| The Chinese solar greenhouse is a unique form of greenhouse in the world, which has beendeveloped fast in the Northeast, North and Northwest of China. The heat is stored in the back wall,gable and soil during the daytime, and in the night the heat is released through these structures in orderto increase the indoor temperature. But due to the limited heat capacity of the wall, the greenhousealways meets the phenomenon of low-temperature. In response to these problems, many scholars havedone a lot of research work to enhance the performance of the thermal and insulation or enhance thesolar greenhouse heat storage capacity. Based the long-term study and the principle of solar energyconversion, the author’s laboratory proposed an active method for the heat storage and release, whichuse the water as the medium of heat storage, aiming to reach the following goals:1,maximize thecollection and storage of heat on the wall;2,improve energy utilization efficiency. In the daytime, thesolar energy is collected and stored in the circulating water, and in the night, the heat is released toenhance the temperature of the greenhouse. Through this method, the traditional passive method of heatstorage is changed to active way, achieving the transferring of the heat in time and space and improvingthe heat storage capacity significantly. Also, the natural method of heat is changed to controlled releaseway, raising the indoor temperature of solar greenhouse in the night. This paper is about this method ofheat storage and release. Based on this theory, the author has designed an active heat storage and releasesystem and has finished some related experiments of this system. The main contents and conclusions ofthis study are as follows:This paper described comprehensively the current development of China’s solar greenhouse and theproblems encountered, and analyzed the research progress of upgrading the performance of heat storageof domestic and foreign.On this basis, the main research contents and objectives of this paper areproposed, and the technical route of this study has been determined.Based on the analysis of solar thermal dynamic change rule of the north wall of the solargreenhouse and analysis of fluid conduction process such as heat collection, storage, and release,improve to impound the fundamental theory of active heat storage and release, laying the theoreticalfoundation for the system design and engineering application of this technology.Introduce the active heat storage and release system design on the basis of comprehensive analysisof commonly used solar water heaters, solar greenhouse production requirements, the working principleof the system and the heat transfer mechanism, which include the heat absorption and release part, theheat storage part and the controlling system part. Otherwise, the paper designed the auxiliaryengineering of active heat storage-release system for the typical Chinese solar greenhouse of60m length,8m across, brick wall, providing technical support for the popularization and application of active heatstorage-release system.The results of the experiment of active heat storage and release in the Chinese solar greenhouseshow that: In the typical weather of winter, the active heat storage-release system can store heat6.9MJ/m2in daytime, and release heat5.7MJ/m2.After heat release by the system in the night, the average indoor temperature is12.35℃,and the average temperature of the contrasted greenhouse is6.04℃,theexperimental greenhouse can increase indoor air temperature6.31℃compared with the contrasted ofgreenhouse. In the overcast/cloudy weather, the experimental greenhouse can increase indoor airtemperature4.64℃. |
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