WO2006035522A1 - Gas turbine apparatus, low calorie content gas feeding apparatus, and method of suppressing rise of calorie content of the gas - Google Patents

Abstract

A gas turbine apparatus, a low calorie content gas feeding apparatus capable of feeding a low calorie content gas as a fuel for gas turbine stabilized by suppressing the sudden rise of its calorie content, and a method of suppressing the rise of calorie content of the gas. The low calorie content gas feeding apparatus comprises a low calorie content gas feed pipe (3) feeding the low calorie content gas to a gas turbine (2), an exhaust gas feed pipe (4) feeding exhaust gas to the low calorie content gas feed pipe (3), a first mixer (6) disposed in a connection part between the low calorie content gas feed pipe (3) and the exhaust gas feed pipe (4), a calorimeter (11) disposed in the low calorie content gas feed pipe (3) and detecting a heated value in the gas, an oxygen analyzer (15) installed on the downstream side of the first mixer (6) in the low calorie content gas feed pipe (3), and a controller (100). The controller (100) feeds the exhaust gas from the exhaust gas feed pipe (4) when the detection value of the calorimeter (11) exceeds a reference value, and based on the detected results of the oxygen analyzer (15), controls an exhaust gas mixing ratio so that it does not come into the inflammable limit of the low calorie content gas.

Description

 Specification

 Gas turbine equipment, low calorie gas supply equipment, and method for suppressing calorie rise of the gas

 Technical field

 [0001] The present invention relates to a gas turbine facility, a low calorie gas supply facility, and a calorie increase suppressing method for the gas. More specifically, in detail, a low calorie gas supply facility that supplies gas turbines with low calorie gas as fuel for the gas turbine, a gas turbine facility equipped with the low calorie gas supply facility, and a low calorie gas for the gas turbine fuel It is related with the method of suppressing the raise of the calorific value (it is also called force Lori) of the.

 Background art

[0002] In the field of iron making, for example, when pig iron is produced by the blast furnace method, a top gas (Blast Furnace Gas, hereinafter referred to as BFG) is generated as a by-product gas from the blast furnace. Since the total calorific value of BFG reaches about half of the calorific value of the used Kotas, BFG is widely used in steelworks to reduce the cost of ironmaking. BFG is generated about 3000Nm ³ per ton of input cortas, and its composition is 10-18% by volume of carbon dioxide (CO)

 2

 , Simply referred to as%), carbon monoxide (CO) is 22-30%, nitrogen (N) is 52-60%, hydrogen (H

 2

 ) Is about 0.5-4%, and methane (CH) is about 0.5-3%.

 twenty four

[0003] In addition to this, BFG contains 2-10 g / Nm ^{3 of} dust. After removing this to about 0. Olg / Nm with a dust remover, hot air is used as fuel gas with a calorific value of about 800 kcal / Nm ^3. Used in furnaces, coke ovens, heating furnaces, boilers, etc. In recent years, gas turbines have also been able to burn low calorie gas due to improvements in technology, and there are an increasing number of cases where BFG is used as gas turbine fuel to generate electricity. The low calorie gas here is defined as a gas whose calorific value is about 12 MJ / Nm ³ or less. As will be described later, the low calorie gas is not limited to blast furnace gas (BFG), but includes many other types of gases such as converter gas (LDG) and mixed gases thereof.

[0004] On the other hand, in recent years, new U and iron manufacturing processes other than the blast furnace method (for example, direct reduction iron methods such as FINEX and COREX) are being developed. The development of a combustion method that can be applied to effective use is awaited. Even if the steel manufacturing process is different, the characteristics (gas composition and calorie) of the by-product gas generated will vary depending on the equipment and operation. Even with the same equipment, it changes from moment to moment according to the characteristics of each raw material and the reaction process, and does not become constant.

 [0005] Looking at calorie, which is the most important characteristic when using by-product gas as fuel for gas turbines, the upper limit of the allowable fluctuation range of calories inherent in each gas turbine (for example, about the average calorie value). + 10%), that is, when the calorific value suddenly increases, the combustion temperature in the combustor of the gas turbine may suddenly become abnormally high. As a result, the PANA portion, turbine stationary blades and rotor blades may be damaged, resulting in a short life. In this case, economical continuous operation of the gas turbine equipment becomes difficult.

 [0006] Technology for diluting with nitrogen gas (N) to suppress the fluctuating calories of by-product gas

 2

 Are known (see, for example, Patent Document 1 and Patent Document 2). However, only N

 When diluting the by-product gas by 2, depending on the variation of calories, expensive inert such as N

 2

 I have to use a lot of gas. Moreover, it is very difficult to secure a large amount of inert gas continuously except for special industrial fields. Furthermore, it is necessary to install a large amount of inert gas storage equipment and various equipment for gas supply including piping. For these reasons, the use of inert gas reduces the economics of gas turbine power generation and hinders the technical advantages of gas turbines that advocate high efficiency.

 Patent Document 1: JP 2002-155762 A

 Patent Document 2: JP-A-9-317499

 Disclosure of the invention

 Problems to be solved by the invention

[0007] The present invention has been made in order to solve the problem to be solved, and the supply of low calorie gas capable of mitigating the calorie rise of the low calorie fuel gas for gas turbines is low in equipment cost and operation cost. An object of the present invention is to provide a facility, a gas turbine facility equipped with this low calorie gas supply facility, and a method for suppressing an increase in the calorific value of low calorie gas for gas turbine fuel. Means for solving the problem

 [0008] For the above purpose, the low-calorie gas supply facility of the present invention comprises:

 A low-calorie gas supply passage for supplying low-calorie gas as fuel gas to the gas turbine;

 An exhaust gas supply passage connected to the low calorie gas supply passage for supplying exhaust gas generated by the combustion facility to the low-power regas supply passage;

 A calorific value detection device for detecting the calorific value in the gas disposed in the low calorie gas supply passage;

 And a control device capable of controlling the exhaust gas supply operation by the exhaust gas supply passage based on the detection result of the calorific value detection device.

[0009] According to the present invention, a large amount of non-combustible gas such as N, carbon dioxide (CO) is included (flammable

 twenty two

 Mixing the exhaust gas from combustion equipment that does not contain gas and is extremely easy to procure can be used to dilute the low calorie gas, thereby suppressing the calorie rise of the low calorie gas. Here, the calorific value detection device includes not only a device that directly measures the calorific value of gas (for example, a so-called calorimeter) but also a device that measures the content of combustible components in the gas.

 [0010] The control device supplies exhaust gas from the exhaust gas supply passage when the maximum allowable calorie value of the fuel gas of the gas turbine is set and the caloric value of the low calorie gas exceeds the maximum allowable calorie set value. Can be configured to.

 [0011] An oxygen concentration detection device is disposed in a portion of the low calorie gas supply passage downstream of the connection portion with the exhaust gas supply passage, and the control device is based on the detection result of the oxygen concentration detection device. Therefore, low calorie gas supply equipment configured to control the exhaust gas supply operation through the exhaust gas supply passage is preferred. This is because the mixing of the exhaust gas containing oxygen with respect to the low calorie gas can be controlled based on the oxygen content of the mixture to prevent ignition of the mixture of low calorie gas and exhaust gas.

[0012] The facility equipped with this oxygen concentration detection device has an allowable mixed volume ratio of exhaust gas set based on the low calorific gas flammability limit information obtained by the control device from the mixing ratio of low calorie gas and exhaust gas. The amount of exhaust gas supplied through the exhaust gas supply passage can be controlled based on the above. [0013] Alternatively, in the equipment equipped with this oxygen concentration detection device, the above-mentioned control device may allow air to be set based on low calorific gas flammability limit information obtained from the mixing ratio of low calorie gas and air. The exhaust gas supply amount through the exhaust gas supply passage can be controlled based on the allowable mixed volume ratio of the exhaust gas calculated based on the oxygen content ratio from the mixing volume ratio.

