Analyzing the Potential of Hybrid and Electric Off-Road Equipment in Reducing Carbon Emissions from Construction Industries

This report quantifies the likely impact recent improvements in emissions technology in the heavy construction equipment fleet will have on national and state-level carbon emissions from construction industries. Specific technologies examined in this report include hybrid and electric-powered off-road equipment. Innovation in the equipment manufacturing industry, and adoption of innovative technology by construction firms, is driven by a wide range of factors, some of which can be influenced by public policy. Therefore, this paper describes policies available to public decision makers at the local, state and national levels that impact equipment use and development decisions, including those that encourage the use of green equipment in government procurement, local level job site emissions regulations, and state and nationally mandated emissions standards, fuel taxes, and direct research subsidies

HYDROSTATIC SYSTEMS FOR ENERGY RECUPERATION IN EARTHMOVING MACHINES

The first part of the paper contains the results of a study into the change in the energy parameters of earthmoving machines during manipulation tasks. The results of the research show that during certain operations of manipulation tasks, in the stop phase, the required energy of the machines has negative values. Modern earthmoving machines have hydrostatic drive systems that accumulate potential negative energy by recuperation and, if necessary, return it to the drive system of the machine for use in other operations of a manipulation task. In the second part of the paper, the analysis of the concepts of hydrostatic drive systems of earthmoving machines that enable energy recuperation is performed in detail

Case Study: Diesel Excavators Compared to Hybrid Excavators

The construction industry is constantly evolving and developing equipment that is more efficient, materials that promote sustainability and practices that emphasize lean construction principles to enhance productivity on projects. Modern day construction projects have become highly reliant on these ideals due to the highly competitive nature of the industry. In regards to heavy civil construction, specifically the underground utilities market, equipment costs count for a large percentage of overall project costs. Reducing these costs allows a contractor to be more competitive. As the focus on infrastructure construction continues to grow and expand, many heavy civil contractors are turning to alternative fuel option for heavy equipment to reduce operating costs and emissions. As a result, many heavy equipment manufacturers have invested into the production of hybrid heavy equipment for these purposes. Conversions from conventional diesel equipment to hybrid equipment have proven savings in operating costs, but for some contractors the more expensive ownership costs do not result in a more efficient machine

Challenges of micro/mild hybridisation for construction machinery and applicability in UK

In recent years, micro/mild hybridisation (MMH) is known as a feasible solution for powertrain development with high fuel efficiency, less energy use and emission and, especially, low cost and simple installation. This paper focuses on the challenges of MMH for construction machines and then, pays attention to its applicability to UK construction machinery. First, hybrid electric configurations are briefly reviewed; and technological challenges towards MMH in construction sector are clearly stated. Second, the current development of construction machinery in UK is analysed to point out the potential for MMH implementation. Thousands of machines manufactured in UK have been sampled for the further study. Third, a methodology for big data capturing, compression and mining is provided for a capable of managing and analysing effectively performances of various construction machine types. By using this method, 96% of data memory can be reduced to store the huge machine data without lacking the necessary information. Forth, an advanced decision tool is built using a fuzzy cognitive map based on the big data mining and knowledge from experts to enables users to define a target machine for MMH utilization. The numerical study with this tool on the sampled machines has been done and finally realized that one class of heavy excavators is the most suitable to apply MMH technology

Influential Factors in the Loading of the Axial Bearing of the Slewing Platform Drive in Hydraulic Excavators

The paper contains the results of the analysis of factors that influence the loading of the axial bearing of the slewing platform drive mechanism in hydraulic excavators. The following influential factors are considered: the operations of the excavator manipulation tasks, the number of drives in the slewing platform mechanism, and the configuration of the excavator kinematic chain. The importance of the influence of these factors is assessed on the basis of the comparison between certain equivalent loads of the platform drive bearing with the diagrams of allowed load capacities of available bearings. The equivalent loads of the platform drive mechanism bearing are determined using the approach of static and dynamic excavator simulation in the programs developed on the basis of the defined mathematical models of the excavator. The equivalent loads are given with regard to the duration of the manipulation task and in the form of a spectrum of equivalent loads determined in the entire operating area of the excavator. The analysis is performed for three different configurations of the kinematic chain of a tracked hydraulic excavator with the mass of around 100000 kg

