gas specific heat ratio and the total pressure loss coefficient of the combustion chamber by fitting includes: using the calculated total pressure loss coefficient of the combustion chamber and the specific heat ratio of the gas at the combustion chamber outlet by curve fitting method, taking the relative load as the independent variable, respectively fitting the total pressure loss coefficient of the combustion chamber σ c And the calculation formula of the specific heat ratio γ of the combustion chamber outlet gas, s c =f(w) γ=g(w) Where w is the relative load of the independent variable, f(w) is the calculation function of the total pressure loss coefficient of the combustion chamber obtained by fitting, and g(w) is the calculation function of the specific heat ratio of the combustion chamber outlet gas obtained by fitting.

2. The method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to claim 1, wherein: The method of establishing a three-dimensional combustion calculation numerical model for the combustion chamber includes: using Thermoflow power plant heat balance analysis software to establish a Thermoflow gas turbine heat balance calculation model for a gas turbine model used in a gas-fired power plant; setting boundary parameters of the calculation model based on historical operating data of the gas turbine; and verifying the accuracy of the calculation model using the historical operating data of the gas turbine; using the verified Thermoflow gas turbine heat balance calculation model to calculate and obtain combustion chamber inlet and outlet boundary parameters of the gas turbine from startup to full load operation; and then using fluid numerical simulation software to establish a three-dimensional combustion numerical model for the combustion chamber; and setting inlet and outlet boundary conditions of the combustion numerical model based on the boundary parameters calculated using the Thermoflow gas turbine heat balance calculation model. The calculation of the combustion chamber flow field characteristic parameters under typical load conditions includes respectively calculating the gas pressure field, temperature field, and velocity field in the gas turbine combustion chamber under 50%, 60%, 70%, 80%, 90%, and 100% typical loads.

3. The method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to claim 2, wherein: The total pressure loss coefficient is expressed as follows: the total pressure P at the inlet of the gas turbine combustor under 50%, 60%, 70%, 80%, 90% and 100% typical loads is obtained by analysis. * 2. Total pressure P at the combustion chamber outlet * 3, expressed as, Among them, σ c Expressed as the total pressure loss coefficient of the combustion chamber.

4. The method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to claim 3, wherein: The formula for calculating the turbine inlet temperature includes utilizing the energy variation characteristics of the high-temperature and high-pressure gas as it expands and performs work in the turbine to establish a formula for calculating the turbine inlet temperature T3, which is expressed as follows: Wherein, T4 is the gas turbine exhaust temperature; P2 is the gas turbine compressor exhaust pressure; P4 is the gas turbine exhaust pressure; The gas turbine exhaust temperature T4, gas turbine compressor exhaust pressure P2, and gas turbine exhaust pressure P4 are obtained from the gas turbine generator set operation data, combined with the combustion chamber total pressure loss coefficient σ c The turbine inlet temperature T3 is calculated using the calculation formula for the combustion chamber outlet gas specific heat ratio γ and the calculation formula for the turbine inlet temperature.

5. The method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to claim 4, characterized in that: The calculated turbine inlet temperature T3 and the combustion pressure pulsation data obtained from the gas turbine generator set operation data are fed back to the gas turbine control system, which makes a judgment: when T 3r -T3≥α, and the combustion pressure pulsation value is less than the alarm value, the IGV opening is output to reduce by 1%; when T 3r -T3≥α, but the combustion pressure pulsation value is greater than the alarm value, the output fuel flow rate increase instruction 0.5%; when T 3r -T3<0, then the output is the instruction to increase the IGV opening by 1%; Among them, T 3r is the turbine inlet temperature limit set in the gas turbine control system, and α is the turbine inlet temperature safety threshold set in the gas turbine control system.

6. The method for optimizing and adjusting the outlet temperature of a gas turbine combustor according to claim 5, characterized in that: The adjustment of the IGV opening and fuel flow rate includes real-time calculation of the turbine inlet temperature and, in combination with the changes in the combustion pressure pulsation data, immediate generation of new IGV and fuel flow control instructions until the turbine inlet temperature T3 is higher than T 3r -α value, so that the turbine inlet temperature T3 is close to the turbine inlet temperature limit T under safe conditions 3r , improve the thermal efficiency of gas turbine power generation.

7. A system based on the method for optimizing and adjusting the gas turbine combustor outlet temperature according to any one of claims 1 to 6, characterized in that: Including combustion model establishment module, flow parameter calculation module, gas specific heat ratio and combustion chamber pressure loss calculation module, gas specific heat ratio and combustion chamber pressure loss fitting module, turbine inlet temperature calculation module, data feedback and adjustment module; The combustion model establishment module establishes a three-dimensional combustion calculation numerical model of the combustion chamber; The flow parameter calculation module calculates the flow field characteristic parameters of the combustion chamber under typical load conditions; The gas specific heat ratio and combustion chamber pressure loss calculation module obtains the gas specific heat ratio at the combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under typical load conditions; The gas specific heat ratio and combustion chamber pressure loss fitting module is used to obtain the calculation formula of the gas specific heat ratio and the combustion chamber total pressure loss coefficient by fitting; The turbine inlet temperature calculation module establishes a turbine inlet temperature calculation formula to calculate the turbine inlet temperature; The data feedback and adjustment module feeds back the calculated turbine inlet temperature and the combustion pressure pulsation data obtained from the gas turbine generator set operation data to the gas turbine control system; and adjusts the IGV opening and fuel flow.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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