The Development of the Hybrid Vaporization and Power Generation System for the Gas Turbine Using LNG Cold

Abstract

We have been developing a hybrid LNG vaporization and power generation system which generates approximately −100°C air and natural gas fuel of a steady heating value since March 2004. In this study, three types of intake-cooling process for the Gas Turbine Combined Cycle (GTCC) ranging from several MW to several hundred MW are reviewed. • Cold air is directly introduced as gas turbine intake air and cooled down to approximately 10°C. • Cold air is compressed to about 5 bars and injected into the middle stage of the compressor as an inter-cool medium. • Cold air is compressed, recuperated and injected into the combustor as a power augmentation medium. In this paper, we describe an outline of the test equipment, configurations of the hybrid vaporization and power generation system for the gas turbine and discuss the possibilities based on exergy analysis for the above three cases.

A Novel Brayton Cycle With the Integration of Liquid Hydrogen Cryogenic Exergy Utilization

“…The introduced air should be dehumidified to avoid frost formation in the LNG evaporator EVA. This could be accomplished in a number of ways, and an effective solution that starts by first cooling the incoming air (stream 1) just sufficiently to condense out the water, followed by desiccant dehumidification to remove the remaining water vapor, was described in [12]. The cooling could easily be accomplished in our cycle by using one of the cold streams between 1 and 5 • C, and desiccant dehumidification of air is standard commercial practice.…”

“…For significant volume reduction it can be stored and transported much more conveniently in the compressed (0.069 m 3 /kg at 200 bar/298 K) or liquid state (0.014 m 3 /kg at 1 bar/20 K). Liquefaction reduces the volume 5-fold more than such compression, using cryogenic vessels which are rather common in the 19 states on the cycle flow sheet source, in a system where the liquefied hydrogen (LH 2 ) (or LNG) is the heat sink [1][2][3][4][5][6][7][8][9][10][11][12][13], for recovering power during the re-evaporation process needed for making the hydrogen (or LNG) usable for power production by combustion or fuel cells. From the energy perspective, this approach is clearly superior to conventional re-evaporation systems which just use the heat of seawater or ambient air, or even burn part of the gasified LH 2 or LNG without any concomitant power production.…”

“…Other methods use the LNG coldness to improve the performance of conventional thermal power cycles. For example, LNG vaporization can be integrated with compressor inlet air cooling in gas turbine power cycles [5,11,12], or in steam turbine condenser system (by cooling the recycled water [13]). Some pilot plants have been built in Japan from the 1970s, combining closedloop Rankine cycles (with pure or multi-component organic working fluids) and direct expansion cycles [1].…”