Development of variable pressure intensifying system

Abstract

The background of this thesis is the problem with multiple hydraulic systems working on the same machine and requiring individual pumps for different pressure levels. This is in many cases space consuming and sometimes also very expensive when special-designed non-mass-produced pumps are used. Combining hydraulic systems with different pressure levels and flows is a relative new way of reducing the costs of hydraulic systems.

This thesis uses an example with two hydraulic systems, one which works within the pressure range of 235...350 bar with a maximum flow of 32 l/min and another system which requires a pressure range of 250...700 bar with a maximum average flow of 18.2 l/min. By using pressure intensifying technologies the two hydraulic systems are combined with the result that, instead of using two pumps with different pressure ranges and flow capacities, only one pump would be needed for both of the systems. The first systems pressure range of 235...350 bars is used and intensified up to the by the second system required 250...700 bar.

First the known technology is studied through patents and literature. On the basis of the known intensifying technologies, an intensifying concept is created. To prove and test the functionality of the concept, a simulation model is made in GT-Suite. The results from this simulation model are presented. The different variables affecting the result and having an impact on a future prototype design are analysed.

The concept presented in this thesis is functioning well at the simulation stage, and on the basis of the results presented, a variable pressure intensifying prototype can be made. With the simulation results it also became clear what things that further needs to be researched before a fully functional for production intensifier can be made as well as ideas of improvements.

Variable pressure intensifying is a technology area which is still quite un-researched and unused. But in areas where high flow with multiple or variable pressure ranges are needed, like for example in water cutting or in places where hydraulic circuits with different pressure ranges could be combined into one single circuit, variable pressure intensifiers could be a technology to consider for getting the costs down, or updating the existing systems to higher pressures without the need to replace the often expensive pump unit.