Method and system for optimizing and adjusting combustion chamber outlet temperature of gas turbine

Abstract

The present invention relates to the technical field of gas turbines, and in particular to a method and system for optimizing and adjusting a combustion chamber outlet temperature of a gas turbine. The method comprises: establishing a three-dimensional combustion numerical calculation model for the combustion chamber, and calculating flow field characteristic parameters of the combustion chamber under typical load conditions; obtaining a specific heat ratio of combustion gas at a combustion chamber outlet and a total pressure loss coefficient of the combustion chamber under the typical load conditions; performing fitting to obtain calculation formulas for the specific heat ratio of the combustion gas and the total pressure loss coefficient of the combustion chamber; establishing a turbine inlet temperature calculation formula to calculate a turbine inlet temperature; and feeding back, to a gas turbine control system, the calculated turbine inlet temperature and combustion pressure pulsation data obtained from operation data of a gas turbine generator set, and adjusting IGV opening and a fuel flow. By precisely adjusting the combustion chamber outlet temperature, the present invention can improve the cycle thermal efficiency of the gas turbine and the operational safety of the gas turbine.

Description

Gas turbine combustor outlet temperature optimization adjustment method and system TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbines, and particularly relates to a gas turbine combustor outlet temperature optimization adjustment method and system. BACKGROUND

[0002] A gas turbine is a highly efficient heat energy conversion device that generates high-temperature and high-pressure gas by burning fuel, and then drives the turbine to rotate to convert into mechanical energy. The combustor outlet temperature is a key parameter in the operation of the gas turbine, which has a crucial influence on the efficiency, safety and life of the entire system, and pollutant emissions. In terms of efficiency, the higher the combustor outlet temperature, the more heat energy can be converted into mechanical energy, thereby improving the energy efficiency of the entire system. However, this process is not unlimited, because too high a combustor outlet temperature can increase the thermal stress of the material and affect the service life of the gas turbine. In terms of safety and life, the combustor and turbine parts of the gas turbine need to use materials that can withstand high temperatures, such as nickel-based alloys. The control of the combustor outlet temperature is crucial to ensure that these high-temperature components do not exceed the heat resistance limit of their materials. In addition, uniform distribution of the combustor outlet temperature can reduce thermal stress and prolong the service life of the components. In terms of emission control, a higher combustor outlet temperature can promote more complete combustion, reducing the emission of unburned hydrocarbons and carbon dioxide, but on the contrary, it will increase the emission of nitrogen oxides (NOx), because high temperature can promote the reaction of nitrogen and oxygen in the air to generate more nitrogen oxides.

[0003] In summary, the control of the combustor outlet temperature of the gas turbine is crucial to ensure the high efficiency, safety, environmental protection and economy of the entire system. Precise control of the combustor outlet temperature is crucial to ensure the safe operation of the gas turbine. By precisely controlling the combustor outlet temperature, not only can the safe operation of the gas turbine be ensured, but also the maintenance cycle and service life of the gas turbine can be effectively prolonged, the maintenance cost of the gas turbine is reduced, and the economic benefit of the gas turbine is improved. SUMMARY

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

[0005] Therefore, the present application provides a gas turbine combustor outlet temperature optimization adjustment method, which can solve the problem that the conventional gas turbine cannot accurately control the combustor outlet temperature.

[0006] To solve the above technical problems, the application provides the following technical scheme, a gas turbine combustion chamber outlet temperature optimization adjustment method, comprising: establishing a three-dimensional combustion calculation numerical model of the combustion chamber, calculating the combustion chamber flow field characteristic parameters under typical load conditions; obtaining the specific heat ratio of the combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under the typical load conditions; fitting the calculation formula of the specific heat ratio of the combustion chamber and the total pressure loss coefficient of the combustion chamber; establishing a turbine inlet temperature calculation formula, calculating the turbine inlet temperature; feeding back the calculated turbine inlet temperature and the combustion pressure fluctuation data obtained from the gas turbine generator set operation data to the gas turbine control system, adjusting the IGV opening degree and the fuel flow.

