Experimental and modelling evaluation of possible solutions for compact design of producer-gas heat exchangers

Abstract

Abstract An experimental and numerical campaign was carried out to investigate the performances of tubes in shell heat exchanger applied to cool down the producer gas of a small-scale commercial wood biomass gasifier built by All Power Labs. Producer gas is contaminated with soot and tars that condensate under 300 °C, for this reason the heat exchanger was designed in order to have an in-situ cleaning mechanism. The heat exchanger was tested both with standard plain tubes and with a set of metal twisted tapes (TT) with the aim of enhancing the heat transfer between producer gas and water. Temperatures and mass flows analyses shown a maximum increase of thermal power output and overall heat transfer coefficient respectively of 19% and 76% when TT are applied to the standard plain tubes in shell heat exchanger. Numerical simulations shown a consistency in the trends giving an average discrepancy with experimental results of the 12%.