The STEP 10 MWe sCO2 Pilot Demonstration Status Update

2020 ◽  
Author(s):  
John Marion ◽  
Brian Lariviere ◽  
Aaron McClung ◽  
Jason Mortzheim ◽  
Robin Ames
Keyword(s):  
Power Generation ◽  
Supercritical Co2 ◽  
Elevated Temperatures ◽  
Waste Heat ◽  
San Antonio ◽  
Test Facility ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Power Cycles ◽  
Wide Range

Abstract A team led by Gas Technology Institute (GTI®), Southwest Research Institute® (SwRI®) and General Electric Global Research (GE-GR), along with the University of Wisconsin and Natural Resources Canada (NRCan), is actively executing a project called “STEP” [Supercritical Transformational Electric Power project], to design, construct, commission, and operate an integrated and reconfigurable 10 MWe sCO2 [supercritical CO2] Pilot Plant Test Facility. The $122* million project is funded $84 million by the US DOE’s National Energy Technology Laboratory (NETL Award Number DE-FE0028979) and $38* million by the team members, component suppliers and others interested in sCO2 technology. The facility is currently under construction and is located at SwRI’s San Antonio, Texas, USA campus. This project is a significant step toward sCO2 cycle based power generation commercialization and is informing the performance, operability, and scale-up to commercial plants. Significant progress has been made. The design phase is complete (Phase 1) and included procurements of long-lead time deliver components. Now well into Phase 2, most major equipment is in fabrication and several completed and delivered. These efforts have already provided valuable project learnings for technology commercialization. A ground-breaking was held in October of 2018 and now civil work and the construction of a dedicated 25,000 ft2 building has progressed and is largely completed at the San Antonio, TX, USA project site. Supercritical CO2 (sCO2) power cycles are Brayton cycles that utilize supercritical CO2 working fluid to convert heat to power. They offer the potential for higher system efficiencies than other energy conversion technologies such as steam Rankine or Organic Rankine cycles this especially when operating at elevated temperatures. sCO2 power cycles are being considered for a wide range of applications including fossil-fired systems, waste heat recovery, concentrated solar power, and nuclear power generation. By the end of this 6-year STEP pilot demo project, the operability of the sCO2 power cycle will be demonstrated and documented starting with facility commissioning as a simple closed recuperated cycle configuration initially operating at a 500°C (932°F) turbine inlet temperature and progressing to a recompression closed Brayton cycle technology (RCBC) configuration operating at 715°C (1319 °F).

The STEP 10 MWe sCO2 Pilot Plant Demonstration

2019 ◽  
Author(s):  
John Marion ◽  
Mike Kutin ◽  
Aaron McClung ◽  
Jason Mortzheim ◽  
Robin Ames
Keyword(s):  
Pilot Plant ◽  
Supercritical Co2 ◽  
Elevated Temperatures ◽  
Waste Heat ◽  
Test Facility ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Plant Design ◽  
Power Cycles ◽  
Wide Range

Abstract A team led by Gas Technology Institute (GTI), Southwest Research Institute® (SwRI®) and General Electric Global Research (GE-GR), along with the University of Wisconsin and Natural Resources Canada (NRCan), is actively executing a project called “STEP” [Supercritical Transformational Electric Power project], to design, construct, commission, and operate an integrated and reconfigurable 10 MWe sCO2 [supercritical CO2] Pilot Plant Test Facility located at SwRI’s San Antonio, Texas campus. The $119 million project is funded $84 million by the US DOE’s National Energy Technology Laboratory (NETL Award Number DE-FE0028979) and $35 million cost share by the team, component suppliers and others interested in sCO2 technology. This project is a significant step toward sCO2 cycle based power generation commercialization and will inform the performance, operability, and scale-up to commercial facilities. Supercritical CO2 (sCO2) power cycles are Brayton cycles that utilize supercritical CO2 working fluid to convert heat into power. They offer the potential for higher system efficiencies than other energy conversion technologies such as steam Rankine or organic Rankine cycles, especially when operating at elevated temperatures. sCO2 power cycles are being considered for a wide range of applications including fossil-fired systems, waste heat recovery, concentrated solar power, and nuclear. The pilot plant design, procurement, fabrication, and construction are ongoing at the time of this publication. By the end of this 6-year project, the operability of the sCO2 power cycle will be demonstrated and documented starting with facility commissioning as a simple closed recuperated cycle configuration initially operating at a 500°C (932°F) turbine inlet temperature and progressing to a recompression closed Brayton cycle technology (RCBC) configuration operating at 715°C (1319 °F).