[0007] As a preferred scheme of the gas turbine combustion chamber outlet temperature optimization adjustment method, the establishment of the three-dimensional combustion calculation numerical model of the combustion chamber comprises: using Thermoflow power plant heat balance analysis software, establishing a Thermoflow gas turbine heat balance calculation model for the gas turbine model used in the gas power plant, setting the boundary parameters of the calculation model according to the historical operation data of the gas turbine, verifying the accuracy of the calculation model by using the historical operation data of the gas turbine, calculating the inlet and outlet boundary parameters of the combustion chamber from the start of the gas turbine to the full load operation by using the verified Thermoflow gas turbine heat balance calculation model, and establishing a three-dimensional combustion numerical model of the combustion chamber by using a fluid numerical simulation software, and setting the inlet and outlet boundary conditions of the combustion numerical model according to the boundary parameters calculated by the Thermoflow gas turbine heat balance calculation model.

[0008] The calculation of the combustion chamber flow field characteristic parameters under the typical load conditions comprises: 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 load.

[0009] As a preferred scheme of the gas turbine combustion chamber outlet temperature optimization adjustment method, the total pressure loss coefficient of the combustion chamber is represented as: analyzing the total pressure P * 2, the outlet total pressure P * 3 of the combustion chamber under 50%, 60%, 70%, 80%, 90% and 100% typical load, and

[0010] Wherein, σ c is the total pressure loss coefficient of the combustion chamber.

[0011] As a preferred scheme of the gas turbine combustor outlet temperature optimization adjustment method, the fitting to obtain the calculation formula of the specific heat ratio of the gas and the total pressure loss coefficient of the combustor comprises: using a curve fitting method, using the calculated total pressure loss coefficient of the combustor and the specific heat ratio of the gas at the combustor outlet, taking the relative load as the independent variable, and fitting to obtain the calculation formula of the total pressure loss coefficient of the combustor and the specific heat ratio of the gas at the combustor outlet respectively, σ c = f(w) γ = g(w)

[0012] Wherein, w is the independent variable relative load, f(w) is the calculation function of the fitted total pressure loss coefficient of the combustor, and g(w) is the calculation function of the fitted specific heat ratio of the gas at the combustor outlet.

[0013] As a preferred scheme of the gas turbine combustor outlet temperature optimization adjustment method, the fitting to obtain the calculation formula of the specific heat ratio of the gas and the total pressure loss coefficient of the combustor comprises: using a curve fitting method, using the calculated total pressure loss coefficient of the combustor and the specific heat ratio of the gas at the combustor outlet, taking the relative load as the independent variable, and fitting to obtain the calculation formula of the total pressure loss coefficient of the combustor and the specific heat ratio of the gas at the combustor outlet respectively, σ

[0014] Wherein, T4 is the turbine exhaust temperature of the gas turbine, P2 is the exhaust pressure of the gas turbine compressor, and P4 is the turbine exhaust pressure of the gas turbine.

[0015] The turbine exhaust temperature T4 of the gas turbine, the exhaust pressure P2 of the gas turbine compressor, and the turbine exhaust pressure P4 of the gas turbine are obtained from the operation data of the gas turbine generator set, and the total pressure loss coefficient σ c of the combustor and the calculation formula of the specific heat ratio γ of the gas at the combustor outlet and the calculation formula of the turbine inlet temperature are combined to calculate the turbine inlet temperature T3.

[0016] As a preferred scheme of the gas turbine combustor outlet temperature optimization adjustment method, the turbine inlet temperature T3 calculated and the combustion pressure fluctuation data obtained from the operation data of the gas turbine generator set are fed back to the gas turbine control system, and the gas turbine control system judges: when T 3r -T3≥α, and the combustion pressure fluctuation value is less than the alarm value, an instruction of reducing the IGV opening by 1% is output; when T 3r -T3≥α, but the combustion pressure fluctuation value is greater than the alarm value, an instruction of increasing the fuel flow by 0.5% is output; when T 3r -T3<0, an instruction of increasing the IGV opening by 1% is output.

[0017] Wherein, T 3r is the turbine inlet temperature limit value set in the gas turbine control system, and α is the turbine inlet temperature safety threshold value set in the gas turbine control system.

[0018] As a preferred scheme of the gas turbine combustor outlet temperature optimization adjustment method, the adjustment of the IGV opening and the fuel flow comprises real-time calculation of the turbine inlet temperature, and generation of new IGV and fuel flow control instructions in combination with the change of the combustion pressure fluctuation data until the turbine inlet temperature T3 is higher than T 3r The value of α makes the turbine inlet temperature T3 close to the turbine inlet temperature limit T 3r , and improves the thermal efficiency of the gas turbine generator.

