JP7117599B2 - Flow measurement device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a technique for accumulating the amount of gas used by a discriminated gas appliance, and more particularly to an accumulating method when the gas appliance is a fuel cell.

2. Description of the Related Art Various gas meter devices have been proposed that identify a gas appliance that has been put into use based on changes in the flow rate of gas flowing through a pipe. A gas meter is disclosed that integrates the amount of gas used in the fuel cell when the specified gas appliance is a household fuel cell (see, for example, Patent Document 1).

According to the method described in Patent Document 1, when a gas appliance is determined to be a fuel cell, it is determined that the flow rate cannot be obtained during a period in which the flow rate of the fuel cell cannot be obtained during a period in which a steep change in flow rate occurs. The flow rate immediately before the fuel cell is used is used to integrate the amount of gas used by the fuel cell.

JP 2013-127444 A

However, in the conventional gas meter, if a fuel cell is identified as a fuel cell and another gas appliance is used while the amount of gas used by this fuel cell is being accumulated, the use of this gas appliance is stopped and the fuel cell is used. Until it can be determined again that the flow rate cannot be obtained, the flow rate immediately before it is determined that the flow rate cannot be obtained is used to accumulate the amount of gas used by the fuel cell. Therefore, it is necessary to determine whether or not there is a change in the flow rate of the fuel cell while constantly monitoring the state of the flow rate change, increasing the load on the microcomputer that performs the determination process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flow rate measuring device capable of accurately accumulating the amount of gas used by a fuel cell without increasing the load on the microcomputer. and

The flow rate measuring device according to the present specification includes flow rate measuring means for measuring the flow rate of a fluid flowing in a flow path at regular time intervals, and gas flow rate measuring means for determining the gas appliance being used from the flow rate value measured by the flow rate measuring means. appliance discrimination means; fuel cell flow rate calculation means for calculating the fuel cell flow rate consumed by the fuel cell from the flow rate value measured by the flow rate measurement means; and integrating the fuel cell flow rate calculated by the fuel cell flow rate calculation means. wherein the fuel cell flow rate calculation means calculates a predetermined number of flow rate values existing in a predetermined flow rate range among the flow rate values measured by the flow rate measurement means in the gas appliance determination means. The fuel cell flow rate is defined as the average flow rate.

As a result, by calculating the average flow rate only from the flow rate range of the fuel cell (more than the first predetermined flow rate and less than the second predetermined flow rate) among the measured flow rates, the amount of gas used by the fuel cell can be accurately integrated. It becomes possible to

According to the flow rate measuring device of the present invention, when accumulating the amount of gas used by the fuel cell, it is possible to perform accurate accumulation without increasing the load on the microcomputer.

1 is a block diagram showing an exemplary configuration of gas meter 100 according to Embodiment 1 of the present invention; FIG. (a) (b) Graphs for explaining the operation of the first embodiment of the present invention Processing flowchart in Embodiment 1 of the present invention (a) (b) Graphs for explaining the operation of the second embodiment of the present invention Processing flowchart in Embodiment 2 of the present invention Graph for explaining the operation of Embodiment 3 of the present invention

A first invention comprises flow rate measuring means for measuring the flow rate of a fluid flowing through a flow path at regular time intervals, and gas appliance discrimination means for discriminating the gas appliance being used from the flow rate value measured by the flow rate measuring means. fuel cell flow rate calculation means for calculating the fuel cell flow rate consumed by the fuel cell from the flow rate value measured by the flow rate measurement means; and fuel cell integration for integrating the fuel cell flow rate calculated by the fuel cell flow rate calculation means. wherein the fuel cell flow rate calculation means calculates an average flow rate calculated from a predetermined number of flow rate values existing in a predetermined flow rate range among the flow rate values measured by the flow rate measurement means in the gas appliance identification means. It is characterized in that the flow rate of the fuel cell is used as the fuel cell flow rate, so that the amount of gas used in the fuel cell can be integrated accurately without increasing the load on the microcomputer.

In a second invention, particularly in the first invention, when the flow rate value newly measured by the flow rate measuring means is within the predetermined flow rate range, the oldest flow rate value is deleted from the predetermined number of flow rate values. is configured by adding a newly measured flow rate value.

