Lowest Life Cycle Cost Research Articles

Identifying Research Topics and Trends in Asset Management for Sustainable Use: A Topic Modeling Approach

Asset management is not new, and research has been conducted in private and public sectors on how to systematically maintain infrastructure or facilities for sustainable use and achieve the level of service desired by users or customers at the lowest life cycle costs. This research identifies the research topics and trends in asset management over the past 30 years. To this end, latent Dirichlet allocation, a topic modeling approach, was applied to articles published in engineering journals and investigated the following three research questions: (1) what have the key topics been for the past three decades? (2) what are the main activities and target sectors of asset management? (3) how have the research topics and keywords changed over the past three decades? The analysis shows that the target field of asset management has broadened while the main activities of asset management have been limited to several popular activities such as life cycle cost analysis and reliability analysis. Some implications and future research directions are also discussed.

Multi-objective capacity optimization of a hybrid energy system in two-stage stochastic programming framework

Hybrid energy system is one main mean to deal with the energy crisis and its capacity optimization is a key to obtain an economical and reliable supply of energy. In this paper, the capacity optimization of a novel hybrid system composed of wind turbine, concentrated solar plant and electric heater is modeled as a multi-objective two-stage stochastic problem, where capacity optimization minimizing the life cycle cost (LCC) and energy management strategy optimization minimizing the loss of power supply probability (LPSP) are integrated. The scenario-based approach is applied to reflect the random characteristics of wind and solar resources. The Pareto set of the problem is obtained by non-dominated sorting genetic algorithm (NSGA-II), whose effectiveness is validated by algorithm comparisons with multi-objective particle swarm optimization (MOPSO) and multi-objective evolutionary algorithm based on decomposition (MOEA/D). Furthermore, techno-economic comparisons with a reference hybrid energy system without electric heater are performed to investigate economic benefits of the electric heater. The comparison results show that the electric heater is beneficial for a lower LCC which is reduced by 1.21%, 1.34%, 1.68%, 3.14%, 4.94% and 4.55% respectively when the LPSP is 0%, 1%, 2%, 3%, 4% and 5%.

Variable-speed-drive-based method for the cost optimization of air filter replacement timing

The flow resistance of air filters accounts for a significant share of the electric energy consumed by fan systems. Due to their inevitable fouling, filters must be replaced periodically. This paper presents a novel variable-speed-drive-based method for online determination of the cost-optimal time to replace the filter of a fan system. The total cost of filtering per filtered volume of air is continuously calculated and when its minimum is reached, filter replacement is recommended. As part of the calculation, the energy cost related to the pressure drop of the filter is estimated using a variable-speed-drive-based filter pressure drop soft sensor. In addition to a variable-speed-drive and manufacturers’ specifications for the fan and filter, no extra equipment is required. As such, the method can be implemented as a programmed feature in a variable-speed drive or in a remote control and monitoring system. Feasibility of the method is verified with simulations and laboratory measurements, and the results suggest that it can realize a lower life-cycle cost of air filtering than the so far prevalent practices of filter replacement timing.

Thorough Investigation Allows Mitigation of Corrosion-Resistant Alloy Pipeline Issues

