阅读说明：本技术 一种nmp热管比较温度源装置和实现方法 (NMP heat pipe temperature source comparison device and implementation method ) 是由 闫小克 童文雨 于 2021-08-05 设计创作，主要内容包括：本发明提出一种NMP热管比较温度源装置,本申请提出一种NMP热管比较温度源装置,其包括：管式加热炉、NMP热管、均热筒、垫块、上保温材料部、下保温材料部、套管、保温棉。本发明提供的NMP热管比较温度源装置将NMP热管的充液口设计在下端盖的中部,避免了充液口设置在热管上部对测温计阱的干扰,也避免了充液口中的少量气体对热管内均温效果的影响。在(200-300)℃温区内,获得了较优的温度稳定性、轴向温场均匀性。(The invention provides an NMP heat pipe comparison temperature source device, which comprises: the device comprises a tubular heating furnace, an NMP heat pipe, a soaking cylinder, a cushion block, an upper heat-insulating material part, a lower heat-insulating material part, a sleeve and heat-insulating cotton. According to the NMP heat pipe comparison temperature source device provided by the invention, the liquid filling port of the NMP heat pipe is designed in the middle of the lower end cover, so that the interference of the liquid filling port arranged at the upper part of the heat pipe on a temperature measuring device trap is avoided, and the influence of a small amount of gas in the liquid filling port on the temperature equalizing effect in the heat pipe is also avoided. In the temperature region of (200-.)

1. An NMP heat pipe comparison temperature source device, characterized in that, the NMP heat pipe comparison temperature source device includes: the device comprises a tubular heating furnace, an NMP heat pipe, a soaking cylinder, a cushion block, an upper heat-insulating material part, a lower heat-insulating material part, a sleeve and heat-insulating cotton;

the middle part of the tubular heating furnace is provided with a longitudinal heating cavity, the circumferential wall of the heating cavity is provided with the soaking cylinder, and the NMP heat pipe is vertically placed in the soaking cylinder; the cushion block is arranged in the soaking cylinder, the NMP heat pipe is placed on the cushion block, the lower heat insulation material part is arranged in the soaking cylinder, the cushion block is arranged on the lower heat insulation material part, and the lower heat insulation material part is made of refractory bricks;

the tubular heating furnace comprises a shell, a heat preservation layer, a temperature control couple, a hearth and a temperature control meter; the shell is cylindrical, the heat-insulating layer is arranged on the inner wall of the shell, a hearth is arranged inside the heat-insulating layer, heating wires are arranged on the side wall of the hearth, and heating currents of the heating wires are controlled by a temperature control meter arranged at the bottom of the tubular heating furnace; the temperature control couple adopts an armored thermocouple, the temperature measuring end of the temperature control couple is arranged in the middle of the tubular heating furnace and extends into the hearth, the lead wire end of the temperature control couple is connected with a temperature control meter, and the temperature control meter controls the heating current of the heating wire according to the furnace temperature measured by the temperature control couple so as to realize the control of the furnace temperature;

the NMP heat pipe comprises an upper end cover, a thermometer trap, a pipe shell, a positioning frame, a trap end cover, NMP working medium, a lower end cover, a lower boss, a liquid charging pipe, a protective cap and a wire mesh; the pipe shell is cylindrical, the upper end cover and the lower end cover are circular, and the upper end port and the lower end port of the pipe shell are respectively welded with the upper end cover and the lower end cover together, so that the upper end cover, the pipe shell and the lower end cover form a sealing structure with a hollow cavity, and the hollow cavity forms a working cavity of the NMP heat pipe; the upper end cover is uniformly provided with a plurality of well counting holes, the lower ends of the well counting holes are horizontally provided with well counting end covers, the well counting holes are used for the temperature measuring wells to pass through, one port of each temperature measuring well is welded with the well counting end cover, and the other port of each temperature measuring well passes through the well counting holes of the upper end cover and is welded together; the positioning frame is welded inside the tube shell and used for fixing the thermometer trap and ensuring the verticality of the thermometer trap and the upper end cover; the silk screen cloth is arranged on the inner wall of a working cavity of the NMP heat pipe and is tightly attached to the outer surface of the thermometer trap and the inner surface of the lower end cover respectively, a sleeve is arranged in the thermometer trap of the heat pipe, heat insulation cotton is plugged into an end port of the trap, an upper heat insulation material part is arranged on the upper portion of the upper end cover, the upper heat insulation material part and the lower heat insulation material part are made of the same material, a through hole for the sleeve to pass through is formed in the upper heat insulation material part, and the diameter of the through hole is slightly larger than that of the sleeve; in order to ensure that the thermodetector trap in the heat pipe is completely positioned at the evaporation section, the liquid filling height of the heat pipe is lower than that of a thermodetector trap end cover, and the surface of the lower end cover in the heat pipe and the surface of the thermodetector trap are attached to two layers of porous silk screens;

