JPS608436Y2 - combustion device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a combustion device that uses a thermoelectric element as a heat collector and is capable of generating electric power with the thermoelectromotive force of the thermoelectric element.

Recently, air blowers have been introduced in heating systems, water heaters, etc. that not only heat air and water using gas burners, but also recover some of the heat using thermoelectric elements to forcefully blow out warm air and forcefully discharge exhaust gas. The applicant is considering using it as a power source.

In this case, the thermoelectromotive force per thermoelectric element is not sufficient to drive the blower, so multiple thermoelectric elements are usually arranged in the position heated by the gas burner and electrically connected in parallel or series. The idea is to get the power you need.

The present invention aims to provide a combustion device in which thermoelectric elements are arranged in such a way that heat collection and power generation can be carried out most efficiently when a plurality of thermoelectric elements are arranged at a burner heating position.

The combustion device of the present invention is characterized in that a space is provided between adjacent thermoelectric elements so that heated gas can pass through them.

The thermoelectric element generates a thermoelectromotive voltage proportional to the temperature difference ΔT between the high temperature end and the low temperature end, and the generated power is ΔT.
The open circuit voltage V is proportional to V.

This is based on the fact that the maximum output condition is reached when the load resistance R1 and the internal resistance Ri have the same value, based on the internal resistance Ri of the thermoelectric element itself.

Therefore, it can be seen that the generated power is strongly influenced by the temperature difference ΔT between the high temperature end and the low temperature end.

Furthermore, when arranging multiple thermoelectric elements, there is a possibility that the movement of the flame of the burner that heats the high-temperature end will be hindered.
In order to ensure the heating of the high temperature end of the thermoelectric element, it is important to set the distance between adjacent thermoelectric elements to an appropriate value.

Therefore, in the present invention, in order to find the optimal adjacent spacing, a plurality of thermoelectric elements IA to IJ are arranged at different intervals as shown in FIG. Heating the high temperature end of 1A to 1J, the thermoelectric element I
Temperature measurements were performed using thermocouples 3A, 3B, 3C, 3D, and 3E provided at the high temperature ends of Bt IDt IFt IH, IJ.

In these figures, the spacing between thermoelectric elements IA, IB, and IC is zero, and the spacing a and b on both sides of thermoelectric element 1D is 1 m.
m, the adjacent spacings C and d on both sides of the thermoelectric element IF are 2, and the adjacent spacings e and f on both sides of the thermoelectric element IH are 3rIr! n1
The adjacent spacing g between the thermoelectric elements II and IJ is set to five positions, respectively.

Further, the interval j between the nomonica burner 2 and each thermoelectric element is set to 8ra, and the difference in height between the tip of the thermoelectric element and the harmonica burner 2 is set to 2.571rIIL.

Note that the thermoelectric element has a cross section of 5 mm x 5 mm and a length of 2 mm.
A laminated thermoelectric element was used.

In this case, each thermoelectric element's low temperature end has a length of 100rrrm and a width of 10Trr! It is fixed to a copper heat sink plate 4 with a thickness of n1 of 3 using a ceramic adhesive.

Table 1 below shows the relationship between the temperature at the high temperature end of the thermoelectric elements IB, ID, IF, IH, and IJ measured using thermocouples 3A to 3E and the adjacent spacing.

(However, the low-temperature end of the thermoelectric element is attached to a copper heat sink plate as shown in FIG. 2.) FIG. 3 shows the relationship between the temperature at the high-temperature end of the thermoelectric element and time.

In this figure, curve U is thermoelectric element IB, curve V is thermoelectric element ID, curve X is thermoelectric element 111, and curve Y is thermoelectric element I.
H1 curve 2 shows the case of thermoelectric element IJ.

According to Table 1 and FIG. 3, it can be seen that if the spacing between adjacent thermoelectric elements is 3 m, there is no difference from the case where they are separated by 5 m or more.

Therefore, in the experimental example of the Monica burner used in this experiment, if the adjacent spacing is set to 3rIrIft or more, the temperature difference between the high temperature end and the low temperature end of the thermoelectric element can be maximized.
The generated power can also be maximized.

FIG. 4 shows an embodiment in which the present invention is applied to a combustion device, particularly a liquid heating device.

In this figure, a plurality of thermoelectric elements 12 are arrayed and fixed via an insulating and heat-resistant adhesive 11 to a metal pipe 10 with good thermal conductivity that constitutes a passage for liquid such as water.

In this case, the thermoelectric element 12 has a cross section of 5 x 5 squares and a length of 20 r.
rrrn laminated thermoelectric element, which is electrically insulated and attached to the metal pipe 10 at the low temperature side end, and the high temperature side is directly heated by the combustion flame 14 of the burner 13.

Each thermoelectric element 12 has an adjacent spacing k of approximately 3rIgIt.
are arranged so as to have

In the configuration of FIG. 4, the hot end of each thermoelectric element 12 and its surroundings are directly heated by the combustion flame 14 of the burner 13, so that each thermoelectric element 12 acts as a heat collector and drains the liquid in the metal pipe 10. Heat.

At this time, since the spacing k between adjacent thermoelectric elements 12 was set to about 3 spaces, the high temperature end of the thermoelectric element 12 was effectively heated to about 800°C.

On the other hand, since the low-temperature end of the thermoelectric element 12 is thermally coupled to the metal pipe 10, it is essentially the same as installing a large-capacity heat sink.For example, if the liquid is water, 1
The temperature will be maintained at 00 to 120°C.

As a result, power generation by thermoelectric elements is performed most efficiently,
A large thermoelectromotive force can be obtained.

In addition, when the purpose is to heat air such as a heating device,
Instead of the metal pipe 10 shown in FIG. 4, a heat radiator having a large number of heat radiating fins may be used.

As mentioned above, according to the present invention, when multiple thermoelectric elements are heated with a burner, each thermoelectric element is provided with a space between adjacent thermoelectric elements, thereby making it possible to improve the power generation efficiency of the thermoelectric elements. Get a combustion device.

[Brief explanation of the drawing]

Figure 1 is a schematic plan view showing the arrangement of thermoelectric elements to find the optimal spacing between thermoelectric elements in the present invention;
The figure is a schematic side view showing the positional relationship between the thermoelectric element and the harmonica burner in the arrangement shown in Fig. 1, Fig. 3 is a graph showing the temperature rise at the high temperature end of the thermoelectric element with respect to heating time, and Fig. 4 is a combustion apparatus of the present invention. FIG. 3 is a cross-sectional view showing an example in which the present invention is particularly applied to a liquid heating device. 1A to IJ, 12...Thermoelectric element, 2...◆・
...Harmonica bunner, 10...Metal pipe, 11...
...Adhesive, 13...Burner, 14...
... Combustion flame.

Claims (1)

[Scope of utility model registration request] A plurality of laminated thermoelectric elements are electrically connected so that a part of the heat of the burner is recovered to obtain electric power for a blower, etc., and the high temperature side end of the plurality of thermoelectric elements is at a height with the burner. In the combustion apparatus, the low temperature side ends of the plurality of thermoelectric elements are arranged in a plate shape, a pipe shape, etc., and the high temperature side ends of the plurality of thermoelectric elements are heated by the combustion flame of the burner. The plurality of thermoelectric elements are arranged with adjoining intervals of 3 or more by adhering and fixing to a heat sink such as a shape, and the flame path of the burner is configured so that the heated gas passes through the spacing between the thermoelectric elements. A combustion device featuring: