JP7257827B2 - Calorie control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calorific value adjusting device for mixing liquefied gas for calorific value adjustment with natural gas flowing in a gas supply channel.

In the case where natural gas obtained by vaporizing liquefied natural gas (LNG) is supplied as city gas, such a calorific value adjusting device mixes natural gas with liquefied gas for calorific value adjustment and evaporates it, thereby reducing the calorific value of city gas. is adjusted to an appropriate range.
As the liquefied gas for calorie adjustment, LPG is often used, but propane, butane, etc. may also be used.

As a conventional example of such calorie adjustment, a venturi pipe connected to a gas supply path is provided, and liquefied petroleum gas as a liquefied gas for calorie adjustment is placed downstream of the throat inside the venturi pipe. There is one in which a liquefied gas supply pipe that blows out to the side is provided (see, for example, Patent Document 1).

FIG. 5 of Patent Document 1 describes that a streamlined Karman vortex reducing device is provided in correspondence with the liquefied gas supply pipe.

Japanese Patent No. 6245544

In the conventional calorific value adjusting device, since the LPG supply pipe is provided inside the venturi pipe, the overall structure is complicated because the LPG supply pipe is installed inside the venturi pipe. Due to the Karman vortices generated on the downstream side of the tube, there is a risk of damage to the inner wall of the venturi tube, etc., so periodic inspections and replacement when damaged have been necessary.
Incidentally, in Patent Document 1, although a Karman vortex reduction device is provided, it cannot eliminate the occurrence of Karman vortices, and it is considered that periodic inspection is indispensable.

The present invention has been made in view of the above-mentioned actual situation, and its object is to simplify the configuration and to omit inspection work, and to increase the range of adjustment of the flow rate of natural gas, Moreover, the object of the present invention is to provide a calorific value adjusting device capable of appropriately mixing and vaporizing liquefied gas for calorific value adjustment even if the flow rate of natural gas fluctuates.

The calorific value adjusting device of the present invention mixes natural gas flowing in a gas supply passage with liquefied gas for calorific value adjustment, and is characterized by:
Each of the plurality of mixers connected in parallel to the gas supply channel has an inlet-side gas channel whose diameter gradually decreases toward the downstream side and a diameter which gradually increases from the downstream end of the inlet-side gas channel toward the downstream side. and a liquefied gas supply port for supplying the liquefied gas in a seeping state is formed on the inner surface of the downstream end of the inlet gas flow channel. is,
for each of the plurality of mixers, a plurality of natural gas flow control units that intermittently interrupt the supply of the natural gas and adjust the supply amount of the natural gas; A plurality of liquefied gas flow control units for adjusting the supply amount are provided,
The operation control unit changes the number of the mixers used for mixing the liquefied gas among the plurality of mixers according to the target flow rate of the natural gas in the standard state. In order to make the actual flow rate of the flowing natural gas within the appropriate range and to make the total value of the flow rate of the natural gas flowing through the mixers used under the reference conditions the target flow rate, setting the mixer for supplying the natural gas and controlling the plurality of natural gas flow controllers to set a supply amount of the natural gas to be supplied to the mixer; and supplying the natural gas. The liquefied gas flow control unit is configured to supply a target amount of the liquefied gas to bring the natural gas into a target calorific value state to the mixer of the above.
Incidentally, the flow rate in the above-mentioned reference state means the flow rate when the temperature of the natural gas is set to a predetermined temperature and the pressure is set to a predetermined pressure. (1 atm) is defined as a reference state.

That is, it has an inlet-side gas flow passage whose diameter gradually decreases toward the downstream side, and an outlet-side gas flow passage whose diameter gradually increases from the downstream end of the inlet-side gas flow passage toward the downstream side. A mixer configured in such a manner that a liquefied gas supply port for supplying the liquefied gas in a state of exuding is formed on the inner surface of the downstream end of the inlet-side gas flow path is attached to the gas supply path through which the natural gas flows. The natural gas and the liquefied gas are mixed and evaporated by supplying the liquefied gas for calorific value adjustment in a state where it seeps out from the liquefied gas supply port.

A mixer having an inlet-side channel and an outlet-side channel has a liquefied gas supply port for supplying the liquefied gas for calorific value adjustment in a seeping state, which is formed in the inner surface portion of the downstream end of the inlet-side gas channel. The mixer does not have any special piping or nozzles for supplying the liquefied gas, so the structure is simple, and Karman vortices are generated inside the mixer. Since there is no risk of damage due to occurrence, periodic inspection can be omitted.

Moreover, a plurality of mixers are connected in parallel to the gas supply passage through which the natural gas flows, and the operation control unit controls the reference flow rate of the natural gas flowing through the mixers according to the target flow rate of the natural gas in the reference state. In order to set the total value of the flow rate in the state to the target flow rate and to set the actual flow rate of the natural gas flowing through the mixer to an appropriate range, the mixer that supplies the natural gas is set among the plurality of mixers, and the mixer A plurality of natural gas flow controllers are controlled so as to set the supply amount of natural gas to be supplied, and a target amount of liquefied gas is supplied to the mixer to which the natural gas is being supplied to bring the natural gas into a target calorific value state. Since the liquefied gas flow controller is controlled to supply the liquefied gas, the flow rate adjustment range of the natural gas is widened, and even if the flow rate of the natural gas fluctuates, the liquefied gas for adjusting the calorific value can be appropriately mixed. It can be evaporated.

To explain, in a mixer in which the liquefied gas is exuded from the liquefied gas supply port, when the actual flow rate (linear velocity) of the natural gas flowing inside the mixer is within an appropriate range, the liquefied gas However, when the actual flow rate of natural gas is less than the lower limit of the appropriate range, it becomes difficult to refine the liquefied gas, and natural Gas and liquefied gas cannot be properly mixed and vaporized, and noise is generated when the actual flow rate of natural gas exceeds the upper limit of the appropriate range.

