A method for accurately calculating micro-turbine performance based on compressor and turbine characteristic maps

Abstract

The present invention discloses a method for accurately calculating the performance of a micro-gas turbine based on the compressor and turbine characteristic diagrams. This algorithm is aimed at the performance calculation of a micro-gas turbine with a regenerator. The algorithm includes five steps. First, the performance parameters of the compressor and turbine under different working conditions are collected, and the collected data are fitted with a B-spline curve; the fitting curve is divided into equal parts, and linear interpolation is performed between adjacent curves at the equal-division points to make up for the data points that have not been collected; each operating point on the compressor performance curve diagram is traversed, and combined with the turbine performance diagram, the overall performance of the micro-gas turbine under all working conditions is calculated using thermodynamic formulas. In order to improve the calculation accuracy, the present invention adopts B-spline curve fitting, which has higher curve smoothness and greatly improves the calculation accuracy. In addition, the number of interpolated curves between the equal-division points and adjacent curves in this algorithm is sufficient to accurately calculate the performance of the micro-gas turbine under all working conditions.

Description

Technical Field

[0001] The present invention relates to the field of micro gas turbine design, control and optimization. It is an algorithm that accurately calculates the performance of a micro gas turbine under all operating conditions based on the compressor and turbine characteristic curves. The calculation results can be used to optimize the design of the compressor and turbine and determine the optimal operating conditions of the micro gas turbine. This model can further be used to perform steady-state control of the micro gas turbine. Background Art

[0002] Microturbines are a new technology widely used in energy, automotive, heating, and power generation. While this technology is still in its early stages of development in China, key technologies, equipment, and operation and maintenance still rely on imports. The primary technical principle is the Brayton cycle with a regenerator. Its main components are a compressor, regenerator, combustor, high-speed permanent magnet motor, and turbine. Due to its low-carbon and environmentally friendly advantages, microturbines are expected to have strong market competitiveness in the future.

[0003] Currently, there is little existing technology for the overall design of micro gas turbines, which can control the performance and efficiency of the gas turbine from a macro perspective, as well as the coordinated optimization between the overall design and the compressor and turbine. Summary of the Invention

[0004] The present invention provides a method for accurately calculating micro-turbine performance based on compressor and turbine characteristic graphs. First, B-spline curve fitting and curve bisection are performed on the collected compressor and turbine data, followed by linear interpolation to compensate for missing data. This method can accurately compensate for missing data in the compressor and turbine characteristic graphs. Furthermore, the overall performance of the micro-turbine can be calculated under all operating conditions. The calculation results intuitively present the overall performance of the micro-turbine under all operating conditions shown on the compressor characteristic graph, as well as provide temperature and pressure parameters for each state throughout the entire cycle.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A method for accurately calculating the performance of a micro-turbine based on compressor and turbine characteristic maps comprises the following steps:

[0007] S1, deploy flow meters and pressure gauges at the compressor and turbine of the micro gas turbine; collect the air flow and compression ratio of the compressor, and the mixed gas flow and expansion ratio of the turbine at different speeds, and draw compressor and turbine characteristic curves;

[0008] S2, performing B-spline curve fitting on the collected data to obtain several smooth curves, and ensuring that most of the collected data pass the fitting curve, thereby improving the calculation performance and accuracy;

[0009] S3, dividing each curve of the compressor and turbine curve graphs into equal parts; the number of equal parts determines the accuracy of the final performance calculation; the more equal parts, the higher the calculation accuracy. To ensure high-precision calculation results, the equal parts in the present invention is set to 10;

[0010] S4, performing linear interpolation between each two curves of the compressor and turbine characteristic curves at equally divided points to compensate for the compressor and turbine data that have not been collected; the more curves interpolated between two curves, the more operating conditions for performance calculation;

[0011] S5, traverses each point on the compressor performance curve, and uses the corrected flow rate and compression ratio of each point as input parameters for calculation, applies thermodynamic formulas, determines the corresponding data point on the turbine performance curve, and further completes the performance calculation of the micro gas turbine under all operating points on the compressor performance curve. The calculation results include overall efficiency, output power, and temperature and pressure of each part of the thermodynamic cycle.

