JP2019211124A - Control device, control system, and program - Google Patents

Abstract

To enable the stable burning of mixed gas having an unknown composition of components.SOLUTION: A control device 8 includes: a flow rate calculation unit 82 for calculating a gas flow rate of mixed gas and an air flow rate of air on the basis of a component ratio of the mixed gas in the case of adjusting the total flow rate constant of the mixed gas having an unknown composition of components and air to be mixed with the mixed gas, and an equivalence rate constant of the mixed gas and the air; a gas flow rate control unit 83 for controlling a flow rate of the mixed gas flowing in gas piping on the basis of the gas flow rate calculated by the gas flow calculation unit 82; and an air flow rate control unit 86 for controlling the flow rate of air flowing in the air piping on the basis of a delay time corresponding to a distance from a measurement position on a route of the gas piping G, at which a measurement unit 3 for measuring a physical amount showing a component ratio of the mixed gas to a gas and air mixing unit β for mixing the mixed gas supplied by the gas piping and air supplied by air piping at a connection part between the gas piping and the air piping, and the air flow rate calculated by the flow rate calculation unit 82.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device, a control system, and a program.

  In recent years, natural gas that enables lower pollution combustion has attracted attention due to an increase in interest in environmental problems. It is known that natural gas has a smaller carbon / hydrogen ratio than petroleum and coal, and emits less carbon dioxide when 1 mol of natural gas is burned. It is also known that when liquefying natural gas during transportation, N and S components are removed, so that NOx (nitrogen oxide) and SOx (sulfur oxide) emissions during combustion are small. .

  Natural gas is a mixture composed of hydrocarbons such as ethane and propane in addition to methane as the main component. It is known that the ratio of each component varies depending on the production area. The amount of heat of natural gas is determined by the abundance ratio of each component. Therefore, when natural gas from different production areas is used, the amount of heat generated is also different.

Usually, natural gas is used in a state of being liquefied and stored in a tank or the like. If the amount of liquefied natural gas in the tank is reduced and a part of the liquefied natural gas is vaporized, a large amount of methane having a small specific gravity tends to exist in the upper part of the tank, and a large amount of propane having a large specific gravity tends to exist in the lower part. is there. When natural gas flows out from such a tank, if the amount of liquefied natural gas in the tank decreases, the convection generated in the vaporized natural gas becomes significant. Thus, when natural gas convects inside the tank, the composition of the natural gas may change periodically. In that case, the amount of heat of the natural gas may periodically change as the composition ratio of the natural gas changes. Thereby, it is assumed that the amount of heat changes abruptly and the flame becomes longer or misfires.
A combustion control method is known that can suppress periodic fluctuations in the amount of heat of natural gas in a continuously operating combustor (Patent Document 1).

JP-A-2018-31499

  The composition of the components of the mixed gas used for combustion may be unknown. For example, when natural gas is stored in different tanks and used from one tank to the other, the natural gas stored in each tank is mixed with natural gas from different production areas. And the fuel composition can be different. Therefore, the fuel composition of natural gas may change with tank switching. As a result, the fuel composition of natural gas has changed, the fuel composition has become unknown, and stable combustion has sometimes occurred.

  This invention is made | formed in view of said point, and provides the control apparatus, control system, and program which can burn the mixed gas whose composition of an ingredient is unknown stably.

  The present invention has been made to solve the above problems, and one aspect of the present invention provides a constant total flow rate of a mixed gas whose composition is unknown and air mixed with the mixed gas, and When the equivalence ratio between the mixed gas and the air is constant, a flow rate calculation unit that calculates the gas flow rate of the mixed gas and the air flow rate of the air based on the component ratio of the mixed gas, and the flow rate Based on the gas flow rate calculated by the calculation unit, a gas flow rate control unit for controlling the flow rate of the mixed gas flowing in the gas pipe, and a measurement unit for measuring a physical quantity indicating a component ratio of the mixed gas are arranged. A gas-air mixing unit that mixes the mixed gas supplied by the gas pipe and the air supplied by the air pipe from a measurement position on the path of the gas pipe at a connection portion between the gas pipe and the air pipe. And an air flow rate control unit that controls the flow rate of the air flowing through the air pipe based on the delay time according to the distance at and the air flow rate calculated by the flow rate calculation unit. .

  Further, according to one aspect of the present invention, in the above control device, the physical quantity is a density of the mixed gas, and a component ratio calculation that calculates a component ratio of the mixed gas based on the density at the measurement position The flow rate calculation unit calculates a gas flow rate of the mixed gas and an air flow rate of the air based on the component ratio of the mixed gas indicated by the density calculated by the component ratio calculation unit. .

  Further, according to one aspect of the present invention, in the above control device, the gas flow rate adjustment valve controlled by the gas flow rate control unit is disposed downstream of the measurement position in the gas pipe, and the air flow rate control unit is The air flow rate of the air is controlled based on the transmission time corresponding to the distance from the measurement position to the gas flow rate adjustment valve.

  In addition, according to one aspect of the present invention, the control device further includes a delay time calculation unit that calculates the delay time based on the density of the mixed gas and the distance.

  Further, according to one aspect of the present invention, the above control device, a gas flow rate adjustment valve that is disposed on the path of the gas pipe and adjusts the flow rate of the mixed gas flowing through the gas pipe, and on the path of the air pipe And an air flow rate adjusting valve that adjusts the flow rate of the air flowing through the air pipe.

  One embodiment of the present invention provides a computer with a constant total flow rate of a mixed gas whose composition is unknown and air mixed with the mixed gas, and a constant equivalence ratio of the mixed gas and the air. A flow rate calculating step for calculating a gas flow rate of the mixed gas and an air flow rate of the air based on the component ratio of the mixed gas, and based on the gas flow rate calculated in the flow rate calculating step. From the measurement position on the path of the gas pipe where a gas flow rate control step for controlling the flow rate of the mixed gas flowing in the gas pipe and a measurement unit for measuring a physical quantity indicating a component ratio of the mixed gas are arranged, Up to a gas-air mixing section that mixes the mixed gas supplied by a gas pipe and the air supplied by an air pipe at a connection portion between the gas pipe and the air pipe. An air flow rate control step for controlling a flow rate of the air flowing in the air pipe based on a delay time according to separation and the air flow rate calculated by the flow rate calculation unit. .

  According to the present invention, it is possible to stably burn a mixed gas whose component composition is unknown.

