Demand for electricity in the United States is expected to grow in the foreseeable future, requiring approximately 200 gigawatts of new generating capacity by 2010. Coal-based power plants built to supply this additional baseload capacity will be required to perform at high thermal efficiency and meet tough environmental regulations, all at competitive electric generating costs. The Department of Energy (DOE) / Pittsburgh Energy Technology Center (PETC) is managing a program called Combustion 2000 that is aimed at developing technologies that will assure the continued use of coal to meet the Nation’s power generating needs well into the 21st century. The High-Performance Power System (HIPPS) element of Combustion 2000 is based on an indirectly fired combined cycle. By using an indirectly fired gas turbine and a conventional steam cycle, HIPPS cleanly produces electricity from coal at a thermal efficiency that is about one-third higher than that of today’s conventional coal-based power plants. DOE/PETC’s HIPPS program, which is described in this paper, aims to demonstrate a commercial-scale prototype plant by 2004. An engineering analysis was performed to assess the feasibility of accelerating the demonstration of HIPPS by using only those materials available today. Results predict attractive efficiencies and competitive electric generating costs for a near-term design. The feasibility of HIPPS as a repowering option has also been examined. Preliminary projections reveal that added generating capacity and reduced emissions can be accomplished at an increased overall plant efficiency and with the potential to minimize capital expenditure.

The next generation of coal-fueled power plants must be efficient, clean, and cost-effective. The U.S. Department of Energy (DOE) sponsors a program to develop an advanced, coal-based power system called HIPPS, or High Performance Power System, to meet these requirements. In the HIPPS cycle, air from a gas turbine compressor is indirectly heated in a coal-fueled furnace and then further heated directly with natural gas to power a gas turbine. Indirect heating of the gas turbine working fluid avoids the problems associated with expansion of a corrosive, coal-derived gas through a turbine. Steam is also generated to power a bottoming Rankine cycle. This paper presents an analysis of the performance of HIPPS that is achievable using current technology and projects the level of performance as technology advances. The HIPPS cycle using current technology produces electricity from coal at a thermal efficiency that is more than 40 percent higher than that of today’s average coal-based power plants. The effect of advanced gas turbines, a novel gas turbine cycle, high performance steam cycles, and advanced coal-fueled furnace materials/designs is estimated with the use of computer-based engineering tools. Promising system configurations for future generations of HIPPS are identified with cycle efficiencies as high as 49.3 percent on a higher heating value basis.

The purpose of this study is to assess the feasibility of incorporating a Humid Air Turbine (HAT) into a coal-based, indirectly fired High Performance Power System (HIPPS). The HIPPS/HAT power plant exhibits a one percentage point greater thermal efficiency than the combined-cycle HIPPS plant. The capital costs for the HIPPS and HIPPS/HAT plants with identical net power output are nearly equivalent at $1380/kW. Levelized cost of electricity (COE) for the same size plants is 5.3 cents/kWh for the HIPPS plant and 5.4 cents/kWh for the HIPPS/HAT plant; the HIPPS/HAT plant improved thermal efficiency is offset by the higher fuel cost associated with a lower coal/natural gas fuel ratio. However, improved environmental performance is associated with the HIPPS/HAT cycle, as evidenced by lower CO 2 , SO 2 , and NO x emissions. Considering the uncertainties associated with the performance and cost estimates of the yet unbuilt components, the HIPPS/HAT and HIPPS power plants are presently considered to be comparable alternatives for future power generation technologies. The Department of Energy’s Combustion 2000 Program will provide revised design specifications and more accurate costs for these components allowing more definitive assessments to be performed.