 [0014] In the equipment provided with the oxygen concentration detection device, an inert gas supply passage for supplying an inert gas is connected to the low calorie gas supply passage, and the control device is a device for the oxygen concentration detection device. It is preferable that the inert gas supply operation by the inert gas supply passage is controlled based on the detection result. For example, when the exhaust gas supply is restricted and thus the calorie rise of the low calorie gas is insufficiently suppressed, the supply of the inert gas can compensate for the calorie fluctuation suppressing effect. Note that a portion of the inert gas supply passage leading to the mixing section may constitute a common passage with the exhaust gas supply passage.

 [0015] An inert gas supply passage for supplying an inert gas is connected to the low calorie gas supply passage, and the control device supplies exhaust gas to the low calorie gas supply passage through the exhaust gas supply passage. In this state, a low-power regas supply facility configured to control the inert gas supply operation through the inert gas supply passage based on the detection result of the calorific value detection device is preferable. This is because if the calorie rise of low calorie gas due to exhaust gas is insufficiently suppressed, it can be compensated by inert gas.

In each of the above facilities, a first tank for temporarily storing low calorie gas is disposed in the low calorie gas supply passage, and the first tank has an inlet and an outlet. It is preferable that the upstream side of the low calorie gas supply passage is connected to the inlet, and the downstream side of the low calorie gas supply passage is connected to the outlet. All of the low caloric gas supplied through the low caloric gas supply passage is temporarily stored in the first tank and mixed in it, thereby reducing the width of the caloric fluctuation and reducing the caloric fluctuation. This is because the speed is reduced, and calorie leveling control by dilution with exhaust gas downstream of the first tank outlet becomes easier. The calorific value detection device described above is installed in the low calorie gas supply passage, and the first tank and the second tank described later are installed in the low calorie gas supply passage. In the installed equipment, since this tank also constitutes a low calorie gas supply passage, it also includes attaching a calorific value detection device to the tank.

 [0017] A second tank for temporarily storing low calorie gas is disposed in the low calorie gas supply passage, and low calorie gas is supplied between the low calorie gas supply passage and the second tank. Passage force A gas inlet passage for feeding into the second tank and an outlet passage for returning the low calorie gas to the second tank force low calorie gas supply passage are provided, and the low calorie gas is supplied to the second tank in the inlet passage. A low-calorie gas supply facility in which a first gas pumping device that pumps the gas toward is preferable. This is because the same action as that of the first tank is performed.

 [0018] It should be noted that both the first tank and the second tank described above may be fixed-type tanks whose internal volume does not change, and the supply and demand tolerance of gas in the conventional gas turbine equipment, etc. It may be an internal volume variation type tank used as a monitoring device (gas holder). The internal volume variation type tank is a tank having an airtightly attached lid member that can move up and down according to the tank internal pressure, and the balance member is maximized by positively moving the lid member up and down by a driving device. A tank or the like that can select an available tank volume.

 [0019] A return passage for returning a part of the low calorie gas to be supplied to the upstream side of the low calorie gas supply passage is provided in the low calorie gas supply passage, and the low calorie gas is supplied to the low calorie gas supply passage in the return passage. A low calorie gas supply facility in which a second gas pumping device for pumping upstream is disposed is preferable. They are the same as those of the first tank.

 [0020] Low-calorie gas supply comprising an exhaust gas blocking device arranged in the exhaust gas supply channel and capable of blocking and opening the passage, and an exhaust gas discharge device arranged upstream of the exhaust gas blocking device Facilities are preferred. For example, a stop valve or a flow control valve can be used as the exhaust gas shut-off device.

[0021] An inert gas blocking device disposed in the inert gas supply passage and capable of blocking and opening the passage, and an inert gas discharge device disposed upstream of the inert gas blocking device. A low-calorie gas supply facility equipped with For example, a stop valve or a flow control valve can be used as the inert gas shut-off device. Inert gas reaching the low calorie gas supply passage When a part of the gas supply passage constitutes a passage common with the exhaust gas supply passage and an exhaust gas cutoff device and an exhaust gas discharge device are provided, the inert gas cutoff device and the exhaust gas cutoff are provided. A single shut-off device that also serves as a device may be provided, or a single discharge device that serves as both an inert gas discharge device and an exhaust gas discharge device may be provided.

 [0022] As the exhaust gas for dilution of the combustion facility, exhaust gas that also generates the gas turbine force, which is a target to which the low calorie gas supply facility supplies fuel, can be used. In addition to using the exhaust gas generated by the gas turbine car directly, it also includes using this exhaust gas as a dilution gas after it is used in a heat recovery boiler.

 [0023] Alternatively, exhaust gas generated from the boiler of the steam power generation facility can be used as the exhaust gas of the combustion facility. Since the exhaust gas generated from boiler boilers in steam power generation facilities has a lower oxygen content than the gas turbine exhaust gas, the mixing ratio can be increased.

 [0024] The gas turbine equipment of the present invention comprises:

 It is equipped with a gas turbine and a low-calorie gas supply facility for supplying low-calorie gas as fuel gas to the gas turbine, and this low-calorie gas supply facility is one of the above-mentioned low-calorie gas supply facilities. .

 [0025] In such a gas turbine facility, a plurality of gas turbines are installed, and each gas turbine is provided with a low calorie gas supply facility, and the above combustion facilities of the low calorie gas supply facility are compatible. A gas turbine other than the gas turbine may be used. That is, gas generated from a gas turbine other than the gas turbine corresponding to the low calorie gas supply facility may be employed as the exhaust gas for dilution for the low calorie gas supply facility.

 [0026] The low calorie gas calorie rise suppressing method for gas turbine fuel of the present invention includes:

 A calorie measurement step for measuring the calorific value of the low calorie gas supplied to the gas turbine as fuel gas;

 An exhaust gas mixing step of mixing the exhaust gas for dilution collected from the combustion equipment into the low calorie gas when the measurement result exceeds the set allowable caloric value.

[0027] The exhaust gas mixing step includes the step of measuring the oxygen concentration of the mixture of low calorie gas and exhaust gas, and the measurement result exceeds the set allowable exhaust gas content obtained from the low calorie gas flammability limit information. Including the step of adjusting the amount of exhaust gas mixed, A rise suppression method is preferred.

 [0028] Further, when it is determined that the calorific value measurement result does not fall below the set allowable caloric value even with the maximum exhaust gas supply, the method further includes a step of mixing an inert gas into the low caloric gas, Preferred method.

 [0029] Then, according to the calorie increase suppressing method including the step of adjusting the exhaust gas mixing amount, if the exhaust gas mixing amount is decreased, the calorific value of the air-fuel mixture exceeds the set allowable caloric value and increases. When it is determined that the set allowable exhaust gas content is exceeded, it is preferable to further include a step of reducing the amount of exhaust gas mixed and supplying an inert gas to the low-strength regas.

 [0030] In the low calorie gas supply facility in which the upstream side and the downstream side of the low calorie gas supply passage are connected to the inlet and outlet of the tank, respectively, the low calorie gas supply passage upstream of the tank and the low calorie gas supply downstream of the tank A return passage can be connected to the passage, and a gas pumping device that pumps fuel gas toward the low calorie gas supply passage upstream of the tank can be installed in the return passage.

 [0031] In the low calorie gas supply facility having the inlet passage and the outlet passage connecting the low calorie gas supply passage and the tank,

 A return passage is connected between the downstream side from the connection point with the outlet passage in the low calorie gas supply passage and the upstream side from the connection point with the inlet passage in the low calorie gas supply passage, and fuel gas is supplied to the return passage. It is possible to install a gas pressure feeding device that pumps toward the upstream low calorie gas supply passage.

 [0032] It is preferable to install a stirring device for stirring the gas inside the tank.

 The invention's effect

 [0033] According to the present invention, the facility for supplying the gas turbine with the low calorie gas that can change the calorie, such as the process by-product gas, is realized by the low facility cost and the operation cost. In order to suppress the caloric rise of low calorie gas that can be used as fuel gas,

 This is because it is possible to easily obtain a large amount of exhaust gas containing a large amount of non-combustible gas.

