JPH057557Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a thermal detection element for detecting the thermal state of the environment of an air conditioner that provides a comfortable environment for the human body. Concerning measures to improve thermal detection accuracy by equalizing surface heat flux.

(Prior art) In general, there is a limit to the ability to maintain indoor thermal conditions that are comfortable for the human body by controlling air conditioners based only on indoor air temperature, and other thermal environment factors include air flux, humidity, and radiation. It is necessary to evaluate the actual residential thermal environment by combining each physical quantity. and,
Thermal detection elements for detecting such thermal conditions are required to be manufactured in such a way that a thermal correlation is established between the element and the human body, based on the thermal equilibrium of the human body. Ru.

By the way, as a thermal detection element of this kind, conventionally, as shown in Japanese Patent Application Laid-Open No. 58-218624, an electric heating element having an electric heater in a hollow spherical shell, and a surface of the heating element are used. Equipped with a temperature measuring device that measures the temperature, the device supplies a predetermined amount of heat to the heating element by energizing the electric heater, and then measures the surface temperature of the heating element to determine the thermal state of the environment, taking into account air flux and radiation. Those that have been designed to detect this are known.

(Problem to be solved by the invention) By the way, the thermal equilibrium equation for such a thermal sensing element is as follows: M=hgr・(Tg−Tr) +hgc・(Tg−Ta) (However, M: supply to the electric heater Heat amount, HGR:
radiant heat transfer coefficient of the heating element, hgc: convective heat transfer coefficient of the heating element, Tg: surface temperature of the heating element, Tr: average radiant temperature of the indoor environment, Ta: room temperature), and the thermal state of the environment can be determined from this formula. However, this theory assumes a constant thermal flux condition for the element.

However, in the above-mentioned conventional thermal sensing element, the electric heater is only installed near the center of the hollow spherical shell, so that only the upper surface of the spherical shell is heated mainly due to internal convection heat transfer. However, there was a problem in that the above-mentioned isothermal flux was not sufficiently satisfied, resulting in poor thermal detection accuracy.

The present invention was developed in view of these points, and its purpose is to uniformly distribute the entire shell by using convection heat transfer within the shell of the heating element as well as heat conduction from the electric heater to the shell. The objective is to satisfy as much as possible the condition of constant heat flux, which is a premise of the theory of the thermal sensing element, and to improve the thermal sensing accuracy.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention is as shown in FIG. The heating element 1 is provided with a temperature measuring device 7 for measuring the surface temperature Tg of the heating element 1, and after supplying a predetermined amount of heat to the heating element 1, the thermal state of the indoor environment is detected based on the surface temperature Tg. This thermal sensing element further has the following configuration added to it. That is, the structure includes a heat conductive member 8 that thermally connects the lower part of the shell 3 and the electric heater 4.

(Function) With the above configuration, in the present invention, heat generated from the electric heater 4 in the shell 3 of the heating element 1 heats the vicinity of the upper surface of the shell 3 by heat transfer by convection, and the heat conduction member The lower part of the shell 3 is heated by the heat conduction by 8, and as a result, the entire shell 3 is heated almost uniformly, and the condition of isothermal flux, which is the premise of the theory of the thermal sensing element, is satisfied. It will be almost full.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a thermal detection element A for controlling an air conditioner according to an embodiment of the present invention. In Figure 1,
Reference numeral 1 denotes a spherical heating element, and the heating element 1 is located in the center of a hollow spherical shell 3 made of a metal with high thermal conductivity such as copper or aluminum, which is fixed through a pipe-shaped support rod 2. An electric heater 4 is enclosed.
A power supply line 6 for supplying power to the electric heater 4 is connected to the electric heater 4 through an electric insulator 5 filled and fixed in the support rod 2. It is fixedly supported within the body 3.

Further, the lower part of the shell 3 and the electric heater 4 are thermally connected by a heat conductive member 8 made of a metal plate having an L-shaped cross section, so that the heat generated by the electric heater 4 is focused on the lower part of the shell 3. It conducts heat effectively.

Further, a thermocouple 7 as a temperature measuring device for measuring the temperature Tg of the surface of the heating element 1 (shell 3) is fixed to the inner surface of the shell 3 of the heating element 1, and the output of the thermocouple 7 is as described above. It is led out of the shell 3 through the electrical insulator 5 and the support rod 2. Then, the electric heater 4 is energized to generate heat, and the heating element 1 has a heat amount M.
In that state, the surface temperature Tg of the heating element 1 is detected by the output voltage of the thermocouple 7, and based on this, the thermal state of the indoor environment is sensed by considering heat loss due to radiation, convection, and moisture heat radiation from the human body. It is designed to be detected in the form of temperature.

