A Layered Software Architecture for a Flexible and Smart Organic Rankine Cycle (ORC) Turbine – Solutions and Case Study

Abstract

Intelligent Technical Systems are the consequent extension of the concept of Mechatronic Systems into the world of software-intensive, networked systems. The concept enhances the functionality and variability of physical (or electro-mechanical) technical systems by adding embedded electronics and software. This adds degrees of freedom (DoF) and controllability to the technical systems. It enhances the effectivity of integrating such systems into distributed infrastructures (e.g. smart grids) via a public network like the internet. Therefore, it enables them for an effective integration into the internet-of-things (IoT) since such Intelligent Technical Systems can add and draw significant functionality and optimisation potential from networking with other systems. They can become an integral part of a distributed system which is coupled via the IoT. Nevertheless, it is important to leverage between local control and distributed control carefully according to the requirements of the technical application. A smart heating grid is an example of a distributed cyber-physical system (CPS) which can be coupled via IoT. Such systems include components like block heat and power plants which produce electricity (fed into the public smart grid) and heat. Smart heating grids benefit from components which can convert heat into electricity in a flexible and controllable way and which can change fast from heat provision to electricity provision and vice-versa. An Organic Rankine Cycle (ORC) Turbine is such a component since it converts exhaust heat into electricity. This takes heat out of the heating grid and puts electricity into the electricity grid instead. Making such an ORC turbine intelligent means optimizing it for the usage in a smart heating grid. The challenge is to design a control software architecture which allows coupling via IoT on the required interaction level of the distributed system while guaranteeing a safe operation on the local level. The ar-Information Technology and Control 2018/2/47 350 ticle is an extended version of a previous article at the ICIST conference. It presents the software architecture of an ORC turbine based on the architecture of the Operator-Controller-Module (OCM). Compared to the previous publication it provides a more in-depth presentation of the prototype implementation of the ORC turbine system. The OCM provides an architecture pattern which allows a seamless integration into a smart heating grid based on an IoT infrastructure while enabling maximum flexibility and efficiency of the local functionality of the turbine.

Landscape of Architecture and Design Patterns for IoT Systems

“…There are 61 IoT patterns (i.e., 43%) in 18 papers [19], [20], [22], [24], [25], [28]- [34], [36], [38], [40], [44], [45], [47] that address specific problems and solutions in IoT. The details are discussed in the subsequent section.…”

“…3) Domain-specific IoT Patterns: IoT architecture and design patterns that address specific problem domains (such as healthcare) and technical domains (such as brain-computer interactions). For example, "operatorcontroller-module (OCM)" [19], [47] is a problemdomain-specific pattern since it addresses a specific problem and solution in the cyber-physical control domain such as operating organic Rankine cycle turbines. 3) Quality Attribute: All systems and software design patterns are expected to address one or more quality attributes.…”

Concepts of a Modular System Architecture for Distributed Robotic Systems

“…The OCM was refined later and was used in several projects of the research cluster "Self-optimizing systems in mechanical engineering (SFB614)" [24] (e.g., the RailCab project [25]). Metropolitan energy systems [26] and ORC turbines [27] have also used the OCM design. The controller level stands for the motor loop with direct access to the technical system.…”

A Quantitative Approach to Analyze Modifiability in Software Architectural Design of Agile Application Systems

“…The workflow management system [18] shows how P&F pattern can be implemented to serve this purpose. A layered software architectural design was developed for the development of a flexible and smart organic rankine cycle (ORC) [20]. This design allows coupling through IoT into smart systems based on the functionalities provided by the reflective operator and the cognitive operator present in the architectural design of the application system.…”