阅读说明：本技术 流量测量装置以及埋入式气量计 (Flow rate measuring device and embedded gas meter ) 是由 山本克行 于 2019-02-08 设计创作，主要内容包括：本发明提供一种流量测量装置以及埋入式气量计。本发明的一个侧面的流量测量装置具有：加热部,其对流体进行加热；温度检测部,其在流体流动的方向上跨过所述加热部而并列设置,对被加热的流体的温度进行检测；流量算出部,其基于从所述温度检测部输出的检测信号,算出流体的流量；角度算出单元,其算出所述温度检测部相对于规定的基准面的倾斜角度；存储部,其将所述流量和所述倾斜角度与流量校正值的关系进行存储；流量校正部,其使用在所述存储部中存储的所述流量校正值,对所述流量进行校正。(The invention provides a flow rate measurement device and an embedded gas meter. The flow rate measuring device according to one aspect of the present invention includes: a heating section that heats a fluid; a temperature detection unit that is provided in parallel across the heating unit in a direction in which the fluid flows, and that detects a temperature of the heated fluid; a flow rate calculation unit that calculates a flow rate of the fluid based on the detection signal output from the temperature detection unit; an angle calculating unit that calculates an inclination angle of the temperature detecting unit with respect to a predetermined reference plane; a storage unit that stores the flow rate and a relationship between the inclination angle and a flow rate correction value; and a flow rate correction unit that corrects the flow rate using the flow rate correction value stored in the storage unit.)

1. A flow rate measurement device, comprising:

a heating section that heats a fluid;

a temperature detection unit that is provided in parallel across the heating unit in a direction in which the fluid flows, and that detects a temperature of the heated fluid;

a flow rate calculation unit that calculates a flow rate of the fluid based on the detection signal output from the temperature detection unit;

an angle calculating unit that calculates an inclination angle of the temperature detecting unit with respect to a predetermined reference plane;

a storage unit that stores the flow rate and a relationship between the inclination angle and a flow rate correction value;

and a flow rate correction unit that corrects the flow rate using the flow rate correction value stored in the storage unit.

2. The flow measuring device of claim 1,

the angle calculating means calculates the inclination angle based on an output of the temperature detecting unit when the fluid does not flow.

3. Flow measuring device according to claim 1 or 2,

further comprising a characteristic value calculation unit for calculating a characteristic value of the fluid based on the detection signal outputted from the temperature detection unit,

the storage section further stores the characteristic value and a relationship between the inclination angle and a characteristic correction value,

the flow rate correction unit further corrects the flow rate using the characteristic correction value stored in the storage unit.

4. The flow rate measurement device according to claim 1 or 2, further comprising:

a second heating section;

a second temperature detection unit that is provided in parallel across the second heating unit in a direction in which the flow of the fluid is interrupted;

a characteristic value calculation unit that calculates a characteristic value of the fluid based on the detection signal output from the second temperature detection unit;

the angle calculating means further calculates an inclination angle of the second temperature detecting unit with respect to a predetermined reference plane based on an output of the second temperature detecting unit.

5. A flow rate measurement device, comprising:

a heating section that heats a fluid;

a temperature detection unit that is provided in parallel across the heating unit in a direction in which the fluid flows, and that detects a temperature of the heated fluid;

a flow rate calculation unit that calculates a flow rate of the fluid based on the detection signal output from the temperature detection unit;

a second heating section;

a second temperature detection unit that is provided in parallel across the second heating unit in a direction in which the flow of the fluid is interrupted;

a characteristic value calculation unit that calculates a characteristic value of the fluid based on the detection signal output from the second temperature detection unit;

an angle calculating unit that calculates an inclination angle of the second temperature detecting unit with respect to a predetermined reference plane based on an output of the second temperature detecting unit;

a storage unit that stores the relationship between the flow rate and the inclination angle of the second temperature detection unit and a flow rate correction value, and also stores the relationship between the characteristic value and the inclination angle of the second temperature detection unit and a characteristic correction value;

and a flow rate correction unit that corrects the flow rate using the flow rate correction value and the characteristic correction value stored in the storage unit.

6. Flow measuring device according to one of claims 3 to 5,

the characteristic value represents at least any one of a pressure, a type, and a temperature of the fluid.

7. An embedded gas meter, which is embedded underground, comprising:

a flow tube through which gas flowing into the buried gas meter flows;

a flow rate measuring device according to any one of claims 1 to 6;

the flow rate measuring device is provided in the flow tube and detects a flow rate of the gas flowing through the flow tube.

Technical Field

The present invention relates to a flow rate measurement device and an embedded gas meter.

Background

As one of methods for calculating the flow rate of the fluid flowing through the flow path, there is a method in which, for example, a thermal flow rate sensor having a heater and a thermopile is provided in the flow path, the fluid is heated by the heater, the temperature distribution information of the heated fluid is detected by the thermopile, and the flow rate of the fluid is calculated based on the detected temperature distribution information. Inventions in which a thermal flow sensor having a heater and a thermopile is provided in a flow path are disclosed in, for example, patent documents 1 to 4.

Disclosure of Invention

Technical problem to be solved by the invention

When the fluid is heated by the heater, it is considered that a convection phenomenon occurs in the vicinity of the heater, and the heat is transferred upward with respect to the horizontal plane. Therefore, when the thermal type flow rate sensor is installed at different angles in the flow path, the output value from the thermopile may change due to the influence of the heat transferred by the convection phenomenon. That is, the inventors of the present invention have found that a difference occurs in the measurement result of the flow rate in the flow path due to the installation angle of the thermal type flow rate sensor, and the flow rate cannot be measured with high accuracy.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique capable of measuring flow with high accuracy even when the installation angle of a thermal flow sensor is different.

Technical solution for solving technical problem

In order to solve the above problems, the present invention adopts the following configuration.

That is, a flow rate measurement device according to one aspect of the present invention includes: a heating section that heats a fluid; a temperature detection unit that is provided in parallel across the heating unit in a fluid flow direction and detects a temperature of the heated fluid; a flow rate calculation unit that calculates a flow rate of the fluid based on the detection signal output from the temperature detection unit; an angle calculating means for calculating an inclination angle of the temperature detecting unit with respect to a predetermined reference plane; a storage unit that stores the flow rate and a relationship between the inclination angle and a flow rate correction value; and a flow rate correction unit that corrects the flow rate using the flow rate correction value stored in the storage unit.

Here, the predetermined reference plane is a predetermined reference plane, for example, a plane such as a horizontal plane or a vertical plane.

With this configuration, the distribution of heat generated by the flow of the fluid can be detected by the temperature detection unit, and the flow rate of the fluid can be calculated. In addition, the inclination angle of the temperature detection unit with respect to the predetermined reference plane can be calculated. Then, the most suitable flow rate correction value corresponding to the calculated flow rate and inclination angle can be selected from among the flow rate correction values stored in the storage unit, and the flow rate can be corrected using the selected flow rate correction value.

That is, this configuration enables correction, that is, elimination of the influence of heat transfer due to the convection phenomenon from the calculated flow rate. In addition, the correction is based on the tilt angle. Therefore, the flow rate can be accurately corrected based on the inclination angle, and a flow rate with high accuracy can be calculated.

In the flow rate measuring device according to one aspect of the present invention, the angle calculating means may calculate the inclination angle based on an output of the temperature detecting unit when the fluid does not flow.

According to this configuration, the output of the temperature detection unit is an output that detects the distribution of heat generated by a convection phenomenon that is not affected by the fluid flow. Therefore, the tilt angle can be calculated with high accuracy.

In the flow rate measuring device according to the one aspect of the present invention, the flow rate correction unit may further include a characteristic value calculation unit that calculates a characteristic value of the fluid based on a detection signal output from the temperature detection unit, the storage unit may further store the characteristic value and a relationship between the inclination angle and a characteristic correction value, and the flow rate correction unit may correct the flow rate using the characteristic correction value stored in the storage unit.

