JP2012154855A - Physical quantity measuring device and physical quantity measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply measure a physical quantity of a heat exchanger tube.SOLUTION: A physical quantity measuring device 10 comprises: a single tube 12A in which a fluid flows and whose physical quantity is known; a multiplex tube 12B in which a fluid flows and whose physical quantity is unknown; a heating device 14 for heating an outer surface of the single tube 12A and an outer surface of the multiplex tube 12B; a thermometer for detecting an outer surface temperature of a portion of the single tube 12A heated by the heating device 14; and a thermometer for detecting an outer surface temperature of a portion of the multiplex tube 12B heated by the heating device 14. The physical quantity measuring device 10 further comprises a physical quantity calculating device 40 for calculating a physical quantity of the multiplex tube 12B by using the outer surface temperature of the single tube 12A detected by the thermometer, the outer surface temperature of the multiplex tube 12B detected by the thermometer and heat flux from the heating device 14.

Description

  The present invention relates to a physical quantity measuring device and a physical quantity measuring method.

  There are various methods for measuring physical quantities such as thermal resistance and thermal conductivity of heat transfer tubes used in heat exchangers and the like.

  For example, in Patent Document 1, as a method for measuring thermal resistance, thermal resistance measurement is performed in which a measurement sample is sandwiched between a heating axis and a cooling axis, and the thermal resistance is obtained from the temperature difference between the front and back surfaces of the measurement sample and the amount of heat. An apparatus is described.

  As a method of measuring thermal conductivity, the sample is irradiated with laser light, and the thermal history curve on the back surface is analyzed to obtain the thermal diffusivity and specific heat. The product of the density of the sample and the obtained thermal diffusivity and specific heat. There is a laser flash method for calculating thermal conductivity from the above.

JP 2008-134111 A

  By the way, a multiple tube as a heat transfer tube is formed by superposing a plurality of tubes, and a physical quantity as a multiple tube is determined according to conditions such as pressure when the tubes are joined to each other. That is, the physical quantity of the multi-pipe may be unknown, and an accurate physical quantity of the multi-pipe cannot be specified unless the formed multi-pipe is actually measured. Further, depending on the processing of the single pipe as the heat transfer pipe, the physical quantity may change before and after the processing, and the physical quantity of the single pipe after the processing may be unknown.

  For this reason, it is desired to easily measure physical quantities of single tubes and multiple tubes used as heat transfer tubes.

  However, the method described in Patent Document 1 must prepare a sample with, for example, a round bar and measure the temperature gradient in the sample, and the laser flash method irradiates a sample in a disk shape with a laser, for example. The physical quantity of the heat transfer tube cannot be measured by a simple method such as using the heat transfer tube as it is.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the physical quantity measuring apparatus and physical quantity measuring method which can measure the physical quantity of a heat exchanger tube easily.

  In order to solve the above problems, the physical quantity measuring device and the physical quantity measuring method of the present invention employ the following means.

  That is, the physical quantity measuring device according to the present invention includes a first tube that is a heat transfer tube with a fluid flowing inside and a known physical quantity, and a second tube that is a heat transfer tube with an unknown fluid and flowing inside. Heating means for heating the outer surface of the first tube and the outer surface of the second tube; and a first temperature detection for detecting an outer surface temperature of a portion of the first tube heated by the heating device. Means, second temperature detecting means for detecting an outer surface temperature of a portion of the second pipe heated by the heating means, and an outer surface temperature of the first pipe detected by the first temperature detecting means. Calculating means for calculating the physical quantity of the second pipe using the outer surface temperature of the second pipe detected by the second temperature detecting means and the value of the heat flux from the heating means. .

According to the present invention, the heating means causes the fluid to flow inside, the outer surface of the first tube, which is a heat transfer tube with a known physical quantity, and the second tube, which is a heat transfer tube with the fluid flowing to the inside and whose physical quantity is unknown. The outer surface of the is heated. Then, the first temperature detection means detects the outer surface temperature of the portion of the first tube that is heated by the heating means, and the second temperature detection means heats the outer surface of the second pipe by the heating means. The outer surface temperature of the part is detected.
The first tube is a tube that serves as a reference for the second tube that serves as a control for measuring the physical quantity, and various physical quantities are specified in advance.

  Then, the outer surface temperature of the first tube detected by the first temperature detecting unit, the outer surface temperature of the second tube detected by the second temperature detecting unit, and the value of the heat flux from the heating unit are calculated by the calculating unit. Used to calculate the physical quantity of the second tube.

