JP4594376B2 - Gas heating value control method and gas heating value control device - Google Patents

Description

  The present invention relates to a gas heating value control method and a gas heating value control device. More specifically, the present invention relates to a gas heat generation amount control method and a gas heat generation amount control apparatus capable of suppressing the heat generation amount fluctuation when the heat generation amount of the gas as the fuel of the combustion facility fluctuates like low calorie gas.

In the steelmaking field, for example, when pig iron is produced by a 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 coke used, BFG is widely used in steelworks to reduce the cost of ironmaking. The composition of BFG is 10 to 18% by volume of carbon dioxide (CO ₂ ) (hereinafter simply referred to as “%”), 22 to 30% of carbon monoxide (CO), and 52 to 60% of nitrogen (N ₂ ). Hydrogen (H ₂ ) is 0.5 to 4%, and methane (CH ₄ ) is 0.5 to 3%.

Because BFG contains 2 to 10 g / Nm ³ of flue dusts in addition to this, after removal of up to about 0.01 g / Nm ³ in the dust collector so as calorific value 800 kcal / Nm ³ about the fuel gas, a hot air furnace, Used in coke ovens, heating furnaces, boilers, etc.

In recent years, gas turbines can also be burned with low calorie gas due to improvements in technology, and the number of cases where power is generated using BFG as a gas turbine fuel is increasing. Here, low calorie gas 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), and includes various types of gases such as converter gas (LDG) and mixed gas thereof.

  On the other hand, in recent years, new iron manufacturing processes other than the blast furnace method (for example, direct reduction iron methods such as FINEX method and COREX method) are being developed, and they are also applied to the effective use of by-product gas generated from such new processes. The development of a combustion method that can do this is awaited. In any steelmaking process, the by-product gas generated is low calorie gas, and its characteristics (gas composition and calorie) vary depending on the equipment and operation contents. Even in the same equipment, the characteristics and reaction processes of each raw material are different. In response, it changes from moment to moment and is not constant.

  Here, looking at the calorie that is the most important characteristic when using this low calorie gas as the fuel gas of a gas turbine, for example, each gas turbine has an upper and lower limit value of the allowable fluctuation range of calorie that is unique to each gas turbine. Have. If the upper limit (for example, about + 10% of the average caloric value) is exceeded, that is, if the caloric value increases rapidly, the combustion temperature in the combustor of the gas turbine may suddenly become an abnormally high temperature. . As a result, there is a possibility that the burner part, turbine stationary blades and moving blades may be damaged and shorten their life, and in such a case, it is difficult to economically operate the gas turbine equipment continuously. Become. Also, if the lower limit is lowered (for example, about -10% of the average calorie value), the output of the gas turbine becomes unstable or causes a misfire trip. In this specification and claims, this low calorie gas is included in the fuel gas.

The calorie fluctuation in which calorie increases or decreases as described above means a change in physical properties related to the calorific value of the fuel gas. Specifically, the calorific value per volume (Kcal / Nm ³ ) and the calorific value per weight (MJ / kg). ) And Wobbe Index (MJ / m ³ ). In this specification and claims, this calorie is also called calorific value, and calorie fluctuation is also called calorific value fluctuation.

  FIG. 11 is a piping diagram showing an outline of a conventional gas turbine power generation facility. The prior art shown in the figure is an example configured to increase or decrease the heat generation amount of fuel gas whose heat generation amount fluctuates. As shown in the figure, when BFG generated in a fuel gas generator (for example, a blast furnace) 100 is supplied as a fuel gas to a gas turbine 101 (or a combustion device such as a thermal power boiler), the amount of generated heat is an expected value (design). In order to maintain the average value, fluctuation range, and change speed as preconditions, a heat reducing gas or a heat increasing gas is mixed in the mixer 102. As the gas mixing method, calorific value measuring devices 104 and 105 are provided on the upstream side and the downstream side of the fuel gas supply passage 103, respectively, and feedforward control is performed with the detection signal of the calorie measuring device 104, and the detection of the calorie measuring device 105 is performed. Feedback control is performed using signals. These signals are input to a controller 106 that compares with a predetermined set value 107 set in advance according to the gas turbine 101. A predetermined control signal is output from the controller 106 to the heat reduction flow adjustment valve 108 or the heat increase flow adjustment valve 113 through the distributor 115, and from the heat reduction gas supply 109 through the supply pipe 110. The heat reducing gas is supplied to the mixer 102 or the heat increasing gas is supplied from the heat increasing gas supply device 114 to the mixer 102 via the supply pipe 110. In addition, 111 is a gas compressor and 112 is a generator.

  FIG. 12 is a graph showing an example of fuel gas calorific value fluctuation at each measurement point of the gas turbine power generation facility of FIG. The horizontal axis represents time (seconds), and the vertical axis represents the calorific value (MJ / kg) of the fuel gas. The two-dot chain line shown in the figure shows the calorie fluctuation of the fuel gas in the low calorie gas supply passage 103, and the solid line shows the calorie fluctuation at the outlet of the mixer 102 as a simulation result in the case of being controlled by this prior art.

  As shown in the figure, the calorific value of the fuel gas supplied from the fuel gas generator 100 fluctuates irregularly and greatly with time as indicated by a two-dot chain line in the figure. Even if feed-forward control and feedback control are performed on this original fluctuation, in this example, the control system is exposed to fluctuations in the fuel gas including excessive short-cycle components and medium-cycle components, and the control system is not effective. It becomes stable and parameter setting of the controller becomes difficult. As a result, depending on the situation, the response is close to the oscillation state as shown by the solid line in the figure. This figure shows an example of oscillating by performing feedforward control and feedback control on a low calorie gas whose fluctuating calorific value fluctuates, and cannot be used as a fuel gas for a gas turbine (combustion facility).

  As this type of conventional technology, for example, there is a fuel gas calorie control device described in Patent Document 1. In this control device, if the calorie of low calorie gas is supplied while causing fluctuations in the average value, fluctuation range, and change speed, in order to suppress this fluctuation, at the moment when the gas that fluctuates calorie reaches the mixer. In addition, it is necessary to select and mix the gas species with the calorie value as an average value and select an appropriate mixing amount. In other words, if the caloric value is equal to or higher than the average value, the amount of heat reducing gas necessary for the average value is mixed, and if the caloric value is equal to or lower than the average value, the amount of the heat increasing gas required to achieve the average value. Must be mixed.

  However, since the operation end is only the mixed gas adjusting valve, if the timing of the gas mixing operation is shifted, excess and deficiency will occur, making it difficult to accurately control calorie fluctuation, and the calorie value cannot be equalized to the level required for the combustion equipment. . For this reason, if the remaining calorie value exceeds the allowable limit of the combustion facility, the operation must be stopped urgently to prevent damage to the combustion facility, and low calorie gas must be released to the atmosphere. Equipment may misfire trip. Further, as the calorie fluctuation speed increases, it becomes more difficult to adjust the gas mixing timing, and it is difficult to perform reliable control only with the mixer and the mixed gas adjusting valve.

  Further, if the calorie fluctuation is short and the fluctuation width is large, the mixed gas regulating valve repeats a large stroke operation, which may damage the valve and shorten its life.

  Furthermore, if the fluctuation range of the calorie becomes excessive and the adjusting valve performs a large stroke operation to mix the gas, it will cause fluctuations in the gas compressor and inlet pressure, resulting in a large disturbance in the fuel supply system to the gas turbine. This leads to instability of gas turbine operation.

Also, when different gases such as nitrogen gas or coke oven gas with different specific gravity are mixed with fuel gas that fluctuates greatly, it is difficult to mix a large amount of gas, and the change range of the mixing amount is large, so a short time immediately after mixing It is difficult to make the mixed gas sufficiently uniform and supply it to the combustion facility, and these nitrogen gas, coke oven gas, etc. will exist as mixed unevenness, causing uneven combustion in the combustion chamber of the combustion facility. , Stable operation becomes difficult. For this reason, it is difficult to use low calorie gas or the like that greatly changes calorie (calorific value fluctuation) as fuel gas.
JP 2004-190632 A

  On the other hand, as described above, the development of technology that can efficiently and stably use low calorie gas whose calorific value constantly changes irregularly as fuel gas in combustion equipment such as gas turbine power generation equipment It is regarded as important from the viewpoints of maintenance and cost reduction.

