R1234ze(Z) and R1233zd(E) vaporisation inside a brazed plate heat exchanger (BPHE).

This paper presents the boiling heat transfer coefficients of R1234ze(Z) and R1233zd(E) inside a commercial Brazed Plate Heat Exchanger (BPHE): the effects of heat flux / mass flux, saturation temperature / pressure, outlet conditions and fluid properties are investigated. The boiling heat transfer coefficients are controlled mainly by heat flux / mass flux and evaporator outlet conditions. R1234ze(Z) exhibits boiling heat transfer coefficients higher than those of R1233zd(E). There is a reasonable agreement between the saturated boiling heat transfer coefficients and the calculated values by a model recently proposed by the present authors.