Züst Engineering AG sees great potential in modelling and simulation. Züst Engineering AG built models modelled relationships and simulated different scenarios for a variety of projects. This is in order to achieve the greatest degree of transparency possible, to showcase mechanisms in and surrounding a system, to learn together and illustrate approaches, with the aim of visualizing their advantages. In the following, two concrete examples to illustrate this:
Modelling and simulation as part of product development
Modern production systems are complex mechatronic ones and a central issue in these kind of systems is thermal management: Certain components need to be kept within a particular temperature range in order to avoid damage or thermal expansion in length of structural parts. The key to success is to take the right decisions at an early stage: The individual sub-systems need to correspond / interact with one another in a way that the thermal requirements can be fulfilled efficiently and economically.
Züst Engineering AG provides a key methodology for this, which is integrally linked to the development process. This makes it possible to evaluate first concepts with regards to the thermal behaviour of the whole system and supports the optimization of thermal properties of individual machine parts at an early stage:
Development and evaluation of first concepts: This is where the “LCE-Tool” comes into it. The “LCE-Tool” is based on a simulation platform developed at ETH Zurich, which Züst Engineering AG has developed further. The tool allows to evaluate the interaction of various machine components in a time efficient way by using existing component models, which are being connected (modelling along the lines of Matlab Simulink, Stella, Dymola, …). The resulting model supplies initial information about the expected resource requirements, ecological consequences as well as heat sorces and temperatures inside the system. This initial model grows in line with the development: New information can be added continuously thus increasing the validity of the model.
Optimization of individual components: The aim of this stage is to systematically reduce heat sources or their effects by a) increasing the efficiency of the components ( =less waste heat) and b) improvement of cooling efficiency (=less increase in temperature) . The latter is achieved by using the “Duct Designer” tool, This tool, which was developed at ETH Zurich, allows for a time efficient evaluation of cooling strategies i.e the geometry / design of cooling ducts, type of coolant and pump. In this way, the correct decision can be made without the use of time-consuming CFD simulations and 3D geometries.
Digital Prototype: The early verification of the system without the necessity of an actual / physical prototype saves time and money but at the same time increases the planning security. Based on the results of the “LCE tool” and “Duct Designer” precise information about the thermal boundary conditions of individual machine components can be provided at an early stage. Using these in a CFD/FEM simulation can verify the thermal requirements the system needs to meet and potential improvement measures can be deducted. (Züst Engineering AG uses Ansys products for this stage.)
Physical Prototyp: If required it is possible to identify the correct measuring points using the digital prototype. This increases the validity of the verification measurements. Information from measurements taken with a physical prototype can be transferred into the model library of the” LCE tool”, which ensures that the knowledge gained can be used for future projects.
Optimised material streams for efficient recycling processes
The current economy in Switzerland is material- as well as energy-intensive. Currently, Switzerland produces 80 to 90 million tons of waste. Out of these, 57 million are excavation material, 17 million tons from dismantling/ demolition, 6 tons municipal waste, 5 tons biogenic waste and 2 tons of hazardous waste. Around 60 tons are recycled, 8 million tons are burned and 19 million tons go into landfill. (Source: BAFU waste and resources department Switzerland; rounded 2017 values). Collecting, sorting, preparing, processing and especially transporting such quantities requires a lot of logistics.
Example for the identification of the most economic material streams.
Züst Engineering AG has the capability and necessary IT infrastructure to deal with demanding optimisations for their customers.
Züst Engineering AG has worked on various studies in the field of efficient recycling processes - some of which for the Bundesamtes für Umwelt BAFU (Swiss federal office for the environment) involving the industry; this is one example:
«Smart Material Flow» in the scrap collection chain
An explorative study involving relevant players / participants in Switzerland:
Switzerland annually produces 1.5 tons of scrap; this is slightly less than 200 kg per capita. The “steel depot” Switzerland amounts to about 8,000 kg of steel per inhabitant. The two large steel works Swiss Steel and Stahl Gerlafingen use approximately 650,000 tons of scrap each – a total of 1.3 million tons per year. This is why the question arises, which ecological potential there is within the collection chain and how this potential can be realized. The basis for the calculation was several “Lean Six Sigma” studies along the collection chain.
Example of a value stream analysis
The study conducted by Züst Engineering AG shows that up to 100,000 tons of CO2 emissions can be saved over the next few years without major investments by “collective problem solving” along the scrap recycling chain. This equally benefits the companies who are part of the value chain “scrap recycling” as well as society and the environment. 100,000 tons are the approximate equivalent of 0.2% of Switzerland’s current CO2 footprint. Saving 100.000 tons of CO2 could for example offset ETH Zurich (20,000 students, 11,000 staff) four times over - i.e. its infrastructure as well as the commute of its staff.
In addition, efficient planning tools were developed which can be used particularly to design lean collection processes; here another example:
«Smart Material Use»
A tool for the economic and ecologic evaluation of material use in companies:
On top of metal scrap, metal processing industrial companies produce a lot of other waste, which needs to be treated and disposed off. This makes analyses noteworthy, which take not only direct revenue and costs from selling the material into consideration but also make further necessary expenses (i.e. indirect costs within the company) visible.
Use of the SMF-tool - illustration of process costs
In the example in the diagram above, 8 different material types – for example steel scrap, copper, sweepings ...- have been analysed and economically evaluated for internal and external processes; these are shown in blue. It shows the personnel costs, rental for containers as well as for logistics. In many companies, these additional costs are hidden in the overheads or respectively overhead rates and thus invisible. When dealing with indirect costs, the focus is on if and how processes can be simplified and optimized. The core question is: Which measures can reduce expenses without having a negative impact on the profit situation (sale of resources) or the waste disposal costs? Or to put it in a different way: Which organisation and division of labour between the company itself and external buyers of recycling materials results in the greatest overall economic benefit?
Züst Engineering AG knows about the challenges of waste collection logistics and can therefore efficiently support companies, communities and cantons with optimizations.