Effect of initial temperature and pressure on the performance of CO2 discharge under gas pressurization

In order to supply CO2 with stable pressure and flow rate to downstream heat transfer system, gas pressurization is an effective scheme. In this paper, five experiments are conducted to study the effect of initial temperature (T-ini,T-CO2) and pressure (P-ini,P-CO2) on the performance of CO2 discharge under gas pressurization. P-ini,P-CO2 and T-ini,T-CO2 are 2.40 similar to- 28.56 MPa and -13.42 similar to 44.16 degrees C, respectively. The initial density is all most constant (approximate to 900 kg/m(3)). Firstly, the pressure and temperature evolutions for two typical conditions are investigated. The whole experimental process is divided into four stages: active pressurization (Stage I), discharge without pressurization (Stage II), discharge with pressurization (Stage III) and discharge with isobaric gas-liquid (Stage IV). Then the system performances of the four stages under different P-ini,P-CO2 and T-ini,T-CO2 are discussed in turn. The results show that CO2 can discharge constantly within a certain pressure range under different P-ini,P-CO2 during Stage III after Stage I and Stage II; In Stage III, the higher P-ini,P-CO2, the lower the discharged density. The pressure drop rate in Stage IV is much lower than that discharge without pressurization. This research will provide an important reference for the discharge of CO2 or other similar fluids under different working conditions.