JP2006132931A - Gas turbine apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas turbine apparatus capable of efficiently removing carbon dioxide gas (for example, carbon dioxide) while performing high efficiency operation. <P>SOLUTION: This gas turbine apparatus comprises a compressor 1 compressing air, a combustor 2 burning the compressed air discharged from the compressor 1 and a fuel, a gas turbine 3 driven by combustion gas from the combustor 2, a recirculation route for recirculating a part of the exhaust gas from the gas turbine to the inlet of the compressor 1, and carbon dioxide gas removing devices 41a, 41b, and 41c installed in the flow passage of the exhaust gas from the gas turbine and reducing a carbon dioxide gas concentration in the combustion exhaust gas produced by leading the air containing the recirculated exhaust gas into the combustor 3 and discharging it to the outside of the combustor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gas turbine device, and more particularly to an exhaust gas recirculation type gas turbine device that circulates exhaust gas to a compressor air inlet side.

  Part of the gas turbine exhaust is returned to the compressor inlet, and the compressor intake temperature is raised to prevent the combustion temperature at partial load and thus the gas turbine exhaust gas temperature from decreasing. Patent Document 1 discloses an exhaust gas recirculation combined plant that prevents a decrease.

  Also, before the recirculated gas turbine exhaust gas enters the compressor, water is sprayed and evaporated, and a cooler is provided in the compressed air path exiting the compressor to supply a cooling medium for heat recovery, and the exhaust gas Patent Document 2 discloses that the heat recovery ratio from the above is improved.

JP-A-7-34900 JP-A-56-14040

However, Patent Document 1 does not disclose anything that can widen the range in which the exhaust gas can be stably recirculated and the partial load operation can be performed with high efficiency. Further, Patent Document 2 does not mention partial load operation.
An object of the present invention is to provide a gas turbine device that can efficiently remove carbon dioxide (for example, carbon dioxide) while achieving high-efficiency operation.

  The present invention relates to a compressor that compresses air, a combustor that combusts compressed air and fuel discharged from the compressor, a gas turbine that is driven by combustion gas from the combustor, and a gas turbine exhaust gas. In a recirculation path for recirculating a part to the compressor inlet, and in a combustion exhaust gas that is installed in a gas turbine exhaust gas flow path and exhausted when air containing the recirculated exhaust gas is introduced into the combustor And a carbon dioxide removing device that reduces the concentration of carbon dioxide in the gas turbine device.

  Thereby, carbon dioxide (for example, carbon dioxide) can be efficiently removed while achieving high-efficiency operation, and downsizing of the carbon dioxide removal facility can be achieved. Since the pressure loss in the gas turbine exhaust path can be reduced by downsizing, it is possible to suppress a decrease in efficiency during operation of the gas turbine and to contribute to high efficiency operation.

  Further, the carbon dioxide gas removing means can be disposed between a branch portion of the exhaust gas path with the recirculation path and a discharge portion for releasing the exhaust gas to the atmosphere. Thereby, based on being able to remove the exhaust gas containing a high concentration carbon dioxide gas, in addition to the above-mentioned effect, the carbon dioxide gas removal efficiency can be maintained high. Moreover, since pressure loss can be reduced more, it can contribute to a further highly efficient driving | operation.

  Alternatively, the carbon dioxide gas removing means may be disposed between the gas turbine and a branch portion of the recirculation path in the exhaust gas path. Thereby, based on being able to supply much gas turbine exhaust gas amount, in addition to the above-mentioned effect, carbon dioxide removal efficiency can be maintained high.

  Alternatively, the carbon dioxide gas removing means can be installed in the recirculation path. Thereby, installation of a carbon dioxide gas removal device is easy. In addition, maintenance of the apparatus becomes easy. Moreover, since the pressure loss in the exhaust part from exhaust gas to the atmosphere can be reduced, the efficiency reduction of the gas turbine can be further suppressed.

  The carbon dioxide gas removal device can use, for example, an amine-based absorbent.

  According to the present invention, it is possible to provide a gas turbine apparatus that can efficiently remove carbon dioxide (for example, carbon dioxide) while achieving high-efficiency operation.

  Reference Example 1 of the present invention is shown in FIG. An exhaust gas recirculation combined plant using a gas turbine intake water spray system sucks air and compresses the compressor (compressor) 1, and combusts from the combustor 2 and the combustor 2 that mix and combust the compressed air and fuel. It is driven by steam generated in the exhaust heat recovery boiler 4 and the exhaust heat recovery boiler 4 that recovers the amount of heat of the exhaust gas from the gas turbine 3 driven by gas and generates heat by exchanging heat with the feed water. The steam turbine 5, the generator 6 coupled to the steam turbine 5, the recirculation means (pipe) 9 for forming a recirculation path for taking out a part of the exhaust gas of the gas turbine 3 and recirculating it to the compressor inlet, and the above-mentioned A recirculation amount control means (exhaust recirculation amount adjusting valve) 10 for controlling the recirculation amount is provided.

  In FIG. 1, the compressor (compressor) 1, the gas turbine 3, the steam turbine 5, and the generator 6 are connected on the same axis, but each turbine may drive each generator.

  A fuel amount control valve (fuel supply system) 7 that controls the amount of fuel supplied to the combustor 2 and a general control device 8 that controls the fuel amount control valve 7 and the recirculation amount control means 10 are provided.

  In Reference Example 1, a spray nozzle 11 that sprays fine droplets is further disposed in the intake duct 17. A water supply flow rate adjustment valve 12 for controlling the spray amount, a water supply tank 13 for storing water, and a water supply pump 14 are arranged in a path for supplying water to the spray nozzle. Further, when an intake air supply means is necessary for the nozzle to obtain fine droplets, an air flow rate adjusting valve 15 is provided in the intake air supply path.

  The fine droplets to be sprayed have a Zautor average particle size (SMD) of about 10 μm.

  The power generation output of the combined plant is operated by operating a fuel amount control valve 7, a recirculation amount control means 10, a spray flow rate (feed water flow rate) adjustment valve 12, and an air flow rate adjustment valve 15 that control the amount of fuel input to the combustor 2. It is determined by adjusting the opening degree. These operation ends are controlled by operation signals from the overall control device 8, and the overall control device 8 receives the load request signal Ld from the central power supply command station 16 for the combined plant, and controls the entire plant to control the air amount, fuel Control the amount and water spray amount appropriately.

  An example of the control of the overall control apparatus will be described with reference to FIG.

  In order to control the amount of fuel, first, the difference between the load request signal Ld and the actual load L is obtained by the subtractor AD1, and the fuel target signal Fd is obtained by the regulator PI1. Then, the deviation between the fuel amount target signal Fd and the actual fuel amount F is obtained by the subtractor AD2, and the fuel amount control valve 7 is adjusted by the regulator PI2 to determine the fuel amount to be introduced into the combustor. In this control, the amount of fuel input to the combustor 2 increases as the load increases.

  Further, in the control of the recirculation amount, in the function generator FG1 that receives the load signal Ld, an output signal S1 that is larger as the load is lower is obtained. This signal S1 is given to the regulator PI3 to control the recirculation amount control means 10.

  Note that the calculated value of the combustion temperature is input to AD2 or AD3, and when calculated by AD2 or AD3, correction is added as necessary so as to suppress fluctuations in the combustion temperature. As the calculated value of the combustion temperature, the exhaust gas temperature and the compressor outlet pressure are input to the FG 2, where the combustion temperature is calculated from the exhaust gas temperature and pressure and output.

