The authors and others at PRC have developed a family of computer‐automated system engineering (CASE) tools which support system requirements analysis, automatic specification preparation, requirements traceability, and rapid access to system engineering reference data. The tools include the following: Design SRATM (requirements analysis tool) Spec WriterTM (automatic specification tool) SpecREFTM (digital image library access)* SpecTRACETM (requirement traceability)* SpecEditorTM (specification editing tool)* These tools have been developed specifically to support the DOD system requirements analysis (SRA) process. They are also used in commercial systems engineering applications. Elements of the SRA process and their specific implementation in PRC CASE tools described in this paper include the following: Functional analysis and decomposition Requirements allocation Design constraint analysis Automatic specification preparation Requirements verification support Requirements traceability * Currently in development.

For the purpose of assessing combustion effects in a small gas turbine engine, there was a requirement to evaluate the rotating temperature and dynamic characteristics of the power turbine rotor module. This assessment required measurements be taken within the engine, during operation up to maximum power, using rotor mounted thermocouples and strain gages. The acquisition of this data necessitated the use of a telemetry system that could be integrated into the existing engine architecture without affecting performance. Due to space constraints, housing of the telemetry module was limited to placement in a hot section. In order to tolerate the high temperature environment, a cooling system was developed as part of the integration effort to maintain telemetry module temperatures within the limit allowed by the electronics. Finite element thermal analysis was used to guide the design of the cooling system. This was to ensure that sufficient airflow was introduced and appropriately distributed to cool the telemetry cavity, and hence electronics, without affecting the performance of the engine. Presented herein is a discussion of the telemetry system, instrumentation design philosophy, cooling system design and verification, and sample of the results acquired through successful execution of the full engine test program.

At the time of the start of the GT PRIME upgrade project, the eight General Electric MS7001 gas turbines in combined cycle service at the Wharton Station of Houston lighting and Power each had 85,000 hours of operation with 2000 starts. The units were ready for their second major overhaul. A number of hot gas path components required replacement at that time. Rather than replacing components one by one, the user devised a Program for Reliability, Improved Maintenance, and Efficiency (GT PRIME). We will discuss turbine condition, design changes, reduced emissions, and increased output in the paper. Actual user experience on maintenance and operating costs resulted in some special requirements to be satisfied in addition to the expected parts replacement. General Electric had developed many improved parts for newer units, all of which could be easily applied to older machines. The use of these newer production MS7001EA parts increase component life, parts availability, inspection intervals, system reliability and performance. These will be described in the paper. These 1972 vintage turbines achieved a 50PPM NOx level by injecting water at a high rate of flow which resulted in the need for more frequent combustion inspection intervals. The development of a dry low NOx system for the unit allowed the combustion inspection interval to double while reducing NOx to 25PPM. The improvement in component efficiencies in the gas path resulted in increased output and improved the heat rate. These changes had a significant impact on customer operating costs which resulted in a very attractive payback period. We will discuss expected versus actual output, heat rate and emissions results for all eight units. The upgrade of the first unit started in 1992 and the last unit was completed in 1996. A detailed listing of uprate program schedule by unit is listed in Figure #1.

Rolls-Royce Dahlewitz, GermanyFor the purpose of assessing combustion effects in a small gas turbine engine, there was a requirement to evaluate the rotating temperature and dynamic characteristics of the power turbine rotor module. This assessment reqtdred measurements be taken within the engine, during operation up to maximum power, using rotor mounted thermocouples and strain gauges. The acquisition of this data necessitated the use of a telemetry system that could be integrated into the existing engine architecture without affecting performance. As a result of space constraints, housing of the telemetry module was limited to placement in a hot section. To tolerate the high temperature environment, a cooling system was developed as part of the integration effort to maintain telemetry module temperatures within the limit allowed by the electronics. Finite element thermal analysis was used to guide the design of the cooling system. This was to ensure that sufficient airflow was introduced and appropriately distributed to cool the telemetry cavity, and hence electronics, without affecting the performance of the engine. Presented herein is a discussion of the telemetry system, instrumentation design philosophy, cooling system design and verification, and sample of the results acquired through successful execution of the full engine test program.