JP2012041907A - Device and method for monitoring intra-enclosure combustion gas leakage of gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for monitoring an intra-enclosure combustion gas leakage of a gas turbine, capable of precisely detecting the leakage of the combustion gas in the enclosure.SOLUTION: The time-series data of an intra-enclosure temperature Ta and an atmospheric temperature Tb input by the process input device 22 are stored in the storage device 23, the correlation graph making unit 24 plots the time-series data in the past predetermined period stored in the storage device 23 and makes the current correlation graph by plotting the newest time-series data of the determined period, the upper limit reference curve making unit 25 makes an envelope showing the upper limit of an intra-enclosure temperature of the reference correlation graph made by the correlation graph making unit as the upper limit reference curve of the intra-enclosure temperature and superposes the upper limit reference curve on the current correlation graph to show the same in the display 27.

Description

  The present invention relates to a combustion gas leakage monitoring apparatus and method in a gas turbine enclosure for monitoring combustion gas leakage in an enclosure containing a gas turbine.

  The gas turbine of a thermal power plant is housed in an enclosure to prevent the vibration and noise of the gas turbine from leaking to the outside, and to prevent the damage from spreading if an abnormality occurs in the gas turbine and a fire occurs. ing. In addition, the enclosure has an air inlet and an air outlet. Air is sucked in from the air inlet, air is exhausted from the air outlet, and ventilation prevents the temperature inside the enclosure from rising too much. It is possible to protect the control equipment and the like, and to perform internal patrols by humans.

  As a ventilation system for gas turbine enclosures, there is one that can be flexibly adapted to ensure high reliability even when operating in cold regions and special areas with large temperature changes, and it can be realized at low cost. (For example, refer to Patent Document 1). Further, there is a gas turbine enclosure in which a temperature abnormality detection unit and a gas leakage detection unit are provided to detect an emergency of the gas turbine (see, for example, Patent Document 2).

Japanese Patent Laying-Open No. 2005-248706 JP 2008-140108 A

  However, not only fuel gas leakage but also combustion gas leakage may occur inside the enclosure. The leak of fuel gas can be detected immediately by the gas detector. On the other hand, if there is leakage of combustion gas, the internal temperature of the enclosure rises due to the high temperature combustion gas, so it can be recognized by detecting the internal temperature, but because the enclosure is ventilated, the amount of leakage is small. It is difficult to understand the temperature rise, and it can be recognized only when the temperature rise due to the combustion gas leakage exceeds the ventilation. However, since combustion gas leakage cannot be detected at an early stage, it is extremely dangerous if a person enters the enclosure without noticing the leakage.

  It is an object of the present invention to provide a gas turbine enclosure combustion gas leakage monitoring apparatus and method capable of accurately detecting leakage of combustion gas in an enclosure even at a stage where the amount of leakage is small.

  According to a first aspect of the present invention, there is provided a gas turbine enclosure combustion gas leakage monitoring apparatus according to a first aspect of the present invention. A storage device that stores time series data of the enclosure internal temperature and the atmospheric temperature, and a reference correlation between the enclosure internal temperature and the atmospheric temperature of the past predetermined period by plotting the time series data of the past predetermined period stored in the storage device The graph is created by the correlation graph creating means that creates a graph and plots the time series data of the latest predetermined period and creates the current correlation graph of the enclosure internal temperature and the atmospheric temperature of the latest predetermined period, and the correlation graph creating means In front of the envelope that indicates the upper limit of the enclosure internal temperature in the reference correlation graph An upper limit reference curve creating means for creating an upper limit reference curve for the internal temperature of the enclosure, and a display device for displaying the upper limit reference curve created by the upper limit reference curve creating means on the current correlation graph created by the correlation graph creating means, It is provided with.

  According to a second aspect of the present invention, there is provided a combustion gas leakage monitoring device for an enclosure of a gas turbine according to the first aspect of the invention, wherein the internal temperature of the enclosure in the monitoring target period in the current correlation graph created by the correlation graph creating means An alarm determination unit is provided that determines a ratio of the internal temperature of the enclosure that exceeds the upper limit reference curve created by the upper limit reference curve creation means and outputs an alarm level according to the ratio.

