JP3220859U - Gas turbine and air turbine combined power generation facilities - Google Patents

Abstract

A gas turbine power generation facility that generates power by burning a fossil fuel and driving a gas turbine, and an air turbine power generation facility that generates power by driving the air turbine with high-temperature air obtained by recovering the exhaust heat are efficiently provided. A combined power generation facility that generates power in an economical combination is provided. A combined power generation facility in which air is heated by the exhaust energy of a gas turbine 5 and the air turbine 24 is driven by the pressurized high-temperature air, and has an appropriate height at the outlet of the exhaust system of the gas turbine 5. Efficiency is achieved by lowering the exhaust pressure of each turbine by setting an air turbine exhaust tower 26 or an exhaust induction tower at the gas turbine exhaust tower 13 and the exhaust system outlet of the air turbine 24 to make the inlets of both turbine exhaust towers negative. It is a combined power generation facility that generates electricity efficiently and economically. [Selection] Figure 1

Description

  The present invention burns fluid fuel such as liquefied natural gas or light oil to drive a gas turbine and generate power by a gas turbine generator, and simultaneously recovers exhaust heat from the gas turbine and drives an air turbine with heated air. The present invention relates to an economical gas turbine and air turbine combined power generation facility that generates electric power with an air turbine generator.

  In the prior patent document, Japanese Patent Application Laid-Open No. 2004-190558, for an equipment that has improved the heat cycle efficiency of combined power generation by providing an induction fan at the outlet of the gas turbine exhaust heat recovery device in the exhaust system of the gas turbine, An installation using an electric motor or steam turbine shaft power as a driving device is disclosed. Further, in the prior patent document, Japanese Patent Application Laid-Open No. 2013-40567, an example using a steam turbine is disclosed as an example of exhaust heat recovery equipment of a gas turbine.

JP 2004-190558 A JP 2013-40567 A

  In the preceding example, Japanese Patent Application Laid-Open No. 2004-190558, specific numerical values of suction pressure, discharge pressure, and wind pressure of the induction fan are not disclosed. Moreover, there is no description regarding the driving power numerical value from the steam turbine generating power to the induction fan. Furthermore, specific numerical values of the draft effect of the chimney installed in the induction fan outlet duct are not described. Furthermore, in the preceding example, Japanese Patent Application Laid-Open No. 2013-40567, there is an example of equipment that uses a heat recovery steam generator in the exhaust gas system of a gas turbine to drive the steam turbine with the generated steam and rotate the steam turbine generator to generate power. It is disclosed.

Means to solve the problem

  A facility has been devised to increase the output of each turbine by making the inlet of the exhaust tower of the gas turbine and air turbine negative pressure. In other words, by installing a gas turbine exhaust tower having a certain height and an air turbine exhaust tower or an air turbine exhaust induction tower at the exhaust duct outlet of the exhaust system of each turbine, the exhaust attraction generated by each exhaust tower It is possible to reduce the exhaust pressure of the exhaust system of each turbine to an appropriate level in consideration of the economics of the equipment cost by utilizing (aka: draft attraction). Further, an air turbine exhaust induction tower is provided at the outlet of the air turbine exhaust system, and a part of the compressed air at the outlet of the air turbine compressor is branched and injected into the lower part of the air turbine exhaust induction tower. Devised equipment to lower

Effect of device

  The combined power generation facilities of gas turbine and air turbine according to this study not only provide economical and highly efficient air conditions (= planned temperature of air turbine inlet / planned pressure condition) but also reasonable planned pressure and temperature of each turbine exhaust system. Clarified. That is, there is an effect of generating stable electric power by a highly efficient and economical combined power generation facility of a gas turbine and an air turbine.

  Furthermore, the present invention is not a conventional combined power generation facility that recovers the exhaust heat of the gas turbine with an exhaust heat recovery boiler and drives the steam turbine to generate electricity, but the present invention recovers the exhaust heat of the gas turbine with air to It is equipment that drives to generate electricity. In the case of the steam turbine system, a large amount of steam turbine cycle water and steam turbine condenser cooling water is required. On the other hand, the combined power generation facility of the present invention can supply inexpensive and stable power in a high temperature dry area where the water resources themselves are valuable and difficult to obtain.

1 shows an overall configuration of a combined power generation facility including a gas turbine and an air turbine. The overall structure of a combined power generation facility with an air turbine exhaust induction tower is shown. The thermal cycle of the gas turbine is shown on the gas turbine air gas temperature versus entropy diagram (Ts diagram of the gas). The thermal cycle of the air turbine is shown on the air temperature-entropy diagram (Ts diagram) of the air turbine. The plan pressure / temperature of the gas turbine air turbine combined power generation equipment of this invention is shown. Figure 6 shows the air turbine exhaust tower inlet temperature versus draft induced pressure change. Fig. 6 shows the air turbine exhaust induction tower inlet temperature versus the air turbine exhaust induction tower static pressure change.

