Abstracto
- An alternative simple method is proposed for the assessment of the ability of liquid materials to transport thermal energy, driven by a temperature gradient. The quantity J = kN × ρ × Cp for different liquids correlates with the corresponding values of thermal conductivity (λ) at p < 0,01, where kN is the Newton’s cooling rate constant of a material of density ρ and heat capacity Cp. The J values of biodiesel, vegetable oils and petroleum-derived long-chain materials are statistically similar. This finding allows taking advantage of the environmentally friendly characteristics of vegetable oils and biodiesel for thermo-solar and low-enthalpy geothermal applications. The empirical regression equation is J / kW K-1 m-3 = 1,5 + 2,2 λ / W K-1 m-1.