Method for determining replacement opportunity of combustion chamber and high and low pressure turbines of marine gas turbine according to gas temperature behind low pressure turbines

Abstract

The invention relates to a method for determining the replacement opportunity of a combustion chamber and a high-low pressure turbine of a marine gas turbine according to the rear gas temperature of the low-pressure turbine, and the method is based on a full-life examination test during the development period of the gas turbine, and the replacement opportunity of the combustion chamber and the high-low pressure turbine is determined before and after the test under the output rated power of the gas turbine. And the change of the low-pressure turbine rear gas temperature correction value is used as a method basis value of the opportunity of overhauling and replacing the combustion chamber and the high-low-pressure turbine. For a specific gas turbine of the type of gas turbine, when a delivery test is carried out, the gas temperature correction value of the low-pressure turbine after the gas turbine through-flow cleaning is changed after the gas turbine runs for a period of time, and when the change value is larger than or equal to the overhaul judgment basis value, overhaul needs to be carried out to replace a combustion chamber and the high-pressure turbine and the low-pressure turbine.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine maintenance and repair, and in particular to a method for determining the replacement timing of a combustion chamber and high- and low-pressure turbines of a marine gas turbine according to the temperature of the combustion gas after a low-pressure turbine. 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 long continuous use time and less load changes; for example, gas turbines used in power plants continuously output power at full load during operation and do not stop for several months, and the operation is stable. The use time and load of marine gas turbines vary according to different use conditions such as anchoring, docking, and sailing, and there are many variable operating conditions in the actual operation process. This variable operating condition operation is likely to affect the life of marine gas turbines.

[0004] There are no clear regulations on the evaluation of the life of marine gas turbines during use and the determination of the overhaul time. During the use of gas turbines, the overhaul time of gas turbines mainly depends on the life of the hot parts combustion chamber and high and low pressure turbines. If the gas turbine runs beyond its life and fails, it will cause great harm. How to determine the time to return to the factory for overhaul to replace the combustion chamber and high and low pressure turbines after a period of use is crucial. Summary of the invention

[0005] In view of the shortcomings in the above-mentioned existing production technology, the applicant provides a method for a marine gas turbine with a reasonable structure, which determines the timing of replacing the combustion chamber and the high and low pressure turbines based on the temperature of the gas after the low pressure turbine, and determines whether the combustion chamber and the high and low pressure turbines need to be replaced according to the change of the temperature of the gas after the low pressure turbine during the continuous operation of the gas turbine.

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

[0007] A method for determining the timing of replacing a combustion chamber and high-pressure and low-pressure turbines of a marine gas turbine according to the temperature of the gas after the low-pressure turbine, comprising the following steps:

[0008] Step 1: Before and after the gas turbine full life test, operate it according to multiple expected operating conditions.

[0009] Step 2: Based on the relationship between the low-pressure turbine after-gas temperature correction value and the power correction value obtained during the operation of the gas turbine before and after the full-life test, the rated operating condition correction value is obtained, which is recorded as W1.0工况修正值 ; Get the low-pressure turbine after-gas temperature correction value corresponding to the rated operating condition correction value before and after the full life test of the gas turbine, denoted as T 4试验前1.0工况修正值 、T 4试验完成后1.0工况修正值 ,

[0010] Step 3: The difference between the corrected values ​​of the low-pressure turbine after-gas temperature before and after the full-life test of the gas turbine is used as the reference for the low-pressure turbine after-gas temperature when replacing the combustion chamber and high- and low-pressure turbines, and is recorded as ΔT 4 .

[0011] In step 1, before and after the full life test of the gas turbine, the gas turbine is operated at actual power at each operating level of 10% of the rated power and above 50% of the rated power.

[0012] In step 2, the specific process of obtaining the rated operating condition correction value is as follows:

[0013] The actual power obtained under each operating condition before and after the full life test of the gas turbine is corrected for atmospheric parameters and output shaft characteristics to obtain a correction value, which is recorded as: W 试验前修正值 , W 试验完成后修正值 ,

[0014] The correction formula is:

[0015]

[0016] Where W 实测值 , P 实测值 、T 实测值 They are respectively the measured power value (kW), the measured atmospheric pressure (Pa), and the measured atmospheric temperature (K); p 0 is standard atmospheric pressure (101300pa), T 0 is the standard atmospheric temperature (300.15K); θ 1 ,θ 2 They are propeller characteristic correction factor and power turbine relative speed correction factor respectively.

