JP7127613B2 - heat transfer sensor - Google Patents

Description

The present invention relates to a heat transfer coefficient sensor that measures the heat transfer coefficient between a first medium and a second medium.

For example, when performing a simulation such as thermal analysis of an environment in which a fluid such as exhaust gas flows in an automobile or the like, the value of the heat transfer coefficient between the fluid and the solid wall surface is required. Therefore, the heat transfer coefficient is measured using a heat transfer coefficient sensor, a heat flow sensor, or the like. A heat flow sensor or the like is attached to the surface of the object to be measured, and measures the amount of heat energy passing through the object per unit area.

For example, in the heat flux sensor of Patent Document 1, when the heat flux is generated in the thickness direction of the sensor substrate, the electromotive force due to the Seebeck effect generated due to the temperature difference between the front surface and the rear surface of the sensor substrate is detected. ing. This heat flux sensor is configured to use two detection units having different thermal resistances in the thickness direction, perform calculations from the detection signals of the two detection units, and output a detection signal in which the thermal resistance due to the sensor substrate is canceled. It is According to this heat flux sensor, a true heat flux is obtained as a detection signal assuming that there is no thermal resistance due to the sensor substrate.

JP 2016-166832 A

The heat flux sensor of Patent Literature 1 eliminates the influence of the thermal resistance of the sensor substrate on the heat flux and accurately detects the heat flux. However, this heat flux sensor does not measure heat transfer coefficient. On the other hand, there is also known a heat transfer coefficient sensor that obtains the heat transfer coefficient from the temperature distribution measured using a large number of thermocouples. However, this heat transfer coefficient sensor measures temperatures over a wide range, and it is difficult to measure the heat transfer coefficient locally with high accuracy. Therefore, it is desired to develop a heat transfer coefficient sensor based on a new measurement principle that can locally measure the heat transfer coefficient with high accuracy.

The present invention has been made in view of such problems, and based on a new measurement principle, a heat transfer coefficient sensor capable of locally and accurately measuring the heat transfer coefficient between a first medium and a second medium. was obtained by trying to provide

One aspect of the present invention is a heat transfer coefficient sensor (1) for measuring the heat transfer coefficient (h) between a first medium (B1) as a solid and a second medium (B2) as a fluid or solid There is
Measurement points (P ), and a first detection circuit (24) that detects a first electromotive force (V1) generated by the measurement point of the first temperature detector. (12) and
Measurement points (P ) is provided, and the thermal resistance (R1, R2) when heat passes in the thickness direction (T) in which the first surface and the second surface are opposed to each other is different from that of the first temperature measuring element. a second detection unit (13) having a second detection circuit (34) for detecting a second electromotive force (V2) generated by the body (3) and the measurement point of the second thermometer;
a heat transfer coefficient calculator (4) that calculates the heat transfer coefficient between the first medium and the second medium using the ratio between the first electromotive force and the second electromotive force. in the sensor.

The heat transfer coefficient sensor of the above aspect introduces a new measurement principle when calculating the heat transfer coefficient using two thermometers known as heat flow sensors, heat flux sensors, and the like. . Specifically, the first detector detects the first electromotive force in the first temperature detector, and the second detector detects the second electromotive force in the second temperature detector. Then, the calculator calculates the heat transfer coefficient between the first medium and the second medium using the ratio between the first electromotive force and the second electromotive force.

In the heat transfer coefficient sensor of the aspect, the first temperature measuring element is arranged between the first medium and the second medium, and the second temperature measuring element is arranged between the first medium and the second medium. Based on the difference between the first thermal resistance in the thickness direction of the first temperature sensing element and the second thermal resistance in the thickness direction of the second temperature sensing element, the first medium and the first Note that there is a difference in heat flux passing between the two media. It is assumed that the temperature difference between the first surface and the second surface of the first temperature sensing element and the second temperature sensing element is the same.

Then, the calculation unit calculates the heat transfer coefficient between the first medium and the second medium based on the relationship between the ratio of the first electromotive force and the second electromotive force. This method of determining the heat transfer coefficient is based on a new measurement principle not found in conventional heat flow sensors, heat flux sensors, and the like. In addition, the first temperature sensing element and the second temperature sensing element can be formed compactly and can be arranged at a local position between the first medium and the second medium.

Therefore, according to the heat transfer coefficient sensor of the one aspect, the heat transfer coefficient between the first medium and the second medium can be locally measured with high accuracy based on the new measurement principle.

In addition, although the symbols in parentheses of each component shown in one aspect of the present invention indicate the correspondence with the symbols in the drawings in the embodiment, each component is not limited only to the contents of the embodiment.

