Three-dimensional thermopile and preparation method thereof

Abstract

The present invention discloses a three-dimensional thermopile and a preparation method thereof, comprising: a plurality of stacked annular heat flux sensors; an inner cylinder penetrating the center of each heat flux sensor; the inner cylinder is configured to be in close contact with the heat transfer surface, and the inner cylinder is configured to have a thermal resistance section with a predetermined height exceeding the plane where the top and bottom heat flux sensors are located; each thermal resistance section is packaged by a matching pad ring and a sealing ring, and the sealing ring is provided with a lead-out port matching the lead-out head of the top or bottom heat flux sensor. The present invention provides a three-dimensional thermopile and a preparation method thereof, which can realize three-dimensional measurement of heat when used in conjunction with a thermal analysis instrument in a laboratory, and has higher measurement accuracy than existing planar measurements, and can effectively reduce response time.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal measurement sensors. More specifically, the present invention relates to (but not limited to) the field of thermal analysis instruments, and is particularly applicable to three-dimensional thermopiles in differential scanning calorimetry (DSC) or differential thermal analysis instruments and a preparation method thereof. Background Art

[0002] Differential thermal analysis provides heat to the sample and reference material simultaneously to maintain thermal equilibrium. When the sample material changes in physical and / or chemical state, heat is transferred to the surrounding environment through the thermal sensor and thermal equilibrium is reestablished. The voltage of the thermal sensor corresponds to the heat flow rate of the conduction. Thermal sensors are also called heat flow sensors or thermal conductivity sensors.

[0003] The heat flow sensor uses the Seebeck effect in the thermoelectric effect of different metals or alloys. It refers to the thermoelectric phenomenon that when two different electrical conductors or semiconductors are connected end to end, the temperature difference at the two ends produces a voltage difference at both ends. For weak temperature changes, a single thermocouple junction does not have sufficient detection sensitivity. Multiple thermocouple junctions need to be connected in series to amplify the temperature difference signal. With an ultra-low noise signal amplifier, it can detect tiny heat changes as low as 10nJ. Precision microcalorimeters often have dozens to thousands of thermocouple junctions.

[0004] DSC (Differential Scanning Calorimeter) is a widely used calorimetric instrument for measuring the temperature and heat associated with the thermal transition of substances. The operating temperature range is usually from room temperature to 300°C, and some even exceed 1000°C. Its heat flow measurement sensor is usually a two-dimensional planar structure. Patents such as CN200910126618.1 and CN105209872A describe a flat-plate thermal analysis sensor with dozens of pairs of thermocouples evenly distributed on a ceramic substrate to form a circular distribution. The measurement sample is placed in a small crucible, and the bottom of the crucible is in contact with the sensor to measure the heat of the sample. This method is suitable for scenarios with small sample quantities and rapid responses.

[0005] Patent CN01138265.1 mentions a heat detection device, which is characterized by a large and small insulated ring, each with the same number of evenly distributed grooves, and a thermocouple welded into a ring-shaped thermopile to form a thermopile unit. However, its structure is too complicated, and the dimensional error caused by too many processing grooves may lead to unbalanced heat distribution. The change in the contact area between the thermocouple node and the ring after welding will also affect the heat transfer uniformity of the sensor.

[0006] If the thermal reaction of the sample is slow, the heat will be distributed throughout the crucible, and about 50% of the heat will be dissipated outward through the crucible surface that does not contact the sensor by convection, radiation, etc. Therefore, for slow reactions, the accuracy of enthalpy measurement is limited. In addition, since the sensor is a planar structure, the number of sensors in series is also limited, usually 20-50 pairs, and the signal resolution and instrument sensitivity are limited by this.

[0007] Thirdly, when it comes to reactions under conditions such as catalysis, adsorption, high pressure, and vacuum, two or even more substances are required to participate, or complex mechanisms are required to achieve mixing, stirring, hydrolysis, etc. Since the crucible volume used in existing DSCs is usually around 100uL, these reactions are also difficult to achieve with DSCs due to space limitations.

