Simulation of Coupled Heat-Mass Transfer in Sea Cucumbers with Heat Pump Drying

Abstract

To study the heat and moisture transfer behavior in sea cucumbers with heat pump convective drying, a multi-physical field coupled model including the velocity field, temperature field, and dilute matter transfer in the porous media of sea cucumbers is built. The heat pump drying experiments verified the results of numerical simulation. The results show that the moisture content on the dry basis of a sea cucumber decreases from the surface to the inside. The sea cucumber’s surface temperature increases gradually with drying until it reaches an equilibrium temperature, while the time required decreases with the increase in wind speed. The dry basis moisture content at the center of three different samples decreases from the initial values of 17.29, 13.48, and 7.73 to 3.25, 1.80, and 0.66, respectively. Further, the surface temperatures reached 40 °C, 33 °C, and 30 °C, which are the same as the inlet temperature. The simulated results were within 11% of the experimental ones, showing good consistency for both the dry basis moisture contents and temperatures. This research proves that a coupled heat and mass transfer model based on the porous medium theory can well describe the heat and mass transfer characteristics of sea cucumber with heat pump drying. It is also useful for studies on drying process optimization and quality improvement of aquatic products with heat pump drying.

Keywords

• heat pump drying
• heat transfer
• mass transfer
• dry basis moisture content