Brief Description of Drawings FIG. 1 is a piping diagram showing an outline of a gas turbine power generation facility including a low calorie gas supply facility according to an embodiment of the present invention.

 [FIG. 2] FIG. 2 is a graph showing the flammability limit of a mixture of low calorie gas and air, with the horizontal axis representing the volume ratio of low calorie gas and the vertical axis representing temperature.

 [FIG. 3] FIG. 3 is a graph showing an example of a state in which the calorie fluctuation of low calorie gas is mitigated by passing through the buffer tank in FIG.

 [FIG. 4] FIG. 4 is a graph showing another example of the state where the calorie fluctuation of the low calorie gas is mitigated by passing through the koffa tank.

 [FIG. 5] FIG. 5 is a graph showing still another example of the state where the calorie fluctuation of the low calorie gas is mitigated by passing through the koffa tank.

 FIG. 6 is a piping diagram showing another example of a buffer tank that can be installed in the gas turbine power generation facility of FIG.

 FIG. 7 is a piping diagram showing yet another example of a buffer tank that can be installed in the gas turbine power generation facility of FIG.

 FIG. 8 is a piping diagram showing still another example of a buffer tank that can be installed in the gas turbine power generation facility of FIG.

 [FIG. 9] FIG. 9 is a graph showing an example of a state where fluctuations in the power calorie of low calorie gas are alleviated by passing through the buffer tank of FIG. 7 or FIG.

 FIG. 10 is a piping diagram showing another example of a calorie fluctuation suppressing means that can be installed in the gas turbine power generation facility of FIG.

 FIG. 11 is a piping diagram showing another example of a buffer tank that can be installed in the gas turbine power generation facility of FIG. 1.

 FIG. 12 is a piping diagram showing still another example of a buffer tank that can be installed in the gas turbine power generation facility of FIG.

 FIG. 13 is a piping diagram showing still another example of a buffer tank that can be installed in the gas turbine power generation facility of FIG. 1.

FIG. 14 is a piping diagram showing yet another example of a buffer tank that can be installed in the gas turbine power generation facility of FIG. 1. Explanation of symbols

 1 ····· Low calorie gas supply equipment

2 "··· Gas turbine

 3 ···· Low calorie gas supply piping

4 "--exhaust gas supply piping

5 ••• N supply piping

 2

 6 ····· First Mixer

 7 ... Second mixer

 8 ···· Dilution gas supply piping

9 ·· 'Dust collector

10 ... The Nota Tank

11 ... calorimeter

 12 ···

13 ... Mixed gas supply piping

14 ... calorimeter

 15 ... Oxygen concentration meter

 16 ······ Low pressure compressor

 17 ... High pressure compressor

 18 ... Cooler

19 ... combustor

20 ... Flow control valve

21 ·· “Filter

22 ·· “Generator

 23 ·· “Filter

24 .. Fan

 25 ... Check valve

 26 ... Stop valve

27 28 ... Flow control valve

 29 ... Exhaust gas discharge pipe

 30 ...

 31 ... Stop valve

 32..Flow meter

 63 ... Flow control

 34 ... Stop valve

 35 ... Check valve

 36 ···· Communication tube

ό7 ··· ¾¾ milestone

ο8 · · · · ί¾Β / ϊ | Open

3 ₉ ... 'Fan

40 ... 'Gas quantity balance monitoring device

41 ···· Communication pipe (exit pipe)

42 · —Tank

 43..Cover member

 44 ... Adjustment weight

 45 ··· (Upstream side) Inlet piping 6 ··· 'Gas quantity balance monitoring device 6a' "tank

 7 ... Pressure detection device

 8 ... Return piping

 9 ···· Return piping

 50 (Downstream side) Inlet piping

51 .. Waste heat recovery boiler

52 ... Chimney

 53 ... Exhaust gas introduction piping

54 ... Cooler 55 Drain piping

 56 · · · · Oxygen analyzer

5 ₇

 100 · · · Control device

 ε · · · · Direct reduced iron equipment

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0036] Embodiments of a low calorie gas supply facility, a gas turbine facility including the same, and a method for suppressing an increase in calorific value of low calorie gas for gas turbine fuel will be described with reference to the accompanying drawings.

FIG. 1 is a piping diagram showing an outline of a gas turbine facility including a low calorie gas supply facility 1 according to an embodiment of the present invention. A gas turbine power generation facility is shown as an example of the gas turbine facility. As mentioned above, low calorie gas is defined as a gas whose calorific value is about 12MjZNm ³ or less. Low calorie gas often changes its calorie characteristics.

 [0038] The low-calorie gas supply facility 1 includes a low-calorie gas supply pipe 3 that supplies by-product gas (hereinafter referred to as low-power regas) generated directly in the reduced iron facility S to the gas turbine 2 as fuel, An exhaust gas supply pipe 4 for supplying combustion exhaust gas to the low calorie gas supply pipe 3 for diluting the caloric gas, and an inert gas supply pipe 5 for supplying an inert gas to the low calorie gas supply pipe 3 are provided. Speak. The reason for mixing combustion exhaust gas to dilute low calorie gas and suppress its rise in calories is because the exhaust gas contains a large amount of non-flammable gases (N, CO, etc.)

 2 2 On the other hand, it contains almost no combustible gas. Since the temperature of the exhaust gas is high, the degree of freedom in selecting the mixing position in the low-pressure regas supply pipe 3 is increased.

[0039] In order to control the operation of the low calorie gas supply facility 1, a control device 100 is provided. In this embodiment, nitrogen gas (N) is used as the inert gas.

 2

 The reactive gas supply pipe is called N supply pipe 5. The inert gas is not limited to N, but CO

 2 2 2 or helium (He).

In the present embodiment, the exhaust gas supply pipe 4 and the N supply pipe 5 are connected to the second mixer 7.

 2

 From the second mixer 7 to the low calorie gas supply pipe 3, a common pipe for exhaust gas and N is connected.

 2

It has been continued. This common pipe is called dilution gas supply pipe 8. This dilution gas supply pipe 8 The first mixer 6 is connected to the low calorie gas supply facility 1. The exhaust gas supply pipe 4 and the N supply pipe 5 may be directly connected to the first mixer 6 without merging the 4 and 5 respectively.

2

 However, in order to reduce the equipment cost, it is preferable to connect both 4 and 5 in advance as shown in the figure. Also, the exhaust gas supply pipe 4 and the N supply pipe 5 are arranged without using the second mixer 7.

 2

 The tubes may be connected directly. However, in order to improve the mixing property of the by-product gas and the dilution gas in the first mixer 6, a mixed gas obtained by uniformly mixing the exhaust gas for dilution and N in advance is used.

 2

 Since it is preferable to send to the first mixer 6, it is preferable to connect via the second mixer 7.

 [0041] In a portion upstream of the first mixer 6 of the low calorie gas supply pipe 3, a dust collector 9 for removing dust from the low calorie gas sent directly from the reduced iron facility S, and a low calorie gas are primarily used. There is a buffer tank 10 for storage. The koffa tank 10 has a relatively large capacity, and low-calorie gas that is stationed while constantly changing in calories is mixed inside the buffer tank 10. The effect will be described later. A calorific value detector 11 for detecting the calorific value of the low-strength regas and a flow meter 12 for measuring the flow rate are installed on the downstream side of the notch tank 10. The installation position of the flow meter 12 is not limited to the upstream side of the first mixer 6. It may be downstream of the first mixer 6. For example, it may be between the high-pressure compressor 17 and the combustor 19 described later.

 The installation position of the heat generation amount detection device 11 is not limited to the downstream side of the buffer tank 10.