  Exhaust towers with reasonable heights are installed at the discharge parts of both turbines of a combined power generation facility consisting of a gas turbine and air turbine, and the output of both turbines is increased by making the inlets of both turbine exhaust towers slightly negative. Examples of a combined power generation facility to be used and a combined power generation facility in which an air turbine exhaust induction tower is provided at an outlet portion of an air turbine will be described below with reference to FIGS.

  FIG. 1 shows a gas turbine power generation facility that generates power by burning a gas or liquid fuel to drive a gas turbine 5 and an air turbine power generation facility that generates power by driving an air turbine 24. Further, FIG. 1 shows an air heater 29 that recovers heat energy of the exhaust gas of the gas turbine 5 with compressed air, a gas turbine power generation facility having a gas turbine exhaust tower 13 having a certain height, and an exhaust of the gas turbine 5. A basic configuration of a combined power generation facility having an air turbine 24 and an air turbine exhaust tower 26 driven by pressurized high-temperature air obtained by collecting heat with an air heater 29 is shown.

  Air in the atmosphere passes through the gas turbine compressor inlet duct 8 of FIG. 1, passes through the gas turbine compressor suction filter 9, and is pressurized by the gas turbine air compressor 4. As conditions for gas turbine performance, the air pressure in the suction atmosphere is 0.1013 MPa, the temperature is 15 ° C. (288 K), and the relative humidity is 60%. Although the pressure ratio of the compressor 4 varies depending on the type of the gas turbine, for example, if the pressure ratio is 14 as a general value, the air pressure at the outlet of the compressor 4, that is, the inlet pressure of the gas turbine 5, is an atmospheric pressure of 0.1013 MPa. The pressure is about 14 times 1.4 MPa.

  The average combustion temperature of the combustor 3 of the gas turbine was the nominal gas turbine combustion temperature at the inlet of the gas turbine 5. The representative value of this temperature is determined by the output and model of the gas turbine. In the present invention, a representative temperature of 1100 ° C. (1373 K) is adopted. Equipment installed in the gas turbine exhaust system, for example, the inlet / outlet temperature of the air heater 29, the high-temperature denitration apparatus 11, the air turbine 24, etc. is the temperature, the thermal efficiency of the gas turbine 5, and the heat loss that goes out of the system from each exhaust gas duct. Determined by temperature difference due to FIG. 5 shows an example of the planned temperature and pressure of these devices.

  The gas turbine fuel that has passed through the fuel pipe 2 passes through the fuel adjustment valve 1 and is sent to the combustor 3. Combustion gas generated in the combustor 3 is mixed with about 1.4 MPa air compressed by the gas turbine compressor 4 and flows into the gas turbine 5 to drive the gas turbine air compressor 4 and the gas turbine generator 6. . The gas turbine starting electric motor 7 is used when starting the gas turbine 5. The gas turbine exhaust gas exiting the gas turbine 5 passes through the air heater 29 and the high temperature denitration device 11 and is discharged out of the system by the draft attraction pressure of the gas turbine exhaust tower 13.

  The exhaust gas entering the gas turbine exhaust tower 13 has a temperature of about 330 ° C., and a draft attraction pressure corresponding to this temperature is generated in the gas turbine exhaust tower 13. This pressure and temperature are shown in FIG.

  The high-temperature gas of about 605 ° C. that has passed through the gas turbine exhaust duct 28 of FIG. 1 flows into the air heater 29, and the air turbine compressor 23 uses a reference atmospheric pressure of about 0.1013 MPa to about 0.5 MPa (pressure ratio of about 5 The compressed air compressed in (1) is heated. The hot gas flows outside the air heating pipe 16 to raise the temperature of the compressed air, and the heated compressed air passes through the air heater outlet pipe 17, the air turbine adjustment valve 18, and the air turbine inlet pipe 19 and passes through the air turbine 24. Flow into. The pressure is about 0.5 MPa and the temperature is 600 ° C. The pressurized hot air drives the air turbine compressor 23 and the air turbine generator 14 to compress the air and generate electric power. The air turbine starting motor 27 is used when starting the air turbine 24.

  About 310 ° C. air leaving the air turbine 24 flows down to the air turbine exhaust tower 26. If the temperature drop of the exhaust air in the air turbine exhaust duct 25 is 5 ° C., the temperature of the air entering the air turbine exhaust tower 26 has a temperature of about 305 ° C., and the draft attraction pressure generated by this temperature is generated. .

