On the Supercritical Carbon Dioxide Recompression Cycle

2021 ◽  
pp. 1-11
Author(s):  
Dongchuan You ◽  
Hameed Metghalchi
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Environmental Safety ◽  
Maximum Temperature ◽  
Exergetic Efficiency ◽  
Parametric Analyses ◽  
Recompression Cycle ◽  
Supercritical Carbon

Abstract Supercritical carbon dioxide Brayton (sCO2) cycle has been studied in recent years and its high efficiency and environmental safety has been investigated. One of the most promising sCO2 design is the Recompression cycle described in the Introduction of the paper. In this paper, an effort has been made to optimize operation of a recompression cycle by performing parametric analyses on pressure ratio, split fraction, and maximum temperature. The effects of varying these parameters on thermal efficiency as well as exergetic efficiency have been determined.

CFD Simulation of a Supercritical Carbon Dioxide Radial-Inflow Turbine, Comparing the Results of Using Real Gas Equation of Estate and Real Gas Property File

2016 ◽  
Vol 846 ◽  
pp. 85-90 ◽  
Author(s):  
Mostafa Odabaee ◽  
Emilie Sauret ◽  
Kamel Hooman
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Cfd Simulation ◽  
Pressure Ratio ◽  
Computational Cost ◽  
Real Gas ◽  
Table Method ◽  
Radial Inflow Turbine ◽  
Solar Resource ◽  
Supercritical Carbon

The present study explores CFD analysis of a supercritical carbon dioxide (SCO2) radial-inflow turbine generating 100kW from a concentrated solar resource of 560oC with a pressure ratio of 2.2. Two methods of real gas property estimations including real gas equation of estate and real gas property (RGP) file - generating a required table from NIST REFPROP - were used. Comparing the numerical results and time consumption of both methods, it was shown that equation of states could insert a significant error in thermodynamic property prediction. Implementing the RGP table method indicated a very good agreement with NIST REFPROP while it had slightly more computational cost compared to the RGP table method.

High-efficiency and minimum-waste continuous kinetic resolution of racemic alcohols by using lipase in supercritical carbon dioxide

2004 ◽  
pp. 2286 ◽  
Author(s):  
Tomoko Matsuda ◽  
Kazunori Watanabe ◽  
Tadao Harada ◽  
Kaoru Nakamura ◽  
Yoshitaka Arita ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Kinetic Resolution ◽  
High Efficiency ◽  
Supercritical Carbon

The Role of Turbomachinery Performance in the Optimization of Supercritical Carbon Dioxide Power Systems

2019 ◽  
Author(s):  
Alessandro Romei ◽  
Paolo Gaetani ◽  
Andrea Giostri ◽  
Giacomo Persico
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Power Systems ◽  
Pressure Ratio ◽  
Plant Size ◽  
Cycle Performance ◽  
Small Contribution ◽  
Compression Process ◽  
Multiple Cycle ◽  
Supercritical Carbon

Abstract The successful penetration of supercritical carbon dioxide (sCO2) power systems in the energy market largely depends on the achievable turbomachinery performance. The present study illustrates a systematic framework where both the compressor and the turbine are designed via validated (within ±2% pts against experiments) mean-line tools and the related impact on cycle performance estimates is quantitatively and qualitatively assessed. A significant effort is devoted to the analysis of centrifugal compressor performance operating close to the critical point, where sharp thermodynamic property variations may make critical the compression process. The analysis is performed for different compressor sizes and pressure ratios, showing a comparatively small contribution of compressor-intake fluid conditions to the machine efficiency, which may achieve technological competitive values (82 ÷ 85%) for representative full-scale sizes. Two polynomial correlations for both turbomachinery efficiencies are devised as a function of proper similarity parameters accounting for machine sizes and loadings. Such correlations can be easily embedded in power cycle optimizations, which are usually carried out assuming constant-turbomachinery efficiency, thus ignoring the effects of plant size and cycle operating parameters. Efficiency correlations are finally exploited to perform several optimizations of a recompressed sCO2 cycle, by varying multiple cycle parameters (i.e. maximum and minimum temperature, pressure ratio and net power output). The results highlight that the replacement of constant-efficiency assumption with the proposed correlations leads to more accurate performance predictions (i.e. cycle efficiency can differ by more than 4% pts), showing in particular that an optimal pressure ratio exists in the range 2 ÷ 5 for all the investigated configurations.

Supercritical Carbon Dioxide Centripetal Compressor—Aerodynamic Design and Analysis of Off Design Conditions

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
Xuefei Du ◽  
Dengtao Yu ◽  
Dan Luo ◽  
Diangui Huang
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Thermal Design ◽  
Test Method ◽  
Characteristic Line ◽  
Supercritical Carbon

Abstract Based on the design of the supercritical carbon dioxide (SCO2) centripetal compressor, this paper adopts the orthogonal design test method to optimize the pear-shaped volute, designs the front guide vane with the third-order Bezier curve, and designs the outlet by the equal section method. The numerical simulation calculation and analysis of the design conditions and variable conditions of the SCO2 centripetal compressor are carried out. The results at design conditions show that the isentropic efficiency is 92%, the pressure ratio is 1.21, and the mass flow rate is 195.9 kg/s, which is close to the thermal design and level simulation results; the results of variable conditions show that the efficiency of the SCO2 centripetal compressor-flow and pressure ratio-flow characteristic line is similar to that of multistage axial flow compressor. The supercritical carbon dioxide centripetal compressor designed in this paper meets the design requirements, and its feasibility is proved through numerical simulation.

High-Efficiency and Minimum-Waste Continuous Kinetic Resolution of Racemic Alcohols by Using Lipase in Supercritical Carbon Dioxide.

