Method for determining replacement time of power turbine of marine gas turbine according to outlet temperature of exhaust volute

Abstract

The invention relates to a method for determining the replacement time of a power turbine of a marine gas turbine according to the outlet temperature of an exhaust volute, and the method is based on a full-life examination test during the development period of the gas turbine, and before the test, after the full-life graph examination test is completed and the through-flow cleaning of the gas turbine is carried out, the replacement time of the power turbine is determined. Under the output rated power correction value of the gas turbine, the change of the outlet temperature correction value of the exhaust volute serves as a judgment basis value of the opportunity of overhauling and replacing the power turbine. And for a specific gas turbine of the type of gas turbine, when a delivery test is carried out, after the gas turbine is operated for a period of time and through-flow cleaning is carried out on the gas turbine, the temperature correction value of the outlet of the exhaust volute changes, and when the change value is larger than or equal to the judgment basis value of the time for overhauling and replacing the power turbine, the power turbine needs to be overhauled and replaced.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbines, in particular to a method for determining a replacement time of a power turbine of a marine gas turbine according to an exhaust volute outlet temperature. Background Art

[0002] Gas turbines are widely used in fields such as ship power and offshore oil platform power generation due to their compact structural layout, good fuel economy indicators, high thermal efficiency, good reliability and long service life, becoming the core power representative of the new generation.

[0003] In actual use, the power output of marine gas turbines is quite different from that of land-based gas turbines. Land-based gas turbines have a longer continuous use time and less load changes. For example, gas turbines used in power plants continuously output power at full load and do not stop for several months. The use time and load of marine gas turbines vary according to different usage conditions such as anchoring, docking, and sailing, and there are many variable working conditions during the actual operation process. As the original power source of power output, the power turbine is subjected to high-temperature flue gas. The power turbine is also affected by the ship's turning and ocean currents, and the speed of the power turbine will continue to change.

[0004] There are no clear regulations on the evaluation of the life of marine gas turbines during use and the determination of the timing of overhaul. If the gas turbine power turbine is operated beyond its service life and the turbine blades are broken, it will cause great harm. How to determine the timing of replacing the power turbine after a period of use is crucial. Summary of the invention

[0005] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a method for determining the timing of replacing the power turbine of a marine gas turbine based on the exhaust volute outlet temperature, and determines the timing of replacing the power turbine of the gas turbine based on the change in exhaust temperature after the power turbine.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for determining the timing of replacing a power turbine of a marine gas turbine based on the exhaust volute outlet temperature.

[0008] The steps include:

[0009] Step 1: Before and after the gas turbine full life test, multiple operating conditions are performed to obtain operating parameters.

[0010] Step 2: The actual power obtained under each working condition before and after the full life test is recorded as W 试验前 , W 试验完成后 , correct the actual power and get the power correction value before and after the test, recorded as W 试验前修正值 , W试验完成后修正值 ,

[0011] The exhaust volute outlet temperature of each working condition before and after the full life test is recorded as T 8试验前 、T 8试验完成后 , for T 8试验前 、T 8试验完成后 Corrected according to atmospheric conditions, the corrected values ​​of the exhaust volute outlet temperature before and after the test are obtained, denoted as T 8试验前修正值 、T 8试验完成后修正值 ;

[0012] According to the relationship between the power correction value and the exhaust volute outlet temperature correction value, the power correction value of the rated working condition is obtained, which is recorded as W 1.0工况修正值 ; Get the corrected values ​​of the exhaust volute outlet temperature under rated conditions, denoted as T 8试验前1.0工况修正值 、T 8试验完成后1.0工况修正值 ,

[0013] Step 3: Use the numerical difference between the exhaust volute outlet temperature correction values ​​before and after the full life assessment test in step 2 as the exhaust volute outlet temperature reference when replacing the power turbine.

[0014] In step one, the gas turbine undergoes a full life spectrum assessment test, and after the test is completed, it is required to be flow-cleaned before operation.