[0017] In step 2, the specific process of obtaining the low-pressure turbine after-gas temperature correction value before and after the gas turbine full life test is as follows:

[0018] The low-pressure turbine after-gas temperature obtained under each operating condition before and after the full-life test of the gas turbine is corrected for atmospheric conditions, total intake pressure loss and exhaust static pressure loss to obtain the gas temperature correction value before and after the full-life test of the gas turbine. The correction formula is:

[0019]

[0020] Where: T4实测值 、T 4修正值 The measured low-pressure turbine exhaust gas temperature, corrected to the specified reference atmospheric conditions and intake and exhaust resistance loss, low-pressure turbine exhaust gas temperature, K; σ 1 , σ 2 They are intake resistance loss and exhaust resistance loss deviation correction coefficients respectively.

[0021] In step 3, the numerical difference ΔT used as the maintenance benchmark 4 =T 4试验完成后1.0工况修正值 -T 4试验前1.0工况修正值 .

[0022] A method for determining the timing of replacing a combustion chamber and high-pressure and low-pressure turbines based on the temperature of the gas after the low-pressure turbine using a marine gas turbine, and a process of applying the method to a real ship, comprises the following steps:

[0023] During the factory delivery test, a gas turbine was operated at a power level of 10% of the rated power and at all levels above 50% of the rated power.

[0024] After the gas turbine has been running for a period of time t, the gas turbine is cleaned by flow through, and after cleaning, the gas turbine is operated at actual power at each gear of 10% of the rated power as one gear and at each gear of 50% of the rated power or more;

[0025] The actual power obtained under various operating conditions at the time of delivery test and after the gas turbine has been cleaned for a period of operation is corrected for atmospheric parameters and output shaft characteristics to obtain the power correction values ​​at the time of delivery test and after the gas turbine has been cleaned for a period of operation, which 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 Post-correction value;

[0026] The low-pressure turbine after-gas 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 atmospheric conditions, total intake pressure loss and exhaust static pressure loss, and the correction values ​​of the low-pressure turbine after-gas temperature at the time of delivery test and after the gas turbine is cleaned after running for a period of time are obtained, which are recorded as: T 4交付试验修正值 、T 4运行一段时间进行燃气轮机通流清洗后修正值 ;

[0027] According to the relationship between the low-pressure turbine after-gas temperature correction value and the power correction value during the delivery test and after the gas turbine is cleaned for a period of operation, the rated operating power correction value and the corresponding low-pressure turbine after-gas temperature correction value during the delivery test and after the gas turbine is cleaned for a period of operation are obtained, which are respectively denoted as W 1.0工况修正值 、T 4交付试验1.0工况修正值 、T 4运行一段时间进行燃气轮机通流清洗后1.0工况修正值 ;

[0028] When T 4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 4交付试验1.0工况修正值≥ΔT 4 When the engine is damaged, it should be returned to the factory for inspection and replacement of the combustion chamber and high and low pressure turbines.

[0029] The beneficial effects of the present invention are as follows:

[0030] The purpose of the present invention is to provide a method for determining the overhaul timing of equipment with unstable operation, such as ships. This article is particularly aimed at combustion chambers, high-pressure and low-pressure turbines, and is a highly targeted solution based on practical operations.

[0031] The present invention is based on a full life assessment test conducted during the development of the gas turbine. Before the test, after the full life spectrum assessment test is completed and after the gas turbine flow cleaning is performed, the temperature change of the low-pressure turbine rear gas temperature caused by continuous operation at the gas turbine output rated power, that is, the corrected value, is used as the basis for the timing of overhauling and replacing the combustion chamber and the high-pressure turbine.

[0032] The method provided by the present invention has relatively few steps and is less difficult to obtain corresponding numerical values. The timing of the overhaul can be known after simple calculation and comparison.

