JP6109577B2 - Hydrogen gas turbine combined cycle power plant - Google Patents

Description

  The present invention relates to a gas turbine combined cycle power plant. More specifically, the present invention relates to a hydrogen-fired gas turbine combined cycle power plant suitable for power generation using hydrogen as a fuel.

  In the following description, the gas turbine combined cycle may be abbreviated as “GTCC”.

  The GTCC power plant is a power plant that uses both gas turbine equipment and steam turbine equipment. Specifically, the combustion gas generated in the combustor of the gas turbine equipment is used for driving the gas turbine, while the exhaust gas discharged from the gas turbine equipment in the exhaust heat recovery boiler of the steam turbine equipment (the driving of the gas turbine) Steam is generated by heat exchange with the combustion gas after being used for the steam, and this steam is used to drive the steam turbine. That is, in the GTCC power plant, the heat efficiency is improved by using the heat of the combustion gas generated in the combustor of the gas turbine equipment in both the gas turbine equipment and the steam turbine equipment.

  By the way, in the GTCC power plant, generally, a combustion gas necessary for driving a gas turbine is generated by burning fossil fuel such as natural gas or petroleum with combustion air. Therefore, the combustion gas always contains carbon dioxide. Further, oxygen contained in combustion air, which is a combustion-supporting gas, is consumed by combustion, so that the oxygen concentration in the combustion gas is also lower than that of air.

  Here, carbon dioxide can have a harmful effect on the human body at a concentration of about 7% (for example, headache, dizziness, nausea, etc.). It goes without saying that an oxygen-deficient atmosphere having a low oxygen concentration can have a harmful effect on the human body. Therefore, in the conventional GTCC power plant, the draft power (exhaust power) from the chimney of the exhaust gas is maintained by maintaining the temperature of the exhaust gas (exhaust gas after heat exchange in the exhaust heat recovery boiler) at a high temperature of about 100 ° C. To prevent the high concentration exhaust gas from falling around the plant.

  For example, in Patent Document 1, exhaust gas temperature detection means for detecting the exhaust gas temperature at the outlet of the exhaust heat recovery boiler, and steam from the exhaust heat recovery boiler to the steam turbine when the temperature detected by the exhaust gas temperature detection means is lower than a set temperature. A control device that outputs an operation signal so as to reduce the opening degree with respect to the steam control valve or the steam stop valve provided in the steam pipe for supplying the steam, and the set temperature is discharged from the exhaust heat recovery boiler It has been proposed to set in order to ensure the draft force in the flue stack. As a specific example, it is proposed that the set temperature is 95 ° C. or higher when the atmospheric temperature is 25 ° C. or higher, and the set temperature is 98 ° C. or higher when the atmospheric temperature is 0 ° C.

Patent No. 4892539

  However, setting the temperature of the exhaust gas to a high temperature as described above limits the amount of heat recovery in the power plant, and has been one of the factors that hinder the improvement of the thermal efficiency of the GTCC power plant.

  Therefore, the present invention eliminates the need to ensure the draft power from the chimney of the exhaust gas by setting the temperature of the exhaust gas to a high temperature, and furthermore, a GTCC power plant that can improve the thermal efficiency by using the heat of that amount. The purpose is to provide.

  As a result of intensive studies by the inventors of the present invention in order to achieve such an object, when a hydrogen-fired GTCC power plant is made using hydrogen (hydrogen gas) as the fuel of the GTCC power plant, carbon dioxide is substantially contained in the exhaust gas. As the oxygen concentration is lower than that of air, the exhaust gas itself has a diffusive power to the sky, and the high concentration exhaust gas does not fall around the plant without setting the exhaust gas temperature to a high temperature. I came to know. And from this knowledge, this inventor can utilize the latent-heat component which was not able to be utilized in conventional GTCC by recovering the heat utilized in order to set the temperature of exhaust gas to high temperature actively. As a result, various studies have been made to arrive at the present invention.

That is, the hydrogen soot gas turbine combined cycle power plant according to claim 1 includes a combustor that generates combustion gas by combusting hydrogen with combustion air, and the gas turbine is driven by the combustion gas to generate power. At least a gas turbine power generation facility and a steam turbine power generation facility that includes a heat recovery steam generator that generates steam by heat exchange with exhaust gas discharged from the gas turbine power generation facility and that generates power by driving the steam turbine with steam provided, the temperature of the exhaust gas is set to be equal to or less than the dew point temperature of the exhaust gas at the outlet of the exhaust heat recovery boiler, the exhaust gas after being heat-exchanged in the exhaust heat recovery boiler is shall be discharged from the chimney.