  According to a third aspect of the present invention, there is provided the gas turbine enclosure combustion gas leakage monitoring apparatus according to the second aspect of the present invention, wherein the upper limit reference curve is given a predetermined margin in the direction of the internal temperature rise of the enclosure, and the alarm determination is performed. The means is characterized in that, instead of the ratio of the internal temperature of the enclosure exceeding the upper limit reference curve, the ratio of the internal temperature of the enclosure exceeding the curve obtained by adding a predetermined margin value to the upper limit reference curve is determined.

  According to a fourth aspect of the present invention, in the gas turbine enclosure combustion gas leakage monitoring apparatus according to the first aspect of the present invention, the correlation graph creating means updates the reference correlation graph at predetermined intervals. The upper limit reference curve creating means updates and creates an upper limit reference line at a predetermined interval based on the updated reference correlation graph.

  According to a fifth aspect of the present invention, there is provided a combustion gas leakage monitoring device for an enclosure of a gas turbine according to any one of the first to fourth aspects, wherein, in addition to the enclosure internal temperature and the atmospheric temperature, there is a correlation with the enclosure internal temperature. The upper limit reference curve and the correlation graph corresponding to the gas turbine output or gas turbine combustion temperature are created using the gas turbine output or gas turbine combustion temperature in FIG.

  According to a sixth aspect of the present invention, there is provided a method for monitoring combustion gas leakage in an enclosure of a gas turbine, wherein an internal temperature and an atmospheric temperature of an enclosure containing a gas turbine are input in time series, and the input internal temperature and atmospheric temperature are Series data is stored, time series data of the past predetermined period stored is plotted to create a reference correlation graph of the enclosure internal temperature and atmospheric temperature of the past predetermined period, and the enclosure internal temperature of the generated reference correlation graph An envelope indicating the upper limit of the enclosure is created as an upper limit reference curve of the enclosure internal temperature, and the time series data of the latest predetermined period is plotted to create a current state correlation graph of the enclosure internal temperature and the atmospheric temperature of the latest predetermined period. The upper limit reference curve is superimposed on the created current correlation graph and displayed. And butterflies.

  According to the first and sixth aspects of the present invention, a reference correlation graph of the enclosure internal temperature and the atmospheric temperature for a predetermined period in the past is created, and an envelope indicating the upper limit of the enclosure internal temperature of the reference correlation graph is set as the enclosure internal temperature. The upper reference curve is created as an upper reference curve, and the upper reference curve is superimposed on the current correlation graph of the enclosure internal temperature and atmospheric temperature for the latest specified period, so the enclosure internal temperature exceeding the upper reference curve can be easily recognized. The leakage of combustion gas in the enclosure can be easily monitored.

  According to the second aspect of the present invention, the ratio of the enclosure internal temperature exceeding the upper limit reference curve among the enclosure internal temperatures in the monitoring target period in the current correlation graph is determined, and an alarm level corresponding to the ratio is output. The alarm level of combustion gas leakage in the enclosure can be easily recognized.

  According to the invention of claim 3, since a predetermined margin value is provided in the upper limit reference curve, it is possible to prevent an unnecessary alarm from occurring.

  According to the invention of claim 4, the reference correlation graph is updated and created at a predetermined interval, and the upper limit reference line is updated and created at a predetermined interval based on the updated reference correlation graph. An upper limit reference line corresponding to the change can be used.

  According to the invention of claim 5, by using the gas turbine output or gas turbine combustion temperature correlated with the enclosure internal temperature in addition to the enclosure internal temperature and the atmospheric temperature, the gas turbine output is the upper limit reference in the intermediate load zone. Since the curve and the correlation graph are created, it is possible to accurately monitor the combustion gas leakage in the enclosure even when the gas turbine output is in the intermediate load zone.

The block diagram of the combustion gas leak monitoring apparatus in the enclosure of the gas turbine which concerns on embodiment of this invention. The graph which shows an example of the correlation graph of the enclosure internal temperature produced | generated by the correlation graph preparation means in embodiment of this invention, and atmospheric temperature. The graph which shows an example of the upper limit reference | standard curve of the enclosure internal temperature created by the upper limit reference | standard curve creation means in embodiment of this invention. The top view of an example of the monitoring screen displayed on the display apparatus in embodiment of this invention. The block diagram of the combustion gas leak monitoring apparatus in the enclosure of the gas turbine which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of a combustion gas leakage monitoring apparatus in an enclosure of a gas turbine according to an embodiment of the present invention. FIG. 1 shows a case where the thermal power plant is a combined cycle power plant.

