Decentralised combined heat and power in the German Ruhr Valley; assessment of factors blocking uptake and integration

Background: In Germany, the energy system is undergoing reorganisation from a centralised system based on fossil fuels and nuclear power to a sustainable system based on decentralised production and consumption of energy, the so-called Energiewende. Recently, there has been more attention to improving energy efficiency in those regions where conventional energy production activities and energy-intensive industries are located, such as the Ruhr area. Although the potential for decentralised combined heat and power (CHP) units is high in this region, local action plans show only modest developments for this technology. In this paper, we address this issue by answering the following research question: Which factors block the uptake and integration of decentralised CHP in the German Ruhr area's energy system? Methods: The multilevel perspective (MLP) was used to analyse the state of system innovation in relation to the uptake and integration of decentralised CHP technology. Prior to the MLP analysis, a stakeholders' analysis was conducted to identify stakeholders' views, positions and experienced barriers regarding the uptake and integration of decentralised CHP technology. Data collection included review of text documents and conducting 11 interviews. Results: Due to many regime barriers blocking niche development, the uptake of decentralised CHP technology is limited. Identified barriers relate to lack of market services and mismatches with user preferences, (sectoral) policies and industrial interests. Conclusions: Observed barriers relate to (i) lack of market services such as financial means for making investments; (ii) user awareness such as unawareness and information deficit regarding the benefits of decentralised CHP to potential users, (iii) the presence of centralised district heating systems, (iv) policy issues such as lack of sufficient policies supporting diffusion of decentralised CHP units, legal stipulations from social housing policies that prevent housing cooperatives from becoming energy producers and district heating systems owned by public and private owners (via concessions contracts); (v) sector issues such as lack of skilledservice-providing companies; and (vi) industrial interested such as the vested interests of the coal and gasindustry. Moreover, many of the mentioned barriers seem interrelated, especially those concerning policy and finance available for making upfront investments

A Systematic Evaluation of Design Freedoms and Restrictions of Lattice Structures Used as Interlock Bonds

Additive manufacturing provides new possibilities in product design compared to traditional manufacturing processes. Particularly additive material extrusion offers the freedom to combine multiple materials in a single component without additional steps. However, combining multiple materials often leads to reduced adhesion, which can hinder the creation of high-strength designs. This issue can be largely mitigated using the geometric freedom of additive manufacturing to produce interlocking structures. This publication investigates the use of lattice structures as interlocking bonds in multi-material applications. The aim is to aid the design of suitable lattice structures by collecting geometric freedoms of lattices, application requirements, and manufacturing constraints, for this information to be used in suitable designs in the future. Initially, the general design freedoms of lattice structures are compiled and explained. Subsequently, these design freedoms are narrowed down based on the specific requirements for interlocking bonds and the limitations imposed by geometry and material combinations during manufacturing. The publication concludes with design recommendations that can be used as the basis for interlock bonds. Suitable lattice designs should aim for high interconnectivity, interconnected porosity, and a high number of similar strut structures, all the while maintaining low dimensions in the interface direction

Multidisciplinary design optimization of a generic b-pillar under package and design constraints

This article introduces a novel constraining approach for structural optimization, which aims to support the conceptual engineer during the early embodiment phase for structural lightweight design. It reduces the time spent on structural engineering studies by enabling optimization algorithms to detect geometric intersections by analyzing the mesh information. This article reviews approaches from the literature focusing on CAD-environments, sampling methods, data analytics and optimization techniques for design and sizing optimization with FE-models. The evaluated approaches are integrated into a Python-based optimization environment. Accordingly, the introduced methodology enables the environment to handle geometric infeasible designs. The presentation of the first results focuses on the feasibility of structural assemblies and the results demonstrate the viability of the NSGA-II for optimization tasks. The example considers the design of a generic b-pillar structure under crash-safety requirements. Using this approach, the NSGA-II algorithm avoids geometric infeasible areas and comparably increases structural performance

Evaluation of Modelling and Simulation Strategies to Investigate the Mechanical Integrity of a Battery Cell Using Finite Element Methods

The mechanical integrity of a lithium ion battery cell can be evaluated using finite element (FE) simulation techniques. In this study, different FE modelling approaches including heterogeneous, homogeneous, hybrid and sandwich methods are presented and analysed. The basic capabilities of the FE-methods and their suitability to simulate a real mechanical safety test procedures on battery cells are investigated by performing a simulation of a spherical indentation test on a sample pouch cell. For each modelling approach, one battery cell model was created. In order to observe the system behaviour, relevant parametric studies involving coefficient of friction and failure strain of separator were performed. This studied showed that these parameters can influence the maximum force and the point of failure of the cell. Furthermore, the influence of an anisotropic separator on the results was also investigated. The advantages and disadvantages of each modelling approach are discussed and a simplified approach with a partial cell modelling is suggested to further reduce the simulation time and complexity