The hydrogen soot gas turbine combined cycle power plant according to claim 2 includes a combustor that generates combustion gas by burning hydrogen with combustion air, and the gas turbine is driven by the combustion gas to generate power. A steam turbine power generation facility including a gas turbine power generation facility and a heat recovery steam generator that generates steam by heat exchange between the gas turbine power generation facility and exhaust gas discharged from the gas turbine power generation facility; Equipped with an evaporator that generates low-boiling-point medium vapor by boiling low-boiling-point medium having a lower boiling point than water by heat exchange with exhaust gas after heat exchange in the heat recovery boiler. At least a bottoming power generation facility that generates power by driving a turbine, and the temperature of the exhaust gas at the outlet of the evaporator is the dew point of the exhaust gas. Degree is set to become less, the exhaust gas after being heat exchanged in the evaporator is shall be discharged from the chimney.

  According to the first aspect of the present invention, since the exhaust gas can be diffused from the chimney to the sky without setting the temperature of the exhaust gas to a high temperature as in the conventional GTCC power plant, it is used in the conventional GTCC power plant. Even the latent heat of the exhaust gas that could not be recovered can be recovered, and the thermal efficiency of the plant can be improved as compared with the prior art.

  According to the second aspect of the present invention, the exhaust gas can be diffused from the chimney to the sky without setting the temperature of the exhaust gas to a high temperature as in the conventional GTCC power plant. Even the latent heat of the exhaust gas that could not be recovered can be recovered, and the thermal efficiency of the plant can be improved as compared with the prior art. Moreover, according to the present invention, it is possible to more efficiently recover heat from the exhaust gas by providing the bottoming power generation facility.

1 is a schematic diagram of a hydrogen-fired GTCC cycle power plant according to a first embodiment of the present invention. It is the schematic of the hydrogen-fired GTCC cycle power plant concerning a second embodiment of the present invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

<First embodiment>
A schematic diagram of a hydrogen-fired GTCC power plant according to a first embodiment of the present invention is shown in FIG. 1 is roughly provided with a gas turbine power generation facility 2 and a steam turbine facility 3. The hydrogen turbine GTCC power plant 1 shown in FIG.

  In the present embodiment, the gas turbine power generation facility 2 includes a combustor 21, a combustion air supply unit 22 that supplies combustion air to the combustor 21, and a hydrogen supply unit that supplies hydrogen (hydrogen gas) to the combustor 21. 23, a water / steam supply means 24 for supplying water (pure water) or steam to the combustor 21, a gas turbine 25 driven by combustion gas supplied from the combustor 21, and driving of the gas turbine 25. It is assumed that a generator A that generates power is provided.

  In the present invention, the combustion method in the combustor 21 is not particularly limited. However, in the present embodiment, in order to reduce NOx, the combustion method in the combustor 21 is a water / steam injection method. Will be described. Specifically, the combustor 21 is a standard combustor of the diffusion combustion system (fuel is directly injected into the combustion chamber and combusted), and hydrogen (hydrogen gas) and water (pure water) or steam are supplied with hydrogen. Hydrogen (hydrogen gas) and water (pure water) or water vapor are simultaneously injected into the combustion chamber of the combustor 21 by being supplied from the means 23 and the water / steam supply means 24 toward the combustor 21. The combustion air is supplied from the combustion air supply means 22 into the combustion chamber of the combustor 21 to perform combustion. The combustion air supply means 22 is, for example, an air compressor that takes in and compresses air and supplies the compressed air to the combustor 21.