the lower boss is arranged in the middle of the lower end cover, one end of the lower boss is welded with the small central hole of the lower end cover, and the other end of the lower boss is radially provided with an external thread which is matched and connected with the internal thread of the protective cap; a through hole is formed in the axis direction of the lower boss, and the inner diameter of the through hole is consistent with the outer diameter of the liquid charging pipe; one port of the liquid charging pipe is welded with the axis through hole of the lower boss, and the other port of the liquid charging pipe is subjected to cold welding and sealing treatment after liquid charging; the material used by the liquid charging pipe is nickel, and the liquid charging pipe is a filling port of an NMP working medium after high-temperature annealing treatment; before the NMP heat pipe is filled, a working cavity of the NMP heat pipe is cleaned and subjected to high-temperature vacuum degassing treatment, the NMP working medium is filled into the working cavity through the liquid filling pipe, the working cavity is sealed by cold welding, and then the protective cap is screwed on the lower boss to protect the liquid filling pipe.

2. A NMP heat pipe comparative temperature source apparatus according to claim 1, wherein said soaking cylinder is made of metal or corundum.

3. A NMP heat pipe comparative temperature source apparatus according to claim 1, wherein said spacer block is made of brass.

4. A NMP heat pipe comparison temperature source apparatus according to claim 1, wherein the metallic components of the NMP heat pipe other than the liquid charging pipe are made of 316L stainless steel.

5. A NMP heat pipe comparative temperature source apparatus according to claim 1, wherein said tubular heating furnace uses fuzzy PID control.

6. A NMP heat pipe comparative temperature source apparatus according to claim 1, wherein the soaking cylinder is made of red copper.

7. A NMP heat pipe comparison temperature source apparatus according to claim 1, wherein said heat-insulating cotton is magnesium aluminum silicate heat-insulating cotton.

8. A NMP heat pipe comparison temperature source apparatus according to claim 1, wherein said sleeve is made of quartz glass.

9. A testing method of NMP heat pipe comparison temperature source based on the NMP heat pipe comparison temperature source device according to any one of claims 1 to 8, characterized in that the testing method comprises the following steps:

step 1: before the sleeve is put into the thermometer trap, the inner wall surface and the outer wall surface of the sleeve are strictly cleaned by absolute ethyl alcohol and then slowly and completely put into the thermometer trap after being cleaned;

step 2: selecting two temperature measuring wells by using two temperature sensors with the same measuring precision and reaction time, placing probes of the temperature sensors at positions 0cm, 4cm, 8cm and 12cm away from the bottoms of the two temperature measuring wells to wait for measuring positions, and simultaneously measuring the temperature change of the two temperature measuring wells in continuous time;

and step 3: using two temperature sensors, selecting a reference position during measurement, using one of the temperature sensors as a reference standard, and measuring the temperature of the position all the time; when another temperature sensor starts to measure, the measuring position should be as close to the reference standard as possible, after a period of measurement, the temperature sensor is moved to other positions to be measured, and after the position is in thermal equilibrium again, the measurement is started again to measure the uniformity of the axial temperature field of the NMP heat pipe comparison temperature source device.

Technical Field

The application relates to an NMP heat pipe comparison temperature source device and a testing method, which can provide a temperature source of (200-.

