Systems and methods for controlling the operation of sootblowers

Abstract

Examples described herein include methods and systems for operating a sootblower for removing deposits from heat transfer surfaces of a boiler. A temperature change of a boiler fluid at one location on its flow path may be calculated during no more than substantially one stroke of the sootblower. The sootblower may then be operating using a frequency of use or a steam output selected based, at least in part, on the calculated temperature change. The temperature change of the boiler fluid during all or a portion of the sootblower stroke may be used as a relative measure of a deposition rate in the vicinity of the sootblower.

1 . A method for operating a sootblower for removing deposits from heat transfer surfaces of a boiler, the method comprising:
 calculating a temperature change of a boiler fluid at one location during no more than substantially one stroke of the sootblower; and   operating the sootblower wherein at least one of a frequency of use or a steam output of the sootblower is selected based, at least in part, on the calculated temperature change.   
   
   
       2 . The method according to  claim 1  wherein the boiler fluid is selected from a group of boiler fluids consisting of combustion gases, steam, and water. 
   
   
       3 . The method according to  claim 1  further comprising measuring the temperature change of the boiler fluid at an output of a generating section, a superheater section, or an economizer section of a boiler. 
   
   
       4 . The method according to  claim 1  wherein the calculating of the temperature change comprises calculating a first temperature change during the no more than substantially one stroke during a first sootblower sequence, and wherein the method further comprises:
 calculating a second temperature change of the boiler fluid during no more than substantially one stroke of the sootblower during a second sootblower sequence; and   averaging the first and second temperature changes;   wherein at least one of the frequency of operation or the steam output of the sootblower is selected based, at least in part, on the average of the first and second temperature changes.   
   
   
       5 . The method according to  claim 1  further comprising normalizing the temperature change by at least one of an average boiler fluid temperature, a steam generation rate, a boiler fuel input rate, a combustion air input rate, or combinations thereof. 
   
   
       6 . The method according to  claim 1  wherein the calculating comprises calculating the temperature change during a fraction of the sootblower stroke and wherein the fraction comprises a forward portion of the stroke or a reverse portion of the stroke. 
   
   
       7 . The method according to  claim 1  further comprising operating a plurality of sootblowers in the boiler, wherein the frequency of use or the steam output of the plurality of sootblowers are selected, based at least in part, on the temperature change. 
   
   
       8 . The method according to  claim 7 , further comprising calculating a plurality of temperature changes of the boiler fluid, each temperature change occurring during no more than one stroke of a respective sootblower; and
 optimizing a frequency of use of each of the respective sootblowers based, at least in part, on the temperature changes.   
   
   
       9 . The method according to  claim 1 , wherein the temperature change is a first temperature change, the method further comprising:
 calculating a second temperature change of the boiler fluid at the one location during a time when no sootblowers upstream of the one location are stroking;   calculating an effective temperature change based, at least in part, on the first and second temperature changes; and   wherein the at least one of the frequency or steam output of the sootblower is selected, based at least in part, on the effective temperature change.   
   
   
       10 . A boiler comprising:
 a furnace configured to combust a fuel and generate combustion gases;   a plurality of heat traps, each of the plurality of heat traps comprising tubes carrying a boiler fluid, the tubes having heat transfer surfaces and configured to transfer heat from the combustion gases to the boiler fluid carried by the tubes;   a temperature sensor configured to measure a temperature of the combustion gases or the boiler fluid;   a plurality of sootblowers, each of the plurality of sootblowers configured to remove deposits from a portion of the heat transfer surfaces in a vicinity of the respective sootblower;   a sootblower controller coupled to the plurality of sootblowers and configured to operate the plurality of sootblowers in accordance with a sootblowing sequence, wherein each of the plurality of sootblowers is operated with a respective frequency and steam output, and wherein the respective frequency or steam output of each of the plurality of sootblowers is selected based, at least in part, on a temperature change measured by the temperature sensor during substantially one stroke or less of the respective sootblower.   
   
   
       11 . The boiler according to  claim 10 , wherein the boiler fluid is selected from a group of boiler fluids consisting of steam and water. 
   
   
       12 . The boiler according to  claim 10 , wherein the temperature sensor is positioned to measure a temperature of the combustion gases or the boiler fluid at an output of a generating section, a superheater section, or an economizer section of the boiler. 
   
   
       13 . The boiler according to  claim 10 , wherein the temperature sensor is positioned to measure a temperature of the combustion gases or the boiler fluid at a location within a generating section, a superheater section, or an economizer section of the boiler. 
   
   
       14 . The boiler according to  claim 10 , wherein the respective frequency or steam output of each of the plurality of sootblowers is selected based, at least in part, on a temperature change measured by the temperature sensor during a fraction of a stroke of the respective sootblower, and wherein the fraction comprises a forward portion of the stroke or a reverse portion of the stroke. 
   
   
       15 . The boiler according to  claim 10 , further comprising a data analyzer, the data analyzer coupled to the temperature sensor and the sootblower controller, wherein the data analyzer is configured to receive temperature measurements from the temperature sensor and sootblower control signals from the controller, wherein the sootblower control signals are indicative of a start or stop of a sootblower stroke for each of the plurality of sootblowers, and wherein the data analyzer is further configured to calculate the temperature change during substantially one stroke or less of each of the respective sootblowers, and couple control signals to the sootblower controller indicative of the selected frequency or steam output of each of the plurality of sootblowers. 
   
   
       16 . The boiler according to  claim 15 , wherein the data analyzer is further configured to calculate the selected frequency or steam output of each of the plurality of sootblowers based on the temperature changes. 
   
