Background: Hydraulic Control Rod Drive Technology（HCRDT） is a newly invented patent and Institute of Nuclear and New Energy Technology Tsinghua University owns HCRDT’s independent intellectual property rights.Purpose: Integrated valve which is made up of three direct action solenoid valves is the key part of this technology

so the performance of the solenoid valve directly affects the function of the integrated valve and the HCRDT.The performance of the coil affects the service behavior of the solenoid valve

so the thermal performance of the coil is researched.Methods: The temperature field of the coil of the direct action solenoid valve was analyzed using the ANSYS software with various currents

the results of which were validated by experiments.Results: The result shows that the temperature of the coil of the solenoid valve increases with the current increasing firstly.Second

the temperature of the inner wall of the coil is higher than that of the exterior wall.The temperature of the middle coil is higher than that of the edge of the coil.Third

the coefficient of thermal conductivity of the coil is obtained.Fourth

the highest temperature of the coil is under the limiting temperature.Furthermore

the comparison of the temperature of the coil achieved by calculation with the one achieved by experiment under different condition shows that the calculation results are rational if the experiment errors are considered.Conclusions: The results can be provided for the parameter design of the solenoid valve.