  Thus, according to the present invention, the physical quantity of the second pipe is calculated by using the outer surface temperature of the first pipe, the outer surface temperature of the second pipe, and the value of the heat flux from the heating means. Thus, the physical quantity of the heat transfer tube can be easily measured using the second tube itself as the heat transfer tube.

  In the physical quantity measuring device according to the present invention, the second tube is a multiple tube formed by superimposing a plurality of tubes, and the calculating means is the first temperature detected by the first temperature detecting means. By dividing the temperature difference between the outer surface temperature of the tube and the outer surface temperature of the second tube detected by the second temperature detecting means by the value of the heat flux from the heating means, The contact thermal resistance may be calculated.

  According to the present invention, the difference in temperature between the outer surface temperature of the first pipe detected by the first temperature detecting means and the outer surface temperature of the second pipe detected by the second temperature detecting means is calculated as the heat flow from the heating means. By dividing by the value of the bundle, the contact thermal resistance of the second pipe, which is a multiple pipe, is calculated, so that the contact thermal resistance of the multiple pipe can be easily measured.

Ｔ_ｉｎ１：第１の管の内面温度、Ｔ_ｉｎ２：第２の管の内面温度、ｒ_ｉｎ１：第１の管の内径の半径、ｒ_ｏｕｔ１：第１の管の外径の半径、ｒ_ｉｎ２：第２の管の内径の半径、ｒ_ｏｕｔ２：第２の管の外径の半径 Further, in the physical quantity measuring device according to the present invention, the calculating means has the outer surface temperature T _out1 of the first pipe detected by the first temperature detecting means, and the second temperature detected by the second temperature detecting means. Based on the outer surface temperature T _{out2 of the} tube and the heat flux q from the heating means, the thermal conductivity λ ₂ of the second tube may be calculated by the following equation.

T _in1 : inner surface temperature of the first tube, T _in2 : inner surface temperature of the second tube, r _in1 : radius of the inner diameter of the first tube, r _out1 : radius of the outer diameter of the first tube, r _in2 : Radius of the inner diameter of the second tube, r _out2 : radius of the outer diameter of the second tube

  According to the present invention, based on the outer surface temperature of the first tube detected by the first temperature detecting unit, the outer surface temperature of the second tube detected by the second temperature detecting unit, and the heat flux from the heating unit. Since the thermal conductivity of the second pipe is calculated using the above formula, the thermal conductivity of the heat transfer pipe can be easily measured.

  In the physical quantity measuring device of the present invention, the heating means may heat the outer surface of the first tube and the outer surface of the second tube with radiant heat.

  According to the present invention, since the outer surface of the first tube and the outer surface of the second tube are heated in a non-contact manner by radiant heat, heating can be performed more uniformly than in the case of heating by contact.

  In the physical quantity measuring device according to the present invention, the heating means covers the outer surface of the first tube and the outer surface of the second tube with a metal block with a gap, and heats the metal block so that the metal block is heated. The outer surface of the first tube and the outer surface of the second tube may be heated by radiant heat emitted from the block.

  According to the present invention, the metal block is once heated uniformly, and the outer surface of the first tube and the outer surface of the second tube are heated by the heated metal block. The outer surface of the tube can be heated more evenly.

  In the physical quantity measuring device of the present invention, black body paint may be applied to the outer surface of the first tube, the outer surface of the second tube, and the surface of the metal block that are heated by the heating unit. .

  According to the present invention, the outer surface of the first tube and the outer surface of the second tube can be heated more efficiently.

  On the other hand, in the physical quantity measuring method according to the present invention, the fluid flows inside, the outer surface of the first pipe, which is a heat transfer tube whose physical quantity is known, and the second, which is a heat transfer pipe whose physical quantity is unknown. A first step of heating the outer surface of the tube, and a first temperature detecting means for detecting an outer surface temperature of a portion of the first tube that is heated by the heating means, and the second tube, A second step of detecting an outer surface temperature of a portion heated by the heating means by a second temperature detecting means; an outer surface temperature of the first pipe detected by the first temperature detecting means; and the second temperature detecting means. And a third step of calculating a physical quantity of the second pipe using the outer surface temperature of the second pipe detected by the above and the value of the heat flux from the heating means.

