In the oxygen combustion CO_2 cycle

heat integration of the air separation unit(ASU) is commonly used to improve the matching of the heat recovery process. However

the ASU heat integration increases the heat recovery load

and the relatively low load ramp rate of the ASU affects the overall performance of the system. To eliminate the need for ASU heat integration and further enhance cycle efficiency

a method involving split adiabatic compression is proposed to balance the thermal capacities of the hot and cold streams. A power generation system model based on the gasification oxygen combustion CO_2 cycle is developed in Aspen

and the thermodynamic performance of the system

as well as the effect of ASU heat integration

are analyzed. A recompression system is also introduced for comparison. The results show that

the conventional system with integrated ASU heat has a net efficiency of 43.39%. Compared with a system without heat integration

the power consumption of the ASU increases by 19.9 MW

while 180.8 MW of heat integration is provided

resulting in a 1.64 percentage points increase in net efficiency. Considering limitations in heat recovery

the optimal split mass flow rate for the recompression system is 258.2 kg/s. Compared with the ASU heat integration

the recompression system reduces the heat recovery load by 59.8 MW

and the average heat exchanger temperature difference is further reduced by 3.1 ℃

improving the net efficiency to 43.52%. The study reveals the mechanism by which heat integration affects the efficiency of the oxygen combustion CO_2 cycle and proposes an optimization to decouple the power cycle from the ASU heat integration through the recompression process

providing theoretical guidance for the parameter design of the recompression system.