JPS584777B2 - average temperature detection tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an average temperature detection tube that detects the average temperature when there is a temperature gradient, such as in hot water in a bathtub.

Figure 1 shows how this type of average temperature detection tube is used to detect the average hot water temperature in a bathtub. 1 is a bathtub, 2 is hot water in the bathtub, 3 is a gas boiler, and 4 is an average temperature. The temperature detection tube 5 is a support for the average temperature detection tube 4, and 6 is an alarm that issues an alarm based on a signal from the average temperature detection tube 4.

Conventional average temperature detection tubes used in such conditions are
As shown in FIG. 2, the inner surface of a rod-shaped sealed hollow container 7 is lined with a capillary material 8 having a capillary action, such as mesh or sintered metal, and this capillary material A working fluid that can evaporate and condense, such as water, alcohol, or chlorofluorocarbon, is sealed and permeated into the hollow container 8, and a heat-sensitive element 9 such as a thermocouple for sensing the vapor temperature of the working fluid is placed inside the hollow container 7. , the output end of this thermal element 9 is the first
It is connected to the alarm device 6 shown in the figure.

The operation of the conventional device having the above configuration will be explained next.

When the hot water 2 in the bathtub 1 is heated by the gas boiler 3, the temperature of the hot water gradually rises, but at this time, a temperature gradient occurs in the hot water 2 in the depth direction such that the upper part is hot and the lower part is cold.

If we assume that the hot water area in the hot water 2 in which the temperature detection tube 4 is immersed is (5) and the cold water area is (B), the water has penetrated into the capillary material 8 inside the temperature detection tube 4. The working fluid is
It is heated by the hot water in the hot water area (G) and evaporates by taking away the heat of vaporization from the hot water.

This evaporation increases the vapor pressure in the evaporation section, and the vapor flows in the direction of lower vapor pressure, that is, to the cold water region [B] as shown by the dashed arrow in Figure 2, where the vapor is cooled, condensed, and liquefied. give off a fever.

The condensed liquid returns to the hot water area (G) by the capillary action of the capillary material 8, as shown by the solid arrow in FIG.

If this kind of hydraulic fluid circulation is performed normally,
The steam temperature of the working fluid is approximately equal to the average temperature of hot water (4) and cold water (B), so the heat sensitive element 9 that detects this steam temperature sends a detected temperature signal to the alarm 6,
If the alarm device 6 is configured to issue an alarm when this detected temperature becomes equal to the set temperature, the average temperature detection tube 4 will detect the average temperature of the hot water 2 in the bathtub 1 in the depth direction. This means that it is possible to tell the temperature that is suitable for people to bathe in, without having to stir the water.

By the way, in this average temperature detection tube 4, the fact that the above-mentioned normal circulation of the working fluid is occurring means that the steam temperature of the working fluid indicates the average temperature of the hot water (5) and the cold water (B). It is a condition.

However, since this temperature detection tube utilizes the capillary action of the capillary material 8 as a force for circulating the working fluid, there is a limit to the amount of circulation of the working fluid.

That is, in Figure 3, hot water (5) and cold water CB
), the temperature difference between the average temperature of both and the hot water (g) becomes large, so the hot water (g)
) The amount of heat that enters the temperature detection tube 4 is large, and therefore the evaporation of the working fluid in the evaporation part within the temperature detection tube 4 increases,
The amount of evaporation may exceed the amount of circulating fluid due to capillary action.

Therefore, in such a case, the evaporation section in the temperature sensing tube 4 will be completely dry, and the working fluid will accumulate in the cold water region (6), and the vapor temperature will indicate the temperature of the cold water (B). become.

Therefore, this average temperature detection tube 4 does not detect the average temperature of hot water (5) and cold water (B), but detects the average temperature of cold water (5).
Therefore, the device shown in FIG. 1 has a drawback in that the water 2 is boiled too much even though it is at an appropriate temperature.

The present invention solves the above-mentioned drawbacks, and the present invention covers the outer surface of a rod-shaped hollow container with a heat insulating material, and provides cutouts reaching the outer wall of the hollow container in at least the upper and lower parts of the heat insulating material in the axial direction. The present invention provides an average temperature detection tube that limits the amount of heat transferred to the inside, thereby allowing normal temperature detection even when the temperature gradient is steep.

Next, the illustrated embodiment will be described.

FIG. 3 shows the present invention applied to the conventional device shown in FIG. A plurality of small holes 11 reaching the outer wall of the hollow container 7 are provided at appropriate intervals over the entire axial length of the hollow container 7.

Although not clearly shown in the figure, the small holes 11 are also provided at appropriate intervals in the circumferential direction of the heat insulating material 11.

All other parts are the same as the conventional device shown in FIG. 2, so the same parts are given the same reference numerals and the explanation thereof will be omitted.