  In the present invention, by using hydrogen as the fuel, it is possible to diffuse the exhaust gas from the chimney to the sky without setting the exhaust gas temperature at the outlet of the exhaust heat recovery boiler to be high as in the case of the conventional GTCC power plant. It is said. Therefore, in this invention, it is possible to collect | recover the latent heat component of the waste gas which was not able to be utilized with the conventional GTCC power plant, and it is easy to improve the thermal efficiency of a plant. Therefore, in the present embodiment, by adopting the water / steam injection method while avoiding the problem of a decrease in the thermal efficiency of the plant, which is a concern when the water / steam injection method is adopted as the combustion method in the combustor 21. It will be possible to benefit. That is, it becomes possible to suppress the generation of NOx by lowering the combustion temperature in the high temperature portion in the combustion chamber of the combustor 21. Further, since a standard combustor of a diffusion combustion system (a system in which fuel is directly injected into the combustion chamber and combusted) can be used as the fuel device 21, the structure of the combustor can be simplified. Furthermore, since it is not necessary to perform complicated supply control of fuel and air as compared with the premixed combustion method, the operation of the gas turbine power generation facility 2 can be facilitated. In addition, an increase in output due to an increase in the mass of the combustion gas passing through the gas turbine can be expected.

  The combustion gas generated in the combustor 21 is used to drive the gas turbine 25 and then supplied to the exhaust heat recovery boiler 31 of the steam turbine power generation facility 3.

  In the present embodiment, the steam turbine power generation facility 3 includes an exhaust heat recovery boiler 31 that generates steam by heat exchange with the exhaust gas from the gas turbine power generation facility 2, and a steam turbine 33 that is driven by the steam from the exhaust heat recovery boiler 31. And a condenser 32 that condenses the water vapor from the steam turbine 33 with cooling water such as seawater. The water produced by condensing the water vapor in the condenser 32 is supplied to the exhaust heat recovery boiler 31 and used for the production of water vapor by heat exchange with the exhaust gas from the gas turbine power generation facility 2. Further, the exhaust gas after heat exchange in the exhaust heat recovery boiler 31 is discharged from the chimney 4 to the atmosphere. A denitration device 34 is provided between the high temperature side and the low temperature side of the exhaust heat recovery boiler 31.

  In the present embodiment, heat exchange in the exhaust heat recovery boiler 31 is performed until the temperature of the exhaust gas after the heat exchange reaches the dew point temperature of the exhaust gas or less. By performing heat exchange in this way, it is possible to recover even the latent heat of the exhaust gas that could not be recovered by the conventional GTCC power plant, and it is easy to improve the thermal efficiency of the plant.

  Here, the heat exchange in the exhaust heat recovery boiler 31 may be performed until the temperature of the exhaust gas after the heat exchange reaches the dew point temperature of the exhaust gas or less as described above, but until the temperature of the exhaust gas reaches 57 ° C. or less. It is preferable to carry out, more preferably to 55 ° C. or lower, more preferably to 53 ° C. or lower, and still more preferably to 50 ° C. or lower. When heat exchange is performed until the temperature of the exhaust gas reaches 57 ° C. or less, according to a trial calculation by the inventors of the present application, even when a water / steam injection method that can reduce the thermal efficiency of the plant is adopted as the combustion method, It is possible to achieve the thermal efficiency of a plant similar to or exceeding that of a gas-fired power plant.

  From the viewpoint of improving the thermal efficiency of the plant, the heat exchange in the exhaust heat recovery boiler 31 is performed by the condenser 32 in which the temperature of the exhaust gas after the heat exchange is determined by the temperature of seawater or the like taken as cooling water. Most preferably, the temperature is determined by the temperature of the condensed water at the outlet and the pinch temperature, for example, 40 ° C to 20 ° C. That is, this temperature is the most suitable temperature as well as the lower limit value of the temperature of the exhaust gas after heat exchange. For example, when seawater having a water temperature of 30 ° C. is used as the cooling water in the condenser 32 and the pinch temperature is + 10 ° C., heat exchange is performed so that the temperature of the exhaust gas after heat exchange is about 40 ° C. Is preferred. For example, when the seawater temperature is low (eg, 10 ° C.) and the pinch temperature is + 10 ° C. in winter, it is most preferable to perform heat exchange so that the temperature of the exhaust gas after heat exchange is about 20 ° C. It is.

