Compared with the unsplit-flow waste-heat recovering system

the waste-heat recovering system with split-flow CO_2 transcritical power cycle (split-flow system) can avoid the temperature interference between various heat exchangers

which can enhance the waste-heat utilization rate of flue gas and the efficiency of regenerator

thus to improve the work ability of the waste heat recovery system.However

the more complex system inevitably results in an increase of the system cost.To solve this problem

based on the MATLAB platform

this paper establishes the economic model of the above split-flow system.The economic efficiency of this system is investigated by using the evaluation parameters such as the unit energy cost (C_(UEC))

the area power ratio (r _(APR)) of heat exchanger

and the environmental payback period (t _(EPP)).The results show that

the C_(UEC) of the split-flow system has advantages in a large and commonly used working conditions

where the inlet temperature of the expander is about 505 K and the inlet pressure is about 13.5 MPa.When the inlet temperature of the expander is higher than 473 K

the r _(APR) of the split-flow system has obvious advantages

which can be at most 11%lower than that of the unsplit-flow system.The t _(EPP) of the split-flow system is better than that of the unsplit-flow system under all working conditions.The split-flow system has a certain competitiveness in economy

especially when the inlet temperature of the expander is higher than 480 K.Finally

for the future research directions

some suggestions are given

such as performing multi-objective optimization on economic parameters

analyzing the coupling of waste heat recovery system and internal combustion engine

and so on.