Turbine characteristic calculation method, system and equipment

Abstract

The invention belongs to the technical field of control, particularly relates to a turbine characteristic calculation method, system and equipment, and aims to solve the problems that an existing turbine characteristic interpolation method is low in precision and too large in calculation amount, does not consider the shape characteristics of a characteristic curve cluster and does not perform targeted analysis to cause interpolation errors. The method comprises the steps that a relative conversion rotating speed-expansion ratio characteristic curve of a turbine is reconstructed into equidistant data, and a plurality of preliminary beta auxiliary lines are formed; data points obtained through reconstruction in the equidistant data and the corresponding conversion flow and isentropic efficiency are connected according to the same serial number marked in a relative conversion rotating speed-expansion ratio characteristic curve of the turbine, and multiple beta auxiliary lines are obtained; turbine working condition parameters are collected and converted into the relative conversion rotating speed Ncor of the current working condition and the expansion ratio of the current working condition, a Lagrange interpolation polynomial of the kth point is constructed, and a current working condition characteristic curve and a current working condition beta auxiliary line are obtained; and interpolating the target point to obtain the turbine characteristics of the current working condition.

Description

Background Art

[0002] The turbine is the core component of the gas turbine power generation system. In order to achieve precise control of the turbine speed, it is necessary to establish a working model of the turbine. To establish the turbine working model, it is necessary to accurately obtain the performance parameters (including flow, output power, efficiency, etc.) of the turbine under different working conditions (including inlet temperature, inlet pressure, outlet pressure, and speed). According to the working principle of the turbine, affected by external environmental conditions, the turbine characteristics obtained under different turbine inlet temperatures and inlet pressures are different, that is, the obtained turbine characteristics are not universal.

[0003] In order to solve the problem of universality of turbine characteristics, Claus Riegler and others proposed a calculation method for conversion parameters based on the similarity criterion of flow field for the characteristics of turbine components, and plotted the conversion parameters into characteristic curves. In actual working process, the working environment of the turbine is often different from the design conditions. When the turbine works at different temperatures and pressures, the performance will change, and the characteristic curve will show different postures. However, in the design and testing of the turbine, only the performance under some conditions will be simulated to form a partial characteristic curve. Therefore, how to use the known characteristic curve to infer the turbine performance at non-design operating points has become an urgent problem to be solved.

[0004] At present, scholars at home and abroad have proposed many methods for calculating non-design operating points. At present, most methods use characteristic curves constructed by known data to calculate target operating characteristics through methods such as exponential expansion or interpolation, but there are many problems such as insufficient accuracy and large amount of calculation. Existing invention patents such as CN116090236 mostly use linear interpolation methods, and the interpolation accuracy is low. CN112100848A and CN110321586 use all known data for interpolation, which improves the accuracy, but the amount of calculation is too large, and the former needs to fit the speed curve after constructing the characteristic curve before calculating the target characteristic point, which is too complicated. At the same time, the actual turbine characteristic curve cluster will have a cross phenomenon, and large errors will occur when all data are used for interpolation without paying attention to the changing trend of the characteristic curve. Especially when the turbine operating condition changes in a large range, the excessively high order of the interpolation polynomial will cause the Runge phenomenon to appear at the edge of the curve, which has a huge impact on the interpolation accuracy. Summary of the invention

[0005] In order to solve the above problems in the prior art, namely, the existing turbine characteristic calculation method has a large amount of calculation, the calculation of the target feature point is too complicated, the error is too high, and when the turbine operating conditions vary widely, the excessively high interpolation polynomial order will cause the Runge phenomenon to appear on the edge of the curve, which has a great impact on the interpolation accuracy. The present invention provides a turbine characteristic calculation method, which includes:

[0006] For the relative conversion speed-expansion ratio characteristic curve of the turbine, select the maximum expansion ratio π on each speed line max and minimum expansion ratio π min As the upper and lower limits, respectively, they are reconstructed into equally spaced data according to the equal expansion ratio intervals and form multiple preliminary β auxiliary lines, wherein each data point in the reconstructed equally spaced data has a sequence number (i, j), i represents the number of characteristic curves, and j represents the number of data points;