  However, in order to stably use a fuel gas such as low calorie gas that constantly fluctuates in calorific value in a combustion facility, the range of variation in calorific value must be suppressed to an allowable range as fuel gas in the combustion facility. But there is no effective way to do that.

  The present invention has been made to solve such a problem, and suppresses the calorific value fluctuation of the low calorie gas or the like supplied as fuel gas to the combustion facility, thereby making the low calorie gas or the like a stable calorific fuel gas. It is an object of the present invention to provide a gas heating value control method that can be supplied and a gas heating value control device.

For the above purpose, the gas calorific value control method of the present invention provides a tank in which a gas inlet and a gas outlet are separately formed to cause time difference mixing in a fuel gas supply passage to a combustion facility. It was suppressed by the tanks in the gas outlet of the tank from the heat value variations of the fuel gas measured upstream of the tank based on the heating value variation of the fuel gas to the simulation model can approximate the characteristic of inhibiting the tank predicting fuel gas calorific value variation, so that the predicted fuel gas calorific value variation is within the allowable range as a fuel gas in the combustion equipment, to reduced heat or Zonetsu the fuel gas downstream of the tank Feedforward control.

  According to this method, the fuel gas supplied from the gas inlet into the tank is formed separately by temporarily storing the fuel gas supplied from time to time in the tank and mixing the time difference therein. Exhausted from the gas outlet. Therefore, even when the calorific value of the fuel gas is fluctuating, the time difference mixing suppresses the range of the calorific value fluctuation and reduces the calorific value fluctuation rate. Then, the fuel gas in which the heat generation amount fluctuation is suppressed is reduced in heat or increased to adjust the gas heat generation amount within the allowable fluctuation range of the combustion facility, so that the heat generation amount fluctuation can be easily adjusted. The time difference mixing means that the fuel gas flowing into the tank continuously with a time delay is mixed with the fuel gas that has already flowed in and stayed there.

  In addition, the fuel gas calorific value fluctuation after suppressing the calorific value fluctuation is measured in the fuel gas supply passage on the downstream side of the tank, and the fluctuation range of the measured calorific value is within the allowable range as the fuel gas of the combustion facility. In order to achieve the above, feedback control may be performed so that the temperature of the fuel gas is reduced or increased on the upstream side of the calorific value measurement point of the fuel gas supply passage.

"Feedback control" in the statements of the specification and claims, the group Dzu rather control the measurement value of the calorific value measuring points, it means to perform upstream of the measurement point.

  “Feed forward control” in the specification and claims refers to performing control based on the measurement value of the calorific value measurement point downstream of the measurement point. As one method of this feedforward control, based on the fuel gas heating value and the flow rate before mixing, the mixing amount of the heat-increasing gas and heat-reducing gas necessary for the heating value after mixing to be the expected value is determined. There is a method of calculating and giving it as a command value, but other methods may be used.

Further, a tank in which a gas inlet and a gas outlet are separately formed and time difference mixing is caused is provided in a fuel gas supply passage to a combustion facility, and a predetermined fuel gas heat generation amount is provided in the fuel gas supply passage upstream of the tank. When the fluctuation of the calorific value exceeding the fluctuation range is measured, the fuel gas is reduced or increased on the upstream side of the tank so that the fluctuation range is within the predetermined fluctuation range, and the heat is reduced or increased by the time difference mixing. based on the simulation model can approximate the characteristic of inhibiting the tank heating value variation of the gas, the fuel gas calorific value of the gas outlet of the tank predicted from heat value variations of the fuel gas measured upstream of the tank feedforward to reduced heat or Zonetsu the fuel gas in the tank downstream side fuel gas supply passage so variation is within the allowable range as a fuel gas in the combustion equipment It may be Gosuru.

In addition, a tank in which a gas inlet and a gas outlet are formed separately to cause time difference mixing is provided in a fuel gas supply passage to a combustion facility, and the fuel gas heat generation amount fluctuation is suppressed by the time difference mixing. based on the simulation model can approximate the characteristic to predict the fuel gas calorific value variation of the gas outlet of the tank from the heat value variations of the fuel gas measured upstream of the tank, the predicted fuel gas calorific value variation and the reduced heat or increasing heat feedforward control fuel gas based on the calorific value variation of the fuel gas supplied to the combustion equipment at the fuel gas supply passage of the tank downstream is measured, the heating value was the measured reduced heat or increasing heat the fuel gas upstream of the fluctuation range of the calorific value measuring point of the fuel gas supply passage to be within the allowable range as a fuel gas in the combustion equipment Fed back control and may be performed in parallel.

Further, a tank in which a gas inlet and a gas outlet are separately formed and time difference mixing occurs is provided in a fuel gas supply passage to a combustion facility, and a predetermined fuel gas heat is generated in the fuel gas supply passage upstream of the tank. When a calorific value fluctuation equal to or greater than the quantity fluctuation width is measured, the fuel gas is reduced or increased on the upstream side of the tank so that the fluctuation width is within a predetermined fluctuation width, and the heat reduction or heat increase is performed by the time difference mixing. characteristics of inhibiting the tank heating value variation of the fuel gas based on a simulation model can approximate the fuel gas heating of the gas outlet of the tank predicted from heat value variations of the fuel gas measured upstream of the tank and the reduced heat or increasing heat feedforward control fuel gas based on the amount variation, the fuel gas supplied to the combustion equipment at the fuel gas supply passage of the tank downstream originating The amount variation is measured, the variation width of the measured calorific value wherein reduced heat the fuel gas upstream of the calorific value measuring point of the fuel gas supply passage to be within the allowable range as a fuel gas for combustion equipment or The feedback control for increasing the heat may be performed in parallel.

The simulation model in the tank at a predetermined flow rate and volume, used to perform a plurality of system signals of the combined addition multiplied by a constant delay corresponding correction of the detector to the time constant and a first-order lag and dead time be able to.

  Further, in the gas calorific value control method, the operation of reducing or increasing the temperature of the fuel gas so that the fluctuation in the calorific value of the fuel gas is within an allowable range as the fuel gas of the combustion facility is performed in the tank or the outer surface of the tank. You may make it carry out.

In the gas heat generation amount control method, the fuel gas heat generation amount fluctuation average value measured on the upstream side of the tank and the fuel gas heat generation amount fluctuation average value measured in the fuel gas supply passage on the downstream side of the tank. After monitoring and detecting an average difference of a certain amount in these calorific value fluctuation average values, the upstream of the tank is adjusted so that the calorific value fluctuation of the fuel gas upstream of the tank approaches the calorific value in the fuel gas supply passage on the downstream side of the tank. The fuel gas may be reduced or increased on the side.

For the above purpose, a gas heating value control device of the present invention is provided in a fuel gas supply passage to a combustion facility, wherein a gas inlet and a gas outlet are formed separately to cause time difference mixing inside, and the tank And a simulation model that can approximate the characteristics of the first calorific value measuring device that measures the fluctuation of the calorific value of the fuel gas in the fuel gas supply passage upstream of the tank and the tank that suppresses the fluctuation of the calorific value due to the time difference mixing. The fuel gas heat generation amount fluctuation at the gas outlet of the tank is predicted from the fuel gas heat generation amount fluctuation measured by the first heat generation amount measuring device , and the predicted fuel gas heat generation amount fluctuation is detected by the combustion facility. A first controller that performs feedforward control so as to reduce or increase the temperature of the fuel gas so as to be within an allowable range as the fuel gas is provided. As the simulation model, in the tank having a predetermined flow rate and volume, a plurality of system signals including primary delay and dead time are added together by a constant, and the time constant is corrected corresponding to the delay of the detector. Can be used.

In addition, the fuel gas supply passage to the combustion facility is provided with a predetermined variation in a tank in which a gas inlet and a gas outlet are separately formed to cause time difference mixing inside, and in the fuel gas supply passage on the upstream side of the tank. first and heating value meter, the first heating value meter the variation width After measuring the heating value variation above a predetermined variation width is predetermined fluctuation range for measuring the heating value variation width or the fuel gas A simulation model capable of approximating the characteristics of the second controller for reducing or increasing the temperature of the fuel gas upstream of the tank so as to be within the range, and the characteristics of the tank for suppressing the heat generation fluctuation of the fuel gas by the time difference mixing based on the first fuel gas calorific value variation of the gas outlet of the tank predicted from heat value variations of the fuel gas measured by the heating value meter is within the allowable range as a fuel gas in the combustion equipment Like May be provided with first controller for feed-forward control such that the fuel gas supply passage reduced heat or Zonetsu the fuel gas in the tank downstream.

