JP2023075809A - Flow rate control system and combustion control system including the same - Google Patents

Abstract

To safely save manpower through automation of various types of adjustment, such as a flow rate of fuel gas, while improving economic efficiency by maintaining a simple configuration without providing a flow meter.SOLUTION: By operating a blower B, combustion gas A is caused to flow in on-site fuel piping H1 via on-site connection piping H3. While a fuel flow control valve RVg is maintained at a predetermined initial set opening and pressure at a primary side inlet is maintained at predetermined fuel flow rate control pressure by using the blower B, pressure at a secondary side outlet is set to be predetermined initial set secondary pressure by using a secondary side fuel pressure adjustment mechanism GV. Then, while fuel piping on-off valves SV1, SV2 are opened and a connection piping on-off valve SV3 is closed, the opening of the fuel flow control valve RVg is controlled on the basis of opening fuel flow rate relation stored in a storage section S3 to control a flow rate of fuel gas G to a target flow rate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a flow rate control system for controlling the flow rate of gas to be controlled, including fuel gas, and a combustion control system having the same.

2. Description of the Related Art Conventionally, as a combustion control system used in an industrial furnace or the like, a pressure equalizing valve system is known (see Patent Document 1). The pressure equalizing valve type combustion control system includes, for example, a fuel pipe connected to the burner and passing fuel gas such as city gas 13A, an air pipe connected to the burner and passing combustion air, and an industrial A temperature controller that controls the output of the burner based on the temperature of the furnace, and a control motor that controls the flow rate of air flowing through the air pipe based on the signal from the temperature controller. a control valve, a pressure equalizing valve that controls the opening of the fuel pipe in a manner corresponding to the air pressure on the secondary side of the control valve of the air pipe, and a blower that feeds combustion air to the air pipe. .
In the pressure equalizing valve type combustion control system, the linkage between the control motor and the control valve is manually adjusted by an expert. Adjustment is required. This also applies to the double linkage type combustion control system.
As another configuration, an electronic linkage type combustion control system is known. In the electronic linkage type, for example, a fuel pipe that is connected to a burner and allows a fuel gas such as city gas 13A to flow, and a fuel pipe that is also connected to the burner. a temperature controller that controls the output of the burner based on the temperature of the industrial furnace; a controller that receives a signal from the temperature controller; and a fuel pipe. An electronic flow meter that measures the flow rate of fuel gas and air flowing through the air pipe and transmits it to the control unit, and the fuel flow rate that controls the flow rate of the fuel gas flowing through the fuel pipe based on the signal from the control unit. It comprises a control valve and an air flow rate control valve for controlling the flow rate of air flowing through the air pipe.
In the electronic linkage system, the flow rate of fuel gas and combustion air is monitored by an electronic flow meter, and the air ratio based thereon is monitored, and the air ratio can be changed by setting in the control section.

JP-A-10-47654

In the above-described pressure equalizing valve type combustion control system, for example, even if the flow rate of the fuel gas deviates from the target value for some reason, the user cannot notice it, and the furnace temperature is adjusted to the set value. There is a risk that it will not be possible to maintain
In addition, since manual adjustment by a skilled person is required to adjust the output, etc., there is also a problem that it is difficult to improve efficiency by saving manpower.
In addition, in order to adjust the flow rate of the fuel gas, etc., it is necessary to provide a relatively expensive electronic flow meter, which is a problem from the viewpoint of economy.

The present invention has been made in view of the above-mentioned problems, and its object is to maintain a simple configuration without a flow meter to improve economic efficiency, and to prevent unintended combustion during adjustment, etc. It is an object of the present invention to provide a fluid flow rate control system and a combustion control system equipped with the same, which can prevent this and can safely realize labor saving by automating various adjustments such as the flow rate of fuel gas.

A flow rate control system for achieving the above object is a flow rate control system for controlling the flow rate of a gas to be controlled including a fuel gas, and is characterized by:
A fuel flow control valve provided in the on-site fuel pipe through which the fuel gas as the control target gas flows, and controlling the opening degree according to a control command from a flow control unit;
The pressure of the secondary side outlet can be adjusted based on the measurement result of a second fuel pressure gauge provided at the outlet of the fuel flow control valve in the on-site fuel piping and provided at the secondary side outlet of the fuel flow control valve. a secondary side fuel pressure adjustment mechanism;
A primary side fuel pressure adjustment mechanism provided at the primary side inlet of the fuel flow control valve in the field fuel pipe and capable of adjusting the pressure at the primary side inlet based on the measurement result of a first fuel pressure gauge;
A fuel pipe on-off valve provided at the most upstream portion of the primary side of the on-site fuel pipe and opening and closing the on-site fuel pipe;
a blower provided in an on-site combustion gas pipe for flowing a combustion gas as an oxidant of the fuel gas, for pumping the combustion gas to the on-site combustion gas pipe; and the on-site combustion on the downstream side of the blower. a combustion gas pipe open/close valve capable of opening and closing the gas pipe for combustion;
The primary side of the fuel flow control valve of the on-site fuel pipe and the secondary side of the fuel pipe on-off valve and the primary side of the combustion gas pipe on-off valve of the on-site combustion gas pipe and the secondary side of the blower In a field facility equipped with a connection pipe opening/closing valve that is provided in a connected field connection pipe and that opens and closes the field connection pipe,
A test fuel pipe having the same diameter as the on-site fuel pipe instead of the on-site fuel pipe, a test combustion gas pipe having the same diameter as the on-site combustion gas pipe instead of the on-site combustion gas pipe, and the on-site connection pipe Instead, each of the field connection pipe and the test connection pipe of the same diameter is provided with a configuration provided in the field equipment, and a fuel flow meter for measuring the flow rate of the fluid flowing through the test fuel pipe. In the test facility, the pressure control unit and the flow control unit that control pressure by the secondary side fuel pressure adjustment mechanism and the primary side fuel pressure adjustment mechanism operate the combustion gas pipe on-off valve and the fuel pipe on-off valve. The connection pipe opening/closing valve is closed and the connection pipe opening/closing valve is opened. In a state where the initial set opening is maintained and the pressure at the primary side inlet is maintained at a predetermined fuel flow rate control pressure by the primary side fuel pressure adjustment mechanism, the secondary side fuel pressure adjustment mechanism is operated to After setting the pressure of the side outlet to a predetermined initial setting secondary pressure, a storage unit for storing the opening degree fuel flow rate relationship between the opening degree of the fuel flow control valve and the flow rate measured by the fuel flow meter ,
In the field equipment, the pressure control unit and the flow control unit close the combustion gas pipe opening/closing valve and the fuel pipe opening/closing valve, open the connection pipe opening/closing valve, and operate the blower. The combustion gas is caused to flow through the on-site fuel pipe through the on-site connection pipe, the fuel flow rate control valve is maintained at a predetermined initial set opening, and the primary side fuel pressure adjustment mechanism controls the primary side With the inlet pressure maintained at a predetermined fuel flow rate control pressure, the secondary side fuel pressure adjustment mechanism sets the pressure at the secondary side outlet to a predetermined initial set secondary pressure, and then opens and closes the fuel pipe. In a state in which the valve is in an open state and the connection pipe opening/closing valve is in a closed state, the fuel gas is controlled by controlling the opening degree of the fuel flow control valve based on the opening degree fuel flow rate relationship stored in the storage unit. The point is that the flow rate of is controlled to the target flow rate.