 For example, it may be upstream of the buffer tank 10. By detecting the gas calorie fluctuation upstream of the buffer tank 10, the heat generation control using the first mixer 6 can be performed more reliably. In addition, a calorific value detector is installed on both the upstream side and downstream side of the noffer tank 10 and the gas calorific fluctuation suppression effect of the buffer tank 10 is monitored by both calorific value detectors. It is possible to grasp the overall performance of the system that suppresses fluctuations in roll force. The calorific value detection device can be directly attached to the buffer tank 10. Another calorific value detection device may be attached to the buffer tank 10 in addition to the calorific value detection device 11 in the low calorie gas supply pipe 3.

Here, the calorific value detection device 11 is a so-called calorimeter that directly measures the calorific value of gas. A device that measures the content (concentration) of combustible components is used. The calorific value detection device 11 can be directly attached to the buffer tank 10. In addition to the calorific value detector 11 on the low calorie gas supply pipe 3, another calorific value detector may be attached to the buffer tank 10. If importance is attached to the detection speed, it is currently preferred to use a combustible gas concentration detector. The type of combustible component contained in the low calorie gas applied and the concentration of the combustible component (for example, carbon monoxide and carbon dioxide as a by-product gas in the direct reduced iron method) are detected. A concentration detector may be used. In this specification, these calorific value detection devices are collectively referred to as “calorimeters”.

[0044] The portion of the low-calorie gas supply pipe 3 downstream from the first mixer 6 may be sent to the gas turbine 2 in a state where it is mixed with the low-calorie gas power S exhaust gas N. Arrangement

2

 The pipe is called mixed gas supply pipe 13. The mixed gas supply pipe 13 is provided with a calorimeter 14 and an oxygen concentration meter 15 for measuring the oxygen concentration in the mixed gas. A low-pressure fuel gas compressor (hereinafter referred to as a low-pressure compressor) 16 and a high-pressure fuel gas compressor (hereinafter referred to as a high-pressure compressor) 17 of the gas turbine 2 are installed on the downstream side of the oxygen concentration meter 15 in that order. Has been. A cooler 18 is provided between the compressors 16 and 17 for cooling the mixed gas, which is a fuel gas. A flow rate adjusting valve (hereinafter referred to as a flow control valve) 20 for adjusting the turbine output is installed in the fuel pipe 13a connected from the high pressure compressor 17 to the combustor 19 of the gas turbine 2. Reference numeral 21 denotes a filter installed in a pipe for supplying exhaust gas to the combustor 19. A generator 22 is connected to the gas turbine 2.

FIG. 1 shows a type in which both the compressors 16 and 17 are rotationally driven by the turbine 2. However, the present invention is not limited to this, and both the compressors 16 and 17 are coaxial with the turbine 2. Instead of being connected, it may be configured to be driven by a dedicated motor. Further, as shown in the figure, an exhaust heat recovery boiler 51 using the exhaust gas of the gas turbine 2 may be installed in the gas turbine power generation facility. The steam obtained from the exhaust heat recovery boiler 51 can be used as process steam. Further, although not shown, a steam turbine for generating electric power with this steam may be installed. The exhaust heat recovery boiler 51 is provided with a chimney 52 for releasing the exhaust gas. This exhaust gas is used not only to dissipate, but also to dilute the low calorie gas that is the fuel of the gas turbine 2 as follows. [0046] Exhaust gas supply equipment will be described. An exhaust gas introduction pipe 53 for sending exhaust gas from the exhaust heat recovery boiler 51 is connected to the exhaust gas supply pipe 4. The exhaust gas introduction pipe 53 is provided with a cooler 54 so that the exhaust gas can be cooled to an appropriate temperature for mixing with low-calorie gas, and moisture in the exhaust gas is removed as much as possible through the drain pipe 55. It is good to do. In the present embodiment, the exhaust gas supplied as the dilution gas to the low calorie gas supply pipe 3 is a force that is the exhaust gas of the gas turbine 2 to which the low calorie gas supply pipe 3 supplies low calorie gas. It is not done. For example, when steam power generation equipment is installed nearby, the exhaust gas from the boiler of this equipment can be used. Furthermore, when there are multiple systems of gas turbine power generation facilities that combine low-calorie gas supply facility 1 and gas turbine 2 as shown in Fig. 1, the exhaust gas from other gas turbines is used as the dilution gas. It can be used as This is because the gas turbine is not stopped even if an abnormality occurs in the exhaust gas introduction pipe 53 or the cooler 54 and the exhaust gas cannot be supplied. In this way, even when other gas turbines introduce exhaust gas from a boiler, they are sent to the exhaust gas supply pipe 4.

 [0047] The exhaust gas supply pipe 4 connected to the exhaust gas introduction pipe 53 is branched, and the fan 24 for sucking the exhaust gas from the exhaust gas introduction pipe 5 3 and pumping it in the exhaust gas supply pipe 4 is convenient for maintenance and the like. Two machines are installed in parallel. A check valve 25 is disposed downstream of each fan 24 to prevent backflow to the fan 24 side. The exhaust gas supply pipe 4 is integrated again on the downstream side of the both check valves 25. A stop valve 26, a flow meter 27, a flow control valve 28, and an oxygen concentration meter 56 are installed in that order in the downstream portion, and are connected to the second mixer 7. Between the stop valve 26 and the flow meter 27 of the exhaust gas supply pipe 4, an exhaust gas discharge pipe 29 for releasing the exhaust gas to the atmosphere is disposed. The exhaust gas discharge pipe 29 is provided with a flow control valve 30.

 [0048] Next, N supply equipment will be described. N Supply piping 5 is stopped in order from the upstream side.

 twenty two

It has a valve 31, a flow meter 32 and a flow control valve 33, and is connected to the second mixer 7. The dilution gas supply pipe 8 from the second mixer 7 to the first mixer 6 is provided with a stop valve 34 and a check valve 35 in order of the upstream force. Check valve 35 is supplied with low-calorie gas as dilution gas This is to prevent backflow into pipe 8. Between the upstream part of the stop valve 34 of the dilution gas supply pipe 8 and the downstream part of the flow control valve 30 of the exhaust gas discharge pipe 29, a mixture of exhaust gas and N is passed through the exhaust gas discharge pipe 29 to the atmosphere. Contact to release

 2

 Tube 36 is connected. The communication pipe 36 is provided with a flow meter 37 and a flow control valve 38. Exhaust gas supply pipe 4 and N supply pipe 5 are separate pipes and extend to the first mixer 6 respectively.

 2

 If installed, a stop valve and a check valve will be installed in each pipe 4 and 5, and the connecting pipe 36 will be deleted. Instead, stop valve 31 and flow meter 3 in N supply pipe 5

 2

 Between the two, an N discharge pipe equipped with a flow control valve is installed.

 2

 [0049] Next, an example of operation control of this facility by the control device 100 will be described. First, the low calorie gas is pumped toward the gas turbine 2 while monitoring the calorimeter 11 and the flow meter 12 of the low calorie gas supply pipe 3. At this time, in the exhaust gas supply pipe 4, the stop valve 26 is opened, the flow control valve 28 is closed, the flow control valve 38 of the communication pipe 36 is closed, and the flow control valve 30 of the exhaust gas discharge pipe 29 is opened. 24 is working. That is, the exhaust gas is sucked and discharged from the exhaust gas discharge pipe 29 to the atmosphere through a chimney (not shown). N Flow control of supply pipe 5

 2

 Valve 33 is closed. The other stop valves 31, 34 are both open.

[0050] In the control device 100, an allowable calorie range for use of the fuel gas of each gas turbine 2 is set. That is, the reference calorie value (for example, 1600 kcalZNm ³ ) and the fluctuation range (for example, ± 10% of the reference calorie value). When the calorific value of the low caloric gas exceeds the upper limit caloric value of this allowable variation (for example, + 10%, 1760 kcal / Nm ³ ), the exhaust gas supply pipe 4 has the flow control valve 28 opened so that the exhaust gas Adjust flow control valve 30 of discharge pipe 29 in the valve closing direction. As a result, the exhaust gas is mixed with the low calorie gas to lower the calorie value within the allowable range. When supplying exhaust gas and when supplying N described later,

 2

 In addition to monitoring the data 11 and the flow meter 12, the calorimeter 14 of the mixed gas supply pipe 13 is monitored in order to determine the appropriateness of the final caloric value. When supplying the exhaust gas, the oxygen concentration of the fuel gas is monitored by the oxygen concentration meter 15 of the low calorie gas supply pipe 3 as described later.

