Characterisation of a controllable loop thermosyphon for precise temperature management

Controllable loop thermosyphon in frequently start-stop operation offers an efficient heat transfer regulation. This low-cost device has a great protentional in precise temperature management of refrigerators, industrial buildings, and cutting-edge equipment. In this study, a test platform is built to investigate the thermodynamic characteristics of controllable loop thermosyphon and its effectiveness on precise temperature control of a fresh-keeping box. The comprehensive behaviours in continuous and start-stop operations are explored using R407C, R410A, R404A and R134a as working fluids. The filling ratios for above refrigerants are optimised, and the influence of thermal boundaries are studied. Given a suitable filling ratio of R407C, the average fresh-keeping temperature is reduced from 25 degrees C to 5 degrees C in 90 min and to 0 degrees C in 180 min during continuous operation. In start-stop operation, a minimum fresh-keeping temperature fluctuation of +/- 0.3 degrees C is achieved at various freshkeeping temperatures. The maximum and average heat transfer rates in the running period are 74.0-94.5 W and 48.3-80.2 W, respectively. Results indicate that the controllable loop thermosyphon with R407C provides efficient heat transfer and thermal control, and thus perform well in precise temperature management.

Automated summary

Controllable loop thermosyphon provides efficient heat transfer and precise temperature control in continuous and start-stop operations, showing great potential in applications such as refrigerators. The use of R407C as the working fluid demonstrates effective heat transfer and thermal control, leading to successful management of precise temperatures.