摘要
为了解植物体温度变化的原因,用热电偶测温仪和Li-cor的自动气象站测定日光温室番茄茎内和果实内部瞬态传导传热量的日变化规律,分析了茎内部传导传热量的趋势。测定了茎气温差,并根据生物传热学理论,估算了番茄植株与空气间的对流热交换量。结果表明,果实表面与中心存在温差,且有明显的日变化。果实瞬态传导传热量最大值为1.29W,相当于晴天中午温室内太阳辐射的0.2%。不同天气条件下植株与环境对流传热有相同的日变化趋势,但白天与夜间不同。夜间失热,揭苫后失热增大,并持续到整个上午,10∶30失热量最大,达到-18.9W/m2。下午至傍晚对流传热为得到热量,13∶30时最高,达到34.9W/m2,这时正是一天中最高气温发生的时间。阴天对流传热日变化幅度明显减少。多云天气介于晴天与阴天的变幅之间,波动较明显。植株与环境间对流传热量比植株内部传导传热量大。
To know the cause of the plant temperature variation, the daily changes of the heat conducted within the tomato fruit and stem in the greenhouse were measured using the thermocouple and Li-cor＇s automatic meteorology station. The temperature differences between the stems and the air were measured, and the convection heat exchanges from the plant to air were calculated according to the theory of biological heat conduction. The results were that there was temperature difference between the surface and the center of the tomato fruit, which had daily changes, and the biggest heat conduction of tomato fruit was 1.29 W, which was about the 0.2% of the solar radiation in the greenhouse during the noon in a clear day. The heat convections between the tomato plant and the environment in different weather conditions had the same trend. In clear day, during the night, the heat convection was at steady loss, at the time of 10：30, it lost most, -18.9 W/m^2; at 11 ： 15 it started to get heat, at 13 ： 30 it was at the peak of getting heat 34.9 W/m^2; from 18： 30 to the next morning, it lost heat. In the overcast day, the biggest and smallest values were reduced. In the cloudy day, the result was within the clear day and the overcast day, and it contained clear fluctuation. The heat convection was bigger than the heat conduction.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2007年第10期220-223,共4页
Transactions of the Chinese Society of Agricultural Engineering
基金
河南省重大科技攻关项目(0322010900)资助
关键词
日光温室
番茄
热传导
对流传热
greenhouse
tomato
heat conduction
convection heat