[0019] Another object of the present application is to provide a gas turbine combustor outlet temperature optimization adjustment system, which improves the combustion efficiency, optimizes the combustor design, ensures accurate understanding of the flow in the combustor, adjusts the fuel ratio, reduces the pressure loss, improves the energy utilization efficiency, realizes prediction and optimization of the gas turbine operation parameters, improves the system stability, ensures reasonable turbine inlet temperature, and realizes high-efficiency and stable operation of the gas turbine.

[0020] As a preferred scheme of the gas turbine combustor outlet temperature optimization adjustment system, 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.

[0021] The combustion model establishment module establishes a three-dimensional combustion calculation numerical model of the combustor.

[0022] The flow parameter calculation module calculates the flow field characteristic parameters of the combustor under typical load conditions.

[0023] The gas specific heat ratio and combustor pressure loss calculation module obtains the gas specific heat ratio and the total pressure loss coefficient of the combustor at the combustor outlet under typical load conditions.

[0024] The gas specific heat ratio and combustor pressure loss fitting module fits to obtain the calculation formula of the gas specific heat ratio and the total pressure loss coefficient of the combustor.

[0025] The turbine inlet temperature calculation module establishes a turbine inlet temperature calculation formula to calculate the turbine inlet temperature.

[0026] The data feedback and adjustment module feeds back the calculated turbine inlet temperature and the combustion pressure fluctuation data obtained from the gas turbine generator set operation data to the gas turbine control system, and adjusts the IGV opening and the fuel flow.

[0027] A computer device comprises a memory and a processor, the memory stores a computer program, characterized in that the processor implements the steps of the method in any one of the gas turbine combustion chamber outlet temperature optimization adjustment methods when executing the computer program.

[0028] A computer readable storage medium, which stores a computer program, characterized in that the computer program implements the steps of the method in any one of the gas turbine combustion chamber outlet temperature optimization adjustment methods when executed by a processor.

[0029] The beneficial effects of the present application: the cycle thermal efficiency of the gas turbine is generally positively correlated with the turbine inlet temperature, and increasing the turbine inlet temperature can improve the cycle thermal efficiency, but due to the high turbine inlet temperature of the gas turbine, it cannot be directly measured, the present scheme calculates the turbine inlet temperature according to the turbine exhaust temperature, compares and analyzes the distance between the calculated turbine inlet temperature and the turbine inlet temperature limit value, and real-time reduces or increases the IGV opening degree, thereby controlling the air flow entering the gas turbine, when the IGV opening degree is reduced, the air flow entering the gas turbine is reduced, the turbine inlet temperature is increased, and the cycle thermal efficiency of the gas turbine is improved; when the IGV opening degree is increased, the air flow entering the gas turbine will increase, the turbine inlet temperature will decrease, the turbine blade will be prevented from being burned and damaged, and the operation safety of the gas turbine is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0031] Fig. 1 is a flowchart of a gas turbine combustion chamber outlet temperature optimization adjustment method provided by an embodiment of the present application.

[0032] Fig. 2 is a combustion chamber three-dimensional entity model of a gas turbine combustion chamber outlet temperature optimization adjustment method provided by an embodiment of the present application.

[0033] Fig. 3 is a combustion chamber three-dimensional numerical model of a gas turbine combustion chamber outlet temperature optimization adjustment method provided by an embodiment of the present application.

[0034] Fig. 4 is a thermoflow gas turbine heat balance calculation result under 100% typical load of a gas turbine combustion chamber outlet temperature optimization adjustment method provided by an embodiment of the present application.

[0035] Figure 5 is the result of the pressure field of the center section of the combustion chamber at 100% typical load according to the method for optimizing and adjusting the outlet temperature of the combustion chamber of the gas turbine provided by one embodiment of the present application.

[0036] Figure 6 is the result of the temperature field of the center section of the combustion chamber at 100% typical load according to the method for optimizing and adjusting the outlet temperature of the combustion chamber of the gas turbine provided by one embodiment of the present application.

[0037] Figure 7 is the result of the velocity field of the center section of the combustion chamber at 100% typical load according to the method for optimizing and adjusting the outlet temperature of the combustion chamber of the gas turbine provided by one embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the protection scope of the present application.