In view of such actual circumstances, the use of a single mixer reduces the flow rate adjustment range of natural gas. A device is provided, and the operation control unit sets the total value of the flow rate of the natural gas flowing through the mixer under the standard state as the target flow rate according to the target flow rate of the natural gas under the standard state, and flows through the mixer. In order to keep the actual flow rate of the natural gas to be within the appropriate range, a plurality of flow control units are controlled so as to set the mixer that supplies the natural gas among the plurality of mixers, so the natural gas flow rate adjustment The range can be increased, and the liquefied gas for calorific value adjustment can be appropriately mixed and evaporated.

In other words, by changing the number of mixers used for mixing liquefied gas out of the plurality of mixers according to fluctuations in the target flow rate of natural gas, it is possible to widen the flow rate adjustment range of natural gas. Moreover, since the actual flow rate of the natural gas flowing through the mixer is within an appropriate range, even if the flow rate of the natural gas fluctuates, the liquefied gas for calorific value adjustment can be appropriately mixed and vaporized.

Then, the operation control unit controls the liquefied gas flow control unit so as to supply a target amount of liquefied gas that brings the natural gas into a target calorific value state to the mixer that supplies the natural gas. The target amount of liquefied gas can be mixed with the natural gas to adjust the natural gas to the target calorific value.

In short, according to the calorific value adjusting device of the present invention, it is possible to simplify the configuration and omit the inspection work, furthermore, widen the flow rate adjustment range of the natural gas, and moreover, the flow rate of the natural gas does not fluctuate. However, the liquefied gas for adjusting the calorific value can be appropriately mixed and evaporated.

A further characteristic configuration of the calorific value adjusting device of the present invention is that, when the target flow rate is increased, the operation control unit controls the natural gas to the mixer that is being supplied to achieve the target flow rate. By increasing the supply amount of the mixer, the actual flow rate of the natural gas flowing through the mixer exceeds the upper limit of the appropriate range , and it is determined that it is necessary to increase the number of the mixers that supply the natural gas. When
First, the natural gas is supplied to the mixer so that the actual flow rate of the natural gas flowing through the mixer becomes a supply amount corresponding to the upper limit of the appropriate range, and the natural gas is supplied to the target flow rate. performing an initial adjustment process for increasing supply of the total amount of the liquefied gas to be supplied to the mixer in which the actual flow rate of the natural gas is the upper limit of the appropriate range;
Next, the amount of natural gas supplied to the mixer whose actual flow rate has reached the upper limit of the appropriate range is reduced, and the natural gas supply to the mixer is newly started to be supplied. Execute increase/decrease adjustment processing for increasing the amount of gas supply,
After that, when the supply amount of the natural gas in the mixer that decreases the supply amount of the natural gas and the supply amount of the natural gas in the mixer that increases the supply amount of the natural gas become the same, The liquefied gas supplied to the natural gas at the target flow rate is divided and supplied to the mixer in which the supply amount of the natural gas is reduced and the mixer in which the supply amount of the natural gas is increased. Execute gas division supply processing,
After that, the total value of the supply amounts of the natural gas flowing through the mixer in which the natural gas supply amount is decreased and the mixer in which the natural gas supply amount is increased is set to the target value. an increasing late adjustment for increasing the supply of said natural gas supplied to said mixer with a reduced supply of said natural gas and said mixer with an increased supply of said natural gas so as to achieve a flow rate; The point is to execute the process.

That is, when the target flow rate is increased, by increasing the amount of natural gas supplied to the mixer that is being supplied with natural gas in order to achieve the target flow rate, the actual flow rate of natural gas flowing through the mixer increases. When the upper limit of the proper range is exceeded, the number of mixers that supply natural gas is increased. In addition, by sequentially executing the increasing late adjustment processing, it is possible to adjust the flow rate of the natural gas at the target flow rate while maintaining the state of mixing and evaporating the natural gas and the liquefied gas in a predetermined manner.

To explain, in the initial adjustment process for increasing, natural gas is supplied to the mixer so that the actual flow rate of natural gas flowing through the mixer during supply of natural gas becomes the supply amount corresponding to the upper limit of the appropriate range. and the total amount of liquefied gas to be supplied to the target flow rate of natural gas is supplied to a mixer in which the actual flow rate of natural gas is the upper limit of the appropriate range, thereby mixing natural gas and liquefied gas as prescribed. The flow rate of the natural gas is increased while maintaining the vaporization state, and the total amount of liquefied gas supplied to the target flow rate of natural gas is supplied to the natural gas.

In the increase/decrease adjustment process for increasing, the amount of natural gas supplied to the mixer whose actual flow rate has reached the upper limit of the appropriate range is reduced, and natural gas is newly supplied to the mixer. By increasing the amount of supply, new natural gas is supplied while continuing to supply natural gas with an actual flow rate within an appropriate range to a mixer to which natural gas is continuously supplied. Natural gas is supplied to the mixer so that the actual flow rate is within the appropriate range.

In the liquefied gas split supply process, the liquefied gas to be supplied to the target flow rate of natural gas is supplied to the mixers that continue to supply natural gas and to the mixers that have newly entered the state of supplying natural gas. Divide and supply.
In this state, the mixers that continue to supply natural gas and the mixers that newly supply natural gas are supplied with natural gas whose actual flow rate is in the appropriate range. The gas and the liquefied gas can be mixed as prescribed and vaporized.

Incidentally, for example, if the number of mixers that continue to supply natural gas is the same as the number of mixers that have newly entered the state of supplying natural gas, the liquefaction unit that supplies natural gas at the target flow rate is the same. The gas will be split in equal amounts between the mixers that continue to supply natural gas and the mixers that are now ready to supply natural gas.

In the late adjustment process for increasing, a mixer with a reduced supply of natural gas (in other words, a mixer that continues to supply natural gas) and a mixer with an increased supply of natural gas (in other words, a mixer that continues to supply natural gas) For example, a mixer that has newly started supplying natural gas) and a mixer that has reduced the supply amount of natural gas so that the total value of the supply amount in the standard state of natural gas flowing through it becomes the target flow rate. By increasing the supply amount of natural gas supplied to the mixer in which the supply amount of natural gas is increased, natural gas and liquefied gas are mixed in a predetermined manner and maintained in a state of vaporization, while maintaining the target flow rate of natural gas. It is necessary to adjust the condition so that the gas can flow.

