JP2019035064A - Gas-controlling device, gas supply system, gas-controlling program - Google Patents

Abstract

To suppress incomplete combustion without changing a flow amount of a combustion air based on an air ratio stationarily set in advance, even if a fuel gas having higher WI than a target value is supplied.SOLUTION: A target-set value WIs of WI of a supply gas is a minimum value WImin of a fluctuation range of WI, or is WImin+β. When WI control is conducted only for dilution control, the target-set value WIs or lower of a fuel gas is supplied because carburation cannot be controlled if WI is made smaller than initially estimated. At this time, a combusted air ratio is increased because a theoretical air quantity of the fuel gas is lowered. But the possibility of CO elevation can be prevented because air change falls within a range where CO-discharging efficiency is secured (CO discharge is controlled sufficiently). Accordingly, a controlled gas for dilution according to an embodiment is used for reducing WI to control WI to a target value, and is used for supplementing a combustion air to be supplied to a combustor 30 in combustion equipment 12, thereby eliminating the preparation of incomplete combustion-preventing measures.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a gas adjustment device for adjusting fuel gas based on at least an index that ensures combustibility, a gas supply system for supplying adjusted fuel gas to a customer, and a gas adjustment program. .

  The so-called city gas is classified into 14 types of gas based on the Wobbe index (hereinafter referred to as WI) and the combustion rate index (hereinafter referred to as MCP), and the supplier supplies the gas of the specified gas type within the supply region. Supply to customers.

  The composition of the gas supplied to the consumer is adjusted so that WI and MCP are in the range of the gas species. In particular, WI is regarded as important.

  In general, a combustor is preferably supplied with a fuel gas having a component composition that provides a predetermined calorific value and WI, and at this time, the design and operation are adjusted so that the thermal efficiency and the combustion state are optimized. Accordingly, in order to realize stable combustion in the combustor, it is preferable that the heat generation amount of the supply gas and the fluctuation of WI are as small as possible.

  In recent years, for example, a liquefied natural gas (hereinafter referred to as LNG) satellite base has been constructed with an increase in demand for city gas (city gas 13A, etc.) in an area where no gas conduit is installed.

  The LNG satellite base is a facility equipped with an LNG storage tank (LNG tank) and a vaporizer. The LNG supplier transports LNG by transport means such as an LNG lorry vehicle and temporarily stores it in the LNG tank. The LNG stored in the LNG tank is vaporized by a vaporizer, and the vaporized gas is supplied to an industrial park or a house.

  In such an LNG satellite supply system, the calorific value and WI of the component composition of the liquid fuel, which is the raw material of the fuel gas, or the component composition change of the supply gas due to the operation status of the vaporizer and the change of the vaporization treatment load, etc. Variations may occur.

  For this reason, adjustment gas (for example, propane gas for increasing heat, air for dilution) is used so that the WI of the supply gas becomes an optimum value, for example, an intermediate value within an allowable range in which proper combustion is possible. A control technique has been proposed (see Patent Document 1).

  At the customer's site, fuel gas controlled to a certain WI is supplied, and the fuel gas flow rate and the combustion air flow rate are adjusted and used in each heat facility of the customer to meet the required heat output. Is the most preferred usage.

  As a reference for suppressing composition fluctuations including WI, Patent Document 2 includes a fan that supplies combustion air to the burner and a fuel supply path that supplies gas fuel to the burner, and the fuel supply path includes WI measurement. And a gas flow rate adjusting valve are provided, and the opening of the gas flow rate adjusting valve is adjusted based on the WI of the gas fuel measured by the WI measuring device, and the amount of heat supplied to the burner is located as desired. Has been.

  In Patent Document 2, the property of the fuel gas is not adjusted for each boiler, but the gas flow rate is adjusted based on the measured WI index, and the WI fluctuation of the fuel gas is permanently suppressed (property adjustment). It is not.

JP, 2006-191024, A JP2013-92315A

  When the fluctuating WI fluctuates outside the allowable range in the high direction (maximum estimated fluctuation range), the WI tends to be excessive.

  For example, when WI adjustment control is performed, if high WI fuel gas exceeding the assumed fluctuation is supplied, control may not catch up, and fuel gas with a higher WI than the setting may be sent to the combustor. . Since this high WI fuel gas has a larger theoretical air amount than the set WI fuel gas, the combustion air amount based on the air ratio set in advance is insufficient, and the air amount is insufficient. Insufficiency can lead to incomplete combustion.

  The present invention suppresses incomplete combustion without changing the flow rate of combustion air supplied based on an air ratio fixedly set in advance even when fuel gas having a WI higher than the target value is supplied. It is an object to obtain a gas regulating device, a gas supply system, and a gas regulating program.

  The gas regulator of the present invention is a combustion regulator that supplies combustion air having a flow rate based on an air ratio set on the assumption that fuel gas having a specific combustibility index is supplied to the combustor. When the flammability index of the fuel gas before being supplied to the air supply means and the combustor is higher than the specific flammability index, it is for reduction corresponding to the difference of the flammability index, and for the combustion And a mixing means for mixing the adjustment gas for dilution, which is for supplementing air, with the fuel gas before being supplied to the combustor.

  According to the present invention, in the combustion air supply means, the combustion air having a flow rate based on the air ratio set on the assumption that fuel gas having a specific combustibility index is supplied to the combustor To supply. That is, the flow rate of combustion air by the combustion air supply means is basically fixed.