  According to the present invention, the heat transfer tube is calculated by calculating the physical quantity of the second tube by using the outer surface temperature of the first tube, the outer surface temperature of the second tube, and the value of the heat flux from the heating means. The physical quantity of the heat transfer tube can be easily measured using the second tube itself.

  The present invention has an excellent effect of simply measuring the physical quantity of the heat transfer tube.

1 is a configuration diagram of a physical quantity measuring device according to a first embodiment of the present invention. It is sectional drawing of the heating apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the electric constitution of the physical quantity calculation apparatus which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the temperature gradient inside a test heat exchanger tube which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the temperature gradient inside a test heat exchanger tube at the time of making the evaluation object pipe | tube concerning 2nd Embodiment of this invention into a single pipe | tube.

  Hereinafter, an embodiment of a physical quantity measuring device and a physical quantity measuring method according to the present invention will be described with reference to the drawings.

[First Embodiment]
The first embodiment of the present invention will be described below.
FIG. 1 is a configuration diagram of a physical quantity measuring device 10 according to the first embodiment. The physical quantity measuring device 10 is a device for measuring a physical quantity of a heat transfer tube used in a heat exchanger or the like.

The physical quantity measuring device 10 includes a single tube 12A through which a fluid flows inside, a multiple tube (in the first embodiment, a double tube) 12B, a single tube 12A formed by overlapping a plurality of tubes through which fluid flows inside. The heating device 14 for heating the outer surface of the tube 12B and the outer surface of the multiple tube 12B, the pump 16 for sending the fluid to the single tube 12A and the multiple tube 12B, and the fluid flowing through the single tube 12A and the multiple tube 12B are cooled. A cooling tower 18 for feeding to the pump 16 is provided.
Thus, the single pipe 12A, the multiple pipe 12B, the pump 16, and the cooling tower 18 are connected by the flow path 19 through which the fluid flows.
More specifically, the multiple tube 12B is a multiple tube formed by overlapping a plurality of tubes in a nested manner and overlapping the opposing outer peripheral surface and inner peripheral surface.

  As an example, the physical quantity measuring device 10 according to the first embodiment includes one single tube 12A and, for example, four multiple tubes 12B that are different in formation process. Further, the single tube 12A according to the first embodiment is a tube (reference tube) serving as a reference for measuring the physical quantity of the multiple tube 12B, and the physical quantity of the single tube 12A is known. On the other hand, the multiple pipe 12B is an evaluation target pipe whose physical quantity is unknown and whose physical quantity is to be measured.

  In the first embodiment, as an example, the single tube 12A and the multiple tube 12B have the same inner diameter and outer diameter. The cross sections of the single tube 12A and the multiple tube 12B are not particularly limited, and may be round or polygonal. Furthermore, the single tube 12A and the multiple tube 12B are made of the same material.

  In the following description, when the single tube 12A and the multiple tube 12B are not distinguished, they are collectively referred to as the test heat transfer tube 12.

Then, the fluid delivered from the pump 16 passes through the strainer 20 and flows equally to the test heat transfer tubes 12 arranged in parallel by the branched flow path 19. The fluid flowing through each test heat transfer tube 12 is collected and returned to the cooling tower 18 when the flow paths 19 gather again.
A valve 21 is provided between each test heat transfer tube 12 and the strainer 20, and the flow of fluid to the corresponding test heat transfer tube 12 can be stopped by closing the valve 21.

  Further, a thermometer 22A is provided on the downstream side of the strainer 20, and the temperature of the fluid before being distributed to each test heat transfer tube 12 is measured by the thermometer 22A. Further, a thermometer 22B for detecting the temperature of the fluid and a flow meter 24 for detecting the flow rate of the fluid are provided for each outlet of each test heat transfer tube 12.

  Furthermore, the bypass channel 26 is connected to the channel 19 upstream of the arrangement position of the strainer 20, and the bypass channel 26 is connected to the cooling tower 18. And the flow volume of the fluid which flows through each test heat exchanger tube 12 is controllable by adjusting the opening degree of the valve 28 provided in the bypass flow path 26.

FIG. 2 is a cross-sectional view of the heating device 14 according to the first embodiment.
The heating device 14 heats the outer surface of the corresponding test heat transfer tube 12 by radiant heat. Since the heating device 14 heats the outer surface of the test heat transfer tube 12 in a non-contact manner by radiant heat, it can be heated more uniformly than in the case of heating by contact.