With this configuration, the characteristic value can be calculated in addition to the flow rate of the fluid. Further, it is also possible to select a characteristic correction value corresponding to the calculated characteristic value and inclination angle from among the characteristic correction values stored in the storage unit, and correct the flow rate using the selected characteristic correction value.

That is, this configuration makes it possible to correct the influence of heat transfer due to the convection phenomenon from the calculated flow rate. The correction is based on the characteristics of the fluid and the angle of inclination. Therefore, the flow rate can be accurately corrected in accordance with the inclination angle. Further, by adding this correction to the correction based on the flow rate and the inclination angle of the fluid, the accuracy of calculating the flow rate can be further improved.

The flow rate measuring device according to the one aspect further includes: the fluid temperature control device may further include a second heating unit, a second temperature detection unit provided in parallel across the second heating unit in a direction in which a flow of the fluid is interrupted, and a characteristic value calculation unit that calculates a characteristic value of the fluid based on a detection signal output from the second temperature detection unit, wherein the angle calculation unit may calculate an inclination angle of the second temperature detection unit with respect to a predetermined reference plane based on an output of the second temperature detection unit.

According to this configuration, the output of the second temperature detection unit is an output in which the influence of the change in the temperature distribution due to the fluid flow is reduced. That is, the characteristic value and the inclination angle of the fluid calculated using the output of the second temperature detection unit are values with high accuracy. Therefore, the accuracy of flow rate correction can be improved by using the characteristic value and the inclination angle in flow rate correction.

In addition, according to this configuration, two tilt angles can be calculated. Therefore, the inclination of the flow rate measurement device can be grasped stereoscopically. Further, the flow rate can be corrected by the two inclination angles. Therefore, the flow rate can be accurately corrected, and the flow rate can be calculated with high accuracy.

In addition, the flow rate measuring device of the one side surface may include: a heating section that heats a fluid; a temperature detection unit that is provided in parallel across the heating unit in a direction in which the fluid flows, and that detects a temperature of the heated fluid; a flow rate calculation unit that calculates a flow rate of the fluid based on the detection signal output from the temperature detection unit; a second heating section; a second temperature detection unit that is provided in parallel across the second heating unit in a direction in which the flow of the fluid is interrupted; a characteristic value calculation unit that calculates a characteristic value of the fluid based on the detection signal output from the second temperature detection unit; an angle calculating unit that calculates an inclination angle of the second temperature detecting unit with respect to a predetermined reference plane based on an output of the second temperature detecting unit; a storage unit that stores the relationship between the flow rate and the inclination angle of the second temperature detection unit and a flow rate correction value, and also stores the relationship between the characteristic value and the inclination angle of the second temperature detection unit and a characteristic correction value; and a flow rate correction unit that corrects the flow rate using the flow rate correction value and the characteristic correction value stored in the storage unit.

With this configuration, the temperature detector can detect the distribution of heat generated by the flow of the fluid and calculate the flow rate of the fluid. Further, the inclination angle and the characteristic value can be calculated based on the output of the second temperature detection unit. Here, the output of the second temperature detection unit is an output in which the influence of the change in the temperature distribution due to the flow of the fluid is reduced. That is, the characteristic value and the inclination angle of the fluid calculated using the output of the second temperature detection unit are values with high accuracy. Further, it is possible to select an optimum flow rate correction value and characteristic correction value corresponding to the calculated flow rate, characteristic value, and inclination angle from among the flow rate correction values and characteristic correction values stored in the storage unit, and correct the flow rate using the selected flow rate correction value and characteristic correction value. That is, the characteristic value and the inclination angle used for correcting the flow rate are highly accurate values, and therefore the accuracy of flow rate correction is high.

In the flow rate measurement device of the one aspect, the characteristic value may indicate at least one of a pressure, a type, and a temperature of the fluid.

According to this configuration, the flow rate can be corrected based on at least any one of the pressure of the fluid, the type of the fluid, and the temperature of the fluid. That is, since the flow rate can be corrected based on a plurality of characteristics of the fluid, the accuracy of flow rate calculation can be improved.

The buried gas meter buried underground includes: a flow pipe through which the gas flowing into the embedded gas meter flows, and a flow rate measurement device on the one side surface, wherein the flow rate measurement device may be an embedded gas meter that is provided in the flow pipe and detects a flow rate of the gas flowing through the flow pipe.

According to this configuration, since the gas meter is sealed, the inside of the flow tube inside the gas meter is less susceptible to the influence of external environmental changes, and the environment such as temperature and humidity is stable. Therefore, according to this configuration, highly accurate flow rate measurement can be performed.

Further, according to this structure, the straight tube length of the flow tube can be extended as much as possible. Therefore, the flow of the gas in the flow pipe is more stable than the flow of the gas flowing in the curved pipe. Therefore, according to this configuration, highly accurate flow rate measurement can be performed.

In addition, according to this configuration, when various sensors are provided inside, the flow rate measuring device and the various sensors may be arranged linearly. Therefore, it is easier to arrange the flow tube linearly, as compared with the case where the various sensors are not linearly but irregularly arranged. That is, this structure is a simple structure, and the number of components forming the structure is also easily reduced. Therefore, the measurement of the gas can be effectively realized, and in addition, the manufacturing cost can be reduced.

In addition, according to this configuration, since the flow rate of the gas can be detected by one flow rate measuring device, downsizing can be achieved. Further, the horizontal piping structure can be formed to reduce the influence of flow rate measurement errors due to convection.

Further, when a conventional gas meter is buried underground, it is considered to be difficult to recognize the installation angle of a flow rate measurement device installed in the gas meter from the ground. Therefore, when the installation angle of the flow rate measuring device is inclined with respect to the horizontal plane, it is considered difficult to correct the measured flow rate in accordance with the inclination. On the other hand, according to this configuration, even in the case where the installation angle of the flow rate measurement device is inclined with respect to the horizontal plane, the gas measured by the flow rate measurement device can be automatically corrected in accordance with the installation angle of the flow rate measurement device. Therefore, high-precision flow measurement can be performed. In addition, even in a situation where it is difficult to set the flow rate measurement device at a desired angle, such as when the ground surface is originally inclined, the gas measured by the flow rate measurement device can be automatically corrected in accordance with the set angle of the flow rate measurement device. That is, according to this configuration, it is possible to provide a highly convenient device that can perform highly accurate flow rate measurement regardless of the installation environment.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a highly accurate flow rate measurement technique even when the installation angles of the thermal type flow rate sensors are different.

Drawings

Fig. 1 schematically illustrates an example of a flow rate measurement device of the present embodiment.

Fig. 2 schematically illustrates an example in which the flow rate measurement device is provided to the flow path section.

Fig. 3 schematically illustrates an example of an enlarged view of the detection element of the present embodiment.

Fig. 4 schematically illustrates an example of a cross section of the flow rate measurement device.

Fig. 5 schematically illustrates an example of an outline of a flow rate measurement device when it is fixed to a flow tube member.

Fig. 6A schematically illustrates an example of temperature distribution at the time of activation of the micro-heater in a state where the fluid does not flow in the flow tube part.

Fig. 6B schematically illustrates an example of temperature distribution when the micro-heater is activated in a state where the fluid flows in the flow tube part.

Fig. 7 schematically illustrates an example of a block diagram showing a functional configuration of a flow rate measurement device.

Fig. 8 schematically illustrates an example of a correspondence table in which, for example, the correspondence between the output of the thermopile and the installation angle is described.

Fig. 9 schematically illustrates an example of a flowchart showing a flow of calculation of the correspondence table.

Fig. 10A schematically illustrates an example of the flow correction value.

Fig. 10B schematically illustrates an example of the pressure correction value.

Fig. 10C schematically illustrates an example of the fluid type correction value.

Fig. 10D schematically illustrates an example of the temperature correction value.

Fig. 11 schematically illustrates an example of a flowchart showing a flow of processing of the flow rate measurement device.

Fig. 12 schematically illustrates an example of a perspective view of a flow rate measurement device and a flow tube member.