  In the combined cycle power plant, exhaust gas that has finished work in the gas turbine 11 is guided to the exhaust heat recovery boiler 12, steam is generated in the exhaust heat recovery boiler 12, and the steam turbine 13 is rotated by the steam to drive the generator 14. And generate electricity. The steam that has finished work in the steam turbine 13 is returned to water by the condenser 15 and returned to the exhaust heat recovery boiler 12.

  The gas turbine 11 includes an air compressor 16, a combustor 17, and a turbine 18. The air compressor 16 supplies oxygen necessary for burning the fuel in the combustor 17 as compressed air. The combustor 17 mixes the compressed air from the air compressor 16 and the fuel to produce fuel. To burn. The combustion gas in the combustor 17 is supplied to the turbine 18 to drive the turbine 18, and the exhaust gas that has finished work in the turbine 18 is discharged to the exhaust heat recovery boiler 12.

  Such a gas turbine 11 is accommodated in an enclosure 19, which is provided with an intake port and an exhaust port (not shown), sucks air from the intake port, and discharges air in the enclosure from the exhaust port. It is ventilated so that the temperature inside does not rise too much.

  In the enclosure 19, a temperature detector 20a for detecting the internal temperature is provided, and a temperature detector 20b for detecting the atmospheric temperature is provided. The enclosure internal temperature Ta detected by the temperature detector 20a and the atmospheric temperature Tb detected by the temperature detector 20b are sent to the process input device 22 of the combustion gas leakage monitoring device 21 in the enclosure in a time-sequential manner at a predetermined sampling period. The data is input and stored in the storage device 23 as time series data.

  The correlation graph creating means 24 plots time series data for a predetermined period stored in the storage device 23, and creates a correlation graph of the enclosure internal temperature Ta and the atmospheric temperature Tb for the predetermined period.

  FIG. 2 is a graph showing an example of a correlation graph between the enclosure internal temperature and the atmospheric temperature created by the correlation graph creating means 24. The vertical axis represents the enclosure internal temperature Ta, and the horizontal axis represents the atmospheric temperature Tb, and time series data for one year is plotted. × is the data for 9 months from the beginning to the 9th month, the black circle is the data for 2 months from the 10th month to the 11th month, the black triangle is the data for the 3rd week of the 12th month, the black square is the remaining 1 Weekly data.

  As the atmospheric temperature Tb increases, a correlation is obtained in which the enclosure internal temperature Ta also increases. Moreover, even if the atmospheric temperature Tb is the same temperature, the enclosure internal temperature Ta has a range because the temperature of the gas turbine changes depending on the output of the gas turbine. When the output of the gas turbine is large, the temperature of the gas turbine increases and the enclosure internal temperature Ta also increases.

  The correlation graph creating means 24 creates a reference correlation graph as a monitoring reference and a current correlation graph to be monitored as a correlation graph as shown in FIG.

  First, prior to monitoring the enclosure internal temperature Ta, a reference correlation graph is created. Since the reference correlation graph is a correlation graph serving as a monitoring reference, it is necessary to create it using time series data when there is no leakage of combustion gas in the enclosure. Therefore, for example, the time series data for a predetermined period in the past is created using the time series data for one year after operation or the time series data for one year after regular inspection.

  The upper limit reference curve creating means 25 creates an envelope indicating the upper limit of the enclosure internal temperature of the reference correlation graph created by the correlation graph creating means 24 as the upper limit reference curve of the enclosure internal temperature.

  FIG. 3 is a graph showing an example of the upper limit reference curve of the enclosure internal temperature created by the upper limit reference curve creating means 25. As shown in FIG. 3, a curve approximating the upper limit envelope of the enclosure internal temperature of the reference correlation graph is created and stored as the upper limit reference curve F.

  Next, when monitoring the enclosure internal temperature Ta, the correlation graph creating means 24 plots the time series data of the latest predetermined period among the time series data stored in the storage device 23, and the latest predetermined Create a current correlation graph of enclosure internal temperature and atmospheric temperature for the period.

  The current correlation graph created by the correlation graph creation means 24 and the upper limit reference curve F created by the upper limit reference curve creation means 25 are output to the output display means 26. The output display means 26 displays the upper limit reference curve F created by the upper limit reference curve creation means 25 on the current correlation graph created by the correlation graph creation means 24 and displays it on the display device 27.

