JP2018072237A - Measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more precisely measure a flow rate of a fluid flowing in a tubular member in a measurement device including a sensor fixed on an outer peripheral surface of the tubular member.SOLUTION: A measurement device includes: a tubular member; a temperature sensor 21B that is fixed on an outer peripheral surface of the tubular member and measures the temperature of a fluid flowing in the tubular member; and a heater 21A that is fixed in an area different from where the temperature sensor 21B of the outer peripheral surface is fixed and supplies the fluid with heat. The temperature sensor 21B includes a heat insulation member 23 having a heat insulation structure in which a cavity 102 is formed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a structure of a measuring apparatus including a sensor fixed to an outer peripheral surface of a tubular member.

  Conventionally, a flow meter for measuring a flow rate of a fluid flowing in a pipe is known. In this regard, Patent Document 1 discloses a flow meter including a temperature sensor and a liquid temperature sensor arranged on the outer wall of a pipe.

JP 2004-69667 A

  When the liquid temperature sensor arranged on the outer wall of the pipe measures the temperature of the fluid flowing in the pipe as in the flowmeter described in Patent Document 1, the temperature of the outer wall of the pipe is actually measured as the temperature of the fluid. doing. In this respect, the invention described in Patent Document 1 prevents an error from occurring between the measured temperature and the actual temperature of the fluid flowing in the pipe depending on the thermal conductivity of the material constituting the pipe. In order to do so, the whole temperature sensor and liquid temperature sensor are covered with a heat insulating member.

  However, in the flowmeter using a solid heat insulating member as in the invention described in Patent Document 1, the influence of outside air can be prevented to a certain extent, but the influence of outside air cannot be effectively prevented. Therefore, since the temperature of the fluid flowing in the pipe cannot be measured more accurately, there is a problem that the flow rate of the fluid cannot be measured more accurately.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to more accurately measure the flow rate of fluid flowing in a tubular member in a measuring device including a sensor fixed to the outer peripheral surface of the tubular member. To do.

  A measuring apparatus according to an embodiment includes a tubular member, a temperature sensor fixed to the outer peripheral surface of the tubular member, and measuring a temperature of a fluid flowing in the tubular member, and the temperature sensor on the outer peripheral surface being fixed. A heater for supplying heat to the fluid, which is fixed to a region different from the region, and the temperature sensor includes a heat insulating member having a heat insulating structure in which a cavity is formed.

  In the measurement apparatus, the heat insulating member includes an insulating film disposed so as to cover the first opening formed by the cavity, and the heat insulating member includes the insulating film disposed on an outer peripheral surface of the tubular member. It may be fixed in such a direction.

  In the measurement apparatus, the heat insulating member may further include a seal member disposed so as to close the cavity in the second opening opposite to the first opening.

  ADVANTAGE OF THE INVENTION According to this invention, in the measuring apparatus containing the sensor fixed to the outer peripheral surface of a tubular member, the flow volume of the fluid which flows through the inside of a tubular member can be measured more correctly.

It is a schematic top view which shows the structural example of the flowmeter which concerns on embodiment. It is sectional drawing seen from the II-II direction of FIG. It is sectional drawing seen from the III-III direction of FIG. It is a perspective view which shows the structural example of the temperature sensor which concerns on 1st Embodiment. It is a perspective view which shows the structural example of the heater which concerns on 1st Embodiment. It is sectional drawing of the temperature sensor which concerns on 2nd Embodiment. It is a perspective view which shows the structural example of the temperature sensor which concerns on 2nd Embodiment.

  Hereinafter, an embodiment will be described with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described below. That is, the present invention can be implemented with various modifications without departing from the spirit of the present invention. In the series of drawings, the same or similar parts are denoted by the same or similar reference numerals.

<First Embodiment>
(Configuration of flow meter)
A flow meter (measurement device) according to the first embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a schematic top view illustrating a configuration example of a flow meter according to the embodiment. As shown in FIG. 1, the flow meter 1 is illustratively a pipe 11A, 11B, 11C (tubular member), a temperature sensor 21B that is fixed to the outer peripheral surface of the pipe 11A and measures the temperature of the fluid flowing in the pipe 11A. And a heater 21A for supplying heat to the fluid, which is fixed in a region different from the region where the temperature sensor 21B on the outer peripheral surface of the piping 11A is fixed, and a flow for measuring the flow rate of the fluid flowing in the piping 11 The sensor 21, the relay board 31 that relays the detection signal from the flow sensor 21 via the wires 33A, 33B, 33C, and 33D, and the sensor that fixes both ends of the pipe 11 via the joint members 51A, 51B, 51C, and 51D A housing 61 is provided. Hereinafter, the pipes 11A, 11B, and 11C will be referred to as pipes 11 unless particularly specified. Hereinafter, the wires 33A, 33B, 33C, and 33D will be referred to as wires 33 unless a member is specified. The joint members 51A, 51B, 51C, and 51D are hereinafter referred to as joint members 51 unless particularly specified.

