JPH0715394B2 - 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. 6, a conventional heat detection device of this type covers a heating element 1 with a coating 2 made of a jelly-like substance whose thermal characteristics are substantially the same as those of the human body, and the coating 2 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 element 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 to determine the thermal sensation of the human body.

SUMMARY OF THE INVENTION However, in the above-mentioned configuration, it is possible to comprehensively judge the influences of ambient temperature, air flow, and radiation temperature,
It was impossible to detect how the individual factors affect.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to detect the thermal effects of air temperature, air flow, and radiant temperature all together with a simple configuration, and also to detect the thermal effect of radiant temperature.

Means for Solving the Problems In order to solve the above-mentioned problems, the heat detection device of the present invention has a hollow body having an opening and good internal surface reflectivity to light and heat, and is provided so as to cover the outer periphery of the hollow body. A heat insulating part made of a material having a good heat insulating property, a porous cover provided at the opening of the hollow body, a heating element made of a substance provided in the hollow body whose electric resistance changes according to its own temperature, and a surrounding area. An air temperature sensor for detecting the air temperature, a control means for maintaining the heating element at different set temperatures, a prediction means for predicting the power supplied to the heating element from the output of the temperature sensor, and an output from the prediction means. The calculation unit compares the electric power supplied to the heating element and calculates the influence of the radiant temperature on the human body.

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. At this time, the shape and dimensions of the hollow body are
Since the ratio of convective heat transfer and radiant heat transfer between the heating element and the surrounding environment is formed to substantially match that of the human body, the heating element is controlled to have a constant temperature by the control means.
Since the magnitude of the load for maintaining Ts is obtained corresponding to the load for maintaining the body temperature of the human body constant, the thermal sensation of the human body can be determined from this. Further, by adding information comparing the output of the prediction means for predicting the electric power supplied to the heating element from the output of the temperature sensor and the electric power supplied to the heating element, the environment can be calculated by a simple calculation in the arithmetic unit. It is possible to determine the effect of radiation temperature. A comfortable space can be easily realized by controlling the air conditioner based on the determination of the thermal sensation and the influence of the radiant temperature.

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 inner surface 11 is formed of a parabolic curved surface, and the heating element 10 is provided at a position substantially at the focal point of the parabolic curved surface of the inner surface 11, so that the radiation from the ambient environment is passed through the porous cover 13 to the heating element. In addition to converging to 10, the heating element
Since 10 is installed in a recess surrounded by a hollow body 12 and via the porous cover 13, it is configured to greatly reduce the velocity of the airflow that is in direct contact with the heating element 10. The radiant heat transfer coefficient and the convective heat transfer coefficient of the heating element 10 can be made substantially equal to the radiant heat transfer coefficient and the average convective heat transfer coefficient of the human body, and the heat load for maintaining the heating element 10 at a constant temperature is the same environment. Gives a high correlation with the heat load required by the human body to maintain its body temperature. Furthermore, there is a correlation between this heat load and the thermal sensation of the human body. That is, the heating element 10 is controlled by the control means 15 so that the heating element 10 generates heat at a constant temperature, and information corresponding to the thermal sensation of the human body can be obtained 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 a constant temperature Ts by the fixed resistor 20 and the fixed resistor 20. When the circuit is operated, the heating element 10 includes the fixed resistor 18, the fixed resistor 19,
The resistance value of the fixed resistor 20 and the temperature of the heating element 10-determined by the resistance characteristic-heats to a constant temperature, but here any of the ambient temperature, wind speed, and radiant temperature changes and the heating element When the temperature of 10 is decreased, the resistance of the heating element 10 which is 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 raises the potential at the point c. As a result, the current flowing through the heating element 10 increases. The amount of heat generated by the heating element 10 increases due to this increase in current, and the temperature of the heating element 10 rises.
Stable at the original temperature. At this time, the load Q required for heat generation of the heating element 10 can be obtained by the potential at the point b or the point c. The heat balance between the surface of the heating element 10 and the environment when the heating element 10 is maintained at the set temperature Ts is given by the following equation.

Q = αc (Ts-Ta) + αr (Ts-Tr) (1) However, Q: Heat dissipation amount per unit surface area of the heating element (load for controlling the temperature of the heating element constant) αc: Heating element Convection heat transfer coefficient between the heating element and the environment Ts: Temperature of the heating element (controlled to be constant) Ta: Temperature αr: Radiation heat transfer coefficient between the heating element and the environment Tr: Ambient radiation temperature On the other hand, when the ambient temperature and the radiation temperature are equal The heat balance of the heating element 10 is as follows.

Q ′ = (αc + αr) × (Ts−Ta) (2) Here, in the block diagram shown in FIG. 4, the porous cover is used.
A predicting means 16 provided near 13 for predicting the electric power supplied to the heat generating element 10 from the output of the temperature sensor 22 for detecting the ambient temperature is the output of the temperature sensor 22 and the heat generation using the air flow shown in FIG. 5 as a parameter. The relationship with the power supplied to the element 10, that is, the storage unit 25 that stores the equation (2), the airflow input unit 24 that inputs the value of the airflow, and the air temperature input unit 23 that inputs the output of the air temperature sensor 22. An output unit 26 that extracts and outputs a predicted value from the storage unit 25 based on the outputs from the input units 23 and 24.
And the air flow input section by the air volume setting of the air conditioner.
From the value of the airflow input to 24 and the output of the temperature sensor 22 input to the temperature input unit 23, the storage unit 25 in the output unit 26
The predicted value Q'of the electric power supplied to the heating element 10 stored in is output.

Next, the calculation unit 16 compares the output Q'from the predicting means 21 with the electric power Q supplied to the heating element 10 to calculate the influence of the radiation temperature on the human body.

That is, according to the equation (1)-(2), Q-Q '= αr (Ta-Tr) (3), and it is possible to accurately detect the influence of radiation on the human body.

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

With two elements, a heating element and an air temperature sensor, the three effects of air temperature, air flow, and radiant temperature are comprehensively applied to the human body's thermal sensation.
It is possible to detect the influence of the radiant temperature, and it is possible to monitor the thermal state of the environment and optimally control the air conditioning equipment based on this information.

[Brief description of drawings]

FIG. 1 is a block diagram of a heat detection device showing 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 device, and FIG. 3 is a control means of the device. FIG. 4 is a circuit diagram showing the above, FIG.
FIG. 5 is a characteristic diagram showing stored contents in the prediction means of the device,
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 ... Insulation part, 15 ... Control means, 16 ... Calculation part, 21 ...
Predictor, 22 ... Air temperature sensor.

Claims (2)

[Claims] 1. A hollow body having an opening having a good inner surface reflectivity against 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 electrical resistance changes according to its own temperature provided inside the hollow body, an air temperature sensor for detecting an ambient temperature, and the heating element maintained at a set temperature. Control means, predicting means for predicting the electric power supplied to the heating element from the output of the temperature sensor, and comparing the output from the predicting means and the electric power supplied to the heating element to the human body of the radiation temperature. A heat detection device including a calculation unit that calculates an influence. 2. The predicting means stores a relationship between the output of the temperature sensor and the electric power supplied to the heating element using the airflow as a parameter, an airflow input unit for inputting the value of the airflow, and the temperature sensor. The thermal detection device according to claim 1, comprising an air temperature input unit for inputting an output, and an output unit for extracting and outputting a predicted value from a storage unit according to an output from the input unit.