In short, according to a further characteristic configuration of the calorific value adjusting device of the present invention, when the target flow rate is increased, even when increasing the number of mixers that supply natural gas, the natural gas and the liquefied gas are The target flow rate of natural gas can be adjusted to flow while maintaining the conditions for proper mixing and vaporization.

A further characteristic configuration of the calorific value adjusting device of the present invention is that, when the target flow rate is reduced, the operation control unit controls the natural flow rate for the plurality of mixers that supply the liquefied gas to achieve the target flow rate. By reducing the amount of gas supplied, the actual flow rate of the natural gas flowing through the mixer falls below the lower limit of the appropriate range, and the number of mixers supplying the natural gas needs to be reduced. When it is determined that
First, the total amount of the liquefied gas to be supplied to the natural gas at the target flow rate is supplied to the mixer to which the supply of the natural gas is continued, and the liquefaction to the mixer to which the supply of the natural gas is stopped. Execute the initial adjustment process for reduction to stop the gas supply,
After that, adjusting the supply amount of the natural gas to the mixer that continues to supply the liquefied gas to the target flow rate, and stopping the supply of the natural gas to the mixer that stops the supply of the liquefied gas. The point is that late adjustment processing for reduction is executed.

That is, when the target flow rate is reduced, by reducing the amount of natural gas supplied to a plurality of mixers that are supplying natural gas to achieve the target flow rate, the amount of natural gas flowing through the mixer is reduced. When the actual flow rate falls below the lower limit of the appropriate range, the number of mixers that supply natural gas is reduced. At this time, the operation control unit sequentially executes the initial adjustment process for reduction and the late adjustment process for reduction. It will be.

To explain, in the initial adjustment process for reduction, the total amount of liquefied gas to be supplied to the natural gas at the target flow rate is supplied to the mixer that continues the supply of natural gas, and the mixing that stops the supply of natural gas. By stopping the supply of the liquefied gas to the vessel, the mixture of the natural gas and the liquefied gas is maintained in a predetermined mixing and vaporizing state by the mixer continuing the supply of the natural gas.

In the late adjustment process for reduction, the supply of natural gas to the mixer that continues to supply liquefied gas is adjusted to the target flow rate, and the supply of natural gas to the mixer that stops the supply of liquefied gas is stopped. As a result, the natural gas and the liquefied gas are mixed in a predetermined manner by the mixer that continues to supply the natural gas, and the target flow rate of the natural gas is adjusted to flow.

In short, according to a further characteristic configuration of the calorific value adjusting device of the present invention, when the target flow rate is reduced, even when the number of mixers that supply natural gas is reduced, natural gas and liquefied gas are mixed in a predetermined manner. The target flow rate of natural gas can be adjusted to flow while maintaining the conditions for proper mixing and vaporization.

A further characteristic configuration of the calorific value adjusting apparatus of the present invention is that the operation control unit, after executing the initial adjustment process for reduction, controls the supply amount for purge to the mixer that stops the supply of the natural gas. The natural gas in an amount obtained by subtracting the purge supply amount from the supply amount of the natural gas corresponding to the target flow rate to the mixer that supplies the natural gas and continues to supply the natural gas. Execute the purge process that continues the supply state for the set time,
After that, the later adjustment processing for reduction is executed.

That is, when the target flow rate is reduced and the number of mixers supplying natural gas is reduced, the operation control unit executes the initial adjustment process for reduction, then executes the purge process, and then The late adjustment process for reduction is executed.

In the purging process, the natural gas corresponding to the target flow rate is supplied to the mixer to which the supply of natural gas is stopped, and the natural gas corresponding to the target flow rate is supplied to the mixer to which the supply of natural gas is continued. The amount of natural gas supplied by subtracting the supply amount for purging from the gas supply amount will be continued for a set period of time. will flow the liquefied gas downstream of the mixer with a purge supply of natural gas.

In addition, since the liquefied gas for calorie adjustment has a higher specific gravity than natural gas, part of the liquefied gas supplied to the mixer may remain at the bottom of the mixer.
Then, when the supply of natural gas to the mixer is started while the liquefied gas remains at the bottom of the mixer, the liquefied gas accumulated at the bottom flows to the downstream side of the mixer at once, and the mixer The calorific value of the natural gas downstream of is likely to deviate significantly from the target calorific state.

Therefore, after executing the initial adjustment process for reduction, the purging process is executed, and then the late adjustment process for reduction is executed, so that the natural gas remains at the bottom of the mixer where the supply of natural gas is stopped. liquefied gas is flowed downstream of the mixer with a purge supply of natural gas and then the supply of natural gas is stopped. It is possible to suppress the liquefied gas from remaining at the bottom of the mixer.

In short, according to the further characteristic configuration of the calorific value adjusting device of the present invention, it is possible to prevent the liquefied gas from stagnating at the bottom of the mixer where the supply of natural gas is stopped.

A further characteristic configuration of the calorific value adjusting device of the present invention is that a natural gas heating section is provided for heating the natural gas supplied to the mixer.

That is, in winter or in cold regions, when natural gas is mixed with liquefied gas, the amount of heat required to evaporate the liquefied gas may be insufficient. By heating, the natural gas can retain the amount of heat that evaporates the liquefied gas.

Therefore, even in winter or in cold regions, when the liquefied gas is mixed with the natural gas, the liquefied gas can be appropriately vaporized by the amount of heat retained in the natural gas.

In short, according to the further characteristic configuration of the calorific value adjusting device of the present invention, when the liquefied gas is mixed with the natural gas, the liquefied gas can be vaporized appropriately.

A further characteristic configuration of the calorific value adjusting device of the present invention is that a liquefied gas heating section for heating the liquefied gas supplied to the mixer is provided.

That is, in winter or in cold regions, when natural gas is mixed with liquefied gas, the amount of heat required to evaporate the liquefied gas may be insufficient. By heating, the liquefied gas can be heated in advance to a state in which it is easy to evaporate.

Therefore, even in winter or in cold regions, when the natural gas is mixed with the liquefied gas, the preheated liquefied gas can be properly evaporated.