[0008] In 1948, Calvet proposed that the sensor wraps the sample pool in 3D. According to the description, one way to achieve this is as follows Figure 1 , the main view is the top view, and the view in the B direction is a single piece of thermocouple sheet. The substrate is quartz or mica, and there are about 30 pairs of thermocouples distributed on its surface. Each pair of thermocouples has independent metal sheets at both ends as the bonding surface of the thermocouple wire, and also as its heat conduction surface. 16 thermocouple sheets together form a circular thermopile. There are 480 pairs of thermocouples in total. The center is the inner channel tube that accommodates the sample pool, and the outside of the thermopile is close to the aluminum heat sink with a round hole.

[0009] Of course, in order to obtain better measurement results, the prior art has improved the structure of the heat flow sensor, such as a new type of thermopile heat flow sensor with application number 202011232954.7, which is formed by overlapping and placing two material sheets of different materials, and realizing electrical conduction between the two material sheets of different materials through thermocouples, thereby forming a thermopile form to amplify the thermoelectric potential difference output, thereby achieving the purpose of increasing the output sensitivity coefficient of the thermopile heat flow sensor, but its application scenario is temperature measurement in a real environment (such as environment), and its measurement method is planar measurement. The sensor is in direct contact with the surface to be measured, thereby realizing temperature measurement. For application research in the laboratory, the measurement environment is no longer limited to plane measurement. Usually in specific experiments, three-dimensional precise measurement effects are required, and current sensors cannot achieve this purpose.

[0010] Figure 8-9It is a three-dimensional heat flow sensor implementation method in the prior art. It is easy to see that the contact surfaces of the thermopile are the inner ring surface of the external uniform heat block and the outer ring surface of the internal circular channel, and they are required to fit tightly. When the temperature rises, the contact surface fit becomes worse due to the difference in expansion coefficients between the thermopile material and the external aluminum heat sink. For example, if the diameter of the thermopile is 38mm, the external heat sink is aluminum, and the thermal expansion coefficient is 23.2e-6 / K. The thermocouple material is E-type, nickel-chromium-constantan 15e-6 / K. The inner channel is a stainless steel tube with an outer diameter of 17mm. When the sensor temperature rises from room temperature to 300°C, according to the circular thermal expansion calculation formula, the gap of the mating surface can be derived from the following formula:

[0011] Δd=d*ΔT(α1-a2);

[0012] Wherein, d is the radius of the thermopile; ΔT is the temperature rise value; α1 is the thermal expansion coefficient of aluminum; α2 is the thermal expansion coefficient of the E-type thermocouple wire, and the thermal expansion coefficient of stainless steel is close to that of the E-type thermocouple wire.

[0013] As can be seen from FIG. 6 , for sensors in the prior art, the gap between the mating surfaces increases with increasing temperature. For example, at 300° C., the gap increases to 40 μm. The thermal conductivity of the thermopile decreases, and at the same time, the response time of the thermopile is increased. The obvious change can also be seen from the actual calibrated calorimetric coefficient versus temperature curve of the thermopile. Summary of the invention

[0014] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0015] In order to achieve these objects and other advantages according to the present invention, there is provided a three-dimensional thermopile, comprising:

[0016] A plurality of stacked annular heat flux sensors, with a heat transfer channel arranged in a ring shape in space at the center;

[0017] An inner cylinder passing through the center of each heat flux sensor;

[0018] Wherein, the inner cylinder is configured to be in close contact with the heat transfer surface, and the inner cylinder is configured to have a thermal resistance section with a predetermined height exceeding the plane where the top layer and the bottom layer heat flux sensors are located;

[0019] Each thermal resistance section is packaged by a matching pad ring and a sealing ring, and the sealing ring is provided with a lead-out port matching with the top or bottom heat flux sensor lead-out head.

[0020] Preferably, each annular heat flow sensor is configured to include:

[0021] Outer ring;

[0022] A plurality of heat transfer mechanisms are arranged inside the outer ring to form a heat transfer channel through spatial layout;

[0023] A plurality of sets of thermocouples are arranged between the outer ring and the heat conducting mechanism to connect each heat conducting mechanism with the outer ring to form an integral whole;

[0024] Wherein, adjacent heat flow sensors are connected through at least two lead-out heads in communication with each group of thermocouples, thereby realizing the series connection of thermocouples in a plurality of heat flow sensors.

