This article presents microcolor schlieren technique for gas leakage detection with medium of liquefied petroleum gas (LPG, 50%C3H8and50%50% C4H10), which can be further applied in pipe gas leakage inspection, e.g. checking gas leakage of condenser and evaporator pipes of air conditioning in the automatic production line.
The plant here is a maze of refining towers, reactors, evaporators, pipes and storage tanks.
To test such system's heat transfer performance and get to know its thermo-fluid dynamics, a test facility for a simplified heat pipe made of one evaporator tube and one condenser has been developed.
Liu et al. [41] studied the boiling heat transfer characteristics of nanofluids in a flat heat pipe evaporator with a micro-grooved heating surface.
The present results demonstrate the applicability of the Q2D methods for both evaporator and heat pipe tests, and the present analyses can be a reference for future thermal management and electronic cooling designs.
However, either high-cost metal nanoparticles solved in water were used as nanofluids or these heat pipes were operated only in a horizontal or limited tilt arrangement, rather than the vertical arrangement, in which their thermal performance deteriorates because nanoparticles always accumulate on the evaporator of heat pipes with evaporation converting water to vapor.
Evaporation at the evaporator of a heat pipe plays an important role in its overall heat transfer performance, especially at low superheat levels.
For applications involving high heat density and low heat load, this study investigates the correlation among superheat, evaporative heat transfer, and the sintered structural parameters of heat pipe evaporators.
One of the reasons is that some elements affecting the efficiency, such as pressure losses in evaporator, condenser and pipes, have not been deeply discussed and optimized.
All properties are derived from the internal specific energy and density, which are determined locally by the integration of mass and energy equations applied to finite volumes of the components: evaporator, condenser and pipes.