Performance Characteristics of an Operating Supercritical CO2 Brayton Cycle

2012 ◽  
Author(s):  
Thomas Conboy ◽  
Steven Wright ◽  
James Pasch ◽  
Darryn Fleming ◽  
Gary Rochau ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Waste Heat ◽  
Electrical Power ◽  
Heat Removal ◽  
Test Facility ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Compact Size ◽  
Test Loop

Supercritical CO2 (S-CO2) power cycles offer the potential for better overall plant economics due to their high power conversion efficiency over a moderate range of heat source temperatures, compact size, and potential use of standard materials in construction [1,2,3,4]. Sandia National Labs (Albuquerque, NM, US) and the US Department of Energy (DOE-NE) are in the process of constructing and operating a megawatt-scale supercritical CO2 split-flow recompression Brayton cycle with contractor Barber-Nichols Inc. [5] (Arvada, CO, US). This facility can be counted among the first and only S-CO2 power producing Brayton cycles anywhere in the world. The Sandia-DOE test-loop has recently concluded a phase of construction that has substantially upgraded the facility by installing additional heaters, a second recuperating printed circuit heat exchanger (PCHE), more waste heat removal capability, higher capacity load banks, higher temperature piping, and more capable scavenging pumps to reduce windage within the turbomachinery. With these additions, the loop has greatly increased its potential for electrical power generation — according to models, as much as 80 kWe per generator depending on loop configuration — and its ability to reach higher temperatures. To date, the loop has been primarily operated as a simple recuperated Brayton cycle, meaning a single turbine, single compressor, and undivided flow paths. In this configuration, the test facility has begun to realize its upgraded capacity by achieving new records in turbine inlet temperature (650°F/615K), shaft speed (52,000 rpm), pressure ratio (1.65), flow rate (2.7 kg/s), and electrical power generated (20kWe). Operation at higher speeds, flow rates, pressures and temperatures has allowed a more revealing look at the performance of essential power cycle components in a supercritical CO2 working fluid, including recuperation and waste heat rejection heat exchangers (PCHEs), turbines and compressors, bearings and seals, as well as auxiliary equipment. In this report, performance of these components to date will be detailed, including a discussion of expected operational limits as higher speeds and temperatures are approached.

Performance Characteristics of an Operating Supercritical CO2 Brayton Cycle

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Thomas Conboy ◽  
Steven Wright ◽  
James Pasch ◽  
Darryn Fleming ◽  
Gary Rochau ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Waste Heat ◽  
Electrical Power ◽  
Heat Removal ◽  
Test Facility ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Compact Size ◽  
Test Loop

Supercritical CO2 (S-CO2) power cycles offer the potential for better overall plant economics due to their high power conversion efficiency over a moderate range of heat source temperatures, compact size, and potential use of standard materials in construction. Sandia National Labs (Albuquerque, NM) and the U.S. Department of Energy (DOE-NE) are in the process of constructing and operating a megawatt-scale supercritical CO2 split-flow recompression Brayton cycle with contractor Barber-Nichols Inc. (Arvada, CO). This facility can be counted among the first and only S-CO2 power producing Brayton cycles anywhere in the world. The Sandia-DOE test-loop has recently concluded a phase of construction that has substantially upgraded the facility by installing additional heaters, a second recuperating printed circuit heat exchanger (PCHE), more waste heat removal capability, higher capacity load banks, higher temperature piping, and more capable scavenging pumps to reduce windage within the turbomachinery. With these additions, the loop has greatly increased its potential for electrical power generation, and its ability to reach higher temperatures. To date, the loop has been primarily operated as a simple recuperated Brayton cycle, meaning a single turbine, single compressor, and undivided flow paths. In this configuration, the test facility has begun to realize its upgraded capacity by achieving new records in turbine inlet temperature (650 °F/615 K), shaft speed (52,000 rpm), pressure ratio (1.65), flow rate (2.7 kg/s), and electrical power generated (20 kWe). Operation at higher speeds, flow rates, pressures, and temperatures has allowed a more revealing look at the performance of essential power cycle components in a supercritical CO2 working fluid, including recuperation and waste heat rejection heat exchangers (PCHEs), turbines and compressors, bearings and seals, as well as auxiliary equipment. In this report, performance of these components to date will be detailed, including a discussion of expected operational limits as higher speeds and temperatures are approached.

