Physical quantity measurement device

Abstract

The purpose of the present disclosure is to provide a physical quantity measurement device in which flow rate measurements of a gas containing moisture can be performed with a small number of components forming a main flow path for measuring flow rate and an auxiliary flow path for discharging water droplets. The physical quantity measurement device according to the present disclosure comprises: a flow path main body provided with an internal space having an opening; a flow path lid for blocking the opening of the flow path main body; a main flow path disposed within the internal space of the flow path main body; an upstream opening part provided on the upstream side of the main flow path; a downstream opening part provided on the downstream side of the main flow path; an auxiliary flow path provided on the outside of the main flow path and connecting the upstream opening part and the downstream opening; and a flow rate measurement sensor provided on the main flow path. The auxiliary flow path is configured as a region enclosed by the flow path main body and the flow path lid.

Description

Physical Quantity Measuring Devices

[0001] The present disclosure relates to a physical quantity measuring device for measuring a physical quantity of gas by removing the influence of water droplets and the like from a fluid containing water.

[0002] Patent Document 1 discloses a physical quantity measuring device that measures the flow rate of a fluid or the concentration of a component contained in the fluid by removing the effects of water droplets and the like from the fluid containing water. In this physical quantity measuring device, a sub-channel for discharging water droplets is formed by inserting a sub-channel forming member into a recess in a channel main body. Furthermore, a channel lid is placed over the recess in the channel main body to form a main channel. In other words, the main channel for measuring the physical quantity and the sub-channel for discharging water droplets are formed using three components: the channel main body, the sub-channel forming member, and the channel lid.

[0003] Japanese Patent Application Laid-Open No. 2022-25751

[0004] An object of the present disclosure is to provide a physical quantity measuring device that, when measuring gas flow rates by removing the effects of water droplets and the like from a fluid containing moisture, enables the formation of a main flow path for measuring gas flow rates and a sub-flow path for discharging water droplets with a two-component configuration.

[0005] The physical quantity measuring device according to the present disclosure comprises a flow path main body, a flow path lid, a main flow path, a flow rate measurement sensor, a signal processing unit, an upstream opening, a downstream opening, and a sub-flow path. The flow path main body comprises an internal space having an opening. The flow path lid closes the opening. The main flow path is disposed in the internal space. The flow rate measurement sensor is provided in the main flow path. The signal processing unit receives a signal from the flow rate measurement sensor and measures the flow rate of the fluid. The upstream opening is provided upstream of the main flow path, and the downstream opening is provided downstream of the main flow path. The sub-flow path is provided outside the main flow path and connects the upstream opening and the downstream opening. The sub-flow path is configured as an area surrounded by the flow path main body and the flow path lid.

[0006] FIG. 1 is a configuration diagram of a physical quantity measuring device including an external perspective view of a flow path section according to a first embodiment. FIG. 2 is an exploded assembly view of the flow path section of FIG. 1 according to the first embodiment. FIG. 3 is a partial cross-sectional exploded assembly view of the flow path section of FIG. 1 according to the first embodiment. FIG. 4A is a schematic cross-sectional view of the flow path section of FIG. 1 according to the first embodiment, taken along line A1-A2. FIG. 4B is an exploded view of the flow path section of FIG. 1. FIG. 5A is a B1-B2 cross-sectional view of the flow path section of FIG. 1 according to the first embodiment. FIG. 5B is a schematic cross-sectional view of the C1-C2 cross section of FIG. 5A. FIG. 6A is a schematic vertical cross-sectional view of the flow path section of a physical quantity measuring device according to a second embodiment. FIG. 6B is an exploded view of the flow path section of a physical quantity measuring device. FIG. 7A is a schematic vertical cross-sectional view of the flow path section of a physical quantity measuring device according to a third embodiment. FIG. 7B is an exploded view of the flow path section of a physical quantity measuring device. FIG. 8 is a partial cross-sectional view of the flow path section of a conventional physical quantity measuring device.

