초록 ▼

This invention relates to a fossil-fired thermal system such as a power plant or steam generator, and, more particularly, to a method for rapid detection of tube failures and their location with the steam generator, without need for direct instumentation, thereby preventing more serious damage and m

This invention relates to a fossil-fired thermal system such as a power plant or steam generator, and, more particularly, to a method for rapid detection of tube failures and their location with the steam generator, without need for direct instumentation, thereby preventing more serious damage and minimizing repair time on the effected heat exchanger. This method is applicable to Input/Loss methods of monitoring fossil-fired thermal systems.

대표청구항 ▼

This invention relates to a fossil-fired thermal system such as a power plant or steam generator, and, more particularly, to a method for rapid detection of tube failures and their location with the steam generator, without need for direct instumentation, thereby preventing more serious damage and m

This invention relates to a fossil-fired thermal system such as a power plant or steam generator, and, more particularly, to a method for rapid detection of tube failures and their location with the steam generator, without need for direct instumentation, thereby preventing more serious damage and minimizing repair time on the effected heat exchanger. This method is applicable to Input/Loss methods of monitoring fossil-fired thermal systems. held at that point, and, if the temperature sensed by said first and second temperature sensor becomes higher than the second predetermined value, keeps the fixing control temperature lower than the temperature set at that point. 4. A fixing control apparatus for performing a fixing process by using a heat roller heated by an induction heating coil, comprising: a first temperature sensor positioned, around said heat roller, within a range of ±45° from a portion where maximum heat is generated by said induction heating coil; a second temperature sensor positioned, around said heat roller, within a range of ±45° from a portion where minimum heat is generated by said induction heating coil; and a central processing unit for performing switching control of a fixing control temperature concerning the temperature of said heat roller on the basis of temperatures sensed by said first and second temperature sensors, wherein at the start of printing, said central processing unit changes the fixing control temperature on the basis of the temperatures sensed by said first and second temperature sensors, said fixing control apparatus further comprises an environmental temperature sensor for sensing an environmental temperature, and on the basis of the environmental temperature sensed by said environmental temperature sensor, said central processing unit changes, in accordance with a sheet to be printed, the fixing control temperature and a threshold value for determining whether an environment is a normal environment or a low-temperature environment on the basis of the environmental temperature sensed by said environmental temperature sensor. 5. A fixing control apparatus for performing a fixing process by using a heat roller heated by an induction heating coil, comprising: a first temperature sensor positioned, around said heat roller, within a range of ±45° from a portion where maximum heat is generated by said induction heating coil; a second temperature sensor positioned, around said heat roller, within a range of ±45° from a portion where minimum heat is generated by said induction heating coil; and a central processing unit for performing switching control of a fixing control temperature concerning the temperature of said heat roller on the basis of temperatures sensed by said first and second temperature sensors, wherein during printing, said central processing unit changes the fixing control temperature for each sheet to be printed whenever a predetermined time elapses, on the basis of a result of comparison of the temperatures sensed by said first and second temperature sensors with a lower-limiting threshold value of a printing permissible range, said fixing control apparatus further comprises an environmental temperature sensor for sensing an environmental temperature, and on the basis of the environmental temperature sensed by said environmental temperature sensor, said central processing unit changes the lower-limiting threshold value. 6. An apparatus according to claim 5, wherein said central processing unit changes a delay time from the start of printing to the start of control of changing the fixing control temperature, on the basis of the temperatures sensed by said first and second temperature sensors. 7. An apparatus according to claim 5, wherein when a predetermined time has elapsed since the start of printing, said central processing unit changes the fixing control temperature in accordance with the temperature sensed by said first or second temperature sensor. 8. An apparatus according to claim 5, wherein when the fixing control temperature lowers to the lower-limiting threshold value and the temperature sensed by said first or second temperature sensor rises to a predetermined temperature, said central processing unit starts the operation of a cooling device for cooling said heat roller, and when the temperature sensed by said first or second temperature sensor lowers to a sec ond predetermined temperature lower than the first predetermined temperature, said central processing unit stops the operation of said cooling device. 9. An apparatus according to claim 8, wherein when at least one of the temperatures sensed by said first and second temperature sensors is lower than the lower-limiting threshold value or higher than an upper-limiting threshold value of a printing permissible range, said central processing unit interrupts the printing operation and starts a pre-run operation, when the temperatures sensed by said first and second temperature sensors fall within the range between the lower- and upper-limiting threshold values, said central processing unit resumes the printing operation, and said central processing unit changes the lower- and upper-limiting threshold values in accordance with the environmental temperature sensed by said environmental temperature sensor and with a sheet to be printed. 