Lowest Life Cycle Cost Research Articles

Optimization of Aeration Diffuser System Design: A Simulation Study

The influence of aeration diffuser system design on electricity usage, effluent water quality, and life-cycle cost in biological wastewater treatment was investigated. A plant-wide model was implemented, and simulations were carried out with different process configurations and aeration systems. Model-aided design of new aeration diffuser systems could significantly decrease electricity usage and life-cycle cost while at the same time avoiding negative effects on the treatment performance. The optimum distribution of diffuser systems in tanks in series was found to be influenced by process configuration, volumetric loading rate, temperature, and the internal recirculation flow rate. Compared with a conventional design approach, increasing the number of diffusers, up to a critical point, led to higher energy efficiency and lower life-cycle cost. This was despite an increasing limitation of the minimum airflow rate, leading to dissolved oxygen levels significantly exceeding control targets. Aeration systems optimized by simulations were found to, independently of process configuration, exhibit 20% lower electricity usage and 16%–18% lower life-cycle costs compared with systems designed based on a more conventional approach typically applied in practice.

Can grid-tied solar photovoltaics lead to residential heating electrification? A techno-economic case study in the midwestern U.S.

This study aims to quantify the techno-economic potential of using solar photovoltaics (PV) to support heat pumps (HP) towards the replacement of natural gas heating in a representative North American residence from a house owner’s point of view. For this purpose, simulations are performed on: (1) a residential natural gas-based heating system and grid electricity, (2) a residential natural gas-based heating system with PV to serve the electric load, (3) a residential HP system with grid electricity, and (4) a residential HP+PV system. Detailed descriptions are provided along with a comprehensive sensitivity analysis for identifying specific boundary conditions that enable lower total life cycle cost. The results show that under typical inflation conditions, the lifecycle cost of natural gas and reversable, air-source heat pumps are nearly identical, however the electricity rate structure makes PV costlier. With higher rates of inflation or lower PV capital costs, PV becomes a hedge against rising prices and encourages the adoption of HPs by also locking in both electricity and heating cost growth. The real internal rate of return for such prosumer technologies is 20x greater than a long-term certificate of deposit, which demonstrates the additional value PV and HP technologies offer prosumers over comparably secure investment vehicles while making substantive reductions in carbon emissions. Using the large volume of results generated, impacts on energy policy are discussed, including rebates, net-metering, and utility business models.

Suitability assessment of high-power energy storage technologies for offshore oil and gas platforms: A life cycle cost perspective

This paper presents a technology suitability assessment (TSA) of high-power energy storage (ES) systems for application in isolated power systems, which is demonstrated through the case of offshore oil and gas platforms (OOGPs). OOGPs operate in very harsh environmental conditions (with limited weight and space), and this requires a specific assessment of which ES technologies are suitable for this application. This work presents a TSA procedure to address this problem. ES can be sized to provide many services. In this paper the focus is on primary frequency control, but the proposed approach can be extended to other services. The ES technologies assessed in detail include flywheels, supercapacitors (SCs), superconducting magnetic energy storage (SMES) and lithium-ion (Li-ion) batteries, which are critically selected from a broader pool of alternatives. A life cycle cost perspective is presented using the case study of an OOGP in the North Sea. A weighted TSA score is calculated, which is estimated from five attributes, namely: weight, space, safety, life cycle cost and operational experience. The results of the case study show that SMES has the lowest life cycle cost but has the highest weight and space requirements, thereby giving it the lowest weighted TSA score. Thus, it is unlikely to be a viable solution for the considered application. On the other hand, SCs require the least weight and space and have the second lowest life cycle cost, which gives them the highest weighted TSA score and makes them the most suitable solution for primary frequency control in an OOGP. Note that the results of the case study depends on the inputs (detailed information about the ES technologies) gathered. However, the most important thing is the methodology and the TSA analysis can always be re-run when more accurate inputs are obtained.

