JPH0672815B2 - Thermal detector - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat detection device for detecting a heat state of an environment in an air conditioner that provides a comfortable environment for humans.

2. Description of the Related Art Conventionally, as shown in FIG. 5, in this type of heat detecting device, a heating element 1 is coated with a coating 2 made of a jelly-like substance whose thermal characteristics are substantially the same as those of a human body, and the coating 2 is formed. A cover 5 formed of a resin such as polyethylene, which has a plurality of ventilation holes 4 and which transmits radiant heat, is provided on the outer side of the covering body 2 and which has a detecting body 3 made of a thermocouple for detecting the temperature of
Has been provided, and a heat detection device having a configuration in which a power supply line 6 to the heating element 1 and a signal line 7 from the detection element 3 are provided has been filed (for example, JP-A-60-170731). Using this element, while supplying a constant amount of power to the power supply line 6, a signal corresponding to the thermal state of the environment is obtained from the signal line 7.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-mentioned configuration, the heating element and the temperature detecting element are individually required, and in addition, a special material and structure of a jelly-like substance are required, and it is always constant. In order to obtain the signal from the constant power supply circuit and the thermocouple for supplying the electric power to the thermal detection element as the temperature, the reference temperature junction compensation /
There is a problem in that a circuit for voltage amplification or the like is additionally required.

The present invention solves the above-mentioned conventional problems, while maintaining a small number of parts and a simple structure, a signal output suitable for collective detection of thermal influences of temperature, air flow, and radiant temperature and microcomputer control, By realizing with a self-heating element and a simple circuit, based on the information corresponding to the thermal sensation of the human body, the air conditioner can be controlled more finely than before and provide a comfortable warm space. And

Means for Solving the Problems In order to solve the above problems, the heat detection device of the present invention is
A hollow body having an opening and having a good inner surface reflectivity to light and heat, a heat insulating portion made of a material having good heat insulating property provided so as to cover the outer periphery of the hollow body, and a porous body provided at the opening of the hollow body. -Shaped cover, a heating element provided inside the hollow body and made of a substance whose electric resistance changes according to its own temperature, a control means for maintaining the heating element at a constant temperature, and a supply means from the control means to the heating element. And a determining means for determining the thermal state of the environment from the generated electric power.

The present invention has the above-mentioned configuration, in which the heat generating element is reflected directly through the porous cover or on the inner surface of the hollow body to exchange radiant heat with surrounding objects and solar radiation, and convection with the secondary airflow inside the hollow body caused by the surrounding airflow. Heat exchange is performed, and the porous cover and the hollow body are heated or cooled by radiant heat exchange between the porous cover and the surrounding objects and solar radiation, thereby performing radiant heat exchange with the heating element. Part of the heat is transferred by conduction. Further, the heat insulating portion can prevent unnecessary thermal influence. At this time, the shape and dimensions of the hollow body are
Since the proportions of convective heat transfer and radiant heat transfer between the heating element and the surrounding environment are formed to substantially match those of the human body, the magnitude of the load for maintaining the heating element at a constant temperature by the control means varies. It is obtained according to the load for keeping the body temperature of the human body constant. Since this load can be extracted as an electric signal and the thermal sensation of the human body can be judged from this output, a comfortable space can be easily realized by controlling the air conditioner based on this judgment. .

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the block diagram shown in FIG. 1, 10 is a heating element using a thermistor. As shown in detail in the partially cut-away perspective view of FIG. 2, the inner surface 11 is plated with aluminum which has good light heat reflectivity. A resinous hollow body (12) is provided with a porous cover (13) having fine openings whose surface is coated with matt black, and further on the outside of the hollow body (12) is a heat insulation part (14) made of styrene foam.
It consists of

The heating element 10 is controlled by the control means 15 so as to always generate heat at a constant temperature, and the determination means 16 can obtain information corresponding to the thermal sensation of the human body from the signal of the control load of the control means 15 at this time.

FIG. 3 shows an embodiment of the control means 15, wherein the heating element 10, the operational amplifier 17, the fixed resistor 18, and the fixed resistor are provided.
The temperature of the heating element 10 is controlled to be constant by the fixed resistor 20 and the fixed resistor 20. When the circuit is operated, the heating element 10 generates heat at a certain temperature determined by the resistance value of the fixed resistor 18, the fixed resistor 19, the fixed resistor 20 and the temperature-resistance characteristic of the heating element 10. However, if any of the ambient temperature, wind speed, or radiant temperature changes and the temperature of the heating element 10 is lowered, the resistance of the heating element 10 as a thermistor rises and the potential at the point b rises. The operational amplifier 17 amplifies the potential difference between the points a and b, and the potential at the point c rises, resulting in an increase in the current flowing through the heating element 10. Due to the increase in this current, the heating value of the heating element 10 increases. As a result, the temperature of the heating element 10 rises and stabilizes at the original temperature. At this time, the potential at the point b or the point c is taken out to the control means 15 and the following processing is performed. The heat balance between the surface of the heating element 10 and the environment is expressed by the following equation.

