School of Energy;
Power & Mechanical Engineering;
North China Electric Power University;
Baoding;
China;
Swan Center for Energy Research;
Newcastle University;
Newcastle Upon Tyne;
UK;
Direct; Expansion; Ground; Source; Heat; Pump; (DXGSHP); Thermodynamic; Performance; HFO-1234yf; HFO-1234zeE; HFC-134a;