In short, according to the further characteristic configuration of the calorific value adjusting device of the present invention, when the liquefied gas is mixed with the natural gas, the liquefied gas can be vaporized appropriately.

A further characteristic configuration of the calorific value adjusting device of the present invention is recovery by flowing the liquefied gas stagnating at the bottom of a liquefied gas supply unit that stores the liquefied gas supplied in a state of exuding from the liquefied gas supply port into a recovery tank. A path, an on-off valve for opening and closing the recovery path, and a transfer section for transferring the liquefied gas recovered in the recovery tank to a plurality of the liquefied gas supply ports are provided.

That is, in a state in which the supply of natural gas to the mixer is stopped, if the liquefied gas remains at the bottom of the liquefied gas supply section, the liquefied gas evaporates and flows out from the liquefied gas supply port, causing the inlet side There is a risk that the inside of the gas flow path and the outlet side gas flow path will be filled with the evaporated liquefied gas.
Then, when the supply of natural gas to the mixer is started while the vaporized liquefied gas fills the interior of the inlet-side gas flow path and the outlet-side gas flow path, the natural gas on the downstream side of the mixer There is a possibility that the amount of heat in the state deviates greatly from the target amount of heat.

According to this characteristic configuration, when the supply of natural gas to the mixer is stopped, the on-off valve that opens and closes the recovery path is opened, and the liquefied gas remaining at the bottom of the liquefied gas supply unit is discharged to the recovery tank through the recovery path. Since the liquefied gas can be recovered, it is possible to avoid a state in which the liquefied gas stays at the bottom of the liquefied gas supply unit.
Incidentally, when supplying natural gas to the mixer, the liquefied gas inside the liquefied gas supply unit is prevented from flowing to the recovery tank by closing the on-off valve that opens and closes the recovery path.

Further, since a conveying unit is provided for conveying the liquefied gas collected in the collection tank to the plurality of liquefied gas supply ports, when supplying the natural gas to the mixer, the liquefied gas collected in the collection tank can be supplied to the plurality of liquefied gas supply ports. By transporting the liquefied gas to the liquefied gas supply port, the liquefied gas recovered in the recovery tank can be used favorably as the liquefied gas for adjusting the calorific value.

In short, according to the further characteristic configuration of the calorific value adjusting device of the present invention, it is possible to avoid the liquefied gas from remaining at the bottom of the mixer, and the liquefied gas recovered in the recovery tank is used for calorific value adjustment. It can be used well as a liquefied gas.

It is a circuit diagram which shows a heat quantity adjustment apparatus. It is a longitudinal side view of a mixer. It is a block diagram which shows a control structure. It is a flow chart which shows increase processing. It is a flowchart which shows a reduction process. It is a circuit diagram which shows the heat quantity adjustment apparatus of another embodiment. It is a circuit diagram which shows the calorie|heat amount adjustment apparatus of further another embodiment.

[Embodiment]
BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
(Overall configuration of calorie adjusting device)
As shown in FIG. 1, the calorific value adjusting device is configured to mix natural gas obtained by vaporizing liquefied natural gas (LNG) with LPG as liquefied gas for calorific value adjustment. A plurality of mixers M are connected in parallel to a gas supply line 1 through which gas flows, and the natural gas from the mixers M whose calorific value has been adjusted is supplied to a consumption part through a combined line 2 as, for example, city gas. is configured as

The mixers M can be implemented in a form in which three or more are provided, but in this embodiment, a case where two mixers M are provided will be described.
That is, a pair of branch passages 3 are provided between the gas supply passage 1 and the combined passage 2, and a mixer M is provided in each of the branch passages 3. As shown in FIG.

As shown in FIG. 2, the mixer M has an inlet-side gas flow path R1 whose diameter gradually decreases toward the downstream side, and an outlet-side gas flow path R1 whose diameter gradually increases toward the downstream side from the downstream end of the inlet-side gas flow path R1. A liquefied gas supply port 4 which is provided with a gas flow path R2 and which supplies LPG in a oozing state is formed in a state of being aligned along the circumferential direction on the inner surface portion of the downstream end of the inlet gas flow path R1. configured in form.
More specifically, an annular liquefied gas supply section 4A to which LPG is supplied is provided so as to surround the connecting portion between the inlet-side gas flow path R1 and the outlet-side gas flow path R2. The LPG is supplied in a state where it seeps out from the liquefied gas supply port 4 .

As shown in FIG. 1, the gas supply path 1 is provided with an upstream calorific value sensor 5A for measuring the calorific value of the natural gas, and the combined channel 2 is provided with a calorific value-adjusted natural gas mixed with LPG. A downstream calorific value sensor 5B for measuring the calorific value and a flow rate sensor 6 for detecting the flow rate of the calorific value-adjusted natural gas in the standard state are provided.
Incidentally, the flow rate in the reference state means the flow rate when the temperature of the natural gas is set to a predetermined temperature and the pressure is set to a predetermined pressure. A state of atmospheric pressure (1 atm) is taken as a reference state.

On the upstream side of the mixer M in each of the pair of branch passages 3, there are a mixer flow sensor 7 for detecting the flow rate of the natural gas flowing in the branch passages 3 in a reference state, and the temperature of the natural gas flowing in the branch passages 3. and a pressure sensor 9 for measuring the pressure of the natural gas flowing through the branch 3 are provided.

Further, at the upstream side of the mixer M in each of the pair of branch passages 3, a natural gas supply intermittence valve 10 for intermitting supply of natural gas to the mixer M and a natural gas supply amount to the mixer M are provided. A regulating natural gas feed rate regulating valve 11 is provided.
Incidentally, the natural gas supply intermittence valve 10 and the natural gas supply amount adjustment valve 11 constitute a natural gas flow control section F that intermittently interrupts the supply of natural gas and adjusts the amount of natural gas supply.

A pair of liquefied gas supply passages 12 for supplying LPG to the liquefied gas supply port 4 (liquefied gas supply section 4A) of each mixer M is provided. An LPG flow rate sensor 13 is provided for detecting the flow rate of .

