JPH03258902A - Electric power plant - Google Patents

Abstract

PURPOSE:To improve combined cycle efficiency by raising temperature of exhaust gas through constituting a closed cycle system of steam which includes an exhaust gas boiler arranged in a downstream side of a gas turbine. CONSTITUTION:Steam is generated at an exhaust gas boiler 11 by means of heat of exhaust gas exhausted from a gas turbine 7 in an inert gas circulation type system. This steam is supplied to a steam turbine 12 as the working fluid, and executes mechanical work. Consequently, a generator 13 is driven, and electric power generation is carried out. The steam, which has done mechanical work in the steam turbine 12, is supplied to a condenser 14, and then cooled and condensed. Then, the condensed water is supplied to the exhaust gas boiler 11 by means of a feed water pump 15. Thus, if temperature at the entrance of the gas turbine 7 reaches above 900 deg.C, temperature of the exhaust gas becomes high enough to carry out exhaust heat recovery. Consequently, it is possible to improve the combined cycle efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a power generation plant, and more particularly to a pollution-free and highly efficient power generation plant using an inert gas circulation system.

In conventional technology power plants, various fuels such as fossil fuels are used to obtain the high temperature working fluid that drives the gas turbine, and this fuel is either supplied with air and combusted, or is mainly nitrogen-based. Gases with complex compositions were generated, which caused the following problems.

(1) NOX, Co. , CO and other pollutants are unavoidable.

(2) If the temperature of the gas turbine is raised to improve efficiency, high-temperature corrosion may occur.

(3) It cannot be said to be the best working fluid for a gas turbine to achieve high efficiency.

Among these problems, in order to solve the pollution problem, an inert gas circulation system has been developed in recent years.

Figure 9 shows an example of this inert gas circulation system,
1 is a combustor, and this combustor 1 contains oxygen (02) and hydrogen (
H3) is supplied from the oxygen storage tank 2 and hydrogen storage tank 3 through pressure regulating valves 4 and 5 and burned, and the resulting water vapor is mixed with inert gas (helium, neon, argon, , xenon, etc.) is mixed in an appropriate amount.

The water vapor and inert gas are then sent to a gas turbine 7 to generate work (power generation), and then sent to a condenser 8 equipped with a gas-liquid separator to be cooled, resulting in a mixture of water and inert gas. is separated into gas and liquid, and the condensed water (H2O
) is taken out.

On the other hand, the remaining inert gas is sent to the aforementioned compressor 6 and compressed, and then circulated to the aforementioned combustor 1. Note that 9 is a generator.

Problems to be Solved by the Invention According to the above-mentioned inert gas circulation system, inert gas is mixed into the combustion of oxygen and hydrogen, and the work of the gas turbine is performed by non-polluting gas (inert gas and water vapor). The problem of pollution is improved by taking out the fuel, but there are the following problems when converting to a combined cycle.

That is, inert gas has a large specific heat ratio and can increase the efficiency of a single gas turbine cycle, but this also lowers the gas turbine exhaust gas temperature, which is a disadvantage when converting to a combined cycle.

Means for Solving the Problems In order to solve the problems of the prior art, the present invention provides a combustor that burns hydrogen and oxygen in an inert gas, a combustor that burns water vapor and an inert gas from the combustor, and a combustor that burns hydrogen and oxygen in an inert gas. An inert gas circulation type consisting of a gas turbine driven by a gas turbine, a condenser that condenses exhaust gas from this gas turbine, and a compressor that compresses inert gas separated from water by this condenser and circulates it to the combustor. An exhaust gas boiler is installed downstream of the gas turbine in the system, and a closed cycle system of steam generated by the exhaust gas boiler is configured to generate electricity.

Further, in the present invention, preferably, methanol decomposition means is installed on the downstream side of the gas turbine, and an outlet of the methanol decomposition means is connected to the inlet side of the combustor.

Furthermore, instead of such a methanol decomposition means, the present invention preferably includes installing a methanol reforming means on the downstream side of the gas turbine, and directing the outlet of the methanol reforming means to the population side of the combustor. Connect to.

Effect According to the above means, if the inlet temperature of the gas turbine in an inert gas circulation system is increased to 900°C or higher, the exhaust gas temperature becomes sufficient for heat recovery, and if the temperature is raised even further, the combined cycle efficiency will be significantly increased. improve.

Also, if this exhaust gas temperature is used for methanol decomposition,
Hydrogen and carbon oxide can be obtained from methanol as fuel, and at the same time, it is possible to further improve the combined cycle efficiency.

Furthermore, if this exhaust gas temperature is used for methanol reforming instead of methanol decomposition, hydrogen can be obtained from methanol as a fuel without lowering the combined cycle efficiency.

Example Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, and the same parts as shown in FIG. 9 are given the same reference numerals, so detailed explanation thereof will be omitted.

According to this embodiment, the downstream side of the gas turbine 7 in the inert gas circulation system including the oxygen/hydrogen combustor 1, the gas turbine 7, the condenser 8, the compressor 6, etc. described in detail with reference to FIG. An exhaust gas boiler 11 is installed on the side, and a closed cycle system of steam generated by the exhaust gas boiler 11 is configured to generate electricity.