In a third invention, particularly in the first or second invention, the fuel cell flow rate calculation means retains the immediately preceding fuel cell flow rate when the flow rate value measured by the flow rate measurement means deviates from the predetermined flow rate range. After that, the average flow rate of the predetermined number of flow values after reaching the predetermined flow rate range is updated as the new fuel cell flow rate.

In a fourth invention, particularly in any one of the first to third inventions, the fuel cell flow rate calculation means determines that the difference between the current flow rate value and the previous flow rate value measured by the flow rate measurement means is a third predetermined value. If the flow rate is greater than or equal to the flow rate, the current value is not included in the calculation of the average flow rate.

In a fifth invention, particularly in any one of the first to fourth inventions, the fuel cell flow rate calculation means calculates the current value of the flow rate measured by the flow rate measurement means from the fuel cell flow rate obtained last time to the fourth When the fuel cell flow rate increases by a predetermined flow rate or more, the previously obtained fuel cell flow rate is maintained, and the fuel cell flow rate is not updated until the fuel cell flow rate decreases by a fifth predetermined flow rate or more from the current average flow rate.

In a sixth invention, particularly in any one of the first to third inventions, the fuel cell integrating means measures a period in which the fuel cell flow rate is not updated by the fuel cell flow rate calculating means, and the fuel cell Integrating the fuel cell flow rate during the period when the fuel cell flow rate is not updated from the difference between the fuel cell flow rate held during the period when the flow rate is not updated and the updated fuel cell flow rate and the time measured by the timing means. It is characterized by complementing values.

An embodiment of a flow rate measuring device according to the present invention will be described below with reference to the accompanying drawings. In the embodiments described below, a gas meter will be used as an example of a flow rate measuring device, and the process will be described. In the drawings, the same components are denoted by the same reference numerals, and the repetitive description of the already described components is omitted. In addition, this invention is not limited by embodiment described below.

(Embodiment 1)
FIG. 1 is a block diagram of a gas meter according to Embodiment 1 of the present invention.

In FIG. 1, the gas meter 100 includes a flow path 101, flow rate measuring means 102, gas appliance determination means 110, section average flow rate calculation means 111, fuel cell operation determination means 112, fuel cell flow rate calculation means 113, and a fuel cell integrating means 114 . Furthermore, the gas meter 100 is connected to the gas pipe 1 , and gas appliances 10 to 12 including fuel cells are connected to the downstream side of the gas meter 100 via the gas pipe 2 .

The ultrasonic flowmeter as the flow rate measuring means 102 emits ultrasonic waves at regular time intervals (for example, every 0.5 seconds or 2 seconds) to the gas as the fluid flowing in the flow path 101 to measure the flow rate. and you can use common ones.

Based on the flow rate value obtained by the flow rate measuring means 102, the gas appliance determination means 110 determines the type of gas appliance (fuel cell , water heater, fan heater, stove, etc.). Note that when the start of use of a gas appliance is detected but the gas appliance cannot be identified, it is assumed that the use of some appliance has started, and the identification result is an unknown appliance.

The fuel cell operation determining means 112 determines whether the fuel cell is currently operating based on the result of determination by the gas appliance determining means 110 .

The fuel cell flow rate calculation means 113 calculates the flow rate of the fuel cell based on the average flow rate calculated by the section average flow rate calculation means 111 when the fuel cell operation determination means 112 determines that the fuel cell is in operation. Details will be described later.

The section average flow rate calculation means 111 is used to calculate an average flow rate using a plurality of flow rate values that satisfy a predetermined condition of the flow rate values measured by the flow rate measurement means 102, and details of which will be described later.

The fuel cell integration means 114 integrates the fuel cell flow rate calculated by the fuel cell flow rate calculation means 113 .

The gas appliance discrimination means 110, section average flow rate calculation means 111, fuel cell operation determination means 112, fuel cell flow rate calculation means 113, and fuel cell integration means 114 are controlled by microcomputers, memories, etc., not shown. Implemented by means 130 .

Next, the operation of the section average flow rate calculation means 111 will be described.