[0033] After the gas turbine completes the full life assessment test, the combustion chamber and turbine and other hot parts have reached the end of their life. The present invention uses water cleaning to restore the performance degradation caused by flow dirt. At the same rated power output, the temperature correction value of the low-pressure turbine after the full life test will increase compared to before the test. The increase value is used as the basis for the timing of replacing the combustion chamber and high and low pressure turbines. When the operating thermal parameters of a certain gas turbine of this type exceed the above-mentioned overhaul judgment basis value, the combustion chamber and high and low pressure turbines should be repaired and replaced. The method has clear logic and is of great significance for gas turbine repair judgment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flowchart of the present invention.

[0035] Figure 2 This is a relationship diagram between the low-pressure turbine rear gas temperature correction value and the power correction value before and after the full life test in the present invention. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0037] A method for determining the replacement timing of the combustion chamber and high-pressure and low-pressure turbines of a marine gas turbine according to the temperature of the gas after the low-pressure turbine, the specific scheme is as follows:

[0038] Step 1: Perform a full life spectrum assessment test on the gas turbine. Before and after the test, the gas turbine is operated at actual power at 10% of the rated power as one gear and at all gears above 50% of the rated power.

[0039] The test mentioned above refers to the completion of the full life spectrum assessment test; the operation of the gas turbine after the test is also required to be carried out after the gas turbine flow cleaning.

[0040] Step 2:

[0041] For the full life spectrum assessment test in step 1, all operating parameters before and after the test are processed according to the following correction steps.

[0042] 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 ; Correct the atmospheric parameters and output shaft characteristics to obtain the power correction values ​​before and after the test, which are recorded as W 试验前修正值 , W 试验完成后修正值 , the correction formula is as follows:

[0043]

[0044] Where: W 实测值 , P 实测值 、T 实测值 are respectively the measured power value (kW), the measured atmospheric pressure (Pa), and the measured atmospheric temperature (K); P 0 is standard atmospheric pressure (101300pa), T 0 is the standard atmospheric temperature (300.15K); θ 1 ,θ 2 They are propeller characteristic correction factor and power turbine relative speed correction factor respectively.

[0045] 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).

[0046] The low-pressure turbine exhaust gas temperature of each operating condition before and after the test is recorded as T 4试验前 、T 4试验完成后 ; Correct the atmospheric conditions, total intake pressure loss and exhaust static pressure loss to obtain the corrected value of the low-pressure turbine exhaust gas temperature before and after the test, recorded as T 4试验前修正值 、T 4试验完成后修正值 , the correction formula is as follows:

[0047]

[0048] Where: T 4实测值 、T 4修正值 They are respectively the measured low-pressure turbine after-gas temperature, the low-pressure turbine after-gas temperature corrected to the specified reference atmospheric conditions and the intake and exhaust resistance loss, K; σ 1 , σ 2Intake resistance loss and exhaust resistance loss deviation correction coefficients respectively.

[0049] According to the relationship between the low-pressure turbine after-gas temperature correction value and the power correction value before and after the test, the power correction value of the 1.0 operating condition (rated operating condition) is obtained, which is recorded as W 1.0工况修正值 The corresponding low-pressure turbine after-gas temperature correction values ​​before and after the test are denoted as T 4试验前1.0工况修正值 、T 4试验完成后1.0工 Condition correction value.

[0050] The relationship between the low-pressure turbine after-gas temperature correction value and the power correction value before and after the test is shown in Figure 2 .

[0051] Step 3: In step 2,

[0052] The numerical difference between the high-pressure compressor speed correction value before and after the test is used as the high-pressure compressor speed reference for overhaul. The high-pressure compressor speed correction value before and after the test is recorded as: T 4试验前1.0工况修正值 、T 4试验完成后1.0工况修正值 , the numerical difference satisfies the following formula:

[0053] ΔT 4 =T 4试验完成后1.0工况修正值 -T 4试验前1.0工况修正值

[0054] ΔT 4 It is the benchmark for the gas temperature after the low-pressure turbine when replacing the combustion chamber and high- and low-pressure turbines.

[0055] The above theoretical method is applied to practical operation and is illustrated by taking a gas turbine as an example.

[0056] For a certain gas turbine of this type, during the factory delivery test, the gas turbine was operated at actual power in each gear with 10% of the rated power as the first gear and 50% of the rated power as the second gear.

