The Working Hydraulics of Valve-Controlled Mobile Machines: Classification and Review

Productivity, reliability, controllability, flexibility and affordable costs represent key aspects in mobile machines. Additionally, due to the high fuel price and to the introduction of stringent emission regulations for diesel engines, the reduction of fuel consumption while persevering the existing performance is the current demand. In order to satisfy and maximize the above requirements, different hydraulic system architectures have been developed during the last decades. Both academia and industry have been investing considerable resources delivering numerous outcomes that require a classification. This review paper closes this gap by analyzing and classifying the working hydraulics of non-hybrid, valve-controlled mobile machines starting from the 1980s to the state-of-the-art. Hydraulic layouts are addressed and categorized by both discussing their fundamentals and evolutions, and by pointing out their pros and cons in a way to provide the readers with a comprehensive overview of the systems currently available on the market and at the research stage

Influence of the Openness of Inlet One-way Valve on the Flow Characteristics in Series-Parallel Centrifugal Pumps

Series-parallel centrifugal pumps realize series and parallel running conditions through unique inlet one-way valve and reversing valve structures. In the running process, changes in the openness of the inlet one-way valve cause changes in the running parameters of the two impellers and in the inner flow field, thereby inducing pressure fluctuation and intensifying unit vibration. In this study, the change law of internal flow of the series-parallel centrifugal pumps was disclosed under different openness degrees of the inlet one-way valve and its internal relationship with pressure fluctuation was clarified by combining numerical simulation and model experiment. The major causes of pressure fluctuation and hydraulic performance changes induced by changes of internal flow field were analyzed. Results show that when the openness of the one-way valve is smaller than 20°, the two impellers present different operational states under parallel connection, which deteriorate the hydraulic performance of pumps. Decreasing the openness of one-way valve can reduce the pressure around the inlet of the second-stage blade and induce eddies; however, it slightly influences the pressure at the inlet of the first-stage blade. With the changes in the openness of the inlet one-way valve, the fluctuation frequency at the occurrence of maximum fluctuation remains the same; however, the fluctuation amplitude changes considerably. The fluctuation amplitude under small openness is lower than that under large openness. Conclusions obtained in the study have important implications in reducing the vibration and noise of series-parallel centrifugal pumps

Investigation of Novel Displacement-Controlled Hydraulic Architectures for Railway Construction and Maintenance Machines

This dissertation aims at showing how to transform hydraulic systems of railway multi-actuator machinery characterized by inefficient state-of-the-art systems into the 21st Century. Designing machines that are highly efficient, productive, reliable, and cost affordable represents the target of this research. In this regard, migrating from valve-controlled architectures to displacement-controlled layouts is the proper answer. Displacement-controlled systems remove the losses generated by flow throttling typical of conventional circuits, allow an easy implementation of energy recovery (e.g. during regenerative braking), and create the possibility for the use of hybrid systems capable of maximizing the downsizing of the combustion engine. One portion of the dissertation focuses on efficient propulsion systems suitable for railway construction and maintenance machines. Two non-hybrid architectures are first proposed, i.e. a novel layout grounded on two independent hydrostatic transmissions (HSTs) and two secondary controlled hydraulic motors (SCHMs) connected in parallel. Three suitable control strategies are developed according to the specific requirements for railway machines and dedicated controllers are implemented. Detailed analyses are conducted via high-fidelity virtual simulations involving accurate modeling of the rail/wheel interface. The performance of the propulsion systems is proven by acceptable velocity tracking, accurate stopping position, achieving regenerative braking, and the expected behavior of the slip coefficients on both axles. Energy efficiency is the main emphasis during representative working cycles, which shows that the independent HSTs are more efficient. They consume 6.6% less energy than the SCHMs working with variable-pressure and 12.8% less energy than the SCHMs controlled with constant-pressure. Additionally, two alternative hybrid propulsion systems are proposed and investigated. These architectures enable a 35% reduction of the baseline machine’s rated engine power without modifying the working hydraulics. Concerning the working hydraulics, the focus is to extend displacement-controlled technology to specific functions on railway construction and maintenance machines. Two specific examples of complete hydraulic circuits for the next generation tamper-liners are proposed. In particular, an innovative approach used to drive displacement-controlled dual function squeeze actuators is presented, implemented, and experimentally validated. This approach combines two functions into a unique actuator, namely squeezing the ballast and vibrating the tamping tools of the work-heads. This results in many advantages, such as variable amplitude and variable frequency of the tamping tools’ vibration, improved reliability of the tamping process, and energy efficient actuation. A motion of the squeeze actuator characterized by a vibration up to 45 Hz, i.e. the frequency used in state-of-the-art systems, is experimentally confirmed. In conclusion, this dissertation demonstrates that displacement-controlled actuation represents the correct solution for next-generation railway construction and maintenance machines

Volume 3 – Conference

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 8: Pneumatics Group 9 | 11: Mobile applications Group 10: Special domains Group 12: Novel system architectures Group 13 | 15: Actuators & sensors Group 14: Safety & reliabilit

