An empirical study on evaporation heat transfer characteristics and flow pattern visualization in tubes with coiled wire inserts

Pressure loss and performance assessment of horizontal spiral coil inserted pipes during forced convective evaporation of R-600a

“…The current empirical results showed that the inserts lead to the growth in pressure drop which is not preferable. On the other hand, as it was reported previously [16], these inserts contribute to the heat transfer coefficients enhancement which is favorable. The pressure loss and heat transfer coefficients are independent from each other and not related by an equation.…”

“…In this part, firstly, the experimental pressure drop results of R-600a during forced convective evaporation in smooth and rough tubes are discussed. Then, the overall effectiveness of spiral coils and the system performance are evaluated considering the current pressure drop results and the previous heat transfer results reported in [16]. Finally, a new correlation is suggested based on the current empirical results in order to predict the pressure drop of R-600a during evaporation within horizontal spring inserted pipes.…”

“…To determine the pressure drop during the test section, a differential pressure drop transducer was installed in the cycle. Further information regarding the test setup can be found in [16].…”

“…Finally, based on the presented data, experimental correlations were suggested so as to predict the pressure losses and coefficients of heat transfer for Isobutane. Shafaee et al [16] experimentally appraised the flow boiling heat transfer performance of a heat-exchanger working with R-600a. In this research, spiral coils with varied geometrical features were utilized inside horizontally located pipes.…”

“…In this research firstly, the pressure drop growth of R-600a during forced convection evaporation in horizontal smooth and spring inserted pipes (rough pipes) is studied. Then, the performance of rough pipes is evaluated by considering the previous results of Shafaee et al [16], to illuminate the overall effectiveness of these inserts. Finally, an experimental correlation is suggested based on the current empirical data in order to predict the pressure drop of R-600a during evaporation in horizontal tubes with spiral coils.…”