JP3882068B2 - Turbine system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for generating power with high efficiency by utilizing thermal energy that has been wastedly released to the atmosphere until now by a turbine system using water vapor as a working medium.
[0002]
[Prior art]
In the conventional combined cycle of a gas turbine and a steam turbine, high-temperature and high-pressure steam is generated using a waste heat boiler and the steam turbine is driven to improve efficiency, but indirect heating is used to drive the steam turbine. For this reason, the temperature of water vapor is limited, and heat is not sufficiently utilized. Also, in order to mainly drive the gas turbine that extracts power, air is compressed by a compressor (compressor) using a large amount of power, and the output that is taken out is the output of the gas turbine minus the power of the compressor. As a result, there is a limit to the improvement in efficiency.
[0003]
As a similar system, there is a hydrogen combustion turbine system using steam as a working medium, but it is not a system for regenerating waste heat. Furthermore, the super garbage power generation system is similar, but by providing a steam compressor after the heat recovery boiler, low-temperature heat can be used, and steam direct heating using oxyfuel combustion, It is different in that playback is performed.
[0004]
[Problems to be solved by the invention]
Currently, the suppression of carbon dioxide cable emission is a major issue, and the need for advanced use of energy is increasing. On the other hand, in the current energy use, most of them are finally discarded as heat and are not used effectively. Also, in conventional gas turbines, air is compressed by a compressor using high-quality energy that can be effectively used as motive power, and the resulting output is the output of the gas turbine minus the compressor power. As a result, there is a limit to improving efficiency.
[0005]
In conventional hydrogen combustion turbines, a large amount of high-quality energy is consumed by the compressor in the gas turbine part due to the heat balance, and as a result, there is a limit to increasing the efficiency. Super garbage power generation has a similar system, but there is no compressor between the waste heat recovery boiler and the gas turbine. Efficiency is limited because heat is used for indirect heating.
[0006]
In order to solve the above-mentioned problems, the present invention uses a low-quality heat energy such as waste heat to generate pressurized water vapor and use it as a working medium, thereby dramatically increasing the power in the compressor. A waste heat utilization turbine system capable of reducing the temperature of recoverable heat and recovering a lot of heat by controlling the pressure of the part where heat is recovered by evaporation of water at the same time as reducing efficiency and improving the efficiency. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention relates to a combined cycle of a gas turbine using steam as a working medium and a steam turbine, a tank storing water, a pump for pumping water from the tank, and a predetermined pressure from the pump. A first heat exchanger that generates pressurized water vapor partially containing a liquid phase by heat exchange with water of low quality external heat energy is supplied from the first heat exchanger A second heat exchanger for generating water vapor in a completely vaporized state by heat exchange again, and a pressure increase / temperature increase by placing pressure on the water vapor in the completely vaporized state disposed after the second heat exchanger A steam compressor, and a reheater that is disposed at a subsequent stage of the steam compressor and that heats the steam supplied from the steam compressor by exchanging heat with high-temperature steam supplied from the gas turbine, and Gas turbine Combustor, a gas turbine driven by the steam supplied from the combustor that is positioned in the inlet section further heating by direct heating by burning the temperature is increased said steam supplied from the reheater If, liquefied steam turbine driven by the steam delivered from the gas turbine through the reheater and a second heat exchanger, the cooling water is supplied from the steam turbine is supplied steam, obtained And a condenser for returning the water to the tank .
[0008]
According to the present invention, by utilizing external low-quality thermal energy, the problem of heat balance in the hydrogen combustion turbine can be solved, and dramatic advanced energy utilization is possible, and waste heat recovery such as super garbage power generation is possible. It is possible to improve the efficiency of the intake system and to use heat of lower quality than that of the incinerator with high efficiency. Further, the recovered thermal energy can be regenerated by oxyfuel combustion, used in a gas turbine, and can be used up to a steam turbine with the same working medium, realizing high efficiency .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a system diagram of a heat regeneration type turbine system according to the present invention when used for hydrogen fuel. In FIG. 1, water having a water temperature of 25.0 ° C. is stored in the tank 1. The water in the tank 1 is pumped up by the pump 2, and water P 1 having a temperature of 25.0 ° C. and a pressure of 1.00 MPa is supplied to the heat exchanger 3. The heat exchanger 3 is supplied with low-quality heat energy such as waste heat from the factory recovered by a medium such as oil, and includes a part of the liquid phase but 70% is converted to water vapor by heat exchange ( Water vapor P2 having a moderately pressurized pressure of 0.7, a temperature of 189.3 ° C., and a pressure of 1.00 MPa is generated, and the water vapor P2 is supplied to the heat exchanger 4.
[0010]
As will be described later, high-temperature steam P8 from the gas turbine 8 is supplied to the heat exchanger 4 via the reheater 6, and all the water is vaporized and becomes 100% steam by the heat exchange again. Fully vaporized water vapor (dryness 1.0, temperature 189.3 ° C., pressure 1.00 MPa) P 3 is supplied to the vapor compressor 5. The vapor compressor 5 applies pressure to the supplied completely vaporized water vapor P3 to increase the pressure and raise the temperature, and further to make high pressure and high temperature water vapor (temperature 431.8 ° C., pressure 5.00 MPa) P4. These heat exchanger 3 and heat exchanger 4 constitute a waste heat recovery boiler.
[0011]