Analysis and Optimization of ORC for Low-Temperature Waste Heat Power Generation

2011 ◽  
Vol 383-390 ◽  
pp. 6614-6620
Author(s):  
Xin Ling Ma ◽  
Xiang Rui Meng ◽  
Xin Li Wei ◽  
Jia Chang ◽  
Hui Li
Keyword(s):  
Power Generation ◽  
Low Temperature ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Heat Power ◽  
Generation System ◽  
Power Generation System

This paper presents energy analysis, thermodynamic calculation and exergy analysis for waste heat power generation system of Organic Rankine Cycle based on the first and second laws of thermodynamics. In order to improve system performance, for low-temperature waste heat of 120°C and R245fa organic working fluid, using Aspen Plus software conducted simulation, optimization and improvement. Results from these analyses show that decreasing the expander inlet temperature, increasing inlet pressure of the expander, and adding regenerative heater can increase thermal and exergy efficiencies, at the same time reduce system irreversibility.

Turbomachinery Flowpath Design and Performance Analysis for Supercritical CO2

2014 ◽  
Author(s):  
Leonid Moroz ◽  
Boris Frolov ◽  
Maksim Burlaka ◽  
Oleg Guriev
Keyword(s):  
Supercritical Co2 ◽  
Waste Heat ◽  
Thermodynamic Characteristics ◽  
Working Fluid ◽  
Radial Clearance ◽  
Power Cycles ◽  
Bending Loads ◽  
And Performance ◽  
Design Options ◽  
Turbomachinery Design

The development of Supercritical CO2 (S-CO2) power cycles is currently a major focus of the engineering and scientific community. The reason for such a growing interest in this type of power can be explained by the significant benefits in size and efficiency of power cycles, which use S-CO2 as a working fluid, as compared to conventional steam power generation. Many areas of application such as nuclear, solar, waste heat, energy storage, and clean coal combustion, are being studied for S-CO2 power production. Most of the publications discussing S-CO2 are concentrated on optimization of the cycle’s thermodynamic characteristics, topping and bottoming and have been conceptualized based on the heat source. At the same time, numerous aspects of turbomachinery design are often overlooked or are not well understood. This article discusses some specific engineering aspects of the design of turbine flow path which uses S-CO2 as a working fluid. The following design options have been studied to determine the best turbine configuration: number of stages, rotational speed, impulse versus reaction, types of stages, and radial clearance influence. The effect of larger bending loads, resulting from high power density on nozzles and blade chords size and, consequently, turbine length, has also been studied. The authors hope that the results presented in the article will help the engineering community design better S-CO2 turbomachinery.

Evaluation of the Optimal Point Variation of the S-CO2 Cycle While Considering Internal Pinch in Recuperator

2018 ◽  
Author(s):  
Seongmin Son ◽  
Jin Young Heo ◽  
Jeong Ik Lee
Keyword(s):  
Specific Heat ◽  
Critical Point ◽  
Supercritical Co2 ◽  
Waste Heat ◽  
Working Fluid ◽  
Point Problem ◽  
Inlet Temperature ◽  
Pinch Point ◽  
Optimal Point ◽  
Power Cycle

