With high thermal efficiency

the supercritical CO_2 Brayton cycle system based on solar particle-receiver has great development potential. By applying a more accurate particle-side heat transfer model

the supercritical CO_2 fluidized bed heat exchanger model is established. On the basis of the operating parameters of the heat exchanger with 100 kW heat transfer power

the external diameter

tube bundle number

particle size and fluidized gas temperature of the heat transfer pipes are optimized. The results show that

under the condition that the flow pressure loss of CO_2 is 0.01 MPa

the optimized tube bundle parameters of the heat exchanger are as follows: the outer diameter of the tube is 10 mm

the thickness of the tube is 2.9 mm

the number of the tubes is 97. When the small particle size particles are selected

the critical fluidization velocity is low

the flow rate is small

so the heat loss of the gas can be effectively reduced

the heat efficiency of the heat exchanger can be improved

and the energy consumption of the fan can be decreased. With the optimized tube bundle parameters

when the particle size increases from 100 μm to 500 μm

the heat loss increases from 70.32 W to 1 176.00 W

the thermal efficiency declines from 99.93% to 98.84%

the fan power consumption increases from 21.60 W to 405.97 W

the inlet temperature of the fluidized gas rises from 570 ℃to 630 ℃

and the thermal efficiency of the heat exchanger increases from 98.52% to 99.64%.