This is because the amount of recirculation increases as the load decreases, so that the combustion temperature, and thus the gas turbine exhaust gas temperature, is prevented from decreasing as the load decreases, preferably the combustion temperature (gas turbine exhaust gas temperature regardless of the load). ) Can be made substantially constant. The function generator FG1 of FIG. 1 has a recirculation ratio of the exhaust gas amount determined according to the load. Therefore, the output signal S1 of the function generator FG1 is not related to the load of the gas turbine exhaust gas temperature in the illustrated example. It can be almost constant. In this way, exhaust enthalpy can be collected to suppress a reduction in efficiency at the time of partial load.

  Thus, the gas turbine exhaust gas temperature can be made substantially constant irrespective of the load.

  Regarding the improvement of the compressor characteristics, in order to prevent the combustion temperature during partial load operation and thus the gas turbine exhaust gas temperature from decreasing, the ambient air and the high temperature gas turbine exhaust gas are mixed into the intake air at the compressor inlet, The lower the load, the greater the amount of gas turbine exhaust gas that is recirculated. However, as the gas turbine exhaust gas increases, the intake air temperature naturally rises, and the temperature in the compressor 1 correspondingly increases. To rise. As shown in FIG. 3, a change occurs in the fluid behavior around the compressor blade. First, normally, if it is designed so that the peripheral speed of the moving blade is constant and the axial flow speed is constant inside the compressor, the apparent speed B flowing into the compressor moving blade as shown in FIG. Parallel to However, when the intake air temperature rises and the compressor internal gas temperature rises, the axial flow velocity A ′ increases as shown in (B), so the incidence α, which is the incident angle of the apparent velocity B, increases in the negative direction. . For this reason, on the rear stage side of the compressor (for example, near the last stage blade) where the temperature rises, flow separation occurs at the blade, resulting in a stalled state, and in severe cases, a negative stall, resulting in stable gas turbine operation. Driving becomes difficult. Therefore, even if the recirculation amount is increased as the gas turbine load decreases, the exhaust gas recirculation amount can be limited, and the range of partial load operation is limited.

  In the case of this reference example, the gas inside the compressor is changed as shown in FIG. 3C by introducing droplets that evaporate in the compressor into the intake air in which the ambient temperature outside air and the high temperature gas turbine exhaust gas are mixed. As a result of cooling, the axial flow speed A ′ on the rear stage side of the compressor is reduced, thereby reducing the incidence α, the apparent speed B becomes parallel to the blades, and stabilization of the compressor characteristics can be obtained. . Since the gas inside the compressor can be cooled by vaporizing the introduced droplets in the compressor, the compressor intake air temperature can be increased, that is, the exhaust gas recirculation amount can be increased. Highly efficient partial load operation range can be expanded.

  FIG. 4 shows the change in the incidence with respect to the spray amount. First of all, gas turbines are usually designed with an atmospheric temperature in the range of 0 ° C to 50 ° C, and during this time, the change in compressor intake temperature causes the incidence to change, but the compressor characteristics are stable. ing. However, when the compressor intake air temperature exceeds this range, the absolute value of the incident increases, and the compressor characteristics become unstable. In severe cases, such as positive stall (stall) or negative stall (choke) Happens.

  In the present invention, by introducing droplets that evaporate in the compressor, the gas inside the compressor is cooled and the incidence is improved. According to FIG. 3, when the intake air temperature is 50 ° C., the incident is at the lower limit of the normal operating range, but the incident is gradually recovered by spraying droplets at the compressor inlet and cooling the gas inside the compressor. When the spraying amount is 1.5%, the incident level is restored to 0 deg. However, as the spray amount increases, a positive stall (stall) becomes a problem this time, so it is necessary to select an appropriate spray amount.

  Thus, by introducing the droplets that evaporate in the compressor, the temperature difference between the compressor inlet and the outlet gas can be reduced. The inlet temperature is substantially constant, and the outlet temperature is decreased or the amount of decrease in the outlet temperature is made larger than the amount of decrease in the inlet temperature.

  For this reason, it is possible to increase the recirculation amount while keeping the compressor outlet temperature substantially constant.

  Therefore, it can be recirculated even during low partial load operation.

  By introducing droplets to be vaporized in the compressor through which the mixed gas flows and evaporating the droplets in the compressor, the efficiency in the partial load situation can be further improved as compared with the case of the prior art. The water droplets entering the compressor are vaporized, and when the vaporization is completed, the gas in the compressor is further subjected to adiabatic compression. At that time, the constant-pressure specific heat of water vapor has a value about twice that of the air-fuel mixture in the vicinity of a typical temperature (300 ° C.) in the compressor. Therefore, in terms of heat capacity, about 2 of the weight of water droplets to be vaporized in terms of air-fuel mixture. There is an effect equivalent to double the mixture as the working fluid. That is, there is an effect (temperature rise suppression effect) in reducing the temperature of the outlet gas mixture of the compressor. In this manner, the action of lowering the temperature of the air-fuel mixture at the compressor outlet occurs due to the vaporization of water droplets in the compressor. The power of the compressor is equal to the difference in the enthalpy of the mixture at the compressor inlet and outlet, and the mixture enthalpy is proportional to the temperature.Therefore, if the mixture temperature at the compressor outlet decreases, the required power of the compressor can be reduced and efficiency can be improved. Can be improved.

Further, assuming that the compressor inlet intake temperature T ₁ , the compressor outlet temperature T ₂ , the combustion temperature T ₃ , and the gas turbine outlet temperature T ₄ , the efficiency η of the gas turbine is approximately given by the following equation.

When the compressor outlet temperature T ₂ is reduced to T ₂ ′ (<T ₂ ) due to vaporization due to the mixing of water spray, the second term on the right side of the above formula becomes small, and it can be seen that the efficiency is also improved by water spray. In other words, the thermal energy Cp (T ₄ −T ₁ ) discarded outside the system from a heat engine called a gas turbine is not much different before and after the application of the present invention, while the input fuel energy Cp (T ₃ −T ₂ ') during the application of the present invention, Cp (T ₂ -T _2' has increased more) that is, as reduction amount of the compressor work. Since the reduction in compressor work is equal to the increase in output, this increase in fuel contributes substantially to the increase in output of the gas turbine. That is, the increased output has a thermal efficiency of 100%. For this reason, the thermal efficiency of a gas turbine can be improved. Since the combustion temperature is kept constant, the thermal efficiency of the bottoming cycle is equal to that before application of the present invention, so that the total thermal efficiency of the combined cycle can be improved.

  On the other hand, in the case where the temperature of the mixed gas introduced into the compressor is simply lowered, there may be a limit although it may be a slight improvement in the characteristics of the compressor shown in FIG.

  Moreover, in the low partial load operation state, the intake air is cooled and the weight flow rate of the intake air introduced into the compressor 1 increases, which may lead to an increase in the load of the gas turbine to be operated in the low load state. Come on.

  If the spray droplets have a large particle size, they collide with the blades and casing of the compressor 1 and vaporize by obtaining heat from the metal, which may hinder the effect of reducing the temperature of the working fluid. For this reason, from such a viewpoint, it is preferable that the droplet diameter is small.

There is a particle size distribution in the spray droplets. From the viewpoint of suppressing collision with the blades and casing of the compressor 1 and preventing erosion of the blades, the sprayed droplets are mainly 50
The particle size should be less than μm. From the viewpoint of reducing the effect on the blade, the maximum particle size is preferably 50 μm or less.

