Selected thermo-energetic parameters of pellets
2015
Božiková, Monika (Slovak University of Agriculture, Nitra (Slovak Republic). Faculty of Engineering, Department of Physics) | Hlaváč, Peter (Slovak University of Agriculture, Nitra (Slovak Republic). Faculty of Engineering, Department of Physics) | Vozárová, Vlasta (Slovak University of Agriculture, Nitra (Slovak Republic). Faculty of Engineering, Department of Physics) | Valach, Michal (Slovak University of Agriculture, Nitra (Slovak Republic). Faculty of Engineering, Department of Physics)
This article deals with thermal properties of selected biofuels (rape straw pellets, straw pellets, softwood pellets, hardwood pellets). Physical parameters as density, heat of combustion, calorific value and basic thermophysical parameters (thermal conductivity, thermal diffusivity and volume specific heat) were measured. For heat of combustion and calorific value was used calorimetric system IKA C5000. In this calorimetric system heat created during the burning process can be determined using by adiabatic measurement procedure. Thermal conductivity and thermal diffusivity of samples were measured by transient method - Extended dynamic plane source (EDPS) method and values of volume specific heat were calculated from obtained experimental results. For each sample were made two series of measurements. In the first series thermal conductivity and thermal diffusivity at constant room temperature 20 °C were measured. Every thermophysical parameter was measured 100 times for each sample. The results were statistically processed. Obtained results of volume specific heat for sample of hardwood pellets was 0.0666×107 J.m-3.K-1. The softwood pellets had lower value of volume specific heat 0.0572 J.m-3.K-1. The highest volume specific heat 0.6562×107 J.m-3.K-1 had straw pellets and than rape straw pellets cp= 0.5122×107J.m-3.K-1. The second series of measurement was focused on combustion heat and calorific value determination. Obtained values of combustion heat were from range 14.3 – 20.2 MJ.kg-1and calorific values were from range 12.2 – 19.0 MJ.kg-1. All presented results are in good agreement with values presented in the literature.
显示更多 [+] 显示较少 [-]