Further, a fuel gas supply passage to the combustion facility is provided, and a gas inlet and a gas outlet are formed separately to cause time difference mixing inside, and the fuel gas is supplied to the fuel gas supply passage upstream of the tank. Measured by the first calorific value measuring instrument based on a first calorific value measuring instrument that measures the calorific value fluctuation and a simulation model that can approximate the characteristics of the tank that suppresses the calorific value fluctuation due to the time difference mixing. The fuel gas heat generation amount fluctuation at the gas outlet of the tank is predicted from the fuel gas heat generation amount fluctuation, and feedforward control is performed to reduce or increase the fuel gas based on the predicted fuel gas heat generation amount fluctuation . a first controller, a first mixer provided in the fuel gas supply passage downstream of the tank, provided downstream of said first mixer, fuel gas supplied to the combustion equipment Said second heating value meter for measuring the calorific value variation, such that the variation range of the calorific value measured by the second heating value meter is within the allowable range as the fuel gas of the combustion equipment first A third controller that performs feedback control for reducing or increasing the temperature of the fuel gas in one mixer in addition to the feedforward control may be provided.

In addition, the fuel gas supply passage to the combustion facility is provided with a predetermined variation in a tank in which a gas inlet and a gas outlet are separately formed to cause time difference mixing inside, and in the fuel gas supply passage on the upstream side of the tank. first and heating value meter, the first heating value meter the variation width After measuring the heating value variation above a predetermined variation width is predetermined fluctuation range for measuring the heating value variation width or the fuel gas Based on a second controller for reducing or increasing the temperature of the fuel gas upstream of the tank and a simulation model capable of approximating the characteristics of the tank that suppresses fluctuations in heat generation by the time difference mixing. such that said first fuel gas calorific value variation of the gas outlet of the tank predicted from heat value variations of the fuel gas measured by the heating value meter is within the allowable range as a fuel gas in the combustion equipment tank A first controller that performs a feedforward control such that reduced heat or Zonetsu the fuel gas in the fuel gas supply passage of the flow side, first provided in the fuel gas supply passage downstream of the tank a mixer provided on the downstream side of the first mixer, a second heating value meter for measuring the heating value variation of the fuel gas supplied to the combustion equipment, said second heating value meter in a reduced heat or increasing heat feedback control of the fuel gas in the first mixer as the variation width of the measured heating value falls within an allowable range as a fuel gas in the combustion equipment in addition to the feed forward control A third controller to perform may be provided.

Further, in the gas heat generation amount control device, a first mixer for reducing or increasing the temperature of the fuel gas so that the variation in the heat generation amount of the fuel gas is within an allowable range as the fuel gas of the combustion facility is provided in the tank or provided in the tank outer surface, may be configured to be reduced heat or Zonetsu fuel gas tank or tank outer surface by said first mixer.

Further, in the gas heating value control unit, a second mixer provided on the upstream side fuel gas supply passage in said tank, and a heating value variation average value of the fuel gas measured upstream of the second mixer A monitoring controller is provided for monitoring the fuel gas calorific value fluctuation average value measured downstream of the second mixer, and the monitoring controller detects an average difference of a certain amount between the two calorific value fluctuation average values. Then, the monitoring controller has a function of reducing or increasing the temperature of the fuel gas in the second mixer so that the variation in the calorific value of the fuel gas upstream of the tank approaches the calorific value of the downstream side of the mixer. You may let them.

  According to the present invention, when low calorie gas or the like that varies in calorific value is supplied as a fuel gas to a combustion facility such as a gas turbine, the calorific value variation corresponding to the combustion facility can be suppressed (relieved) by time difference mixing. The fuel gas can be easily reduced or increased in temperature. In other words, by reducing the amplitude of the calorific value fluctuation with the tank, it is possible to suppress fluctuations in the short cycle and middle cycle, and mainly leave only the fluctuations in the long cycle, so that the fuel gas is reduced in heat or increased in heat. By doing so, it is possible to easily make the fuel gas whose calorific value fluctuates into a fuel gas that can be stably used in the combustion facility. In this way, continuous stable operation of the equipment can be realized by suppressing the fluctuation of the calorific value within the allowable fluctuation range of the gas whose calorific value fluctuates as the fuel gas of the combustion equipment.

FIG. 1 is a piping diagram showing an outline of a gas turbine power generation facility including a gas heating value control device according to a first embodiment of the present invention. FIG. 2 is a graph showing a state in which the heat generation amount fluctuation is suppressed by the gas heat generation amount control device of FIG. FIG. 3 is a piping diagram showing an outline of a part of a gas turbine power generation facility including a gas heating value control device according to a second embodiment of the present invention. FIG. 4 is a graph showing a state in which the heat generation amount fluctuation is alleviated by the gas heat generation amount control device of FIG. FIG. 5 is a piping diagram showing an outline of a part of a gas turbine power generation facility including a gas heating value control device according to a third embodiment of the present invention. FIG. 6 is a block diagram showing an example of a simulation model in the gas heating value control apparatus according to the third embodiment of FIG. FIG. 7 is a piping diagram showing an outline of a part of a gas turbine power generation facility including a gas heating value control device according to a fourth embodiment of the present invention. FIG. 8 is a graph showing a state in which the heat generation amount fluctuation is alleviated by the gas heat generation amount control device of FIG. FIG. 9 is a piping diagram showing an outline of a part of a gas turbine power generation facility including a gas heating value control device according to a fifth embodiment of the present invention. FIG. 10 is a block diagram showing an example of a simulation model in the gas heating value control apparatus according to the fifth embodiment of FIG. FIG. 11 is a piping diagram showing an outline of a conventional gas turbine power generation facility. FIG. 12 is a graph showing fluctuations in heat generation in the gas turbine power generation facility of FIG.

DESCRIPTION OF SYMBOLS 1 .... Gas calorific value control device 2 .... Gas turbine 3 .... Fuel gas supply passage 4 .... Fuel gas generator 5 .... Tank 6 .... Gas inlet 7. ... Gas outlet 8 ... Mixer 9 ... Gas compressor 10 ... Generator 11 ... Control gas supply pipe 12 ... Heat reduction flow control valve 13 ...・ ・ Heat reduction gas supply 14 ・ ・ ・ ・ Flow adjustment valve for heat increase 15 ・ ・ ・ ・ Heat increase gas supply 16 ・ ・ ・ ・ Heat generation meter 17 ・ ・ ・ ・ Input path 18 ・ ・ ・ ・ Setting Value 19 ... First controller 20 ... Output path 21 ... Distributor 22 ... Flow rate 23 ... Second calorific value measuring instrument 24 ... Input path 25 ... Second controller 26 ... Output path 27 ... Gas heating value control device 29 ... Third heating value measuring device 30 ... Input path Path 31 ··· Simulator 32 ··· Route 33 · · · Gas heating value control device 35 · · · Gas heating value control device 37 · · · Second mixer 38 · · · Third control (Monitoring controller)
39 ... Output path 40 ... Distributor 41 ... Heat reduction flow control valve 42 ... Heat reduction gas supply 43 ... Heat increase flow control valve 44 ...・ Increased gas supply 45 ・ ・ ・ ・ Second control gas supply piping 46 ・ ・ ・ ・ Gas heat generation amount control device S ・ ・ ・ ・ Gas turbine power generation equipment

  A gas heating value control apparatus and control method thereof according to the present invention will be described with reference to the accompanying drawings. In the following description, a gas turbine will be described as an example of combustion equipment. In the following embodiments, an example in which the heat generation amount of the fuel gas can be reduced or increased will be described.

  FIG. 1 shows an outline of a gas turbine power generation facility S including a gas heating value control device 1 according to a first embodiment of the present invention. The present invention is applied to a fuel gas supply passage 3 for supplying fuel gas to a gas turbine 2. It is a piping diagram in which the gas calorific value control device 1 is provided.

  The fuel gas supply passage 3 is configured to supply low gas calorific gas or the like (hereinafter referred to as “fuel gas”) generated in a fuel gas generator 4 (for example, a blast furnace) to the gas turbine 2 as fuel. The fuel gas supply passage 3 is provided with a tank 5 in which a gas inlet 6 and a gas outlet 7 are separately formed.