[0025] Preferably, a matching annular platform is provided on the inner side wall of the outer ring so that the longitudinal section of the outer ring presents a T-shaped or L-shaped structure in space, and the annular platform constitutes a heat-conducting surface matching each group of thermocouples.

[0026] Preferably, the surfaces of the outer ring and the inner cylinder are both provided with matching insulating layers;

[0027] Among them, the annular platform is provided with a plurality of U-shaped or flat-plate-shaped fixing parts, one end of each group of thermocouples is connected to the corresponding heat-conducting mechanism, and the other end is respectively connected to two adjacent fixing parts, so that each group of thermocouples and the fixing parts and the heat-conducting mechanism are connected in series in space.

[0028] Preferably, a matching first silver paste layer is provided on the upper surface of the fixing member and on the connection point between the thermocouple and the upper surface of the fixing member.

[0029] Preferably, the heat conducting mechanism is configured to be an L-shaped structure, so as to have a mounting surface that matches the thermocouple and a heat transfer surface that matches the inner cylinder in space;

[0030] A matching second silver paste layer is disposed on the upper surface of the mounting surface and on the connection point between the thermocouple and the upper surface of the mounting surface.

[0031] Preferably, the length of each thermal resistance segment is configured to be 25 mm-35 mm.

[0032] A method for preparing a three-dimensional thermopile, comprising:

[0033] Step 1, preparing a plurality of heat flow sensors;

[0034] Step 2: Connect the upper and lower adjacent heat flux sensors through lead-out headers to form a thermopile;

[0035] Step 3: insert the inner tube into the center of the thermopile and extend both ends of the inner tube outward by about 30 mm to form a thermal resistance section;

[0036] Step 4: respectively set matching pad rings and sealing rings on each thermal resistance section, and make the lead-out head of the heat flux sensor on one side pass through the lead-out hole to obtain a three-dimensional thermopile.

[0037] Preferably, in step 1, the preparation method of each heat flow sensor is configured to include:

[0038] S10, preparing an outer ring of the T-shaped structure, and performing surface treatment on the outer ring to make it have insulation properties;

[0039] S10, preparing a plurality of L-structured heat conducting mechanisms, welding two thermocouples on the mounting surface of each heat conducting mechanism, and arranging them in a V-shape in space;

[0040] S10, clamping a plurality of fixings on the outer ring, and welding the thermocouples on each heat conducting mechanism to the upper surface of the adjacent fixings, so that each heat conducting mechanism forms a heat transfer channel in a ring layout around the outer ring in space;

[0041] S10, two lead-out terminals, one long and one short, are arranged on the platform of the outer ring;

[0042] S10, coating a silver paste layer on the upper surface of the fixing part and the mounting surface, and on the connection points between the thermocouple and the fixing part and the mounting surface.

[0043] Preferably, it also includes:

[0044] Step five, a circular heat sink block having at least two thermopile accommodating cavities is provided, the accommodating cavities are arranged in a differential manner, one of which is used as a reference and the other is used as a measurement, and the sealing ring of each thermopile is fixed to the accommodating cavity by interference fit or welding.

[0045] The present invention includes at least the following beneficial effects: the thermopile of the present invention, through the coordination of various components, can realize three-dimensional curved surface heat flow measurement when coordinated with a thermal analysis instrument in a laboratory. Compared with existing plane measurements, its measurement accuracy is higher and the response time can be effectively reduced.

[0046] The heat flux sensor (thermocouple ring) of the present invention is arranged in a ring structure, and a plurality of heat flux sensors can be easily connected in series to form a thermopile. When performing three-dimensional curved surface heat flux measurement, the matching surface of the thermopile and the heat sink for heat conduction is changed from the existing planar thermal expansion direction to a vertical thermal expansion direction, which greatly reduces the gap between the sensor and the uniform heat body matching surface, solves the problem that the matching gap increases with increasing temperature, improves the calorimetric coefficient of the sensor at high temperature, and reduces the time constant of the sensor in the entire temperature range.

