Title :
Efficiency of a flashing flow nozzle
Author :
Bunch, Thomas K. ; Kornhauser, A.A. ; Alexandrian, Michael P.
Author_Institution :
Westvaco Corp. Res. Center, Covington, VA, USA
Abstract :
The efficiency of a flashing flow nozzle using R134A in an energy system using geothermal high pressure hot water, is calculated from a combination of thrust, flow, pressure, and temperature measurements. In order to promote nucleation within the nozzle, the inlet flow is seeded with small bubbles. Nozzle efficiencies are found to range from 33 to 47%. Increasing total mass of seeding bubbles (increasing inlet quality) and decreasing size of seeding bubbles is found to increase nozzle efficiency. Thermodynamic nonequilibrium in the nozzle is evaluated by comparing the flow rate to that predicted by homogenous equilibrium and frozen flow models. The same inlet flow changes that increase efficiency decrease thermodynamic nonequilibrium. The measured nozzle efficiencies are much higher than predicted by a homogenous equilibrium model with a normal shock in the diverging section
Keywords :
bubbles; flow measurement; geothermal power; nonequilibrium thermodynamics; nozzles; pressure measurement; temperature measurement; 33 to 47 percent; R134A; diverging section; energy system; flashing flow nozzle; flow measurement; flow rate; frozen flow models; geothermal high pressure hot water; homogenous equilibrium model; inlet flow changes; inlet flow seeding; nozzle efficiencies; pressure measurement; small bubbles; temperature measurement; thermodynamic nonequilibrium; thrust measurement; Fluid flow measurement; Kinetic energy; Mechanical engineering; Milling machines; Predictive models; Refrigeration; Temperature measurement; Testing; Thermodynamics; Turbines;
Conference_Titel :
Energy Conversion Engineering Conference, 1996. IECEC 96., Proceedings of the 31st Intersociety
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-3547-3
DOI :
10.1109/IECEC.1996.553341