Further, the smaller the particle size, the more uniformly the droplets can be distributed in the inflowing air, and the Sautor average particle size (SMD) is used from the viewpoint of suppressing the temperature distribution in the compressor. It is preferable to make it 30 μm or less. Since the droplets ejected from the spray nozzle have a particle size distribution, it is not easy to measure at the maximum particle size. In practice, the droplets measured with the Sautor average particle size (SM.D.) as described above are used. Adaptable. Although it is preferable that the particle size is small, the spray nozzle for producing droplets with a small particle size requires high-precision manufacturing technology, so the lower limit that can be technically reduced is the practical range of the particle size. . Therefore, from the viewpoint, for example, the main particle size, the maximum particle size, or the average particle size is 1 μm, respectively. In addition, since the energy for generation increases as the droplet size becomes smaller, the lower limit may be determined in consideration of the energy used for generating the droplet. In general, the surface of the contact surface is good if it is floated in the atmosphere and is not easily dropped.

  The time for the air to pass through the compressor is short, and from the viewpoint of favorably vaporizing the droplets during this period and increasing the vaporization efficiency, the Sautor average particle size (SDM) is preferably 30 μm or less.

  In addition, since the high precision manufacturing technique is requested | required of the spray nozzle which produces the droplet of a small particle size, the minimum which can be made small technically becomes the minimum of the said particle size. For example, 1 μm.

  This is because if the droplet is too large, it is difficult to vaporize the droplet with a compressor.

  The droplet introduction amount can be adjusted by the gas turbine exhaust gas recirculation amount, the mixture inlet temperature, or the compressor outlet temperature. From the viewpoint of controlling the compressor outlet temperature to a constant value, the spray amount can be set to 7%, which is the upper limit of the recirculation amount, and the introduction range can be made lower than this. More water droplets are sprayed when the recirculation amount is larger than when the recirculation amount is small.

  Alternatively, the position of the spray nozzle may be provided in the compressor to spray droplets on the compressed gas.

  The position of the spray nozzle 11 will be specifically described with reference to FIG. Here, 18 indicates IGV.

  The spray nozzle is installed at any position from 11a to 11d. The spray nozzle 11a is installed at a predetermined interval from the compressor inlet. However, if a silencer is installed in the intake duct 17, it is installed downstream from it. Thereby, as described above, in addition to obtaining a high-efficiency partial load operation, in the case of increasing the output operation with high efficiency, some of the droplets are vaporized before being introduced into the compressor, Furthermore, it is preferable at the point which can introduce | transduce into a compressor and can vaporize a compressor further during a flow.

  The spray nozzle 11b is a nozzle installed on an introduction blade installed at the most upstream part, which is an introduction part of a compressor installed at the compressor inlet. Air supply path and water supply path will be installed inside the wing. Thereby, it can suppress that it becomes the resistance of the flow by a spray nozzle, and it can spray a droplet, without providing the space for nozzle installation anew.

  The spray nozzle 11c is installed between the guide vane and the IGV. It can suppress that the sprayed droplet evaporates until it enters in the compressor 1, and the weight flow rate of mixed gas increases. From the viewpoint of not disturbing the flow, it is preferable to provide it near the IGV.

  In this way, continuous vaporization in the compressor can be obtained by using 11a to 11c. Further, by vaporizing much on the relatively upstream side in the compressor, the compressor discharge temperature can be further reduced, and an increase in the compressor discharge temperature can be suppressed.

  The spray nozzle 11d is provided in the intermediate stage of the compressor. Since an event such as stalling of the compressor blades is likely to occur in the rear blades, the compressor blades may be installed in the middle intermediate compressor stage. In such a case, as shown in the enlarged view, a nozzle is installed on the stationary blade, and water supply means and air supply means are provided in the blade.

  Such spray droplets flowing down into the compressor move between the blades of the compressor 1 along the streamline. In the compressor, the intake air is heated by adiabatic compression, and the droplets are transported to the rear side wing while reducing the particle size while being vaporized from the surface. In this process, the latent heat of vaporization necessary for vaporization depends on the air-fuel mixture in the compressor, so the temperature of the mixed gas in the compressor is lowered.

  The spray amount of the spray nozzle 11 is controlled to correspond to the recirculation amount of the gas turbine exhaust gas. For example, when the recirculation amount is large, the spray amount is controlled to be larger than when the recirculation amount is small.

  When the gas turbine of the combined plant is in partial load operation, a mixed gas of the gas turbine exhaust gas that has passed through the recirculation pipe 9 and the air that is supplied via the intake duct 17 is introduced into the compressor 1, and the compressor 1 contains the mixed gas. Is compressed and discharged.

  In this state, the fine droplets are sprayed from the spray nozzle 11 and introduced into the compressor, and the compressor 1 is vaporized while flowing down.

  By increasing or decreasing the spray amount in accordance with the recirculation amount, it is possible to widen the range of partial load operation in which exhaust recirculation can be performed with high efficiency compared to simple exhaust gas recirculation. Furthermore, more efficient operation can be performed during partial load operation.

  It is possible to improve the characteristics of the compressor which has been lowered due to the rise in the intake air temperature of the compressor accompanying the increase of the recirculation amount in the operation at the low load among the partial loads.

  The control of the spray amount will be described with reference to FIG.

  In this control, in the function generator FG1 that receives the load request signal Ld, the output signal S1 that becomes larger as the load becomes lower and the gas turbine exhaust gas temperature and the compressor in the function generator FG2 to correct the combustion temperature change in actual operation. A combustion temperature signal estimated from the outlet pressure is applied to the subtractor AD3 to output a corrected recirculation ratio signal of the function generator FG1. By inputting this signal to the function generator FG3, an output signal S2 of the water droplet spray amount with respect to the recirculation amount that increases as the recirculation amount increases is obtained, and this signal S2 and the actually measured compression are obtained. The machine outlet gas temperature is applied to the subtractor ADI4, and the corrected spray amount signal of the function generator FG3 is output. The spray flow rate (feed water flow rate) adjustment valve 12 is controlled by giving this signal to the regulator P14. With this control, the spray amount can be controlled in accordance with the recirculation ratio.

  If necessary to make fine droplets, the air flow rate control valve 15 may be opened. FIG. 5 shows a control line of the spray rate with respect to the recirculation rate when the exhaust gas temperature is constant. The spray rate increases almost linearly with respect to the recirculation rate.

By the recirculation operation, the incidence of the blades in the compressor changes as described above, but it can be returned to the state before the exhaust gas recirculation by the control by the control line. For example, when the atmospheric temperature is 15 ° C., about 3% spray amount (outside air weight base) with 10% recirculation amount based on exhaust weight flow rate, and about 5.5% with 20% recirculation amount To do.

  FIG. 9 shows the relationship between the mixture intake air temperature and the recirculation rate for each load. The air-fuel mixture (volumetric flow rate) sucked into the compressor 1 is constant regardless of the load because the gas turbine 3 rotates at a constant speed. As the load becomes lower, the exhaust gas recirculation amount increases and the intake air temperature at the compressor inlet increases accordingly. On the other hand, when the recirculation amount increases and the mixed intake air temperature increases, the gas turbine output decreases as the compressor inlet suction weight flow rate decreases. In the case of a simple recirculation gas turbine like the prior art, the upper limit of the compressor intake air temperature is 50 ° C. in consideration of the stall of the last stage blades, etc., which limits the recirculation amount and the gas turbine output reduction. become. However, the fluid behavior around the compressor blades is improved by spraying fine droplets at the compressor inlet and cooling the gas inside the compressor according to this reference example. Operation is possible, and more efficient partial load operation is possible. The temperature of the compressed air exiting the compressor 1 drops due to vaporization of water droplets in the compressor, and the combustion temperature can be kept constant by increasing the amount of fuel input. Next, the combustion gas works in the process of adiabatic expansion in the gas turbine 3, and a part of the combustion gas is consumed to drive the compressor 1 and the generator 6, so the net output corresponds to the difference.