  Here, when the combustibility index of the fuel gas before being supplied to the combustor is higher than the specific combustibility index, the theoretical air amount increases (the required air flow rate increases) and the fixed combustion occurs. The air flow rate is not enough.

  Therefore, in the mixing means, when the combustibility index of the fuel gas before being supplied to the combustor is higher than the specific combustibility index, the mixing means is for reducing the difference in combustibility index, and the combustion air The adjustment gas for dilution, which is a supplement, is mixed with the fuel gas before being supplied to the combustor.

  For example, by using a gas having the same function as combustion air as the adjustment gas for dilution, it is possible to appropriately reduce the combustibility index of the fuel gas and at the same time maintain the air ratio at a preset air ratio. it can.

  In the present invention, the mixing means sets the target value of the fuel gas combustibility index within a range from a minimum value of an estimated fluctuation range of the fuel gas combustibility index or a value obtained by subtracting a predetermined value from the minimum value. Setting means for setting, acquisition means for acquiring the combustibility index of the fuel gas before being supplied to the combustor, and the combustibility index acquired by the acquisition means become the target value set by the setting means And a flow rate control means for controlling the flow rate of the adjustment gas for dilution mixed with the fuel gas.

  In order to control the fuel gas in one direction of dilution, the setting means subtracts the target value of the fuel gas combustibility index from the minimum value of the estimated fluctuation range of the fuel gas combustibility index or a predetermined value from the minimum value. Set within the range up to the specified value.

  The acquisition unit acquires a combustibility index of the fuel gas before being supplied to the combustor. The flow rate control unit controls the flow rate of the adjustment gas so that the combustibility index acquired by the acquisition unit becomes a target value. Thereby, adjustment of a combustibility parameter | index can be supplemented with the adjustment gas for dilution.

  For example, by using a gas having the same function as combustion air as the adjustment gas for dilution, it is possible to appropriately reduce the combustibility index of the fuel gas and at the same time maintain the air ratio at a preset air ratio. it can.

  In the present invention, the combustibility index of the fuel gas may be the component composition fluctuation of the liquid fuel that is the fuel gas raw material, the operating status of the vaporizer when the liquid fuel that is the fuel gas raw material is vaporized, or the fuel gas. It is characterized in that it fluctuates within a fluctuation range estimated from fluctuations in the component composition of the fuel gas accompanying fluctuations in the processing load during the vaporization process.

  If the fluctuation range of the flammability index of the fuel gas can be estimated, it becomes easy to set a target value that can be adjusted in one direction with the adjustment gas.

  In the present invention, the gas adjusting device is provided in the middle of the satellite gas piping for supplying the fuel gas after vaporizing the fluid raw material supplied and stored in the satellite facility by the supply means to the combustor. It is characterized by.

  It is possible to provide a gas regulator in a satellite gas pipe that transports a fluid raw material to the satellite facility in advance and supplies the vaporized fuel gas to the combustor in the satellite facility.

  In the present invention, the supply means is a transport means including a tank lorry or a transfer means for transferring a raw material from a supply source to a satellite facility by a conduit.

  As a means for supplying the raw material to the satellite facility, when the raw material is, for example, LNG (liquefied natural gas), it is a liquid and is generally transported by land by a transport means represented by a tank lorry. However, it may be a transfer means for transferring a fluid raw material from a supply source to a satellite facility using a conduit.

  The present invention is characterized in that the gas adjusting device is provided in the middle of a gas supply conduit for supplying the fuel gas after vaporizing the fluid raw material stored in the storage tank to the combustor.

  After vaporizing the non-gaseous raw material stored in the storage tank, a gas adjusting device can be provided in the gas supply conduit that supplies the target combustor. For example, a storage tank may be provided in a harbor where the LNG ship is anchored, the raw material temporarily stored in the storage tank may be taken out, and the gas regulator of the present invention may be installed in a conduit immediately after vaporization.

  The gas supply system of the present invention includes the gas adjusting device, a vaporization processing device that generates a fuel gas before the adjustment of the combustibility index by vaporizing the liquid fuel, and supplies the fuel gas to the gas adjusting device, And a combustion facility provided with a combustor for combusting the fuel gas supplied by the gas regulator.

  According to the present invention, for example, combustion air having a flow rate based on an air ratio set on the assumption that fuel gas having a specific combustibility index is supplied to the combustor is supplied to the combustor. That is, the flow rate of combustion air is basically fixed.

  If the fuel gas combustibility index before being supplied to the combustor is higher than a specific combustibility index, it is for reduction that is equivalent to the difference of the combustibility index and for supplementing the combustion air The adjustment gas is mixed with the fuel gas before being supplied to the combustor.

  By using a gas having a function equivalent to that of combustion air as the adjustment gas for dilution, it is possible to reduce the combustibility index of the fuel gas and at the same time maintain the air ratio at a preset air ratio.

  As described above, in the present invention, even if a fuel gas having a WI higher than the target value is supplied, the flow rate of the combustion air supplied based on the air ratio fixedly set in advance is not changed. Combustion can be suppressed.