[0007] The data points reconstructed from the equally spaced data and the corresponding converted flow rate and isentropic efficiency are connected according to the same sequence number marked in the relative converted speed-expansion ratio characteristic curve of the turbine to obtain a plurality of β auxiliary lines;

[0008] Collect turbine operating parameters and convert them into the current relative conversion speed N cor and the current working condition expansion ratio π, based on the relative conversion speed-expansion ratio characteristic curve with multiple β auxiliary lines, constructing the Lagrangian interpolation polynomial of the kth data point, searching for the intersection point in the relative conversion speed-expansion ratio characteristic curve of the turbine, grouping the original characteristic curve according to the relative conversion speed and the curve position where the intersection point is located, confirming the corresponding group of the turbine according to the current working condition relative conversion speed, interpolating using the quadratic or cubic Lagrangian method, and obtaining the current working condition characteristic curve;

[0009] According to the relative position of the expansion ratio of the current working condition in the relative conversion speed-expansion ratio characteristic curve, interpolation is performed using an interpolation method other than Lagrange interpolation to obtain the current working condition characteristic curve and the current working condition β auxiliary line;

[0010] The target points in the current operating condition characteristic curve and the current operating condition β auxiliary line are interpolated to obtain the current operating condition turbine characteristics.

[0011] In some preferred embodiments, the turbine operating parameters are collected and converted into the current operating relative conversion speed N cor The expansion ratio π of the current working condition is:

[0012]

[0013] Among them, P Tin represents the turbine inlet pressure, P Tout Indicates the turbine outlet pressure, N ref represents the turbine design point speed, T ref represents the turbine design inlet temperature, N represents the actual turbine speed, T in represents the turbine inlet temperature, T std =288.15K, indicating standard temperature.

[0014] In some preferred embodiments, the Lagrange interpolation polynomial L for constructing the kth data point k (π) is:

[0015]

[0016] Among them, π represents the current operating expansion ratio, π k Indicates the current expansion ratio of the kth point, π k+1 Indicates the current operating expansion ratio of the k+1th point, π k-1 Indicates the current expansion ratio of the k-1th point, π m It represents the current working condition expansion ratio of the mth data point, and m means that each β auxiliary line has m data points participating in the interpolation calculation.

[0017] In some preferred embodiments, the method for obtaining the current operating condition characteristic curve and the current operating condition β auxiliary line is:

[0018] Based on the Lagrange interpolation polynomial L of the k-th point k (π), calculate the converted flow G corresponding to the interpolation coordinate point of the jth β auxiliary line cor,j and the isentropic efficiency η corresponding to the interpolation coordinate point j :

[0019]

[0020] Among them, π j represents the current expansion ratio of the jth point, η k represents the isentropic efficiency corresponding to the kth point;

[0021] Determine the intersection point between the original characteristic curves and the two original characteristic curves that intersect N a and N b (a<b);

[0022] According to the relative conversion speed N of the current working conditions cor The area enclosed by the original characteristic curve (N1~N n ) are interpolated, specifically:

[0023] If the relative conversion speed N of the current working condition cor Smaller than the area enclosed by the original characteristic curve, that is, N cor When N<N1, N1 represents the relative conversion speed corresponding to the first original characteristic curve, N n Indicates the relative conversion speed corresponding to the last original characteristic curve. Each β auxiliary line has m = a data points participating in the interpolation calculation. Select N1 to N a The Lagrange interpolation calculation is performed using a β auxiliary line between:

[0024]

[0025] If the relative conversion speed N of the current working condition cor It is within the area enclosed by the original characteristic curve, that is, N1≤N cor ≤N n , each β auxiliary line has m = n data points participating in the interpolation calculation, and all β auxiliary lines are selected for Lagrange interpolation calculation:

[0026]

[0027] If the relative conversion speed N of the current working condition cor is larger than the area enclosed by the original characteristic curve, that is, N cor >N n , select N b To N n The n-b+1 β auxiliary lines between them are used for Lagrange interpolation calculation:

[0028]

[0029] The current operating condition characteristic curve and the current operating condition β auxiliary line are obtained after Lagrange interpolation.

