JP2010231730A - High temperature alarm indicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform high temperature display that notifies danger of a high temperature object by a non-electric source by using a thermoelectric conversion module. <P>SOLUTION: One of the thermoelectric conversion module 17 is brought into close contact with a heat conduction unit 16b of a heat receiving plate 16 comprising a heat receiving unit 16a and the heat conduction unit 16b, and a heat sink 19 is brought into close contact with the other. The heat receiving unit 16a of the heat receiving plate 16 is arranged in a housing 11 having a heat generation source 12 with voltage applied thereto, and the heat conduction unit 16b is arranged outside the housing 11 through the housing 11. By this configuration, heat of the heat generation source 12 having high temperature is transferred to the thermoelectric conversion module 17 directly (without going through the surface of the housing 11) to increase difference of temperature and to increase electromotive force, which can operate a displaying means for displaying a high temperature state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high-temperature alarm display for notifying that a neutral point grounding resistor, a filter resistor, a load resistor, etc. are dangerous when a voltage is applied and the temperature becomes high. is there.

Examples of a heat source that becomes high temperature when a voltage is applied include a neutral point grounding resistor, a filter resistor, and a load resistor.
Such a resistor becomes hot because a voltage is applied and a large current flows. For this reason, a dangerous name plate is pasted on the housing containing these resistors.

  However, since the nameplate as described above displays only characters, even if the color of the characters is changed to red, it is difficult to stand out. In addition, the same display is displayed at normal temperature and high temperature, and the alertness to danger is diminished. Therefore, there is a risk of being damaged when the housing is actually heated.

As one method for solving such a problem, Patent Document 1 describes a temperature display device 2 as shown in FIG. 11, for example.
The display device 2 includes a sensor unit that detects the surface temperature of the high temperature body 1 and a temperature display unit that displays the temperature detected by the sensor unit. The high temperature body 1 supports the sensor unit and the display unit with a frame. It is to be attached to the surface with adhesive or screws.
That is, the sensor unit of the display device 2 has a structure in which a plurality of thermoelectric conversion modules constituted by a plurality of Peltier elements are sandwiched between a high temperature side heat collecting plate and a low temperature side heat collecting plate. Then, one high temperature side heat collecting plate sandwiching the thermoelectric conversion modules is attached to the surface of the high temperature body 1.
By doing this, the electromotive force generated by the temperature difference between the high temperature side (surface temperature of the high temperature body 1) and the low temperature side (air temperature) is detected and the surface temperature of the high temperature body 1 is displayed, and the voltage generated by the temperature difference is displayed. The power of the display device 2 is covered by power.
Thus, in this display device 2, by attaching to the high temperature body 1, the surface temperature can be known at a glance so that the exposed high temperature body 1 is touched by a hand or a combustible material is brought into contact with the display device 2. There is nothing to do.

JP 2004-309330 A

By the way, it is said that a person will be burned when touched at 70 ° C. for about 1 second. In the above, it is necessary to display when the surface temperature of the high-temperature body becomes about 60 ° C. to 70 ° C. Therefore, in the above, when the surface temperature of the casing is 60 ° C. to 70 ° C. and the air temperature is 25 ° C., the casing must operate with an electromotive force obtained with a temperature difference of about 35 ° C. to 45 ° C.
However, since thermoelectric conversion modules such as Peltier elements have low conversion efficiency to electric power, it is difficult to implement unless a large number of thermoelectric modules are prepared, which is a big problem.

  Accordingly, an object of the present invention is to enable high-temperature display to be performed without a power source using a thermoelectric conversion module.

  In order to solve the above problems, in the present invention, a heat input plate composed of a heat receiving portion and a heat conduction portion, a thermoelectric conversion module that closely contacts one of the heat conduction portions of the heat input plate, and the thermoelectric conversion module The heat receiving plate of the heat input plate is disposed in a housing having a heat source to which a voltage is applied, and the heat conducting portion is disposed outside the housing through the housing. The display means is operated by an electromotive force based on a temperature difference applied to the thermoelectric conversion module, and a configuration in which a high temperature state is notified is adopted.

