A study on thermal calculation method for a plastic greenhouse with solar energy storage and heating

摘要

Plastic greenhouse has been widely used in agriculture and horticulture due to its prolonging period for crops growth. In this work, an approach that stores solar energy in the daytime and provides heat by earth-tube at night was proposed, and then applied to a plastic greenhouse to elevate the inside air temperature. A one-dimensional dynamic model was established to assist the design of the solar energy storage and heating system and to evaluate the system performance. Using the model developed in Matlab, the date-hour change patterns of characteristic temperatures in the plastic greenhouse were obtained, through calculating the heat gains of various surfaces and heat storage by hour from solar radiation and solving the unsteady-state heat conduction equation in the structure components of the greenhouse. The calculated results show good agreement with the measured data, indicating that the method is valid and can be applied to the design of solar energy storage and heating system as well as the thermal performance analysis of greenhouses. (C) 2016 Elsevier Ltd. All rights reserved.