scholarly journals Exergetic performance and comparative assessment of bottoming power cycles operating with carbon dioxide–based binary mixture as working fluid

2020 ◽  
Vol 44 (10) ◽  
pp. 7957-7973 ◽  
Author(s):  
Muhammad Haroon ◽  
Abubakr Ayub ◽  
Nadeem A. Sheikh ◽  
Muhammad Imran
Keyword(s):  
Carbon Dioxide ◽  
Binary Mixture ◽  
Comparative Assessment ◽  
Working Fluid ◽  
Power Cycles

Computation of Thermodynamic Properties of Carbon Dioxide in the Range 0–750 Deg C

1970 ◽  
Vol 92 (3) ◽  
pp. 301-309 ◽  
Author(s):  
G. Angelino ◽  
E. Macchi
Keyword(s):  
Carbon Dioxide ◽  
Thermal Properties ◽  
High Temperature ◽  
Thermodynamic Properties ◽  
Thermodynamic Functions ◽  
Critical Region ◽  
Density Measurement ◽  
Working Fluid ◽  
Power Cycles ◽  
Wide Range

The computation of power cycles employing carbon dioxide as working fluid and extending down to the critical region requires the knowledge of the thermodynamic properties of CO2 within a wide range of pressures and temperatures. Available data are recognized to be insufficient or insufficiently accurate chiefly in the vicinity of the critical dome. Newly published density and specific heat measurements are employed to compute thermodynamic functions at temperatures between 0 and 50 deg C, where the need of better data is more urgent. Methods for the computation of thermal properties from density measurement in the low and in the high temperature range are presented and discussed. Results are reported of the computation of entropy and enthalpy of CO2 in the range 150–750 deg C and 40–600 atm. The probable precision of the tables is inferred from an error analysis based on the generation, by means of a computer program of a set of pseudoexperimental points which, treated as actual measurements, yield useful information about the accuracy of the calculation procedure.

Application of Supercritical Fluids in Thermal- and Nuclear-Power Engineering

2021 ◽  
pp. 601-658
Author(s):  
Igor L. Pioro
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Supercritical Fluids ◽  
Nuclear Power ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Thermal Power Plants ◽  
Power Cycles

Supercritical Fluids (SCFs) have unique thermophyscial properties and heat-transfer characteristics, which make them very attractive for use in power industry. In this chapter, specifics of thermophysical properties and heat transfer of SCFs such as water, carbon dioxide, and helium are considered and discussed. Also, particularities of heat transfer at Supercritical Pressures (SCPs) are presented, and the most accurate heat-transfer correlations are listed. Supercritical Water (SCW) is widely used as the working fluid in the SCP Rankine “steam”-turbine cycle in fossil-fuel thermal power plants. This increase in thermal efficiency is possible by application of high-temperature reactors and power cycles. Currently, six concepts of Generation-IV reactors are being developed, with coolant outlet temperatures of 500°C~1000°C. SCFs will be used as coolants (helium in GFRs and VHTRs, and SCW in SCWRs) and/or working fluids in power cycles (helium, mixture of nitrogen (80%) and helium (20%), nitrogen and carbon dioxide in Brayton gas-turbine cycles, and SCW/“steam” in Rankine cycle).

scholarly journals Exergetic, Economic and Exergo-Environmental Analysis of Bottoming Power Cycles Operating with CO2-Based Binary Mixture

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5080
Author(s):  
Muhammad Haroon ◽  
Nadeem Ahmed Sheikh ◽  
Abubakr Ayub ◽  
Rasikh Tariq ◽  
Farooq Sher ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Binary Mixture ◽  
Pressure Ratio ◽  
Economic Value ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Levelized Cost Of Electricity ◽  
Power Cycles ◽  
Partial Heating ◽  
Additive Compound

This study focused on investigating the bottoming power cycles operating with CO2-based binary mixture, taking into account exergetic, economic and exergo-environmental impact indices. The main intent is to assess the benefits of employing a CO2-based mixture working fluid in closed Brayton bottoming power cycles in comparison with pure CO2 working fluid. Firstly, selection criteria for the choice of suitable additive compound for CO2-based binary mixture is delineated and the composition of the binary mixture is decided based on required cycle minimum temperature. The decided CO2-C7H8 binary mixture with a 0.9 mole fraction of CO2 is analyzed in two cycle configurations: Simple regenerative cycle (SRC) and Partial heating cycle (PHC). Comparative analysis among two configurations with selected working fluid are carried out. Thermodynamic analyses at varying cycle pressure ratio shows that cycle with CO2-C7H8 mixture shows maximum power output and exergy efficiency at rather higher cycle pressure ratio compared to pure CO2 power cycles. PHC with CO2-C7H8 mixture shows 28.68% increment in exergy efficiency with the levelized cost of electricity (LCOE) 21.62% higher than pure CO2 PHC. Whereas, SRC with CO2-C7H8 mixture shows 25.17% increment in exergy efficiency with LCOE 57.14% higher than pure CO2 SRC. Besides showing lower economic value, cycles with a CO2-C7H8 mixture saves larger CO2 emissions and also shows greater exergo-environmental impact improvement and plant sustainability index.

