Physical Quantity Measuring Devices

Abstract

To provide a physical quantity measurement device that can measure the flow rate of fluid to be measured and the concentration of components even if the fluid to be measured includes water droplets.SOLUTION: A physical quantity measurement device 20 comprises: a main channel 1 through which fluid to be measured flows; a sub channel 11 through which water droplets flow; and a measuring instrument that measures the flow rate of the fluid to be measured flowing in the main channel 1 or the concentration of components included in the fluid to be measured.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a physical quantity measuring device for measuring the flow rate of a fluid or the concentration of a component contained in the fluid by removing the effects of water droplets from the fluid containing water. [Background technology]

[0002] 2. Description of the Related Art There are applications in which it is necessary to measure the flow rate of a fluid and the concentration of a component contained in the fluid without being affected by water droplets contained in the fluid.

[0003] 2. Description of the Related Art Conventionally, a known measuring device for measuring the flow rate of a fluid is one in which a measurement flow path is divided into multiple parts to improve the two-dimensionality of the flow and thereby improve the measurement accuracy (see, for example, Patent Document 1).

[0004] FIG. 5 shows a cross-sectional view of the ultrasonic flowmeter described in Patent Document 1.

[0005] In this ultrasonic flowmeter, a measurement flow path 101 is divided into multiple layers by multiple partition plates 102 to form a multilayer flow path 103, and chamber sections 104 are provided on the upstream and downstream sides of this multilayer flow path 103, and a pair of ultrasonic transmitters and receivers 105 are arranged facing each other across this chamber section 104.

[0006] In this multi-layer flow channel 103, ultrasonic waves are propagated to measure the flow velocity, thereby measuring the flow rate. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 9-43015 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the above conventional configuration, when water droplets are mixed into the fluid, the water droplets get mixed into the multi-layered section, blocking the propagation of the ultrasonic waves, making it impossible to guarantee the accuracy of ultrasonic measurement, and the accumulated water droplets cannot be discharged, making the device unusable.In addition, because of the chamber configuration that occupies a large spatial volume upstream and downstream of the measurement flow path, the measurement device becomes large and cannot be made compact.

[0009] The present invention is devised to solve the above-mentioned problems in the conventional art, and aims to provide a physical quantity measuring device that can measure the flow rate of a fluid and the concentration of components contained in a fluid even if water droplets are contained in a gas phase fluid. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems in the conventional technology, the physical quantity measuring device of the present invention comprises a main flow path through which a measured fluid flows, a secondary flow path through which droplets flow, and a measuring instrument that measures the flow rate of the measured fluid flowing in the main flow path or the concentration of a component contained in the measured fluid. Effect of the Invention

[0011] The physical quantity measuring device of the present invention has a secondary flow path provided outside a main flow path consisting of a multilayer section, which is positioned below the main flow path in the direction of gravity, and the ultrasonic transmitter / receiver is positioned so that it protrudes into the flow in the multilayer section.This prevents water droplets from entering the ultrasonic propagation path and from adhering to the ultrasonic transmitter / receiver, making it possible to measure the fluid flow rate and the concentration of components contained in the measured fluid even if the flowing in measured fluid contains water droplets. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view showing a configuration of a physical quantity measuring device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the cross section AA of FIG. 1 according to the first embodiment of the present invention. [Diagram 3] FIG. 2 is a cross-sectional view of a flow path portion taken along line BB in FIG. 1 according to the first embodiment of the present invention. [Figure 4] FIG. 13 is an enlarged view of a portion C showing an inlet side of a sub-flow passage in the first embodiment of the present invention; [Diagram 5] Cross-sectional view showing the configuration of a conventional ultrasonic flowmeter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The first invention is a physical quantity measuring device comprising: a main flow path with a rectangular cross section through which a fluid to be measured flows; a multilayer section in which a partition plate is arranged to divide the main flow path into multiple layers; a pair of ultrasonic transmitters and receivers arranged in the multilayer section; an upstream opening provided on the upstream side of the multilayer section; a downstream opening provided on the downstream side of the multilayer section; a secondary flow path provided outside the multilayer section and connecting the upstream opening and the downstream opening; a temperature sensor for detecting the temperature of the fluid to be measured; and a signal processing unit for receiving signals from the pair of ultrasonic transmitters and signals from the temperature sensor and measuring the flow rate and component concentration of the fluid, wherein the secondary flow path is arranged at a position below the main flow path in the direction of gravity, the upstream opening is arranged near the upstream end of the multilayer section, the downstream opening is arranged near the downstream end of the multilayer section, and the ultrasonic transmitters and receivers are arranged to protrude into the flow in the multilayer section, and the device aims to suppress the intrusion of water droplets into the multilayer section through which ultrasonic waves propagate and the adhesion of water droplets to the ultrasonic transmitters and receivers. This prevents deterioration of the ultrasonic transmission and reception characteristics in the ultrasonic propagation path, and makes it possible to measure the flow rate of the fluid and the concentration of components contained in the fluid even if the incoming flow contains water droplets.

