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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.47 [2009] >
IJPAP Vol.47(12) [December 2009] >
| Title: | Ecological, exergetic efficiency and heating load optimizations for irreversible variable-temperature heat reservoir simple air heat pump cycles |
| Authors: | Bi, Yuehong
Chen, Lingen
Sun, Fengrui |
| Keywords: | Thermodynamic optimization
Irreversible air heat pump
Variable-temperature heat reservoir
Heating load
Exergetic efficiency
Ecological function |
| Issue Date: | Dec-2009 |
| Publisher: | CSIR |
| Abstract: | Thermodynamic
optimization of an irreversible air heat pump with variable-temperature heat
reservoirs and hot- and cold-side counter-flow heat exchangers has been studied.
The expressions of the heating load, the exergetic efficiency and the
ecological function of the heat pump cycle are derived. Performance comparisons
among exergetic efficiency optimization, ecological optimization and
traditional heating load optimization objectives are done. The effect of the
pressure ratio of the compressor, the allocation of heat exchanger inventory
and the heat capacity rate matching between the working fluid and the heat
reservoirs on the optimal performance of the cycle has been investigated by
detailed numerical examples. When the performance optimization of the cycle is
carried out by selecting the pressure ratio, three optimization objectives give
simultaneously attention to the coefficient of performance (COP). The pressure
ratio should be the one that is little bigger than the optimum pressure ratio
corresponding to maximum COP, however, the results of three optimization
objectives are consistent by optimizing the allocation of heat exchanger
inventory and optimizing the heat capacity rate matching between the working
fluid and the heat reservoirs. The optimum allocations of heat conductance are
close to each other, and they are all less than 0.5. The results may provide
guidelines for the design and optimization of practical air heat pump plants. |
| Page(s): | 852-862 |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.47(12) [December 2009]
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