  FIG. 2 shows an installation in which an air turbine exhaust induction tower 34 is installed in place of the air turbine exhaust tower 26 of FIG. 1 in order to increase the negative pressure at the inlet of the air turbine exhaust tower 26 of FIG. A part of the compressed air is taken out from the air turbine compressor outlet pipe 15 in FIG. 2, and this compressed air passes through the air turbine compressor branch pipe 30 and the compressed air adjusting device 31 and is compressed through the compressed air adjusting device outlet duct 32. It is sent to the air introduction duct 33. The compressed air that has passed through the compressed air introduction duct 33 is combined with the exhaust air of the air turbine 24 that has passed through the air turbine exhaust duct 25, thereby increasing the dynamic pressure of the exhaust air flowing in the air turbine exhaust induction tower 34. Reduce static pressure. By reducing the static pressure of the air turbine exhaust attraction tower 34, the attraction pressure of the air turbine exhaust attraction tower 34 increases and the output of the air turbine 24 increases.

  FIG. 3 shows a gas turbine thermal cycle 4 point E → F point → G point → H point on a gas turbine air gas temperature vs. entropy diagram (Ts diagram of gas). In FIG. 3, the air is compressed by the gas turbine compressor 4 from the inlet air atmospheric pressure / temperature (0.1013 MPa / 15 ° C.) of the gas turbine 5 and is increased in pressure to about 1.4 MPa / 370 ° C. Is shown from point E to point F. Next, the point at which the fuel temperature is increased by burning the fuel in the combustor and the typical combustion temperature is 1100 ° C. (1373 K) is indicated by the G point. Next, the gas turbine exhaust gas leaving the gas turbine 5 passes through the air heater 29, the air heater outlet duct 10, the high temperature denitration device 11, and the high temperature denitration device outlet duct 12 and flows to the gas turbine exhaust tower 13. At this time, pressure loss is generated in the exhaust gas. Assuming that the total of these pressure losses is ΔP1, the exhaust pressure of the gas turbine 5 becomes the reference atmospheric pressure 0.1013 MPa + ΔP1, and can only expand up to point H in FIG. 3, and is surrounded by three points, point E → point H → point I. The amount of energy that cannot be recovered becomes lost energy.

  Some kind of exhaust gas equipment is installed in the exhaust system of the gas turbine, and it is impossible to set ΔP1 to “0”, but it is as close as possible to the point I in FIG. 3 where the pressure is reduced to the outside air reference pressure of 0.1013 MPa. Obtaining the gas turbine exhaust pressure, for example, setting the height of the exhaust tower to an appropriate height in consideration of economy is one of effective means for improving the gas turbine efficiency.

  FIG. 4 is a diagram showing the air turbine power generation cycle according to the present invention at points A → B → C → D on an air temperature-air entropy diagram (Ts diagram of air). The atmospheric pressure at the inlet of the air turbine compressor is 0.1013 MPa, the temperature is 15 ° C., the relative humidity is 60%, and this is a reference state. This state is indicated by symbol A in FIG. 4 and is the state at the inlet of the air turbine air compressor 23. The inlet air condition of the compressor 23 depends on the local weather conditions. Thereafter, the compressor outlet pressure is compressed to about 0.5 MPa by the compressor 23. If the typical compression efficiency is about 82%, the compressed air temperature is about 207 ° C. This state is indicated by symbol B in FIG. Next, this air is heated by an air heater 29 to about 600 ° C. with gas turbine exhaust gas. This state is indicated by symbol C in FIG. Next, this air is expanded in the air turbine 24 to an atmospheric pressure of about 0.1013 MPa to generate power generation and air compression power. When the turbine efficiency is a typical value of about 88%, the turbine outlet air temperature is about 310 ° C. This state is indicated by symbol D in FIG. Next, the air turbine exhaust air that has exited D passes through the air turbine exhaust duct 25 and is sucked out by the attraction pressure of the air turbine exhaust tower 26 and discharged out of the system.

  FIG. 5 shows an example of an appropriate planned pressure / planned temperature for each device when planning a combined power generation facility of a gas turbine and an air turbine. Each of the air heater 29, the high temperature denitration device 11, the gas turbine exhaust duct 28, the air heater outlet duct 10 and the high temperature denitration device outlet duct 12 installed between the gas turbine 5 outlet exhaust portion and the gas turbine exhaust tower 13 inlet portion. Assuming that the total value of pressure loss is ΔP1, the exhaust pressure of the gas turbine 5 is atmospheric pressure + ΔP1. On the other hand, the pressure at the inlet of the gas turbine exhaust tower 13 is the atmospheric pressure-attraction pressure ΔP3 of the gas turbine exhaust tower.

