| Energy saving has become the theme of the times in the Twenty-first century. Around therational development and efficient use of energy, the world engaged in a fierce competition.The phase change energy storage technology has become the forefront of the field in energydevelopment and utilization. China is rich in light and heat resources. Greenhouse as a passivesolar building in China has a broad development prospects. But, it has Large temperaturedifference between day and night and artificial heating in winter in the application. Phasechange energy storage technologies used in the greenhouse, using its phase change thermalstorage performance, you can adjust the temperature in the greenhouse and replace the winterheating. It has great significance for China’s agricultural development.The test select of Butyl Stearate and Isopropyl Palmitate as organic phase changematerials. Using DSC, elect the Butyl Stearate and the mass ratio of Butyl Stearate andIsopropyl Palmitate with8:2of the two materials as a greenhouse using low-temperaturephase change materials. Butyl Stearate begins to melt at19.38°C, the peak temperature is21.56°C, the latent heat value is104.7J/g in the warming phase; starts to solidify at23.80°C, the peak temperature is19.93℃, the latent heat value is106.8J/g in the cooling phase.The other phase change material begins to melt at12.83°C, the peak temperature is17.04°C, the latent heat value is109.3J/g in the warming phase; starts to solidify at16.52°C, thepeak temperature is14.70℃, the latent heat value is103.7J/g in the cooling phase.Using the selected phase change materials and polystyrene particles prepared to the formstable phase change material by vacuum adsorption method. Butyl Stearate/polystyrene formstable phase change material’s peak cooling and heating phase transition temperature were18.41℃and19.91℃. Butyl Stearate-Isopropyl Palmitate/polystyrene form stable phasechange material’s peak cooling and heating phase transition temperature were14.50℃and16.60℃. By the thermal cycling, FT-IR and SEM test, the two stable phase change materialhave good thermal cycling performance, chemical stability and apparent structural stability.Using the two form stable phase change materials with concrete materials, prepare thephase change concrete. By the test of dry apparent density, compressive strength, waterabsorption, softening coefficient and thermal conductivity properties, Show that in line withthe ratio of cement: fly ash: activator: sand: gravel: ceramic=20:25:3:17:10:25concrete materials added to the mass fraction of8%of the form stable phase change material, thematerials’ material having the best performance. Water absorption and softening factor meetthe requirements. The thermal conductivity is0.36W/m K. The compressive strength ismore than5Mpa and the apparent density in1400Kg/m3meet the requirements of thestructure of insulating lightweight concrete block.The test selected Butyl Stearate with its phase transition temperature of19.93°C~21.56°C as phase change materials for the greenhouse to solve the Large temperaturedifference between day and night. And selected Butyl Stearate and Isopropyl Palmitate8:2mass ratio of the two materials as low temperature phase change materials for the greenhouseto solve the artificial heating in winter. It can improve the utilization of solar energy, bettercontrol of greenhouse temperature.At the same time, the prepared phase change materials and mixing concrete materialswas prepared to the phase change concrete block used in the greenhouse. It can reduce thethickness of the wall, to simplify the construction, saving the space in the greenhouse, improving thegreenhouse land utilization. So it is a development direction for the next in the phase changematerial and greenhouse combined application. |
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