  The exhaust gas after heat exchange in the exhaust heat recovery boiler 31 is exhausted from the chimney 4. Here, the exhaust gas after heat exchange in the exhaust heat recovery boiler 31 does not substantially contain carbon dioxide and has an oxygen concentration lower than that of air. Therefore, unlike the conventional GTCC power plant, the diffusion power of the exhaust gas from the chimney 4 to the sky is ensured without setting the temperature of the exhaust gas to a high temperature of about 100 ° C. Therefore, even when the temperature of the exhaust gas is set to be equal to or lower than the dew point as described above, the diffusion force of the exhaust gas from the chimney 4 to the sky is ensured. Incidentally, even if the temperature of the exhaust gas after heat exchange is a temperature determined by the water temperature and the pinch temperature of the condensed water at the outlet of the condenser 32 determined by the temperature of seawater or the like taken as cooling water, The temperature is higher than the ambient temperature (air temperature), and the exhaust gas temperature is lower than the ambient temperature (air temperature), so that the diffusion power of the exhaust gas from the chimney 4 to the sky does not decrease.

  From the exhaust gas after heat exchange in the exhaust heat recovery boiler 31, water generated by condensation is discharged. When the water / steam injection method is adopted as the combustion method in the combustor 21, this water is It is also possible to reuse the water / steam injected into the combustor 21 after processing necessary for reuse such as neutralization, filtration and deoxygenation is performed in a water treatment device (not shown). In this case, it is possible to reduce the amount of water supplied as a raw material for water / steam injected into the combustor or to eliminate the need for water supply.

<Second Embodiment>
A schematic diagram of a hydrogen-fired GTCC power plant according to the second embodiment of the present invention is shown in FIG. 2 is provided with a bottoming cycle power generation facility 5 at the rear stage of the steam turbine power generation facility 3, and after the heat exchange is performed by the evaporator 51 of the bottoming cycle power generation facility 5. It differs from the hydrogen soot GTCC power plant according to the first embodiment in that the exhaust gas is discharged from the chimney 4.

  Since the gas turbine power generation facility 2 and the steam turbine power generation facility 3 are basically the same as the hydrogen-fired GTCC power generation plant according to the first embodiment, the description thereof is omitted. However, in the present embodiment, heat exchange with the exhaust gas discharged from the gas turbine power generation facility 2 is performed using the exhaust heat recovery boiler 31 of the steam turbine power generation facility 3 and the evaporator 51 of the bottoming power generation facility 5 together. In conjunction with this point, the bottoming power generation facility 5 will be described below.

  In the present embodiment, the bottoming power generation facility 5 includes an evaporator 51 that generates a low-boiling-point vapor by boiling a low-boiling-point medium having a boiling point lower than that of water by heat exchange with the exhaust gas from the exhaust heat recovery boiler 31, and evaporation. A low-boiling-point medium steam turbine 53 that is driven by the low-boiling-point medium steam from the vessel 51 and a condenser 52 that condenses the low-boiling-point medium steam from the low-boiling-point medium steam turbine 53 with cooling water such as seawater. The low-boiling-point medium produced by condensing the low-boiling-point medium vapor in the condenser 52 is supplied to the evaporator 51 and used for generating low-boiling-point medium vapor by heat exchange with the exhaust gas from the exhaust heat recovery boiler 31. Further, the exhaust gas after the heat exchange in the evaporator 51 is discharged from the chimney 4 into the atmosphere.

  The water generated by the condensation is discharged from the exhaust gas after heat exchange in the evaporator 51. When the water / steam injection method is adopted as the combustion method in the combustor 21, this water is treated with water. The apparatus (not shown) can be reused as water / steam injected into the combustor 21 after processing necessary for reuse such as neutralization, filtration, and deoxygenation. In this case, it is possible to reduce the amount of water supplied as a raw material for water / steam injected into the combustor or to eliminate the need for water supply.

  The low-boiling point medium is not particularly limited as long as it has a lower boiling point than water. (For example, pentane and hexane).

  In the present embodiment, heat exchange between the exhaust heat recovery boiler 31 and the evaporator 51 is performed until the temperature of the exhaust gas after the heat exchange in the evaporator 51 reaches the dew point temperature of the exhaust gas or less. By performing heat exchange in this way, it is possible to recover even the latent heat of the exhaust gas that could not be recovered by the conventional GTCC power plant, and it is easy to improve the thermal efficiency of the plant.