It is a figure which shows an example of the control system which concerns on embodiment of this invention. It is a figure which shows an example of a structure of the control apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the simulation fuel supply system of the fuel which consists of three types of gas which concerns on embodiment of this invention. It is a figure which shows an example of the flame height which concerns on embodiment of this invention. It is a figure which shows an example of the component ratio of the simulation fuel gas which concerns on embodiment of this invention. It is a figure which shows an example of the method of the change of the flow volume of each gas contained in the simulation fuel gas which concerns on embodiment of this invention. It is a figure which shows an example of the fuel flow constant conditions based on embodiment of this invention. It is a figure which shows an example of the equivalence ratio fixed conditions which concern on embodiment of this invention. It is a figure which shows an example of the calculation method of the delay time which concerns on embodiment of this invention. It is a figure which shows an example of the relationship between the volume fraction of methane which concerns on embodiment of this invention, and the output value of a gas density meter. It is a figure which shows an example of the relationship between the correction value of the gas massflow controller which concerns on embodiment of this invention, and the volume fraction of methane. It is a figure which shows an example of the time change of the various variables in the fuel composition switching conditions using the gas density meter which concerns on embodiment of this invention. It is a figure which shows an example of the experimental result in each condition which concerns on embodiment of this invention. It is a figure which shows an example of the experimental result in the equivalent ratio constant conditions for the comparison with this embodiment. It is a figure which shows an example of the experimental result in the fuel flow constant conditions for the comparison with this embodiment. It is a figure which shows the 1st example of the experimental result in the air flow control for the comparison with this embodiment. It is a figure which shows the 2nd example of the experimental result in the fuel flow control for the comparison with this embodiment.

(Embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating an example of a control system S according to the present embodiment. The control system S includes a natural gas supply system R1, a gas density meter 3, a gas mass flow controller (MFC) 4, a signal converter 5, a compressor 6, a valve V1, an air mass flow controller 7, and a control device 8. And an AD / DA conversion board 9, a burner 10, a gas pipe GP1, a gas pipe GP2, a gas pipe GP3, and an air pipe AP.

  The natural gas supply system R1 supplies the natural gas G0 to the control system S. The natural gas supply system R1 includes a gas tank 1, a gas tank 2, a valve V11, a valve V12, and a gas pipe GP0. The natural gas supply system R1 is connected to the gas density meter 3 via the gas pipe GP1.

The gas tank 1 stores the first natural gas. The valve V11 is provided between the gas tank 1 and the gas pipe GP0. The valve V11 allows the first natural gas to flow from the gas tank 1 to the gas pipe GP0 at a constant pressure.
The gas tank 2 stores the second natural gas. Here, the composition ratio of the second natural gas is different from the composition ratio of the first natural gas. The valve V12 is provided between the gas tank 2 and the gas pipe GP0. The valve V12 allows the second natural gas to flow from the gas tank 2 to the gas pipe GP0 at a constant pressure.
The valve V11 and the valve V12 are pressure reducing valves.

The natural gas G0 is supplied from the gas tank 1 or the gas tank 2. The natural gas G 0 is supplied from the first natural gas supplied from the gas tank 1, the second natural gas supplied from the gas tank 2, or the first natural gas supplied from the gas tank 1 and the gas tank 2. It is a mixed gas with the second natural gas.
The gas pipe GP0 is connected to the gas pipe GP1 through the position P.
Hereinafter, the natural gas G0 may be distinguished by changing the names such as the gas G1 before density measurement, the gas G2 after density measurement, and the gas G3 after flow rate adjustment according to the gas pipe through which the natural gas G0 passes.

The gas density meter 3 measures the density of the pre-density measurement gas G1 flowing from the gas pipe GP1. Here, the gas G1 before density measurement is the natural gas G0 supplied from the natural gas supply system R1.
As an example, the gas density meter 3 is a vibration type gas density meter. The gas density meter 3 incorporates a thin-walled cylindrical vibrator (resonator), and its resonance frequency changes depending on the density of the pre-density measurement gas G1 that flows around it. The gas density meter 3 measures the density of the gas G1 before density measurement by measuring the resonance frequency.

The gas density meter 3 is connected to a gas mass flow controller 4 via a gas pipe GP2. The density G1 before the density measurement is measured by the gas density meter 3 and flows into the gas mass flow controller 4 as the density gas G2 after the density measurement. The time taken for the gas G2 after density measurement to reach the gas mass flow controller 4 from the gas density meter 3 through the gas pipe GP2 is referred to as a transmission time t _t . That is, the transmission time t _t is a time according to the distance from the measurement position on the gas piping path where the gas density meter 3 is arranged to the gas mass flow controller 4.

  On the other hand, the gas density meter 3 is connected to the signal converter 5 by wiring for input / output signals. The gas density meter 3 outputs a current indicating the measured density value to the signal converter 5.

The gas mass flow controller 4 controls the flow rate of the gas G <b> 2 after density measurement based on the control of the control device 8. The gas mass flow controller 4 is a valve that is arranged on the path of the gas pipe and adjusts the flow rate of the natural gas G0 that flows through the gas pipe. The gas mass flow controller 4 is disposed downstream of the gas density meter 3.
The gas mass flow controller 4 is controlled by the control device 8 via the AD / DA conversion board 9. The gas mass flow controller 4 is connected to the AD / DA conversion board 9 by wiring for input / output signals.

The gas mass flow controller 4 is connected to the junction β through the gas pipe GP3. After the density measurement, the gas G2 is controlled in flow rate by the gas mass flow controller 4 and flows into the junction β as the gas G3 after flow rate adjustment. Flow rate adjusted gas G3 is, through the gas pipe GP3 that the time t _d delay the time to reach the gas mass flow controller 4 to the joining point beta. Further, the length of the gas pipe GP3 is set to a length L. The length L is equal to the distance from the gas mass flow controller 4 to the junction point β.

  The signal converter 5 converts the current value output from the gas density meter 3 into a voltage value. The signal converter 5 supplies the converted voltage value to the AD / DA conversion board 9. The signal converter 5 is connected to the AD / DA conversion board 9 by wiring for input / output signals.

  The compressor 6 supplies the air AR to the junction β through the valve V1 and the air mass flow controller 7. The valve V <b> 1 is provided between the compressor 6 and the air mass flow controller 7. The valve V1 causes the air AR to flow from the compressor 6 to the air mass flow controller 7 at a constant pressure. The valve V1 is a pressure reducing valve.

The air mass flow controller 7 controls the flow rate of the air AR based on the control of the control device 8. The air mass flow controller 7 is a valve that is disposed on the path of the air pipe AP and adjusts the flow rate of the air AR that flows through the air pipe AP. The air mass flow controller 7 is connected to the junction β through the air pipe AP. The air AR whose flow rate is controlled by the air mass flow controller 7 flows into the junction β.
The air mass flow controller 7 is connected to the AD / DA conversion board 9 by wiring for input / output signals.

