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Corporate Carbon Reduction Programs
Published in Stephen A. Roosa, Arun G. Jhaveri, Carbon Reduction:, 2020
Stephen A. Roosa, Arun G. Jhaveri
In addition to its gasoline-powered vehicles, UPS operates the industry’s largest alternative fuel and low-emissions vehicle fleet. In an effort to improve its performance the company is exploring hydraulic hybrid and hybrid-electric vehicles.35 The hydraulic hybrid uses no batteries or electric motors, and instead mates the truck’s diesel engine with a hydraulic propulsion system, consisting of a series of hydraulic storage tanks and pumps.36 This system replaces the conventional drivetrain and offers benefits similar to other gas/diesel-electric hybrids such as regenerative braking. The system is capable of increasing the fuel economy and reducing CO2 emissions by 40%.37 UPS has recently secured leases for 42 three-wheeled Xebra Trucks (an electric utility vehicle) as part of a pilot program in Petaluma, California, to reduce emissions, increase profits and reduce transportation costs.38 The company has also committed to the purchase of 167 delivery vehicles that use compressed natural gas, in addition to approximately 800 such vehicles they already use in the U.S. The new vehicles will be deployed in Dallas, Atlanta and four locations in California.
PhD theses completed in 2018
Published in International Journal of Fluid Power, 2018
Hybrid vehicles have become a popular alternative to conventional powertrain architectures by offering improved fuel efficiency along with various other environmental benefits. Among them, hydraulic hybrid vehicles (HHVs) have several benefits, which make it the superior technology for certain applications over other types of hybrid vehicles, such as lower component costs, more environmentally friendly construction materials, higher power densities and more regenerative energy available from braking. There have been various studies on HHVs, such as energy management optimisation, control strategies for various system configurations, the effect of system parameters on the hybrid system and proposals for novel hybrid architectures. One area not been thoroughly covered in the past is a detailed modelling and examination of the thermal characteristics for HHVs due to a difficulty of describing the rapid thermal transients in the unsteady state systems.
Robustness and performance evaluations for simulation-based control and component parameter optimization for a series hydraulic hybrid vehicle
Published in Engineering Optimization, 2020
Katharina Baer, Liselott Ericson, Petter Krus
An hydraulic hybrid drivetrain adds hydraulic energy storage and power-converting components to a traditional, typically combustion-engine-based, transmission in order to modulate the engine load and to allow energy recuperation, ideally leading to improved fuel efficiency and lower emissions. In contrast to its electric counterpart, fluid power technology is characterized through a higher power density and lower energy density, making hydraulic hybridization particularly interesting for applications with high power transients, and additionally for vehicles and machines with existing hydraulic circuits (such as forest and construction machinery or refuse trucks) (Stelson et al. 2008).
Hydraulic hybrid passenger vehicle: Fuel savings possibilities
Published in Mechanics Based Design of Structures and Machines, 2022
Tarsis Prado Barbosa, Leonardo Adolpho Rodrigues da Silva, Fabrício José Pacheco Pujatti, Juan Carlos Horta Gutiérrez
The hydraulic hybrid architecture is composed of hydraulic pumps and motors and the recovered energy from braking events is stored in the form of pressurized fluid in accumulators. This energy is later used to drive the hydraulic motors and accelerate the vehicle. Furthermore, the hydraulic powertrain has other advantages when compared to the hybrid electric: longer life, lower cost, higher power density, higher recovery capacity of kinetic energy by regenerative braking devices and no environmental issues (Rydberg 2009).