Supercritical CO2 Cycle Development at Pratt and Whitney Rocketdyne

Abstract

Pratt & Whitney Rocketdyne’s extensive experience in both the rocket engine and energy industries, provides an effective underpinning for work in supercritical CO2 power cycle development. Our current thrusts are supercritical CO2 power conversion for a LMR, a solar power system using molten salt energy storage, and a zero emission coal power system. Key observations from our nuclear power application work is that large, highly-effective heat exchangers will need to be developed, system architecture is driven by start-up operations, etc. along with steady-state full-power operations, and the large volumetric flow rates associated with this cycle coupled with the desire to keep pressure losses low will lead to parallel runs of large diameter pipe. Our solar power work is focused on developing a system architecture that can take advantage of the full thermal storage temperature spectrum while maintaining the high-efficiency and low-cost potential of this cycle. And in the fossil-fuel arena, the efficiency improvements derived from supercritical CO2 are particularly interesting as a way to make up the losses that are caused by CO2 sequestration.

Extension of the supercritical carbon dioxide brayton cycle to low reactor power operation: investigations using the coupled anl plant dynamics code-SAS4A/SASSYS-1 liquid metal reactor code system.

“…Recently, an alternative configuration, called "split-shaft", was proposed by Pratt & Whitney Rocketdyne [4]. In this configuration, schematically illustrated in Figure 4-1 (bottom section), the compressors and the generator are mounted on separate shafts.…”

“…The main advantage of the split-shaft configuration is a decoupling of the compressors from the generator, allowing the compressors to operate at basically any speed. One benefit of this approach is that the compressors can be designed for higher (than grid frequency) speed potentially providing higher efficiency, smaller blades, and fewer stages for the compressors [4]. Another, and possibly the most important, advantage of the speed decoupling is that in transients the compressor speed can be varied independent of the generator speed resulting in more efficient off-design operation of the compressors.…”

Układy gazowo-parowe z CO2 jako czynnikiem roboczym

“…Prace badawcze skierowane na opracowanie efektywnych maszyn, takich jak pompy, sprężarki, turbiny do technologii CCS oraz badania materiało-we, mogą być również wykorzystane w obiegach z CO2 [2,3,9]. Dwutlenek węgla może znaleźć zastosowanie zarówno w konwencjonalnych siłowniach, jak i niekonwencjonalnych układach siłowni jądrowych ze stopionym metalem, w układach magazynowania energii słonecznej w postaci stopionych soli i zeroemisyjnych technologii węglowych [4].…”

Thermodynamic Analysis of Supercritical CO2 Power Cycle with Fluidized Bed Coal Combustion

“…Pratt and Whitney Rocketdyne [21] developed Zero Emission Power and Steam (ZEPS) plant which adopted a pressurized fluidized bed combustor (PFBC) with combined cycle that modified S-CO 2 cycle was used as the topping cycle and steam cycle was used as the bottoming cycle. The ZEPS plant efficiency could increase by 9.4% compared with oxy-combustion atmospheric boiler.…”