The control device 8 controls the gas mass flow controller 4 and the air mass flow controller 7 via the AD / DA conversion board 9. That is, the control device 8 controls the flow rate of the adjusted gas G3 flowing out of the gas mass flow controller 4 and the flow rate of the air AR flowing out of the air mass flow controller 7.
The control device 8 is connected to the AD / DA conversion board 9 by wiring for input / output signals. The control device 8 is, for example, a PC (Personal Computer).

The AD / DA conversion board 9 acquires the density value of the gas G1 before density measurement supplied by the gas density meter 3 through the signal converter 5. The AD / DA conversion board 9 supplies the acquired density value of the gas G1 before density measurement to the control device 8.
The AD / DA conversion board 9 supplies a control signal for controlling the gas mass flow controller 4 to the gas mass flow controller 4 via the input / output signal wiring based on the control of the control device 8.
The AD / DA conversion board 9 supplies a control signal for controlling the air mass flow controller 7 to the air mass flow controller 7 via the wiring for input / output signals based on the control of the control device 8.

  The burner 10 burns the air mixed gas G4 flowing from the confluence point β to form a flame. Here, the air mixed gas G4 is a gas in which the flow-adjusted gas G3 passing through the gas pipe GP3 and the air AR passing through the air pipe AP are mixed.

Next, the configuration of the control device 8 will be described with reference to FIG.
FIG. 2 is a diagram illustrating an example of the configuration of the control device 8 according to the present embodiment. The control device 8 includes a density acquisition unit 80, a component ratio calculation unit 81, a flow rate calculation unit 82, a gas flow rate control unit 83, a delay time calculation unit 84, a storage unit 85, and an air flow rate control unit 86. Prepare.

The density acquisition unit 80 acquires the density value of the gas G2 after density measurement measured by the gas density meter 3. Here, the density acquisition unit 80 acquires the density value of the gas G <b> 2 after density measurement via the signal converter 5 and the AD / DA conversion board 9. However, in FIG. 2, the signal converter 5 and the AD / DA conversion board 9 are omitted.
The density acquisition unit 80 supplies the acquired density value of the post-density measurement gas G <b> 2 to the component ratio calculation unit 81. In addition, the density acquisition unit 80 supplies the acquired density value of the post-density measurement gas G <b> 2 to the delay time calculation unit 84.

  The component ratio calculation unit 81 calculates the component ratio of the density-measured gas G2 from the density value of the density-measurement gas G2 acquired by the density acquisition unit 80. The component ratio calculation unit 81 supplies the calculated component ratio of the density-measured gas G <b> 2 to the flow rate calculation unit 82.

  Here, the density value of the density-measured gas G2 acquired by the density acquisition unit 80 is the density value of the natural gas G0 at the measurement position on the path of the gas pipe where the gas density meter 3 is disposed. Therefore, the component ratio calculation unit 81 is a component of the mixed gas based on the density of the natural gas G0 at the measurement position on the path of the gas pipe where the gas density meter 3 for measuring the density indicating the component ratio of the natural gas G0 is arranged. Calculate the ratio.

The flow rate calculation unit 82 calculates the gas flow rate of the adjusted gas G3 flowing out from the gas mass flow controller 4 and the air flow rate of the air AR based on the component ratio of the density-measured gas G2 calculated by the component ratio calculation unit 81. To do. Here, when the total flow rate of the flow-adjusted gas G3 and the air AR is constant and the equivalence ratio of the flow-adjusted gas G3 and the air AR is constant, the flow rate calculation unit 82 is configured to supply the gas flow rate of the flow-adjusted gas G3 And the air flow rate of the air AR are calculated.
The flow rate calculation unit 82 supplies gas flow rate information indicating the calculated gas flow rate to the gas flow rate control unit 83. Further, the flow rate calculation unit 82 supplies air flow rate information indicating the calculated air flow rate to the air flow rate control unit 86.

Here, the constant total flow rate of the gas G3 after flow adjustment and the air AR means that the flow rate of the gas G3 after flow adjustment flowing into the junction β and the flow rate of the air AR flowing into the junction β are constant. This is the condition. That is, the constant total flow rate of the flow-adjusted gas G3 and the air AR is a condition in which the flow rate of the air mixed gas G4 flowing out from the junction β is constant.
The constant equivalence ratio between the gas G3 after flow adjustment and the air AR is a value obtained by dividing the volume ratio between the gas G3 after flow adjustment and the air AR by the volume ratio of fuel and air in the theoretical mixing ratio. 1).

Here, Q _fuel represents the volume of the gas G3 after the flow adjustment, and Q _air represents the volume of the air AR. The stoichiometric fuel / air ratio (F / A) _st represents the volume ratio of the fuel and air in the theoretical mixing ratio.
The constant equivalence ratio between the flow-adjusted gas G3 and the air AR is a condition in which the equivalence ratio of the air mixed gas G4 flowing out from the junction β is constant.

  As described above, the flow rate calculation unit 82 has a constant total flow rate between the natural gas G0 whose component composition is unknown and the air AR mixed with the natural gas G0, and an equivalence ratio between the natural gas G0 and the air AR. In the case of being constant, the gas flow rate of the natural gas G0 and the air flow rate of the air AR are calculated based on the component ratio of the natural gas G0. Here, the component ratio of the natural gas G0 is a component ratio indicated by the density of the natural gas G0 calculated by the component ratio calculation unit 81. Therefore, the flow rate calculation unit 82 calculates the gas flow rate of the natural gas G0 and the air flow rate of the air AR based on the component ratio of the natural gas G0 indicated by the density of the natural gas G0 calculated by the component ratio calculation unit 81.

The gas flow rate controller 83 controls the gas mass flow controller 4 based on the gas flow rate information supplied by the gas flow rate controller 83. The gas flow rate control unit 83 controls the flow rate of the gas G3 after the flow rate adjustment by controlling the gas mass flow controller 4. Here, the gas flow rate control unit 83 supplies a signal for controlling the flow rate of the gas G3 after the flow rate adjustment to the gas mass flow controller 4 via the AD / DA conversion board 9.
As described above, the gas flow rate control unit 83 controls the flow rate of the natural gas G0 flowing through the gas pipe GP3 based on the gas flow rate calculated by the flow rate calculation unit 82.