[0051] If it is determined from the measurement result of the calorimeter 14 of the mixed gas supply pipe 13 that the calorie value still does not fall within the allowable range even with the maximum exhaust gas supply, the flow rate of the N supply pipe 5 N is mixed with low calorie gas by adjusting the flow control valve 33 to open while monitoring a total of 32.

 2

 At the same time, the caloric value is lowered within the allowable range. At this time, while monitoring the flow meter 15 of the mixed gas supply pipe 13, the flow control valve 30 of the exhaust gas discharge pipe 29 is adjusted in the valve opening direction to release the exhaust gas and reduce the mixing amount. As described above, the calorie of low calorie gas is prevented from exceeding the allowable upper limit.

[0052] Next, connecting the connecting pipe 36 from the dilution gas supply pipe 8 to the exhaust gas discharge pipe 29,

 2 or explanation of the point that the mixture (diluted gas) of N and exhaust gas can be released into the atmosphere.

2

 To do. The amount of dilution gas is normally controlled by flow control valves 28, 33. If the detection value of the calorimeter 11 in the low calorie gas supply pipe 3 decreases rapidly, the control by the flow control valves 28 and 33 may cause a problem in response. In such a case, a part of the dilution gas is released to the atmosphere by the flow control valve 38 of the communication pipe 36, so that the supply amount of the dilution gas is drastically reduced to cope with a sudden decrease in the calorie value.

[0053] Since the exhaust gas of the gas turbine 2 contains about 10-13% oxygen, the oxygen content (oxygen concentration) of the mixed gas increases if the exhaust gas is mixed with low calorie gas. If a certain percentage of oxygen is contained in the combustible gas, the combustible gas will theoretically enter the combustible range at the predetermined temperature. Before falling into this situation, exhaust gas supply must be limited. At that time, when it is necessary to lower the calorific value of the low calorie gas, N is supplied and mixed while reducing the amount of exhaust gas mixed into the low calorie gas as described above.

 2

 [0054] The oxygen content varies depending on the type of exhaust gas. In the combustion gas of gas turbines using low calorie gas as fuel, the oxygen content (volume ratio) is about 10-13%, but the boiler exhaust gas used for steam power generation has about 3-6% oxygen. Does not contain power. Therefore, for each exhaust gas to be used, the flammability limit of the mixed gas of the exhaust gas and low calorie gas is obtained by the volume ratio of low calorie gas or exhaust gas, and based on this data, the maximum allowable mixture ratio of exhaust gas is determined. It may be set.

[0055] On the other hand, since air contains oxygen at a constant volume ratio (invariable at about 21%), the flammability limit of the mixture of air and low calorie gas is calculated for the volume ratio of low calorie gas or air. It is convenient to set the maximum allowable mixing ratio of air and calculate and set the maximum allowable mixing ratio of exhaust gas based on this data and the ratio of oxygen content. The For example, the maximum allowable mixing ratio of air is multiplied by the ratio between the oxygen content of air (21%) and the oxygen content of the exhaust gas used (approximately 10-13% for gas turbine combustion gases). This will be described below.

 [0056] FIG. 2 shows the flammability limit of the mixed gas of low calorie gas and air in relation to the volume ratio of low calorie gas and the temperature. The curve with black circles on the left in the figure shows the minimum volume ratio of low calorie gas (maximum volume ratio of air) in the combustible range of the mixed gas. The curve with the black square mark on the right shows the maximum volume ratio of low calorie gas (minimum volume ratio of air) in the combustible range of the mixed gas. The range between the two curves is the combustible range. Since the caloric value of low calorie gas fluctuates, both the above curves also fluctuate. Therefore, the maximum allowable mixing volume ratio of air is set in the control device 100 in consideration of the safety factor based on such data. For example, as shown in Fig. 2, the volume ratio of air is 20% (volume ratio of low calorie gas is 80%). Connected to the black square mark on the right side, the ratio is set to a smaller ratio (20%) than the minimum volume ratio of air shown by the elliptic curve. However, this figure is an example.

 [0057] The ratio of the oxygen content of air and gas turbine exhaust gas is 21Z13. The oxygen content of the exhaust gas is 13% for safety. Since the maximum allowable mixing volume ratio of air is 20%, the maximum allowable mixing volume ratio of exhaust gas is 20% X 21/13 = 32%. The maximum allowable mixing volume ratio of boiler exhaust gas is 20% X 21/6 = 70%. The maximum allowable mixing volume ratio of these exhaust gases is set in the control device 100, which is the maximum allowable mixing volume ratio derived from the combustible limit of the mixed gas. For example, if the volume ratio of gas turbine exhaust gas is slightly smaller than the upper limit (32%), for example, exceeds 25%, the amount of exhaust gas mixed is reduced as described above, and N is supplied as necessary. This control is a low calorie gas supply

 2

 This is based on the detection results of the flow meter 12 in the pipe 3 and the flow meter 27 in the exhaust gas supply pipe 4. Furthermore, both the oxygen concentration of the mixed gas and the oxygen concentration of the exhaust gas are constantly monitored by the oxygen concentration meters 15 and 56. This is to cope with unexpected fluctuations in oxygen concentration

Next, the function and effect of the buffer tank 10 in FIG. 1 will be described. As shown in the figure, the buffer tank 10 has an inlet 10a to which the low-calorie gas supply pipe 3 on the upstream side is connected, An outlet 10b to which the low-calorie gas supply pipe 3 on the downstream side is connected is formed. Therefore, all of the low caloric gas that has been sent flows into the buffer tank 10. In the buffer tank 10 of FIG. 1, the inlet 10a and the outlet 10b are formed in the vicinity of the lower end of the tank peripheral wall, but are not particularly limited to these formation positions, for example, the middle part of the tank peripheral wall, the upper part, the bottom part of the tank, etc. You may form in.

[0059] The buffer tank has a large volume, for example, a low calorie gas supply pipe 3 having a diameter of about 2-3 m, and a volume of about 20000-200000 m ³ is installed. The low calorie gas sent with the calorie changing from time to time is mixed in the buffer tank. In this specification, mixing of gas in a tank means mixing of time differences. That is, the low calorie gas that has flowed into the buffer tank 10 at the same time is distributed to a portion where the partial force flowing out from the outlet 10b stays in the buffer tank 10 until late. On the other hand, since new gas continuously flows in from the inlet 10a, the gas that has flowed in the past and the gas that has flowed in are continuously mixed. This is called time difference mixing. As a result of this time difference mixing, the fluctuation range of the calorie of the low calorie gas exiting from the outlet 10b of the notfer tank 10 is reduced, and the fluctuation speed is reduced. That is, calorie fluctuation is greatly reduced (suppressed). If calorie fluctuations are mitigated in advance in this way, it becomes very easy to control the rise in calorie by dilution of exhaust gas etc. downstream. The above phenomenon will be described with reference to FIGS. 3 to 8, FIG. 11 and FIG.

