Method for determining performance degradation of gas turbine according to real-time operating parameters

Abstract

The invention relates to a method for determining performance degradation of a gas turbine according to real-time operating parameters, which comprises the following steps of: based on the real-time operating parameters, selecting the rotating speed of a high-pressure compressor and the rear air pressure of the high-pressure compressor under rated working conditions at different air inlet temperatures for real-time conversion, and further calculating the performance degradation index variable of the gas turbine according to the performance degradation index variable of the gas turbine. The thermal efficiency under different indexes is obtained by using the linear relation between the decline index variable and the thermal efficiency, so that the performance decline value is obtained, and the cleaning time of the through-flow part is determined. According to the method, the performance degradation index variable of the gas turbine is provided by utilizing the characteristics that after the performance degradation of the gas turbine, the rotating speed of the high-pressure compressor is increased and the air pressure behind the high-pressure compressor is reduced, the problem that the thermal efficiency cannot be measured due to objective condition limitation is avoided, and the method is easy to operate and has important significance on the operation of the gas turbine.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines, and in particular to a method for determining gas turbine performance degradation based on real-time operating parameters. Background Art

[0002] Currently, the timing of gas turbine performance degradation and the cleaning of the flow passage are primarily based on gas turbine efficiency. However, thermal efficiency measurement is affected by the accuracy of power measurement, fuel lower heating value testing, and fuel flow measurement. Furthermore, the unique operating environments of gas turbines used in offshore oil platforms and ship propulsion impose certain limitations on accurate thermal efficiency measurement, all of which can affect the determination of gas turbine performance degradation. Summary of the Invention

[0003] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides a method for determining the performance degradation of a gas turbine based on real-time operating parameters. The high-pressure compressor speed and the air pressure after the high-pressure compressor under rated operating conditions at different inlet temperatures are selected for real-time conversion to obtain the linear relationship between the performance degradation indicator variable and the thermal efficiency of the gas turbine, and the cleaning timing is determined based on the linear relationship, thereby solving the problem of difficult measurement accuracy.

[0004] The technical solutions adopted in the present invention are as follows:

[0005] A method for determining gas turbine performance degradation based on real-time operating parameters comprises the following steps:

[0006] Step 1: Select the high-pressure compressor speed and the air pressure after the high-pressure compressor at different inlet temperatures when the current test is running stably and the actual rated operating power (±1 kW).

[0007] Step 2: Correct the high-pressure compressor speed (N2) and the air pressure after the high-pressure compressor (P2) at different intake temperatures in step 1. The correction method is as follows.

[0008]

[0009] Where, T 标准 300.15K = (27 + 273.15);

[0010] T 实时 is the intake air temperature, unit (K);

[0011] P 标准 For standard atmospheric pressure, take 101300 Pa;

[0012] P 实时 is the real-time atmospheric pressure, unit (pa);

[0013] P2 is the air pressure after the high-pressure compressor, unit (Mpa);

[0014] N2 is the high-pressure compressor speed, unit (r / min).

[0015] Step 3: Change the N 2折合 、P 2折合 Take the average value, N 2折合平均 、P 2折合平均 ,Pick

[0016] ε is defined as the gas turbine performance degradation indicator variable.

[0017] Step 4: Take ε and gas turbine thermal efficiency η at different time periods, establish a linear relationship between Δε and Δη, and obtain the thermal efficiency η under different ε, and then obtain the performance degradation value and determine the cleaning time of the flow part.

[0018] The beneficial effects of the present invention are as follows:

[0019] Based on real-time operating parameters, the present invention selects high-pressure compressor speed (N2) and high-pressure compressor outlet pressure (P2) under rated operating conditions at different inlet temperatures and performs real-time conversion to obtain a gas turbine performance degradation indicator variable ε. Utilizing the linear relationship between ε and thermal efficiency η, the thermal efficiency η at different ε levels is calculated, thereby determining the performance degradation value and the timing for cleaning the flow passage. This method utilizes the characteristic that high-pressure compressor speed increases and outlet pressure decreases after gas turbine performance degradation to propose a gas turbine performance degradation indicator variable, circumventing the problem of inaccurate thermal efficiency measurement due to objective conditions. The method is easy to operate and has important implications for gas turbine operation. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are described below.

[0021] The specific process of applying the method of the present application to a specific gas turbine to measure performance degradation is as follows.

[0022] Step 1: Select the high-pressure compressor speed and the air pressure after the high-pressure compressor at different inlet temperatures when the gas turbine is in stable operation and the actual rated operating condition deviation is (±1 kW) during different operating periods, as shown in Tables 1 to 5.

[0023] In this embodiment, the operating periods of the gas turbine are: 1200 hours, 1100 hours, 950 hours, 900 hours, and 600 hours.

