Heat dissipation characteristics of coil heating bed system using low temperature hot water

Proposes a coil heating bed system using low temperature hot water. Analyses the heat transfer mechanism of the bed system, and establishes a mathematical model for the thermal process. Using a method of numerical simulation combined with experiment, studies the effect of the design parameters, including coil pipe diameter, coil pipe spacing and operating water temperature, on the heat dissipation characteristics of the system. The results show that the operating water temperature has the dominant effect on the heat dissipation, and the pipe diameter and spacing of the coil have less effect. The bed system needs 1 h, 2 h, 10 h to reach the steady state in a period of daytime heating, nighttime heating and discontinue heating, respectively. The maximum heat dissipating capacity of the bed system during the day and night are 308 W/m2 and 36 W/m2, respectively. The error between numerical calculation results and test results is within 6%, which meets the requirement of accuracy.