Efficient utilization of industrial waste heat by low temperature heat driven power cycles – an integrated approach for Swedish Industry

Funded by: Energimyndigheten

Time period: 2021-01-01 – 2022-06-30

Project members: KTH Royal Institute of Technology 

Background

Industrial waste heat can be efficiently utilized by aid of low temperature heat driven power cycles. However, commercially available systems typically use non-sustainable working fluids (HFCs) with high global warming
potential. Typical designs are also often based on bulky shell and tube type heat exchangers leading to large and costly charge of working fluid. The knowledge on how to select the most suitable working fluid and size these systems in relations to available heat sources and sinks is critical for economic and technical success and a methodological approach to do so is thus needed.

Low temperature power cycles have been around for many years. Early attempts used ozone depleting working fluids like CFC-114 and 113 for low and high temperature systems. Development in Sweden started early at Svenska Rotormaskiner, SRM in the 60ties and 70ties (later transformed to OPCON) and the product POWER BOX was developed. Applications for the technology have been of various kinds for example as a so-called bottoming cycle for large diesel engines in projects where small scale cycles are integrated into modern diesel engines as an efficient way to raise engine overall efficiency with several percent. Projects are on-going involving major truck manufacturers such as Scania. The OPCON Power Box was for example installed in Eskilstuna forutilization of waste heat in flue gasses from a bioenergy plant. Another recent example is the development by Againity.

Aim and objectives

The goal of the project is to provide industry and academia with up-to-date and state-of the art knowledge on how low temperature power cycles can contribute to increased energy efficiency and mitigated emissions in Swedish Industry.

The project will also utilize, summarize and communicate results obtained in previous state-of the art research undertaken in the projects COPRO and HIGHEFF but now adapted for typical Swedish industry. This means that knowledge compilations and dissemination of information is a key part of this project.

Additionally, the project will help to maintain and further deepen the competence at the department of Energy Technology at KTH in the area of low temperature heat driven power cycles.

Outcomes

The project will provide three use cases (with possible minor alterations) developed in dialogue with industry but also a generic methodology to evaluate utilization of waste heat for power production. The results will be published in both scientific journals and as use-case reports suitable for dissemination to industry. It is key that the project ensures that the proposed solutions obtains the highest possible relevance to the industry who will be future end-users, by including concrete industry specific conditions and constraints. It is therefore critical to enable technology evaluation in a work-shop dialogue format with industry under realistic conditions and system boundaries, securing a format that is familiar and relatable to the target industries.

Project contact persons