[0012] Furthermore, in the step S2, the corrected flow rate data and compression ratio (or expansion ratio) data are stored in arrays x and y respectively in MATLAB, and the function spapi(n, x, y) is called, where n is set to 3, representing a 3rd order spline curve fitting. The fitting curve is shown in the attached figure. Figure 4 , the resulting fitted curve consists of a sufficient number of data points. If the number of data points for the fitted curve is insufficient, use the interp1() function in MATLAB to perform linear interpolation on the data points, inserting several more points between each two fitted data points. This step ensures high accuracy in subsequent performance calculations.

[0013] Furthermore, in the step S3:

[0014] The main idea of ​​dividing each curve of the compressor and turbine curve graph into equal parts is: the data points of the fitting curve (P1(x1, y1), P2(x2, y2), ...., P n (x n ,y n )) is large enough and the interval between any two points is small enough, so the distance between any two points satisfies the following formula:

[0015] when

[0016] in, Using this method, the length of the entire curve can be obtained by summing the distances between each two points. Note that the number of data points for the fitted curve should be large enough to ensure the accuracy of the calculation. Given that the number of equal divisions N is 10, the coordinates of each equal division point can be calculated by the following steps:

[0017] S31, calculate the distance between every two adjacent data points:

[0018] There are n data points in total, and n-1 distances can be calculated as follows:

[0019]

[0020] S32, calculate the distances from all points on the fitting curve to the first point P1 (x1, y1) by summing, as follows:

[0021]

[0022] And store these n distances in a one-dimensional array L

[0023] S33, divide the curve into N segments, the length of each segment is L seg ,as follows:

[0024]

[0025] S34, determine P1 (x1, y1) to any equally divided point P d The distance is as follows:

[0026] L D =N D L seg

[0027] Among them, N D From P1 to P d The number of equally divided segments

[0028] S35, calculate the difference between each element in array L and L D The difference is as follows:

[0029]

[0030] because and L D The starting point is the same, both are P1, and the difference calculated above represents P d to P i distance;

[0031] S36, in step S35, find the minimum |ΔL|; when P d Infinitely close to P i When ΔL approaches 0, we can find the corresponding element L(I) and subscript I in the array L according to the minimum |ΔL|. Using the subscript, we can get the closest equal division point P in the data set. d Data point P I (x(I), y(I)). As long as the number of data points is large enough, P IIt is infinitely close to the equal division point and can be considered as the equal division point.

[0032] Further, in the step S4:

[0033] The specific steps for linear interpolation of the compressor and turbine characteristic curves are as follows:

[0034] S41, unify the speed of the compressor and turbine to the corrected speed, as shown in the following formula:

[0035]

[0036]

[0037] Where N1 is the compressor speed; N4 is the turbine correction speed; T1 is the compressor inlet temperature; T4 is the turbine inlet temperature; T 1，ref and T 4，ref All are reference temperatures;

[0038] S42, linear interpolation is performed using the corrected speed to compensate for missing data. The corresponding corrected flow rate and other related parameters, such as the compression ratio, need to be calculated through linear interpolation. The interpolation formula is as follows: Furthermore, in step S5, the specific steps of calculating the overall performance of the micro gas turbine are:

[0039] S51: Determine the compressor inlet state. Given the inlet air temperature R1 and pressure P1, the enthalpy value h1 of the air at that temperature can be obtained by looking up the table.