  A part of the exhaust gas of the gas turbine 3 is recirculated as a part of the intake air of the compressor 1 via the exhaust gas recirculation means 9 and the control means (exhaust gas recirculation amount adjusting valve) 10. The exhaust heat recovery boiler 4 generates high-pressure steam, which drives the steam turbine 5 and the generator 6 to generate electricity.

FIG. 10 shows a comparison of the efficiency reduction for each load in the combined cycle with the efficiency of the normal combined cycle, the exhaust gas recirculation combined cycle, and the present reference example. The cycle heat efficiency of a normal combined cycle is not so much reduced until the 90% load, where the operation is performed at a constant combustion temperature by IGV, etc., but the efficiency decreases because the combustion temperature decreases when the operation is less than 90% load. At 25% load, which is a load that is abruptly reduced and is determined from the constraints on the bottoming side, the efficiency is reduced by about 40% in relative value. The range where the combustion temperature constant operation by the IGV or the like is performed differs somewhat depending on the equipment. However, in many cases, the load is up to 80% even if it is small. The exhaust recirculation combined cycle has a smaller decrease in cycle thermal efficiency than the normal combined cycle, but it is about
It can only operate up to 65% load. On the other hand, in the present invention, by cooling the compressor internal gas, the reduction in efficiency is further reduced for each load by reducing the compressor power and improving the thermal efficiency by increasing the output. It is possible to operate up to a load. Theoretically, it is possible to operate up to a load of about 30% at which the oxygen concentration in the gas turbine exhaust gas becomes zero, and the efficiency reduction is about 10%.

  The lower limit is preferably determined by the setting of the equipment, etc., and in general, it is considered that there are many cases of recirculation up to at least 50% load.

  In addition, FIG. 10 considers the operation | movement by control of IGV etc. in the area | region of 100 to 90% or 80% in plant load (If it is not a combined cycle plant but a mere gas turbine device, it is a gas turbine load. The same hereafter). However, the present invention is not limited to this, and when the load drops from 100%, the recirculation amount may be controlled accordingly. If the recirculation amount is increased as the load is lower, the combustion temperature is set to 1430 ° C., and the compressor outlet temperature is set not to be higher than 370 ° C. For example, when constant control at 370 ° C. is performed, the plant load is 74%. The compressor inlet temperature was 150 ° C., 112 ° C. at a load of 50%, and 240 ° C. at a load of 30%. Introducing droplets that evaporate in the compressor as in this reference example and lowering the compressor outlet temperature can avoid inconveniences occurring on the downstream side of the compressor. For this reason, it is possible to control the amount of droplets evaporated in the compressor to be controlled to increase the recirculation ratio so as to increase the temperature of the mixed gas at the compressor inlet. In addition, the recirculation amount can be increased more than the recirculated plant, and the operation can be performed with the recirculation amount increased to a low partial load region.

  Further, in this reference example, when the plant load is at least 50% to 80%, the spray amount is increased as the recirculation amount increases, and the recirculation amount continuously increases as the load decreases. Can be controlled.

  Further, the recirculation amount is controlled corresponding to the load so as to suppress fluctuations in the combustion temperature of the combustor when the plant load is at least 50% to 80% (for example, the recirculation amount is reduced as the load decreases). It is possible to control the increase in the temperature of the compressed air at the outlet of the compressor by introducing droplets into the compressor.

  The overall control device 8 can perform the following control.

  The recirculation amount and the droplet spray amount are controlled corresponding to the load so as to suppress fluctuations in the combustion temperature of the combustor when the plant load is between 50% and 80%. By increasing the amount of recirculation as the load decreases and controlling the spray amount to increase, the decrease in combustion temperature is suppressed and maintained high, enabling high-efficiency operation over a wide range of partial loads. It becomes.

  In addition, the recirculation amount is controlled corresponding to the load so as to suppress fluctuations in the combustion temperature of the combustor when the plant load is between 50% and 80%, and droplets are introduced into the compressor to exit the compressor Suppresses the temperature rise of compressed air. As the recirculation amount increases, the compressor outlet temperature rises, so that droplets are introduced into the compressor and evaporated in the compressor so that the temperature is maintained within an allowable range.

  In addition, the amount of gas turbine exhaust gas that is returned to the compressor inlet in response to the change in the plant load is adjusted, and the load is adapted to suppress fluctuations in the combustion temperature of the combustor when the plant load is between 50% and 80%. Then, the recirculation amount is controlled, and the spray amount of the droplets vaporized while flowing down in the compressor is controlled, so that the recirculation amount is continuously increased as the load decreases. If you try to control the amount of recirculation to increase as the load decreases, there is an upper limit on the amount of increase in the amount of recirculation due to the convenience of the compressor, but you can adjust the amount of droplets that evaporate in the compressor. By controlling so that the amount of introduced droplets increases as the load decreases, the recirculation amount can be controlled to increase continuously as the load decreases in a wide partial load range.

  In addition, since the said upper limit is the load of the upper limit which performs recirculation, when making it recirculate when it becomes lower than 100%, the said upper limit range becomes large. In addition, since the lower limit is determined by the setting of the device, depending on the device, it is possible to control to increase the recirculation amount to a lower range.

  Reference Example 2 will be described with reference to FIG. The basic configuration is the same as in Reference Example 1. In Reference Example 1, the spray amount is controlled in accordance with the exhaust gas recirculation amount. In this reference example, the control of the exhaust gas recirculation amount is the same as that in the first reference example. The method for controlling the spray amount differs depending on the gas temperature measured in step (1). The equipment configuration of the combined plant is the same as that of the first reference example, but a means for measuring the compressor outlet gas temperature and inputting this signal to the overall control device 8 is added as a spray amount control means. The overall control device 8 of this reference example is shown in FIG. In this reference example, the compressor outlet gas temperature measured as shown in FIG. 7 is input to the function generator FG3, and preferably, the temperature of the compressor outlet gas before the exhaust gas is recirculated is suppressed. The amount of spray that is constant is calculated. Control is performed so that the spray amount increases as the outlet temperature is higher. The spray flow rate (feed water flow rate) adjusting valve 12 is controlled by the controller PI4 from the obtained spray amount signal. On the other hand, since the combustion temperature may change due to spraying, the fuel flow rate when droplet spraying is corrected by applying the spray amount signal to the load request signal Ld and the fuel flow rate signal obtained from the actual load L is corrected. Control and achieve constant combustion temperature. FIG. 8 shows a control line for calculating the compressor outlet gas temperature before exhaust gas recirculation from the compressor outlet gas temperature at an atmospheric temperature of 15 ° C. as an example. With 10% exhaust gas recirculation, the compressor outlet gas temperature is about 450 ° C, but if about 2.5% spraying is performed at the compressor inlet, the compressor outlet gas before exhaust gas recirculation is used. Constant temperature operation is possible. Note that the compressor outlet gas temperature varies with the difference in atmospheric temperature even if the exhaust gas recirculation amount is constant, so it is desirable to use a control line with the atmospheric temperature as a parameter. As a result, it is possible to perform an operation that does not follow minute output fluctuations and temperature fluctuations, and the operation control is facilitated.

  Since the temperature at the rear stage of the compressor, which causes inconvenience in compression, is directly reflected, more accurate operation can be performed.

  Reference Example 3 will be described with reference to FIG. Basically, the same structure as in Reference Example 1 can be used.