  As shown in FIG. 5, when the combustion temperature of a general gas turbine is 1100 ° C., the gas turbine 5 outlet temperature is reduced to about 605 ° C. depending on the efficiency. This exhaust gas is introduced into the air heater 29, and high-temperature air of about 600 ° C. is generated by the heat energy of the exhaust gas. This air is introduced into the air turbine 24 to drive the air turbine 24, lowering the air turbine exhaust gas temperature to about 310 ° C. and guiding it to the air turbine exhaust tower 26. The air turbine exhaust tower draft attraction pressure corresponding to this temperature is 0.61 mAq from FIG. If the height of the air turbine exhaust tower is 10 m, an attractive pressure ΔP4 of the air turbine exhaust tower 26 is generated about 6.1 mAq. The planned pressure loss ΔP2 of the air turbine exhaust duct 25 depends on the internal structure and the internal size. Judging from the actual pressure loss value of the air duct, the design pressure loss ΔP2 of the air turbine exhaust duct 25 can be designed to be less than about 6.1 mAq of the air turbine induced pressure ΔP4.

  FIG. 6 shows a change in air turbine draft attraction pressure corresponding to a change in air temperature at the inlet of the air turbine exhaust tower 26. The specific value of the attraction pressure is calculated by calculating the difference in specific gravity between the specific gravity of air at an atmospheric temperature of 15 ° C., a pressure of 0.1013 MPa and a relative humidity of 60%, and the specific gravity of the exhaust air temperature at the inlet of the air turbine exhaust tower. Calculated. Since the saturation temperature of the humid air when the atmospheric pressure is a standard pressure of 0.1013 MPa is 100 ° C., as shown in FIG. 6, the draft attraction pressure between 15 ° C. and 100 ° C. when the exhaust temperature rises as shown in FIG. It suddenly rises to about 0.5 mAq. After the water saturation temperature exceeds 100 ° C., the wet steam changes to dry steam, so that the draft of the draft attraction pressure tends to increase gradually, and the pressure increase amount increases the exhaust air temperature from 100 ° C. to 500 ° C. Even if it is increased, the change in draft attraction pressure is as small as 0.5 to 0.7 mAq and the range of increase is about 0.2 mAq.

The draft attraction pressure at the inlet of the air turbine exhaust tower 26 is approximately 0.615 kg / m ³ of the specific gravity of air at an air temperature of 305 ° C. of the air turbine exhaust tower 26, external reference large pressure / temperature / humidity conditions (0.1013 MPa). The specific gravity at / 15 ° C./60%) is 1.222 kg / m ³ , and the difference between the two is 0.607 kg / m ³ . Therefore, the draft attraction pressure per 1 m of the air turbine exhaust tower is the difference between the two and becomes 0.605 mAq.

  The gas turbine exhaust gas that has exited the air heater 29 passes through the air heater outlet duct 10, the high-temperature denitration device 11, and the high-temperature denitration device outlet duct 12 and flows down to the gas turbine exhaust tower 13. The temperature of this gas is about 330 ° C. This change in gas specific gravity cannot be determined unconditionally because it varies depending on the combustion temperature of the gas turbine, the type of machine, the type of fuel, and the atmospheric conditions. However, the draft drawing pressure characteristic chart for air shown in FIG. 6 is similar to the draft drawing pressure characteristic chart for gas turbine exhaust gas. That is, a rough draft attraction pressure per 1 m of the gas turbine exhaust tower can be estimated.

  The combustion temperature of the gas turbine taken up in the present invention is a general temperature of 1100 ° C. From FIG. 3, the gas turbine exhaust gas temperature is about 605.degree. If the gas temperature drop width in the air heater is about 275 ° C., the inlet gas temperature of the gas turbine exhaust tower 13 is about 330 ° C. Therefore, from FIG. 6, it can be estimated that the draft attraction pressure per 1 m of the gas turbine exhaust tower 13 is about 0.62 mAq.

  If the height of the gas turbine exhaust tower is typically 10 m, the attraction pressure of the gas turbine exhaust tower 13 can be estimated to be about 6.2 mAq. The gas turbine exhaust part pressure loss ΔP1 shown in FIG. 5 mainly depends on the internal structure and size of the air heater 29 and the high-temperature denitration device 11 and the length of each device. Judging from the actual value of each device having the same type of results, the gas turbine exhaust section pressure loss ΔP1 can be designed to be less than or equal to the attractive pressure of about 6.2 mAq.

