JP2009163541A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply device, capable of controlling the flow rate of fuel gas with a heating value as a management value, and further optimizing the mixing ratio of air and/or oxygen according to the heating value owned by the fuel gas. <P>SOLUTION: A first flow adjustment device for controlling flow rate of fuel gas controls a calorific flow rate of fuel gas, determines a heating value ratio thereof to fuel gas in a reference state from a heating value of the fuel gas, and reports it together with the flow rate of the fuel gas to a second flow adjustment device. The second flow adjustment device for controlling flow rate of air and/or oxygen determines optimum mixing ratio [A/F], [O<SB>2</SB>/F] of air and/or oxygen to be mixed to the fuel gas according to the reported heating value ratio, and adjusts the flow rate of air and/or oxygen based on the mixing ratio [A/F], [O<SB>2</SB>/F] and the flow rate of the fuel gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a fuel supply capable of optimizing the mixing ratio of air and / or oxygen in accordance with the calorific value of the fuel gas when the fuel gas is mixed with air and / or oxygen and supplied to the fuel gas combustion system. Relates to the device.

  When fuel gas is burned using a burner, the fuel gas supply amount (fuel gas flow rate) and air supply amount (air flow rate) supplied to the burner are adjusted to optimize the combustion state, respectively. The ratio of the air mass to the fuel gas mass in the air-fuel mixture, that is, the so-called air-fuel ratio [A / F] is made constant. In such air-fuel ratio control, for example, the mass flow rate of the fuel gas and the mass flow rate of air are measured using a thermal mass flow sensor, for example, and at least one of the flow rates of the fuel gas and air ( (Mass flow rate) is adjusted (controlled) (see, for example, Patent Document 1).

Further, when performing the above-described air-fuel ratio control, if there are a plurality of types having different compositions as the fuel gas or the composition ratio changes, the amount of combustion heat and the amount of heat generated per unit time are obtained. Is also proposed to be fed back to the flow rate control (see, for example, Patent Document 2). Even when air and oxygen are mixed in the fuel gas and the mixture is supplied to the burner and burned, the mass flow rates of the fuel gas, air and oxygen are measured, and each of these components is measured. It has also been proposed to control each flow rate so as to achieve an ideal mixing ratio (see, for example, Patent Document 3).
JP 2002-267159 A JP 2003-35612 A JP 2007-87029 A

  By the way, in a burner used in a glass tube sealing process or the like, it is required to control the combustion amount with high accuracy. However, as described above, the supply amount is controlled based on the mass flow rate of the fuel gas, and each flow rate of air and oxygen is controlled so that each component of the fuel gas, air and oxygen has an ideal mixing ratio. However, when the composition of the fuel gas changes, there is a problem that the combustion amount (heat generation amount) of the fuel gas (air mixture) cannot be maintained at a desired control value. Moreover, since the gas density also changes with the change in the composition of the fuel gas, there arises a problem that the mixing ratio also deviates from the ideal state. These problems also cause incomplete combustion of fuel gas.

  The present invention has been made in consideration of such circumstances, and its purpose is to control the flow rate of the fuel gas using the heating value as a control value regardless of the difference or change in the composition of the fuel gas. An object of the present invention is to provide a fuel supply device capable of optimizing the mixing ratio of air and / or oxygen in accordance with the amount of heat generated.