  Specifically, the heating device 14 according to the first embodiment covers the outer surface of the test heat transfer tube 12 with a metal block 30 with a gap, and heats the metal block 30 with a heater 32 wound around the outer periphery. Thus, the outer surface of the test heat transfer tube 12 is heated by the radiant heat emitted from the metal block 30.

  Thereby, the metal block 30 is once heated uniformly, and the sample heat transfer tube 12 is heated by the heated metal block 30. Therefore, for example, compared with the case where the outer surface of each test heat transfer tube 12 is simply heated by a heater, the outer surface of each test heat transfer tube 12 can be heated more evenly. The accuracy can be further increased. In the first embodiment, copper having high thermal conductivity is used as the metal block 30 as an example, but another metal may be used as the metal block 30.

  A black body paint is applied to the outer surface of the test heat transfer tube 12 and the surface of the metal block 30 that are heated by the heating device 14. Thereby, the outer surface of the single tube 12A and the outer surface of the multiple tube 12B are heated more efficiently. Note that the black body paint is, for example, black and may be any known one as long as the emissivity is high (for example, 0.9 or more).

  The physical quantity measuring device 10 according to the first embodiment is heated by the thermometer 22C for detecting the outer surface temperature of the portion heated by the heating device 14 in each single tube 12A and the heating device 14 in the multiple tube 12B. There is provided a thermometer 22D for detecting the outer surface temperature of the portion. In addition, it is preferable that thermometer 22C, 22D is arrange | positioned in the approximate center of the part currently heated with the heating apparatus 14 in the test heat exchanger tube 12. As shown in FIG.

  In this way, the fluid delivered from the pump 16 flows to the heated test heat transfer tube 12 with the same state quantity (the same temperature and the same flow rate), is heated by the test heat transfer tube 12, and goes to the cooling tower 18. Cooled by returning. The fluid flowing to the test heat transfer tube 12 is set to, for example, 20 ° C. by the cooling tower 18, and the heating device 14 heats the outer surface of the test heat transfer tube 12 to, for example, 400 ° C.

Furthermore, the physical quantity measuring device 10 includes a physical quantity calculating device 40 (see FIG. 1).
The physical quantity calculation device 40 is evaluated based on the outer surface temperature of the single tube 12A detected by the thermometer 22C, the outer surface temperature of the multiple tube 12B detected by the thermometer 22D, and the heat flux from the heating device 14. The physical quantity of the multiple tube 12B that is the target tube is calculated.

  FIG. 3 is a block diagram showing an electrical configuration of the physical quantity calculation device 40 according to the first embodiment.

  The physical quantity calculation device 40 according to the present embodiment includes a CPU (Central Processing Unit) 42 that controls the operation of the entire physical quantity calculation device 40, a ROM (Read Only Memory) 44 in which various programs, various parameters, and the like are stored in advance. A RAM (Random Access Memory) 46 used as a work area at the time of program execution and an HDD (Hard Disk Drive) 48 as a storage means for storing various programs and various data are provided.

  Furthermore, the physical quantity calculation device 40 is configured by a keyboard, a mouse, and the like, and includes an operation input unit 50 that receives input of various operations, an image display unit 52 such as a liquid crystal display device, and thermometers 22A and 22B. , 22C, 22D, and an external interface 54 for receiving temperature data indicating the temperatures detected by the thermometers 22A, 22C, 22D.

  The CPU 42, ROM 44, RAM 46, HDD 48, operation input unit 50, image display unit 52, and external interface 54 are electrically connected to each other via a system bus 58. Therefore, the CPU 42 accesses the ROM 44, RAM 46, and HDD 48, grasps the operation state of the operation input unit 50, displays an image on the image display unit 52, and receives from the thermometers 22A, 22C, 22D via the external interface 54. Temperature data can be received.

  The HDD 48 stores test heat transfer tube data indicating the inner diameter, outer diameter, and various physical quantities of the single pipe 12A, and the inner diameter and outer diameter of each multiple pipe 12B.

