SUMMARY OF A DESIGN COMPARISON OF CESIUM AND POTASSIUM AS WORKING FLUIDS IN INTEGRATED RANKINE CYCLE SPACE POWER PLANTS.

The wear and compatibility characteristics of selected bearing materials, including surface coatings and cemented refractory carbides were investigated in support of a pump development program for advanced Rankine cycle space power plants employing high temperature lithium and NaK. Compatibility of candidate materials with 1100-deg lithium in Cb-1 Zr alloy was studied in tilting capsule tests for durations to 7000 hr. The wear behavior of material combinations was evaluated with a rotating disk-static shoe assembly in lithium and NaK to 1000 deg. The best compatibility and wear characteristics were exhibited by high density molybdenum cemented carbides. Carburized Cb-1 Zr alloy wear resistance was inconsistent but, under the best conditions, was nearly equivalent to that of the cemented carbides. Plasma sprayed coatings of tungsten carbide and WC-Co gave encouraging results in NaK, but additional development of the coating process appeared necessary to assure reliable control of adhesion and performance.

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Air Cooled Two-Stage Rankine Cycles for Large Power Plants Operating With Different Working Fluids: Performance, Size and Cost

Volume 2: Reliability, Availability and Maintainability (RAM); Plant Systems, Structures, Components and Materials Issues; Simple and Combined Cycles; Advanced Energy Systems and Renewables (Wind, Solar and Geothermal); Energy Water Nexus; Thermal Hydraulics and CFD; Nuclear Plant Design, Licensing and Construction; Performance Testing and Performance Test Codes ◽

10.1115/power2013-98075 ◽

2013 ◽

Author(s):

Bo Liu ◽

Franck David ◽

Philippe Riviere ◽

Christophe Coquelet ◽

Renaud Gicquel

Keyword(s):

Heat Exchangers ◽

Power Plants ◽

Rankine Cycle ◽

Working Fluid ◽

Two Stage ◽

Large Power ◽

Water Steam ◽

Working Fluids ◽

Organic Fluids ◽

Installation Cost

A two stage Rankine cycle for power generation is presented in this paper. It is made of a water steam Rankine cycle and an Organic Rankine bottoming Cycle. By using an organic working fluid with higher density than water, it is possible to reduce the installation size and to use an air-cooled condenser. Following our previous studies, 3 high critical temperature organic fluids, R245fa, R365mfc, isopentane (iC5) and ammonia are tested as potential candidates for this application. The performances of the two stage Rankine cycle operating with those different working fluids are evaluated for a nuclear plant case. The size of system components (heat exchangers and turbine) is estimated for each tested fluid. The influences of their thermodynamic and transport properties are analyzed. In addition, an estimation of the installation cost is done by introducing cost functions.

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A Quantitative Method of Screening Working Fluids for Rankine-Cycle Power Plants

ASME 1967 Gas Turbine Conference and Products Show ◽

10.1115/67-gt-12 ◽

1967 ◽

Author(s):

Stephen Luchter

Keyword(s):

Power Plants ◽

Quantitative Method ◽

Power Level ◽

Rankine Cycle ◽

Single Stage ◽

Graphical Form ◽

Working Fluid ◽

Working Fluids

A method has been developed to relate the power-level range over which a particular Rankine-cycle working fluid is applicable as a function of rpm and turbine diameter. These results can be used in screening candidate working fluids. Typical results are presented in graphical form. They show that a fluid well-suited for one power level is not necessarily well-suited for some other power level. The analysis and typical results are applicable to single-stage turbines; however, the method can be extended to multistage designs.

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