Expansion refrigeration can obtain relatively larger temperature drop

and it had the potential of utilization on industrial energy saving

such as cryogenics air separation

light hydrocarbon recovery

expansion valve replacement and mine cooling

etc. At present

lots of large-scale gas expansion refrigeration systems have been applied in many industrial fields. In many actual industrial processes

there were tremendous demands for small-scale gas expansion refrigeration units. However

those systems didn't realize commercial application due to technical and economic bottleneck. So research and development small-scale reverse Brayton cycle refrigeration system was very important to energy conservation and emission reduction for our country. In this paper

a typical process of reverse Brayton cycle refrigeration system was presented and the thermodynamic model was established

the influence factors of internal heat exchanger and the adiabatic efficiency of expanders were analyzed. From the simulation result

it was concluded that internal heat exchanger couldn't improve the coefficient of performance for entire system

but could decrease the outlet temperature of expander efficiently. With the increase of reheat temperature difference

the effect of reheat reduced. Those works can provide the theoretic basis to study on small-scale reverse Brayton cycle refrigeration system.