Optimization and adjustment method and system for outlet temperature of combustion chamber of gas turbine

Abstract

The invention relates to the technical field of gas turbines, in particular to a gas turbine combustion chamber outlet temperature optimizing and adjusting method and system.The method comprises the steps that a combustion chamber three-dimensional combustion calculation numerical model is established, and combustion chamber flow field characteristic parameters under the typical load working condition are calculated; the gas specific heat ratio of a combustion chamber outlet and the total pressure loss coefficient of the combustion chamber under the typical load working condition are obtained; fitting to obtain a calculation formula of 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; and the turbine inlet temperature obtained through calculation and combustion pressure pulsation data obtained from the operation data of the gas turbine generator set are fed back to a gas turbine control system, and the IGV opening degree and the fuel flow are adjusted. By accurately adjusting the outlet temperature of the combustion chamber, the circulating heat efficiency of the gas turbine and the operation safety of the gas turbine can be improved.

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 heat energy conversion device that generates high-temperature and high-pressure gas by burning fuel, which in turn drives the turbine to rotate and converts it into mechanical energy. The combustion chamber outlet temperature is a key parameter in the operation of a gas turbine and has a vital impact on the efficiency, safety, life, and pollutant emissions of the entire system. In terms of efficiency, the higher the combustion chamber outlet temperature, the more thermal energy can be converted into mechanical energy, thereby improving the energy efficiency of the entire system. However, this process is not unlimited, because excessively high combustion chamber outlet temperatures may cause increased thermal stress in the material, affecting the life of the gas turbine. In terms of safety and life, the combustion chamber 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 combustion chamber outlet temperature is crucial to ensure that these high-temperature components do not exceed the heat resistance limit of their materials. In addition, the uniform distribution of the combustion chamber outlet temperature can reduce thermal stress and extend the service life of the components. In terms of emission control, although a higher combustion chamber outlet temperature can promote more complete combustion and reduce the emission of unburned hydrocarbons and carbon dioxide, it will increase nitrogen oxide (NOx) emissions on the contrary, because high temperatures can promote the reaction of nitrogen and oxygen in the air to produce more nitrogen oxides.

[0003] In summary, the control of the gas turbine combustion chamber outlet temperature is crucial to ensure the high efficiency, safety, environmental protection and economy of the entire system. Accurate control of the combustion chamber outlet temperature is crucial to ensure the safe operation of the gas turbine. By accurately controlling the combustion chamber outlet temperature, not only can the safe operation of the gas turbine be guaranteed, but also the maintenance cycle and service life of the gas turbine can be effectively extended, the maintenance cost of the gas turbine can be reduced, and the economic benefits of the gas turbine can be improved. Summary of the invention

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

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

[0006] To solve the above 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 the 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, 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 solution of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber described in the present invention, the establishment of a three-dimensional combustion calculation numerical model of the combustion chamber includes: 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 the boundary parameters of the calculation model according to the historical operation data of the gas turbine, and verifying the accuracy of the calculation model using the historical operation 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 combustion chamber 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 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;

[0008] The calculation of the combustion chamber flow field characteristic parameters under typical load conditions includes respectively calculating and obtaining the gas pressure field, temperature field, and velocity field in the combustion chamber of the gas turbine 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 combustion chamber according to the present invention, the total pressure loss coefficient of the combustion chamber is expressed as follows: the total pressure loss coefficient of the combustion chamber at the inlet of the gas turbine combustion chamber under typical loads of 50%, 60%, 70%, 80%, 90% and 100% is obtained by analysis. * 2. Total pressure at the combustion chamber outlet P * 3, expressed as,

[0010]

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

[0012] As a preferred solution of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to the present invention, the calculation formula for fitting the specific heat ratio of the gas and the total pressure loss coefficient of the combustion chamber includes: adopting 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 combustion chamber outlet, taking the relative load as the independent variable, respectively fitting the calculation formulas for the total pressure loss coefficient of the combustion chamber and the specific heat ratio of the gas at the combustion chamber outlet,

[0013] σ c =f(w)

[0014] γ=g(w)

[0015] Among them, 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 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 combustion chamber according to the present invention, the formula for calculating the turbine inlet temperature is established by utilizing the energy variation characteristics of the high-temperature and high-pressure gas expanding and working 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 by 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 turbine inlet temperature T3 obtained by calculation and the combustion pressure pulsation 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 determines: when T 3r -T3≥α, and the combustion pressure pulsation value is less than the alarm value, the IGV opening is reduced by 1%; 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%; when T 3r -T3<0, then the command to increase the IGV opening by 1% is output;

[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 adjusting of the IGV opening and the fuel flow rate includes calculating the turbine inlet temperature in real time, and generating new IGV and fuel flow rate control instructions in real time in combination with the change of the combustion pressure pulsation data, 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 solution of the gas turbine combustion chamber outlet temperature optimization and adjustment system described in the present invention, it includes: a combustion model establishment 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;

[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 fit and obtain a calculation formula for the gas specific heat ratio and the combustion chamber total pressure loss coefficient;

[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 comprises 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, since the turbine inlet temperature of a gas turbine is relatively high, it cannot be directly measured. The present invention calculates the turbine inlet temperature based on the turbine exhaust temperature, compares and analyzes the distance between the calculated value of the turbine inlet temperature and the turbine inlet temperature limit, and reduces or increases the IGV opening in real time, thereby controlling the air flow rate entering the gas turbine. When the IGV opening is reduced, the air flow rate entering the gas turbine is reduced, 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 rate 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 accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying 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 by 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 by an 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 an embodiment of the present invention.

