Structural Optimization and Test Analysis of Hot Platen in Small-Scale Laminator

To address the temperature non-uniformity of heating platens in small-scale photovoltaic (PV) module laminators, this study develops a wire-wound hot platen with a Square loop layout and arithmetic-progression wire spacing. The heating wires are represented by an equivalent surface-heat-flux boundary, and CFD simulations are used to evaluate the effects of wiring layout, wire length, and spacing on the temperature field. The optimized Square loop layout reduces the full-field working-surface-temperature standard deviation from 1.887 °C to 0.552 °C, a reduction of 70.8%. A FLUENT-UDF incremental PID model is then developed using the top-surface area-weighted average temperature as feedback. At the 4800 s endpoint, the simulated controlled average is 150.55 °C, with a steady-state error of +0.55 °C and a maximum positive deviation of approximately 0.96 °C at approximately 4480 s; the holding-stage response shows a small limit-cycle oscillation of approximately ±1 °C. The local center-point temperature T1 is 153.0 °C, indicating a center-to-edge spatial non-uniformity that is distinct from the controller overshoot. A small-scale laminator platform with 13 thermocouples was used to benchmark the simulated platen-level temperature field. The measured 13-point average temperature is 150.55 °C, the maximum temperature difference is 3.0 °C, and the 13-point sample standard deviation is 1.05 °C; the maximum absolute error and mean absolute error are 1.30 °C and 0.913 °C, respectively. These results support the proposed surface-heat-flux model and incremental PID design for small laminator hot platens under the tested platen-level conditions.