Study On Solar Heating And Cooling Wall Panels

With the high proportion of building energy consumption in the total energy consumption, it is of great importance to relieve the shortage of the conventional energy resource and improve the building environment by incorporating the renewable energy such as solar energy into buildings. This paper aims at utilizing solar energy, natural energy and nocturnal radiation in a combination way. The solar water heating technology and radiative cooling technology are combined to develop a wall-typed solar heating and cooling panel-SHCP which can be perfectly integrated with building envelopes. These panels can be used as building roofs and fa?ades or components of roofs and fa?ades.The solar heating and radiative cooling system experimental setup was established. The time constant of the solar heating and cooling panel was measured to provide the theoretical foundation to separate and recombine the time-dependent experimental data and analyze the transient performances of the system. The heating and cooling performances of the solar heating and radiative cooling system with and without air gap were measured, and the system without an air gap has the better heating performance, while the air-gapped one has the better cooling performance. The performances of the solar heating and radiative cooling system with different coating materials were measured, and the coating material with higher absorptivity and lower emissivity is in favor of heating performance of the solar heating and radiative cooling system. The performances of the solar heating and radiative cooling system were measured under typical sunny day and cloudy day.The transient two-dimensional mathematical model of the solar heating and radiative cooling system was established, which mainly includes the transient two-dimensional model of the solar panel and one-dimensional model for depicting water flow in the collector tubes. The mathematical model can analyze in detail the energy transfer process of the solar heating and cooling panel, and the temperature distribution of the solar heating and cooling panel and the water outlet temperature can be obtained, and then the heating and cooling performances of the solar heating and radiative cooling system are achieved. The thermal construction and optical properties of the solar heating and cooling panel are designed and optimized by terms of the mathematical model. And then the influences of the mass flow rate, installation orientations and inclination angles of the solar heating and cooling panel to the performances are simulated. The optimal structure of the solar heating and cooling panel are achieved under different application conditions.