Study On Heat Dissipation Characteristics Of Solar Bed Based On The Difference Of Heat Demand Between Day And Night

The proportion of building energy consumption in the primary energy consumption increased year by year in China,while the energy consumption of heating and air conditioning is an important part of building energy consumption.In the northern area with abundant solar energy resources,solar heating technology is an effective way to improve the indoor thermal environment in winter.But the heat collected by solar heating system hard to meet the heat demands for fully heated room because the solar radiation has the features of low energy density and discontinuous fluctuation.Research shows that there is a different in demand for indoor thermal environment between day and night.This paper proposes a kind of flexibly adjustable heating bed end,which can meet the indoor thermal environment in day and at night.This paper introduces the structure,size and working principle of the solar bed system.An experimental platform was built in an artificial climate chamber and the heat dissipation characteristics of the solar bed at the period of preheating,stable operating and intermittent under different conditions was studied experimentally.During the preheating period of the bed,the thermal response of the bed in heating is fast and the heat dissipation reaches the stable state about in 2 hours in the different conditions.During the intermittent period of the bed,the heat dissipation is slow and it needs more than 10 hours.The primary and secondary order of the heat dissipation factors has been got.Set up a physical model of the solar bed system.Analysis the air flow and heat transfer process on the surface of the pipe,the cavity layer and the bed body surfaces of the model.Establish the mathematical models of thermal process and get the simplified calculation method of the solar bed.Lay a theoretical basis for the analysis of heat dissipation characteristics and the influence on indoor thermal environment of the system.The method of numerical simulation of flow and heat transfer is used to analysis the heat dissipation characteristics of the solar bed system,which focuses on the different conditions of pipe water temperature and pipe spacing.Analysis the matching bed structure,operation management and design parameters of different operating conditions between day and night also.The accuracy of the mathematical model is verified by the comparison between the experiment and simulation.In addition,the model of the bed-room was also established and the bed system's heating effect in the room was also analyzed.Research presents the basis of the design parameters for pipe spacing and pipe water temperature in different conditions.The control method for different operating conditions during daytime and nighttime are also given.The results of simulation show that the heat dissipation of the solar bed unit area during the daytime can research 325 W and meet the thermal demand of indoor.While the pipe water temperature range recommended at night is between 37°C to 45°C in order to meet the sleeping thermal environment.Based on the research by experiment and theory analysis,master the heat dissipation characteristics of the solar bed and the heating situation of this solar bed system.The production of this system lays the foundation for the application of low temperature heating and the popularization of the flexible end.