  FIG. 4 is a plan view of an example of a monitoring screen displayed on the display device 27. This monitoring screen displays the upper limit reference curve F superimposed on the current correlation graph. As shown in FIG. 4, data exceeding the upper reference curve F is plotted, and the data is black triangle and black square data. The black triangle is the data for the third week of the 12th month, and the black square is the data for the remaining one week, so the temperature Ta in the enclosure has increased from the previous month compared to the reference correlation graph. I understand that. Therefore, it can be determined that the combustion gas in the enclosure is leaking.

  Here, the reference correlation graph is created using the time series data for one year after the start of operation or the time series data for one year after the periodic inspection, but may be updated and created at a predetermined interval. Good. This is because the correlation graph changes with the aging of the gas turbine, so that the correlation graph matches the actual characteristics. In this case, the upper limit reference curve creating means 25 updates and creates the upper limit reference line F at a predetermined interval based on the updated reference correlation graph.

  Next, another embodiment of the present invention will be described. FIG. 5 is a configuration diagram of a combustion gas leakage monitoring device in an enclosure of a gas turbine according to another embodiment of the present invention. In the other embodiment, an alarm determination means 28 for determining an alarm level and an alarm device 29 are added to the embodiment shown in FIG. The same elements as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  In FIG. 5, the alarm determination means 28 inputs the current correlation graph created by the correlation graph creation means 24 and the upper limit reference curve F created by the upper limit reference curve creation means 25, and data exceeding the upper limit reference curve F is input. Determine if it is plotted. When data exceeding the upper limit reference curve F is plotted, data exceeding the upper limit reference curve F for a predetermined monitoring target period, for example, one month before the present is counted. Then, the ratio of the enclosure internal temperature exceeding the upper limit reference curve F is determined by dividing by the number of data sampled in one month one month before the present. A plurality of levels are determined as the alarm level, which alarm level is determined and output to the alarm device 29.

  For example, if the enclosure internal temperature Ta is sampled four times a day, 120 data are obtained in one month (30 days), of which 20 data exceed the upper limit reference curve F. In this case, the ratio of the enclosure internal temperature exceeding the upper reference curve F is calculated as 20/120 = 0.167 (16.7%). And when the alarm level is set to 6 levels of 0% to 5%, 5% to 10%, 10% to 25%, 25% to 50%, 50% to 75%, 75% or more Determines that the alarm level is 10% to 25% in the third stage and outputs the alarm level to the alarm device 29. As a result, the alarm level is known, so it is possible to easily determine whether or not to take an emergency measure. Although the alarm level is output to the alarm device 29, it may be output to the display device 27, or may be displayed on both the alarm device 29 and the display device 27.

  Further, a predetermined margin value is provided in the enclosure internal temperature increasing direction with respect to the upper limit reference curve F, and the alarm determination means 28 replaces the ratio of the enclosure internal temperature exceeding the upper limit reference curve F with the upper limit reference curve F. You may make it determine the ratio of the internal temperature of the enclosure exceeding the curve which added the predetermined margin value. That is, a margin value of several degrees C. is given to the upper limit reference curve F, and the alarm level is determined according to the ratio of data exceeding the margin value. This is because the enclosure internal temperature may be several degrees higher than the upper limit reference curve F during periodic inspections. By setting a margin value (dead zone) of about several degrees Celsius, unnecessary alarms can be prevented from occurring.

  In the above description, the upper reference curve is created using the reference correlation graph between the enclosure internal temperature and the atmospheric temperature, and the leakage of the combustion gas in the enclosure is monitored by comparing the current correlation graph with the upper reference curve. However, in addition to the enclosure internal temperature and the atmospheric temperature, the upper reference curve and correlation graph corresponding to the gas turbine output or gas turbine combustion temperature using the gas turbine output or gas turbine combustion temperature correlated with the enclosure internal temperature You may make it create.

  Normally, since the gas turbine 11 is operated at the rated output, the upper limit reference curve is created using the enclosure internal temperature at the rated output of the gas turbine 11. On the other hand, the gas turbine 11 may be operated in an intermediate load zone smaller than the rated output, and in this case, the enclosure internal temperature also decreases. For this reason, when operating in an intermediate load zone and monitoring leakage of combustion gas in the enclosure using the upper limit reference curve created using the enclosure internal temperature at the rated output, the range does not exceed the upper limit reference curve. In some cases, the combustion gas leakage in the enclosure may have occurred.