Further, each liquefied gas supply path 12 is provided with an LPG supply intermittence valve 14 for intermitting LPG supply to the mixer M, and an LPG flow control valve 15 for adjusting the amount of LPG supplied to the mixer M. ing.
Incidentally, the LPG supply intermittence valve 14 and the LPG flow control valve 15 constitute a liquefied gas flow controller G that intermittently interrupts the supply of LPG and adjusts the amount of LPG supplied.

(control configuration)
As shown in FIG. 3, an operation control unit H for controlling the natural gas flow control unit F and the liquefied gas flow control unit G is provided. It is configured to be commanded from the integrated control unit K.
In other words, the integrated control unit K instructs the operation control unit (not shown) of the natural gas vaporization supply unit (not shown) to vaporize liquefied natural gas (LNG) and supply natural gas according to the consumption of natural gas. It is configured to command a target supply amount of natural gas in the standard state, and similarly to command a target flow rate of natural gas in the standard state to the operation control unit H of the calorific value adjusting device.

Then, the operation control unit H sets the total value of the flow rates of the natural gas flowing through the mixer M under the reference conditions as the target flow rate according to the target flow rate of the natural gas under the reference conditions, and sets the natural gas flowing through the mixer M to the target flow rate. In order to keep the actual flow rate of the gas in an appropriate range, the mixer M for supplying natural gas is set among the plurality of mixers M, and a plurality of natural gas generators are set so as to set the supply amount of natural gas to be supplied to the mixer M. The liquefied gas flow control unit G is controlled so as to control the gas flow control unit F and supply a target amount of LPG (liquefied gas) to bring the natural gas into a target calorific value state to the mixer M that supplies the natural gas. configured to control.

Incidentally, in this embodiment, the supply pressure for supplying natural gas to the mixer M is 3 to 8 MPaG, and the supply pressure for supplying LPG to the liquefied gas supply port 4 of the mixer M is the supply pressure for natural gas. , and the appropriate range of the actual flow rate of the natural gas flowing through the mixer M is the inlet side gas flow path R1 and the outlet side gas flow path R2 in the mixer M. For example, the linear velocity of the natural gas flowing through the connection point (the point where the cross-sectional area of the flow path is the smallest) is set in the range of 20 to 80 m/s.

That is, the operation control unit H determines an increase or decrease in the amount of natural gas supplied to the mixer M based on the commanded target flow rate and the flow rate of natural gas detected by the flow rate sensor 6, When increasing the amount of natural gas, performing an increase process for increasing the amount of natural gas supplied to the mixers M in a form that includes increasing the number of mixers M that supply natural gas, and In the case of reducing the amount of natural gas, it is configured to perform a reduction process for reducing the amount of natural gas supplied to the mixers M in a form including reducing the number of mixers M that supply natural gas. It is
Although the increase processing and decrease processing will be described later, the operation control unit H repeatedly executes the increase processing and decrease processing.

Further, the operation control unit H obtains the target amount of LPG to be supplied to bring the natural gas into the target calorie state based on the calorific value of the natural gas detected by the upstream calorific value sensor 5A and the commanded target flow rate. Then, the liquefied gas flow controller G is controlled to supply the obtained target amount of LPG, and the target amount of LPG is corrected based on the calorie of the natural gas detected by the downstream heat sensor 5B. It is configured to perform an LPG supply process.

That is, the operation control unit H obtains the unit amount of LPG required to bring the unit amount of natural gas into the target calorific value state based on the calorific value of the natural gas detected by the upstream calorific value sensor 5A. The target amount of LPG is obtained based on the obtained unit amount of LPG and the commanded target flow rate.
Then, the operation control unit H adjusts the LPG flow rate adjustment valve 15 so that the information detected by the mixer flow rate sensor 7 becomes the obtained target amount of LPG. If the calorie-adjusted calorie of the natural gas deviates from the target calorie state based on the calorie of the natural gas, the target calorie of the LPG is corrected.

Incidentally, when natural gas is supplied to two mixers M, the target amount of LPG is divided and a divided target amount is assigned to each mixer M. The LPG flow rate control valve 15 provided for each mixer M is adjusted so that the detected value of the mixer flow rate sensor 7 becomes the divided target amount.

In addition, when executing the above-described increase processing and decrease processing, the operation control unit H changes the number of mixers M to which natural gas is supplied. It is configured to control the liquefied gas flow controller G even in the increase process and the decrease process, such as stopping the supply of LPG.

(Details of increase processing)
As shown in FIG. 4, in the increase process, first, the instructed target flow rate and the natural gas flow rate detected by the flow sensor 6 are compared to determine the amount of natural gas to be supplied to the mixer M. Determine whether or not it is necessary to increase (#1).
When it is determined in the process #1 that there is no need to increase the supply amount of the natural gas supplied to the mixer M, another process such as a decrease process is performed.

When it is determined in the process of #1 that it is necessary to increase the amount of natural gas supplied to the mixer M, it is subsequently determined whether it is necessary to increase the number of mixers M that supply natural gas. (#2).
In other words, by increasing the amount of natural gas supplied to the mixer M that is currently supplying natural gas in order to achieve the commanded target flow rate, the actual flow rate of the natural gas flowing through the mixer M reaches the upper limit of the appropriate range. When it exceeds, it is determined that it is necessary to increase the number of mixers M for supplying natural gas, and when the actual flow rate of natural gas flowing through the mixer M does not exceed the upper limit of the appropriate range, natural gas is supplied. It is determined that there is no need to increase the number of mixers M.

Incidentally, the actual flow rate of the natural gas flowing through the mixer M is the flow rate of the natural gas in the standard state detected by the mixer flow sensor 7, the temperature of the natural gas detected by the temperature sensor 8, and the pressure It is calculated based on the pressure of the natural gas detected by the sensor 9 .

In the process of #2, when it is determined that the number of mixers M supplying natural gas does not need to be increased, the amount of natural gas supplied to the mixers M currently supplying natural gas is changed according to the instruction. A supply amount increase process is executed to increase the flow rate to the target flow rate (#3), and then other processes such as a decrease process are performed.
When the supply amount increase process is executed, the LPG supply process for adjusting the supply amount of LPG is executed in order to bring the commanded target flow rate of the natural gas to the target calorie state.

