The Research About Intelligent Temperature Control System Applying In Tea Drying Machine

Tea Tea coal-fired hot blast stove is widely used as automatic chain drying machine heatingdevice. But because of its low heat energy utilization rate is only30%-40%, and the airtemperature is not stable, is not conducive to the efficient use of energy and tea factory teaquality improvement. By using the industrial automatic control technology, the intelligenttemperature control system of hot blast stove for energy saving reformation of constanttemperature, in order to solve the problem which is the tea factory production problems.Tea drying machine intelligent control system of constant temperature heat using frequencyconversion fan instead of the traditional fan, through the PLC intelligent control exhaust fanfrequency, change the exhaust fan speed, so that the exhaust fan speed and coal-fired condition,air temperature to achieve the best matching. In the case of heat load, frequency conversion fanpaid work can reduce, coal consumption is effectively reduced, the temperature of tea dryingmachine are effectively guaranteed. So the tea stove temperature control system is energy saving,coal saving, stable tea drying quality and other advantages, has broad prospects for development.Through field test, simulation test, biochemical experiment method on the tea dryertemperature control system performance characteristics, intelligent temperature control systemapplication before and after tea drying quality, different temperature and temperature fluctuationon tea quality influence, intelligent temperature control system, the comprehensive economicbenefits were analyzed, and reached the following conclusions:(1) Tea drying machine of intelligent temperature control system can effectively control thetemperature of hot air: the system after the application of hot air temperature and the settemperature is no notable difference, which temperature difference of less than5℃, itscoefficient of variation is much smaller than the artificial control of B processing. Show teadrying machine intelligent temperature control system of hot blast temperature compared withthe manual control accuracy and stability are improved.(2) Tea drying machine of intelligent temperature control system can effectively improvethe tea factory environment: the ventilator frequency regulation, noise and wind speed aresignificant changes, when the mean power frequency of25Hz, ventilator noise from66.28dB to55.26dB; wind speed by mean velocity15.51m/s to5.03m/s, exhaust smoke volume from theaverage smoke exhaust volume by1786.97m3/h to580.11m3/h, the amplitude is reduced by60%.(3) Tea drying machine of intelligent temperature control system applied to indicate: In the system early tea drying: intelligent temperature control system compared with themanual control of the same batch of raw water content coefficient of variation is small, relativelyuniform moisture content of tea; tea biochemical components of various treatments had littledifference, the overall intelligent temperature control system in tea polyphenols, caffeine, aminoacids, flavonoids, soluble sugar content than the artificial control increased slightly, but did notreach significant level; It is slightly higher than the artificial control of sensory evaluation of tea,tea quality is stable.In the refined tea drying: intelligent temperature control compared with the manual control,the same batch of tea caffeine, amino acids, flavonoids, soluble sugar, water extract the amonggroup variation coefficients were less than manual processing, tea contains ingredients morestable. The tea polyphenols, amino acids, soluble sugar content of intelligent temperature controlcompared with the manual control differences, reached5%significant level. Caffeine, flavone,water extract content difference is lesser, mutual or. Through refined tea review analysis,intelligent temperature control of refined tea quality is superior to manual control, tea qualitystability and uniformity can be improved effectively.(4) The different temperature and temperature fluctuation in tea drying in the study suggestthat:In the system early tea drying: temperature fluctuations in the raw water impact, because theinitial drying the main purpose is to dissipate moisture, drying time is short and fast.Temperature fluctuations, the higher water content did not reach drying requirements. Initialdrying on tea contains ingredients of small effect, different treatments between tea polyphenols,amino acids, soluble sugar, caffeine, water extract content were not significant difference.Flavone content increased along with the increment of temperature, different temperaturedifferences are significant at5%level. From the tea leaf analysis, temperature control oforganoleptic quality of tea is better than poikilothermic treatment organoleptic quality of tea.In the refined tea drying: with the rise of temperature, temperature fluctuation rangeexpansion of caffeine, amino acids, soluble sugar content decreased significantly; the teapolyphenol content with temperature fluctuation range expansion, the difference between the twogroups at the5%significance level; water extract content with the temperature increasing,increased first and decreased after. Different temperature and temperature fluctuation processingof sensory evaluation of tea differences, where C2D1processing of sensory evaluation of tea thatscored the highest, the drying temperature under120℃is favor for tea quality formation. (5) The economic benefits analysis showed: in the living rock tea factory as an example ayear tea factory coal cost about￥162961.54, obvious coal saving effect; the intelligenttemperature control system makes the fan working frequency by controlled50Hz as averagefrequency of less than25Hz, fan power consumption is significantly reduced, saving about￥5695.97a year; intelligent temperature control system by frequency conversion constanttemperature control of the quality of the tea has been improved to a certain extent, the economicbenefit estimation for15-30million, benefit is apparent. The living rock tea factory transforms5tea dryer coal-fired hot blast furnace, a total of￥62500,5sets of intelligent temperature controlsystem to produce economic benefits including coal, electricity, tea quality improvement, total￥318657.51-468657.51million, profit is the investment of5.1-7.5times.The results show that: the tea drying machine of intelligent temperature control system hasobtained good effect to stability of tea drying temperature, saving energy and reducingconsumption, improve the quality of tea to tea, to the economic increase has remarkablepromotion effect.