[0060] Fig. 3 shows the relaxation (suppression) of calorie fluctuation when low calorie gas that fluctuates in calorie is supplied at a flow rate of 500000 Nm ³ / hr when the volume of buffer tank 10 in Fig. 1 is 200000 m ^3. It is a graph which shows the simulation result of a state. The horizontal axis represents time (minutes), and the vertical axis represents the gas calorie value (kcal / Nm ³ ), which is the calorific value of low calorie gas. In addition, the curve indicated by the broken line in the figure indicates the calorie fluctuation (original fluctuation) of the low calorie gas sent to the buffer tank 10. This is an actually measured sample. The curve represented by the solid line comes out of the buffer tank 10 and shows the calorie fluctuation (after-suppression fluctuation) of low calorific gas. As shown in the figure, the calorie of the low calorific gas before entering the buffer tank 10 varies from about 1530 kcal / Nm ³ force to about 2360 kcal ZNm ³ . In other words, it has a fluctuation range of about ± 21% of the average value of these two values (hereinafter simply referred to as the average value) (1945kcalZNm ³ ). Bufftan According to the result of theoretical calculation of caloric fluctuation of low calorie gas coming out of K 10, it is 1780kcal / Nm ³ force 1960kcalZNm ³ and the fluctuation range is suppressed to about 5% of the average value (1870kcalZNm ³ ), The As shown in the figure, even for the fluctuation period, the short period component and the medium period component are greatly suppressed. This effect tends to become more prominent as the volume of the buffer tank increases with respect to the low calorie gas supply flow rate. If the fluctuation range of the original fluctuation is small, it is effective to reduce the volume of the buffer tank from the economic point of view.

[0061] FIG. 4 shows the state of attenuation of calorie fluctuation when the volume of the low-calorie gas is 500000 Nm ³ Zhr and the volume of the buffer tank 10 is 100000 m ³ which is half of the above. The calorie fluctuation in this case is also suppressed by buffer tank 10 to the range of 1700 kcal / Nm ³ force up to 2 040 kcal / Nm ³ , and the fluctuation range is about ± 9% of the average value (1970 kcalZNm ³ ).

[0062] FIG. 5 shows a decay state of calorie fluctuation when the volume of the buffer tank 10 is set to 50000 m ³ in the facility in which low calorie gas is supplied at a flow rate of 200,000 Nm ³ Zhr. Calorie variance in this case also is suppressed in a range of up to 1740KcalZNm ³ Power et 2010KcalZNm 3 by the buffer tank 10, the variation width of about ± 7. 2% of the average value (1875kcalZNm ^3).

[0063] Although not shown in the drawing, in a facility where low calorie gas is supplied at a flow rate of 200,000 Nm ³ Zhr, if the volume of the koffa tank 10 is 25000 m ³ , half of the above, the fluctuation width is an average value (1875 kcal ZNm ³ ) of about ± 12%.

[0064] As shown in FIG. 6, in a facility where low calorie gas is supplied at a flow rate of 200,000 Nm ³ Zhr, two buffer tanks 10 with a volume of 25000 m ³ are installed in parallel, and both units are in normal operation. It can be used to use only one tank only for unsteady situations such as periodic inspections and malfunctions.

[0065] As described above, the calorie fluctuation of the low calorie gas is greatly suppressed without the active control only by providing the notch tank. As a result, control for mixing exhaust gas and inert gas downstream is very easy. For example, if the calorie fluctuation width of the fuel gas of gas turbine 2 is set to 10% of the standard calorie value (average value), the average value of the fluctuating calorie downstream of the noffer tank is The reference calorie value set for gas turbine 2 In order to match, it is only necessary to provide a buffer tank with a volume that can meet the specifications and supply a certain ratio of exhaust gas downstream. With regard to the operation of supplying exhaust gas, it is not necessary to consider the state of calorie fluctuation of low calorie gas.

 [0066] In an extreme case, if the average calorific value of the calorie fluctuating after passing through the notch tank 10 is almost the same as the reference calorie value set in the gas turbine 2, the exhaust gas supply equipment and inert gas Supply equipment is no longer needed. Even if both facilities are provided, the facility may be operated with the stop valve 34 of the dilution gas supply pipe 8 in FIG. 1 closed. Of course, if the calorie fluctuation of the generated low calorie gas is not large, it is possible to cope with only the exhaust gas supply equipment and the inert gas supply equipment that does not require the installation of a nota tank.

 FIG. 7 shows another buffer tank 42. This buffer tank 42 is sometimes used in conventional gas turbine equipment, and is included in the device 40 for monitoring the gas amount balance. This gas amount balance monitoring device 40 is for balancing the amount of low calorie gas sent from the upstream side with the amount of gas consumed required by the gas turbine. When there are fluctuations in the amount of gas supplied or load fluctuations in the gas turbine, it is necessary to balance supply and consumption. When the supply is unexpectedly excessive, it is released into the atmosphere. When the supply is insufficient, the load on the gas turbine is reduced or some operations are stopped.

 [0068] This gas amount balance monitoring device 40 has a tank 42 connected to the low calorie gas supply pipe 3 by a communication pipe 41, and an upper end opening of the tank 42 is hermetically closed and can be moved up and down in the tank. A lid member 43 is provided, and an adjustment weight 44 is provided on the lid member 43, for example. The lid member 43 moves up and down in the tank by a balance between the total weight of its own weight, the weight of the weight 44 and the push-down force due to atmospheric pressure, and the push-up force caused by the internal pressure of the tank 42. Accordingly, the lid member 43 moves up and down in accordance with a change in the balance between the supply amount and consumption amount of low calorie gas. While monitoring the vertical movement of the lid member 43, measures such as atmospheric gas diffusion and turbine load reduction are taken.

[0069] The gas amount balance monitoring device 40 is used for suppressing calorie fluctuation. This tank 42 is an inlet that communicates with the low-calorie gas supply pipe 3 in addition to the communication pipe 41 described above. Piping 45 is connected. The inlet pipe 45 is provided with a fan 39 for sending low calorie gas into the tank 42. Since the inlet pipe 45 is connected to the upstream side of the low calorie gas supply pipe 3 from the communication pipe 41, the fan 39 can be omitted by piping design taking pressure loss into consideration. The same applies to the upstream side inlet pipe 45 shown in FIGS. A part of the low caloric gas supplied flows into the tank 42 through the inlet pipe 45, the low caloric gas is mixed in the tank 42, and the same amount of gas passes through the communication pipe 41 to supply low caloric gas from the tank 42. Return to piping 3. In this case, the communication pipe 41 can also be called an outlet pipe. The buffer tank 42 is connected to an inlet pipe 45 and an outlet pipe 41 constituting a bypass pipe of the low calorie gas supply pipe 3, so to speak, it is installed in parallel to the low calorie gas supply pipe 3.

 FIG. 8 shows another gas amount balance monitoring device 46 that can be used as calorie fluctuation suppressing means. The gas amount balance monitoring device 46 has a more economical configuration, and has an airtight tank 46 a that is connected to the low calorie gas supply pipe 3 by a communication pipe 41. A pressure detector 47 is installed in the tank 46a, and the internal pressure of the tank 46a is constantly monitored. When the detected pressure reaches the upper limit, the control device 100 issues a command to increase the gas consumption in the facility, and balances the gas supply and demand. The other structure is the same as that of the above-mentioned device 40 (Fig. 7), and can be fully used as a calorie fluctuation suppressing means.

[0071] FIG. 9 is Oite to the facilities low calorie gas varying calorific is supplied at a flow rate 500,000 nm ³ / hr, the volume of the tank 42 (46a) in FIG. 7 or 8 and 200000M ^3, by the fan 39 This shows the state of mitigation of calorie fluctuation when 200000 Nm ³ Zhr of the flow of 500000 Nm ³ Zhr is sent to tank 42 (46a). The curve shown with a broken line in the figure shows the calorie fluctuation (original fluctuation) of the low calorie gas sent directly from the reduced iron facility S! This is the actual measurement sample described above. The curve represented by the two-dot chain line shows the simulation result of the calorie fluctuation (transient fluctuation) of the low calorie gas leaving the tank 42 and passing through the communication pipe 41. The curve shown by the solid line shows the calorie fluctuation (the fluctuation after suppression) of the gas that reaches the first mixer 6 through the low calorie gas supply pipe 3 downstream of the communication pipe 41. The calorific value of the low caloric gas before entering tank 42 (46a), which is the same as described above, has a fluctuation range of about ± 21% of the average value (1945kcalZNm ³ ). However, the tank 42 (46a) force is also low in calorie through the communication pipe 41. Calorie variance of gas after merging into the gas supply pipe 3 is from 1690KcalZNm ³ to 2100kc al / Nm ^3, the fluctuation range is suppressed to about ± 11% of the average value (1895kcalZNm ^3). This number is an example.