Sustainability assessment of economic, environmental and social impacts, feed-food competition and economic robustness of dairy and beef farming systems in South Western Europe

Sustainability assessment of economic, environmental and social impacts, feed-food competition and economic robustness of dairy and beef farming systems in South Western Europe

Nonlinear Analysis of External Post-Tensioning anchorage of Concrete Segment

Abstract: Precast concrete segmental bridges (PCSBs) have been the most common design technology used in the last decades. In these studies Non-linear structural performances of externally prestressed, precast concrete segmental bridges (PCSB). PCSBs with externally prestressed tendons have become very popular in construction because of economical and safety reasons, fast and practical construction, and outstanding serviceability. External tendons technique is widely used because it allows to inspect the cables and to replace them or to reinforce the tendons in case of damage while such kinds of actions are difficult to be taken in case of internal prestressing. It is widely recognized that segmental bridges have better durability, lower life-cycle costs and higher quality for maintenance than other types of bridges. However, there is lack of reliable computational model for analyzing behavior of post-tensioned PCSBs. Experimental analysis of bridge segment required more cost, time and effort for the analysis and also take cake of quality of material, cast process, curing, and testing. This research presents the results of stress and strain state of the local bearing area caused by a Prestressed cable anchor in reinforced concrete bridge segment. Nonlinear analysis of anchorage and rebar, concrete segment can be carried out by analytical solution calculated with the reference of ACI 318/19. ANSYS software is used for model and analyze the structure. The analysis process was carried out in 3 types : linear elastic analysis, nonlinear elastic analysis, and nonlinear analysis considering the destruction of concrete, and the value is compared with ANSYS software ( static structure).

Modeling And Simulation of a Reliable Hybrid (Pv/Diesel) Power System with Energy Storage in Batteries for University Library, Bayero University, Kano State, Nigeria

Due to unreliability of power supply from national grid, high cost of diesel and maintenance of generators being an alternate for national grid, there is need to adopt a renewable energy source for efficient and reliable power supply. Savings associated with conversion of a stand-alone diesel generator powered system to a reliable PV/Diesel hybrid power system with energy storage in batteries for Bayero University Kano Library using HOMER software was presented in this study. The economic parameter of merit used in selecting an optimum energy system from set of configurations was total Net Present Cost (NPC) in billions of naira. Generator + PV + Battery system has a total NPC of (₦ 1.17B) and saves (₦ 0.9B), Generator + PV system has a total NPC of (₦ 1.68B) and saves (₦0.4B), Generator + Battery system has a total NPC of (₦ 2.05B) and saves (₦ 0.03B), PV + Battery system has a total NPC of (₦ 2.28B) and saves (₦ - 0.2B) when all compared with Generator-only system (₦ 2.08B). It can be seen that the best case is the PV + Gen + Battery system. Even though it has the highest capital cost, but it resulted to the least net present cost (NPC); as such, PV + Gen + Battery system is the optimized model to fulfill the load demands. Therefore, this research work shows that the integration of PV with battery storage into the existing diesel stand-alone system in the University library is more reliable at the lowest lifecycle cost.

Comparative life cycle assesment (LCA) and life cycle cost analysis (LCCA) of precast and cast–in–place buildings in United States

Comparative life cycle assesment (LCA) and life cycle cost analysis (LCCA) of precast and cast–in–place buildings in United States

Geometric Quality Assessment of Prefabricated Steel Box Girder Components Using 3D Laser Scanning and Building Information Model

Prefabricated steel box girders (SBGs) are widely adopted in bridge engineering due to their light weight and low lifecycle cost. To smoothly assemble SBG components on a construction site, it is necessary to inspect their geometric quality and ensure that all the as-is SBG components have the correct dimensions. However, the traditional inspection method is time-consuming and error-prone. This study developed a non-contact geometric quality assessment technique based on 3D laser scanning to accurately assess the locations and dimensions of SBG components. First, a robust normal-based region-growing algorithm was developed to divide the SBG components into segments with different labels. The scanned data related to the T ribs were then extracted through the proposed subtraction algorithm after the identification of the steel cabin. Lastly, the required items for geometric quality inspection were calculated based on the extracted as-is SBG components. The feasibility of the proposed geometric quality assessment method was validated through a real SBG project. Field test results showed that the developed inspection technique could assess the geometric quality of prefabricated SBG components in a more accurate and efficient manner compared to traditional measurement approaches.