FIG. 2(a) shows changes in the flow rate when the stove is used while the fuel cell is in operation, and a part of the period during which the stove is in operation is omitted.

The change in the flow rate of the gas used in the fuel cell is gentle, and the flow rate range is characterized by changing within a predetermined flow rate range (for example, a first predetermined flow rate of 20 L/h to a second predetermined flow rate of 75 L/h), FIG. 2(a) shows a state in which the flow rate is gradually increasing, and also shows a state in which the stove is used while the fuel cell is operating. At the same time, the total flow rate changes beyond the upper limit of the predetermined flow rate range (second predetermined flow rate), and returns to the flow rate of only the fuel cell when the use of the stove is stopped.

FIG. 2(b) is an enlarged view of the time axis of FIG. 2(a), showing changes in flow rate when the stove is started and stopped, and flow rate values (black circles) measured by the flow rate measuring means 102 at regular intervals. ing.

Here, the section average flow rate calculation means 111 forms sections for each predetermined number (here, eight) of the measured flow rate values, and calculates the average flow rate based on the predetermined number of flow rate values. At that time, only the flow rate value within the flow range of the fuel cell is used. Therefore, in the case of the flow rate values shown in FIG. 2(b), Section 3, Section 4, and Section 5 are excluded.

In the method of forming sections in the section average flow rate calculation means 111 described above, a new section is set every time eight measured values are obtained. In such a case, the oldest flow rate value is deleted and the newly measured flow rate value (current value) is added to obtain the successive average flow rate (hereinafter referred to as the moving average flow rate) while replacing the flow rate value belonging to the section. method is fine. In this case, it is possible to obtain an average flow rate excluding flow rate values that deviate from a predetermined range due to temporary flow rate fluctuations.

Also, when calculating the moving average flow rate, even if the newly measured flow rate value (current value) is within the specified flow rate range, the current value is compared with the previously measured flow rate value (previous value). If there is a difference of a predetermined flow rate (third predetermined flow rate) or more, by excluding the current value, a temporary flow rate fluctuation can be excluded, and an accurate average flow rate can be obtained.

Next, the operation of the fuel cell flow rate calculation means 113 and the integration processing in the fuel cell integration means 114 will be described.

FIG. 3 shows a flow chart of the fuel cell integration process of this embodiment.
First, the fuel cell flow rate calculation means 113 confirms whether or not the fuel cell is in operation by the fuel cell operation determination means 112 (S101). exit without doing If it is in operation (Yes in S101), it is confirmed whether the average flow rate has been updated by the section average flow rate calculation means 111, that is, whether the section average flow rate calculation means 111 has obtained a new average flow rate (S102), If it has been updated (Yes in S102), the average flow rate updated by the section average flow rate calculation means 111 is set as the flow rate of the fuel cell (S103). The final average flow rate is set as the flow rate of the fuel cell.

Then, the fuel cell integrating means 114 integrates the flow rate of the fuel cell in step S103 or step S104. That is, in the case of the change in flow rate shown in FIG. The average flow rate is integrated as the flow rate of the fuel cell in each section.

After that, since the average flow rate is updated in section 6, the average flow rate in section 6 is set as the fuel cell flow rate and integrated as the gas usage amount of the fuel cell.

As described above, the integrated flow rate as the amount of gas used by the fuel cell can be obtained from the flow rate value within the predetermined flow rate range. The same processing can be performed even when using the moving average flow rate.

(Embodiment 2)
Embodiment 2 will be described below with reference to FIG. The configuration of the gas meter according to the present embodiment is the same as that of the first embodiment, and the explanation is omitted.

FIG. 4(a) shows a state in which a certain gas appliance has been used for a certain period of time while the fuel cell is in operation. In this case, according to Embodiment 1, the total flow rate is integrated as the gas usage amount of the fuel cell. In particular, this tendency is observed immediately after the start of the fuel cell because the gas flow rate is small. As a countermeasure, in the present embodiment, the amount of gas used by the fuel cell can be accurately integrated by the following method.

FIG. 4(b) is an enlarged view of the time axis of FIG. 4(a), showing changes in flow rate at the start and stop of operation of a certain gas appliance and flow rate values (black circles) measured by the flow rate measuring means 102 at regular intervals. is shown.

