Motive flow calculation through ejectors for transcritical CO2 heat pumps. Comparison between new experimental data and predictive methods

34th UIT Heat Transfer Conference 2016

Boccardi, G.^1 ; Lillo, G.^2 ; Mastrullo, R.^2 ; Mauro, A.W.^2 ; Pieve, M.^1 ; Trinchieri, R.^1

Energy Department Production, Conversion and Use of Energy Division, Laboratory of Development of Chemical Processes and Thermofluidynamic, ENEA, C.R.Casaccia - Via Anguillarese 301, Roma

00123, Italy^1

Department of Industrial Engineering, Federico II University of Naples, p.le Tecchio, 80, Napoli

80125, Italy^2

关键词: Choked-flow condition;    Developed countries;    Environmental policy;    Flow calculations;    Mass flow rate;    Predictive methods;    Statistical comparisons;    Throttling valves;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/796/1/012040/pdf
DOI  :  10.1088/1742-6596/796/1/012040

来源: IOP

【 摘 要 】

The revival of CO2as refrigerant is due to new restrictions in the use of current refrigerants in developed countries, as consequence of environmental policy agreements. An optimal design of each part is necessary to overcome the possible penalty in performance, and the use of ejectors instead of throttling valves can improve the performance. Especially for applications as CO2HPs for space heating, the use of ejectors has been little investigated. The data collected in a cooperation project between ENEA (C.R. Casaccia) and Federico II University of Naples have been used to experimentally characterize several ejectors in terms of motive mass flow rate, both in transcritical CO2conditions and not. A statistical comparison is presented in order to assess the reliability of predictive methods available in the open literature for choked flow conditions.