[0038] Figure 4 The 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 combustion chamber according to an embodiment of the present invention, and shows the pressure field result of the central cross section of the combustion chamber under 100% typical load.

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

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

[0042] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art 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 the combustion chamber pressure loss coefficient to calculate the turbine inlet pressure, and then calculates the turbine inlet temperature T3. The method is simple and feasible, and has high implementation efficiency.

[0044] This scheme does not require experiments. It only establishes 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 of the gas turbine combustion chamber under different loads. 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 the 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 gas turbine turbine inlet temperature limit 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 gas turbine turbine inlet temperature under partial load, thereby improving the thermal efficiency of the gas turbine cycle.

[0046] This solution makes up for the defect that the gas turbine turbine inlet temperature cannot be directly measured, making the gas turbine turbine inlet temperature control 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 combustion chamber.

[0048] 2) Due to the high temperature of the gas at the outlet of the gas turbine combustion chamber, there is generally no measuring point to directly measure the pressure and temperature of the gas at the outlet of the combustion chamber. In order to obtain the combustion chamber inlet and outlet boundary parameters required for the analysis of the three-dimensional combustion calculation numerical model of the gas turbine combustion chamber, the Thermoflow power plant heat balance analysis professional software is used to establish the Thermoflow gas turbine heat balance calculation model for the gas turbine model 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 using the historical operation data of the gas turbine. The verified Thermoflow gas turbine heat balance calculation model is used to calculate the combustion chamber inlet and outlet boundary parameters of the gas turbine from startup to full load operation. Considering that the pollutant emissions will exceed the standard when the gas turbine is running at low load, the gas turbine generator set generally operates in the load range of 50% to 100%. Therefore, the above method is mainly used to calculate the boundary parameters such as the mass flow rate of air and fuel at the inlet of the gas turbine combustion chamber, temperature, and the outlet pressure of the combustion chamber under typical loads such as 50%, 60%, 70%, 80%, 90% and 100%. The typical load can be selected and determined according to the load point of the gas turbine power plant. In the three-dimensional combustion calculation numerical model of the gas turbine combustion chamber established in the first step, the combustion chamber inlet and outlet boundary parameters calculated in the second step are set, and the gas pressure field, temperature field, and velocity field in the gas turbine combustion chamber under typical loads such as 50%, 60%, 70%, 80%, 90% and 100% are calculated.

[0049] 3) According to the calculation results of step 2, the total pressure P2* at the inlet of the gas turbine combustion chamber, the total pressure P3* at the outlet of the combustion chamber and the specific heat ratio γ of the combustion chamber outlet gas are analyzed and obtained under typical loads of 50%, 60%, 70%, 80%, 90% and 100%, and the formula is used to obtain 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 calculated in 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 doing work in the turbine, the calculation formula of turbine inlet temperature T3 (i.e. combustion chamber outlet temperature) is established:

[0055]

[0056] Where T4 is the gas turbine exhaust temperature; P2 is the gas turbine compressor exhaust pressure; 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 operation 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 reduced by 1%; 2. When T 3r -T3≥α, but the combustion pressure pulsation value is greater than the alarm value, then the command to increase the fuel flow by 0.5% is output; 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 T3 for the first time. 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 scheme of a method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber in this embodiment. It should be noted that the technical scheme of the system of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber and the technical scheme of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber described above belong to the same concept, and the details of the technical scheme of the system of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber in this embodiment that are not described in detail can all be referred to the description of the technical scheme of the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber described above.

[0061] The gas turbine combustion chamber outlet temperature optimization and adjustment system in this embodiment includes a combustion model establishment 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;

[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 fit and obtain a calculation formula for the gas specific heat ratio and the combustion chamber total pressure loss coefficient;

[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, which is applicable to a method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber, and includes:

[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, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

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

[0071] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a 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, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0072] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated 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 to build a three-dimensional numerical model of the combustion chamber. Figure 3 .