[0047] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1is a schematic diagram of the external structure of a thermopile in one embodiment of the present invention;

[0049] Figure 2 It is a schematic diagram of the structure in which a plurality of heat flow sensors cooperate with an inner cylinder in one embodiment of the present invention;

[0050] Figure 3 A schematic diagram of the side structure of a heat flow sensor in one embodiment of the present invention;

[0051] Figure 4 for Figure 3 A schematic diagram of the cross-section magnified structure of the middle K region;

[0052] Figure 5 It is a schematic diagram of the side view structure of a heat flow sensor in another embodiment of the present invention;

[0053] Figure 6 It is a schematic diagram of the structure of the thermopile and the heat sink block in one embodiment of the present invention;

[0054] Figure 7 A comparison diagram of the calorimetric coefficient versus temperature curves in the sensor of the present invention and the prior art;

[0055] Figure 8 One of the views of a three-dimensional heat flow sensor in a three-dimensional form in the prior art;

[0056] Fig. 9 for Figure 8 B view. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0058] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0059] It should be noted that in the description of the present invention, the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0060] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] Figure 1-2 A three-dimensional thermopile according to the present invention is shown, which includes:

[0062] A plurality of stacked annular heat flux sensors 1, with a heat transfer channel arranged in a ring shape in space at the center;

[0063] An inner tube (inner channel) 2 is provided in the center of each heat flux sensor. The inner channel constitutes the inner heat transfer part of the thermopile. The materials that can be used include aluminum, stainless steel, thermal conductive ceramics, etc. The inner channel is characterized in that it is closely attached to the inner heat transfer surface of all heat conduction mechanisms.

[0064] The inner cylinder is configured to be in close contact with the heat transfer surface, and the inner cylinder is configured to have a thermal resistance section 210 with a predetermined height exceeding the plane where the top and bottom heat flux sensors are located, and the length of each thermal resistance section is configured to be 25mm-35mm. As a preferred solution, each thermal resistance section is obtained by extending outward from both ends of the inner channel by about 30mm;

[0065] Each thermal resistance section is encapsulated by a matching pad ring 3 and a sealing ring 4. The sealing ring is provided with a lead-out port (not shown) that matches the top or bottom heat flux sensor lead-out head. In actual application, a pad ring and a sealing ring with appropriate height are selected (the pad ring matches the thermopile, and the sealing ring matches the inner channel of the thermopile), the extra height of the inner channel at both ends is filled, and a lead-out opening for the thermocouple is reserved in the sealing ring at the tail. In this scheme, a thermopile capable of three-dimensional measurement is obtained by stacking heat flux sensors of annular structure. In actual application, the medium to be measured is set in a heat transfer channel formed by stacking multiple heat flux sensors, and the existing planar measurement method is changed to a three-dimensional measurement. When performing three-dimensional measurement, the matching surface of the thermopile and the heat sink is changed from the existing planar thermal expansion direction to a vertical thermal expansion direction, which greatly reduces the gap between the sensor and the uniform heat body, solves the problem that the matching gap increases with the increase of temperature, and improves the calorimetric coefficient of the sensor at high temperature (such as Figure 7 As shown in Figure 2), the time constant of the sensor over the entire temperature range is reduced.

[0066] like Figure 3-5In another example, each annular heat flow sensor is configured to include:

[0067] The outer ring 110, as the outer heat-conducting ring of the sensor (or called the outer heat-uniform ring, as an isothermal body), is made of a material with good thermal conductivity, such as aluminum or high thermal conductivity ceramics;

[0068] A plurality of heat-conducting mechanisms 120 are arranged inside the outer ring to form a heat transfer channel through spatial layout. The heat-conducting mechanisms are metal sheets for inner ring heat transfer. Through the spatial layout of the plurality of heat-conducting mechanisms, a heat transfer channel with a ring-shaped layout is obtained at the center. The stacking of the heat flow sensors can extend the heat transfer channel as required to meet specific measurement needs. The outer ring spatially constitutes an external isothermal body. A heat transfer channel is formed between the outside and the heat-conducting mechanism through thermocouples to achieve the transfer of heat energy from the outside to the inside.

