초록 ▼

A method and apparatus for monitoring the condition of a thermal barrier coating on the vanes and blades of a combustion turbine relies on a piezoelectric or electrostrictive effect, or tribo-charging generated within the coating. Gas flowing through the turbine will apply pressure to the vanes and

A method and apparatus for monitoring the condition of a thermal barrier coating on the vanes and blades of a combustion turbine relies on a piezoelectric or electrostrictive effect, or tribo-charging generated within the coating. Gas flowing through the turbine will apply pressure to the vanes and blades, resulting in a strain on the blades and vanes, and causing friction as it passes the vanes and blades. An electric current is generated between the coating and vane or blade, either by a pressure-induced piezoelectric effect, a strain-induced electrostrictive effect, or friction-induced tribo-charging. This current causes a radio frequency signal, which can be detected by a high temperature antenna as the blade passes the antenna. One blade may be intentionally designed to produce a signal different from the remaining blades, thereby becoming a marking blade. After amplification and filtering, the radio signals may be analyzed and stored. Changes in the signals produced may indicate a deterioration of the coating. Counting the number of signals from the marking blade can determine the specific blade or vane requiring service.

대표청구항 ▼

A method and apparatus for monitoring the condition of a thermal barrier coating on the vanes and blades of a combustion turbine relies on a piezoelectric or electrostrictive effect, or tribo-charging generated within the coating. Gas flowing through the turbine will apply pressure to the vanes and