10. A fixing control method of performing a fixing process by using a heat roller heated by an induction heating coil, wherein switching control of a fixing control temperature concerning the temperature of the heat roller is performed on the basis of a temperature sensed by a first temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where maximum heat is generated by the induction heating coil, and a temperature sensed by a second temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where minimum heat is generated by the induction heating coil, and wherein when power supply to the induction heating coil is started, the fixing control temperature and the pre-run start temperature is lowered as the temperature sensed by the first or second temperature sensor rises. 11. A method according to claim 10, wherein in a normal environment in which an environmental temperature sensed by an environmental temperature sensor is higher than a threshold value, the fixing control temperature is lowered whenever a predetermined time elapses while the temperature sensed by the first or second temperature sensor is lower than a first predetermined value, and, if the temperature sensed by the first and second temperature sensor becomes higher than the first predetermined value, the fixing control temperature set at that point is maintained, and in a low-temperature environment in which the environmental temperature sensed by the environmental temperature sensor is lower than the threshold value, while the temperature sensed by the first or second temperature sensor is lower than a second predetermined value higher than the first predetermined value, the fixing control temperature is maintained at a temperature held at that point, and, if the temperature sensed by the first and second temperature sensor becomes higher than the second predetermined value, the fixing control temperature is kept lower than the temperature set at that point. 12. A fixing control method of performing a fixing process by using a heat roller heated by an induction heating coil, wherein switching control of a fixing control temperature concerning the temperature of the heat roller is performed on the basis of a temperature sensed by a first temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where maximum heat is generated by the induction heating coil, and a temperature sensed by a second temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where minimum heat is generated by the induction heating coil, wherein when power supply to the induction heating coil is started, at least one of the fixing control temperature, a pre-run start temperature at which pre-run is started, and a ready display temperature pertaining to temperature display in a ready state is changed on the basis of the temperatures sensed by the first and second temperature sensors, where in on the basis of an environmental temperature sensed using an environmental temperature sensor, at least one of the fixing control temperature, the pre-run start temperature, and the ready display temperature is changed, and wherein the fixing control temperature is lowered as the temperature sensed by the first or second temperature sensor rises. 13. A fixing control method of performing a fixing process by using a heat roller heated by an induction heating coil, wherein switching control of a fixing control temperature concerning the temperature of the heat roller is performed on the basis of a temperature sensed by a first temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where maximum heat is generated by the induction heating coil, and a temperature sensed by a second temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where minimum heat is generated by the induction heating coil, and wherein at the start of printing, the fixing control temperature is changed on the basis of the temperatures sensed by the first and second temperature sensors, and on the basis of an environmental temperature sensed by an environmental temperature sensor, the fixing control temperature and a threshold value for determining whether an environment is a normal environment or a low-temperature environment on the basis of the environmental temperature sensed by the environmental temperature sensor, are changed in accordance with a sheet to be printed. 14. A fixing control method of performing a fixing process by using a heat roller heated by an induction heating coil, wherein switching control of a fixing control temperature concerning the temperature of the heat roller is performed on the basis of a temperature sensed by a first temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where maximum heat is generated by the induction heating coil, and a temperature sensed by a second temperature sensor positioned, around the heat roller, within a range of ±45° from a portion where minimum heat is generated by the induction heating coil, and wherein during printing, the fixing control temperature is changed for each sheet to be printed whenever a predetermined time elapses, on the basis of a result of comparison of the temperatures sensed by the first and second temperature sensors with a lower-limiting threshold value of a printing permissible range, and on the basis of an environmental temperature sensed by an environmental temperature sensor, the lower-limiting threshold value is changed. 15. A method according to claim 14, wherein a delay time from the start of printing to the start of control of changing the fixing control temperature is changed on the basis of the temperatures sensed by the first and second temperature sensors. 16. A method according to claim 14, wherein when a predetermined time has elapsed since the start of printing, the fixing control temperature is changed in accordance with the temperature sensed by the first or second temperature sensor. 