In the process of #2, when it is determined that the number of mixers M for supplying natural gas needs to be increased, the initial adjustment process for increase (#4), the increase/decrease adjustment process for increase (#5), The liquefied gas split supply process (#6) and the late adjustment process for increase (#7) are sequentially executed, and then other processes such as the decrease process are performed.

In the initial adjustment process for increase (#4), the natural gas is supplied to the mixer M so that the actual flow rate of the natural gas flowing through the mixer M during the supply of natural gas becomes a supply amount corresponding to the upper limit of the appropriate range. In addition, the process of supplying the total amount of liquefied gas supplied to the natural gas at the target flow rate to the mixer M in which the actual flow rate of the natural gas is the upper limit of the appropriate range is executed.

In the increase/decrease adjustment process for increase (#5), the amount of natural gas supplied to the mixer M in which the actual flow rate of natural gas has reached the upper limit of the appropriate range is reduced, and the supply of natural gas is newly started. Increasing the supply of natural gas to the vessel M includes reducing the supply of natural gas to the mixer M and increasing the supply of natural gas to the mixer M. are the same.

In the liquefied gas split supply process (#6), the supply amount of natural gas in the mixer M that decreases the supply amount of natural gas and the supply amount of natural gas in the mixer M that increases the supply amount of natural gas are the same. , first, the mixer M, which increases the supply amount of natural gas, is filled with a small amount of liquefied gas for a set period of time (for example, 6 minutes), and then , the liquefied gas to be supplied to the target flow rate of natural gas is divided and supplied to the mixer M in which the supply amount of natural gas is reduced and the mixer M in which the supply amount of natural gas is increased.
In this embodiment, the liquefied gas to be supplied to the target flow rate of natural gas is divided into a pair of mixers M in equal amounts.

In the late adjustment process for increasing (#7), the supply amount of natural gas flowing through the mixer M in which the supply amount of natural gas is decreased and the mixer M in which the supply amount of natural gas is increased is measured under the reference condition. A process of increasing the supply amount of natural gas supplied to the mixer M with a reduced natural gas supply amount and the mixer M with an increased natural gas supply amount so that the total value of is equal to the target flow rate. executed.

(Details of reduction processing)
As shown in FIG. 5, in the reduction process, first, the commanded target flow rate and the natural gas flow rate detected by the flow rate sensor 6 are compared to determine the amount of natural gas supplied to the mixer M. It is determined whether or not it is necessary to decrease (#11).
When it is determined in the process of #11 that the amount of natural gas supplied to the mixer M does not need to be decreased, another process such as an increase process is performed.

If it is determined in the process of #11 that the amount of natural gas supplied to the mixer M needs to be reduced, then whether or not it is necessary to reduce the number of mixers M that supply natural gas. (#12).
In other words, by reducing the amount of natural gas supplied to the mixer M that is being supplied with natural gas in order to achieve the instructed target flow rate, the actual flow rate of the natural gas flowing through the mixer M falls below the lower limit of the appropriate range. When the actual flow rate of natural gas flowing through the mixer M does not fall below the lower limit of the appropriate range (when it is above the lower limit), it is determined that it is necessary to reduce the number of mixers M supplying natural gas. , it is determined that there is no need to reduce the number of mixers M supplying natural gas.

Incidentally, the actual flow rate of the natural gas flowing through the mixer M is the flow rate of the natural gas in the standard state detected by the mixer flow sensor 7, the temperature of the natural gas detected by the temperature sensor 8, and the pressure It is calculated based on the pressure of the natural gas detected by the sensor 9 .

In the process of #12, when it is determined that the number of mixers M supplying natural gas does not need to be reduced, the amount of natural gas supplied to the mixers M currently supplying natural gas is changed according to the command. A supply amount reduction process for reducing the flow rate to the target flow rate is executed (#13), and then other processes such as an increase process are performed.
When the supply amount reduction process is executed, the LPG supply process for adjusting the supply amount of LPG is executed in order to bring the commanded target flow rate of the natural gas to the target calorie state.

In the process of #12, when it is determined that it is necessary to reduce the number of mixers M that supply natural gas, the initial adjustment process for reduction (#14), the purge process (#15) and the latter period for reduction The adjustment process (#16) is sequentially executed, and then other processes such as an increase process are performed.

In the initial adjustment process for reduction (#14), the total amount of liquefied gas to be supplied to the natural gas at the target flow rate is supplied to the mixer M that continues the supply of natural gas, and the mixing that stops the supply of natural gas. A process of stopping the supply of liquefied gas to the vessel M is executed.

In the purging process (#15), the natural gas supply amount for purging is supplied to the mixer M for which the natural gas supply is stopped, and the natural gas supply is continued for the mixer M, A process of continuing to supply natural gas in an amount obtained by subtracting the supply amount for purging from the supply amount of natural gas corresponding to the target flow rate for a set period of time is executed.

In the late adjustment process for reduction (#16), the amount of natural gas supplied to the mixer M, to which the liquefied gas continues to be supplied, is adjusted to the target flow rate, and the natural gas to the mixer M, to which the supply of liquefied gas is stopped. A process of stopping the gas supply is executed.

As described above, in the present embodiment, the natural gas is supplied to the pair of mixers M, and the natural gas is supplied to one of the pair of mixers. LPG is mixed with natural gas by maintaining the actual flow rate of natural gas supplied to the mixer M within an appropriate range in both the state of increasing the number of units to be switched and the state of decreasing the number of units to be switched from the dual supply state to the one-sided supply state. vaporization can be done appropriately.

[Another embodiment]
Next, another embodiment of the present invention will be described. Since the basic configuration of this another embodiment is the same as that of the above embodiment, the same configurations as those of the above embodiment are denoted by the same reference numerals as those of the above embodiment. and detailed description is omitted.

As shown in FIG. 6, a natural gas heating section 16 for heating the natural gas supplied to the mixer M is provided in each of the pair of branch passages 3 .
A liquefied gas heating unit 17 for heating the liquefied gas supplied to the mixer M is provided in each of the pair of liquefied gas supply paths 12 .