Goal Oriented Provision of Design Principles for Additive Manufacturing to Support Conceptual Design

Additive Manufacturing (AM) offers a new degree in design freedom. However, in order to exploit AM's potentials in end-use products a methodical approach and suitable tools especially during conceptual design are needed. This paper presents a methodology for application in industrial practice, which should support the component conception for additively manufactured products. The approach focuses on a benefit-oriented preparation and provision of knowledge. In addition to general design methods for abstraction and promotion of creativity, AM-specific tools are introduced which support the provision of solution principles and process-specific restrictions. A broad applicability of the solution principles is ensured by an expansion of the solution space through abstraction. Consequently, product developers are sensitised to the new design possibilities of AM, on the one hand. On the other hand, they are supported in a holistic exploitation of design potentials in ideation in order to foster innovative solution ideas. Finally, the methodological procedure and the developed tools will be demonstrated in a workshop by using an example from industrial practice of the automotive sector

An Approach to Complement Model-Based Vehicle Development by Implementing Future Scenarios

Today, vehicle development is already in a process of substantial transformation. Mobility trends can be derived from global megatrends and have a significant influence on the requirements of the developed vehicles. The sociological, technological, economic, ecological, and political developments can be determined by using the scenario technique. The results are recorded in the form of differently shaped scenarios; however, they are mainly document-based. In order to ensure a holistic approach in the sense of model-based systems engineering and to be able to trace the interrelationships of the fast-changing trends and requirements, it is necessary to implement future scenarios in the system model. For this purpose, a method is proposed that enables the consideration of future scenarios in model-based vehicle development. The procedure of the method is presented, and the location of the future scenarios within the system architectures is named. The method is applied and the resulting system views are derived based on the application example of an autonomous people mover. With the help of the described method, it is possible to show the effects of a change of scenario (e.g., best-case and worst-case) and the connections with the highest level of requirements: stakeholder need

Development of Decision–Model and Strategies for Allaying Biased Choices in Design and Development Processes

The design and development processes are full of decisions. Ranging from simple and straightforward to complex and elaborated. These decisions are taken by individuals that constantly rely on their intuition and heuristics to support their decision-making processes. Although heuristics tend to be very helpful, in many cases, they can lead to cognitive biases. This article postulates a method to recognize some of these biases and to apply dedicated strategies to diminish their effects. To do so, the study reviews different decision models in engineering design and consolidates them into one; here, called ABC decision model—ABC stands for Allaying Biased Choices. This model consists of four phases describing four different decision types. Subsequently, four matching strategy sets are prescribed to target some of the most prone biases on those phases. Then, to demonstrate the application opportunities of this method, the ABC decision model is applied to the process of Strategic Release Planning (SRP). Finally, to show the theory in real-world conditions, the results of a pilot industrial application are presented. This article offers promising opportunities for allaying biased choices in design and development processe

Characterization of the Anisotropic Electrical Properties of Additively Manufactured Structures Made from Electrically Conductive Composites by Material Extrusion

Additive manufacturing (AM) of components using material extrusion (MEX) offers the potential for the integration of functions through the use of multi-material design, such as sensors, actuators, energy storage, and electrical connections. However, there is a significant gap in the availability of electrical composite properties, which is essential for informed design of electrical functional structures in the product development process. This study addresses this gap by systematically evaluating the resistivity (DC, direct current) of 14 commercially available filaments as unprocessed filament feedstock, extruded fibers, and fabricated MEX-structures. The analysis of the MEX-structures considers the influence of anisotropic electrical properties induced by the selective material deposition inherent to MEX. The results demonstrate that composites containing fillers with a high aspect ratio, such as carbon nanotubes (CNT) and graphene, significantly enhance conductivity and improve the reproducibility of MEX structures. Notably, the extrusion of filaments into MEX structures generally leads to an increase in resistivity; however, composites with CNT or graphene exhibit less reduction in conductivity and lower variability compared to those containing only carbon black (CB) or graphite. These findings underscore the importance of filler selection and composition in optimizing the electrical performance of MEX structures

Development of a Modeling Language to Connect Features, Functions and Components

AbstractIn order to select the components for a technical system, a detailed description of the systems features is necessary. For this purpose feature-trees are currently preferred. By selecting features from these feature-trees the corresponding components are chosen. Within the development process it is also useful to describe the functions of the technical system as well and to associate these functions with the components. For this functional-networks are used so far, which describe the dependencies between the different functions. But feature-trees and functional-networks are considered separately and not associated with the components within one model. For this reason, the features and functions of a system are usually chosen in advance. So there are two independent ways to choose components for one product. By evolution and reusing of existing components it is possible to create systems with new features or functions. If it would be possible to describe feature, functions and components within one language, proposals for new components could be made. In this paper an approach for describing features, functions and components with one language is introduced