Real-time efficiency index of a steam power plant: A systems approach

Abstract

The present system of recording efficiency parameters under process performance of a steam power plant (SPP) includes specific fuel consumption, auxiliary power consumption, and demineralized water for make-up used during past-specific period, without their integration into a single process performance or efficiency index. For developing integrated efficiency index in real time frame, the use of a process performance digraph (PPD) comprising of P i's as nodes and p ij's as interconnection among the nodes as obtained from the system structure graph (SSG) of SPP has been demonstrated. Each c ij of SSG corresponds to a process, such as air fuel mixing, combustion of mixtuer, generation and expansion of steam and its condensation back into water for recirculation in boiler, etc., taking place in the SPP and corresponds to a P i of PPD. The PPD is then analysed for determining the efficiency of the SPP using matrix method following systems approach. Variable permanent process performance matrix and its variable permanent function (VPF-p) have been derived from the PPD for the analysis. The real-time efficiency index (RTEI) has been introduced which is the ratio of the values of (VPF-p) in realtime (RT) situation (VPF-p)RT to its achievable design value (VPF-p). It reflects the RT rate of consumption of various inputs like demineralized water make-up, auxiliary power and fuel consumption, etc. It provides a more scientific method for ranking the performance of an SPP. The proposed model is capable of analysing in RT the performance of various systems of the SPP, taking into account simultaneously the failure of various equipments in these systems. A step-by-step procedure for calculation of RTEI has also been suggested and illustrated by giving an example.