PDF Publication Title:
Text from PDF Page: 018
Energies 2017, 10, 413 18 of 26 According to Imran et al. [17], scroll expanders represent the best choice when the power output of the system is in the range of 1–25 kW. These expanders show higher performance when the expansion is slightly wet and the volumetric ratio between the inlet and the outlet sections of the machine is limited (see Figure 8). In the 1–10-kW power range, rotary vane expanders represent another suitable solution for ORC applications. Some recently-published papers present experimental measurements and evaluations of rotary vane machines [112,113]. Vane expanders can work with fluids at low temperature and pressure, e.g., Qiu et al. [86] proposed a vane expander that can handle 120 °C and 7 bar. Rotary vane expanders result in low rotational speeds, the ability to work in the presence of liquid and minimal maintenance cost [59]. The interested reader may refer to the following studies, among others, for details on the design of rotary vane expanders: [114–116]. Lemort et al. [117], in their work on the comparison of piston, screw and scroll expanders, state that screw expanders cover the power range above 20 kW. Qiu et al. [86] in their work explain that screw expanders in the power range below 10 kW are hard to find on the market, due to difficulties in their sealing. At a commercial level, EXA, Enogia and Mattei developed ORC systems in the range of 1–10 kW (see Table 2). Qiu et al. [86] provide an overview of the prices of different types of ORC expanders. 4.2. ORC Plants of 20–70 kW The 20–70-kW power range represents a grey area in the expander selection. The weight and size of volumetric expanders increase exponentially when the power output of the system exceeds 20 kW. Turbo expanders require a high rotational speed that may lead to a failure of the bearings. Furthermore, the high rotational speed of turbo machines complicates the coupling between the turbo expander and an off-the-shelf electric generator. Peterson et al. [118] state that radial turbines are considered for power outputs above 50 kW. Franchetti et al. [83] poses a limit of 70 krpm for the rotational speed of radial turbines. Fiaschi et al. [119] proposed a radial turbine mean line model, showing that a rotational speed of up to 44 krpm is needed for the production of 50 kW power (the total to static efficiency being about 70%). Kang [103] performed an experimental study on a radial expander in the 30-kW range. He experimentally achieved an efficiency up to 78.7%. Hsieh et al. [106] performed an experimental investigation of a 20-kW screw expander, reaching an efficiency of 57% and producing 19.7 kW. Leibowitz et al. [104], in their analysis on cost effective small-scale ORC systems in the 20–50-kW range, identify that twin screw expanders are the most promising. He states that twin screw expanders can reach efficiencies of 70% during low speed operation and that their cost of installation is approximately 1500–2000 $/kW. Several ORC companies are developing prototypes in this power range (see Figure 9 and Table 2). Among the expanders available, radial and screw represent the most recurrent choices. The major drawback of radial turbines is represented by their high rotational speeds in the power range of 20–70 kW, while that of screw expanders is represented by their high leakage losses (which are proportional to the size of the machine) [17]. 4.3. ORC Plants of 70–100 kW The power range of 70–100 kW represents an attractive market for ORC companies. As depicted in Table 2, different companies are developing ORC systems in this power range. Despite a large commercial interest, the number of studies that report experimental results of ORC systems in the 70–100-kW power range is limited (see Figure 9). Fu et al. [120] presented a literature review in which they highlighted the lack of experimental studies on ORC systems with a power output exceeding 50 kW. Figure 9 and Table 2 show that turbo expanders are favoured over volumetric machines in the power range of 70–100 kW. The rotational speed of turbo machines decreases exponentially when the power output exceeds 70 kW. This prevents the bearings from failure and allows the coupling ofPDF 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 | RSS | AMP |