  By adopting such a configuration, the heat input plate receives heat from a heat generation source in the housing at the heat receiving portion disposed in the housing, and the heat conducting portion transmits the heat to one of the thermoelectric conversion modules. For this reason, the heat of the high temperature heat source can be directly transmitted to the thermoelectric conversion module (without passing through the surface of the housing). At this time, the other side of the thermoelectric conversion module is cooled by the heat radiating plate. As a result, the temperature difference applied to the thermoelectric conversion module can be increased, and the electromotive force of the thermoelectric conversion module can be increased.

  In addition, at this time, it is possible to employ a configuration in which the heat input plate is supported on the housing via a heat insulating member to seal the gap and thermally separate and eliminate air loss.

  By adopting such a configuration, the heat input plate is thermally separated by the housing and the heat insulating member by filling a gap formed between the heat input plate and the housing through which the heat input plate is passed, thereby generating a heat source. Prevents heat from leaking to the housing through the heat input plate. By doing in this way, it can supply only to a thermoelectric conversion module, without reducing the thermal energy taken in from the heat-input board. And while making the electromotive force of a thermoelectric conversion module large, the use with an airtight apparatus is also enabled.

  In addition, at this time, the heat input plate is formed with a material having a large volume specific heat and a heat storage function, and a heat sink is formed with a material having a low heat capacity and a high heat conductivity. can do.

  By adopting such a configuration, a large temperature difference can be maintained for a long time by making the heat input plate have a large volume specific heat and a heat storage effect. On the other hand, the heat radiation plate has a small volume specific heat but good thermal conductivity, thereby increasing the temperature difference applied to the thermoelectric conversion module due to the heat radiation effect on the outside air and increasing the electromotive force of the thermoelectric conversion module. For example, the heat dissipation effect can be increased by providing fins or the like on the heat dissipation plate to increase the surface area. By doing so, it is possible to generate power for a long time.

  Moreover, the structure which formed either the infrared absorption layer or the insulating layer or both in the heat receiving part of the said heat-input plate at this time is employable.

  By adopting such a configuration, the amount of heat recovered in the infrared absorption layer is increased and the temperature of the heat receiving part is increased. By doing so, the temperature difference applied to the thermoelectric conversion module is increased, and the electromotive force of the thermoelectric conversion module is increased. Further, by providing the insulating layer, the heat receiving portion can be brought close to a heat source to which a high voltage is applied. Therefore, the temperature difference applied to the thermoelectric conversion module can be increased by bringing the heat receiving portion closer to receive heat at a high temperature, so that the electromotive force of the thermoelectric conversion module can be increased.

  Moreover, the structure which connected the heat-input board, the heat sink, and the housing | casing with the conductor whose heat conduction is extremely smaller than a thermoelectric conversion module at this time is employable.

By adopting such a configuration, the thermoelectric conversion module sandwiched between the heat input plate and the heat radiating plate and the casing can be set to substantially the same potential. Therefore, it is possible to prevent insulation damage of the thermoelectric conversion module due to indefinite voltage.
At this time, since the heat input plate and the heat radiating plate are connected by a conductor with extremely small heat conduction, the conduction of heat from the heat input plate to the heat radiating plate can be extremely reduced.

  At this time, the heat receiving portion of the heat input plate is opposed to the heat source, and the radiant heat energy and air convection heat energy from the heat source are recovered by one heat input plate and supplied to the thermoelectric conversion module. Thus, it is possible to employ a configuration in which a warning sign is displayed with the generated voltage.

  By adopting such a configuration, two types of heat energy can be efficiently received from the heat source. One heat energy is directly received by radiant heat flow by bending the heat receiving portion and facing the heat source. The other heat energy is heat energy by air convection and indirectly receives heat energy from the heat generation source in the entire heat receiving section. Since two kinds of thermal energy can be received in this way, the thermal energy can be efficiently recovered.

  Since the present invention is configured as described above, it is possible to indicate that it is dangerous at high temperatures.