The delay time calculation unit 84 calculates a delay time TDT corresponding to the distance from the measurement position on the path of the gas pipe where the gas density meter 3 is arranged to the junction point β. In the delay time TDT, after the density measurement, the gas G2 flows into the gas mass flow controller 4 from the gas density meter 3 through the gas pipe GP2, flows out from the gas mass flow controller 4 as the gas G3 after adjusting the flow rate, and passes through the gas pipe GP3. This is the time taken to reach the junction β. Therefore, the delay time TDT is equal to the time obtained by adding the transmission time t _t and the delay time t _d .
Delay time calculating unit 84 and a transmission time t _t and the delay time t _d is calculated, by adding the calculated transmission time t _t and the delay time t _d may be delay time TDT.

Here, an example will be described in which the delay time calculation unit 84 calculates a correction value for correcting the initial delay time TDT0 calculated in advance to calculate the delay time TDT.
The delay time calculation unit 84 acquires the density value of the density-measured gas G2 supplied by the density acquisition unit 80. The delay time calculation unit 84 acquires the delay time information 850 from the storage unit 85. Here, the delay time information 850 is information indicating the initial delay time TDT0. The initial delay time _td0 is a value of the delay time TDT calculated in advance according to the length of the gas pipe GP2 and the length of the gas pipe GP3 (length L).

  The delay time calculation unit 84 calculates the delay time TDT by correcting the initial delay time TDT0 indicated by the delay time information 850 based on the acquired density value of the density measurement gas G2. That is, the delay time calculation unit 84 calculates a correction value for correcting the initial delay time TDT0 calculated in advance.

Here, the initial delay time TDT0 is a time calculated based on the distance from the measurement position on the path of the gas pipe where the gas density meter 3 is disposed to the junction β. Therefore, the delay time calculation unit 84 calculates the delay time TDT based on the density of the natural gas G0 and the distance from the measurement position on the path of the gas pipe where the gas density meter 3 is disposed to the junction β. To do.
The delay time calculation unit 84 supplies the calculated delay time TDT to the air flow rate control unit 86.
The storage unit 85 stores delay time information 850.

  The air flow rate control unit 86 controls the flow rate of the air AR flowing through the air pipe AP based on the delay time TDT calculated by the delay time calculation unit 84 and the air flow rate of the air AR calculated by the flow rate calculation unit 82.

Here, the delay time TDT calculated by the delay time calculation unit 84 refers to the gas pipe from the measurement position on the path of the gas pipe where the gas density meter 3 for measuring the density indicating the component ratio of the gas G2 after density measurement is arranged. This is the time according to the distance to the junction point β where the flow-adjusted gas G3 supplied by GP3 and the air AR supplied by the air pipe AP are mixed at the connection between the gas pipe GP3 and the air pipe AP.
Accordingly, the air flow rate control unit 86, from the measurement position on the path of the gas pipe where the gas density meter 3 for measuring the physical quantity indicating the component ratio of the natural gas G0 is disposed, the natural gas G0 and the air supplied by the gas pipe. Based on the delay time TDT according to the distance to the junction β where the air AR supplied by the pipe is mixed at the connection between the gas pipe and the air pipe AP, and the air flow rate calculated by the flow rate calculation unit 82, The flow rate of the air AR flowing through the air pipe AP is controlled. Here, the physical quantity indicating the component ratio of the natural gas G0 is the density of the mixed gas.

Further, the air flow rate control unit 86 may control the air flow rate of the air AR based on the transmission time t _t calculated by the delay time calculation unit 84. Here, the air flow rate control unit 86 may control the air flow rate of the air AR based on the transmission time t _t in addition to the delay time t _d , or the air flow rate of the air AR based only on the transmission time t _t. May be controlled.

In the present embodiment, the case where the delay time calculation unit 84 calculates a correction value for correcting the initial delay time t _d0 calculated in advance has been described as an example, but the present invention is not limited thereto. The delay time calculation unit 84 may calculate the delay time TDT based on the density value of the density-measured gas G2. When the delay time calculation unit 84 calculates the delay time TDT based on the density value of the gas G2 after density measurement, the delay time information 850 may not be stored in the storage unit 85.

  Moreover, although this embodiment demonstrates the case where the value of the density of the mixed gas which the density acquisition part 80 acquires is measured by the gas density meter 3, it does not restrict to this. The density value of the mixed gas acquired by the density acquisition unit 80 may be measured by, for example, an optical method using a laser, gas chromatography, or the like.

  Hereinafter, in order to explain the effect of the control system S, the control system S includes a simulated fuel supply system R2 instead of the natural gas supply system R1, and controls the flow rate of the mixed gas having a known component ratio. explain.

  FIG. 3 is a diagram illustrating an example of a simulated fuel supply system R2 for fuel composed of three types of gases according to the present embodiment. The simulated fuel supply system R2 is connected to the control system S shown in FIG. 1 at the position P, and supplies the simulated fuel gas G10 to the control system S. Here, the simulated fuel gas G10 is a mixed gas for simulating natural gas, and includes methane, ethane, and propane. It is known that the combustion characteristics of natural gas are almost the same as the combustion characteristics of three types of mixed gas of methane, ethane, and propane. The component ratio of the simulated fuel gas G10 is known. The component ratio of the simulated fuel gas G10 will be described later with reference to FIG.

  The simulated fuel supply system R2 includes a methane cylinder C1, an ethane cylinder C2, a propane cylinder C3, a valve V21, a valve V22, and a valve V23, a gas mass flow controller 21, a gas mass flow controller 22, a gas mass flow controller 23, and a valve. V3 and gas piping GP10 are provided.

The methane cylinder C1 stores methane. The valve V21 is provided between the methane cylinder C1 and the gas mass flow controller 21. The valve V21 allows methane to flow from the methane cylinder C1 to the gas mass flow controller 21 at a constant pressure.
The ethane cylinder C2 stores ethane. The valve V22 is provided between the ethane cylinder C2 and the gas mass flow controller 22. The valve V22 allows ethane to flow from the ethane cylinder C2 to the gas mass flow controller 22 at a constant pressure.
The propane cylinder C3 stores propane. The valve V23 is provided between the propane cylinder C3 and the gas mass flow controller 23. The valve V23 allows propane to flow from the propane cylinder C3 to the gas mass flow controller 23 at a constant pressure.

  The gas mass flow controller 21 controls the flow rate of methane. The gas mass flow controller 22 controls the flow rate of ethane. The gas mass flow controller 23 controls the flow rate of propane. The gas mass flow controller 21, the gas mass flow controller 22, and the gas mass flow controller 23 are controlled by the control device 8 via the AD / DA conversion board 9.

  The methane gas supplied from the gas mass flow controller 21, the ethane gas supplied from the gas mass flow controller 22, and the propane gas supplied from the gas mass flow controller 23 are merged and mixed at the merge point α. Each mixed gas flows into the position P through the gas pipe GP10 as the simulated fuel gas G10.