  The feature of this reference example is that a mixed gas temperature detection device is provided at the compressor inlet, and the spray amount is controlled based on the temperature of the temperature detection device.

  For example, the overall control device 8 controls to spray more droplets when the mixed gas temperature entering the compressor is higher than when it is low. Further, the spray amount is controlled so as to be the compressor outlet temperature before exhaust gas recirculation.

  As a result, high-efficiency operation can be performed even during partial load operation even at low partial loads.

  Reference Example 4 will be described with reference to FIG. Basically, the same structure as in Reference Example 1 can be used.

  The feature of this reference example is that the overall control device 8 controls the spray amount based on a signal from the plant load measuring device.

  For example, it controls to spray more droplets when the load is lower than when the load is high. Further, the spray amount is controlled so as to be the compressor outlet temperature before exhaust gas recirculation.

  As a result, high-efficiency operation can be performed even during partial load operation even at low partial loads.

  As a result, since the load is often measured even during normal operation, such a signal can be used and can be easily controlled.

  Reference Example 5 will be described with reference to FIG.

  A basic configuration similar to that of Reference Example 1 can be used. The reference example and the device are the gas turbine device without the exhaust heat recovery boiler 4 to which the gas turbine 3 exhaust gas is supplied and the steam turbine to which the steam generated in the waste heat recovery boiler 4 is supplied.

  As described in the first reference example, the droplets introduced into the compressor through which the mixed gas of the gas turbine exhaust gas and air that has passed through the recirculation path flows, and the introduced droplets flow down the compressor. A spraying device adapted to vaporize. Accordingly, the gas turbine exhaust gas amount returned to the compressor inlet in response to the load change of the gas turbine is adjusted, and the mixed gas of the gas turbine exhaust gas and air that has passed through the recirculation path by spraying droplets from the spray device The droplets were introduced into the compressor through which the gas flowed, and the introduced droplets were vaporized while flowing down the compressor.

  And a spray amount control device that controls the spray amount of the droplets corresponding to the recirculation amount. Further, in response to the plant load, control is performed such that more spray is applied when the load is low than when the load is high.

  Further, the spray amount is controlled in accordance with the temperature change of the mixed gas introduced into the inlet of the compressor. Control is performed so that the amount of spray becomes higher when the mixed gas temperature is higher than when the mixed gas temperature is lower.

  Thus, as described above, the compressor internal gas temperature can be lowered and the characteristics of the compressor can be improved, so that the exhaust gas recirculation amount can be increased and the partial load operation range can be expanded. Further, the thermal efficiency can be further increased as compared with the exhaust gas recirculation type gas turbine apparatus due to the effect of water droplet spraying on the compressor intake air.

  Reference Example 6 will be described with reference to FIGS.

  In Reference Example 6, the spray amount and the recirculation amount are controlled based on the compressor intake temperature.

  A schematic diagram of this reference example is shown in FIG.

  Basically, the same structure as the schematic diagram of the reference example 1 can be taken.

  In this reference example, exhaust gas recirculated from the downstream side of the exhaust heat recovery boiler 4 is guided.

  The pipe 9 as an example of the exhaust gas recirculation means for extracting a part of the exhaust gas from the gas turbine 3 may be any of the exhaust heat recovery boiler, the exhaust heat recovery boiler inlet and the outlet, but effectively uses the heat in the exhaust gas. In order to utilize, it is good to take out from an exhaust heat recovery boiler exit part like this reference example.

  A fuel amount control valve 7 for controlling the amount of fuel input to the combustor 2, an exhaust gas recirculation amount adjustment valve 10 as a recirculation amount control means, a feed water flow rate adjustment valve 12, and an air flow rate adjustment valve 15 are used as operation ends. Are controlled by an operation signal from the overall control device 8. With this operation, the power generation efficiency of the combined plant can be controlled. A signal from a temperature detector 18 that detects the temperature of the air supplied to the compressor is transmitted to the overall control device. Preferably, the signal of the humidity detector 19 is further transmitted. The temperature detector 18 and the humidity detector 19 can be installed at the junction of the recirculated exhaust gas or upstream of the spray nozzle 11.

  The entire plant is controlled by a command from the overall control device 8, and the recirculation amount, fuel amount, air amount, and water spray amount are appropriately controlled. For example, the compressor inlet temperature is used as an input to increase plant efficiency and control so that the plant load is constant.

  FIG. 12 shows an example of an outline of the control mechanism of the overall control device. First, the difference between the load request signal Ld and the actual load L is obtained by the subtractor AD1, and the fuel target signal Fd is obtained by the regulator PI1. Then, the deviation between the fuel amount target signal Fd and the actual fuel amount F is obtained by the subtractor AD2, and the fuel amount control valve 7 is adjusted by the regulator PI2 to determine the fuel amount to be introduced into the combustor. In this way, the fuel amount can be controlled. For example, in this control, the amount of fuel input to the combustor 2 can be increased as the load increases.

Also, from the compressor inlet temperature, preferably further from the compressor inlet humidity, the function generator 3
At (FG12), a recirculation amount command signal S1 is issued. This signal is given to the regulator P13 to control the recirculation control means 10. Further, a spray amount command signal S2 from the spray nozzle 11 is output from the function generator 3 (FG 12). This signal is given to the regulator P14, and controls the feed water flow rate adjustment valve 12 and the air flow rate adjustment valve 15 to control the spray guess of the droplets from the spray nozzle 11.

  Further, it is preferable that the combustion temperature is estimated from the gas turbine exhaust gas temperature and the compressor outlet pressure in the function generator 4 (FG12), and applied to the subtractor AD2 to perform the fuel amount correction control.

  When the compressor inlet temperature or the outside air temperature fluctuates, the fuel is adjusted in accordance with the fluctuation, thereby contributing to suppressing the combustion temperature fluctuation and making the combustion temperature constant. In order to realize high plant efficiency operation, it is important to keep the combustion temperature constant. However, in actual operation, the combustion temperature may change. If the operation is performed so as to suppress fluctuations in the combustion temperature based on the actual combustion temperature estimated from the machine discharge pressure, the operation can be performed while suppressing a decrease in the combustion temperature during water spraying or recirculation. This prevents the fuel temperature from decreasing and the efficiency from decreasing.

  Further, it is preferable to obtain a deviation between the load request signal Ld and the actual load L by the subtractor AD1 and correct the output of the function generator 3. This contributes to a constant load.

  It is preferable to realize the highest plant efficiency operation by the output of the function generator 3.

  Since the plant efficiency may change in actual operation, the difference between the required plant efficiency ηd and the actual plant efficiency η is calculated by the subtractor AD5, and the output of the subtractor AD5 is applied to the subtractor AD3 and the subtractor AD4. It is preferable to modify the output of the generator 1. As a result, high-efficiency operation can be achieved even during actual operation.

  The function generator 3 calculates the combustion temperature based on the signal from the exhaust gas temperature detector 24 and the signal from the temperature detector 23 of the compressor discharge air, and outputs the signal to AD2. For example, it can be calculated that the combustion temperature is higher when the exhaust gas temperature is lower than that when the exhaust gas temperature is low, and the combustion temperature is higher when the exhaust gas temperature is higher than when the compressor discharge pressure is low.

  It is also conceivable to output a numerical value corresponding to the combustion temperature by other means.

  The function generator 4 controls the spray amount of the spray nozzle 11 based on the compressor inlet temperature. It also controls the amount of recirculation. The spray amount and the like are preferably corrected based on the compressor inlet air humidity. The spray amount (or spray amount limit value) increases as the temperature increases, and the spray amount (or spray amount limit value) can increase when the humidity is lower than when the humidity is high.