FIG. 4 is an explanatory diagram showing a heat transfer coefficient sensor having a first detection section, a second detection section, and a calculation section according to the embodiment; FIG. 4 is an explanatory diagram showing an arrangement environment of a first medium and a second medium according to the embodiment; FIG. 4 is an explanatory diagram showing an arrangement environment of a first medium and a second medium on which heat transfer coefficient sensors are arranged according to the embodiment; Explanatory drawing which shows the cross section of the 1st temperature sensing element or the 2nd temperature sensing element concerning embodiment. FIG. 4 is an explanatory diagram showing the arrangement state of the first temperature sensing element and the second temperature sensing element according to the embodiment; FIG. 4 is an explanatory diagram showing another arrangement state of the first temperature sensing element and the second temperature sensing element according to the embodiment; 5 is a graph showing the relationship between thermal resistance and heat transfer rate when the heat transfer rate changes according to the embodiment; 4 is a graph showing a relationship map between heat transfer coefficient and output voltage ratio according to the embodiment;

A preferred embodiment of the heat transfer coefficient sensor described above will be described with reference to the drawings.
<Embodiment>
As shown in FIGS. 1 to 3, the heat transfer coefficient sensor 1 of this embodiment measures the heat transfer coefficient h between a first medium B1 as a solid and a second medium B2 as a fluid. . Here, FIG. 1 shows the configuration of the heat transfer coefficient sensor 1, FIG. 2 shows the arrangement environment of the first medium B1 and the second medium B2, and FIG. 3 shows the arrangement of the heat transfer coefficient sensor 1. The arrangement environment of the first medium B1 and the second medium B2 is shown.

The heat transfer coefficient sensor 1 includes a first detection section 12 having a first temperature sensing element 2 and a first detection circuit 24, a second detection section 13 having a second temperature sensing element 3 and a second detection circuit 34, a calculation a part 4; The first temperature sensing element 2 measures on a first surface 201 located on the side of the first medium B1 and on a second surface 202 located on the side of the second medium B2 opposite to the first surface 201. has a point P. The first detection circuit 24 is configured to detect a first electromotive force (first output voltage) V1 generated by the measurement point P of the first temperature sensing element 2 .

The second temperature sensing element 3 measures on a first surface 301 located on the side of the first medium B1 and on a second surface 302 located on the side of the second medium B2 opposite to the first surface 301, respectively. has a point P. The second thermal resistance R2 of the second temperature sensing element 3 when heat passes in the thickness direction T in which the first surface 301 and the second surface 302 face each other is It differs from the first thermal resistance R1 of the first temperature sensing element 2 when heat passes in the thickness direction T. The second detection circuit 34 is configured to detect a second electromotive force (second output voltage) V2 generated by the measurement point P of the second temperature sensing element 3 . The calculator 4 is configured to calculate the heat transfer coefficient h between the first medium B1 and the second medium B2 using the ratio between the first electromotive force V1 and the second electromotive force V2.

The heat transfer coefficient sensor 1 of this embodiment will be described in detail below.
(Heat transfer coefficient sensor 1)
As shown in FIG. 2, the heat transfer coefficient sensor 1 is used to measure the heat transfer coefficient h in an environment where heat transfer occurs between solid and gas, solid and liquid, and solid and solid. The heat transfer coefficient h can be measured by the heat transfer coefficient sensor 1 to be input as the heat transfer coefficient h between various media B1 and B2 under the environment where the simulation is performed when performing a simulation such as thermal analysis. can. The heat transfer coefficient h between the media B1 and B2 is actually measured by the heat transfer coefficient sensor 1, and the actually measured value of the heat transfer coefficient h is used to improve the accuracy of simulation such as thermal analysis. can be done.

The heat transfer coefficient sensor 1 is composed of a combination of mechanical components and electrical components. The first temperature sensing element 2 and the second temperature sensing element 3 constitute mechanical components attached to the solid wall surface B11 as the object to be measured. The first detection circuit 24, the second detection circuit 34, and the calculator 4 constitute electrical components using electronic components, computers, and the like.

(First medium B1, second medium B2)
An object for which the heat transfer coefficient h is measured by the heat transfer coefficient sensor 1 can be a pipe, a device, or the like through which various fluids flow. The measurement object of the heat transfer coefficient h can be, for example, various devices through which a refrigerant flows. In this case, the first medium B1 can be a metal member as a solid, and the second medium B2 can be a refrigerant as a fluid.