  Here, the heat exchange between the exhaust heat recovery boiler 31 and the evaporator 51 may be performed until the temperature of the exhaust gas after the heat exchange in the evaporator 51 reaches the dew point temperature or less of the exhaust gas as described above. It is preferable to carry out until the temperature reaches 57 ° C or lower, more preferably to 55 ° C or lower, further preferably to 53 ° C or lower, and to 50 ° C or lower. It is still preferred.

  From the viewpoint of improving the thermal efficiency of the plant, the heat exchange between the exhaust heat recovery boiler 31 and the evaporator 51 is performed such that the temperature of the exhaust gas after the heat exchange in the evaporator 51 is the temperature of seawater or the like taken as cooling water. It is most preferable to carry out until the temperature determined by the water temperature and the pinch temperature of the condensed water at the outlet of the condenser 52 determined by the above, for example, 40 ° C to 20 ° C. That is, this temperature is the lower limit of the temperature of the exhaust gas after heat exchange in the evaporator 51 and is the most suitable temperature. For example, when seawater having a water temperature of 30 ° C. is used as cooling water in the condenser 52 and the pinch temperature is + 10 ° C., heat exchange is performed so that the temperature of the exhaust gas after heat exchange in the evaporator 51 is about 40 ° C. Most preferred to do. For example, when the seawater temperature is low (eg, 10 ° C.) and the pinch temperature is + 10 ° C. in winter, heat exchange is performed so that the temperature of the exhaust gas after heat exchange in the evaporator 51 is about 20 ° C. Is most preferred.

  The exhaust gas after heat exchange in the evaporator 51 is discharged from the chimney 4. Here, the exhaust gas after the heat exchange in the evaporator 51 does not substantially contain carbon dioxide, and the oxygen concentration is lower than that of air. Therefore, unlike the conventional GTCC power plant, the diffusion power of the exhaust gas from the chimney 4 to the sky is ensured without setting the temperature of the exhaust gas to a high temperature of about 100 ° C. Therefore, even when the temperature of the exhaust gas is set to be equal to or lower than the dew point as described above, the diffusion force of the exhaust gas from the chimney 4 to the sky is ensured. Incidentally, even if the temperature of the exhaust gas after the heat exchange in the evaporator 51 is a temperature determined by the temperature of the low boiling point medium and the pinch temperature at the outlet of the condenser 52 determined by the temperature of seawater or the like taken as cooling water, The flue gas outlet temperature is higher than the ambient temperature (air temperature), and the exhaust gas temperature is lower than the ambient temperature (air temperature), so that the diffusion power of the exhaust gas from the chimney 4 to the sky does not decrease.

  Here, the distribution of the heat recovery amount from the exhaust gas in the exhaust heat recovery boiler 31 and the evaporator 51 is particularly limited if the temperature of the final exhaust gas discharged from the evaporator 51 is lowered to the target temperature. It is not something. For example, the heat exchange is performed until the temperature of the exhaust gas reaches about 100 ° C. in the exhaust heat recovery boiler 31 as in the case of the conventional GTCC power plant, and then the heat exchange is performed until the temperature decreases to the target temperature in the evaporator 51. May be. Alternatively, heat exchange may be performed until the temperature of the exhaust gas becomes less than 100 ° C. in the exhaust heat recovery boiler 31, and then heat exchange may be performed until the temperature decreases to the target temperature in the evaporator 51. Alternatively, the heat exchange in the exhaust heat recovery boiler 31 may be stopped at a stage where the temperature of the exhaust gas is higher than 100 ° C., and the heat exchange may be performed until the evaporator 51 decreases to the target temperature.

  By using the bottoming power generation equipment 5 together as in the present embodiment, heat exchange can be performed more efficiently. In particular, in the present embodiment, in addition to being able to make the temperature of the exhaust gas be equal to or lower than the dew point temperature, by burning hydrogen, and in the case where the water / steam injection method is adopted as the combustion method in the combustor 21, Because the amount of heat is recovered more than the conventional GTCC plant, the load for heat recovery can be distributed to the exhaust heat recovery boiler 31 and the evaporator 51 to recover the exhaust heat more efficiently. Therefore, it is possible to easily improve the thermal efficiency of the plant.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

  For example, the gas turbine power generation facility 2 may appropriately employ a known or new one within a range where the effects of the present invention can be achieved. For example, in the above-described embodiment, the water / steam injection method is adopted as a combustion method in the combustor 21 for reducing NOx. However, if the combustion gas can be generated using hydrogen as a fuel, A combustion method other than the method may be adopted. For example, in the premixed combustion method in which the generation of local high-temperature flame is eliminated and the generation of NOx can be suppressed, and the fuel and oxidant are mixed and burned in advance, combustion gas can be generated using hydrogen as fuel. A combustion method other than the water / steam injection method may be employed.