  When the detected temperature of the air supplied to the compressor is in the first temperature range in which the temperature is set, the recirculation is performed, the spraying of the droplets from the spraying device is stopped, and the detected temperature is the first temperature. In the case of the second temperature region higher than the region, the recirculation is stopped, the spraying of the droplets from the spraying device is stopped, and in the case of the third temperature region higher than the second temperature region, the Control is performed to stop recirculation and spray the droplets from the spraying device.

  An upper limit and a lower limit temperature of a region where the efficiency of the combined plant is high are set, a switching temperature between the first temperature range and the second temperature range, a switching temperature between the second temperature range and the third temperature range, It is preferable to do. It is preferable to set each temperature from a temperature of 15 ° C. or higher and 22 ° C. or lower where the efficiency of the combined plant is high. When it deviates from this area depending on the plant, it is preferable to set according to the plant.

  The compressor inlet temperature is monitored, and the recirculation amount and the water spray amount are controlled so that the compressor inlet temperature becomes the highest in plant efficiency and the plant load is always constant.

  In the case of the first temperature region, for example, when the compressor inlet temperature is lower than the intake air temperature region where the plant efficiency is high, the lower the intake air temperature in the function generator FG3 that receives the compressor inlet temperature, the more A signal S1 that increases the circulation rate is obtained.

  This signal S1 is given to the regulator PI3 to control the recirculation amount control means 10. The signal S1 can be used as a limit value of the recirculation amount by controlling the recirculation amount by a desired output or the like.

  In the case of the second temperature range, recirculation and spraying of droplets from the spray nozzle 11 are stopped. In the third temperature region, for example, when the compressor inlet temperature is higher than the intake air temperature at which the plant efficiency is high, the intake air temperature is high in the function generator FG1 having the compressor inlet temperature and humidity as inputs. A signal S2 is obtained in which the spray rate increases as the value decreases.

  This signal S2 is given to the regulator PI4 to control the feed water flow rate adjustment valve 12 and the air flow rate adjustment valve 15.

  As a result, even if the outside air temperature fluctuates, the compressor inlet temperature can be made constant by the recirculation amount control and the spray amount control, or the fluctuation can be suppressed satisfactorily. However, the combined plant can be operated with high plant efficiency.

  At that time, since the first temperature range and the third temperature range are provided via the second temperature range, the atmospheric temperature with high plant efficiency changes depending on the relative humidity, but the second temperature range is set. By doing so, it is not necessary to consider the change in the atmospheric temperature at which the plant is at the maximum due to the relative humidity. Therefore, the operation control of the plant can be facilitated and more realistic operation can be performed. In addition, when the outside air temperature fluctuates, it is possible to facilitate control in the second temperature range where the efficiency of the combined plant is high. Even if there is a change in the outside air temperature, a desired output can be obtained stably and with high efficiency.

  Thereby, a highly reliable plant with respect to a temperature change can be formed.

  In some cases, the second temperature region can be narrowed to a certain set temperature. In such a case, it can be applied when a more efficient operation is intended. The exhaust gas recirculation system and the water spray system can be switched over at the boundary of the atmospheric temperature with high plant efficiency. This facilitates the control system.

  The high efficiency operation will be described in detail below. Plant efficiency is determined by plant output (gas turbine output and steam turbine output) and fuel flow rate. FIG. 14 shows the efficiency characteristics depending on the atmospheric temperature. When the atmospheric temperature becomes lower than the atmospheric temperature at which the plant efficiency is maximum, the compressor suction weight flow rate increases. On the other hand, since the combustion temperature is constant, the fuel flow rate increases and the gas turbine output increases.

  As an effect on the steam cycle, there is an increase in the gas turbine exhaust gas flow rate due to an increase in the compressor suction weight flow rate and a decrease in the gas turbine exhaust gas temperature due to the lower atmospheric temperature, but the influence of the gas turbine exhaust gas flow rate is large, Steam turbine output also increases.

  However, since the increase rate of the steam turbine output is small with respect to the increase rate of the gas turbine output, the increase rate as the plant output becomes small and the plant efficiency decreases.

  On the other hand, if the atmospheric temperature becomes higher than the atmospheric temperature at which the plant efficiency is the highest, the fuel flow rate also decreases and the gas turbine output and steam turbine output decrease as the compressor suction weight flow rate decreases, but the gas turbine output decreases. The ratio is large and the plant efficiency decreases.

  FIG. 15 shows the relationship between the atmospheric temperature and the plant output. The plant output changes depending on the atmospheric temperature, and the plant output increases as the atmospheric temperature decreases, and becomes a broken line. However, in an actual power plant, an authorized output is defined, and it is considered that operation exceeding the output is not performed. Therefore, when the approval output is obtained, the operation of the approval output is constant regardless of the atmospheric temperature as indicated by the solid line. At this time, the turbine is operated with a partial load. Further, when the atmospheric temperature increases, the plant turbine output decreases because the gas turbine compressor suction weight flow rate and the fuel flow rate decrease.

  FIG. 16 shows the plant efficiency characteristics depending on the atmospheric temperature.

  In the above-described combined plant, since the gas turbine becomes a partial load operation when the authorized output is constant, the plant efficiency is extremely lowered. However, according to this reference example, the gas turbine intake air temperature can be set to the same state as the atmospheric temperature with high plant efficiency.

  For example, the plant efficiency can be improved by about 0 to 1.5% relative to the gas turbine exhaust gas flow rate at a recirculation rate of 0 to 40%. In addition, when the compressor inlet temperature is higher than the atmospheric temperature in the region where the plant efficiency is high, droplets are sprayed from the water spray nozzle 11 to the gas turbine intake air, and the spray is 0 to 0.2% with respect to the gas turbine intake air flow rate. It is possible to improve the plant efficiency by relative amount by about 0.1%.

  Therefore, when the atmospheric temperature is low, the exhaust gas recirculation system can return a part of the gas turbine exhaust gas to the compressor inlet, thereby reducing the compressor suction weight flow rate and reducing the plant output. It is possible to operate with a constant authorization output without load operation. In addition, when the atmospheric temperature is high, the intake water spray system can increase the compressor suction weight flow rate and increase the plant output, enabling high-efficiency and constant load operation regardless of the atmospheric temperature. . Reference Example 7 will be described with reference to FIGS.

  Reference Example 7 can basically have the structure of Reference Example 6. In contrast to the control in Reference Example 6, the recirculation is performed in the first temperature range in which the detected temperature of the air temperature supplied to the compressor is set, and spraying of droplets from the spray device is stopped. When the detected temperature is in the second temperature range higher than the first temperature range, both the droplet spraying from the spray device are activated, and the third temperature range is higher than the second temperature range. In this case, the control is performed such that the recirculation is stopped and droplets are sprayed from the spraying device.

  The switching temperature between the first temperature region and the second temperature region and the switching temperature between the second temperature region and the third temperature region can be set in the same manner as in Reference Example 6. FIG. 13 shows an example of the control line.

  First, in the first temperature range (for example, when the compressor inlet temperature is lower than the compressor inlet temperature at which the plant efficiency is maximum), the recirculation amount is increased as the compressor inlet temperature is lower. be able to.

In the second temperature range (for example, the temperature range including the compressor inlet temperature at which the plant inlet temperature maximizes the plant efficiency), the gas turbine exhaust gas is recirculated and the droplet spraying from the water spray nozzle 11 is performed. .