(First temperature sensing element 2, second temperature sensing element 3)
As shown in FIGS. 1 and 4, the first temperature sensing element 2 and the second temperature sensing element 3 are composed of conductive portions 21 and 31 and insulating portions 22 and 32 that insulate the conductive portions 21 and 31. . The conductive portions 21 and 31 are measured at the ends of the P-type semiconductors 211 and 311 and the N-type semiconductors 212 and 312 on the side of the first surfaces 201 and 301 and the ends on the side of the second surfaces 202 and 302. A point P is formed, and a plurality of P-type semiconductors 211, 311 and N-type semiconductors 212, 312 are electrically connected in series via conductors 213, 313 alternately. The P-type semiconductors 211, 311 and the N-type semiconductors 212, 312 constitute thermoelectric conversion elements that convert heat into electric power. For the P-type semiconductors 211 and 311 and the N-type semiconductors 212 and 312, for example, a bismuth-tellurium-based (Bi—Te-based) material can be used.

In the first temperature sensing element 2 and the second temperature sensing element 3, the P-type semiconductors 211, 311 and the N-type semiconductors 212, 312 are embedded in the insulating portions 22, 32 with both end surfaces in contact with the conductors 213, 313. It is The insulating portions 22 and 32 are made of an insulating material such as thermoplastic resin. Insulating protective sheets 221 and 321 are provided on the surfaces of the conductors 213 and 313 and the surfaces of the insulating portions 22 and 32, respectively. Surfaces 201 and 202 of the first temperature sensing element 2 and surfaces 301 and 302 of the second temperature sensing element 3 are surfaces of protective sheets 221 and 321 . The measurement point P of the first temperature sensing element 2 and the measurement point P of the second temperature sensing element 3 are a plurality of conductors 213 and 213, to which the end surfaces of the P-type semiconductors 211 and 311 and the end surfaces of the N-type semiconductors 212 and 312 are connected. 313 is formed.

The first temperature sensing element 2 and the second temperature sensing element 3 can be formed in various shapes as long as they are adjacent to each other. For example, as shown in FIG. 5, either one of the first temperature sensing element 2 and the second temperature sensing element 3 can be arranged in the central part, and the other can be arranged in the outer peripheral part. Also, as shown in FIG. 6, the first temperature sensing element 2 and the second temperature sensing element 3 can be arranged side by side adjacent to each other.

(First detection circuit 24, second detection circuit 34)
As shown in FIG. 1 , the first detection circuit 24 is configured to detect a first electromotive force V1 generated at both ends of the conducting portion 21 of the first temperature sensing element 2 . The first electromotive force V1 is a voltage generated in the plurality of P-type semiconductors 211 and N-type semiconductors 212 in the conducting portion 21 of the first temperature sensing element 2 due to the difference between the temperature of the first medium B1 and the temperature of the second medium B2. is. The second detection circuit 34 is configured to detect the second electromotive force V2 generated at both ends of the conductive portion 31 of the second temperature sensing element 3 . The second electromotive force V2 is a voltage generated in the plurality of P-type semiconductors 311 and N-type semiconductors 312 in the conductive portion 31 of the second temperature sensing element 3 due to the difference between the temperature of the first medium B1 and the temperature of the second medium B2. is.

(Affixing layers 23, 33)
As shown in FIG. 1, the first temperature sensing element 2 and the second temperature sensing element 3 of this embodiment are formed in the same shape. The first surface 201 of the first temperature sensing element 2 is provided with an attachment layer 23 for attaching the first temperature sensing element 2 to the wall surface B11 of the first medium B1. A first surface 301 of the second temperature sensing element 3 is provided with an attachment layer 33 for attaching the second temperature sensing element 3 to the wall surface B11 of the first medium B1. The first temperature sensing element 2 and the second temperature sensing element 3 are attached to the wall surface B11 of the first medium B1 while being adjacent to each other.

The sticking layers 23 and 33 can be an adhesive layer made of an adhesive, an adhesive layer made of an adhesive, or the like. Various materials that can be held on the wall surface B11 of the first medium B1 can be used for the attachment layers 23 and 33 .