[0015] In step 2, the power correction values ​​before and after the test satisfy the following formula:

[0016]

[0017] Where W 实测值 is the measured power, in kw,

[0018] P 实测值 is the measured atmospheric pressure, in units of pa,

[0019] T 实测值 is the measured atmospheric temperature, in K,

[0020] P 0 is standard atmospheric pressure, 101300pa,

[0021] T 0 is the standard atmospheric temperature, 300.15K,

[0022] θ 1 ,θ 2 They are propeller characteristic correction factor and power turbine relative speed correction factor respectively.

[0023] In step two, .

[0024] The exhaust volute outlet temperature is corrected for atmospheric conditions using the following correction formula:

[0025]

[0026] Where, T 8实测值 To measure the exhaust volute outlet temperature,

[0027] T 8修正值 It is the correction value of the exhaust volute outlet temperature.

[0028] The numerical difference between the exhaust volute outlet temperature correction values ​​before and after the full life test in step 2 is recorded as ΔT 8 , ΔT 8 =T 8试验完成后1.0工况修正值 -T 8试验前1.0工况修正值 .

[0029] A method for determining the timing of replacing a power turbine of a marine gas turbine based on the exhaust volute outlet temperature is applied to a process of actual ship maintenance, comprising the following steps:

[0030] During the factory delivery test, a gas turbine of this type was operated at actual power at each gear above 50% of the rated power, with 10% of the rated power as one gear.

[0031] After the gas turbine has been running for a period of time t, the gas turbine is cleaned. After cleaning, the actual power is operated at 10% of the rated power as a gear and at each gear above 50% of the rated power. The actual power obtained at each working condition during the delivery test and after running for a period of time for gas turbine flow cleaning is corrected for atmospheric parameters and output shaft characteristics. The actual power is recorded as: W 交付试验 , W 运行一段时间进行燃气轮机通流清洗后 ,

[0032] The corrected power correction value is recorded as:

[0033] W 交付试验修正值 , W 运行一段时间进行燃气轮机通流清洗后修正值 ,

[0034] The exhaust volute outlet temperature of each operating condition at the time of delivery test and after the gas turbine is cleaned after running for a period of time is corrected for the atmospheric conditions. The exhaust volute outlet temperature is recorded as:

[0035] T 8交付试验 、T 8运行一段时间进行燃气轮机通流清洗后 ,

[0036] The corrected temperature correction value is recorded as:

[0037] T 8交付试验修正值 、T 8运行一段时间进行燃气轮机通流清洗后修正值 ,

[0038] According to the relationship between the exhaust volute outlet temperature correction value and the power correction value after the gas turbine is cleaned during the delivery test and after running for a period of time, the rated operating power correction value W is obtained. 1.0工况修正值 , corresponding to the delivery test, the exhaust volute outlet temperature correction value T after running for a period of time and performing gas turbine flow cleaning 8交付试验1.0工况修正值 、T 8运行一段时间进行燃气轮机通流清洗后1.0工况修正值 ,

[0039] When T 8运行一段时间进行燃气轮机通流清洗后1.0工况修正值 -T 8交付试验1.0工况修正值 ≥ΔT 8 The power turbine should be replaced after the inspection. 8 The relationship between the exhaust volute outlet temperature correction value and the power correction value before and after the full life test can be obtained.

[0040] The beneficial effects of the present invention are as follows:

[0041] The present application discloses a method for determining the timing of replacing a power turbine of a marine gas turbine based on the exhaust volute outlet temperature. The method is based on a full life assessment test conducted during the development of the gas turbine. Before and after the test (after completing the full life spectrum assessment test and performing gas turbine flow cleaning), the change in the exhaust volute outlet temperature correction value at the rated power (corrected value) of the gas turbine output is used as the basis for determining the replacement of the power turbine.

