A method and device for constructing an acoustic natural frequency prediction model

Abstract

The present invention discloses a method and device for constructing an acoustic natural frequency prediction model, including: obtaining a target entity model carrying a flow field grid; determining target values of first inlet boundary parameters corresponding to the first load coefficient at each combustion moment according to the initial value of the first inlet boundary parameter of the first load coefficient, a preset phase value, a preset pulsation amplitude ratio of the inlet boundary parameter, an upper limit value of the acoustic natural frequency of the combustion chamber, a frequency step size, and a plurality of preset combustion moments; constructing a combustion chamber flow field numerical simulation model corresponding to the first load coefficient based on the target entity model, the target values of the first inlet boundary parameters, the initial values of other inlet boundary parameters, the initial values of the outlet boundary parameters, and constraint conditions; calculating the combustion chamber flow field numerical simulation models corresponding to each load coefficient to generate acoustic natural frequencies corresponding to each load coefficient; and constructing a prediction model of the load coefficient and the acoustic natural frequency based on all load coefficients and the acoustic natural frequencies corresponding to each load coefficient.

Description

Technical Field

[0001] The present invention relates to the field of gas turbines, and particularly to a method and device for constructing an acoustic natural frequency prediction model. Background Art

[0002] The acoustic natural frequency of a gas turbine combustor is a characteristic parameter of the combustor that must be focused on during the combustor design process. It is directly related to the excitation frequency of possible thermoacoustic coupling oscillating combustion in the combustor, and has an important guiding role in combustion state diagnosis and combustion stability control.

[0003] Most of the domestic in-service heavy gas turbines are introduced from foreign gas turbine manufacturing plants. Due to technical confidentiality factors, foreign gas turbine manufacturers do not disclose the acoustic natural frequency of the gas turbine combustors they design, which is not conducive to the operation and maintenance personnel of gas turbine power plants to accurately judge the combustion state in the combustor and cannot effectively prevent the occurrence of combustor failures.

[0004] However, in the prior art, the acoustic natural frequency of a gas turbine combustor is obtained through combustion experiments, but this experiment is costly and time-consuming. Therefore, how to quickly and accurately obtain the acoustic natural frequency of a gas turbine has become an urgent problem to be solved currently. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art that the process of obtaining the acoustic natural frequency is complex and the acquisition cost is high, so as to provide a method and device for constructing an acoustic natural frequency prediction model.

[0006] In a first aspect, the present invention provides a method for constructing an acoustic natural frequency prediction model, including:

[0007] Perform flow field meshing on the solid model of the pre-built gas turbine combustor to obtain the target solid model with the flow field mesh; obtain the initial values of the inlet boundary parameters corresponding to each of the multiple load coefficients and the initial values of the outlet boundary parameters corresponding to each of the load coefficients, where the inlet boundary parameters include multiple ones; select the first inlet boundary parameter from the multiple inlet boundary parameters; determine the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated, the frequency step, and the j-th combustion moment among the multiple preset combustion moments, where the first load coefficient is any one of the multiple load coefficients and j is a positive integer; based on the target solid model, the target values of the first inlet boundary parameter at each combustion moment, the initial values of the other inlet boundary parameters except the first inlet boundary parameter among the multiple inlet boundary parameters, the initial values of the outlet boundary parameters, and the pre-configured constraint conditions, construct the combustion chamber flow field numerical simulation model corresponding to the first load coefficient; perform transient numerical calculations on the combustion chamber flow field numerical simulation models corresponding to each load coefficient respectively to generate the acoustic natural frequencies corresponding to each load coefficient; based on all the load coefficients and the acoustic natural frequencies corresponding to each load coefficient, construct a prediction model between the load coefficient and the acoustic natural frequency.

[0008] According to the present invention, based on the target solid model with the flow field mesh, the target values of the first inlet boundary parameter corresponding to each of the multiple load coefficients, the initial values of the other inlet boundary parameters except the first inlet boundary parameter corresponding to each of the multiple load coefficients, and the pre-configured constraint conditions, construct the combustion chamber flow field numerical simulation model corresponding to each load coefficient respectively, perform transient numerical calculations on the combustion chamber flow field numerical simulation models corresponding to each load coefficient respectively to generate the acoustic natural frequencies corresponding to each load coefficient, and based on all the load coefficients and the acoustic natural frequencies corresponding to each load coefficient, construct a prediction model between the load coefficient and the acoustic natural frequency; through the constructed prediction model, the acoustic natural frequency at any load coefficient can be obtained, solving the defects in the prior art that the process of obtaining the acoustic natural frequency is complex and the acquisition cost is high. Moreover, in the actual application process, the staff can determine the acoustic natural frequency corresponding to any order at any time according to the actual load condition of the gas turbine. On the one hand, it improves the work efficiency of the operator, on the other hand, it also improves the convenience of obtaining the acoustic natural frequency and reduces the acquisition cost at the same time.

[0009] Combined with the first aspect, in the first embodiment of the first aspect, according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated, the frequency step, and the j-th combustion moment among multiple preset combustion moments, determine the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment, specifically including:

[0010] Determine the number of summation times according to the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated and the frequency step; according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summation times, the frequency step, and the j-th combustion moment among multiple preset combustion moments, determine the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment.

[0011] In this embodiment, according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summation times, the frequency step, and the j-th combustion moment among multiple preset combustion moments, determine the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment. As the target value of the first inlet boundary parameter changes at different combustion moments, the pressure pulsation at the combustor inlet and the pressure pulsation inside the combustor also change accordingly. Furthermore, determine the acoustic natural frequency at the first load coefficient according to the pressure pulsation at the combustor inlet and the pressure pulsation inside the combustor.

[0012] Combined with the first aspect, in the second embodiment of the first aspect, according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summation times, the frequency step, and the j-th combustion moment among multiple preset combustion moments, determine the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment, which is achieved through the following formula:

[0013]

[0014] where F is the target value of the first inlet boundary parameter corresponding to the first load coefficient, A is the initial value of the first inlet boundary parameter corresponding to the first load coefficient, n is the number of summation times, m is the preset pulsation amplitude ratio of the inlet boundary parameter, △ω is the frequency step, is the preset phase value, t j is the j-th preset combustion moment.