As shown in the figure, in this embodiment, the thickness t1 in the thickness direction T of the adhesive layer 23 in the first temperature sensing element 2 and the thickness t2 in the thickness direction T of the adhesive layer 33 in the second temperature sensing element 3 are different from each other. different. Along with this, the thickness u1 in the thickness direction T of the first temperature sensing element 2 including the thickness t1 in the thickness direction T of the adhesive layer 23, and the second temperature sensing element including the thickness t2 in the thickness direction T of the attaching layer 33 The thickness u2 in the thickness direction T of 3 is different from each other. The material of each portion of the first temperature sensing element 2 including the adhesive layer 23 is the same as the material of each portion of the second temperature sensing element 3 including the adhesive layer 33 . A first thermal resistance R1, which is the thermal resistance in the thickness direction T of the first temperature sensing element 2, and a second thermal resistance R2, which is the thermal resistance in the thickness direction T of the second temperature sensing element 3, are formed in each adhesion layer. They differ from each other by the different thicknesses of 23,33.

The first thermal resistance R1 indicates the difficulty of heat conduction when heat passes through the thickness direction T of the first temperature sensing element 2, and the second thermal resistance R2 indicates the thickness direction T of the second temperature sensing element 3. Indicates the difficulty of heat transfer when heat passes through. The first thermal resistance R1 is indicated as a value when heat passes from the outer surface 231 of the adhesive layer 23 to the second surface 202 of the first temperature sensing element 2. FIG. The second thermal resistance R2 is indicated as a value when heat passes from the outer surface 331 of the sticking layer 33 to the second surface 302 of the second temperature sensing element 3 .

In this embodiment, the values of the first electromotive force V1 and the second electromotive force V2 when the heat transfer coefficient h is actually measured for the prototype of the heat transfer coefficient sensor 1 are stored. As will be described later, the heat transfer coefficient sensor 1 as a product uses a relationship map M obtained by obtaining the relationship between the ratio of the first electromotive force V1 and the second electromotive force V2 and the heat transfer coefficient h. Therefore, the heat transfer coefficient sensor 1 can be measured without actually measuring the values of the first thermal resistance R1 of the first temperature sensing element 2 and the second thermal resistance R2 of the second temperature sensing element 3. The heat transfer coefficient h can be measured by

The first thermal resistance R1 and the second thermal resistance R2 can be made different from each other by making the material of the insulating portion 22 of the first temperature sensing element 2 and the material of the insulating portion 32 of the second temperature sensing element 3 different. can. The first thermal resistance R1 and the second thermal resistance R2 are made different from each other by making the thickness of the first temperature sensing element 2 in the thickness direction T different from the thickness of the second temperature sensing element 3 in the thickness direction T. can also

The difference between the first electromotive force V1 detected by the first detection circuit 24 and the second electromotive force V2 detected by the second detection circuit 34 is the first thermal resistance R1 of the first temperature sensing element 2 and the second It increases as the difference from the second thermal resistance R2 of the temperature measuring element 3 increases. The larger the difference between the first electromotive force V1 and the second electromotive force V2, the higher the resolution (accuracy) when obtaining the heat transfer coefficient h. Therefore, it is preferable that the thickness of the first temperature detector 2 including the adhesive layer 23 and the thickness of the second temperature detector 3 including the adhesive layer 33 are different as much as possible.

(Theoretical formula for heat transfer coefficient h)
As shown in FIG. 2, in a state where the temperature sensors 2 and 3 are not arranged on the wall surface B11 of the first medium B1 as a solid, the heat flow between the first medium B1 and the second medium B2 as a fluid is The flux q [W/m ² ] is determined by the temperature difference ΔT [K] between the first medium B1 and the second medium B2 and the thermal resistance R [K· m ² /W] and q=ΔT/R. Also, the heat transfer coefficient h [W/(m ² ·K)] is expressed as h=1/R as the reciprocal of the thermal resistance R [K·m ² /W].

[W] (Watt) is also expressed as [J/s] (Joule/second), and heat flux q [W/m ² ] is expressed by q [J/(m ² ·s)]. Moreover, the heat flux q is generally understood as the amount of heat that traverses a unit area per unit time. A unit area at the interface between B1 and the second medium B2 can be regarded as the amount of heat transferred per unit time. The thermal resistance R between the first medium B1 and the second medium B2 represents how difficult it is for heat to pass through the interface between the first medium B1 and the second medium B2.

On the other hand, as shown in FIG. 3, in a state where the temperature sensors 2 and 3 are arranged on the wall surface B11 of the first medium B1, the heat flux qx [W/m ² ] are the temperature difference ΔT [K] between the first medium B1 and the second medium B2, the thermal resistance Rx [K·m ² /W] in the thickness direction T of the temperature sensors 2 and 3, and the temperature sensor Using the thermal resistance R [K·m ² /W] between the bodies 2, 3 and the second medium B2, qx=ΔT/(R+Rx). Here, the thermal resistance R between the first medium B1 and the second medium B2 and the thermal resistance R between the temperature detectors 2 and 3 and the second medium B2 are both indicated by the same thermal resistance R. .