It is the schematic of the satellite base for sharing the fuel gas which concerns on this Embodiment to a consumer. It is the schematic which shows the structure of the control system for the fuel gas adjustment apparatus which concerns on this Embodiment, piping of a combustion installation, and WI adjustment control. 7 shows the gas properties (WI, MCP) of seven types (supply gas A to supply gas G: all belonging to the city gas 13A group) assumed as an example for verifying the effect of the present invention. (A) is a time-dependent fluctuation characteristic diagram of WI according to the first embodiment, and (B) is a WI-fuel gas flow rate adjustment characteristic diagram. (A) is a characteristic diagram showing the respective relationship between WI and density with respect to the total calorific value of the supply gas (seven types of supply gas A to supply gas G assumed here as an example); It is a density-WI table characteristic view of the same supply gas. It is a schematic block diagram of the controller with which WI adjustment control which concerns on this Embodiment is performed. It is a flowchart which shows the WI adjustment (dilution) control routine performed with the WI adjustment control part which concerns on this Embodiment. It is a characteristic view for verifying the operation management control burden for suppressing the fluctuation | variation of WI which concerns on this Embodiment, (A) is a fuel gas composition and fuel gas specific gravity characteristic view after dilution adjustment with respect to supply gas, ( B) is a flow rate characteristic diagram for the supply gas, and (C) is a combustion air flow rate and combustion air ratio characteristic diagram for the supply gas. It is a characteristic diagram for verifying the characteristic peculiar to the dilution adjustment, and (A) is a WI-theoretical air amount A characteristic diagram of the supply gas (seven types of supply gas A to supply gas G assumed as an example this time). (B) is a general combustion air ratio-carbon monoxide CO concentration characteristic diagram. It is a time-dependent fluctuation | variation characteristic figure of WI for verifying the characteristic peculiar to dilution adjustment, (A) shows the time of WI fluctuation within an assumption range, and (B) shows the time of WI fluctuation exceeding an assumption range. It is the schematic of the fuel gas adjusting device which concerns on the modification 1, (A) is the schematic similar to what was applied in 1st Embodiment and 2nd Embodiment, (B) is a WI meter mixed Schematic diagram arranged upstream of the mixer, (C) Schematic diagram of providing a WI meter with a bypass downstream of the mixer, (D) WI meter with a bypass provided upstream of the mixer FIG. It is the schematic of the fuel gas adjusting device which concerns on the modification 2, (A) is the schematic (no buffer) equivalent to what was applied in 1st Embodiment and 2nd Embodiment, (B) is (C) is a schematic diagram in which a buffer is provided on the upstream side of the mixer, (D) is a schematic diagram in which buffers are provided on the upstream side and the downstream side of the mixer. is there. It is the schematic which shows the installation state of the fuel gas regulator which concerns on the modification 3 of this Embodiment. In Modification 3, it is a schematic diagram of a fuel gas adjustment device that executes WI adjustment control (this embodiment) using adjustment gas for dilution. In Modification 3, it is a flowchart when performing WI adjustment control by dilution according to the present embodiment.

  FIG. 1 shows a schematic diagram of a satellite base 10 for supplying fuel gas according to the present embodiment to consumers.

  The satellite base 10 is a base for supplying so-called city gas by supplying fuel (for example, LNG) to an area where a gas conduit is not installed.

  Details about city gas.

  City gas is classified into 14 types of gas based on the Wobbe index (hereinafter referred to as WI) and combustion rate index (hereinafter referred to as MCP), and the supplier supplies the gas of the specified gas type within the supply area. Supply to customers.

WI is a numerical value expressed by the equation (1), which is obtained by dividing the total calorific value H (MJ / Nm ³ ) of the gas by the square root of the specific gravity s of the gas with respect to the air. Moreover, MCP is represented by Formula (2).

  here,

WI: Wobbe index

H: Total calorific value of gas H (MJ / Nm ³ )

s: Gas specific gravity (air = 1)

MCP: Burning rate index

Si: Combustion rate of component i

fi: Coefficient related to component i

Ai: volume percentage of component i in gas

K: Damping coefficient

It is.

As an example, the gas species (referred to as city gas 13A) mainly composed of methane (CH ₄ ) is defined as 52.7 ≦ WI ≦ 57.2 as the range of WI, and 35 ≦ MCP ≦ as the range of MCP. 47 (see FIG. 3).

  FIG. 3 shows the gas properties (WI, MCP) of seven types (supply gas A to supply gas G: all belonging to the city gas 13A group) assumed as examples for the purpose of verifying the effect of the present invention. .

  The component composition of the gas supplied to the consumer is adjusted so that WI and MCP are in the above-described range of the gas type of the city gas 13A, and then supplied to the combustion facility 12 (see FIG. 1).

  As shown in FIG. 1, the satellite base 10 includes an LNG tank 14. The LNG tank 14 is configured such that a lorry 16 transports and replenishes LNG regularly or irregularly. In addition, the replenishment of the LNG to the LNG tank 14 is not limited to the moving means such as the lorry 16, but is replenished via a conduit that transports the liquid as it is from the LNG base (for example, the LNG storage tank provided in the harbor). Supply means may be applied.

  The LNG tank 14 is connected to the vaporizer 20 via a pipe 18, and the LNG stored in the LNG tank 14 is supplied to the vaporizer 20 via this pipe 18.

  In the carburetor 20, LNG is vaporized to generate a supply gas that is a base of the fuel gas.

  The vaporizer 20 is connected to a fuel gas adjusting device 24 via a pipe 22.

  The supply gas generated by being vaporized by the vaporizer 20 is supplied to the fuel gas adjusting device 24 via the pipe 22.

  The gas type of the supply gas obtained by being vaporized by the vaporizer 20 is, for example, city gas 13A. As a more specific composition, methane gas is the main component, and in addition, ethane gas, propane gas, butane gas and the like are contained.