[0015] Combined with the first aspect, in the third embodiment of the first aspect, the acoustic natural frequencies corresponding to each load factor include multiple. Based on all the load factors and the acoustic natural frequencies corresponding to each load factor, a prediction model between the load factor and the acoustic natural frequency is constructed, including:

[0016] Determine the order of each acoustic natural frequency corresponding to each load factor respectively; extract all the target acoustic natural frequencies at the target order from the acoustic natural frequencies corresponding to all the load factors respectively, where the target order is any one of multiple orders; fit all the target acoustic natural frequencies corresponding to the target order to generate a prediction model between the load factor and the acoustic natural frequency corresponding to the target order.

[0017] In this embodiment, all the load factors and the acoustic natural frequencies corresponding to each load factor are used as basic data. The acoustic natural frequencies at each load factor corresponding to the target order are obtained from the basic data, and a model between the load factor and the acoustic natural frequency corresponding to the target order is constructed based on the acoustic natural frequencies at each load factor corresponding to the target order. Through this model, the acoustic natural frequencies corresponding to the target order at any load factor can be obtained, thereby improving the convenience of obtaining the acoustic natural frequency.

[0018] Combined with the first aspect, in the fourth embodiment of the first aspect, generating the acoustic natural frequencies corresponding to each load factor includes:

[0019] Obtain a pre-constructed first curve corresponding to the first load factor, where the first curve is the pressure pulsation disturbance curve at the inlet boundary of the combustion chamber; determine a second curve corresponding to the first load factor based on the acoustic natural frequency corresponding to the first load factor, where the second curve is the pressure pulsation disturbance curve inside the combustion chamber corresponding to the first load factor; determine the acoustic natural frequency corresponding to the first load factor based on the first curve and the second curve.

[0020] Combined with the first aspect, in the fifth embodiment of the first aspect, determining the multi-order acoustic natural frequencies corresponding to the first load factor based on the first curve and the second curve includes:

[0021] The first curve is converted into a third curve by using a first transformation method, and the second curve is converted into a fourth curve by using the first transformation method. The abscissa of the third curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude at the inlet of the combustion chamber corresponding to each frequency. The abscissa of the fourth curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude inside the combustion chamber corresponding to each frequency. The first amplitude corresponding to the first frequency value is obtained from the third curve, and the first amplitude is the pressure pulsation amplitude at the inlet of the combustion chamber corresponding to the first frequency value. The second amplitude corresponding to the first frequency value is obtained from the fourth curve, and the second amplitude is the pressure pulsation amplitude inside the combustion chamber corresponding to the first frequency value. When the second amplitude is greater than or equal to a preset threshold, the first frequency is determined as the first acoustic natural frequency corresponding to the first load factor, and the preset threshold is a preset ratio of the first amplitude.

[0022] In this embodiment, both the first curve and the second curve are time-domain diagrams, and both the third curve and the fourth curve are frequency-domain diagrams. Since the frequency-domain diagram can intuitively present the frequency and the pressure pulsation amplitude corresponding to the frequency, the first curve is converted into the third curve, and the second curve is converted into the fourth curve, which is convenient for directly obtaining the pressure pulsation amplitude at the inlet boundary of the combustion chamber and the pressure pulsation amplitude inside the combustion chamber corresponding to the same frequency value from the curves, so as to directly determine whether the current frequency is the acoustic natural frequency according to the obtained pressure pulsation amplitude at the inlet boundary of the combustion chamber and the pressure pulsation amplitude inside the combustion chamber, thereby ensuring that the process of determining the acoustic natural frequency is simpler and more accurate.

[0023] In a second aspect, the present invention provides an apparatus for constructing an acoustic natural frequency prediction model, including:

[0024] A partitioning module for performing flow field grid partitioning on the solid model of a pre-built gas turbine combustor to obtain a target solid model with flow field grids; an acquisition module for acquiring the initial values of the inlet boundary parameters corresponding to each of multiple load coefficients and the initial values of the outlet boundary parameters corresponding to each of the multiple load coefficients, wherein the inlet boundary parameters include multiple ones; a selection module for selecting a first inlet boundary parameter from the multiple inlet boundary parameters; a determination module for determining, according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, a preset phase value, a preset pulsation amplitude ratio of the inlet boundary parameter, the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated, a frequency step, and the j-th combustion moment among multiple preset combustion moments, the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment, wherein the first load coefficient is any one of the multiple load coefficients and j is a positive integer; a first construction module for constructing a numerical simulation model of the combustor flow field corresponding to the first load coefficient based on the target solid model, the target values of the first inlet boundary parameter at each combustion moment, the initial values of the other inlet boundary parameters except the first inlet boundary parameter among the multiple inlet boundary parameters, the initial value of the outlet boundary parameter, and a pre-configured constraint condition; a generation module for performing transient numerical calculation on the numerical simulation model of the combustor flow field corresponding to each load coefficient respectively to generate the acoustic natural frequency corresponding to each load coefficient; a second construction module for constructing a prediction model between the load coefficient and the acoustic natural frequency based on all the load coefficients and the acoustic natural frequencies corresponding to each load coefficient.

[0025] Combined with the second aspect, in the first embodiment of the second aspect, the determination module specifically includes:

[0026] A first determination sub-module for determining the summation times according to the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated and the frequency step; a second determination sub-module for determining, according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the summation times, the frequency step, and the j-th preset combustion moment, the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment.

[0027] In a third aspect, the present invention provides a computer device, including: a memory and a processor, which are communicatively connected to each other, the memory is used for storing a computer program, and when the computer program is executed by the processor, the processor executes the method for constructing the acoustic natural frequency prediction model according to any one of the contents of the invention.

