To explore the feasibility of applying carbon nanotubes (CNTs)/paraffin composites to heat pump water heater system as phase change heat storage media,the heat transfer characteristics of phase change thermal storage heat pump water heater were analyzed and discussed.It was shown that the heating and cooling rates of nanocomposite phase change materials were significantly improved upon the addition of CNTs nanoparticles,and the heat pump heat water with thermal storage had good stability in heat storage and release process.There were some differences in the distribution of temperature field in phase change heat storage system,especially in the exothermic stage.Thermal “stagnation” occurred near the corner of the outlet of water medium,so it was necessary to increase the amount of materials appropriately.Compared with traditional regenerative heat pump water heater with water tank,the volume of regenerator of heat pump water heater was reduced by about 1/2 with the addition of nanocomposites,and the thermal efficiency can reach 86%.The running experimental results of the heat pump water heater suggested the reliability of designment of the thermal energy storage and the feasibility of CNTs/paraffin using in the heat pump water heater.The temperature of CNTs/paraffin composites rised faster and the heat transfer time was shorter at higher ambient temperature.Obviously,ambient temperature had a significant impact on the performance of heat pump system.
Tu Zhigang, Li Xinfang, Zhao Sufen, Tang Linxin, Xiong Ligui
. Influence of CNTs filler on performance of phase change thermal storage heat pump water heater[J]. New Chemical Materials, 2020
, 48(11)
: 158
-162
.
DOI: 10.19817/j.cnki.issn 1006-3536.2020.11.035
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