The recent significant rise in space cooling energy demand due to the massive use of air-conditioning systems has adversely changed buildings’energy use patterns globally.The updated energy technology perspectives hi...The recent significant rise in space cooling energy demand due to the massive use of air-conditioning systems has adversely changed buildings’energy use patterns globally.The updated energy technology perspectives highlight the need for innovative cooling systems to address this growing cooling demand.Phase change material embedded radiant chilled ceiling(PCM-RCC)has lately acquired popularity as they offer more efficient space cooling together with further demand-side flexibility.Recent advancements in PCM-RCC applications have increased the necessity for reliable simulation models to assist professionals in identifying improved designs and operating settings.In this study,a transient simulation model of PCM-RCC has been developed and validated using measured data in a full-scale test cabin equipped with newly developed PCM ceiling panels.This model,developed in the TRNSYS simulation studio,includes Type 399 that uses the Crank-Nicolson algorithm coupled with the enthalpy function to solve transient heat transfer in PCM ceiling panels.The developed model is validated in both free-running and active operation modes,and its quality is then evaluated using several validation metrics.The results obtained in multiple operating scenarios confirm that the model simulates the transient behaviour of the PCM-RCC system with an accuracy within±10%.Aided by this validated model,which offers the user detailed flexibilities in the system design and its associated operating schemas,PCM-RCC’s potentials regarding peak load shifting,energy savings,and enhanced thermal comfort can be investigated more reliably.展开更多
Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely u...Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely used practice in public buildings throughout China, including government offices, schools and hospitals. To investigate the damage mechanism of suspended ceilings, a series of three-dimensional shake table tests was conducted to reproduce the observed damage. A full-scale reinforced concrete frame was constructed as the testing frame for the ceiling, which was single-story and infilled with brick masonry walls to represent the local construction of low-rise buildings. In general, the ceiling in the tests exhibited similar damage phenomena as the field observations, such as higher vulnerability of perimeter elements and extensive damage to the cross runners. However, it exhibited lower fragility in terms of peak ground/roof accelerations at the initiation of damage. Further investigations are needed to clarify the reasons for this behavior.展开更多
文摘The recent significant rise in space cooling energy demand due to the massive use of air-conditioning systems has adversely changed buildings’energy use patterns globally.The updated energy technology perspectives highlight the need for innovative cooling systems to address this growing cooling demand.Phase change material embedded radiant chilled ceiling(PCM-RCC)has lately acquired popularity as they offer more efficient space cooling together with further demand-side flexibility.Recent advancements in PCM-RCC applications have increased the necessity for reliable simulation models to assist professionals in identifying improved designs and operating settings.In this study,a transient simulation model of PCM-RCC has been developed and validated using measured data in a full-scale test cabin equipped with newly developed PCM ceiling panels.This model,developed in the TRNSYS simulation studio,includes Type 399 that uses the Crank-Nicolson algorithm coupled with the enthalpy function to solve transient heat transfer in PCM ceiling panels.The developed model is validated in both free-running and active operation modes,and its quality is then evaluated using several validation metrics.The results obtained in multiple operating scenarios confirm that the model simulates the transient behaviour of the PCM-RCC system with an accuracy within±10%.Aided by this validated model,which offers the user detailed flexibilities in the system design and its associated operating schemas,PCM-RCC’s potentials regarding peak load shifting,energy savings,and enhanced thermal comfort can be investigated more reliably.
基金Research fund for earthquake engineering of China Earthquake Administration(201508023)a project of the National Science&Technology Support Program during the Twelfth Five-year Plan Period of China(2015BAK17B03)a general program of National Natural Science Foundation of China(51578515)
文摘Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely used practice in public buildings throughout China, including government offices, schools and hospitals. To investigate the damage mechanism of suspended ceilings, a series of three-dimensional shake table tests was conducted to reproduce the observed damage. A full-scale reinforced concrete frame was constructed as the testing frame for the ceiling, which was single-story and infilled with brick masonry walls to represent the local construction of low-rise buildings. In general, the ceiling in the tests exhibited similar damage phenomena as the field observations, such as higher vulnerability of perimeter elements and extensive damage to the cross runners. However, it exhibited lower fragility in terms of peak ground/roof accelerations at the initiation of damage. Further investigations are needed to clarify the reasons for this behavior.