In the above characteristic configuration, the pressure on the primary side of the fuel flow control valve can be maintained at a constant pressure by the primary side fuel pressure adjustment mechanism using a test facility having a pipe of the same diameter as the pipe of the field equipment, and The pressure on the secondary side of the fuel flow control valve can be adjusted to a predetermined pressure by the secondary side fuel pressure adjusting mechanism.
As a result, in both the test equipment and the field equipment, the pressure on the secondary side of the fuel flow control valve can be adjusted to be constant regardless of the pressure loss on the secondary side of the field equipment and the test equipment, and the test equipment and the field equipment In both cases, the relationship between the degree of opening of the fuel flow rate control valve and the fuel flow rate can be maintained at the same relationship.
As a result, the obtained opening degree fuel flow rate relationship between the opening degree of the fuel flow control valve and the flow rate through the test fuel pipe can be used as it is in the field equipment.
In other words, the opening degree fuel flow rate relationship obtained by the test facility can be used in common in various field facilities with different pressure losses on the secondary side of the fuel flow control valve. By controlling the opening degree of the fuel flow control valve based on the known opening degree-fuel flow rate relationship without providing a flow meter, the flow rate of the fuel flowing through the field piping can be controlled to a desired flow rate.
Furthermore, since the control does not require manual adjustment by a skilled person, it is possible to improve efficiency by saving manpower.
In particular, in the above-described characteristic configuration, the combustion gas is used instead of the fuel gas in acquiring the opening degree fuel flow rate relationship related to the fuel gas, so safety can be improved compared to the case where the fuel gas flows. In addition, when initializing the primary pressure and secondary pressure of the fuel flow control valve in the field equipment, it is possible to use the combustion gas instead of the fuel gas, so it is safer than the case of using the fuel gas. can be improved.
As described above, it is possible to prevent unintended combustion, etc. during adjustment, etc., while maintaining a simple configuration without a flow meter and improving economic efficiency. A humanized fluid flow control system can be realized.

A further feature configuration of the flow control system is:
The on-site connection pipe is provided with a first check valve that prevents the fuel gas from flowing from the on-site fuel pipe to the on-site combustion gas pipe,
The test connecting pipe is provided with a second check valve for blocking the flow of the fuel gas from the test fuel pipe to the test combustion gas pipe.

By providing the first check valve in the field connection pipe and the second check valve in the test connection pipe as in the above characteristic configuration, the fuel gas is supplied to the field combustion gas pipe and the test combustion gas pipe. contamination can be prevented.

A further feature configuration of the flow control system is:
The on-site equipment and the test equipment are provided with an interlock mechanism for maintaining the closed state of the connection pipe opening/closing valve when the fuel pipe opening/closing valve is in the open state.

According to the above characteristic configuration, in the on-site equipment, when the fuel gas is flowing through the on-site fuel pipe, the closed state of the on-site connection pipe is maintained. can be prevented from being mixed in, and the risk of flashback occurring in the on-site combustion gas piping can be avoided.
In addition, the same action and effect can be obtained in the test facility as well.

A further feature configuration of the flow control system is:
The flow rate control unit uses a corrected fuel flow rate Q' obtained by correcting the flow rate Q measured by the fuel flow meter by the conversion formula shown in the following [Equation 1], where s is the specific gravity of the fuel gas. Then, the opening degree fuel flow rate relation is derived.
Q′=Q/√s [Formula 1]

According to the above characteristic configuration, the post-correction fuel flow rate Q' obtained by properly correcting the provisional fuel flow rate Q obtained by flowing the combustion gas using its specific gravity is used to obtain the post-correction fuel flow rate Q'. and the opening degree of the fuel flow rate control valve can be derived.

