Gas compressor

About: Gas compressor is a research topic. Over the lifetime, 91817 publications have been published within this topic receiving 552209 citations.

Environment control unit for turbine engine

Abstract: An environmental control unit to supply cool dry air to an aircraft cabin has a plurality of bleed air sources from an aircraft engine compressor supplying working fluid to an air cycle cooling circuit An electronic control computer having a plurality of inputs and selects a bleed air source depending upon cabin cooling and pressurization requirements A speed control valve responsive to an output from the control computer, modulates the flow of working fluid through a turbo-alternator, thereby synchronizing the frequency of electrical power produced by the turbo-alternator with that of an aircraft engine alternator The turbo-alternator supplies additional electrical power to the aircraft, thereby minimizing the deleterious effect of warm air bled from the engine compressor on aircraft performance

Review on CO2 heat pump water heater for residential use in Japan

Abstract: The present study presents an overview of CO2 heat pump water heater for residential use in Japan. The contents include the general background, current market, and the technology evolvement of the transcritical CO2 system, especially on the key components like compressor and gas cooler. Some cutting edge technology associated with the high efficient compressors and its integration with expander, such as swing compressor, sub-compressor, two-stage compressor, scroll expander, and dual-sided scroll-type expander are elaborated in this review. Some ingenious tube designs to promote the performance of gas cooler are also studied. In practice, the dominant thermal resistance may occur in the CO2 side or water side, thereby implementing twisted tube or dimple tubes may be quite effective. The placement of enhancement on the water side is especially effective when the operational pressure is close to the critical pressure whereas heat transfer enhancement is more helpful if the operational pressure is comparatively high. For augmentation on the CO2 side, it would be more beneficial to place enhancement a distance away from the pseudo-critical region.

Detailed thermodynamic characterization of hermetic reciprocating compressors

Abstract: The aim of this paper is the detailed analysis of different well-known thermodynamic efficiencies usually used to characterize hermetic compressors. Attention is focussed on the volumetric efficiency, the isentropic efficiency, and the combined mechanical–electrical efficiency. A procedure is presented to detach these efficiencies into their main components (physical sub-processes) to get deeper insight on the overall behavior. The volumetric efficiency is split into partial efficiencies related to pressure drop and heat transfer effects, supercharging effects, superdischarging effects, leakages, etc. The isentropic efficiency is detached using two different points of view: the work associated to the individual sub-processes (compression, discharge, expansion, suction), and the work associated to the underpressures, overpressures, and between the inlet and outlet mean compressor pressures. Finally, the combined mechanical–electrical efficiency is related to the heat transfer losses/gains, and to the exergy transfers and exergy destroyed. Even though some of the concepts introduced in the paper can be applied to different kinds of compressors, the discussion is specially focussed on hermetic reciprocating compressors. An advanced simulation model developed by the authors has been used to generate data to illustrate the possibilities of the detailed thermodynamic characterization proposed. The criteria developed are useful tools for comparison purposes, to characterize compressors, and to assist designers during the optimization process.

Compressor diaphragm assembly

Abstract: A compressor diaphragm assembly (64) for combustion turbines includes a plurality of vanes (66), each of which is formed with an integral inner shroud (68) and an integral outer shroud (70), joined together by connecting bars (74) fitted into grooves (72) in the shrouds (68, 70) of the vanes (66) so as to provide for transfer of loads between the vanes (66).

Turbine Engine Clearance Control Systems: Current Practices and Future Directions

Abstract: Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.