| The temperature greatly affects on not only the growth of plants but also the using efficiency of greenhouse, so it has long been an important direction for greenhouse research work. The measure that it can increase the earth temperature by solar-water heater as auxiliary heating apparatus is studied in this paper. In view of the optimum temperature at the roots of plants, the air temperature in the greenhouse may be lowered by 3-6℃, thus reducing the new perspective, and an effective way to save energy as well. This paper, for the first time, makes a systematic study on auxiliary-heating apparatus in both theory and experiment, and provides basis for promotion and application of auxiliary-heating apparatus in solar greenhouse.The area of experimental plot corresponding to solar water heater with certern area can be confirmed through thermal computation. For the auxiliary heating system in the solar greenhouse, this paper, for the first time,sets up an unsteady state soil heat-transferring mathematical model. We employ the calculating method of finite difference to solve the mathematical model, and compile a dynamic simulation program for the soil teperature field in the solar greenhouse with the auxiliary heating system.Design a solar water heater auxiliary-heating system in experiment greenhouse, and study on it's using effect. Through comparing the heat supply in cycle of single time and double times with the greenhouse equipped without this auxiliary-heating system, the result shows: when the average air temperature outside greenhouse is -1℃, this system can heighten soil temperature by 2.2℃. Through comparing the coalescent of auxiliary-heating apparatus and drip-irrigation under plastic film and the greenhouse equipped without this approach, the conclusion that the approach can reduce air humidity by 5% can been drawn.after simulating the parameter's effect on soil temperature field with mathematical model, we make this heating system more perfect and more economic.
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