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, in some cases, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted.

[0015] It should be noted that 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.

[0016] (Embodiment 1) The first embodiment will be described with reference to FIGS. 1 to 4. FIG.

[0017] Fig. 1 is a cross-sectional view of the configuration of a physical quantity measuring device in a first embodiment of the present invention, and Fig. 2 is a plan view showing the AA section of Fig. 1. Fig. 3 is a cross-sectional view of a flow path portion at the BB section of Fig. 1, and Fig. 4 is an enlarged view of part C showing the inlet side of a sub-flow path in Fig. 1. Note that the cross-sectional view of Fig. 1 is a cross-sectional view taken along the line D-D of Fig. 3 in order to make the structure of the sub-flow path easier to understand.

[0018] In Fig. 1, a physical quantity measuring device 20 has an inlet 4 through which a fluid to be measured flows in and an outlet 5 through which the fluid to be measured flows out. As shown in Fig. 3, a main flow path 1 in which the flow rate and component concentration are measured has a rectangular cross section, with the long side having a width W and the short side having a height H, which is divided into multiple layers by multiple partition plates 2 arranged approximately horizontally to form a multi-layer section 3. In this embodiment, the flow path is divided into six layers by five partition plates 2.

[0019] This increases the aspect ratio of the cross section of each layer, creating a flow path that realizes two-dimensional flow. As shown in Figure 2, in this multilayer section 3, a pair of ultrasonic transmitters 6 and 7 are arranged facing each other at approximately the center of the stacking direction of the multilayer section 3 in a direction that diagonally crosses the multilayer flow, forming an ultrasonic propagation path.

[0020] Additionally, the upstream ultrasonic transmitter / receiver 6 and the downstream ultrasonic transmitter / receiver 7 are disposed in the multilayer section 3 so as to protrude into the flow. In order to allow the ultrasonic transmitters / receivers 6, 7 to protrude into the flow, a notch 8 is provided in the partition plate 2 to prevent the ultrasonic transmitters / receivers 6, 7 from coming into contact with each other. Furthermore, in this notch 8, the gap L between the tips of the ultrasonic transmitters / receivers 6, 7 (the ultrasonic transmitting / receiving parts) and the partition plate 2 is dimensioned so that when water droplets in the measured fluid accumulate and stick to the tips due to surface tension, they do not remain at the tips of the ultrasonic transmitters / receivers 6, 7 or drip off.

[0021] In Figure 1, an upstream opening 9 is provided below the upstream end of a multilayer section 3 formed by multiple partition plates 2, and a downstream opening 10 is provided below the downstream end of the multilayer section 3, and a secondary flow path 11 connecting the upstream opening 9 and the downstream opening 10 is arranged so as to be below the main flow path 1 in the direction of gravity (the downward direction in Figure 1).

[0022] This sub-channel 11 is composed of a channel that sequentially connects an upstream slit-shaped opening 9 (details shown in FIG. 4) with a width W and a gap G that extends in the width W direction of the multi-layer section 3, an upstream inclined channel 12 that extends diagonally downward, a water channel 13 provided at the bottom, a downstream inclined channel 14 that extends diagonally upward, and a downstream slit-shaped opening 10 with a width W and a gap G (not shown) that extends in the width W direction of the multi-layer section 3, as on the upstream side. The upstream inclined channel 12 and the downstream opening 10 both lead to the water channel 13 with a width W and a gap G. As shown in FIG. 3, two water channels 13 are arranged at both ends in the width W direction, and both have a rectangular cross section with a width W1 and a height F. The channel height F is set to a dimension that allows the water to flow without stagnation even if an expected amount of water flows in.

[0023] In this way, the sub-flow passage 11 is provided below the main flow passage 1 in the direction of gravity. In addition, when in use, the main flow passage 1 and the sub-flow passage 11 are installed with a slight inclination as a whole so that the downstream side faces downward.