[0007] At the time the inventors arrived at the present disclosure, a method for forming a sub-channel for removing water droplets from a fluid to be measured, with the aim of measuring a physical quantity such as the flow rate of a gas containing moisture, was available as shown in FIG. 8 . FIG. 8 is a partial cross-sectional view of a flow channel portion of this physical quantity measuring device 100. In this configuration, a sub-channel 104 for discharging water droplets was formed by inserting a sub-channel forming member 103 into a recess 102 in a flow channel main body 101. In this case, a main flow channel 105 through which the physical quantity was measured was formed by covering the recess 102 in the flow channel main body 101 with a flow channel lid 106. In other words, the main flow channel 105 and the sub-channel 104 were typically formed using three components: the flow channel main body 101, the sub-channel forming member 103, and the flow channel lid 106.

[0008] However, the inventors discovered that the method using these three components had the problem of making the configuration complicated, and in order to solve this problem, they came up with the subject matter of the present disclosure.

[0009] Therefore, the physical quantity measuring device of the present disclosure includes a flow channel body, a flow channel lid, a main flow channel, a flow rate measurement sensor, a signal processing unit, an upstream opening, a downstream opening, and a sub-flow channel. The flow channel body includes an internal space having an opening. The flow channel lid closes the opening. The main flow channel is disposed in the internal space. The flow rate measurement sensor is provided in the main flow channel. The signal processing unit receives a signal from the flow rate measurement sensor and measures the flow rate of the fluid. The upstream opening is provided upstream of the main flow channel, and the downstream opening is provided downstream of the main flow channel. The sub-flow channel is provided outside the main flow channel and connects the upstream opening and the downstream opening. By configuring the sub-flow channel as an area surrounded by the flow channel body and the flow channel lid, the main flow channel for measuring the physical quantity and the sub-flow channel for discharging water droplets can be formed using only two parts: a convex flow channel lid and a flow channel body having a concave space, by covering the former with the latter. The "outside of the main flow path" where the sub-flow path is provided refers to the space formed by the flow path body and the flow path cover other than the space that becomes the main flow path.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted.

[0011] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0012] First Embodiment Hereinafter, a first embodiment will be described with reference to FIGS. 1 to 5B.

[0013] 1 is a configuration diagram of a physical quantity measuring device including an external perspective view of a flow path section according to a first embodiment of the present disclosure, FIG. 2 is an exploded assembly view of the flow path section in FIG. 1, FIG. 3 is a partial cross-sectional assembly view of the flow path section in FIG. 1, FIGS. 4A and 4B are an A1-A2 cross-sectional view and an exploded view of the flow path section in FIG. 1, and FIGS. 5A and 5B are a B1-B2 cross-sectional view and a C1-C2 cross-sectional view of the flow path section in FIG. 1.

[0014] 1, the flow path section 1 has a fluid inlet 2 through which the fluid to be measured flows in and a fluid outlet 3 through which the fluid to be measured flows out. The flow path section 1 also has a pressure sensor 4, a relative humidity sensor 5 (hereinafter referred to as a humidity sensor), temperature sensors 6 and 7 provided upstream and downstream in the flow direction, and ultrasonic transmitter-receivers (flow rate measurement sensors) 8a and 8b arranged upstream and downstream in the flow direction, facing each other at an angle to the flow direction.

[0015] 2, 3, 4A and 4B, which will be used hereinafter, the pressure sensor 4, humidity sensor 5, temperature sensors 6 and 7 and their mounting holes etc. are omitted.

[0016] 4A and 4B, which are cross sections taken along the line A1-A2 in Fig. 1, the flow path portion 1 is configured by inserting the convex portion 12a of the flow path cover 12, which has an upward convex shape, into the flow path main body 11, which has an internal space 10, which has a downward concave shape, to close the opening 10a. The main flow path 9, in which the flow rate of the fluid to be measured is measured, is formed by the space generated between the tip of the convex portion 12a of the flow path cover 12 and the internal space 10, with the flat portion 12b of the flow path cover 12 abutting against the step portion 11b of the flow path main body 11. The space corresponding to the main flow path 9 is shown by a dashed line in Fig. 3.