[0075] 2) Using Thermoflow power plant heat balance analysis professional software, establish a 9FA gas turbine heat balance calculation model. According to the historical operation data of the gas turbine, the calculation model inlet atmospheric pressure is set to 1.001 bar, the atmospheric temperature is 21.49 ° C, the relative humidity is 79%, and the load is set to 100%. The calculation results are shown in Figure 4The power plant gas turbine operation data shows that the combustion chamber inlet air pressure is 15.5bar and the temperature is 400℃. The pressure and temperature results calculated by Thermoflow are 15.46bar 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 regular operating load points of the gas turbine of a gas power plant are 50%, 65%, 80%, 95% and 100%, the above loads are taken as typical loads, and 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. At 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 10.12bar. At 65% load, the inlet air temperature of the combustion chamber is 374°C, the flow rate is 385kg / s, the inlet fuel temperature of the combustion chamber is 185°C, the flow rate is 10.674kg / s, and the outlet pressure of the combustion chamber is 11.59bar. At 80% load, the inlet air temperature of the combustion chamber is 385°C, the flow rate is 436.4kg / s, the inlet fuel temperature of the combustion chamber is 185°C, the flow rate is 12.168kg / s, and the outlet pressure of the combustion chamber is 13.18bar. At 95% load, the inlet air temperature of the combustion chamber is 392°C, the flow rate is 490.4kg / s, the inlet fuel temperature of the combustion chamber is 185°C, the flow rate is 13.608kg / s, and the outlet pressure of the combustion chamber is 14.79bar. At 100% load, the combustion chamber inlet air temperature is 399.8°C, the flow rate is 493kg / s, the combustion chamber inlet fuel temperature is 185°C, the flow rate is 13.77kg / s, and the combustion chamber outlet pressure is 14.88bar.

[0076] 3) According to 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, velocity, etc. 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 of 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 calculated in 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] Among them, w is the relative loading of the independent variable.

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

[0082]

[0083] Among them, T4 is the gas turbine turbine exhaust temperature; P2 is the gas turbine compressor exhaust pressure; P4 is the gas turbine 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 γ of the combustion chamber outlet gas is 0.0396 and 1.283698. The turbine inlet temperature T3 is calculated using formula (5) to be 1546.3K.

[0085] 7) The maximum amplitude of the combustion pressure pulsation at this time is obtained from the real-time database of a class F gas turbine generator set in a power plant, which is 0.67 kPa. The gas turbine control system is analyzed to obtain the gas turbine turbine inlet temperature limit T 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 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%.

[0086] 8) After executing the control command issued by the gas turbine control system in step 7, the real-time calculation of 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 judges in real time: 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 combustion chamber, characterized in that: 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 formula of the specific heat ratio of the gas and the total pressure loss coefficient of the combustion chamber is obtained by fitting; Establish the turbine inlet temperature calculation formula to calculate the turbine inlet temperature; The calculated turbine inlet temperature and the combustion pressure pulsation data obtained from the gas turbine generator set operation data are fed back to the gas turbine control system to adjust the IGV opening and fuel flow.

2. A method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to claim 1, characterized in that: The establishment of the three-dimensional combustion calculation numerical model of the combustion chamber includes: 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, and verifying the accuracy of the calculation model using the historical operation 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 combustion chamber of the gas turbine from startup to full load operation, and then using fluid numerical simulation software to establish the 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 calculation of the combustion chamber flow field characteristic parameters under typical load conditions includes respectively calculating and obtaining the gas pressure field, temperature field, and velocity field in the combustion chamber of the gas turbine under 50%, 60%, 70%, 80%, 90%, and 100% typical loads.

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

4. A method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to claim 3, characterized in that: The calculation formula for obtaining the gas specific heat ratio and the combustion chamber total pressure loss coefficient by fitting includes: adopting a curve fitting method, using the calculated combustion chamber total pressure loss coefficient and the combustion chamber outlet gas specific heat ratio, taking the relative load as an independent variable, respectively fitting the calculation formulas for obtaining the combustion chamber total pressure loss coefficient and the combustion chamber outlet gas specific heat ratio γ, s c =f(w) γ=g(w) Among them, 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 combustion chamber outlet gas obtained by fitting.

5. A method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to claim 4, characterized in that: The formula for calculating the turbine inlet temperature includes using the energy variation characteristics of the high-temperature and high-pressure gas expanding and working 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 by using the calculation formula for the combustion chamber outlet gas specific heat ratio γ and the calculation formula for the turbine inlet temperature.

6. A method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to claim 5, 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 reduced by 1%; 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%; when T 3r -T3<0, then the command to increase the IGV opening by 1% is output; 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.

7. A method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to claim 6, characterized in that: The adjustment of the IGV opening and the fuel flow rate includes calculating the turbine inlet temperature in real time and generating new IGV and fuel flow rate control instructions in real time in combination with the change of the combustion pressure pulsation data 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.

8. A system based on the method for optimizing and adjusting the outlet temperature of a gas turbine combustion chamber according to any one of claims 1 to 7, 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 fit and obtain a calculation formula for the gas specific heat ratio and the combustion chamber total pressure loss coefficient; 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.

9. 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 7 are implemented.

10. 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 7 are implemented.

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