[0030] In some preferred embodiments, the current operating condition characteristic curve and the target point in the current operating condition β auxiliary line are interpolated once to obtain the current operating condition turbine characteristic, specifically:

[0031] Select a target point in the current operating condition characteristic curve, use the expansion ratio π corresponding to the target point as the abscissa of the interpolation point, and represent the data points on the current operating condition characteristic curve corresponding to the abscissa of the interpolation point as π from small to large according to the expansion ratio. i , i=1,2,……,j:

[0032] According to the relationship between the abscissa of the interpolation point and the characteristic curve of the current working condition, the secondary Lagrange interpolation is performed respectively;

[0033] When π≤π1 or π≥π j , that is, when the expansion ratio corresponding to the target point is outside the current operating characteristic curve, the two data points at the endpoints are used for linear Lagrange interpolation:

[0034]

[0035]

[0036] When π1<π≤π2 or π j-1 ≤π<π j When , quadratic Lagrange interpolation is performed using three data points near the endpoints:

[0037] When π1<π≤π2, the quadratic Lagrange interpolation is:

[0038]

[0039] When π j-1 ≤π<π j The quadratic Lagrange interpolation is:

[0040]

[0041] When π2<π<π j-1 When , use the first two data points and the last data point close to the horizontal coordinate of the target point for quadratic Lagrange interpolation:

[0042]

[0043] Get the turbine characteristics of the current working conditions.

[0044] Another aspect of the present invention provides a turbine characteristic calculation system, comprising:

[0045] The numerical reconstruction module is configured to convert the relative speed-expansion ratio characteristic curve of the turbine and select the maximum expansion ratio π on each speed line max and minimum expansion ratio π min As the upper and lower limits, respectively, they are reconstructed into equally spaced data according to the equal expansion ratio intervals and form multiple preliminary β auxiliary lines, wherein each data point in the reconstructed equally spaced data has a sequence number (i, j), i represents the number of characteristic curves, and j represents the number of data points;

[0046] A curve drawing module is configured to connect the data points reconstructed from the equally spaced data and the corresponding converted flow rates and isentropic efficiencies according to the same serial numbers marked in the relative converted speed-expansion ratio characteristic curve of the turbine to obtain a plurality of β auxiliary lines; Characteristic line interpolation module, configured to collect turbine operating parameters and convert them into the current operating relative conversion speed N cor and the current working condition expansion ratio π, based on the relative conversion speed-expansion ratio characteristic curve with multiple β auxiliary lines, constructing a Lagrangian interpolation polynomial with the kth data point, searching for the intersection point in the relative conversion speed-expansion ratio characteristic curve of the turbine, grouping the original characteristic curve according to the relative conversion speed and the curve position where the intersection point is located, confirming the corresponding group of the turbine according to the current working condition relative conversion speed, interpolating using the quadratic or cubic Lagrangian method, and obtaining the current working condition characteristic curve;

[0047] According to the relative position of the expansion ratio of the current working condition in the relative conversion speed-expansion ratio characteristic curve, interpolation is performed using an interpolation method other than Lagrange interpolation to obtain the current working condition characteristic curve and the current working condition β auxiliary line;

[0048] The target interpolation module is configured to interpolate the target points in the current operating condition characteristic curve and the current operating condition β auxiliary line to obtain the current operating condition turbine characteristics.

[0049] According to a third aspect of the present invention, an electronic device is provided, comprising:

[0050] at least one processor; and

[0051] a memory communicatively connected to at least one of the processors; wherein,

[0052] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned turbine characteristic calculation method.

[0053] According to a fourth aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned turbine characteristic calculation method.

[0054] Beneficial effects of the present invention:

[0055] The present invention solves the problems of low precision of the existing linear interpolation method; the problem of excessive calculation amount when calculating the target characteristics by constructing auxiliary lines; and the problem of interpolation error caused by not considering the shape characteristics of the characteristic curve cluster itself and not conducting targeted analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0057] Figure 1 is a schematic flow chart of a method for calculating turbine characteristics in an embodiment of the present invention;

[0058] Figure 2 is a schematic diagram of a relative converted speed-expansion ratio characteristic curve of a turbine in an embodiment of the present invention;

[0059] Figure 3 is a schematic diagram of a preliminary β auxiliary line in an embodiment of the present invention;