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 30149, “Corrosion Resistant Alloy Pipeline: Creating Knowledge Behind the Scenes,” by M. Hasbi A. Razak and Nur Izyan Mukhtar, Petronas, prepared for the 2020 Offshore Technology Conference Asia, originally scheduled to be held in Kuala Lumpur, 2-6 November. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission. High-pressure/high-temperature (HP/HT) environments in offshore gas fields with a significant presence of carbon dioxide (CO2) and hydrogen sulfide (H2S) in the full well stream demand the use of corrosion-resistant alloy (CRA) pipelines. This pipeline system comprises a metallurgically bonded CRA layer, produced by roll bonding and known as metallurgical cladded pipe (MCP), and a mechanically expanded and fitted CRA layer in a backing steel known as mechanical lined pipe (MLP). The complete paper outlines specific issues, mitigation steps, and lessons learned during the development phase of the CRA pipeline. Pipeline System and Materials To achieve the lowest life-cycle cost, CRA pipeline designed to handle a maximum partial pressure of 18 bar of CO2 and 13 mbar of H2S at a maximum temperature of 150°C was selected for an offshore gas field. The pipeline system consists of two types of CRA line pipe, MCP and MLP. The pipeline system is divided into Zone 1 and Zone 2. The areas of application of MLP and MCP are summarized in Table 1. MLP Challenges The MLP challenges experienced are subdivided in the complete paper according to the development phase of the pipeline during which they were experienced (i.e., during the manufacturing or installation stages). Undulation Appearance on the Internal Surface of the MLP. Undulation, in this context, refers to a wavy appearance of the internal surface of the CRA pipe, which was found after the mechanical expansion process. Fig. 1 shows a sample of undulation in the line pipe. Several factors were suspected to have caused the undulation in the internal CRA surface after the hydroforming process. One such factor was the manufacturing process of the seamless carbon-steel (CS) backing pipe, which involves a pipe-piercing process using a conical device to pierce billets to create hollow, seamless pipes. To determine the actual cause, additional inspection and testing on MLP were performed. Visual inspection found that the undulation appearance on the CRA liner is similar to the CS backing-pipe contour, proving that undulation in the CRA liner was caused by the liner being plastically deformed and following the contour of the CS backing pipe. Wall-Thickness Measurement of CS Backing Pipe. Thickness measurement was performed at selected areas in circumferential and longitudinal directions of the pipe. The circumferential thickness measurement determined that significant thickness variations existed in the CS backing pipe. Some of the measured wall thicknesses already exceeded the maximum positive tolerance of the seamless pipe-wall thickness.

Optimal Renovation Strategies through Life-Cycle Analysis in a Pilot Building Located in a Mild Mediterranean Climate

The 2030 climate and energy framework includes EU-wide targets and policy objectives for the period 2021–2030 of (1) at least 55% cuts in greenhouse gas emissions (from 1990 levels); (2) at least 32% share for renewable energy; and (3) at least 32.5% improvement in energy efficiency. In this context, the methodology of the cost-optimal level from the life-cycle cost approach has been applied to calculate the cost of renovating the existing building stock in Europe. The aim of this research is to analyze a pilot building using the cost-optimal methodology to determine the renovation measures that lead to the lowest life-cycle cost during the estimated economic life of the building. The case under study is an apartment building located in a mild Mediterranean climate (Castellon, SP). A package of 12 optimal solutions has been obtained to show the importance of the choice of the elements and systems for renovating building envelopes and how energy and economic aspects influence this choice. Simulations have shown that these packages of optimal solutions (different configurations for the building envelope, thermal bridges, airtightness and ventilation, and domestic hot water production systems) can provide savings in the primary energy consumption of up to 60%.

Transitioning to clean energy transportation services: Life-cycle cost analysis for vehicle fleets

Comprehensive global decarbonization requires that transportation services cease to rely on fossil fuels for power generation. This paper develops a generic, time-driven life-cycle cost model for mobility services to address two closely related questions central to the emergence of clean energy transportation services: (i) the utilization rates (hours of operation) that determine how alternative drivetrains rank in terms of their cost, and (ii) the cost-efficient share of clean energy drivetrains in a vehicle fleet composed of competing drivetrains. The model compares alternative drivetrains with different environmental and economic characteristics in terms of their life-cycle cost for any given duty cycle. The critical utilization rate that equates any two drivetrains in terms of their life-cycle cost is shown to also provide the optimization criterion for the efficient mix of vehicles in a fleet. This model framework is then calibrated in the context of urban transit buses, on the basis of actual cost- and operational data for an entire bus fleet. In particular, our analysis highlights how the economic comparison between diesel and battery-electric transit buses depends on the specifics of the duty cycle (route) to be served. While electric buses entail substantially higher upfront acquisition costs, the results show that they obtain lower life-cycle costs once utilization rates exceed only 20% of the annual hours, even for less favorable duty cycles. At the same time, the current economics of the service profile examined in our study still calls for the overall fleet to have a one-third share of diesel drivetrains.