Schematic showing the installation status of the embodiment Cross-sectional view of the embodiment Action explanatory drawing showing other modes (A) Front view of heat sink of embodiment, (b) Action explanatory drawing which shows the other aspect of (a) Block diagram of circuit of embodiment (A) Operation explanatory diagram of the thermal circuit of the embodiment (with a heat insulating member), (b) Operation explanatory diagram showing a thermal circuit without the heat insulating member (A), (b) Action explanatory drawing of Example 1 (A), (b) Action explanatory drawing of Example 2 Schematic diagram showing the connection of Example 3 Action explanatory drawing which shows the connection state of the high temperature warning indicator of Example 3 Perspective view of conventional example

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 schematically shows a device having a heat source (resistor box) 12 inside a housing (cubicle) 11 and a high-temperature alarm indicator 10 of the present application applied thereto. It shows a neutral point ground resistor, an inrush current suppression resistor, a filter resistor, etc. used in the system.

That is, the housing 11 has a structure in which a resistor box 12 containing a resistor is housed in a cubic metal container as shown in FIG. 1, and the resistor box 12 is supported by an insulator 13. The structure is electrically insulated from the housing 11. Further, a terminal 14 as shown in FIG. 1 is provided in the housing 11 to connect the voltage source and the internal resistor box 12. Further, an attachment window 15 is provided on the side surface of the housing 11 to attach the high temperature alarm indicator 10.
Here, as described later, in order to insert the heat input plate 16 of the high temperature alarm indicator 10, the mounting window 15 is provided in the housing 11, but the mounting is not limited to the window 15. Absent. As long as the heat receiving portion 16a and the heat conducting portion 16b of the heat input plate 16 can communicate with each other, a slit or a hole may be used, and the shape is not limited.

  As shown in FIG. 2, the high-temperature alarm indicator 10 in this form includes a heat input plate 16, a thermoelectric conversion module 17, a heat insulating member 20 for sealing, a mounting plate 18, a heat radiating plate 19 that also serves as a nameplate, and display means (hereinafter referred to as a display unit). LED display part) 23, and is structured to be screwed to the window 15 for mounting the housing 11 (for this reason, screwing around the mounting window as described later) Through-hole for use).

In this embodiment, as shown in FIG. 2, the heat input plate 16 has an L-shaped cross-sectional shape bent outward by 90 degrees, and includes a heat receiving portion 16a and a heat conducting portion 16b.
The heat receiving portion 16a receives heat energy from a heat source at an L-shaped vertical portion with its tip bent outward. On the other hand, the heat conducting part 16 b is an L-shaped horizontal part and conducts the heat energy received by the heat receiving part 16 a to the thermoelectric conversion module 17.
If a material such as aluminum having good heat conduction is used for the heat input plate 16, the responsiveness can be improved. In addition, if a stainless steel plate having a low volumetric heat but poor heat conduction is used (a mild steel plate can be used in addition to stainless steel), a large temperature difference can be maintained for a long time due to a heat storage effect. Here, stainless steel is used to achieve a heat storage effect.
Note that stainless steel may be used for the heat receiving portion 16a, and aluminum may be used for the heat conducting portion 16b to combine both characteristics.
Further, depending on the positions of the resistor box 12 and the heat input plate 16 which are heat sources, an L-type heat input plate 16 may be used as shown in FIG. That is, the shape of the heat input plate 16 is appropriately changed according to the positional relationship between the resistor box 12 and the heat input plate 16, and the heat input from the resistor box 12 can be recovered in the most efficient manner. It is determined by experience.

The thermoelectric conversion module 17 is a plate formed by combining a large number of thermoelectric conversion elements. One surface is brought into close contact with the heat conducting portion 16b of the heat input plate 16, and the heat radiating plate 19 is brought into close contact with the other surface.
The conversion module 17 can improve power generation efficiency by using an element in which a material to be used is changed according to the temperature of the resistor box 12 as a heat source. For example, in the case of normal temperature to 500K, a bismuth / tellurium type is used. Further, if it is 800K, a lead / tellurium-based material can be used, and if it is 1000K, a silicon-germanium-based material can be used.
Furthermore, non-oxide type typified by telluride type materials, oxide type typified by layered cobalt oxide type, etc. can also be used.

