Alkali-metal, Rankine-cycle power systems for electric propulsion.

1967 ◽  
Vol 4 (7) ◽  
pp. 852-858 ◽  
Author(s):  
MORRIS A. ZIPKIN
Author(s):  
Antonio Agresta ◽  
Antonella Ingenito ◽  
Roberto Andriani ◽  
Fausto Gamma

Following the increasing interest of aero-naval industry to design and build systems that might provide fuel and energy savings, this study wants to point out the possibility to produce an increase in the power output from the prime mover propulsion systems of aircrafts. The complexity of using steam heat recovery systems, as well as the lower expected cycle efficiencies, temperature limitations, toxicity, material compatibilities, and/or costs of organic fluids in Rankine cycle power systems, precludes their consideration as a solution to power improvement for this application in turboprop engines. The power improvement system must also comply with the space constraints inherent with onboard power plants, as well as the interest to be economical with respect to the cost of the power recovery system compared to the fuel that can be saved per flight exercise. A waste heat recovery application of the CO2 supercritical cycle will culminate in the sizing of the major components.


Author(s):  
I K Smith

The world market for systems for power recovery from low-grade heat sources is of the order of £1 billion per annum. Many of these sources are hot liquids or gases from which conventional power systems convert less than 2.5 per cent of the available heat into useful power when the fluid is initially at a temperature of 100° C rising to 8–9 per cent at an initial temperature of 200°C. Consideration of the maximum work recoverable from such single-phase heat sources leads to the concept of an ideal trilateral cycle as the optimum means of power recovery. The trilateral flash cycle (TFC) system is one means of approaching this ideal which involves liquid heating only and two-phase expansion of vapour. Previous work related to this is reviewed and details of analytical studies are given which compare such a system with various types of simple Rankine cycle. It is shown that provided two-phase expanders can be made to attain adiabatic efficiencies of more than 75 per cent, the TFC system can produce outputs of up to 80 per cent more than simple Rankine cycle systems in the recovery of power from hot liquid streams in the 100–200°C temperature range. The estimated cost per unit net output is approximately equal to that of Rankine cycle systems. The preferred working fluids for TFC power plants are light hydrocarbons.


2020 ◽  
Vol 178 ◽  
pp. 115527 ◽  
Author(s):  
Enrico Baldasso ◽  
Maria E. Mondejar ◽  
Jesper Graa Andreasen ◽  
Kari Anne Tveitaskog Rønnenfelt ◽  
Bent Ørndrup Nielsen ◽  
...  

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