  Therefore, the enclosure internal temperature corresponding to each output of the gas turbine 11 or the gas turbine combustion temperature is monitored, and an upper limit reference curve corresponding to each output of the gas turbine 11 or the gas turbine combustion temperature is created. In this case, the upper limit reference curve created using the enclosure internal temperature at the rated output is corrected using the gas turbine output or gas turbine combustion temperature correlated with the enclosure internal temperature, and the gas turbine output or gas turbine is corrected. An upper limit reference curve corresponding to the combustion temperature may be created.

  Thereby, the combustion gas leakage in the enclosure can be accurately monitored in accordance with each output of the gas turbine or the gas turbine temperature.

DESCRIPTION OF SYMBOLS 11 ... Gas turbine, 12 ... Waste heat recovery boiler, 13 ... Steam turbine, 14 ... Generator, 15 ... Condenser, 16 ... Air compressor, 17 ... Combustor, 18 ... Turbine, 19 ... Enclosure, 20 ... Temperature Detector, 21 ... Combustion gas leakage monitoring device in enclosure, 22 ... Process input device, 23 ... Storage device, 24 ... Correlation graph creation means, 25 ... Upper reference curve creation means, 26 ... Output display means, 27 ... Display device, 28 ... alarm determination means, 29 ... alarm device

Claims (6)

A process input device for inputting the internal temperature and the atmospheric temperature of the enclosure containing the gas turbine in time series;
A storage device for storing time series data of the enclosure internal temperature and the atmospheric temperature input by the process input device;
The time series data of the past predetermined period stored in the storage device is plotted to create a reference correlation graph of the enclosure internal temperature and the atmospheric temperature of the past predetermined period, and the latest time series data of the predetermined period is plotted Correlation graph creating means for creating a current state correlation graph of the enclosure internal temperature and the atmospheric temperature for a predetermined period;
Upper limit reference curve creating means for creating an envelope indicating the upper limit of the enclosure internal temperature of the reference correlation graph created by the correlation graph creating means as an upper limit reference curve of the enclosure internal temperature;
Combustion gas leakage monitoring in an enclosure of a gas turbine, comprising: a display device that displays the upper limit reference curve created by the upper limit reference curve creation unit on the current correlation graph created by the correlation graph creation unit apparatus.   Of the internal temperature of the enclosure in the monitoring target period in the current correlation graph created by the correlation graph creating means, determine the ratio of the enclosure internal temperature exceeding the upper reference curve created by the upper reference curve creating means, and to that ratio 2. The gas turbine enclosure combustion gas leakage monitoring apparatus according to claim 1, further comprising alarm determination means for outputting a corresponding alarm level.   A predetermined margin value is provided in the enclosure internal temperature rising direction with respect to the upper limit reference curve, and the alarm determination means replaces the ratio of the enclosure internal temperature exceeding the upper limit reference curve with a predetermined margin in the upper limit reference curve. The apparatus for monitoring leakage of combustion gas in an enclosure of a gas turbine according to claim 2, wherein the ratio of the internal temperature of the enclosure exceeding a curve to which a margin value is added is determined.   The correlation graph creation means updates and creates a reference correlation graph at a predetermined interval, and the upper limit reference curve creation means updates and creates an upper limit reference line at a predetermined interval based on the updated reference correlation graph. The combustion gas leakage monitoring device in an enclosure of a gas turbine according to any one of claims 1 to 3.   Using the gas turbine output or gas turbine combustion temperature correlated with the enclosure internal temperature in addition to the enclosure internal temperature and atmospheric temperature, the upper reference curve and the correlation graph corresponding to the gas turbine output or gas turbine combustion temperature are created. The combustion gas leakage monitoring device in a gas turbine enclosure according to any one of claims 1 to 4, wherein: Input the internal temperature and atmospheric temperature of the enclosure containing the gas turbine in time series,
Store the input time series data of the enclosure internal temperature and atmospheric temperature,
Plot the time-series data of the past predetermined period stored, create a reference correlation graph of the enclosure internal temperature and the atmospheric temperature of the past predetermined period,
Create an envelope indicating the upper limit of the enclosure internal temperature of the created reference correlation graph as an upper limit reference curve of the enclosure internal temperature,
Plot the time series data of the latest predetermined period to create a current state correlation graph of the enclosure internal temperature and the atmospheric temperature of the latest predetermined period,
A method for monitoring combustion gas leakage in an enclosure of a gas turbine, wherein the upper limit reference curve is superimposed on the created current correlation graph and output.

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