[0042] For a specific gas turbine of this type, the exhaust volute outlet temperature correction value changes during delivery testing and after gas turbine flow cleaning after running for a period of time. When the change value is greater than or equal to the above-mentioned overhaul judgment basis value, an overhaul should be carried out and the power turbine should be replaced.

[0043] After the gas turbine completes the full life assessment test, the performance of the power turbine as a power output heat component will decline, and the temperature of the gas behind the power turbine will change accordingly. The present invention uses water cleaning to restore the performance degradation caused by flow dirt. At the same rated power output, the exhaust volute outlet temperature correction value will increase after the full life test compared to before the test. The increase value is used as the basis for the timing of replacing the power turbine. When the exhaust volute outlet temperature of a gas turbine of this type exceeds the above-mentioned overhaul judgment basis value, it should be replaced. The method has clear logic and is of great significance for replacing the power turbine of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a diagram showing the relationship between the exhaust volute outlet temperature correction value and the power correction value before and after the test of the present invention.

[0045] Figure 2 It is a block diagram of the working principle of the present invention. DETAILED DESCRIPTION

[0046] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0047] Before gas turbines are officially put into use, they must undergo full life cycle assessment tests.

[0048] Step 1: Perform a full life map test on the gas turbine. After completing the full life map test, the gas turbine needs to be cleaned. For the sake of convenience, the full life map test will be referred to as "test" in the following text.

[0049] Before the test, after the test and after the cleaning, the gas turbine was operated in multiple operating conditions. The gas turbine was operated at 10% of the rated power as one gear, and at each gear above 50% of the rated power.

[0050] Step 2: Modify the parameters obtained from the experiment in step 1.

[0051] The actual power obtained under each working condition before and after the test is recorded as W 试验前 , W 试验完成后 , W 试验前 , W 试验完成后 The atmospheric parameters and output shaft characteristics are corrected to obtain the power correction values ​​before and after the test, recorded as W 试验前修正值 , W 试验完成后修正值 The correction formula is as follows:

[0052]

[0053] Where W 实测值 , P 实测值 、T 实测值 are respectively the measured power value (kw), the measured atmospheric pressure value (pa), and the measured atmospheric temperature (K), P 0 The standard atmospheric pressure is 101300pa, T 0 The standard atmospheric temperature is 300.15K, θ 1 θ 2 They are propeller characteristic correction factor and power turbine relative speed correction factor respectively.

[0054] For details on the correction method, please refer to the Ship Industry Standard of the People's Republic of China "Data Processing Method for Thermal Performance Test of Ship Gas Turbines" (CB 20429-2018).

[0055] The exhaust volute outlet temperature of each working condition before and after the test is recorded as T 8试验前 、T 8试验完成后 , T 8试验前 、T 8试验完成后 The atmospheric conditions were corrected to obtain the corrected values ​​of the exhaust volute outlet temperature before and after the test, recorded as T 8试验前修正值 、T8试验完成后修正值 .

[0056]

[0057] Where, T 8实测值 、T 8修正值 They are respectively the measured exhaust volute outlet temperature and the exhaust volute outlet temperature correction value, the unit is K.

[0058] According to the relationship between the exhaust volute outlet temperature correction value and the power correction value before and after the test, refer to Figure 1 , get the power correction value under the 1.0 working condition, that is, the rated working condition power correction value. Recorded as W 1.0工况修正值 The corrected value of the exhaust volute outlet temperature before and after the test corresponding to the rated operating power correction value is denoted as T 8试验前1.0工况修正值 、T 8试验完成后1.0工况修正值 .

[0059] Step 3: The numerical difference ΔT between the exhaust volute outlet temperature correction values ​​before and after the test calculated in step 2 is 8 , as the exhaust volute outlet temperature benchmark for overhaul and replacement of power turbines.

[0060] ΔT 8 =T 8试验完成后1.0工况修正值 -T 8试验前1.0工况修正值

[0061] The above method is applied to the monitoring and maintenance of gas turbines on a real ship, and a gas turbine is used as an example to illustrate the method.

