Influence of supply air temperature fluctuation on temperature control accuracy of constant-temperature undulator tunnels

Due to the particularity of scientific devices in the undulator tunnel, very strict requirements are put forward on the stability of the air temperature in the tunnel. Taking a constant-temperature undulator tunnel as the research object, a physical model is established using PHOENICS software, and the influence of the supply air temperature fluctuation on the temperature stability of the constant temperature area in the tunnel is studied by the numerical simulation method, in order to determine the critical value of temperature fluctuation. The results show that when the supply air temperature fluctuates, the closer the air is to the two ends of the tunnel, the smaller the temperature fluctuation. When the supply air temperature fluctuation value is ±0.200 ℃, the temperature fluctuation value is between -0.013 ℃ and 0.180 ℃ in the axial direction of the constant temperature area in the tunnel, and between -0.029 ℃ and 0.187 ℃ in the radial direction within 30 minutes. Therefore, in order to meet the requirement of temperature control accuracy (±0.200 ℃) in the constant temperature area of the undulator tunnel, the fluctuation of supply air temperature should not exceed 0.200 ℃.