Mulya Juarsa

The performance of solar collector CPC (compound parabolic concentrator) type with three pipes covered by glass tubes

Indonesia is a tropical country that has potential energy of solar radiation worth of 4.5 until 4.8 kWh/m2. However, this potential has not been utilized regularly. This paper will discuss the performance of solar collector compound parabolic concentrator (CPC) type with water as the working fluid. This CPC solar collector utilized three pipes covered by glass tubes. This paper has contribution to provide the temperature achievement between three pipes covered by glass tubes with and without glass cover of solar collector CPC type. The research conducted by varying the water flow rate of 1 l/m up to 6 l/m with three pipes arranged in series and parallel. From the results, the used of solar collector CPC type in the current study shows that the decrease of solar radiation, which was caused by climate change, did not influence the heat absorbance by water in the pipe. Therefore, the design of the solar collector in this research has potential to be used in future when solar radiation are used as the energy ...

Preliminary investigation of natural circulation stability in FASSIP-01 experimental facility using RELAP5 code

Natural circulation has an important role in the safety system of a nuclear reactor. It is part of passive system, which is operated without any external prime mover. The behavior of natural circulation shall be known to be effectively incorporated in the safety system of a nuclear reactor. This paper describes the preliminary results of the study on natural circulation conducted at a vertical rectangular experimental facility FASSIP-01. The RELAP5 code is used to simulate the experiment. The goal is to study the validity of the RELAP 5 model to analyze the natural circulation in FASSIP-01. The simulation could provide a reasonable good results describing the natural circulation established in the rectangular loop of FASSIP-01. However, there are still discrepancies with the experimental results, especially with regard to mass flow rate and temperature distribution in the loop. The model needs be improved and further comprehensive data from experiments are necessitated for better validation, as well.Natural circulation has an important role in the safety system of a nuclear reactor. It is part of passive system, which is operated without any external prime mover. The behavior of natural circulation shall be known to be effectively incorporated in the safety system of a nuclear reactor. This paper describes the preliminary results of the study on natural circulation conducted at a vertical rectangular experimental facility FASSIP-01. The RELAP5 code is used to simulate the experiment. The goal is to study the validity of the RELAP 5 model to analyze the natural circulation in FASSIP-01. The simulation could provide a reasonable good results describing the natural circulation established in the rectangular loop of FASSIP-01. However, there are still discrepancies with the experimental results, especially with regard to mass flow rate and temperature distribution in the loop. The model needs be improved and further comprehensive data from experiments are necessitated for better validation, as well.

Preliminary investigation of wickless-heat pipe as passive cooling system in emergency cooling tank

To improve the thermal safety of a nuclear power plant, a wickless-heat pipe is proposed as a passive cooling system on an emergency cooling tank. Heat pipe will keep the water in the emergency cooling tank on normal operating temperature. The objective of this preliminary research is to investigate the characteristics of the wickless-heat pipe. RELAP/SCDAPSIM/MOD3.4 thermal-hydraulic code was used to analyze the characteristics of the wickless-heat pipe. The simulation results will be used as a basis for designing the future experimental investigations of the proposed wickless-heat pipe. The influence of the hot water temperature in the emergency cooling tank and the mass flow rate of coolant on the water jacket were investigated. The hot water temperature in the emergency cooling tank was varied, i.e. 60, 70, and 80°C. The mass flow rate of condenser coolant in the water jacket was varied, i.e. 2, 4, and 8 L/min. The initial pressure of the heat pipe was -74 cm Hg. De-mineralized water, which serves as heat pipe working fluid, was charged with filling ratio of 80%. The working fluid in the heat pipe can circulate naturally in stable condition if cooling water could absorb the latent heat in condenser. The simulation results showed that for constant hot water temperature, the increasing of condenser coolant volumetric flow rate will decrease the temperature of evaporator and condenser. While for constant condenser coolant volumetric flow rate, the increasing of hot water temperature will increase the temperature of evaporator and condenser.To improve the thermal safety of a nuclear power plant, a wickless-heat pipe is proposed as a passive cooling system on an emergency cooling tank. Heat pipe will keep the water in the emergency cooling tank on normal operating temperature. The objective of this preliminary research is to investigate the characteristics of the wickless-heat pipe. RELAP/SCDAPSIM/MOD3.4 thermal-hydraulic code was used to analyze the characteristics of the wickless-heat pipe. The simulation results will be used as a basis for designing the future experimental investigations of the proposed wickless-heat pipe. The influence of the hot water temperature in the emergency cooling tank and the mass flow rate of coolant on the water jacket were investigated. The hot water temperature in the emergency cooling tank was varied, i.e. 60, 70, and 80°C. The mass flow rate of condenser coolant in the water jacket was varied, i.e. 2, 4, and 8 L/min. The initial pressure of the heat pipe was -74 cm Hg. De-mineralized water, which serves as ...