scholarly journals An optimization of redundant measurements location for thermal capacity of power unit steam boiler calculations using data reconciliation method

Energy ◽  
2015 ◽  
Vol 92 ◽  
pp. 135-141 ◽  
Author(s):  
Marcin Szega ◽  
Grzegorz Tadeusz Nowak
Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 815
Author(s):  
João Rodrigues ◽  
Michael Lahr

When working with economic accounts it may occur that multiple estimates of a single datum exist, with different degrees of uncertainty or data quality. This paper addresses the problem of defining a method that can reconcile conflicting estimates, given best guess and uncertainty values. We proceeded from first principles, using two different routes. First, under an entropy-based approach, the data reconciliation problem is addressed as a particular case of a wider data balancing problem, and an alternative setting is found in which the multiple estimates are replaced by a single one. Afterwards, under an axiomatic approach, a set of properties is defined, which characterizes the ideal data reconciliation method. Under both approaches, the conclusion is that the formula for the reconciliation of best guesses is a weighted arithmetic average, with the inverse of uncertainties as weights, and that the formula for the reconciliation of uncertainties is a harmonic average.


1993 ◽  
Vol 17 ◽  
pp. S257-S262 ◽  
Author(s):  
M. Meyer ◽  
H. Pingaud ◽  
M. Enjalbert

Author(s):  
Zengqian Wang ◽  
Jingjin Ji ◽  
Xinghao Wang ◽  
Bo Sun ◽  
Lei He ◽  
...  

Performance acceptance test for gas-steam Combined Cycle Power Plant (CCPP) is of great significance for both equipment manufacturer and customer. The influence of measurement error on the calculation of guaranteed performance data as power output and heat rate can lead to unnecessary loss for either party. Commonly used uncertainty analysis method based on ASME PTC 19.1 would require all measuring instrumentation working at designed accuracy range. Meanwhile, due to the complexity of CCPP system and large number of measuring items, and as well the propagation of measurement and data reduction error, the uncertainty of corrected performance data could be significant. In this paper, process data reconciliation method based on VDI 2048 is introduced. With access to complete performance test data from a CCPP project, data reconciliation calculation is performed with an appropriate thermodynamic model. Several measurement values with gross error are identified and verified in heat balance calculation. Moreover, after recalculating with the reconciled data instead of raw data for the corrected power output and heat rate, comparison with the common uncertainty analysis method is also carried out. It is shown that with this reconciliation method, it is not only possible to find out gross errors such as instrumentation drift, but also able to dramatically increase the test result accuracy, which is of great value for both manufacturer and customer.


Author(s):  
David E. Martinez ◽  
Joan Carles Bruno ◽  
Miguel J. Bagajewicz ◽  
Alberto Coronas

Performance data obtained from measurements of process variables usually do not obey material and energy conservation laws. This is why a data reconciliation process, that is, the adjustment of measured data to obey the conservation laws and other constraints is necessary in order to characterize the real performance of equipment, processes, or the whole plant. The information on the partial load and off-design operation performance of absorption chillers is scarce. Real operation of these units do not always coincides with the expected performance according to the data provided by the manufacturer due to site specific conditions. On the other hand the data reconciliation procedure has been extensively applied mainly only for open cycles with a moderate number of recycle streams. The objective of this work is the development and application of the data reconciliation technique to analyse the performance of absorption chillers using rigorous thermodynamic properties for the calculation of the P-V-T equilibrium properties and enthalpies. We present in this paper the preliminary test results for one of the absorption chiller components, the evaporator.


2000 ◽  
Vol 23 (6) ◽  
pp. 565-573 ◽  
Author(s):  
K. Pouliot ◽  
J. Thibault ◽  
A. Garnier ◽  
G. Acuña Leiva

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