The hot corrosion tests of the austenitic TP347HFG in molten sulfates with and without external stresses were conducted at 700 and 750 oC. The corroded specimens of different conditions were investigated through measu...
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In spray cooling system, the liquid coolant is broken into numerous fine droplets through a spray nozzle to cool the target. The liquid nitrogen spray could obtain low cooling temperature and excellent heat transfer p...
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ISBN:
(纸本)9782362150128
In spray cooling system, the liquid coolant is broken into numerous fine droplets through a spray nozzle to cool the target. The liquid nitrogen spray could obtain low cooling temperature and excellent heat transfer performance with phase change in a large temperature difference. It can be widely used in low temperature tunnel cooling, ground simulation environment and laser therapy. The open loop liquid nitrogen spray platform is built to investigate the nitrogen spray characteristics. The solid cone vortex nozzle WL32 (3.18 mm diameter) and fine fog nozzle P66 (1.68 mm diameter) are used in the experiment. The spray pressure differences (0.25MPa to 0.8MPa) are sourced by the high pressure room temperature gas nitrogen and controlled through a manual valve. In the experiment, the spray field is recorded by a high speed camera (HG-100K from Redlake Co.) and the diameter of the spray droplet from WL32 is analyzed through the Malvern Spraytec laser particle size analyzer. The pressure difference between nozzle inlet and outlet has different influence on the spray angle of WL32 and P66. The quantity of spray droplets of WL32 increases with the increasing pressure, which leads to the improvement of the atomizing effect and the decline of Sauter Mean Diameter.
A closed loop spray cooling system with R134 - A as spray medium was used to investigate the performance of spray cooling characteristic. The heat transfer parameters such as heat flux, heat transfer coefficient and t...
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ISBN:
(纸本)9782362150128
A closed loop spray cooling system with R134 - A as spray medium was used to investigate the performance of spray cooling characteristic. The heat transfer parameters such as heat flux, heat transfer coefficient and target surface temperature were studied under different volumetric flow rate and spray chamber pressure. The single-phase heat transfer region and the phase-change heat transfer region were analyzed at different heat fluxes. The results show that the heat flux, critical heat flux (CHF) and heat transfer coefficient directly relate with volumetric flow rate. The higher flow rate and spray chamber pressure could achieve higher CHF with better heat transfer performance. And the different relationship between heat transfer coefficient and surface temperature was obtained at different spray cooling period.
In this paper a dynamic model of transcritical CO2 ejector expansion refrigeration cycle with two-stage evaporation (EERC-TE) is established to track the transient response of system parameter at two regulation method...
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ISBN:
(纸本)9782362150128
In this paper a dynamic model of transcritical CO2 ejector expansion refrigeration cycle with two-stage evaporation (EERC-TE) is established to track the transient response of system parameter at two regulation methods which includes the vapour quality adjustment and the entrainment ratio adjustment. The effectiveness of system model is verified and the results show the predictions have a agreement with the experimental data. Based on the unit change of ejector nozzle throat area and volume flow rate of chilled water of the second evaporator, the dynamic responses of pressure in gas cooler, the first and second evaporator, mass flow rate of primary flow, entrainment ratio and vapour quality of separator inlet are compared. The regulation of ejector nozzle throat area causes relatively large system responses compared to that of chilled water flow rate of the second evaporator. This work is useful to guide system control and the improvement of system performance.
Two-phase flashing spray holds a special interest in the safety area. High pressure liquids or liquefied gases accidentally released from small hole in chemical or nuclear industry can form two-phase mixtures due to t...
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A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an eth...
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A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an ethanolic solution of 1-dodecanethiol, and then extracting the coordination compounds formed between noble metal ions and 1-dodecanethiol into a non-polar organic solvent. A number of characterization techniques, including inductively coupled plasma atomic emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis demonstrate that this protocol could be applied to extract a wide variety of noble metal ions from water to dichlorometh- ane with an efficiency of 〉96%, and has high selectivity for the separation of the noble metal ions from other transition metals. It is therefore an attractive alternative for the extraction of noble metals from water, soil, or waste printed circuit boards.
A two-way coupling three-dimensional Vortex-In-Cell (VIC) method is developed for the simulation of gas-solid turbulent flow. The evolution of vortex elements and the motion of solid particles are tracked in the Lagra...
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A two-way coupling three-dimensional Vortex-In-Cell (VIC) method is developed for the simulation of gas-solid turbulent flow. The evolution of vortex elements and the motion of solid particles are tracked in the Lagrangian frame, while the flow field is solved by the vorticity Poisson equation on the Eulerian grid. Two-way coupling is implemented by introducing a vorticity source term induced by the motion of particle. This method is applied to simulate the particulate jet generated by solid particles falling from a circular orifice into unbounded quiescent air. The simulation results agree well with the experiment conducted by Ogata, which confirmed the validation of this method. The simulation results demonstrate that the air velocity radial distribution due to the particulate jet satisfies Gaussian distribution. The particle flow rate has little influence on the spread of particles, while velocity of particles increases with increasing the particle flow rate.
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