Research On Ecological Environment For Reinforced Concrete Underground Granary

Reinforced concrete underground granary is a new underground granary relying on Thenational "Twelfth Five" science and technology support program (2011BAD03B00), its strongmechanical properties, supporting advanced technology, modern design, solved thedependence on the terrain. Its unique grain storage environment is the reason and purpose ofthe new underground grain storage structures, so environmental research ecology ofreinforced concrete underground grain storage barn has important implications for the use andpromotion of green energy stored grain structure. Based on the grain storage environmenttheory, environmental studies conducted ecological granary storage based on CFD(Computational Fluid Dynamics) simulation method of reinforced concrete underground,including mechanical ventilation state and quasi-static conditions based on CFD. The maincontents are as follows:1. A mathematical model of coupled heat and moisture transfer was presented in thispaper to forest the ventilation process of the granary. Based on the model proposed, UDFsources are developed by using C language to simulate heat and moisture processes that occurin the stored grains. Taken a large warehouse as an example, a three-dimensional physicalmodel of a real large warehouse was established. The heat and moisture transfer in a real bigwarehouse during the cooling ventilation, with measured temperature and moisture of air wasstudied by CFD simulation method and experimental method. The mathematical modelproposed was validated by comparing between predicted and measured grain temperature.2. Numerical simulation of temperature field for reinforced concrete undergroundgranary under mechanical ventilation. Based on the coupled heat and moisture transfer instored grains in a reinforced concrete underground granary, the computational fluid dynamics(CFD) method was used. Taken unit volume of mechanical ventilation as the variable factor,two critical ventilation rates for different ventilation purposes from Technical regulation ofaeration for grain storage as the upper limit and lower limit were selected. For the effectgenerated by the two critical ventilation rates, curve of the effective time with volume wasobtained from the analysis of temperature. The results showed that variation of temperature field of reinforced concrete underground granary under mechanical ventilation.3.Quasistatic temperature field simulation of reinforced concrete underground granarygrain.CFD mathematical models and simulation schemes were established with determiningthe simulation area and boundary conditions，dividing grids and selecting models according tostructure of underground granary and environmental temperature. In this paper, the CFDmethod was used to simulate the temperature field of stored bulk grain in large-diameterconcrete underground granary without ventilation. The physical models of large-diameterconcrete underground granary were introduced in detail. The temperature fields and thetemperature changes with ambient temperature and geometric dimension relations weresimulated by using the method described above．The results of research show the temperatureof stored bulk grain tend to be similar to the temperature of the constant temperature layer soil;moreover, the column of air duct of underground granary can help cool the stored bulk grainin underground granary uniformly.4. The condensation causes and control measures under mechanical ventilation andquasi-static states of reinforced concrete underground granary. Analysis of the condensationcauses of existing grain storage structures under mechanical ventilation and quasi-static states,propose appropriate measures for prevention of condensation; analysis of reinforced concreteunderground granary condensation reasons under mechanical ventilation and quasi-staticstates, noting that control grain moisture and air temperature and humidity values whenenter the granary are the most critical. Correct operation of mechanical ventilation to avoidmechanical ventilation during condensation.