An accurate calorimeter-based method for the thermal characterization of heat pipes

• A novel method for the accurate thermal characterization of heat pipes. The performance a sample sintered copper pipe was investigated. Improved uncertainty < 7.5 % in resistance, range inputs. data reveal that previous techniques overestimate This study presents can be used to accurately determine cylindrical pipe. In method, is placed between two stainless steel 304 blocks, configured as radial calorimeters achieve contact with evaporator and condenser sections flexible isothermal electrical heater mat surrounds block, liquid-cooled wrapped around block remove heat. High precision thermistors ( ± 0.01 K) positioned at fixed locations within are measure supplied extracted from condenser. One-dimensional conduction assumed occur each calorimeter, this enables quantification flows temperature readings. assumption verified by steady-state analysis radial, axial circumferential differences based on recorded lowest highest Furthermore, numerical model confirm end effects have negligible influence calorimeter. concludes most commonly pipes greatly (15–32% input powers 7.5–25 W respectively) due inaccurate into calorimetric technique reported here achieves uncertainties resistance <7.5% low loads (<12.5 W) <6% higher (>12.5 W). Moreover, significant improvement experimental efficiency, values >75% all inputs study. use current obviates requirement calculating losses ambient, hence achieving effective conductivity