A New Dynamic and Vertical Photovoltaic Integrated Building Envelope for High-Rise Glaze-Facade Buildings

Substantially glazed facades are extensively used in contemporary high-rise buildings to achieve attractive architectural aesthetics.Inherent conflicts exist among architectural aesthetics,building energy consumption,and solar energy harvesting for glazed facades.In this study,we addressed these conflicts by introducing a new dynamic and vertical photovoltaic integrated building envelope(dvPVBE)that offers extraordinary flexibility with weather-responsive slat angles and blind positions,superior architectural aesthetics,and notable energy-saving potential.Three hierarchical control strategies were proposed for different scenarios of the dvPVBE:power generation priority(PGP),natural daylight priority(NDP),and energy-saving priority(ESP).Moreover,the PGP and ESP strategies were further analyzed in the simulation of a dvPVBE.An office room integrated with a dvPVBE was modeled using EnergyPlus.The influence of the dvPVBE in improving the building energy efficiency and corresponding optimal slat angles was investigated under the PGP and ESP control strategies.The results indicate that the application of dvPVBEs in Beijing can provide up to 131%of the annual energy demand of office rooms and significantly increase the annual net energy output by at least 226%compared with static photovoltaic(PV)blinds.The concept of this novel dvPVBE offers a viable approach by which the thermal load,daylight penetration,and energy generation can be effectively regulated.

Research on Dynamic Model's Building of Active Magnetic Suspension Systems

An experimental method is introduced in this paper to build the dynamics of AMSS (the active magnetic suspension system), which doesn’t depend on system’s physical parameters. The rotor can be reliably suspended under the unit feedback control system designed with the primary dynamic model obtained. Online identification in frequency domain is processed to give the precise model. Comparisons show that the experimental method is much closer to the precise model than the theoretic method based on magnetic circuit law. So this experimental method is a good choice to build the primary dynamic model of AMSS.

Editorial: Special subject on the mechanical behavior of fire dynamics in high-rise buildings

With rapid economic and social development in China, high-rise buildings have continuously sprung up since 2006. However, several big fire accidents in high-rise buildings such as the Beijing Television Cultural Center fire in 2009 and the Shanghai Jing＇an District fire in 2010 etc. have claimed people＇s lives and caused huge amounts of economic and property losses,

Wind tunnel test and numerical simulation of wind pressure on a high-rise building

We carried out a wind tunnel test to measure cladding loads for a high-rise building of 295 m in height, which would be located in the business center of Chongqing Municipality, P. R. China. The rigid model was used to determine fluctuating local pressures on the exterior surfaces of the building. The wind tunnel test results show the cr/tical zone of wind pressures on building surfaces in both standalone and interference conditions. The computational fluid dynamics （CFD） was conducted by using the FLUENT Code to compare with the wind tunnel test results, and the steady three-dimensional turbulent flow with Realizable k-ε as a turbulence model was used. The CFD results are agree with the wind tunnel test results in regards to distributions of wind pressures over a high-rise building＇s surfaces.

Physics-constrained graph modeling for building thermal dynamics

In this paper,we propose a graph model embedded with compact physical equations for modeling the thermal dynamics of buildings.The principles of heat flow across various components in the building,such as walls and doors,fit the message-passing strategy used by Graph Neural networks(GNNs).The proposed method is to represent the multi-zone building as a graph,in which only zones are considered as nodes,and any heat flow between zones is modeled as an edge based on prior knowledge of the building structure.Furthermore,the thermal dynamics of these components are described by compact models in the graph.GNNs are further employed to train model parameters from collected data.During model training,our proposed method enforces physical constraints(e.g.,zone sizes and connections)on model parameters and propagates the penalty in the loss function of GNN.Such constraints are essential to ensure model robustness and interpretability.We evaluate the effectiveness of the proposed modeling approach on a realistic dataset with multiple zones.The results demonstrate a satisfactory accuracy in the prediction of multi-zone temperature.Moreover,we illustrate that the new model can reliably learn hidden physical parameters with incomplete data.

CUBATURES FOR MEDIUM-SIZED PLUS ENERGY BUILDINGS

INTRODUCTION On the basis of dynamic building simulations within a maximal realistic framework,it may be useful with respect to the overall energy balance to dispense with pursuing a minimal surface/volume ratio of buildings-thus minimizing heat losses across the building shell-in favor of solar energy use.The specific use of the building(here:office or residential)plays a crucial role.Balancing the energy demand for heating and cooling and a possible photovoltaic yield,a surplus is possible in all cases under investigation.Long,low unobstructed buildings perform best due to large portions of roof area suitable for solar energy use.For tall buildings with less roof area,parts of the facades may be used for solar applications which makes them also perform better than compact designs.If the total energy demand including auxiliary energy for HVAC and especially electricity for the office and residential usages,respectively,is considered,compact cubatures of the size considered here(about 3500 m^(2))are not capable of providing positive energy balances.Residential usage performs worse than office use.Investigations are performed for the climatic conditions of Berlin,Germany.

nZEB:bridging the gap between design forecast and actual performance data

The nZEB objectives have raised the standard of building performance and changed the way in which buildings are designed and used.Although energy dynamic simulation tools are potentially the most suitable way for accurately evaluating and forecasting the thermal performance,they need several data inputs and user’s knowledge that can affect the reliability of the results.It is precisely these two aspects that proved to be particularly critical,since the reliability of the ICT calculation tools has been widely proven in recent time.However,in order to foster credibility in sustainable architecture,bridging the gap between predicted and measured performance is pivotal to boost the building market towards energy efficiency and provide reliable data to inhabitant,investors and policy maker.The present research aims to identify and quantify the main factors that affect the energy performance gap through a detailed energy analysis carried out on a case study,which can be considered one of the first nearly zero energy residential complex built in Italy.Based on the analysis,the study identifies the main causes of the deviation between the calculated and measured data and demonstrates how it is possible to achieve very reliable models and,therefore,real buildings.Although the procedure traces a classic model calibration scheme,actually it consists of a verification of possible downstream errors mainly due to human factors,such as the provision of incorrect technical data or inappropriate operation.Some observations on the technical,management and regulatory gaps that may generate these errors are reported at the end of the study,together with practical suggestions that can provide effective solutions.