Abstract
The evaporation heat transfer coefficient of (R-744) in a horizontal tube was investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and evaporator (test section). The test section consists of a smooth, horizontal stainless steel tube of inner diameter of 4.57mm. The experiments were conducted at mass flux of 400 to , saturation temperature of 5 to , and heat flux of 10 to . The test results showed the heat transfer of has a greater effect on nucleate boiling more than convective boiling. Mass flux of does not affect nucleate boiling too much. In comparison with test results and existing correlations, All of the existing correlations for the heat transfer coefficient underestimated the experimental data. However Jung et al.`s correlation showed a good agreement with the experimental data. Therefore, it is necessary to develope accurate predictions determining the evaporation heat transfer coefficient of in horizontal tubes.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
