Improving performance of the evaporative cooling system inside the greenhouses and its effect on tomato productivity [electronic resource].
تحسين أداء نظام التبريد التبخرى داخل البيوت المحمية وتأثيرها على إنتاجية الطماطم.
- p.80-94
Includes references.
An experimental study was conducted to determine the performance of two evaporative cooling systems, as well as the gradients of temperature and humidity along a greenhouse. The first system was the cooling unit, (CU) compared with the traditional fan-pad one, (F-P). The cooling unit was connected with two perforated ducts inside the greenhouse. The air temperatures and relative humidities on the longitudinal axis were measured outside and just after leaving the media and at each one meter from the pad media. They were also, measured in the traverse axis parallel to the pad media at distances 0.5, 1.5, 2.5 and 3.5 m from the edge of the greenhouse. A steady state mathematical model was modified to predict the greenhouse air temperature according to the state of the air just leaving the cooling media. According to the experimental results, the non-uniform temperature changes were observed along the greenhouses for the two systems. The average temperatures of the CU greenhouse were 27.9, 30.4, 33.2, 29.1 and 27.9 °C for ou.tside ambient temperatures of 28.7, 32.4, 35.4, 32.1 and 29.4 °C, respectively. The ranges of temperature gradient inside the CU greenhouse were 2.1, 2.1, 2.2, 2.2, and 2.1 °C. While in the F-P greenhouse, they were 5.9, 7.4, 8.2, 5.9 and 6.1 °C for the same ambient temperatures. The average air temperature entering to greenhouse was approximately 6.82 and 7.09c lower than the outside air temperature for CU and F-P systems. The greenhouse of CU system was higher in the relative humidity than F-P one. The average relative humidities were 69.0 and 61.8% for the CU and Fp greenhouses, respectively, with increase percent 12.38%. The averages CU efficiencies were 77.55% and 74.79o/o in the first and second days, respectively, while they were 72.97% and 70.19% for the same days for F-P system.
Summary in Arabic.
Tomatoes--Yield Tomatoes--Cooling Tomatoes--Effect of temperature on Greenhouses plants