TY - GEN
T1 - The viability of capacity control of high temperature heat pump water heaters operating non-azeotropic mixtures
AU - Liebenberg, Leon
AU - Meyer, Josua P.
N1 - Publisher Copyright:
Copyright © 1997 by ASME.
PY - 1997
Y1 - 1997
N2 - A high temperature electrically-operated heat pump water heater is evaluated in terms of the viability of employing capacity control using non-azeotropic refrigerant mixtures (NARMs). The system coefficient of performance (COP) is improved by introducing capacity control, which offers continuous modulation by varying heat pump capacity to match the load. This is accomplished by using a non-azeotropic refrigerant mixture (NARM) and clumging the composition (x) of the circulating mixture. The NARM R-22/ R-I42b is selected due to the requirement for a high condensing temperature and a wide capacity range. The life-cycle cost effectiveness of this heat pump is compared with that of a conventional heat pump (operating a pure fluid). Computer simulations show that the capacity-controlled heat pump, operating between compositions of 100% R-22 and 70% R-22, shows a 29.6% improvement in energy conversion when compared with a conventional R-22 heat pump water heater. The payback periods of the capacity-controlled systems, are strongly dependent on electricity tariff, additional system cost, and period and duration of heat pump operation.
AB - A high temperature electrically-operated heat pump water heater is evaluated in terms of the viability of employing capacity control using non-azeotropic refrigerant mixtures (NARMs). The system coefficient of performance (COP) is improved by introducing capacity control, which offers continuous modulation by varying heat pump capacity to match the load. This is accomplished by using a non-azeotropic refrigerant mixture (NARM) and clumging the composition (x) of the circulating mixture. The NARM R-22/ R-I42b is selected due to the requirement for a high condensing temperature and a wide capacity range. The life-cycle cost effectiveness of this heat pump is compared with that of a conventional heat pump (operating a pure fluid). Computer simulations show that the capacity-controlled heat pump, operating between compositions of 100% R-22 and 70% R-22, shows a 29.6% improvement in energy conversion when compared with a conventional R-22 heat pump water heater. The payback periods of the capacity-controlled systems, are strongly dependent on electricity tariff, additional system cost, and period and duration of heat pump operation.
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U2 - 10.1115/97-AA-028
DO - 10.1115/97-AA-028
M3 - Conference contribution
AN - SCOPUS:84928485565
T3 - Proceedings of the ASME Turbo Expo
BT - ASME 1997 Turbo Asia Conference, TA 1997
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 1997 Turbo Asia Conference, TA 1997
Y2 - 30 September 1997 through 2 October 1997
ER -