A further feature configuration of the flow control system is:
In the test facility, the storage unit causes the pressure control unit and the flow control unit to close the combustion gas pipe opening/closing valve and the fuel pipe opening/closing valve and to open the connection pipe opening/closing valve. A blower is operated to cause the combustion gas to flow through the test fuel pipe through the test connection pipe, and the fuel flow rate control valve is maintained at a predetermined initial set opening, and the primary side fuel pressure adjustment mechanism After setting the pressure of the secondary side outlet to a predetermined initial setting secondary pressure by the secondary side fuel pressure adjustment mechanism in a state where the pressure of the primary side inlet is maintained at a predetermined fuel flow rate control pressure, , which stores the pressure fuel flow rate relationship between the pressure at the secondary side outlet measured by the second fuel pressure gauge and the flow rate measured by the fuel flow meter,
In the on-site equipment, the flow rate control unit adjusts the opening degree of the fuel flow control valve according to the opening degree fuel flow rate relationship in a state where the fuel pipe opening and closing valve is in an open state and the connection pipe opening and closing valve is in a closed state. When the flow rate of the fuel gas is controlled to the target flow rate, the controlled flow rate of the fuel gas is the pressure at the secondary outlet measured by the second fuel pressure gauge. The present invention is provided with an abnormality determination unit that determines that the flow rate control is abnormal when the flow rate is different from the flow rate derived from the pressure-fuel-flow rate relationship.

According to the above characteristic configuration, it is determined whether or not the flow rate derived from the opening degree fuel flow rate relationship is equal to the flow rate derived based on the pressure at the secondary outlet of the fuel flow rate control valve and the pressure fuel flow rate relationship. By monitoring, it is possible to confirm whether or not the flow rate of the fuel gas flowing through the on-site fuel pipe obtained by controlling the fuel flow control valve based on the opening degree fuel flow rate relationship is an appropriate flow rate.
That is, using this principle, the abnormality determination unit controls the opening degree of the fuel flow rate control valve in accordance with the opening degree fuel flow rate relationship to control the flow rate of the fuel gas to the target flow rate. If the flow rate derived from the pressure of the secondary outlet measured by the meter and the pressure fuel flow rate relationship is different from the target flow rate, it is determined that the flow control is abnormal, and the flow rate of the fuel gas is controlled to the target flow rate. Abnormality can be determined satisfactorily.

A combustion control system for achieving the above object is provided with the above-described flow rate control system, and the fuel gas whose flow rate is controlled by the flow rate control system and flows through the on-site fuel piping and the on-site combustion gas piping. A combustion control system comprising a burner through which the flowing combustion gas is directed, characterized by:
In the on-site equipment, the flow rate control unit controls the flow rate of the fuel gas using the common opening degree-fuel flow rate relationship for different types of burners.

According to the above characteristic configuration, even when burners having different pressure losses are used in the field equipment, the pressure at the secondary side outlet of the fuel flow control valve is controlled by the secondary side pressure adjustment mechanism to be constant. Since the effects of different pressure losses of different burners can be eliminated, and fuel gas flow rate control can be executed using a common opening degree fuel flow rate relationship for different burners, it is simple without installing an electronic flow meter in the field equipment. It is possible to build a highly economical system.

A further characteristic configuration of the combustion control system includes the above-described flow control system, and the fuel gas whose flow rate is controlled by the flow control system and flows through the on-site fuel pipe and the on-site combustion gas pipe. A combustion control system comprising a burner through which the combustion gas is directed,
In the on-site equipment, the abnormality determination unit uses the pressure fuel flow rate relationship common to different types of burners to determine the flow rate control abnormality.

According to the above characteristic configuration, even when burners having different pressure losses are used in the field equipment, the pressure at the secondary side outlet of the flow control valve is controlled by the secondary side pressure adjustment mechanism to be different. Since the influence of different pressure losses of the burners can be eliminated, and the common pressure fuel flow rate relationship can be used for different types of burners, flow control abnormality can be judged, so it is simple without installing an electronic flow meter in the field equipment. It is possible to build a highly economical system.

A further feature configuration of the flow control system is:
The point is that the blower for pumping the combustion gas is shared as the primary side fuel pressure adjusting mechanism.

According to the above characteristic configuration, the blower for pressure-feeding the combustion gas to the burner can be used in common as the primary side fuel pressure adjustment mechanism for controlling the flow rate of the fuel gas. The configuration can be simplified as compared with the case where it is provided.

1 is a schematic configuration diagram of a combustion control system according to an embodiment; FIG. It is a schematic block diagram which shows the test equipment which concerns on embodiment. It is a graph chart which shows the opening air flow rate relationship in combustion air. It is a graph chart which shows the pressure air flow rate relationship in combustion air. FIG. 4 is a graph showing the relationship between burner head pressure and flow rate. It is a graph chart which shows the opening degree fuel flow rate relationship in fuel gas. It is a graph chart which shows the pressure fuel flow rate relationship in fuel gas. FIG. 4 is a schematic configuration diagram of a combustion control system according to another embodiment; FIG. 4 is a graph showing changes over time in opening degrees of a fuel flow rate control valve and a pressure regulation valve as a secondary side pressure regulation mechanism when controlling the flow rate of fuel gas in the combustion control system according to the embodiment. FIG. 4 is a graph showing temporal changes in the primary pressure and secondary pressure of the fuel flow control valve when controlling the flow rate of fuel gas in the combustion control system according to the embodiment. FIG. 4 is a graph showing temporal changes in the flow rate of fuel gas when the flow rate of fuel gas is controlled in the combustion control system according to the embodiment.