Fig. 13 schematically illustrates an example of the relationship of the detection element to the flow of the fluid air stream.

Fig. 14 schematically illustrates an example of a block diagram showing a functional configuration of a flow rate measurement device.

Fig. 15 schematically illustrates an example in which a flow rate measurement device is disposed in a flow tube member having two flow path portions, a main flow path portion and a sub flow path portion.

Fig. 16 schematically illustrates an example of a partially enlarged view of the sub flow path portion.

Fig. 17 schematically illustrates an example of a cross-sectional view when the flow rate measurement device is provided in the flow tube member.

Fig. 18 schematically illustrates an example of an outline of a flow rate measurement device installed in, for example, a gas meter buried underground.

Fig. 19 schematically illustrates an example of a partially enlarged view of the gas meter.

Fig. 20 schematically illustrates an example of the configuration overview of the electronic substrate.

Detailed Description

An embodiment of one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described below with reference to the drawings. However, the present embodiment described below is merely an example of the present invention in all aspects. Of course, various modifications and alterations can be made without departing from the scope of the invention. That is, in the practice of the present invention, the specific configuration corresponding to the embodiment can be appropriately adopted.

Application example § 1

An example of a scenario to which the present invention is applied will be described with reference to fig. 1. Fig. 1 schematically illustrates an example of a flow rate measurement device 100 of the present embodiment. The flow rate measurement device 100 includes: a detection element 1, a control unit 2, and a circuit board 3 on which the detection element 1 and the control unit 2 are mounted. A predetermined fluid flows through the flow tube member 4. Further, one flow path portion 5 is formed at an upper portion of the flow tube member 4. The flow rate measurement device 100 is fixed to the flow tube member 4 such that the detection element 1 is positioned in the flow path section 5. The detection element 1 includes a micro-heater and a thermopile arranged in parallel across the micro-heater. The thermopile is substantially rectangular in shape. The detection element 1 is a so-called thermal flow sensor.

Here, the flow rate of the fluid is calculated as follows. When the fluid flows through the flow tube member 4, the vicinity of the micro-heater is heated when the micro-heater is activated. Also, a signal related to the temperature near the micro-heater is output from the thermopile. When the micro-heater is used for heating during fluid flow, the heat from the micro-heater is biased to spread by the influence of the fluid flow. The deflected thermal diffusion is measured by the thermopile, and the flow rate of the fluid is calculated.

Incidentally, when a fluid is heated by a micro-heater, a convection phenomenon occurs in the vicinity of the micro-heater, and heat is transferred upward with respect to a horizontal plane. Fig. 2 shows an example in which the flow rate measurement device 100 is provided in the flow path section 5, and for example, the angle of the direction in which the micro-heater 6 and the thermopiles 7A and 7B are arranged with respect to the horizontal plane is approximately 90 degrees. When the flow rate measuring apparatus 100 is set at the above-described angle, the thermopile 7A or 7B detects the diffusion of heat including the heat transfer due to the convection phenomenon, instead of simply detecting the diffusion of heat due to the flow of the fluid. That is, it is necessary to correct the flow rate in consideration of the influence of heat generated by the convection phenomenon.

In the example of fig. 2, although the installation angle of the flow rate measurement device 100 is approximately 90 degrees, even when the installation angle is other than 90 degrees, the influence of heat transfer due to convection phenomenon is included in the outputs of the thermopiles 7A and 7B, and the degree of the influence depends on the installation angle. That is, it is necessary to calculate the installation angle of the flow rate measurement device 100 and correct the flow rate according to the installation angle. The degree of influence of heat transfer due to the convection phenomenon included in the output of the thermopile 7A or 7B also depends on the flow rate and characteristics of the fluid. Therefore, the flow rate needs to be corrected in consideration of the flow rate and characteristics of the fluid.

The installation angle of the flow rate measurement device 100 is calculated as follows. First, in the process of calculating the installation angle of the flow rate measurement device 100, the relationship between the output of the thermopile 7A or 7B and the installation angle of the flow rate measurement device 100 is created in advance. The flow rate measurement device 100 is first installed inside the flow path section 5 at a certain installation angle. Then, the flow of the fluid is stopped at a position where the flow rate measurement device 100 is provided. Then, the micro-heater 6 is activated to heat the vicinity of the micro-heater 6. In this way, a convection phenomenon occurs in the vicinity of the micro-heater 6, and heat is transferred upward with respect to the horizontal plane. Then, the thermopile 7A or 7B detects the distribution information of the heat generated by the convection phenomenon, and a predetermined signal is output from the thermopile 7A or 7B. Then, the relationship between the output of the thermopile 7A or 7B and the installation angle of the flow rate measurement device 100 is stored. Then, the installation angle of the flow rate measurement device 100 is changed, and the above operation is repeated. Through the above-described flow, the relationship between the output of the thermopile 7A or 7B and the installation angle of the flow rate measurement device 100 is prepared in advance.

Next, the installation angle of the flow rate measurement device 100 can be determined as follows. First, the flow rate measurement device 100 is installed in the flow path section 5, and the flow of the fluid is stopped at the position where the flow rate measurement device 100 is installed. Then, the micro-heater 6 is activated to heat the vicinity of the micro-heater 6. In this way, a convection phenomenon occurs in the vicinity of the micro-heater 6, and heat is transferred upward with respect to the horizontal plane. Then, the thermopile 7A or 7B detects the distribution information of the heat generated by the convection phenomenon, and a predetermined signal is output from the thermopile 7A or 7B. Then, the installation angle of the flow rate measurement device 100 is calculated using the output of the thermopile 7A or 7B, the relationship between the output of the thermopile 7A or 7B and the installation angle of the flow rate measurement device 100, which is created in advance.

In addition, the heat diffusion in the vicinity of the micro-heater 6 depends not only on the flow rate of the fluid but also on the characteristics of the fluid. In other words, the fluid characteristics can be calculated from the output of the thermopile 7A or 7B.

Using the installation angle of the flow rate measurement device 100 calculated above and the characteristics of the fluid, correction is performed to eliminate the influence of heat transfer due to the convection phenomenon from the calculated flow rate. In the correction of the flow rate, a correction coefficient relating to the characteristic of the fluid and the setting angle is determined in advance. Then, by multiplying the flow rate by a correction coefficient, correction of the flow rate is performed. Through the above flow, a flow rate with high accuracy can be calculated.

As described above, in the present embodiment, it is possible to provide a highly accurate flow rate measurement technique even when the installation angle of the thermal type flow rate sensor is different.

Construction example 2

[ hardware configuration ]

Next, an example of the flow rate measurement device according to the present embodiment will be described. The flow rate measurement device 100 of the present embodiment is provided in a flow tube inside a gas meter, an air conditioner (provided in an air duct space), a medical device, or a fuel cell, for example, and can measure the flow rate of a fluid flowing in the flow tube. As shown in fig. 1, the flow rate measurement device 100 includes: a detection element 1, a control unit 2, and a circuit board 3 on which the detection element 1 and the control unit 2 are mounted.

Fig. 3 schematically illustrates an example of an enlarged view of the detection element 1 of the present embodiment. The detection element 1 includes a micro-heater 6 and thermopiles 7A and 7B. Here, the micro-heater 6 is an example of the "heating section" of the present invention. The thermopiles 7A and 7B are examples of the "temperature detection unit" of the present invention. The micro heater 6 is, for example, a resistor made of polysilicon, and is provided in the central portion of the detection element 1. The thermopiles 7A and 7B are arranged in parallel across the micro-heater 6.

Fig. 4 schematically illustrates an example of a cross section of the flow rate measurement device 100. Insulating films 8 are formed on the upper and lower sides of the micro-heater 6 and the thermopiles 7A and 7B. Further, the circuit board 3 below the thermopiles 7A, 7B is provided with a cavity 9. Fig. 5 schematically illustrates an example of an outline view when the flow rate measurement device 100 is fixed to the flow tube member 4. The detection element 1 is provided to be fitted into a central portion of the flow path portion 5. The detection element 1 is provided such that the thermopile 7A is on the upstream side in the fluid flow direction and the thermopile 7B is on the downstream side.