[0039] Embodiment 1, referring to Figure 1, is the first embodiment of the present application, which provides a method for optimizing and adjusting the outlet temperature of the combustion chamber of the gas turbine, comprising: the present scheme uses the inlet pressure P2 of the combustion chamber and combines the pressure loss coefficient of the combustion chamber to calculate the turbine inlet pressure, and then calculates the turbine inlet temperature T3, which is simple and feasible, and has high implementation efficiency.

[0040] The present scheme does not need to be tested, but only needs to establish a gas turbine heat balance calculation model and a gas turbine combustion chamber numerical model, and uses a curve fitting method to obtain the total pressure loss coefficient σ c and the specific heat ratio γ of the combustion chamber outlet gas at different loads, which improves the calculation accuracy of the turbine inlet temperature.

[0041] The present scheme retrieves the operating parameters such as the inlet pressure P2 of the combustion chamber, the turbine exhaust pressure P4, and the turbine exhaust temperature T4 in the real-time database of the gas turbine generator set, and can calculate the turbine inlet temperature in real time, and compare it with the turbine inlet temperature limit value in real time. According to the distance between the comparison result and the turbine inlet temperature safety threshold α, the IGV opening and the fuel flow are adjusted in real time, the turbine inlet temperature of the gas turbine is improved at partial load, and the cycle thermal efficiency of the gas turbine is improved.

[0042] The scheme makes up the defect that the turbine inlet temperature of the gas turbine cannot be directly measured, and makes the turbine inlet temperature control of the gas turbine more accurate, can improve the cycle thermal efficiency of the gas turbine at low load, can increase the IGV opening at high load, increase the air flow into the gas turbine, reduce the turbine inlet temperature, prevent turbine blade burning, and improve the operation safety of the gas turbine.

[0043] 1), establish a three-dimensional combustion calculation numerical model of the combustion chamber of the gas turbine.

[0044] 2), because the outlet gas temperature of the combustion chamber of the gas turbine is high, generally no measuring point is directly measured to measure the pressure and temperature of the outlet gas of the combustion chamber, in order to obtain the inlet and outlet boundary parameters required for the three-dimensional combustion calculation numerical model of the combustion chamber of the gas turbine, a Thermoflow gas turbine heat balance calculation model is established by using Thermoflow power plant heat balance analysis professional software, according to the type of gas turbine used in the gas power plant, the boundary parameters of the calculation model are set according to the historical operation data of the gas turbine, and the accuracy of the calculation model is verified by using the historical operation data of the gas turbine. The inlet and outlet boundary parameters of the combustion chamber of the gas turbine from start-up to full load operation are calculated by using the verified Thermoflow gas turbine heat balance calculation model. Considering that the pollutant emission of the gas turbine will exceed the standard at low load, the gas turbine generator set generally works in the load interval of 50% to 100%. Therefore, the above method is mainly used to calculate the inlet air and fuel mass flow, temperature and outlet pressure of the combustion chamber of the gas turbine at typical loads of 50%, 60%, 70%, 80%, 90% and 100%, and the typical load can be selected and determined according to the frequently operated load point of the gas turbine. In the three-dimensional combustion calculation numerical model of the combustion chamber of the gas turbine established in the first step, the inlet and outlet boundary parameters of the combustion chamber are set according to the calculation results of the second step, and the pressure field, temperature field and velocity field in the combustion chamber of the gas turbine at typical loads of 50%, 60%, 70%, 80%, 90% and 100% are calculated respectively.

[0045] 3), according to the calculation results of step 2, the total pressure P2* of the combustion chamber inlet, the total pressure P3* of the combustion chamber outlet and the specific heat ratio γ of the combustion chamber outlet gas at typical loads of 50%, 60%, 70%, 80%, 90% and 100% are analyzed and obtained, and the total pressure loss coefficient σ of the combustion chamber is calculated by using the formula c .

[0046] 4), the total pressure loss coefficient σ of the combustion chamber c and the specific heat ratio γ of the combustion chamber outlet gas calculated in step 3 are fitted by using the curve fitting method, and the total pressure loss coefficient σ of the combustion chamber c ​and the calculation formula of the specific heat ratio γ of the gas at the outlet of the combustion chamber. σ c = f(w) γ = g(w) (1)

[0047] In the formula, w is the independent variable relative load, 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 gas at the outlet of the combustion chamber obtained by fitting.