Life-Cycle Cost Analysis (LCCA) comparison of pavements (Flexible, rigid and rigid-admixed with cow bone ASH)

Life Cycle Cost Analysis (LCCA) acts as a decision support tool in economic evaluation of cost (agency and user) during pavement type selection, maintenance and rehabilitation strategy. The Life cycle cost analysis was done using the Present worth of Cost method. Technical Recommendations for Highway (TRH) 12 (pavement rehabilitation investigation and design) analysis was used for calculating the agency cost which entailed the initial rehabilitation, maintenance, future and salvage cost. The LCCA analysis period for this study was taken as 40 years as the analysis period have to be sufficiently long to reflect long-term cost differences associated with reasonable design strategies. The result of the study shows that the present worth cost for the varying Pavement presents the options available for decision making. The result revealed that the initial cost of Rigid pavement is the highest followed by the initial cost of Rigid pavement with 15% CBA while flexible Pavement has the lowest initial cost. However, considering the result showing the present worth cost for the varying pavement types present worth cost of flexible pavement is the highest followed by Rigid pavement and Rigid pavement with 15% CBA has the lowest life cycle cost. The study recommended that Rigid pavement with 15% CBA should be considered because it gives the lowest life cycle cost and the initial cost is relatively low.

Dual Battery Control System of Lead Acid and Lithium Ferro Phosphate with Switching Technique

The increase in electric vehicles needs to be supported by the existence of reliable energy storage devices. The battery, as an energy storage system, has its advantages and disadvantages. The combination of different battery types is chosen since the battery is one of the energy storage systems with mature technology and low life cycle cost. A solution that can be proposed to cover the weakness of each battery is the use of the Dual Battery System (DBS). In this project, a dual battery control system with a combination of Valve Regulated Lead Acid (VRLA) and Lithium Ferro Phosphate (LFP) batteries was developed using the switching method. Battery selection switching is determined by the specification and operational set point of the battery used. The experimental testing was carried out. The result of the research conducted showed that the current sensor accuracy was 83.75% and the voltage sensor accuracy was 94.25% while the current sensor precision value was 64.91% and the voltage sensor precision was 99.74%. The use of a dual battery system can save energy in a VLRA battery compare with a single VLRA battery by up to 68.62%, whereas in LFP battery by up to 29.48%. This means it gives the advantages of longer distances of traveling in electric vehicles.

МОЛНИЕЗАЩИТНЫЕ ПОКРЫТИЯ МОТОГОНДОЛ АВИАЦИОННЫХ ДВИГАТЕЛЕЙ ИЗ ПОЛИМЕРНЫХ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ ЧАСТЬ 1. АНАЛИЗ СУЩЕСТВУЮЩИХ ТИПОВ МОЛНИЕЗАЩИТ

The overview of the existing and upcoming types of aircraft engines polymeric composite nacelles lightning protection is presented. It is demonstrated that at present the most widely-used technologies of polymer composites lightning protection in the world and domestic aviation industry consist in using metal foils and meshes. However, the relative weight of the lightning protection comprised of metal foils and meshes (including adhesive and erosion layers) may result in a significant weight gain up to 0.7–0.9 kg per each square meter of the polymer composite nacelle surface. Additionally, the principal disadvantage of metal meshes is high percentage of the open area (80–90 %) leading to decreased engine EMI protection in the event of exposure to electromagnetic impulse from the lightning strike or L/HIRF. Currently, intensive scientific studies are performed in the field of aviation equipment lightning protection in different universities, institutes and companies, mainly in the USA, Europe, Russia and Japan. The potential lightning protection problem solution addressed by the large number of scientific papers is use of coatings made of heatproof polymer composites and polymer binders modified by carbon nanoparticles to develop a better material conductivity. However, this technology is characterized by high costs, low repairability, etc. Various spraying methods are studied. It has been found out that for the lightning protection of the advanced types of nacelles the highly competitive engineering solution is the one that ensures a cardinally low relative weight and high reliability, manufacturability, high EMI protection L/HIRF, low engine life cycle costs including easy in-service repair.

