A heat pump evaporator using the falling film technique

This paper presents a new heat pump evaporator. The evaporator is a vertical shell-and-tube heat exchanger utilizing the falling film principle on both the shell and the tube side. The advantages with this arrangement are:- Dirty water can be used since the evaporator can be cleaned without shutting down the unit.- Low pressure drops.- High heat transfer coefficients.- Relatively low investment cost.Measurements of the heat transfer for the evaporation of pure R12 (no oil contamination) gave length average heat transfer coefficients in the range of 2000-5000 W/m2K depending on the heat flux