Design of injector test bench: Selection, design and assembly of the fuel and oil system for a second generation DME injector

Abstract

Consulta en la Biblioteca ETSI Industriales (Riunet)

[EN] The goal of this Final Project is to develop an Injector Test Bench compatible with Dimethyl Ether (DME) and diesel. The reason why we want to work with both diesel and DME is to be able to explore the advantages of Diesel-DME blends in future experiments. Both fuels are used in this project, with a larger focus on DME. The reason is that due to its low emissions of contaminating gases, it is a great alternative to other fuels. With this project, and others that deal with this alternative fuel, the goal is to promote its use in the occident in order to protect the environment, as they currently do in Japan. The final objective of this project is to study the possibility of implementing multi-shots during the pre-combustion phase in the engine. By finding the perfect point in time to introduce the multi-shot, we can highly improve the motor efficiency. To accomplish this, it is necessary to understand the chemistry of the DME combustion. Dr. William de Ojeda, who is sponsoring this project, is working in many projects related with DME in collaboration with the Michigan Technological University. The team of engineers at this university highly supports Dr. de Ojeda’s projects by providing the chemistry of the DME combustion. This information is vital in better understanding the nature of DME and studying how to enhance the efficiency of the engine. However, this project is not going to go as far as the multi-shot experiment. The main objective is to build an injector test bench, where experiments can be performed and results transferred to improve the software model. The first step of this project is to create a 3-D model of the bench by using the software Autodesk Inventor. This part is essential to know exactly what elements are needed for the construction of the bench. This drawing is beneficial for two reasons. First, this will eliminate having to buy elements that will not be used, and second it represents how all the parts connect with each other. Therefore the main focus of this project is to design the 3-D model of the bench and then apply that to the construction of the actual bench. The model to be verified has been programmed by Dr. William de Ojeda using the MATLAB application called Simulink. We want to reproduce the behavior of DME and diesel during the injection with the model. In order to do that it is necessary to adjust that model with the parameters that are obtained from the experiments with the bench. Once we know that the model works exactly like the real installation, we can use it to simulate the behavior of the full injection system of a DME engine. This will permit us to not only compare the nature of the DME and diesel but also simulate how the mixture of these two fuels would behave. By simulating this blend we can learn the benefits of working with DME and diesel at the same time. This is what makes this model so powerful and what motivates us to initiate this project.