The heat radiating plate 19 is smaller in volume specific heat and heat capacity than the heat input plate 16 and has a good thermal conductivity. Here, a flat one made of aluminum (copper, copper alloy, etc. can also be used) is used. ing. Further, as shown in FIG. 2, the mounting plate 18 and the heat radiating plate 19 have insertion holes for assembly so that they can be screwed.
Incidentally, if the shape is allowed, if the fins are attached to the heat radiating plate 19, the heat radiation effect can be further improved.

The heat radiating plate 19, the LED display unit 23, and the thermoelectric conversion module 17 are fixed to a mounting plate 18 as shown in FIG. 4A, for example. A heat radiating plate (also used as a nameplate) 19 is provided adjacent to (in parallel with) the sign by the LED display unit 23, and the heat radiating plate 19 is used as a name plate to indicate "high temperature attention" so that it can be used as a display means It is a thing. The mounting plate 18 is screwed to the housing 11.
The heat radiating plate 19 is made of aluminum, copper, copper alloy or the like having a smaller volume specific heat and heat capacity and higher thermal conductivity than the heat input plate 16 in order to improve the heat radiating effect, and its thickness is a heat capacity for radiating heat. It is decided according to. At this time, if the shape is allowed, the heat radiation effect can be further improved by providing fins or the like.
Further, the LED display unit 23 adjacent to the heat radiating plate (nameplate) 19 on which “high temperature caution” is displayed is connected to a large number of LEDs 21 to the thermoelectric conversion module 17 as shown in FIG. 5, for example, “HOT”. The sign such as is displayed.
Incidentally, although the LED display unit 23 of this form displays the sign of “HOT”, it is natural that other signs can be changed if the arrangement of the LEDs 21 is changed.
At this time, since the LED 21 has a low voltage and a low current, even a small electromotive force of the thermoelectric conversion module 17 can be connected and used in parallel as shown in FIG. 5, the number can be adjusted in accordance with the display contents. It can be done relatively easily. At this time, if the LED 21 is rich in color, it is possible to easily recognize the degree of danger by the color. Therefore, by adopting a red LED 21, the dangerous state can be understood in an instant. .
Further, in this embodiment, the heat radiating plate (also used as the nameplate) 19 and the LED display portion 23 are provided on the mounting plate 18, but the present invention is not limited to this. Of course, the mounting plate 18 and the mounting plate 18 may be provided separately from each other. Also, the display method is not limited to the lighting display of the LED 21. For example, as shown in FIG. 4B, the entire heat radiating plate 19 may be used as a name plate, and the LED 21 may be used as a backlight to illuminate the “high temperature caution” on the name plate. An alarm sound may be used.

  In this embodiment, the heat insulating member 20 is made of, for example, a material based on silicon rubber such as heat-resistant foam rubber, so that heat insulation and confidentiality can be obtained.

This configuration is configured as described above. For example, the high temperature alarm indicator 10 is assembled as follows.
For example, the thermoelectric conversion module 17 is closely attached to the heat conducting portion 16b of the heat input plate 16 via a heat conducting sheet (not shown). Further, after the heat radiating plate 19 is brought into intimate contact with the thermoelectric conversion module 17 in intimate contact with the heat conducting portion 16b through a heat conducting sheet (not shown), the spacer 22 (in this embodiment, the spacer 22 is inserted in the assembly insertion hole) Are screwed to the mounting plate 18 using screw holes at both ends. At that time, the heat insulating member 20 is sandwiched between the mounting plate 18 and the heat conducting portion 16 b of the heat input plate 16.