 [0072] As described above, it is also possible to suppress the change in gas calorie using the existing equipment having the tank 42 (46a). Further, the low calorie gas can be easily diluted with the exhaust gas downstream. In FIG. 7 and FIG. 8, the inlet pipe 45 for feeding the low calorie gas into the tank 42 (46a) is connected to the upstream side of the outlet pipe 41 in the low calorie gas supply pipe 3. The pipe 41 may be connected downstream. A plurality of both pipes 41 and 45 may be provided.

 [0073] FIG. 10 shows another calorie fluctuation suppressing means. This means is a return pipe 48 arranged in the low calorie gas supply pipe 3 for returning a part of the low calorie gas to the upstream side of the low calorie gas supply pipe 3. The return pipe 48 is provided with a fan 39 for pumping low calorie gas upstream. The return pipe 48 shown in the drawing is configured so that the suction force at one power point is also branched into a plurality of branch pipes 48a and is configured to return to the original low calorie gas supply pipe 3. Good. Further, a single return pipe may be provided at each of a plurality of different parts of the low calorie gas supply pipe 3. The low calorie gas is mixed with the new low calorie gas when it is returned to the upstream of the low-strength regas supply pipe 3, and the calorie fluctuation is reduced. To increase this effect, lengthen the return pipe 48 and increase the volume ratio of the return gas volume to the supply gas volume.

 Although not shown, the same buffer tank 42 for the gas amount balance monitoring device 40 as shown in FIG. 7 may be replaced with the fixed internal volume type buffer tank in FIG. That is, the notch tank 42 in FIG. 7 is connected to the inlet pipe 45 and the communication pipe 41 that constitute the binos pipe of the low calorie gas supply pipe 3. You may connect directly. Specifically, the upstream side of the low calorie gas supply pipe 3 may be directly connected to the inlet formed in the nota tank 42, and the upstream side of the low calorie gas supply pipe 3 may be directly connected to the outlet.

 FIG. 11 shows a piping mode substantially the same as the piping mode as described above.

The buffer tank 42 in FIG. 11 is the same as that for the gas amount balance monitoring device 40 shown in FIG. Fattank 42. The difference is the mode of piping connecting the low calorie gas supply piping 3. In the piping mode of FIG. 11, the low-calorie gas supply pipe 3 of FIG. 7 is removed from the connection part with the inlet pipe 45 to the connection part with the communication pipe 41, and the fan 39 on the inlet pipe 45 is further removed. It has been removed. That is, the low-calorie gas supply pipe 3 on the upstream side is connected to the inlet 42a, and the low-calorie gas supply pipe 3 on the downstream side is connected to the outlet 42b. In other words, the buffer tank 10 shown in FIG. 1 is replaced with the tank 42 for the gas amount balance monitoring device 40. Such a pipe is a mode that can be easily modified when the existing gas amount balance monitoring device 40 is also used as a gas calorie fluctuation suppressing device.

Further, as shown in the figure, a stirring device 57 such as a fan may be installed inside the tank 42 to stir the gas. This is to promote gas mixing in the tank and thereby achieve more effective calorie fluctuation suppression. As a form of installation of the stirring device 57, it is preferable that the force near the outlet 42b of the tank is installed in the vicinity of the outlet 42b so that the gas can flow toward the inside of the tank. . The stirring device 57 is not limited to the tank 42 in FIG. 11, but can be installed in the tanks 10, 42, and 46a shown in other drawings and other tanks that can exert a calorie suppressing effect. . It is preferable that the electric motor 57a, etc., serving as the rotational drive unit of the stirring device 57 is installed outside the tank.

FIG. 12 also shows a buffer tank 42 installed in parallel to the low calorie gas supply pipe 3 as in the tank of FIG. As shown in the figure, an outlet pipe 41 is connected between the outlet 42b of the tank 42 and the low calorie gas supply pipe 3, and the upstream side of the connection of the inlet 42a of the tank 42 and the outlet pipe 41 in the low calorie gas supply pipe 3 An inlet pipe 45 is connected between the two. Therefore, this inlet pipe 45 is referred to as an upstream side inlet pipe 45. On the other hand, a further inlet 50a is formed in the tank 42, and an inlet pipe 50 connected to the downstream side of the connection portion with the outlet pipe 41 in the low calorie gas supply pipe 3 is connected to the inlet 50a. This inlet pipe 50 is referred to as a downstream inlet pipe 50. Both inlet pipes 45 and 50 are provided with a fan 39 for sending low calorie gas to the tank 42. As shown in the figure, the upstream inlet pipe 45 and the downstream inlet pipe 50 are connected to the tank 42 at the connection positions (the inlets 42a and 50a). According to this configuration, a part of the low calorie gas is pumped into the tank 42 from the upstream side of the low calorie gas supply pipe 3 through the upstream side inlet pipe 45 and at the same time downstream from the downstream side of the low calorie gas supply pipe 3. A part of the low calorie gas is pumped through the inlet pipe 50, mixed and flows out from the outlet 42b to the outlet pipe 41. In other words, since a part of the low calorie gas in which the calorie fluctuation is suppressed circulates, mixing for a long time is realized in the tank. The longer the length of the downstream inlet pipe 50, the longer the residence time of the mixed gas, and the more preferable mixing is realized. The downstream inlet pipe 50 is a force connected to the inlet 50a of the tank 4 2 from the downstream side of the low calorie gas supply pipe 3.From the downstream side, upstream from the connection with the upstream inlet pipe 45 of the low calorie gas supply pipe 3 You can connect to the side.

 FIG. 13 also shows a buffer tank 42 installed in parallel to the low calorie gas supply pipe 3. Between the tank 42 and the low calorie gas supply pipe 3 as shown in the figure, the communication pipe 41 and the downstream side inlet pipe 50 as the outlet pipe are connected. The downstream inlet pipe 50 is provided with a fan 39 for sending low calorie gas to the tank 42.

 [0080] According to the configuration, even if the downstream inlet pipe 50 is connected to the downstream side from the connection with the outlet pipe 41 in the low calorie gas supply pipe 3, the low calorie gas is downstream from the fan 39. It is fed into the tank 42 through, mixed and flows out from the outlet 42b to the outlet pipe 41. In other words, effective mixing is achieved because a part of the low calorie gas with suppressed calorie fluctuation circulates. The longer the length of the downstream inlet pipe 50, the longer the mixing in the tank is realized.

 [0081] The tank 42 shown in FIG. 14 has two types of inlets 42a and 49a. One inlet 42a is connected to the upstream low calorie gas supply pipe 3, the outlet 42b is connected to the downstream low calorie gas supply pipe 3, and the other inlet 49a is connected to the downstream low calorie gas supply pipe 3. Return pipe 49 is connected. The two inlets 42a and 49a are formed close to each other. The return pipe 49 is provided with a fan 39 for sending low calorie gas into the tank.

[0082] According to the powerful configuration, a part of the low calorie gas whose calorie fluctuation is suppressed in the tank 42 is returned to the tank 42 and mixed again, so that more preferable mixing is realized. The longer the length of the return pipe 49, the longer the residence time of the mixed gas. Above return pipe 49 May be connected from the downstream side of the low-calorie gas supply pipe 3 to the upstream side of the tank in the low-calorie gas supply pipe 3 from the downstream side connected to the inlet 49a of the tank 42.

