Unsteady Thermal Insulation Performance Of Subtropical Oyster Shell Wall Structure

In recent years,people have paid more and more attention to thermal insulation and energy-saving technology in the field of building heat transfer,and the design needs brought by locality and local culture have also made people pay more attention to the modern value of traditional building materials and construction methods.In this paper,the thermal insulation performance of the oyster shell wall enclosure structure in the subtropical region is studied,the thermal parameters of the oyster shell are measured by the Hot Disk experiment,the single-chamber calculation model of the enclosure structure is established,and the unsteady convolution based on the linear time-invariant system is used.Calculate and solve the room temperature full response of the oyster shell wall envelope under external disturbance thermal excitation,and rank the thermal insulation performance of five non-transparent envelope structures.Based on the BECS energy consumption software,a single-room model located in the subtropical city of Guangzhou is established The simulation calculation of the outdoor thermal excitation response under five different envelope structures is carried out,and the thermal insulation performance of the five different envelope structures is obtained.The main research contents are as follows:(1)The thermal parameters of the oyster shell were determined based on the Hot Disk method,which was used in the calculation of the full response of the system indoor temperature of the oyster shell wall enclosure.The steady-state heat transfer equations and the unsteady heat transfer equations of the envelope are deduced,the single-chamber calculation model is proposed,and the response of the unit step function and the unit impulse function in the single-chamber thermal equilibrium system is introduced.(2)A non-steady-state convolution calculation method based on a linear time-invariant system is proposed to solve the full response of the system indoor temperature of the oyster shell wall enclosure under the excitation of external disturbance heat,and the dual thermal response of outdoor temperature fluctuation and outdoor radiation equivalent temperature is proposed.The step response function and the impulse response function under the excitation action are used to solve the total indoor temperature response of the system for five different enclosure structures including the oyster shell wall by convolution calculation,and the Maple mathematical software is used to solve the thermal excitation response function.The images are superimposed to draw indoor temperature response images of five different structures,and the ranking of the thermal insulation performance of the envelope structure is obtained.(3)Based on the BECS energy consumption simulation software,the heat transfer research was carried out on the single-chamber models of five different enclosure structures such as the oyster shell wall,and the single-chamber structure model was established.The hourly temperature ranking under different structural conditions is verified with the conclusion of the system temperature response solved by the unsteady convolution calculation.The research results show that the thermal insulation performance of each enclosure structure is ranked as follows: structure b> structure a> structure c1> structure c2> structure d,indicating that the oyster shell wall enclosure structure has excellent thermal insulation performance,and its performance is close to 30 mm EPS board insulation structure.