  The pipe 11 is a tubular member that allows fluid to pass therethrough. For example, the pipe 11 has an appropriate inner diameter corresponding to the flow rate of the fluid, a wall thickness that can withstand the pressure of the fluid, and an optimum length, and these sizes are determined from the use conditions. The pipe 11 is preferably formed of a material having a mechanical strength required as a tubular member and a relatively low thermal conductivity, and is made of a material such as glass, plastic, Teflon (registered trademark), or the like. In addition, as thickness of the piping 11, the thickness which can endure the clamping pressure of the coupling members 51A to 51D mentioned later and the pressure of the fluid which flows through the piping 11 is required. However, as shown in FIGS. 2, 3, and 6 to be described later, in the region where the heater 21A and the temperature sensor 21B are fixed, the thickness of the pipe 11A is locally reduced to such an extent that the heat conduction is hardly hindered. It has been counterbored. The heater 21 </ b> A and the temperature sensor 21 </ b> B are fixed on a face that has been spotted (the spot face S) of the pipe 11 </ b> A. Note that the portion that has been spotted has a thickness of, for example, about several tens of micrometers.

  Both ends of the pipe 11A are connected to the joint members 51B and 51C, one end of the pipe 11B is connected to the joint member 51A, and one end of the pipe 11C is connected to the joint member 51D. The pipe 11A and the pipe 11B are connected via joint members 51A and 51B, and the pipe 11A and the pipe 11C are connected via joint members 51C and 51D. The pipes 11A to 11C may be manufactured from the same member or may be manufactured from different members.

  The relay board 31 is a board that relays a detection signal from the flow sensor 21. The relay board 31 is electrically connected to the heater 21A included in the flow sensor 21 via wires 33A and 33B, for example, and is electrically connected to the temperature sensor 21B included in the flow sensor 21 via wires 33C and 33D. It is connected to the.

  For example, the relay substrate 31 relays an electrical signal corresponding to the electrical resistance of the resistance element included in the flow sensor 21 via each wire 33. The relay board 31 outputs a detection signal from the flow sensor 21 to a flow rate measurement unit (not shown) via each wire 41A, 41B, 41C, 41D connected to each electrical connection unit 35A, 35B, 35C, 35D. To do. Note that the electrical connection portions 35A, 35B, 35C, and 35D are referred to as the electrical connection portion 35 unless a member is specified. The wires 41 </ b> A, 41 </ b> B, 41 </ b> C, and 41 </ b> D are also referred to as wires 41 when no member is specified.

  The relay substrate 31 is provided with notches N1 and N2, and the flow sensor 21 is configured to be located at the notches N1 and N2. For example, the relay board 31 is provided with a plurality of cutouts N1 and N2, the temperature sensor 21B is located in one cutout N2, and the heater 21A is located in another cutout N1. Configured. There is no restriction | limiting in the number of the notches N, One may be sufficient and three or more may be sufficient.

  The wires 33 and 41 may be configured to include a material capable of transmitting an electrical signal, and examples thereof include metal wires such as gold wires and copper wires, but are not limited thereto.

  As shown in FIG. 1, the sensor housing 61 is a member that houses the flow sensor 21. The joint member 51 is connected to at least one end of the pipe 11 and connects the pipe 11A and the pipe 11B and connects the pipe 11A and the pipe 11C. At least one end of the pipe 11 is fixed to the sensor housing 61 by a joint member 51. The joint member 51 is made of a member having mechanical strength as a joint, for example, ceramic, plastic, stainless steel, or the like.

  FIG. 2 is a cross-sectional view seen from the direction II-II in FIG. FIG. 3 is a cross-sectional view seen from the III-III direction of FIG. As shown in FIGS. 2 and 3, the flow sensor 21 is used by being fixed to the outer peripheral surface of the pipe 11 </ b> A that is a portion sandwiched between the joint members 51 of the pipe 11. For example, the flow sensor 21 is fixed to a region upstream of the fluid flow on the outer peripheral surface of the pipe 11A, and a temperature sensor 21B that measures the temperature of the fluid and a region where the temperature sensor 21B on the outer peripheral surface is fixed. A heater 21A that is fixed to a different region on the downstream side of the fluid flow and supplies heat to the fluid is provided.

  As shown in FIG. 2, the bottom surface of the temperature sensor 21 </ b> B is configured to be separated from the relay board 31. Further, as shown in FIG. 3, the bottom surface of the heater 21 </ b> A is configured to be separated from the relay substrate 31.

