Power plants – Combustion products used as motive fluid – Combustion products generator
Reexamination Certificate
2002-11-04
2004-01-20
Casaregola, Louis J. (Department: 3746)
Power plants
Combustion products used as motive fluid
Combustion products generator
C060S806000
Reexamination Certificate
active
06679059
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine plant, and in particular, to a gas turbine plant which previously heats a fuel supplied to a gas turbine combustor of the gas turbine plant and enhances a quantity of heat so as to improve a plant heat (thermal) efficiency.
In a gas turbine plant, it has been known that the plant heat efficiency is improves if an inlet combustion temperature of a gas turbine is made high. The plant heat efficiency is calculated from a ratio of a gas turbine power to a fuel supplied to a gas turbine combustor.
Therefore, how to reduce a fuel to be supplied to the gas turbine combustor, or how to enhance an output of the gas turbine is an important matter in order to improve the plant heat efficiency.
In view of the gas turbine output power in the light of the improvement of the plant heat efficiency, there is a problem of an increase in a power per unit combustion gas flow (specific power). However, an improvement of flow characteristic of a gas turbine blade and a reduction in other mechanical loss have already reached the limit, and it is difficult to greatly improve the flow characteristic and reduce the mechanical loss.
On the other hand, in order to reduce fuel consumption so as to improve the plant heat efficiency, it is important to improve a quantity of heat of fuel itself.
Recently, there has been disclosed Japanese Patent No. 2540646 as means for improving the quantity of heat of fuel itself. As shown in
FIG. 29
, the Japanese Patent No. 2540646 relates to a so-called multi-shaft type combined cycle power generation plant which is constructed in such a manner that a shaft of a gas turbine plant
2
connected to an exhaust heat recovery boiler
1
is separated, and a steam turbine plant
3
is independently provided. A gas turbine combustor
4
is provided with a heat exchanger
5
, and a heated water generated from an economizer
6
of the exhaust heat recovery boiler
1
is used as a heating source to be supplied to the heat exchanger
5
, and thus, a heat exchange of a fuel F supplied to the gas turbine combustor
4
is made to increase a quantity of heat.
As described above, in the Japanese Patent No. 2540646, efforts have been made to reduce fuel consumption and to improve a plant heat efficiency because there is an anxiety that fossil fuel resources are exhausted in near future.
In the prior art shown in
FIG. 29
, a heated water on an outlet side of the economizer
6
having a relatively small influence on load fluctuation is used as a heating source of the heat exchanger
5
so as to heat the fuel F, and then, a gas turbine driving gas (main flow gas) having the same temperature is generated by a fuel flow rate relatively smaller that that of the conventional case, and thus, a plant heat efficiency is improved. However, the heated water on the outlet side of the economizer
6
has been used as a heating source of the fuel F, and for this reason, there have arisen several problems.
Primarily, the temperature of heated water generated from the economizer
6
is set on the basis of heat balance of the whole plant regardless of heating the fuel F. For this reason, the temperature of the heated water becomes high by heating the fuel, and then, a saturation pressure based on the high temperature of heated water excessively becomes high. Thus, a feed water pump
6
a
requires a high pressure rising force, and thus, this is a factor of increasing the cost.
During partial load operation, when a flow rate of the heat water supplied to the heat exchanger
5
becomes low, a quantity of feed water from the feed water pump
6
a
passing through the economizer
6
becomes low. In this case, however, an internal pressure of the feed water pump rises, and for this reason, the heat water discharged from the economizer
6
exceeds a saturation temperature. As a result, there is the possibility that steaming is generated.
Further, the heated water of the economizer
6
is used as a heating source of the fuel F. In this case, however, the aforesaid construction is applied to only the combined cycle power generation plant. For example, in the case of a simple cycle gas turbine, it is difficult to secure a heating source, and for this reason, there has been required a gas turbine plant which can readily secure the heating source.
As described above, the prior art shown in
FIG. 29
can improve the plant heat efficiency, but provides the aforesaid several problems.
SUMMARY OF THE INVENTION
A primary object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art described above and to provide a gas turbine plant capable of relatively reducing a flow rate of fuel so as to improve a plant heat efficiency without giving any influence to other constituent equipments when using the gas turbine plant itself as a heating source for heating a fuel.
This and other objects can be achieved according to the present invention by providing, in one aspect, a gas turbine plant comprising:
an air compressor;
a gas turbine;
a driven equipment, the air compressor, the gas turbine and the driven equipment being operatively connected in series;
a gas turbine combustor arranged between the air compressor and the gas turbine;
a fuel system for supplying a fuel to the gas turbine combustor; and
a heat exchange section for heating the fuel from the fuel system by means of a high pressure air as a heating source from the air compressor.
In a preferred embodiment, the heat exchange section is housed in the air compressor or mounted to a casing of the air compressor, and in the case of mounting to the casing, a fuel passage is formed by an outer cover covering an outer periphery of the casing, one side of the fuel passage being provided with a fuel inlet and a fuel outlet and another side of the fuel passage is provided with a connecting pipe.
In another aspect, there is provided a gas turbine plant comprising:
an air compressor;
a gas turbine;
a driven equipment, the air compressor, the gas turbine and the driven equipment being operatively connected in series;
a gas turbine combustor arranged between the air compressor and the gas turbine;
a fuel system for supplying a fuel to the gas turbine combustor;
an extraction closed circuit system provided for the air compressor; and
a heat exchange section provided for the extraction closed circuit system for heating the fuel supplied to the gas turbine combustor from the fuel system.
In a further aspect, there is provided a gas turbine plant comprising:
an air compressor;
a gas turbine including an exhaust gas system;
a driven equipment, the air compressor, the gas turbine and the driven equipment being operatively connected in series;
a gas turbine combustor arranged between the air compressor and the gas turbine;
a fuel system for supplying a fuel to the gas turbine combustor; and
a heat exchange section provided for the exhaust gas system of the gas turbine for heating the fuel supplied to the gas turbine combustor from the fuel system.
In a still further aspect, there is provided a gas turbine plant comprising:
an air compressor;
a gas turbine including a high temperature section;
a driven equipment, the air compressor, the gas turbine and the driven equipment being operatively connected in series;
a gas turbine combustor arranged between the air compressor and the gas turbine;
a fuel system for supplying a fuel to the gas turbine combustor;
a high pressure air supply system operatively connected to the high temperature section of the gas turbine for supplying a high pressure air from the air compressor thereto;
a heat exchange section provided for the high pressure air supply system for heating the fuel supplied to the gas turbine combustor from the fuel system, the high pressure air after the heating being supplied to the high temperature section of the gas turbine as a cooling medium; and
a high pressure air recovery system for recovering the an overall quantity or part of the high pressure air to the air compressor after cooling the high temperature sec
Ito Shokou
Kobayashi Tadashi
Koga Akinori
Okamura Takanari
Sasaki Takashi
Casaregola Louis J.
Kabushiki Kaisha Toshiba
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