[0028] Fourthly, the present invention provides a computer-readable storage medium for storing computer instructions, which, when executed by a processor, implement the method for constructing an acoustic natural frequency prediction model according to any one of the contents of the invention. Description of the Drawings

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 It is a flowchart of the method for constructing an acoustic natural frequency prediction model provided in the embodiments of the present invention;

[0031] Figure 2 It is a time-domain curve graph of the pressure pulsation disturbance at the combustion chamber inlet boundary provided in the embodiments of the present invention;

[0032] Figure 3 It is a time-domain curve graph of the pressure pulsation disturbance inside the combustion chamber provided in the embodiments of the present invention;

[0033] Figure 4 It is a frequency-domain curve graph of the pressure pulsation disturbance at the combustion chamber inlet boundary provided in the embodiments of the present invention;

[0034] Figure 5 It is a frequency-domain curve graph of the pressure pulsation disturbance inside the combustion chamber provided in the embodiments of the present invention;

[0035] Figure 6 It is a connection diagram of the device for constructing an acoustic natural frequency prediction model provided in the embodiments of the present invention;

[0036] Figure 7 It is a connection diagram of the computer device provided in the embodiments of the present invention. Detailed Embodiments

[0037] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0038] The present invention discloses a method for constructing an acoustic natural frequency prediction model, as Figure 1 shown, the method includes the following steps:

[0039] Step S1: Perform a flow field grid division on the pre-built solid model of the gas turbine combustor to obtain the target solid model with the flow field grid carried thereon.

[0040] Specifically, the pre-built solid model of the gas turbine combustor can be divided into unstructured tetrahedral elements or structured hexahedral elements suitable for the finite volume method by using a meshing tool. After the division, the skewness value of the flow field grid elements of the combustor is obtained to check the quality of the divided flow field grid elements. When the skewness value is not higher than 0.92, it indicates that the quality of the flow field grid elements is qualified, and thus the target solid model with the flow field grid can be obtained. When the skewness value is higher than 0.92, it indicates that the quality of the flow field grid elements is unqualified, and the meshing method needs to be readjusted for meshing until the quality of all the flow field grid elements is qualified.

[0041] Specifically, the meshing tool can be Fluent, Flotherm, etc.

[0042] Specifically, before step S1, a solid model of the gas turbine combustor is established according to the design drawing of the gas turbine combustor.

[0043] Step S2: Obtain the initial values of the inlet boundary parameters corresponding to each of the multiple load factors and the initial values of the outlet boundary parameters corresponding to each of the multiple load factors.

[0044] Specifically, there are multiple inlet boundary parameters and multiple outlet boundary parameters; the load factor is the load factor of the rated power of the combustor, and its value range is [0 - 1]. For example, the initial values of the inlet boundary parameters of the gas turbine at 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% rated loads and the initial values of the outlet boundary parameters of the gas turbine at 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% rated loads can be obtained.

[0045] Specifically, the initial values of the inlet boundary parameters and the initial values of the outlet boundary parameters corresponding to any one load factor are queried from the design parameter table or the working operation parameter table of the gas turbine.

[0046] Step S3: Select the first inlet boundary parameter from the multiple inlet boundary parameters.

[0047] Specifically, the inlet boundary parameters of the combustion chamber are air pressure, air mass flow rate, air temperature, fuel pressure, fuel mass flow rate, fuel temperature, and the outlet boundary parameters of the combustion chamber are gas pressure, gas mass flow rate, gas temperature; among them, the first inlet boundary parameter can be any one of the multiple inlet boundary parameters, such as fuel pressure or air mass flow rate, etc.

[0048] Step S4: Determine the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment among multiple preset combustion moments according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the upper limit value of the acoustic natural frequency of the gas turbine combustion chamber to be investigated, the frequency step size.

[0049] Specifically, the first load coefficient is any one of multiple load coefficients, and j is a positive integer.

[0050] Specifically, since the relationship between the combustion moment and the first inlet boundary parameter conforms to a sine function, a sine model can be constructed first, and then the amplitude is determined based on the initial value of the first inlet boundary parameter corresponding to the first load coefficient and the preset pulsation amplitude ratio of the inlet boundary parameter, the preset phase value is used as the phase, the frequency is determined based on the upper limit value of the acoustic natural frequency of the gas turbine combustion chamber and the frequency step size, and a mapping relationship between the combustion moment corresponding to the first load coefficient and the target value of the first inlet boundary parameter is constructed based on the constructed model and the above parameters. According to this mapping relationship, the target value of the first inlet boundary parameter corresponding to the first load coefficient at each preset combustion moment can be determined.

[0051] Step S5: Based on the target entity model, the target values of the first inlet boundary parameter at each combustion moment, the initial values of the other inlet boundary parameters except the first inlet boundary parameter among the multiple inlet boundary parameters, the initial values of the outlet boundary parameters, and the pre-configured constraint conditions, construct a combustion chamber flow field numerical simulation model corresponding to the first load coefficient respectively.

[0052] Specifically, the pre-configured constraint conditions include a combustion model and a turbulence model. Usually, the k-ε model can be selected as the turbulence model, and the eddy dissipation model can be selected as the combustion model.

[0053] Specifically, after determining the target values of the air mass flow rate corresponding to each combustion moment at a 5% load coefficient, a combustion chamber flow field numerical simulation model corresponding to the 5% load coefficient is constructed according to the obtained target entity model, the target values of the air mass flow rate at a 5% load coefficient, the initial values of the other inlet boundary parameters at a 5% load coefficient, the initial values of the outlet boundary parameters at a 5% load coefficient, and the selected combustion model and turbulence model.

[0054] Step S6: Perform transient numerical calculations on the numerical simulation models of the combustion chamber flow fields corresponding to each load coefficient respectively, to generate the acoustic natural frequencies corresponding to each load coefficient. Specifically, performing transient numerical calculations on the numerical simulation models of the combustion chamber flow fields corresponding to each load coefficient respectively belongs to the prior art, so there will be no further detailed explanation here.

[0055] It should be noted that each load coefficient corresponds to multiple acoustic natural frequencies. For multiple acoustic natural frequencies, they can also be sorted according to the numerical values of the natural frequencies. Then, determine the order of the acoustic natural frequency according to its position in the sorting; for example, after the acoustic natural frequencies at 5% rated load are sorted in ascending order as 50Hz, 120Hz, 160Hz, 210Hz, the first-order acoustic natural frequency corresponding to 5% rated load is 50Hz, the second-order acoustic natural frequency is 120Hz, the third-order acoustic natural frequency is 160Hz, and the fourth-order acoustic natural frequency is 210Hz; or, after the acoustic natural frequencies at 5% rated load are sorted in ascending order as 50Hz, 51Hz, 52Hz, 53Hz, the first-order acoustic natural frequency corresponding to 5% rated load is 50Hz, the second-order acoustic natural frequency is 51Hz, the third-order acoustic natural frequency is 52Hz, and the fourth-order acoustic natural frequency is 53Hz.