When the temperature detectors 2 and 3 are arranged on the wall surface B11 of the first medium B1, the heat flux qx is the unit area of the temperature detectors 2 and 3 arranged on the wall surface B11 of the first medium B1, and A unit area of the interface between the warm bodies 2, 3 and the second medium B2 can be regarded as the amount of heat transferred per unit time. The thermal resistance Rx in the thickness direction T of the temperature detectors 2 and 3 represents the difficulty of heat passing through the temperature detectors 2 and 3 in the thickness direction T. FIG.

The heat flux q1 [W/m ² ] when the first temperature sensing element 2 is arranged on the wall surface B11 of the first medium B1 is the first thermal resistance R1 [K· m ² /W] and expressed by the formula q1=ΔT/(R+R1). The heat flux q2 [W/m ² ] when the second temperature sensing element 3 is arranged on the wall surface B11 of the first medium B1 is the second thermal resistance R2 [W/m 2 ] in the thickness direction T of the second temperature sensing element 3 [ K·m ² /W], q2=ΔT/(R+R2).

A heat flux q when the temperature sensors 2 and 3 are not arranged on the wall surface B11 of the first medium B1, and a heat flux q1 when the first temperature sensor 2 is arranged on the wall surface B11 of the first medium B1. is expressed as q1/q=R/(R+R1)=1/(1+R1/R). Here, the thermal resistance R is the reciprocal of the heat transfer coefficient h and is expressed as q1/q=1/(1+R1·h).

Similarly, the heat flux q when the temperature detectors 2 and 3 are not arranged on the wall surface B11 of the first medium B1 and the heat flow when the second temperature detector 3 is arranged on the wall surface B11 of the first medium B1 The relation q2/q with bundle q2 is expressed as q2/q=R/(R+R2)=1/(1+R2/R). Here, the thermal resistance R is the reciprocal of the heat transfer coefficient h and is expressed as q2/q=1/(1+R2·h).

Using the formula q1/q=1/(1+R1·h) and the formula q2/q=1/(1+R2·h) and eliminating q, q1+q1·R1·h=q2+q2·R2·h Become. Furthermore, when transformed into an equation for h, the heat transfer coefficient h is h=(q1-q2)/(q2.R2-q1.R1).

In the heat transfer coefficient sensor 1, the heat flux q1 through the first temperature sensing element 2 is expressed by q1=V1/k using the first electromotive force V1 as the output voltage and the sensitivity coefficient k. Also, the heat flux q2 through the second temperature sensing element 3 is expressed by q2=V2/k using the second electromotive force V2 as the output voltage and the sensitivity coefficient k. Since the sensitivity coefficient k is treated as a constant, the equation is simplified here to q1=V1 and q2=V2. • R1).

In the heat transfer coefficient sensor 1, in order to use the ratio between the first electromotive force V1 and the second electromotive force V2, the formula for the heat transfer coefficient h is changed to h=(V1/V2-1)/(R2 −(V1/V2)·R1). The formula for heat transfer coefficient h can also be expressed as h=(1-V2/V1)/((V2/V1)R2-R1) by interchanging the numerator and denominator of V1 and V2. As can be seen from the equation for the heat transfer coefficient h, the heat transfer coefficient h is a function of the first electromotive force V1 and the second electromotive force V2, assuming that the first thermal resistance R1 and the second thermal resistance R2 are constant values. know that it is required.

(Relationship between thermal resistances R1, R2 and heat transfer rate qx/q)
The heat flux qx between the first medium B1 and the second medium B2 when the temperature detectors 2 and 3 are arranged, and the first medium B1 and the second medium B1 when the temperature detectors 2 and 3 are not arranged. The ratio of the heat flux q to the medium B2 is expressed as the heat transfer coefficient qx/q. Then, using the equation q=ΔT/R for the heat flux q described above and the equation qx=ΔT/(R+Rx) for the heat flux qx, the heat transfer coefficient qx/q is obtained by qx/q=1/( 1+Rx/R)=1/(1+Rx·h).