[0060] Figure 4 is a schematic diagram of obtaining multiple β auxiliary lines in an embodiment of the present invention;

[0061] Figure 5is a schematic diagram of the characteristic curve crossing phenomenon in an embodiment of the present invention;

[0062] Figure 6 is a schematic diagram of a characteristic line of a current operating condition in an embodiment of the present invention;

[0063] Figure 7 It is a comparison diagram of the effects of partial segment quadratic interpolation and full data interpolation in an embodiment of the present invention. DETAILED DESCRIPTION

[0064] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0065] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0066] In order to more clearly explain the turbine characteristic calculation method of the present invention, the following is combined with Figure 1 Each step in the embodiment of the present invention is described in detail.

[0067] The turbine characteristic calculation method of the first embodiment of the present invention includes steps S10 to S40, and each step is described in detail as follows:

[0068] This embodiment takes a certain type of turbine driven by high-temperature and high-pressure gas controlled by a solenoid valve as an example to explain in detail a turbine characteristic calculation method applicable to a wide range of operating conditions.

[0069] Step S10, for the relative conversion speed-expansion ratio characteristic curve of the turbine, select the maximum expansion ratio π on each speed line max and minimum expansion ratio π min As the upper and lower limits, respectively, they are reconstructed into equally spaced data according to the equal expansion ratio intervals and form multiple preliminary β auxiliary lines, wherein each data point in the reconstructed equally spaced data has a sequence number (i, j), i represents the number of characteristic curves, and j represents the number of data points;

[0070] The relative conversion speed-expansion ratio characteristic curve of the turbine is as follows: Figure 2 As shown in the figure, some turbine data can be obtained through CFD simulation, bench test, etc. The subsequent characteristic calculation steps are based on the appendix Figure 2 The original characteristic line and data expansion are shown. Figure 2 In the turbine characteristic curve, the horizontal axis is the expansion ratio π, and the vertical axis is the converted flow rate G cor and isentropic efficiency η, each curve represents a relative conversion speed N corTurbine characteristics.

[0071] Since the original turbine characteristic data mostly show scattered characteristics and the data points are spaced at different intervals, which affects the subsequent data processing, it is necessary to reconstruct the original data.

[0072] Within the expansion ratio range, the number of interval points on each constant speed expansion ratio characteristic line is the same; the interval points with the same serial number on each constant speed expansion ratio characteristic line are connected to preliminarily form the characteristic curve diagram of the β auxiliary line as shown in the figure below: Figure 3 shown.

[0073] In this embodiment, the turbine operating condition parameters are collected and converted into the current operating condition relative conversion speed N cor The expansion ratio π of the current working condition is:

[0074]

[0075] Among them, P Tin represents the turbine inlet pressure, P Tout Indicates the turbine outlet pressure, N ref represents the turbine design point speed, T ref Indicates the turbine design inlet temperature, N represents, T in Indicates that T std Since the turbine outlet is directly connected to the outside world, it is assumed that the turbine outlet pressure is atmospheric pressure (P Tout =0.101MPa), relative conversion speed N cor Is a dimensionless quantity.

[0076] Step S20, the data points reconstructed from the equally spaced data and the corresponding converted flow rate and isentropic efficiency are connected according to the same serial number marked in the relative converted speed-expansion ratio characteristic curve of the turbine to obtain multiple β auxiliary lines; the schematic diagram of the β auxiliary line in the characteristic diagram is as follows: Figure 4 shown. Step S30: Collect turbine operating parameters and convert them into the current operating relative conversion speed N cor and the current working condition expansion ratio π, based on the relative conversion speed-expansion ratio characteristic curve with multiple β auxiliary lines, constructing a Lagrangian interpolation polynomial with the kth data point, searching for the intersection point in the relative conversion speed-expansion ratio characteristic curve of the turbine, grouping the original characteristic curve according to the relative conversion speed and the curve position where the intersection point is located, confirming the corresponding group of the turbine according to the current working condition relative conversion speed, interpolating using the quadratic or cubic Lagrangian method, and obtaining the current working condition characteristic curve;