[0056] Step S7: Based on all load coefficients and the acoustic natural frequencies corresponding to each load coefficient, construct a prediction model between the load coefficient and the acoustic natural frequency.

[0057] Specifically, after obtaining the acoustic natural frequencies corresponding to each load coefficient, obtain the acoustic natural frequencies corresponding to the target order under each load coefficient. The commonly used data fitting method can be used to fit the acoustic natural frequencies corresponding to the target order under each load coefficient, and fit them into a curve formed by the load coefficient and the acoustic natural frequency. According to the fitted curve, construct a prediction model between the load coefficient corresponding to the target order and the acoustic natural frequency. The commonly used mathematical fitting method can be the least squares curve fitting method, and the constructed prediction model can be a function between the load coefficient and the acoustic natural frequency.

[0058] Based on the target entity model with a flow field grid, the target value of the first inlet boundary parameter corresponding to each of the multiple load coefficients, the initial values of other inlet boundary parameters except the first inlet boundary parameter corresponding to each of the multiple load coefficients, and the pre-configured constraint conditions, a numerical simulation model of the combustor flow field corresponding to each load coefficient is constructed, and transient numerical calculations are performed on the numerical simulation model of the combustor flow field corresponding to each load coefficient to generate multiple acoustic natural frequencies corresponding to each load coefficient. Then, based on all the load coefficients and the acoustic natural frequencies corresponding to each load coefficient, a prediction model between the load coefficient and the acoustic natural frequency is constructed. Through the constructed prediction model, the acoustic natural frequency of any order under any load coefficient can be obtained, which solves the defects in the prior art that the process of obtaining the acoustic natural frequency is complex and the acquisition cost is high. Moreover, in the actual application process, the staff can determine the acoustic natural frequency corresponding to any order according to the actual load condition of the gas turbine at any time. On the one hand, it improves the work efficiency of the operator, on the other hand, it also improves the convenience of obtaining the acoustic natural frequency and reduces the acquisition cost.

[0059] In an alternative embodiment, according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated, the frequency step, and the j-th combustion moment among multiple preset combustion moments, determining the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment specifically includes:

[0060] Determining the number of summation times according to the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated and the frequency step; determining the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summation times, the frequency step, and the j-th preset combustion moment.

[0061] Exemplarily, first, the target frequency values within the acoustic natural frequency range of the gas turbine combustor and the summation times can be determined according to the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated and the frequency step. For example, if the upper limit value of the acoustic natural frequency of the A-type gas turbine combustor to be investigated is 100 Hz and the frequency step is 10, then the summation times is, for example, 100 / 10 = 10, that is, there are 10 target frequency values. For the convenience of illustration, we can determine the target frequency values within the acoustic natural frequency range of the gas turbine combustor in gradients of 10 Hz. For example, there are 10 target frequency values within the acoustic natural frequency range of the gas turbine combustor, which are 10 Hz, 20 Hz, 30 Hz, 40 Hz, 50 Hz, 60 Hz, 70 Hz, 80 Hz, 90 Hz, and 100 Hz respectively. Of course, in addition to obtaining 10 target frequency values in this way, other methods can also be used to obtain them. In this application, only one feasible implementation method is listed, and as for how to determine 10 target frequency values, it can be completely determined according to the actual situation.

[0062] Then, according to each target frequency value, as well as the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, and the preset inlet boundary parameter pulsation amplitude ratio, the mapping relationship between the combustion moment corresponding to the first load coefficient at each target frequency value and the target value of the first inlet boundary parameter is constructed. The specific mapping relationship can be reflected by the following formula:

[0063]

[0064] where, F i is the target value of the first inlet boundary parameter at each combustion moment corresponding to the first target frequency value, A is the initial value of the first inlet boundary parameter corresponding to the first load coefficient, m is the preset inlet boundary parameter pulsation amplitude ratio, ω i is the target frequency value, is the preset phase value, t j is the jth preset combustion moment. Therefore, in the above embodiment, 10 target frequency values correspond to 10 mapping relationships.

[0065] Finally, after obtaining the mapping relationship corresponding to each target frequency value, the 10 mapping relationships corresponding to the 10 target frequency values are merged. The merged function is the target mapping relationship between the combustion moment corresponding to the first load coefficient and the target value of the first inlet boundary parameter, and the target value of the first inlet boundary parameter corresponding to the first load coefficient at each preset combustion moment is determined according to this target mapping relationship.

[0066] In a specific example, the mapping relationships corresponding to the 10 target frequency values are:

[0067]

[0068]

[0069] ……

[0070]

[0071]

[0072] Merge the above 10 mapping relationships, and the merged mapping relationship is:

[0073]

[0074] Finally, the target value of the first inlet boundary parameter corresponding to each preset combustion moment under the first load coefficient can be determined according to the merged mapping relationship.

[0075] In this embodiment, the target value of the first inlet boundary parameter corresponding to the first load coefficient at each preset combustion moment is determined by the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summations, and the frequency step size. By monitoring the target value of the first inlet boundary parameter at different combustion moments, the pressure pulsation curve at the inlet of the combustion chamber is generated, and then the acoustic natural frequency under the first load coefficient is determined according to the pressure pulsation curve at the inlet of the combustion chamber and the pressure pulsation curve inside the combustion chamber.

[0076] In an alternative embodiment, according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summations, the frequency step size, and the j-th preset combustion moment, the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment is determined, which is achieved by the following formula:

[0077]

[0078] where F is the target value of the first inlet boundary parameter corresponding to the first load coefficient, A is the initial value of the first inlet boundary parameter corresponding to the first load coefficient, n is the number of summations, The round() function represents rounding up, m is the preset pulsation amplitude ratio of the inlet boundary parameter, △ω is the frequency step size, is the preset phase value, t j is the j-th preset combustion moment.

