WORKING FLUIDS FOR HIGH TEMPERATURE, 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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An Ericsson Cycle GT Design by LNG Cryogenic Heat Utilization

Volume 2: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations ◽

10.1115/2000-gt-0166 ◽

2000 ◽

Cited By ~ 3

Author(s):

Kirk Hanawa

Keyword(s):

High Temperature ◽

Heat Exchangers ◽

Power Plants ◽

Sea Water ◽

Rankine Cycle ◽

Exhaust Gas ◽

Energy Potential ◽

Thermodynamic Cycles ◽

Cycle Temperature ◽

Better Than

In many LNG receiving terminals worldwide, the cryogenic heat of imported LNG which was liquefied by using 10% energy of natural gas supply1), 2), has been wasted into the sea water mainly through heat exchangers like ORVs (Open Rack Vaporizer)3). This cryogenic heat of 110 K (-256 F) class is considered, however, as an excellent energy source to apply thermodynamic cycles. Several literature, accordingly, are found to improve such high-grade energy potential of LNG regasification process as a low temperature sink, combining with fired heater at 1,100 K (1520 F) class or GT main exhaust gas at 700 K (800 F) class as a high temperature source, through Brayton and Rankine cycles5),6),7),8),9). This paper presents a typical example of closed “Ericsson” cycle which has the minimum cycle temperature of 157 K (-176 F) from LNG cryogenic heat and the maximum of 550 K (531 F) from the partial HRSG exit heat mixed with the partial GT exit gas. This closed gas turbine, from viewpoints of minor modification to existing power plants and no energy impacts for high temperature source, which would be better than the above-described idea, is able to offer 35% thermal efficiency. And it is recognized that this system would be superior to existing cryogenic generation systems of 20% class operated by Rankine Cycle.

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Application of Supercritical Pressures in Power Engineering

Advanced Applications of Supercritical Fluids in Energy Systems - Advances in Chemical and Materials Engineering ◽

10.4018/978-1-5225-2047-4.ch013 ◽

2017 ◽

pp. 404-457

Author(s):

Igor Pioro ◽

Mohammed Mahdi ◽

Roman Popov

Keyword(s):

Heat Transfer ◽

Carbon Dioxide ◽

High Temperature ◽

Gas Turbine ◽

Power Plants ◽

Thermal Power ◽

Rankine Cycle ◽

Working Fluid ◽

Thermal Power Plants ◽

Power Cycles

SuperCritical Fluids (SCFs) have unique thermophyscial properties and heat-transfer characteristics, which make them very attractive for use in power industry. In this chapter, specifics of thermophysical properties and heat transfer of SCFs such as water, carbon dioxide and helium are considered and discussed. Also, particularities of heat transfer at SuperCritical Pressures (SCPs) are presented, and the most accurate heat-transfer correlations are listed. SuperCritical Water (SCW) is widely used as the working fluid in the SCP Rankine “steam”-turbine cycle in fossil-fuel thermal power plants. This increase in thermal efficiency is possible by application of high-temperature reactors and power cycles. Currently, six concepts of Generation-IV reactors are being developed, with coolant outlet temperatures of 500°C~1000°C. SCFs will be used as coolants (helium in GFRs and VHTRs; and SCW in SCWRs) and/or working fluids in power cycles (helium; mixture of nitrogen (80%) and helium [20%]; nitrogen, and carbon dioxide in Brayton gas-turbine cycles; and SCW “steam” in Rankine cycle).

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Process Systems Engineering Evaluation of Prospective Working Fluids for Organic Rankine Cycles Facilitated by Biogas Combustion Flue Gases

Frontiers in Energy Research ◽

10.3389/fenrg.2021.663261 ◽

2021 ◽

Vol 9 ◽

Author(s):

Muhammad Abdul Qyyum ◽

Ahmad Naquash ◽

Wahid Ali ◽

Junaid Haider ◽

Adnan Aslam Noon ◽

...

Keyword(s):

High Temperature ◽

Systems Engineering ◽

Waste Heat ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Flue Gases ◽

Total Annual Cost ◽

Working Fluids ◽

Process Systems ◽

Process System

The organic Rankine cycle (ORC) has recently emerged as a practical approach for generating electricity from low-to-high-temperature waste industrial streams. Several ORC-based waste heat utilization plants are already operational; however, improving plant cost-effectiveness and competitiveness is challenging. The use of thermally efficient and cost-competitive working fluids (WFs) improves the overall efficiency and economics of ORC systems. This study evaluates ORC systems, facilitated by biogas combustion flue gases, using n-butanol, i-butanol, and methylcyclohexane, as WFs technically and economically, from a process system engineering perspective. Furthermore, the performance of the aforementioned WFs is compared with that of toluene, a well-known WF, and it is concluded that i-butanol and n-butanol are the most competitive alternatives in terms of work output, exergy efficiency, thermal efficiency, total annual cost, and annual profit. Moreover, the i-butanol and n-butanol-based ORC systems yielded 24.4 and 23.4% more power, respectively, than the toluene-based ORC system; in addition, they exhibited competitive thermal (18.4 and 18.3%, respectively) and exergy efficiencies (38 and 37.7%, respectively). Moreover, economically, i-butanol and n-butanol showed the potential of generating 48.7 and 46% more profit than that of toluene. Therefore, this study concludes that i-butanol and n-butanol are promising WFs for high-temperature ORC systems, and their technical and economic performance compares with that of toluene. The findings of this study will lead to energy efficient ORC systems for generating power.

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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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Using the Peng-Robinson Equation of State to Explore Working Fluids for Higher Temperature Organic Rankine Cycles

Volume 6A: Energy ◽

10.1115/imece2014-37969 ◽

2014 ◽

Cited By ~ 1

Author(s):

Vincent D. Romanin ◽

Alfonso Rodriguez ◽

Jean Toutain ◽

Sonia Fereres

Keyword(s):

High Temperature ◽

Rankine Cycle ◽

Temperature Limit ◽

Working Fluids ◽

High Temperature Limit ◽

Fluid Properties ◽

Organic Rankine Cycles ◽

Organic Fluids ◽

Cycle Efficiency

Organic Rankine Cycles (ORCs) are primarily used in low-temperature/low-grade heat recovery systems, where water cycles are not efficient enough to economically extract work. For this reason, ORC analysis and ORC fluids have focused on low (< 300 °C) temperatures. Because the Carnot efficiency of a Rankine cycle increases with temperature, the high temperature limit of organic fluids is of interest for exploring the boundary between the economic advantages of organic fluids versus water in Rankine cycles. In this study, the high temperature limit of working fluids and the role of fluid properties on cycle efficiency for critical/subcritical ORCs are investigated. The performance of a wide range of organic fluids is evaluated through the development of thermal property calculator coded in MATLAB using the Peng-Robinson Equation of State (PREOS) and the Design Institute for Physical PRoperties (DIPPR) database correlations for heat capacity. This process allows for the development of an efficient property calculator that allows the rapid characterization of the thermodynamic performance of a large number of working fluids. A regenerative Rankine cycle for organic fluids was compared to a reheated Rankine cycle for water, for temperatures between 100 and 800 °C, with different cycle boundary conditions. The role of working fluid properties such as boiling temperature, critical point, molecular weight, and acentric factor on cycle performance are evaluated. It was found that the limits of efficiency of most of the fluids analyzed results from the limits of the high and low temperature of the cycle. Efficiency improvements due to a combined cycle with two ORCs are also examined. Finally, given the limits and performance of the fluids analyzed, desirable fluid properties for efficient high temperature ORCs are discussed.

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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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