  The tank 5 has a predetermined volume, and is configured such that fuel gas passing through the fuel gas supply passage 3 enters from the gas inlet 6 and exits from the gas outlet 7. The tank 5 functions as a buffer tank, and the fuel gas whose calorific value changes continuously from the gas inlet 6 flows into the inside continuously, and is mixed with the fuel gas that has already flowed in and stopped, and is formed separately. Since it is discharged from the gas outlet 7, even when the calorific value of the fuel gas fluctuates, the time difference mixing reduces the range of the calorific value variation and also reduces the calorific value fluctuation rate. .

  That is, the fuel gas that has flowed into the tank 5 at the same time is distributed from a portion that flows out of the gas outlet 7 relatively early to a portion that stays in the tank 5 from late. On the other hand, since new gas continuously flows in from the gas inlet 6, the gas that has flown in the past and the gas that has flowed in are continuously mixed. That is, the fuel gas that changes in the calorific value flowing into the tank 5 every moment is mixed in the tank 5 in this manner. In this specification and claims, this is called time difference mixing, and the tank 5 exerts a function of suppressing the heat amount fluctuation of the fuel gas by the action of time difference mixing. As a result, the calorific value fluctuation range of the fuel gas exiting from the gas outlet 7 of the tank 5 is reduced, and the fluctuation speed is reduced. That is, the calorific value fluctuation is greatly suppressed (relieved).

As a buffer effect by the tank 5, if the fluctuation of the gas inlet 6 is a sin curve of the angular velocity ω, the mixing in the tank 5 is complete mixing, and the time constant is T, the outlet fluctuation amplitude / inlet fluctuation amplitude. = Gain = 1 / (1 + ω2 · T2) ^1/2 . From this, when ω or T (that is, the tank capacity) is large, Gain is small, that is, the fluctuation range of the heat generation amount at the outlet is reduced, and the fluctuation suppressing effect can be achieved. The diagram shown in the upper part of the fuel gas supply passage 3 schematically shows the variation in the calorific value of the fuel gas.

  The time difference mixing by the tank 5 is an important configuration, and the fuel gas is time difference mixed by the tank 5 so as to alleviate the calorific value fluctuation in advance, and the fuel gas calorific value fluctuation on the downstream side of the tank 5 The control for adjusting the temperature within the allowable fluctuation range of the gas characteristics of the combustion facility by reducing or increasing the temperature is made stable.

  The tank 5 is not limited to a structure as long as it has a predetermined volume. For example, the tank may be of a fixed internal volume type in which the volume does not change, or may be a tank of a variable internal volume type used as a device (gas holder) for monitoring the gas supply and demand balance in a conventional gas turbine facility or the like. The internal volume variation type tank is a tank having an airtightly attached lid member that can move up and down according to the internal pressure of the tank. By using these tanks, it is possible to obtain a tank 5 that can exhibit the effect of suppressing fluctuations in the calorific value of the fuel gas. Furthermore, a plurality of tanks 5 may be arranged in series or in parallel.

  Furthermore, in order to perform the time difference mixing inside the tank 5 more effectively, the tank 5 is provided with a stirring device for stirring and mixing the fuel gas flowing in from the gas inlet 6, or flows in from the gas inlet 6. A perforated plate or the like that mixes the fuel gas through a large number of holes may be incorporated.

  Further, on the downstream side of the tank of the fuel gas supply passage 3, in order to suppress fluctuation in the calorific value of the fuel gas discharged from the tank 5, the fuel gas is mixed with a heat reducing or increasing gas. A vessel 8 is provided. A gas compressor 9 that compresses the fuel gas and a gas turbine 2 that combusts the fuel gas compressed by the gas compressor 9 are provided on the downstream side of the mixer 8. 10 is configured to be driven.

  The mixer 8 is connected to a control gas supply pipe 11 for supplying a gas for heat reduction or heat increase. The control gas supply pipe 11 includes a heat reduction gas supply 13 connected via a heat reduction flow rate adjusting valve 12 for adjusting the flow rate of the heat reduction gas, and a heat increase flow rate for adjusting the flow rate of the heat increase gas. A heat-increasing gas supplier 15 connected via a regulating valve 14 is provided.

As the heat reducing gas, an inert gas, air, steam, waste nitrogen, exhaust gas discharged from a combustion facility, or the like can be used. Nitrogen gas (N ₂ ) can be suitably employed as the inert gas, but of course, the inert gas is not limited to N ₂ and may be carbon dioxide (CO ₂ ), helium (He), or the like. As the heat-increasing gas, natural gas, coke oven gas (COG), or the like, which is medium / high calorie gas, can be employed.

  On the other hand, the fuel gas supply passage 3 on the downstream side of the mixer 8 is provided with a calorific value measuring device 16 for measuring the calorific value of the fuel gas in the fuel gas supply passage. As the calorific value measuring device 16, a so-called calorimeter that directly measures the calorific value of gas, a device that measures the content (concentration) of combustible components, and the like are used. When importance is attached to the detection speed, it is preferable to use a combustible gas concentration detector at present. Further, a concentration detector that detects the concentration of the combustible component that is mainly included in the applied fuel gas or that combusts the main calorific value fluctuation may be used.

  The calorific value measuring device 16 monitors the calorific value of the fuel gas on the downstream side of the mixer 8. The measured value measured by the calorific value measuring device 16 is input via the input path 17 to the first controller 19 that compares with a predetermined set value 18 set in advance according to the gas turbine 2 (combustion equipment). . The first controller 19 is a PI controller. The first controller 19 manages feedback control. As a result of comparison by the first controller 19, a control signal for reducing or increasing the temperature of the fuel gas in the fuel gas supply passage 3 is sent from the output path 20 through the distributor 21 to the heat reduction flow rate adjusting valve 12 or It is configured to output to the heat increase flow control valve 14. Thereby, feedback control is performed.

  Hereinafter, by the gas heat generation amount control device 1 of the first embodiment configured as described above, the fuel gas whose heat generation amount fluctuates in the fuel gas supply passage 3 is changed in the heat generation amount fluctuation range of the gas turbine 2 (combustion facility). A description will be given of the control for making the fuel gas within an allowable range that can be used stably as a fuel gas.

  The fuel gas supplied from the fuel gas generator 4 through the fuel gas supply passage 3 enters from the gas inlet 6 of the tank 5 and is mixed in the tank 5 with time difference. In this tank 5, as described above, even if the fuel gas flowing into the tank 5 from time to time flows into the tank 5 at the same time, the fuel gas flows into the tank 5 from the portion that flows out of the gas outlet 7 relatively early to the later time. Therefore, the new gas that continuously flows in and the gas that has flown in the past are continuously mixed, and the fluctuation amount of the calorific value of the fuel gas supplied from the fuel gas generator 4 is distributed. Large fluctuations are suppressed, and the fuel gas exiting from the gas outlet is in a state in which large fluctuations in calorific value are suppressed (relaxed).

  In this way, the fuel gas supply passage 3 provided in the fuel gas supply passage 3 can suppress the large fluctuation in the calorific value of the fuel gas in the tank 5 that can realize the time difference mixing of the fuel gas, and as a result, the control for mixing the heat reduction or the heat increase gas downstream. To reduce heat generation fluctuation.

FIG. 2 is a graph showing a state in which the calorific value variation is suppressed (relaxed) by the gas calorific value control device of FIG. FIG. 2 shows a simulation result of the suppression (relaxation) state of calorie fluctuation when fuel gas that fluctuates in calorie is supplied at a flow rate of 280000 Nm ³ / hr when the volume of the tank 5 in FIG. 1 is 40000 m ^3. It is shown. The horizontal axis indicates time (seconds), and the vertical axis indicates the gas calorie value (MJ / kg) that is the calorific value of the fuel gas.

