JPS6136607B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for measuring the amount of radiation heat of an object using an infrared camera as a sensor.

In recent years, heat loss management, which involves predicting abnormalities in objects through thermal image analysis and minimizing heat radiation loss from the objects, has become increasingly important from the perspective of energy conservation. The conventional methods of calculating heat loss are to measure the surface temperature of an object using a contact thermometer and calculate it based on that data, or to attach a special sensor to the object and emit heat from the surface of the object. The method used was to use a heat flow meter, which directly displayed the heat loss caused by heat loss in calorie units.
However, these contact measurement methods have the disadvantage that the calculation of the amount of heat loss is only a rough estimate, as the only way to estimate the heat loss at points other than the measurement points is based on the measured values from a few to a dozen points. It was hot. Furthermore, if the target object, such as a plant's piping, is spread over a very wide area, only partial management is possible. A solution to these shortcomings is to take a thermal image obtained with an infrared camera, measure the area of the abnormal part on the photograph, convert it to the area of the object, and calculate this area and the temperature of the abnormal part. There is a method to calculate the amount of heat loss from the method, but it has the drawback that it requires time and effort to save the data and process the calculations.

The present invention uses an infrared camera that detects the amount of infrared rays emitted by an object and reconstructs changes in the amount of infrared rays as an image.The present invention uses an infrared camera that detects the amount of infrared rays emitted by an object and reconstructs the changes in this amount of infrared rays as an image. The present invention aims to provide a radiation calorific value measurement device that can determine the amount of loss.

The radiation calorific value measurement device of the present invention includes an infrared detection means that optically scans an object, detects the amount of infrared rays emitted by each part of the object, and outputs a thermal image signal, and an output signal of the detection means that reduces the output signal. means for storing one screen worth of images; means for classifying and outputting thermal image signals from the storage means into signals of multiple levels according to temperature differences; and counting the number of pixels for each level from the classified signals. Means for calculating the true area of a region of the object at the temperature level from this count value and previously input area calculation parameters; and means for determining the amount of heat dissipated at the temperature level from the above.

Hereinafter, details of the present invention will be explained with reference to the drawings. The drawing is a block diagram showing the configuration of a radiation calorific value measuring device according to an embodiment of the present invention. Reference numeral 10 denotes an infrared detection means that optically scans an object, detects the amount of infrared rays emitted by each part of the object, and outputs a thermal image signal. Specifically, an infrared camera can be used. Such an infrared camera 10 is applicable to a relatively low-speed mechanical raster scanning mechanism, a photoelectric conversion device, and an image reproducing device, such as the one disclosed in Japanese Patent Publication No. 49-31664 as an "optical mechanical raster scanning device". A small and easily portable device comprising a light source and performing both raster scanning and image reproduction is suitable. 20 is an image storage means for storing image signals from the infrared camera 10. The image storage means 20 includes an A/D converter 21 that performs analog-to-digital conversion of an image signal taken out from an infrared detection section (not shown) that generates an electric signal proportional to the temperature (infrared radiation amount) of the object of the infrared camera 10.
, a frame memory write circuit 22 for writing the digital image signal output from the converter 21 into the frame memory 23, and a frame memory 23 for storing one screen worth of digital image signals under the control of the write circuit 22. It is composed of. When the image stored in the frame memory 23 is observed, it is read out by the TV display means 30 provided as necessary and displayed on the TV. TV display means 30
is a frame memory readout circuit 31 that reads out images stored in the frame memory 23 by standard TV scanning.
and a TV video signal read out by the reading circuit 31 and displaying the digital image on the monitor TV 33.
It is composed of a generator 32 and a monitor TV 33. Note that in order to display the ever-changing thermal image on TV in real time, writing and reading (access) to the frame memory 23 are performed in a time-division manner. In this way, infrared camera 1
The image signal from 0 is stored in the image storage means 20 and
The TV display means 30 displays the image on the monitor TV 33 as a monochromatic grayscale image or a pseudocolor image.
In addition, when obtaining a pseudo-color image, a color distributor (not shown) is provided between the frame memory readout circuit 31 and the TV video generator 32, and a color distributor (not shown) is provided between the frame memory readout circuit 31 and the TV video generator 32, and a color distributor (not shown) is provided between the frame memory readout circuit 31 and the TV video generator 32. colored according to. By observing the thermal image displayed on the monitor TV 33 in this manner, it is possible to clearly observe which part of the object is abnormally emitting infrared rays.

Next, a method of determining the amount of heat dissipated for each temperature distribution of a thermal image will be explained.