In FIG. 7, the horizontal axis represents thermal resistance Rx [K·m ² /W] and the vertical axis represents heat transfer rate qx/q [−]. A relational graph plotting the values of qx/q is shown when a value of 0.0001 to 0.1 is substituted for Rx and a value of 100 to 1000 is substituted for the heat transfer coefficient h. The thermal resistance Rx on the horizontal axis of the figure is indicated by a logarithmic scale. As shown in the figure, the line of the heat transfer coefficient qx/q becomes a plurality of curves arranged vertically depending on the difference in the heat transfer coefficient h. The line of the heat transfer rate qx/q shows the relationship that the heat transfer rate qx/q decreases as the thermal resistance Rx increases, and the heat transfer rate qx/q decreases as the heat transfer rate h increases. be

In the figure, the thermal resistance Rx is a value specific to the temperature detectors 2 and 3, the value of the first thermal resistance R1 for the first temperature detector 2 and the second thermal resistance The value of R2 is fixed as a constant value. In the figure, the first thermal resistance R1 of the first temperature sensing element 2 is around 0.003, and the second thermal resistance R2 of the second temperature sensing element 3 is around 0.04.

Then, when the heat transfer coefficient h takes a specific value, the heat transfer coefficient q1/q for the first temperature sensing element 2 having a constant first thermal resistance R1 and the heat transfer coefficient q1/q for the first temperature sensing element 2 having a constant second thermal resistance R2 2 The heat transfer rate q2/q for the temperature detector 3 can be read. The heat transfer rate q1/q for the first temperature sensing element 2 is proportional to the first electromotive force (first output voltage) V1 from the relationship q1=V1/k. The heat transfer rate q2/q becomes a value proportional to the second electromotive force (second output voltage) V2 from the relationship q2=V2/k. The calculator 4 of this embodiment uses the correlation between the heat transfer coefficient h and the output voltage ratio, which is the ratio between the first electromotive force V1 and the second electromotive force V2. This correlation can be seen from the graph in FIG.

(calculation unit 4)
As shown in FIG. 8, the calculation unit 4 is created when the map is created before the heat transfer coefficient sensor 1 is used, and the first electromotive force (first output voltage) V1 and the second electromotive force (second output voltage) ) has a relationship map M in which the relationship between the ratio to V2 and the heat transfer coefficient h is obtained. The relationship map M obtained for the prototype of the heat transfer coefficient sensor 1 is stored in the calculation unit 4 of the product of the heat transfer coefficient sensor 1 . The relationship map M is obtained as a relationship between the ratio between the first electromotive force V1 and the second electromotive force V2 and the heat transfer coefficient h at the time of map creation. In this embodiment, the ratio between the first electromotive force V1 and the second electromotive force V2 is the value V1/V2 obtained by dividing the first electromotive force V1 by the second electromotive force V2, and this is defined as the output voltage ratio V1/V2. show.

The relationship map M measures the relationship between the ratio between the first electromotive force V1 and the second electromotive force V2 and the heat transfer coefficient h when the actually manufactured heat transfer coefficient sensor 1 is used experimentally. to create. More specifically, the relationship map M arranges the first temperature sensing element 2 and the second temperature sensing element 3 of the heat transfer coefficient sensor 1 on the wall surface B11 of the first medium B1, the temperature of the first medium B1, the 2. The first electromotive force V1 and the second electromotive force V2 are measured when the heat transfer coefficient h is changed by changing the temperature of the medium B2, etc., and the output voltage ratio V1/V2 is calculated. be. The output voltage ratio V1/V2 in FIG. 8 is shown with a sensitivity coefficient k of 1. The sensitivity coefficient k is indicated as a coefficient (constant) determined by the characteristics of the heat transfer coefficient sensor 1 and the like.

Further, when creating the map, the first electromotive force V1 and the second electromotive force V2 are measured, and the respective temperatures of the first medium B1 and the second medium B2 are measured using an external measuring device to obtain a true Measure the heat transfer coefficient h. Then, a relationship map M is created based on the output voltage ratio V1/V2 and the heat transfer coefficient h measured for a plurality of cases where the heat transfer coefficient h is different.

More specifically, the measuring device has a plurality of temperature measuring devices such as thermocouples embedded in the first medium B1 and temperature measuring devices such as thermocouples arranged in the second medium B2. The true heat transfer coefficient h in the relationship map M is the temperature difference ΔT between the first medium B1 and the second medium B2, the heat flux q passing from the first medium B1 to the second medium B2, and the heat flux q passing through the first medium B1. Using the inherent thermal conductivity λ and the temperature gradient dT/dx in the passing direction of the heat flux q in the first medium B1, it is obtained based on the formula h = q / ΔT, q = λ (dT / dx) be done.