That is, in the inert gas circulation system, the heat of the exhaust gas from the gas turbine 7 generates steam (or a fluid whose state changes at room temperature or higher, such as Freon) in the exhaust gas boiler If, and this steam is used as a working fluid in the steam turbine. 12 and performs work, thereby driving the generator 13 and generating electricity. and steam turbine 1
The steam that has done work in step 2 is supplied to a condenser 14 where it is cooled and condensed, and the condensed water is supplied to the above-mentioned exhaust gas boiler 11 by a feed pump 15.

In the power generation plant shown in Figure 1 above, the inlet temperature of the gas turbine 7 in the inert gas circulation system is set to 9.
When the temperature is set to 00° C. or higher, the turbine exhaust gas temperature becomes sufficient to recover exhaust heat and exceeds the conventional gas turbine combined cycle efficiency, and this tendency becomes stronger as the gas turbine population temperature increases.

Figure 2 shows a gas turbine population pressure of 15 kg/cm2a,
An example of calculation using argon gas as the inert gas is shown. This indicates that when the gas turbine inlet temperature is 1500°C, the efficiency is improved by 10% compared to the conventional gas turbine combined cycle efficiency and by 15% compared to the inert gas circulation type gas turbine single cycle efficiency shown in Figure 9. There is.

Furthermore, as a modification, although not shown, a reheating device may be installed downstream of the gas turbine 7 shown in FIG. 1 to further improve the gas turbine efficiency.

That is, in the embodiment shown in FIG. 1, the inert gas discharged from the compressor 6 is directly introduced into the combustor 1, but the inlet temperature of the gas turbine 7 is set to a temperature higher than 900°C, for example, 1400°C or higher. In this case, it is necessary to raise the temperature of the inert gas before it enters the combustor 1 above that in the case of the embodiment shown in FIG. For this reason, a reheating device is installed downstream of the gas turbine 7, and the inert gas leaving the compressor 6 is once sent to this reheating device, and the heat of the exhaust gas from the gas turbine 7 is used to regenerate the gas. By heating and then introducing it into the combustor 1, gas turbine efficiency can be further improved.

Next, FIG. 3 shows a second embodiment of the present invention, and the same parts as those shown in FIG. 1 are given the same reference numerals, so detailed explanation thereof will be omitted.

According to this embodiment, the hydrogen storage tank 3 and its associated pressure regulating valve 5 in the first embodiment shown in FIG. A methanol decomposition means is installed in the methanol decomposition means, and the outlet of this methanol decomposition means is connected to the inlet side of the combustor l.

That is, the methanol in the methanol storage tank 21 (
CH! OH) is pumped by a pressure pump 22, heated by the heat of exhaust gas from the gas turbine 7, and then supplied to a methanol decomposition device 23, where methanol decomposition is performed. This decomposition reaction is CH,OH+heat-2H,+C
It is expressed as O.

Then, hydrogen (H
2) and - carbon oxide (CO) are supplied to the combustor 1,
It is combined with oxygen (0□) and burned in an inert gas.

Further, according to this embodiment, C
An L separator M24 is installed, and CO2 is separated from the inert gas sent from the condenser 8 to the tank 25.
It is designed to be stored in

The power plant shown in FIG. 3 is equipped with a steam closed cycle system including an exhaust gas boiler 11 installed downstream of the gas turbine 7 in an inert gas circulation system, similar to the power plant shown in FIG. Therefore, if the inlet temperature of the gas turbine is increased to 900℃ or higher,
The turbine exhaust gas temperature becomes sufficient for exhaust heat recovery to exceed the conventional gas turbine combined cycle efficiency, and this tendency becomes stronger as the gas turbine population temperature increases.

Since the exhaust gas temperature of the gas turbine 7 is also used for methanol decomposition, the combined cycle efficiency can be further improved by several percent, and hydrogen and carbon oxide can be obtained from methanol as fuel. .

Furthermore, by separating and storing CO2, it is possible to contribute to measures to prevent CO2 generation from environmental problems caused by CO2 generation from power generation equipment using fossil fuels.

In the embodiment shown in FIG. 3, the methanol pumped by the pressure pump 22 is heated by the heat of the exhaust gas from the gas turbine 7 on the upstream side of the exhaust gas boiler 11. For example, as shown in FIG. 4, methanol is heated by the heat of the exhaust gas after passing through the exhaust gas boiler 11, or as shown in FIG. It is also possible to heat the methanol at the same time as the water in the tank.

Next, FIG. 6 shows a third embodiment of the present invention, in which the same parts as shown in FIG. 1 are denoted by the same reference numerals, so detailed explanation thereof will be omitted.

According to this embodiment, the hydrogen storage tank 3 and its associated pressure regulating valve 5 in the first embodiment shown in FIG. A methanol reforming means is installed in the combustor 1, and the outlet of this methanol reforming means is connected to the inlet side of the combustor 1.