Seasonal storage of residential exhaust air and sewage waste heat

Most Finnish residential buildings have been built before ventilation heat recovery options became mandatory. Exhaust air heat pumps are an effective way to reduce emissions, but they cannot cover all heating demand. Ground-source heat pumps can be designed to meet all loads, but they require corresponding amounts of space both above and below ground. This simulation study combines residential ventilation and sewage waste heat with a ground-source heat pump system to improve system sustainability and cost-effectiveness. A hybrid waste heat and ground-source heat pump system was shown to have 20% lower life cycle costs compared to a pure ground-source heat pump system. It also maintained sustainable ground temperature levels over the long term, while reducing above-ground space requirements by 95%.

The Economics of Electric Vehicles

Electric vehicles (EVs) powered by renewable electricity are a centerpiece of efforts to decarbonize transportation. EV advocates also claim benefits from local pollution reductions, lower life-cycle costs to consumers, and improved energy security. We examine the theory and evidence behind these claims and evaluate when the market will produce the optimal path of EV adoption. Optimal EV policy is nuanced. While EVs driven in some locations reduce pollution, they increase pollution in others. While many consumers enjoy cost savings from EVs, some experience net benefits from choosing gasoline-powered cars, even after accounting for EV subsidies. And depending on the dynamic benefits of stimulating EV adoption today, optimal policy might front-load stimulus, even though the environmental benefits of EV adoption are likely to increase over time as electricity grids become cleaner. Reflecting these nuances, the policy landscape is complicated and often creates conflicting incentives for EV adoption in regions with ambitious adoption goals. We highlight several themes for policy design, including 1) promoting regional variation in EV policies that align private incentives with social benefits, 2) pursuing a time-path of policies that follows the trajectory of marginal benefits, and 3) rationalizing electricity and gasoline prices to reflect their social marginal cost. On the extensive margin, purchase incentives should ramp-down as learning-by-doing and network externalities that may exist diminish; on the intensive margin, gasoline should become relative more expensive than electricity (per mile traveled) to reflect cleaner marginal emissions from electricity generation.

A Glance On Radiant Cooling Technology For Heating And Cooling For Residential And Commercial Building Application

As we know that nowadays due to the hot and humid weather and the increasing temperature, a high amount of energy consumption is used for heating and cooling purposes in residential as well as in commercial buildings for air conditioning systems. To overcome this problem and to reduce energy consumption is a challenging task. People required good thermal comfort in an indoor environment so, the use of radiant heating and cooling system is a better way. This concept is used to cool or heat by absorbing or taking sensible heat in the indoor environment by thermal radiation. This system uses water as a thermal medium to cool or heat the room space. The radiant system has three types discussed in these papers for cooling and heating. The paper describes an overall study regarding radiant heating and cooling systems. It includes types of the radiant cooling system, comfort level from the radiant system, energy-saving and cooling load calculations for the designing of the system. It reduces the energy lost due to the duct leakage and reduces the manufacturing cost for the ducting system. It also has a lower life cycle cost compared to conventional. The paper includes the rules formed for the radiant design system i.e. ASHRAE Standard 55 and ISO7730. The Paper concludes that the radiant cooling and heating system is efficient as compared with conventional air-conditioning systems.

A comprehensive comparative investigation on solar heating and cooling technologies from a thermo‐economic viewpoint—A dynamic simulation

AbstractThe yearly thermo‐economic performance is dynamically investigated for three solar heating and cooling systems: solar heating and absorption cooling (SHAC), solar heating and ejector cooling (SHEC), and heating and solar vapor compression cooling (HSVC). First, the effects of important design parameters on the thermo‐economic performance of the systems to supply the heating and cooling loads of the building are evaluated. The systems are parametrically analyzed with the weather conditions of Tehran, Iran. The results show that the life cycle costs (LCC) of the SHAC and HSVC systems are alike and much lower than those of the SHEC system. The HSVC system exhibits the best performance from exergetic and solar fraction viewpoints. The comparative analysis shows that the energy efficiencies of the SHAC and SHEC systems are higher in colder climatic conditions. However, the collector efficiency of the HSVC system declines in colder climates, mainly due to the lower solar intensities relative to in hotter climates. Further, the solar fraction of the SHAC system is higher than the SHEC technology under all climatic conditions. Moreover, higher values of solar fractions are obtained under colder weather conditions for the SHEC and HSVC systems. The best economic performance is observed for the SHAC and HSVC technologies, having significantly lower LCCs than the SHEC system. These lower LCCs under colder climatic conditions are due to the lower cost of supplying the heating load compared to the cooling load. Furthermore, all systems exhibit enhanced exergetic performance in colder weather conditions. The yearly thermo‐economic performance is dynamically investigated for three solar heating and cooling systems: SHAC, SHEC, and HSVC. In addition, the effects of important design parameters on the thermo‐economic performance of the systems to supply the heating and cooling loads of the building are evaluated.