[0040] S52: Select the compressor performance parameters, select the point on the compressor characteristic curve performance diagram, and obtain the corrected air flow m 修正空气流量 , efficiency η c and compression ratio π c , the compressor air flow can be calculated by the following formula

[0041]

[0042] S53: Determine the compressor outlet state. The compressor outlet temperature T2 can be calculated using a thermodynamic formula as follows:

[0043]

[0044] where γ c is the specific heat ratio of air, and the enthalpy value h2 can be obtained by looking up the table according to the temperature T2;

[0045] S54: The expansion ratio π of the turbine can be determined based on the pressure loss of each part of the cycle t ;

[0046] S55: Determine the corresponding operating point on the turbine characteristic curve using the expansion ratio in step S54 and the corrected speed in step S52, and obtain relevant performance parameters of the turbine, such as efficiency η t and Mixed gas flow It can be calculated by the following formula:

[0047]

[0048] Where P4 and T4 are the pressure and temperature at the turbine inlet; P 4，ref and T 4，ref is the reference value;

[0049] S56: Determine the temperature T4 at the turbine inlet. The calculation formula is as follows:

[0050]

[0051] Where: γ t is the specific heat ratio of the mixed gas; T5 is the turbine outlet temperature, a known quantity;

[0052] S57: Determine the combustion chamber inlet temperature T3, calculated using the following formula:

[0053] T3=∈(T5-T2)+T2

[0054] Where ∈ is the regenerator efficiency;

[0055] S58: Determine the fuel flow rate In the combustion chamber, assuming adiabatic conditions, the fuel flow rate can be calculated based on the heat of fuel combustion being equal to the enthalpy change of the mixed gas. as follows:

[0056]

[0057] Where LHV is the lower heating value of the fuel;

[0058] S59: Determine the temperature T6 of the mixed gas outlet of the regenerator. According to the relevant properties of the heat exchanger, this temperature can be calculated by the following formula:

[0059]

[0060] S510: Calculate the output power of the entire micro gas turbine as follows:

[0061]

[0062] where η mech is the mechanical efficiency; η elec is the power conversion efficiency; b is the gas leakage coefficient,

[0063] By traversing each operating point on the compressor characteristic curve, the performance diagram of the micro gas turbine under all operating conditions is calculated.

[0064] Beneficial effects

[0065] Compared with existing technologies, this method utilizes data processing methods such as B-spline curve fitting and curve bisection to improve the accuracy of compressor and turbine characteristic curves, compensating for missing data with high precision, and enabling the determination of operating parameters at almost any point in the curves. This improves the accuracy and breadth of subsequent calculations of the overall performance of the micro-gas turbine. Furthermore, the present invention provides a macroscopic view of the overall performance of the micro-gas turbine under all operating conditions, enabling comprehensive optimization and design. It also enables coordinated optimization of the compressor and turbine to meet the overall design requirements of the micro-gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 A flowchart of the steps of a method for high-precision calculation of the performance of a micro gas turbine under all operating conditions based on compressor and turbine characteristic curves provided by an embodiment of the present invention;

[0067] Figure 2 A compressor characteristic curve diagram for a high-precision calculation method of the performance of a micro gas turbine under all operating conditions based on compressor and turbine characteristic curve diagrams provided in an embodiment of the present invention;

[0068] Figure 3 A turbine characteristic curve diagram for a high-precision calculation method of the performance of a micro gas turbine under all operating conditions based on compressor and turbine characteristic curve diagrams provided in an embodiment of the present invention;

[0069] Figure 4 A curve fitting diagram of a high-precision calculation method for the performance of a micro gas turbine under all operating conditions based on the compressor and turbine characteristic curve diagrams provided by an embodiment of the present invention;

[0070] Figure 5 A graph showing a high-precision calculation method for the performance of a micro gas turbine under all operating conditions based on a compressor and turbine characteristic curve diagram provided by an embodiment of the present invention;

[0071] Figure 6 The interpolated compressor characteristic curve diagram of the method for high-precision calculation of the performance of a micro gas turbine under all working conditions based on the compressor and turbine characteristic curve diagrams provided by the embodiment of the present invention;

[0072] Figure 7The turbine characteristic curve diagram after interpolation according to the high-precision calculation method for the performance of a micro gas turbine under all working conditions based on the compressor and turbine characteristic curve diagrams provided by the embodiment of the present invention;

[0073] Figure 8 A performance diagram of a method for high-precision calculation of the performance of a micro gas turbine under all working conditions based on a compressor and turbine characteristic curve diagram provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0074] The following describes the technical solution of the present invention in detail with reference to the accompanying drawings. The embodiment described in the present invention is only one embodiment of the present invention and does not represent all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiment of the present invention without inventive effort are within the scope of protection of the present invention.

