Compact and High Efficient Rankine-evaporator Following Economical Targets

Within the public funded project “KompACT”, Rankine cycle evaporators for Waste Heat Recovery systems are under development. Target for the evaporator development is the selection of designs being capable for future economical operations under real world industrial conditions. Therefore, specific focus was set on providing the best economic key values under consideration of earnings based on heat transfer performance and correlated total costs of ownership. The evaluation of different evaporator designs and the selection of the final design are guided by a utility analysis methodology developed within the project. Two conventional steam boilers serve as a component benchmark. Currently, two evaporator designs based on the Twin-Round-Tube-principle were selected: The TwinRound-Tube-Box-Design B1 is extremely compact, light, flexible and targets applications for low and medium heat performance ranges up to approx. 350 kWth. Due to the compact size, installation and operation costs are significantly reduced, offering the best economic values. The Twin-Round-Tube-Cylinder-Design Z3 provides maximum performance and can easily be adapted to different customer requirements. From an economic perspective, the design seems promising to serve a power range of 200 kWth up to 1,000 kWth as industrial target applications. In 2021, thermal tests will be done on a prototype test bench at TH Nuernberg to validate thermal simulations, prove thermal function and guide the final manufacturing design work. In 2022, it is planned to build up a full scale 250 kWth-prototype providing 40 kWel to be installed and operated at the 526 kWel - MicroRankine pilot plant in Nuernberg.