The Experimental Study On Dehumidifying Of Solar Greenhouse

The greenhouse producers are facing one of the biggest problems which are the high humidity results in the decrease of crop yield and quality at present, and the high humidity also is inconvenient to work in the greenhouse, therefore improve the humidity of the greenhouse environment inside is imperative. The best humidity range from 50% to 80% for the most of crops in greenhouse, but because of irrigation and crop transpiration in greenhouse the humidity is easy to more than 90% and even reached 100%, the high humidity is conducive to reproduce mold, it is not only bad for plant growth and production, and cause crop physiological disorders but also make the plant transpiration is restricted and influence of root system on soil nutrients absorption and utilization, and aggravate the occurrence and spread of various plant diseases.The dehumidifier has been used for dehumidification in solar greenhouse. First of all find the best ventilation openings for corresponding situation dehumidification by ANSYS FLUENT in autumn. Then compare dehumidifier to ventilation in the dehumidification and energy consumption, working out the autumn sunshine natural ventilation heat loss is 15036.62 sJ /, it is 11.391 times of the dehumidifier in energy consumption. Dehumidifier for the greenhouse humidity reduced by 10% each hour, and release 1.5L water, maintain a constant temperature in greenhouse. Secondly use dehumidifier to control the RH in greenhouse in the winter. Limited by the temperature the service time of dehumidifier is 11 am to 16 pm, when dehumidifier set RH is 70% it worked 1.12 h making the mean relative humidity at 63.01%, and it is 5.06% RH lower than without dehumidifier. When dehumidifier set RH is 60% it worked 2.02 h making the mean relative humidity at 55.10%, and it is 12.97% RH lower than without dehumidifier. Thirdly put the dehumidifier in to the production practice of the greenhouse in spring. Estimates by greenhouse users that the cucumber yield of experimental part more than 200 kilogram than control part, it is an increase of 520 Yuan, and earn 292.89 Yuan. At last observe the parameters of time distribution in greenhouse of the dog days, find that without using any dehumidification methods it is keeping within the scope of the crops of the RH in greenhouse.Through the test of all the year round, the dehumidification mode of the northeast region is using the dehumidifier to control the RH in winter when ventilation can not be used. The natural ventilation can keep within the scope of the crops of RH in greenhouse and do not need other dehumidification methods. Open the tectonic window for a lot of ventilation at high temperature and open the skylight for a small amount of ventilation at low temperature in the spring and autumn season, dehumidifier can be used throughout the day with natural ventilation system to control the RH inside the greenhouse.