Experimental study on natural circulation flow based on temperature variation heating tank section in FASSIP-03 NT loop.

Reactor accidents caused by cooling function disturbances that occur due to an AC power source or station blackout (SBO) are an important reason for a passive cooling system that does not require external input power. The cooling system needed is a cooling system that utilizes the working principle of natural circulation (NC). The working principle of natural circulation occurs due to differences in the functional fluid density in the heating and cooling sections. The heated fluid will absorb heat from the heater so that the fluid has a lower density and will experience a Buoyancy force, then after passing through the cooler the heat will be released and the fluid will flow back into the heater with the help of the Gravitational force. The FASSIP-03 NT loop is a test loop to analyze natural circulation phenomena using Nanobubbles fluid. However, before using Nanobubbles working fluid, it is necessary to have tool characteristics on the FASSIP-03 NT loop using water working fluid to determine practical limits and phenomena that may occur in the FASSIP-03 NT loop using Nanobubbles working fluid. The FASSIP-03 NT loop has a total length of 11,71 meters, with a difference in the height of the heat source and heat sink of 3.05 meters. This study focuses on analyzing the temperature difference in the heat source and heat sink sections, the flow rate in the loop, and the rate of energy change in the heat source and heat sink sections to study the natural circulation (NC) flow that occurs in the FASSIP-03 NT loop with water fluid. The temperature variation by HTS 70°C, 80°C, and 90°C. The results of this experiment indicate that the temperature difference between the inlet and outlet fluids in the heat source pipe and the inlet and outlet in the heatsink pipe affects the flow rate and the rate of energy changes that occur in the FASSIP-03 NT loop. The greater the temperature difference, the more significant the energy and flow changes happen in the FASSIP-03 NT loop. [ABSTRACT FROM AUTHOR]