[0079] Exemplarily, for a certain model of gas turbine, if the upper limit f of the acoustic natural frequency of the combustion chamber to be investigated is determined to be 150 Hz and the frequency step Δω is taken as 5 Hz, then the summation number n is 30; the pulsation amplitude ratio m of the combustion chamber inlet boundary parameter is taken as 5%, and the initial phase is taken as any random number within the range of [0, 2π], A is taken as the initial value of the air mass flow rate when the load coefficient of the gas turbine is 10%. After each parameter is determined, using the above formula, the target value of the air mass flow rate corresponding to each combustion moment when the load coefficient is 10% is determined; through the pressure monitoring point at the combustion chamber inlet boundary, the pressure pulsation disturbance value corresponding to the air mass flow rate disturbance is monitored at different combustion moments, and a pressure pulsation disturbance curve at the combustion chamber inlet boundary corresponding to 10% load is generated according to each combustion moment and the pressure pulsation disturbance value corresponding to each combustion moment. This curve is used to combine and compare with the pressure pulsation disturbance curve inside the combustion chamber corresponding to 10% load, and the acoustic natural frequency corresponding to 10% load coefficient is determined according to the comparison result.

[0080] In an alternative embodiment, there are multiple acoustic natural frequencies corresponding to each load coefficient. Based on all the load coefficients and the acoustic natural frequencies corresponding to each load coefficient, a prediction model between the load coefficient and the acoustic natural frequency is constructed, including:

[0081] Determine the order of each acoustic natural frequency corresponding to each load coefficient respectively; extract all the target acoustic natural frequencies at the target order from the acoustic natural frequencies corresponding to all the load coefficients respectively, where the target order is any one of multiple orders; fit all the target acoustic natural frequencies corresponding to the target order to generate a prediction model between the load coefficient and the acoustic natural frequency corresponding to the target order.

[0082] Exemplarily, the multi-order acoustic natural frequencies (unit: Hertz, Hz) of a certain model of gas turbine at each load coefficient are shown in Table 1:

[0083]

[0084] Table 1

[0085] From all the multi - order acoustic natural frequencies corresponding to different load factors, all the target acoustic natural frequencies at the target order are extracted. For example, when the target order is the first order, the first - order acoustic natural frequencies at each load factor are obtained: 62.54Hz, 65.92Hz, 70.39Hz, 74.59Hz, 77.44Hz, 79.66Hz, 80.74Hz, 81.54Hz, 81.99Hz, 81.99Hz, 81.99Hz, 81.99Hz. The first - order acoustic natural frequencies at each load factor are curve - fitted using a mathematical fitting method to determine the calculation formula for the acoustic natural frequency of the combustion chamber at different load factors:

[0086] y = a+bx+cx 2 +dx 3

[0087] where x is the load factor of the gas turbine, y is the first - order acoustic natural frequency of the gas - turbine combustion chamber at this load factor, and a, b, c, d are the fitted coefficients. According to the above method, the mapping relationship between the load factor of the gas - turbine combustion chamber and the acoustic natural frequency corresponding to each order can be obtained. For example, after fitting all the acoustic natural frequencies in Table 1 in the above way, the coefficients corresponding to each order are shown in Table 2.

[0088]

[0089] Table 2

[0090] Substitute the corresponding coefficients into the above calculation formula, and the mapping relationship between the load factor of the combustion chamber of Model A gas turbine and the acoustic natural frequencies corresponding to each order can be obtained. When obtaining the third - order acoustic natural frequency of Model A gas turbine at a load factor of 32%, first find the mapping relationship corresponding to the third order in Model A, and then substitute the load factor of 32% as the independent variable into the mapping relationship to obtain the third - order acoustic natural frequency of Model A gas turbine at a load factor of 32%.

[0091] Exemplarily, when the orders of the acoustic natural frequencies corresponding to all load factors are not exactly the same, for example, among the natural frequencies corresponding to all load factors of a gas turbine of model A, only the acoustic natural frequency corresponding to the 5% load factor has 5 orders, and the acoustic natural frequencies corresponding to the remaining load factors all have 6 orders. When fitting the mapping relationship between the load factor corresponding to 6 orders and the acoustic natural frequency, it is necessary to ensure that each load factor corresponds to an acoustic natural frequency of 6 orders. Therefore, at this time, it is necessary to modify the upper limit value of the acoustic natural frequency of the combustion chamber to be observed corresponding to the 5% load factor, so as to re-determine the target value of the first inlet boundary parameter corresponding to the 5% load factor, re-establish the numerical simulation model of the combustion chamber flow field corresponding to the 5% load factor, and use the new numerical simulation model of the combustion chamber flow field to perform transient calculations to obtain the acoustic natural frequency, and judge whether there is an acoustic natural frequency of 6 orders. When there is an acoustic natural frequency of 6 orders, the mapping relationship between the load factor corresponding to 6 orders and the acoustic natural frequency can be started to be fitted; when there is no acoustic natural frequency of 6 orders, continue to execute the above method until there is an acoustic natural frequency of 6 orders in the acoustic natural frequencies corresponding to the 5% load factor, and then it can be stopped.

[0092] In this embodiment, all load factors and the acoustic natural frequencies corresponding to each load factor are used as basic data. The acoustic natural frequencies under each load factor corresponding to the target order are obtained from the basic data, and a model between the load factor corresponding to the target order and the acoustic natural frequency is constructed based on the acoustic natural frequencies under each load factor corresponding to the target order. Through this model, the acoustic natural frequency corresponding to the target order under any load factor can be obtained, thereby improving the convenience of obtaining the acoustic natural frequency.

[0093] In an alternative embodiment, generating the acoustic natural frequency corresponding to each load factor includes:

[0094] Obtain a pre-constructed first curve corresponding to the first load factor, where the first curve is the pressure pulsation disturbance curve at the inlet boundary of the combustion chamber; based on the acoustic natural frequency corresponding to the first load factor, determine a second curve corresponding to the first load factor, where the second curve is the pressure pulsation disturbance curve inside the combustion chamber corresponding to the first load factor; determine the acoustic natural frequency corresponding to the first load factor based on the first curve and the second curve.

[0095] Exemplarily, pressure monitoring points are respectively set at two positions, namely, at the combustion chamber inlet boundary of the first load coefficient and inside the combustion chamber of the first load coefficient. According to the pressure pulsation disturbance values corresponding to each combustion moment monitored at the combustion chamber inlet boundary, a first curve corresponding to the first load coefficient is constructed based on the combustion moment and the pressure pulsation disturbance value corresponding to this combustion moment. According to the pressure pulsation disturbance values corresponding to each combustion moment monitored inside the combustion chamber, a second curve corresponding to the first load coefficient is constructed based on the combustion moment and the pressure pulsation disturbance value corresponding to this combustion moment. Among them, the first curve and the second curve are time-domain curve graphs, and then the acoustic natural frequency corresponding to the first load coefficient is determined according to the first curve graph and the second curve graph.