[0069] A plurality of sets of thermocouples 130 are disposed between the outer ring and the heat conducting mechanism to connect each heat conducting mechanism with the outer ring to form an integral whole;

[0070] Among them, adjacent heat flow sensors are connected through lead-out terminals A 131 and lead-out terminals B 132 which are connected to each group of thermocouples. In multiple annular heat flow sensors, series connection is achieved through thermocouples, and the series connection of thermocouples in multiple heat flow sensors is achieved. In practical applications, the series-connected thermocouples have two lead-out terminals, one long and one short, and the length of the longer thermocouple lead-out terminal should be long enough so that it can be connected to the shorter lead-out terminal on the thermocouple ring of the upper layer. By superimposing multiple layers of annular heat flow sensors, hundreds of pairs of thermocouples can be connected in series, and the superposition of multiple layers of heat flow sensors can easily form the required thermoelectric pile. In further applications, the lead-out terminals can be set on one side so that the long lead-out terminal passes through the heat flow sensor of the upper layer to be connected to the shorter lead-out terminal, or the two lead-out terminals can be respectively set at the upper and lower ends for easy connection. Figure 3 The invention shows a lead-out method that is easy to prepare in engineering, and a single thermocouple or no thermocouple is set at a position matching with the lead-out. The heat transfer mechanism is connected with a fixing part or other parts in space, and a matching extension part is set on the fixing part to fix the thermocouple lead-out, and to connect or fix the position with other parts. The annular heat flow sensor of the present invention has an annular structure layout in space, so that after stacking multiple heat flow sensors, a three-dimensional heat transfer channel matching with the medium to be measured can be provided in space, realizing three-dimensional curved surface heat flow measurement, which can be widely used in scenes requiring thermal analysis in laboratories.

[0071] like Figure 3 , 5In another example, a matching annular platform 111 is provided on the inner side wall of the outer ring so that the longitudinal section of the outer ring is T-shaped or L-shaped in space, and the annular platform constitutes a heat-conducting surface that matches each group of thermocouples. In this structure, the part of the outer ring extending inward constitutes a load-bearing platform, which serves as a heat-conducting surface that matches the thermocouple, and its cross-section is T-shaped in space. In actual application, the platform is a ring that is vertical to the outer ring in space, and the structure is complete. However, when used, it can also be grooved as needed, but this groove will lead to uneven heat conduction, so it is not used as a preferred solution.

[0072] like Figure 3 , 5 In another example, the surfaces of the outer ring and the inner cylinder are both provided with matching insulating layers (not shown). In practical applications, the outer ring and the inner cylinder are surface treated so that the surfaces thereof have an insulating layer with a membrane structure, which has the characteristic of surface insulation;

[0073] Among them, the annular platform is provided with a plurality of U-shaped or flat-plate-shaped fixing members 140, one end of each group of thermocouples is connected to the corresponding heat-conducting mechanism, and the other end is respectively connected to two adjacent fixing members, so that each group of thermocouples and the fixing members and the heat-conducting mechanism are in a series state in space. In specific applications, the fixing members are about 20 metal sheets distributed on the platform, and the specific number can be appropriately adjusted according to parameters such as the circumference of the platform. The metal sheets are designed as follows Figure 4 U-shaped structure or Figure 5 If the flat plate structure is adopted Figure 4 In the case of a U-shaped structure, the lengths of the two freely extending arms can be the same or slightly different depending on the application requirements;

[0074] When used, the fixture features two arms arranged in a U-shape in space that can clamp the platform, making it difficult for the fixture made of metal sheets to move and supporting the galvanic wire. The metal sheets and the platform are in good contact, forming a stable and reliable heat conduction path in the vertical direction. Even at high temperatures, when the platform and the metal sheet have relative horizontal displacement due to differences in expansion coefficients, the heat conduction is negligible because the heat conduction direction is vertical, and all metal sheets have the same contact area with the mounting platform, ensuring that the heat flow through the galvanic wire can flow in or out evenly in all directions;

[0075] The fixing member and the heat-conducting surface are connected via a resin layer, and its function is to achieve a fixed connection between the fixing member and the heat-conducting surface through the bonding effect of the resin layer, thereby ensuring the stability between the components.