In order to achieve the above-described object, a fuel supply device according to the present invention includes a first flow rate adjustment device having a flow rate adjustment valve that adjusts the flow rate of fuel gas, and a flow rate adjustment valve that adjusts the flow rate of air and / or oxygen. An apparatus comprising a second flow rate adjusting device in parallel with the fuel gas, and mixing the fuel gas with air and / or oxygen and supplying the fuel gas to the combustion system,
The first flow rate adjusting device includes:
<a1> a calorific flow rate calculating means for obtaining a calorific flow rate of the fuel gas from an output of a thermal mass flow sensor provided in the flow path of the fuel gas;
<a2> A first control unit that adjusts the flow rate of the fuel gas by controlling the flow rate adjusting valve according to the heat flow rate set as the control target value and the heat flow rate of the fuel gas determined by the heat flow rate calculation means. Flow rate adjusting means,
<a3> a calorific value detection means for obtaining a calorific value per unit volume of the fuel gas;
<a4> The calorific value ratio of the fuel gas based on the calorific value per unit volume in the reference state of the fuel gas obtained in advance and the calorific value per unit volume of the fuel gas obtained by the calorific value detection means Calorific value ratio calculating means for obtaining
<a5> The second flow rate adjusting device is notified of the heat value ratio of the fuel gas obtained by the calorific value ratio calculating means and the flow rate of the fuel gas adjusted by the first flow rate adjusting means. And a notification means for
The second flow rate adjusting device includes:
<b1> Optimum mixing ratio [A / F] of the air and the fuel gas for optimally burning the fuel gas according to the calorific value ratio of the fuel gas notified from the first flow rate adjusting means And / or a mixing ratio setting means for obtaining an optimal mixing ratio [O ₂ / F] of oxygen and fuel gas;
<b2> The flow rate according to the flow rate of the fuel gas notified from the first flow rate adjusting means and the mixing ratios [A / F] and [O ₂ / F] obtained by the mixing ratio setting means. And a second flow rate adjusting means for controlling the flow rate of the air and / or oxygen by controlling an adjustment valve.

  Incidentally, the fuel gas is a CH-based gas, and the calorific flow rate calculation means refers to the thermal formula with reference to, for example, a table describing the relationship between the output of the thermal mass flow sensor and the calorific flow rate of the fuel gas. The heat flow rate of the fuel gas is determined according to the output of the mass flow sensor. Preferably, the heat generation amount detection means is, for example, from the output of the thermal mass flow sensor in a state where the flow of the fuel gas is stopped, or when the driving condition of the thermal mass flow sensor is changed. The calorific value per unit volume of the fuel gas is obtained from a change in output of the mass flow sensor or from an output of a calorific sensor provided in the thermal mass flow sensor.

  According to the fuel supply apparatus having the above configuration, the heat flow rate of the fuel gas is obtained from the output of the thermal mass flow sensor that detects the mass flow rate of the fuel gas in the heat flow rate calculation means, and is set as the control target value in the flow rate control means. Since the operation of the flow rate adjustment valve is controlled by comparing the heat quantity flow rate obtained with the heat quantity flow rate obtained by the heat quantity flow rate calculation means, the flow rate of the fuel gas is made constant at the heat quantity flow rate set as the control target value. Can do. That is, the flow rate of the fuel gas can be controlled using the heat flow rate determined by the mass flow rate of the fuel gas and the calorific value per unit volume of the fuel gas as a management value.

Further, a ratio of a calorific value per unit volume of the fuel gas to a calorific value per unit volume in the reference state of the fuel gas obtained in advance, that is, a calorific value ratio is obtained, and air and / or oxygen is determined according to the calorific value ratio Therefore, the air / fuel gas mixing ratio [A / F] and / or the oxygen / fuel gas mixing ratio [O ₂ / F] can be optimized.

  Therefore, even when the composition (type) of the fuel gas is different from the assumed composition (type) or when the composition of the fuel gas itself changes, the fuel gas is focused on the amount of heat generated by the fuel gas. The flow rate of air and / or oxygen can be optimized in accordance with the calorific value ratio, so that stable combustion of the fuel gas can be realized simply and effectively. . In addition, since the relationship between the output of the thermal mass flow sensor and the heat flow rate of the fuel gas is obtained in advance and described as a table, the heat flow rate of the fuel gas can be easily obtained according to the sensor output. The effect that the burden of flow control does not increase so much is exhibited.

Hereinafter, a fuel supply apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a fuel supply device according to this embodiment. 10 is a flow rate control device [first flow rate adjusting means] for controlling the supply amount of fuel gas (F), and 20 is supply of air (A) A flow rate control device [second flow rate adjusting means] for controlling the amount, and 30 is a flow rate control device [second flow rate adjusting means] for controlling the supply amount of oxygen (O ₂ ). These flow rate supply devices 10, 20, 30 are provided in parallel, and the fuel gas, air, and oxygen supplied through the respective flow rate supply devices 10, 20, 30 are controlled by the mixer 41, Then, the mixture is sequentially mixed through the burner 43 and supplied to the burner 43 as a combustor. Incidentally, the first flow rate supply device 10 plays a role of controlling the supply amount of the fuel gas in accordance with the required combustion amount (heat generation amount) in the burner 43, and each of the second flow rate supply devices 20. , 30 play a role of controlling the supply amounts of air and oxygen for complete combustion of the fuel gas in accordance with the supply amount of the fuel gas.

