With buildings around the world accounting for nearly one-third of global energy demand and the availability of fossil fuels constantly on the decline, there is a need to ensure that this energy demand is efficiently and effectively managed using renewable energy now more than ever. Most research and case studies have focused on energy efficiency of ‘new’ buildings. In this study, both technical and financial viability of Net Zero Energy Buildings (NZEB) for ‘existing’ buildings will be highlighted. A rigorous review of open literatures concerning seven principal areas that in themselves define the concept of NZEB building is carried out. In practice, a suitable option of the NZEB solutions is needed for the evaluation and improvement for a specific geographical area. The evaluation and improvement has been carried out using a novel hierarchy-flow chart coupled with a Building Information Model (BIM). This BIM or digital twin is then used to thoroughly visualize each option, promote collaboration among stakeholders, and accurately estimate associated costs and associated technical issues encountered with producing an NZEB in a pre-determined location. This paper also provides a future model for NZEB applications in existing buildings, which applies renewable technologies to the building by aiming to identify ultimate benefit of the building especially in terms of effectiveness and efficiency in energy consumption. It is revealed that the digital twin is proven to be feasible for all renewable technologies applied on the NZEB buildings. Based on the case study in the UK, it can be affirmed that the suitable NZEB solution for an existing building can achieve the 23 year return period.

/pdf/a-digital-twin-evaluation-of-net-zero-energy-building-for-4me8sjvnpw.pdf

A Digital-Twin Evaluation of Net Zero Energy Building for Existing Buildings

Benchmarking on railway safety performance using Bayesian inference, decision tree and petri-net techniques based on long-term accidental data sets

A railway turnout is an essential infrastructure for managing railway traffic flexibility. In contrast, it imposes restrictions on train operations such as lower operational speeds through the turnout due to the complex movements of trains over the turnout. This results in the large-amplitude dynamic responses of the train-turnout interaction. Previous studies have focused on the train-turnout interactions entailing the wheel-rail contact forces and stresses. Very few of the studies considered the effects of the contact forces on the turnout structure and its components such as sleepers and bearers. Those previous studies neglected the dynamic forces and estimated the behavior of train-turnout interactions based on quasi-static calculations. In reality, turnouts are subjected to high impact forces, which can be higher than the permissible track forces. Consequently, a numerical model capable of determining impact forces was developed here, to evaluate the dynamic behaviors of a railway turnout and their effects on such turnout components as bearers, ballast, and so on. The model consists of a structured beam grillage laying on an elastic foundation with rigid wheelsets and a bogie. The model was verified by field measurements. The new insight stemmed from this study shows that neglecting the contribution of dynamic forces can result in the unsafe underestimation of train turnout behaviors.

/pdf/new-insights-from-multibody-dynamic-analyses-of-a-turnout-5an9j26qg0.pdf

New Insights from Multibody Dynamic Analyses of a Turnout System under Impact Loads

The stability of train timetables plays an important role in ensuring the safety and punctuality of train operations. Meanwhile, a reasonable stop plan has a significant effect on passenger and energy consumption. Existing research has focused exclusively on adjusting timetables after delays occur, or on adjusting them without considering stop plans. By contrast, in this study, we developed a train timetable and stop plan synchronization optimization model that is passenger and energy-saving oriented. The following objectives were considered for minimization: probability of train delays, energy consumption, and travel time of the trains. A parallelism selection genetic algorithm was designed to solve the model. The section of high-speed railway from Nanjing South to Shanghai Hongqiao was utilized as a case study to evaluate the proposed model. The results showed that, while meeting passenger demand, the proposed optimization approach increased the punctuality rate by 12.55% and decreased the energy consumption by 8.16%.

Passenger and energy-saving oriented train timetable and stop plan synchronization optimization model

The present study proposes an economic indicator to support the evaluation of aircraft End of Life (EoL) strategies in view of the increasing demand with regards to aircraft decommissioning. This indicator can be used to evaluate an economic performance and to facilitate the trade-off studies among different strategies. First, Disposal and Recycle (D&R) scenarios related to stakeholders are investigated to identify the core concepts for the economic evaluation. Next, we extracted the aircraft D&R process from various real-life practices. In order to obtain the economic measure for the engineering process, a method of estimating the D&R cost and values are developed by integrating product, process and cost properties. This analysis is demonstrated on an averaged data set and two EoL aircraft cases. In addition, sensitivity analysis is performed to evaluate the impact of the D&R cost, residual value, and salvage value. Results show that the disassembly and dismantling of an aircraft engine possesses relatively more economic gains than that for the aircraft. The main factors influencing the proposed D&R economic indicator are the salvage value and D&R cost for economically efficient D&R cases. In addition, delaying the disposal and recycle process for EoL aircraft can lead to economically unfavorable solutions. The economic indicator combined with the evaluation methods is widely applicable for evaluations of engineering products EoL solutions, and implies a significant contribution of this research to decision making for such complex systems in terms sustainable policy.

/pdf/disposal-and-recycle-economic-assessment-for-aircraft-and-3exs32oeua.pdf

Disposal and Recycle Economic Assessment for Aircraft and Engine End of Life Solution Evaluation

https://research.birmingham.ac.uk/portal/files/55242774/J._Cleaner_Production_Nov_2018.pdf

De’Von Jennings

Papers

A through-life evaluation of end-of-life rolling stocks considering asset recycling, energy recovering, and financial benefit