17. A method according to claim 14, wherein when the fixing control temperature lowers to the lower-limiting threshold value and the temperature sensed by the first or second temperature sensor rises to a predetermined temperature, the operation of a cooling device for cooling the heat roller is started, and when the temperature sensed by the first or second temperature sensor lowers to a second predetermined temperature lower than the first predetermined temperature, the operation of the cooling device is stopped. 18. (Original) A method according to claim 17, wherein when at least one of the temperatures sensed by the first and second temperature sensors is lower than the lower-limiting threshold value or higher than an upper-limiting threshold value of a printing permissible range, the printing operation is interrupted an d a pre-run operation is started, when the temperatures sensed by the first and second temperature sensors fall within the range between the lower- and upper-limiting threshold values, the printing operation is resumed, and the lower- and upper-limiting threshold values are changed in accordance with the environmental temperature sensed by the environmental temperature sensor and with a sheet to be printed. the step (db-1), said voltage signals acquired from said thermal sensing producer is amplified by a first amplifier circuit before outputting to said analog/digital converter, for amplifying said voltage signals and suppressing said noise residing in said voltage signals and improving said signal-to-noise ratio. 3. A processing method for motion measurement, as recited in claim 2, wherein in the step (db-4), said input analog signals from said digital/analog converter for driving said heater device is amplified in a second amplifier circuit before outputting to said heater device. 4. A processing method for motion measurement, comprising the steps of: (a) producing three-axis angular rate signals by an angular rate producer and three-axis acceleration signals by an acceleration producer; (b) converting said three-axis angular rate signals into digital angular increments and converting said input three-axis acceleration signals into digital velocity increments in an angular increment and velocity increment producer; (c) computing attitude and heading angle measurements using said three-axis digital angular increments and said three-axis velocity increments in an attitude and heading processor; and (d) maintaining a predetermined operating temperature throughout said above steps, wherein said predetermined operating temperature is a constant designated temperature selected between 150° F. and 185° F.; wherein the step (b) further comprises the steps of: (b.1) integrating said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals for a predetermined time interval to accumulate said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals as a raw three-axis angular increment and a raw three-axis velocity increment for said predetermined time interval to achieve accumulated angular increments and accumulated velocity increments, for removing noise signals that are non-directly proportional to said carrier angular rate and acceleration within said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals, improving signal-to-noise ratio, and removing said high frequency signals in said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals; (b.2) forming an angular reset voltage pulse and a velocity reset voltage pulse as an angular scale and a velocity scale respectively; (b.3) measuring said voltage values of said three-axis accumulated angular increments and said three-axis accumulated velocity increments with said angular reset voltage pulse and said velocity reset voltage pulse respectively to acquire angular increment counts and velocity increment counts as a digital form of angular and velocity measurements respectively; and (b.4) scaling said voltage values of said three-axis accumulated angular and velocity increments into real three-axis angular and velocity increment voltage values; wherein the step (d) further comprises the steps of: (db-1) producing temperature voltage signals by a thermal sensing producer to an analog/digital converter; (db-2) sampling said temperature voltage signals in said analog/digital converter and digitizing said sampled voltage signals, and said digital signals are output to an input/output interface circuit; (db-3) computing digital temperature commands in a temperature controller using said input digital temperature voltage signals from said input/output interface circuit, a temperature sensor scale factor, and said predetermined operating temperature of said angular rate producer and acceleration producer, wherein said digital temperature commands are fed back to said input/output interface circuit; and (db-4) converting said digital temperature commands input from said input/output interface circuit in said digital/analog converter into analog signals which are output to a heater devi ce to provide adequate heat for maintaining said predetermined operating temperature throughout said processing method. 5. A processing method for motion measurement, as recited in claim 4, wherein in the step (db-1), said voltage signals acquired from said thermal sensing producer is amplified by a first amplifier circuit before outputting to said analog/digital converter, for amplifying said voltage signals and suppressing said noise residing in said voltage signals and improving said signal-to-noise ratio. 6. A processing method for motion measurement, as recited in claim 5, wherein in the step (db-4), said input analog signals from said digital/analog converter for driving said heater device is amplified in a second amplifier circuit before outputting to said heater device. 