Energy in Agriculture最新文献

A single-cylinder, four-stroke, direct-injection diesel engine fuelled with 1 : 1 volumetric blend of rapeseed oil (Brassica juncea L.) and conventional diesel fuel was run satisfactorily for 324 h at approximately 85% of the full-rated power output without any major alteration to the engine. Its performance deteriorated with the cumulative hours of operation, but could be restored to normal by decarbonising exhaust manifold and fuel injector tip after every 100 h of operation. Wear in various engine components was not abnormal. Limited tests of engine lubricating oil revealed no abnormality over the regular oil-change period.

Cardamom drying (curing) is an important energy-consuming process. Existing curing chambers in India have many flaws, the major one being a very low thermal efficiency resulting in a huge waste of firewood.

In the present paper, a mathematical model has been developed to study the heat transfer characteristics of conventional curing chambers. The conventional heat exchanger has been found to be the major cause for their low efficiencies. Based on the model, ways of improving the thermal efficiency of cardamom curing chambers are suggested.

Mechanized farming depends to a large extent on the petroleum fuel used for traction. The inevitable depletion of petroleum resources will have far-reaching consequences on large-scale farming vital for the future, unless renewable energy alternatives can be found. A good way of doing this is to evolve within each farming unit a self-sustaining energy scheme.

The paper describes the development and testing of concentric-vortex type, agricultural residue-fired furnace which can be used for heating the air to a grain dryer. Measurements were made of furnace combustion efficiency at various fuel feedrates and air flow rates. The highest furnace efficiency obtained was 85% at a feed rate of 82 kg/h and an air flow rate of 1810 kg/h. The temperature of the flue gas varied from 420 to 870°C at various feed rates and air flow rates. The maximum heat release occurred when the furnace was supplied with 310% excess air over that needed for complete combustion. The turndown ratio for the furnace varied from 3.1 to 1, on a wet basis moisture content.

Approximately one-third of the idle cropland in the Piedmont counties of the five southern states, Virginia, North Carolina, South Carolina, Georgia and Alabama, would have to be planted in sweet sorghum with an average yield of 40 t/ha to produce a volume of ethanol equal tro the volume of petroleum fuel purchased by farmers in the Piedmont counties (518 million L/year), assuming that 65% of the fermentable sugar is extracted. If the by-products are ensiled for cattle feed, it is sufficient to feed 1.5 times the entire cattle population of the Piedmont of Virginia, and 3.0, 0.78, 1.25 and 1.16 times the Piedmont cattle population in North Carolina, South Carolina, Georgia and Alabama, respectively.

Cotton plant residues have shown promise as a biomass material for thermal energy. Therefore, equipment must be available to efficiently harvest the plants. A counterrotating-wheel plant puller was evaluated as a method to harvest cotton stubble from the soil. Power required to rotate the pulling wheels in the laboratory increased with a decrease in tire pressure and an increase in force between the wheels. Static pull forces on steel rods and a wood dowel held between the pulling wheels could be increased by changing tire pressure and force between the pulling wheels. Static pull forces determined in the laboratory were useful in evaluating the unit's ability to pull cotton stubble in the field. The pulling wheels were effective in pulling 97% of the cotton stubble. They operated efficiently at tire pressures between 69 and 124 kPa with 2.7–3.6 kN of force between the pulling wheels while traveling at velocities up to 8 km/h.