A modeling study on heat transfer fluid system of 50 MW parabolic trough solar thermal power plant is conducted using AFT Fathom.The simulation of heat transfer fluid flow distribution in the collector circuits is proposed under three low flow conditions.In this simulation，the operation parameters，such as DNI value

meteorological condition

site condition

layout of the heat collection field and operation mode are all based on the actual data of a certain project.The simulation results show that uneven flow distribution exists among collector circuits under low flow conditions.Discontinuous flow appears in some circuits under the lowest 8.4% design point flow condition.Based on the collector control strategy

impacts of the uneven flow distribution on power generation are estimated.Under 33.5% and 16.8% design point conditions

decreases in power generation are not significant.While under 8.4% design point condition

the power generation decreases by 20.65%

indicating a significant impact.