That is, it is mixed with methanol (CHsOH) supplied from the methanol storage tank 31 or a part of the water (H2O) discharged from the condenser 8, and then pumped by the pressurizing pump 32 to form exhaust gas from the gas turbine 7. After that, it is supplied to the methanol reforming device 33, where methanol reforming is performed.

This reforming reaction is CH30)H-H20+ heat → 3H2+
It is expressed as CO2.

The CO3 generated by this methanol reforming is separated from hydrogen (H2) in the CO7 separator 34 and stored in the tank 35, while the hydrogen (H2) is supplied to the combustor 1 and converted into oxygen (02). Mixed and combusted under inert gas.

The power generation plant shown in FIG. 6 is equipped with a steam closed cycle system including an exhaust gas boiler 11 installed downstream of the gas turbine 7 in an inert gas circulation system, similar to the power plant shown in FIG. Therefore, if the gas turbine inlet temperature is set to 900°C or higher, the turbine exhaust gas temperature will be sufficient to recover waste heat.
It exceeds the conventional gas turbine combined cycle efficiency, and this tendency becomes stronger as the gas turbine population temperature increases.

Since the exhaust gas temperature of the gas turbine 7 is also used for methanol reforming, hydrogen fuel can be obtained from methanol without lowering the combined cycle efficiency.

Furthermore, by separating and storing CO2, it is possible to contribute to measures to prevent CO2 generation, in response to environmental problems caused by CO2 generation from power generation equipment using fossil fuels.

Note that in the embodiment shown in FIG.
It is designed to be heated by the heat of the exhaust gas from the gas turbine 7 on the upstream side of the gas turbine, but as a modified example, methanol and water are heated by the heat of the exhaust gas after passing through the exhaust gas boiler 11, as shown in FIG. Alternatively, the mixture of methanol and water can be heated simultaneously with the water in the exhaust gas boiler 11 by the heat of the exhaust gas from the gas turbine 7, as shown in FIG. .

Effects of the Invention As described above, according to the present invention, inert gas is mixed into the combustion of oxygen and hydrogen, and the work of the gas turbine is extracted by non-polluting gas (inert gas and water vapor), thereby eliminating pollution. This is a power generation plant configured with a steam closed cycle system including an exhaust gas boiler installed downstream of the gas turbine in an inert gas circulation system that improves the problem, and the population temperature of the gas turbine is raised to 900 ° C. By doing the above, the exhaust gas temperature becomes sufficient for heat recovery, and by further increasing the temperature, the combined cycle efficiency can be significantly improved.

Further, preferably, a methanol decomposition means is installed on the downstream side of the gas turbine and the exhaust gas temperature is utilized for methanol decomposition, thereby further improving the combined cycle efficiency and converting methanol into hydrogen and carbon oxide. can be obtained as a fuel, thus making it possible to use methanol fuel, which is effective as an energy alternative to petroleum.

Furthermore, by installing methanol reforming means instead of methanol decomposition means on the downstream side of the gas turbine and using the exhaust gas temperature for methanol reforming, it is possible to obtain hydrogen fuel from methanol without lowering the combined cycle efficiency. Therefore, it becomes possible to use methanol fuel, which is effective as an energy alternative to petroleum.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing a power generation plant according to the first embodiment of the present invention, Fig. 2 is a diagram for explaining the effect of improving cycle efficiency, and Fig. 3 is a diagram showing the power generation plant according to the second embodiment of the present invention. The system diagrams showing the power plant, Figures 4 and 5, are based on this second diagram.
A system diagram showing two different modifications of the embodiment, FIG. 6 is a system diagram showing a power generation plant according to a third embodiment of the present invention, and FIGS. 7 and 8 show two different modifications of the third embodiment. System diagram showing an example, FIG. 9 is a system diagram showing a conventional example. 1. Combustor, 2. Oxygen storage tank, 3. Hydrogen storage tank, 4, 5. Pressure regulating valve, 6. Compressor, 7.
・Gas turbine, 8... Compressor, 9... Generator,
11. Exhaust gas boiler, 12. Steam turbine, 13.
- Generator, 14... Capacitor, 15... Water pump,
21.31...methanol storage tank, 22.33...
Pressure pump, 23...methanol decomposition device, 33...methanol reformer, 2434...CO, separation device, 25
．． 35...CO, storage tank.

Claims (1)

[Claims] 1. A combustor that burns hydrogen and oxygen in an inert gas;
A gas turbine driven by steam and inert gas from this combustor, a condenser that condenses exhaust gas from this gas turbine, and a condenser that compresses the inert gas separated from water and supplies it to the combustor. An exhaust gas boiler is installed downstream of the gas turbine in an inert gas circulation system consisting of a circulating compressor, and a closed cycle system is configured for the steam generated by the exhaust gas boiler to generate electricity. Features of power generation plants. 2. The power generation system according to claim 1, wherein methanol decomposition means is installed downstream of the gas turbine, and an outlet of the methanol decomposition means is connected to an inlet side of the combustor. 3. The power generation system according to claim 1, wherein methanol reforming means is installed downstream of the gas turbine, and an outlet of the methanol reforming means is connected to an inlet side of the combustor.