  As shown in FIG. 2, the temperature sensor 21B includes a heat insulating member 23B having a heat insulating structure in which a cavity 102B is formed.

  FIG. 4 is a perspective view illustrating a configuration example of the temperature sensor according to the embodiment. As shown in FIGS. 2 and 4, the heat insulating member 23B of the temperature sensor 21B is exemplarily disposed so as to cover the base 101B and the opening O1 (first opening) formed by the cavity 102B penetrating the base 101B. The insulation film 103B, the resistance temperature sensor 107 (resistance element) provided on the insulation film 103B, and the electrical signal corresponding to the physical quantity detected by the resistance temperature sensor 107 are output via the wires 33C and 33D. Connecting portions 109C and 109D.

  The heat insulating member 23B is fixed in such a direction that the insulating film 103B is disposed on the outer peripheral surface of the pipe 11A. By fixing the heat insulating member 23B to the pipe 11A in this manner, the ambient temperature of the resistance temperature detector 107 provided on the insulating film 103B is reduced from the outside air having a lower thermal conductivity than the solid as the heat insulating material, such as air. Covered with containing gas. Therefore, in the temperature sensor 21B fixed to the outer peripheral surface of the tubular member, the temperature of the fluid flowing in the tubular member can be measured more accurately.

  FIG. 5 is a perspective view illustrating a configuration example of the heater according to the first embodiment. As shown in FIGS. 3 and 5, the heat insulating member 23A of the heater 21A is illustratively an insulating film 103A disposed so as to cover the base 101A and the opening O2 formed by the cavity 102A penetrating the base 101A. And a temperature measuring resistance element 104 provided on the insulating film 103A, and electrical connection portions 109A and 109B that output electrical signals corresponding to physical quantities detected by the temperature measuring resistance element 104 via the wires 33A and 33B.

  The heat insulating member 23 may be fixed to the pipe 11A along the center line C shown in FIGS. 4 and 5 via a heat conductive adhesive (not shown). For example, the heat conductive adhesive is a heat conductive material interposed between the flow sensor 21 and the outer wall of the pipe 11A. The heat conductive adhesive efficiently transfers the heat of the flow sensor 21 to the fluid inside the pipe, and transfers the heat inside the pipe 11 to the flow sensor 21. Become. For example, the heat conductive adhesive is applied to a pipe fixing region, and the insulating film 103 disposed on the base 101 is fixed to the outer wall of the pipe 11A via the heat conductive adhesive. The thermally conductive adhesive is an adhesive that fixes the flow sensor 21 and the pipe 11A by being cured.

  The heat conductive adhesive includes an adhesive having a property of conducting heat, for example, a paste that is a mixture of a conductive filler and a binder resin. The conductive filler includes a metal having a property of conducting heat, for example, metal fine powder such as silver, copper, gold, iron, nickel, and aluminum, or carbon black. In addition, the binder resin includes a resin having a property of adhering, fixing, or joining the objects, for example, a resin such as an epoxy resin, a polyester resin, a urethane resin, a phenol resin, and an imide resin.

As the material of the base 101, a material having high thermal conductivity and suitable for fine processing, for example, silicon (Si) can be used. As a material of the insulating film 103, silicon oxide (SiO ₂ ) or the like can be used. Further, platinum (Pt) or the like can be used as the material of each of the resistance temperature measuring elements 104 and 107.

(Flow measurement method)
Here, a measurement method of the flow sensor 21 will be described. The heater 21A of the flow sensor 21 supplies heat to the fluid so that the temperature is higher than the temperature of the fluid flowing through the pipe 11 (measured temperature of the temperature sensor 21B). For example, when the heater 21A supplies heat to the fluid so as to be 10 ° C. higher than the measured temperature, when the measured temperature is 20 ° C., the heater 21A supplies heat so that the temperature of the fluid becomes 30 ° C. That is, the set temperature of the heater 21A, which is a temperature higher than the measured temperature by a certain temperature, changes according to the measured temperature. The heater 21A supplies heat to the fluid corresponding to the difference between the measured temperature and the set temperature so as to raise the temperature of the fluid.

  And it is known that the amount of electric power for the heater 21A to supply the fluid with the amount of heat corresponding to the difference between the measured temperature and the set temperature has a correlation with the flow velocity and flow rate of the fluid flowing in the pipe 11. Yes. For this reason, it is possible to measure at least one of the flow velocity and the flow rate of the fluid flowing through the pipe 11 based on the amount of electric power for supplying heat corresponding to the difference between the measured temperature and the set temperature to the fluid.