  Moreover, you may make it employ | adopt suitably a well-known or new thing as long as the steam turbine power generation equipment 3 can show the effect of this invention.

  Further, the bottoming power generation facility 5 may appropriately employ a known or new one within a range where the effects of the present invention can be achieved.

  In addition, the chimney 4 may have a height equivalent to that of the conventional GTCC power generation facility, but in the case of the present invention, the exhaust gas substantially does not contain carbon dioxide. There is no risk of carbon falling. Therefore, the height of the chimney 4 may be lowered within a range in which the steam condensed around the plant does not fall.

  Furthermore, in the above-described embodiment, the generator A is shared by the gas turbine power generation facility 2 and the steam turbine power generation facility 3, and the generator B is provided independently by the bottoming cycle power generation facility 5. The installation form of the generator is not limited to this form. For example, the gas turbine power generation facility 2, the steam turbine power generation facility 3, and the bottoming cycle power generation facility 5 may be provided independently, or may be provided so as to be shared by any two or more facilities. Good.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
The composition of the exhaust gas from the GTCC power plant due to the difference in fuel was examined.

  Table 1 shows an example of the composition of exhaust gas (100 ° C., 40 ° C.) when natural gas is used as fuel and combustion-supporting gas is burned as air. The data shown in Table 1 was obtained by chemical equilibrium calculation.

  Table 2 shows the composition of exhaust gas (100 ° C., 40 ° C.) when hydrogen gas is used as the fuel and combustion is performed by the water / steam injection method using the combustion-supporting gas as the air. The composition shown in Table 2 was obtained by calculating using fuel: water injection mass = 1: 1.5 and using chemical equilibrium calculation.

  As reference data, Table 3 shows the composition of air (30 ° C.).

  As shown in Table 1, the exhaust gas from the GTCC power plant using natural gas as the fuel contains a large amount of carbon dioxide. Since the molecular weight of carbon dioxide is larger than the average molecular weight of air, the exhaust gas is maintained at a high temperature to ensure the draft power from the chimney, and the carbon dioxide is diffused into the sky, so that high-concentration exhaust gas containing carbon dioxide is planted. It is necessary to prevent it from descending to the surroundings. On the other hand, as shown in Table 2, the exhaust gas from the GTCC power plant using hydrogen as the fuel does not substantially contain carbon dioxide (the air contains carbon dioxide). However, since the amount is only 300 to 500 ppm (0.03 to 0.05%), the amount is almost negligible), and the oxygen concentration is also lower than that of air. In particular, even at 40 ° C., which is a temperature lower than the dew point temperature of exhaust gas, carbon dioxide is not contained in the exhaust gas, the oxygen concentration is lower than that of air, and the density is lower than that of air. Therefore, in the case of a hydrogen-fired GTCC power plant, the exhaust gas itself has a diffusive power to the sky without maintaining the temperature of the exhaust gas at a high temperature as in the case of a natural gas-fired GTCC power plant. It became clear that the exhaust gas of the plant never dropped. And from this, it became clear that the heat recovery from the exhaust gas can be performed until the temperature of the exhaust gas reaches the dew point temperature or less, and the thermal efficiency of the plant can be improved using the latent heat content of the exhaust gas. .

(Example 2)
For liquefied natural gas (LNG) 焚 GTCC and hydrogen (H ₂ ) 焚 GTCC, thermal efficiency was analyzed and compared. The analysis was performed by chemical equilibrium calculation from the fuel composition, air composition, temperature and pressure. In the following description, “GT” means a gas turbine, “ST” means a steam turbine, and “HRSG” means an exhaust heat recovery boiler.

(1) LNG 焚 GTCC
The analysis was performed as follows for LNG 焚 GTCC.