Background

The heat pipe is used as an efficient heat transfer element and conducts heat transfer by means of phase change of working media in the pipe. Because of its excellent thermal conductivity and isothermal property, it can be extensively used in the fields of energy source, astronavigation, military industry and metering, etc. In the field of temperature measurement, the heat pipe is used as an isothermal furnace lining, so that the reproduction level of ITS-90 international temperature scale defined fixed points and the temperature field uniformity of the variable temperature black body can be improved. The tin freezing point (231.928 ℃) is a very important fixed point for definition and is currently reproduced by single-stage or three-stage heating furnaces. In order to improve the tin solidification fixed point recurrence level, it is important to select a proper medium-temperature section heat pipe medium near the solidification point temperature. At present, few working media can be selected for the heat pipe. NMP as one kind of organic heat transferring medium has the advantages of low density, low boiling point, great latent heat of vaporization, low saturated vapor pressure, high heat stability, etc. The chemical property is inactive, and the paint has no corrosivity on some metal materials such as carbon steel, aluminum, nickel and the like.

In contrast, the applicant has previously participated in the research on NMP as the working medium of the heat pipe, see "experimental research on the starting performance and isothermal performance of the N-methylpyrrolidone heat pipe" (journal of metrology, vol. 49, 2 nd, page 170-174), in which two heat pipes using NMP as the working medium of the heat pipe are manufactured by the institute of metrology science, and the starting performance and isothermal performance of the NMP heat pipe are studied by means of heating and temperature measurement, so as to determine the temperature range in which the NMP heat pipe can work. However, the NMP heat pipe manufactured so far is only in the experimental stage, and is not actually applied to the reproduction of the tin solidification fixed point and the calibration of the thermometer. In addition, in the practical use process, it is found that the liquid filling ports of the existing NMP heat pipe and other types of medium-high temperature heat pipes are located on the upper end face of the heat pipe, and the heat pipe serving as a temperature equalizing body is generally manufactured into a ring cylinder, so that the liquid filling ports are necessarily arranged eccentrically to the center of the upper end face of the heat pipe, after the liquid filling is completed, a redundant cavity is formed inside the liquid filling ports, and a very small amount of gas may be retained inside the cavity. Therefore, it is necessary to provide a new NMP heat pipe comparison temperature source device to improve the tin solidification fixed point recurrence level and achieve high precision calibration of the thermometer.

Disclosure of Invention

The invention provides an NMP heat pipe comparison temperature source device, which comprises: the device comprises a tubular heating furnace, an NMP heat pipe, a soaking cylinder, a cushion block, an upper heat-insulating material part, a lower heat-insulating material part, a sleeve and heat-insulating cotton. The tubular heating furnace is provided with a longitudinal heating cavity in the middle, the circumferential wall of the heating cavity is provided with the heat equalizing cylinder, and the heat equalizing cylinder is made of a material with better heat conducting property, such as metal or corundum. The NMP heat pipe is vertically arranged in the soaking cylinder. The NMP heat pipe is arranged on the cushion block, the cushion block is made of a material with good heat resistance and certain mechanical strength, such as brass. The lower heat insulation material part is arranged in the heat equalizing cylinder, the cushion block is arranged on the lower heat insulation material part, and the lower heat insulation material part is made of refractory bricks.

The tubular heating furnace comprises a shell, a heat preservation layer, a temperature control couple, a hearth and a temperature control meter. The shell is the cylinder, the heat preservation sets up the inner wall at the shell, the inside furnace that is of heat preservation, be provided with the heater strip on the furnace lateral wall, the heating current of heater strip is controlled by the temperature control table that sets up in tubular heating furnace bottom. The temperature control couple adopts an armored thermocouple with a proper range, the temperature measuring end of the temperature control couple is arranged in the middle of the tubular heating furnace and extends into the hearth, the lead end of the temperature control couple is connected with a temperature control meter, and the temperature control meter controls the heating current of the heating wire according to the furnace temperature measured by the temperature control couple so as to control the furnace temperature.

