In order to overcome the deterioration of heat transfer caused by two-phase flow and avoid the flow separation

the steam-water separator was replaced by introducing the drain water flashtank into solar energy collection system.Integration between direct steam generation(DSG) system and a 300MW coal-fired power plant was conducted.To ensure the steam parameters at outlet of the DSG system are equivalent with that at extraction point of turbine a length calculation model of the preheat section and superheat section in the DSG heat collection system in which the working fluid is only water and steam(gas phase)was put forward

and a steam amount control model was also presented.Furthermore

five design schemes for using steam at outlet of the DSG system to replace the first five stage extraction steam in turbine of the 300 MW coal-fired power unit were proposed

and the thermal economy of each scheme was calculated.The results showed that

the scheme that using steam at outlet of the heat collection system to replace the third stage extraction steam of turbine had the highest thermoelectric conversion rate(0.324).