[0017] In FIG. 4A , the sub-channel 13 is an area surrounded by the groove 14 provided on the side surface of the convex portion 12 a of the channel cover 12 and the side surface 11 a of the concave portion of the channel body 11 .

[0018] As shown in Fig. 4A, the main flow path 9, in which the flow rate of the fluid to be measured is measured, has a rectangular cross section with a long side having a width W and a short side having a height H, and the main flow path 9 is divided into multiple layers by partition plates 15 arranged in a substantially horizontal direction to form a multi-layer section 16. The three-dimensional appearance is as shown in Fig. 3.

[0019] 4A , the height Ha of the short side of each divided layer is smaller than the height H before division, and the aspect ratio (W / Ha) of each layer of the multilayer section 16 is larger than before division, which improves the two-dimensionality of the flow and uniforms the flow velocity distribution in the width direction of the main flow channel 9. Furthermore, by making the height Ha of the short side of each layer equal, the uniformity of the flow velocity distribution in each layer is also improved, and overall flow straightening is achieved.

[0020] 3, 5A, and 5B, the upstream side of the sub-channel 13 is connected to an upstream opening 17 that opens to the upstream side of the main channel 9, and the downstream side is connected to a downstream opening 18 that opens to the downstream side of the main channel 9. In this way, the sub-channel 13 is located outside the main channel 9 and is disposed below the main channel 9 in the direction of gravity.

[0021] 5A, in the multilayer section 16, a pair of ultrasonic transmitter-receivers 8a and 8b are disposed facing each other in a diagonal direction relative to the flow direction of the fluid to be measured so that ultrasonic waves cross the flow of the fluid to be measured. In addition, the upstream ultrasonic transmitter-receiver 8a and the downstream ultrasonic transmitter-receiver 8b are disposed so as to partially protrude into the multilayer section 16.

[0022] 5A indicates the ultrasonic propagation path between the ultrasonic transmitters and receivers 8a and 8b. In order to allow the ultrasonic transmitters and receivers 8a and 8b to protrude into the flow of the fluid to be measured, a notch 19 is provided in the partition plate 15 to prevent the ultrasonic transmitters and receivers 8a and 8b from abutting against the partition plate 15. In addition, at this notch 19, the gap d between the tips of the ultrasonic transmitters and receivers 8a and 8b and the partition plate 15 is set to a dimension such that water droplets in the fluid to be measured accumulate and adhere due to surface tension, dripping off the tips of the ultrasonic transmitters and receivers 8a and 8b without remaining on the tips.

[0023] As shown in FIG. 1, various sensors such as temperature sensors 6 and 7, a pressure sensor 4, and a humidity sensor 5 are arranged in the flow path section 1 to measure the temperature, pressure, and relative humidity of the fluid to be measured, and all of these are attached to the flow path main body 11, just like the ultrasonic transmitter / receivers 8a and 8b.

[0024] 5A, the temperature sensors 6 and 7 are located upstream and downstream of the ultrasonic propagation path M where the flow velocity is measured, and are arranged so that their average value corresponds to the temperature at the center of the ultrasonic propagation path M. The pressure sensor 4 is located on the outermost layer of the multilayer section 16 at the center of the ultrasonic propagation path M, but the main flow path 9 is connected internally by the presence of the notch 19, so that an average pressure can be obtained. The humidity sensor 5 is located downstream of the multilayer section 16. This allows the humidity sensor 5 to perform measurements at a position where it is not affected by turbulence in the ultrasonic propagation path M and is less affected by water droplets, etc.