The high temperature alarm indicator 10 assembled in this way is attached to the window 15 for attaching the housing 11. For example, when the heat receiving portion 16 a of the heat input plate 16 is inserted from the outside of the window 15 and the heat conducting portion 16 b of the heat input plate 16 reaches the window 15, ) And the through holes around the window 15 are screwed together.
By providing the heat insulating member 20 in this way, as shown in the thermal circuit of FIG. _6A , compared to the case without the heat insulating member 20 of FIG. 6B, the heat insulating member 20 has a high temperature alarm as a thermal resistance _Rth20. The display 10 and the housing 11 can be thermally blocked so that most of the heat energy of the heat input plate 16 is conducted to the thermoelectric conversion module 17 of the high temperature alarm display 10. Here, J2 shown in FIG. 1 is radiant heat energy, and J3 is air convection heat energy.
Furthermore, the heat insulating material 20 prevents the heat from diffusing from the gap by sealing the gap, and prevents the display from being unable to display due to the decrease in electromotive force due to the temperature drop due to the diffusion. Moreover, since the gap can be closed, it can be applied to a sealed type or a gas-filled type.

In the high temperature alarm display 10 installed in the casing in this way, the heat input plate 16 receives two types of thermal energy from the resistor box 12 inside the casing 11 as shown in FIG.
First, one is radiant heat energy J2, which is received directly by the bent tip of the heat receiving portion 16a facing the resistor box 12. On the other hand, J3 is heat energy by air convection and indirectly receives heat from the resistor box 12 in the entire heat receiving portion 16a.
The heat received by the heat receiving portion 16a is conducted to one surface of the thermoelectric conversion module 17 through the heat conducting portion 16b.
At this time, since the heat input plate 16 is formed of a material having a large volume specific heat and a heat storage function, a large temperature difference can be maintained for a long time. On the other hand, the heat sink 19 is smaller in volume specific heat than the heat input plate 16 but has a good thermal conductivity. Therefore, a large temperature difference between the both surfaces of the thermoelectric conversion module 17 can be generated over a long period of time. it can. Therefore, power generation for a long time is possible, and the display time can be extended.

Normally, this temperature difference is expected to be about 350 ° C to 700 ° C for the surface temperature of resistors, for example, neutral point ground resistors, inrush current suppression resistors, and filter resistors used in power systems. If the outside air temperature is 25 ° C., the applied temperature difference is 325 ° C. to 675 ° C. Therefore, a temperature difference that generates a sufficient electromotive force can be obtained even through the resistor box 12. As a result, a sufficient electromotive force for display can be obtained from the thermoelectric conversion module 17 with a small amount of power generation.
Therefore, when the outer surface temperature of the housing 11 reaches a dangerous temperature (60 ° C. to 70 ° C.) for humans, an electromotive force capable of turning on the LED 21 is obtained.
At this time, it is natural that the number and type of thermoelectric conversion modules 17 or the type and size of the heat input plate 16 and the mounting position are optimally determined for lighting.

  Therefore, when the resistor box 12 generates heat and the temperature inside the housing 11 rises, the LED 21 can be automatically turned on to display a sign that informs that it is dangerous.

  In this way, when the temperature inside the housing 11 rises, it can be displayed with a sign that an electromotive force is generated and it is dangerous. Therefore, no external power supply is required. As a result, the cost is low and there are few types of parts, so it can be used for a long time without maintenance. Moreover, since an external power supply is not required, it is energy saving.

In the first embodiment, as shown in FIGS. 7A and 7B, an infrared absorption layer 25 is formed on the surface of the heat receiving portion 16a of the heat input plate 16 will be described.
That is, by forming the infrared absorption layer 25 on the surface of the heat receiving portion 16a, the heat recovery rate is increased and the electromotive force of the thermoelectric conversion module 17 is increased.
Specifically, for example, by forming a plating layer such as chrome black (black chrome) or nickel black (black nickel), the infrared recovery rate is high and the infrared radiation is extremely reduced. At this time, it is natural to use one having heat resistance in accordance with the heat generation temperature of the resistor box 12. For example, carbon black or the like having high heat resistance, high infrared recovery rate, and extremely low infrared radiation may be mixed and applied to the heat resistant paint.
Further, instead of the plating layer, a nanostructure may be formed on the surface to have selective absorption characteristics.

