RU2513054C1 - Gas turbine engine health variation estimation and fault-finding in operation - Google Patents

Abstract

FIELD: engines and pumps.SUBSTANCE: proposed procedure uses extra parameter, that is, complete gas temperature downstream of low-pressure turbinemeasured at, at least, eight points equally spaced apart in datum cross-section. Mean temperature is defined to preset its maximum permissible deviation from initial magnitude in operation. Defined are thermocouples with engine maximum and minimum temperatures by measured current temperatures in operation. Engine health is estimated by maximum permissible deviation from mean temperature and by maximum permissible difference between maximum and minimum temperatures. Location of thermocouples with maximum and minimum temperatures allows defining of faulty assembly and fault cause. Engine health is estimated at temperature differenceat the points of maximum and minimum temperature not exceeding 110°C temperature deviation at all points not exceeding 10°.EFFECT: higher precision and reliability, better operation efficiency.2 cl, 1 dwg, 3 tbl

Description

The invention relates to the field of testing and operation of gas turbine engines, in particular double-circuit ones, namely, to monitoring the technical condition during their testing and operation to make a decision on their maintenance and further operation.

Of the known methods, the closest to the proposed one is a method for assessing changes in the technical condition of a gas turbine engine and determining places and causes of malfunctions during operation, including measuring parameters characterizing the environment and operating conditions of the engine, fixing the initial values of the parameters at the beginning of operation, measuring current values of parameters during operating time and assessment of the technical condition, establishing the reasons for its changes in the maximum permissible deviation when comparing and Merenii current engine parameters and baseline / RU №2168163 ^IPC7 G01M 15/00. Published: May 27, 2001 /.

The disadvantage of this method is that due to the use of averaged parameters characterizing the environment and operating conditions of the engine, it provides only a generalized estimate of the changes occurring in the engine components during operation, and does not accurately identify the specific cause or assembly that caused the deterioration of the technical condition of the engine , which leads to untimely delayed or, conversely, premature engine shutdown.

The objective of the invention is most accurately in the process of operation to determine the need for maintenance of the engine and determine the causes that led to the deterioration of the engine parameters and the need to stop operation.

The expected technical result is the determination of the places of clogging, wear, damage to the flow path of the gas-air duct, in order to maintain the required operating condition and operational characteristics and increase the operational efficiency of the gas turbine engine.

, измеренную не менее чем в 8 точках, равномерно распределенных по окружности в характерном сечении, определяют среднюю температуру и предварительно устанавливают предельно допустимое отклонение средней температуры от ее исходных значений в процессе эксплуатации, определяют точки с максимальной и минимальной температурой для исходных значений и измеренных текущих температур двигателя в процессе эксплуатации, а оценку изменений технического состояния, установление мест расположения неисправных узлов и причин неисправностей в процессе эксплуатации осуществляют по предельно допустимым отклонениям от средней температуры, месту расположения точек с максимальной и минимальной температурой и допустимой разнице между максимальной и минимальной температурой при сравнении измеренных текущих температур и их исходных значений.The technical result is achieved by the fact that in the known method for assessing changes in the technical condition of a gas turbine engine and determining the causes of malfunctions during operation, including measuring parameters characterizing the environment and operating conditions of the engine, fixing the initial values of the parameters at the beginning of operation, measuring the current values of the parameters during operation, assessment of the technical condition and determination of the reasons for the changes in the maximum permissible deviation when comparing the measured current pa ametrov engine and starting values of the proposal, as an additional parameter for evaluation of the technical condition of the engine changes selected full gas temperature for low pressure turbine $$-T_{\mathrm{four}}^{*}$$

measured at least 8 points uniformly distributed around a circle in a characteristic section, determine the average temperature and pre-set the maximum permissible deviation of the average temperature from its initial values during operation, determine the points with maximum and minimum temperatures for the initial values and measured current temperatures engine during operation, and the assessment of changes in the technical condition, the location of faulty components and the causes of malfunctions in the process All operations are carried out according to the maximum permissible deviations from the average temperature, the location of the points with the maximum and minimum temperatures and the permissible difference between the maximum and minimum temperatures when comparing the measured current temperatures and their initial values.