[0025] Next, the configuration of the signal processing system will be explained using Figure 1. The control unit 20 is electrically connected to the ultrasonic transmitter / receivers 8a and 8b, and is configured to be able to send and receive signals thereto. It is also provided with a signal processing unit 21 that receives signals from the control unit 20 and performs flow rate calculation processing. This signal processing unit 21 not only sends and receives signals from the control unit 20, but also signals from the pressure sensor 4, humidity sensor 5, and temperature sensors 6 and 7, and is electrically connected to these sensors, so that it not only performs the above flow rate calculation processing but also various other arithmetic processing.

[0026] In this way, the flow path section 1, the control section 20, and the signal processing section 21 constitute a physical quantity measuring device 22.

[0027] As shown in FIG. 2, in this embodiment, the multi-layer section 16 is divided into six layers by five partition plates 15, and the assembly structure of these partition plates 15 will be described next.

[0028] 2, the convex portion 12a of the flow path cover 12 is provided with mounting portions 23 having screw holes for assembling the partition plates 15 on the upstream and downstream sides. The partition plates 15 are provided with through holes (not shown) at locations corresponding to the mounting portions 23, and are fixed to the mounting portions 23 with screws in a state where they are stacked one on top of the other using spacers 24 so that the interval between the upper and lower partition plates 15 is Ha.

[0029] The multilayer portion 16 formed by assembling the partition plate 15 in this manner is attached to the convex-shaped flow path cover 12. The flow path main body 11 is integrated with the flow path cover 12 via a packing 25 that provides an airtight seal, thereby forming the flow path portion 1.

[0030] [1-2. Operation] The operation and function of the physical quantity measuring device 22 configured as above will be described below.

[0031] The assembly procedure for the flow path section 1 will be described with reference to FIG. 3 . First, the partition plates 15 are stacked and assembled in order via spacers 24 so that the spacing between them is equal to Ha shown in FIG. 4A , and then secured to the mounting section 23 with screws. The multilayer section 16 formed by assembling the partition plates 15 in this manner is attached to the convex section 12a of the flow path lid 12. The flow path body 11 having the downwardly recessed internal space 10 is placed over the flow path lid 12, and the flow path section 1 is assembled by pressing the packing 25 to ensure an airtight seal. At this time, the space in which the multilayer section 16 is disposed becomes the main flow path 9. Furthermore, in the cross-sectional view of FIG. 4A , the groove 14 provided on the side surface of the convex section 12a of the flow path lid 12 becomes the area surrounded by the recessed side surface 11a of the flow path body 11, and this portion becomes the sub-flow path 13.

[0032] As can be seen from this process, the main flow path 9 and the sub-flow path 13 are simultaneously formed simply by placing the flow path body 11 over the flow path cover 12, which has the grooves 14 for forming the sub-flow path 13, from above. This reduces costs by requiring only two parts, and improves workability. Furthermore, since the grooves 14 that form the sub-flow path 13 are formed on the side surfaces of the protruding portions 12a of the flow path cover 12, the assembly work can be performed while observing the state of the sub-flow path 13. This makes it easy to check for abnormalities in the sub-flow path 13, such as deformation of the flow path or the inclusion of foreign matter.

[0033] Next, the flow of the fluid to be measured will be described with reference to FIGS. 3, 4A, 4B, 5A and 5B.

[0034] 3, the fluid to be measured flows in through a fluid inlet 2 and flows out through a fluid outlet 3. The process during this period will be described in detail below.

[0035] That is, the flow F of the fluid to be measured that flows in from the pipe-shaped fluid inlet 2 is divided into a flow fs toward the main flow path 9 formed by the multilayer portion 16 and a flow fm toward the upstream opening 17 in the inlet space portion CH1 where the cross-sectional area in the flow direction is expanded. The flow fs toward the main flow path 9 passes through the multilayer portion 16 and then reaches the outlet space portion CH2.

