外文翻譯---果蔬太陽能干燥脫水裝置設(shè)計(jì)(參考版)
2025-01-19 12:07本頁面
【正文】 There are different results when metal and nonmetal are used as the material of the porous matrix, respectively. The increase speed of the air temperature is quicker when aluminum is used as the material of the porous wall. In contrast, the increase speed of the air temperature bees slower when rock is used as the material of the porous wall. Consequently, the permeability and material of the porous wall should be carefully selected to reduce the cost of the porous solar wall.Based on the thermal analysis, the structure of the porous solar wall is improved and a new porous solar wall is designed to reduce convection and radiation heat exchanges between the porous wall and the ambient. The glass plate is located between the porous wall and the ambient to form a glass duct, which can reduce heat losses and collect hot air by using greenhouse effective. Additionally, the fan is located in the duct near the inside surface of the porous wall. Under the action of the fan, the ambient air flows into the porous wall and exchanges heat with the porous wall. Then the air is heated to certain value to demand for heating in winter. Based on the twodimensional steady NavierStokes equations, BrinkmanForchheimer Extended Darcy model and energy twoequation model for saturated porous medium, the flow and heat transfer in the new porous solar wall system with glass duct and fan are simulated. The results show that the design of the fan has significant influence on the flow field and temperature field, the flow resistance will decrease and the thermal efficiency of porous wall will increase with a decrease in the inlet velocity, the porous wall with the glass duct can decrease lengthwave radiation and collect hot air. So the new porous solar wall system can obtain a higher thermal efficiency as pared with a conventional one.A new greenhouse with heatstorage porous wall is designed, in which the north wall is a heatstorage porous wall. Equal diameter, uniform and semitransparent porous balls are used as the material of the porous solar wall, which can collect and store solar energy to heat the air in the greenhouse, and condition the thermal environment in the greenhouse. Their effect both can be exerted fully by bining the greenhouse with the heatstorage porous wall, which causes the higher solar energy utilization efficiency. Based on BrinkmanForchheimer Extended Darcy model and energy twoequation model with internal heat source for saturated porous medium kE turbulent model, the flow and heat transfer characteristics of solar greenhouse system are simulated. Additionally, the influence of the porous wall with layered porosity on the characteristics of the greenhouse is also analyzed by numerical simulation further. The results show that the inlet parameters of the greenhouse and the structure of the porous wall have great effect on the temperature field, the flow field and the pressure field. So, for a certain structure of the greenhouse, the porous wall should be designed and the fan operation should be also conditioned reasonably according to the admired thermal environment in the greenhouse.Two kinds of new solar heating systems with a new porous heat storage wall are designed, which have different ventilation patterns. Based on kE turbulent model, BrinkmanForchheimer Extended Darcy model and energy twoequation mode
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