Effect of temperature and Reynolds number on the galvanic corrosion of the Copper/AISI316L pair in LiBr solutions using a Zero Resistance- Ammeter (ZRA)

摘要

Nowadays, lithium bromide (LiBr) is the most commonly used absorbent in absorption systems, but it can cause serious corrosion problems. Especially, these corrosion problems enhance with temperature and fluid flow. Double effect LiBr absorption machines are widely used because of their high efficiency due to the elevated temperatures that are reached inside these systems. There is very little research on the influence of temperature on the galvanic corrosion in LiBr solutions under hydrodynamic conditions. A circuit designed in a previous work lets us study dynamic corrosion in situ by means of electrochemical measurements without breaking pipe continuity.The aim of this work is to study both the effect of temperature and Reynolds number on the galvanic corrosion of the copper/AISI 316L pair in an 850 g/L LiBr solution. Galvanic current density and galvanic potential values were measured by means of a Zero-Resistance Ammeter (ZRA). The experiments were carried out in an oxygen-free environment at 25 °C, 50 °C and 75 °C for a range of Reynolds numbers from 1,456 to 5,066 during 8 hours.Both temperature and Reynolds number increase the galvanic corrosion rate. Moreover, influence of temperature on the galvanic current density and galvanic potential is higher than the effect of the Reynolds number.