TY - GEN
T1 - A better steam engine
T2 - World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference
AU - Norwood, Zack
AU - Kammen, Daniel
AU - Callaway, Duncan
AU - Dibble, Robert
PY - 2012
Y1 - 2012
N2 - We present analysis and design aimed at the development of a small-scale solar system that would compete with available distributed technologies for heat and electricity generation. In developing such a system we focus on the small-scale expander because no suitable product of less than 10kW has yet been commercialized for this application. The thermodynamic cycle operates as follows: Water (or another working fluid), is pumped to high pressure (∼1000 kPa), heated in a concentrating solar collector to greater than 473K, then expanded producing work on a shaft attached to a generator. The cooled fluid exits the expander and is condensed back to its original state. Ideally, the cold reservoir, to which the working fluid dumps energy, is some useful thermal load, hence completing the combined heat and power Rankine cycle. The test system consists of a compressed air expander (a prototype designed by Katrix, Inc. of Australia) connected to an induction motor driven by a variable frequency drive (VFD) enabling expander testing at varying shaft speeds. Results of the expander testing are a qualified success. We report isentropic efficiency (80-95%) and pressure ratio (6-11) at the tested speeds, both of which are impressive for a device this small and simple. Future refinements could lead to a new class of expanders with unequaled low-cost and highperformance for use in solar combined heat and power.
AB - We present analysis and design aimed at the development of a small-scale solar system that would compete with available distributed technologies for heat and electricity generation. In developing such a system we focus on the small-scale expander because no suitable product of less than 10kW has yet been commercialized for this application. The thermodynamic cycle operates as follows: Water (or another working fluid), is pumped to high pressure (∼1000 kPa), heated in a concentrating solar collector to greater than 473K, then expanded producing work on a shaft attached to a generator. The cooled fluid exits the expander and is condensed back to its original state. Ideally, the cold reservoir, to which the working fluid dumps energy, is some useful thermal load, hence completing the combined heat and power Rankine cycle. The test system consists of a compressed air expander (a prototype designed by Katrix, Inc. of Australia) connected to an induction motor driven by a variable frequency drive (VFD) enabling expander testing at varying shaft speeds. Results of the expander testing are a qualified success. We report isentropic efficiency (80-95%) and pressure ratio (6-11) at the tested speeds, both of which are impressive for a device this small and simple. Future refinements could lead to a new class of expanders with unequaled low-cost and highperformance for use in solar combined heat and power.
UR - http://www.scopus.com/inward/record.url?scp=84871560297&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84871560297
SN - 9781622760923
T3 - World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conferen
SP - 1
EP - 8
BT - World Renewable Energy Forum, WREF 2012, Including World Renewable Energy Congress XII and Colorado Renewable Energy Society (CRES) Annual Conference
Y2 - 13 May 2012 through 17 May 2012
ER -