40 is a classification means for classifying the image signal of the infrared camera 10 into appropriately set temperature (brightness) levels (in this embodiment, 16 levels) and outputting the same. The classification means 40 is an infrared camera 10
More specifically, a switch 41 for arbitrarily extracting an image signal for one screen from the digitized image signal output from the frame memory writing circuit 22 of the image storage means 20; and a decoder 42 that classifies the image signal into multiple levels (16 levels) of signals based on temperature differences and outputs the signals. The output from the decoder 42 is input to the area calculation means 50, which counts the number of input pixels for each level, and calculates the true area of the area of the object at the temperature level based on this count. are required respectively. The area calculation means 50 includes the same number of counters C ₁ to C _o as the number of output signals (number of levels) of the decoder 42 and an area calculator.
It is composed of S ₁ to S _o and an area calculation parameter generator 51. The counters C ₁ to C _o count only the pixels at a specific temperature level that are sequentially input from the decoder 42, and the counters C ₁ to C
Output each to _o . The area calculators S ₁ to _{S o} receive the number of pixels input from the counters C ₁ to _{C o} corresponding to each calculator, and the input from an area calculation parameter generator 51 consisting of, for example, a keyboard provided on the device panel. Object and infrared camera 1
The distance to The area of the back of the area at the same temperature level is calculated and output to the dissipated heat calculation means 60. Dissipated heat calculation means 60
is the same number of radiated heat amount calculators as area calculators S ₁ to _{S o}
It consists of _Q1 , _Qo , and a dissipated heat calculation parameter generator 61. Dissipated heat amount calculator Q ₁
〜Q _o are respectively corresponding area calculators S ₁ 〜S _o
The outside temperature and natural convection coefficient are input from the radiated heat amount parameter generator 61, which consists of, for example, a keyboard installed on the equipment panel (correction is required in the case of forced convection with wind).
From the emissivity that varies depending on the material, shape, and surface condition of the object to be measured, and the temperature of the area on the object at the same temperature level from the decoder 42, the same temperature level on the object is determined by the following formula. Calculate the amount of heat dissipated in a certain area. The amount of heat dissipated Q can be determined by Q = (Hc + Hr) (Tn - To). (Tn is the temperature of the area on the object at the same temperature level, To is the outside air temperature.) Here, Hc is the natural convection coefficient, Hc = 2.2 (Tn - To), Hr is the radiant heat transfer coefficient, Hr =4.88×10 ⁻⁸ P _s {(Tn+273) ⁴ −(To+273) ⁴ }/(Tn−To) (Ps is the emissivity with the black body set to 1) In other words, the outside temperature To and the measurement target If we know the emissivity Ps, which varies depending on the object, we can determine the amount of heat dissipated in each area at the same temperature level.

The amount of heat dissipated in each area at the same temperature level on the object to be measured, measured as described above, is processed in various ways depending on the measurement purpose and used. As an example of this, abnormal heat dissipation parts and normal heat dissipation parts of the object are identified from the thermal image displayed on the monitor TV 33 based on the temperature distribution of the object, and a separate keyboard (not shown) is used. ), the outputs of the dissipated heat amount calculators Q ₁ to Q _o are divided into abnormal portions and normal portions and added. If the total amount of heat dissipated from the abnormal part is Q' and the total amount of heat dissipated from the normal part is Q'', then the amount of heat calculated by {Q' - Q'' x abnormal area / normal area} is the heat loss related to the abnormality. , a calculation circuit (not shown) for performing such calculations may be provided after the keyboard or the like.

When the final output data is processed as described above, it is desirable to have a format as shown in the attached reference output data in consideration of storage stability, quantitative properties, etc. In particular, with regard to thermal images, conventionally most cases have been saved as photographs, but due to the difficulties involved in taking them (labor, mistakes, etc.) and the ambiguity of thermal images (even pseudo-color display uses 10 to 20 different colors) Therefore, colors of the same color family may be adjacent to each other.) remains. If a pseudo mark thermal image display method as shown in the reference output data is used, the drawbacks of the photographic method are eliminated and all data can be printed out immediately. This type of final data output format is expected to become one of the future data output formats as printer devices become smaller and more sophisticated.

As is clear from the above explanation, according to the radiant heat measurement device of the present invention, even if the object to be measured, such as the pipes of a plant, is spread over a very wide range, the temperature distribution can be instantly known. It is possible to accurately measure the amount of heat loss, and it can be processed in various ways depending on the measurement purpose and used for heat loss management.

In addition, since it is possible to perform calculations on heat loss at the same time as thermal image observation without relying on a manual, the desired data can be quickly obtained, which is highly effective.

[Brief explanation of the drawing]

The drawing is a block diagram showing the configuration of a radiation calorific value measuring device according to an embodiment of the present invention. 10... Infrared camera, 20... Image storage means, 30... TV display means, 40... Classification means,
50... Area calculation means, 60... Dissipated heat amount calculation means.

Claims (1)

[Claims] 1. Infrared detection means for optically scanning an object to detect the amount of infrared rays emitted by each part of the object and outputting a thermal image signal, means for storing at least one screen worth of output signals from this detection means, and this memory. means for classifying and outputting thermal image signals from the means into signals of multiple levels according to temperature differences, counting the number of pixels for each level from the classified signals, and calculating the number of pixels for each level from the classified signals, Means for calculating the true area of the area of the object at the temperature level from the area calculation parameter, and calculating the amount of heat dissipated at the temperature level from the true area and the previously inputted heat amount calculation parameter. A radiant heat amount measuring device comprising: means.