[0075] See also Figure 1 The present invention provides a method for accurately calculating the performance of a micro-turbine based on a compressor and turbine characteristic diagram, comprising the following steps: S1, collecting the performance of the compressor and turbine at different speeds, and drawing a performance curve diagram, see Figure 2 and 3 ; S2, perform B-spline curve fitting on the collected data so that the compressor and turbine performance graphs are smooth curves and pass through most of the collected data points, thereby improving the calculation accuracy of the performance; S3, divide each curve of the compressor and turbine curve graph into equal parts; the number of equal parts determines the accuracy of the final performance calculation. The more equal parts, the higher the calculation accuracy. To ensure high-precision calculation results, the equal parts in the present invention is 10; S4, perform linear interpolation between each two curves of the compressor and turbine characteristic curve graph according to the equal division points to make up for the compressor and turbine data that have not been collected; the more curves interpolated between the two curves, the more working conditions for performance calculation; S5, traverse each point on the compressor performance curve graph, and use the corrected flow and compression ratio of each point as the input parameters for calculation, apply thermodynamic formulas, determine the corresponding data points on the turbine performance curve graph, and further complete the performance calculation of the micro gas turbine under all working points on the compressor performance graph. The calculation results include overall efficiency, output power, and temperature and pressure of each part of the thermodynamic cycle. In this embodiment, data processing methods such as B-spline curve fitting and curve bisection are used to improve the accuracy of the compressor and turbine characteristic curves, and missing data is compensated with high precision, allowing the operating parameters of almost any point in the curves to be obtained. This improves the accuracy and breadth of subsequent calculations of the overall performance of the micro-gas turbine. Furthermore, the present invention provides a macroscopic view of the overall performance of the micro-gas turbine under all operating conditions, which can be used for overall optimization and design. It can also coordinate the optimization of the compressor and turbine to meet the overall design requirements of the micro-gas turbine.

[0076] As an optimization solution of an embodiment of the present invention, the S2 step is specifically as follows: in MATLAB, the corrected flow rate data and compression ratio data at each speed of the compressor are stored in arrays x and y respectively, and the function spapi(n, x, y) is called, where n is set to 3, representing a 3rd-order spline curve fitting. This method can obtain data points that form a fitting curve; depending on the different fitting curves, the number of fitting data points obtained is between 200 and 1000. To ensure high accuracy of the calculation, in MATLAB, the interpl() function is used to interpolate several data points between every two data points, and the number of data points of all fitting curves is increased to at least 1000. The obtained fitting curve is shown in the attached figure. Figure 4 .

[0077] As an optimization solution of the embodiment of the present invention, in the step S3,

[0078] The main idea of ​​dividing each curve of the compressor and turbine curve graph into equal parts is: the data points of the fitting curve (P1(x1, y1), P2(x2, y2), ...., P n (x n ,y n )) is large enough, in the embodiment of the present invention, n≥1000; the interval between each two points is small enough, so the distance between each two points satisfies the following formula:

[0079] when

[0080] in, Using this method, the length of the entire curve can be obtained by summing the distances between each two points. Note that the number of data points for the fitted curve should be large enough to ensure the accuracy of the calculation. Given that the number of equal divisions N is 10, the coordinates of each equal division point can be calculated by the following steps:

[0081] Calculate the distance between every two adjacent data points:

[0082] There are n data points in total, and n-1 distances can be calculated as follows:

[0083]

[0084]

[0085] The distances from all points on the fitted curve to the first point P1(x1, y1) are calculated by summing as follows:

[0086]

[0087] And store these n distances in a one-dimensional array L

[0088] Divide the curve into N segments, each segment has a length of L seg ,as follows:

[0089]

[0090] Determine P1(x1, y1) to any equally divided point P d The distance is as follows:

[0091] L D =N D L seg

[0092] Among them, N D From P1 to P d The number of equal segments between

[0093] Calculate the difference between each element in array L and L D The difference is as follows:

[0094]

[0095] because and L D The starting point is the same, both are P1, and the difference calculated above represents P d to P i distance.

[0096] In the step S35, the minimum |ΔL| is found; when P d Infinitely close to P ( When ΔL approaches 0, we can find the corresponding element L(I) and subscript I in the array L according to the minimum |ΔL|. Using the subscript, we can get the closest equal division point P in the data set. d Data point P I (x(I), y(I)). As long as the number of data points is large enough, P I It is infinitely close to the equal division point and can be considered as the equal division point. The curve equal division result is shown in the attached Figure 5 .

[0097] Further, in the step S4:

[0098] The specific steps for linear interpolation of the compressor and turbine characteristic curves are as follows:

[0099] S41, unify the speed of the compressor and turbine to the corrected speed, as shown in the following formula:

[0100]

[0101]

[0102] Where N1 is the compressor speed; N4 is the turbine correction speed; T1 is the compressor inlet temperature; T4 is the turbine inlet temperature; T 1，ref and T 4，ref are all reference temperatures. In this embodiment, T 1，ref =298K,P 1，ref =101325Pa, T 4，ref =1176.4K,P 4，ref =305400Pa.

[0103] The corrected speed is used for linear interpolation to make up for the missing data. The parameters required for linear interpolation are shown in Table 1, where N p is the rotational speed that needs to be interpolated, which is a known quantity; the corresponding corrected flow rate and other related parameters, such as the compression ratio, need to be calculated through linear interpolation.

[0104] Table 1 Linear interpolation parameters

[0105]

[0106] The interpolation formula is as follows:

[0107] The final interpolated compressor and turbine characteristic curves are shown in the attached Figure 6 and 7 .

[0108] Furthermore, in step S5, the specific steps of calculating the overall performance of the micro gas turbine are:

[0109] S51: Determine the compressor inlet state. Given the inlet air temperature T1 and pressure P1, the enthalpy value h1 of the air at that temperature can be obtained by looking up the table.

[0110] S52: Select the compressor performance parameters, select the point on the compressor characteristic curve performance diagram, and obtain the corrected air flow m 修正空气流量 , efficiency η c and compression ratio π c The compressor air flow can be calculated by the following formula

[0111]

[0112] S53: Determine the compressor outlet state. The compressor outlet temperature T2 can be calculated using a thermodynamic formula as follows:

[0113]

[0114] where γ c is the specific heat ratio of air. The enthalpy value h2 can be obtained by looking up the table according to the temperature T2.

[0115] S54: The expansion ratio π of the turbine can be determined based on the pressure loss of each part of the cycle t

[0116] S55: Determine the corresponding operating point on the turbine characteristic curve using the expansion ratio in step S54 and the corrected speed in step S52, and obtain relevant performance parameters of the turbine, such as efficiency η t and Mixed gas flow It can be calculated by the following formula:

[0117]

[0118] Where P4 and T4 are the pressure and temperature at the turbine inlet; P 4，ref and T 4，ref is the reference value;

[0119] S56: Determine the temperature T4 at the turbine inlet. The calculation formula is as follows:

[0120]

[0121] Where: γ t is the specific heat ratio of the mixed gas; T5 is the turbine outlet temperature, a known quantity;

[0122] S57: Determine the combustion chamber inlet temperature T3, calculated using the following formula:

[0123] T3=∈(T5-T2)+T2

[0124] Where ∈ is the regenerator efficiency;

[0125] S58: Determine the fuel flow rate In the combustion chamber, assuming adiabatic conditions, the fuel flow rate can be calculated based on the heat of fuel combustion being equal to the enthalpy change of the mixed gas. as follows:

[0126]

[0127] Where LHV is the lower heating value of the fuel;

[0128] S59: Determine the temperature T6 of the mixed gas outlet of the regenerator. According to the relevant properties of the heat exchanger, this temperature can be calculated by the following formula:

[0129]

[0130] S510: Calculate the output power of the entire micro gas turbine as follows:

[0131]

[0132] where ηmech is the mechanical efficiency; η elec is the power conversion efficiency; b is the gas leakage coefficient.

[0133] Under the above working conditions, the calculation parameters involved are shown in Table 3; under the selected working conditions, the final calculation results are shown in Table 4. The compressor and turbine data in the embodiment of the present invention are from Capstone C65. Under this selected working condition, the theoretical calculation result should be around 65kW. The calculation result in Table 4 is 66.15kW, which is very close to the theoretical value, reflecting the high accuracy of the algorithm described in the present invention. After traversing every working point on the compressor characteristic curve, the performance diagram of the micro gas turbine under all working conditions is shown in the attached figure. Figure 8 .

[0134] Table 2 Parameters involved in the calculation

[0135]

[0136]

[0137] Table 3 Calculation results of the embodiment

[0138] Power generation (kW) Total efficiency (%) Speed ​​(RPM) <![CDATA[T4(K)]]> <![CDATA[T5(K)]]> 66.15 31.62 73000 1215.3 946

[0139] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for accurately calculating the performance of a micro-turbine based on compressor and turbine characteristic maps, characterized in that: The steps include: S1, deploy flow meters and pressure gauges at the compressor and turbine of the micro gas turbine; collect the air flow and compression ratio of the compressor, and the mixed gas flow and expansion ratio of the turbine at different speeds, and draw compressor and turbine characteristic curves; S2, performing B-spline curve fitting on the collected data to obtain several smooth curves, and ensuring that most of the collected data pass through the fitting curve, thereby improving the performance calculation accuracy; S3, divide each curve of the compressor and turbine curve graph into equal parts; the number of equal parts determines the accuracy of the final performance calculation; the more equal parts, the higher the calculation accuracy; S4, performing linear interpolation between each two curves of the compressor and turbine characteristic curves at equally divided points to compensate for the compressor and turbine data that have not been collected; the more curves interpolated between two curves, the more operating conditions for performance calculation; S5, traversing each point on the compressor performance curve, and using the corrected flow rate and compression ratio at each point as input parameters for calculation, applying thermodynamic formulas to determine the corresponding data point on the turbine performance curve, and further completing the performance calculation of the micro gas turbine at all operating points on the compressor performance curve; the calculation results include overall efficiency, output power, and temperature and pressure of each part of the thermodynamic cycle; Specifically, S5 is: S51: Determine the compressor inlet state. Given the inlet air temperature T1 and pressure P1, look up the table to obtain the enthalpy value h1 of the air at that temperature. S52: Select the compressor performance parameters, select the points on the compressor characteristic curve performance diagram, and obtain the corrected air flow Efficiency η c and compression ratio π c , compressor air flow Calculated by the following formula: S53: Determine the compressor outlet state. The compressor outlet temperature T2 is calculated using a thermodynamic formula as follows: Among them, γ c is the specific heat ratio of air, and the enthalpy value h2 is obtained by looking up the table according to the temperature T2; S54: Determine the turbine expansion ratio π based on the pressure losses in each part of the cycle t ; S55: Determine the corresponding operating point on the turbine characteristic curve using the expansion ratio in S54 and the corrected speed in S52, and obtain the turbine's related performance parameters, such as efficiency η t and Mixed gas flow Calculated by the following formula: Among them, P4 and T4 are the pressure and temperature at the turbine inlet; P 4,ref and T 4,ref is the reference value; S56: Determine the temperature T4 at the turbine inlet. The calculation formula is as follows: where γ t is the ratio of specific heats of the mixed gas; T5 is the turbine outlet temperature, a known quantity; S57: Determine the combustion chamber inlet temperature T3, calculated using the following formula: T3=∈(T5-T2)+T2 Where, ∈ is the regenerator efficiency; S58: Determine the fuel flow rate In the combustion chamber, assuming adiabatic conditions, the fuel flow rate is calculated based on the heat of fuel combustion being equal to the enthalpy change of the mixed gas. as follows: Where LHV is the lower heating value of the fuel; S59: Determine the temperature T6 of the mixed gas outlet of the regenerator. According to the relevant properties of the heat exchanger, this temperature is calculated by the following formula: S510: Calculate the output power of the entire micro gas turbine as follows: Among them, η mech is the mechanical efficiency; η elec is the power conversion efficiency; b is the gas leakage coefficient.