The steam P4 passes through the reheater 6 to which the steam (temperature 657.8 ° C., pressure 0.20 MPa) P7 higher than the steam P4 is supplied from the gas turbine 8, and heat is exchanged in the reheater 6. As a result, the temperature is further increased, the temperature is further increased, and further high-temperature steam (temperature 600.0 ° C., pressure 5.00 MPa) P5 is supplied to the combustor 7. Gases of hydrogen and oxygen are supplied to the combustor 7, and the temperature is further increased in the combustor 7 by direct heating by the combustion of both gases, and even higher temperature water vapor (temperature 1323 ° C., pressure 5.00 MPa). ) P6 and supplied to the gas turbine 8.
[0012]
In the gas turbine 8, a high-temperature, high-pressure steam P6 having a turbine inlet temperature of 1323 ° C. and a turbine inlet pressure of 5 MPa is supplied, and the gas turbine 8 is driven. By driving the gas turbine 8, attached devices such as a generator attached to the gas turbine 8 are also driven. The steam P6 is supplied with steam (temperature: 657.8 ° C., pressure: 0.20 MPa) P7 whose temperature and pressure are reduced by the consumption of heat and pressure energy components by the driving of the gas turbine 8.
[0013]
Since the steam P4 having a slightly lower temperature is supplied from the steam compressor 5 to the reheater 6 as described above, the steam P7 supplied from the gas turbine 8 passes through the reheater 6 and further has a temperature. The steam P8 is lowered (temperature 511.4 ° C., pressure 0.20 MPa), and the steam P8 is supplied to the heat exchanger 4. As described above, the heat exchanger 4 is supplied with the steam P2 including a partial liquid phase having a lower temperature from the heat exchanger 3, so that the steam P8 supplied from the reheater 6 is Then, the steam is further reduced in temperature (temperature 253.9 ° C., pressure 0.20 MPa) P9 and supplied to the steam turbine 9.
[0014]
When the steam P9 is supplied, the steam turbine 9 is driven, and an accessory device such as a generator attached to the steam turbine 9 is also driven by the driving of the steam turbine 9. When the steam turbine 9 is driven, the steam P9 again becomes steam P10 (temperature 46.3 ° C., pressure 0.01 MPa, dryness 0.964) P10 whose temperature and pressure are further reduced due to consumption of heat and pressure energy components, It is supplied to the condenser 10. Cooling water is supplied to the condenser 10, and the water vapor P <b> 10 is liquefied by further reducing the temperature and pressure, and water P <b> 1 (temperature 25.0 ° C., pressure 0.01 MPa) is returned to the tank 1.
[0015]
Itoguchihate the system according to the embodiment of the present invention were analyzed by the system analysis software, temperature 600 ° C. in the combustor inlet, turbine inlet temperature 1323 ° C., turbine inlet pressure 5 MPa, temperature levels 200 ° C. of the waste heat recovering In the following, the thermal efficiency is about 41% when including the recovered heat, but considering that it is not useful from the temperature level, and considering the efficiency with only hydrogen without including these, it is higher than 75%. Efficiency. (Efficiency calculations do not include hydrogen, oxygen compression, cooling water, or waste heat circulation power.)
[0016]
Again, the recovered heat is a low-use energy, a level of energy that is exhausted without much use in steelmaking, cleaning, chemical factories, etc. , and can be easily supplied from geothermal and solar heat. The temperature range of the level.
[0017]
In this example, hydrogen is used as the fuel. However, a hydrocarbon-based fuel such as methane can also be used by providing a vacuum pump for carbon dioxide recovery after the condenser.
[0018]
【The invention's effect】
As is apparent from the above description, the present invention reduces the recovered heat temperature using a heat regeneration type turbine system using water vapor as a working medium and a compressor at the subsequent stage when water evaporation is used during heat recovery. A mechanism for recovering a lot of heat, and its steam is directly heated by oxyfuel combustion and used for a gas turbine and a steam turbine. Thus, the recovered heat energy regenerated by oxyfuel combustion, using a gas turbine, with the same working medium, can be utilized to steam turbines, it can realize high efficiency.
[0019]
With the heat recovery system according to the present invention, currently, it is possible to effectively utilize the thermal energy of low quality which is wasted, and also lead to effective utilization of the fuel, there is a flight thermocline energy conservation effect. And this turbine system can effectively use energy such as waste heat from a factory or an incinerator, geothermal heat, and sunlight.
[Brief description of the drawings]
FIG. 1 is a system diagram of a turbine system according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tank 2 Pump 3 Heat exchanger 4 Heat exchanger 5 Steam compressor 6 Reheater 7 Combustor 8 Gas turbine 9 Steam turbine 10 Condenser P1 Water P2-P10 Steam

Claims (1)

In combined cycle of gas turbine and steam turbine using steam as working medium,
A tank in which water is stored, a pump that draws water from the tank, and water supplied at a predetermined pressure from the pump is pressurized to partially include a liquid phase by heat exchange with external low-quality heat energy. A first heat exchanger for generating water vapor , a second heat exchanger for generating water vapor supplied from the first heat exchanger into water vapor in a completely vaporized state by heat exchange again, and the second heat exchanger A steam compressor that is arranged at the rear stage of the heat exchanger and pressurizes and raises the temperature by applying pressure to the steam in the completely vaporized state, and the steam that is arranged at the rear stage of the steam compressor and supplied from the steam compressor , A reheater that heats and exchanges heat with high-temperature steam supplied from a gas turbine; and the heated water vapor that is disposed at the inlet of the gas turbine and is supplied from the reheater directly by combustion the combustor further heating by Do heating A gas turbine driven by the steam supplied from the combustor, and a steam turbine driven by steam fed from the gas turbine through the reheater and a second heat exchanger, the cooling water supply And a condenser for liquefying the water vapor supplied from the steam turbine and returning the obtained water to the tank .

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