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The vapor between the pressure P2 and P3 is said to be supersaturated or supercooled and this type of flow in nozzles is known as supersaturated or metastable flow of steam.
What is the effect of supersaturation in nozzle?
1. In a nozzle, the effect of supersaturation is to increase the dryness fraction of steam.
What is steam supersaturation?
Supersaturation, or the failure of steam to condense when the saturated condition is reached in an expansion, has long been a matter of interest to engineers.
What are the effects of super saturation on discharge and heat drop?
Thus the effect of supersaturation is to reduce the enthalpy drop slightly during the expansion and consequently a corresponding reduction in final velocity. The final dryness fraction and entropy are also increased and the measured discharge is greater than that theoretically calculated.
What is the Wilson line?
Explanation: Wilson line is the locus of points at which the limit of undercooling is reached and the condensation commences. At this state the normal conditions of thermal equilibrium are also restored. Wilson line is not conventionally shown in a Mollier chart.
What are the effect of supersaturation flow?
Effect of Supersaturated flow in nozzle: The effect of supersaturated is to reduce the heat drop slightly during the expansion and consequently a corresponding reduction in final velocity. The final dryness fraction and the entropy also increased and the measured discharge is greater than that theoretically calculated.
What is supersaturation degree?
Hereafter, the degree of supersaturation is expressed by the supersaturation ratio, DS, which is defined by the ratio of dose concentration to equilibrium solubility. If the supersaturation was sufficiently large, rapid crystallization occurred to decrease the concentration to the equilibrium solubility.
What is supersaturation compressible flow?
The increase in measured discharge to the theoretically calculated discharge is due to the time lag in condensation of steam and thus the steam remains in the dry state instead of wet; this phenomenon is called “Supersaturation”. Sometimes, the steam in this condition is said to be in a metastable state.
What is value of index of expansion for supersaturated steam?
1.3
Explanation: In case of supersaturated steam the index of expansion is assumed to be same as that for superheated steam i.e. 1.3.
What is Wilson line in thermodynamics?
The points at which this condensation occurs vary depending upon conditions and are scattered in a band somewhat below the saturation line as shown in Figure 1. This band is known as the Wilson Line. The phenomenon of metastable equilibrium is associated with the surface effects on very small drops and bubbles.
What is supersaturation ratio?
(3,8) The supersaturation ratio (S) is defined as , where nl,SS is the moles of gas in the liquid phase at the supersaturated state and n l,SS * is the theoretical moles of gas that should be in the liquid phase at a given pressure.