  In addition, the measurement method of the flow velocity and flow rate of the fluid in the flow sensor 21 is not limited to the above, and other measurement methods may be employed. Note that the heater 21A and the temperature sensor 21B of the flow sensor 21 do not necessarily need to be separated from each other and fixed to the pipe 11, and the heater 21A and the temperature sensor 21B may be integrally fixed to the pipe 11. Good.

  As described above, in the flow meter according to the present embodiment, the temperature sensor 21B fixed to the outer peripheral surface of the pipe 11A, the heater 21A fixed to a region different from the region where the temperature sensor 21B is fixed, The temperature sensor 21B includes a heat insulating member 23B having a heat insulating structure in which a cavity 102B is formed. Therefore, in the flow meter 1 including the sensor 21 fixed to the outer peripheral surface of the pipe 11, the temperature of the fluid flowing in the pipe 11 can be measured more accurately, so that the flow rate of the fluid can be measured more accurately. it can.

Second Embodiment
The flow meter of the second embodiment is different from the first embodiment in that in addition to the configuration of the flow meter of the first embodiment, a seal member disposed so as to close the cavity is further provided. Below, a different point from 1st Embodiment is demonstrated especially.

  FIG. 6 is a cross-sectional view of the flow meter when viewed from the same direction as the II-II direction in FIG. 1. FIG. 7 is a perspective view illustrating a configuration example of the temperature sensor according to the present embodiment.

  As shown in FIGS. 6 and 7, the heat insulating member 23B of the temperature sensor 21B is exemplarily disposed so as to cover the base 101B and the opening O1 (first opening) formed by the cavity 102B penetrating the base 101B. The insulating film 103B, the temperature measuring resistance element 107 (resistive element) provided on the insulating film 103B, and the sealing member disposed so as to close the cavity 102B in the opening O3 (second opening) opposite to the opening O1 110 and electrical connection portions 109C and 109D that output electrical signals corresponding to the physical quantities detected by the resistance temperature detector 107 via the wires 33C and 33D.

The seal member 110 may be any member that can block the cavity 102B, and is made of, for example, a material containing glass, ceramic, or the like. Note that the seal member is not limited to these, and may be made of a material containing silicon, plastic, or the like.

  Here, regarding heat conduction, only heat radiation occurs and no heat conduction occurs in a vacuum, and therefore, the seal member 110 is disposed so as to close the cavity 102B in the opening O3 opposite to the opening O1, thereby providing the cavity 102B. Can be kept in a vacuum state, the heat insulation effect can be further enhanced.

  The cavity 102B may be filled with another gas having a heat insulating effect in addition to being kept in a vacuum state or being filled with air.

  As described above, the flow meter according to the present embodiment includes the seal member 110 disposed so as to close the cavity 102B in the opening O3 opposite to the opening O1. Therefore, in addition to the effect of the first embodiment, the heat insulation effect can be further increased, so that the fluid flow rate can be measured more accurately.

(Other embodiments)
The above-described embodiments are for facilitating understanding of the present invention, and are not to be construed as limiting the present invention. Moreover, the above-described embodiment is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described above. That is, the present invention can be implemented with various modifications (combining the embodiments) without departing from the spirit of the present invention.

  In each of the above-described embodiments, the flow meter is used as the measurement device and the flow sensor is used as the sensor.However, the measurement device is not limited thereto, and any measurement device may be used as long as the sensor is installed on the outer wall of the pipe. For example, a calorimeter may be used as the measuring device, and a calorimeter sensor may be used as the sensor.

DESCRIPTION OF SYMBOLS 1 Flowmeter 11 Piping 21 Flow sensor 21A Heater 21B Temperature sensor 23 Heat insulation member 31 Relay board 33, 41 Wire 35, 109 Electrical connection part 51 Joint member 61 Sensor housing 101 Base body 102 Cavity 103 Insulating film 104, 107 Resistance temperature sensor 110 Sealing member

Claims (3)

A tubular member;
A temperature sensor fixed to the outer peripheral surface of the tubular member and measuring the temperature of a fluid flowing in the tubular member;
A heater for supplying heat to the fluid, which is fixed to a region different from a region where the temperature sensor of the outer peripheral surface is fixed;
With
The temperature sensor includes a heat insulating member having a heat insulating structure in which a cavity is formed.
measuring device. The heat insulating member is
An insulating film arranged to cover the first opening formed by the cavity;
The heat insulating member is fixed in an orientation such that the insulating film is disposed on the outer peripheral surface of the tubular member.
The measuring apparatus according to claim 1. The heat insulating member further includes a seal member disposed so as to close the cavity in a second opening opposite to the first opening.
The measuring apparatus according to claim 2.