In the second embodiment, for example, an electrical insulating layer 26 as shown in FIG. 8 is provided on the heat input plate 16 to increase the amount of heat recovered (here, the insulating layer 26 is the infrared absorbing layer 25). However, the present invention is not limited to this, for example, it may be under the infrared absorption layer 25 or the infrared absorption layer 25 may not be provided.
That is, as shown in FIG. 1, the high-temperature alarm display 10 collects thermal energy via the heat input plate 16 by using the radiant heat energy J2 and the air convection heat energy J3, but the resistor box 12 and the heat input plate 16 If the interval (gap) is reduced, the amount of heat recovered increases. On the other hand, the withstand voltage of the insulation is reduced, the discharge is easily generated and the thermoelectric conversion module 17 is damaged, and the function of the device itself is lost. In order to prevent this, the insulating layer 26 is formed. At this time, it is necessary to select the insulating layer 26 having good infrared absorption. Specifically, for example, an insulating layer of an insulating coating with a heat-resistant high airtight film may be formed on the heat receiving portion 16a of the heat input plate 16.

  The third embodiment is for preventing dielectric breakdown of the high temperature alarm indicator 10 from the voltage applied to the resistor box 12 as shown in FIG. 9, and as shown in FIG. 9 and FIG. 11, the mounting plate 18, the heat input plate 16 and the heat radiating plate 19 are connected by a conductor 30. At this time, it is necessary to employ a conductor 30 having a low thermal conductivity so that the temperature difference between the heat input plate and the heat radiating plate is not reduced. Specifically, for example, by reducing the diameter, a jumper wire or the like having a thermal conductivity of about 1/10 to 1/100 of the thermoelectric conversion module 17 can be used as the conductor 30.

  According to the present invention, for example, a light display can be made without a power source to notify that a high temperature state is dangerous. Therefore, such an effective display can be used for a danger display, for example, in a steam duct through which high temperature steam passes or a flue through which high temperature smoke passes.

DESCRIPTION OF SYMBOLS 10 High temperature alarm indicator 11 Housing | casing 12 Resistor box 15 Window 16 Heat input plate 16a Heat receiving part 16b Heat conduction part 17 Thermoelectric conversion module 18 Mounting plate 19 Heat sink (also used for nameplate)
20 Thermal insulation member 21 LED
22 Spacer 23 LED display part 25 Infrared absorption layer 26 Insulating layer 30 Conductor

Claims (6)

A heat input plate composed of a heat receiving portion and a heat conducting portion;
A thermoelectric conversion module in close contact with the heat conducting portion of the heat input plate;
A heat sink closely contacting the other of the thermoelectric conversion module;
Display means,
An electromotive force based on a temperature difference applied to the thermoelectric conversion module by arranging the heat receiving portion of the heat input plate in a housing having a heat source to which a voltage is applied, and arranging a heat conducting portion outside the housing through the housing. A high temperature alarm indicator that activates the display means to notify the high temperature state.   The high temperature alarm indicator according to claim 1, wherein the heat input plate is supported by a housing via a heat insulating member to seal a gap and to be thermally separated, and to eliminate air loss.   3. The high temperature alarm according to claim 1 or 2, wherein the heat input plate is formed of a material having a large volume specific heat and a heat storage effect, and the heat radiating plate is formed of a material having a smaller volume specific heat than the heat input plate and having a good thermal conductivity. display.   The high temperature alarm indicator according to any one of claims 1 to 3, wherein either one or both of an infrared absorption layer and an insulating layer are formed on the heat receiving portion of the heat input plate.   The high temperature alarm display according to any one of claims 1 to 4, wherein the heat input plate, the heat radiating plate, and the housing are connected by a conductor having a lower thermal conductivity than the heat input plate, and the housing and the heat source are connected. vessel.   The heat receiving part of the heat input plate is opposed to the heat source, and the radiant heat energy and air convection heat energy from the heat source are recovered by one heat input plate and supplied to the thermoelectric conversion module. The high temperature alarm indicator according to any one of claims 1 to 5, wherein an alarm sign is displayed.

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