  FIG. 7 shows changes in static pressure of the air turbine exhaust attraction tower 34 per 1 m height of the air turbine exhaust attraction tower 34 with respect to changes in the exhaust air temperature at the inlet of the air turbine exhaust attraction tower 34, and the flow velocity in the air turbine exhaust attraction tower 34. Shown as a parameter.

  When the inlet temperature of the air turbine exhaust attraction tower 34 in FIG. 7 rises to 0 ° C. to 100 ° C., the static pressure of the air turbine exhaust attraction tower 34 increases, but when the temperature rises to 100 ° C. to 500 ° C., the air turbine exhaust attraction is induced. The increase in the static pressure of the tower 34 decreases. However, when the average flow velocity of the air turbine exhaust attraction tower 34 is increased from 1.11 m / s to 1.6 m / s, the static pressure of the air turbine exhaust attraction tower 34 decreases and the negative pressure of the air turbine exhaust pressure increases. As a result, the output of the air turbine 24 increases.

  Although an increase in gas or air turbine output due to a decrease in the exhaust pressure of the gas turbine 5 or the air turbine 24 can be expected, the gas or air turbine and each air compressor are connected to the atmosphere through an air flow path, and negative pressure below atmospheric pressure is detected. The pressure region is from the gas or air turbine exhaust part outlet to the gas or air turbine exhaust tower inlet, and the upstream side from the gas or air turbine exhaust part outlet is a positive pressure operating region higher than atmospheric pressure. Thus, it is necessary to plan the height of each tower in consideration of the economics of each exhaust tower and exhaust attraction tower.

DESCRIPTION OF SYMBOLS 1 Fuel regulating valve 2 Fuel piping 3 Combustor 4 Gas turbine air compressor 5 Gas turbine 6 Gas turbine generator 7 Gas turbine starting electric motor 8 Gas turbine compressor inlet duct 9 Gas turbine compressor suction filter
DESCRIPTION OF SYMBOLS 10 Air heater exit duct 11 High temperature denitration apparatus 12 High temperature denitration apparatus exit duct 13 Gas turbine exhaust tower 14 Air turbine generator 15 Air turbine compressor exit pipe 16 Air heating pipe 17 Air heater outlet pipe 18 Air turbine adjustment valve 19 Air Turbine inlet pipe 20 Air turbine compressor inlet duct 21 Air turbine compressor suction filter
22 Air turbine inlet duct 23 Air turbine compressor 24 Air turbine 25 Air turbine exhaust duct 26 Air turbine exhaust tower 27 Air turbine starter motor 28 Gas turbine exhaust duct 29 Air heater 30 Air turbine compressor branch pipe 31 Compressed air adjustment device 32 Compressed air conditioner outlet duct 33 Compressed air introduction duct 34 Air turbine exhaust induction tower

Claims (2)

  Combustor for burning fluid fuel such as liquefied natural gas or light oil, gas turbine driven by combustion gas, gas turbine generator driven by the gas turbine, and air for heating air with the exhaust gas of the gas turbine A heater, an air turbine driven by pressurized high-temperature air heated by the air heater, an air turbine generator driven by the air turbine, and a gas provided to be connected to the air heater outlet duct A turbine exhaust tower and an air turbine exhaust tower provided so as to be connected to an air turbine outlet duct. The gas turbine exhaust tower inlet and the air turbine exhaust tower inlet pressure are determined by a draft attraction pressure of each exhaust tower. A combined power generation facility using a gas turbine and an air turbine, wherein the turbine output is increased by lowering the exhaust pressure of each turbine in a negative pressure state   A gas turbine that burns fluid fuel such as liquefied natural gas or light oil, a gas turbine generator that is driven by the gas turbine, an air heater that heats air using the exhaust gas of the gas turbine, and the air heater An air turbine driven by heated pressurized hot air, an air turbine generator driven by the air turbine, a gas turbine exhaust tower provided at the exhaust duct outlet of the air heater outlet duct, and an air turbine compression A pipe that branches a part of the compressed air from the compressor of the compressor and sends the compressed air to the air turbine exhaust induction tower, a compressed air adjustment device that adjusts the branched compressed air, and an outlet of the air turbine exhaust duct By the air turbine exhaust induction tower, the gas turbine exhaust tower inlet and the air turbine exhaust tower inlet pressure are in a negative pressure state due to the draft induction pressure of each exhaust tower. Gas turbine and air turbine combined power generation facility, characterized by increasing the turbine output by lowering the exhaust pressure of the turbine to.

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