Method of feeding, with impure nitrogen, the combustion chamber of a gas turbine combined with an air distillation unit, and corresponding electricity generation plant
AssigneeL'Air Liquide, Societe Anonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude
InventorsGiovanni Massimo, Jean Marc Peyron
Life of this patent
Estimating the term…
Abstract
The air distillation unit (2) has a low-pressure column (11C) which operates clearly above atmospheric pressure. The waste nitrogen coming from this column serves to purge, under low pressure, the air purification adsorbers 10A, 10B) in order to desorb at them of the contaminants (water and CO2), then is mixed with the impure nitrogen stream sent directly to the nitrogen compressor (14) which feeds the combustion chamber (8) of the gas turbine (1). At the start of regeneration, each adsorber is decompressed down to atmospheric pressure, then brought back up to the low pressure by means of impure nitrogen.
Claims12
Method of feeding, with impure nitrogen, the combustion chamber (8) of a gas turbine (1) combined with an air distillation unit (2), the air distillation unit being equipped with an apparatus (10) for purifying air of water and of CO2 by adsorption, this apparatus comprising two adsorbers (10A, 10B), each one of which follows an operating cycle which comprises, alternately and cyclically;
- a co-current adsorption phase at a high pressure (HP) of the cycle, and a regeneration phase, the regeneration phase comprising a decompression step (a), a step (c) of counter-current purging by waste gas from the air distillation unit coming from a low-pressure column (11C) of this unit, and a step (d) of recompressing the adsorber up to the high pressure of the cycle, characterized in that:
- the low-pressure column (11C) operates at a low pressure (LP) which is clearly greater than atmospheric pressure (AP);
- the waste gas is used almost at the said low pressure (LP) for the purging step (c);
- the decompression step (a) is continued down to a minimum pressure (AP) of the cycle which is clearly less than the said low pressure (LP);
- between the decompression step (a) and the purging step (c), a partial repressurization step (b) i inserted, in which the adsorber (OA, 10B) is repressurized by means of waste gas up to almost the purging pressure (LP);
- and
- the waste gas coming from the adsorber during the purging step (c) is mixed with the waste gas produced by the air distillation unit (2), and the mixture is compressed by a nitrogen compressor (14) in order to feed the combustion chamber (8) of the gas turbine (1).
Electricity generation plant, of the type comprising a gas turbine (1), an air distillation unit (2) producing impure nitrogen, the air distillation unit being equipped with an apparatus (10) for purifying air of water and of CO2 by adsorption, this apparatus comp-rising at least two, preferably only two, adsorbers (10A, 10B), each one of which follows an operating cycle which comprises, alternatively and cyclically, a co-current adsorption phase at a high pressure (HP) of the cycle, and a regeneration phase, the regeneration phase comprising a decompression step (a), a step (c) of counter-current purging by waste gas From the air distillation unit coming from A low-pressure column (11C) of this unit, and a step (d) of recompressing the adsorber up to the high pressure of the cycle, and a nitrogen compressor (14), the intake of which is connected to the air distillation unit by means of a feed pipe (13), and the delivery side of which is connected to the combustion chamber (8) of the gas turbine/and in which:
- the air distillation unit (2) produces impure nitrogen under a low pressure (Tp) which is clearly greater than atmospheric pressure (AP);
- a first impure nitrogen pipe (17, 24) fitted with a valve connects the air distillation unit to the purified air outlet of each adsorber (10A, 10B);
- and
- a second impure nitrogen pipe (22, 18) fitted with a valve connects the air inlet of each adsorber to the said feed pipe (13).
Dependencies are inferred from the claim text.