The NMP heat pipe comprises an upper end cover, a thermometer trap, a pipe shell, a positioning frame, a trap end cover, NMP working medium, a lower end cover, a lower boss, a liquid charging pipe, a protective cap and a wire mesh. The pipe shell is cylindrical, the upper end cover and the lower end cover are circular, and the upper end port and the lower end port of the pipe shell are respectively welded with the upper end cover and the lower end cover together, so that the upper end cover, the pipe shell and the lower end cover form a sealing structure with a hollow cavity, and the hollow cavity forms a working cavity of the NMP heat pipe; the upper end cover is uniformly provided with a plurality of well counting holes, the lower ends of the well counting holes are horizontally provided with well counting end covers, the well counting holes are used for the temperature measuring wells to pass through, one port of each temperature measuring well is welded with the well counting end cover, and the other port of each temperature measuring well passes through the well counting holes of the upper end cover and is welded together; the positioning frame is welded inside the tube shell and used for fixing the thermometer trap and ensuring the verticality of the thermometer trap and the upper end cover; the wire mesh cloth is arranged on the inner wall of the working cavity of the NMP heat pipe and is tightly attached to the outer surface of the temperature detector well and the inner surface of the lower end cover respectively. The thermometer trap of the heat pipe is internally provided with a sleeve, the port of the thermometer trap is plugged with heat insulation cotton, the upper part of the upper end cover is provided with an upper heat insulation material part, the upper heat insulation material part and the lower heat insulation material part are made of the same material, the upper heat insulation material part is provided with a through hole for the sleeve to pass through, and the diameter of the through hole is slightly larger than that of the sleeve. In order to ensure that the thermodetector trap in the heat pipe is completely positioned at the evaporation section, the liquid filling height of the heat pipe is lower than that of the end cover of the thermodetector trap, and in addition, the surface of the end cover in the heat pipe and the surface of the thermodetector trap are attached to two layers of porous silk screens.

The lower boss is arranged in the middle of the lower end cover, one end of the lower boss is welded with the small central hole of the lower end cover, and the other end of the lower boss is radially provided with an external thread which is matched and connected with the internal thread of the protective cap; a through hole is formed in the axis direction of the lower boss, and the inner diameter of the through hole is consistent with the outer diameter of the liquid charging pipe; one port of the liquid charging pipe is welded with the axis through hole of the lower boss, and the other port of the liquid charging pipe is subjected to cold welding sealing treatment after liquid charging. The material that the liquid filling pipe used is nickel, through high temperature annealing treatment, is the filling mouth of NMP working medium. Before the NMP heat pipe is filled, a working cavity of the NMP heat pipe is cleaned and subjected to high-temperature vacuum degassing treatment, the NMP working medium is filled into the working cavity through the liquid filling pipe, the working cavity is sealed by cold welding, and then the protective cap is screwed on the lower boss to protect the liquid filling pipe.

Except the liquid filling pipe, all metal components of the NMP heat pipe are made of 316L stainless steel. The tubular heating furnace is controlled by fuzzy PID, and the soaking cylinder is made of red copper.

Further, the heat preservation cotton is magnesium aluminum silicate heat preservation cotton, and the sleeve is made of quartz glass.

The application provides a test method for comparing temperature sources of NMP heat pipes, which is based on the NMP heat pipes, and comprises the following steps:

step 1: before the sleeve is put into the thermometer trap, the inner wall surface and the outer wall surface of the sleeve are strictly cleaned by absolute ethyl alcohol and then slowly and completely put into the thermometer trap after being cleaned.

Step 2: selecting two temperature measuring wells by using two temperature sensors with the same measuring precision and reaction time, placing probes of the temperature sensors at positions 0cm, 4cm, 8cm and 12cm away from the bottoms of the two temperature measuring wells to wait for measuring positions, and simultaneously measuring the temperature change of the two temperature measuring wells in continuous time;

and step 3: using two temperature sensors, selecting a reference position during measurement, using one of the temperature sensors as a reference standard, and measuring the temperature of the position all the time; when another temperature sensor starts to measure, the measuring position should be as close to the reference standard as possible, after a period of measurement, the temperature sensor is moved to other positions to be measured, and after the position is in thermal equilibrium again, the measurement is started again to measure the uniformity of the axial temperature field of the NMP heat pipe comparison temperature source device.