в точках с максимальной и минимальной температурой не более 110°C и отклонениях температуры во всех точках от среднего значения не более 10°C.Assessment of the technical condition is carried out at a temperature difference $$-T_{\mathrm{four}}^{*}$$

at points with a maximum and minimum temperature of not more than 110 ° C and temperature deviations at all points from the average value of not more than 10 ° C.

The proposed method for determining the places of clogging and wear of the material part of the engine (for example, burnout blades of nozzle apparatuses) is based on determining the change in the temperature field behind the turbine. To determine the temperature field, they are installed behind the turbine along the perimeter of the thermocouple in the amount necessary to determine the most complete picture of the temperature field. They use the condition that the total area of installed thermocouples should not exceed more than three percent of the area of the flow part of the power plant.

, разность между минимальным и максимальным показанием термопар $$\Delta T_4^{*}{}_{\max -\min }$$

и для определения конкретного места засорения используют показания каждой термопары $$T_4^{*}{}_i$$

. Перед применением метода необходимо задаться предельными отклонениями $$\Delta T_4^{*}{}_{ср}$$

, достигаемыми в процессе эксплуатации.When using the method, indicators such as the average value of thermocouple readings are used $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R}$$

, the difference between the minimum and maximum thermocouple reading $$\Delta T_{\mathrm{four}}^{*}{}_{\max -\min }$$

and to determine the specific clogging site, the readings of each thermocouple are used $$T_{\mathrm{four}}^{*}{}_i$$

. Before applying the method, it is necessary to set the maximum deviations $$\Delta T_{\mathrm{four}}^{*}{}_{\mathrm{from}R}$$

achieved during operation.

. The maximum deviations are determined by the calculation and statistical method, that is, during operation, thermocouple readings are recorded and engine components are inspected, and if damage to the engine material is detected as a result of inspection, thermocouple readings are analyzed, as a result of which a set of statistics sets the maximum deviation for diagnostic signs $$(\Delta T_{\mathrm{four}}^{*}{}_{\max -\min },T_{\mathrm{four}}^{*}{}_{\mathrm{from}R},T_{\mathrm{four}}^{*}{}_i,\Delta T_{\mathrm{four}}^{*}{}_{\mathrm{from}R})$$

.

The proposed method for assessing changes in the technical condition of a gas turbine engine and establishing the causes of changes during operation involves the following procedure.

баз для каждой термопары, для среднего значения $$T_4^{*}{}_{ср\text{ баз}}$$

, определяют минимальное и максимальное значение показаний термопар $$T_4^{*}{}_{\max },T_4^{*}{}_{\min }$$

и вычисляют $$\Delta T_4^{*}{}_{\max -\min }$$

. Определяют предельно допустимые значения отклонений для среднего значения $$T_4^{*}{}_{ср\text{ пред}}$$

по $$\Delta T_4^{*}{}_{\max \min }$$

и определяют место расположения термопар по разнице $$T_{4i}^{*}-T_{4\text{ ср доп}}^{*}$$

.When carrying out acceptance tests before delivering the engine to the customer, the gas temperature is measured with thermocouples at least eight points distributed uniformly around the circumference at a constant value of the reduced rotor speed n_1pr, and get the initial (base) values $$T_{\mathrm{four}}^{*}{}_{b\mathrm{but}s}$$

 bases for each thermocouple, for the average value $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R\text{bases}}$$

, determine the minimum and maximum values of thermocouple readings $$T_{\mathrm{four}}^{*}{}_{\max },T_{\mathrm{four}}^{*}{}_{\min }$$

 and calculate $$\Delta T_{\mathrm{four}}^{*}{}_{\max -\min }$$

. The maximum permissible deviation values for the mean value are determined $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R\text{before}}$$

by $$\Delta T_{\mathrm{four}}^{*}{}_{\max \min }$$

 and determine the location of the thermocouples by the difference $$T_{\mathrm{four}i}^{*}-T_{\mathrm{four}\text{Wed add}}^{*}$$

.

