ShareSummary
Expansion work recovering devices (EWRDs) such as the refrigerant ejector or expander can significantly improve the cycle efficiency of transcritical R-744 systems by approaching isentropic expansion. This paper uses a thermodynamic property chart to visualize the work recovery potentials of such devices. Two distinguished cases regarding the operational characteristics of an internal heat exchanger (IHX) are discussed and the possible interferences with the EWRD potentials are analyzed. The thermodynamic property chart reveals how the use of an IHX reduces the EWRD potential by competing for the same temperature difference. While the assessments of the effects on cooling capacity are readily available, it is generally more complex to predict the associated changes in COP. Thus, a numerical system model is used to address the issue of how efficient the EWRD has to be in order to reduce or eliminate the need for an IHX. For the system investigated it was found than an approximately 50% efficient ejector can replace a 60% effective IHX in order to achieve identical COPs at a given cooling capacity in a transcritical R-744 cycle.
Available documents
Format PDF
Available
Public price
20 €
Member price*
15 €
* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).
Details
- Original title: A thermodynamic property chart as a visual aid to illustrate the interference between expansion work recovery and internal heat exchange.
- Record ID : 2007-1901
- Languages: English
- Source: 2006 Purdue Conferences. 18th International Compressor Engineering Conference at Purdue & 11th International Refrigeration and Air-Conditioning Conference at Purdue [CD-ROM].
- Publication date: 2006/07/17
Links
See other articles from the proceedings (157)
See the conference proceedings
Indexing
-
Themes:
Thermodynamics and changes of state;
Expansion systems;
Refrigerant circulation: piping, control, automation, safety;
CO2;
Other energy-saving and energy-recovery systems;
Containment, refrigerant charge reduction - Keywords: Energy; Recovery; Expansion; Transcritical cycle; Thermodynamic cycle; Refrigerant; CO2
-
Observation of CO2 transcritical expansion proc...
- Author(s) : FUKUTA M., HIGASIYAMA M., YANAGISAWA T., et al.
- Date : 2008/07/14
- Languages : English
- Source: 2008 Purdue Conferences. 19th International Compressor Engineering Conference at Purdue & 12th International Refrigeration and Air-Conditioning Conference at Purdue [CD-ROM].
- Formats : PDF
View record
-
Praktische Erfahrungen transkritischer CO2-Kält...
- Author(s) : HEYL P., MAURER T.
- Date : 2001/12
- Languages : German
- Source: KI Luft Kältetech. - vol. 37 - n. 12
View record
-
Axial and radial force control for CO2 scroll e...
- Author(s) : HIWATA A., IKEDA A., MORIMOTO T., et al.
- Date : 2008/07/14
- Languages : English
- Source: 2008 Purdue Conferences. 19th International Compressor Engineering Conference at Purdue & 12th International Refrigeration and Air-Conditioning Conference at Purdue [CD-ROM].
- Formats : PDF
View record
-
An on-line control method of optimal heat rejec...
- Author(s) : KIM M. S., MIN S. K.
- Date : 2012/06/25
- Languages : English
- Source: 10th IIR-Gustav Lorentzen Conference on Natural Working Fluids (GL2012). Proceedings. Delft, The Netherlands, June 25-27, 2012.
- Formats : PDF
View record
-
Modelling and experimental investigation on the...
- Author(s) : YANG B., SUN S., PENG X., et al.
- Date : 2008/07/14
- Languages : English
- Source: 2008 Purdue Conferences. 19th International Compressor Engineering Conference at Purdue & 12th International Refrigeration and Air-Conditioning Conference at Purdue [CD-ROM].
- Formats : PDF
View record