7. A processing method for motion measurement, comprising the steps of: (a) producing three-axis angular rate signals by an angular rate producer and three-axis acceleration signals by an acceleration producer; (b) converting said three-axis angular rate signals into digital angular Increments and converting said input three-axis acceleration signals into digital velocity increments in an angular increment and velocity increment producer; (c) computing attitude and heading angle measurements using said three-axis digital angular increments and said three-axis velocity increments in an attitude and heading processor; and (d) maintaining a predetermined operating temperature throughout said above steps, wherein said predetermined operating temperature is a constant designated temperature selected between 150° F. and 185° F.; wherein said angular rate producer and said acceleration producer are MEMS angular rate device array and acceleration device array and said outputting signals of said angular rate producer and said acceleration producer are analog voltage signals; wherein the step (b) further comprises the steps of: (b.1) integrating said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals for a predetermined time interval to accumulate said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals as a raw three-axis angular increment and a raw three-axis velocity increment for said predetermined time interval to achieve accumulated angular increments and accumulated velocity increments, for removing noise signals that are non-directly proportional to said carrier angular rate and acceleration within said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals, improving signal-to-noise ratio, and removing said high frequency signals in said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals; (b.2) forming an angular reset voltage pulse and a velocity reset voltage pulse as an angular scale and a velocity scale respectively; (b.3) measuring said voltage values of said three-axis accumulated angular increments and said three-axis accumulated velocity increments with said angular reset voltage pulse and said velocity reset voltage pulse respectively to acquire angular increment counts and velocity increment counts as a digital form of angular and velocity measurements respectively; and (b.4) scaling said voltage values of said three-axis accumulated angular and velocity increments into real three-axis angular and velocity increment voltage values; wherein the step (d) further comprises the steps of: (db-1) producing temperature voltage signals by a thermal sensing producer to an analog/digital converter; (db-2) sampling said temperature voltage signals in said analog/digital converter and digitizing said sampled temperature voltage signals to digital signals which are output to said temperature controller; (db-3) computing digital temperature commands in a temperature controller using said input digital signals from said analog/digital c onverter, a temperature sensor scale factor, and a pre-determined operating temperature of said angular rate producer and acceleration producer, wherein said digital temperature commands are fed back to a digital/analog converter, and (db-4) converting said digital temperature commands input from said temperature controller in said digital/analog converter into analog signals which are output to a heater device to provide adequate heat for maintaining said predetermined operating temperature throughout said processing method. 8. A processing method for motion measurement, as recited in claim 7, wherein in the step (db-1), said voltage signals acquired from said thermal sensing producer is amplified by a first amplifier circuit before outputting to said analog/digital converter, for amplifying said voltage signals and suppressing said noise residing in said voltage signals and improving said signal-to-noise ratio. 9. A processing method for motion measurement. as recited in claim 8, wherein in the step (db-4), said input analog signals from said digital/analog converter for driving said heater device is amplified in a second amplifier circuit before outputting to said heater device. 10. A processing method for motion measurement, comprising the steps of: (a) producing three-axis angular rate signals by an angular rate producer and three-axis acceleration signals by an acceleration producer; (b) converting said three-axis angular rate signals into digital angular increments and converting said input three-axis acceleration signals into digital velocity increments in an angular increment and velocity increment producer; (c) computing attitude and heading angle measurements using said three-axis digital angular increments and said three-axis velocity increments in an attitude and heading processor; and (d) maintaining a predetermined operating temperature throughout said above steps, wherein said predetermined operating temperature is a constant designated temperature selected between 150° F. and 185° F.; wherein said angular rate producer and said acceleration producer are MEMS angular rate device array and acceleration device array and said outputting signals of said angular rate producer and said acceleration producer are analog voltage signals; wherein the step (b) further comprises the steps of: (b.1) integrating said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals for a predetermined time interval to accumulate said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals as a raw three-axis angular increment and a raw three-axis velocity increment for said predetermined time interval to achieve accumulated angular increments and accumulated velocity increments, for removing noise signals that are non-directly proportional to said carrier angular rate and acceleration within said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals, improving signal-to-noise ratio, and removing said high frequency signals in said three-axis analog angular rate voltage signals and said three-axis analog acceleration voltage signals; (b.2) forming an angular reset voltage pulse and a velocity reset voltage pulse as an angular scale and a velocity scale respectively; (b.3) measuring said voltage values of said three-axis accumulated angular increments and said three-axis accumulated velocity increments with said angular reset voltage pulse and said velocity reset voltage pulse respectively to acquire angular increment counts and velocity increment counts as a digital form of angular and velocity measurements respectively; and (b.4) scaling said voltage values of said three-axis accumulated angular and velocity increments into real three-axis angular and velocity increment voltage values; wherein the step (d) further comprises the steps of: (db-1) producing temperature volta