[0062] For a gas turbine of this type, during the factory delivery test, the gas turbine was operated at actual power in gears ranging from 10% of the rated power as one gear to 50% of the rated power or above.

[0063] After the gas turbine has been running for a period of time t, the gas turbine is subjected to flow cleaning. After cleaning, the gas turbine is operated at actual power at various operating conditions with 10% of the rated power as one gear and 50% of the rated power as the next gear.

[0064] The actual power of each operating condition at the two time nodes, when the delivery test is carried out and after the flow cleaning is completed, is corrected and recorded as W 交付试验 , W 运行一段时间进行燃气轮机通流清洗后 ; The corrected values ​​are recorded as: W 交付试验修正值 , W 运行一段时间进行燃气轮机通流清洗后修正值 .

[0065] The exhaust volute outlet temperature of each operating condition at the time of delivery test and after the gas turbine is cleaned after running for a period of time is corrected for the atmospheric conditions. The measured temperature before correction is recorded as T 8交付试验 、T 8运行一段时间进行燃气轮机通流清洗后 ; The corrected temperature correction value is recorded as T8交付试验修正值 、T 8运行一段时间进行燃气轮机通流清洗后修正值 .

[0066] According to the relationship between the exhaust volute outlet temperature correction value of these two nodes and the power correction value during the delivery test and after the gas turbine is cleaned after running for a period of time, the power correction value under the 1.0 condition is obtained, that is, the power correction value under the rated condition, which is recorded as W 1.0工况修正值 The corresponding delivery test under rated conditions and the exhaust volute outlet temperature correction values ​​after the gas turbine is cleaned after running for a period of time are recorded as T 8交付试验1.0工况修正值 、T 8运行一段时间进行燃气轮机通流清洗后1.0工况修正值 .

[0067] When T 8运行一段时间进行燃气轮机通流清洗后1.0工况修正值 -T 8交付试验1.0工况修正值 ≥ΔT 8时 , the power turbine should be replaced after the repair. Figure 1 , when the working condition is 1.0, the corresponding exhaust volute outlet temperature correction values ​​are 0.9719 before the test and 0.9803 after the test, that is:

[0068] ΔT 8 =0.9803-0.9719=0.0084,

[0069] T 8运行一段时间进行燃气轮机通流清洗后1.0工况修正值 -T 8交付试验1.0工况修正值 When ≥0.0084, it is necessary to return to the factory for inspection and replacement of the power turbine.

[0070] 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 form of modification may be made within the scope of protection of the present invention.

Claims

1. A method for determining the timing of replacing a power turbine of a marine gas turbine based on the exhaust volute outlet temperature, characterized in that: The steps include: Step 1: Before and after the gas turbine full life test, multiple operating conditions are performed to obtain operating parameters. Step 2: The actual power obtained under each working condition before and after the full life test is recorded as W 试验前 , W 试验完成后 , correct the actual power and get the power correction value before and after the test, recorded as W 试验前修正值 , W 试验完成后修正值 , The exhaust volute outlet temperature of each working condition before and after the full life test is recorded as T 8试验前 , T 8试验完成后 , for T 8试验前 , T 8试验完成后 Corrected according to atmospheric conditions, the corrected values ​​of the exhaust volute outlet temperature before and after the test are obtained, denoted as T 8试验前修正值 , T 8试验完成后修正值 ; According to the relationship between the power correction value and the exhaust volute outlet temperature correction value, the power correction value of the rated working condition is obtained, which is recorded as W 1.0工况修正值 ; The exhaust volute outlet temperature correction values ​​under rated conditions are obtained and are denoted as T 8试验前1.0工况修正值 , T 8试验完成后1.0工况修正值 , Step 3: Use the numerical difference between the exhaust volute outlet temperature correction values ​​before and after the full life assessment test in step 2 as the exhaust volute outlet temperature reference when replacing the power turbine.