  The valve V3 is installed in a flow path that leads to outside air. The valve V3 controls the flow rate of the simulated fuel gas G10 without depending on the flow rate of methane supplied from the gas mass flow controller 21, ethane supplied from the gas mass flow controller 22, and propane supplied from the gas mass flow controller 23. It is a valve.

In the present embodiment, the flame height H is measured in order to examine the stability of the flame formed in the burner 10. Here, the flame height H will be described with reference to FIG.
FIG. 4 is a diagram illustrating an example of the flame height H according to the present embodiment. The flame height H is the height from the outlet of the burner 10 to the tip of the flame. The flame height H is measured, for example, by photographing the behavior of the flame using a high-speed camera equipped with an image intensifier.

Next, the component ratio of the simulated fuel gas G10 will be described.
FIG. 5 is a diagram illustrating an example of the component ratio of the simulated fuel gas G10 according to the present embodiment. In this embodiment, the simulated fuel gas G10 having five component ratios of methane, ethane, and propane is used. However, a case where the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E will be described below as an example.

A method of changing the flow rate of each gas contained in the simulated fuel gas G10 will be described.
FIG. 6 is a diagram illustrating an example of a method of changing the flow rate of each gas included in the simulated fuel gas G10 according to the present embodiment. In this embodiment, the gas mass flow controller 21, the gas mass flow controller 22, the gas mass flow controller 23, and the air mass flow controller 7 are used to control the flow rates of methane, ethane, propane, and air AR, and the components of the simulated fuel gas G10. Realize a transient change in ratio.

When the simulated fuel gas G10 was switched from one component ratio to another, the flow rate of each gas contained in the simulated fuel gas G10 was changed linearly. Here, the time required for the switching transition time was t _v.
The control device 8 supplies a signal for controlling the flow rate to the gas mass flow controller 21, the gas mass flow controller 22, the gas mass flow controller 23, and the air mass flow controller 7 every 20 ms, and switches the flow rate of each gas.

Next, with reference to FIG. 7 and FIG. 8, the conditions regarding the flow rates of the simulated fuel gas G10 and the air in the transient change in the component ratio of the simulated fuel gas G10 will be described.
FIG. 7 is a view showing an example of a constant fuel flow rate condition according to the present embodiment. Here, the total flow rate is the sum of the flow rate of the simulated fuel gas G10 and the flow rate of the air AR. Under the constant fuel flow rate condition, the flow rate of the simulated fuel gas G10 and the flow rate of the air AR are kept constant, and the component ratio of the simulated fuel gas G10 is switched. As an example, the total flow rate of the present embodiment is a flow rate at which the average flow velocity of the air mixed gas G4 at the outlet of the burner 10 is 0.8 m / s.

  FIG. 8 is a diagram illustrating an example of a constant equivalence ratio condition according to the present embodiment. Under the equivalence ratio constant condition, the component ratio of the simulated fuel gas G10 is switched so that the equivalence ratio becomes a constant value. In the equivalent ratio constant condition of the present embodiment, the equivalent ratio is a constant value of 0.85 as an example.

In the control system S of the present embodiment, the air flow rate is calculated based on the delay time TDT. Unlike the control system S, when the air flow rate is calculated without being based on the delay time TDT, the flame height H varies with time and overshoots.
Here, the change in flow rate is transmitted by pressure propagation. Therefore, the change in flow rate is transmitted at the speed of sound. On the other hand, the change in the component ratio is transmitted at the convection velocity. The speed at which the change in the component ratio is transmitted is slower than the speed at which the change in the flow rate propagates. In the control system S, in the control of the fuel flow rate, the time required for transmitting the change in flow rate is so short that it can be ignored, but the time required for transmitting the change in component ratio is so long that it cannot be ignored. It is considered that the overshoot occurs in the flame height H because the delay time TDT occurs according to the length from the position where the change in the component ratio has occurred to the junction point β.

  For comparison with the present embodiment, an experimental result in the case where the air flow rate is calculated without being based on the delay time TDT will be described with reference to FIGS. 14 and 15. 14 and 15 show graphs showing the fuel flow rate at the junction point α, the fuel flow rate at the junction point β, the air flow rate, and the equivalence ratio at the junction point β, respectively. Here, the fuel flow rate is the flow rate of the simulated fuel gas G10.

  FIG. 14 is a diagram illustrating an example of an experimental result under a constant equivalence ratio condition for comparison with the present embodiment. In the example of FIG. 14, the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E under the constant equivalence ratio condition.

First, changes in component ratio of the simulated fuel gas G10 at confluence alpha, and changes in the fuel flow rate occurs only transition time _{t v} (time t11~ time t12). When a change in the component ratio of the simulated fuel gas G10 and a change in the fuel flow rate occur at the merge point α, the air flow rate changes simultaneously (time t11 to time t12).
However, the fuel flow rate changes instantaneously at the junction point β (time t11 to time t12), but until the change in the component ratio reaches the junction point β from the junction point α, the length of the flow path of the simulated fuel gas G10 is increased. Only a delay time t _d (time t11 to time t13) corresponding to the time is required.
Therefore, the simulated fuel gas G10 of the component ratio type A flows at a smaller flow rate than that assumed for the simulated fuel gas G10 of the component ratio type E, and the equivalent ratio becomes smaller than the assumed equivalent ratio condition. Since the equivalent ratio is smaller than the assumption of the constant equivalent ratio condition, it is considered that overshoot occurs in the flame height H.

FIG. 15 is a diagram illustrating an example of an experimental result under a constant fuel flow rate condition for comparison with the present embodiment. In the example of FIG. 15, the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E under the constant fuel flow rate condition (time t21 to time t22). Note that the air flow rate is constant under the constant fuel flow rate condition.
First, changes in component ratio of the simulated fuel gas G10 at confluence α occurs only transition time t _v. Here, the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E as the component ratio type A decreases linearly and the component ratio type E increases linearly. When the change ratio of components of the simulated fuel gas G10 occurs only transition time t _v the confluence alpha, it changes in component ratio of the confluence β in simulated fuel gas G10 occurs only delay time t _d after the transition time t _v (the time t23 to time t24).

The fuel flow rate constant conditions, the change in the change in the air flow and the fuel flow does not occur, the change in the equivalent ratio due to the delay time t _d does not occur, the outlet variation of component ratio in the burner 10 is a time to reach are changed. Under the constant fuel flow rate condition, the magnitude of the change in the flame height H does not depend on the length of the simulated fuel gas G10 flow path, and the change start time varies depending on the length of the flow path.