   
       17 . The boiler according to  claim 15 , wherein the temperature change comprises a first temperature change measured during a first sootblowing sequence, and wherein the data analyzer is further configured to calculate a second temperature change during substantially one stroke or less of each of the plurality of sootblowers during a second sootblowing sequence, and wherein the data analyzer is further configured to average the first and second temperature changes;
 wherein at least one of the frequency of operation or the steam output of each of the plurality of sootblowers is selected based, at least in part, on the average of the first and second temperature changes.   
   
   
       18 . The boiler according to  claim 15 , wherein the data analyzer is further configured to normalize the temperature change by at least one of an average boiler fluid temperature, a steam generation rate, a boiler fuel input rate, a combustion air input rate, or combinations thereof. 
   
   
       19 . The boiler according to  claim 15 , wherein the data analyzer is further configured to optimize a frequency of use of each of the respective sootblowers based, at least in part, on the temperature changes. 
   
   
       20 . The boiler according to  claim 15 , wherein the temperature change during substantially one stroke or less of the respective sootblower is a first temperature change, and wherein the data analyzer is further configured to calculate a second temperature change of the combustion gases or other boiler fluid during a time none of the sootblowers upstream of the temperature sensor are stroking, and combine the second temperature change with the respective first temperature changes to yield respective effective temperature changes for each sootblower, and wherein the frequency or steam output of each of the sootblowers is based, at least in part, on the respective effective temperature changes. 
   
   
       21 . A data analyzer comprising:
 a first input configured to receive temperature measurements of a boiler fluid from a temperature sensor within a boiler;   a second input configured to receive a signal from a sootblower controller indicative of a first position in a sootblower stroke; and   a processing unit coupled to the first and second inputs and configured to receive the temperature measurements and the signal from the sootblower controller, wherein the processing unit is configured to calculate a temperature change of the boiler fluid during substantially one stroke or less of the sootblower, wherein the calculation is based at least in part on a temperature measurement corresponding to the first position of the sootblower stroke; the processing unit further configured to select at least one of a frequency of use or steam output of the sootblower based, at least in part, on the temperature change, the processing unit further configured to provide the selected frequency or steam output to the sootblower controller.   
   
   
       22 . The data analyzer according to  claim 21 , wherein the boiler fluid is selected from a group of boiler fluids consisting of combustion gases, steam, and water. 
   
   
       23 . The data analyzer according to  claim 21 , wherein the temperature measurements are taken from an output of a generating section, a superheater section, or an economizer section of the boiler. 
   
   
       24 . The data analyzer according to  claim 21 , wherein the selected frequency or steam output of each of the sootblower is selected based, at least in part, on a temperature change measured by the temperature sensor during a fraction of a stroke of the sootblower, and wherein the fraction comprises a forward portion of the stroke or a reverse portion of the stroke. 
   
   
       25 . The data analyzer according to  claim 21 , wherein the data analyzer is further configured to normalize the temperature change by at least one of an average boiler fluid temperature, a steam generation rate, a boiler fuel input rate, a combustion air input rate, or combinations thereof. 
   
   
       26 . The data analyzer according to  claim 21 , wherein the temperature change is a first temperature change, and wherein the data analyzer is further configured to calculate a second temperature change of the boiler fluid at the location of the temperature sensor during a time when no sootblowers downstream of the location are stroking, the data analyzer further configured to combine the first and second temperature changes to yield an effective temperature change, and wherein the frequency of use or the steam output of the sootblower is based, at least in part, on the effective temperature change. 
   
   
       27 . The data analyzer according to  claim 21 , wherein the second input is further configured to receive a plurality of signals from the sootblower controller, each indicative of a position of a respective sootblower of a plurality of sootblowers, wherein the processing unit is further configured to calculate the temperature change during substantially one stroke or less of each of the respective sootblowers in the plurality of sootblowers, and provide control signals to the sootblower controller indicative of a selected frequency or steam output for each of the plurality of sootblowers. 
   
   
       28 . The data analyzer according to  claim 27 , wherein the processing unit is further configured to optimize a frequency of use of each of the respective sootblowers based, at least in part, on the temperature changes. 
   
   
       29 . The data analyzer according to  claim 21 , wherein the temperature change comprises a first temperature change measured during a first sootblowing sequence, and wherein the processing unit is further configured to calculate a second temperature change during substantially one stroke or less of the sootblower during a second sootblowing sequence, and wherein the processing unit is further configured to average the first and second temperature changes;
 wherein at least one of the frequency of operation or the steam output of the sootblower is selected based, at least in part, on the average of the first and second temperature changes.   
   
   
       30 . A system comprising:
 the data analyzer according to  claim 21 ; and   the temperature sensor configured to couple to the second input and further configured for placement in the boiler.   
   
   
       31 . A method for measuring carryover of ash or other fouling material from the boiler, the method comprising:
 receiving temperature measurements of a boiler fluid from a location within the boiler;   receiving an indication of a time during which sootblowers upstream of the location are not in operation; and   calculating a temperature change of the boiler fluid during the time the sootblowers upstream of the location are not in operation.   
   
   
       32 . The method according to  claim 31 , wherein the boiler fluid is selected from a group of boiler fluids consisting of combustion gas, steam, and water. 
   
   
       33 . The method according to  claim 31 , wherein the location is within a generating section, a superheater section, or an economizer section of the boiler. 
   
   
       34 . The method according to  claim 31 , wherein the location is at an output of a generating section, a superheater section, or an economizer section of the boiler.