PDF Publication Title:
Text from PDF Page: 011
Energies 2017, 10, 413 11 of 26 3. Working Fluid Selection The selection of the working fluid is a key aspect in the design of ORC systems. The literature reports hundreds of studies on this topic. However, the authors did not identify a single fluid that is suitable for all applications. For example, Figure 6 reports a work performed by Wang et al. [58] that clearly highlights that the optimal working fluid is strongly dependent on the temperature of the heat source. The working fluid selection has an impact on the thermodynamic performance, size and cost of the system. Therefore, its correct selection is crucial at the design phase of an ORC plant. 320 K Temperature increase 500 K R 143a R 22 R 32 R 290 R 134a R 227ea R 152a R 124 CF3I R 236fa R 600a R 142b R 236ea Isobutene Butene R 600 R 245fa Neopentene R 245ca R 123 R 365mfc R 601a R 601 R 141b Figure 6. The optimal working fluid selection as a function of the heat source temperature [58]. The aim of this section is two-fold. Firstly, the most common methodologies used by ORC experts to tackle the problem of working fluid selection are outlined. Subsequently, the effect of the fluid thermo physical parameters on the design of the ORC components is discussed. The optimal organic fluid has to be selected among dozens of different options available. As a first step, it is useful to categorize fluids into different groups. A first categorization can be based on chemical composition. Organic compounds can be classified as alkanes, fluorinated alkanes, ethers, fluorinated ethers, aromatics, linear siloxanes, PFCs, HFOs, HFCs, etc. Another major classification is based on the slope of the saturated vapour curve, whereby fluids are categorized as wet, isentropic and dry. Wet fluids, isentropic fluids and dry fluids present, respectively, a negative, an infinite and a positive slope of the saturated vapour curve. According to Bao and Zhao [59], dry and isentropic working fluids are to be preferred in ORC applications. This is for multiple reasons. As opposed to wet fluids, dry and isentropic fluids can remain in the vapour phase throughout the expansion process, thus avoiding the erosion of the blades. Furthermore, dry and isentropic fluids allow one to minimize the level of de-superheating, hence reducing the overall heat transfer surface, which in turn lowers the cost of the system. Bao and Zhao [59] underline that the use of an extremely dry working fluid implies the need for a regenerated cycle to improve the performance of the system, which might increase the size and cost of the plant. It can be concluded that there exists a trade-off between performance and cost that strongly depends on the selection of the type of organic fluid. An additional categorization of organic fluids is dictated by government regulators. The increase in popularity of organic compounds in several applications led to the phasing-out of fluids that are dangerous for people and the environment. GWP (Global Warming Potential) and ODP (Ozone Depletion Potential) measure the impact of fluids to the environment [60]. The National Fire Protection Association (NFPA) developed a system to quantify the equivalent health, flammability and reactivity for chemicals commonly used in industry [61]. ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) published several handbooks offering guidelines for the selection of proper engineering fluids [62]. The first step in the process of fluid selection is to pinpoint a limited number of fluids that meet the requirements dictated by government regulators. Then, thermo-physical properties, such as autoignition temperature, deterioration temperature and freezing point, are typically checked toPDF Image | Small Scale Organic Rankine Cycle (ORC)
PDF Search Title:
Small Scale Organic Rankine Cycle (ORC)Original File Name Searched:
energies-10-00413-v2.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)