Exergy analysis of electrically- and thermally-driven engines to drive heat pumps: An exhaustive comparative study
The choice of driving a heat pump with an electrically$$-$$or a thermally-driven engine is a vexing question complicated by the carbon footprint and environmental impact of using electricity versus natural gas (or waste heat) as the main driver for the respective engines. The amount of useful work generated by these two distinct engines is the focal point of this paper, which addresses a key question: which engine presents a better choice for a given heat pumping application within the constraints of energy and environmental stewardship? Extensive use of energy, exergy, and availability analysis is necessary to quantify the useful work and to examine the issue holistically for both types of engines. The methodology explains why the output of work from these two distinct engines to satisfy a given load is vastly different, a direct consequence of their inherent Irreversibility. Thermodynamic consistency is guaranteed by satisfaction of the First and Second Laws applied to closed systems and their subsystems. The general conclusion is that thermally-driven engines are not industrious converters of heat to mechanical work.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Building Technologies Research and Integration Center (BTRIC)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- Grant/Contract Number:
- AC05-00OR22725; FWP/IAN CEBT002
- OSTI ID:
- 1349607
- Alternate ID(s):
- OSTI ID: 1414303
- Journal Information:
- International Journal of Refrigeration, Vol. 76, Issue C; ISSN 0140-7007
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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