The flow control systems 100 and 200 and the combustion control system 300 according to the embodiments of the present invention maintain a simple configuration without providing a flow meter to improve economic efficiency, while preventing unintended combustion during adjustment and the like. The present invention relates to a method capable of preventing the occurrence of such a problem and safely realizing manpower saving by automating various adjustments such as the flow rate of fuel gas.
Flow control systems 100 and 200 and a combustion control system 300 according to this embodiment will be described below with reference to FIGS.

The combustion control system 300 according to this embodiment includes, as shown in FIG. (an example of gas for industrial use), a control device S realized in a form in which hardware and software cooperate, and a burner BNa, and the inside of the industrial furnace R is specified configured to heat to a temperature.

<Flow rate control system 100 for fuel gas G>
The flow rate control system 100 for the fuel gas G, as shown in FIG. and a second fuel pressure gauge P2g provided at the outlet of the fuel flow control valve RVg in the field fuel pipe H1 and at the secondary side outlet of the fuel flow control valve RVg. Based on the measurement result of the secondary side fuel pressure adjustment mechanism GV that can adjust the pressure of the secondary side outlet and the first fuel pressure gauge P1g provided at the primary side inlet of the fuel flow control valve RVg in the field fuel pipe H1 An inverter-type blower B as a primary side fuel pressure adjustment mechanism capable of adjusting the pressure at the primary side inlet based on the above, and a fuel pipe that is provided at the most upstream portion of the primary side with the on-site fuel pipe H1 and opens and closes the on-site fuel pipe H1. A first solenoid valve SV1 and a second solenoid valve SV2 as on-off valves and a field air pipe H2 (an example of a gas pipe for field combustion) through which combustion air A flows are provided. An air flow rate control valve RVa is provided as a combustion gas pipe opening/closing valve for opening/closing the on-site air pipe H2 on the downstream side of the blower B for pumping the air A.
That is, in the on-site facility 100a, the blower B as the primary side fuel pressure adjusting mechanism has a common configuration with the blower B for pumping the combustion air A to the on-site air pipe H2.

Further, the flow rate control system 100 for the fuel gas G controls the primary side of the fuel flow control valve RVg of the field fuel pipe H1, the secondary side of the first solenoid valve SV1 and the second solenoid valve SV2, and the air flow rate of the field air pipe H2. In the field equipment 100a provided in the field connection pipe H3 connecting the primary side of the control valve RVa and the secondary side of the blower B, and provided with the connection pipe opening/closing valve SV3 for opening and closing the field connection pipe H3, the details will be described later. However, a storage unit S3 for storing the opening degree fuel flow rate relationship (shown in FIG. 6) between the opening degree of the fuel flow control valve RVg and the flow rate of the fuel gas G flowing through the on-site fuel pipe H1, and the fuel flow control valve It comprises a flow rate control section S1 for controlling the flow rate of the fuel gas G by RVg, and a pressure control section S4 for controlling the pressure by the secondary side fuel pressure adjustment mechanism GV and the blower B as the primary side fuel pressure adjustment mechanism. The storage unit S3, the flow rate control unit S1, and the pressure control unit S4 are implemented in the control device S in a form in which hardware such as a CPU and memory cooperates with software.

Here, the overall configuration of the flow rate control system 100 related to the fuel gas G, that is, the configuration of the combustion control system 300 will be described. The flow control unit S1 of the control device S controls the flow rate of the fuel gas G and the combustion air A guided to the burner BNa so that the temperature measured by the temperature sensor ND for measuring the temperature of the to control.
In the on-site facility 100a, the on-site fuel pipe H1 that guides the fuel gas G to the burner BNa includes, in order from the downstream side (secondary side), a secondary side fuel pressure adjustment mechanism GV, a second fuel pressure gauge P2g, and a fuel flow control valve RVg. , a first fuel pressure gauge P1g, a governor GA capable of adjusting the pressure on the primary side of the fuel flow control valve RVg to a predetermined set pressure, a first solenoid valve SV1 and a second solenoid valve SV2.
The on-site air pipe H2 for guiding the combustion air A to the burner BNa includes, in order from the downstream side (secondary side), a third air pressure gauge P3a, a pressure regulating valve BVa, a second air pressure gauge P2a, and an air flow rate control valve RVa. , a first air pressure gauge P1a, and a blower B are provided.
Here, the third air pressure gauge P3a measures the head pressure of the burner BNa at the primary side inlet of the burner BNa of the on-site air pipe H2. is a configuration for checking whether the relationship between , and flow rate is consistent with known values.

Next, the test facility 400 for acquiring the opening degree fuel flow rate relationship stored in the storage section S3 will be described based on FIG. Note that, in the test equipment 400, control lines from various pressure gauges are not shown due to space limitations of the drawing.
The test facility 400 includes a test fuel pipe H1x having the same diameter as the field fuel pipe H1 instead of the field fuel pipe H1, a test air pipe H2x having the same diameter as the field air pipe H2 instead of the field air pipe H2, and a field connection. Instead of the pipe H3, the field connection pipe H3 and the test connection pipe H3x having the same diameter are each provided with a configuration provided in the field equipment 100a, and a first flow rate for measuring the flow rate of the fluid flowing through the test fuel pipe H1x. A meter F1 (an example of a fuel flow meter) is provided.
Here, as a configuration provided in the field facility 100a, the test fuel pipe H1x that guides the fuel gas G to the burner BNa is arranged in order from the downstream side (secondary side), the secondary side fuel pressure adjustment mechanism GV, the second fuel pressure A meter P2g, a fuel flow control valve RVg, a first fuel pressure gauge P1g, a governor GA capable of adjusting the pressure on the primary side of the fuel flow control valve RVg to a predetermined set pressure, a first solenoid valve SV1 and a second solenoid valve SV2. is provided. Further, a third air pressure gauge P3a, a pressure regulating valve BVa, a second An air pressure gauge P2a, an air flow rate control valve RVa, a first air pressure gauge P1a, and a blower B are provided, and a flow control section Ss1, a storage section Ss3, and a pressure control section Ss4 are provided as the controller Ss.
As a configuration related to acquisition of the opening degree air flow rate relationship in the flow rate control system 200 related to the combustion air A to be described later, the test air pipe H2x is provided with a flow rate of the fluid flowing through the test air pipe H2x. 2 with a flow meter F2.