Referring now to FIGS. 16 and 17, taking into account the delay time t _d, the experimental results will be described in the case of keeping the equivalent ratio of the simulated fuel gas G10 in converging β constant.
FIG. 16 is a diagram illustrating a first example of experimental results in air flow control for comparison with the present embodiment. In the example of FIG. 16, the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E under the constant equivalence ratio condition (time t31 to time t32). However, in the example of FIG. 16, the change in the component ratio of the simulated fuel gas G10 causes the fuel flow rate of the simulated fuel gas G10 to be smaller than that assumed under the constant equivalence ratio condition.

Fuel flow, smaller than envisaged in the equivalent ratio constant conditions, are controlled to be only temporarily reduced during the air flow rate is the delay time t _d. Therefore, although the equivalence ratio is kept constant, the total flow rate temporarily decreases (time t31 to time t34). In the example of FIG. 16, the total flow rate is controlled so that the average flow velocity of the air mixed gas G4 at the outlet of the burner 10 is 0.8 m / s before and after the change in the component ratio of the simulated fuel gas G10. Yes.

FIG. 17 is a diagram illustrating a second example of an experimental result in fuel flow control for comparison with the present embodiment. In the example of FIG. 17, the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E under the constant equivalence ratio condition (time t41 to time t42).
The fuel flow rate is maintained at a value corresponding to the component ratio type A until the delay time t _d elapses after the change in the component ratio of the simulated fuel gas G10 at the junction α. As a result, the fuel flow rate does not change until the change in the component ratio reaches the confluence point β (time t41 to time t43). The air flow rate does not change until the change in the component ratio reaches the confluence point β (time t41 to time t43). Therefore, in the example of FIG. 17, the equivalence ratio and the total flow rate are kept constant. Here, the total flow rate is controlled so that the average flow velocity of the air mixed gas G4 at the outlet of the burner 10 is 0.8 m / s.

In the control based on the delay time t _d in FIGS. 16 and 17, it is necessary to calculate the delay time t _d corresponding to the length L of the flow path leading to the merging point β from the confluent point alpha. Referring now to FIG. 9 will be described a method of calculating the delay time t _d.
FIG. 9 is a diagram illustrating an example of a delay time calculation method according to the present embodiment. Delay time t _d is dependent on the fuel flow rate. Here, in order to change the fuel flow time, also time-varying delay time t _d. So when the volume of the simulated fuel gas G10 which corresponds to the delay time _{t d} and the volume Vd (t), the volume Vd (t) is expressed using equation (2).

Here, the area A _channel is the cross-sectional area of the flow path from the junction point α to the junction point β. On the other hand, the volume Vd (t) can be expressed using Equation (3).

Here, the flow rate Q _fuel (t) is the fuel flow rate. Therefore, by solving the equation for the delay time t _d to be obtained to clear the volume Vd (t) from equation (2) and (3), the delay time t _d is calculated. However, the integration of Expression (3) is calculated by treating time and the flow rate Q _fuel (t) as discrete values as shown in FIG.

Next, referring to FIG. 10 and FIG. 11, a method of measuring the density of the simulated fuel gas G10 with the gas density meter 3, and detecting a change in the component ratio of the simulated fuel gas G10 and controlling the flow rate by the control device 8 is described. explain.
FIG. 10 is a diagram illustrating an example of the relationship between the volume fraction of methane and the output value of the gas density meter 3 according to the present embodiment. The graph GR1 shows the relationship between the volume fraction of methane and the output value of the gas density meter 3 with respect to the predetermined component ratio of the simulated fuel gas G10 in the steady state.

  In the component ratio of the predetermined simulated fuel gas G10 in the steady state, for each volume fraction of methane, a volume fraction of methane, a volume fraction of ethane, and a volume fraction of propane are combined. However, in the component ratio of the predetermined simulated fuel gas G10 in the steady state, the ratio between the volume fraction of ethane and the volume fraction of propane was 5: 1 regardless of the volume fraction of methane.

  From the graph GR1, the volume fraction of methane and the output value of the gas density meter 3 are linear. Therefore, the volume fraction of methane can be calculated from the output value of the gas density meter 3 from the graph GR1. Further, the component ratio of the simulated fuel gas G10 can be calculated from the volume fraction of methane using the predetermined component ratio of the simulated fuel gas G10 in the steady state.

  Next, the relationship between the component ratio of the simulated fuel gas G10 and the flow rate of the gas output from the gas mass flow controller 4 will be described with reference to FIG.

FIG. 11 is a diagram illustrating an example of the relationship between the correction value of the gas mass flow controller 4 according to the present embodiment and the volume fraction of methane. The flow rate of the gas output from the gas mass flow controller 4 depends on the type of flowing gas. Therefore, when the component ratio of the simulated fuel gas G10 changes, the output flow rate changes even if the same value of flow rate is given to the gas mass flow controller 4. Therefore, it is necessary to calibrate the flow rate instruction value and the actual flow rate.
A coefficient kMFC for correcting the actual flow rate Aoutput with respect to the flow rate instruction value Qinput is defined using equation (4).

The graph GR2 shows the relationship between the coefficient k _MFC , which is a correction coefficient of the gas mass flow controller 4, and the volume fraction of methane. The graph GR2 is approximated by a gas tank quadratic function.

Next, a method for calculating the fuel flow rate from the volume fraction of methane will be described. The equivalent ratio r is represented by the above-described formula (1). The volume fraction of methane [Phi _{CH4, C2H6} and the volume fraction of the ethane [Phi, when the volume fraction of propane and [Phi _C3H8, stoichiometric fuel-air ratio of the formula (1) (F / A) _st formula (5) It is expressed using

Therefore, the stoichiometric fuel / air ratio (F / A) _st is expressed as a function of the volume fraction of methane. However, the value of the international standard atmosphere was used for the volume fraction of oxygen in the air. Further, the total flow rate Q _total is expressed as in Expression (6).

Under the constant equivalence ratio condition and the constant fuel flow rate, the flow rate Q _fuel and the air flow rate Q _air can be expressed by the equations (1), (5), and (6) if the volume fraction of methane is known. It can be calculated using (7) and equation (8).

In the flow path system in which the gas density meter 3 is installed, it takes a transmission time t _t until the simulated fuel gas G10 having the component ratio output from the gas density meter 3 reaches the gas mass flow controller 4. Further, to the outlet and a simulated fuel gas G10 to confluence β gas mass flow controller 4 reaches such delayed time t _d. Therefore, the instruction value Q _input to the gas mass flow controller 4 at time t is expressed by equation (9) from equations (4) and (7).

Here, Φ _input is the volume fraction of methane obtained from the density value of the simulated fuel gas G10 measured by the gas density meter 3.