Design of a photovoltaic solar pumping system for drinking water supply in the municipality of La Libertad (El Salvador)

The project being drawn up aims to determine the possibilities of supplying drinking water to communities located in isolated areas and with scarce economic resources in countries located in Central America using photovoltaic solar as a source of energy supply. The chosen site of the project will be the community of Miramar located in the municipality of La Libertad belonging to El Salvador. In the project, a description of the different types of renewable energy that currently exist, and in a particular way, the operation of photovoltaic solar energy will be explained, with an exposition of how this type of energy is currently in the world and in El Salvador. The drafted project basically consists of the definition and dimensioning of a system for pumping water from a well to a reservoir to supply the Miramar community using a photovoltaic solar installation as a source of energy for the pump motor. In such a way that, considering the population of the Miramar community and its twenty-year projection, its water needs will be calculated based on the operating hours of the pump motor, according to the peak hours of the most unfavorable month at the project site, and taking into account the manometric height of the pumping, the required pump motor will be dimensioned. Once the pump motor has been selected, first exposing the different types of pumping that can be used and the reasons for the choice made, the photovoltaic installation is dimensioned. Likewise, the different components of the photovoltaic installation are described, such as: the solar panels, their configuration, and the inverter conversion of the generated direct current to alternating current, with the definition of their technical characteristics, and a theoretical explanation of the electricity generation through photovoltaic panels and its mechanical transformation in the pumping system. Finally, an analysis of the investment of the project is carried out that allows water to be pumped from a well to a deposit in isolated areas, such as the Miramar community in El Salvador, where there is no possibility of connection to the grid, using due to that, photovoltaic solar energy. It concludes with a list of advantages and disadvantages of this type of solution to address the problem of supplying water from a well to isolated populations by pumping them, without connection to the electric grid, and having scarce economic resources.Ingeniería de la Energí

Fluid technology (selected components, devices, and systems): A compilation

Developments in fluid technology and hydraulic equipment are presented. The subjects considered are: (1) the use of fluids in the operation of switches, amplifiers, and servo devices, (2) devices and data for laboratory use in the study of fluid dynamics, and (3) the use of fluids as controls and certain methods of controlling fluids

Applied Strategy to Characterize the Energy Improvement Using PATs in a Water Supply System

