キム ムジュン 理工総研が募集する次席研究員
KIM Moojoong Researcher
理工学術院総合研究所 齋藤 潔 研究室
Waseda Research Institute for Science and Engineering
To counter global warming, the interest in next generation lower GWP(Global Warming Potential)new refrigerants increases with their thermodynamics and heat transfer characteristics. But since these refirigerantare mixture of some refrigerants and some of them are non-azeotropic, the heat transfer mechanism has not been clarified yet. This researchaims to grasp the heat transfer mechanisms of next generation lower GWP refrigerants (R454C, R466A, etc.) during evaporation and condensation processes in the smoothed circular tube. The measurement experiment of the heat transfer coefficient and pressuredrop will be performed under various kinds of conditions such as temperature, mass flow rate, and inlet quality of the refrigerant with visulalization techniqus of high speed camera and PIV. Finally, semi-empirical besed formula will be developed.
The research plan for the purpose as below:1.Setup the experimental bench, making the two-phase flow controlled with mass flow rate, temperature, and quality.2.The experimental bench and procedure will be validated using R32, the typical refrigerant in this research field.3.The measurement and data reduction of HTC will be performed for the low GWP refrigerant (R454C, R466A, etc.)4.Semi-empirical based correlations of heat transfer and pressure drop are developed for the system design. Prospects: The information of HTC of low GWP refrigerants is essential information for the pre-designing process of HVAC system. The accurate simulation and development process can be established through the result of this research. This finally realizes the optimum device & system design.