  FIG. 12 is a diagram illustrating an example of a temporal change of various variables in the fuel composition switching condition using the gas density meter 3 according to the present embodiment. In FIG. 12, the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E.

First, the flow rate of the gas at the confluence point α is changed during each transition time t _v (time t1~ time t2), the component ratio of the simulated fuel gas G10 in converging α is changed.
Next, the density of the simulated fuel gas G10 at the position where the gas density meter 3 is disposed changes (time t3 to time t4).

The coefficient k _MFC of the gas mass flow controller 4 is calibrated according to the change in the component ratio of the simulated fuel gas G10 (time t5 to time t6). The fuel flow rate at the position where the gas mass flow controller 4 is disposed is controlled with a delay of the transmission time t _t and the delay time t _d . Here, the transmission time t _t is a time taken for the simulated fuel gas G10 to propagate from the gas density meter 3 to the gas mass flow controller 4 through the gas pipe GP2. The delay time t _d is simulated fuel gas G10 confluence β from the gas mass flow controller 4 is the time taken to propagate the gas pipe GP3.
The transmission time t _t is calculated using the equations (2) and (3) in the same manner as the delay time t _d .

The gas flow rate of the simulated fuel gas G10 is controlled by the gas mass flow controller 4 with a delay of the transmission time t _t and the delay time t _d (time t7 to time t8). Since the change in the flow rate is transmitted by pressure propagation, the fuel flow rate at the confluence point β changes almost simultaneously with the change in the fuel flow rate in the gas mass flow controller 4 (time t7 to time t8).

FIG. 13 is a diagram illustrating an example of an experimental result under each condition according to the present embodiment. In FIG. 13, the temporal change of the flame height H is shown under five types of conditions: constant fuel flow rate, constant equivalence ratio, air flow rate control, fuel flow rate control, and density meter control. Here, FIG. 13 shows the temporal change of the flame height H when the transition time _tv is 1 s and the distance from the junction point α to the junction point β is 1500 mm. In FIG. 13, the component ratio of the simulated fuel gas G10 changes from the component ratio type A to the component ratio type E.

Fuel flow rate constant conditions, and in the equivalent ratio constant conditions, control in consideration of the delay time t _d is not performed. Air flow control, and in the fuel flow rate control, control in consideration of the delay time t _d is carried out. In the density meter control, the fuel flow rate and the air flow rate are controlled based on the density of the simulated fuel gas G10 measured by the gas density meter 3 by the control device 8.

It is the fuel flow rate control that most suppresses fluctuations in the five condition flame heights H in FIG. In the fuel flow control, the variation in the flame height H is caused only by the change in the calorific value flow rate due to the switching of the component ratio of the simulated fuel gas G10. In the fuel flow control, the difference between the maximum value and the minimum value of the flame height H is about 0.7 mm.
On the other hand, in the air flow rate control, fluctuations in the flame height H due to the increase / decrease in the air flow rate and the response delay of the gas mass flow controller 4 were observed. In the air flow rate control, the difference between the maximum value and the minimum value of the flame height H is about 2.6 mm.

In the density meter control, the fluctuation of the flame height H is caused by a change in the density distribution of the simulated fuel gas G10 due to Taylor diffusion and a delay in the response of the gas density meter 3. In the density meter control, the difference between the maximum value and the minimum value of the flame height H is about 1.4 mm. In the density meter control, the fluctuation of the flame height H can be suppressed as compared with the fuel flow constant condition and the equivalent ratio constant condition. Further, the fluctuation of the flame height H in the density meter control is not significantly larger than the fluctuation of the flame height H in the fuel flow control.
Therefore, in the density meter control controlled by the control device 8 based on the density of the simulated fuel gas G10 measured by the gas density meter 3, the fluctuation of the flame height H can be suppressed.

As described above, the control device 8 according to the present embodiment includes the flow rate calculation unit 82, the gas flow rate control unit 83, and the air flow rate control unit 86.
The flow rate calculation unit 82 has a constant total flow rate of the mixed gas (natural gas G0, simulated fuel gas G10) whose component composition is unknown and the air AR mixed with the mixed gas (natural gas G0, simulated fuel gas G10), In addition, when the equivalence ratio of the mixed gas (natural gas G0, simulated fuel gas G10) and the air AR is constant, the mixed gas (natural gas G0, simulated fuel gas G10) is determined based on the component ratio of the mixed gas (natural gas G0, simulated fuel gas G10). The gas flow rate of the gas G0 and the simulated fuel gas G10) and the air flow rate of the air are calculated.
The gas flow rate control unit 83 controls the flow rate of the mixed gas (natural gas G0, simulated fuel gas G10) flowing in the gas pipe based on the gas flow rate calculated by the flow rate calculation unit 82.
The air flow rate control unit 86 is a mixture supplied by a gas pipe from a measurement position on the path of the gas pipe where a measurement unit (gas density meter 3) that measures a physical quantity (density) indicating a component ratio of the mixed gas is arranged. According to the distance to the gas-air mixing part (confluence β) that mixes the gas (natural gas G0, simulated fuel gas G10) and the air AR supplied by the air pipe AP at the connection between the gas pipe and the air pipe AP. The flow rate of the air AR flowing through the air pipe AP is controlled based on the delay time TDT and the air flow rate calculated by the flow rate calculation unit 82.

  With this configuration, the control device 8 according to the present embodiment can control the air flow rate of the air AR based on the delay time TDT, and thus can stably burn a mixed gas whose component composition is unknown.

In addition, the control device 8 according to the present embodiment further includes a component ratio calculation unit 81. In the control device 8 according to the present embodiment, the physical quantity indicating the component ratio of the mixed gas is the density of the mixed gas (natural gas G0, simulated fuel gas G10).
The component ratio calculation unit 81 is a density indicating the component ratio of the mixed gas at the measurement position on the path of the gas pipe in which the measurement unit (gas density meter 3) that measures the physical quantity (density) indicating the component ratio of the mixed gas is arranged. Based on the above, the component ratio of the mixed gas (natural gas G0, simulated fuel gas G10) is calculated.
The flow rate calculation unit 82 is a gas of the mixed gas (natural gas G0, simulated fuel gas G10) based on the component ratio of the mixed gas (natural gas G0, simulated fuel gas G10) indicated by the density calculated by the component ratio calculation unit 81. The flow rate and the air flow rate of the air AR are calculated.

  With this configuration, the control device 8 according to the present embodiment can calculate the component ratio of the mixed gas in a shorter time compared to the case where chromatography or the like is used. Therefore, when the chromatography or the like is used even if the composition of the mixed gas changes. In comparison, the mixed gas can be combusted stably.