2. A method for accurately calculating micro-turbine performance based on compressor and turbine characteristic diagrams as described in claim 1, wherein S2 is specifically as follows: in MATLAB, the corrected flow data and compression ratio or expansion ratio data are stored in arrays x and y respectively, and the function spapi(n,x,y) is called, where n is set to 3, representing a third-order spline curve fitting. The obtained fitting curve is composed of a large number of data points. When the number of data points of the fitting curve is not sufficient, in MATLAB, the interp1() function is used to linearly interpolate the data points, that is, to insert a number of points between every two fitting data points.

3. The method for accurately calculating micro-turbine performance based on compressor and turbine characteristic maps according to claim 1, wherein S3 specifically comprises: The main idea of ​​dividing each curve of the compressor and turbine curve graph into equal parts is: the data points of the fitting curve (P1(x1,y1),P2(x2,y2),…,P n (x n ,y n )) more, the interval between each two points is small, so the distance between each two points satisfies the following formula: when in, Using this method, the length of the entire curve is obtained by summing the distances between every two points. Given that the number of equal divisions N is 10, the coordinates of each equal division point are calculated using the following steps: S31, calculate the distance between every two adjacent data points: There are n data points in total, and n-1 distances are calculated as follows: S32, calculate the distances from all points on the fitting curve to the first point P1 (x1, y1) by summing as follows: And store these n distances in a one-dimensional array L; S33, divide the curve into N segments, the length of each segment is L seg ,as follows: S34, determine P1(x1,y1) to any equally divided point P d The distance is as follows: L D =N D L seg Among them, N D From P1 to P D The number of equally divided segments between S35, calculate the difference between each element in array L and L D The difference is as follows: because and L D The starting point is the same, both are P1, and the difference calculated above represents P d to P i distance; S36, in said S35, find the minimum |ΔL|; when P d Infinitely close to P i When ΔL approaches 0, find the corresponding element L(I) and subscript I in the array L according to the minimum |ΔL|; use the subscript to obtain the closest equal division point P in the data set. d Data point P I (x(I), y(I)); As long as the number of data points is large, P I Anything that is infinitely close to the equidivision point is considered to be the equidivision point.

4. The method for accurately calculating the performance of a micro-turbine based on a compressor and turbine characteristic map according to claim 1, wherein the step S4 comprises: The specific steps for linear interpolation of the compressor and turbine characteristic curves are as follows: S41, unify the speed of the compressor and turbine to the corrected speed, as shown in the following formula: in, N1 is the compressor speed; N4 is the turbine speed; T1 is the compressor inlet temperature; T4 is the turbine inlet temperature; T 1,ref and T 4,ref All are reference temperatures; S42, linear interpolation is performed using the corrected speed to compensate for missing data; the corresponding corrected flow rate and other related parameters, such as the compression ratio, need to be calculated through linear interpolation.

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