[ principle of flow measurement ]

Next, the principle of flow rate detection using the detection element 1 will be described. Fig. 6A schematically illustrates an example of temperature distribution when the micro-heater 6 is activated in a state where no fluid flows in the flow tube member 4. On the other hand, fig. 6B schematically illustrates an example of the temperature distribution when the micro-heater 6 is activated in a state where the fluid flows through the flow tube member 4. When no fluid flows through the flow tube unit 4, the heat from the micro-heater 6 is symmetrically diffused around the micro-heater 6. Therefore, there is no difference in the outputs of the thermopiles 7A and 7B. On the other hand, when a fluid flows through the flow tube unit 4, the heat from the micro-heater 6 is not diffused symmetrically about the micro-heater 6 but diffused further toward the thermopile 7B side downstream due to the influence of the fluid flow. Therefore, the outputs of the thermopiles 7A and 7B differ. Further, the more the flow rate of the fluid is, the larger the difference in the output is. The relationship between the fluid flow rate and the difference between the outputs of the thermopiles 7A and 7B is shown by the following number 1, for example.

[ number 1]

Here, Δ V represents the flow rate of the fluid, T_ARepresents the output value, T, of the thermopile 7A_BRepresents the output value of the thermopile 7B. In addition, v_fA and b are constants for the flow rate of the fluid. In the present embodiment, the flow rate is calculated based on the principle described above.

The heat diffusion in the vicinity of the micro-heater 6 depends not only on the flow rate of the fluid but also on the characteristics such as the type of the fluid. In other words, the characteristics such as the type of fluid can be calculated from the output of the thermopile 7A or 7B. The outputs of the thermopiles 7A and 7B are temperature-dependent signals. Therefore, it is needless to say that the temperature of the fluid can be detected from the output of the thermopile 7A or 7B by stopping the micro-heater 6.

[ functional Structure ]

Fig. 7 schematically illustrates an example of a block diagram showing a functional configuration of the flow rate measurement device 100. The control unit 2 includes a flow rate calculation unit 10, and the flow rate calculation unit 10 receives signals output from the thermopiles 7A and 7B, and calculates the flow rate of the fluid based on the difference between the outputs of the thermopiles 7A and 7B. The flow rate calculating unit 10 is an example of the "flow rate calculating unit" of the present invention. The number 1 is used to calculate the flow rate of the fluid from the difference between the outputs of the thermopiles 7A and 7B.

Incidentally, when the fluid is heated by the micro-heater 6, a convection phenomenon occurs in the vicinity of the micro-heater 6, and the heat is transferred upward with respect to the horizontal plane. Fig. 2 shows an example in which the flow rate measurement device 100 is provided in the flow path section 5, and for example, the angle of the direction in which the micro-heater 6 and the thermopiles 7A and 7B are arranged with respect to the horizontal plane is approximately 90 degrees. The thermopiles 7A and 7B detect the diffusion of heat including the movement of heat due to the convection phenomenon, not the simple detection of the diffusion of heat due to the flow of fluid. That is, it is necessary to correct the flow rate in consideration of the influence of heat generated by the convection phenomenon. In addition, the degree of influence of heat transfer due to the convection phenomenon depends on characteristics such as the installation angle of the flow rate measurement device 100, the flow rate of the fluid, and the pressure, type, and temperature of the fluid. Therefore, it is necessary to correct the calculated flow rate in consideration of characteristics such as the installation angle of the flow rate measurement device 100, the flow rate of the fluid, and the pressure, type, and temperature of the fluid.

Therefore, the control unit 2 includes an installation angle calculation unit 11 that calculates an installation angle of the flow rate measurement device 100. Here, the installation angle is an angle of the thermopile 7A (width direction) with respect to the horizontal plane in the direction in which the micro-heater 6 is aligned with the thermopiles 7A and 7B, and is an example of the "inclination angle" in the present invention. That is, the angle calculating unit 11 is provided to calculate the angle of the fluid flow direction with respect to the horizontal plane. The horizontal plane is an example of the "predetermined reference plane" in the present invention. The installation angle calculating unit 11 is an example of the "angle calculating means" of the present invention. Fig. 7 shows an example in which the installation angle calculating unit 11 receives a signal output from the thermopile 7A. The control unit 2 further includes a flow rate correction unit 12, and the flow rate correction unit 12 corrects the flow rate based on the calculated installation angle, the flow rate of the fluid, or characteristics such as the pressure, type, and temperature of the fluid.

In addition, the installation angle calculation unit 11 uses the correspondence table 13 between the output of the thermopile 7A or 7B and the installation angle of the flow rate measurement device 100 when calculating the installation angle of the flow rate measurement device 100. The flow rate measurement device 100 further includes a storage unit 14, and the correspondence table 13 is stored in the storage unit 14. Fig. 8 schematically illustrates an example of the correspondence table 13 in which the correspondence between the output of the thermopile 7A and the installation angle is described, for example. The correspondence table 13 should be created in advance. The correspondence table 13 may also describe the correspondence between the output of the thermopile 7B and the installation angle. Fig. 9 schematically illustrates an example of a flowchart showing a flow of calculation of the correspondence table 13. In the following, the details of the calculation flow of the correspondence table 13 shown in fig. 9 will be described. The following calculation flow is only an example, and each process in the calculation flow may be changed if possible. Note that, the calculation flow described below may be omitted, replaced, or added as appropriate according to the embodiment.

(step S101)

First, the flow rate measurement device 100 is installed inside the flow path portion 5 at a certain installation angle.

(step S102)

Next, the flow of the fluid is stopped at a position where the flow rate measurement device 100 is provided.

(step S103)

Next, the micro-heater 6 is activated to heat the vicinity of the micro-heater 6. In this way, a convection phenomenon occurs in the vicinity of the micro-heater 6, and heat is transferred upward with respect to the horizontal plane.

(step S104)

The thermopile 7A or 7B detects the distribution information of the heat generated by the convection phenomenon, and a predetermined signal is output from the thermopile 7A or 7B.

(step S105)

The relationship between the output of the thermopile 7A or 7B and the set angle is stored. Then, the set angle is changed, and the above-described steps S101 to S105 are repeated.

(step S106)

When the desired relationship between the output of the thermopile 7A or 7B and the set angle is stored, the repetition of steps S101 to S105 ends. Here, the step of setting the angle may be any number of degrees.

The correspondence table 13 created by the above-described flow is stored in the storage unit 14 in advance.

The control unit 2 further includes a pressure calculation unit 15 that calculates the pressure of the fluid used when the flow rate is corrected by the flow rate correction unit 12. Here, the pressure calculation unit 15 is an example of the "characteristic value calculation unit" of the present invention. The pressure calculation unit 15 receives the flow rate information calculated by the flow rate calculation unit 10, and calculates the pressure based on the flow rate, the cross-sectional area of the flow path unit 5, the fluid density, and the like.

The control unit 2 further includes a fluid type derivation unit 16, and the fluid type derivation unit 16 derives the type of fluid used when the flow rate is corrected by the flow rate correction unit 12. Here, the fluid type deriving unit 16 is an example of the "characteristic value calculating unit" of the present invention. The fluid type derivation section 16 receives a signal output from the thermopile 7A or 7B. Fig. 7 shows an example of receiving a signal output from the thermopile 7A.

The control unit 2 further includes a temperature calculation unit 17, and the temperature calculation unit 17 calculates the temperature of the fluid used when the flow rate is corrected by the flow rate correction unit 12. Here, the temperature calculating unit 17 is an example of the "temperature calculating unit" of the present invention. The temperature calculating unit 17 receives a signal output from the thermopile 7A or 7B. Fig. 7 shows an example of receiving a signal output from the thermopile 7A.