[0057] After the gas turbine has been running for a period of time t, the gas turbine is flow-cleaned. After cleaning, the gas turbine is operated at actual power at a level of 10% of the rated power and at various levels above 50% of the rated power.

[0058] The actual power obtained under various operating conditions during the delivery test and after a period of operation for gas turbine flow cleaning 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 ; Correct the atmospheric parameters and output shaft characteristics to obtain the power correction values ​​at the time of delivery test and after the gas turbine is cleaned after running for a period of time, which 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 .

[0059] The low-pressure turbine after-gas temperature of each operating condition at the time of delivery test and after running for a period of time for gas turbine flow cleaning is recorded as T 4交付试验 、T 4运行一段时间进行燃气轮机通流清洗后 ; Correct the atmospheric conditions, total intake pressure loss and exhaust static pressure loss, and obtain the low-pressure turbine after-gas temperature correction values ​​at the time of delivery test and after running for a period of time for gas turbine flow cleaning, which are recorded as: T 4交付试验修正值 、T 4运行一段时间进行燃气轮机通流清洗 After correction value.

[0060] According to the relationship between the temperature correction value of the low-pressure turbine after-gas after-flow cleaning during the delivery test and after a period of operation, the power correction value of the 1.0 condition (rated condition) is obtained, which is recorded as W 1.0工况修正值 , and the corresponding correction values ​​of the low-pressure turbine after-gas temperature at the delivery test and after a period of operation for gas turbine flow cleaning are denoted as T 4交付试验1.0工况修正值 、T 4运行一段时间进行燃气轮机通流清洗后1.0工况修正值 .

[0061] In ΔT 4 =T 4试验完成后1.0工况修正值 -T 4试验前1.0工况修正值 Under the premise, when T 4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 4交付试验1.0工况修正值 ≥ΔT 4 When the engine is damaged, it should be returned to the factory for inspection and replacement of the combustion chamber and high and low pressure turbines.

[0062] according to Figure 2 ,1.0 working condition, the corresponding low-pressure turbine exhaust gas temperature before and after the test is 0.9511 and 0.9651 respectively, that is, ΔT 4 =0.9651-0.9511=0.014. 4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 4交付试验1.0工况修正值 When ≥0.014, the system should be returned to the factory for inspection and replacement of the combustion chamber and high and low pressure turbines.

[0063] The present application discloses a method for determining the timing of replacing the combustion chamber and high- and low-pressure turbines of a marine gas turbine based on the temperature of the gas after the low-pressure turbine. 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 after the gas turbine flow cleaning), the change in the correction value of the low-pressure turbine rear gas temperature under the gas turbine output rated power correction value is used as the method basis value for the timing of overhauling and replacing the combustion chamber and the high- and low-pressure turbines.

[0064] For a specific gas turbine of this type, the change in the correction value of the gas temperature after the low-pressure turbine is determined during delivery testing and after the gas turbine flow is cleaned 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 to replace the combustion chamber and the high and low-pressure turbines.

[0065] 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 replacement timing of the combustion chamber and high-pressure and low-pressure turbines of a marine gas turbine according to the temperature of the gas after the low-pressure turbine, characterized in that: The steps include: Step 1: Before and after the gas turbine full life test, operate it according to multiple expected operating conditions. Step 2: Based on the relationship between the low-pressure turbine after-gas temperature correction value and the power correction value obtained during the operation of the gas turbine before and after the full-life test, the rated operating condition correction value is obtained, which is recorded as W 1.0工况修正值 ; Get the low-pressure turbine after-gas temperature correction value corresponding to the rated operating condition correction value before and after the full life test of the gas turbine, denoted as T 4试验前1.0工况修正值 、T 4试验完成后1.0工况修正值 , Step 3: The numerical difference between the correction values ​​of the low-pressure turbine after-gas temperature before and after the gas turbine full life test is used as the basis for replacing the low-pressure turbine after-gas temperature of the combustion chamber and high and low-pressure turbines, and is recorded as ΔT4.