During operation, control the change in thermocouple readings.

баз указывает на то, что произошло засорение в данном секторе форсунки основной камеры сгорания и либо информирует о прогаре соплового блока.1. Exceeding the maximum permissible parameter values $$\Delta T_{\mathrm{four}}^{*}{}_{\max -\min }$$

bases indicates that there is a blockage in the nozzle sector of the main combustion chamber and either informs about burnout of the nozzle block.

баз свидетельствует об ухудшении характеристик компрессоров и турбин плюс засорении форсунок основной камеры сгорания.2. Exceeding the maximum permissible parameter values $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R}$$

bases indicates a deterioration in the performance of compressors and turbines plus clogged nozzles of the main combustion chamber.

3. Exceeding the maximum permissible values of the readings of each thermocouple T ₄ * bases allows you to determine the sector where the nozzle of the main combustion chamber is clogged or burnout of the nozzle block.

When the maximum permissible parameter values of at least one of the three go beyond the boundaries, they stop operation and conduct engine inspections. Based on the results of inspections, they decide to carry out repairs.

The drawing shows the layout of thermocouples.

Example. Before the engine is delivered to the customer, the gas temperature is measured behind the turbine at a constant reduced value of the rotor speed n _1pr = 95%, while the thermocouples are placed in accordance with the above layout of the thermocouples. Thermocouples measure the temperature in individual sectors of the engine and signal the state of the engine components in the sectors.

As a result of the measurements, the following temperatures were obtained:

T ^* ₄₁ = 702 ° C; T ^* ₄₂ = 709 ° C; T ^* ₄₃ = 705 ° C; T ^* ₄₄ = 710 ° C; T ^* ₄₅ = 710 ° C; T ^* ₄₆ = 700 ° C; T ^* ₄₇ = 690 ° C; T ^* ₄₈ = 730 ° C.

температуру по результатам измерений.Determined the average $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R}$$

temperature according to the measurement results.

. $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R}={\displaystyle \sum T_{\mathrm{four}i}^{*}}/8=709.5°C$$

.

=690°C на термопаре T^* ₄₇.According to the measurement results, the maximum temperature = 730 ° C was obtained, which was recorded on the thermocouples T ^* ₄₅ and T ^* ₄₈ , and the minimum temperature was obtained $$T_{\mathrm{four}}^{*}{}_{\min }$$

= 690 ° C on a thermocouple T ^* ₄₇ .

The difference between the maximum and minimum temperatures is determined:

$$\Delta T_{\mathrm{four}}^{*}{}_{\max -\min }=T_{\mathrm{four}}^{*}{}_{\max }-T_{\mathrm{four}}^{*}{}_{\min }=730-690=40°C.$$

=709,5°C, и $$\Delta T_4^{*}{}_{\max \min }$$

=40°C принимают за исходные (базовые). Последнее значение температуры также характеризует интервал отклонений от средней базовой температуры, в котором должны располагаться все значения замеров термопар или (±20)°C.Since these temperatures are installed on the new engine before delivery to the customer, the temperature values are determined by the design features and they are not affected by possible malfunction of the nodes. Value $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R}$$

= 709.5 ° C, and $$\Delta T_{\mathrm{four}}^{*}{}_{\max \min }$$

= 40 ° C is taken as the source (base). The last temperature value also characterizes the deviation interval from the average base temperature, in which all measurement values of thermocouples or (± 20) ° C should be located.

=719,5°C и предельно допустимое значение разности между максимальной и минимальной температурами $$\Delta T_4^{*}{}_{\max \min }$$

=110°C, до которой могут увеличиться их значение в процессе эксплуатации двигателя.For this engine configuration, the maximum permissible value of the average temperature was assigned $$T_{\mathrm{four}}^{*}{}_{\mathrm{from}R}$$

= 719.5 ° C and the maximum permissible difference between the maximum and minimum temperatures $$\Delta T_{\mathrm{four}}^{*}{}_{\max \min }$$

= 110 ° C, to which their value may increase during the operation of the engine.