The natural gas heating unit 16 is configured in a heat exchange type for exchanging heat between a heat medium such as seawater and natural gas.
Similarly, the liquefied gas heating unit 17 is configured in a heat exchange type for exchanging heat between a heating medium such as seawater and the liquefied gas.

By providing the natural gas heating unit 16 and the liquefied gas heating unit 17 in this way, it is possible to appropriately evaporate LPG (liquefied gas) mixed with natural gas even in winter or in cold regions.

By the way, if both the natural gas heating section 16 and the liquefied gas heating section 17 are provided, a large amount of heat can be applied to evaporate LPG (liquefied gas). Alternatively, one of the unit 16 and the liquefied gas heating unit 17 may be provided.

[Still another embodiment]
Next, another embodiment of the present invention will be described. Since the basic configuration of this another embodiment is the same as that of the above embodiment, the same configuration as that of the above embodiment is the same as that of the above embodiment. , and detailed description thereof is omitted.
Also, in this further embodiment, since a pair of mixers M are provided with a similar configuration, one of the pair of mixers M will be described as a representative.

As shown in FIG. 7, the LPG (liquefied gas) remaining at the bottom of a liquefied gas supply section 4A that stores LPG (liquefied gas) supplied in a state exuding from the liquefied gas supply port 4 is collected by flowing it into a collection tank T. An on-off valve 19 for opening and closing the path 18 and the recovery path 18 is provided.
When the natural gas is allowed to flow into the mixer M, the on-off valve 19 is closed, and when the supply of natural gas to the mixer M is stopped, the on-off valve 19 is opened. As a result, the LPG (liquefied gas) remaining at the bottom of the liquefied gas supply section 4A is allowed to flow through the recovery path 18 and be recovered in the recovery tank T. As shown in FIG.

Further, a transfer section J is provided for transferring LPG (liquefied gas) recovered in the recovery tank T to a plurality of liquefied gas supply ports 4 .
The conveying unit J includes a conveying pump 20 for conveying LPG (liquefied gas) collected in the collection tank T, a natural gas introduction passage 21 for guiding the natural gas in the gas supply line 1 to the collection tank T as a conveying pressure medium, and , and a liquefied gas guide path 22 for guiding LPG (liquefied gas) recovered in the recovery tank T to the liquefied gas supply path 12 .

More specifically, a pump path portion 22A in which the conveying pump 20 is disposed and a detour portion 22B that bypasses the conveying pump 20 are provided in parallel at a side portion of the liquefied gas guide passage 22 adjacent to the recovery tank T. A first valve 23A for opening and closing the pump path portion 22A and a second valve 23B for opening and closing the detour portion 22B are provided.
Further, the natural gas introduction passage 21 is provided with an introduction passage opening/closing valve 24 for opening and closing the natural gas introduction passage 21 and an introduction amount adjustment valve 25 for adjusting the introduction amount of the natural gas.

Then, by operating the transport pump 20 with the introduction path opening/closing valve 24 and the second valve 23B closed and the first valve 23A open, the LPG recovered in the recovery tank T is transported to the liquefied gas supply path 12. By opening the introduction path opening/closing valve 24 and the second valve 23B and closing the first valve 23A, the LPG recovered in the recovery tank T is transferred to the liquefied gas supply path 12 under the pressure of the natural gas. It is configured to be in a natural gas delivery state for delivery to the

Therefore, when the supply of natural gas to the mixer M is stopped, the on-off valve 19 for opening and closing the recovery path 18 is opened to allow the liquefied gas remaining at the bottom of the liquefied gas supply section 4A to flow through the recovery path 18 into the recovery tank T. Therefore, it is possible to prevent the liquefied gas from stagnating at the bottom of the liquefied gas supply section 4A.
Incidentally, when the natural gas is supplied to the mixer M, the on-off valve 19 that opens and closes the recovery path 18 is closed so that the LPG (liquefied gas) inside the liquefied gas supply unit 4A does not flow into the recovery tank T. do.

Further, since a transporting part J is provided for transporting LPG (liquefied gas) recovered in the recovery tank T to the plurality of liquefied gas supply ports 4, when supplying the natural gas to the mixer M, the recovery tank T The liquefied gas recovered in the recovery tank T can be used as the liquefied gas for calorie adjustment by conveying the recovered liquefied gas to the plurality of liquefied gas supply ports 4 .

That is, when the internal pressure of the mixer M is in a high pressure state, the LPG collected in the recovery tank T can be conveyed by the conveying force of the conveying pump 20 in the pump conveying state, and the interior of the mixer M is degassed. When pressurized, it can be placed in the natural gas delivery state to deliver the recovered LPG to the recovery tank T at the pressure of the natural gas.

Incidentally, although detailed explanation is omitted, the operation control unit H executes opening/closing control of the opening/closing valve 19 and transportation control of the transportation unit J at an appropriate timing according to the heat quantity adjustment using the mixer M. become.

[Other alternative embodiments]
Other embodiments are listed below.
(1) In the above embodiment, another embodiment, and further another embodiment, the case where a pair of mixers M is provided is illustrated, but the present invention can be applied similarly even when three or more mixers M are provided. can be implemented.
For example, during times of the day when natural gas consumption is high, a target flow rate using three mixers M is commanded, and during times of day when natural gas consumption is low, only one mixer M is commanded. , the number of mixers M is determined as follows.

In the increase process, even if the state of supplying natural gas to one mixer M is switched to the state of supplying natural gas to two mixers M, the actual amount of natural gas flowing through those two mixers M is increased. Since the flow rate exceeds the upper limit of the appropriate range, it is determined that the number of mixers M supplying natural gas needs to be increased to three.
In the reduction process, even if the state of supplying natural gas to three mixers M is switched to the state of supplying natural gas to two mixers M, the actual amount of natural gas flowing through those two mixers M is reduced. Since the flow rate falls below the lower limit of the appropriate range, it is determined that the number of mixers M supplying natural gas needs to be reduced to one.

(2) In the above embodiment, another embodiment, and another embodiment, the case of supplying LPG as the liquefied gas was illustrated, but propane, butane, or the like can be used as the liquefied gas.