  In the carburetor 20, fluctuations in the calorific value and WI are caused by fluctuations in the component composition of the liquid fuel that is the raw material of the fuel gas, or by fluctuations in the component composition of the supply gas that accompanies fluctuations in the operating status of the carburetor 20 and the vaporization treatment load. May occur (see FIG. 4A).

  Therefore, in addition to the pipe 22 from the vaporizer 20, one end of a pipe 26 for supplying the adjustment gas is connected to the fuel gas adjustment device 24.

  In the present embodiment, the adjustment gas is one direction of dilution adjustment, and for example, air is applied. A blower or the like (not shown) is connected to the other end of the pipe 26 and can be supplied constantly. By using this adjustment gas for dilution (for example, air), the WI of the supply gas is the minimum value WImin of the estimated fluctuation range shown in FIG. 4A, or less (WImin + β, β is a negative number). β is not particularly limited, but there is no practical problem as long as it is about 10% or less of the average value of the WI of a gas species that is generally applied (here, city gas 13A).

  As shown in FIG. 1, the fuel gas adjusting device 24 is connected to the combustion facility 12 via a pipe 28. In the fuel gas adjusting device 24, the fuel gas whose WI has been adjusted is supplied to the combustion facility 12 via the pipe 28 by supplying the adjustment gas for dilution to the supply gas.

  FIG. 2 is a schematic diagram showing the configuration of the control system for the fuel gas adjustment device 24 and the piping of the combustion facility 12 and the WI adjustment control according to the present embodiment.

  As shown in FIG. 2, the combustion facility 12 is a facility for burning fuel gas by the combustor 30. Examples of the combustion facility 12 include a gas turbine, a gas engine, or an industrial furnace.

  Connected to the combustor 30 are a fuel gas branch pipe 32 branched from a pipe 28 from the fuel gas adjusting device 24 and an air branch pipe 36 branched from a pipe 34 for supplying combustion air, Each combustor 30 is burned at a predetermined combustion amount and combustion air ratio.

  In order to adjust the combustion amount and the combustion air ratio, each fuel gas branch pipe 32 is provided with a fuel gas adjustment valve 38, and a pipe 34 for supplying combustion air is provided with an air adjustment valve 40. .

The fuel gas adjustment valve 38 is adjusted according to the property (especially WI) of the supply gas. As shown in FIG. 4B, the smaller the WI, the higher the flow rate (the more the flow rate is increased). ) To adjust to an appropriate amount of combustion. In the present embodiment, WI is assumed to be the minimum value WImin of the estimated fluctuation range or an error (WImin + β, β is a negative number) when it is expected (for example, WI = 50 MJ / Nm ³ ), The fuel gas flow rate Qg corresponding to the WI is set.

  (Fuel gas adjusting device 24)

  As shown in FIG. 2, the fuel gas adjusting device 24 includes a mixer 42. The mixer 42 can be a venturi mixer or the like. In addition, the structure which mixes gas by opening / closing control of a solenoid valve etc. may be sufficient.

  A pipe 22 from the vaporizer 20 (see FIG. 1) is connected to the main inlet 42A of the mixer 42. Further, a pipe 26 for introducing a diluting adjustment gas is connected to the auxiliary inlet 42B of the mixer 42. In addition, a flow rate adjusting unit 44 is interposed in the pipe 26 so that the flow rate of the adjustment gas for dilution sent to the mixer 42 is adjusted. The flow rate adjusting unit 44 is connected to the controller 50.

  In the mixer 42, the supply gas introduced from the main inlet 42 </ b> A and the adjustment gas for dilution introduced by the flow rate adjusting unit 44 and introduced from the auxiliary inlet 42 </ b> B are mixed to generate fuel gas.

  On the other hand, a pipe 28 for supplying fuel gas to the combustion facility 12 is connected to the outlet 42 </ b> C of the mixer 42.

  Here, a WI meter 46 for detecting WI is interposed in the pipe 28 on the downstream side of the mixer 42. The WI meter can directly detect WI.

  In place of the WI meter, a detector (X / M) for detecting the variable X of the fuel gas may be applied. The variable X is a generic name of variables indicating the detection target, and may be any variable X that can finally acquire a WI (Wobbe index). As X / M, a density meter, a calorific value meter, and the like that detect a density correlated with WI can be applied. That is, the WI can be indirectly acquired from the correlated variable X (density, heat generation amount, etc.) based on the conversion table stored in advance.

  FIG. 5A shows the relationship between the WI and the density with respect to the total calorific value of the supply gas (seven types of gas (supply gas A to supply gas G assumed as an example this time (see FIG. 3)). FIG. As can be seen from FIG. 5A, the WI and the density are almost directly proportional to the total calorific value. In other words, it can be seen that there is also a correlation between WI and density.

  Therefore, for example, when the variable X of the detector (X / M) is a density, a table (density-WI table) as shown in FIG. The density can be detected by a detector in place of the total 46, and the WI can be acquired based on the density-WI table.

  If the WI can be acquired, the target to be indirectly detected is not limited to the density and the calorific value, and may be an analyzer that analyzes a part or all of the composition of the fuel gas. The part of the composition of the fuel gas includes, for example, the content of propane gas that most affects WI and has a large fluctuation range.

  The WI meter 46 is connected to the controller 50.

  As shown in FIG. 6, the controller 50 includes a microcomputer 52. The microcomputer 52 includes a CPU 52A, a RAM 52B, a ROM 52C, an input / output unit (I / O) 52D, and a data bus and a control bus for connecting them. Bus 52E.