ChemInform ◽  
2005 ◽  
Vol 36 (12) ◽  
Author(s):  
Tomoko Matsuda ◽  
Kazunori Watanabe ◽  
Tadao Harada ◽  
Kaoru Nakamura ◽  
Yoshitaka Arita ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Kinetic Resolution ◽  
High Efficiency ◽  
Supercritical Carbon

Combined Cycle Engine Cascades Achieving High Efficiency

2016 ◽  
Author(s):  
Andy Schroder ◽  
Mark G. Turner ◽  
Rory A. Roberts
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Fuel Cell ◽  
Supercritical Carbon Dioxide ◽  
High Efficiency ◽  
Waste Heat ◽  
Combined Cycle ◽  
Design Parameters ◽  
Topping Cycle ◽  
Supercritical Carbon

Two combined cycle engine cascade concepts are presented in this paper. The first uses a traditional open loop gas turbine engine (Brayton cycle) with a combustor as the topping cycle and a series of supercritical carbon dioxide (S–CO2) engines as intermediate cycles and a bottoming cycle. A global optimization of the engine design parameters was conducted to maximize the combined efficiency of all of the engines. A combined cycle efficiency of 65.0% is predicted. The second combined cycle configuration utilizes a fuel cell inside of the topping cycle in addition to a combustor. The fuel cell utilizes methane fuel. The waste heat from the fuel cell is used to heat the high pressure air. A combustor is also used to burn the excess fuel not usable by the fuel cell. After being heated, the high pressure, high temperature air expands through a turbine to atmospheric pressure. The low pressure, intermediate temperature exhaust air is then used to power a cascade of supercritical carbon dioxide engines. A combined efficiency of 73.1% using the fuel lower heating value is predicted with this combined fuel cell and heat engine device. Details of thermodynamics as well as the (S–CO2) engines are given.

Supercritical carbon dioxide as a green media in textile dyeing: A review

2017 ◽  
Vol 88 (10) ◽  
pp. 1184-1212 ◽  
Author(s):  
Tarek Abou Elmaaty ◽  
Eman Abd El-Aziz
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
High Efficiency ◽  
Manufacturing Processes ◽  
Great Role ◽  
Textile Dyeing ◽  
Save Energy ◽  
Natural Fabrics ◽  
Supercritical Carbon

This review highlights the great role of supercritical carbon dioxide fluid technology in textile dyeing processes. The unequivocal physical characteristics of supercritical carbon dioxide are presented and further researched to continue the development of high efficiency, compact dyeing to save energy and water in manufacturing processes. This review also focuses on the solubility of the dyes in scCO2 as well as the application of the technology to both synthetic and natural fabrics. Some factors relating to the economics of sustainable scCO2 technology are also outlined.

scholarly journals Aerodynamic Optimization Design of a 150 kW High Performance Supercritical Carbon Dioxide Centrifugal Compressor without a High Speed Requirement

2020 ◽  
Vol 10 (6) ◽  
pp. 2093 ◽  
Author(s):  
Dongbo Shi ◽  
Yonghui Xie
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
High Speed ◽  
Design Method ◽  
Pressure Ratio ◽  
Aerodynamic Optimization ◽  
Design Software ◽  
Supercritical Carbon

Supercritical carbon dioxide (S-CO2) Brayton cycle technology has the advantages of excellent energy density and heat transfer. The compressor is the most critical and complex component of the cycle. Especially, in order to make the system more reliable and economical, the design method of a high efficiency compressor without a high speed requirement is particularly important. In this paper, thermodynamic design software of a S-CO2 centrifugal compressor is developed. It is used to design the 150 kW grade S-CO2 compressor at the speed of 40,000 rpm. The performance of the initial design is carried out by a 3-D aerodynamic analysis. The aerodynamic optimization includes three aspects: numerical calculation, design software and the flow part geometry parameters. The aerodynamic performance and the off-design performance of the optimal design are obtained. The results show that the total static efficiency of the compressor is 79.54%. The total pressure ratio is up to 1.9. The performance is excellent, and it can operate normally within the mass flow rate range of 5.97 kg/s to 11.05 kg/s. This research provides an intelligent and efficient design method for S-CO2 centrifugal compressors with a low flow rate and low speed, but high pressure ratio.

Effect of Flow Acceleration and Buoyancy on Thermalhydraulics of sCO2 in Mini/Micro-Channel

2021 ◽  
pp. 161-182
Author(s):  
Nitesh Kumar ◽  
Dipankar Narayan Basu ◽  
Lin Chen
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Supercritical Fluids ◽  
High Efficiency ◽  
Thermal Characteristics ◽  
Flow Acceleration ◽  
Power Cycle ◽  
Numerical Studies ◽  
Major Interest ◽  
Supercritical Carbon

Supercritical fluids have found enhanced applications in several sectors. High efficiency and high compactness associated with supercritical carbon dioxide power cycle are of major interest to the thermal engineers. Additionally, due to environment friendly properties, such as zero ODP, considerably lower GWP, non-toxic and nonflammable supercritical carbon dioxide has emerged as a potential substitute of conventional refrigerants. The peculiar properties of supercritical fluids ensured distinct flow and thermal characteristics of supercritical systems. Therefore, the chapter is aimed to discuss the thermalhydraulic characteristics of supercritical carbon dioxide in minichannel and microchannel. Both experimental and numerical studies on flow and thermal behavior of supercritical carbon dioxide will be discussed. The focus of this chapter is to examine the effect of buoyancy and flow acceleration on heat transfer performance. Considering the widespread applicability, the comprehensive discussion introduced in the chapter will affirmatively help the researchers.

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