Thermal conductivity, specific heat, thermal diffusivity, and emissivity of stored canola seeds with their temperature and moisture content

Abstract

Density (ρ), specific heat (cp), thermal conductivity (k), diffusivity (α), and emissivity (ε) of canola seeds (Brassica napus L.) are important engineering parameters in the design of storage, heating, and cooling systems. The properties were determined at moisture content (MC) ranging from 5% to 11% (M/M) wet basis (w.b.) and temperature from 40 to 90°C. Bulk (ρb) and particle (ρp) densities of stored canola seeds decreased with temperature and ranged from 654.0 to 664.8kgm−3 and 1047 to 1131kgm−3, respectively. The cp of stored canola seeds increased with temperature and MC, and ranged from 2180 to 3498Jkg−1°C−1. The k of stored canola seeds at ρb and ρp increased with temperature and MC and ranged from 0.06 to 0.13Wm−1·°C−1 and 0.15 to 0.25Wm−1°C−1, respectively. The α of stored canola seeds at ρb and ρp were calculated from the measured k, cp, and ρ, and ranged from 0.40×10−8 to 5.7×10−8m2s−1, and 6.1×10−8 to 8.0×10−8m2s−1. The α of stored canola seeds at ρb increased with temperature and MC. The α of stored canola seeds at ρp exhibited descending–ascending trends with increasing MC at different temperatures except 40°C. The ε of stored canola seeds decreased with MC and temperature and ranged from 0.93 to 0.99. Based on the experimental data, regression models for all the properties were developed.