Moreover, in the control apparatus 8 which concerns on this embodiment, the gas flow rate adjustment valve (gas mass flow controller 4) which the gas flow rate control part 83 controls is a gas piping by which a measurement part (gas density meter 3) is arrange | positioned in gas piping. It is arranged downstream of the measurement position on the path. The air flow rate controller 86 controls the air flow rate of the air AR based on the transmission time t _t corresponding to the distance from the measurement position to the gas flow rate adjustment valve (gas mass flow controller 4).

  With this configuration, in the control device 8 according to the present embodiment, the unburned gas can be combusted more stably than in the case where the control time is not based on the transmission time.

  In addition, the control device 8 according to the present embodiment further includes a delay time calculation unit 84. The delay time calculation unit 84 calculates the delay time TDT from the density of the mixed gas (natural gas G0, simulated fuel gas G10) and the measurement position on the gas piping path where the measurement unit (gas density meter 3) is arranged. A gas-air mixing unit (confluence) that mixes the mixed gas (natural gas G0, simulated fuel gas G10) supplied by the gas pipe and the air AR supplied by the air pipe AP at the connection between the gas pipe and the air pipe AP. It is calculated based on the distance to β).

  With this configuration, in the control device 8 according to the present embodiment, the unburned gas can be burned more stably as compared with the case based on a predetermined delay time.

The control system S according to the present embodiment includes a control device 8, a gas flow rate adjustment valve (gas mass flow controller 4), and an air flow rate adjustment valve (air mass flow controller 7).
The gas flow rate adjusting valve (gas mass flow controller 4) is disposed on the gas piping path, and adjusts the flow rate of the mixed gas (natural gas G0, simulated fuel gas G10) flowing through the gas piping.
The air flow rate adjusting valve (air mass flow controller 7) is arranged on the path of the air pipe AP, and adjusts the flow rate of the air AR flowing through the air pipe AP.
With this configuration, in the control system S according to the present embodiment, the air flow rate of the air AR can be controlled based on the delay time TDT, so that a mixed gas whose component composition is unknown can be stably burned.

Note that a part of the control device 8 in the above-described embodiment, for example, the density acquisition unit 80, the component ratio calculation unit 81, the flow rate calculation unit 82, the gas flow rate control unit 83, the delay time calculation unit 84, and the air flow rate control unit 86. May be realized by a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed. Here, the “computer system” is a computer system built in the control device 8 and includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In this case, a volatile memory inside a computer system that serves as a server or a client may be included that holds a program for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.
Moreover, you may implement | achieve part or all of the control apparatus 8 in embodiment mentioned above as integrated circuits, such as LSI (Large Scale Integration). Each functional block of the control device 8 may be individually made into a processor, or a part or all of them may be integrated into a processor. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, in the case where an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology may be used.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

S ... Control system, 1 ... Gas tank, 2 ... Gas tank, 3 ... Gas density meter, 4 ... Gas mass flow controller, 5 ... Signal converter, 6 ... Compressor, 7 ... Air mass flow controller, 8 ... Control device, 9 ... AD / DA conversion board, 10 ... burner, R1 ... natural gas supply system, R2 ... simulated fuel supply system, GP0, GP1, GP2, GP3, GP10 ... gas piping, AP ... air piping, C1 ... methane cylinder, C2 ... ethane cylinder, C3: propane cylinder, V1, V11, V12, V21, V22, V23, V3 ... valve, 21, 22, 23 ... gas mass flow controller, 80 ... density acquisition unit, 81 ... component ratio calculation unit, 82 ... flow rate calculation unit, 83 ... Gas flow rate control unit, 84 ... Delay time calculation unit, 85 ... Storage unit, 850 ... Delay time information, 86 ... Air flow rate Control unit

Claims (6)

Based on the component ratio of the mixed gas when the total flow rate of the mixed gas whose composition of the component is unknown and the air mixed with the mixed gas is constant and the equivalence ratio of the mixed gas and the air is constant A flow rate calculation unit for calculating a gas flow rate of the mixed gas and an air flow rate of the air;
Based on the gas flow rate calculated by the flow rate calculation unit, a gas flow rate control unit that controls the flow rate of the mixed gas flowing in the gas pipe;
The mixed gas supplied by the gas pipe and the air supplied by the air pipe are measured from a measurement position on the path of the gas pipe where a measurement unit for measuring a physical quantity indicating the component ratio of the mixed gas is arranged. Based on the delay time according to the distance to the gas-air mixing unit to be mixed at the connection between the gas pipe and the air pipe, and the air flow rate calculated by the flow rate calculation unit, the air flow in the air pipe A control device comprising: an air flow rate control unit that controls a flow rate of air. The physical quantity is the density of the mixed gas,
A component ratio calculation unit that calculates a component ratio of the mixed gas based on the density at the measurement position;
The flow rate calculation unit calculates a gas flow rate of the mixed gas and an air flow rate of the air based on the component ratio of the mixed gas indicated by the density calculated by the component ratio calculation unit. Control device. The gas flow rate adjustment valve controlled by the gas flow rate control unit is disposed downstream of the measurement position in the gas pipe,
The control device according to claim 1, wherein the air flow rate control unit controls the air flow rate of the air based on a transmission time corresponding to a distance from the measurement position to the gas flow rate adjustment valve. The control device according to any one of claims 1 to 3, further comprising a delay time calculation unit that calculates the delay time based on a density of the mixed gas and the distance. The control device according to any one of claims 1 to 4,
A gas flow rate adjusting valve that is disposed on the path of the gas pipe and adjusts the flow rate of the mixed gas flowing through the gas pipe;
A control system comprising: an air flow rate adjusting valve that is arranged on a path of the air pipe and adjusts a flow rate of the air flowing through the air pipe. On the computer,
Based on the component ratio of the mixed gas when the total flow rate of the mixed gas whose composition of the component is unknown and the air mixed with the mixed gas is constant and the equivalence ratio of the mixed gas and the air is constant A flow rate calculating step for calculating a gas flow rate of the mixed gas and an air flow rate of the air;
A gas flow rate control step for controlling the flow rate of the mixed gas flowing in the gas pipe based on the gas flow rate calculated in the flow rate calculation step;
The mixed gas supplied by the gas pipe and the air supplied by the air pipe are measured from a measurement position on the path of the gas pipe where a measurement unit for measuring a physical quantity indicating the component ratio of the mixed gas is arranged. Based on the delay time corresponding to the distance to the gas / air mixing section to be mixed at the connection portion between the gas pipe and the air pipe, and the air flow rate calculated in the flow rate calculation step, the air pipe flows. An air flow rate control step for controlling the flow rate of the air.