  As shown in the figure, as an example in which the fluctuation range of the calorific value by the tank 5 is suppressed, for example, the fluctuation of the calorific value (original fluctuation) of the fuel gas supplied from the fuel gas generator 4 is shown in FIG. As shown by the dotted line, there is a great variation depending on the time, but the calorific value fluctuation at the tank outlet after the time difference mixing in the tank 5 (fluctuation after suppression) shows a large calorific value fluctuation as shown by the dotted line in the figure. It will be in a suppressed state. Specifically, the gas calorie of the fuel gas before entering the tank 5 varies from about 5.3 MJ / kg to about 8.8 MJ / kg, but the gas calorie of the fuel gas exiting the tank 5 is about From 5.8 MJ / kg to about 6.8 MJ / kg, the fluctuation range is greatly reduced. Further, as shown in the figure, with respect to the fluctuation cycle, the short-cycle and middle-cycle fluctuations are removed, and the long-cycle fluctuation mainly remains. This effect tends to become more prominent as the volume of the tank 5 is increased with respect to the fuel gas supply flow rate. If the cycle of the original fluctuation is short and the fluctuation width is small, it is effective to reduce the volume of the tank 5 from the viewpoint of economy.

On the other hand, the calorific value measuring device 16 provided on the downstream side of the mixer 8 measures the calorific value of the fuel gas in the fuel gas supply passage 3. The measurement value measured by the calorific value measuring device 16 is input to the first controller 19 via the input path 17. In the first controller 19, the measured value sent from the calorific value measuring device 16 is compared with a predetermined set value 18 set in advance according to the gas turbine 2.

  As a result of the comparison, when it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3 from the measured value detected by the calorific value measuring device 16, the heat reduction flow rate from the output route 20 via the distributor 21. A control signal is sent to the regulating valve 12, and a predetermined amount of reduced heat gas is supplied from the reduced heat gas supply device 13 to the mixer 8. In addition, when it is necessary to increase the temperature of the fuel gas, a control signal is sent from the output path 20 to the heat increase flow control valve 14 via the distributor 21, and a predetermined amount of increase is generated from the heat increase gas supplier 15. Hot gas is supplied to the mixer 8. In this manner, the fluctuation range of the calorific value of the fuel gas supplied to the gas turbine 2 is controlled so as not to exceed the allowable range as the fuel gas of the gas turbine 2. As shown by the solid line in FIG. 2, the heat generation fluctuation after being controlled by the mixer 8 is suppressed to a large heat generation fluctuation with a long period and a small heat generation fluctuation as a fuel gas of the gas turbine 2. A stable fuel gas can be obtained in which the fluctuation of the heat generation amount is suppressed within the allowable fluctuation range.

  Thus, according to the gas heating value control device 1 of the first embodiment, when the fuel gas is reduced or increased in temperature by the mixer 8, the fuel gas in which the large heating value fluctuation is suppressed by the tank 5 as described above. On the other hand, it is possible to easily control to a stable calorific value by performing feedback control in which heat is reduced or mixed with a heat-increased gas based on the calorific value fluctuation on the downstream side of the mixer 8. In addition, since the control is performed on the fuel gas in a state where a large variation in the heat generation amount is suppressed, the amount of heat reduction or heat increase gas supplied into the fuel gas is reduced.

  Further, for example, if the fluctuation range of the calorific value of the fuel gas of the gas turbine 2 is set to ± 10% of the reference calorific value (average value), the average value of the calorific value downstream of the tank 5 is calculated. In order to match the reference calorific value set in the gas turbine 2, it may be sufficient to supply a constant ratio of control gas on the downstream side by providing the tank 5 having a volume that can meet the specifications. .

  In this embodiment, the example in which the heat generation amount of the fuel gas is reduced or increased has been described. However, depending on the conditions, control may be performed so that the heat reducing gas and the heat increasing gas are supplied simultaneously. In addition, depending on the conditions of the fuel gas and the combustion facility, a configuration in which only heat reduction or only heat increase may be performed, and only one of them may suppress fluctuations in the calorific value of the fuel gas.

  Further, the mixer 8 may be provided inside the tank 5 or on the outer surface of the tank 5, and the fuel gas may be reduced or increased in temperature inside or outside the tank 5. If comprised in this way, an installation can be made compact.

  FIG. 3 is a piping diagram showing an outline of a part of a gas turbine power generation facility including a gas heating value control device according to a second embodiment of the present invention. This second embodiment is a mixing in the first embodiment. In addition to feedback control based on a signal from a calorific value measuring device 16 provided downstream of the vessel 8, the calorific value fluctuation of the fuel gas in the fuel gas supply passage 3 between the tank 5 and the mixer 8 is measured. This is an embodiment in which feedforward control is performed. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in the drawing, a second calorific value measuring device 23 is provided in the fuel gas supply passage 3 between the tank 5 and the mixer 8. The calorific value of the fuel gas in the fuel gas supply passage 3 measured by the second calorific value meter 23 is input to the second controller 25 via the input path 24. From the second controller 25 in the second embodiment, a control signal is output for the remaining heat generation amount fluctuation remaining in the fuel gas whose heat generation amount fluctuation is suppressed by the tank 5. The second controller 25 governs feedforward control and may be formed integrally with the first controller 19.

  On the other hand, as in the first embodiment, the measured value of the calorific value of the fuel gas in the fuel gas supply passage 3 measured by the calorific value measuring device 16 provided on the downstream side of the mixer 8 is input to the input path 17. To the first controller 19 and is compared with a predetermined set value 18 set in advance according to the gas turbine 2 by the first controller 19 to reduce the temperature of the fuel gas in the fuel gas supply passage 3. When necessary, a heat reduction control signal is output to the output path 20, and when it is necessary to increase heat, a heat increase control signal is output to the output path 20.

  The heat reduction or heat increase control signal is corrected by the heat reduction or heat increase control signal output from the second controller 25 via the output path 26. As a result of correcting the control signal from the first controller 19 with the control signal from the second controller 25, if it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3, it is reduced via the distributor 21. A control signal is sent to the heat flow regulating valve 12, and a predetermined amount of the reduced heat gas is supplied from the reduced heat gas supply device 13 to the mixer 8. Further, when it is necessary to increase the temperature of the fuel gas, a control signal is sent to the heat increase flow control valve 14 via the distributor 21, and a predetermined amount of the heat increase gas is mixed from the heat increase gas supply unit 15. Is supplied to the vessel 8.

  According to the gas calorific value control device 27 of the second embodiment, when the fuel gas is reduced or increased in temperature by the mixer 8, the large calorific value fluctuation is suppressed by the tank 5 as in the first embodiment. In addition to control for adjusting the calorific value by feedback control that mixes heat-reducing gas or heat-reducing gas based on fluctuations in calorific value on the downstream side of the mixer, fuel discharged from the tank 5 on the upstream side of the mixer 8 Since the heat generation amount is adjusted by feedforward control in which the heat is reduced or mixed with the heat-increased gas based on the heat generation amount fluctuation remaining in the gas, a predetermined value that is stable following the heat generation amount fluctuation that is faster than in the first embodiment. It becomes possible to adjust the heat generation amount within the fluctuation range. Also in this case, since the adjustment is made for the fuel gas in a state where a large variation in the heat generation amount is suppressed, the amount of heat reduction or heat increase gas supplied into the fuel gas is reduced.

In the second embodiment, the feedforward control is performed in addition to the feedback control. However, since the fuel gas downstream of the tank has a heat generation amount fluctuation range reduced by the tank 5, Based on the calorific value and flow rate of the fuel gas in the fuel gas supply passage 3 measured by the second calorific value meter 23 input to the second controller 25, the second controller 25 preliminarily sends the gas turbine 2 to the gas turbine 2. When it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3 by comparison with a predetermined set value 18 set accordingly, it is necessary to output a heat reduction control signal to the output path 20 to increase the temperature. In some cases, a control signal for increasing heat may be output to the output path 20. In this case, the feedforward control calculates the mixing amount necessary for the heating value after mixing to be a predetermined value based on the heating value and flow rate of the fuel gas before mixing the heat increasing and decreasing heat gas, Necessary amount mixing control is performed such that the mixing amount is given as a command value (target value) and mixing is performed. This control is performed by feedforward control only by the second controller 25.

  FIG. 4 is a graph showing a state in which the heat generation amount fluctuation is alleviated by the gas heat generation amount control device 27 of FIG. FIG. 4 shows a state simulated under the same conditions as in FIG. According to the second embodiment, as shown by a solid line in the figure, compared to FIG. 2 described above, the calorific value fluctuation after being controlled by the mixer 8 has a long period of time because the large calorific value fluctuation is suppressed. The amount of heat generation is small, and the fuel gas can be stabilized within the allowable range as the fuel gas of the gas turbine 2.

