Analysis and Evaluation of Theoretical Optimisation Potentials in Determining the Unit Efficiency Using Real Measurement Data

Project Number 303

Measurements for determining the unit efficiency of power plants are carried out for both acceptance tests and trial runs and serve inter alia to monitor the economical operation of the plant and determine basic data for the load distributor.

Usually, the so-called "indirect method" as described in the DIN standard 1942 and incorporated in the current DIN EN standard 12952-15 is used for determining the unit efficiency of coal-fired power plants to VDI 3986. To this end, the boiler efficiency is determined via the steam generator losses since measurements of large solid fuel mass flows are not very accurate.

The University of Ljubljana has carried out numerous acceptance measurements and trial runs of Slovene power plants, applying the DIN EN standard 12952-15. During this process, opportunities were identified to improve the quality of results by consistently applying complex physical and mathematical connections and models. A summary of optimisation options not yet implemented in practice to date was published by the University of Ljubljana in the VGB PowerTech Journal 03/2006.

Under the present research projects, optimisations suggested by the research centre are to be applied for the first time to one brown coal unit and one hard coal unit each (E.ON, Vattenfall). Thereafter the unit efficiency will be redetermined on the basis of concrete measurement data to facilitate the analysis and evaluation of the real influence of the optimisations on the calculation result.

The investigations will complement the outline conditions in applying the DIN EN standard 12952-15 as determined by the VGB "Unit Efficiency" project group, which were focussed on the radiation losses of the steam generator. This project group will support and control the project carried out from August till October 2007 under the guidance of Dr. Andrej Senegacnik at the Faculty of Mechanical Engineering of the University of Ljubljana.