Furthermore, on the outer surface of the shell 3 of the heating element 1,
A thin radiant material layer 9 is made of a fluororesin such as tetrafluoroethylene resin (RTFE) and a predetermined pigment such as titanium oxide (TiO ₂ ), which has an emissivity that roughly matches the spectral emissivity of human skin or clothing. The radiant heat transfer coefficient of the human body and the like is matched with the radiant heat transfer coefficient of the heating element 1 to accurately detect the sensible temperature.

Therefore, in the thermal sensing element A having the above configuration, within the shell 3 of the heating element 1 in which the electric heater 4 is enclosed, the heat generated from the electric heater 4 is as follows.
Due to the convection, heat is transferred to the vicinity of the upper surface of the shell 3 and the upper part of the shell 3 is heated, and a heat conductive member 8 that thermally connects the lower part of the shell 3 and the electric heater 4
The heat is transferred to the lower part of the shell 3 by thermal conduction, and the lower part of the shell 3 is heated, so that the entire shell 3 is heated almost uniformly by both of them. Furthermore, since the shell 3 is made of a metal with high thermal conductivity, the shell 3 can be heated more uniformly due to its heat conduction. From this, the isothermal flux condition, which is a prerequisite for the thermal equilibrium equation of thermal sensing element A, is almost satisfied, so the thermal state can be detected with high accuracy, and the air conditioner can be controlled based on this. Therefore, it is possible to improve the comfort of the indoor environment.

Here, an example of the manufacturing method of the hollow spherical shell 3 will be explained with reference to FIG. A plurality of band-shaped metal guide plates 11 (three in the figure) are fixed to the inner surface of the joint portion of the shell 10 by spot welding or soldering from the inner surface, and the guide plates 11 are fixed to the inner surface of the joint portion of the shell 10. It is formed by joining both hemispherical shells 10, 10 through the guide plate 11 and fixing the other hemispherical shell 10 by soldering or the like. The shell 3 thus obtained has high sphericity without any protrusions or steps on its surface, has low contact thermal resistance at the joint, and can be manufactured robustly and inexpensively.

In addition, the thermocouple 7 can be
can be fixed without the problem of heat resistance caused by adhesive. That is, as shown in FIG.
bulges out a part inward to form a presser part 12,
When fixing the guide plate 11 to the hemispherical shell 10, the thermocouple 7 is crimped with the holding part 12 to fix it. An adhesive may also be used during this fixing. As a result, the thermocouple 7 is fixed by crimping the holding part 12, so there is no need to use adhesive, and even if it is used, only a small amount is needed, so it is possible to suppress the increase in thermal resistance caused by adhesive, and output There is no variation in temperature, and even with a simple structure, it can be fixed firmly and inexpensively.

Furthermore, in the above description, a hollow spherical shell body 3 has been described, but other hollow cylindrical shell bodies can also be used.

In addition, as for the heat conductive member 8 that thermally connects the electric heater 4 and the shell 3, instead of making thermal contact only with the lower part of the shell 3 as in the above embodiment, the lower part of the shell 3 is Thermal contact may be made more closely as the layers move toward the top, and may be made sparser toward the top.
The point is that heat conduction from the electric heater 4 should be made greater toward the lower part of the shell 3 in order to compensate for convective heat transfer.

(Effects of the Invention) As explained above, according to the thermal detection element of the present invention, convection heat is transferred to the upper part of the shell 3 by the heat generated by the electric heater 4 in the heating element 1, and the heat conduction member 8 The heat conduction in the lower part increases and the shell body 3
Since the entire device is heated almost uniformly, it is possible to satisfy the equal thermal flux condition, which is a premise of the theory of thermal sensing elements, and improve thermal sensing accuracy.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a schematic diagram of a thermal sensing element, Fig. 2 is an exploded perspective view showing a method for manufacturing a hollow spherical shell, and Fig. 3 shows a method for fixing a thermocouple. FIG. 3 is a perspective view of main parts. DESCRIPTION OF SYMBOLS 1... Heating element, 3... Shell body, 4... Electric heater, 7... Thermocouple, 8... Heat conduction member.

Claims (1)

[Scope of utility model registration request] A heating element 1 having an electric heater 4 built into a hollow shell 3, and a temperature measuring device 7 for measuring the surface temperature Tg of the heating element 1, supplying heat to the heating element 1, The thermal detection element detects the thermal state of the indoor environment based on the surface temperature Tg, and is characterized by having a heat conductive member 8 that thermally connects the lower part of the shell 3 and the electric heater 4. Heat detection element.