[0048] 5) The calculation formula of the turbine inlet temperature T3 (i.e. the outlet temperature of the combustion chamber) is established by using the energy change characteristics of the high-temperature and high-pressure gas in the turbine:

[0049] In the formula, T4 is the turbine exhaust temperature of the gas turbine, P2 is the exhaust pressure of the gas turbine compressor, and P4 is the turbine exhaust pressure of the gas turbine.

[0050] 6) The turbine exhaust temperature T4, the exhaust pressure P2 of the gas turbine compressor, and the turbine exhaust pressure P4 of the gas turbine are obtained from the operation data of the gas turbine generator set, and the turbine inlet temperature T3 is calculated by combining formula (1) and formula (2).

[0051] 7) The calculated turbine inlet temperature T3 and the combustion pressure fluctuation data obtained from the operation data of the gas turbine generator set are fed back 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 value set in the gas turbine control system, and α is the turbine inlet temperature safety threshold value set in the gas turbine control system), and the combustion pressure fluctuation value is less than the alarm value, the IGV opening degree is reduced by 1%; 2) when T 3r -T3≥α, but the combustion pressure fluctuation value is greater than the alarm value, the fuel flow is increased by 0.5%; 3) when T 3r -T3<0, the IGV opening degree is increased by 1%.

[0052] 8) After executing the control instruction of the gas turbine control system in step 7, the turbine inlet temperature is calculated in real time, and the new IGV and fuel flow control instructions are generated in real time according to the change of the combustion pressure fluctuation data, until the turbine inlet temperature T3 is higher than T 3r -α for the first time, so that the turbine inlet temperature T3 is as close as possible to the turbine inlet temperature limit value T 3r under safe conditions, and the thermal efficiency of the gas turbine generator is improved.

[0053] The above is a schematic scheme of the gas turbine combustor outlet temperature optimization adjustment method of the embodiment. It should be noted that the technical scheme of the gas turbine combustor outlet temperature optimization adjustment method system belongs to the same concept as the technical scheme of the above-mentioned gas turbine combustor outlet temperature optimization adjustment method. The technical scheme of the gas turbine combustor outlet temperature optimization adjustment method system in the embodiment is not described in detail. Details can be seen from the description of the technical scheme of the above-mentioned gas turbine combustor outlet temperature optimization adjustment method.

[0054] The gas turbine combustor outlet temperature optimization adjustment system in the 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.

[0055] The combustion model establishment module establishes a three-dimensional combustion calculation numerical model of the combustor.

[0056] The flow parameter calculation module calculates the flow field characteristic parameters of the combustor under typical load conditions.

[0057] The gas specific heat ratio and combustor pressure loss calculation module obtains the gas specific heat ratio and the total pressure loss coefficient of the combustor outlet under typical load conditions.

[0058] The gas specific heat ratio and combustor pressure loss fitting module fits to obtain the calculation formula of the gas specific heat ratio and the total pressure loss coefficient of the combustor.

[0059] The turbine inlet temperature calculation module establishes a turbine inlet temperature calculation formula to calculate the turbine inlet temperature.

[0060] The data feedback and adjustment module feeds back the calculated turbine inlet temperature and the combustion pressure fluctuation data obtained from the gas turbine generator set operation data to the gas turbine control system, and adjusts the IGV opening degree and the fuel flow.

[0061] The embodiment also provides a computing device suitable for the case of the gas turbine combustor outlet temperature optimization adjustment method, which includes:

[0062] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0063] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered a list of executable instructions for implementing logic functions, and can be specifically embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or in conjunction with these instructions execution systems, apparatuses, or devices. For the 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 connection with an instruction execution system, apparatus, or device, or in conjunction with these instruction execution systems, apparatuses, or devices.

[0064] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electrical devices), a portable computer diskette (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, as the program can be electronically obtained, for example, by optical scanning of the paper or other medium, followed by editing, interpreting, or otherwise processing the program as necessary, and then storing it in a computer memory.

