New heat conversion technologies need to be developed and improved to take advantage of the necessary increase in the supply of renewable energy. The Organic Rankine Cycle is well suited for these applications, mainly because of its ability to recover low-grade heat and the possibility to be implemented in decentralized lower-capacity power plants. In this paper, an overview of the different ORC applications is presented. A market review is proposed including cost figures for several commercial ORC modules and manufacturers. An in-depth analysis of the technical challenges related to the technology, such as working fluid selection and expansion machine issues is then reported. Technological constraints and optimization methods are extensively described and discussed. Finally, the current trends in research and development for the next generation of Organic Rankine Cycles are presented.

Techno-economic survey of Organic Rankine Cycle (ORC) systems

How to effectively utilize low and medium temperature energy is one of the solutions to alleviate the energy shortage and environmental pollution problems. In the past twenty years, because of its feasibility and reliability, organic Rankine cycle has received widespread attentions and researches. In this paper, it reviews the selections of working fluids and expanders for organic Rankine cycle, including an analysis of the influence of working fluids' category and their thermodynamic and physical properties on the organic Rankine cycle's performance, a summary of pure and mixed working fluids' screening researches for organic Rankine cycle, a comparison of pure and mixture working fluids' applications and a discussion of all types of expansion machines' operating characteristics, which would be beneficial to select the optimal working fluid and suitable expansion machine for an effective organic Rankine cycle system.

A review of working fluid and expander selections for organic Rankine cycle

https://www.sfu.ca/~mbahrami/ENSC%20461/Project/Some%20papers%20for%20CO2%20Ref/Fundamental%20process%20and%20system%20design%20issues%20in%20CO2%20vapor%20compression%20systems.pdf

Fundamental process and system design issues in CO2 vapor compression systems

https://hal.archives-ouvertes.fr/hal-00781353/document

Thermo-economic optimization of waste heat recovery Organic Rankine Cycles

The organic Rankine cycle (ORC) is commonly accepted as a viable technology to convert low temperature heat into electricity. Furthermore, ORCs are designed for unmanned operation with little maintenance. Because of these excellent characteristics, several ORC waste heat recovery plants are already in operation. Although the basic ORC is gradually adopted into industry, the need of increased cost-effectiveness persists. Therefore, a next logical step is the development of new ORC architectures. Even though there has been a strong renaissance towards ORC research in the last decade, ORC architectures have received relatively little attention. Several barriers can be listed. First, there is the difficulty in assessing the additional complexity of the system. While several advanced cycle designs appear promising from a thermodynamic viewpoint, it is not clear that these represent viable economic solutions. Secondly, there is a lack of experimental data from open literature. Additionally, there is the challenge of coping with various boundary conditions from literature, which makes an objective comparison difficult. In this article an overview is presented of ORC architectures. The performance evaluation criteria and boundary conditions are clearly stated. As well, an overview of the available experimental data is given.

Review of organic Rankine cycle (ORC) architectures for waste heat recovery

Screw Compressors: Mathematical Modelling and Performance Calculation

An extensive research and development programme carried out at City University, London, has led to an improved level of understanding of how Lysholm twin screw machines may be used to recover power from two-phase flash expansion processes. The mode of operation of such machines is described together with the various types of rotor shapes used. Details are given of a computer simulation of the expansion process which was used to analyse 636 test results. These were obtained from earlier investigations as well as those of the authors and include three different working fluids, varying rotor profiles and sizes and power outputs of 5–850 kW. Good agreement was obtained between predicted and measured performance parameters and statistical analyses of the results indicate that this is unlikely to be improved without the development of more refined methods of two-phase flow analysis than are currently in use. Included in the tests are a set of measurements of pressure-volume changes within the expander carried o...

Development of the Trilateral Flash Cycle System: Part 3: The Design of High-Efficiency Two-Phase Screw Expanders

/pdf/experimental-investigation-of-the-influence-of-oil-injection-4ymehdj4c7.pdf

Experimental Investigation of the Influence of Oil Injection Upon the Screw Compressor Working Process

Computational Fluid Dynamics in Screw Machines.- Grid Generation of Screw Machine Geometry.- Applications.- Conclusions.

Screw Compressors: Three Dimensional Computational Fluid Dynamics and Solid Fluid Interaction

http://www.staff.city.ac.uk/~ra601/optimrev.pdf

Nikola Stosic

Papers

Screw Compressors: Mathematical Modelling and Performance Calculation

Development of the Trilateral Flash Cycle System: Part 3: The Design of High-Efficiency Two-Phase Screw Expanders

Experimental Investigation of the Influence of Oil Injection Upon the Screw Compressor Working Process

Screw Compressors: Three Dimensional Computational Fluid Dynamics and Solid Fluid Interaction

Optimisation of screw compressors