The Supercritical CO2 power cycle (S-CO2 cycle) is the power cycle that adopts CO2 as a working fluid and is designed to have a compression process near the critical point of CO2. Due to the non-linearity of CO2 pyhsical properties near the critical point, the S-CO2 cycle needs relatively less compression work. Therefore, the efficiency of the S-CO2 cycle is higher than traditional gas cycles. Furthermore, because of the relatively high system minimum pressure (near the critical point, ∼7.39 MPa), an S-CO2 cycle can be composed of smaller turbomachines. Considering these advantages, nowadays, there are many attempts to apply S-CO2 cycles to various fields, such as waste heat recovery, nuclear, coal, concentrated solar power plant and so on. These non-linear pyhsical properties become the cause of some unique issues. One of the most significant issues is the internal pinch point problem in a recuperator. Unlike the traditional gas-to-gas heat exchanger, each hot and cold side of the S-CO2 recuperator goes through the severe change of specific heat. This dramatic change of specific heat may cause the internal pinch point of the recuperator. When the internal pinch point phenomenon occurs, the performance of the recuperator may not able to be evaluated from the pre-fixed effectiveness. This can be an issue when the compressor inlet temperature decreases to transcritical or subcritical region. This may alter the optimal point of the S-CO2 power cycle. In this paper, optimal design points and optimal performance of the S-CO2 power cycle are tracked with the consideration of the internal pinch point phenomenon. While changing the system boundary conditions, the optimal point variation due to internal pinch point phenomenon is evaluated and compared with a traditional methodology. This research is progressed with an in-house integrated S-CO2 power cycle analysis code, which is named KAIST – ESCA (Evaluator for Supercritical CO2 Cycle based on Adjoint method). The target cycle layouts are Simple Recuperated, Intercooling, Recompression and Recompression with intercooling layouts. Both of the S-CO2 Rankine and Brayton cycles conditions are considered.

Performance of N2O4 Gas Cycles for Solar Power Applications

1979 ◽  
Vol 193 (1) ◽  
pp. 313-320 ◽  
Author(s):  
G. Angelino
Keyword(s):  
Waste Heat ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Power Cycles ◽  
Average Temperature ◽  
Power Stations ◽  
Turbine Inlet ◽  
Compressor Inlet ◽  
Cycle Efficiency

The use of N2O4 as the working fluid in gas turbine power cycles is recognized as a potential instrument for improving cycle efficiency at moderate top temperatures while maintaining the technical advantages connected with the waste heat rejection at a comparatively high average temperature. Solar central receiver power stations, whose economic effectiveness is very sensitive to cycle efficiency and which must often reject their waste heat into the atmosphere, could usefully adopt this fluid. The thermodynamic reasons which explain the peculiar behaviour of N2O4 as the Brayton cycle working fluid are discussed. With respect to inert gas cycles, N2O4 permits, for a given efficiency, a reduction in turbine inlet temperature by 200-250°C. At a given turbine inlet temperature, the dissociating character of N2O4 allows overall efficiencies similar to those of steam cycles (at least for moderate plant capacities and provided N2O4 and steam cycles reject their waste heat at comparable temperatures). The relatively long relaxation time of the second step of the N2O4 dissociation can represent a problem mainly for the regenerator. A cycle is presented where regeneration at a pressure higher than the compressor inlet pressure can alleviate this problem.

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.

scholarly journals Parametric Optimization and Thermodynamic Performance Comparison of Organic Trans-Critical Cycle, Steam Flash Cycle, and Steam Dual-Pressure Cycle for Waste Heat Recovery

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4623 ◽  
Author(s):  
Liya Ren ◽  
Huaixin Wang
Keyword(s):  
Heat Source ◽  
Power Output ◽  
Initial Temperature ◽  
Waste Heat ◽  
Cycle Performance ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Thermodynamic Performance ◽  
Pressure Cycle ◽  
Net Power Output

Compared with the basic organic and steam Rankine cycles, the organic trans-critical cycle (OTC), steam flash cycle (SFC) and steam dual-pressure cycle (SDC) can be regarded as the improved cycle configurations for the waste heat power recovery since they can achieve better temperature matching between the heat source and working fluid in the heat addition process. This study investigates and compares the thermodynamic performance of the OTC, SFC, and SDC based on the waste heat source from the cement kiln with an initial temperature of 320 °C and mass flow rate of 86.2 kg/s. The effects of the main parameters on the cycle performance are analyzed and the parameter optimization is performed with net power output as the objective function. Results indicate that the maximum net power output of SDC is slightly higher than that of SFC and the OTC using n-pentane provides a 19.74% increase in net power output over the SDC since it can achieve the higher use of waste heat and higher turbine efficiency. However, the turbine inlet temperature of the OTC is limited by the thermal stability of the organic working fluid, hence the SDC outputs more power than that of the OTC when the initial temperature of the exhaust gas exceeds 415 °C.

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