[0076] like Figure 3 , 5In another example, a matching first silver paste layer (not shown) is provided on the upper surface of the fixing part and the connection point between the thermocouple and the upper surface of the fixing part. In actual application, the upper part of the fixing part made of metal sheet is welded to the thermocouple 130a and the thermocouple 130b. The optional methods include laser welding, spot welding, etc. After welding, the welding points and the upper surface of the fixing part are coated with silver paste. This not only reduces the contact resistance of the thermocouple 130a and the thermocouple 130b, but also quickly and evenly conducts the heat at the node of the thermocouple to the fixing part, which is beneficial to reduce the thermal response time of the sensor.

[0077] like Figure 3 , 5 In another example, the heat conducting mechanism is configured as an L-shaped structure, so as to have a mounting surface 121 that matches the thermocouple, which is also a welding surface of the thermocouple, and a heat transfer surface 122 that matches the inner cylinder;

[0078] A matching second silver paste layer (not shown) is provided on the upper surface of the mounting surface and the connection points between the thermocouple and the upper surface of the mounting surface. In the present embodiment, the internal heat transfer structure of the sensor is an L-shaped metal sheet having a mounting surface and a heat transfer surface. When used, the mounting surface is welded together with the thermocouple 130a and the thermocouple 130b, and is also coated with silver paste to reduce the contact resistance. At the same time, the heat at the nodes of the thermocouple is quickly and evenly conducted to the heat conducting mechanism, which is beneficial to reducing the thermal response time of the sensor.

[0079] A method for preparing a three-dimensional thermopile, comprising:

[0080] Step 1, preparing a plurality of heat flow sensors;

[0081] Step 2: Connect the upper and lower adjacent heat flux sensors through lead-out headers to form a thermopile;

[0082] Step 3: insert the inner tube into the center of the thermopile and extend both ends of the inner tube outward by about 30 mm to form a thermal resistance section;

[0083] Step four, respectively set matching pad rings and sealing rings on each thermal resistance section, and make the lead-out head of the heat flux sensor on one side pass through the lead-out hole to obtain a three-dimensional thermopile. Compared with the existing technology, the thermopile obtained in this way is more conducive to engineering implementation, and the controllability of the equipment structure connection is better, it can be assembled as needed, and it has better adaptability.

[0084] Step 5: Figure 6, a circular heat sink block 5 having at least two thermopile accommodating cavities 510 is provided, the accommodating cavities are arranged in a differential manner, one of which is used as a reference and the other is used as a measurement, and the sealing ring of each thermopile is fixed to the accommodating cavity by interference fit or welding. The thermopile is placed in the external circular heat sink block, and the same material as the outer ring of the sensor is selected to eliminate the problem caused by thermal expansion. The sealing ring and the heat sink are fixed to each other by interference fit or welding. In order to improve the anti-interference performance and expand its application, two completely identical thermopiles are often arranged in a differential manner: one is used as a reference and the other is used as a measurement.

[0085] In step 1, the preparation method of each heat flow sensor is configured to include:

[0086] S10, preparing an outer ring of the T-shaped structure, and performing surface treatment on the outer ring to make it have insulation properties;

[0087] S10, preparing a plurality of L-structured heat conducting mechanisms, welding two thermocouples on the mounting surface of each heat conducting mechanism, and arranging them in a V-shape in space;

[0088] S10, clamping a plurality of fixings on the outer ring, and welding the thermocouples on each heat conducting mechanism to the upper surface of the adjacent fixings, so that each heat conducting mechanism forms a heat transfer channel in a ring layout around the outer ring in space;

[0089] S10, two lead-out terminals, one long and one short, are arranged on the platform of the outer ring;

[0090] S10, respectively coating a silver paste layer on the upper surface of the fixing part, the mounting surface, and the connection points between the thermocouple and the fixing part and the mounting surface. In this way, the corresponding annular heat flow sensor is obtained, so that in actual application, it can be stacked as needed to form a thermopile that can perform three-dimensional measurement, and the engineering implementation is simpler.

[0091] The above solution is only an illustration of a preferred embodiment, but is not limited thereto. When implementing the present invention, appropriate replacement and / or modification can be performed according to user needs.

