屋顶全开启型Venlo式温室的降温效果

Cooling Effect of Open-Roof Venlo Greenhouse

通过测试屋顶全开启型与屋顶通风窗型两种Venlo式温室在不同设定条件下的温度变化,建立两种温室室内与室外白天温度变化曲线;结合两种温室自然通风条件下通风比变化与强制降温条件下湿帘风机运行状态,进行屋顶全开启型Venlo式温室降温效果的分析.在自然通风降温条件,晴天时屋顶全开启型温室比屋顶通风窗型温室降温更迅速,室温更低,更接近设定温度;阴天时差异不明显,屋顶全开启型温室1d中室内最高温度高于室外温度0～2.35℃,低于屋顶通风窗型温室1d中最高温度0～5.25℃;在强制降温开启的条件下,屋顶全开启型温室湿帘风机启动迟,停止早,湿帘风机运行时间要比屋顶通风窗开窗型温室运行时间少1.5h,能够在不影响降温效果的情况下减少温室降温能耗.屋顶全开启型Venlo式温室大幅增加了温室的开窗通风比,显著提高了Venlo式温室自然通风的降温效果,并减少了温室强制降温的运行成本.

In order to provide a theoretical basis for optimizing the structure design of the greenhouse and to provide a reference for environmental control, the cooling effect of the open-roof Venlo greenhouse was compared with the roof vent Venlo greenhouse. By testing the open-roof Venlo greenhouse and the roof vent Venlo greenhouse under different conditions of temperature setting, daytime temperature curve of greenhouse indoor and outside were created. And the cooling effects of the two kinds of greenhouses were analyzed according to the change of roof ventilation ratios, and the conditions of under natural ventilation conditions and wet pad-fan running situations by forced cooling. In sunny day and under natural ventilation cooling conditions, the open-roof Venlo greenhouse was more quickly to be cool, and could reach the lower temperature, and be closer to the set temperature than the roof vent Venlo greenhouse; the difference was not significant in cloudy days. The highest day temperature of the open-roof Venlo greenhouse was higher than the outdoor temperature about 0-2.4℃, it was less than the highest day temperature of the roof vent Venlo greenhouse which was 0-5.2 ℃. The wet pad-fan of open-roof greenhouse started up later and stoped earlier than the roof vent greenhouse, while wet pad-fan running time of open-roof vent greenhouse was less than the roof vent greenhouse about 1. 5 hours. Open-roof vent greenhouse could reduce greenhouse cooling energy consumption without compromising cooling effect situation. Open-roof vent greenhouse sharply increased roof ventilation ratio of greenhouse, significantly improved the Venlo greenhouse natural ventilation cooling effect and reduced the operating costs of greenhouse forced cooling.