[0077] According to the relative position of the expansion ratio of the current working condition in the relative conversion speed-expansion ratio characteristic curve, interpolation is performed using an interpolation method other than Lagrange interpolation to obtain the current working condition characteristic curve and the current working condition β auxiliary line;

[0078] In this embodiment, the number of constructed data points is the kth Lagrange interpolation polynomial L k (π) is:

[0079]

[0080] Among them, π represents the current operating expansion ratio, π k Indicates the current expansion ratio of the kth point, π k+1 Indicates the current operating expansion ratio of the k+1th point, π k-1 Indicates the current expansion ratio of the k-1th point, π m It represents the current working condition expansion ratio of the mth data point, and m means that each β auxiliary line has m data points participating in the interpolation calculation.

[0081] According to Figure 3 The auxiliary line generation diagram shown in the figure is formed by the known data. The two curves with the largest and smallest expansion ratios in the auxiliary line are Lagrange interpolation. The relative conversion speed is used as the horizontal coordinate to obtain the upper and lower limits of the expansion ratio corresponding to the target working condition, and it is divided into j parts. The vertical coordinates of the j points formed are the expansion ratio π required for characteristic interpolation. j .

[0082] In the original characteristic diagram, interpolation calculation is performed along the existing j β auxiliary lines, and the horizontal coordinate of the interpolation point is the intersection expansion ratio obtained in the previous step. By connecting the calculated interpolation points, the target speed characteristic line formed by the j interpolation points can be obtained.

[0083] As Figure 5 Taking the part of the original characteristic line shown as an example, some characteristic curves cross and the β auxiliary line has a large turn at the intersection. If the relative conversion speed of the current working condition is within the existing characteristic curve range, there will be no large interpolation error due to the dense data; when the current working condition is outside the existing characteristic curve range, using the complete β auxiliary line for interpolation calculation will result in a large error. In order to avoid the error caused by the intersection of the original characteristic line to the interpolation fitting, the intercepted β auxiliary line is selected according to the area to which the target characteristic point belongs for Lagrangian interpolation calculation.

[0084] In this embodiment, the method for obtaining the current operating condition characteristic curve and the current operating condition β auxiliary line is:

[0085] N cor The area with speed less than N1 is classified as low speed area, and N1≤N cor ≤N n The area is divided into the middle area and Ncor >N n The area is divided into high-speed areas, and different parameters are selected for Lagrangian interpolation calculation.

[0086] Based on the Lagrange interpolation polynomial L of the k-th point k (π), calculate the converted flow G corresponding to the interpolation coordinate point of the jth β auxiliary line cor,j and the isentropic efficiency η corresponding to the interpolation coordinate point j :

[0087]

[0088] Among them, π j represents the current expansion ratio of the jth point, η k represents the isentropic efficiency corresponding to the kth point;

[0089] Determine the intersection point between the original characteristic curves and the two original characteristic curves that intersect N a and N b (a<b);

[0090] According to the relative conversion speed N of the current working conditions cor The area enclosed by the original characteristic curve (N1~N n ) are interpolated, specifically:

[0091] If the relative conversion speed N of the current working condition cor Smaller than the area enclosed by the original characteristic curve, that is, N cor When N<N1, N1 represents the relative conversion speed corresponding to the first original characteristic curve, N n Indicates the relative conversion speed corresponding to the last original characteristic curve. Each β auxiliary line has m = a data points participating in the interpolation calculation. Select N1 to N a The Lagrange interpolation calculation is performed using a β auxiliary line between:

[0092]

[0093] If the relative conversion speed N of the current working condition cor It is within the area enclosed by the original characteristic curve, that is, N1≤N cor ≤N n , each β auxiliary line has m = n data points participating in the interpolation calculation, and all β auxiliary lines are selected for Lagrange interpolation calculation:

[0094]

[0095] If the relative conversion speed N of the current working condition cor is larger than the area enclosed by the original characteristic curve, that is, N cor >Nn , select N b To N n The n-b+1 β auxiliary lines between them are used for Lagrange interpolation calculation:

[0096]

[0097] After Lagrange interpolation, the current operating condition characteristic curve and the current operating condition β auxiliary line are obtained. The current operating condition characteristic curve is as follows: Figure 6 shown.