  FIG. 5 is a piping diagram showing an outline of a part of a gas turbine power generation facility including a gas heating value control device according to the third embodiment of the present invention. This third embodiment is a gas inlet 6 of the tank 5 in advance. A simulation model in which the heat generation amount variation at the gas outlet 7 is predicted from the heat generation amount variation at the gas outlet 7 is created, and the fuel gas heat generation amount signal measured by the third heat generation amount measuring device 29 provided on the upstream side of the tank 5 is converted into the simulation model. Based on this, the heat generation amount fluctuation at the outlet of the tank 5 is predicted, and feedforward control for reducing or increasing the heat by the mixer 8 is performed. In addition, the same code | symbol is attached | subjected to the structure same as the said 2nd Embodiment, and the description is abbreviate | omitted.

  As shown in the figure, a third calorific value measuring device 29 is provided in the fuel gas supply passage 3 upstream of the tank 5. The calorific value of the fuel gas in the fuel gas supply passage 3 measured by the third calorific value measuring device 29 is input via the input path 30 to the simulator 31 incorporating the simulation model.

The simulation model incorporated in advance in the simulator 31 is created as a simulation model corresponding to the volume and shape of the buffer tank to be used, based on the result of simulating the buffer tank model by the finite element method or the like. As this simulation model, for example, in a tank 5 of a predetermined gas flow rate and volume, a plurality of first-order lag and dead time system signals multiplied by a constant number are added together, and the time constant corresponds to the detector delay. Make a correction.

FIG. 6 is a block diagram showing an example of a simulation model in the gas heating value control apparatus according to the third embodiment of FIG. The simulation model is created by adding and multiplying the signals of the first-order lag and dead time systems by a constant, but this figure shows an example based on three systems for explanation. Specifically, with respect to the measurement signal from the third calorific value measuring device 29, the first-order lag of the measuring device is compensated by delay compensation (1 + Ta * s) / (1 + Tb * s) illustrated upstream of the simulation model, A linear combination of a plurality of first-order lag systems and dead time systems is added to the signal by multiplying by a constant, and the heat generation amount fluctuation at the gas outlet 7 of the tank 5 is predicted. Each symbol in FIG. 6 is s; Laplace transform parameter, Ta, Tb; delay compensation constant, T1, T2, T3; first order delay, L1, L2, L3; dead time, G1, G2, G3; , Respectively.

A signal of fluctuation of the heat generation amount at the gas outlet 7 of the tank 5 predicted by such a simulation model is output to the second controller 25 via the path 32. In the second controller 25, a signal output via the path 32 is compared with a predetermined set value 18 set in advance according to the gas turbine 2.

  As a result of the comparison, when it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3 from the measurement value measured by the third calorific value measuring device 29, the heat is reduced from the output route 20 via the distributor 21. A control signal is sent to the flow rate adjusting valve 12, and a predetermined amount of reduced heat gas is supplied from the reduced heat gas supply device 13 to the mixer 8. In addition, when it is necessary to increase the temperature of the fuel gas, a control signal is sent from the output path 20 to the heat increase flow control valve 14 via the distributor 21, and a predetermined amount of increase is generated from the heat increase gas supplier 15. Hot gas is supplied to the mixer 8.

  According to the gas calorific value control device 33 of the third embodiment, even if a rapid calorific value fluctuation occurs in the fuel gas, the rapid calorific value fluctuation is measured on the upstream side of the tank 5, and the calorific value fluctuation is measured. Since the control according to the above is performed based on the simulation model, it is possible to suppress the calorific value fluctuation with good followability. Moreover, even when a measurement time delay occurs in the second calorific value measuring device 23 in the second embodiment, the gas calorific value control device 33 in the third embodiment can cope with it.

  FIG. 7 is a piping diagram showing an outline of a part of a gas turbine power generation facility including a gas heating value control device according to a fourth embodiment of the present invention. This fourth embodiment is the same as the third embodiment. The feedback control of the first or second embodiment is added to the feedforward control. In addition, the same code | symbol is attached | subjected to the structure same as the said 2nd, 3rd embodiment, and the description is abbreviate | omitted.

  As shown in the drawing, in addition to the configuration of FIG. 5, the measured value of the fuel gas heat generation amount in the fuel gas supply passage 3 measured by the heat generation amount measuring device 16 provided on the downstream side of the mixer is the first controller 19. Is compared with a predetermined set value 18 set in advance according to the gas turbine 2 by the first controller 19, and if it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3, the output path A heat reduction control signal is output to the output path 20 when it is necessary to increase the heat.

  The heat reduction or heat increase feedback control signal is corrected by the heat reduction or heat increase feedforward control signal output from the second controller 25. As a result of correcting the control signal from the first controller 19 with the control signal from the second controller 25, if it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3, it is reduced via the distributor 21. A control signal is sent to the heat flow regulating valve 12, and a predetermined amount of the reduced heat gas is supplied from the reduced heat gas supply device 13 to the mixer 8. Further, when it is necessary to increase the temperature of the fuel gas, a control signal is sent to the heat increase flow control valve 14 via the distributor 21, and a predetermined amount of the heat increase gas is mixed from the heat increase gas supply unit 15. Is supplied to the vessel 8.

  FIG. 8 is a graph showing a state in which the calorific value fluctuation is suppressed (relieved) by the gas calorific value control device of FIG. 7. As described above, the calorific value fluctuation of the fuel gas on the upstream side of the tank 5 is based on the simulation model. As shown by the solid line, the calorific value fluctuation after the feedforward control that is controlled by the feedback control and the feedback control that is controlled based on the fluctuation of the calorific value of the fuel gas on the downstream side of the mixer 8 is large. Is suppressed to a small amount of heat generation fluctuation with a long cycle, and the fuel gas can be stabilized within the allowable fluctuation range as the fuel gas of the gas turbine 2.

  That is, according to the gas calorific value control device 35 of the fourth embodiment, even if a rapid calorific value fluctuation occurs in the fuel gas, the rapid calorific value fluctuation is measured on the upstream side of the tank 5, and the calorific value fluctuation is measured. Since the control according to the above is performed based on the simulation model, it is possible to suppress the calorific value fluctuation with good followability. Moreover, according to the gas heat generation amount control device 35 of the fourth embodiment, when the measurement time delay occurs in the second heat generation amount measuring device 23 as in the gas heat generation amount control device 27 of the second embodiment. But you can.

  Furthermore, in this embodiment, the feedforward control incorporating a simulation model that can approximate the actual tank characteristics is applied in the simulator 31, and the measurement time of the third calorific value measuring device 29 provided upstream of the tank 5 is applied. However, it makes use of the long tank residence time to compensate for the measurement time delay and accurately predicts the amount of heat generated at the outlet of the tank. Continuous stable operation of the equipment can be realized by suppressing the fluctuation range of the remaining heat generation amount on the entry side within the allowable limit range.

  FIG. 9 is a piping diagram showing an outline of part of a gas turbine power generation facility including a gas heating value control device according to a fifth embodiment of the present invention. This fifth embodiment is in addition to the fourth embodiment. As shown in the diagram schematically shown in the upper part of the fuel gas supply passage 3, the fuel gas calorific value fluctuation average value can be controlled even when it rises or falls within a certain range. is there. In addition, the same code | symbol is attached | subjected to the structure same as the said 4th Embodiment, and the description is abbreviate | omitted.

  As shown in the figure, in the fifth embodiment, a second mixer 37 is provided in the fuel gas supply passage 3 upstream of the tank 5, and the second fuel gas supply passage 3 upstream of the second mixer 37 is provided with the second mixer 37. Three calorific value measuring devices 29 are provided. The calorific value of the fuel gas in the fuel gas supply passage 3 measured by the third calorific value measuring device 29 is input from the input path 30 to the third controller 38. In addition, the third controller 38 also receives the calorific value of the fuel gas measured by the calorific value meter 16 provided on the downstream side of the mixer 8 provided on the downstream side of the tank 5 from the input path 17. Has been. The third controller 38 monitors whether the average value of the calorific value fluctuation on the upstream side of the tank 5 has a certain range of rise or fall relative to the average value of the calorific value fluctuation on the downstream side of the mixer 8. Has been. The third controller 38 is a monitoring controller.