The storage unit 14 stores a correction value for eliminating the influence of heat transfer due to the convection phenomenon from the calculated flow rate. This correction value is used when the flow rate is corrected in the flow rate correction section 12. One of the correction values is a flow rate correction value related to the set angle and the flow rate of the fluid. Fig. 10A schematically illustrates an example of the flow correction value. The flow rate correction value is an example of "relationship between the flow rate and the inclination angle and the flow rate correction value" of the present invention.

In addition, one of the correction values is a pressure correction value related to the set angle and the pressure of the fluid. Fig. 10B schematically illustrates an example of the pressure correction value. The pressure correction value is an example of "relationship between the characteristic value and the inclination angle and the characteristic correction value" of the present invention.

In addition, one of the correction values is a fluid type correction value relating to the set angle and the type of fluid. Fig. 10C schematically illustrates an example of the fluid type correction value. The fluid type correction value is an example of "relationship between the characteristic value and the inclination angle and the characteristic correction value" of the present invention.

In addition, one of the correction values is a temperature correction value related to the set angle and the temperature of the fluid. Fig. 10D schematically illustrates an example of the temperature correction value. The temperature correction value is an example of "relationship between the characteristic value and the inclination angle and the characteristic correction value" of the present invention.

Action example 3

Next, an operation example of the flow rate measurement device 100 will be described with reference to fig. 11. Fig. 11 schematically illustrates an example of a flowchart showing a flow of processing of the flow rate measurement device 100. The process flow described below is only an example, and each process may be changed as necessary. Note that, the process flow described below can be appropriately omitted, replaced, and added according to the embodiment.

(step S201)

In a state where the fluid flows through the channel part 5, the micro-heater 6 is activated. When the micro-heater 6 is activated, the vicinity of the micro-heater 6 is heated. Then, signals relating to the temperature in the vicinity of the micro-heater 6 are output from the thermopiles 7A and 7B. The outputs of the thermopiles 7A and 7B are transmitted to the flow rate calculation unit 10. Then, the flow rate calculating unit 10 calculates the flow rate of the fluid based on the difference between the outputs of the thermopiles 7A and 7B.

(step S202)

The pressure calculating unit 15 calculates the pressure based on the flow rate information received from the flow rate calculating unit 10, the cross-sectional area of the flow path unit 5, the fluid density, and the like.

(step S203)

The output of the thermopile 7A or 7B is sent to the fluid type derivation unit 16. Then, in the fluid type derivation section 16, the type of fluid is derived based on the output of the thermopile 7A or 7B.

(step S204)

The outputs of the thermopiles 7A, 7B are transmitted to the temperature calculation unit 17. Then, the temperature calculating unit 17 calculates the temperature of the fluid based on the output of the thermopile 7A or 7B. However, the outputs of the thermopiles 7A and 7B sent to the temperature calculation unit 17 are outputs when the micro-heater 6 is in a stopped state.

(step S205)

Next, in step S205, the installation angle of the flow rate measurement device 100 is calculated.

(step S205-1)

The flow of the fluid is stopped at a position where the flow rate measurement device 100 is provided.

(step S205-2)

In the vicinity of the micro heater 6, a convection phenomenon occurs, and heat is transferred upward with respect to a horizontal plane. When the flow of the fluid stops, the thermopile 7A or 7B detects the distribution information of the heat generated by the convection phenomenon without being affected by the flow of the fluid, and transmits the output of the thermopile 7A or 7B to the installation angle calculating unit 11.

(step S205-3)

The installation angle calculating unit 11 receives the output of the thermopile 7A or 7B. Then, referring to the correspondence table 13 stored in the storage unit 14, the set angle corresponding to the output value closest to the received output value of the thermopile 7A or 7B is determined as the set angle of the flow rate measurement device 100. However, the installation angle calculation unit 11 may calculate the installation angle of the flow rate measurement device 100 by referring to the correspondence table 13 and proportionally assigning the installation angles corresponding to the two output values before and after the output value closest to the received output value of the thermopile 7A or 7B. In step S205, the installation angle of the flow rate measurement device 100 can be determined by the above-described flow.

The installation angle calculation unit 11 calculates the installation angle from the output of the thermopile 7A or 7B, but may calculate the installation angle from the difference between the outputs of the thermopiles 7A and 7B. In this case, a correspondence table 13 is prepared in advance for the difference between the outputs of the thermopiles 7A and 7B and the installation angle.

(step S206)

In step S206, the correction value used when the flow rate correction is performed in the flow rate correction unit 12 is determined from among the correction values used when the flow rate correction is performed stored in the storage unit 14.

(step S206-1)

In step S206-1, determination of the flow rate correction value is performed. The flow rate correction value most suitable for the flow rate calculated in step S201 and the setting angle calculated in step S205 is selected from the flow rate correction value data shown in fig. 10A.

(step S206-2)

In step S206-2, determination of the pressure correction value is performed. A pressure correction value most suitable for the pressure calculated in step S202 and the setting angle calculated in step S205 is selected from the pressure correction value data shown in fig. 10B.

(step S206-3)

In step S206-3, determination of the fluid type correction value is performed. The fluid type correction value most suitable for the type of fluid derived in step S203 and the set angle calculated in step S205 is selected from the fluid type correction value data shown in fig. 10C.

(step S206-4)

In step S206-4, determination of the temperature correction value is performed. The temperature correction value most suitable for the temperature of the fluid calculated in step S204 and the setting angle calculated in step S205 is selected from the temperature correction value data shown in fig. 10D.

(step S207)

In step S207, the correction of the flow rate is performed using each correction value determined in step S206. Specifically, the flow rate correction unit 12 multiplies the flow rate calculated by the flow rate calculation unit 10 in step S201 by the flow rate correction value, the pressure correction value, the fluid type correction value, and the temperature correction value determined in step S206.

The flow rate measurement device 100 performs correction of the flow rate by executing the above-described steps S201 to S207.

[ Effect/Effect ]

As described above, in the present embodiment, the flow rate measurement device 100 can detect the distribution of heat generated by the flow of the fluid by the detection element 1 which is a thermal flow sensor, and calculate the flow rate of the fluid. The flow rate measurement device 100 may also determine fluid characteristics such as the pressure of the fluid, the type of the fluid, and the temperature of the fluid.

The flow rate measurement device 100 can calculate an angle (installation angle) of a direction in which the micro-heater 6 and the thermopiles 7A and 7B are arranged with respect to a horizontal plane.

Then, from among the flow rate correction value, the pressure correction value, the fluid type correction value, and the temperature correction value stored in the storage unit 14, correction values that are most suitable for the calculated flow rate, the characteristics such as the pressure/type/temperature of the fluid, and the setting angle are selected, and the flow rate is corrected by multiplying the selected flow rate correction value, the pressure correction value, the fluid type correction value, and the temperature correction value by the calculated flow rate. That is, the flow rate measurement device 100 eliminates the influence of heat transfer due to the convection phenomenon from the calculated flow rate. Also, the correction is based on characteristics such as the flow rate, pressure/type/temperature, and the like of the fluid and the set angle of the flow rate measurement device 100. Therefore, the flow rate can be accurately corrected according to the installation angle of the flow rate measurement device 100, and the flow rate can be calculated with high accuracy.

In the present embodiment, the flow of the fluid is stopped when the installation angle of the flow rate measurement device 100 is calculated. Therefore, the output of the thermopile 7A or 7B is an output for detecting the distribution of heat generated by the convection phenomenon that is not affected by the fluid flow. Therefore, the installation angle can be calculated with high accuracy.

In addition, in the present embodiment, since the flow rate is corrected based on a plurality of characteristics of the fluid, such as the pressure of the fluid, the type of the fluid, and the temperature of the fluid, the accuracy of flow rate calculation can be improved.

Modification example 4

The embodiments of the present invention have been described in detail, but the above description is merely illustrative of the present invention in all aspects. Various modifications and changes may be made without departing from the scope of the present invention. For example, the following modifications can be made. In the following, the same reference numerals are used for the same main components as those of the above embodiment, and the description thereof is omitted as appropriate for the same points as those of the above embodiment. The following modifications can be combined as appropriate.

