This paper deals with the experimental analysis of a Closed Loop Two-Phase Thermosyphon of small size (vertical height lower than 2 m) and low input power (lower than 1 kW). As reported in the literature the thermal performance are affected by parameters as: filling ratio, working fluid, tube diameter, vertical size and input power. These parameters influence the mass flow rate which naturally circulates inside the loop. The authors have designed and realized an experimental CLTPT to experimentally analyze the circulating mass flow rate in connection with the thermal performances. The test rig consists of an evaporator realized with a glass pipe of 10 mm of internal diameter and a water cooled horizontal condenser. This apparatus allows the mass flow rate to be measured by means an integral measurement. The mass circulation shows an unstable periodic behavior a different two-phase flow pattern map at different heat load. The visualization of the flow patterns made with a high speed videocamera allows the measurement of the transient vapor quality and the frequency of the periodic flow. The heat and mass transfer is analyzed in dependence of the different variables: heat input (0-1000 W), filling ratio and subcooling rate.
EXPERIMENTAL ANALYSIS OF THE INSTABILITIES EFFECT ON THE THERMAL PERFORMANCE OF A CLOSED LOOP TWO-PHASE THERMOSYPHON
FILIPPESCHI, SAURO;FRANCO, ALESSANDRO
2013-01-01
Abstract
This paper deals with the experimental analysis of a Closed Loop Two-Phase Thermosyphon of small size (vertical height lower than 2 m) and low input power (lower than 1 kW). As reported in the literature the thermal performance are affected by parameters as: filling ratio, working fluid, tube diameter, vertical size and input power. These parameters influence the mass flow rate which naturally circulates inside the loop. The authors have designed and realized an experimental CLTPT to experimentally analyze the circulating mass flow rate in connection with the thermal performances. The test rig consists of an evaporator realized with a glass pipe of 10 mm of internal diameter and a water cooled horizontal condenser. This apparatus allows the mass flow rate to be measured by means an integral measurement. The mass circulation shows an unstable periodic behavior a different two-phase flow pattern map at different heat load. The visualization of the flow patterns made with a high speed videocamera allows the measurement of the transient vapor quality and the frequency of the periodic flow. The heat and mass transfer is analyzed in dependence of the different variables: heat input (0-1000 W), filling ratio and subcooling rate.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
