Problems of calculation the energy efficiency of a dual-fuel steam boiler fired with industrial waste gases

The article presents the problems of calculation the energy efficiency of a dual-fuel steam boiler OPG-430 type operated in an industrial CHP plant fired with blast-furnace and coke-oven gases. The available special measurements were used to calculate the energy efficiency of the boiler. These measurements have been made for varying thermal loads of the boiler and different proportions of individual gases in the fuel feeding the boiler. The energy efficiency of the boiler was calculated using the direct method and the indirect method in accordance with the algorithm included in the EN 12952-15 standard. Due to the occurring measurement redundancy, advanced data validation and reconciliation of measurements in steam boiler energy balancing in accordance with the methodology included in VDI 2048 guidelines was used. Discussion of the results of the energy efficiency of the boiler calculations obtained in different variants of the use of measurement data was carried out. In addition, the energy characteristic of the boiler was developed using the stepwise regression method. Obtained results of the energy efficiency of the boiler calculations clearly showed the necessity of using balance methods with the use of advanced data validation and reconciliation method of measurements in the case of measurements redundancy.