CN101938861B - Linear heat source type heater for protecting and heating plate devices - Google Patents

Abstract

A line heat source heater for a protective hot plate device in the technical field of measuring devices, comprising: a heating plate, a protective plate, an electric heating wire and fixing pins, wherein: the heating plate is fixedly arranged in the center of the protective plate, and one end of several fixing pins It is radially arranged on the side of the heating plate, the other end of the fixing pin is located in the slot hole of the protective plate, and the electric heating wire covered with a ceramic sleeve is located in the groove of the heating plate and the protective plate. The invention improves the uniformity of the surface temperature of the linear heat source heater, reduces the radiation heat exchange in the radial direction of the heating plate, and improves the accuracy of the thermal conductivity measurement.

Description

Wire source heaters for guarded hot plate installations

technical field

The invention relates to the technical field of measuring devices, in particular to a wire heat source heater for a protective hot plate device.

Background technique

At present, in the research, development, production and application of some thermal insulation materials, it is necessary to accurately measure the thermal conductivity of the material. Due to the lack of standardization of the heating plate used in the protective hot plate device, at present, many protective hot plate thermal conductivity test devices use a square heater as the heating plate on the high temperature side, resulting in uneven temperature at the corners of the heating plate, which greatly affects the accuracy of the measurement. With precision, it is not enough to accurately determine the thermal conductivity of thermal insulation materials. Therefore, the selection of the heater type and the determination of the embedded position of the heating wire are very critical to the measurement of the thermal conductivity of solid materials by the protective hot plate device, which directly affects the accuracy and authority of the test data.

After searching the existing technical literature, it was found that the "Double Sample Protected Hot Plate High Temperature Thermal Conductivity Instrument" disclosed in Chinese Patent No. ZL88217498.3 introduced a double sample protected hot plate high temperature instrument for measuring the thermal conductivity or thermal resistance of non-metallic solids Thermal conductivity meter, the test temperature range is 500K～1000K. The heater is made of silicon carbide, which not only increases the test temperature but also reduces the cost; the main heater is heated by AC with constant wall temperature, and then heated by DC with constant heat flow, which improves the test speed; the outer tubular heater is made of carbide rod; The microcomputer realizes the accurate acquisition and processing of multi-channel weak signals. The invention does not specify which type of heater is used and where the heating wire is positioned.

A further search found that the "heat pipe plate type thermal conductivity tester" disclosed in Chinese Patent No. ZL200620103469.9 adopts a Dewar vessel with a flange on the upper end, and a test device is suspended inside the Dewar vessel. The flat heat pipe with good temperature uniformity is used as the hot and cold plate of the thermal conductivity instrument, and is arranged on the upper and lower sides of the sample to maintain the isothermal surface on both sides of the sample; The convective heat dissipation loss of heat. This invention also does not illustrate what kind of heater adopts and the position that heating wire is positioned.

Chinese Patent No. ZL200720063809.4 discloses "a good conductor thermal conductivity tester", which uses a good conductor thermal conductivity tester, hot end temperature control sensor, thermal insulation material, cold end temperature control sensor, semiconductor cooling sheet, heating Radiators, radiators, bases. The hot end of the material to be tested is equipped with a heater. The end face of the cold end of the material to be tested is close to one side of the semiconductor cooling plate, and the other side of the semiconductor cooling plate is close to the radiator. The temperature control sensor of the cold end and the semiconductor cooling plate pass through the cable. It is electrically connected with the cold end temperature control cable base, and the cold end temperature setting adjustment knob is used to adjust the required temperature of the cold end of the material to be tested. This invention also does not specify what type of heater is used and the position where the heating wire is positioned.

Contents of the invention

The present invention aims at the above-mentioned deficiencies in the prior art, and provides a line heat source heater for a protective hot plate device, which improves the uniformity of the surface temperature of the line heat source heater, reduces the radial heat transfer of the heating plate, and improves The accuracy of the thermal conductivity measurement is improved.