[0098] Step S40, interpolating the current operating condition characteristic curve and the target point in the current operating condition β auxiliary line to obtain the current operating condition turbine characteristic.

[0099] In this embodiment, the current operating condition characteristic curve and the target point in the current operating condition β auxiliary line are interpolated once to obtain the current operating condition turbine characteristic, which is specifically:

[0100] Select a target point in the current operating condition characteristic curve, use the expansion ratio π corresponding to the target point as the abscissa of the interpolation point, and represent the data points on the current operating condition characteristic curve corresponding to the abscissa of the interpolation point as π from small to large according to the expansion ratio. i , i=1,2,……,j:

[0101] According to the relationship between the abscissa of the interpolation point and the characteristic curve of the current working condition, the secondary Lagrange interpolation is performed respectively;

[0102] When π≤π1 or π≥π j , that is, when the expansion ratio corresponding to the target point is outside the current operating characteristic curve, the two data points at the endpoints are used for linear Lagrange interpolation:

[0103]

[0104]

[0105] When π1<π≤π2 or π j-1 ≤π<π j When , quadratic Lagrange interpolation is performed using three data points near the endpoints:

[0106] When π1<π≤π2, the quadratic Lagrange interpolation is:

[0107]

[0108] When π j-1 ≤π<π j The quadratic Lagrange interpolation is:

[0109]

[0110] When π2<π<π j-1 When , use the first two data points and the last data point close to the horizontal coordinate of the target point for quadratic Lagrange interpolation:

[0111]

[0112] Get the turbine characteristics of the current working conditions.

[0113] The use of this method to calculate turbine characteristics has obvious advantages over other methods that do not distinguish the characteristic range and use all data points for interpolation calculation. The comparison of the characteristic curves calculated by this method and the traditional method is shown in the appendix. Figure 7 This method avoids the Runge phenomenon at the end, and compared with cubic spline interpolation, it reduces the order and number of interpolation polynomials, and significantly reduces the amount of calculation.

[0114] Although the various steps in the above embodiment are described in the above-mentioned order, those skilled in the art can understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the scope of protection of the present invention.

[0115] A turbine characteristic calculation system according to a second embodiment of the present invention comprises:

[0116] The numerical reconstruction module is configured to convert the relative speed-expansion ratio characteristic curve of the turbine and select the maximum expansion ratio π on each speed line max and minimum expansion ratio π min As the upper and lower limits, respectively, they are reconstructed into equally spaced data according to the equal expansion ratio intervals and form multiple preliminary β auxiliary lines, wherein each data point in the reconstructed equally spaced data has a sequence number (i, j), i represents the number of characteristic curves, and j represents the number of data points;

[0117] A curve drawing module is configured to connect the data points reconstructed from the equally spaced data and the corresponding converted flow rates and isentropic efficiencies according to the same serial numbers marked in the relative converted speed-expansion ratio characteristic curve of the turbine to obtain a plurality of β auxiliary lines;

[0118] Characteristic line interpolation module, configured to collect turbine operating parameters and convert them into the current operating relative conversion speed N corand the current working condition expansion ratio π, based on the relative conversion speed-expansion ratio characteristic curve with multiple β auxiliary lines, constructing the Lagrangian interpolation polynomial of the kth data point, searching for the intersection point in the relative conversion speed-expansion ratio characteristic curve of the turbine, grouping the original characteristic curve according to the size of the relative conversion speed and the curve position where the intersection point is located, confirming the corresponding group of the turbine according to the current working condition relative conversion speed, interpolating using the quadratic or cubic Lagrangian method, and obtaining the current working condition characteristic curve and the current working condition β auxiliary line;

[0119] The target interpolation module is configured to interpolate the target points in the current operating condition characteristic curve and the current operating condition β auxiliary line to obtain the current operating condition turbine characteristics.

[0120] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the system described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0121] It should be noted that the turbine characteristic calculation system provided in the above embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be decomposed or combined. For example, the modules in the above embodiment can be combined into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the modules or steps, and are not regarded as improper limitations of the present invention.

[0122] An electronic device according to a third embodiment of the present invention includes:

[0123] at least one processor; and

[0124] a memory communicatively connected to at least one of the processors; wherein,

[0125] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned turbine characteristic calculation method.