[0065] It should be understood that various aspects of the application can be implemented in hardware, software, firmware or a combination of them. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, implementation can be with any or a combination of the following technologies, which are all well-known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon an application of data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0066] Example 2, referring to Figs. 2-7, is a second embodiment of the application, which provides a method for optimizing adjustment of the outlet temperature of a gas turbine combustor, and through experiments, scientifically demonstrates the beneficial effects of the application.

[0067] 1) A certain gas power plant uses a 9FA type gas turbine, a three-dimensional solid model of the gas turbine combustor is established by using UG modeling software, as shown in Fig. 2, and the solid model established by UG is meshed by using ANSYS commercial software to build a three-dimensional numerical model of the combustor, as shown in Fig. 3.

[0068] 2) Using Thermoflow power plant heat balance analysis professional software, a 9FA type gas turbine heat balance calculation model is established, according to the historical operation data of the gas turbine, the calculation model inlet atmospheric pressure is set to 1.001 bar, atmospheric temperature is 21.49℃, relative humidity is 79%, load setting is 100%, the calculation results are shown in Figure 4, the power plant gas turbine operation data shows that the combustion chamber inlet air pressure is 15.5 bar, the temperature is 400℃, the pressure and temperature results calculated by Thermoflow are 15.46 bar and 399.8℃ respectively, which verifies the accuracy of the established Thermoflow gas turbine heat balance calculation model. In view of the fact that the frequently operated load points of the gas turbine of a certain gas power plant are 50%, 65%, 80%, 95% and 100%, therefore, the above loads are taken as typical loads, the verified Thermoflow gas turbine heat balance calculation model is used to calculate the inlet and outlet boundary parameters of the combustion chamber under the above typical loads. Under 50% load, the combustion chamber inlet air temperature is 358℃, the flow rate is 341.6kg / s, the combustion chamber inlet fuel temperature is 185℃, the flow rate is 9.054kg / s, and the combustion chamber outlet pressure is 10.12 bar. Under 65% load, the combustion chamber inlet air temperature is 374℃, the flow rate is 385kg / s, the combustion chamber inlet fuel temperature is 185℃, the flow rate is 10.674kg / s, and the combustion chamber outlet pressure is 11.59 bar. Under 80% load, the combustion chamber inlet air temperature is 385℃, the flow rate is 436.4kg / s, the combustion chamber inlet fuel temperature is 185℃, the flow rate is 12.168kg / s, and the combustion chamber outlet pressure is 13.18 bar. Under 95% load, the combustion chamber inlet air temperature is 392℃, the flow rate is 490.4kg / s, the combustion chamber inlet fuel temperature is 185℃, the flow rate is 13.608kg / s, and the combustion chamber outlet pressure is 14.79 bar. Under 100% load, the combustion chamber inlet air temperature is 399.8℃, the flow rate is 493kg / s, the combustion chamber inlet fuel temperature is 185℃, the flow rate is 13.77kg / s, and the combustion chamber outlet pressure is 14.88 bar.

[0069] 3) According to the combustion chamber inlet and outlet boundary parameters calculated in step 2, the combustion chamber three-dimensional numerical model established in step 1 is used to calculate the pressure, temperature, velocity and other flow field parameters of the gas turbine combustion chamber under 50%, 65%, 80%, 95% and 100% typical loads respectively, part of the results are shown in Figures 5 to 7, the combustion chamber inlet total pressure P2* and the combustion chamber outlet total pressure P3* are read from the numerical calculation results respectively, and the formula is used to calculate the total pressure loss coefficient σ of the combustion chamber under 50%, 65%, 80%, 95% and 100% typical loads respectively cThe values ​​were 0.038, 0.0386, 0.0392, 0.0398, and 0.04. From the numerical calculation results, the specific heat ratio γ of the combustion chamber outlet gas under typical loads of 50%, 65%, 80%, 95%, and 100% were obtained as 1.33087, 1.31899, 1.28342, 1.28386, and 1.28393, respectively.

[0070] 4) Using the curve fitting method, the total pressure loss coefficient σ of the combustion chamber obtained in step 3 is used in the combustion chamber. c Using the specific heat ratio γ of the combustion chamber outlet gas and the relative load as the independent variable, the total pressure loss coefficient σ of the combustion chamber is obtained by fitting the data. c The formula for calculating the specific heat ratio γ of the combustion chamber outlet gas. σ c =0.004w+0.036 0.5≤w≤1.0 (3)

[0071] Where w is the relative loading of the independent variable.