[0036] On the other hand, the flow fm that has flowed into the upstream opening 17 passes through the sub-channel 13, then flows out from the downstream opening 18 and reaches the outlet space CH2. The two flows fs and fm join in the outlet space CH2, and the joined flows flow out from the fluid outlet 3. Figure 4A shows the positional relationship between the main channel 9 and the sub-channel 13 in a cross section perpendicular to the flow direction, and Figure 5B shows it in a cross section parallel to the flow direction.

[0037] As shown in Figure 5A, a pair of ultrasonic transmitters and receivers 8a and 8b are arranged relative to the flow in the main flow path 9, and these are used to measure the flow rate, as described below. In addition, the pressure sensor 4 and temperature sensors 6 and 7 measure the pressure and temperature of the flow in the main flow path 9, respectively. The humidity sensor 5 on the downstream side measures humidity. In this way, the main flow path 9 is a flow path that measures the physical quantity of the fluid to be measured. On the other hand, as can be seen in Figure 5B, the sub-flow path 13 is a flow path that bypasses the main flow path 9, and no physical quantity is measured in the sub-flow path 13.

[0038] Next, the behavior of these components when the fluid to be measured contains water or droplets such as water droplets will be described.

[0039] As shown in Figures 3 and 5B, the flow path section 1 is installed horizontally or with the downstream side facing downward in the direction of gravity. Under these conditions, some of the moisture and droplets (hereinafter referred to as "bypass fluid") flowing in with the fluid to be measured from the fluid inlet 2 drips downward due to gravity in the inlet space CH1 with an expanded cross-sectional area and flows into the secondary flow path 13 from the upstream opening 17. The bypass fluid then flows downstream in the secondary flow path 13, flows out of the outlet space CH2 from the downstream opening 18 provided on the downstream side, merges with the flow that has passed through the main flow path, and flows out of the fluid outlet 3. At this time, the bypass fluid flowing in the secondary flow path 13 can easily merge with the flow in the main flow path due to the attraction effect of the flow in the main flow path. As described above, the moisture and droplets that flow into the secondary flow path 13 are bypassed without interfering with the measurement of physical quantities in the main flow path 9.

[0040] On the other hand, in Figures 3 and 5B, of the moisture and droplets that flow in from the fluid inlet 2 along with the fluid to be measured, the fluid that does not drip downward due to gravity in the inlet space CH1 and does not flow into the secondary flow path 13 from the upstream opening 17 flows into the multilayer section 16 of the main flow path 9.

[0041] A portion of such fluid aggregates and adheres to the partition plate 15 and flows downstream as a flowing liquid on the surface of the partition plate 15. At this time, some of the fine droplets that do not aggregate and adhere to the partition plate are absorbed into the flowing liquid, thereby further reducing the moisture and droplets in the fluid to be measured.

[0042] Next, measures to prevent moisture or droplets that have flowed into the multilayer portion 16 from adhering to the ultrasonic transmitter / receivers 8a and 8b will be described with reference to FIGS. 5A and 5B.

[0043] Because the ultrasonic transmitters and receivers 8a and 8b are configured to protrude into the multilayer section 16, moisture and liquid droplets that have flowed along the surface of the multilayer section 16 tend to adhere to them. However, the partition plate 15 of the multilayer section 16 is provided with a notch 19, which provides a gap d between the ultrasonic transmitters and receivers 8a and 8b and the notch 19. This gap d is sized to prevent accumulation due to surface tension between the ultrasonic transmitting and receiving surfaces of the ultrasonic transmitters and receivers 8a and 8b and the notch 19, so moisture and liquid droplets do not drip downward and affect the transmitting and receiving surfaces.

[0044] In this way, the fluid to be measured flowing through the multilayer portion 16, which is the measurement portion, is reduced in moisture and droplets, making it suitable for measurement. In addition, deterioration of ultrasonic characteristics due to droplets adhering to the transmitting and receiving surfaces of the ultrasonic transmitters and receivers 8a and 8b that transmit and receive ultrasonic waves is prevented.

