Thermoelectric Cooling Technology Applied To Control Nurient Solution Temperature Of Tomatoes Cultivated By DFT Hydroponics

In recent years, with the adjustment of agricultural production structures and rising of the living standard, the agriculture tourisms in our country have been growing rapidly. And the characteristics such as novelty, specialties and rareness were taken great care of when the agriculture tourisms gardens were designed. It was very easy to realize the above properties according to changes of places and seasons by adopting the hydroponics technology. The Deep Flow Technique (DFT) of hydroponics has come to be utilized widely because of its special attributes such as great convenience, high adaptation and little pollution in our country. But the methods to control the nutrient solution temperature of DFT are not advanced relatively and very flexible. So the thermoelectric cooling technology which is friendly to environment, flexible to control and convenient to adjust has been adopted to control the nutrient solution temperature of DFT systems. Experimental researches about the temperature control systems based on the thermoelectric cooling technology have been carried out. An example of the thermoelectric cooling technology applied to the agricultural and bio-environmental controlling research fields has been provided.1 The mathematic model of the thermoelectric temperature control device was constructed by analyzing the fundamental of thermoelectric technology. Experimental results showed that the determination coefficient of the model and experimental results was beyond 0.74.So conclusions can be draw that the model was validate and accurate under experimental circumstance.2 A set of temperature control system has been accomplished. The system was used to control roots area environment of the infinite-growth-type tomato cultivated by the DFT hydroponics technique. And experiments have been done in the experimental greenhouse of the Horticultural Engineering Center of China Agricultural University.3 Experimental results showed that the temperature demands of the roots area of infinite-growth-type tomatoes cultivated by the DFT hydroponics could be satisfied by the temperature control system. And the potential productivity of the tomatoes was able to be realized.4 Finally, the designing principal of temperature control system of different scale under current tomato hydroponics system adopted by agricultural tourism gardens was presented by analyzing the actual horticultural production in our country and optimizing the ratio of characteristics to market price.