Showing papers on "Subcooling published in 1975"

Critical flow of saturated and subcooled water at high pressure. [PWR; BWR]

Abstract: Critical flow rate measurements have been made with saturated and subcooled water to determine the effect of fluid enthalpy, flow geometry and size, and flow length. These tests were conducted by blowing down vessels from an initial fluid pressure of 1000 psia (6895 kN/m/sup 2/) with the discharging fluid temperature between 450 and 550 F (232 and 288 C). The results clearly demonstrate the influence of metastable and/or nonequilibrium, thermodynamic states for flow lengths less than about 5 in. (127 mm). Data for different diameter nozzles, from 0.5 to 3.0-in. (12.7 to 76.2 mm), are presented which suggest that the critical mass flux decreases with increasing diameter.

Cascaded refrigeration cycles for liquefying low-boiling gaseous mixtures

Abstract: Process for the at least partial liquefaction of a low-boiling gaseous mixture, which is under pressure, wherein the gaseous mixture is precooled in heat exchange with a vaporizing refrigerant, purified during the course of the precooling step, and, after the precooling step, is subjected to a preliminary separation, characterized in that the at least partial liquefaction of the gaseous fraction obtained during the preliminary separation is carried out in heat exchange with a vaporizing multicomponent gas, the partial liquefaction of which takes place by precooling, and the completed liquefaction and subcooling of which takes place in one stage against itself.

Pressure distribution in a converging-diverging nozzle during two-phase choked flow of subcooled nitrogen

Abstract: Choked flow rates and axial pressure distributions were measured for subcooled nitrogen in a converging-diverging nozzle with a constant area section in the throat region. Stagnation pressures ranged from slightly above saturation to twice the thermodynamic critical pressure. Stagnation temperatures ranged from 0.75 to 1.03 times the thermodynamic critical temperature. The choking plane is at the divergence end of the constant area throat section. At high stagnation pressures the fluid stays liquid well into the constant area throat region; at near saturation stagnation pressures it appears that vaporization occurs at or before the entrance to the constant area throat region. The throat-to-stagnation pressure ratio data exhibits an anomalous flat region, and this anomaly is related to the two-phase process. The fluid is metastably all liquid below the saturation pressure.

Preassembled refrigerant subcooling unit

Abstract: A preassembled unit for subcooling the refrigerant in existing air conditioning and refrigeration systems to a temperature less than its saturated vaporization temperature The unit is installable in existing refrigeration systems and has the capability to increase the efficiency of such systems A coaxial tube heat exchanger includes a refrigerant tube to be connected between the system condenser and expansion valve, and a cooling medium tube through which a flow of cooling water is provided A thermostatically-operated control valve is utilized to adjust the flow of water in response to the refrigerant outlet temperature The control valve ensures that only the minimum quantity of water necessary to reduce the refrigerant temperature to a selected value is used The heat exchanger and control valve are completely enclosed in a block of plastic foam to prevent a high ambient temperature from affecting these elements An alternative embodiment of the invention includes a spray head to be attached to an air-cooled condenser and arranged to discharge the outlet cooling water so as to impinge on the condenser heat exchange surfaces The resultant evaporation of the water removes additional heat from the condenser and contributes to an additional increase in system efficiency

Thermal properties of butter

Abstract: Further studies will be necessary to fully evaluate the effects of water, salt and composition of the fat upon the thermal properties. Also, the influence of temperature history and subcooling on liquid-solid fractions of fat, solution and water will require additional investiga tion. LITERATUREREVIEW

Critical Heat Fluxes for Curved Surfaces during Subcooled Flow Boiling

Abstract: Experimental and analytical studies of the critical heat flux for subcooled flows of Freon 113 over concave, convex and straight surfaces have been conducted. Correlation functions for the critical...

Critical Heat Flux Measurements in a Full Scale Rod Cluster

Abstract: Critical heat flux data obtained for boiling water flow with a full-scale rod cluster of a water cooled reactor. The tests were performed on the effects of unknown parameters such as rod cluster eccentricity, spacer pitch and fuel configuration. From the experiment, the following conclusions are obtained : 1) The existence of low and high flow velocity burn-out regions was confirmed for rod cluster and the boundary between these two regions was almost the same as that for the round tube. 2) Rod cluster eccentricity has a marked effect on burn-out. An eccentricity of 0.6 mm lowers the critical heat flux by approximately 20%. 3) Burn-out is affected considerably by spacer pitch. If the spacer pitch is changed from 420 mm to 260 mm, critical heat flux increases by 38% maximum. 4) Critical heat flux can be increased by improvement of the fuel configuration. Test conditions were as follows ; pressure 70 kg/cm2, mass velocity 0.1∼10.7 × 106 kg/m2h, inlet subcooling 5∼200 kcal/kg, eccentricity 0∼1.0 mm and spacer pitch 260∼420mm.