A Proof-of-Concept of a Reliability-Based Life-Cycle Cost Optimization Framework for Activated Sludge Processes

Wastewater treatment plants need their reliability to be properly assessed to preserve society’s health and availability of water resources. To date, no wastewater treatment plant framework comprehends the reliability of the system, considering the influence of uncertain parameters, and the total costs during the lifespan of the project. Here, an innovative framework combining a reliability analysis, a reliability-sensitivity analysis, and a life-cycle cost assessment is presented as a proof-of-concept tool for reliability-based life-cycle cost optimization of an activated sludge process due to its common application in sanitation worldwide. The results indicate (1) great variability of the reliability scenario due to the influent loads, (2) the sludge volumetric index exerts the most influence on the system’s reliability and risk expenditures, and (3) an optimum scenario associated with the lowest life-cycle cost and an annual failure rate of 19 day of failure year−1 can be obtained via an exhaustive simulation protocol. The framework demonstrates to be a promising tool for techno-economic analysis of activated sludge processes, as well as to optimize project expenditures based on its reliability to withstand different influent loads. This proof-of-concept optimization framework is expected to find multiple applications not only in sanitation and water treatment but also in other industries while supporting sustainable development goals.

Value-Based Seismic Performance Optimization of Steel Frames Equipped with Viscous Dampers

ABSTRACT Recent studies showed that while code-compliant structures can generally protect the safety of the occupants, they may exhibit extensive damages during strong earthquake events. On the other hand, structures are generally designed to satisfy the seismic code requirements with the least initial cost regardless of their life cycle cost. In recent years, value-based design has been considered as an effective alternative for code-based design procedures. In this method, as well as the initial cost of the structure, a comprehensive consequence modeling is performed in the design process. In this paper, for the first time, a value-based design optimization method is developed for seismic enhancement of existing RBS steel frames using nonlinear viscous dampers. The efficiency of the method is demonstrated through 4-, 8-, and 12-story frames designed for low, medium, and high earthquake intensity levels, while the life cycle costs are evaluated using FEMA P-58. A time-based approach is carried out to consider different earthquake events and their corresponding probability of occurrence in a specific range of intensities. For dynamic analysis of the structures, the Endurance Time (ET) method is adopted to significantly reduce the computational costs while providing accurate results. The Genetic Algorithm (GA) is then used to optimize the damping coefficient of the viscous dampers for minimum life cycle cost. The results, in general, indicate the efficiency of the proposed method in increasing the total economic value of the studied structures with the least additional cost. It is shown that shorter structures and those designed in high-seismic risk regions benefit more from using optimized viscous dampers, leading to up to 42% lower life cycle costs. The results of this study should prove useful in more efficient strengthening design of existing steel frames.

A Novel Gripper with Integrated Rotary Unit and Force Control for Pick and Place Applications

Modern electrical grippers have lower life-cycle costs compared to pneumatic ones. Furthermore, they provide force control, making it possible to grasp objects with different fragility using a single device. At the same time, electrical grippers have a higher end-effector weight, installed on the robot’s flange and lower closing speed, preventing them from replacing pneumatic solutions in high dynamic Pick and Place applications. This research faces both issues by synthesizing a novel gripper mechanism based on a Torque Distribution Gearbox, which makes it possible to relocate the electric motors to the static frame of a delta robot. The proposed gripper not only has a lower mass and a higher closing speed than competitive electric solutions, but it also provides unlimited rotation around the vertical axis. The performance of the gripper was tested in experimental studies, which showed that a created aluminum prototype provides a precise force control in the range from 3 N to 48 N with an accuracy not worse than 1.27 N. Moreover, its finger’s speed is 3.1–56 times higher than market available electrical grippers, which makes it comparable by this parameter with pneumatic solutions used in high dynamic Pick and Place applications.