[EN] Sustainable development has been an idea raised in recent years. The results are related to the improvement and the use of new technologies to maximize efficiency in water management. However, energy consumption has been increasing as a consequence of new management and uses of water. Especially in pressurized water distribution systems, the use of pressure reduction valves (PRVs) increases the water usage efficiency but it decreases the energy consumption efficiency, since the valves dissipate energy that could be recovered. This research presents a proposal of a recovery system based on the installation of pumps used as turbines (PATs). These machines are located in different points of the high-pressure water distribution system in the Valencia Metropolitan System (Spain). An annual estimate of the theoretical recoverable energy as well as the "ideal" pump for each point were proposed. The theoretical recovered energy value was 847,301 kWh/year for a specific analyzed point. Besides, the characteristic curves of thePATsfrom a selected point were determined, estimating an improvement in the sustainable indexes. The calculus of these green parameters showed that the implementation of this solution caused a reduction in consumed energy of 1.50 kWh/m(3).Authors greatly acknowledge financial support from the "Catedra Aguas de Valencia" in the grant "Analysis of recoverable hydraulic energy using recovery systems in supply systems" for the first author of this contribution.Camilo Rosado, LE.; López Jiménez, PA.; Sánchez-Romero, F.; Conejos Fuertes, P.; Pérez-Sánchez, M. (2020). Applied Strategy to Characterize the Energy Improvement Using PATs in a Water Supply System. Water. 12(6):1-22. https://doi.org/10.3390/w12061818S122126Biggs, E. M., Bruce, E., Boruff, B., Duncan, J. M. A., Horsley, J., Pauli, N., … Imanari, Y. (2015). Sustainable development and the water–energy–food nexus: A perspective on livelihoods. Environmental Science & Policy, 54, 389-397. doi:10.1016/j.envsci.2015.08.002Gupta, A. D., & Kulat, K. (2018). Leakage reduction in water distribution system using efficient pressure management techniques. Case study: Nagpur, India. Water Supply, 18(6), 2015-2027. doi:10.2166/ws.2018.023Creaco, E., & Walski, T. (2017). Economic Analysis of Pressure Control for Leakage and Pipe Burst Reduction. Journal of Water Resources Planning and Management, 143(12), 04017074. doi:10.1061/(asce)wr.1943-5452.0000846Di Nardo, A., Di Natale, M., Giudicianni, C., Greco, R., & Santonastaso, G. F. (2017). Weighted spectral clustering for water distribution network partitioning. Applied Network Science, 2(1). doi:10.1007/s41109-017-0033-4Creaco, E., & Haidar, H. (2019). Multiobjective Optimization of Control Valve Installation and DMA Creation for Reducing Leakage in Water Distribution Networks. Journal of Water Resources Planning and Management, 145(10), 04019046. doi:10.1061/(asce)wr.1943-5452.0001114Santonastaso, G. F., Di Nardo, A., & Creaco, E. (2019). Dual topology for partitioning of water distribution networks considering actual valve locations. Urban Water Journal, 16(7), 469-479. doi:10.1080/1573062x.2019.1669201Pérez-Sánchez, M., Sánchez-Romero, F. J., López-Jiménez, P. A., & Ramos, H. M. (2018). PATs selection towards sustainability in irrigation networks: Simulated annealing as a water management tool. Renewable Energy, 116, 234-249. doi:10.1016/j.renene.2017.09.060Fernández García, I., & Mc Nabola, A. (2020). Maximizing Hydropower Generation in Gravity Water Distribution Networks: Determining the Optimal Location and Number of Pumps as Turbines. Journal of Water Resources Planning and Management, 146(1), 04019066. doi:10.1061/(asce)wr.1943-5452.0001152Creaco, E., Galuppini, G., Campisano, A., Ciaponi, C., & Pezzinga, G. (2020). A Bi-Objective Approach for Optimizing the Installation of PATs in Systems of Transmission Mains. Water, 12(2), 330. doi:10.3390/w12020330Bonthuys, G. J., van Dijk, M., & Cavazzini, G. (2020). Energy Recovery and Leakage-Reduction Optimization of Water Distribution Systems Using Hydro Turbines. Journal of Water Resources Planning and Management, 146(5), 04020026. doi:10.1061/(asce)wr.1943-5452.0001203Alberizzi, J. C., Renzi, M., Righetti, M., Pisaturo, G. R., & Rossi, M. (2019). Speed and Pressure Controls of Pumps-as-Turbines Installed in Branch of Water-Distribution Network Subjected to Highly Variable Flow Rates. Energies, 12(24), 4738. doi:10.3390/en12244738Rossi, M., Nigro, A., Pisaturo, G. R., & Renzi, M. (2019). Technical and economic analysis of Pumps-as-Turbines (PaTs) used in an Italian Water Distribution Network (WDN) for electrical energy production. Energy Procedia, 158, 117-122. doi:10.1016/j.egypro.2019.01.055Pérez-Sánchez, M., Sánchez-Romero, F., Ramos, H., & López-Jiménez, P. (2016). Modeling Irrigation Networks for the Quantification of Potential Energy Recovering: A Case Study. Water, 8(6), 234. doi:10.3390/w8060234Ramos, H. M., Zilhao, M., López-Jiménez, P. A., & Pérez-Sánchez, M. (2019). Sustainable water-energy nexus in the optimization of the BBC golf-course using renewable energies. Urban Water Journal, 16(3), 215-224. doi:10.1080/1573062x.2019.1648529Novara, D., & McNabola, A. (2018). A model for the extrapolation of the characteristic curves of Pumps as Turbines from a datum Best Efficiency Point. Energy Conversion and Management, 174, 1-7. doi:10.1016/j.enconman.2018.07.091Pérez-Sánchez, M., Sánchez-Romero, F. J., Ramos, H. M., & López-Jiménez, P. A. (2020). Improved Planning of Energy Recovery in Water Systems Using a New Analytic Approach to PAT Performance Curves. Water, 12(2), 468. doi:10.3390/w12020468Del Teso, R., Gómez, E., Estruch-Juan, E., & Cabrera, E. (2019). Topographic Energy Management in Water Distribution Systems. Water Resources Management, 33(12), 4385-4400. doi:10.1007/s11269-019-02375-9Stepanoff, A. J. (1957). Radial- und Axialpumpen. doi:10.1007/978-3-662-25101-0Yang, S.-S., Derakhshan, S., & Kong, F.-Y. (2012). Theoretical, numerical and experimental prediction of pump as turbine performance. Renewable Energy, 48, 507-513. doi:10.1016/j.renene.2012.06.002Barbarelli, S., Amelio, M., & Florio, G. (2017). Experimental activity at test rig validating correlations to select pumps running as turbines in microhydro plants. Energy Conversion and Management, 149, 781-797. doi:10.1016/j.enconman.2017.03.013Fernandes, J. F. P., Pérez-Sánchez, M., da Silva, F. F., López-Jiménez, P. A., Ramos, H. M., & Branco, P. J. C. (2019). Optimal energy efficiency of isolated PAT systems by SEIG excitation tuning. Energy Conversion and Management, 183, 391-405. doi:10.1016/j.enconman.2019.01.01

ENERGETIC OPTIMIZATION OF WATER PUMPING IN DISTRIBUTION SYSTEMS

The paper presents some different solutions for the functional optimization of pumps in big water distribution systems. These solutions lead to the increasing of the power efficiency and a correlation of the pumped flow with the real consumption in the system, which result in an energy saving up to 30%, an important fact in the present energy conditions

Volume 2 – Conference: Wednesday, March 9

10. Internationales Fluidtechnisches Kolloquium:Group 1 | 2: Novel System Structures Group 3 | 5: Pumps Group 4: Thermal Behaviour Group 6: Industrial Hydraulic