  A user interface (UI) 54 and an HDD (hard disk drive) 56 are connected to the I / O 52D. The UI 54 includes, for example, an operation unit 54A and a display unit 54B. The operation unit 54A receives an instruction from a user, and the display unit 54B notifies a processing status (fuel gas generation status). As the UI 54, a touch panel in which the operation unit 54A and the display unit 54B are integrated may be applied.

  Further, the I / O 52D is connected with a WI meter 46 as an input system device, and is connected with a flow rate adjusting unit 44 as an output system.

  The ROM 52C (or HDD 56) stores a WI adjustment control program, and the CPU 52A operates according to the WI adjustment control program. That is, the microcomputer 52 of the controller 50 functions as the WI adjustment control unit 58 (see FIG. 2) by causing the CPU 52A to execute a WI adjustment control program stored in the ROM 52C, for example.

  In the CPU 52A, based on the information of the WI detected by the WI meter 46 (if the detection target is a variable X other than WI, the density, the calorific value, etc., in which WI can be indirectly acquired), the fuel gas is set to the target The flow rate of the adjustment gas for dilution mixed with the supply gas is set so as to be WI, and the flow rate adjustment unit 44 is controlled.

  In this embodiment, the WI adjustment control is executed using the general-purpose microcomputer 52, but it is realized by a hardware configuration such as a dedicated device such as an ASIC (Application Specific Integrated Circuit) or a programmable logic device. Alternatively, it may be realized by a combination of a plurality of types of hardware configurations.

In the present embodiment, as an example, the set target value WIs of the mixed gas WI is set to 50 MJ / Nm ³ that is equal to or less than the estimated fluctuation range of the supplied gas WI and deviates from the WI range of the city gas 13A group. (See FIG. 4A).

  The set target value WIs may be the minimum value WImin of the estimated fluctuation range of the supply gas WI (WIs ← WImin), or may be a value WImin + β obtained by adding a predetermined negative error β to the minimum value WImin ( WIs ← WImin + β, β is a negative number). The minus error β is set to make the WI adjustment control one direction of dilution in addition to the allowable error of the fluctuation range of the supply gas WI.

  Hereinafter, the operation of the present embodiment will be described with reference to the flowchart of FIG.

  FIG. 7 is a flowchart showing a WI adjustment (dilution) control routine executed by the WI adjustment control unit 58. This processing of the WI adjustment control unit 58 indicates that it is processed as a WI adjustment control program executed by the CPU 52A of the versatile microcomputer 52. A device incorporating a dedicated logic such as an ASIC may be applied as the WI adjustment control unit 58.

  First, as an initial setting, in step 200, the minimum value WImin of the allowable fluctuation range of WI is acquired from the gas type of the supply gas, and the process proceeds to step 202. In step 202, the set target value WIs is set to the minimum value WImin acquired in step 200 (WIs ← WImin), and the process proceeds to step 204. The set target value WIs may be a value WImin + β obtained by adding a predetermined minus error β to the minimum value WImin (WIs ← WImin + β). In step 204, the initial setting is completed by storing WIs, and the process proceeds to step 206.

  Note that the initial settings in steps 200 to 204 are not essential, and the process may be started from step 206 in a state where the set target value WIs has already been stored.

  In step 206, it is determined whether or not supply of supply gas has started, that is, whether or not LNG is sent out from the LNG tank 14 and vaporization by the vaporizer 20 is started and supply gas is generated. Wait until When an affirmative determination is made at step 206, the routine proceeds to step 208 where the WI meter 46 detects the WI of the supply gas.

  When a detector (X / M) other than the WI meter 46 is used, a WI can be obtained by reading a conversion table stored in advance after detecting a detection target (for example, density, calorific value, etc.). Good.

  In the next step 210, the preset target value WIs stored in advance is read out, and then the process proceeds to step 212 to calculate the difference ΔWI between the set target value WIs and the detected value WI (ΔWI = WI−WIs). In this embodiment, since detected value> set target value WIs, the difference ΔWI is always a positive number. On the other hand, when the difference ΔWI is a negative number, an error may be issued because a certain error (system error, deviation from the WI allowable range of the supply gas, etc.) is considered.

  At the same time as the alarm, it is determined whether or not to stop the operation of the system depending on the degree of the difference ΔWI value, and the difference ΔWI is a very small negative number. If a program for setting ΔWI (negative number) to “0” is incorporated, the system can continue to operate.

  In the next step 214, the flow rate of the adjustment gas for dilution is determined based on the difference ΔWI calculated in step 212, and then the flow proceeds to step 216 to control the flow rate adjustment unit 44 to control the adjustment gas for dilution. The flow rate of (for example, air) is adjusted. The adjusted adjustment gas for dilution is sent to the mixer 42.

  As a result, the WI value of the fuel gas is maintained at the set target value WIs and sent to the combustion facility 12.

  In the next step 218, it is determined whether or not the supply has been completed. If a negative determination is made, the process returns to step 208 and the above steps are repeated. If the determination at step 218 is affirmative, this routine ends.

  Below, the operation management control burden for suppressing the fluctuation | variation of WI in this Embodiment is verified (refer FIG. 8).

The target value WIs to be set is set to 50.0 (MJ / Nm ³ ) with respect to fluctuations in WI of the supply gas (seven types of supply gas A to supply gas G illustrated here: see FIG. 3).