＜4.1＞

Fig. 12 schematically illustrates an example of a perspective view of the flow rate measurement device 100A and the flow tube member 4A. As shown in fig. 12, the flow rate measurement device 100A includes a detection element 18 in addition to the detection element 1 and the control unit 2. The flow tube member 4A has one flow path, not shown, which follows the flow of the fluid, like the flow path section 5 of the flow tube member 4, and the detection element 1 and the detection element 18 are provided in parallel in the direction of cutting off the flow of the fluid in the one flow path. The detection element 18 is a thermal flow sensor of the same type as the detection element 1, and has a micro-heater 6A and thermopiles 7C, 7D as the detection element 1. Here, the micro-heater 6A is an example of the "second heating section" of the present invention. The thermopiles 7C and 7D are examples of the "second temperature detection unit" according to the present invention.

Fig. 13 schematically illustrates an example of the relationship of the detection element 18 with the flow of the fluid airflow. The detection element 18 is arranged in a direction in which the micro-heater 6A and the thermopiles 7C, 7D block the flow of fluid, and is provided in one flow path of the flow tube unit 4A.

Here, since the temperature distribution is shifted to the downstream side by the flow of the fluid, the change in the temperature distribution in the direction of cutting off the flow is smaller than the change in the temperature distribution in the direction of the flow of the fluid. Therefore, the change in the output characteristics of the thermopiles 7C and 7D due to the change in the temperature distribution can be reduced. Therefore, the influence of the change in the temperature distribution due to the flow of the fluid can be reduced, and the characteristic value can be measured by the detection element 18.

Further, since the longitudinal direction of the micro-heater 6A is arranged along the flow direction of the fluid, the micro-heater 6A can heat the fluid over a wide range in the flow direction of the fluid. Therefore, even when the temperature distribution is shifted to the downstream side by the flow of the fluid, the change in the output characteristics of the thermopiles 7C and 7D can be reduced. Therefore, the influence of the change in the temperature distribution due to the fluid flow can be reduced, and the characteristic value can be measured by the detection element 18.

Further, since the longitudinal directions of the thermopiles 7C and 7D are arranged along the flow direction of the fluid, the thermopiles 7C and 7D can detect the temperature over a wide range in the flow direction of the fluid. Therefore, even when the temperature distribution is shifted to the downstream side by the flow of the fluid, the change in the output characteristics of the thermopiles 7C and 7D can be reduced. Therefore, the influence of the change in the temperature distribution due to the flow of the fluid can be reduced, and the characteristic value can be measured.

Fig. 14 schematically illustrates an example of a block diagram showing a functional configuration of the flow rate measurement device 100A. The flow rate measuring device 100A includes an angle calculating unit 11A, and the angle calculating unit 11A receives the output of the thermopile 7C or 7D, obtains the output of the thermopile 7C or 7D, and calculates an angle of a direction in which the micro-heater 6A and the thermopiles 7C and 7D are juxtaposed with respect to a horizontal plane. That is, the installation angle calculating unit 11A calculates an angle in the direction of cutting off the flow of the fluid with respect to, for example, a horizontal plane. Here, the installation angle calculated by the installation angle calculation unit 11A is an example of the "inclination angle of the second temperature detection unit" in the present invention. Further, the relationship between the output of the thermopile 7C or 7C and the installation angle of the flow rate measurement device 100 is previously established. Then, the installation angle of the flow rate measurement device 100A is calculated from the relationship between the output of the thermopile 7C or 7D and the installation angle of the flow rate measurement device 100.

However, the outputs of the thermopiles 7C and 7D reduce the influence due to the flow of the fluid. Therefore, when the installation angle is calculated by the installation angle calculating unit 11A, it is not necessary to stop the flow of the fluid as in step S205-1.

The storage unit 14 of the flow rate measurement device 100A stores a correction value relating to an angle of a direction in which the micro-heater 6A and the thermopiles 7C, 7D are juxtaposed with respect to a horizontal plane, and characteristics such as a flow rate of the fluid or a pressure, a type, and a temperature of the fluid.

In the present modification, the fluid type derivation unit 16 and the temperature calculation unit 17 receive the outputs of the thermopiles 7C and 7D, and determine an average value of the outputs of the thermopiles 7C and 7D. Then, the type of fluid and the temperature of the fluid are calculated from the average value of the outputs of the thermopiles 7C and 7D.

[ Effect/Effect ]

In the case of the flow rate measurement device 100A, outputs of the thermopiles 7C and 7D, which are reduced in the influence of a change in temperature distribution due to the flow of the fluid, are used when calculating the installation angle, the type of the fluid, and the temperature of the fluid. Therefore, the installation angle, the type of fluid, and the temperature of the fluid can be calculated with high accuracy. Further, the accuracy of the flow rate correction can be improved by using the installation angle, the type of fluid, and the temperature of the fluid, which are calculated with high accuracy. In the present modification, when the installation angle is calculated by the installation angle calculating unit 11A, it is not necessary to stop the flow of the fluid as in step S205-1. Therefore, the set angle can be detected easily.

＜4.2＞

In the modification < 4.1 >, the angle in the direction in which the fluid flows is calculated with respect to the horizontal plane by the installation angle calculation unit 11A using the outputs of the thermopiles 7C and 7D, but the angle in the direction in which the fluid flows may be calculated with respect to the horizontal plane by the installation angle calculation unit 11.

In the case of the flow rate measurement device 100A described above, the storage unit 14 stores correction values relating to the angle and flow rate of the flow direction of the fluid with respect to the horizontal plane, the pressure/fluid type/temperature, and correction values relating to the angle and flow rate of the direction in which the flow of the fluid is cut off with respect to the horizontal plane, the pressure/fluid type/temperature.

[ Effect/Effect ]

In addition to the effects of the modification of < 4.1 >, the flow rate measuring device 100A may calculate the angle of the direction of fluid flow with respect to the horizontal plane in the installation angle calculating unit 11 using the detection element 1, and calculate two installation angles of the direction of fluid flow cutoff with respect to the horizontal plane in the installation angle calculating unit 11A using the detection element 18. Therefore, the inclination of the flow rate measurement device 100A can be grasped stereoscopically. Further, the calculated flow rate can be corrected based on the two set angles. Therefore, the flow rate can be accurately corrected, and the flow rate can be calculated with high accuracy.

＜4.3＞

In the modification of < 4.1 >, < 4.2 >, the detection element 1 and the detection element 18 are provided in one flow path of the flow tube unit 4A, but the detection element 1 and the detection element 18 may be provided in different flow paths. Fig. 15 schematically illustrates an example in which a flow rate measurement device 100B is provided in a flow tube member 4B having two flow path sections, namely, a main flow path section 19 and a sub flow path section 20.

Here, the flow rate measurement device 100B includes: a disk-shaped circuit board 21, a cover 22 covering the outer surface of the circuit board 21, and a sealing material 23 for bonding the circuit board 21 and the flow tube member 4B. The flow tube member 4B includes two flow path portions, i.e., a main flow path portion 19 and a sub flow path portion 20. The main flow path portion 19 is a tubular member. The sub-flow path portion 20 is located on the side of the main flow path portion 19, and has a sub-flow path formed therein. Fig. 16 schematically illustrates an example of a partially enlarged view of the sub flow path portion 20. The main channel section 19 and the sub channel section 20 communicate with each other via an inflow channel 24 and an outflow channel 25. The sub-channel section 20 includes a first channel 26 branched from the inflow channel 24 and provided with the detection element 1, and a second channel 27 branched from the inflow channel 24 and provided with the detection element 18. The first channel 26 and the second channel 27 branched from the inflow channel 24 are joined together to form the outflow channel 25.

The first flow path 26 is a substantially コ -shaped flow path. The first flow path 26 has a detection element arrangement portion 28A at a middle portion in the longitudinal direction (direction parallel to the main flow path portion 19), and the detection element arrangement portion 28A is provided with the detection element 1 used for detecting the flow rate of the fluid.