[0045] Next, the measurement operation will be described. As shown in Fig. 4A, the main flow path 9 with a rectangular cross section is divided by a partition plate 15, and each divided flow path has a multilayer section 16 with a large aspect ratio, thereby rectifying the flow and maintaining a stable flow state over a wide flow rate range from low to high. Under this condition, ultrasonic waves are transmitted and received via the ultrasonic propagation path M by the ultrasonic transmitter / receiver 8a and the ultrasonic transmitter / receiver 8b, as shown in Fig. 5A.

[0046] Such ultrasonic transmission and reception operations are performed by the control unit 20 shown in Fig. 1, and the flow velocity V can be determined from the data obtained thereby using the known reciprocal propagation time difference method in the signal processing unit 21. The flow rate Q of the fluid to be measured can be determined by multiplying this flow velocity V by the flow path cross-sectional area S and then by a correction flow coefficient k. That is, the flow rate Q can be determined using the formula "Q = k x V x S". At this time, the previously determined flow rate Q can be converted into a value under standard conditions in the signal processing unit 21 using the pressure obtained from the pressure sensor 4 and the temperature obtained from the temperature sensors 6 and 7, which are obtained at the same time.

[0047] That is, the flow rate can be calculated based on the propagation time obtained from the pair of ultrasonic transmitters and receivers 8a and 8b using a conventionally known method, and the flow rate under standard conditions can be obtained by correcting this value for temperature and pressure.

[0048] It is also possible to determine the concentration of a specific gas H in the fluid to be measured by a known method based on the relative humidity obtained from the humidity sensor 5 and the propagation time obtained from the ultrasonic transmitter-receivers 8a and 8b.

[0049] [1-3. Effects, etc.] As described above, in the present embodiment, the physical quantity measuring device 22 simultaneously forms the main flow path 9 and the sub-flow paths 13 by covering the flow path lid 12, in which the grooves 14 for forming the sub-flow paths 13 are formed, with the flow path main body 11 from above.

[0050] This reduces the number of components required to configure the main flow path 9 and the sub-flow path 13 to just two, thereby reducing costs and improving assembly workability when creating a physical quantity measuring device equipped with a water droplet removal function. Furthermore, by forming the groove 14 that forms the sub-flow path 13 on the side surface of the protruding portion 12a of the flow path cover 12, the assembly work can be performed while observing the state of the sub-flow path 13, making it easy to check for abnormalities in the sub-flow path 13, such as flow path deformation or the inclusion of foreign matter.

[0051] Furthermore, since the main flow path 9 is formed using a concave flow path body 11, the ultrasonic transmitter / receivers 8a, 8b, temperature sensors 6, 7, pressure sensor 4, and humidity sensor 5 for measurements can all be attached to the flow path body 11, thereby simplifying the overall configuration.

[0052] Second Embodiment Hereinafter, a second embodiment will be described with reference to FIGS. 6A and 6B.

[0053] 6A and 6B are schematic vertical cross-sectional views of a flow path portion of a physical quantity measuring device according to a second embodiment of the present disclosure.

[0054] The only difference between the second embodiment and the first embodiment is the flow path cover. Therefore, only this part will be described in Figures 6A and 6B. The other parts are the same as those in the first embodiment, and therefore will not be described. Furthermore, the same parts as those in the first embodiment will be described using the same reference numerals as those in the first embodiment.

[0055] 6A and 6B , the flow path portion 31 is composed of a flow path main body 11 and a flow path lid 32. A groove 34 is formed in a flat plate portion 33 of the flow path lid 32. By placing the flow path main body 11 on the flow path lid 32 from above, the opening 10a is closed and a sub-flow path 35 is formed.

[0056] [2-2. Operation] The operation and function of the flow path portion 31 of the physical quantity measuring device configured as above will be described below.