  In this reference example, FIG. 13 shows a case where the second temperature range is 19 ° C. or more and 25 ° C. or less. Preferably, the second temperature range is divided into a high temperature side region and a low temperature side region of the set value. The set value is preferably set based on a value with high efficiency of the combine implant. For example, it can be set to 15 ° C. to 22 ° C. The second temperature region can also be set from the set value with about plus or minus 2 ° C. to 3 ° C.

  The second temperature range may be set to a temperature range where the plant can operate stably. Specifically, the compressor inlet temperature width may be about 5 ° C.

  In the low temperature region, the recirculation amount is kept constant and the intake water spray system is operated. It is preferable to set the spray amount of the droplets from the water spray nozzle (or the limit value of the spray amount) to be higher when the temperature is higher than when the temperature is low. The spray amount can be controlled so that the plant load is constant and the compressor inlet temperature is high so that the plant efficiency is high. Until the compressor inlet temperature reaches the compressor inlet temperature at which the plant efficiency becomes maximum, the recirculation amount is constant, and the spray amount can be controlled to increase as the compressor inlet temperature increases.

  In the high temperature side region, it is preferable to control the spray amount to be constant and to reduce the recirculation amount when the air temperature supplied to the compressor is higher than when it is low.

  In the third temperature range (for example, when the compressor inlet temperature is higher than the compressor inlet temperature at which the plant efficiency is the highest), the recirculation of the gas turbine exhaust gas is stopped and the water spray from the water spray nozzle 11 is stopped. Do. For example, the control can be performed such that the spray amount increases as the compressor inlet temperature increases.

  As a result, even if the outside air temperature fluctuates, high-efficiency constant driving is possible.

  Even when the outside air temperature fluctuates, since there is a region where both the recirculation of the combustion exhaust gas and the droplet spraying from the water spray nozzle 11 are performed, switching in the second temperature range is performed smoothly.

  Moreover, the possibility that the efficiency and output in the temperature range where the plant efficiency is high can be suppressed. Smooth liquid spraying and recirculation can be achieved smoothly, output fluctuations can be suppressed, and fluctuations from the desired output can be suppressed.

In the second temperature region, a region where switching between water spray from the water spray nozzle 11 and recirculation of the gas turbine exhaust gas occurs in the vicinity of this temperature region (for example, a temperature region in which the combined plant can perform high-efficiency operation). By forming a temperature region in which the water droplet spraying and recirculation are performed as in the example, even if the outside air temperature changes suddenly, a quick response can be made and high efficiency operation can be performed. Further, even if the outside air temperature fluctuates, it can greatly contribute to an operation (preferably a constant load operation) with high efficiency and reduced load fluctuation. In particular, it becomes easy to suppress fluctuations in the output of the appropriate liquid spray amount and recirculation amount due to fluctuations in the outside air temperature in the second temperature range.

  Examples of the present invention will be described. First, Example 1 will be described with reference to FIG.

  In the first embodiment, when carbon dioxide (for example, carbon dioxide) in the gas turbine exhaust gas is reduced, the carbon dioxide concentration mechanism for concentrating the carbon dioxide gas and the carbon dioxide contained by supplying the exhaust gas containing the concentrated carbon dioxide gas. A carbon dioxide gas removing device 41 for reducing the gas concentration is provided.

  As described above, the carbon dioxide-containing exhaust gas enriched with carbon dioxide can be introduced into the carbon dioxide removal device 41 to reduce the carbon dioxide gas. For example, compared with a case where the carbon dioxide removal device is simply installed in the gas turbine plant. Carbon dioxide can be removed with high efficiency. Moreover, when it has the same removal performance as the carbon dioxide removal apparatus installed in the conventional plant, the carbon dioxide removal apparatus can be downsized.

  For this reason, since the carbon dioxide removal apparatus installed in the flow path through which the gas turbine exhaust gas flows can be reduced in size, pressure loss can be suppressed and it can contribute to the highly efficient operation of the gas turbine.

  In addition, as the carbon dioxide gas concentration mechanism, the gas turbine exhaust gas is operated by recirculating the gas turbine exhaust gas as in this embodiment to generate a high concentration carbon dioxide exhaust gas. By forming the gas turbine so as to be introduced into the gas removal device, the gas turbine can be operated more efficiently.

  Thus, carbon dioxide gas can be removed with high efficiency while achieving high-efficiency operation of the gas turbine, so that it has the basic effect of forming an environment-friendly gas turbine or combined plant in consideration of the environment.

  Further, it is more preferable to operate the spray nozzle 11 as in the above-described embodiment.

  Here, the ratio of the carbon dioxide in exhaust gas with respect to a recirculation rate is shown in FIG. As described above, in the exhaust gas recirculation plant, the gas turbine exhaust gas is returned to the gas turbine intake side and circulated in the gas turbine cycle, whereby the concentration of carbon dioxide becomes higher than that in the conventional plant. As the amount of recirculation increases, the concentration of carbon dioxide in the exhaust gas also increases. For this reason, the carbon dioxide removal efficiency is also increased. When the oxygen concentration in the gas turbine exhaust gas is zero, that is, when the exhaust gas recirculation ratio is 75%, the carbon dioxide concentration in the exhaust gas is about four times that in the conventional plant. In order to achieve a recirculation operation with high combustion stability of the gas turbine while removing the carbon dioxide gas with high efficiency, the recirculation amount is preferably less than 75% of the flow rate of the gas turbine exhaust gas.

  Since the performance of the carbon dioxide removal device is proportional to the concentration, volume flow rate, and transmission area of the carbon dioxide gas, if the performance of the carbon dioxide removal device is the same, if the carbon dioxide concentration is quadrupled, the transmission area is reduced to 1 / Can be 4. In addition, for example, by operating in a region where the recirculation rate is 3/4 or less of the gas turbine exhaust gas and the recirculation rate is high, carbon dioxide can be removed more efficiently, and the amount of heat recovered to the plant increases and increases. Contributes to efficient operation.

  Example 1 can basically have the structure of Reference Example 6. In addition to the structure of Reference Example 6, an example in which a carbon dioxide gas removal device 41a is set in the exhaust path 31 is shown.

  The exhaust gas discharged from the gas turbine 3 is supplied to the upstream side of the compressor 1 through the recirculation means 9. A mixed gas of the atmosphere and the recirculated exhaust gas is introduced into the compressor 1 and pressurized. The mixed gas and fuel discharged from the compressor 1 are introduced into the combustor 2 and burned. Combustion exhaust gas having a higher carbon dioxide concentration than a simple gas turbine without the recirculation means 9 is discharged from the combustor 2 to drive the gas turbine 3. A part of the exhaust gas having a high carbon dioxide concentration is branched to the recirculation means 9, and the rest is introduced into the carbon dioxide removal device 41a installed in the exhaust gas passage 31 downstream from the branch portion to reduce the carbon dioxide concentration. The exhaust gas whose carbon dioxide concentration has been reduced is discharged into the atmosphere from a chimney or the like.

  Thereby, in addition to the basic effect, compared with the case where the present carbon dioxide gas removing device 41 is installed in the exhaust gas path 32 or the recirculation means 9 between the gas turbine and the branching portion of the recirculation means 9, The carbon dioxide concentration in the exhaust gas supplied to the carbon dioxide removing device 41 can be kept high. For this reason, the driving | operation which removes a carbon dioxide gas at high efficiency in this point can be performed. For this reason, when high efficiency is not required, the carbon dioxide gas removing device 41 can be downsized while obtaining desired performance. In addition, the pressure loss in the gas turbine exhaust gas path can be reduced for downsizing, and this can also contribute to the highly efficient operation of the gas turbine. Further, among the gas turbine exhaust gas flow rate, the flow rate discharged to the remaining atmosphere branched by the recirculation means 9 is introduced into the carbon dioxide gas removal device 9, so that the flow rate can be reduced, and pressure loss is also reduced in this respect. It can be suppressed and contributes to high efficiency operation of the gas turbine.