[0126] A fourth embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned turbine characteristic calculation method.

[0127] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the storage device and processing device described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0128] Those skilled in the art should be able to appreciate that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software or a combination of the two, and the programs corresponding to the software modules and method steps can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the technical field. In order to clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0129] The terms "first", "second", etc. are used to distinguish similar objects rather than to describe or indicate a particular order or sequence.

[0130] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0131] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for calculating turbine characteristics, characterized in that: The method comprises: For the turbine's relative conversion speed-expansion ratio characteristic curve, select the maximum expansion ratio π on each speed line max and minimum expansion ratio π min As the upper and lower limits, respectively, they are reconstructed into equally spaced data according to the equal expansion ratio intervals and form multiple preliminary β auxiliary lines, wherein each data point in the reconstructed equally spaced data has a sequence number (i, j), i represents the number of characteristic curves, and j represents the number of data points; The data points reconstructed from the equally spaced data and the corresponding converted flow rate and isentropic efficiency are connected according to the same sequence number marked in the relative converted speed-expansion ratio characteristic curve of the turbine to obtain a plurality of β auxiliary lines; Collect turbine operating parameters and convert them into the current relative conversion speed N cor and the current working condition expansion ratio π, based on the relative conversion speed-expansion ratio characteristic curve with multiple β auxiliary lines, constructing a Lagrangian interpolation polynomial with the kth data point, searching for the intersection point in the relative conversion speed-expansion ratio characteristic curve of the turbine, grouping the original characteristic curve according to the relative conversion speed and the curve position where the intersection point is located, confirming the corresponding group of the turbine according to the current working condition relative conversion speed, interpolating using the quadratic or cubic Lagrangian method, and obtaining the current working condition characteristic curve; According to the relative position of the expansion ratio of the current working condition in the relative conversion speed-expansion ratio characteristic curve, interpolation is performed using an interpolation method other than Lagrange interpolation to obtain the current working condition characteristic curve and the current working condition β auxiliary line; The target points in the current operating condition characteristic curve and the current operating condition β auxiliary line are interpolated to obtain the current operating condition turbine characteristics.

2. A turbine characteristic calculation method according to claim 1, characterized in that: The turbine operating parameters are collected and converted into the current operating condition relative conversion speed N cor The expansion ratio π of the current working condition is: Among them, P Tin represents the turbine inlet pressure, P Tout Indicates the turbine outlet pressure, N ref represents the turbine design point speed, T ref represents the turbine design inlet temperature, N represents the actual turbine speed, T in represents the turbine inlet temperature, T std =288.15K, indicating standard temperature.

3. A turbine characteristic calculation method according to claim 2, characterized in that: The number of constructed data points is the kth Lagrange interpolation polynomial L k (π) is: Among them, π represents the current operating expansion ratio, π k Indicates the current expansion ratio of the kth point, π k+1 Indicates the current operating expansion ratio of the k+1th point, π k-1 Indicates the current expansion ratio of the k-1th point, π m It represents the current working condition expansion ratio of the mth data point, and m means that each β auxiliary line has m data points participating in the interpolation calculation.

4. A turbine characteristic calculation method according to claim 3, characterized in that: The method for obtaining the current operating condition characteristic curve and the current operating condition β auxiliary line is: Based on the k-th Lagrange interpolation polynomial L k (π), calculate the converted flow G corresponding to the interpolation coordinate point of the jth β auxiliary line cor,j and the isentropic efficiency η corresponding to the interpolation coordinate point j : Among them, π j represents the current expansion ratio of the jth point, η k represents the isentropic efficiency corresponding to the kth point; Determine the intersection point between the original characteristic curves and the two original characteristic curves that intersect N a and N b (a<b); According to the relative conversion speed N of the current working conditions cor The area enclosed by the original characteristic curve (N1~N n ) are interpolated, specifically: If the relative conversion speed N of the current working condition cor Smaller than the area enclosed by the original characteristic curve, that is, N cor When N<N1, N1 represents the relative conversion speed corresponding to the first original characteristic curve, N n Indicates the relative conversion speed corresponding to the last original characteristic curve. Each β auxiliary line has m = a data points participating in the interpolation calculation. Select N1 to N a The Lagrange interpolation calculation is performed using a β auxiliary line between: If the relative conversion speed N of the current working condition cor It is within the area enclosed by the original characteristic curve, that is, N1≤N cor ≤N n , each β auxiliary line has m = n data points participating in the interpolation calculation, and all β auxiliary lines are selected for Lagrange interpolation calculation: If the relative conversion speed N of the current working condition cor is larger than the area enclosed by the original characteristic curve, that is, N cor >N n , select N b To N n The n-b+1 β auxiliary lines between them are used for Lagrange interpolation calculation: The current operating condition characteristic curve and the current operating condition β auxiliary line are obtained after Lagrange interpolation.