[0057] 6A and 6B, the groove 34 forming the sub-flow path 35 is formed in the flat plate portion 33 of the flow path cover 32, so that the flow path cover 32 can be produced by molding with a simple mold configuration. The operation of water droplets flowing out via the sub-flow path 35 is the same as in the first embodiment.

[0058] 2-3. Effects, etc. As described above, in this embodiment, the flow path portion 31 of the physical quantity measuring device has the grooves 34 that form the sub-flow paths 35 formed in the flat plate portion 33 of the flow path cover 32 .

[0059] This allows the flow path cover 32 to be produced by molding using a simple mold configuration.

[0060] Third Embodiment Hereinafter, a third embodiment will be described with reference to FIGS. 7A and 7B.

[0061] 7A and 7B are vertical cross-sectional views of a flow path portion of a physical quantity measuring device according to a third embodiment of the present disclosure.

[0062] The only difference between the third embodiment and the first embodiment is the sub-flow path configuration. Therefore, only this part will be described with reference to Figures 7A and 7B. The other parts are the same as those of the first embodiment, so a description thereof will be omitted.

[0063] 7A and 7B , the flow path portion 41 is composed of a flow path main body 42 and a flow path lid 43. A groove 45 is formed on a recess side surface 42a that forms an internal space 44 of the flow path main body 42. By placing the flow path main body 42 on the flow path lid 43 from above, the opening 44a is closed and a sub-flow path 46 is formed.

[0064] [3-2. Operation] The operation and function of the flow path portion 41 of the physical quantity measuring device configured as above will be described below.

[0065] 7A and 7B, the groove 45 forming the sub-flow path 46 is formed on the recess side surface 42a of the flow path main body 42, so that the flow path main body 42 can be produced by molding with a simple mold configuration. The operation of water droplets flowing out via the sub-flow path 46 is the same as in the first embodiment.

[0066] [3-3. Effects, etc.] As described above, in the present embodiment, in the flow path portion 41 of the physical quantity measuring device, the groove 45 forming the sub-flow path 46 is formed on the recess side surface 42 a forming the internal space 44 of the flow path main body 42.

[0067] This allows the flow path body 42 to be produced by molding using a simple mold configuration.

[0068] As described above, the first, second, and third embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the first, second, and third embodiments to create new embodiments.

[0069] Therefore, other embodiments will be exemplified below.

[0070] In the first embodiment, a pair of ultrasonic transmitter-receivers 8a and 8b is used to measure the flow rate, but a thermal sensor may also be used. In this case, it is not necessary to provide a pair, so for example, in the example shown in Figure 1, it is sufficient to simply place a thermal sensor in place of the ultrasonic transmitter-receiver 8a.

[0071] In the first embodiment, the pair of ultrasonic transmitter-receivers 8 a, 8 b and the humidity sensor are used as an example of concentration measurement, but a concentration sensor capable of measuring the concentration of a specific gas may also be used. In this case, it is sufficient to simply place the pair of ultrasonic transmitter-receivers 8 a, 8 b or a thermal sensor as a flow rate measurement sensor and the concentration sensor in place of the humidity sensor 5.

[0072] In this embodiment, the main flow path 9 is divided into multiple layers by the partition plates 15 to form the multi-layer portion 16, but it goes without saying that the main flow path 9 may be a single layer without using the partition plates 15.

[0073] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0074] (Summary) The above-described embodiments and the like disclose the following aspects.

[0075] A physical quantity measuring device (100) of a first aspect includes a flow path main body (11), a flow path lid (12), a main flow path (9), a flow rate measurement sensor, a signal processing unit (21), an upstream opening (17), a downstream opening (18), and a sub-flow path (13, 35, 46). The flow path main body (11) includes an internal space (10) having an opening (10a). The flow path lid (12) closes the opening (10a). The main flow path (9) is disposed in the internal space (10). The flow rate measurement sensor is provided in the main flow path (9). The signal processing unit (21) receives a signal from the flow rate measurement sensor and measures the flow rate of the fluid. The upstream opening (17) is provided upstream of the main flow path (9), and the downstream opening (18) is provided downstream of the main flow path (9). The sub-channels (13, 35, 46) are provided outside the main channel (9) and connect the upstream opening (17) and the downstream opening (18). The sub-channels (13, 35, 46) are configured as areas surrounded by the channel body (11) and the channel cover (12).