Q = αc (Ts-Ta) + _αr (Ts-Tr) However, Q: heat dissipation amount per unit surface area of the heating element (load for controlling the temperature of the heating element to be constant) αc: heating element and environment Convection heat transfer coefficient Ts: Temperature of heating element (controlled to be constant) Ta: Temperature αr: Radiation heat transfer coefficient between heating element and environment Tr: Ambient radiant temperature The inner surface 11 is a parabolic curve surface and the heating element 10 is Since the inner surface 11 is provided at a position substantially at the focal point of the parabolic curve surface, the radiation from the surrounding environment is converged to the heating element 10 through the porous cover 13, and the heating element 10 has a hollow periphery. The heating element 10 is installed in the recess surrounded by the body 12 and the porous cover 13 is interposed between the heating element 10 and the heating element 10. The radiant heat transfer coefficient αr and the convective heat transfer coefficient αc are calculated as The heat transfer coefficient and the average convective heat transfer coefficient can be approximately equalized, and the heat load for maintaining the heating element 10 at a constant temperature has a high correlation with the heat load required for the human body to maintain its body temperature in the same environment. can get. The judging means 16 is a table for correcting the non-linearity of the thermistor in the ROM of the one-chip microcomputer, and the relation between the load signal obtained by the control means 14 as shown in FIG. Or it is also in the form of a table, and this makes it possible to obtain an output that is almost equivalent to the thermal sensation of the human body caused by the temperature, air flow, and radiant temperature in that environment, so if you control the air conditioning equipment so that this sensation becomes neutral, A comfortable environment is always maintained.

According to the above configuration, it is possible to detect the influence of the radiation on the wall surface or the like, which is of particular interest because it has directivity to the radiation.
Further, since the radiation is converged and the sensitivity is increased, the shape of the heat generating element 10 can be made relatively small, and the driving can be performed with small power consumption. Furthermore, the influence of the directionality on the air flow is small, and the influence can be detected equally in any direction.

Since the porous cover made of stainless steel is used, the heating element and the inner surface are not inadvertently scratched by a finger, a pencil or the like during use.

By providing the heat insulating portion made of styrofoam, the detecting portion including the heat generating element 10, the hollow body 12, the porous cover 13, and the heat insulating portion 14 can block the thermal influence of the member to be installed.

Although a thermistor is used as the heating element here, a platinum resistor or the like may be used instead of the thermistor, and the inner surface 11 is also manufactured by resin molding a curved surface and vapor-depositing a metal such as aluminum on the surface. Is possible.

The curved surface shape of the inner surface 13 is not limited to a simple parabolic curve, but a Winston mirror-like structure can be used. The porous cover may be made of not only stainless steel but also other metal or resin.

Next, another embodiment of the present invention will be described with reference to FIG. 5 is different from the above embodiment in that a porous cover is used.
This is because 13 is made of punched metal with curvature.Also in this structure, the convection heat transfer coefficient and radiant heat transfer coefficient are maintained equivalent to those of the human body by changing the aperture ratio, and the sheet metal and curvature The strength of the porous cover 13 is improved by the presence of the porous cover 13, and there is an effect that the cover is not likely to be damaged even when the present heat detection device is built in the remote control unit or the like.

EFFECTS OF THE INVENTION As described above, according to the heat detection device of the present invention, the following effects can be obtained.

(1) The convection and radiant heat transfer coefficient of the heating element can be substantially matched with the value of the human body by the hollow body that reflects the radiant heat and reduces the air flow together with the porous cover, and the heating element can be kept at a constant temperature by the control means. Since the configuration is maintained, a high correlation can be obtained between the magnitude of the load and the thermal sensation of the human body, and optimal air conditioning equipment can be restricted.

(2) Since the thermal state of the environment is detected by the change in electric power, and the level of the thermal state is determined based on this,
Information that is easy and easy to use can be given to the air conditioning equipment.

(3) Since the configuration is simple, high performance can be obtained at a low cost with a small number of parts, and it is easy to manufacture and has a wide range of applications as a sensor for heating and cooling equipment.

[Brief description of drawings]

FIG. 1 is a block diagram showing the structure of a heat detecting device according to an embodiment of the present invention, FIG. 2 is a partially cutaway perspective view showing the structure of a heating element and a hollow body of the heat detecting device, and FIG. 3 is the same. FIG. 4 is a circuit diagram of the control means of the heat detection device, FIG. 4 is a characteristic diagram showing the contents of the determination made by the determination means of the heat detection device, and FIG. 5 is a partially cutaway perspective view showing the other embodiment. FIG. 6 is a partially cutaway perspective view showing a structure of a detection body of a conventional heat detection device. 10 ... Heating element, 12 ... Hollow body, 13 ... Porous cover,
14 ... Heat insulation part, 15 ... Control means, 16 ... Judgment means.

Claims (3)

[Claims] 1. A hollow body having an opening and having a good inner surface reflectivity to light and heat, a heat insulating portion made of a material having a good heat insulating property so as to cover the outer periphery of the hollow body, and an opening of the hollow body. A porous cover provided in a portion, a heating element made of a substance whose electric resistance changes according to the temperature of the heating element provided inside the hollow body, control means for maintaining the heating element at a constant temperature, and the control means A heat detection device, comprising: a determination unit that determines the heat state of the environment from the electric power supplied to the heating element. 2. The heat detection device according to claim 1, wherein the hollow body has a concave shape, and the heat generating element is provided at a substantially focal point of the concave shape. 3. The heat detection device according to claim 1, wherein the porous cover has a shape with a convex curvature on the outside.