Numerical analysis of high temperature gas flow through conical micronozzle

Abstract Micro-propulsion is considered to be the emerging technology for the propulsion of micro and micro aerospace vehicles as it is preferred over mesoscale thruster due to lower overall life-cycle cost and launching costs. Hence this paper investigates the influence of critical parameters like the Nozzle Pressure Ratio (NPR) and Reynolds number (Re) on the operational characteristics of the micronozzle. A conical nozzle with throat diameter 710 µm and exit/throat area ratio ∼2.14 has been designed and is analyzed numerically by using a model based on pressure-based coupled implicit for various NPR, the backpressure with three Res namely, 1000, 1500, and 2000. The performance of this micronozzle has been characterized in terms of thrust, thrust coefficient, and specific impulse for all three Re cases. A subsequent analysis of the subsonic layer reveals that the nozzle is subjected to high viscous losses at low NPRs, which are independent of Re.

Algorithmic Strategy for Simultaneous Optimization of Design and Maintenance of Multi-Component Industrial Systems

This article describes a new approach to simultaneous optimization of design and maintenance of large-scale multi-component industrial systems. This approach, in a form of an algorithm, aims to help designers in the search for solutions by characterizing the components and their architecture including maintenance issues. The aim is to improve the performance of the industrial systems by maximizing the Total Operational Reliability (TOR) at the lowest Life Cycle Cost (LCC). In the case of this research, the term "design" refers to the reliability properties of the components, possible redundancies, faulty component accessibility, and the ability to improve the component real-time monitoring architecture. The term “maintenance” refers to maintenance plan adapted to the opportunistic dynamic maintenance plan. Simultaneous optimization of design and maintenance is achieved by a two-level hybrid algorithm using evolutionary (genetic) algorithms. The first level identifies the optimal design solutions calculated relative to the TOR and the LCC. The second proposes a dynamic maintenance plan that maximizes the reliability of the system throughout its operating life.

Optimasi Desain Pembangkit Listrik Kapasitas 200 kW Menggunakan Tenaga Matahari dengan Sistem Pumped Storage

This research was conducted by analyzing and optimizing the design of solar power plants with pumped storage systems as a source of renewable energy for remote areas in Indonesia. This research is very important to be done to solve the problem of meeting the electricity needs, especially in remote areas. The scheme is implementing 5 options in the pumped storage system. The system design is calculated and analyzed then optimization is done using Ansys fluent software. After that, all options are analyzed and compared in terms of economics related to Life-Cycle Cost (LCC) and Break Event Point (BEP) to get the best scheme. It was found that option A is better than other options in terms of system implementation because it requires the smallest number of pumps. From an economic standpoint, the LCC for option A is 63% lower than option C and higher than option B, D and E which are 2%, 5% and 25%, respectively. The lowest LCC is obtained by option E but has its own challenges in its application because it requires 540 pumps. The fastest BEP is obtained by option A with 9.47 years followed by an option D with 9.6 years. The longest BEP with 12.74 years was obtained by an Option C. Therefore, the use of pumped storage systems in solar power plants as an alternative renewable energy provides opportunities that are technically very possible and have the potential for continuous power supply in remote areas.

