Analysis of curing performance and application effect of bulk curing barns using different types of energy

【Objective】 To explore curing performance and application effect of bulk curing barns using different types of energy，so as to provide theoretical basis for green curing，energy saving，emission reduction，quality improvement and efficiency improvement of tobacco leaves.【Method】Taking bulk curing barn of coal-fired heating as control（CK），equipment cost，operation parameters，malfunction occurrence，curing performance，energy and labor consumption，pollutant emission during curing，the differences of economically relevant traits and comprehensive quality（color，softness，chemical composition and sensory quality）difference of flue-cured tobacco leaves were compared and analyzed in built-in new energy bulk curing barn using biomass heating of Treatment 1（T1）and new energy bulk curing barn using air source heat pump+solar heating assistance of Treatment 2（T2）.【Result】Compared with CK，biomass barn in T1 had moderate equipment cost and better curing performance，while T2 cost the highest in terms of barn equipment and transformation with slower heating rate and temperature stabilization.Barn equipment malfunction of T1 and T2 occurred less.The order of curing energy and labor consumption cost of bulk curing barn using different types of energy was： CK（2.63 yuan/kg）> T1（2.32 yuan/kg）>T2（1.19 yuan/kg），and significant difference was found between treatments（P<0.05，the same below）.Average of total pollutant emission（dust+SO₂+NO_X+NO）in CK at different temperatures during curing was 4.34 times higher than that of T1，while the averages at 42，54 and 67℃ were 7.74，3.46 and 3.28 times higher than that of T1.T2 in which barn used electric and solar energy emitted a negligible amount of pollutant emission during curing.Proportions of high-class tobacco，orange-yellow tobacco and average price of orange-yellow tobacco leaves in T1 were the highest；proportions of variegated tobacco and tobacco leaves out of grade（curing loss）were the lowest than that of CK and T2；moreover，the proportion of high-class tobacco in T1 was significantly higher than that of CK and T2，increased by 8.01% and 16.05%，respectively.L value，a color parameter of flue-cured tobacco leaves，of CK and T1 treatment was significantly higher than that of T2 treatment，increased by 7.22% and 6.32% respectively；and their b values were higher too，showing that flue-cured tobacco leaves of CK and T1 were brighter and yellower；a value，a color parameter，of fluecured tobacco leaves of CK（10.64）was significantly lower than that of T2（12.73），indicating that T2 imposed stronger orange color on tobacco leaves.Softness of flue-cured tobacco leaves of T1 and T2 was better，and their softness values were 73.01% and 52.08% of CK，significantly lower than that of CK.Compared with CK，flue-cured tobacco leaves of T1 was the best in chemical composition coordination and sensory quality evaluation，while such indocators T2 treatment were moderate.【Conclusion】The built-in new energy bulk curing barn using biomass heating has good curing performance and application effect，so it is one of the main replacements of bulk curing barn of coal-fired heating at present，and it is suitable to be popularized in the areas with fully equipped biomass fuel and related facilities.The flue-cured tobacco leaves have strong orange color，good softness and ecological benefit in new energy bulk curing barn using air source heat pump+solar heating assistance，pointing out an important direction of flue-cured tobacco curing in the future.