  Air is used as the adjustment gas for dilution, and dilution is performed according to the detection value WI.

As shown in FIG. 8A, the mixing ratio of air necessary for the various supply gases of the supply gas A to the supply gas G to reach the set target value WIs of 50.0 (MJ / Nm ³ ), Comparing the total calorific value and specific gravity of the mixed gas (fuel gas), it can be seen that the higher the air dilution ratio, the higher the total calorific value and specific gravity of the mixed gas (fuel gas).

  Further, as shown in FIG. 8B, for example, when the supply gas F is supplied, the gas flow rate is set by adjusting the opening of the fuel gas adjustment valve 38, and the combustion amount Ip of the combustor 30 becomes 125 kW. In such a case, the flow rate of the fuel gas (mixed gas) required to achieve the combustion amount Ip = 125 kW in the supply gas other than the supply gas F is different. Even if it is constant (the opening degree set when the supply gas F is supplied), the flow rate of the actually flowing fuel gas (mixed gas) also changes in the same manner as the required flow rate of the fuel gas (mixed gas), and the fuel gas at a substantially required flow rate. Since (mixed gas) flows, the combustion amount Ip = 125 kW is maintained even if the WI of the supply gas varies.

  Further, as shown in FIG. 8C, for example, when supplying the supply gas F, the opening degree of the air regulating valve 40 is adjusted so that the combustion air flow rate is set to a combustion air ratio λ of 1.2. In this case, the flow rate of combustion air required for the combustion air ratio λ to be 1.2 in the supply gas other than the supply gas F is different, but the flow rate of combustion air supplied from the blower is constant (set when the supply gas F is supplied). Even when the operation is performed in a flow rate state, the diluted air previously mixed with the supply gas is also used for combustion according to the WI of the supply gas. The set value (combustion air ratio λ = 1.2) is substantially constant.

  (Characteristic when WI adjustment control is dilution control)

  As shown in FIG. 9A, when the WI of the supply gas varies, the theoretical air amount A necessary for combustion varies. At this time, by performing the WI adjustment control according to the present embodiment (one-way control by the dilution gas (for example, air)), combustion with a constant air ratio is continued regardless of the fluctuation state of the WI of the supply gas. .

  In general, the combustion air ratio λ is set to an appropriate value in consideration of CO (monocarbon) emission and thermal efficiency. That is, the CO (monocarbon) emission is suppressed within an allowable range (close to 0), and the combustion air ratio λ is set to a sufficiently low value to minimize exhaust gas loss (FIG. 9B ))

  Here, as shown in FIG. 10A, a case is considered in which a WI fluctuation exceeding the assumption occurs with respect to a normally assumed WI fluctuation state (same as FIG. 4A).

  First, as a comparative example, when the WI adjustment control is only the heat increase control, if the WI is higher than expected, it cannot be diluted, so the fuel gas equal to or higher than the set target value WIs is supplied. At this time, since the theoretical air amount A of the fuel gas increases, the combustion air ratio λ decreases, and there is a possibility that the risk of incomplete combustion (CO increase) due to air shortage increases (leftward in FIG. 9B). (See arrow A). For this reason, for example, it is necessary to perform control such as expanding the assumed WI fluctuation range.

  On the other hand, when the WI adjustment control is only the dilution control as in the present embodiment, the heat increase control cannot be performed when the WI is less than the expected WI. (Refer to the dotted line circled region in FIG. 10B).

  At this time, since the theoretical air amount A of the fuel gas decreases, the combustion air ratio λ increases (see the right-pointing arrow B in FIG. 9B). However, as shown in FIG. 9B, since the combustion air ratio changes within a range in which the CO emission performance is ensured (exhaust CO is sufficiently suppressed), the risk of CO increase can be avoided. Become.

  That is, the adjustment gas for dilution according to the present embodiment is used for reducing WI for controlling to the target value of WI, and also for supplementing combustion air supplied to the combustor 30 of the combustion facility 12. Therefore, it is not necessary to take measures for improving incomplete combustion separately.

  As described above, in the present embodiment, it is possible to reduce the operation management control burden for suppressing fluctuations in WI.

  Further, according to the present embodiment, the set target value WIs of the mixed gas WI is set to the minimum value WImin of the fluctuation range of the supply gas WI, or the value WImin + β obtained by adding the predetermined negative error β to the minimum value WImin. did. For this reason, when the WI of the supply gas that fluctuates within the allowable range is controlled to the set target value WIs, it is only necessary to provide equipment for diluting and mixing the dilution gas (for example, air) into the mixed gas. In other words, since the facility for mixing the adjustment gas for increasing the heat with the mixed gas is unnecessary, the facility for controlling the WI is compared with the case where the WI is controlled to be constant by the intermediate value of the fluctuation range of the WI of the mixed gas. It can be simplified.

  (Modification common to the present embodiment)

  Below, the modification which can be applied in this Embodiment is shown.

  "Modification 1 (WI meter 46 configuration)"

  Modification 1 has a configuration in which the arrangement position of the WI meter 46 is different. FIG. 11A illustrates an application example (basic configuration) in this embodiment.

  With respect to this basic configuration, a WI meter 46 may be arranged on the upstream side of the mixer 42 as shown in FIG. In this case, the WI meter 46 may be left on the downstream side of the mixer 42 and the WI may be detected upstream and downstream of the mixer 42.

  Further, as shown in FIG. 11C, a bypass pipe 28A may be provided in the pipe 28 on the downstream side of the mixer 42, and a WI meter 46 may be provided in the bypass pipe 28A.

