Effect of graphenenano-fluid on heat pipe thermal performance for passive heat removal in nuclear spent fuel storage pool

Abstract

Abstract. After Fukushima Dai-ichi nuclear power reactor accident, spent fuel in spent fuel storage pool (SFSP) became an important thing to pay attention to, due to its decay heat release. If station blackout occurred, the active system for SFSP cooling system will experience malfunction to remove the product of decay heat. To keep spent fuel safe, heat pipe as passive cooling system device can be used to remove spent fuel decay heat even if the active cooling system failed. Heat pipe with 6 m on length will be proposed as apassive cooling system in SFSP. For that, it is necessary to analyze the effect of Graphene nano-fluid as heat pipe working fluid. The objective of this research is to know the effect on Graphene nano-fluid to enhance the heat pipe thermal performance and to know the heat transfer phenomena inside the heat pipe based on Graphene nano-fluid. Graphene nano-fluid with 1% weight concentration was used as working fluid with filling ratio of 80%. The experimental investigation is conducted with varying the evaporator heat load of 1000, 1500, 2000, and 2500 W. Water as coolant flows in thecondenser with aconstant volumetric flow rate of 8 L/min. The experiment results show that there was anovershoot, zigzag and stable phenomena inside the heat pipe. The thermal resistance of heat pipe is obtained at 0.015 o C/W. The use of Graphene nano-fluid as working fluid can enhance the heat pipe thermal performance significantly and can be used as an alternative working fluid in heat pipe for thepassive cooling system in SFSP of nuclear power plant.

Investigation on the Performance of a Wickless-Heat Pipe Using Graphene Nanofluid for Passive Cooling System

“…In overall, the use of nanographene improves the thermal performance of the heat pipe. This investigation results are in agreement with the results obtained by other researchers [28,30,34]. The thermal resistance of vertical straight wickless-heat pipe using Graphene nanofluid obtained was compared with other researchers result.…”

“…The preliminary investigation was only focused on the effect of heat load given to the heat pipe evaporator with 1 % Graphene nanofluid weight concentration. Our preliminary result showed that the use of Graphene nanofluid could enhance the thermal performance of the heat pipe to transfer heat from the heat source to the heat sink [34].…”

“…Preparation process to dissolve nanographene and demineralized water nanofluid[34] RESULTS AND DISCUSSIONTransient temperature distributionThe measurement of vertical straight wickless-heat pipe transient temperatures with variation of filling ratio, heat load, and coolant volumetric flow rate were depicted in Figs. 4 to 12.Figures 4 to 6 show the measurements of transient temperature distribution on the outside wall of the vertical straight wickless-heat pipe at filling ratio of 40 %; heat loads of 1000 W, 1500 W, 2000 W, and 2500 W for coolant volumetric flow rates of 4 L/min, 6 L/min, and 8 L/min, respectively.…”