Reducing energy consumption of hammering with electric excavators

Abstract. The aim of this master’s thesis is to research methods to reduce the energy consumption of hammering with electric excavators. To understand the energy consumption of hammering, the structure and energy consumption of a conventional excavator is explained thoroughly. The knowledge of a conventional excavator also lays foundation for studying the electric excavator. An electric excavator is not yet a widely used machine so different operating principles and models are presented in the work. Different technologies are described for utilizing electricity in hammering. Energy consumption of hammering is researched by measurements of the current situation. Measuring the power losses in hammering brings forward the challenges in the conventional hydraulic system and the excavator use in hammering. In addition to the measurements, hammer concepts are designed utilizing the technology researched. Quantitative and qualitative properties of the concepts are reviewed. The size of the power losses of hammering can be seen in the results of the measurements. The magnitude of the losses depend on what type of hammering work is done. The different hammering concepts bring large potential in reducing the energy consumption. The concepts also have new features, which can affect the productivity. The technology used in the different concepts still needs to be researched more and desired features deter- mined. The measurements show the magnitude of power losses in this excavator, but a working cycle should be determined to measure the energy consumption.Iskuvasaroinnin energiankulutuksen pienentäminen sähköisellä kaivinkoneella. Tiivistelmä. Tämän työn tavoitteena on tutkia tapoja, jolla iskuvasaroinnin energiankulutusta pystytään pienentämään sähköisellä kaivinkoneella. Iskuvasaroinnin energiankulutuksen ymmärtämiseksi työssä perehdytään perinteisen kaivinkoneen rakenteeseen ja energiankulutukseen. Perinteiseen kaivinkoneeseen perehtyminen luo myös pohjaa sähköisen kaivinkoneen toiminnan ymmärtämiseen. Sähköinen kaivinkone ei ole vielä yleisesti käytetty laite, joten sen eri toimintaperiaatteita käsitellään tässä työssä. Erilaisia teknologioita esitetään siihen, kuinka sähköä voidaan hyödyntää iskuvasaroinnissa. Iskuvasaroinnin energiankulutusta tutkitaan myös kokeellisesti. Tehohäviömittaukset iskuvasaroinnissa tuovat esiin tämän hetken ongelman kaivinkoneen hydrauliikkajärjestelmässä ja kaivinkoneen käytöstä iskuvasaroinnissa. Mittausten lisäksi työssä suunnitellaan sähköenergiaa hyödyntäviä iskuvasarakonsepteja. Konsepteja arvioidaan sekä energiatehokkuden kannalta että laadullisesti. Mittaustulokset tuovat esiin hydraulisten häviöiden suuruuden. Eri tyyppisissä iskuvasaroinnissa tehohäviöt ovat eri suuruisia johtuen kaivinkoneen hydrauliikasta. Eri konseptit tuovat suurta potentiaalia energiankulutuksen pienentämiseen sähköä hyödyntäen. Konseptit tarjoavat myös uusia ominaisuuksia rikotukseen. Konsepteissa käytettäviin teknologioihin pitää syventyä jatkossa vielä tarkemmin ja halutut laadulliset ominaisuudet tulee määrittää. Mittaustulokset osoittavat häviöiden suuruuden, mutta energiankulutuksen mittaamiseksi tulisi määrittää työsykli iskuvasaroinnille

Energy analysis of a hybrid electro-hydraulic system for efficient mobile hydraulics

Energy efficiency plays a significant role in mobile hydraulics due to the high amount of carbon dioxide and pollutants being released into the atmosphere. Efficiency improvements are urgently needed, so the electrification of mobile hydraulics represents a fantastic opportunity in this regard. This approach leads to electro-hydraulic systems that remove functional flow throttling in control valves and enable energy recovery. Fuels savings were already demonstrated in simulation, but the literature does not offer entire energy analyses of these electro-hydraulic solutions. This limitation prevents complete system-level comprehension and does not give enough insight to pinpoint areas for further efficiency improvements. Thus, this paper focuses on a hybrid system for excavators based on electro-hydraulic drives that is compared against the original valve-controlled layout. The objective is to quantify the energy flows insight the excavator during relevant operations and highlight the resulting energy losses. The outcomes confirm that electro-hydraulic solutions are suitable for a low-carbon economy. They indicate hydraulic actuators, speed-controlled pumps, and electric motors as the critical components for further energy efficiency enhancement excluding the combustion engine

Energy saving solutions for a hydraulic excavator

Abstract Nowadays the improvement of energy efficiency and the reduction of pollutant emissions are the major challenges that the mobile machinery manufacturers have to face with. With rising fuel prices and increasingly stringent regulations, the development of energy saving solutions and efficient hydraulic system have become a priority for researchers and OEM's. One of the most effective approach is the machine hybridization but other solutions can be adopted. This paper proposes with the aid of mathematical tools energy saving solutions for an excavator equipped with a load sensing hydraulic system. A comprehensive energy analysis was conducted through the excavator model to highlight the energy dissipations along the system. Different solutions to reduce losses and improve fuel saving including energy recovery from boom and arm and the introduction of a second pump in the flow generation unit were identified and investigated in detail. Finally, combining the proposed solutions, a new hydraulic hybrid excavator concept was obtained with a 15% of fuel saving

Trends and Hybridization Factor for Heavy-Duty Working Vehicles

Reducing the environmental impact of ground vehicles is one of the most important issues in modern society. Construction and agricultural vehicles contribute to pollution due to their huge power trains, which consume a large amount of petrol and produce many exhaust emissions. In this study, several recently proposed hybrid electric architectures of heavy-duty working vehicles are presented and described. Producers have recently shown considerable attention to similar research, which, however, are still at the initial stages of development. In addition, despite having some similarities with the automotive field, the working machine sector has technical features that require specific studies and the development of specific solutions. In this work, the advantages and disadvantages of hybrid electric solutions are pointed out, focusing on the greater electromechanical complexity of the machines and their components. A specific hybridization factor for working vehicles is introduced, taking into account both the driving and the loading requirements in order to classify and compare the different hybrid solutions

modelling and energy comparison of system layouts for a hydraulic excavator

Abstract For decades the improvement of energy efficiency in mobile hydraulics has forced the research world to develop energy saving solutions and to redesign existing hydraulic circuits. This paper presents an overview about the state of the art of excavator valve systems based on open centre flow control (OFC) and a load sensing principle (LS). The purpose of this study is to compare different hydraulic systems on a middle size (9ton) excavator and to analyse the differences in term of energy saving and fuel consumption. Starting from a validate mathematical model of the considered hydraulic excavator whose functioning is in LS logic, many alternatives are proposed as flow on demand system, positive and negative flow control. Systems comparison has been done on typical excavator working cycles as trench digging and levelling referring to the JCMAS standard. An optimization tool, based on genetic algorithm, has been exploited for the definition of the optimal spool areas to reduce the pressure losses and by-pass flow rate maintaining identical controllability and performance