Now, in acquiring the opening degree fuel flow rate relationship, in the test facility 400, the flow control unit Ss1 and the pressure control unit Ss4 of the control device Ss operate the air flow control valve RVa and the first solenoid valve SV1 and the second solenoid valve SV2. In addition to opening the connection pipe opening/closing valve SV3, the blower B is operated to allow combustion air A to flow through the test fuel pipe H1x through the test connection pipe H3x. In a state where the initial set opening (for example, 100%) is maintained and the pressure at the primary side inlet is maintained at a predetermined fuel flow rate control pressure (maintained at 6 kPa ± 0.05 kPa for 30 seconds) with the blower B, the secondary After setting the pressure of the secondary side outlet to a predetermined initial setting secondary pressure (maintaining 5 kPa ± 0.05 kPa for 30 seconds) with the side fuel pressure adjustment mechanism GV, the opening of the fuel flow control valve RVg and the first flow rate An opening degree fuel flow rate relationship is acquired as a relationship with the flow rate measured by the total F1.

Incidentally, when acquiring the opening degree fuel flow rate relation in the test facility 400, the opening degrees of the fuel flow rate control valve RVg and the secondary side fuel pressure adjustment mechanism GV change with time as shown in FIG. The primary pressure and secondary pressure of the valve RVg change as shown in FIG. 10, and the flow rate of the combustion air A flowing through the test fuel pipe H1x changes as shown in FIG.
In addition, when acquiring the opening degree fuel flow rate relationship, since the combustion air A is flowed instead of the fuel gas G, the flow rate control unit Ss1 controls the flow rate Q measured by the first flow meter F1. , the opening degree fuel flow rate relationship is derived using the corrected fuel flow rate Q′ corrected by the conversion formula shown in the following [Equation 1], where s is the specific gravity of the fuel gas G.
Q′=Q/√s [Formula 1]

As described above, using the opening degree fuel flow rate relationship acquired by the test facility 400, the flow rate control system 100 relating to the fuel gas G performs the following control.
That is, in the field equipment 100a, the flow control unit S1 and the pressure control unit S4 of the control device S close the air flow control valve RVa, the first solenoid valve SV1, and the second solenoid valve SV2, and open the connection pipe opening/closing valve SV3. At the same time, the blower B is actuated to allow the combustion air A to flow through the field fuel pipe H1 through the field connection pipe H3, and the fuel flow control valve RVg is set to a predetermined initial set opening (for example, 100%). , and the blower B maintains the pressure at the primary side inlet at a predetermined fuel flow rate control pressure (maintaining 6 kPa ± 0.05 kPa for 30 seconds), and the secondary side fuel pressure adjustment mechanism GV After setting the side outlet pressure to a predetermined initial set secondary pressure (maintaining 5 kPa±0.05 kPa for 30 seconds), the blower B is stopped and the connecting pipe opening/closing valve SV3 is closed.
After that, the first solenoid valve SV1 and the second solenoid valve SV2 are opened, and the opening degree of the fuel flow control valve RVg is controlled based on the opening degree fuel flow rate relationship (shown in FIG. 6) stored in the storage section S3. Then, the flow rate of the fuel gas G is controlled to the target flow rate.

Incidentally, in order to prevent the fuel gas G from flowing into the on-site air pipe H2 and the test air pipe H2x, which are pipes through which the combustion air A flows, the on-site connection pipe H3 is provided with a combustion A first check valve GV3 for blocking the flow of fuel gas G from the on-site fuel pipe H1 to the on-site air pipe H2 is provided downstream of the connection pipe opening/closing valve SV3 in the flow direction of the air A. Further, in the test connection pipe H3x, a second check valve for blocking the flow of the fuel gas G from the test fuel pipe H1x to the test air pipe H2x in the flow direction of the combustion air A in the test connection pipe H3x. GV3 is provided.
Furthermore, when the fuel gas G is supplied to the field fuel pipe H1 or the test fuel pipe H1x, between the field fuel pipe H1 and the field air pipe H2 or between the test fuel pipe H1x and the test air pipe H2x In order to isolate, in the field equipment 100a and the test equipment 400, an interlock mechanism (not shown) that maintains the closed state of the connection pipe opening/closing valve SV3 when the first solenoid valve SV1 and the second solenoid valve SV2 are in the open state is provided.

