TY - JOUR
T1 - Transcritical carbon dioxide microchannel heat pump water heaters
T2 - Part II-system simulation and optimization
AU - Goodman, Christopher
AU - Fronk, Brian M.
AU - Garimella, Srinivas
N1 - Funding Information:
Financial support from the US Army Ft. BelVoir office through a subcontract from Modine Manufacturing Company is gratefully acknowledged. The authors also thank Modine Manufacturing Company for supplying several of the test heat exchangers and associated components. Assistance from, and insightful discussions with Mr. John Manzione, Dr. Stephen B. Memory, Mr. David Garski, Mr. Sam Collier, and Mr. Mark Hoehne for conducting this research are also acknowledged.
PY - 2011/6
Y1 - 2011/6
N2 - This paper presents the development of a transcritical CO2 heat pump water heating system model incorporating analytical heat exchanger models and an empirical compressor model. This study investigated the effects of a suction line heat exchanger (SLHX) and once-through versus recirculating water heating schemes. The once-through systems outperformed the recirculating systems by 10% for the system without an SLHX and 15% with an SLHX. However, a gas cooler twice as large is required. The SLHX was shown to benefit system performance at higher evaporator temperatures with improvements of 16.5% for the once-through and 4% for the recirculating systems. This study can be used to improve the design of microchannel based transcritical CO2 heat pumps; evaluate the impact of varying water inlet temperature, desired outlet temperature and evaporation temperature on system performance; and quantify the effect of differential diurnal electricity rates on system operating costs for these different operation schemes.
AB - This paper presents the development of a transcritical CO2 heat pump water heating system model incorporating analytical heat exchanger models and an empirical compressor model. This study investigated the effects of a suction line heat exchanger (SLHX) and once-through versus recirculating water heating schemes. The once-through systems outperformed the recirculating systems by 10% for the system without an SLHX and 15% with an SLHX. However, a gas cooler twice as large is required. The SLHX was shown to benefit system performance at higher evaporator temperatures with improvements of 16.5% for the once-through and 4% for the recirculating systems. This study can be used to improve the design of microchannel based transcritical CO2 heat pumps; evaluate the impact of varying water inlet temperature, desired outlet temperature and evaporation temperature on system performance; and quantify the effect of differential diurnal electricity rates on system operating costs for these different operation schemes.
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U2 - 10.1016/j.ijrefrig.2010.12.001
DO - 10.1016/j.ijrefrig.2010.12.001
M3 - Article
AN - SCOPUS:79955881986
SN - 0140-7007
VL - 34
SP - 870
EP - 880
JO - International Journal of Refrigeration
JF - International Journal of Refrigeration
IS - 4
ER -