The average temperature detection tube according to the above configuration is as shown in FIG.
When immersed in hot water 2, which has a hot water region (5) and a cold water region (b), heat exchange occurs between the working fluid in the hollow container T and the hot water 2 through the small hole 11. It is done.

That is, similar to the conventional device, the hot water (5) evaporates the working fluid in the hollow container 7, this vapor is cooled and condensed by the cold water (6), and the liquefied working fluid is absorbed by the capillary action of the capillary material 8. The steam temperature of the working fluid becomes approximately equal to the average temperature of the hot water (5) and the cold water.

However, in the average temperature detection tube according to the present invention, the area where the hollow container 7 is in contact with the hot water 2 is only a small area of the small hole 11 provided in the heat insulating material 10. The amount of heat transferred to the hollow container 7 is small even when there is a large temperature difference between the hot water (g) and the cold water (6).
The amount of evaporation of the working fluid in the hollow container T is much smaller than in conventional devices.

Therefore, the amount of circulating fluid due to the capillary action of the capillary material 8 is also smaller than in conventional devices, and the amount of circulating fluid due to the capillary action does not reach its limit.

For this reason, the circulation of the working fluid within the hollow container 7 is limited to hot water (
Even if the temperature difference between 5) and the cold water [B] is small, the operation is performed normally, and the steam temperature of the working fluid matches the average temperature of the hot water 2 in the plurality of small holes 11 provided in the insulation material 10. This will be approximately equal to the average temperature of the entire hot water 2.

By the way, in this embodiment, since the small holes 11 are provided at appropriate intervals over the entire axial length of the heat insulating material 10, the steam temperature of the working fluid is equal to the average temperature of the hot water 2 over the entire length of the average temperature detection tube. It indicates the temperature, which temperature will be sensed by the heat sensitive element 9.

Therefore, if this detection tube is used as shown in Figure 1, even if the temperature gradient of hot water 2 differs greatly in the depth direction, the average temperature will be accurately detected and the temperature will be suitable for people to enter. When the temperature reaches the temperature, the alarm 6 can be activated.

Contrary to the above case, if it is known from the characteristics of the temperature gradient that the average temperature of the liquid at the upper and lower ends is equal to the average liquid temperature at the middle part, The purpose can also be achieved by eliminating the small holes 11 and providing small holes 11 only in the upper and lower parts.

In addition, although the small hole 11 was illustrated in the said Example as a notch provided in the heat insulating material and reaching the outer wall of the hollow container, it goes without saying that the shape of the notch is not limited to this.

For example, the notch may be formed of a narrow groove continuous in the axial direction of the heat insulating material 10, and a plurality of these grooves may be provided in the circumferential direction of the heat insulating material 10.

Further, even when the notch is formed by a hole, it can be formed into a truncated conical shape in order to minimize the temperature gradient within the hole.

In addition, in the above embodiment, the average temperature detection tube according to the present invention is used to detect the average temperature of hot water in a bathtub. Of course, it can be used for detecting.

As described above, the average temperature detection tube according to the present invention covers the outer surface of the conventional average temperature detection tube with a heat insulating material, and partially provides a notch reaching the outer wall of the hollow container in at least the upper and lower parts of the heat insulating material in the axial direction. Therefore, even when there is a large temperature gradient in the vertical direction of the liquid temperature to be measured, the circulation due to the capillary action of the working liquid operates normally without reaching its limit, and the average temperature of the liquid can be detected. be.

[Brief explanation of the drawing]

Fig. 1 is a simplified sectional view showing how the average liquid temperature detection tube is used to detect the temperature of hot water in a bathtub, Fig. 2 is a longitudinal sectional view showing a conventional average temperature detection tube, and Fig. 3 is a diagram showing the present invention. FIG. 2 is a longitudinal cross-sectional view showing an example of the average temperature sensing tube according to the invention. T...Hollow container, 8...Capillary material, 9
...Thermal element, 10...Thermal insulation material, 11
・・・・・・Small hole (notch).

Claims (1)

[Claims] 1. The inner surface of a sealed rod-shaped hollow container is lined with a capillary material having capillary action, and the inside of the hollow container is filled with evaporation,
In an average temperature detection tube that encloses a working fluid that can cause condensation and is further equipped with a detection means for detecting the vapor temperature of the working fluid, the outer surface of the hollow container is covered with a heat insulating material, and the outer surface of the hollow container is covered with a heat insulating material at least in the axial direction of the heat insulating material. An average temperature detection tube characterized in that the upper and lower portions are partially provided with notches that reach the outer wall of the hollow container. 2. The average temperature sensing tube according to claim 1, wherein the cutout of the heat insulating material is composed of small holes, and the small holes are provided at intervals over the entire axial length of the heat insulating material. 3. The average temperature detection tube according to claim 1, wherein the cutout of the heat insulating material is composed of a narrow groove continuous in the axial direction of the heat insulating material, and a plurality of these grooves are provided in the circumferential direction of the heat insulating material. .