As shown in FIG. 8, when the heat transfer coefficient sensor 1 is used, the calculation unit 4 calculates the first electromotive force V1 detected by the first detection circuit 24 and the The heat transfer coefficient h between the first medium B1 and the second medium B2 is calculated by comparing the output voltage ratio V1/V2, which is the ratio of the second electromotive force V2 applied to the ing. The calculation unit 4 is constructed in a sensor amplifier in which the relationship map M, an arithmetic circuit, and the like are formed. A sensor amplifier is configured by a computer.

Further, in the calculator 4, instead of using the ratio between the first electromotive force V1 and the second electromotive force V2, as shown in FIG. 8, the difference R1− It is also possible to use the slope θ determined by R2 and the difference q1/q−q2/q in the heat transfer rate between the first thermal resistance R1 and the second thermal resistance R2. Further, in the calculation unit 4, instead of using the ratio between the first electromotive force V1 and the second electromotive force V2, a value V2/V1 obtained by dividing the second electromotive force V2 by the first electromotive force V1 can be used. .

(Control method of heat transfer coefficient sensor 1 (when sensor is used))
At the time of map creation, a heat transfer coefficient h measurement test is performed on a prototype of the heat transfer coefficient sensor 1, and a relationship map M between the heat transfer coefficient h and the output voltage ratio V1/V2 is created. is stored in the calculation unit 4. Next, when the sensor is used, the first temperature sensing element 2 and the second temperature sensing element 3 of the heat transfer coefficient sensor 1 are attached to the wall surface B11 of the first medium B1. The first detection circuit 24 detects the first electromotive force V1 generated in the conductive portion 21 of the first temperature sensing element 2, and the second detection circuit 34 detects the first electromotive force V1 generated in the conductive portion 31 of the second temperature sensing element 3. 2 electromotive force V2 is detected.

Next, the calculator 4 calculates the output voltage ratio V1/V2, which is the ratio between the first electromotive force V1 and the second electromotive force V2, and compares the output voltage ratio V1/V2 with the relationship map M. , the heat transfer coefficient h corresponding to the output voltage ratio V1/V2 is obtained from the relationship map M. Thus, the heat transfer coefficient sensor 1 can measure the heat transfer coefficient h between the first medium B1 and the second medium B2.

(Effect)
The heat transfer coefficient sensor 1 of this embodiment introduces a new measurement principle when calculating the heat transfer coefficient h using two temperature sensors 2 and 3 known as heat flow sensors, heat flux sensors, and the like. It is what I did. Specifically, the first detector 12 detects the first electromotive force V1 generated at both ends of the conducting portion 21 of the first temperature sensing element 2, and the second detecting portion 13 detects the conducting portion of the second temperature sensing element 3. A second electromotive force V2 generated at both ends of 31 is detected. Then, the calculation unit 4 compares the output voltage ratio V1/V2, which is the ratio between the first electromotive force V1 and the second electromotive force V2, against the relationship map M between the output voltage ratio V1/V2 and the heat transfer coefficient h. Then, the heat transfer coefficient h between the first medium B1 and the second medium B2 is calculated.

In the heat transfer coefficient sensor 1 of this embodiment, the case where the first temperature sensing element 2 is arranged between the first medium B1 and the second medium B2, and the case where the first medium B1 and the second medium B2 , the first thermal resistance R1 in the thickness direction T of the first temperature sensing element 2 and the second thermal resistance R2 in the thickness direction T of the second temperature sensing element 3 Note that the heat fluxes q1 and q2 passing between the first medium B1 and the second medium B2 are different due to the difference in . The temperature difference between the outer surface 231 of the adhesive layer 23 of the first temperature detector 2 and the second surface 202 of the first temperature detector 2 and the outer surface 331 of the adhesive layer 33 of the second temperature detector 3 and the second surface 302 of the second temperature sensing element 3 are assumed to be the same.

Then, the calculation unit 4 calculates the heat transfer coefficient h between the first medium B1 and the second medium B2 based on the relationship between the first medium B1 and the second medium B2 and the output voltage ratio V1/V2. The method of determining the heat transfer coefficient h is based on a new measurement principle not found in conventional heat flow sensors, heat flux sensors, and the like. The first temperature sensing element 2 and the second temperature sensing element 3 can be made compact and arranged at a local position between the first medium B1 and the second medium B2.

Also, in order to measure the heat transfer coefficient h, it is conceivable to use one temperature sensing element and measure the electromotive force generated in this temperature sensing element. However, in this case, the electromotive force is measured, and the temperature difference between the first medium B1 and the second medium is the difference between the surface temperature of the first medium B1 and the surface temperature of the thermometer ( It becomes necessary to measure the temperature difference at the heat exchange interface). However, it is not easy to measure this temperature difference, and there are cases where the temperature difference is measured at a site different from the site where the temperature difference needs to be measured. Also, the thermal resistance of the temperature measuring element may affect the value of the heat transfer coefficient as an error.