FIG. 4 is a schematic diagram showing a temperature gradient inside the test heat transfer tube 12. The solid line in FIG. 4 shows the temperature gradient of the single tube 12A, and the broken line shows the temperature gradient of the multiple tube 12B (double tube).
As shown in FIG. 4, the inner surface of the test heat transfer tube 12 is substantially the same as the temperature of the fluid, and due to the heating to the outer surface, the temperature rises from the inner surface toward the outer surface.
Specifically, the temperature of the single tube 12A continuously increases from the inner surface toward the outer surface. On the other hand, in the multiple tube 12B, a steep temperature change occurs at the joint surface (heat transfer tube joint surface) between the tubes. This is due to the influence of the contact thermal resistance caused by the contact between the tubes constituting the multiple tube 12B.

As described above, the multiple tube 12B formed by overlapping a plurality of tubes generates contact thermal resistance due to the contact between the tubes, but the single tube 12A formed by a single tube. No contact thermal resistance occurs.
This contact thermal resistance is considered to change depending on conditions such as pressure when joining the tubes, but the value can be accurately specified only by actual measurement.

Therefore, the physical quantity calculation device 40 according to the first embodiment calculates the contact thermal resistance of the multiple pipe 12B with reference to the single pipe 12A having no contact thermal resistance.
In calculating the contact thermal resistance, the physical quantity measuring device 10 makes the current flow rate to the heater 32 of each heating device 14 coincide with each other to thereby adjust the heat flow rate q (W / W from the heating device 14 to each test heat transfer tube 12. m ² ) are matched.
Thereafter, the physical quantity measuring device 10 detects the outer surface temperature of the portion heated by the heating device 14 in the single tube 12A with the thermometer 22C, and also determines the outer surface temperature of the portion heated by the heating device 14 in the multiple tube 12B. Detect with thermometer 22D.

Then, the CPU 42 included in the physical quantity calculation device 40 calculates the contact thermal resistance of the multiple pipe 12B based on the following formula.
First, when the inner surface temperature (° C.) of the test heat transfer tube 12 is T _in and the outer surface temperature (° C.) of the test heat transfer tube 12 is T _out , the temperature difference ΔT is expressed by the following equation (4). expressed. Incidentally, alpha _in the test heat transfer coefficient試伝heat pipe ^{12 (W / m 2 K)} , λ is the thermal conductivity of the test試伝heat pipe _{12 (W / mK), r} in the inner diameter of the test試伝heat pipe 12 The radius (m) and r _out are the radius (m) of the outer diameter of the test heat transfer tube 12, R is the contact thermal resistance (m ² K / W), and each value is stored in advance in the HDD 48 as the test heat transfer tube data. Has been.

（５）式における添え字の“１”は、単管１２Ａを示している。なお、外面温度Ｔ_ｏｕｔ１は、温度計２２Ｃによって検出された温度であり、内面温度T_ｉｎ１は、温度計２２Ａによって検出された温度、すなわち各供試伝熱管１２へ流れる流体の温度であり、各供試伝熱管１２で共通の温度である。また、熱伝導率λは、単管１２Ａ及び多重管１２Ｂ共に材質が同じであるため、同じであるとする。 The contact thermal resistance R is 0 (zero) in the case of the single tube 12A. For this reason, the temperature difference resulting from the heat transfer coefficient in the test heat transfer tube 12 is expressed by the following equation (5) from the detection result of the temperature in the single tube 12A. Incidentally, the inner surface temperature _{T in} of the test試伝heat pipe 12 is determined from the average value of the thermometer 22A and a thermometer 22B.

The subscript “1” in the equation (5) indicates the single tube 12A. The outer surface temperature T _out1 is the temperature detected by the thermometer 22C, and the inner surface temperature T _in1 is the temperature detected by the thermometer 22A, that is, the temperature of the fluid flowing to each test heat transfer tube 12, The temperature is common to the test heat transfer tubes 12. Further, it is assumed that the thermal conductivity λ is the same because the single tube 12A and the multiple tube 12B are made of the same material.

（６）式における添え字の“２”は、多重管１２Ｂを示している。 Then, the physical quantity calculating device 40 according to the first embodiment, based on the relationship shown in the above equations (4) and (5), is simply detected by the thermometer 22C as expressed in the following equation (6). By dividing the temperature difference between the outer surface temperature T _out1 of the tube 12A and the outer surface temperature T _out2 of the multiple tube 12B detected by the thermometer 22D by the heat flux q from the heating device 14, the contact thermal resistance of the multiple tube 12B. R is calculated. Note that the value of the heat flow rate q is specified in advance by the value of the current flowing to the heater 32.

The subscript “2” in the equation (6) indicates the multiple tube 12B.