Now, in the flow rate control system 100 related to the fuel gas G that has been explained so far, the set opening degrees of various valve elements may deviate during continued use. The flow rate controlled by the control may deviate from the target flow rate.
Therefore, in the test facility 400, the storage unit S3 is configured such that the flow rate control unit Ss1 and the pressure control unit Ss4 of the control device Ss close the air flow control valve RVa and the first solenoid valve SV1 and the second solenoid valve SV2 to close the connecting pipes. The on-off valve SV3 is opened, and the blower B is operated to allow the combustion air A to flow through the test fuel pipe H1x through the test connection pipe H3x, and the fuel flow control valve RVg is set to a predetermined opening ( For example, 100%), and the pressure of the primary side inlet is maintained at a predetermined fuel flow rate control pressure by the blower B (maintaining 6 kPa ± 0.05 kPa for 30 seconds), the secondary side fuel pressure adjustment mechanism GV After setting the pressure of the secondary side outlet to a predetermined initial setting secondary pressure (maintaining 5 kPa ± 0.05 kPa for 30 seconds), the pressure of the secondary side outlet measured by the second fuel pressure gauge P2g and The pressure fuel flow rate relationship (shown in FIG. 7) with the flow rate measured by the first flow meter F1 is stored.
Furthermore, in the field equipment 100a, the flow rate control unit S1 of the control device S stops the blower B and closes the connection pipe opening/closing valve SV3, and then opens the first solenoid valve SV1 and the second solenoid valve SV2. , when the opening degree of the fuel flow control valve RVg is controlled by the opening degree fuel flow rate relationship (shown in FIG. 6) to control the flow rate of the fuel gas G to the target flow rate, the controlled fuel gas G Abnormality determination to determine flow control abnormality when the flow rate is different from the flow rate derived from the pressure of the secondary side outlet measured by the second fuel pressure gauge P2g and the pressure fuel flow rate relationship (shown in FIG. 7) A part S2 is provided.
When the abnormality determination unit S2 determines that the flow rate control is abnormal and it is displayed on a display unit (not shown) such as a monitor, the administrator performs various settings of the flow control system 100 related to the fuel gas G again. do.

<Flow rate control system 200 for combustion air A>
Also in the flow control system 200 related to the combustion air A, the acquired opening degree air flow rate relationship (illustrated in FIG. 3) is used to flow the combustion air A through the field air pipe H2 and the test air pipe H2x. , controls the flow rate of combustion air A;
In the flow control system 200 related to the combustion air A, in acquiring the opening air flow rate relationship, in the test facility 400, the flow control unit Ss1 and the pressure control unit S4 of the control device Ss close the connection pipe opening/closing valve SV3. At the same time, the blower B is operated to allow the combustion air A to flow through the test air pipe H2x, and the air flow rate control valve RVa is maintained at a predetermined initial set opening (for example, 100%). In a state where the pressure at the primary side inlet is maintained at a predetermined air flow control pressure (8.0 kPa ± 0.05 kPa maintained for 30 seconds), the pressure regulating valve BVa as the secondary side air pressure regulating mechanism After setting the side outlet pressure to a predetermined initial setting secondary pressure (maintaining 4.0 kPa ± 0.05 kPa for 30 seconds), the opening of the air flow control valve RVa and the flow rate measured by the second flow meter F2 , the opening degree air flow rate relationship (shown in FIG. 3) is acquired.
As described above, the following control is performed in the flow rate control system 200 related to the combustion air A using the opening degree air flow rate relation acquired by the test facility 400 .
That is, in the field equipment 200a, the flow rate control section S1 and the pressure control section S4 of the controller S close the connecting pipe opening/closing valve SV3, and operate the blower B to pass the combustion air A through the field air pipe H2. The air flow rate control valve RVa is maintained at a predetermined initial set opening (for example, 100%), and the blower B maintains the pressure at the primary side inlet at a predetermined air flow rate control pressure (8.0 kPa±0. 05 kPa for 30 seconds), the pressure at the secondary outlet is set to a predetermined initial set secondary pressure (maintained at 4.0 kPa ± 0.05 kPa for 30 seconds) with the pressure regulating valve BVa, Based on the opening air flow rate relationship (shown in FIG. 3) stored in the storage section S3, the opening of the air flow control valve RVa is controlled to control the flow rate of the combustion air A to the target flow rate.

In the flow rate control system 200 for the combustion air A, the flow rate is controlled based on the opening degree air flow rate relationship due to deviations in the set opening degrees of various valve elements during continued use. However, it may deviate from the target flow rate.
Therefore, in the test facility 400, the storage unit S3 causes the flow rate control unit Ss1 and the pressure control unit Ss4 of the control device Ss to close the connection pipe opening/closing valve SV3 and operate the blower B to test the combustion air A. The air flow control valve RVa is maintained at a predetermined initial set opening (for example, 100%) by the air pipe H2x, and the blower B maintains the pressure at the primary side inlet at a predetermined air flow control pressure (8 0 kPa ± 0.05 kPa for 30 seconds), the pressure of the secondary side outlet is set to a predetermined initial setting secondary pressure by the pressure regulating valve BVa as the secondary side air pressure regulating mechanism (4 0 kPa ± 0.05 kPa for 30 seconds), the pressure air flow rate relationship between the pressure at the secondary side outlet measured by the second air pressure gauge P2a and the flow rate measured by the second flow meter F2 ( 4), and in the field equipment 200a, the flow control unit S1 of the control device S closes the connection pipe opening/closing valve SV3, and the opening degree air flow rate relationship (illustrated in FIG. 3) When controlling the opening degree of the air flow control valve RVa to control the flow rate of the combustion air A to the target flow rate, the controlled flow rate of the combustion air A is measured by the second air pressure gauge P2a. An abnormality determination unit S2 is provided for determining that the flow rate control is abnormal when the flow rate is different from the flow rate derived from the pressure at the secondary side outlet and the pressure air flow rate relationship (shown in FIG. 4).
When the abnormality determination unit S2 determines that the flow rate control is abnormal and it is displayed on a display unit (not shown) such as a monitor, the administrator resets various settings of the flow control system 200 related to the combustion air A. Execute.

