In addition to capacity and acquisition costs, energy efficiency and fuel-saving work over the entire service life of the machine are the most important decision-making criteria for every owner. SENNEBOGEN is convincing through innovative solutions that save energy; for some time now with the pioneering electric drives, and currently with the low consumption E-Series, as well as the balance materials handling machines product series. The newly developed energy recovery system, Green Hybrid, offers additional high savings potential, thanks to intelligent recovery technology via a nitrogen accumulator - maximum efficiency and savings of as much as 30 % are possible.
The Green Hybrid system is a combination of hydraulic system and gas pressure accumulator and functions in a manner similar to that of a spring, which is compressed when lowering the equipment in order to additionally make this force available with the next lift. In the design of the cylinder, for the moving parts of the equipment, SENNEBOGEN relies on a functionally proven and standardized hydraulic cylinder. Thus the design ensures that all functional elements, pressures, temperatures or seals completely correspond to the proven solutions required for demanding materials handling implementation. Due to the pressure of the hydraulic fluid in the cylinder in the rear of the machine, a gas volume is compressed in multiple piston accumulators and the energy obtained through the lowering movement is buffered in gas pressure tanks.
With the Green Hybrid energy recovery system, the hydraulic system component in the piston accumulators is separated from the system component with the technical gases. The quantity of hydraulic oil, as well as the quantity of gas in the system, can be individually adjusted. As opposed to other systems that merely use the volume in the cylinder for gas compression, in the Green Hybrid system, a volume that is several times greater is available via the gas pressure accumulator. Through this measure, relatively low compression is achieved in the gas pressure tanks; this means that the pressure in the gas - regardless of the work position of the hydraulic cylinder - changes to a lesser degree. The positive result of this concept is that the force that the system imparts to the hydraulic cylinder is virtually constant over the complete spring path and thus a uniformly high level of energy is fed into the system. Through this measure the machine is virtually equally supported in all work areas and the primary energy required for drive is significantly less.
In accordance with the laws of thermodynamics, gases that are highly compressed heat up depending on their volume. The fact that in the Green Hybrid system, only relatively minor compression of the gas is necessary, means that temperature fluctuations are substantially less pronounced than is the case with a conventional system, in which the gas is more highly compressed in a single cylinder, and thus is continuously subject to significant temperature changes. Moreover, a system with fewer temperature and pressure fluctuations works much more effectively - higher efficiency occurs so that the accumulated energy can be returned into the system virtually completely as force. Components are protected and the reliability of the system is increased.
A compressed gas in pressure vessels is subject to special safety regulations for the protection of man and machine. Consequently installation of the gas accumulator tanks at a protected location is recommended. With the Green Hybrid system the gas accumulator tanks are encapsulated in the rear area of the machine. Surrounded by rear ballast and other heavy machine parts, the requirements imposed on safe installation of the system in the machine are satisfied in the best manner possible. For safe transport and setup of the machine, the pressure on the hydraulic side must merely be relieved by draining oil into the hydraulic tank. The Green Hybrid system enables filling for commissioning via standard connections as part of the service procedure, directly on-site by a specialist for technical gases. Simultaneously the hydraulic system is filled automatically via the proven SENCON machine control via infeed through the pump.