[0096] In an alternative embodiment, determining the multi-order acoustic natural frequencies corresponding to the first load coefficient based on the first curve and the second curve includes:

[0097] The first curve is transformed into a third curve by using a first transformation method, and the second curve is transformed into a fourth curve by using the first transformation method. The abscissa of the third curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude at the combustion chamber inlet corresponding to each frequency. The abscissa of the fourth curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude inside the combustion chamber corresponding to each frequency. The first amplitude corresponding to the first frequency value is obtained from the third curve, and the first amplitude is the pressure pulsation amplitude at the combustion chamber inlet corresponding to the first frequency value. The second amplitude corresponding to the first frequency value is obtained from the fourth curve, and the second amplitude is the pressure pulsation amplitude inside the combustion chamber corresponding to the first frequency value. When the second amplitude is greater than or equal to a preset threshold, the first frequency is determined as the first acoustic natural frequency corresponding to the first load coefficient, and the preset threshold is a preset ratio of the first amplitude.

[0098] Specifically, the multiple acoustic natural frequencies corresponding to the first load coefficient include the first acoustic natural frequency.

[0099] Exemplarily, Fourier transforms are respectively performed on the time-domain curve of the pressure pulsation disturbance at the combustion chamber inlet boundary and the time-domain curve of the pressure pulsation disturbance inside the combustion chamber. The time-domain curve of the pressure pulsation disturbance at the combustion chamber inlet boundary, that is, the first curve, is transformed into the frequency-domain curve of the pressure pulsation disturbance at the combustion chamber inlet boundary, that is, the third curve. The time-domain curve of the pressure pulsation disturbance inside the combustion chamber is transformed into the frequency-domain curve of the pressure pulsation disturbance inside the combustion chamber, that is, the fourth curve. The first curve is as Figure 2 shown, the second curve is as Figure 3 shown, the third curve is as Figure 4 shown, and the fourth curve is as Figure 5 shown.

[0100] After converting the first curve and the second curve into the third curve and the fourth curve respectively, the first amplitude and the second amplitude corresponding to the same frequency are obtained from the third curve and the fourth curve respectively. For example, the first amplitude of 2000 Pa corresponding to 50 Hz is obtained from the third curve, and the second amplitude of 900 Pa corresponding to 50 Hz is obtained from the fourth curve. It is judged whether the second amplitude is greater than or equal to a preset threshold. Generally, the preset threshold is 80% of the first amplitude. Then, in this embodiment, the preset threshold is 2000 * 80% = 1600 Pa. Since the second amplitude of 900 Pa < 1600 Pa, it indicates that 50 Hz is not the acoustic natural frequency.

[0101] For example, the first amplitude of 2000 Pa corresponding to 90 Hz is obtained from the third curve, and the second amplitude of 4000 Pa corresponding to 90 Hz is obtained from the fourth curve. Then, in this embodiment, the preset threshold is still 2000 * 80% = 1600 Pa. Since the second amplitude of 4000 Pa > 1600 Pa, it indicates that 90 Hz is the acoustic natural frequency.

[0102] In the above manner, the acoustic natural frequency corresponding to a certain load coefficient is determined according to the third curve and the fourth curve corresponding to the load coefficient, and a prediction model between the load coefficient and the acoustic natural frequency is constructed according to all the load coefficients and the acoustic natural frequency corresponding to each load coefficient.

[0103] In this embodiment, both the first curve and the second curve are time-domain diagrams, and both the third curve and the fourth curve are frequency-domain diagrams. Since the frequency-domain diagram can visually present the frequency and the pressure pulsation amplitude corresponding to the frequency, the first curve is converted into the third curve, and the second curve is converted into the fourth curve, which is convenient for directly obtaining the pressure pulsation amplitude at the combustion chamber inlet boundary and the pressure pulsation amplitude inside the combustion chamber corresponding to the same frequency value from the curves. Thus, it can be directly determined whether the current frequency is the acoustic natural frequency according to the obtained pressure pulsation amplitude at the combustion chamber inlet boundary and the pressure pulsation amplitude inside the combustion chamber, thereby ensuring that the process of determining the acoustic natural frequency is simpler and more accurate.

[0104] In another embodiment of the present invention, the present invention provides a device for constructing an acoustic natural frequency prediction model, as Figure 6 shown, including:

[0105] A division module 61, configured to perform flow field grid division on a pre-constructed solid model of a gas turbine combustion chamber to obtain a target solid model carrying flow field grids;

[0106] An acquisition module 62, configured to acquire the initial value of the inlet boundary parameters corresponding to each of the multiple load coefficients and the initial value of the outlet boundary parameters corresponding to each of the multiple load coefficients, where the inlet boundary parameters include multiple;

[0107] A selection module 63 is configured to select a first inlet boundary parameter from a plurality of inlet boundary parameters;

[0108] A determination module 64 is configured to determine a target value of the first inlet boundary parameter corresponding to the first load factor at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load factor, a preset phase value, a preset pulsation amplitude ratio of the inlet boundary parameter, an upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated, a frequency step, and the j-th combustion moment among a plurality of preset combustion moments, wherein the first load factor is any one of a plurality of load factors, and j is a positive integer;

[0109] A first construction module 65 is configured to construct a numerical simulation model of the combustor flow field corresponding to the first load factor respectively based on a target entity model, the target values of the first inlet boundary parameter at each combustion moment respectively, the initial values of the other inlet boundary parameters except the first inlet boundary parameter among the plurality of inlet boundary parameters, the initial value of the outlet boundary parameter, and pre-configured constraint conditions;

[0110] A generation module 66 is configured to perform transient numerical calculations on the numerical simulation models of the combustor flow field corresponding to each load factor respectively, and generate acoustic natural frequencies corresponding to each load factor;

[0111] A second construction module 67 is configured to construct a prediction model between the load factor and the acoustic natural frequency based on all the load factors and the acoustic natural frequencies corresponding to each load factor.

[0112] Combined with the second aspect, in the first embodiment of the second aspect, the determination module specifically includes:

[0113] A first determination sub-module is configured to determine the number of summations according to the upper limit value of the acoustic natural frequency of the gas turbine combustor to be investigated and the frequency step; a second determination sub-module is configured to determine the target value of the first inlet boundary parameter corresponding to the first load factor at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load factor, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summations, the frequency step, and the j-th preset combustion moment.

