Evaluation of improvements to Brayton cycle performance. Final report

Technical Report · Thu May 29 00:00:00 EDT 1986

OSTI ID:5225115

Spasyk, M A

This study addresses the problem of finding an energy-conversion method to take advantage of the high-maximum cycle temperatures achieved with solar central receivers. Most current practice is to use steam-based heat engines with solar receivers but these Rankine cycles cannot operate at the higher possible temperatures. Derivatives of gas-based Brayton cycles are considered to take advantage of the expected increased cycle performance of higher temperatures. Computer modeling was done to examine the effect of maximum temperature on efficiency of two Brayton cycle derivatives and a simple Brayton cycle (GT). The modified Brayton cycles include a combination of intercooling, regeneration, and reheat (IGT) and a Brayton cycle with steam injection (STIG). The turbine inlet temperature, the steam-to-air injection mass ratio (for the STIG), and the compression pressure ratios were treated as parameters in the analysis. Both First Law and Second Law efficiencies were examined. Efficiencies were highest for the IGT followed by the STIG and GT, respectively. Considerable improvements in specific work output were demonstrated by the STIG over both the IGT and GT systems. First and Second law analyses show a gradual increase of efficiency with turbine inlet temperature with diminishing returns at higher temperatures.

• Research Organization: Army Military Personnel Center, Alexandria, VA (USA)
• OSTI ID: 5225115
• Report Number(s): AD-A-169018/9/XAB
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300000 -- Direct Energy Conversion
42 ENGINEERING
425001* -- Engineering-- Power Cycles-- Brayton-- (1980-)
BRAYTON CYCLE
COMPRESSION RATIO
COMPUTERIZED SIMULATION
CONVERSION
EFFICIENCY
ENERGY CONVERSION
GAS TURBINES
HIGH TEMPERATURE
INJECTION
INTAKE
MACHINERY
SIMULATION
STEAM
THERMODYNAMIC CYCLES
TURBINES
TURBOMACHINERY