According to the NMP heat pipe comparison temperature source device provided by the invention, the liquid filling port of the NMP heat pipe is designed in the middle of the lower end cover, so that the interference of the liquid filling port arranged at the upper part of the heat pipe on a temperature measuring device trap is avoided, and the influence of a small amount of gas in the liquid filling port on the temperature equalizing effect in the heat pipe is also avoided. In the temperature range of (200-.

Drawings

FIG. 1 is a schematic view of an apparatus of the present invention;

FIG. 2 is a schematic diagram of an NMP heat pipe of the present invention;

FIG. 3 is a top view of an NMP heat pipe of the present invention;

FIG. 4 is a schematic diagram of a method for testing a comparative temperature source of an NMP heat pipe according to the present invention.

Detailed Description

The invention is further described with reference to the drawings and the detailed description.

In one embodiment, referring to fig. 1, the present application provides an NMP heat pipe comparison temperature source apparatus, comprising: the device comprises a tubular heating furnace 1, an NMP heat pipe 2, a soaking cylinder 3, a cushion block 4, an upper heat-insulating material part 7, a lower heat-insulating material part 5, a sleeve 6 and heat-insulating cotton 8. The middle part of the tubular heating furnace 1 is provided with a longitudinal heating cavity, the circumferential wall of the heating cavity is provided with the soaking cylinder 3, and the soaking cylinder 3 is made of a material with better heat conductivity, such as metal or corundum. The NMP heat pipe 2 is vertically arranged in the soaking cylinder 3. The NMP heat pipe is characterized in that the cushion block 4 is arranged in the soaking cylinder 3, the NMP heat pipe 2 is placed on the cushion block 4, the cushion block 4 is made of a material which has good heat resistance and certain mechanical strength, and plays a role in fixing and supporting the NMP heat pipe 2, for example, the cushion block is made of brass. The lower heat-insulating material part 5 is arranged in the soaking cylinder 3, the cushion block 4 is arranged on the lower heat-insulating material part 5, and the lower heat-insulating material part 5 is made of a material with better heat insulating performance, such as refractory bricks, and plays roles of supporting the cushion block 4 and insulating heat.

The tubular heating furnace 1 comprises a shell 101, an insulating layer 102, a temperature control couple 103, a hearth 104 and a temperature control meter 105. The shell 101 is cylindrical, the heat insulation layer 102 is arranged on the inner wall of the shell 101 and plays a role in isolating heat in the furnace, the hearth 104 is arranged inside the heat insulation layer 102, heating wires are arranged on the side wall of the hearth 104, and heating currents of the heating wires are controlled by a temperature control meter 105 arranged at the bottom of the tubular heating furnace 1. The temperature control couple 103 is an armored thermocouple with a proper range, the temperature measuring end of the thermocouple is arranged in the middle of the tubular heating furnace 1 and extends into the hearth 104, the lead end of the thermocouple is connected with a temperature control meter 105, and the temperature control meter 105 controls the heating current of the heating wire according to the furnace temperature measured by the temperature control couple 103 so as to control the furnace temperature.