2. The method for determining the timing of replacing the power turbine of a marine gas turbine according to the exhaust volute outlet temperature as claimed in claim 1, characterized in that: In step one, the gas turbine undergoes a full life spectrum assessment test, and after the test is completed, it is required to be flow-cleaned before operation.

3. The method for determining the timing of replacing the power turbine of a marine gas turbine according to the exhaust volute outlet temperature as claimed in claim 1, characterized in that: In step 2, the power correction values ​​before and after the test satisfy the following formula: Where W 实测值 is the measured power, in kw, P 实测值 is the measured atmospheric pressure, in units of pa, T 实测值 is the measured atmospheric temperature, in K, P0 is standard atmospheric pressure, 101300pa, T0 is the standard atmospheric temperature, 300.15K, θ1 and θ2 are the propeller characteristic correction coefficient and the power turbine relative speed correction coefficient respectively.

4. The method for determining the timing of replacing the power turbine of a marine gas turbine according to the exhaust volute outlet temperature as claimed in claim 1, characterized in that: In step two, .

5. The method for determining the timing of replacing the power turbine of a marine gas turbine according to the exhaust volute outlet temperature as claimed in claim 1, characterized in that: The exhaust volute outlet temperature is corrected for atmospheric conditions using the following correction formula: Where, T 8实测值 To measure the exhaust volute outlet temperature, T 8修正值 It is the correction value of the exhaust volute outlet temperature.

6. The method for determining the timing of replacing the power turbine of a marine gas turbine according to the exhaust volute outlet temperature as claimed in claim 1, characterized in that: The numerical difference between the exhaust volute outlet temperature correction values ​​before and after the full life test in step 2 is recorded as ΔT8, ΔT8 = T 8试验完成后1.0工况修正值 -T 8试验前1.0工况 Correction value.

7. A method for determining the timing of replacing a power turbine according to the exhaust volute outlet temperature of a marine gas turbine according to claim 1, applied to a process of actual ship maintenance, characterized in that: The steps include: During the factory delivery test, a gas turbine of this type was operated at actual power at each gear above 50% of the rated power, with 10% of the rated power as one gear. After the gas turbine has been running for a period of time t, the gas turbine is cleaned by flow through. After cleaning, the gas turbine is operated at a rated power level of 10% and above 50% of the rated power. The actual power obtained under various operating conditions during the delivery test and after a period of operation for gas turbine flow cleaning is corrected for atmospheric parameters and output shaft characteristics, and the actual power is recorded as: IN 交付试验 ,IN 运行一段时间进行燃气轮机通流清洗后 , The corrected power correction value is recorded as: IN 交付试验修正值 ,IN 运行一段时间进行燃气轮机通流清洗后修正值 , The exhaust volute outlet temperature of each operating condition at the time of delivery test and after the gas turbine is cleaned after running for a period of time is corrected for the atmospheric conditions. The exhaust volute outlet temperature is recorded as: T 8交付试验 、T 8运行一段时间进行燃气轮机通流清洗后 , The corrected temperature correction value is recorded as: T 8交付试验修正值 、T 8运行一段时间进行燃气轮机通流清洗后修正值 , According to the relationship between the exhaust volute outlet temperature correction value and the power correction value after the gas turbine is cleaned during the delivery test and after running for a period of time, the rated operating power correction value W is obtained. 1.0工况修正值 , corresponding to the delivery test, the exhaust volute outlet temperature correction value T after running for a period of time and performing gas turbine flow cleaning 8交付试验1.0工况修正值 , T 8运行一段时间进行燃气轮机通流清洗后1.0工况修正值 , When T 8运行一段时间进行燃气轮机通流清洗后1.0工况修正值 -T 8交付试验1.0工况修正值 ≥ΔT8 should be returned to the factory for inspection and replacement of the power turbine. ΔT8 can be obtained by looking up the relationship between the exhaust volute outlet temperature correction value and the power correction value before and after the full life test.

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