  Then, when an increase or decrease of a certain width is measured in the average value of the variation in the calorific value of the fuel gas on the upstream side of the tank 5, it is reduced from the third controller 38 via the output path 39 and the distributor 40. In the case of heating, a control signal for supplying a predetermined amount of heat reduction gas from the heat reduction gas supply unit 42 to the second mixer 37 from the second control gas supply pipe 45 is output to the heat reduction flow rate adjustment valve 41, In the case of heating, a control signal for supplying a predetermined amount of the heat-up gas from the heat-up gas supply device 44 to the second mixer 37 from the second control gas supply pipe 45 is output to the heat-up flow adjustment valve 43.

  On the other hand, the calorific value of the fuel gas in the fuel gas supply passage 3 measured by the third calorific value measuring device 29 is also input to a simulator 31 incorporating a simulation model. A control signal output from the third controller 38 to the output path 39 is also input to the simulator 31.

  FIG. 10 is a block diagram showing an example of a simulation model incorporated in advance in the simulator 31 in the gas heating value control device 46 according to the fifth embodiment. In this figure, as described on the upstream side of the tank 5 in FIG. 9, a case where the heat generation amount fluctuation with a high average value is reduced will be described. In this case, the case where the heat reduction gas supply device 42 is supplied to the second mixer 37 by controlling the heat reduction flow rate adjustment valve 41 of FIG. 9 will be described. This simulation model is also created by adding a plurality of first-order lag and dead time system signals multiplied by a constant, but this figure also shows an example based on three systems for explanation.

  Further, in the case of this simulation model, correction is performed on the upstream side of the simulation model in the case where a difference occurs in the fuel gas calorific value variation average value on the upstream side of the tank 5. Specifically, with respect to the measurement signal from the third calorific value measuring device 29, the first-order lag of the measuring device is compensated by delay compensation (1 + Ta * s) / (1 + Tb * s) illustrated upstream of the simulation model, The third controller 38 performs correction after supplying the heat reducing gas to correct the average value difference of the calorific value fluctuation with respect to the signal, and a plurality of primary delays and dead time with respect to the corrected signal. The signal of the system is multiplied by a constant and added to predict the fluctuation of the heat generation at the gas outlet 7 of the tank 5. Each symbol in FIG. 10 is the same as that in FIG. 6, and s: Laplace transform parameter, Ta, Tb; delay compensation constant, T1, T2, T3; first order delay, L1, L2, L3; dead time, G1, G2, G3; constant multiplication factors, respectively. The expression in the second controller 25 is a differential expression for fluctuation.

  Then, a calorific value fluctuation signal at the gas outlet 7 of the tank 5 predicted by such a simulation model is output to the second controller 25 via the path 32. The second controller 25 outputs a control signal for the remainder of the calorific value fluctuation predicted to remain in the fuel gas in which the average difference in calorific value fluctuation is suppressed by the tank 5.

  On the other hand, as in the fourth embodiment, the measured value of the calorific value of the fuel gas in the fuel gas supply passage 3 measured by the calorific value measuring device 16 provided on the downstream side of the mixer 8 is the first controller 19. Is compared with a predetermined set value 18 set in advance according to the gas turbine 2 by the first controller 19, and if it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3, the output path A heat reduction control signal is output to 20.

  The heat reduction control signal is corrected by the control signal output from the second controller 25 to the output path 26. As a result of correcting the control signal from the first controller 19 with the control signal from the second controller 25, if it is necessary to reduce the temperature of the fuel gas in the fuel gas supply passage 3, it is reduced via the distributor 21. A control signal is sent to the heat flow regulating valve 12, and a predetermined amount of the reduced heat gas is supplied from the reduced heat gas supply device 13 to the mixer 8. Thereby, the calorific value of the fuel gas is adjusted within the allowable fluctuation range.

  Here, an example of reducing the temperature of the fuel gas has been described. However, when it is necessary to increase the temperature of the fuel gas, a control signal is sent via the distributor 21 to the flow rate adjusting valve 14 for increasing the temperature of the heated gas. A predetermined amount of the heat increasing gas is supplied from the supplier 15 to the mixer 8.

  According to the gas calorific value control device 46 of the fifth embodiment, even if a certain amount of rise or fall occurs in the average value of the fluctuation in the calorific value of the fuel gas, the rise or fall of the average value is detected on the upstream side of the tank 5. Therefore, even if the fuel gas has a change in the average value of the calorific value variation, it can be stably controlled to be within the allowable range as the fuel gas of the gas turbine 2.

  In this case, depending on the conditions, control may be performed so that the heat-reducing gas and the heat-reducing gas are supplied simultaneously, and depending on the fuel gas conditions, only heat reduction or only heat increase may be performed. Thus, the fuel gas calorific value variation average value may be suppressed by only one side.

  If the gas calorific value control device (method) of the embodiment described above is applied, the fluctuation of the calorific value of various fuel gases is reliably suppressed and stabilized within the allowable range of the combustion equipment, and used effectively and efficiently. can do.

  Moreover, in embodiment described above, although the gas turbine is illustrated as a combustion equipment, the combustion equipment in this invention is not limited to a gas turbine. These gas heat generation amount control devices can also be applied to other combustion facilities such as boilers, heating furnaces, incinerators, and the like.

  Further, in the above-described embodiment, the example in which the calorific value of the fuel gas can be reduced or increased has been described, but a configuration in which only heat reduction or only increase in heat may be performed. And you may comprise so that both heat reduction or heat increase can be performed simultaneously.

  Moreover, in embodiment described above, the controller provided with each separate function is provided, However, You may integrate arbitrarily.

  Furthermore, the fuel gas used includes blast furnace gas (BFG), converter gas (LDG), coal bed gas contained in the coal bed ("Coal mines gas", referred to as CMG), direct reduction iron manufacturing method and melting By-product gas generated by the reduced iron manufacturing method, tail gas generated in GTL (Gas-to-Liquid) process, by-product gas generated from oil sand during oil refining process, by dust incineration using plasma Gas generated, methane gas (Landfill gas) generated in the process of fermenting and decomposing general waste including raw garbage in the landfill, and by-product gas generated by chemically reacting other similar raw materials, etc. Low calorie gas and the like. Further, the fuel gas includes not only low calorie gas but also medium calorie gas and high calorie gas. Of course, as the fuel gas, the present invention can be applied not only to the above gas alone, but also to a mixture of two or more gases as appropriate, and to a gas obtained by mixing these gases.

  In addition, any of the above-described embodiments is a conceptual diagram for explaining the basic function, and actually relates to related auxiliary devices and mounted products (for example, valves, activation devices, transformers, circuit breakers, tanks, etc.). Is omitted and not described.

  The present invention can be used as a gas calorific value control device that suppresses fluctuations in the calorific value of gas whose gas characteristics fluctuate and supplies it as a stable fuel gas to a combustion facility such as a gas turbine, a boiler, a heating furnace, or an incinerator. .

Claims (14)

