SIMULATION OF THE INDIRECT NATURAL-CONVECTION SOLAR DRYING OF ROUGH RICE

被引:64
作者
BALA, BK [1 ]
WOODS, JL [1 ]
机构
[1] UNIV NEWCASTLE UPON TYNE,DEPT AGR & ENVIRONM SCI,NEWCASTLE TYNE NE1 7RU,TYNE & WEAR,ENGLAND
关键词
D O I
10.1016/0038-092X(94)90632-7
中图分类号
TE [石油、天然气工业]; TK [能源与动力工程];
学科分类号
0807 ; 0820 ;
摘要
A mathematical model to simulate the indirect natural convection solar drying of rough rice is presented. The temperatures along the collector are described by a numerical solution. The drying of the grain is described by the introduction of a deep-bed solution procedure. The variation of the air temperature in the collector and across the air bed is incorporated in the prediction of the thermal buoyancy effect. The results show that, at the low air flow rates produced by natural convection, the drying wave moves slowly and the layer of grain cannot be considered uniform, with serious overdrying taking place in the bottom layer. The deep bed model is therefore essential in order to obtain a realistic simulation. Also, due to the temperature drop across the bed, the chimney height makes little contribution to buoyancy. Sensitivity analysis showed the system to be most sensitive to grain bed depth and collector length and least to chimney height and cover to absorber spacing. The simulation results have a number of practical implications. The grain bed should be turned regularly to avoid over-drying and give a tempering effect. The collector and plenum chamber upstream of the grain bed should be well sealed to contain the buoyancy pressure. The effect on performance of reducing or removing the chimney should be examined.
引用
收藏
页码:259 / 266
页数:8
相关论文
共 31 条
[1]  
[Anonymous], 1977, HDB ESSENTIAL FORMUL
[2]  
Bailey P. H., 1972, THESIS U NEWCASTLE T
[3]   SIMULTANEOUS HEAT AND MASS TRANSFER DURING COOLING OF A DEEP BED OF BIOLOGICAL PRODUCTS UNDER VARYING INLET AIR CONDITIONS [J].
BAKKERARKEMA, FW ;
BICKERT, WG ;
PATTERSON, RJ .
JOURNAL OF AGRICULTURAL ENGINEERING RESEARCH, 1967, 12 (04) :297-+
[4]  
Bala B. K., 1983, THESIS U NEWCASTLE T
[5]   SIMULATION OF DEEP BED MALT DRYING [J].
BALA, BK ;
WOODS, JL .
JOURNAL OF AGRICULTURAL ENGINEERING RESEARCH, 1984, 30 (03) :235-244
[6]  
BALA BK, 1990, 1ST P WORLD REN EN C, P938
[7]   ATMOSPHERIC RADIATION NEAR THE SURFACE OF THE GROUND - A SUMMARY FOR ENGINEERS [J].
BLISS, RW .
SOLAR ENERGY, 1961, 5 (03) :103-120
[8]   HEAT AND MOISTURE TRANSFER IN VENTILATED GRAIN [J].
BOYCE, DS .
JOURNAL OF AGRICULTURAL ENGINEERING RESEARCH, 1966, 11 (04) :255-&
[9]  
DALY BB, 1979, WOOD PRACTICAL GUIDE
[10]  
Duffie JA, 1980, SOLAR ENG THERMAL PR