[0024] Table 1 Speed ​​and temperature at different intake air temperatures during 1200 hours of operation

[0025]

[0026] Table 2 Speed ​​and temperature at different intake air temperatures during 1100 hours of operation

[0027]

[0028]

[0029] Table 3 Speed ​​and temperature at different intake air temperatures during 950 hours of operation

[0030]

[0031] Table 4 Speed ​​and temperature at different intake air temperatures during 900 hours of operation

[0032]

[0033]

[0034] Table 5 Speed ​​and temperature at different intake air temperatures during 600 hours of operation

[0035]

[0036] Step 2: Correct the high-pressure compressor speed N2 and the air pressure after the high-pressure compressor P2 at different operating periods and different intake air temperatures of the gas turbine in step 1. The correction results are shown in Tables 1 to 5 above.

[0037] The correction method is as follows:

[0038]

[0039] Where, T 标准 =300.15K=(27+273.15); T 实时 is the intake air temperature, unit (K); P 标准 is the standard atmospheric pressure, which is 101300 Pa; P 实时 is the real-time atmospheric pressure, unit (pa); P2 is the air pressure after the high-pressure compressor, unit (Mpa); N2 is the high-pressure compressor speed, unit (r / min).

[0040] Step 3: Convert the N at different inlet temperatures in step 2 2折合 、P 2折合 Take the average value respectively, record it as: N 2折合平均 、P 2折合平均 The calculation results are shown in Tables 1 to 5 above.

[0041]

[0042] The ε for the 1200-hour period, 1100-hour period, 950-hour period, 900-hour period, and 600-hour period are 4555.29, 4551.05, 4539.70, 4504.78, and 4459.83, respectively.

[0043] ε is defined as the gas turbine performance degradation indicator variable.

[0044] Step 4: Take ε at different time periods, measure the thermal efficiency η of the gas turbine at the corresponding time periods, establish a linear relationship between Δε and Δη, and obtain the thermal efficiency η under different ε, and then obtain the performance degradation value and determine the cleaning time of the flow part.

[0045] Through thermal efficiency measurement, the unit thermal efficiency η is 42.5% during the 600-hour operation period; the unit thermal efficiency η is 42.38% during the 900-hour operation period;

[0046] The linear relationship between Δε and Δη is:

[0047] (42.50-42.38) / (4459.83-4504.78)=0.002669;

[0048] If the thermal efficiency η decreases by 0.5%, water cleaning should be performed, and ε should be increased:

[0049] When 0.5 / 0.002669=187.3046, i.e., ε=187.3046+4459.83=4647.1346, the flow-through portion is cleaned.

[0050] Performance declines from 600 hours to 1200 hours of operation

[0051] Δε=4555.29-4459.83=95.46, thermal efficiency reduction Δη=95.46×0.002669=0.255%.

[0052] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. A method for determining gas turbine performance degradation based on real-time operating parameters, characterized in that: The high-pressure compressor speed and the air pressure after the high-pressure compressor under rated operating conditions at different inlet temperatures are selected for real-time conversion correction to obtain the conversion value; the conversion value is averaged, and the ratio of the average values ​​is used as the gas turbine performance degradation indicator variable. A linear relationship is obtained according to a gas turbine performance degradation indicator variable and a measured thermal efficiency of the gas turbine, and a performance degradation value and a cleaning timing of a flow-through portion are obtained according to the linear relationship.

2. The method for determining gas turbine performance degradation based on real-time operating parameters according to claim 1, characterized in that: The steps include: Step 1: Select the high-pressure compressor speed and the air pressure after the high-pressure compressor at different inlet temperatures when the current test is running stably and the rated operating power is actually generated, and record them as N2 and P2 respectively. Step 2: Modify N2 and P2 obtained in step 1 to obtain N 2折合 、P 2折合 , Step 3: Convert the N at different inlet temperatures in step 2 2折合 、P 2折合 Take the average value and get N 2折合平均 、P 2折合平均 ,Pick ε is the gas turbine performance degradation indicator variable, Step 4: Take the linear relationship between ε, η, Δε and Δη at different time periods, and obtain the thermal efficiency η under different ε based on the linear relationship, and then obtain the performance degradation value and determine the cleaning time of the flow-through part.

3. The method for determining gas turbine performance degradation based on real-time operating parameters according to claim 2, wherein: In step 1, the error range of the actual rated operating power is (±1KW).

4. The method for determining gas turbine performance degradation based on real-time operating parameters according to claim 2, wherein: In step 2, the correction method is: Where, T 标准 300.15K = (27 + 273.15); T 实时 is the intake air temperature, unit (K); P 标准 For standard atmospheric pressure, take 101300 Pa; P 实时 is the real-time atmospheric pressure, unit (pa); P2 is the air pressure after the high-pressure compressor, unit (Mpa); N2 is the high-pressure compressor speed, unit (r / min).

5. The method for determining gas turbine performance degradation based on real-time operating parameters according to claim 2, wherein: In step 4, the linear relationship between Δε and Δη is Δε / Δη.

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