[0114] In an alternative embodiment, the determination module is implemented by the following formula:

[0115]

[0116] Wherein, F is the target value of the first inlet boundary parameter corresponding to the first load coefficient, A is the initial value of the first inlet boundary parameter corresponding to the first load coefficient, n is the number of summation times, m is the preset pulsation amplitude ratio of the inlet boundary parameter, △ω is the frequency step, is the preset phase value, t j is the jth set combustion moment in the table.

[0117] In an alternative embodiment, the second construction module includes:

[0118] A determination sub-module, configured to respectively determine the order of each acoustic natural frequency corresponding to each load coefficient; an extraction sub-module, configured to extract all target acoustic natural frequencies at the target order from the acoustic natural frequencies respectively corresponding to all load coefficients, where the target order is any one of multiple orders; a generation sub-module, configured to fit all target acoustic natural frequencies corresponding to the target order, and generate a prediction model between the load coefficient and the acoustic natural frequency corresponding to the target order.

[0119] In an alternative embodiment, the generation sub-module includes:

[0120] An acquisition unit, configured to acquire a first curve pre-constructed corresponding to the first load coefficient, where the first curve is the pressure pulsation disturbance curve at the combustion chamber inlet boundary; a first determination unit, configured to determine a second curve corresponding to the first load coefficient based on the acoustic natural frequency corresponding to the first load coefficient, where the second curve is the pressure pulsation disturbance curve inside the combustion chamber corresponding to the first load coefficient; a second determination unit, configured to determine the acoustic natural frequency corresponding to the first load coefficient based on the first curve and the second curve.

[0121] In an alternative embodiment, the second determination unit includes:

[0122] A transformation sub-unit, configured to convert the first curve into a third curve by using a first transformation method, and convert the second curve into a fourth curve by using the first transformation method, wherein the abscissa of the third curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude at the combustion chamber inlet corresponding to each frequency, and the abscissa of the fourth curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude inside the combustion chamber corresponding to each frequency; a first acquisition sub-unit, configured to acquire a first amplitude corresponding to a first frequency value from the third curve, where the first amplitude is the pressure pulsation amplitude at the combustion chamber inlet corresponding to the first frequency value; a second acquisition sub-unit, configured to acquire a second amplitude corresponding to the first frequency value from the fourth curve, where the second amplitude is the pressure pulsation amplitude inside the combustion chamber corresponding to the first frequency value; a third determination sub-unit, configured to, when the second amplitude is greater than or equal to a preset threshold, determine the first frequency as the first acoustic natural frequency corresponding to the first load coefficient, where the preset threshold is a preset ratio of the first amplitude.

[0123] This embodiment provides a computer device, such as Figure 7 shown, the computer device may include at least one processor 71, at least one communication interface 72, at least one communication bus 73, and at least one memory 74. Among them, the communication interface 72 may include a display screen (Display) and a keyboard (Keyboard). Optionally, the communication interface 72 may further include a standard wired interface and a wireless interface. The memory 74 may be a high-speed RAM memory (Random Access Memory, volatile random access memory), or a non-volatile memory, such as at least one disk memory. Optionally, the memory 74 may also be at least one storage device located far from the aforementioned processor 71. Among them, the processor 71 may be combined with Figure 7 the described device, an application program is stored in the memory 74, and the processor 71 calls the program code stored in the memory 74 to execute the method for constructing the acoustic natural frequency prediction model in any of the above method embodiments.

[0124] Among them, the communication bus 73 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The communication bus 73 may be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 7 only a thick line is used to represent it in, but it does not mean that there is only one bus or one type of bus.

[0125] Among them, the memory 74 may include a volatile memory (English: volatile memory), such as a random access memory (English: random-access memory, abbreviation: RAM); the memory may also include a non-volatile memory (English: non-volatile memory), such as a flash memory (English: flash memory), a hard disk (English: hard disk drive, abbreviation: HDD) or a solid-state drive (English: solid-state drive, abbreviation: SSD); the memory 74 may further include a combination of the above types of memories.

[0126] Among them, the processor 71 may be a central processing unit (English: central processing unit, abbreviation: CPU), a network processor (English: network processor, abbreviation: NP), or a combination of a CPU and an NP.

[0127] Among them, the processor 71 may further include a hardware chip. The above-mentioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The above-mentioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. Optionally, the memory 74 is also used to store program instructions. The processor 71 can call the program instructions to implement the method for constructing the acoustic natural frequency prediction model in any embodiment of the present invention.

[0128] This embodiment provides a computer-readable storage medium. The computer storage medium stores computer-executable instructions, and the computer-executable instructions can execute the method for constructing the acoustic natural frequency prediction model in any of the above method embodiments. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memories.

[0129] Obviously, the above embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for constructing an acoustic natural frequency prediction model, characterized in that, it includes: Performing flow field grid division on the physical model of the pre-constructed gas turbine combustion chamber to obtain a target physical model with flow field grids; Obtaining the initial values of the inlet boundary parameters corresponding to each of the multiple load coefficients and the initial values of the outlet boundary parameters corresponding to each of the load coefficients, where the inlet boundary parameters include multiple ones; Selecting a first inlet boundary parameter from the multiple inlet boundary parameters; According to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the upper limit value of the acoustic natural frequency of the gas turbine combustion chamber, the frequency step, and the j-th combustion moment among multiple preset combustion moments, determining the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment, where the first load coefficient is any one of the multiple load coefficients and j is a positive integer; Based on the target physical model, the target values of the first inlet boundary parameter at each of the combustion moments, the initial values of the other inlet boundary parameters except the first inlet boundary parameter among the multiple inlet boundary parameters, the initial values of the outlet boundary parameters, and the pre-configured constraint conditions, constructing a combustion chamber flow field numerical simulation model corresponding to the first load coefficient; Performing transient numerical calculations on the combustion chamber flow field numerical simulation models corresponding to each of the load coefficients respectively to generate the acoustic natural frequencies corresponding to each of the load coefficients; Based on all the load coefficients and the acoustic natural frequencies corresponding to each of the load coefficients, constructing a prediction model between the load coefficients and the acoustic natural frequencies.

