**8. Appendix**

420 Heat Exchangers – Basics Design Applications

Fig. 17. (a) Streamlines in the left half of the channel; (b) Close up of the flow pattern; (c)

An experimental investigation has been conducted to measure the condensation heat transfer coefficient and the pressure drop of R410A and R22 in BPHEs with chevron angles of 20, 35, and 45 degrees. The experimental data were taken at two different condensation temperatures of 20°C and 30°C in the range of mass flux of 14-34 kg/m2s with a heat flux of

 Both the heat transfer coefficient and the pressure drop increased proportionally with the mass flux and the vapor quality and inversely with the condensation temperature and the chevron angle. Those effects must be carefully considered in the design of a

 A comparison of the data for R410A and R22 showed that the heat transfer coefficient for R410A was about 0 - 10 % larger and the pressure drop about 2- 21 % lower than

 Correlations for the Nusselt number and the friction factor with the geometric parameters were suggested for the tested BPHEs within 20 % (r.m.s. deviation: 10.9 %)

Although compact heat exchangers with corrugated plates offer many advantages compared to conventional heat exchangers, their main drawback is the absence of a general design method. The variation of their basic geometric details (i.e. aspect ratio, shape and angle of the corrugations) produces various design configurations, but this variety, although it increases the ability of compact heat exchangers to adapt to different applications, renders

those for R22. Therefore, R410A is a suitable alternative refrigerant for R22.

Photo of the flow in the cross-corrugated geometry [14].

BPHE due their opposing effects.

for Nu and 15 % (r.m.s. deviation: 10 %) for f.

**7. Conclusion** 

4.7 -5.3 kW/m2.

## **Nomenclature**


The Characteristics of Brazed Plate Heat Exchangers with Different Chevron Angles 423

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#### **Subscripts**