Modeling Off-Design and Part-Load Performance of Supercritical Carbon Dioxide Power Cycles

2013 ◽  
Author(s):  
John J. Dyreby ◽  
Sanford A. Klein ◽  
Gregory F. Nellis ◽  
Douglas T. Reindl
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Ambient Air ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Heat Rejection ◽  
Power Cycles ◽  
Part Load ◽  
Dry Cooling ◽  
Supercritical Carbon

Continuing efforts to increase the efficiency of utility-scale electricity generation has resulted in considerable interest in Brayton cycles operating with supercritical carbon dioxide (S-CO2). One of the advantages of S-CO2 Brayton cycles, compared to the more traditional steam Rankine cycle, is that equal or greater thermal efficiencies can be realized using significantly smaller turbomachinery. Another advantage is that heat rejection is not limited by the saturation temperature of the working fluid, facilitating dry cooling of the cycle (i.e., the use of ambient air as the sole heat rejection medium). While dry cooling is especially advantageous for power generation in arid climates, the reduction in water consumption at any location is of growing interest due to likely tighter environmental regulations being enacted in the future. Daily and seasonal weather variations coupled with electric load variations means the plant will operate away from its design point the majority of the year. Models capable of predicting the off-design and part-load performance of S-CO2 power cycles are necessary for evaluating cycle configurations and turbomachinery designs. This paper presents a flexible modeling methodology capable of predicting the steady state performance of various S-CO2 cycle configurations for both design and off-design ambient conditions, including part-load plant operation. The models assume supercritical CO2 as the working fluid for both a simple recuperated Brayton cycle and a more complex recompression Brayton cycle.

scholarly journals Corrosion and Erosion Behavior in Supercritical CO2 Power Cycles

2014 ◽  
Author(s):  
Darryn Fleming ◽  
Alan Kruizenga ◽  
James Pasch ◽  
Tom Conboy ◽  
Matt Carlson
Keyword(s):  
Carbon Dioxide ◽  
Stainless Steel ◽  
Intergranular Corrosion ◽  
Supercritical Co2 ◽  
Power Production ◽  
Operating Conditions ◽  
Working Fluid ◽  
Power Cycles ◽  
Power Cycle ◽  
Potential Issue

Supercritical Carbon Dioxide (S-CO2) is emerging as a potential working fluid in power-production Brayton cycles. As a result, concerns have been raised regarding fluid purity within the power cycle loops. Additionally, investigations into the longevity of the S-CO2 power cycle materials are being conducted to quantify the advantages of using S-CO2 versus other fluids, since S-CO2 promises substantially higher efficiencies. One potential issue with S-CO2 systems is intergranular corrosion [1]. At this time, Sandia National Laboratories (SNL) is establishing a materials baseline through the analysis of 1) “as received” stainless steel piping, and 2) piping exposed to S-CO2 under typical operating conditions with SNL’s Brayton systems. Results from ongoing investigations are presented. A second issue that SNL has discovered involves substantial erosion in the turbine blade and inlet nozzle. It is believed that this is caused by small particulates that originate from different materials around the loop that are entrained by the S-CO2 to the nozzle, where they impact the inlet nozzle vanes, causing erosion. We believe that, in some way, this is linked to the purity of the S-CO2, the corrosion contaminants, and the metal particulates that are present in the loop and its components.

Application of Supercritical Pressures in Power Engineering

2017 ◽  
pp. 404-457
Author(s):  
Igor Pioro ◽  
Mohammed Mahdi ◽  
Roman Popov
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
High Temperature ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Thermal Power Plants ◽  
Power Cycles

SuperCritical Fluids (SCFs) have unique thermophyscial properties and heat-transfer characteristics, which make them very attractive for use in power industry. In this chapter, specifics of thermophysical properties and heat transfer of SCFs such as water, carbon dioxide and helium are considered and discussed. Also, particularities of heat transfer at SuperCritical Pressures (SCPs) are presented, and the most accurate heat-transfer correlations are listed. SuperCritical Water (SCW) is widely used as the working fluid in the SCP Rankine “steam”-turbine cycle in fossil-fuel thermal power plants. This increase in thermal efficiency is possible by application of high-temperature reactors and power cycles. Currently, six concepts of Generation-IV reactors are being developed, with coolant outlet temperatures of 500°C~1000°C. SCFs will be used as coolants (helium in GFRs and VHTRs; and SCW in SCWRs) and/or working fluids in power cycles (helium; mixture of nitrogen (80%) and helium [20%]; nitrogen, and carbon dioxide in Brayton gas-turbine cycles; and SCW “steam” in Rankine cycle).

scholarly journals Measurements of Density and Sound Speed in Mixtures Relevant to Supercritical CO2 Cycles