As shown in FIGS. 2-4, the NMP heat pipe comprises an upper end cover 201, a thermometric trap 202, a pipe shell 203, a positioning frame 204, a trap end cover 206, NMP working medium 206, a lower end cover 207, a lower boss 208, a liquid charging pipe 209, a protective cap 210 and a wire mesh 211. The tube shell 203 is cylindrical, the upper end cover 201 and the lower end cover 207 are circular, and the upper end port and the lower end port of the tube shell 203 are respectively welded with the upper end cover 201 and the lower end cover 207 together, so that the upper end cover 201, the tube shell 203 and the lower end cover 207 form a sealing structure with a hollow cavity, and the hollow cavity forms a working cavity of the NMP heat pipe; the upper end cover 201 is uniformly provided with a plurality of measuring trap holes, as shown in fig. 3, the heat pipe is provided with 5 thermometric measuring traps, 5 measuring traps are numbered as 1#, 2#, 3#, 4#, and 5#, the lower ends of the measuring traps are horizontally provided with measuring trap end covers 206, the lower surfaces of the measuring trap end covers 206 and the lower end covers 207 have a certain height, the height is set according to the liquid filling amount, the measuring trap holes are used for the thermometric measuring traps 205 to pass through, one port of the thermometric measuring traps 205 is welded with the measuring trap end covers 206, and the other port of the thermometric measuring traps 205 passes through the measuring traps of the upper end cover 201 and is welded together; the positioning frame 204 is welded inside the tube shell 203, fixes the thermometer trap 202 and ensures the perpendicularity of the thermometer trap and the upper end cover 201; the silk screen 211 is arranged on the inner wall of the working cavity of the NMP heat pipe and is tightly attached to the outer surface of the temperature detector trap 202 and the inner surface of the lower end cover 207 respectively. The thermometer trap 202 of the heat pipe is internally provided with a sleeve 6, the sleeve 6 is used for protecting the measuring end of the thermometer, the port of the thermometer trap is plugged with heat-insulating cotton 8, the upper part of the upper end cover 201 is provided with an upper heat-insulating material part 7, the upper heat-insulating material part 7 and the lower heat-insulating material part 5 are made of the same material, different from the above, the upper heat-insulating material part 7 is provided with a through hole for the sleeve 6 to pass through, and the diameter of the through hole is slightly larger than that of the sleeve 6. In order to ensure that the thermodetector trap in the heat pipe is completely positioned at the evaporation section, the liquid filling height of the heat pipe is lower than that of the end cover 206 of the thermodetector trap, and in addition, the surface of the end cover in the heat pipe and the surface of the thermodetector trap are attached to two layers of porous wire nets, so that the boiling evaporation of the NMP working medium and the backflow of condensate are facilitated.

The lower boss 208 is arranged in the middle of the lower end cover 207, one end of the lower boss 208 is welded with a small central hole of the lower end cover 207, and the other end of the lower boss 208 is radially provided with an external thread which is matched and connected with the internal thread of the protective cap 210; a through hole is formed in the axis direction of the lower boss 208, and the inner diameter of the through hole is consistent with the outer diameter of the liquid charging pipe 209; one port of the liquid charging pipe 209 is welded with the axial through hole of the lower boss 208, and the other port is subjected to cold welding and sealing treatment after liquid charging. The material used by the liquid charging pipe 209 is nickel, and the liquid charging pipe is a charging port of NMP working medium after high-temperature annealing treatment. Before the NMP heat pipe is filled, a working cavity of the NMP heat pipe is cleaned and subjected to high-temperature vacuum degassing treatment, the NMP working medium is filled into the working cavity through the liquid filling pipe 209, cold welding is adopted for sealing, and then the protective cap 210 is screwed on the lower boss 208 to protect the liquid filling pipe 209. Through the design, the liquid filling port of the NMP heat pipe is designed in the middle of the lower end cover 207, so that the interference of the liquid filling port arranged at the upper part of the heat pipe on the temperature detector trap 205 is avoided, and the influence of a small amount of gas in the liquid filling port on the temperature equalizing effect in the heat pipe is also avoided.

Except the liquid filling pipe 209, all metal components of the NMP heat pipe 2 are made of 316L stainless steel, are compatible with NMP working medium and can bear certain pressure, and deformation or cracking of the heat pipe caused by overlarge vapor pressure or overhigh temperature in the pipe is avoided. The tubular heating furnace 1 adopts fuzzy PID control, can obviously reduce the overshoot of the system, shorten the adjusting time, provide better temperature stability and meet the actual use requirement of the system. The soaking cylinder 3 is made of red copper and is used for improving the uniformity of a vertical temperature field of the hearth.

Furthermore, the heat preservation cotton 8 is magnesium aluminum silicate heat preservation cotton, so that the influence of heat loss on the temperature stability and the axial temperature field uniformity of the temperature source device compared with the NMP heat pipe can be reduced. The sleeve 6 is made of quartz glass and has low heat conductivity coefficient.

In a second embodiment, the present application provides a method for testing a comparison temperature source of an NMP heat pipe, which is based on the comparison temperature source of the NMP heat pipe in the first embodiment, and the specific method includes the following steps:

step 1: before the sleeve is put into the thermometer trap, the inner wall surface and the outer wall surface of the sleeve are strictly cleaned by absolute ethyl alcohol and then slowly and completely put into the thermometer trap after being cleaned.