First, the actual data of GTCC was transferred to Mitsubishi Heavy Industries Technical Report vol. 46, no. 2 (2009), p. Acquired with reference to 30-33.
-Combustor outlet temperature: 1500 [° C]
-GTCC efficiency: 53.54 [%] (higher heating value standard)

The data of the gas turbine was acquired from 2012 Gus Turbine World HANDBOOK (page 89).
-Gas turbine pressure ratio: 21
・ Exhaust gas temperature: 1089 [F]
Exhaust gas flow rate: 1625 [lb / s]

  Next, the GT output and the GT input heat amount were calculated. Specifically, the compressor power and the compressor outlet temperature were calculated assuming the compressor efficiency. Furthermore, as a result of calculating the GT output and the input heat amount with the exhaust gas temperature and the exhaust gas flow rate as described above, the GT output was 334 [MW] and the GT input heat amount was 924 [MW]. As a result of calculating the GTCC efficiency from this result, it was 36.15 [%]. The ST efficiency was 17.39 [%] (= 53.54 [%]-36.15 [%]). The ST output was 161 [MW] (= 924 [MW] × 17.39 [%] / 100).

  The amount of heat recovered when the heat recovery from the exhaust gas was performed until the temperature of the exhaust gas reached 1089 [F] (587.2 [° C.]) to 100 [° C.] was calculated to be 549 [kJ / kg] × 1625 [lb / s].

The efficiency of LNG 焚 GTCC used in the calculation was defined as follows (that is, the numerical values obtained above were rounded as follows).
・ GTCC efficiency: 54 [%]
-GT output: 334 [MW]
・ GT efficiency: 36 [%]
-GT combustor outlet temperature: 1500 [° C]
-ST output: 161 [MW]

(2) H ₂焚 GTCC
The analysis was performed as follows for H ₂ GTCC.

  As a NOx reduction measure, it was assumed that water was added 1.5 times the fuel mass, and the GT output was assumed to be the same as that in the case of LNG (334 [MW]). Then, a fuel amount (input heat amount) at which the combustor outlet temperature becomes 1500 [° C.] is calculated (1006 [MW]), and GT efficiency is calculated to be 33 [%] (= 334 [MW] / 1006 [MW] × 100).

  Next, when the heat recovery from the exhaust gas was performed until the exhaust gas temperature was changed from 1089 [F] (587 [° C.]) to 100 [° C.], the amount of heat recovered was calculated to be 588 [kJ / kg]. × 1625 [lb / s]. When the ST output was calculated from this calculation result, it was 172 [MW] (= 161 [MW] × 588 [kJ / kg] / 549 [kJ / kg]). Moreover, as a result of calculating the thermal efficiency of the whole plant, it was set to 50 [%] (= (334 [MW] +172 [MW]) / 1006 [MW] × 100).

  Further, when heat recovery from the exhaust gas was performed until the exhaust gas temperature reached 1089 [F] (587 [° C.]) to 40 [° C.], the amount of heat recovered was calculated to be 894 [kJ / kg] × It was 1625 [lb / s]. When the ST output was calculated from this calculation result, it was 262 [MW] (= 161 [MW] × 894 [kJ / kg] / 549 [kJ / kg]). Moreover, as a result of calculating the thermal efficiency of the whole plant, it was 59 [%] (= (334 [MW] +262 [MW]) / 1006 [MW] × 100).

In the case of LNG 焚 GTCC, the thermal efficiency of the whole plant reaches 54 [%] as described above, and the thermal efficiency of GT is about 36 [%]. In order to reduce NOx in H ₂焚 GTCC, water or steam is injected about 1.0 to 1.5 times the fuel, but 1.1 times the amount of fuel is required to keep the gas turbine inlet temperature constant. I need it.

  On the other hand, since water or steam is injected, the mass of the combustion gas passing through the gas turbine increases by about 0.5 [%] and the output slightly increases. However, the thermal efficiency of GT decreases to about 33%.

Further, the amount of heat of the exhaust gas is 1.25 times larger in H ₂焚 GTCC than in LNG 焚 GTCC due to an increase in latent heat. However, as with LNG 焚 GTCC, when heat recovery is performed only in the exhaust heat recovery boiler up to about 100 [° C] (about 83% of the heat amount of the exhaust gas), the recoverable heat amount is compared with LNG 焚 GTCC. As a result, the increase is just over 5%. Therefore, the GTCC efficiency is reduced to 50 [%] as it is.