Techno-economic comparison of wet and dry cooling systems for combined cycle power plants in different climatic zones

For combined-cycle power plants, the two most dominant steam condenser cooling options are the wet-cooling tower and the air-cooled (dry) systems. The wet cooling system is commonly installed on plants located in areas with available water sources, while the dry system is typically preferred in areas where water is scarce. However, owing to the increasing regulations on water conservation, water usage costs and improvements on cooling system designs, a new approach is required for the optimal selection of plant cooling systems, incorporating site climatic conditions, amongst other considerations. This study presents a comparative techno-economic analysis of a steam turbine cycle with wet- and dry- cooling systems for five typical tropical locations in Nigeria with different climatic conditions and water usage costs. The results show that in the hot (ambient temperatures >33 °C) and dry regions (relative humidity <65%) namely Sahel, Sudan, and Guinea savannah, the plant with wet cooling generated more net power outputs with lower life-cycle costs, operating and maintenance costs than with dry cooling. Thus, for these three regions, the wet cooling system is the best option. But for the Tropical Rainforest and Coastal zones with low ambient temperatures (≤31 °C) and high relative humidity values (≥76%), the performance and cost implications of the plant with dry cooling was more favourable due to lower system sizes and costs requirements. Parametric investigations revealed that high ambient temperature increased the size and costs requirements of air-cooled systems while relative humidity significantly influenced the total power consumption of water-cooled systems.

A Glance on Radiant Cooling Technology for Heating and Cooling for Residential and Commercial Building Application

As we know that nowadays due to the hot and humid weather and the increasing temperature the high amount of energy consumption is used for the heating &amp; cooling purpose in residential as well as in commercial building for air conditioning systems. To overcome this problem and to reduce the energy consumption as well as good thermal comfort to people in the indoor environment, use the radiant heating &amp; cooling system is a better way. This concept is used to cool or heat the room and absorbs the indoor sensible heat by thermal radiation. The system removes heat by using less energy and more energy-efficient. This system uses water as a medium to cool or heat the room space. There are three types discussed in these papers for cooling &amp; heating. In this paper, we did an overall study regarding radiant heating and cooling systems. It reduces the energy lost due to the duct leakage. It also has a lower life cycle cost compared to conventional. In this paper, we have reviewed how to reduce energy consumption and give thermal comfortable air-condition through radiant cooling and chilled ceiling panel system.

Effect of Different Workscope Strategies on Wind Turbine Gearbox Life Cycle Repair Costs

The wind turbine industry is beginning to establish orthodoxies governing the repair of gearboxes, including policies governing the replacement of bearings during gearbox heavy maintenance events. Some maintainers recommend replacing all of the bearings, every time, regardless of condition or age. At the same time, others prefer to only replace the failed bearing. The former rationale achieves availability by spending more money than absolutely necessary; the latter sacrifices reliability in exchange for a lower shop visit cost. Even though neither approach results in the lowest Life Cycle Cost, no standard practice has yet been implemented to methodically determine what would be the best approach. Furthermore, as gearboxes approach the end of their planned service lives, a different strategy may be called-for. This paper presents an illustrative example of using a reliability-based statistical analysis to determine which strategy will yield the lowest Life Cycle Cost for wind turbine gearboxes.

Cost-Effcient Transition to Clean Energy Transportation Services

Comprehensive global decarbonization requires transportation services cease to rely on fossil fuels for power generation. This paper develops a generic, time-driven life-cycle cost model for mobility services to address two closely related questions central to the emergence of clean energy transportation services: (i) the utilization rates (hours of operation) that determine how alternative drivetrains can be ranked in terms of their cost, and (ii) the cost-efficient share of clean energy drivetrains in a vehicle fleet composed of competing drivetrains. The model ranks alternative drivetrains with different environmental and economic characteristics in terms of their life-cycle cost for any given duty cycle. The critical utilization rate that equates any two drivetrains in terms of their life-cycle cost is shown to also provide the optimization criterion for the efficient mix of vehicles in a fleet. This model framework is then calibrated in the context of urban transit buses, on the basis of actual cost- and operational data for an entire bus fleet. In particular, our analysis highlights how the economic comparison between diesel and battery-electric transit buses depends on the specifics of the duty cycle (route) to be served. While electric buses entail substantially higher upfront acquisition costs, the results show that they obtain lower life-cycle costs once utilization rates exceed only 20% of the annual hours, even for less favorable duty cycles. At the same time, the current economics of the service profile examined in our study still calls for the overall fleet to have a one-third share of diesel drivetrains.