The Department of Energy’s Federal Energy Technology Center (FETC) is sponsoring the Combustion 2000 Program aimed at introducing clean and more efficient advanced technology coal-based power systems in the early 21st century. As part of this program, the United Technologies Research Center has assembled a seven member team to identify and develop the technology for a High Performance Power Systems (HIPPS) that will provide in the near term, 47% efficiency (HHV), and meet emission goals only one-tenth of current New Source Performance Standards for coal-fired power plants. In addition, the team is identifying advanced technologies that could result in HIPPS with efficiencies approaching 55% (HHV). The HIPPS is a combined cycle that uses a coal-fired High Temperature Advanced Furnace (HITAF) to preheat compressor discharge air in both convective and radiant heaters. The heated air is then sent to the gas turbine where additional fuel, either natural gas or distillate, is burned to raise the temperature to the levels of modern gas turbines. Steam is raised in the HITAF and in a Heat Recovery Steam Generator for the steam bottoming cycle. With state-of-the-art frame type gas turbines, the efficiency goal of 47% is met in a system with more than two-thirds of the heat input furnished by coal. By using advanced aeroderivative engine technology, HIPPS in combined-cycle and Humid Air Turbine (HAT) cycle configurations could result in efficiencies of over 50% and could approach 55%. The following paper contains descriptions of the HIPPS concept including the HITAF and heat exchangers, and of the various gas turbine configurations. Projections of HIPPS performance, emissions including significant reduction in greenhouse gases are given. Application of HIPPS to repowering is discussed.

Several advanced, coal- and biomass-based combustion turbine power generation technologies using solid fuels (IGCC, PFBC, Topping-PFBC, HIPPS) are currently under development and demonstration. A key developing technology in these power generation systems is the hot gas filter. These power generation technologies must utilize highly reliable and efficient hot gas filter systems if their full thermal efficiency and cost potential is to be realized. This paper reviews the recent test and design progress made by Westinghouse in the development and demonstration of hot gas ceramic barrier filters toward the goal of reliability. The objective of this work is to develop and qualify, through analysis and testing, practical hot gas ceramic barrier filter systems that meet the performance and operational requirements for these applications.

The U.S. Department of Energy/Federal Energy Technology Center (DOE/FETC)-sponsored High Performance Power Systems (HIPPS) program headed by United Technologies Research Center has identified coal-based combined-cycle power systems using advanced technology gas turbines that could operate at efficiencies approaching 55% (HHV). The HIPPS uses a High Temperature Advanced Furnace (HITAF) to preheat combustion turbine air. The HITAF’s metallic air heaters include a radiator section located in the furnace slagging zone and a convection section located in the downstream portion. The compressor discharge air is heated to 925 C – 1150 C. Additional heat for the turbine, if required in the cycle, is added by special low-NOx gas-fired combustors. The HITAF design has been successfully tested at the desired temperatures for short durations at the Energy and Environmental Research Center, Grand Forks, ND, with tests continuing to expand the systems experience and capabilities. The HIPPS concept with its HITAF advanced air heater are valuable technology candidates for integration into Vision 21, the DoE’s evolving plan to utilize coal and other fossil fuels in energy complexes producing power, chemicals, process heat and other byproducts. For example, the HIPPS would be combined with high temperature fuel cells, e.g., the solid oxide fuel cell (SOFC), resulting in power systems having overall electrical efficiencies greater than 60% (HHV) with 50% or more of the energy input from coal. These power plants would have near zero emissions with a goal for power costs 10% below current coal-fired systems. Emissions of CO 2 , an important greenhouse gas, will be drastically reduced by the higher efficiencies of HIPPS cycles. Very important from a power and coproduction market viewpoint, HIPPS can be an attractive repowering technology. This will allow Vision 21 technology to be used in those plants that seek to continue using coal and other alternative solid fuels to capture the economic benefits of their low energy costs. Here, HIPPS adds high efficiency; increased capacity; load following and dispatching flexibility, as well as important environmental benefits to sites having existing fuel and transmission infrastructure.

Advanced, coal- and biomass-based gas turbine power generation technologies (IGCC, PFBC, PCFBC, HIPPS) are currently under development and demonstration. Efforts at the Siemens Westinghouse Power Corporation (SWPC) have been focused on the development and commercialization of hot gas filter systems as an enabling technology for power generation. As part of the commercialization effort, SWPC has been actively involved in the development of advanced filter materials and component configuration, has participated in numerous surveillance programs characterizing the material properties and microstructure of field tested filter elements, and has undertaken an extended accelerated filter life testing program. This paper reviews SWPC’s material and component assessment efforts, identifying the performance, stability, and life of porous oxide- and nonoxide-based ceramic, as well as metal and intermetallic filters used in advanced, high temperature, coal combustion systems.