In the embodiment described above, the force exemplifying by-product gas generated by the direct reduction iron-making method as the low calorie gas to be used is not limited to this. Low calorie gas includes blast furnace gas (BFG), converter gas (LDG), coal bed gas (Coal mine gas, expressed as CMG), by-product gas generated by smelting reduction ironmaking, General gas, including Tail gas generated in Gas-to-Liquid (GTL) process, by-product gas generated by oil refining process from oil sand, gas generated by incineration using plasma, and garbage Low-calorie gas such as by-product gas generated by the chemical reaction of methane gas (Landfill gas) generated during fermentation and decomposition of waste in its landfill and other similar raw materials included. Of course, not only the above gas but also a gas whose calorific value is less than about 12 MJ / Nm ³ as a result of mixing a plurality of different gases, such as a mixed gas of BFG and LDG.

 Industrial applicability

[0084] According to the present invention, stable combustion is achieved by suppressing an abnormal increase in combustion temperature by diluting a large amount of low-calorie gas whose calorie changes from time to time with low-oxygen concentration exhaust gas that is easy to collect. Can be continued. In other words, the above-mentioned effects can be obtained by low equipment costs and operation costs.

Claims

The scope of the claims

 [1] a low calorie gas supply passage for supplying low calorie gas as fuel gas to the gas turbine;

 An exhaust gas supply passage connected to the low calorie gas supply passage for supplying exhaust gas generated in the combustion facility to the low calorie gas supply passage;

 A calorific value detection device for detecting the calorific value in the gas disposed in the low calorie gas supply passage;

 A low calorie gas supply facility comprising a control device capable of controlling an exhaust gas supply operation through the exhaust gas supply passage based on a detection result of the calorific value detection device.

 [2] When the control device sets the maximum allowable calorie value of the fuel gas of the gas turbine, and the caloric value of the low calorie gas exceeds the maximum allowable calorie setting value, the exhaust gas supply passage power and the exhaust gas 2. The low calorie gas supply facility according to claim 1, wherein the low calorie gas supply facility is configured to supply gas.

 [3] In the low calorie gas supply passage, an oxygen concentration detection device is disposed at a site downstream of the connection with the exhaust gas supply passage.

 2. The low calorie gas supply facility according to claim 1, wherein the control device is configured to control an exhaust gas supply operation by the exhaust gas supply passage based on a detection result of the oxygen concentration detection device.

 [4] The above control device supplies exhaust gas through the exhaust gas supply passage based on the allowable mixing volume ratio of the exhaust gas based on the low calorie gas flammability limit information obtained from the mixture ratio of low calorie gas and exhaust gas. 4. The low calorie gas supply facility according to claim 3, wherein the low calorie gas supply facility is configured to control the amount.

 [5] Based on the ratio of oxygen content from the allowable mixing volume ratio of air set based on the low calorific gas flammability limit information obtained from the low calorific gas and air mixing ratio 4. The low calorie gas supply facility according to claim 3, wherein the supply amount of exhaust gas through the exhaust gas supply passage is controlled based on the allowable mixing volume ratio of the exhaust gas calculated in the above.

 [6] An inert gas supply passage for supplying an inert gas is connected to the low calorie gas supply passage,

The control device is configured to provide an inert gas supply passage based on the detection result of the oxygen concentration detection device. The low-calorie gas supply facility according to any one of claims 3 to 5, wherein the low-calorie gas supply facility is configured to control an inert gas supply operation by the gas generator.

[7] An inert gas supply passage for supplying an inert gas is connected to the low calorie gas supply passage,

 The control device controls the inert gas supply operation by the inert gas supply passage based on the detection result of the calorific value detection device when the exhaust gas is supplied to the low calorie gas supply passage by the exhaust gas supply passage. 2. The low calorie gas supply facility according to claim 1, wherein the facility is configured.

 [8] A first tank for temporarily storing low calorie gas is disposed in the low calorie gas supply passage,

 2. The first tank has an inlet and an outlet, the upstream side of the low calorie gas supply passage is connected to the inlet, and the downstream side of the low calorie gas supply passage is connected to the outlet. Low calorie gas supply equipment.

[9] A second tank for temporarily storing low calorie gas is installed in the low calorie gas supply passage,

 Between the low-calorie gas supply passage and the second tank, the low-calorie gas is supplied to the low-calorie gas supply passage, the gas inlet passage for feeding the second tank, and the low-calorie gas is returned to the second tank force at the low-calorie gas supply passage. And are arranged,

 2. The low calorie gas supply facility according to claim 1, wherein a first gas pumping device for pumping low calorie gas toward the second tank is disposed in the inlet passage.

[10] The low-calorie gas supply passage is provided with a return passage for returning a part of the low-calorie gas to be supplied to the upstream side of the low-calorie gas supply passage, and the low-calorie gas is supplied into the return passage. The low-calorie gas supply facility according to claim 1, further comprising a second gas pumping device for pumping toward the upstream side of the passage.

11. An exhaust gas blocking device that is disposed in the exhaust gas supply passage and that can block and open the passage, and an exhaust gas discharge device that is disposed upstream of the exhaust gas blocking device. The low calorie gas supply facility described.

[12] An inert gas disposed in the inert gas supply passage and capable of blocking and opening the passage. 7. A low calorie gas supply facility according to claim 6, further comprising: a gas shut-off device; and an inert gas discharge device disposed upstream of the inert gas shut-off device.

13. The low calorie gas supply facility according to claim 1, wherein the combustion facility is the turbine.

[14] The low calorie gas supply facility according to claim 1, wherein the combustion facility is a boiler of a steam power generation facility.

 [15] gas turbine,

 A low-calorie gas supply facility for supplying low-calorie gas as fuel gas to the gas turbine,

 15. A gas turbine facility, wherein the low calorie gas supply facility is the low power regas supply facility according to any one of claims 1 to 14.

16. A plurality of gas turbines are installed, each gas turbine is provided with a low calorie gas supply facility, and the combustion facility of the low calorie gas supply facility is a gas turbine other than the corresponding gas turbine. 15. The gas turbine equipment according to 15.

[17] a calorie measurement step for measuring the calorific value of the low calorie gas supplied to the gas turbine as fuel gas;

 When the measurement result exceeds the set allowable caloric value, the calorie rise suppression of the low calorific gas for gas turbine fuel comprising the step of mixing the exhaust gas for dilution collected from the combustion equipment into the low calorie gas Method.

 [18] The above exhaust gas mixing step measures the oxygen concentration of the mixture of low calorie gas and exhaust gas, and the measurement result exceeds the set allowable exhaust gas content obtained from the low calorie gas flammability limit information. 18. The calorie increase suppressing method according to claim 17, further comprising a step of adjusting the amount of mixed exhaust gas.

 [19] The method according to claim 17, further comprising the step of mixing an inert gas into the low calorie gas when it is determined that the calorific value measurement result is less than a set allowable caloric value even with the maximum exhaust gas supply. Calorie rise suppression method.

[20] Decrease the amount of exhaust gas mixed when it is determined that the amount of heat generated by the mixture exceeds the set allowable caloric value if the amount of exhaust gas mixed is reduced, and if the amount exceeds the set allowable exhaust gas content if increased And further comprising the step of supplying an inert gas to the low calorie gas. Item 18. The method for suppressing caloric elevation according to Item 18.

[21] A return passage is connected between the low calorie gas supply passage upstream of the tank and the low calorie gas supply passage downstream of the tank,

 9. The low calorie gas supply facility according to claim 8, wherein a gas pressure feeding device for pressure-feeding fuel gas toward the low calorie gas supply passage upstream of the tank is installed in the return passage.

[22] A return passage is connected between the downstream side from the connection point to the outlet passage in the low calorie gas supply passage and the upstream side from the connection point to the inlet passage in the low calorie gas supply passage.

 10. The low calorie gas supply facility according to claim 9, wherein a gas pumping device for pumping fuel gas toward the upstream low calorie gas supply passage is installed in the return passage.

[23] The low calorie gas supply facility according to [8] or [9], wherein a stirring device for stirring gas is installed in the tank.