2. The method for determining the replacement timing of the combustion chamber and the high-pressure and low-pressure turbines of a marine gas turbine according to the temperature of the gas after the low-pressure turbine as claimed in claim 1, characterized in that: In step 1, before and after the full life test of the gas turbine, the gas turbine is operated at actual power at each operating level of 10% of the rated power and above 50% of the rated power.

3. The method for determining the replacement timing of the combustion chamber and the high and low pressure turbines of a marine gas turbine according to the temperature of the gas after the low pressure turbine as claimed in claim 1, characterized in that: In step 2, the specific process of obtaining the rated operating condition correction value is as follows: The actual power obtained under each operating condition before and after the full life test of the gas turbine is corrected for atmospheric parameters and output shaft characteristics to obtain a correction value, which is recorded as: W 试验前修正值 , W 试验完成后修正值 , The correction formula is: Where W 实测值 , P 实测值 、T 实测值 are the measured power value (kW), measured atmospheric pressure (Pa), and measured atmospheric temperature (K), respectively; p0 is the standard atmospheric pressure (101300 Pa), and T0 is the standard atmospheric temperature (300.15 K); θ1 and θ2 are the propeller characteristic correction coefficient and the power turbine relative speed correction coefficient, respectively.

4. The method for determining the replacement timing of the combustion chamber and the high and low pressure turbines of a marine gas turbine according to the temperature of the gas after the low pressure turbine as claimed in claim 1, characterized in that: In step 2, the specific process of obtaining the low-pressure turbine after-gas temperature correction value before and after the gas turbine full life test is as follows: The low-pressure turbine after-gas temperature obtained under each operating condition before and after the full-life test of the gas turbine is corrected for atmospheric conditions, total intake pressure loss and exhaust static pressure loss to obtain the gas temperature correction value before and after the full-life test of the gas turbine. The correction formula is: Where: T 4实测值 、T 4修正值 are the measured low-pressure turbine after-gas temperature, the low-pressure turbine after-gas temperature corrected to the specified reference atmospheric conditions and the intake and exhaust resistance loss, K; σ1 and σ2 are the intake resistance loss and exhaust resistance loss deviation correction coefficients, respectively.

5. The method for determining the replacement timing of the combustion chamber and the high-pressure and low-pressure turbines of a marine gas turbine according to the temperature of the gas after the low-pressure turbine as claimed in claim 1, characterized in that: In step 3, the numerical difference ΔT4=T4 as the maintenance benchmark 试验完成后1.0工况修正值 -T4 试验前1.0工况修正值 .

6. A process of using the method of determining the timing of replacing the combustion chamber and high-pressure and low-pressure turbines according to the temperature of the gas after the low-pressure turbine of a marine gas turbine according to claim 1, and carrying out actual ship application, characterized in that: The steps include: During the factory delivery test, a gas turbine was operated at a power level of 10% of the rated power and at all levels above 50% of the rated power. After the gas turbine has been running for a period of time t, the gas turbine is cleaned by flow through, and after cleaning, the gas turbine is operated at actual power at each gear of 10% of the rated power as one gear and at each gear of 50% of the rated power or more; The actual power obtained under various operating conditions at the time of delivery test and after the gas turbine has been cleaned for a period of operation is corrected for atmospheric parameters and output shaft characteristics to obtain the power correction values ​​at the time of delivery test and after the gas turbine has been cleaned for a period of operation, which 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 The low-pressure turbine after-gas 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 atmospheric conditions, total intake pressure loss and exhaust static pressure loss, and the correction values ​​of the low-pressure turbine after-gas temperature at the time of delivery test and after the gas turbine is cleaned after running for a period of time are obtained, which are recorded as: T 4交付试验修正值 、T 4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 low-pressure turbine after-gas temperature correction value and the power correction value during the delivery test and after the gas turbine is cleaned for a period of operation, the rated operating power correction value and the corresponding low-pressure turbine after-gas temperature correction value during the delivery test and after the gas turbine is cleaned for a period of operation are obtained, which are respectively denoted as W 1.0工况修正值 、T 4交付试验1.0工况修正值 、T 4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 4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 4交付试验1.0工况修正值 When ≥ΔT4, the vehicle should be returned to the factory for inspection and replacement of the combustion chamber and high- and low-pressure turbines.

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