DEVELOPMENT OF HOT/COLD PLATE APPARATUS FOR DETERMINING HEAT TRANSPORT MECHANISMS IN MULCH MATERIALS

摘要

To study the effects of mulches and crop residues on soil temperature, researchers have frequently used simulation models. In such models, quantification of heat transport within the mulch material is often weak and heat transport mechanisms are poorly understood. In this paper we describe an apparatus to quantify heat transport through dry mulch materials. In addition, heat transport mechanisms (conduction, thermal radiation, free and forced convection) can be identified and quantified using this apparatus. The apparatus consists of precisely controlled and monitored 0.9 m by 0.9 m hot and cold plates. The hot plate actually consists of three component plates: a test, a guard, and a bottom plate that are individually controlled (temperature) and monitored (temperature and power). The guard plate surrounds the test plate, minimizing undesired lateral heat flow. The bottom plate is positioned in parallel with the test and guard plates to insure that all wattage into the test plate moves off the top of the plate through the mulch. The correct functioning of the hot plate was verified using three reference materials with a known thermal resistance