Email Document Reference

Enter your email address below and the reference for this document will be sent to shortly from webmaster@ceesi.com.

Title: Correction For K Factor Of Gas Turbine Flow Meter
Author: Xue Chunling, Sun Yanzuo
Source: Flomeko 2003
Year Published: 2003
Abstract: According to the International Standard ISO 9951 all gas turbine flow meters should have a maximum permissible relative error of 1% over the higher flow range (from 0.2Qmax to Q max ), in the lower flow range ( Qmin to 0.2Qmax ) the maximum permissible relative error is 2%. Usually the linearity of k factors, in percent, is used to express the basic relative error of a gas turbine meter. That means in the higher flow range the gas turbine meters shall have maximum permissible linearity of 1%, and in the lower flow range the gas turbine meters shall have maximum permissible linearity of 2%. The method commonly used to determine the mean k factor, K0 , is: At first, the values of Kmax and Kmin are found out in the higher flow range, and then the mean K factor, K0 , is calculated. Finally, the maximum deviation of K factors from K0 in the higher and lower flow ranges are evaluated to make an error judgment. In some cases this method might introduce a bias error into the K0, because the shapes of K factor signature curves ( the different modes of K factors distribution in different flow range) were not considered. Therefore, it is necessary to make different corrections for K0 in different cases. Our approaches are as follows: When Kmin appears in the lower flow range and the Kmax appears in the higher flow range, K0 (A Kmax + Kmin )/2, here A1.0099 When the Kmax appears in the lower flow range and the Kmin appears in the higher flow range, K0 (B Kmax + Kmin )/2,here B0.9902 When both the Kmax and the Kmin appear simultaneously in the same lower or higher flow range, K0 (C Kmax + Kmin )/2, here C1.0. During the individual calibration of each turbine meter this method has shown clear positive effects. While consideration was given to meters performance in the higher flow range, the performance of turbine meter in the lower flow range has been improved, therefore, more gas turbine meters are ensured to be up to standard. Based on the European Standard PrEN12261:1998 Turbine Gas Meter, the WME (Weighted Mean Errors ) were calculated. The WME show that this is an easy method to obtain the proper value of mean K factor for gas turbine meter.

In order to prevent spam and automated file downloads for documents within the Measurement Library, please follow the instructions below and then you will be able to email a reference to this article.