A method and apparatus for monitoring the condition of a thermal barrier coating on the vanes and blades of a combustion turbine relies on a piezoelectric or electrostrictive effect, or tribo-charging generated within the coating. Gas flowing through the turbine will apply pressure to the vanes and blades, resulting in a strain on the blades and vanes, and causing friction as it passes the vanes and blades. An electric current is generated between the coating and vane or blade, either by a pressure-induced piezoelectric effect, a strain-induced electrostrictive effect, or friction-induced tribo-charging. This current causes a radio frequency signal, which can be detected by a high temperature antenna as the blade passes the antenna. One blade may be intentionally designed to produce a signal different from the remaining blades, thereby becoming a marking blade. After amplification and filtering, the radio signals may be analyzed and stored. Changes in the signals produced may indicate a deterioration of the coating. Counting the number of signals from the marking blade can determine the specific blade or vane requiring service. riation exceeds a target threshold; wherein the value of the charging current is varied cyclically from an initial value, wherein the corresponding temperature variation is compared with the target threshold, and wherein the amplitude of the temperature variation is determined by comparison between the measured temperature of the battery and the ambient temperature (C0). 3. The process according to claim 2, wherein recharging is temporarily interrupted so as to measure the ambient temperature (C0). 4. The process according to claim 3, wherein the ambient temperature (C0) is measured when the measured temperature variation tends to deviate from the target threshold. 5. The process according to claim 3, wherein the ambient temperature (C0) is measured by temporarily forcing the target value to zero. 6. The process according to claim 2, wherein the amplitude of the temperature variation is determined by calculating the sum of the ambient temperature and of the value of the target threshold and subtracting the measured temperature. 7. The process according to claim 6, wherein the result of the calculation is integrated over a specific duration. 8. A process for controlling the recharging of a battery from a current generator, the process comprising: applying a charging current to the battery; monitoring the temperature of the battery so as to search for and measure a temperature variation; and reducing the value of the charging current if the temperature variation exceeds a target threshold; wherein the value of the charging current is varied cyclically from an initial value, wherein the corresponding temperature variation is compared with the target threshold, and wherein the value of the mean current is adjusted by letting the current flow for a variable percentage of the time. 9. A process for controlling the recharging of a battery from a current generator, the process comprising: applying a charging current to the battery; monitoring the temperature of the battery so as to search for and measure a temperature variation; and reducing the value of the charging current if the temperature variation exceeds a target threshold; wherein the value of the charging current is varied cyclically from an initial value, wherein the corresponding temperature variation is compared with the target threshold, and wherein to fix a maximum allowable value of the recharging current: a resistor, of value specific to the battery, is mounted in series with a current supply circuit to form a divider bridge which is supplied from the battery, the voltage of the midpoint of the divider bridge is measured and the maximum current is deduced from this, by consulting a pre-established table. 10. The process according to claim 9, wherein to determine the temperature of the battery, a resistive element of temperature-sensitive value is interposed in series, in the middle of the divider bridge, and it is coupled thermally with the battery, the identification resistor is short-circuited through a link of reference potential, the voltage is measured of a terminal of the resistive element, which terminal is opposite another terminal at the reference potential, and the temperature of the resistive element and hence of the battery is deduced from this, by consulting a pre-established table. 11. The process according to claim 8, wherein the value of the temperature variation is determined by comparison between a heating slope and a cooling slope. 12. The process according to claim 8, wherein the amplitude of the temperature variation is determined by comparison between the measured temperature of the battery and the ambient temperature (C0). 13. The process according to claim 1, wherein the amplitude of the temperature variation is determined by comparison between the measured temperature of the battery and the ambient temperature (C0). 14. The process according to claim 4, wherein the ambient temperature (C0) is measured by tem porarily forcing the target value to zero. 15. The process according to claim 3, wherein the amplitude of the temperature variation is determined by calculating the sum of the ambient temperature and of the value of the target threshold and subtracting the measured temperature. 16. The process according to claim 4, wherein the amplitude of the temperature variation is determined by calculating the sum of the ambient temperature and of the value of the target threshold and subtracting the measured temperature. 17. The process according to claim 5, wherein the amplitude of the temperature variation is determined by calculating the sum of the ambient temperature and of the value of the target threshold and subtracting the measured temperature. 18. The process according to claim 1, wherein the value of the mean current is adjusted by letting the current flow for a variable percentage of the time. 19. The process according to claim 1, wherein to fix a maximum allowable value of the recharging current: a resistor, of value specific to the battery, is mounted in series with a current supply circuit to form a divider bridge which is supplied from the battery, the voltage of the midpoint of the divider bridge is measured and the maximum current is deduced from this by consulting a pre-established table. 20. A device for controlling recharging of a battery configured so as to be supplied by a current charger, the device comprising: means for measuring the temperature of the battery; means for providing a target threshold value of temperature variation of the battery; means of variation for varying the recharging current; sequencer means for cyclically controlling the means of variation; and means of calculation, linked at input to the threshold-providing means and to the temperature-measuring means so as to determine therefrom a temperature variation value and to control means of adjusting the current in accordance with the deviation between the temperature variation and the threshold value. 21. The device according to claim 20, wherein the means of adjustment include a series element for controlling cyclic flow of current pulses of adjustable duration. 22. The device according to claim 20, wherein the calculating means include a summator circuit configured so as to receive the measured temperature value, to add thereto the threshold value and to deduct therefrom an ambient temperature value and to control accordingly an integrator circuit for calculating the temperature variation. 23. The device according to claim 22, wherein the integrator circuit controls a circuit for determining the mean charging current, controlling the means of adjustment. 24. The device according to claim 22, wherein the integrator circuit controls a circuit for calculating the ambient temperature. 25. The device according to claims 22, wherein the calculating means include comparator means for comparing, with a threshold, the deviation between the measured temperature modulation and the target value and for controlling an ambient temperature measurement cycle if the deviation exceeds the threshold. 26. The device according to claim 21, wherein the calculating means include a summator circuit configured so as to receive the measured temperature value, to add thereto the threshold value and to deduct therefrom an ambient temperature value and to control accordingly an integrator circuit for calculating the temperature variation. 27. The device according to claim 23, wherein the integrator circuit controls a circuit for calculating the ambient temperature. 28. Device according to claims 21, wherein the calculating means include comparator means for comparing, with a threshold, the deviation between the measured temperature modulation and the target value and for controlling an ambient temperature measurement cycle if the deviation exceeds the threshold. 29. A device for controlling recharging of a battery configured so as to be supplied by a current