PDF Publication Title:
Text from PDF Page: 007
fluids) require a high degree of superheating, while some isentropic fluids such as the R245fa or R365mfc require a low one. Most of the dry working fluids such as the butane heptane or n-pentane are operating at saturated conditions due to the positive slope of their diagram, which avoids the need of superheating the working fluid before its expansion. As Figure 3 and Table 3 show, the working fluids giving the highest potential of improvement are alkanes, followed by the HFOs and HFCs, while the cycloalkanes do not show an appreciable efficiency increase when installing a recuperator unit. Even though ethane is the working fluid showing the highest potential of improvement when installing a recuperator unit, its performance is still one of the worst among all the analyzed working fluids. The highest efficiency gains are observed for the dry working fluids, because they have higher recuperation potentials than wet working fluids (ethanol and methanol experience an efficiency drop of 0.22% and 0.32% respectively when a regenerator unit is used). For the simple cycle layout, propylene shows the best results, operating at transcritical conditions and reaching an efficiency of 32.69%. For the recuperated cycle, R1234yf becomes the best working fluid, reaching a second law plant efficiency of 33.46%. It can also be seen that, while for the simple cycle layout many fluids are working at saturated conditions, for the recuperated configuration they show a better performance operating at superheated conditions. The reason is that a higher power production can be achieved when superheating, but this makes the cooling load to be higher (Bao and Zhao, 2013) unless a recuperator is used to decrease the cooling load and avoid wasted heat. Regarding inorganic working fluids, the results for ammonia deviate from the tendency of Figure 3, while the H2O is giving the worst performance. For both H2O and ammonia, the recuperator is cooling down the working fluid at the inlet of the evaporator. Also, H2O is giving the lowest power output. This is a consequence of the too low enthalpy drop taking place across the turbine for avoiding wet expansion. Regarding CO2, it is also giving a low second law efficiency that improves with the use of a recuperator but it is still lower than the one for the rest of organic fluids. The results of this work indicate that the studied inorganic working fluids are not recommended for power generation in Rankine Cycles with low-heat source temperatures and low power capacities. The Backwork Ratio (BWR) was plotted as a function of Tcrit in Figure 4. It can be seen that those working fluids with the lowest critical temperatures (from 0oC to 92oC) are giving the highest BWRs. For subcritical cycles with a critical temperature between 100oC and 160oC, the simple cycles have higher BWRs than the recuperated cycles, due to the lower power production and higher power consumption they have. For those working fluids with critical temperatures higher than 160oC, the BWRs of the recuperated and simple cycles are very similar, since they can operate at lower pressures, guaranteeing a low pump power that does not appreciably change when moving from one cycle layout to another. Finally, for toluene, the working fluid with the highest critical temperature, the maximum pressure to guarantee an efficient heat transfer process is the lowest one (0.33 bar), and this results into the lowest power consumption among all the results (only 0.39 kW), giving the lowest BWR. The choice of the working fluid depends on the application at hand. If the target is power generation, the working fluids giving the highest second law efficiencies (those ones with a critical temperature close to the highest temperature of the cycle) should be chosen. Among these fluids, an economic analysis should be carried out to determine whether the use of a recuperator is justified or not. For those working fluids with a low second law efficiency, the power production is lower when comparing to the rest, and, since the amount of heat into the cycle is fixed, the heat rejected in the condenser is higher. This means that those working fluids with a low second law efficiency may have a promising potential for co-generation if the rejected heat in the condenser is used. For example, the ethane, with a second law efficiency of 21.15% rejects 2326.23 kW in the condenser at an inlet temperature of almost 56 oC, while the recuperated propylene rejects 2225.36 kW with a plant efficiency of 33.42% and an inlet condenser temperature lower than 32 oC. [oC] DOI: 10.3384/ecp17138251 Proceedings of the 58th SIMS 257 September 25th - 27th, Reykjavik, Iceland Figure 4. Influence of the critical temperature on the BWR for all the simulated working fluidsPDF Image | ORC for Power Generation Low Temperature Geothermal Heat Source
PDF Search Title:
ORC for Power Generation Low Temperature Geothermal Heat SourceOriginal File Name Searched:
ecp17138034.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 |