2. The method for constructing an acoustic natural frequency prediction model according to claim 1, characterized in that, The step of determining the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the upper limit value of the acoustic natural frequency of the gas turbine combustion chamber, the frequency step, and the j-th combustion moment among multiple preset combustion moments specifically includes: Determining the number of summation times according to the upper limit value of the acoustic natural frequency of the gas turbine combustion chamber and the frequency step; Determining the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summation times, the frequency step, and the j-th preset combustion moment.

3. The method for constructing an acoustic natural frequency prediction model according to claim 2, characterized in that, Determine the target value of the first inlet boundary parameter corresponding to the first load coefficient at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load coefficient, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the number of summations, the frequency step, and the j-th preset combustion moment, which is realized by the following formula: Wherein, F is the target value of the first inlet boundary parameter corresponding to the first load factor, A is the initial value of the first inlet boundary parameter corresponding to the first load factor, n is the number of summation times, m is the preset pulsation amplitude ratio of the inlet boundary parameter, Δω is the frequency step size, is the preset phase value, t j is the j-th preset combustion moment.

4. The method for constructing an acoustic natural frequency prediction model according to any one of claims 1-3, characterized in that, There are multiple acoustic natural frequencies corresponding to each load coefficient. Based on all the load coefficients and the acoustic natural frequencies corresponding to each load coefficient, constructing a prediction model between the load coefficient and the acoustic natural frequency includes: Determine the order of each acoustic natural frequency corresponding to each load coefficient respectively; extract all target acoustic natural frequencies at the target order from the acoustic natural frequencies corresponding to all the load coefficients respectively, and the target order is any one of multiple orders; Fit all the target acoustic natural frequencies corresponding to the target order to generate a prediction model between the load coefficient and the acoustic natural frequency corresponding to the target order.

5. The method for constructing an acoustic natural frequency prediction model according to claim 1, characterized in that, Generating the acoustic natural frequency corresponding to each load coefficient includes: Obtain a pre-constructed first curve corresponding to the first load coefficient, and the first curve is a pressure pulsation disturbance curve at the combustion chamber inlet boundary; Based on the acoustic natural frequency corresponding to the first load coefficient, determine a second curve corresponding to the first load coefficient, and the second curve is a pressure pulsation disturbance curve inside the combustion chamber corresponding to the first load coefficient; Determine the acoustic natural frequency corresponding to the first load coefficient based on the first curve and the second curve.

6. The method for constructing an acoustic natural frequency prediction model according to claim 5, characterized in that, The determining the multi-order acoustic natural frequency corresponding to the first load coefficient based on the first curve and the second curve includes: Use a first transformation method to transform the first curve into a third curve, and use the first transformation method to transform the second curve into a fourth curve. Wherein, the abscissa of the third curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude at the combustion chamber inlet corresponding to each frequency respectively. The abscissa of the fourth curve is used to indicate the frequency, and the ordinate is used to indicate the pressure pulsation amplitude inside the combustion chamber corresponding to each frequency respectively; Obtain a first amplitude corresponding to a first frequency value from the third curve, and the first amplitude is the pressure pulsation amplitude at the combustion chamber inlet corresponding to the first frequency value; Obtain a second amplitude corresponding to the first frequency value from the fourth curve, and the second amplitude is the pressure pulsation amplitude inside the combustion chamber corresponding to the first frequency value; When the second amplitude is greater than or equal to a preset threshold, the first frequency is determined as the first acoustic natural frequency corresponding to the first load factor, and the preset threshold is a preset ratio of the first amplitude.

7. An apparatus for constructing an acoustic natural frequency prediction model, Characterized in that, Comprising: A partitioning module, configured to perform a flow field grid partitioning on a solid model of a gas turbine combustor to be constructed, and obtain a target solid model carrying a flow field grid; An obtaining module, configured to obtain initial values of inlet boundary parameters corresponding to each of a plurality of load factors and initial values of outlet boundary parameters corresponding to each of the load factors, wherein the inlet boundary parameters include a plurality of; A selecting module, configured to select a first inlet boundary parameter from the plurality of inlet boundary parameters; A determining module, configured to determine a target value of the first inlet boundary parameter corresponding to the first load factor at the j-th preset combustion moment among a plurality of preset combustion moments according to the initial value of the first inlet boundary parameter corresponding to the first load factor, a preset phase value, a preset pulsation amplitude ratio of the inlet boundary parameter, an upper limit value of the acoustic natural frequency of the gas turbine combustor, a frequency step, and the j-th preset combustion moment, wherein the first load factor is any one of the plurality of load factors, and j is a positive integer; A first constructing module, configured to construct a numerical simulation model of the combustor flow field corresponding to the first load factor based on the target solid model, the target values of the first inlet boundary parameter at each of the combustion moments, the initial values of other inlet boundary parameters except the first inlet boundary parameter among the plurality of inlet boundary parameters, the initial values of the outlet boundary parameters, and a pre-configured constraint condition; A generating module, configured to perform transient numerical calculations on the numerical simulation models of the combustor flow field corresponding to each of the load factors, and generate acoustic natural frequencies corresponding to each of the load factors; A second constructing module, configured to construct a prediction model between the load factor and the acoustic natural frequency based on all the load factors and the acoustic natural frequencies corresponding to each of the load factors.

8. The apparatus for constructing an acoustic natural frequency prediction model according to claim 7, Characterized in that, The determining module specifically includes: A first determining sub-module, configured to determine a summation number according to the upper limit value of the acoustic natural frequency of the gas turbine combustor and the frequency step; A second determining sub-module, configured to determine the target value of the first inlet boundary parameter corresponding to the first load factor at the j-th preset combustion moment according to the initial value of the first inlet boundary parameter corresponding to the first load factor, the preset phase value, the preset pulsation amplitude ratio of the inlet boundary parameter, the summation number, the frequency step, and the j-th preset combustion moment.

9. A computer device, Characterized in that, Comprising: A memory and a processor, which are communicatively connected to each other. The memory is used to store a computer program. When the computer program is executed by the processor, the processor is caused to execute the method for constructing an acoustic natural frequency prediction model according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium is used to store computer instructions, and when the computer instructions are executed by a processor, the method for constructing an acoustic natural frequency prediction model according to any one of claims 1 to 6 is implemented.

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