  Each of the flow control devices 10, 20, and 30 is basically provided in the fuel gas (air, oxygen) flow passage 1 as shown in FIG. 1 and FIG. A thermal mass flow sensor 3 that includes a flow rate adjusting valve (valve) 2 that adjusts the flow rate of gas (air, oxygen) and detects the mass flow rate of fuel gas (air, oxygen) that flows through the flow path 1. Is provided. The valve opening degree of the flow rate adjusting valve 2 is controlled by a valve control circuit 4 that is driven according to the flow rate detected by the thermal mass flow rate sensor 3. In particular, the flow rate adjusting valve (valve) 2 operates under the control of the control calculator 5, the flow rate detected using the thermal mass flow sensor 3, and the control target value set in the control calculator 5. The flow rate of the fuel gas (air, oxygen) is adjusted by feedback control so that there is no deviation from (flow rate).

  Incidentally, the flow rate control devices 10, 20, and 30 configured by including the flow rate adjusting valve 2 and the thermal mass flow rate sensor 3 described above are fuel gas (air, oxygen) as schematically shown in FIG. A flow rate adjusting valve (valve) 2 in which a thermal mass flow sensor 3 is provided on a flow path body 11 in which the flow path 1 is formed so as to face the flow path 1 and the valve opening degree is controlled by a solenoid mechanism 12. Is incorporated into the flow path body 11 so as to partition between the inlet and the outlet of the flow path 1. Further, in this flow control device, the drive unit 13 on which the control arithmetic unit 5 and the valve control circuit 4 described above are mounted is integrally assembled on the outside of the flow path body 11. The flow control device and the thermal mass flow sensor 3 having the above-described configuration are well known as introduced in the above-mentioned Patent Document 3 and the like.

In the present invention, the output of the thermal mass flow sensor 3 for detecting the mass flow rate of the fuel gas (air, oxygen) in the flow rate control devices 10, 20, 30 basically configured as described above is We focus on the fact that it is proportional to the heat flow rate of the fuel gas (air, oxygen). That is, the thermal mass flow sensor 3 used for detecting the mass flow rate Fm of the fuel gas (air, oxygen) detects the temperature distribution of the fluid (fuel gas, air, oxygen) in the vicinity of the sensor. The distribution varies depending on the thermal diffusivity α of the fuel gas (air, oxygen) and the flow velocity (volume flow rate) of the fuel gas (air, oxygen). Incidentally, the thermal diffusivity α of the fuel gas (air, oxygen) is λ, the thermal conductivity of the fuel gas (air, oxygen), ρ, the density of the fuel gas (air, oxygen), and the fuel gas (air, oxygen). Α = λ / (ρ × Cp) where Cp is the specific heat of
As given.

  On the other hand, the calorific value Qv per unit volume of the fuel gas varies depending on its composition (type). For example, the calorific value Qv per unit volume at a reference temperature (for example, 0 ° C.) of a CH gas that is a general fuel gas is As shown in the table.

  The difference in the calorific value Qv per unit volume of the fuel gas is mainly caused by the difference in the gas density ρ accompanying the difference in the composition of the fuel gas. Therefore, when the composition of the fuel gas whose mass flow rate Fm is detected using the thermal mass flow sensor 3 changes, the gas density ρ of the fuel gas changes accordingly, and further along with the change of the gas density ρ. Thus, the mass flow rate Fm detected by the thermal mass flow sensor 3 changes.

