High Speed Hydraulic Valve Power Consumption In A Switched Inertance Hydraulic Converter System
Date
2024-12-10
Authors
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Type
Thesis
Degree Level
Masters
Abstract
Hydraulic systems are ubiquitous in many industrial applications due to their high power density, precise control, and durability. Not all applications warrant expensive and complicated high efficiency technologies.
Instead, many basic systems use a fixed displacement pump with a restrictive pressure reducing valve to control the power to the load. These conventional systems suffer from significant energy inefficiencies, especially
when operating below the maximum power output of the system. This thesis presents the development and optimization of a Switched Inertance Hydraulic Converter (SIHC) system, a novel approach that aims to overcome these limitations by using fluid inertia and fast switching valve technology.
SIHC systems use a fast switching valve to rapidly pulse the fluid and an inertance tube to boost flow
through the system. The duty cycle of the valve controls the power to the load. The valve is a challenging part of current systems. It needs to be switched rapidly in order to ensure an efficient system. In addition, the valve power requirements must be minimized for an efficient system overall.
The research begins with a review of conventional hydraulic systems, identifying their primary inefficiencies. Other high speed valve technologies that have been developed are further discussed. A detailed mathematical model of the SIHC system is then developed. This system is then simulated to capture the dynamic behaviour of key components. The valve and inertance tube parameters are optimized to obtain the most efficient system possible. Simulations based on this model demonstrate that the SIHC system can significantly improve energy efficiency by controlling power flow without throttling the pressure through a conventional valve.
Simulations indicate that the SIHC system can achieve a system efficiency of 94.7% at a duty cycle of 50%. The duty cycle of 50% was chosen because it is a challenging power output level for a conventional
system. The system achieved a flow rate of 5 L/min and delivered 552.7 W to the load. The valve consumed 1.73 W of power, which represents 0.3% of the input power to the system. At this operating point this system is 85% more efficient than a conventional system. A theoretical valve with similar parameters, but a variable
duty cycle, is shown to have an efficiency of over 80% from output power levels from 1-90% of its capacity.
The research identifies challenges in the practical implementation of the SIHC system, particularly in the
design and operation of the fast switching valve. Further work is recommended to refine valve technologies,
begin prototype development, and validate the system through experimental testing. Moreover, broader
application studies should be done to determine specific use cases for this technology. Studies should be done to determine how high the initial costs for a SIHC system would be, and what development would be necessary to reduce this cost and make the system more financially competitive. The SIHC system presents a viable
and innovative alternative to conventional hydraulic systems, offering increased efficiency without significant
system complications. With further research and development, this technology has the potential to change hydraulic power transmission, contributing to more sustainable and energy efficient industrial practices.
Description
Keywords
Hydraulics, Switched Inertance, High Speed Valves
Citation
Degree
Master of Science (M.Sc.)
Department
Mechanical Engineering
Program
Mechanical Engineering