On the other hand, in the heat transfer coefficient sensor 1 of this embodiment, the use of the two temperature sensors 2 and 3 eliminates the need to measure the temperature difference between the first medium B1 and the second medium B2. In addition, the heat transfer coefficient h is obtained by considering the thermal resistances R1 and R2 of the two temperature detectors 2 and 3, so that the measurement accuracy of the heat transfer coefficient h can be improved.

Therefore, according to the heat transfer coefficient sensor 1 of the present embodiment, the heat transfer coefficient h between the first medium B1 and the second medium B2 can be locally measured with high accuracy based on a new measurement principle. .

The present invention is not limited to only the embodiments, and further different embodiments can be configured without departing from the scope of the invention. In addition, the present invention includes various modifications, modifications within the equivalent range, and the like. Further, the technical idea of the present invention also includes combinations, forms, and the like of various constituent elements assumed from the present invention.

Reference Signs List 1 heat transfer coefficient sensor 12 first detector 13 second detector 2 first temperature detector 24 first detector circuit 3 second temperature detector 34 second detector circuit 4 calculator

Claims (4)

A heat transfer coefficient sensor (1) for measuring the heat transfer coefficient (h) between a first medium (B1) as a solid and a second medium (B2) as a fluid or solid,
measurement points (P) on a first surface (201) positioned on the side of the first medium and a second surface (202) on the side opposite to the first surface and positioned on the side of the second medium; and a first detection circuit (24) that detects a first electromotive force (V1) generated by the measurement point of the first temperature sensing element (2) provided with the first detection section ( 12) and
Measuring points (P) on a first surface (301) located on the side of the first medium and a second surface (302) located on the side of the second medium opposite to the first surface (301). is provided, and the thermal resistance (R1, R2) when heat passes in the thickness direction (T) in which the first surface and the second surface are opposed to each other is different from the first temperature detector. (3), and a second detection unit (13) having a second detection circuit (34) that detects a second electromotive force (V2) generated by the measurement point of the second thermometer;
a heat transfer coefficient calculator (4) that calculates the heat transfer coefficient between the first medium and the second medium using the ratio between the first electromotive force and the second electromotive force. sensor. The calculation unit
Having a relationship map (M) that is created at the time of map creation before use of the heat transfer coefficient sensor and obtains the relationship between the ratio of the first electromotive force and the second electromotive force and the heat transfer coefficient and
Further, when the heat transfer coefficient sensor is used, the ratio between the first electromotive force detected by the first detection circuit and the second electromotive force detected by the second detection circuit is 2. The heat transfer coefficient sensor of claim 1, configured to calculate the heat transfer coefficient against the relationship map. In the first temperature sensing element, the P-type semiconductor (211) and the N-type semiconductor (212) are positioned at the end on the first surface side and the end on the second surface side, and the measuring point is It has conductive portions (21) in which a plurality of conductive portions are alternately connected in series via conductors (213), and an insulating portion (22) made of an insulating material and surrounding the conductive portions. ,
The first detection circuit is configured to detect, as the first electromotive force, an electromotive force generated at both ends of the conductive portion of the first thermometer,
In the second temperature sensing element, the P-type semiconductor (311) and the N-type semiconductor (312) are arranged such that the measuring point is positioned at the end on the first surface side and the end on the second surface side. It has a conductive portion (31) in which a plurality of pieces are electrically connected in series alternately via conductors (313), and an insulating portion (32) made of an insulating material and surrounding the conductive portion (32). ,
3. The heat transfer coefficient according to claim 1, wherein said second detection circuit is configured to detect, as said second electromotive force, an electromotive force generated at both ends of said conductive portion of said second thermometer. sensor. The thermal resistance (R1) of the first temperature detector and the thermal resistance (R2) of the second temperature detector are
a material of each portion constituting the first temperature sensing element and a material of each portion constituting the second temperature sensing element;
The thickness (u1) in the thickness direction of the first temperature detector and the thickness (u2) in the thickness direction of the second temperature detector,
and the material or thickness (t1) in the thickness direction of the sticking layer (23) for sticking the first temperature sensing element to the first medium, and sticking the second temperature sensing element to the first medium The heat transfer coefficient sensor according to any one of claims 1 to 3, wherein at least one of the material and the thickness (t2) in the thickness direction of the adhesive layer (33) for the .

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