The Effect of Water Flow Velocity on Heat Collection Performance of Active Heat Storage and Release System for Solar Greenhouses

In order to explore the influence of water velocity on the heat collection performance of the active heat storage and release system for solar greenhouses in Table l and, six different flow rates were selected for treatment in this experiment. The comprehensive heat transfer coefficient of the active heat storage and release system at the heat collection stage was calculated by measuring the indoor solar radiation intensity, indoor air temperature and measured water tank temperature. The prediction model of water temperature in the heat collection stage was established, and the initial value of water temperature and the comprehensive heat transfer coefficient were input through MATLAB software. The simulated value of water temperature was compared with the measured value and the results showed that the best heat transfer effect could be achieved when the water flow speed was 1.0 m3h-1. The average relative error between the simulated water tank temperature and the measured value is 2.70–6.91%. The results indicate that the model is established correctly, and the variation trend of water temperature can be predicted according to the model in the heat collection stage.