5. A turbine characteristic calculation method according to claim 4, characterized in that: The current working condition characteristic curve and the target point in the current working condition β auxiliary line are interpolated once to obtain the current working condition turbine characteristic, which is specifically: Select a target point in the current operating condition characteristic curve, use the expansion ratio π corresponding to the target point as the abscissa of the interpolation point, and represent the data points on the current operating condition characteristic curve corresponding to the abscissa of the interpolation point as π from small to large according to the expansion ratio. i , i=1,2,……,j: According to the relationship between the abscissa of the interpolation point and the characteristic curve of the current working condition, the secondary Lagrange interpolation is performed respectively; When π≤π1 or π≥π j , that is, when the expansion ratio corresponding to the target point is outside the current operating characteristic curve, the two data points at the endpoints are used for linear Lagrange interpolation: When π1<π≤π2 or π j-1 ≤π<π j When , quadratic Lagrange interpolation is performed using the three data points closest to the endpoints: When π1<π≤π2, the quadratic Lagrange interpolation is: When π j-1 ≤π<π j The quadratic Lagrange interpolation is: When π2<π<π j-1 When , use the first two data points and the last data point close to the horizontal coordinate of the target point for quadratic Lagrange interpolation: Obtain turbine characteristics of current operating conditions.

6. A turbine characteristic calculation system, characterized in that: include: The numerical reconstruction module is configured to convert the relative speed-expansion ratio characteristic curve of the turbine and select the maximum expansion ratio π on each speed line max and minimum expansion ratio π min As the upper and lower limits, respectively, they are reconstructed into equally spaced data according to the equal expansion ratio intervals and form multiple preliminary β auxiliary lines, wherein each data point in the reconstructed equally spaced data has a sequence number (i, j), i represents the number of characteristic curves, and j represents the number of data points; A curve drawing module is configured to connect the data points reconstructed from the equally spaced data and the corresponding converted flow rates and isentropic efficiencies according to the same serial numbers marked in the relative converted speed-expansion ratio characteristic curve of the turbine to obtain a plurality of β auxiliary lines; Characteristic line interpolation module, configured to collect turbine operating parameters and convert them into the current operating relative conversion speed N cor and the current working condition expansion ratio π, based on the relative conversion speed-expansion ratio characteristic curve with multiple β auxiliary lines, constructing the Lagrangian interpolation polynomial of the kth data point, searching for the intersection point in the relative conversion speed-expansion ratio characteristic curve of the turbine, grouping the original characteristic curve according to the size of the relative conversion speed and the curve position where the intersection point is located, confirming the corresponding group of the turbine according to the current working condition relative conversion speed, interpolating using the quadratic or cubic Lagrangian method, and obtaining the current working condition characteristic curve and the current working condition β auxiliary line; According to the relative position of the expansion ratio of the current working condition in the relative conversion speed-expansion ratio characteristic curve, interpolation is performed using an interpolation method other than Lagrange interpolation to obtain the current working condition characteristic curve and the current working condition β auxiliary line; The target interpolation module is configured to interpolate the target points in the current operating condition characteristic curve and the current operating condition β auxiliary line to obtain the current operating condition turbine characteristics.

7. An electronic device comprising: at least one processor; as well as a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the turbine characteristic calculation method according to any one of claims 1 to 5. 8 . A computer-readable storage medium storing computer instructions, wherein the computer instructions are used to be executed by the computer to implement the turbine characteristic calculation method according to claim 1 .

Images