Nội dung

Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Fuel Cell/Micro-Turbine Combined Cycle Final Report August 1998 – December 1999 By Larry J. Chaney Mike R. Tharp Tom W. Wolf Tim A. Fuller Joe J. Hartvigson December 1999 DOE Contract: DE-AC26-98FT40454 McDermott Technology, Inc. 1562 Beeson Street Alliance, OH 44601 Northern Research and Engineering Corporation 32 Exeter Street Portsmouth, NH 03801 Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor contractor nor any subcontractor thereunder, makes any warranty, express or implied, or assumes any legal liability or responsibility, for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Disclaimer McDermott Technology, Inc. assumes no liability with respect to the use of, or for damages resulting from the use of, or makes any warranty or representation regarding any information, apparatus, method, or process disclosed in this report. McDermott Technology, Inc. expressly excludes any and all warranties either expressed or implied, which might arise under law or custom or trade, including without limitation, warranties of merchantability and of fitness for specified or intended purpose. Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com ABSTRACT A wide variety of conceptual design studies have been conducted that describe ultra-high efficiency fossil power plant cycles. The most promising of these ultra-high efficiency cycles incorporate high temperature fuel cells with a gas turbine. Combining fuel cells with a gas turbine increases overall cycle efficiency while reducing per kilowatt emissions. This study has demonstrated that the unique approach taken to combining a fuel cell and gas turbine has both technical and economic merit. The approach used in this study eliminates most of the gas turbine integration problems associated with hybrid fuel cell turbine systems. By using a micro-turbine, and a non-pressurized fuel cell the total system size (kW) and complexity has been reduced substantially from those presented in other studies, while maintaining over 70% efficiency. The reduced system size can be particularly attractive in the deregulated electrical generation/distribution environment where the market may not demand multi-megawatt central stations systems. The small size also opens up the niche markets to this high efficiency, low emission electrical generation option. Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Table of Contents 1.0 2.0 3.0 4.0 List of Acronyms and Abbreviations .......................................................................1 Executive Summary.................................................................................................2 Introduction..............................................................................................................3 Results and Discussion.............................................................................................5 2.1.1 Process Description...................................................................................5 2.1.2 Engine/Fuel Cell Integration Concepts ...................................................10 2.1.3 Design Assumptions................................................................................21 2.1.4 Major Equipment.....................................................................................23 2.1.5 Input Data and Heat and Material Balance .............................................28 2.1.6 Modeling Approach and Methodology...................................................28 2.2 Process/Equipment Uncertainties and Development Requirements .......36 2.2.1 Fuel Cell Issues .......................................................................................36 2.3 System Capital Costs...............................................................................42 2.4 Annual Operating Costs..........................................................................43 2.5 Opportunities for Improvement and Suggested Work ............................43 2.5.1 Market Introduction - 200 kW System....................................................43 Conclusions ............................................................................................................49 References ..............................................................................................................50 i Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com List of Figures Figure 1 - Cpn 4 Stack Module ............................................................................................5 Figure 2 - Fuel Cell Micro Turbine Combined Cycle ..........................................................7 Figure 3 - Concept A, Isometric View ...............................................................................12 Figure 4 - Concept A, Plan View .......................................................................................13 Figure 5 - Concept A, Elevation View...............................................................................14 Figure 6 - Concept B, Isometric View ...............................................................................15 Figure 7 - Concept B, Isometric View ...............................................................................16 Figure 8 - Concept B, Plan View .......................................................................................17 Figure 9 - Concept B, Elevation View ...............................................................................18 Figure 10 - Recuperator Arrangement ...............................................................................21 Figure 11 - Compressor Flow.............................................................................................32 Figure 12 - Exhaust Temperature.......................................................................................32 Figure 13 - Engine Electrical Power Output ......................................................................33 Figure 14 - Hot Side Recuperator Inlet Temperature.........................................................33 