Heat Transfer and Pressure Drop in Cross-Flow Welded Plate Heat Exchanger for Ammonia Synthesis Column

Abstract

Plate Heat Exchanger (PHE) is one of the modern types of compact heat transfer equipment, which can significantly enhance the heat recuperation and improve efficiency of energy usage in many industrial applications. The construction of welded PHE (WPHE) can significantly widen the range of its application on temperature and pressure. The results of experimental study of heat transfer and pressure drop in a model of WPHE specially designed for work in ammonia synthesis columns are presented. The model consists of the round plates with special form of corrugations. The plates are welded together forming a pack with channels for two heat exchanging streams. The streams are in a cross flow that correspond to one pass of the multipass WPHE with overall counter-current flow. It is shown that for calculation of heat transfer effectiveness can be used the cross flow model where fluid in one channel is mixed, but in another unmixed. The Equations for calculation of film heat transfer coefficients and pressure drop are presented, which can be used in earlier developed method of WPHE design. The validity of the Equations and developed method of WPHE design is confirmed by the data of tests with WPHE installed in ammonia synthesis column at temperature up to 520 °C and pressure 32 MPa.