Abstract:The development process of grain storage ventilation technology in China was discussed in detail, including progress in grain storage in controlling temperature, saving energy, decreasing loss, intelligent control, in-store drying, pest control and research on ventilation mode and theory, which provided reference for understanding the latest theory and application of ventilation technology.

Abstract:The research and applications of new technology of green grain storage in recent years were summarized, including low temperature grain storage, irradiation disinsection, controlled atmosphere storage, biological control, environmental hygiene control, inert powder control and forecast, etc. It provided reference for further practice and application of new technology of green grain storage.

Abstract:Lateral ventilation system for grain storage has the advantages of conveniently and quickly loading and unloading grains, saving the manpower and material resources. The effect of ventilation uniformity plays an important role in grain storage system. The nitrogen concentration and nitrogen flow uniformity which in the lateral ventilation process of stored bulk grain was analyzed based on the finite volume method of computational fluid dynamics (CFD). The result showed that nitrogen concentration in the whole stored grain was very uniform during lateral ventilation for filling nitrogen, which provided hypoxic environment for storage. It provided a valuable reference for the optimization design of lateral ventilation system.

Abstract:The changes of the temperature and moisture in the closed grain warehouse were studied by numerical simulation. The factors of the warehouse were simplified, and a mathematical model was set. The relationship between respiration and the changes of the temperature and moisture in the grain bulk was studied. When the initial temperature in the grain bulk was high, the effect of respiration on the temperature and moisture was very significant. It provided a theoretical basis for reasonable "human intervention" to the environment of grain bulk.

Abstract:The application of transverse ventilation system in large warehouse (60×21) for wheat storage was studied, and the system was designed. The air velocity, volume, pressure and resistance of the ventilation system and the static pressure in the grain bulk were detected. The results showed that both the total resistance of ventilation system and the unit profile resistance of grain bulk increased along with the increase of the unit aeration volume, which should be no more than 7m3/h•t during the aeration application. The coefficient of variation of static pressure in the grain bulk was small, which reflected high uniformity of airflow distribution.

Abstract:With a set of transverse ventilation system installed in a paddy warehouse, and some Pitot tubes embedded in the paddy heap in advance, the airspeed, airflow, pressure distribution and the resistance of each part of this transverse ventilation system were measured. The test indicated that compared with vertically ventilation, the unit resistance of paddy heap by transverse ventilation system was much lower. And in the range of economical airflow rate, the total resistance of transverse ventilation system was no more than 1000 Pa. Furthermore, the air was equally dispersed into the entire grain pile. In conclusion, it was feasible that transverse ventilation system was applied in paddy warehouse, and it was efficient to cool down the grain pile.

Abstract:In order to calculate the resistance of grain heap when ventilated with vertical ventilation system, an experiment was carried out in an experimental store house with 180t wheat to detect the resistance in grain heap during vertical bidirectional ventilation with different direction and superficial gas velocity. The results indicated that during vertical ventilation, the resistance existed both on and inside the grain heap.The total resistance of grain heap was the sum of the facial resistance and the interior resistances. There was no strictly proportional relationship between the total resistance and the height of the pile. Comparing the upwards vertical ventilation with the downwards vertical ventilation, there was obvious difference between facial resistance and interior resistance, the higher the airflow, the larger the difference, which illuminated that the grain heap is anisotropic.

Abstract:The variation and calculation method of grain resistance under different conditions of transverse and vertical ventilation was researched with the square-bin stored 180t corn as test-bin. The transverse and vertical ventilation equipment was designed and installed in the test-bin respectively. The grain resistance was got under different ventilation modes by experiments. The results showed that the unit grain resistance of transverse ventilation was 1time lower than that of vertical ventilation and the anisotropy in stored corn was significant. The formula of grain resistance under the transverse ventilation was firstly obtained by experiments. Likewise, one under the vertical ventilation was also got. The formulas indicated that the character of stored corn resistance was accord with the mechanics laws of porous media. Thus the grain resistance was calculated either accurately by Hunter binomial formula of porous media or approximately by Shedd power function formula.

Abstract:The application of the technology of transverse ventilation for cooling wheat in warehouse was studied. The result showed that the ventilation path of transverse ventilation was more than treble that of tradition ventilation; heat exchange efficiency was significantly improved; the amount of cold air was not wasted; the energy consumption was decreased; the temperature uniformity inside of the heap was much better. The temperature in the height direction of wheat pile was consistent. The average difference of temperature gradient along the cool air direction was less than 0.5 ℃/m. The application effect of transverse ventilation technology for cooling grain in the warehouse was similar to the traditional vertical cooling ventilation,and the cooling efficiency was higher and the temperature uniformity was much better.

Abstract:The phosphine transverse circumfluent fumigation system for paddy warehouse (with span of 18 m) was designed and the application of the technology in paddy storage was studied. The concentration of phosphine in the grain bulk and the ventilation ducts was detected during the fumigation. The results showed that the concentration of phosphine in the vertical and horizontal cross sections of the grain bulk distributed evenly. Compared with the traditional fumigation in whole warehouse, the concentration of phosphine distributed evenly, and needed less time to reach to the insecticidal concentration by transverse ventilation. The concentration of phosphine could maintain longer in the film sealed grain bulk, which decreased phosphine dosage efficiently.

Abstract:The phosphine transverse circumfluent fumigation system for wheat warehouse (60 m×21 m) was designed and the application of the technology in wheat storage was studied. The concentration of phosphine in the grain bulk and the ventilation ducts was detected during the fumigation. The results showed that the concentration of phosphine in the vertical and horizontal cross sections of the grain bulk distributed evenly. Compared with the traditional fumigation in whole warehouse, the concentration of phosphine distributed evenly, and needed less time to reach to the insecticidal concentration by transverse ventilation. The concentration of phosphine could maintain longer in the film sealed grain bulk, which decreased phosphine dosage efficiently.

Abstract:The new technology that the food grade inert dust was sprayed into space and driven into the interspace of grain pile by ventilation fans is called technology of food grade inert dust aerosol control insects. The effect of the new technology was assessed by the test in grain store houses with transverse ventilation. Results showed that the aerosol phase of the inert powder can take the particles initiative to come into contact with pests of the grain heap to kill the pests. When the aerosol concentration was about 0.5 mg/kg, many kinds of pests in the grain store houses, especially Cryptolestes pusillus, were effectively killed.

Abstract:In order to enhance the cognition of the risk factors when working within the limited space and improve the working safety coefficient, the concept of limited space, the classification of grain warehouse limited space, the identification of typical harmful factors in the limited space, and the operations safety protection in grain warehouse limited space etc were discussed.