After establishing the initial (base) temperature values, the gas temperature is measured behind the turbine during engine operation at the same speed value as at the beginning of operation.

Data on comparative tests are given in tables 1-3.

The analysis shows that during the first control measurement, the measured parameters do not exceed the maximum permissible temperature values indicated in table 1, the operation of the engine continues.

When analyzing the second control measurement (table 3), the maximum permissible difference between the maximum and minimum temperatures is exceeded, both an increase in the gas temperature in the thermocouple sector No. T ₄₅ and a decrease in temperature in the thermocouple installation sector No. T ₄₇ , while the maximum permissible average temperature remained within tolerance. Such a change in the maximum permissible value indicates that it is necessary to shut down the operation and perform an inspection in the installation sectors of the above thermocouples. Moreover, in the installation sector of thermocouple No. T ₄₅ , where there was an increase in gas temperature, which indicates a possible burnout of the turbine nozzle apparatus, a more thorough inspection is necessary. In the installation sector of thermocouple No. T _47, it is necessary to inspect the nozzles of the main combustion chamber for clogging, coking. Based on the results of inspections, the degree of damage or clogging of the material part is determined and a decision is made to continue operation or to repair the engine.

From consideration of the data obtained during the third control measurement (table 3), the maximum permissible average gas temperature is exceeded, while the maximum permissible difference between the maximum and minimum gas temperatures remains within the tolerance. Such a change in the maximum permissible values indicates a probable contamination of the engine flow passage. In this case, it is necessary to inspect the flow part and flush the gas-air path of the engine to restore the parameters with subsequent continued operation.

When analyzing the results of the fourth control measurement, a complex excess of the maximum permissible values established at the beginning of operation is noted, which indicates a contamination of the flow part, and possible destruction of nozzle devices in the installation sector of thermocouple No. T ₄₃ , and also about the clogging of the nozzles of the main combustion chamber in the sector Thermocouple installations No. T ₄₈ . It is urgent to stop operation and carry out an inspection of the engine duct.

An example is given as a special case. When using the method, it is necessary in a similar way to monitor the remaining diagnostic indicators specified in the invention. When at least one of the indicators exits, the engine is shut down with subsequent inspections in the deviation zones and decision-making based on the inspection results.

The use of the invention allows to increase the accuracy of determining the places of clogging, wear, damage to the flow part of the gas-air duct, to increase the reliability of maintaining the required operating condition and operational characteristics, to increase the operational efficiency of a gas turbine engine.

Claims (2)

1. A method for assessing changes in the technical condition of a gas turbine engine and determining the causes of malfunctions during operation, including measuring parameters characterizing the environment and operating conditions of the engine, fixing the initial values of the parameters at the beginning of operation, measuring current values of the parameters during operation, assessing the technical condition and determining the causes changes in the maximum permissible deviation when comparing the measured current engine parameters and the initial values, different t m, which is an additional parameter for evaluation of the technical condition of the engine changes selected full gas temperature for low pressure turbine $$-T_{\mathrm{four}}^{*}$$

measured with thermocouples at least 8 points uniformly set around a circle in a characteristic section, determine the average temperature and pre-set the maximum permissible deviation of the average temperature from its original value during operation, determine the thermocouples with the maximum and minimum temperature values, and measured and the current engine temperatures during operation, assess changes in the technical condition by the maximum allowable deviations from the average temperature and by according to the permissible deviations of the difference between the maximum and minimum temperature values, and the location of the thermocouples with maximum and minimum temperatures determines the location of the faulty unit and the cause of the malfunction. 2. A method for assessing changes in the technical condition of a gas turbine engine and determining the causes of malfunctions during operation according to claim 1, characterized in that the technical condition is evaluated at a temperature difference $$-T_{\mathrm{four}}^{*}$$

at points with a maximum and minimum temperature of not more than 110 ° C and temperature deviations at all points from the average value of not more than 10 ° C.

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