Figure 15 - Compressor Flow.............................................................................................34 Figure 16 - Compressor Pressure Ratio..............................................................................34 Figure 17 - Compressor Efficiency....................................................................................35 Figure 18 - Overall Expansion Efficiency..........................................................................35 Figure 19 - PSOFC Performance Map ...............................................................................41 Figure 20 - Current Density Vs. Cell Voltage And Power Density...................................44 Figure 21 - NREC PowerWorks 70kWe gas-turbine cogeneration system.......................48 Figure 22 - PowerWorks 100RT Chiller with direct-drive centrifugal compressor ..........49 Figure 23 – 180 kW PSOFC/MicroTurbine System..........................................................54 ii Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com List of Tables Table 1 - State Parameters for 700 kW Fuel Cell/Micro-Turbine Combined Cycle............6 Table 2 - Design Parameters for 700 kW Fuel Cell/Micro-Turbine Combined Cycle ........8 Table 3 - Performance Study for 700 kW Fuel Cell/Micro-Turbine Combined Cycle........8 Table 4 - Component Duty Summary for 700 kW fuel Cell/Micro-Turbine Combined Cycle ....................................................................................................................9 Table 5 - Hybrid Recuperator Options ...............................................................................21 Table 6 - Key System Parameters for 700 kW Fuel Cell/Micro-Turbine Combined Cycle ..................................................................................................................22 Table 7 - Comparison of Transmission Efficiencies.........................................................26 Table 8 - Component Pressure Losses..............................................................................29 Table 9 - PSOFC/Microturbine Capital Costs ..................................................................42 Table 10 - State Parameters for 180 kW Fuel Cell/Micro-Turbine Combined Cycle .......46 Table 11 - Design Parameters for 180 kW Fuel Cell/Micro-Turbine Combined Cycle ....46 Table 12 - Performance Summary for 180 kW Fuel Cell/Micro-Turbine Combined Cycle ..................................................................................................................48 Table 13 - Component Duty Summary for 180 kW Fuel Cell/Micro-Turbine Combined Cycle ..................................................................................................................48 iii Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com List of Acronyms and Abbreviations AC AES ASR BOP cfm COE CpnT M DC DOE GRI HEFPP HHV HT kW kWe LHV MM Btu MTI MW NREC ODS OEM PLC PM2000 PowerWorks™ PSOFC SI SOFCo TIT TCE VHT Alternating Current Advanced Energy System Area Specific Resistance (O*cm2 ) Balance of Plant Cubic feet per minute Cost of Electricity Co-planar, n-stack Direct Current United States Department of Energy Gas Research Institute High Efficiency Fossil Power Plant Higher Heating Value High Temperature Kilowatt (1000 W) Kilowatt Electric (1000 W) Lower Heating Value Million British Thermal Units McDermott Technology Inc. Megawatt (1,000,000 W) Northern Research and Engineering Oxide Dispersion Strengthened Original Equipment Manufacturer Programmable Logic Controller Advanced metallic material from Plansee GmbH, Germany NREC’s micro turbine Planar Solid Oxide Fuel Cell SI is an abbreviation for “Le Systeme Internationale d’Unites.” Solid Oxide Fuel Cell Company Research and Development Limited Partnership with MTI andCeramatec Turbine Inlet Temperature Coefficient of thermal expansion High Temperature 1 Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com 2 Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com EXECUTIVE SUMMARY A wide variety of conceptual design studies have been conducted that describe ultra-high efficiency fossil power plant cycles. The most promising of these ultra-high efficiency cycles incorporate high temperature fuel cells with a gas turbine. Combining fuel cells with a gas turbine increases overall cycle efficiency while reducing per kilowatt emissions. Fuel cells are widely recognized as one of the most promising family of technologies to meet future power generation requirements. Since fuel cells directly convert fuel and an oxidant into electricity through an electrochemical process, they can achieve operating efficiencies approaching 70% - nearly twice the efficiency of conventional internal combustion engines. Fuel cells produce very low levels of pollutant emissions (NOx , SOx , and CO2 ). They are also amenable to high-volume production as standardized power modules. This conceptual study has demonstrated that the unique approach taken to combining a fuel cell and gas turbine has both technical and economic merit. By using a microturbine, and a non-pressurized fuel cell the total system size (kW) has been reduced substantially from those presented in other studies, while maintaining over 70% efficiency. The approach used in this study eliminates most of the gas turbine integration problems associated with hybrid fuel cell turbine systems. The reduced system size can be particularly attractive in the deregulated electrical generation/distribution environment where the market may not demand multi-megawatt central stations systems. The small size also opens up the niche markets to this high efficiency, low emission electrical generation option. While the study has discovered no technical obstacles to success, a sub-scale technology demonstration would reduce the risk of performance and enable a full-scale commercial offering. Demonstrating a full size micro-turbine, with a single fuel cell module would prove the concept as well as the major components and balance of plant that would be needed in a full-scale system. 3