Boosting productivity with tech

Boosting productivity with tech

Shear behaviour of vertical inter-module connection with bolts and shear keys for MSCs

Shear behaviour of vertical inter-module connection with bolts and shear keys for MSCs

Parametric analysis of railway infrastructure for improved performance and lower life-cycle costs using machine learning techniques

Rigorous and efficient management of the railway infrastructure is crucial to avoid accidents and reduce operation and maintenance costs. This requires in-depth knowledge of the assets, the interaction among them and the effect that each track parameter has on the overall infrastructure performance. In this study, a large set of studies are carried out, on a previously calibrated finite element slab track model, where the relevant track parameters are varied within their usual ranges. The results are then used to train and validate a series of predictive models based on Machine Learning algorithms. This methodology provides greater understanding and enhanced prediction of the behaviour of tracks, which are composed of multiple variables such as the soil/subgrade, supporting layers, sleepers, pads and rails. The study also considers train axle loads and service speeds, which are other key elements that influence the track performance. The results show that the parameters that have greatest influence on the railway infrastructure are the properties of the soil, characteristics of the rail pads and the axle loads. This work can support the implementation of predictive maintenance procedures for railway tracks and the development of innovative technological solutions, providing responses to the industrial needs of reducing costs and contributing to improve the competitiveness of railway transport.

Electrolyzer cell-methanation/Sabatier reactors integration for power-to-gas energy storage: Thermo-economic analysis and multi-objective optimization

Electrolyzer cell-methanation/Sabatier reactors integration for power-to-gas energy storage: Thermo-economic analysis and multi-objective optimization

Editorial: Special Issue on Smart and Green Infrastructures with Optimum Life Cycle Solutions

Editorial: Special Issue on Smart and Green Infrastructures with Optimum Life Cycle Solutions

Sustainable cooling cycles by algorithmically supported design of decentral pump systems

Sustainable cooling cycles by algorithmically supported design of decentral pump systems

Comparative Analysis on Roof Covering Materials Sustainability as Constructed by Bamboo and Corrugated Galvanized Iron Sheet in Rural Areas Around Wolkite, Ethiopia

One of the most important components of any building is the roof, which protects the interior of the building from environmental influences. It is sustainable to switch roofing materials from expensive roofing materials to inexpensive and environmentally friendly materials. Today's roofing materials have negative effects on the environment due to the manufacturing process. Therefore, this research has mainly focused on the development of sustainable roofing materials through life cycle cost analysis. Approximately ten bamboo samples from homeowners in the Wolkite area and one Adama corrugated galvanized sheet were taken to analyze the life cycle costs. Data on the ecological and socio-economic aspects of the selected roofing materials were collected with the help of interviews and questionnaires. The cost of galvanized corrugated iron sheet of 1.8m2 was $38.19 while the cost of bamboo was $3.91; the researchers concluded that treated bamboo roofs have lower life cycle costs per 1.8 square meters (approximately 89.76% less than corrugated galvanized iron), more environmentally friendly. And also using bamboo as roofing material, create a good job opportunity for the society by cultivating and preparing bamboo to the construction input.

A Bayesian Pipe Failure Prediction for Optimizing Pipe Renewal Time in Water Distribution Networks

The sustainable management of the water supply system requires methodologies to monitor, repair, or replace the aging infrastructure, but more importantly, it must be able to assess the condition of the networks and predict their behavior over time. Among other infrastructure systems, the water distribution network is one of the essential civil infrastructure systems; therefore, the effective maintenance and renewal of the infrastructure’s physical assets are essential. This article aims to determine pipe failure prediction to optimize pipe renewal time. This research methodology investigates the most appropriate parameters for predicting pipe failure in the optimization. In particular, the non-homogeneous Poisson process (NHPP) with the Markov chain Monte Carlo (MCMC) approach is presented for Bayesian inference, while maximum likelihood (ML) is applied for frequentist inference as a comparison method. It is concluded that the two estimations are relatively appropriate for predicting failures, but MCMC estimation is closer to the total observed data. Based on life-cycle cost (LCC) analysis, the MCMC estimation generates flatter LCC curves and lower LCC values than the ML estimation, which affects the decision making of optimum pipe renewal in water distribution networks.

Direct shear performance of UHPC Multi-Keyed epoxy joint

Direct shear performance of UHPC Multi-Keyed epoxy joint