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Suhyeon Park ◽  
Justin Urso ◽  
K.R.V. (Raghu) Manikantachari ◽  
Ashvin Hosangadi ◽  
Andrea Zambon ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sound Speed ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Working Fluid ◽  
Power Cycles ◽  
Frequency Detection ◽  
Temperature And Pressure ◽  
Power Generation Systems ◽  
Piezoelectric Pressure Sensor

Abstract The objective of this research is to validate properties of mixtures relevant to supercritical carbon dioxide (sCO2) power cycles. Direct-fired sCO2 cycles are a promising technology for the future power generation systems. The working fluid of sCO2 cycles will be near and above critical point of CO2. One of the challenges is that the simulation of mixtures should consider real gas behavior. Expected operating conditions of Allam cycles reach up to 300 bar and 1000 °C. Characterizing the mixtures at the extreme conditions is an important issue in current researches and industrial applications. Thermophysical properties of mixtures may be beyond the valid range of the widely used database such as NIST REFPROP. Experimental data of mixture properties in the literature are limited which is necessary to develop high-fidelity design tools for sCO2 power cycles. We measured the density and sound speed of several multi-component mixtures. A temperature-controlled high-pressure test cell was used for the density measurements. Sound speed was measured by resonant frequency detection using an external speaker and a piezoelectric pressure sensor. Mixtures studied in this work include carbon dioxide, methane, oxygen, and water vapor. Properties of pure CO2 were measured to show the validity of our technique. Compositions were selected to be close to frozen mixtures at the inlet, mid-progress, and exhaust conditions of a model sCO2 combustor in the previous numerical simulation work. Corresponding reaction progress variables (RPV) were RPV = 0, 0.5, and 1. Temperature and pressure conditions of experiments are 310–450 K and 0–150 bar. In our study, density and sound speed from the NIST REFPROP database agree with experimental measurements within the range of our measurement uncertainties.

Measurements of Density and Sound Speed in Mixtures Relevant to sCO2 Power Cycles

2020 ◽  
Author(s):  
Suhyeon Park ◽  
Justin Urso ◽  
K. R. V. (Raghu) Manikantachari ◽  
Ashvin Hosangadi ◽  
Andrea Zambon ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sound Speed ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Working Fluid ◽  
Power Cycles ◽  
Frequency Detection ◽  
Temperature And Pressure ◽  
Power Generation Systems ◽  
Piezoelectric Pressure Sensor

Abstract The objective of this research is to validate properties of mixtures relevant to supercritical carbon dioxide (sCO2) power cycles. Direct fired sCO2 cycles are promising technology for the future power generation systems. The working fluid of sCO2 cycles will be near and above critical point of CO2. One of the challenges is that the simulation of mixtures should consider real gas behavior. Expected operating conditions of Allam cycles reach up to 300 bar and 1000 °C. Characterizing the mixtures at the extreme conditions is an important issue in current researches and industrial applications. Thermophysical properties of mixtures may be beyond the valid range of the widely used database such as NIST REFPROP. Experimental data of mixtures properties in the literature is limited which is necessary to develop high-fidelity design tools for sCO2 power cycles. We measured density and sound speed of several multi-component mixtures. A temperature-controlled high-pressure test cell was used for the density measurements. Sound speed was measured by resonant frequency detection using an external speaker and a piezoelectric pressure sensor. Mixtures studied in this work includes carbon dioxide, methane, oxygen and water vapor. Properties of pure CO2 were measured to show the validity of our technique. Compositions were selected to be close to frozen mixtures at the inlet, mid-progress and exhaust conditions of a model sCO2 combustor in the previous numerical simulation work. Corresponding reaction progress variables (RPV) were RPV = 0, 0.5, and 1. Temperature and pressure conditions of experiments are 310–450 K, and 0–150 bar. In our study, density and sound speed from NIST REFPROP database agree with experimental measurements within the range of our measurement uncertainties.

scholarly journals Influence of the initial parameters on the thermodynamic efficiency of carbon dioxide power cycles

2022 ◽  
Vol 2150 (1) ◽  
pp. 012011
Author(s):  
P A Shchinnikov ◽  
I S Sadkin ◽  
A P Shchinnikov ◽  
N F Cheganova ◽  
N I Vorogushina
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Initial Temperature ◽  
Great Influence ◽  
Working Fluid ◽  
Thermodynamic Efficiency ◽  
Regenerative Heat ◽  
Power Cycles ◽  
Power Cycle ◽  
Temperature And Pressure

Abstract This paper considers the main CO2 power cycle configurations based on the Allam and JIHT cycles. In particular, the authors of the article have proposed new configurations of the power cycle. The efficiency of these cycles is studied as a function of the initial temperature and pressure of the working fluid. The thermodynamic efficiency can reach 65–66%. It is shown that the presence of regenerative heat transfer and the properties of supercritical carbon dioxide have a great influence on the thermal efficiency.

Sign in / Sign up

Export Citation Format

Share Document