  Further, even when the recirculation amount is controlled to vary, the control of the carbon dioxide gas discharged to the atmosphere becomes easy.

  As the carbon dioxide removal device 41, for example, a device having a carbon dioxide removal performance that reduces the concentration of carbon dioxide supplied to the carbon dioxide removal device by about 5% to 10% can be used. For example, an amine-based absorbent can be used.

  Further, for example, when the exhaust heat recovery boiler 4 is located downstream of the branch portion of the recirculation means 9, the carbon dioxide gas removal device is disposed downstream of the exhaust heat recovery boiler from the viewpoint of further downsizing and material strength. Preferably there is. From the simplification of the equipment of the exhaust gas path, it can be considered to install in the exhaust heat recovery boiler.

  A second embodiment will be described with reference to FIG.

  In Example 2, the structure of Example 1 can be basically adopted.

  In the second embodiment, instead of the carbon dioxide removing device 41a of the first embodiment, a carbon dioxide removing device 41b is installed in the exhaust gas path 32 between the gas turbine and the branching portion to the recirculation means 9.

  The exhaust gas discharged from the gas turbine 3 is supplied to the upstream side of the compressor 1 through the recirculation means 9. A mixed gas of the atmosphere and the recirculated exhaust gas is introduced into the compressor 1 and pressurized. The mixed gas and fuel discharged from the compressor 1 are introduced into the combustor 2 and burned. Combustion exhaust gas having a higher carbon dioxide concentration than a simple gas turbine without the recirculation means 9 is discharged from the combustor 2 to drive the gas turbine 3. The high carbon dioxide concentration exhaust gas is introduced into the carbon dioxide removal device 41b to reduce the carbon dioxide concentration. A part of the exhaust gas having a reduced carbon dioxide concentration is branched to the recirculation means 9, and the rest is discharged from the chimney or the like to the atmosphere.

  In this way, in addition to the basic effect of the first embodiment, the carbon dioxide gas removal device removes the exhaust gas having a large flow rate and the high carbon dioxide gas concentration than the case where the carbon dioxide gas removal means 41 is installed in the recirculation means 9 or the exhaust gas path 31. 41b. For this reason, the carbon dioxide trapping amount per unit volume of the carbon dioxide remover 41b is increased, and the carbon dioxide removal efficiency can be improved. If high efficiency is not required, the carbon dioxide gas removing device 41 can be downsized while obtaining desired performance.

  A third embodiment will be described with reference to FIG.

  In Example 3, the structure of Example 1 can be basically adopted.

  In the third embodiment, a carbon dioxide removal device 41c is installed in the recirculation means 9 in place of the carbon dioxide removal device 41a of the first embodiment.

  The exhaust gas discharged from the gas turbine 3 is supplied to the upstream side of the compressor 1 through the recirculation means 9. A mixed gas of the atmosphere and the recirculated exhaust gas is introduced into the compressor 1 and pressurized. The mixed gas and fuel discharged from the compressor 1 are introduced into the combustor 2 and burned. Combustion exhaust gas having a higher carbon dioxide concentration than a simple gas turbine without the recirculation means 9 is discharged from the combustor 2 to drive the gas turbine 3. A part of the exhaust gas having a high carbon dioxide concentration is branched to the recirculation means 9, and the rest is discharged to the atmosphere from a chimney or the like. The exhaust gas branched to the recirculation means 9 is introduced into the carbon dioxide gas removing device 41b to reduce the carbon dioxide gas concentration. The exhaust gas whose carbon dioxide concentration has been reduced is supplied to the compressor 1 again.

  In this way, in addition to the basic effect of the first embodiment, it is not necessary to install the carbon dioxide gas removing device 41 that generates pressure loss in the path from the exhaust gas to the atmosphere, which contributes to high efficiency operation of the gas turbine. Can do. In addition, it is easy to install the carbon dioxide gas removing device 41c including the case where it is additionally installed in an already installed gas turbine plant. Further, in the gas turbine plant that uses the recirculation means as necessary, the carbon dioxide gas removal device 41c is installed separately from the system in which the gas turbine exhaust gas always flows, so that maintenance becomes easy. For example, even when the carbon dioxide gas removing device 41c is maintained, it is conceivable that the maintenance can be performed while the gas turbine operation is continued by closing the exhaust gas flowing into the recirculation line.

The schematic diagram of the reference example of this invention. The control schematic diagram of a general control apparatus. The figure which shows the wing periphery fluid behavior inside a compressor. The figure which shows the incidence change in the compressor by water spray. The figure which shows the relationship between a recirculation rate and a spray rate. Spray nozzle position schematic diagram. The control schematic diagram of a general control apparatus. The figure which shows the relationship between compressor exit temperature and a spray rate. The figure which shows the relationship of load-recirculation rate-mixture temperature. The figure which shows the thermal efficiency with respect to load. The schematic diagram of the reference example of this invention. The control schematic diagram of a general control apparatus. The schematic diagram of a control line. The schematic diagram which shows the efficiency characteristic by atmospheric temperature. Schematic diagram showing atmospheric temperature and plant output. The schematic diagram which shows the plant efficiency by atmospheric temperature. The schematic diagram of the Example of this invention. The schematic diagram which shows the ratio of the oxygen and carbon dioxide in exhaust gas with respect to a recirculation rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Combustor, 3 ... Gas turbine, 4 ... Waste heat recovery boiler (HRSG), 5 ... Steam turbine, 6 ... Generator, 7 ... Fuel supply system, 8 ... General control apparatus, 9 ... Exhaust gas re- Circulating means, 10 ... exhaust recirculation amount adjustment valve, 11 ... spray nozzle, 12 ... feed water flow rate adjustment valve, 13 ... feed water tank, 14 ... feed water pump, 15 ... air flow rate adjustment valve, 16 ... central power supply command station.

Claims (5)

A compressor that compresses air, a combustor that combusts compressed air and fuel discharged from the compressor, a gas turbine that is driven by combustion gas from the combustor, and a part of the gas turbine exhaust gas. A recirculation path for recirculation to the compressor inlet;
A carbon dioxide removal device that is installed in a gas turbine exhaust gas flow path and reduces the carbon dioxide concentration in the combustion exhaust gas discharged by introducing air containing the recirculated exhaust gas into the combustor;
A gas turbine apparatus comprising: The gas turbine apparatus according to claim 1, wherein
The carbon dioxide gas removing device is disposed between a branch portion of the exhaust gas path and the recirculation path, and a discharge section that discharges the exhaust gas to the atmosphere. The gas turbine apparatus according to claim 1, wherein
The carbon dioxide gas removing device is disposed between a branch portion of the gas turbine and the recirculation path in the exhaust gas path. The gas turbine apparatus according to claim 1, wherein
The gas turbine apparatus, wherein the carbon dioxide gas removing means is installed in the recirculation path. Air is compressed by a compressor, the compressed air and fuel are combusted by a combustor, a gas turbine is driven by combustion exhaust gas from the combustor, and a part of the exhaust gas passes through a recirculation path to the compressor. Recirculate to the entrance,
A method of operating a gas turbine apparatus, wherein fuel is burned in the combustor using the air containing the recirculated exhaust gas, and the concentration of carbon dioxide in the combustion exhaust gas discharged by the combustion is reduced. .

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