Step 2: selecting two temperature measuring wells by using two temperature sensors with the same measuring precision and reaction time, placing probes of the temperature sensors at positions 0cm, 4cm, 8cm and 12cm away from the bottoms of the two temperature measuring wells to wait for measuring positions, and simultaneously measuring the temperature change of the two temperature measuring wells in continuous time;

and step 3: using two temperature sensors, selecting a reference position during measurement, using one of the temperature sensors as a reference standard, and measuring the temperature of the position all the time; when another temperature sensor starts to measure, the measuring position should be as close to the reference standard as possible, after a period of measurement, the temperature sensor is moved to other positions to be measured, and after the position is in thermal equilibrium again, the measurement is started again to measure the uniformity of the axial temperature field of the NMP heat pipe comparison temperature source device.

FIG. 4 is a schematic diagram of a testing method of an NMP heat pipe comparison temperature source, wherein an auxiliary temperature acquisition and data processing system is added for auxiliary testing on the basis of the NMP heat pipe comparison temperature source device. The system comprises 2 thermometers and 1 temperature bridge. The thermometric instrument is a microK400 high-precision thermometric bridge produced by ISOTECH in England, has high precision, can realize multi-path data acquisition, the set data acquisition time interval is 2s, in order to reduce the heat transferred to the outside in the axial direction of the standard platinum resistance thermometer, the outer protective tubes of the two selected standard platinum resistance thermometers are made of quartz glass materials with lower heat conductivity coefficients, and are verified and calibrated by China institute of metrology science and research.

In order to test the stability of the NMP heat pipe comparison temperature source device in the temperature region of 200-300 ℃, the temperature stability of the bottom of the NMP heat pipe metering well is tested at different control temperatures. The standard platinum resistance thermometers used during the test were placed at the bottom of the thermometer wells numbered 1# and 2# respectively. And after the temperature of the heat pipe reaches thermal balance, the temperature measuring bridge records the temperature values measured by the standard platinum resistance thermometer every 2s, finally selects data with good stability within 45 minutes, takes out the maximum value and the minimum value of all the temperature values acquired within the time period, and calculates the +/-1/2 difference value as the fluctuation degree of the heat pipe calibration furnace so as to evaluate the stability of the temperature of the heat pipe. The results of the temperature stability test at the bottom of # 1 and # 2 at the controlled temperatures of 200 deg.C, 250 deg.C, 280 deg.C, and 300 deg.C are shown in Table 1.

TABLE 1 temperature stability at different control temperatures

In order to test the stability of the temperature field within 12cm from the bottom of the measuring trap, a temperature point within the temperature range of 200-300 ℃ is selected, the temperature of the furnace is controlled at 250 ℃, and the stability of four positions 0cm, 4cm, 8cm and 12cm from the bottom of the measuring trap is tested respectively. In the test, standard platinum resistance thermometers SPRT5263 and SPRT9598 were placed in # 1 and # 3, respectively, for testing. The measurement is started from the bottom of each measuring well, and after a period of time, the two standard platinum resistance thermometers are simultaneously moved to the position 4cm away from the bottom of the measuring well for measurement until the temperature stability at the position 12cm away from the bottom of the measuring well is measured. The experimental data selects the result of good stability within 45 minutes when the heat pipe is in a thermal equilibrium state. The test results are shown in table 2.

TABLE 2 temperature stability at different heights

The conclusion can be drawn from the test methods described above: in the temperature region of 200-300 ℃, the NMP heat pipe has better temperature stability than plus or minus 0.006 ℃ compared with the 45-minute temperature stability of a temperature source device, and has better temperature stability.

Compared with the prior art, the NMP heat pipe comparison temperature source device provided by the invention obtains better temperature stability and axial temperature field uniformity in the temperature range of 200-300 ℃, so that the NMP heat pipe comparison temperature source device can be used as a novel temperature source, can improve the recurrence level of tin solidifying point 231.928 ℃ defined by ITS-90 international temperature standard, and is popularized and applied in the field of temperature measurement.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and any person skilled in the art can conceive of changes or substitutions within the technical scope of the present invention.