Danfoss

Optimized Charging and Flushing System for Harvesters

Description of the company

Leading the world’s green transition

Global megatrends such as climate change, electrification, digitalization/AI and urbanization continue to create significant opportunities. Global megatrends are more relevant now than ever to transform the world and create a sustainable future. At Danfoss, being part of the solution to build a better future is what our purpose is all about. We engineer solutions that increase machine productivity, reduce emissions, lower energy consumption, and enable electrification.

Danfoss is engineering tomorrow, building a better future

Energy efficiency is the fastest route to net zero. Energy efficiency alone can deliver over 40% of the emissions reductions needed by 2040. Energy efficient technologies empower smart communities and industries to create healthier and more comfortable solutions with less waste.

Situation

A loop flushing system is included in closed-circuit hydrostatic systems to help in system cooling. Hot oil is flushed out of the working loop and filled up with cooler oil from a charge system. It is an important part of a closed-circuit hydraulic system and influences the whole application behavior.

The schematic in Image Description 1 shows a closed-circuit with a flushing system integrated in the motor endcap.

Image Description 2 shows a cross-sectional view of the flushing system (shuttle valve and relief valve) that is used in a H1B hydrostatic motor.

Today the flushing of a hydrostatic propel system is designed for the worst condition (hottest day with the highest load) typically. Hence, maximum flushing of oil is happening irrespective of operating conditions or actual temperature of oil in the circuit. This creates losses, which can be avoided when the temperature is controlled in the system by only flushing out oil which is needed to get the needed system temperature level.

Problem

Today, the flushing of a hydrostatic propel system is designed for the worst condition (hottest day with the highest load) typically. Hence, maximum flushing of oil is happening irrespective of operating conditions or actual temperature of oil in the circuit.

Aims of the project 

Understand the today´s flushing system limitations and work on potential solutions, which will reduce the system flushing losses and improve system efficiency.

Scopes

Create a simulation model of a propel system to evaluate the temperature increase based on power losses in the hydrostatic system for a generic harvester duty cycle. Calculate thermal losses which need to be replaced. Perform DoE (design of engineering) simulations of different designs of area of flow in a variable flushing valve to maintain system oil temperature.

Create a simulation model of a propel system to evaluate the temperature increase based on power losses in the hydrostatic system for a generic harvester duty cycle. Calculate thermal losses which need to be replaced. Perform DoE (design of engineering) simulations of different designs of area of flow in a variable flushing valve to maintain system oil temperature.

Defining possible solutions for variable flushing and charging to the system and showcase improvement in overall system efficiency.

Key deliverables are:

1. High fidelity simulation model of propel system to predict thermal losses of the system
2. Presentation of thermal losses in the simulation model and its validation
3. Provide design options to optimize variable flow of flushing valve to reduce losses in the flushing system in the final presentation.

Target group (students)

Mechanical engineering students

System simulation capability will be advantageous

Dates
Please save these dates: Fishing for Experience Termine

Registration
You can apply for Fishing for Experience online.