  Furthermore, as shown in FIG. 11D, a bypass pipe 22A may be provided in the pipe 22 on the upstream side of the mixer 42, and a WI meter 46 may be provided in the bypass pipe 22A. In this case, the bypass pipe 28 </ b> A and the WI meter 46 may be left on the downstream side of the mixer 42, and WI may be detected upstream and downstream of the mixer 42.

  "Modification 2 (Additional configuration of buffer)"

  The second modification is a configuration in which a buffer for mitigating and absorbing excessive property fluctuations of gas (mixed gas and / or fuel gas) is provided in the piping system. FIG. 12A shows an application example (a configuration without a buffer) in this embodiment.

  As shown in FIG. 12 (B), a buffer 60 may be provided on the downstream side of the mixer 42 (and further on the downstream side of the WI meter 46) for this bufferless configuration.

  Further, as shown in FIG. 12C, a buffer 62 may be provided in the pipe 22 on the upstream side of the mixer 42.

  Further, as shown in FIG. 12D, a buffer 60 may be provided in the pipe 28 on the downstream side of the mixer 42, and a buffer 62 may be provided in the pipe 22 on the upstream side of the mixer 42.

  Each of the buffers 60 and 62 may be a container or the like that functions as a buffer device that relaxes and absorbs excessive property fluctuations of gas.

  "Modification 3 (Installation location of fuel gas adjusting device 24 and its peripheral devices)"

  In the present embodiment, the case where the fuel gas adjusting device 24 (and the device of the carburetor 20) is installed in the satellite base 10 is shown. That is, the LNG is transported to the LNG tank 14 of the satellite base 10 by the lorry 16 and supplied to the combustor 30 (gas consumer) of the combustion facility 12 provided in the satellite base 10.

  On the other hand, in the third modification, the fuel gas adjusting device 24 and its peripheral devices are installed at the transport source that stores the raw material before adjustment, and the fuel gas that has been adjusted at the transport source is passed through the gas conduit. In this mode, the fuel is supplied to the remote combustion facility 12.

  FIG. 13 is a schematic diagram of the peripheral equipment of the fuel gas adjusting device 24 according to the third modification.

  The base of the fuel gas adjusting device 24 is installed in a harbor area 72 where the LNG tanker 70 arrives and departs.

  When the LNG tanker 70 loaded with LNG arrives at the port 72A of the port area 72, a pipe 75 (FIG. 13) is detachable between the transport tank 70T of the LNG tanker 70 and the LNG storage tank 74 installed at the port 72A. Then, the connection is shown by a dotted arrow.

  Thereby, the LNG in the transport tank 70T is transferred to the storage tank 74 and stored. In addition, although a base (installation place of the storage tank 74) is not limited to the port area | region 72, the LNG tank 14 (refer FIG. 1) in a satellite base is the limitation of the amount of storage and the gas customer destination to supply. The difference between the above and other conditions makes a clear difference.

  The storage tank 74 and the fuel gas adjusting device 24 are connected by a pipe 18. For this reason, the LNG stored in the storage tank 74 is supplied to the fuel gas adjusting device 24 via the pipe 18.

  The fuel gas adjusting device 24, the vaporizer 20, a pipe 22 for vaporizing the supply gas to the fuel gas adjusting device 24, and a pipe 26 for supplying the adjusting gas (dilution gas) to the fuel gas adjusting device 24 The configuration of is the same as the first embodiment and the second embodiment. For this reason, in the modification 3, detailed description of each component for WI adjustment control centering on the fuel gas adjustment apparatus 24 is abbreviate | omitted.

  The equipment of Modification 3 shown in FIG. 13 can be applied to the above-described embodiment (WI adjustment control by dilution) (the same applies to Modification 1 and Modification 2).

  FIG. 14 is a schematic diagram of the fuel gas adjusting device 24 that executes WI adjustment control (this embodiment) using the adjustment gas for dilution in the third modification.

  The fuel gas adjusting device 24 in the third modification has the same configuration as the fuel gas adjusting device 24 described in the present embodiment, and the different configuration is the fuel gas after the WI is adjusted from the fuel gas adjusting device 24. The gas conduit 76 is connected to the outlet.

  In the third modification, fuel gas is supplied to the combustion facility 12 (see FIG. 13) in which no satellite base exists. In other words, LNG is vaporized in the port area 72 immediately after being discharged from the storage tank 74, and supplied to the target combustion facility 12 through the gas conduit 76.

  FIG. 15 is a flowchart when executing WI adjustment control by dilution according to the present embodiment in the third modification. The same steps as those in FIG. 7 (the present embodiment) are denoted by the same step numbers.

  First, as an initial setting, in step 200A, the minimum value WImin of the estimated fluctuation range allowed for WI is acquired from the gas type of LNG as the raw material, and the routine proceeds to step 202. In step 202, the set target value WIs is set to the minimum value WImin acquired in step 200A (WIs ← WImin), and the process proceeds to step 204. The set target value WIs may be a value WImin + β obtained by adding a predetermined minus error β to the minimum value WImin (WIs ← WImin + β). In step 204, the initial setting is completed by storing WIs, and the process proceeds to step 206.

  Note that the initial settings in steps 200A to 204 are not essential, and the processing may be started from step 206 in a state where the set target value WIs has already been stored.

