ORCNEXT - THE NEXT GENERATION ORGANIC RANKINE CYCLES
Time Period: From February 2012 to February 2016
Total Budget: 2.657.300 €
Financing: IWT SBO program
Today process industry (cement, glass, paper, plastic, chemical, …) has to deal with an enormous amount of waste heat. Experts assume that the annual unused industrial waste heat potential amounts to 140TWh in Europe alone, implying a CO2 reduction potential of about 14M ton of CO2 per annum. This waste heat is typically available at a low(er) temperature and can be recovered in the form of electrical power with Organic Rankine Cycles (ORC) technology. Hence, ORC technology has a big economical potential and helps to realise the EU ’20-20-20’ goals.
Several companies offer ORC for waste heat recovery. There is not only a lot of interest in this type of technology, there is still a big amount of waste heat in industry for which ORCs could be used. This is up till now not the case. Analysis shows that investments in these cycles are often not favourable if pay back time or IRR is considered.
To the opinion of the consortium this has to do with two main technical reasons.
Firstly the efficiencies of the cycles are too low for low temperature waste heat sources, resulting in too low energy production. Secondly, the current ORC’s on the market aim at a too high waste energy flow. First research will be aimed at new cycle architectures raising efficiency. One promising step is going towards supercritical cycles, using supercritical fluids. This is a trend also seen in refrigeration systems and chillers. The progress will be realised through thermodynamic modelling and experimental validation. An improvement of about a factor of 20-25%, which is similar to steam cycle improvements, should be envisaged.
Secondly the aim is to investigate efficient systems for smaller power ranges. Aiming at opening the potential for a lot of small scale systems on the market. Therefore specific expander technology has to be developed, by means of advanced CFD algorithms. This development will be done in close cooperation with an industrial research partner.
Two other important factors are also influencing the potential application of these systems.
First it is of great importance to develop smart control algorithms which can take care of varying load. The project results will open again more possibilities for these cycles as a lot of heat sources have a strong variable character.
Secondly, financial and economical constraints and possibilities have to be clearly understood. In previous studies the combined effort of economists and engineers has proven to give fruitful research results. Therefore the whole project will not only be benchmarked to technical possibilities but also to financial and economical benefits.