Analysis of Integrated Coal Gasification System/Compressed-Air Energy Storage Power Plant Concepts

This paper presents the results of a project targeted at developing cost effective power plant concept with integrated Coal Gasification System (CGS) and with Compressed Air Energy Storage (CAES) plant. The developed concepts, denoted as CGS/CAES, provide for continuous operation of CGS and the reheat turboexpander train which are high temperature components, thus improving their operation and extending life resource. A parametric thermodynamic analysis is performed for several CGS/CAES concepts differentiated by their turbomachinery parameters, CGS arrangements, operating cycles, and hours of daily generation. A qualitative cost estimate is made using a variety of sources including published EPRI reports and extensive in-house cost data. A technical and cost comparison is made to the Integrated Gasification Combined Cycle (IGCC) plant.

Repowering of a Combined Cycle Plant

Demand for power in the United States is projected to increase between 2 and 4 percent per year for the next 10 years based on various studies. At the same time, the rise in environmental regulatory restrictions has made it increasingly difficult and expensive for utilities to meet these growing power demands with traditional power sources. During the 1960’s and 70’s hundreds of gas turbine electric generating units were installed in the United States. Many are now approaching the end of their useful economic lives owing to increased maintenance and fuel costs. With the major advances in both fuel efficiency and exhaust gas emission quality power producers are looking toward the repowering of existing plants with modern gas turbines such as the FT8. (Day and Koehler, 1988) This paper describes the design of Turbo Power and Marine Systems’ (Turbo Power) FT8® repowering package for the present FT4 powered plant at Public Service Electric and Gas Company’s (PSE&G) Burlington Generating Station. Given the objectives of minimum design effort and minimum field construction time, the retrofit package provides an optimal blending of existing FT4 and standard FT8 equipment. Performance, impact on operation, reliability, and availability of the FT8 industrial gas turbine were also important considerations in the retrofit design.

Use of Circulating Fluidized Bed Combustors in Compressed Air Energy Storage Systems

This paper presents the results of a study conducted by Energy Storage and Power Consultants, Inc. (ESPC) in close cooperation with Electric Power Research Institute (EPRI). The objective is to develop and analyze compressed air energy storage (CAES) power plant concepts which utilize coal-fired circulating fluidized bed combustors (CFBC) for heating air during generation periods.

Application of Air Saturation to Integrated Coal Gasification/CAES Power Plants

Several studies have recently been conducted with the objective of finding cost-effective applications of coal gasification technology for intermediate load electrical power generation, e.g. 4000 hours per year.

Assessment of Refrigeration-Type Cooling of Inlet Air for Essex Unit No. 9

The intent of this assessment is to determine the economic and technical feasibility of the reduction of compressor-inlet-air temperature by providing a cooling coil at the entrance to the turbine’s inlet-air section to improve performance and reduce operating costs. To achieve the desired cooling of the inlet air to the turbine’s compressor, it is proposed to use indirect cooling from a mechanical-vapor compression-type chiller in combination with cool storage. Two types of cool storage are examined, including chilled-water storage and ice storage. A sizing methodology for the chiller and storage capacity was formulated by PSE&G to maximize the economic attractiveness which a cooling capability can achieve under the power-pool rules. The study considered an energy/thermal assessment to predict turbine performance and electrical output with and without inlet-air cooling. Total benefits include a capacity benefit, net power-generation increase and turbine fuel-input savings less operating costs. Based on the capital cost of the alternatives, simple paybacks were determined.