Thermal network calculation model for phase change material with SPICE circuit simulator

Abstract

The SPICE model of phase change material (PCM) for thermal network transient calculation was investigated. The nonlinear behavior of PCM due to latent heat was modeled by using the voltage dependent current source and the capacitor. A latent heat is stored in the capacitor as electric charges. Corresponding to the PCM phase state, such as solid, liquid and mixed phases, the dependent current source is controlled with PCM temperature and the latent heat quantity of PCM. Since the melting point of PCM has a distribution, the model in which multiple PCM models having different melting points and capacitor capacities were connected in parallel was employed. To validate the numerical simulation model, the aluminum case with PCM sealed inside was prepared. The sample was heated with a rubber heater from the bottom with different heat quantities. The temperature changes of the upper and lower surfaces were measured with thermocouples. The results showed the error between simulated and measured values were below ±4 °C and the calculation time took below real-time. This simulation model can be applied to cooling system optimization and temperature control system.

Keywords

• phase change material
• thermal design
• thermal network method
• temperature transient
• spice model