[0076] The physical quantity measuring device (100) of the second aspect is the first aspect, characterized in that the sub-channels (13, 35) are configured by grooves (14, 34) formed in the channel cover (12).

[0077] The physical quantity measuring device (100) of the third aspect is the first aspect, characterized in that the sub-channel (46) is constituted by a groove (45) formed in the channel main body (11).

[0078] A fourth aspect of the physical quantity measuring device (100) is any one of the first to third aspects, in which the main flow path (9) has a rectangular cross-sectional shape and a multi-layer portion (16) formed by partition plates (15) that divide the main flow path (9) into multiple layers. The flow rate measurement sensor is disposed in the multi-layer portion (16).

[0079] A physical quantity measuring device (100) of a fifth aspect is any one of the first to fourth aspects, wherein the flow rate measuring sensor is a pair of ultrasonic transducers (8a, 8b).

[0080] The present disclosure provides a low-cost gas flow measurement device with a water droplet removal function when the fluid being measured contains moisture or water droplets, and can be widely applied as a flow rate measurement or concentration measurement device in fuel cells for various purposes.

[0081] REFERENCE SIGNS LIST 1 Flow path section 2 Fluid inlet 3 Fluid outlet 4 Pressure sensor 5 Relative humidity sensor (humidity sensor) 6 Temperature sensor 7 Temperature sensor 8a Ultrasonic transmitter / receiver (flow rate measurement sensor) 8b Ultrasonic transmitter / receiver (flow rate measurement sensor) 9 Main flow path 10 Internal space 10a Opening 11 Flow path main body 11a Recessed portion side surface 12 Flow path lid 12a Convex portion 12b Flat plate portion 13 Sub-flow path 14 Groove 15 Partition plate 16 Multilayer portion 17 Upstream opening 18 Downstream opening 19 Notch portion 20 Control unit 21 Signal processing unit 22 Physical quantity measuring device 23 Mounting portion 24 Spacer 25 Packing 31 Flow path section 32 Flow path lid 33 Flat plate portion 34 Groove 35 Sub-flow path 41 Flow path section 42 Flow path main body 42a Recess side surface 43 Flow path cover 44 Internal space 44a Opening 45 Groove 46 Sub-flow path

Claims

1. A flow path body having an internal space with an opening; a flow path cover for closing the opening; A main flow path disposed in the internal space; A flow rate measurement sensor provided in the main flow path; a signal processing unit that receives a signal from the flow rate measurement sensor and measures the flow rate of the fluid; An upstream opening provided on the upstream side of the main flow path; A downstream opening provided on the downstream side of the main flow path; a sub-channel provided outside the main channel and connecting the upstream opening and the downstream opening, The physical quantity measuring device, wherein the sub-channel is configured as an area surrounded by the channel body and the channel cover.

2. 2. The physical quantity measuring device according to claim 1, wherein the sub-channel is constituted by a groove formed in the channel cover.

3. 2. The physical quantity measuring device according to claim 1, wherein the sub-flow passage is constituted by a groove formed in the flow passage body.

4. 2. The physical quantity measuring device according to claim 1, wherein the main flow path has a rectangular cross-sectional shape, and has a multi-layer portion constituted by partition plates that divide the main flow path into multiple layers, and the flow measurement sensor is disposed in the multi-layer portion.

5. 5. The physical quantity measuring device according to claim 1, wherein the flow rate measuring sensor is a pair of ultrasonic transmitter-receivers.