اسم المؤلف:
ايسر عبد الرزاق الاميري
اسم المشرف:
حسين علي جواد
زينب فاضل مهدي
المستخلص:
The improvement of energy saving in heat pipe heat exchanger system was investigated .Theoretical work was done to study the effect of coating with nanomaterials on the thermal performance of HPHE to enhance the energy saving. Temperature distribution and thermal resistance for different nano materials (BN, WC, HFB2, MgO and MOSi2), metal and metal oxide (Ag, Cu, AL, BeO, Al2O3 and CuO) on fins were studied. The maximum enhancement of the thermal performance at the evaporator section in steady state operation condition was (5.072, 5.063, 5.075 and 5.069) for (WC, HFB2, MgO and MOSi2) respectively and (5.829) for (BN) at the same section in transient operation condition while at the same section in steady state operation condition (5.063, 5.064, 5.07, 5.068, 5.075 and 5.076) for (Ag, Cu, AL, BeO, Al2O3 and CuO) respectively was detected. The best nano material for enhancement the thermal performance of HPHE are BN for nanomaterial ,Al for nano metal and CuO for nano metal oxide .The thermal performance of seven thicknesses of CuO coating layers on HPHE fins was also studied. Results showed that the enhancement of the thermal performance is decreasing with the increment of coating thickness at the evaporator section of transient conditions (5.076, 5.075, 5.073, 5.072, 5.070, 5.068 and 5.067) for (10, 25, 50, 75, 100,125and150)μm thicknesses respectively. Experimental work was done to examine the general performance of thermosyphon heat pipe at four concentrations (0.05, 0.2, 0.6 and 1) wt. % of nanofluid. Two CW diode lasers (532,650) nm were used as a detection system to determine the variation of the concentration within the system operation. The results showed that fourteen percent reduction in thermal resistance is detected for 0.05wt.% relative to the DI - water . The shorter time of steady state condition of operation, the higher values of total thermal effectiveness, energy saving and energy balance ratio of HPHE were satisfied at 0.05wt.%. The maximum value of relative powers of 0.05wt% nanofluid concentration is detected compared with the other concentrationsdue to the low density of nanofluid concentration. The start sensing and ending detection powers are (0.1, 1) W respectively of this type of nanofluid.