The present invention is achieved through the following technical solutions. The present invention includes: a heating plate, a protective plate, an electric heating wire and fixing pins, wherein: the heating plate is fixedly arranged in the center of the protective plate, and one end of several fixing pins is radially arranged on the heating plate The other end of the fixing pin is located in the slot of the protective plate, and the electric heating wire covered with a ceramic sleeve is located in the groove of the heating plate and the protective plate.

The outer side of the heating plate and the inner side of the protective plate are respectively provided with triangular grooves to reduce the radiation heat transfer in the radial direction of the heating plate and improve the uniformity of the temperature field on the test surface of the heating plate.

The heating plate is provided with a mirror-symmetrical first groove, which includes eight sections of arc-shaped grooves, eight semicircular transition grooves and four sections of linear grooves, wherein: the two ends of the semicircular transition grooves are respectively connected to the Shaped groove or linear groove connected.

The inner wall radius of the first groove is 1.5mm;

The protective plate is provided with a mirror-symmetrical second groove, which includes ten sections of arc-shaped grooves and eight semicircular transition grooves, wherein: the two ends of the semicircular transition grooves are respectively connected with the arc-shaped grooves.

The electric heating wire covered with a ceramic sleeve is embedded in the first groove and the second groove.

The radius of the inner wall of the second groove is 1.5 mm.

The fixing slots are specifically located on the inner side of the protective plate at an angle of 120°.

The length of the fixing pin is 0.8 mm, and the fixing pin is arranged radially.

Compared with the existing technology. The square heating plate adopts square arrangement of electric heating wires, resulting in uneven temperature at the corners. The invention effectively improves the uniformity of the surface temperature of the line heat source heater, reduces the radial heat transfer of the heating plate, and makes the heating The plate is one-dimensional heat transfer, which improves the accuracy of thermal conductivity measurement.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Figure 2 is a front view of the heating plate structure.

Figure 3 is a top view of the heating plate structure.

Figure 4 is a front view of the protective plate structure.

Figure 5 is a top view of the protective plate structure.

Fig. 6 is a partial sectional view of the fixing pin structure.

Figure 7 is a detailed view of the structure of the fixing pin.

Fig. 8 is a right view of the detailed view of the fixing pin structure.

Fig. 9 is a detailed top view of the fixing pin structure.

Detailed ways

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following implementation example.

As shown in Figure 1, this embodiment includes: two heating plates 1, two protective plates 2, bolts 3, fixing pins 4 and electric heating wires (not shown), wherein: the heating plate 1 is fixedly arranged on the protective plate 2 One end of the fixed pin 4 is arranged radially on the side of the heating plate 1, the other end of the fixed pin 4 is located in the slot 11 of the protective plate 2, and the electric heating wire covered with a ceramic sleeve is located between the heating plate 1 and the protective plate. 2 in the first groove 5 and the second groove 6.

The surrounding of the heating plate 1 is engraved with a heating plate groove 7 with a triangular cross-section to effectively reduce radial radiation heat transfer.

As shown in Figure 2, the heating plate 1 is provided with a mirror-symmetrical first groove 5, the first groove 5 includes eight sections of arc-shaped grooves, eight semicircular transition grooves and four sections of linear grooves, wherein: The two ends of the semicircular transition groove are respectively connected with the arc groove or the straight groove;

The surrounding of the heating plate 1 is engraved with a heating plate groove 7 with a triangular cross-section to effectively reduce radial radiation heat transfer.

The diameter of the heating plate 1 is 119.8 mm, and the heating plate 1 is fixed by screwing M3 bolts into the threaded holes 6 .

The heating plate groove 7 is on the outside of the heating plate, and its cross section is triangular.

As shown in Figure 4, the protective plate 2 is provided with a mirror-symmetrical second groove, which includes ten sections of arc-shaped grooves and eight semicircular transition grooves, wherein: the two ends of the semicircular transition grooves are respectively Connected to the arc groove.