(3) In the above embodiment, another embodiment, and another embodiment, when the upper side heat sensor 5A and the lower side heat sensor 5B are provided, and the heat amount is adjusted by the feedforward control mode and the feedback control mode. was exemplified, but only the downstream heat sensor 5B may be provided and the heat quantity may be adjusted by a feedback control mode.

(4) In the above embodiment, another embodiment, and a further embodiment, the case of producing city gas by adjusting the calorie of natural gas was exemplified, but the calorie adjustment device of the present invention can be used for various gases other than city gas. It can also be applied when manufacturing

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

1 gas supply path 4 liquefied gas supply port 4A liquefied gas supply section 16 natural gas heating section 17 liquefied gas heating section 18 recovery path 19 on-off valve F natural gas flow control section G liquefied gas flow control section H operation control section J transfer section M Mixer R1 Inlet-side gas flow path R2 Outlet-side gas flow path

Claims (7)

A calorific value adjusting device for mixing natural gas flowing in a gas supply channel with liquefied gas for calorific value adjustment,
Each of the plurality of mixers connected in parallel to the gas supply channel has an inlet-side gas channel whose diameter gradually decreases toward the downstream side and a diameter which gradually increases from the downstream end of the inlet-side gas channel toward the downstream side. and a liquefied gas supply port for supplying the liquefied gas in a seeping state is formed on the inner surface of the downstream end of the inlet gas flow channel. is,
for each of the plurality of mixers, a plurality of natural gas flow control units that intermittently interrupt the supply of the natural gas and adjust the supply amount of the natural gas; A plurality of liquefied gas flow control units for adjusting the supply amount are provided,
The operation control unit changes the number of the mixers used for mixing the liquefied gas among the plurality of mixers according to the target flow rate of the natural gas in the standard state. In order to make the actual flow rate of the flowing natural gas within the appropriate range and to make the total value of the flow rate of the natural gas flowing through the mixers used under the reference conditions the target flow rate, setting the mixer for supplying the natural gas and controlling the plurality of natural gas flow controllers to set a supply amount of the natural gas to be supplied to the mixer; and supplying the natural gas. and a calorific value adjusting device configured to control the liquefied gas flow controller so as to supply a target quantity of the liquefied gas to bring the natural gas into a target calorific value state to the mixer of the above. When the target flow rate is increased, the operation control unit increases the supply amount of the natural gas to the mixer to which the natural gas is being supplied to achieve the target flow rate. When it is determined that the actual flow rate of the flowing natural gas exceeds the upper limit of the appropriate range and it is necessary to increase the number of the mixers that supply the natural gas ,
First, the natural gas is supplied to the mixer so that the actual flow rate of the natural gas flowing through the mixer becomes a supply amount corresponding to the upper limit of the appropriate range, and the natural gas is supplied to the target flow rate. performing an initial adjustment process for increasing supply of the total amount of the liquefied gas to be supplied to the mixer in which the actual flow rate of the natural gas is the upper limit of the appropriate range;
Next, the amount of natural gas supplied to the mixer whose actual flow rate has reached the upper limit of the appropriate range is reduced, and the natural gas supply to the mixer is newly started to be supplied. Execute increase/decrease adjustment processing for increasing the amount of gas supply,
After that, when the supply amount of the natural gas in the mixer that decreases the supply amount of the natural gas and the supply amount of the natural gas in the mixer that increases the supply amount of the natural gas become the same, The liquefied gas supplied to the natural gas at the target flow rate is divided and supplied to the mixer in which the supply amount of the natural gas is reduced and the mixer in which the supply amount of the natural gas is increased. Execute gas division supply processing,
After that, the total value of the supply amounts of the natural gas flowing through the mixer in which the natural gas supply amount is decreased and the mixer in which the natural gas supply amount is increased is set to the target value. an increasing late adjustment for increasing the supply of said natural gas supplied to said mixer with a reduced supply of said natural gas and said mixer with an increased supply of said natural gas so as to achieve a flow rate; 2. The calorific value adjusting device according to claim 1, which performs processing. When the target flow rate is reduced, the operation control unit reduces the supply amount of the natural gas to the plurality of mixers that supply the liquefied gas in order to achieve the target flow rate. When it is determined that the actual flow rate of the natural gas flowing through is below the lower limit of the appropriate range and it is necessary to reduce the number of the mixers supplying the natural gas ,
First, the total amount of the liquefied gas to be supplied to the natural gas at the target flow rate is supplied to the mixer to which the supply of the natural gas is continued, and the liquefaction to the mixer to which the supply of the natural gas is stopped. Execute the initial adjustment process for reduction to stop the gas supply,
After that, adjusting the supply amount of the natural gas to the mixer that continues to supply the liquefied gas to the target flow rate, and stopping the supply of the natural gas to the mixer that stops the supply of the liquefied gas. 3. The calorific value adjustment device according to claim 1 or 2, wherein the late adjustment process for reduction is executed. After executing the initial adjustment process for reduction, the operation control unit supplies a purge supply amount of the natural gas to the mixer for which supply of the natural gas is stopped, and supplies the natural gas to the mixer. Execution of a purge process for continuing supply of the natural gas in an amount obtained by subtracting the purge supply amount from the supply amount of the natural gas corresponding to the target flow rate to the mixer that continues to be supplied for a set period of time. death,
4. The calorific value adjustment device according to claim 3, wherein the late adjustment process for reduction is executed thereafter. The calorific value adjustment device according to any one of claims 1 to 4, further comprising a natural gas heating section for heating the natural gas supplied to the mixer. The calorific value adjusting device according to any one of claims 1 to 5, further comprising a liquefied gas heating section for heating the liquefied gas supplied to the mixer. a recovery path for flowing the liquefied gas retained at the bottom of a liquefied gas supply unit that stores the liquefied gas supplied in a state exuding from the liquefied gas supply port to a recovery tank; an on-off valve that opens and closes the recovery path; 7. The calorific value adjusting device according to any one of claims 1 to 6, further comprising a conveying unit that conveys the liquefied gas recovered in the recovery tank to a plurality of the liquefied gas supply ports.

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