  In step 206, it is determined whether or not supply of supply gas has started, that is, whether or not LNG is sent out from the LNG tank 14 and vaporization by the vaporizer 20 is started and supply gas is generated. Wait until When an affirmative determination is made at step 206, the routine proceeds to step 208 where the WI meter 46 detects the WI of the supply gas.

  When a detector (X / M) other than the WI meter is used, a WI can be obtained by reading a conversion table stored in advance after detecting a detection target (for example, density, calorific value, etc.). .

  In the next step 210, the preset target value WIs stored in advance is read out, and then the process proceeds to step 212 to calculate the difference ΔWI between the set target value WIs and the detected value WI (ΔWI = WI−WIs). In the modified example 3, since the detection value> the set target value WIs, the difference ΔWI is always a positive number. On the other hand, when the difference ΔWI is a negative number, an error may be issued because a certain error (system error, deviation from the WI allowable range of the supply gas, etc.) is considered.

  At the same time as the alarm, it is determined whether or not to stop the system operation according to the degree of the difference ΔWI value. If the difference ΔWI is a very small negative number and the system operation is continued, If a program for setting a certain difference ΔWI (negative number) to “0” is incorporated, the system can continue to operate.

  In the next step 214, the flow rate of the adjustment gas for dilution is determined based on the difference ΔWI calculated in step 210, and then the process proceeds to step 216 to control the flow rate adjustment unit 44 to control the adjustment gas for dilution. The flow rate of (for example, air) is adjusted. The adjusted adjustment gas for dilution is sent to the mixer 42.

  As a result, the WI value of the fuel gas is maintained at the set target value WIs and sent to the combustion facility 12.

  In the next step 218, it is determined whether or not the supply has been completed. If a negative determination is made, the process returns to step 208 and the above steps are repeated. If the determination at step 218 is affirmative, this routine ends.

  In addition, in all the forms described above (this embodiment, and Modifications 1 to 3), an odorizer for intentionally attaching an odor is attached in the middle of the gas (gas) pipeline, for example, It is preferable to detect a gas leak or the like more quickly than an odorless gas.

10 Satellite Base 12 Combustion Equipment 14 LNG Tank 16 Raleigh 18 Piping 20 Vaporizer 22 Piping 24 Fuel Gas Regulator 26 Piping (Mixing Means)
28 Piping 30 Combustor 32 Fuel gas branch pipe 34 Piping (combustion air supply means)
36 Air branch pipe (combustion air supply means)
38 Fuel gas regulating valve 40 Air regulating valve (combustion air supply means)
42 Mixer (mixing means)
42A Main inlet 42B Sub inlet 42C Outlet 44 Flow rate adjusting unit (flow rate control means)
46 WI meter (acquisition means)
50 controller (flow rate control means)
52 microcomputer 52A CPU
52B RAM
52C ROM
52D I / O (input / output unit)
52E Bus 54 User Interface (UI)
54A Operation unit (setting means)
54B Display 56 HDD (Hard Disk Drive)
58 WI adjustment controller (flow rate control means)
60 buffer 62 buffer 70 LNG tanker 70T transport tank 72 port area 72A port 74 storage tank 76 gas conduit

Claims (8)

Combustion air supply means for supplying combustion air at a flow rate based on an air ratio set on the assumption that fuel gas of a specific combustibility index is supplied to the combustor;
When the combustibility index of the fuel gas before being supplied to the combustor is higher than the specific combustibility index, it is for reduction corresponding to the difference of the combustibility index and for supplementing the combustion air Mixing means for mixing a dilution gas for dilution with fuel gas before being supplied to the combustor;
A gas regulating device. The mixing means comprises:
Setting means for setting a target value of the fuel gas combustibility index within a range from a minimum value of an estimated fluctuation range of the fuel gas combustibility index or a value obtained by subtracting a predetermined value from the minimum value;
Obtaining means for obtaining a flammability index of fuel gas before being supplied to the combustor;
Flow rate control means for controlling the flow rate of the adjustment gas for dilution mixed with the fuel gas so that the combustibility index obtained by the obtaining means becomes the target value set by the setting means;
The gas regulator according to claim 1, comprising:   The combustibility index of the fuel gas includes the component composition fluctuations of the liquid fuel that is the raw material of the fuel gas, the operating status of the vaporizer when the liquid fuel that is the raw material of the fuel gas is vaporized, or when the fuel gas is vaporized The gas regulator according to claim 1 or 2, wherein the gas regulator varies within a fluctuation range estimated from fluctuations in the component composition of the fuel gas accompanying fluctuations in the processing load. The gas regulator according to any one of claims 1 to 3,
A gas adjusting device, characterized in that it is provided in the middle of a satellite gas pipe for supplying fuel gas after vaporizing a fluid raw material supplied to and stored in satellite facilities by a supply means.   5. The gas regulator according to claim 4, wherein the supply means is a transport means including a tank lorry or a transfer means for transferring a raw material from a supply source to a satellite facility by a conduit. The gas regulator according to any one of claims 1 to 3,
A gas regulator comprising a gas supply conduit for supplying fuel gas after vaporizing a fluid raw material stored in a storage tank to a combustor. A gas regulator according to any one of claims 1 to 6,
By vaporizing the liquid fuel, a fuel gas that is before adjustment of the flammability index is generated and supplied to the gas adjustment device;
Combustion equipment comprising a combustor for combusting the fuel gas supplied by the gas regulator;
Having a gas supply system. Computer
The gas adjustment program for functioning as a control part in the gas regulator of any one of Claims 1-6.