[0024] As shown in Fig. 2, a pair of temperature sensors 15 are provided on the upstream and downstream sides of the main flow path 1, at positions that do not affect the flow of the multilayer flow path where measurement is performed. The positions are set so that the temperature of the fluid to be measured in the ultrasonic propagation path can be calculated by averaging the temperatures measured by the two temperature sensors 15. Furthermore, a pressure sensor 16 is provided across multiple layers in the center of the multilayer section 3 to measure the pressure of the fluid in the same layer as the ultrasonic propagation path.

[0025] 1, the pair of ultrasonic transmitters / receivers 6, 7, temperature sensor 15, and pressure sensor 16 shown above are electrically connected to a signal processor 17 (not shown), and this signal processor 17 receives signals from the pair of ultrasonic transmitters / receivers 6, 7 and the temperature sensor 15 and pressure sensor 16 to measure the flow velocity and flow rate of the fluid to be measured, and further measures the component concentrations of the fluid to be measured. The results of measurement processing by this signal processor 17 are displayed on a display unit 18.

[0026] Next, the operation of the physical quantity measuring device of the present invention will be described.

[0027] In Fig. 1, the fluid to be measured, which is gas containing water droplets, flows through main flow path 1 in the direction indicated by the white arrow E from inlet 4, and some of the water droplets drip downward due to gravity. Next, some of the water droplets that collide with the upstream end 2a of partition plate 2 of multilayer section 3 provided in main flow path 1 drip downward. The water droplets that drip due to gravity and the water droplets that drip after colliding with the upstream end 2a of partition plate 2 flow into sub-flow path 11 from a slit-shaped upstream opening 9 opened near the upstream end 2a of multilayer section 3.

[0028] Water droplets that flow into the secondary flow passage 11 from the upstream opening 9 flow through the tapered upstream ramp 12 into the water passage 13 provided at the bottom. The water passage 13 has a flow passage height F set to an appropriate dimension as shown in Figure 3, which prevents water droplets from stagnating and increases fluidity. Water droplets flowing in the water passage 13 flow through the downstream ramp 14 that extends diagonally upward at the downstream opening 10, exits from the slit-shaped downstream opening 10, merges with the flow of the main flow passage 1, and flows out from the outlet 5.

[0029] The physical quantity measuring device 20 is installed so that the water passages 13 of the main flow path 1 and the sub-flow path 11 are inclined obliquely toward the downstream. Therefore, the flow in the sub-flow path 11 is generated by the action of gravity due to the water passage 13 of the sub-flow path 11 being inclined downward toward the downstream, and the attraction effect of the flow flowing out from the multi-layer section 3.

[0030] In this way, the intrusion of water droplets into the multilayer section 3 is suppressed, but there may be some water droplets that have not dripped onto the upstream end of the partition plate 2 of the multilayer section 3. These water droplets adhere to the partition plate 2 and flow downstream on the surface of the partition plate 2, and do not directly affect the ultrasonic propagation.

[0031] Furthermore, tiny water droplets in the fluid to be measured flow into the layers of the multilayer section 3, but since both ultrasonic transmitters and receivers 6 and 7 protrude into the flow path, these tiny water droplets simply collide with and adhere to the sides of the ultrasonic transmitters and receivers 6 and 7, and do not adhere to the surfaces of the ultrasonic transmitters and receivers 6 and 7, where they would affect the transmission and reception of ultrasonic waves.

[0032] In this way, in the multi-layer portion 3, large water droplets are not generated, and the transmission and reception of ultrasonic propagation signals between the ultrasonic transmitter / receivers 6 and 7 is guaranteed without being affected by minute water droplets.

[0033] On the other hand, since a pair of temperature sensors 15 are provided on the upstream and downstream sides of the main flow path 1 at positions avoiding the multilayer section 3, the temperatures measured by these two temperature sensors 15 can be averaged to accurately measure the temperature of the fluid to be measured in the ultrasonic propagation path.

[0034] In addition, in order to measure the pressure of the measured fluid in the same layer as the ultrasonic propagation path, the pressure sensor 16 is arranged so that its pressure-receiving surface spans multiple layers in the center of the multi-layer section 3 as shown in Figure 1, so that accurate pressure measurement is possible.

[0035] Using the thus obtained propagation time of transmission and reception by the pair of ultrasonic transmitters and receivers 6 and 7, the flow velocity and flow rate are determined by the well-known reciprocal propagation time difference method.