The second flow path 27 is also formed into a substantially コ -shaped flow path, similarly to the first flow path 26. The second channel 27 has a detection element arrangement portion 28B at a middle portion in the longitudinal direction (direction parallel to the main channel portion 19), and the detection element arrangement portion 28B is provided with the detection element 18 that measures the thermal diffusivity of the fluid. Here, the micro-heater 6A and the thermopiles 7C and 7D of the detection element 18 are not shown, but are arranged in parallel in the direction of interrupting the flow of the fluid.

The flow rate measurement device 100B is fixed to the flow tube member 4B in the following manner. First, the sub-flow path portion 20 and the circuit board 21 are bonded to each other by the seal material 23. After that, the surface of the circuit board 21 is covered with the cover 22. The fixing method described above can ensure airtightness inside the sub flow path section 20. Therefore, the air outside the flow tube member 4B does not enter the sub-flow path portion 20, and the detection of the flow rate and the physical property value is not affected.

Fig. 17 schematically illustrates an example of a cross-sectional view when the flow rate measurement device 100B is provided in the pipe member 4B. The flow tube member 4B has a resistor 29 in the vicinity of the secondary flow path portion 20. When a fluid flows through the main channel portion 19, a part of the fluid is blocked by the resistor 29 and flows into the sub channel portion 20 through the inflow channel 24. Then, a fluid having the same physical properties such as temperature and pressure flows into the first channel 26 and the second channel 27 branched from the sub-channel portion 20.

[ Effect/Effect ]

In the flow rate measurement device 100B, the flow rates of the fluids branched into the first flow path 26 and the second flow path 27 can be individually controlled by adjusting the widths of the flow paths. Therefore, the flow rate of the fluid flowing through the first flow path 26 can be controlled according to the detection range of the detection element 1, and the flow rate of the fluid flowing through the second flow path 27 can be controlled according to the detection range of the detection element 18.

Therefore, the flow rate measurement device 100B can detect the physical property value of the fluid at the optimum flow rate corresponding to the unique detection range of each detection element, and therefore, the detection accuracy can be improved. Therefore, the flow rate and the characteristic value can be calculated with high accuracy and corrected.

＜4.4＞

In the above embodiment, the installation angle of the flow rate measurement device is calculated by the detection element 1 or 18, but an inclination sensor may be provided instead of detecting the installation angle of the flow rate measurement device by using the detection elements 1 and 18. Here, the tilt sensor is an example of the "angle calculating means" of the present invention. In this case, the installation angle calculation unit receives a signal output from the inclination sensor and calculates an inclination angle of the thermopile with respect to a predetermined reference surface, that is, an installation angle of the flow rate measurement device. In this modification, the installation angle of the flow rate measurement device can be detected without using the output of the thermopile.

In the above-described embodiment, the reference plane of the installation angle of the flow rate measurement device is a horizontal plane, but any plane may be used as long as it is a reference plane.

In the above-described embodiment, the set angle is calculated from the output of the thermopile, but the flow rate may be corrected without calculating the set angle.

The installation angle in the above-described embodiment can be calculated without any limitation in direction by using the output of the thermopile and the difference information of the output of the thermopile. That is, for example, the installation angle calculation unit 11 can calculate the installation angle in the direction of interrupting the flow of the fluid, in addition to the installation angle in the direction of the flow of the fluid with respect to the horizontal plane, by using the difference information between the output of the thermopile 7A or 7B and the outputs of the thermopiles 7A and 7B. For example, the installation angle calculation unit 11A can calculate the installation angle of the direction of fluid flow in addition to the installation angle of the direction of fluid flow with respect to the horizontal plane by using the output of the thermopile 7C or 7D and the difference information of the outputs of the thermopiles 7C and 7D.

In the modification of the above embodiment, the installation angle of the flow rate measuring device, the type of fluid, and the temperature of the fluid are calculated from the average value of the outputs of the thermopiles 7C and 7D, but the installation angle of the flow rate measuring device, the type of fluid, and the temperature of the fluid may be calculated from the output of one side of the thermopile 7C or 7D.

＜4.5＞

Fig. 18 schematically illustrates an example of an outline of a gas meter 50 in which the flow rate measurement device 100C is installed, for example, underground. The existing gas meters are all directed to miniaturization and embedding from the viewpoint of architectural style. As an example of a conventional gas meter, there is a membrane type gas meter, but it is difficult to miniaturize the gas meter due to a limitation in the measurement principle. Therefore, although development of turbine type and fluid type gas meters has been made, no sufficient results have been obtained. Therefore, currently, miniaturization of the gas Meter can be achieved by putting a USM (Ultrasonic Meter) into practical use.

However, since the conventional gas meter incorporates a safety device including a pressure sensor (based on atmospheric pressure) for monitoring the pressure of the supplied gas, a vent hole to the atmosphere needs to be provided in a housing of the gas meter incorporating the pressure sensor, and it is difficult to bury the gas meter in the ground where the gas meter may be submerged in water.

The gas meter 50 shown in fig. 18 is an underground buried gas meter, and is provided, for example, in a house 51 in the middle of an underground pipe 53 through which gas supplied to a facility 52 using gas passes. The flow rate measurement device 100C is provided inside the gas meter 50 and measures the flow rate of the gas.

Fig. 19 schematically illustrates an example of a partially enlarged view of the gas meter 50. The gas meter 50 has a flow pipe part 54 through which gas passes inside. The gas meter 50 includes connection screws 56A and 56B, and the connection screws 56A and 56B are provided in the middle of the pipe 53, connect the pipe 53 to the flow pipe member 54, and fix the connection portions 55A and 55B, respectively. Here, the gas meter 50 is provided facing the same direction (lateral direction in the example of fig. 19) as the coupling direction of the coupling portion 55A and the coupling direction of the coupling portion 55B.

The gas meter 50 further includes a flow rate measurement device 100C that measures gas passing through the inside of the flow tube unit 54. The gas meter 50 further includes an absolute pressure sensor 57 that detects the supply pressure of the gas flowing through the flow tube unit 54, in addition to the flow rate measurement device 100C. Here, the absolute pressure sensor 57 is provided in a linear form in parallel with the flow rate measurement device 100C. The gas meter 50 further includes a shut-off valve 58 for shutting off the flow of gas in the flow pipe member 54. In addition, the gas meter 50 has an electronic substrate 59. Fig. 20 schematically illustrates an example of the configuration overview of the electronic substrate 59. A wiring pattern is formed of metal on the surface of the electronic substrate 59, and the wiring pattern is electrically connected to the flow rate measurement device 100C. A custom IC (integrated circuit) 60 for measurement for measuring an output from the flow rate measurement device 100C is mounted on the surface of the electronic substrate 59. The wiring pattern of the electronic board 59 is electrically connected to the gate valve 58. The opening degree of the shut valve 58 is controlled by elements mounted on the surface of the electronic substrate 59. The gas meter 50 has an earthquake sensor 61 on the electronic substrate 59, and the earthquake sensor 61 senses an earthquake and operates the shut valve 58 to shut off the flow of gas when the oscillation is equal to or greater than a predetermined value. Further, an absolute pressure sensor 57 is mounted on the back surface of the electronic substrate 59. The gas meter 50 includes a battery 62 on an electronic substrate 59, and the battery 62 generates electric power for driving the flow rate measurement device 100C, the shut valve 58, the absolute pressure sensor 57, and the like. The gas meter 50 has a housing 63 for protecting the flow rate measuring device 100C, the absolute pressure sensor 57, the shut-off valve 58, the electronic board 59, various elements on the electronic board 59, the flow tube member 54, and the like.

According to the gas meter 50 described above, the absolute pressure sensor 57 provided in the gas meter 50 does not require a vent to the atmosphere, and therefore the housing 63 can be sealed. Therefore, the gas meter 50 may be buried. Further, since the gas meter 50 is sealed, the inside of the flow tube member 54 is not easily affected by changes in the external environment, and the environment such as temperature and humidity is stable. Therefore, according to the gas meter 50 described above, it is possible to perform flow measurement with high accuracy.

