The paper presents the algorithms for a flue gas/water waste-heat exchanger with and without condensation of water vapour contained in flue gas with experimental validation of theoretical results. The algorithms were used for calculations of the area of a heat exchanger using waste heat from a pulverised brown coal fired steam boiler operating in a power unit with a capacity of 900 MWe. In calculation of the condensing part, the calculation results obtained with two algorithms were compared (Colburn-Hobler and VDI algorithms). The VDI algorithm allowed to take into account the condensation of water vapour for flue gas temperatures above the temperature of the water dew point. Thanks to this, it was possible to calculate more accurately the required heat transfer area, which resulted in its reduction by 19 %. In addition, the influence of the mass transfer on the heat transfer area was taken into account, which contributed to a further reduction in the calculated size of the heat exchanger - in total by 28% as compared with the Colburn-Hobler algorithm. The presented VDI algorithm was used to design a 312 kW pilot-scale condensing heat exchanger installed in PGE Belchatow power plant. Obtained experimental results are in a good agreement with calculated values.

JO - Chemical and Process Engineering L1 - http://journals.pan.pl/Content/84998/PDF/05-paper.pdf L2 - http://journals.pan.pl/Content/84998 IS - No 4 December EP - 461 KW - condensation heat recovery KW - calculation of the heat and mass transfer KW - heat exchanger KW - waste heat ER - A1 - Rączka, Paweł A1 - Wójs, Kazimierz PB - Polish Academy of Sciences Committee of Chemical and Process Engineering JF - Chemical and Process Engineering SP - 447 T1 - Methods of Thermal Calculations for a Condensing Waste-Heat Exchanger UR - http://journals.pan.pl/dlibra/docmetadata?id=84998 DOI - 10.2478/cpe-2014-0034