Here, when the flow rate value newly measured by the flow rate measurement means 102 is within a predetermined flow rate range, the section average flow rate calculation means 111 deletes the oldest flow rate value and adds the newly measured flow rate value. A method of obtaining an average flow rate (moving average flow rate) while replacing the flow rate values belonging to the section by is used. Therefore, while the measured flow rate value is within the predetermined flow rate range, a new average flow rate is obtained and updated each time the flow rate is measured.

The operation of the fuel cell flow rate calculation means 113 in this embodiment will be described below with reference to FIG. 4(b).

The fuel cell flow rate calculation means 113 determines that the difference between the previous value V(n) and the current value V(n+1) is small in the interval n where the current value V(n) measured by the flow rate measurement means 102 is the fourth predetermined value. The average flow rate Vave(n) obtained from eight flow rate values including the previous value V(n−1) and the current value V(n) is taken as the fuel cell flow rate.

Next, in the section n+1 where the current value is V(n+1), the difference ΔVa (increased flow rate) between the current value V(n+1) and the previous average flow rate Vave(n) is calculated, and this difference ΔVa is the predetermined flow rate ( (fourth predetermined flow rate) or more. In this case, the fuel cell flow rate calculation means 113 adopts the calculated average flow rate Vave(n+1) including the current value V(n+1) as the flow rate of the fuel cell. Instead, the average flow rate Vave(n) obtained last time is adopted, and this average flow rate Vave(n) is held in a storage unit (not shown).

Thereafter, when the difference ΔVx between the current value V(x) and the held average flow rate Vave(n) is equal to or greater than the fourth predetermined flow rate, the fuel cell flow rate calculation means 113 calculates the held average flow rate as the fuel cell flow rate. Take Vave(n).

At the same time, the fuel cell flow rate calculation means 113 compares the average flow rate Vave(x) obtained during the period in which the gas appliance is in operation with the current value V(x) to determine whether or not there is a decrease of the fifth predetermined flow rate or more. Until it is confirmed, the retained average flow rate Vave(n) is continued to be adopted as the fuel cell flow rate.

Then, when the decrease ΔVb of the current value V(m−7) with respect to Vave(x) is equal to or greater than the fifth predetermined flow rate, the interval m measured from the current value V(m−7) to V(m) The average flow rate Vave(m) of the eight flow rate values is updated as a new fuel cell flow rate.

Next, the above operation will be described together with the integration processing in the fuel cell integration means 114 using the flow chart of FIG.

First, the fuel cell flow rate calculation means 113 confirms whether or not the fuel cell is in operation by the fuel cell operation determination means 112 (S201). exit without doing If it is in operation (Yes in S201), the flow rate value measured by the flow rate measuring means 102 is acquired as the current value VT (S202), and the difference ΔVa from the previous average flow rate VaveL is calculated (S203). is calculated (S204).

Next, it is confirmed whether or not ΔVa is equal to or greater than a fourth predetermined flow rate (S205). A flag indicating the presence is set (S207), and the previous average flow rate VaveL is set as the flow rate of the fuel cell (S208). If the flow rate is less than the fourth predetermined flow rate, the newly obtained average flow rate VaveT is updated as the fuel cell flow rate (S209).

Next, it is checked whether other gas appliances are in operation (S210), and if the other gas appliances are not in operation, the process proceeds to fuel cell integration processing (S217). If other gas appliances are in operation, the difference ΔVb (decrease amount) between the average flow rate VaveT obtained this time and the current value VT is obtained (S211), and it is confirmed whether the difference ΔVb is equal to or greater than the fifth predetermined flow rate (S212). ), and if it is less than the fifth predetermined flow rate, the previous average flow rate VaveL is set as the flow rate of the fuel cell (S213), and the average flow rate VaveT is saved.

In step S212, if it is determined that the difference ΔVb is equal to or greater than the fifth predetermined flow rate, the current average flow rate VaveT, which is the updated average flow rate, is set as the flow rate of the fuel cell (S215), and the flow rate of other gas appliances other than the fuel cell is set. A flag indicating that there is operation is reset (S216).