Now, in the combustion control system 300 including the flow rate control system 100 for the fuel gas G described above and the burner BNa provided with the flow rate control system 200 for the combustion air A, the control device S The flow rate control unit S1 controls the flow rate of the fuel gas G using a common opening degree fuel flow rate relationship for different types of burners BNa, and controls the flow rate of the fuel gas G using a common opening degree air flow rate relationship for different types of burners BNa. The flow rate of combustion air A is controlled.
That is, as shown in FIG. 6, the opening degree fuel flow rate relationship has a common relationship for burners BNa with different head pressures. can do. In addition, as shown in FIG. 3, the opening air flow rate relationship has a common relationship for burners BNa with different head pressures. can do.

Further, in the combustion control system 300, in the field equipment 100a, 200a, the abnormality determination section S2 uses a common pressure fuel flow rate relationship for different types of burners BNa to determine the flow rate control abnormality of the fuel gas G. At the same time, the flow rate control abnormality of the combustion air A is determined using a common pressure air flow rate relationship for different types of burners BNa.
That is, as shown in FIG. 7, the pressure fuel flow rate relationship has a common relationship for burners BNa with different head pressures, so that one pressure fuel flow rate relationship can be diverted to various sites. can be done. In addition, as shown in FIG. 4, the pressure air flow rate relationship has a common relationship for burners BNa with different head pressures, so that one pressure air flow rate relationship can be diverted to various sites. can be done.

[Another embodiment]
(1) In the above embodiment, the combustion air A was used as the combustion gas, but oxygen-enriched gas, for example, may be used as the combustion gas.

(2) The combustion control system 300 is not limited to heating the industrial furnace R, and can be widely applied to burners such as glass melting furnaces and metal forging equipment.

(3) Although not described in detail in the above embodiment, the following configuration and control may be adopted in an environment where the temperature of the field equipment 100a, 200a changes greatly.
That is, in the test equipment 400, the opening degree fuel flow rate relationship is acquired for each temperature of the fuel gas G flowing through the test fuel pipe H1x, and in the field equipment 100a, the temperature of the fuel gas G measured in the field fuel pipe H1 is measured. The flow rate control of the fuel gas G and the combustion air A may be performed based on the relationship between the opening degree fuel flow rate and the temperature.
In addition, in the test equipment 400, the opening degree air flow rate relationship is acquired for each temperature of the combustion air A flowing through the test air pipe H2x, and in the field equipment 200a, the combustion air measured in the field air pipe H2 The flow rate control of the combustion air A may be performed based on the opening degree air flow rate relationship at the A temperature.

(4) In the above embodiment, the governor GA may be employed as the secondary side fuel pressure adjustment mechanism GV.
In this case, as shown in FIG. 8, the connection point between the field connection pipe H3 of the field equipment 100a and the field fuel pipe H1 is connected between the governor GA and the first solenoid valve SV1. is controlled to be constant.

In the above embodiment, a configuration example using the air flow rate control valve RVa as the combustion gas pipe opening/closing valve has been shown, but a configuration including an opening/closing valve separate from the air flow rate control valve RVa may be adopted.

It should be noted that the configurations disclosed in the above embodiments (including other embodiments, the same shall apply hereinafter) can be applied in combination with configurations disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in this specification are exemplifications, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention.

The flow control system of the present invention and the combustion control system equipped with the same can prevent unintended combustion, etc. during adjustment, etc., while maintaining a simple configuration without providing a flow meter and improving economic efficiency. In addition, it can be effectively used as a fluid flow rate control system and a combustion control system having the same that can safely realize manpower saving by automating various adjustments such as the flow rate of fuel gas.

100, 200: flow control systems 100a, 200a: field equipment 300: combustion control system 400: test equipment A: combustion air B: blower BNa: burner F1: first flowmeter F2: second flowmeter G: fuel gas GV : Secondary side fuel pressure adjustment mechanism GV3 : First check valve, second check valve H1 : Field fuel pipe H1x : Test fuel pipe H2 : Field air pipe H2x : Test air pipe H3 : Field connection pipe H3x : Test connection Piping P1g: First fuel pressure gauge P2g: Second fuel pressure gauge Q: Flow rate Q': Corrected fuel flow rate RVg: Fuel flow rate control valve S: Control device S1: Flow rate control section S2: Abnormality determination section S3: Storage section S4 : Pressure control unit SV1 : First solenoid valve SV2 : Second solenoid valve SV3 : Connection pipe opening/closing valve RVa : Air flow rate control valve

Claims (8)