[0036] In addition, the concentration of a component contained in the fluid to be measured can be determined using a known method based on the sound speed obtained using the propagation time of transmission and reception and the measurement value of the temperature sensor 15.

[0037] The pressure value measured by the pressure sensor 16 is used for correction when conversion to standard conditions is required to obtain the concentration of a component.

[0038] As described above, according to this embodiment, the sub-flow path 11 can prevent water droplets from entering the multilayer section 3 through which the ultrasonic waves propagate, and by arranging the ultrasonic transmitters and receivers 6 and 7 protruding into the main flow path, adhesion of water droplets to the transmitting and receiving surfaces of the ultrasonic transmitters and receivers 6 and 7 can be prevented. Therefore, even if the measured fluid flowing into the physical quantity measuring device contains water droplets, the flow rate of the measured fluid and the concentration of components contained in the measured fluid can be measured.

[0039] In the embodiment of the present invention, the multilayer section 3 is shown to have the partition plate 2 installed almost horizontally, but the partition plate may also be installed vertically, in which case some of the water droplets generated by collision can be made to drip down the partition plate more easily.

[0040] Also, although a pair of temperature sensors 15 are provided on the upstream and downstream sides in the embodiment, a single temperature sensor may be sufficient in cases where the temperature gradient of the fluid is small, making it possible to reduce costs.

[0041] In addition, although the pressure sensor 16 has been shown to be arranged horizontally (i.e., left and right in Figure 3) on the partition plate 2 so that its pressure-receiving surface faces the central multiple layers of the multi-layer section 3, it may also be arranged vertically (i.e., up and down in Figure 3) on the partition plate 2 on the outermost layer side of the multi-layer section 3, and in particular, when arranged on the signal processing section 17 side (i.e., upward in Figure 3), it is possible to make the configuration more compact and reduce costs by, for example, integrating it with the control board section that constitutes the signal processing section 17 and simplifying the connection wiring.

[0042] In addition, in order to measure the concentration of components, it is also possible to use a thermal sensor or a hydrogen sensor other than ultrasonic sensors.

[0043] Although the example has been described in which water droplets are mixed into the fluid to be measured, the same effect is expected not only for water droplets but also for droplets of liquids other than water. [Industrial Applicability]

[0044] As described above, the physical quantity measuring device of the present invention can provide a measuring device configured to cause water droplets in a fluid to flow into a sub-flow path and suppress water droplets in the main flow path, and can be applied not only as a device having both a flow meter and component measurement, but also as a device with only a flow meter or a device with only component measurement, thereby realizing a highly versatile physical quantity measuring device. [Explanation of symbols]

[0045] 1 Main channel 2 Partition 3 Multilayer section 6, 7 Ultrasonic Transducer 9 Upstream opening 10 Downstream opening 11 Subchannel 15 Temperature Sensor 17 Signal Processing Section 20 Physical Quantity Measuring Devices

Claims

1. a main flow path through which a fluid to be measured flows; A sub-channel through which droplets flow; a measuring instrument for measuring a flow rate of the measurement target fluid flowing through the main flow path or a concentration of a component contained in the measurement target fluid; Physical quantity measuring device.

2. The sub-channel is disposed below the main channel in the direction of gravity. The physical quantity measuring device according to claim 1 .

3. Further comprising a partition plate dividing the main flow path into multiple layers. The physical quantity measuring device according to claim 2 .

4. The upstream opening of the sub-channel is located at a position where droplets that collide with and drop against the upstream end of the partition plate can flow in. The physical quantity measuring device according to claim 3 .

5. The measuring instrument is A pair of ultrasonic transmitters and receivers for measuring a propagation time of ultrasonic waves in the fluid to be measured. The physical quantity measuring device according to claim 1 .

6. The sub-channel is disposed below the main channel in the direction of gravity. The physical quantity measuring device according to claim 5 .

7. The pair of ultrasonic transmitters are arranged to protrude into the main flow path. The physical quantity measuring device according to claim 5 or 6.

8. Further comprising a partition plate dividing the main flow path into multiple layers. The physical quantity measuring device according to claim 7.

9. The partition plate has a notch portion that provides a gap between the pair of ultrasonic transmitters and receivers. The physical quantity measuring device according to claim 8 .

10. The upstream opening of the sub-flow passage is located at a position where moisture that collides with and drips down from the upstream end of the partition plate can flow in. The physical quantity measuring device according to claim 8 .

11. The main flow path and the sub flow path are installed with an inclination such that the downstream side is downward in the gravity direction. The physical quantity measuring device according to claim 1 .

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