On the other hand, if the amount of heat is recovered to about 40 [° C.] with HRSG, it will be possible to recover about 90% of the heat amount of the exhaust gas, and the heat amount of the exhaust gas will increase by 1.25 times compared to NG 焚 GTCC. Together with this, the amount of heat recovered by HRSG increases to 1.6 times that of LNGＬGTCC. As a result, the output at ST also increased 1.6 times, and it became clear that the thermal efficiency of H ₂焚 GTCC reached 59 [%].

(Example 3)
It was examined exhaust gas temperature of the _{H 2-fired} GTCC having the same efficiency and thermal efficiency of the LNG-fired GTCC calculated in Example 2. The analysis was performed by chemical equilibrium calculation as in Example 2.

First, the GTCC output of H ₂焚 GTCC when the LNG 焚 GTCC efficiency (54 [%]) is achieved is calculated as an input heat amount of 1006 [MW], resulting in 543.24 [MW] (= 1006 [MW] × 54 [%] / 100). Moreover, as a result of calculating ST output by setting GT output to 334 [MW], it became 209 [MW] (= 543 [MW] -334 [MW]).

Next, assuming that the ST efficiency of H ₂焚 GTCC is the same as the ST efficiency of LNG 焚 GTCC, the enthalpy to be obtained by HRSG was calculated to be 714 [kJ / kg] (= 209 MW × 549 [ kJ / kg] / 161 [MW]).

Next, in the component ratio of H ₂焚 GTCC, the enthalpy obtained by dividing the exhaust gas enthalpy at the GT outlet (590 [° C.]) by 714 [kJ / kg] recovered by HRSG and the pressure (1 atm) are specified. As a result of chemical equilibrium calculation, the exhaust gas temperature at the HRSG outlet was estimated to be 57 [° C.].

From the above, the chimney inlet temperature of H ₂焚 GTCC, which has the same efficiency as LNG 焚 GTCC, becomes 57 [° C], and the exhaust gas temperature is 57 ° C or less, so that water / steam is used as the combustion method in the combustor. in H _2-fired GTCC employing the injection method, equal or more thermal efficiency of the conventional LNG-fired GTCC be obtained revealed.

DESCRIPTION OF SYMBOLS 1, 1 'Hydrogen gas GTCC power generation plant 2 Gas turbine power generation equipment 3 Steam turbine power generation equipment 4 Chimney 5 Bottoming power generation equipment 21 Combustor 22 Air supply means 23 Hydrogen supply means 24 Water / steam supply means 25 Gas turbine 31 Exhaust heat recovery boiler 32 Condenser 33 Steam turbine 34 Denitration device 51 Evaporator 52 Condenser 53 Low boiling point steam turbine A, B Generator

Claims (2)

A gas turbine power generation facility comprising a combustor that generates hydrogen by burning hydrogen with combustion air, wherein a gas turbine is driven by the combustion gas to generate electric power;
A waste heat recovery boiler that generates steam by heat exchange with the exhaust gas discharged from the gas turbine power generation facility, and at least a steam turbine power generation facility that generates power by driving a steam turbine with the steam;
The temperature of the exhaust gas at the outlet of the exhaust heat recovery boiler is set to be below the dew point temperature of the exhaust gas, the exhaust gas after being heat-exchanged and said Rukoto discharged from the chimney by the exhaust heat recovery boiler Hydrogen-fired gas turbine combined cycle power plant. A gas turbine power generation facility comprising a combustor that generates hydrogen by burning hydrogen with combustion air, wherein a gas turbine is driven by the combustion gas to generate electric power;
A steam turbine power generation facility comprising a heat recovery steam generator that generates steam by heat exchange with the exhaust gas discharged from the gas turbine power generation facility, wherein the steam turbine is driven by the steam to generate power;
An evaporator for boiling a low-boiling-point medium having a boiling point lower than that of water by heat exchange with the exhaust gas after being heat-exchanged by the exhaust heat recovery boiler; At least a bottoming medium steam turbine driven by a bottoming power generation facility in which power generation is performed.
The temperature of the exhaust gas at the outlet of the evaporator, is set to be below the dew point temperature of the flue gas, hydrogen-fired gas exhaust after being heat exchanged in the evaporator is characterized Rukoto is discharged from a chimney Turbine combined cycle power plant.

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