As described above, the physical quantity measuring apparatus 10 according to the first embodiment includes a single pipe 12A in which a fluid flows inside and a physical quantity is known, a multiple pipe 12B in which fluid flows inside and a physical quantity is unknown, and a single pipe 12B. A heating device 14 for heating the outer surface of the tube 12A and the outer surface of the multiple tube 12B, a thermometer 22C for detecting the outer surface temperature of a portion of the single tube 12A heated by the heating device 14, and a heating device for the multiple tube 12B 14D, and a thermometer 22D for detecting the outer surface temperature of the portion heated by 14.
The physical quantity calculation device 40 included in the physical quantity measuring device 10 includes an outer surface temperature of the single tube 12A detected by the thermometer 22C, an outer surface temperature of the multiple tube 12B detected by the thermometer 22D, and a heat flux from the heating device 14. Is used to calculate the physical quantity of the multiple tube 12B.
Therefore, the physical quantity measuring device 10 according to the first embodiment can easily measure the physical quantity of the multiple tube as the heat transfer tube.

Further, the physical quantity measuring device 10 according to the first embodiment uses a heating device to calculate a temperature difference between the outer surface temperature of the single tube 12A detected by the thermometer 22C and the outer surface temperature of the multiple tube 12B detected by the thermometer 22D. By dividing by the heat flux from 14, the contact thermal resistance of the multiple tube 12B is calculated.
Therefore, the physical quantity measuring device 10 according to the first embodiment can easily measure the contact thermal resistance of the multiple tube 12B.

  In the first embodiment, the configuration in which the multiple tube 12B is a double tube has been described. However, the present invention is not limited to this, and the multiple tube 12B is more than a triple tube in which three or more tubes are overlapped. It is good. In the case of this form, the contact thermal resistance calculated in the first embodiment is the sum of the contact thermal resistances generated at two or more heat transfer tube joint surfaces.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described.
The configuration of the physical quantity measurement device 10 according to the second embodiment is the same as the configuration of the physical quantity measurement device 10 according to the first embodiment shown in FIGS.

  The physical quantity measuring device 10 according to the second embodiment measures the thermal conductivity (equivalent thermal conductivity including contact thermal resistance) of the multiple tube 12B.

First, the temperature difference ΔT ₁ between the inner surface temperature and the outer surface temperature of the single tube 12A serving as the reference tube is expressed by the following equation (7).

For this reason, the temperature difference resulting from the heat transfer coefficient in the test heat transfer tube 12 is expressed by the following equation (8) from the detection result of the temperature in the single tube 12A.

And from these relationships, the thermal conductivity λ ₂ of the multiple tube 12B is calculated from the following equation (9).

なお、多重管１２Ｂの内面温度Ｔ_ｉｎ２は、内面温度Ｔ_ｉｎ１と同様に、温度計２２Ａで検出された温度と温度計２２Ｂで検出された温度の平均値から求められる温度である。 ΔT ₂ is a temperature difference between the inner surface temperature and the outer surface temperature of the multiple tube 12B, and is calculated from the following equation (10).

The inner surface temperature T _in2 of the multiple tube 12B is a temperature obtained from the average value of the temperature detected by the thermometer 22A and the temperature detected by the thermometer 22B, similarly to the inner surface temperature T _in1 .

  From the above, the physical quantity measuring device 10 according to the second embodiment can easily calculate the equivalent thermal conductivity including the contact thermal resistance of the multiple tube 12B.

Further, the physical quantity measuring device 10 according to the second embodiment calculates the thermal conductivity of the single pipe as the evaluation target pipe by using a single pipe whose physical quantity is unknown instead of the multiple pipe 12B as the evaluation target pipe. May be.
As a single pipe as an evaluation target pipe, a single pipe having a different material from the single pipe 12A as a reference pipe or the same material as the single pipe 12A but a different processing method, a single pipe whose surface is coated, etc. Various single tubes are targeted.
When the evaluation target pipe is a single pipe, as shown in FIG. 5, the temperature change due to the influence of the contact thermal resistance does not occur as in the case where the evaluation target pipe is a multiple pipe.

  As mentioned above, although this invention was demonstrated using said each embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiments without departing from the gist of the invention, and embodiments to which the changes or improvements are added are also included in the technical scope of the present invention.

  For example, in each of the above-described embodiments, the form in which water is used as the fluid flowing through the physical quantity measuring device 10 has been described. However, the present invention is not limited to this, and a liquid or gas other than water is used as the fluid. It is good also as a form.