A fuel gas supply passage to the combustion facility is provided with a tank in which the gas inlet and the gas outlet are formed separately and time difference mixing occurs inside,
The tank in the gas outlet of the tank from the heat value variations of the fuel gas measured upstream of said time difference the tank based on a simulation model can approximate the characteristic of inhibiting the tank heating value variation of the fuel gas by mixing Predicts the fuel gas calorific value fluctuation suppressed by
As the predicted fuel gas calorific value variation is within the allowable range as a fuel gas in the combustion equipment, feed forward control so as to decrease heat or Zonetsu the fuel gas downstream of the tank, gas heating value Control method. A fuel gas supply passage to the combustion facility is provided with a tank in which the gas inlet and the gas outlet are formed separately and time difference mixing occurs inside,
When the calorific value fluctuation exceeding the predetermined fuel gas calorific value fluctuation width is measured in the fuel gas supply passage on the upstream side of the tank, the fuel gas is reduced on the upstream side of the tank so that the fluctuation width is within the predetermined fluctuation width. Heat or heat up,
Based on a simulation model that can approximate the characteristics of the tank that suppresses fluctuations in the calorific value of the fuel gas that has been reduced or increased in temperature due to the time difference mixing, predicted from the fluctuation in the calorific value of the fuel gas measured upstream of the tank and said gas outlet of the fuel gas calorific value variation feed to reduced heat or Zonetsu fuel gas in the fuel gas supply passage in the tank downstream to be within the allowable range as a fuel gas in the combustion equipment of the tank Gas calorific value control method with forward control. A fuel gas supply passage to the combustion facility is provided with a tank in which the gas inlet and the gas outlet are formed separately and time difference mixing occurs inside,
Based on the simulation model can approximate the characteristics of the tank to suppress the heat generation amount of fluctuation of the fuel gas by the time difference mixing, the gas outlet of the tank from the heat value variations of the fuel gas measured upstream of the tank Predict fuel gas heat generation fluctuation,
Feedforward control for reducing or increasing the temperature of the fuel gas based on the predicted fluctuation in the heat generation amount of the fuel gas;
The heating value variation of the fuel gas supplied to the combustion equipment at the fuel gas supply passage of the tank downstream is measured,
And the reduced heat or increasing heat feedback control of the fuel gas upstream of the fuel gas supply passage to be within the allowable range of the calorific value measuring point variation range of calorific value and the measurement as a fuel gas in the combustion equipment A method for controlling the calorific value of gas, which is performed in parallel. A fuel gas supply passage to the combustion facility is provided with a tank in which the gas inlet and the gas outlet are formed separately and time difference mixing occurs inside,
When a heat generation amount fluctuation greater than a predetermined fuel gas heat generation amount fluctuation range is measured in the fuel gas supply passage upstream of the tank, the fuel gas is supplied upstream of the tank so that the fluctuation range is within a predetermined fluctuation range. Reduce or increase heat,
Based on a simulation model that can approximate the characteristics of the tank that suppresses fluctuations in the calorific value of the fuel gas that has been reduced or increased in temperature due to the time difference mixing, predicted from the fluctuation in the calorific value of the fuel gas measured upstream of the tank and the reduced heat or increasing heat feedforward control fuel gas based on the fuel gas calorific value variation of the gas outlet of the tank was,
The heating value variation of the fuel gas supplied to the combustion equipment at the fuel gas supply passage of the tank downstream is measured,
And the reduced heat or increasing heat feedback control of the fuel gas upstream of the fuel gas supply passage to be within the allowable range of the calorific value measuring point variation range of calorific value and the measurement as a fuel gas in the combustion equipment Gas calorific value control method to perform in parallel. The simulation model in the tank at a predetermined flow rate and volume, is performed a plurality of system signals of the combined addition multiplied by a constant delay corresponding correction of the detector to the time constant and a first-order lag and dead time The gas calorific value control method according to any one of claims 1 to 4 . In the gas calorific value control method according to claim 1 ,
A method for controlling the amount of heat generated from a gas so as to reduce or increase the temperature of the fuel gas so that the fluctuation in the amount of heat generated by the fuel gas falls within an allowable range as a fuel gas for a combustion facility. . In the gas calorific value control method according to claim 3 or 4 ,
The fuel gas calorific value fluctuation average value measured on the upstream side of the tank and the fuel gas calorific value fluctuation average value measured in the fuel gas supply passage on the downstream side of the tank are monitored,
When an average difference of a certain amount is detected in these calorific value fluctuation average values, the fuel on the upstream side of the tank is brought close to the calorific value of the fuel gas supply passage on the downstream side of the tank. Gas calorific value control method for reducing or increasing the temperature of gas. A tank provided in a fuel gas supply passage to a combustion facility, in which a gas inlet and a gas outlet are separately formed , and time difference mixing is caused inside;
A first calorific value measuring device for measuring a calorific value fluctuation of fuel gas in the fuel gas supply passage on the upstream side of the tank;
Based on a simulation model capable of approximating the characteristics of the tank that suppresses fluctuations in calorific value due to the time difference mixing, from the calorific value fluctuation of the fuel gas measured by the first calorific value measuring instrument, the gas outlet of the tank predicting fuel gas calorific value variation, the first feedforward control such that the predicted fuel gas calorific value variation is reduced heat or Zonetsu the fuel gas such that the permissible range of the fuel gas in the combustion equipment A gas calorific value control device provided with a controller. A tank provided in a fuel gas supply passage to a combustion facility, in which a gas inlet and a gas outlet are separately formed , and time difference mixing is caused inside;
A first calorific value measuring device for measuring a calorific value fluctuation of fuel gas having a predetermined fluctuation width or more in the fuel gas supply passage upstream of the tank;
When the first calorific value measuring instrument measures a calorific value fluctuation equal to or greater than a predetermined fluctuation range, the fuel gas is reduced or increased on the upstream side of the tank so that the fluctuation range is within a predetermined fluctuation range . Two controllers,
Based on the simulation model can approximate the characteristic of inhibiting the tank heating value variation of the fuel gas by the time difference mixing, the tank predicted from heat value variations of the fuel gas measured by the first heating value meter feedforward control so that the fuel gas calorific value variation of the gas outlet is reduced heat or Zonetsu the fuel gas in the fuel gas supply passage of the tank downstream to be within the allowable range as a fuel gas in the combustion equipment A gas heat generation amount control device provided with a first controller. A tank provided in a fuel gas supply passage to a combustion facility, in which a gas inlet and a gas outlet are separately formed , and time difference mixing is caused inside;
A first calorific value measuring device for measuring a calorific value fluctuation of fuel gas in the fuel gas supply passage on the upstream side of the tank;
Based on a simulation model capable of approximating the characteristics of the tank that suppresses fluctuations in calorific value due to the time difference mixing, from the calorific value fluctuation of the fuel gas measured by the first calorific value measuring instrument, the gas outlet of the tank predicting fuel gas calorific value variation, a first control unit for performing a reduced heat or increasing heat feedforward control fuel gas based on the estimated fuel gas calorific value variation,
A first mixer provided in the fuel gas supply passage downstream of the tank,
Provided downstream of said first mixer, a second heating value meter for measuring the heating value variation of the fuel gas supplied to the combustion equipment,
The second heating value meter in the measured reduced heat or increasing heat feedback control of the fuel gas fluctuation range of the amount of heat generated by the first mixer to be within the allowable range as a fuel gas in the combustion equipment And a third controller for performing the above in addition to the feedforward control. A tank provided in a fuel gas supply passage to a combustion facility, in which a gas inlet and a gas outlet are separately formed , and time difference mixing is caused inside;
A first calorific value measuring device for measuring a calorific value fluctuation of fuel gas having a predetermined fluctuation width or more in the fuel gas supply passage upstream of the tank;
The first of the heat reduced heat or increasing the fuel gas on the upstream side of the tank as Once in heating value meter measures the heating value variation above a predetermined variation width the variation range is within a predetermined fluctuation range Two controllers,
The gas outlet of the tank predicted from the calorific value fluctuation of the fuel gas measured by the first calorific value measuring instrument based on a simulation model that can approximate the characteristic of the tank that suppresses the calorific value fluctuation by the time difference mixing the heating value variation of the fuel gas to perform the feedforward control to reduced heat or Zonetsu the fuel gas in the fuel gas supply passage of the tank downstream to be within the allowable range as a fuel gas in the combustion equipment 1 controller;
A first mixer provided in the fuel gas supply passage downstream of the tank,
Provided downstream of said first mixer, a second heating value meter for measuring the heating value variation of the fuel gas supplied to the combustion equipment,
The second heating value meter in the measured reduced heat or increasing heat feedback control of the fuel gas fluctuation range of the amount of heat generated by the first mixer to be within the allowable range as a fuel gas in the combustion equipment And a third controller for performing the above in addition to the feedforward control. In the gas calorific value control device according to claim 8 ,
A first mixer for reducing or increasing the temperature of the fuel gas is provided in the tank or on the outer surface of the tank so that the fuel gas calorific value fluctuation is within an allowable range as the fuel gas of the combustion facility;
The constructed to reduced heat or Zonetsu fuel gas tank or tank outer surface by the first mixer, gas heating amount control device. In the gas calorific value control device according to claim 10 or 11 ,
A second mixer is provided in the fuel gas supply passage on the upstream side of the tank,
And calorific variation average value of the fuel gas measured by the upstream side of the second mixer, the monitoring controller that monitors the calorific variation average value of the fuel gas measured downstream of the second mixer Provided,
When the monitoring controller detects a certain average difference between the two calorific value fluctuation average values, the second mixing is performed so that the calorific value fluctuation of the fuel gas upstream of the tank approaches the calorific value downstream of the mixer. A gas calorific value control device in which the monitoring controller is provided with a function of reducing or increasing the temperature of the fuel gas with a gas generator. The simulation model adds a plurality of system signals including a primary delay and dead time in a constant flow rate and a volume of the tank and adds them together by a constant, and corrects the time constant corresponding to the delay of the detector. The gas heating value control device according to any one of claims 8 to 13.

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