Then, in step S217, the fuel cell integrating means 114 integrates the fuel cell flow rate set in any one of steps S208, S209, S214, and S215.

By the above processing, even when a gas appliance that does not exceed the second predetermined flow rate is operated, the gas usage amount of the fuel cell can be accurately integrated.

(Embodiment 3)
Embodiment 3 will be described below with reference to FIG. The configuration of the gas meter according to the present embodiment is the same as that of the first embodiment, and the explanation is omitted. FIG. 6 shows the fuel cell flow rate used for the integration of the fuel cell in the second embodiment in FIG. 4(b). The average flow rate Vave(n) (dotted line A) of section n is integrated until it is updated with the average flow rate Vave(m).

However, when the flow rate of the fuel cell gradually increases as shown in the figure, a difference from the actual integrated value occurs. As a countermeasure for this, the present embodiment aims to complement this period.

Specifically, linear approximation is performed in the period in which the fuel cell flow rate increases from Vave(n) to Vave(m). Able to quantify accurately.

The embodiments of the present invention have been described above. The above descriptions of the embodiments are illustrative of the present invention and are not intended to limit the present invention. Further, an embodiment is also possible in which each component described in the above embodiment is appropriately combined. The present invention can be modified, replaced, added, omitted, etc. within the scope of the claims or equivalents thereof.

INDUSTRIAL APPLICABILITY As described above, the flow rate measuring device according to the present invention can accurately calculate the amount of gas used by a fuel cell, and therefore can be applied to a gas meter or the like for integrating gas flow rates of city gas and LP gas.

10 to 12 gas appliances 100 gas meter (flow measuring device)
REFERENCE SIGNS LIST 101 flow path 102 flow rate measurement means 110 gas appliance determination means 111 section average flow rate calculation means 112 fuel cell operation determination means 114 fuel cell integration means 130 control means

Claims (5)

a flow rate measuring means for measuring the flow rate of the fluid flowing through the channel at regular time intervals;
a gas appliance discriminating means for discriminating the gas appliance being used from the flow rate value measured by the flow rate measuring means;
fuel cell flow rate calculation means for calculating the fuel cell flow rate consumed by the fuel cell from the flow rate value measured by the flow rate measurement means;
fuel cell integration means for integrating the fuel cell flow rate calculated by the fuel cell flow rate calculation means;
with
The fuel cell flow rate calculation means determines an average flow rate calculated from a predetermined number of flow rate values existing in a predetermined flow rate range among the flow rate values measured by the flow rate measurement means in the gas appliance determination means as a fuel cell flow rate , When the flow rate value measured by the flow rate measuring means deviates from the predetermined flow rate range, the immediately preceding fuel cell flow rate is maintained, and then the average flow rate of the predetermined number of flow rate values after reaching the predetermined flow rate range is newly calculated. A flow rate measuring device characterized by updating as a fuel cell flow rate. The predetermined number of flow rate values is formed by deleting the oldest flow rate value and adding the newly measured flow rate value when the flow rate value newly measured by the flow rate measuring means is within the predetermined flow rate range. The flow rate measuring device according to claim 1, characterized in that: When the difference between the current flow rate value and the previous flow rate value measured by the flow rate measuring means is equal to or greater than a third predetermined flow rate, the fuel cell flow rate calculation means does not include the current value when calculating the average flow rate. The flow measuring device according to claim 1 or 2 , characterized by: When the current flow rate value measured by the flow rate measuring means increases by a fourth predetermined flow rate or more from the fuel cell flow rate obtained last time, the fuel cell flow rate calculating means holds the previously obtained fuel cell flow rate and calculates the current flow rate. 4. The flow rate measuring device according to any one of claims 1 to 3 , wherein the fuel cell flow rate is not updated until the flow rate decreases by a fifth predetermined flow rate or more from the average flow rate. The fuel cell integrating means counts a period in which the fuel cell flow rate is not updated by the fuel cell flow rate calculating means, and the fuel cell flow rate held during the period in which the fuel cell flow rate is not updated is 5. The integrated value of the fuel cell flow rate during a period in which the fuel cell flow rate is not updated is interpolated from the difference in the fuel cell flow rate and the time measured by the timing means. The flow measuring device according to .

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