JPH06108877A - Gas turbine single power generation system - Google Patents

Abstract

PURPOSE:To reduce the amount of exhausted NOX, and to provide high output and high efficiency even when a gas turbine is provided in a single manner. CONSTITUTION:In a gas turbine single power generation system provided with a denitration device 7 for removing NOX out of a combustion exhaust gas exhausted from a singly provided gas turbine 4, an exhaust heat recovery boiler 6 for cooling the exhaust gas is provided between the gas turbine 4 and the denitration device 7. A steam injection system 8 for injecting all of the steam generated by the exhaust heat recovery boiler 6 into a gas turbine combustor 3, is provided. Denitration is carried out by means of high temperature catalyst by the denitration device 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine independent power generation system.

[0002]

2. Description of the Related Art When a gas turbine alone is used to generate electric power, problems such as the amount of nitrogen oxides (hereinafter referred to as NO _X ) and economic problems arise. However, there is a case where it is absolutely necessary to generate power for emergency use, and it is desirable to adopt a gas turbine independent power generation system that is relatively easy to operate as a countermeasure in such cases.

[0003]

However, one of the problems when the gas turbine is installed alone is an environmental problem due to NO _X generated in the gas turbine as described above. Therefore, it is necessary to take measures to reduce the NO _X amount. Then, when a high-efficiency gas turbine is independently installed, there are the following points that need to be considered in order to reduce NO _X.

(1) Exhaust gas temperature is high: Even if a denitration device that removes NO _X from the combustion exhaust gas discharged from the gas turbine is installed, there is a limit to the applicable temperature of the catalyst of the denitration device (usually 300 ° C.). ˜400 ° C.), and therefore the conventionally commonly used catalysts cannot be used. For this reason, even if the improved high-temperature catalyst is used, it is necessary to reduce the temperature of the exhaust gas between the gas turbine and the denitration device by several tens to several hundreds of degrees Celsius in order to obtain a high denitration rate.

In the case of a combined plant, in order to solve the problem of the operating temperature of the catalyst, a denitration device is installed in the proper temperature range of the exhaust heat recovery boiler.

(2) High denitrification rate is required: Since the output of the gas turbine is large, the amount of exhaust gas is large. Therefore,
It is necessary to keep the amount of NO _X emitted low in order to protect the local environment.

The present invention has been made to solve the problem in the case of installing such a gas turbine alone. Even if the gas turbine is installed alone, the NO _X emission amount can be extremely reduced, Moreover, it is an object of the present invention to provide a power generation system that can obtain high output and high efficiency.

[0008]

In order to solve the above problems, the present invention provides a gas turbine single power generation system including a denitration device for removing NO _x from combustion exhaust gas discharged from a gas turbine, wherein An exhaust heat recovery boiler for exhaust gas cooling is installed between the gas turbine and the denitration device, and a steam injection system for injecting all of the steam generated in the exhaust heat recovery boiler into the gas turbine combustor is provided. Is.

[0009]

According to the above means, the exhaust heat recovery boiler generates steam by the heat of recovery of its own exhaust gas and injects the steam into the gas turbine combustor, whereby the flame temperature is lowered,
The amount of NO _X produced can be suppressed. Moreover, since the exhaust gas flow rate increases by the amount of steam injection, the output of the gas turbine increases. Furthermore, the heat of the exhaust gas can be effectively used, resulting in high efficiency.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a system diagram showing an embodiment of a gas turbine single power generation system according to the present invention.

In FIG. 1, reference numeral 1 is a gas turbine power generator installed independently, and is composed of an air compressor 2, a gas turbine combustor 3, a gas turbine 4 and a generator 5. That is, the fuel and the air compressed by the compressor 2 are supplied to the gas turbine combustor 3 and burned, and the combustion gas is introduced into the gas turbine 4, whereby the generator 5 is driven. ing.