  However, the density ρ of the fuel gas containing the above-described CH-based gas is proportional to the reciprocal [1 / α] of the thermal diffusivity α as shown in FIG. 4 regardless of the difference in the composition. Further, the calorific value Qv per unit volume of the fuel gas composed of the CH-based gas is proportional to the density ρ regardless of the composition as shown in FIG. The thermal mass flow sensor 3 used for detecting the mass flow rate Vm of the fuel gas obtains an output corresponding to the temperature distribution of the fuel gas in the vicinity of the sensor, and the temperature distribution is the flow rate Fv of the fluid (fuel gas). It varies depending on the calorific value Qv per unit volume. In other words, the signal (sensor output) output from the thermal mass flow sensor 3 is proportional to the calorific value Qv per unit volume regardless of the composition of the CH-based fuel gas, and at the same time the flow velocity (volume flow rate) Fv. It is proportional to Therefore, the signal (sensor output) output from the thermal mass flow sensor 3 is relatively defined as the product of the calorific value Q per unit volume of the fuel gas and its flow velocity (volume flow rate) Fv as shown in FIG. It can be said that it has a one-to-one relationship with the heat quantity flow rate Fc.

  Therefore, in the first flow rate control device 10 in the fuel supply device according to the present invention, the volume flow rate Fv of the fuel gas and the unit volume of the fuel gas from the output (sensor output) of the thermal mass flow rate sensor 3 are determined. There is provided a calorific flow rate detecting unit (caloric flow rate calculating means) 6 for obtaining a calorific flow rate Fc of the fuel gas determined by the calorific value Qv. That is, instead of obtaining the mass flow rate Fm of the fuel gas from the output (sensor output) of the thermal mass flow sensor 3, the heat quantity flow rate Fc of the fuel gas is obtained.

  Then, as the control target value to be given to the control calculator 5, the heat quantity flow Fo for directly managing the heat quantity given to the combustion system such as the burner is set, and this management set value (heat quantity flow Fo) and the heat quantity flow rate are set. The operation of the flow rate adjusting valve 2 described above is controlled so that the heat flow rate Fc of the fuel gas becomes the set flow rate Fo by comparing with the heat flow rate Fc obtained by the detection unit (heat flow rate calculation means) 6. It is characterized by that. In this case, the control calculator 5 functions as a fuel gas flow rate control means based on the heat flow rate Fc detected using the thermal mass flow rate sensor 3.

  According to the first flow control device 10 configured as described above, the heat flow rate Fc of the fuel gas is directly detected from the output (sensor output) of the thermal mass flow sensor 3, and the detected heat flow rate Fc is detected. And the heat flow rate Fo set as the control target value, the operation of the flow rate adjustment valve 2 is controlled to adjust the flow rate (heat flow rate; calorific value) F of the fuel gas. Even if it changes, the calorific value flow rate (heat generation amount) Fc of the fuel gas supplied to the combustion system such as the burner through the flow rate control device (flow rate adjusting valve 2) can be kept constant and stable.

  In particular, the flow rate control is performed by paying attention to the calorific value Qv of the fuel gas, unlike the flow rate control of the fuel gas based on the mass flow rate Fm detected using the conventional general thermal mass flow sensor 3. The heat flow rate (heat generation amount) Fc can be made constant by reliably following not only the flow rate variation but also the heat generation amount variation caused by the composition change. Therefore, it is not necessary to determine whether the change in the output of the thermal mass flow sensor 3 is caused by the change in the flow rate or the change in the amount of heat accompanying the change in the composition, and the calorific value Qv possessed by the fuel gas. As a result, it is possible to achieve a practically great effect such as the ability to stably perform the flow control focusing on the above.

Incidentally, in order to stably and completely burn the above-described fuel gas, it is necessary to mix air and oxygen in the fuel gas at an appropriate ratio as described above. Incidentally, the ideal mixture ratio of air and fuel gas in the air-fuel mixture when burning CH fuel gas completely (ideal air-fuel ratio; A / F), and the ideal mixture ratio of oxygen and fuel gas, so-called ideal The acid fuel ratio [O ₂ / F] is as shown in the following table.

That is, when the composition of the combustion gas changes, the ideal air fuel ratio [A / F] and the ideal acid fuel ratio [O ₂ / F] also change accordingly. Therefore, in the fuel supply apparatus according to the present invention, the flow rate control of the fuel gas is controlled in accordance with the heat generation flow rate in the first flow rate control device 10 as shown in FIG. Thus, the calorific value per unit volume of the fuel gas flowing through the first flow rate control device 10 is obtained, and the calorific value per unit volume in the reference state of the type of fuel gas assumed in advance is obtained as described above. A change in the calorific value is evaluated by obtaining a ratio (calorific value ratio) with the calorific value per unit volume of the fuel gas.