[0092] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0093] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A three-dimensional thermopile, characterized in that: include: A plurality of stacked annular heat flux sensors, with a heat transfer channel arranged in a ring shape in space at the center; An inner cylinder passing through the center of each heat flux sensor; Wherein, the inner cylinder is configured to be in close contact with the heat transfer surface, and the inner cylinder is configured to have a thermal resistance section with a predetermined height exceeding the plane where the top layer and the bottom layer heat flux sensors are located; Each thermal resistance section is encapsulated by a matching pad ring and a sealing ring, and the sealing ring is provided with a lead-out port matching with the top or bottom heat flux sensor lead-out head; Each annular heat flow sensor is configured to include: Outer ring; A plurality of heat transfer mechanisms are arranged inside the outer ring to form a heat transfer channel through spatial layout; A plurality of sets of thermocouples are arranged between the outer ring and the heat conducting mechanism to connect each heat conducting mechanism with the outer ring to form an integral whole; Wherein, adjacent heat flow sensors are connected through at least two lead-out terminals in communication with each group of thermocouples, so as to realize the series connection of thermocouples in a plurality of heat flow sensors; The inner side wall of the outer ring is provided with a matching annular platform so that the longitudinal section of the outer ring is T-shaped or L-shaped in space, and the annular platform constitutes a heat conducting surface matching each group of thermocouples; The surfaces of the outer ring and the inner cylinder are both provided with matching insulating layers; The annular platform is provided with a plurality of U-shaped or flat-plate-shaped fixings, one end of each group of thermocouples is connected to the corresponding heat-conducting mechanism, and the other end is respectively connected to two adjacent fixings, so that each group of thermocouples, the fixings and the heat-conducting mechanism are in series in space; The fixing member is connected to the heat conducting surface via a resin layer.

2. The three-dimensional thermopile according to claim 1, characterized in that: A matching first silver paste layer is arranged on the upper surface of the fixing piece and on the connection point between the thermocouple and the upper surface of the fixing piece.

3. The three-dimensional thermopile according to claim 1, characterized in that: The heat conducting mechanism is configured to be an L-shaped structure, so as to have a mounting surface matching the thermocouple and a heat transfer surface matching the inner cylinder in space; A matching second silver paste layer is disposed on the upper surface of the mounting surface and on the connection point between the thermocouple and the upper surface of the mounting surface.

4. The three-dimensional thermopile according to claim 1, characterized in that: The length of each thermal resistance section is configured to be 25mm-35mm.

5. A method for preparing a three-dimensional thermopile as claimed in any one of claims 1 to 4, characterized in that: include: Step 1, preparing a plurality of heat flow sensors; Step 2: Connect the upper and lower adjacent heat flux sensors through lead-out headers to form a thermopile; Step 3: insert the inner tube into the center of the thermopile and extend both ends of the inner tube outward by about 30 mm to form a thermal resistance section; Step 4: respectively arrange matching pad rings and sealing rings on each thermal resistance section, and make the lead-out head of the heat flux sensor on one side pass through the lead-out hole to obtain a three-dimensional thermopile; In step 1, the preparation method of each heat flow sensor is configured to include: S10, preparing an outer ring of the T-shaped structure, and performing surface treatment on the outer ring to make it have insulation properties; S10, preparing a plurality of L-structured heat conducting mechanisms, welding two thermocouples on the mounting surface of each heat conducting mechanism, and arranging them in a V-shape in space; S10, clamping a plurality of fixings on the outer ring, and welding the thermocouples on each heat conducting mechanism to the upper surface of the adjacent fixings, so that each heat conducting mechanism forms a heat transfer channel in a ring layout around the outer ring in space; S10, two lead-out terminals, one long and one short, are arranged on the platform of the outer ring; S10, coating a silver paste layer on the upper surface of the fixing part and the mounting surface, and on the connection points between the thermocouple and the fixing part and the mounting surface.

6. The method for preparing a three-dimensional thermopile according to claim 5, characterized in that: Also includes: Step five, a circular heat sink block having at least two thermopile accommodating cavities is provided, the accommodating cavities are arranged in a differential manner, one of which is used as a reference and the other is used as a measurement, and the sealing ring of each thermopile is fixed to the accommodating cavity by interference fit or welding.

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