A flow rate control system for controlling the flow rate of a gas to be controlled including a fuel gas,
A fuel flow control valve provided in the on-site fuel pipe through which the fuel gas as the control target gas flows, and controlling the opening degree according to a control command from a flow control unit;
The pressure of the secondary side outlet can be adjusted based on the measurement result of a second fuel pressure gauge provided at the outlet of the fuel flow control valve in the on-site fuel piping and provided at the secondary side outlet of the fuel flow control valve. a secondary side fuel pressure adjustment mechanism;
A primary side fuel pressure adjustment mechanism provided at the primary side inlet of the fuel flow control valve in the field fuel pipe and capable of adjusting the pressure at the primary side inlet based on the measurement result of a first fuel pressure gauge;
A fuel pipe on-off valve provided at the most upstream portion of the primary side of the on-site fuel pipe and opening and closing the on-site fuel pipe;
a blower provided in an on-site combustion gas pipe for flowing a combustion gas as an oxidant of the fuel gas, for pumping the combustion gas to the on-site combustion gas pipe; and the on-site combustion on the downstream side of the blower. a combustion gas pipe open/close valve capable of opening and closing the gas pipe for combustion;
The primary side of the fuel flow control valve of the on-site fuel pipe and the secondary side of the fuel pipe on-off valve and the primary side of the combustion gas pipe on-off valve of the on-site combustion gas pipe and the secondary side of the blower In a field facility equipped with a connection pipe opening/closing valve that is provided in a connected field connection pipe and that opens and closes the field connection pipe,
A test fuel pipe having the same diameter as the on-site fuel pipe instead of the on-site fuel pipe, a test combustion gas pipe having the same diameter as the on-site combustion gas pipe instead of the on-site combustion gas pipe, and the on-site connection pipe Instead, each of the field connection pipe and the test connection pipe of the same diameter is provided with a configuration provided in the field equipment, and a fuel flow meter for measuring the flow rate of the fluid flowing through the test fuel pipe. In the test facility, the pressure control unit and the flow control unit that control pressure by the secondary side fuel pressure adjustment mechanism and the primary side fuel pressure adjustment mechanism operate the combustion gas pipe on-off valve and the fuel pipe on-off valve. The connection pipe opening/closing valve is closed and the connection pipe opening/closing valve is opened. In a state where the initial set opening is maintained and the pressure at the primary side inlet is maintained at a predetermined fuel flow rate control pressure by the primary side fuel pressure adjustment mechanism, the secondary side fuel pressure adjustment mechanism is operated to After setting the pressure of the side outlet to a predetermined initial setting secondary pressure, a storage unit for storing the opening degree fuel flow rate relationship between the opening degree of the fuel flow control valve and the flow rate measured by the fuel flow meter ,
In the field equipment, the pressure control unit and the flow control unit close the combustion gas pipe opening/closing valve and the fuel pipe opening/closing valve, open the connection pipe opening/closing valve, and operate the blower. The combustion gas is caused to flow through the on-site fuel pipe through the on-site connection pipe, the fuel flow rate control valve is maintained at a predetermined initial set opening, and the primary side fuel pressure adjustment mechanism controls the primary side With the inlet pressure maintained at a predetermined fuel flow rate control pressure, the secondary side fuel pressure adjustment mechanism sets the pressure at the secondary side outlet to a predetermined initial set secondary pressure, and then opens and closes the fuel pipe. In a state in which the valve is in an open state and the connection pipe opening/closing valve is in a closed state, the fuel gas is controlled by controlling the opening degree of the fuel flow control valve based on the opening degree fuel flow rate relationship stored in the storage unit. A flow rate control system that controls the flow rate of to the target flow rate. The on-site connection pipe is provided with a first check valve that prevents the fuel gas from flowing from the on-site fuel pipe to the on-site combustion gas pipe,
2. The flow rate control system according to claim 1, wherein the test connecting pipe is provided with a second check valve that prevents the fuel gas from flowing from the test fuel pipe to the test combustion gas pipe. 3. The flow rate control according to claim 1, wherein the on-site equipment and the test equipment are provided with an interlock mechanism for maintaining the closed state of the connection pipe opening/closing valve when the fuel pipe opening/closing valve is in the open state. system. The flow rate control unit uses a corrected fuel flow rate Q' obtained by correcting the flow rate Q measured by the fuel flow meter by the conversion formula shown in the following [Equation 1], where s is the specific gravity of the fuel gas. 4. The flow rate control system according to any one of claims 1 to 3, wherein the opening degree fuel flow rate relationship is derived.
Q′=Q/√s [Formula 1] In the test facility, the storage unit causes the pressure control unit and the flow control unit to close the combustion gas pipe opening/closing valve and the fuel pipe opening/closing valve and to open the connection pipe opening/closing valve. A blower is operated to cause the combustion gas to flow through the test fuel pipe through the test connection pipe, and the fuel flow rate control valve is maintained at a predetermined initial set opening, and the primary side fuel pressure adjustment mechanism After setting the pressure of the secondary side outlet to a predetermined initial setting secondary pressure by the secondary side fuel pressure adjustment mechanism in a state where the pressure of the primary side inlet is maintained at a predetermined fuel flow rate control pressure, , which stores the pressure fuel flow rate relationship between the pressure at the secondary side outlet measured by the second fuel pressure gauge and the flow rate measured by the fuel flow meter,
In the on-site equipment, the flow rate control unit adjusts the opening degree of the fuel flow control valve according to the opening degree fuel flow rate relationship in a state where the fuel pipe opening and closing valve is in an open state and the connection pipe opening and closing valve is in a closed state. When the flow rate of the fuel gas is controlled to the target flow rate, the controlled flow rate of the fuel gas is the pressure at the secondary outlet measured by the second fuel pressure gauge. The flow rate control system according to any one of claims 1 to 4, further comprising an abnormality determination unit that determines that flow rate control is abnormal when the flow rate is different from the flow rate derived from the pressure-fuel flow rate relationship. A flow control system according to any one of claims 1 to 5 is provided, and the fuel gas whose flow rate is controlled by the flow control system and flows through the on-site fuel pipe and the on-site combustion gas pipe are circulated. a combustion control system comprising a burner through which the combustion gas to
In the on-site equipment, the flow rate control unit controls the flow rate of the fuel gas using the common opening degree fuel flow rate relationship for different types of burners. The flow rate control system according to claim 5 is provided, and the fuel gas flowing through the on-site fuel piping whose flow rate is controlled by the flow control system and the combustion gas flowing through the on-site combustion gas piping are controlled. A combustion control system with a directed burner, comprising:
In the on-site equipment, the abnormality determination unit is a combustion control system that determines the flow rate control abnormality using the common pressure fuel flow rate relationship for different types of burners. 8. The combustion control system according to claim 6, wherein said blower for pumping said combustion gas is shared as said primary side fuel pressure adjusting mechanism.

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