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.

In highly developed countries, a significant progress in the use of alternative and clean energy sources has recently been observed. The

European Union has implemented a programme to build wind turbines. It is estimated that in the coming years, thanks to the support in tax

and credit, the global energy will develop very intensively.

Many components of the wind turbines are castings. The basic material used for these castings is ductile iron, which in this particular case

must meet high requirements imposed by the operating conditions of wind turbines. Anticipating an increase in customer demand for this

type of castings, Krakodlew SA has decided to modernize its foundry using the ability to obtain external financing.

The ductile iron manufacturing technology is now being developed and adapted to the specific conditions of the foundry plant, including

the melting process yielding cast material with the required chemical composition, the technology of moulding, and the conditions for

possible secondary metallurgy, spheroidizing treatment and graphitizing inoculation. The fulfilment of the imposed conditions for the

casting production demands the use of advanced casting technologies introduced to the manufacturing process.

The development of technology to launch the production of ductile iron castings for the wind power industry was supported by The

National Centre for Research and Development (NCBiR). This article presents part of research on the binding kinetics of furan resin sands

and choice of their composition for moulds and cores to make heavy castings used as components of equipment for the wind power

industry.