Then, the first flow rate control device 10 notifies the second flow rate control devices 20 and 30 of the calorific value ratio of the fuel gas and the flow rate of the fuel gas obtained as described above, while the second flow rate control device 20 and 30 respectively. The flow rate control devices 20 and 30 control the flow rates of air and oxygen to be mixed with the fuel gas according to the flow rate of the fuel gas and the calorific value ratio notified from the first flow rate control device 10, respectively. . In particular, the second flow control devices 20 and 30 determine the optimum mixing ratio [A / F] and [O ₂ / F] of air and oxygen to be mixed with the fuel gas in accordance with the notified calorific value ratio of the fuel gas. The flow rate of air and oxygen is controlled by calculating the supply amount (set flow rate) of air and oxygen according to the flow rate of the fuel gas. By the flow rate control, the air-fuel mixture is adjusted to an ideal mixture ratio and supplied to the burner 43.

  That is, in the fuel supply apparatus according to the present invention, in addition to the above-described configuration of the first flow rate control device 10, a calorific value detection means 7 for obtaining a calorific value per unit volume of the fuel gas as shown in FIG. And the calorific value per unit volume in the reference state of the CH-based fuel gas obtained in advance and the calorific value per unit volume of the fuel gas obtained by the calorific value detection means 7, A calorific value ratio calculating means 8 for obtaining a calorific value ratio of the fuel gas is provided. Then, the calorific value ratio of the fuel gas obtained by the calorific value ratio calculating means 8 and the flow rate of the fuel gas obtained by the calorific flow rate detecting unit 6 are respectively notified to the second flow rate control devices 20 and 30. It is configured to output.

  On the other hand, the second flow rate control device 20 has an ideal mixing ratio [ideal air-fuel ratio; A / F] of the air and the fuel gas necessary for complete combustion of the CH-based fuel gas. A table 21 registered in advance according to the calorific value ratio associated with the mass is provided. In the second flow rate control device 20, the table 21 is referred to according to the calorific value ratio notified from the first flow rate control device 10, and the air to be mixed with the fuel gas and the fuel gas are previously described. The optimum value of the air-fuel ratio [A / F] is obtained, and the flow rate setting unit 22 controls the supply amount of air to be mixed with the fuel gas according to the air-fuel ratio [A / F] and the flow rate of the fuel gas. It is calculated as a value.

Similarly, the second flow rate control device 30 has an ideal mixing ratio between the mass of oxygen and the mass of fuel gas required for complete combustion of the CH-based fuel gas, the so-called ideal acid fuel ratio [O ₂ / F. ] Is registered in advance according to the calorific value ratio associated with the mass of the fuel gas. In the second flow rate control device 30, the table 31 is referred to according to the calorific value ratio notified from the first flow rate control device 10, and the oxygen and the fuel gas to be mixed with the fuel gas are referred to above. to determine the optimum value of the acid ratio [O 2 _{/ F]} was, the flow rate setting unit 32 controls the supply amount of oxygen to be mixed with the fuel gas in accordance with the flow rate of the fuel gas and the acid ratio [O 2 _{/ F]} It is calculated as a target value.

  Each of these second flow rate control devices 20 and 30 has the air and oxygen flow rates detected by the calorific flow rate sensor 3 and the air and oxygen in accordance with the control target value (flow rate) set as described above. By controlling the oxygen supply amount, the air and oxygen supply amounts are optimized in accordance with the heat generation flow rate of the fuel gas. As a result, the mixing ratio of the fuel gas, air, and oxygen through the mixers 41 and 42 is optimized according to the calorific value of the fuel gas, and the mixture is supplied to the burner 43.

  The calorific value detection means 7 in the first flow rate control device 10 described above generates, for example, the calorific value per unit volume of the fuel gas from the output of the thermal mass flow sensor 3 when the flow of the fuel gas is stopped. It is configured to determine Qv. Specifically, when the flow rate adjusting valve (valve) 2 is closed and the flow of the fuel gas is stopped, the mass (gas density) of the fuel gas is obtained from the output of the thermal mass flow sensor 3, and this gas The heat generation amount is detected using the fact that the density is proportional to the heat generation amount Qv per unit volume of the fuel gas.

