Applied Energy

2020年第9期（总第48卷第355期）建筑节能■国际文
摘
Applied Energy（Vol．276-277，2020）
（1）A framework for analyzing city-wide impact of building-integrated renewable energy，by Jeonghun Song，Seung Jin
Song，Vol．276，2020，115489
Abstract：As the building-integrated renewables increase in the urban energy mix，it is important to assess the collective effects of building-integrated renewables at city scale．Estimation of the total energy supply and capacity of renewables，variations in the energy from the grid，and CO
2
emission would aid renewable energy policy evaluation．However，analyzing the collective effects considering the optimal energy system for each building in a city is difficult due to a large number of buildings（on the order of 105）．Therefore，this study proposes a new framework for analyzing the city-wide impact of increased building-integrated renewables．To reduce the number of optimization，clusters of buildings with similar characteristics and one virtual representative building for each cluster are generated．For apartment buildings，the characteristics are the floor area and roof area per household．For non-residential buildings，the characteristics are the shapes of the monthly electricity and gas usages，the ratio between the annual gas and electricity usages，and normalized roof area．To generate clusters of similar non-residential buildings，k-Means Clustering Algorithm and Genetic Algorithm have been applied．The proposed framework has been validated by comparing the collective results from i）optimization of4425actual apartment buildings and2779actual non-residential buildings in an urban district；and ii）optimization of corresponding957representative apartment buildings and176representative non-residential buildings．Total energy supply and capacity of each renewable energy source，total monthly electricity and gas from the grid，and total hourly electricity from the grid show good agreement．As a demonstration，the proposed framework has been applied to the city of Seoul，Korea for a future scenario of building energy obligation－i）to estimate the total capacities and energy supply of the building-integrated renewables and the change in the energy from the grid；and ii）to evaluate the cost-effectiveness of the
obligation based on the unit cost of CO
2
reduction for varying renewable energy requirements for the buildings．
Keywords：Urban energy；Building-integrated renewable energy；
k-Means Clustering；Genetic Algorithm；Energy policy；CO
2 reduction
From：https：//www．sciencedirect．com/science/article/pii/ S0306261920310011
（2）Modeling and analysis of heat emissions from buildings to ambient air，by Tianzhen Hong，Martina Ferrando，Xuan Luo，et al，Vo．277，2020，115566
Abstract：Heat emissions from buildings is a significant source of anthropogenic heat influencing the urban microclimate；however，they are usually oversimplified in urban climate and microclimate modeling．This study developed a bottom-up physics-based approach to calculate heat emissions from buildings to the ambient air and implemented the approach in EnergyPlus．A simple result verification was conducted by comparing the EnergyPlus simulated results against the spreadsheet calculations．Simulations covering16commercial building types，four climates，and two energy efficiency levels were conducted to understand and evaluate the building heat emissions and their temporal patterns as well as three major components：（1）building envelope （convective heat transfer to ambient air），（2）zones（air exfiltration and exhaust air），and（3）HVAC systems（relief air and heat rejection from condensers or cooling towers）．The main findings are：（1）heat emissions are usually higher than the site energy use（about2.5times），and their dynamics should be considered；（2）building characteristics and their energy systems lead to differences in heat emission contributions from the three components，and their dynamics，for example，in the warehouse models，the envelope component accounts for90.4%，while it is 12.7%for the large office models；（3）for most building typologies，the climate has a strong impact on heat emissions，for example，buildings with dominant heat emissions from the zone exhaust air and/or the HVAC reject heat，a general decrease in heat emissions in hotter climates is observed，while envelope-dominated buildings show the opposite；and（4）building technologies that reduce energy use in buildings may perform differently in reducing heat emissions．The developed heat emissions calculation method can be adopted in EnergyPlus and most other building energy modeling programs．It can provide dynamic building heat emissions as an input to urban climate computational fluid dynamics（CFD）models at a higher spatial and temporal resolution than is currently available，to improve the simulation accuracy of the urban microclimate and capture the urban heat island effect and urban overheating．
Keywords：Buildings heat emission；Building performance simulation；Urban heat island effect；Urban environment；Microclimate；Anthropogenic heat
From：https：//www．sciencedirect．com/science/article/pii/ S0306261920310783
（3）Smoothing control of solar photovoltaic generation using building thermal loads，by Zhimin Jiang，Jie Cai，Paul S．Moses，Vol．277，2020，115523
Abstract：Distributed energy resources such as solar photovoltaic （PV）systems are seeing significant expansion in power grids worldwide．However，serious system integration issues have arisen including voltage fluctuations and accelerated aging of voltage regulation devices，when adopting mass amounts of volatile energy resources onto legacy distribution networks originally designed for unidirectional power flow．Building heating，ventilation and air-conditioning（HVAC）systems，collocated with the distributed generation，can be considered as flexible loads due to the inherent building thermal inertia．HVAC systems can be proactively controlled to improve voltage regulation of distribution networks with high PV penetrations．This paper presents a smoothing solution that modulates HVAC power in response to volatile PV generation as a means to mitigate fluctuations in the net demand and generation．To demonstrate the effectiveness and evaluate performance gains，hardware-in-the-loop（HIL）tests were carried out using a3-ton variable-speed heat pump．The HIL tests leveraged a building thermal dynamic model and a steady-state power flow model for a33-bus distribution network to capture realistic indoor thermal responses and distribution voltage variations during PV smoothing control．Test results showed that the developed strategy was effective in reducing variations of net demand and generation with negligible impact on indoor comfort．More than55%reductions of voltage fluctuation were achieved and tap operations of voltage regulators could be fully or partially eliminated with proactive PV smoothing．
Keywords：Photovoltaic smoothing；Ｒenewable mitigation；Distribution voltage regulation；Demand side management From：https：//www．sciencedirect．com/science/article/pii/ S0306261920310357
（2020－09－25《建筑节能》杂志社侯恩哲摘录）
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