  Moreover, although each said embodiment demonstrated the form which calculates | requires the inner surface temperature of each test heat exchanger tube 12 from the average value of the temperature detected by the thermometer 22A and the temperature detected by the thermometer 22B, this invention Is not limited to this, and a thermometer is installed on the inner surface of each test heat transfer tube 12 (a position facing the thermometers 22C and 22D for detecting the outer surface temperature), and the temperature detected by the thermometer It is good also as a form which makes inner surface temperature of the sample heat exchanger tube 12 into.

  Moreover, although each said embodiment demonstrated the form in which each test heat exchanger tube 12 was arrange | positioned in parallel in the physical quantity measuring apparatus 10, this invention is not limited to this, Each test heat exchanger tube 12 may be arranged in series. In the case of this configuration, for example, thermometers that detect the temperature of the fluid are disposed at the inlet and outlet of each test heat transfer tube 12.

DESCRIPTION OF SYMBOLS 10 Physical quantity measuring device 12A Single pipe 12B Multiple pipe 14 Heating device 22A Thermometer 22B Thermometer 22C Thermometer 22D Thermometer 30 Metal block 40 Physical quantity calculation apparatus

Claims (7)

A first pipe which is a heat transfer pipe whose fluid flows inside and whose physical quantity is known;
A second pipe which is a heat transfer pipe whose fluid flows inside and whose physical quantity is unknown;
Heating means for heating the outer surface of the first tube and the outer surface of the second tube;
First temperature detecting means for detecting an outer surface temperature of a portion of the first pipe that is heated by the heating means;
Second temperature detection means for detecting an outer surface temperature of a portion of the second pipe that is heated by the heating means;
The outer surface temperature of the first pipe detected by the first temperature detecting means, the outer surface temperature of the second pipe detected by the second temperature detecting means, and the value of the heat flux from the heating means are used. Calculating means for calculating a physical quantity of the second pipe;
A physical quantity measuring device. The second tube is a multiple tube formed by overlapping a plurality of tubes,
The calculating means calculates the temperature difference between the outer surface temperature of the first pipe detected by the first temperature detecting means and the outer surface temperature of the second pipe detected by the second temperature detecting means. The physical quantity measuring apparatus according to claim 1, wherein the contact thermal resistance of the second pipe is calculated by dividing by a value of heat flux from the means. The calculating means includes an outer surface temperature T _out1 of the first pipe detected by the first temperature detecting means, an outer surface temperature T _out2 of the second pipe detected by the second temperature detecting means, and the heating. The physical quantity measuring device according to claim 1, wherein the thermal conductivity λ ₂ of the second pipe is calculated by the following formula based on the heat flux q from the means.

T _in1 : inner surface temperature of the first tube, T _in2 : inner surface temperature of the second tube, r _in1 : radius of the inner diameter of the first tube, r _out1 : radius of the outer diameter of the first tube, r _in2 : Radius of the inner diameter of the second tube, r _out2 : radius of the outer diameter of the second tube   4. The physical quantity measuring device according to claim 1, wherein the heating unit heats an outer surface of the first tube and an outer surface of the second tube by radiant heat. 5.   The heating means covers the outer surface of the first tube and the outer surface of the second tube with a metal block with a gap, and heats the metal block, whereby the first heat is generated by the radiant heat generated from the metal block. The physical quantity measuring apparatus according to claim 4, wherein the outer surface of the tube and the outer surface of the second tube are heated.   The physical quantity according to claim 4 or 5, wherein black body paint is applied to an outer surface of the first tube, an outer surface of the second tube, and a surface of the metal block heated by the heating unit. measuring device. A first step of heating an outer surface of a first tube that is a heat transfer tube with a fluid flowing inside and a known physical quantity, and an outer surface of a second tube that is a heat transfer tube with an unknown physical quantity and flowing inside. ,
In the first tube, the outer surface temperature of the portion heated by the heating unit is detected by the first temperature detecting unit, and the outer surface temperature of the portion heated by the heating unit in the second tube is determined. A second step of detecting by the second temperature detecting means;
The outer surface temperature of the first pipe detected by the first temperature detecting means, the outer surface temperature of the second pipe detected by the second temperature detecting means, and the value of the heat flux from the heating means are used. A third step of calculating a physical quantity of the second pipe;
A physical quantity measuring method including:

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