Method for identifying damage on a compressor

Abstract

Described herein is a method for identifying damage on a compressor having an intake side and a discharge side, including the following steps: (i) detecting measurement data of the intake pressure (p1) and intake temperature (T1) measurement variables on the intake side, as well as end pressure (p2) and end temperature (T2) on the discharge side; (ii) determining a calculated end temperature (T2b), a calculated intake temperature (T1b), a calculated end pressure (p2b) or a calculated intake pressure (p1b) as a target variable, representing a good operating state of the compressor, as a function of the measurement data of max. three of the measurement variables (p1, T1, p2, T2); (iii) determining a comparison variable from at least one of the measurement variables (p1, T1, p2, T2) not used in step (ii); and (iv) comparing the comparison variable and the target variable as a gauge of damage to the compressor.

1 . A method for identifying damage on a compressor having an intake side and a discharge side, comprising the steps:
 (i) acquiring measurement data of the measurement variables intake pressure (p1) and intake temperature (T1) on the intake side and end pressure (p2) and end temperature (T2) on the discharge side;   (ii) determining a calculated end temperature (T2b), a calculated intake temperature (T1b), a calculated end pressure (p2b) or a calculated intake pressure (p1b) as a target variable which represents a good state of the compressor, as a function of the measurement data of a maximum of three of the measurement variables (p1, T1, p2, T2);   (iii) determining a comparison variable from at least one of the measurement variables (p1, T1, p2, T2) not used in step (ii); and   (iv) comparing the comparison variable and the target variable as a measure of damage on the compressor;   characterized in that the target variable determined in step (ii) is determined according to an isentropic compression model including the isentropic exponent (κ) of the gas to be compressed and a correction factor (η), and the correction factor (η) is adjusted on the basis of measurement data.   
     
     
         2 . The method as claimed in  claim 1 , wherein in step (ii) a calculated end temperature (T2b) is determined as the target variable as a function of the measurement data of the end pressure (p2), the intake pressure (p1) and the intake temperature (T1) in accordance with the equation
     T 2 b=T 1/η·( p 2/ p 1){circumflex over ( )}(1−1/κ),
   and in step (iii) the measured end temperature (T2) is determined as the comparison variable, wherein the correction factor η is calculated in accordance with the equation
   η= a·T 1+ b·p 2/ p 1+ c  
 
   and the factors a, b and c are determined by regression from measurement data of p2, p1 and T1.   
     
     
         3 . The method as claimed in  claim 1 , wherein in step (ii) a calculated intake temperature (T1b) is determined as the target variable as a function of the measurement data of the intake pressure (p1), the end pressure (p2) and the end temperature (T2) in accordance with the equation
     T 1 b=T 2·η·( p 1/ p 2)−(1−1/κ),
   and in step (iii) the measured intake temperature (T1) is determined as the comparison variable, wherein the correction factor η is calculated in accordance with the equation
   η= a·T 2+ b·p 1/ p 2+ c  
 
   and the factors a, b and c are determined by regression from measurement data of end temperature (T2), intake pressure (p1) and end pressure (p2).   
     
     
         4 . The method as claimed in  claim 1 , wherein in step (ii) a calculated end pressure (p2b) is determined as the target variable as a function of the measurement data of the end temperature (T2), the intake pressure (p1) and the intake temperature (T1) in accordance with the equation
     p 2 b=p 1·(η· T 2/ T 1)−(κ/(κ−1)),
   and in step (iii) the measured end pressure (p2) is determined as the comparison variable, wherein the correction factor η is calculated in accordance with the equation
   η= a·p 1+ b·T 2/ T 1+ c  
 
   and the factors a, b and c are determined by regression from measurement data of intake temperature (T1), intake pressure (p1) and end temperature (T2).   
     
     
         5 . The method as claimed in  claim 1 , wherein in step (ii) a calculated intake pressure (p1b) is determined as the target variable as a function of the measurement data of the intake temperature (T1), the end pressure (p2) and the end temperature (T2) in accordance with the equation
     p 1 b=p 2·( T 1/ T 2/η){circumflex over ( )}(κ/(κ−1)),
   and in step (iii) the measured intake pressure (p1) is determined as the comparison variable, wherein the correction factor η is calculated in accordance with the equation
   η= a·p 2+ b·T 1/ T 2+ c  
 
   and the factors a, b and c are determined by regression from measurement data of intake temperature (T1), end temperature (T2) and end pressure (p2).   
     
     
         6 . The method as claimed in  claim 1 , wherein the compressor has a plurality of compressor stages and method steps (i) to (iv) are carried out for at least two compressor stages. 
     
     
         7 . A computer program product with program code which, when the computer program is executed on a suitable computer system, is suitable for carrying out a method as claimed in  claim 1 . 
     
     
         8 . A computer program product having a computer-readable medium and a computer program, stored on the computer-readable medium, with program code means which are suitable, when the computer program is run on a suitable computer system, for carrying out the method as claimed in  claim 1 . 
     
     
         9 . The method as claimed in  claim 1 , wherein the compressor has a plurality of compressor stages and method steps (i) to (iv) are carried out for all the compressor stages.