[0072] 5) Establish the calculation formula for turbine inlet temperature T3 (i.e., combustion chamber outlet temperature):

[0073] Where T4 is the exhaust temperature of the gas turbine; P2 is the exhaust pressure of the gas turbine compressor; and P4 is the exhaust pressure of the gas turbine.

[0074] 6) From the real-time database of a certain power plant's F-class gas turbine generator set, the combustion chamber inlet pressure P2 is 1.56 MPa, the turbine exhaust pressure P4 is 0.105357 MPa, and the turbine exhaust temperature T4 is 860 K when the generator set is at 90% load. The total pressure loss coefficient σ of the combustion chamber is calculated using formulas (3) and (4). c The specific heat ratio of the combustion chamber outlet gas γ is 1.283698, and the turbine inlet temperature T3 is calculated to be 1546.3K using formula (5).

[0075] 7) The highest amplitude of combustion pressure pulsation was obtained from the real-time database of a certain power plant's F-class gas turbine generator set, which was 0.67 kPa. Analysis of the gas turbine control system yielded the gas turbine inlet temperature limit T. 3r 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 the combustion pressure pulsation data obtained from the gas turbine generator set operation data are fed back to the gas turbine control system. The gas turbine control system calculates and judges in real time: 1620-1546.3=73.7>α, and the combustion pressure pulsation value is less than the alarm value, then outputs a command to reduce the IGV opening by 1%.

[0076] 8), after the execution of the control command of step 7, the turbine inlet temperature T3 is calculated as 1568.2K, the maximum amplitude of the combustion pressure fluctuation is 0.65kPa, the gas turbine control system continues to output the command of reducing the IGV opening by 1%, and the turbine inlet temperature T3 is calculated again as 1612.2K after adjustment, the maximum amplitude of the combustion pressure fluctuation is 0.66kPa, the gas turbine control system calculates in real time and judges that 1620-1612.2=7.8<α, the turbine inlet temperature T3 is higher than T 3r for the first time, and the value of α indicates that the turbine inlet temperature has reached the optimal value.

Claims

1. A method of optimizing adjustment of a gas turbine combustor outlet temperature, characterized by: comprising, a three-dimensional combustion calculation numerical model of the combustion chamber is established, and flow field characteristic parameters of the combustion chamber under typical load conditions are calculated; a gas specific heat ratio at the outlet of the combustion chamber under typical load conditions and a total pressure loss coefficient of the combustion chamber are obtained; a calculation formula of the gas specific heat ratio and the total pressure loss coefficient of the combustion chamber is fitted; a turbine inlet temperature calculation formula is established, and the turbine inlet temperature is calculated; the calculated turbine inlet temperature and combustion pressure fluctuation data obtained from the gas turbine generator set operation data are fed back to the gas turbine control system to adjust the IGV opening degree and the fuel flow.

2. A method for optimizing adjustment of a gas turbine combustor outlet temperature as recited in claim 1, characterized by: The three-dimensional combustion calculation numerical model of the combustion chamber comprises: using Thermoflow power plant heat balance analysis software, establishing 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 operation data of the gas turbine, verifying the accuracy of the calculation model by using the historical operation data of the gas turbine, and using the verified Thermoflow gas turbine heat balance calculation model to calculate the inlet and outlet boundary parameters of the combustion chamber of the gas turbine under the conditions of starting the machine to full load operation, and then using a fluid numerical simulation software to establish a three-dimensional combustion numerical model of the combustion chamber, and setting the inlet and outlet boundary conditions of the combustion numerical model according to the boundary parameters calculated by the Thermoflow gas turbine heat balance calculation model. The flow field characteristic parameters of the combustion chamber under typical load conditions comprise: the gas pressure field, the temperature field and the velocity field in the combustion chamber of the gas turbine under 50%, 60%, 70%, 80%, 90% and 100% typical loads are calculated respectively.

3. A method of optimizing adjustment of a gas turbine combustor outlet temperature as recited in claim 2, characterized by: The total pressure loss coefficient is expressed as, P * 2, the total pressure at the outlet of the combustion chamber P * 3, is expressed as, where σ c represents the total pressure loss coefficient of the combustion chamber.

