PDF Publication Title:
Text from PDF Page: 004
446 H. Jung, J. Hwang / Energy 75 (2014) 443e452 The remainder of the current section will deal with factors necessary to consider when selecting the working fluid. The se- lection of the working fluid is done according to the laws and regulations of South Korea. 2.2.1. Toxicity Toxicity should be considered for the safety of workers, the public and the marine ecosystem in the event of a leakage of the working fluid. We determined toxicity levels based on standards defined as the LC50 (50% Lethal Concentration) and by the Ministry of the Environment of the Republic of Korea. In Table 2, the working fluids are classified in terms of which of them less appropriate because they contain toxic chemicals as defined in the ‘chemical management regulations’ [10,18]. Based on the LC50 value, the table shows that the toxicity levels follows the sequence of R143A > R125 > R32 ~ R410A > R134A. A lower LC50 indicates the substance is, more toxic. 2.2.2. Environmental performance The impact of the working fluid on the GWP (global warming potential) as well as the ODP (ozone depletion potential) was considered for an environmental protection analysis [19]. Table 3 shows the ozone depletion potential and global warming potential of the candidate working fluids. The ozone depletion ability of the working fluids is compared with fluorocarbon tri- chloride (CFCI3) which has a value of 1.0. 2.2.3. Flammability The flammability of the working fluid is also considered during the selection process to improve the operations of the demon- stration facility, and to ensure worker safety and the safety of the C- OTEC cycle processes. In particular, after the C-OTEC system is installed in an actual power plant and operation commences, if the PRC is influenced by the ignition of the working fluid, large scale damage can be ex- pected. Flammable conditions are determined by the ignition temperature and the combustion ranges of the candidate working fluids [10]. Table 4 shows the flammability and combustion ranges of the candidate working fluids. 2.2.4. Electrical properties The C-OTEC system must be installed in the vicinity of the PRC. In this scenario, if the working fluid leaks, it can cause a malfunc- tion if it seeps into the generator or into other electrical compo- nents in the power plant. In particular, if the working fluid has high electrical conductivity or a high dielectric constant, it can affect the performance of the generator and other electrical elements with internal electric field. Table 5 shows that the working fluids under study here have dielectric constants ranging from 1.013 to 14.27 and higher re- sistivity (!3920 MU m) than those of air or rubber. Thus, it would be safe to use any of the candidates with respect to these factors [20,21]. Meurer et al. [22] noted that these working fluids can be Table 3 Comparison of GWP and ODP of working fluids. Working fluid R32 R125 R134A R143A R410A Table 4 Combustion limits of working fluids. GWP 550 3400 1300 4300 2000 Flame limit Lower Upper 14.0% 31.0% e e e e 13.0% e e e ODP 0 0 0 0 0 Working fluid R32 R125 R134A R143A R410A Auto ignition temperature 647.13 C e >743C e >750C Remark Table 2 Toxicity comparison by LC50 value. Product Result R32 LC50 inhalation R125 LC50 inhalation R134A LC50 inhalation R143A LC50 inhalation R410A LC50 inhalation Table 5 Electrical properties of liquid refrigerants. strong insulators with hermetically sealed motor compressors, which are widely used. 2.2.5. Economy The efficiency of C-OTEC compared to a typical commercial power plant cycle is very low because C-OTEC uses only a maximum temperature difference of 20 Ce30 C. However C- OTEC uses the latent heat of steam exhausted from the turbine and therefore, it does not require fuel for the production of steam, making it competitive when used in conventional power plants. It is necessary to consider and evaluate many factors while performing an economic feasibility study. However, in this paper, we consider only those elements which are directly related to the cycle, as this study mainly involves a conceptual design phase [23]. If it is considering that the amount of heat transfer from PRC to C-OTEC is constant then the R32 and R410A fluids have slightly better efficiency. However, the efficiency varies by only 5% from the lowest case which was provided by R125 [10]. The size of the turbine is a very important parameter, as this size is directly related to the production cost. Therefore, it is important to consider factors that influence the size of the turbine. First, the size of the turbine would be smaller, if the heat exchanged from the evaporator is controlled at a constant rate. Second, the latent heat and saturated specific volume define the size of the turbine. A larger specific volume of vapor and less latent heat would lead to a larger turbine size. The size of the turbine is significantly reduced when using R32 or R410A compared the other candidates. The size of the turbine in the case of R134A, is twice as large as those in the cases of R410A and R32, as shown in Table 1. Hence, the use of R32 or R410A will be beneficial economically in terms of the initial installation cost savings. We can also predict two facts from Table 1. First, if the operating pressure of the working fluid is high, the piping design costs Flammable Non-flammable Non-flammable Extremely flammable Non-flammable Working fluid R32 R125 R134A R143A R410A Temperature Ambient 20 Ambient 25 Ambient ( C) Volume Dielectric resistivity (MU m) constant e 14.27 e 4.94 17,700 9.51 e 1.013 3920 7.78 Species Dose Exposure 4h 4h 4h 1h 4h Rat Rat Rat Rat Rat !520,000 ppm 800,000 ppm >500,000 ppm 1,080,000 ppm !520,000 ppmPDF Image | Feasibility study of a combined Ocean Thermal Energy Conversion method in South Korea
PDF Search Title:
Feasibility study of a combined Ocean Thermal Energy Conversion method in South KoreaOriginal File Name Searched:
10.1016_j.energy.2014.07.096_Feasibility_study_of_a_combined_Ocean_Thermal_Energy_Conversion_method_in_South_Korea.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 |