In addition, according to the gas meter 50 described above, the connection direction of the connection portion 55A, 55B to which the flow pipe member 54 and the pipe 53 are connected faces the same direction. Therefore, the straight tube length of the flow tube member 54 can be extended as much as possible. Therefore, the flow of the gas in the flow pipe member 54 is more stable than the flow of the gas flowing in the curved pipe, and therefore, the gas meter 50 described above can perform a highly accurate flow rate measurement.

In addition, according to the gas meter 50 described above, various sensors such as the flow rate measurement device 100C and the absolute pressure sensor 57 are arranged in a linear shape. Therefore, it is easier to arrange the flow tube member 54 linearly, as compared with the case where the various sensors are not linearly but irregularly arranged. That is, the gas meter 50 can be made simple in structure, and the number of components forming the gas meter 50 can be reduced easily. Therefore, the measurement of the gas can be effectively achieved, and in addition, the manufacturing cost of the gas meter 50 is reduced.

In addition, according to the gas meter 50 described above, since the flow rate of the gas can be detected by one element such as the flow rate measurement device 100C, the gas meter 50 can be downsized. Further, the horizontal piping structure can be formed so as to reduce the influence of flow measurement errors due to convection.

Further, when a conventional gas meter is buried underground, it is considered to be difficult to recognize an installation angle of a flow rate measurement device installed in the gas meter from the ground. Therefore, when the installation angle of the flow rate measuring device is inclined with respect to the horizontal plane, it is considered difficult to correct the measured flow rate in accordance with the inclination. However, in the case of the embedded gas meter 50 having the flow rate measurement device 100C as described above, even in the case where the installation angle of the flow rate measurement device 100C is inclined with respect to the horizontal plane, the gas measured by the flow rate measurement device 100C can be automatically corrected in accordance with the installation angle of the flow rate measurement device 100C. Therefore, high-precision flow measurement can be performed. In addition, even in a situation where it is difficult to set the flow rate measurement device 100C at a desired angle, such as when the ground surface is originally inclined, the gas measured by the flow rate measurement device 100C can be automatically corrected in accordance with the set angle of the flow rate measurement device 100C. That is, the gas meter 50 is a highly convenient device capable of performing highly accurate flow measurement regardless of the installation environment.

The shut-off valve 58 provided in the gas meter 50 is preferably arranged such that the flow rate measuring device 100C and the absolute pressure sensor 57 are linearly arranged. By providing the shut-off valve 58 in this way, even when the opening degree of the shut-off valve 58 is changed, turbulence of the gas inside the flow pipe member 54 can be reduced, and the influence on the gas measurement by the flow rate measurement device 100C or the absolute pressure sensor 57 can be reduced.

The embodiments and the modifications disclosed above may be combined separately.

In the following, the main components of the present invention are described by reference numerals in order to compare them with the configurations of the embodiments.

< first invention >

A flow rate measurement device (100) having:

a heating unit (6) that heats a fluid;

temperature detection units (7A, 7B) that are provided in parallel across the heating unit (6) in the direction of fluid flow and that detect the temperature of the heated fluid;

a flow rate calculation unit (10) that calculates the flow rate of the fluid based on the detection signals output from the temperature detection units (7A, 7B);

an angle calculation means (11) for calculating the inclination angle of the temperature detection units (7A, 7B) with respect to a predetermined reference plane;

a storage unit (14) that stores the flow rate and the relationship between the inclination angle and the flow rate correction value;

and a flow rate correction unit (12) that corrects the flow rate using the flow rate correction value stored in the storage unit (14).

< second invention >

The flow rate measurement device (100) according to the first invention,

the angle calculation means (11) calculates the inclination angle based on the output of the temperature detection units (7A, 7B) when no fluid flows.

< third invention >

The flow rate measurement device (100) according to the first or second invention,

further comprises characteristic value calculation units (15, 16, 17) for calculating the characteristic value of the fluid based on the detection signals outputted from the temperature detection units (7A, 7B),

the storage unit (14) further stores the characteristic value and a relationship between the inclination angle and a characteristic correction value,

the flow rate correction unit (12) further corrects the flow rate using the characteristic correction value stored in the storage unit (14).

< fourth invention >

The flow rate measurement device (100A, 100B) according to the first or second invention further includes:

a second heating unit (6A);

second temperature detection units (7C, 7D) that are provided in parallel across the second heating unit (6A) in the direction in which the flow of fluid is interrupted;

characteristic value calculation units (15, 16, 17) that calculate a characteristic value of the fluid based on the detection signals output from the second temperature detection units (7C, 7D);

the angle calculation means (11A) also calculates the angle of inclination of the second temperature detection unit with respect to a predetermined reference plane based on the output of the second temperature detection unit (7C, 7D).

< fifth invention >

A flow rate measurement device (100A, 100B) is provided with:

a heating unit (6) that heats a fluid;

temperature detection units (7A, 7B) that are provided in parallel across the heating unit (6) in the direction of fluid flow and that detect the temperature of the heated fluid;

a flow rate calculation unit (10) that calculates the flow rate of the fluid based on the detection signals output from the temperature detection units (7A, 7B);

a second heating unit (6A);

second temperature detection units (7C, 7D) that are provided in parallel across the second heating unit (6A) in the direction in which the flow of fluid is interrupted;

characteristic value calculation units (15, 16, 17) that calculate a characteristic value of the fluid based on the detection signals output from the second temperature detection units (7C, 7D);

an angle calculation means (11A) for calculating the inclination angle of the second temperature detection unit (7C, 7D) with respect to a predetermined reference plane based on the output of the second temperature detection unit (7C, 7D);

a storage unit (14) that stores the flow rate and the relationship between the inclination angle of the second temperature detection unit (7C, 7D) and the flow rate correction value, and also stores the characteristic value and the relationship between the inclination angle of the second temperature detection unit (7C, 7D) and the characteristic correction value;

and a flow rate correction unit (10) that corrects the flow rate using the flow rate correction value and the characteristic correction value stored in the storage unit (14).

< sixth invention >

The flow rate measurement device (100, 100A, 100B) according to any one of the third to fifth inventions,

the characteristic value represents at least any one of a pressure, a type, and a temperature of the fluid.

< seventh invention >

An embedded gas meter (50) embedded underground, comprising:

a flow pipe (54) through which the gas flowing into the buried gas meter (50) flows;

a flow rate measurement device (100C) according to any one of the first to sixth inventions;

the flow rate measurement device (100C) is provided in the flow pipe (54) and detects the flow rate of the gas flowing through the flow pipe (54).

Description of the reference numerals

1, 18 detection elements; 2 a control unit; 3, 21 a circuit substrate; 4, 4A, 4B flow tube components; 5a flow path section; 6, 6A microheater; 7, 7A, 7B, 7C, 7D thermopiles; 8 an insulating film; 9 a cavity; 10a flow rate calculating unit; 11, 11A is provided with an angle calculating part; 12 a flow rate correction unit; 13 a correspondence table; 14 a storage unit; 15 a pressure calculation unit; 16 a fluid type lead-out portion; 17 a temperature calculating unit; 19 a main channel part; 20 auxiliary flow path parts; 22 a cover body; 23 a seal member; 24 an inflow channel; 25 outflow channel; 26 a first flow path; 27 a second flow path; 28A detecting element disposing section; 28B a detection element arrangement portion; 29 a resistor; 50 buried gas meter; 51 a house; 52, a device; 53 piping; 54 a flow tube member; 55A, 55B linking portion; 56A, 56B connecting screws; 57 an absolute pressure sensor; a 58 cut-off valve; 59 an electronic substrate; 60 custom IC for measurement; 61 seismic sensors; 62 a battery; 63 a basket body; 100, 100A, 100B, 100C flow measurement devices.