4. A method of optimised adjustment of a gas turbine combustor outlet temperature as recited in claim 3, c h a r a c t e r i z e d b y that: The fitting obtains the calculation formula of the specific heat ratio of the gas and the total pressure loss coefficient of the combustion chamber, including: using a curve fitting method, using the calculated total pressure loss coefficient of the combustion chamber and the specific heat ratio of the gas at the outlet of the combustion chamber, taking the relative load as the independent variable, respectively fitting to obtain the calculation formula of the total pressure loss coefficient of the combustion chamber and the specific heat ratio γ of the gas at the outlet of the combustion chamber, σ c = f(w) γ = g(w) Wherein, w is the relative load of the independent variable, f(w) is the calculation function of the fitted total pressure loss coefficient of the combustion chamber, and g(w) is the calculation function of the fitted gas specific heat ratio at the outlet of the combustion chamber.

5. A method of optimised adjustment of a gas turbine combustor outlet temperature as recited in claim 4, c h a r a c t e r i z e d b y that: The calculation formula of the turbine inlet temperature T3 is established by using the energy variation characteristics of the high-temperature and high-pressure gas during the expansion and work in the turbine. Wherein, T4 is the turbine exhaust temperature of the gas turbine; P2 is the compressor discharge pressure of the gas turbine; and P4 is the turbine exhaust pressure of the gas turbine. The turbine exhaust temperature T4, the turbine compressor exhaust pressure P2, and the turbine exhaust pressure P4 are obtained from the gas turbine generator set operation data, and the turbine inlet temperature T3 is calculated by using the calculation formulae of the combustion chamber total pressure loss coefficient σ c and the combustion chamber outlet gas specific heat ratio γ and the calculation formula of the turbine inlet temperature.

6. A method of optimised adjustment of a gas turbine combustor outlet temperature as recited in claim 5, characterized by: The turbine inlet temperature T3 calculated and the combustion pressure fluctuation data obtained from the gas turbine generator set operation data are fed back to the gas turbine control system, and the gas turbine control system judges: when T 3r T3≥α, and the combustion pressure fluctuation value is less than the alarm value, an instruction of reducing the IGV opening by 1% is output; when T 3r T3≥α, but the combustion pressure fluctuation value is greater than the alarm value, an instruction of increasing the fuel flow by 0.5% is output; when T 3r T3<0, an instruction of increasing the IGV opening by 1% is output; where T 3r is the turbine inlet temperature limit set in the gas turbine control system, and a is the turbine inlet temperature safety threshold set in the gas turbine control system.

7. A method of optimizing adjustment of a gas turbine combustor outlet temperature as recited in claim 6, characterized by: The adjustment of IGV opening and fuel flow includes real-time calculation of turbine inlet temperature, and combination of combustion pressure fluctuation data change, instant generation of new IGV and fuel flow control instructions until the turbine inlet temperature T3 is higher than T 3r for the first time, and the value of α makes the turbine inlet temperature T3 close to the turbine inlet temperature limit T 3r under safe conditions, and improves the thermal efficiency of gas turbine power generation.

8. A system for optimizing the temperature at the outlet of a combustion chamber of a gas turbine based on the method according to any one of claims 1 to 7, characterized in that: comprising, a combustion model establishing module, a flow parameter calculation module, a gas specific heat ratio and combustion chamber pressure loss calculation module, a gas specific heat ratio and combustion chamber pressure loss fitting module, a turbine inlet temperature calculation module, and a data feedback and adjustment module; The combustion model establishing module establishes a three-dimensional combustion calculation numerical model of the combustion chamber; The flow parameter calculation module calculates 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 a gas specific heat ratio at the outlet of the combustion chamber under typical load conditions and a total pressure loss coefficient of the combustion chamber; The gas specific heat ratio and combustion chamber pressure loss fitting module fits a calculation formula of the gas specific heat ratio and the total pressure loss coefficient of the combustion chamber; The turbine inlet temperature calculation module establishes a turbine inlet temperature calculation formula, and calculates the turbine inlet temperature; The data feedback and adjustment module feeds back the calculated turbine inlet temperature and the combustion pressure fluctuation data obtained from the gas turbine generator set operation data to the gas turbine control system, and adjusts the IGV opening degree and the fuel flow. 9.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-8 when the computer program is executed by the processor. The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 7.

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