The protective plate groove 10 is engraved on the inner side of the protective plate 2 to effectively reduce the radiation heat transfer in the radial direction of the heating plate 1 , and the cross section of the protective plate groove 10 is triangular.

The radius of the second groove 5 is 1.5 mm.

The heating plate 1 and the protective plate 2 are respectively provided with a first threaded hole 6 and a second threaded hole 9 to set the bolt 3, and the first threaded hole 6 and the second threaded hole 9 are both T-shaped holes and Evenly distributed at an angle of 45°.

The heating plate 1 and the protective plate 2 are made of T2 oxygen-free copper material.

As shown in FIG. 6 , the fixing slots 11 are uniformly distributed at 120°. As shown in Figures 7-9, the fixing pin 4 is made of austenitic 304 stainless steel with external threads.

The advantages of this embodiment include: (1) A circular heating plate is adopted, and the temperature of the test surface of the heating plate is made more uniform by rationally arranging the groove structure. (2) The circular protective heat is adopted, and the test of the protective plate shows that the temperature is uniform through the reasonable arrangement of the groove structure, and the temperature is adjusted by reasonably controlling the power of the electric heating wire to reduce the radial heat dissipation of the heating plate to ensure that the heating plate is One-dimensional cooling. (3) Fixed pins are used, adjust the depth of screwing the fixed pins into the threaded holes, rotate the heating plate at a certain angle and fix it in the slot hole inside the protective plate, so that the heating plate is accurately fixed in the middle of the protective plate. (4) Three austenitic 304 stainless steel fixing pins with low thermal conductivity are used to fix the heating plate in the middle of the protective plate, which greatly reduces the change of the temperature field at the outer edge of the heating plate due to contact heat conduction, and improves the test surface temperature of the heating plate. Uniformity. (5) By making grooves with triangular cross-sections on the outside of the heating plate and the inside of the protective plate, the radial heat transfer of the heating plate can be effectively reduced, and the uniformity of the temperature field on the test surface of the heating plate can be improved.

Claims (6)

1. a protective heat plate device is with line heat source formula well heater, comprise: heating plate, protective shield, electrical heating wire and fixing pin, wherein: heating plate is fixedly installed on the central authorities of protective shield, heating plate and protective shield are in the same plane, one end of some fixing pins is along the side that radially is arranged at circular heating plate of circular heating plate, the other end of fixing pin is arranged in the slotted eye of protective shield, cover has the electrical heating wire of porcelain bushing to be positioned at the first groove and second groove of heating plate and protective shield, it is characterized in that:

Described heating plate is provided with the first groove of mirror image symmetry, and this first groove comprises eight sections deep-slotted chip breakers, eight semicircle ramp pans and four sections straight-line grooves, and wherein: the two ends of semicircle ramp pan are connected with deep-slotted chip breaker or straight-line groove respectively;

Described protective shield is provided with the second groove of mirror image symmetry, and this second groove comprises ten sections deep-slotted chip breakers, eight semicircle ramp pans, and wherein: the two ends of semicircle ramp pan link to each other with deep-slotted chip breaker respectively.

2. described protective heat plate device is characterized in that with line heat source formula well heater according to claim 1, and the cross section of the inboard groove of the outside of described heating plate and protective shield is triangular in shape.

3. described protective heat plate device is characterized in that with line heat source formula well heater according to claim 1, and the inwall radius of described the first groove is 1.5mm.

4. described protective heat plate device is characterized in that with line heat source formula well heater according to claim 1, and the inwall radius of described the second groove is 1.5mm.

5. described protective heat plate device is characterized in that with line heat source formula well heater according to claim 1, and the slotted eye of described protective shield specifically is positioned at the medial surface of protective shield, between the slotted eye with 120 ° of spaced sets.

6. described protective heat plate device is characterized in that with line heat source formula well heater according to claim 1, and the length of described fixing pin is 0.8mm.

Images