  Instead of such a calorific value detection method, for example, a so-called gas reservoir portion in which the fuel gas only enters a part of the fuel gas passage 1, that is, no flow of the fuel gas occurs, is recessed. The thermal mass flow sensor 3a independent from the thermal mass flow sensor 3 is provided in the gas reservoir, and the output of the thermal mass flow sensor 3a is performed in parallel with the detection of the thermal flow rate Fc described above. Of course, the calorific value Qv per unit volume of the fuel gas can be obtained. In this way, the calorific value Qv per unit volume of the fuel gas can be obtained while the fuel gas is continuously flowing without closing the flow rate adjusting valve (valve) 2 and stopping the flow of the fuel gas. It can be obtained.

  Alternatively, for example, as disclosed in JP-T-2004-514138, the heater power when the heater temperature, which is the driving condition of the thermal mass flow sensor 3, is changed in two stages, is obtained, and from these heater powers, respectively. The calorific value detecting means 7 can be configured to obtain the calorific value Qv per unit volume from the obtained thermal conductivity λ of the fuel gas according to the relationship between the thermal conductivity λ and the density of the fuel gas. .

  In addition, the calorific value ratio calculation means 8 has a calorific value Qv per unit volume of the fuel gas obtained by the calorific value detection means 7 as described above, and a reference state obtained in advance for the assumed type of fuel gas. The ratio of the calorific value per unit volume to Qs, that is, the calorific value ratio [Qv / Qs] is obtained. The calorific value Qs per unit volume in the reference state of the fuel gas is, for example, the calorific value Qs per unit volume obtained in advance for each type of fuel gas by specifying the type of fuel gas to be controlled. Is obtained by referring to a table (not shown) in which is described.

In this way, the calorific value ratio [Qv / Qs] of the fuel gas is obtained by the calorific value ratio calculation means 7 to determine how much the calorific value Qv of the fuel gas is from the calorific value Qs of the fuel gas assumed in advance. It becomes possible to grasp whether it is changing. Incidentally, the cause of the change in the calorific value Qv of the fuel gas is exclusively the change in the composition of the fuel gas. As the composition changes, the optimum ideal air / fuel ratio [A / F] and ideal acid / fuel ratio [O ₂ / F] for burning the fuel gas also change. Therefore, if the flow rates of air and oxygen are controlled in accordance with the calorific value ratio [Qv / Qs] and the heat amount flow rate Fc of the fuel gas in the second flow rate control devices 20 and 30 as described above, It becomes possible to optimize the air fuel ratio [A / F] and the acid fuel ratio [O ₂ / F] in forming the air-fuel mixture. Conceptually, for example, when the calorific value ratio of the CH-based fuel gas is obtained as [1.1], it is determined that the calorific value is increased by 10% with the change in the composition of the fuel gas, The supply amount of air and oxygen necessary for the combustion of the fuel gas may be increased by 10%.

  Thus, according to the fuel supply apparatus configured as described above, the supply amount of the fuel gas is controlled on the basis of the heat generation flow rate based on the heat generation amount of the fuel gas. Regardless of the calorific value per unit volume of the gas, the supply calorific value of the fuel gas can be accurately controlled. Moreover, even when the composition of the fuel gas is different from the composition assumed in advance and the calorific value per unit volume of the fuel gas is different from the calorific value per unit volume of the assumed type of fuel gas, it is obtained as described above. Since the flow rates of air and oxygen are optimized according to the calorific value ratio, air and oxygen can be mixed with the fuel gas at an optimum ratio according to the composition (heat value) of the fuel gas. Therefore, it is possible to completely burn the combustion gas in a state in which the mixing ratio of air and oxygen is optimized, and the effects of being able to stably optimize the combustion temperature, the state of the flame, and the like are exhibited.