Further, an exhaust heat recovery boiler 6 for cooling the exhaust gas from the gas turbine 4 to a proper temperature at the inlet of the denitration device,
It is installed between the gas turbine 4 and the denitration device 7 using a high temperature catalyst. A steam injection system 8 for injecting all of the steam generated in the exhaust heat recovery boiler 6 into the gas turbine combustor 3 is provided. In addition, 9 is a chimney.

As described above, the exhaust heat recovery boiler 6 is provided between the independently installed gas turbine 4 and the denitration device 7, and in this portion, the feed water is heated by the heat of recovery of the self-exhaust gas to generate steam, and the steam is generated. By injecting into the gas turbine combustor 3, the flame temperature drops and the NO _X production amount can be suppressed. Further, since the exhaust gas flow rate increases by the amount of steam injection, the output of the gas turbine 4 increases. Furthermore, the heat of the exhaust gas can be effectively used, resulting in high efficiency.

Since the amount of heat recovered from the exhaust gas is small by performing denitration by the high temperature catalyst in the denitration device 7, the amount of water used in the exhaust heat recovery boiler 6 is almost the same as the amount of steam injected to the gas turbine combustor 3. Good and very little NO
It can be an _X amount.

Next, Table 1 below shows a case in which steam generated in the exhaust heat recovery boiler 6 is injected into the gas turbine combustor 3 according to the present invention as shown in FIG. 1, and a comparison of the present invention. In the case where neither steam nor water is injected into the gas turbine combustor 3 as shown in FIG. 2, and in the case where water is injected into the gas turbine combustor 3 as shown in FIG. efficiency, NO _X concentration, denitration unit inlet amount of NO _X, denitrator outlet amount of NO _X represents by comparing the fuel consumption and water consumption. 2 and 3, the same parts as those shown in FIG. 1 are designated by the same reference numerals, and the duplicated description will be omitted.

However, in all cases, the atmospheric temperature was 35 ° C., the fuel was LNG, and the feed water temperature to the exhaust heat recovery boiler 6 was 30 ° C. Further, the exhaust gas from the gas turbine 4 is cooled to 500 ° C. by the exhaust heat recovery boiler 6,
It was made to generate vapor of kg / cm ² and 350 ° C. Further, the denitration rate in the denitration device 7 was set to 90%.

[0017]

[Table 1]

It can be qualitatively understood from the results shown in Table 1 that steam injection has the best output and efficiency, and that the amount of NO _X produced decreases by injecting water and steam. Since the fuel consumption amount is reduced, the NO _X production amount is reduced as compared with the water injection. Therefore, these results show that the case of steam injection is the best system.

[0019]

As described above, according to the present invention, the problems in the case where the gas turbine is installed alone, that is, the problems that the exhaust gas temperature is high and the high denitration rate is required, are solved,
Even if the gas turbine is installed alone, it is possible to provide a power generation system that can significantly reduce the NO _X emission amount and can obtain high output and high efficiency.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a gas turbine single power generation system according to the present invention.

FIG. 2 is a system diagram showing an example of a gas turbine independent power generation system compared with the present invention.

FIG. 3 is a system diagram showing another example of a gas turbine independent power generation system compared with the present invention.

[Explanation of symbols]

 1 gas turbine power generator 2 air compressor 3 gas turbine combustor 4 gas turbine 5 generator 6 exhaust heat recovery boiler 7 denitration device 8 steam injection system 9 chimney

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kenichi Irie 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Sanryo Heavy Industries Co., Ltd.

Claims (1)

[Claims] 1. A gas turbine single power generation system comprising a denitration device for removing nitrogen oxides from combustion exhaust gas discharged from a gas turbine, wherein exhaust heat for exhaust gas cooling is provided between the gas turbine and the denitration device. A gas turbine independent power generation system comprising a recovery boiler and a steam injection system for injecting all of the steam generated in the exhaust heat recovery boiler into the gas turbine combustor.