  The present invention is not limited to the embodiment described above. For example, the mass flow rate detected by the thermal mass flow sensor 3 can be output in parallel with the heat flow rate obtained by the heat flow rate detection unit 6. Each of the flow control devices 10, 20, and 30 can be configured to selectively set the flow control based on the calorific flow and the flow control based on the mass flow. As for the flow rate control for air and oxygen, the mass flow rate control may be performed assuming that the components are constant. Needless to say, the present invention is also applicable to a fuel supply apparatus that mixes only one of air and oxygen with fuel gas. Furthermore, it is of course possible to incorporate functions such as known temperature correction means as appropriate, and the present invention can be implemented with various modifications without departing from the gist thereof.

1 is a schematic configuration diagram of a fuel supply device according to an embodiment of the present invention. FIG. 2 is a schematic functional configuration diagram of a flow control device used in the fuel supply device shown in FIG. 1. The figure which shows the example of the flow-path structure of the flow control apparatus shown in FIG. The figure which shows the relationship between the density of CH type fuel gas, and the reciprocal [1 / (alpha)] of thermal diffusivity (alpha). The figure which shows the relationship between the density of CH type fuel gas, and the emitted-heat amount per unit volume. The figure which shows the relationship between the calorie | heat amount flow rate of fuel gas, and the sensor output of a thermal mass flow sensor.

Explanation of symbols

1 Fuel gas flow path 2 Flow control valve (valve)
3 Thermal mass flow sensor 4 Valve control circuit 5 Control calculator 6 Heat quantity flow detector (heat quantity flow calculation means)
7 Heat generation amount detection means 8 Heat generation amount ratio calculation means 10, 20, 30 Flow rate control device 21 A / F table 22 Flow rate setting unit 31 O2 / F table 32 Flow rate setting unit

Claims (3)

A fuel supply device that mixes air and / or oxygen with fuel gas and supplies the fuel gas to a combustion system of the fuel gas, the first flow rate adjustment device having a flow rate adjustment valve for adjusting the flow rate of the fuel gas, A second flow control device having a flow control valve for adjusting the flow rate of air and / or oxygen,
The first flow rate adjusting device includes a calorific flow rate calculating means for obtaining a calorific flow rate of the fuel gas from an output of a thermal mass flow sensor provided in the fuel gas passage,
A first flow rate adjustment for adjusting the flow rate of the fuel gas by controlling the flow rate adjusting valve according to the heat flow rate set as the control target value and the heat flow rate of the fuel gas obtained by the heat flow rate calculation means Means,
A calorific value detection means for obtaining a calorific value per unit volume of the fuel gas;
Heat generation for obtaining a heat generation ratio of the fuel gas from a heat generation amount per unit volume in the reference state of the fuel gas determined in advance and a heat generation amount per unit volume of the fuel gas determined by the heat generation amount detection means A quantity ratio calculating means;
Notifying means for notifying the second flow rate adjusting device of the calorific value ratio of the fuel gas obtained by the calorific value ratio calculating means and the flow rate of the fuel gas adjusted by the first flow rate adjusting means. And
The second flow rate adjusting device is configured to optimally mix the air and the fuel gas in order to optimally burn the fuel gas in accordance with the calorific value ratio of the fuel gas notified from the first flow rate adjusting unit. A ratio [A / F] and / or a mixture ratio ratio setting means for obtaining an optimum mixture ratio [O ₂ / F] of oxygen and fuel gas;
The flow rate adjusting valve is controlled according to the flow rate of the fuel gas notified from the first flow rate adjusting means and the mixing ratios [A / F] and [O ₂ / F] obtained by the mixing ratio setting means. And a second flow rate adjusting means for controlling the flow rate of the air and / or oxygen to control the fuel supply device. The fuel gas is a CH gas,
The calorific flow rate calculation means refers to a table describing the relationship between the output of the thermal mass flow sensor and the thermal flow rate of the fuel gas, and the calorific flow rate of the fuel gas according to the output of the thermal mass flow sensor The fuel supply device according to claim 1, wherein   The calorific value detection means is configured to output the thermal mass flow sensor from the output of the thermal mass flow sensor in a state where the flow of the fuel gas is stopped or when the driving condition of the thermal mass flow sensor is changed. 2. The fuel supply device according to claim 1, wherein a heat generation amount per unit volume of the fuel gas is obtained from an output change or an output of a calorific sensor provided in the thermal mass flow sensor.

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