JPH02147927A - Temperature measuring system - Google Patents

Abstract

PURPOSE:To reduce wiring costs or the like by providing a plurality of temperature measuring elements each with an A/D converter, which is connected to a central processing unit through a signal data transmission cable to secure a high measuring accuracy. CONSTITUTION:For example, sheath type thermocouples 2 and 2 are arranged securely at specified points of a furnace 1 to measure temperatures at a plurality of points in the furnace 1 of a thermal power station or the like and head sections thereof are equipped with converters 3-3 respectively and the converters 3-3 each contain an A/D converter with which a termoelectromotive force is converted into a digital signal to be outputted to an output terminal. The converters 3-3 are connected to an instrument disc 5 provided at a control chamber at the center through an optical cable 4. Light output signal is connected to the optical cable 4 through a photocoupler or the like to perform a serial transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a temperature measurement system mainly used as an industrial instrument, and particularly to a temperature measurement system equipped with a plurality of temperature measurement elements.

[Prior Art] Conventionally, temperature measuring devices for measuring the temperature of furnaces in thermal power plants, etc., have been widely used, for example, using temperature measuring elements using thermocouples or resistance thermometers. . These temperature measuring devices are placed at various locations in the furnace, and the measured temperature output is sent to the instrumentation F! installed in the central control room. 1
It is intensively transmitted and displayed on i, etc.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, when the temperature of a furnace in a thermal power plant or the like is centrally transmitted and displayed on an instrument panel installed in a central control room, a large number of A long compensating lead wire or a long instrumentation cable must be routed, which poses problems in that the wiring work becomes expensive and the measurement accuracy deteriorates. It has also been proposed to provide a converter in the middle of the wiring, but this has not yet been able to sufficiently improve the measurement accuracy and sufficiently reduce the construction cost.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, it is an object of the present invention to provide a temperature measurement system that can improve measurement accuracy and sufficiently reduce costs for wiring work, etc.

[Means for Solving the Problems] The object of the present invention is to provide a plurality of temperature measuring elements whose electrical characteristics change due to temperature changes, and to convert the changes in the electrical characteristics of these temperature measuring elements into temperature measurement signals. In a temperature measuring device comprising temperature converting means, each of the plurality of temperature measuring elements is provided with an A/D converter, and these A/D converters are centrally connected via a single data transmission cable. This is achieved by a temperature measurement system characterized in that it is connected to an arithmetic processing unit.

[Function] That is, according to the temperature measurement system according to the present invention described above, since the plurality of temperature measurement elements arranged at various locations are each equipped with an A/D converter, a long compensating lead wire or a long High measurement accuracy can be ensured without reducing measurement accuracy due to instrumentation cables.Furthermore, since these A/D converters are connected to the central processing unit via a single data transmission cable, It is possible to reduce the number of wiring conductors, and thereby also reduce wiring costs.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

First, FIG. 2 shows the structure of a temperature measuring section 10 used in a temperature measuring system according to an embodiment of the present invention. The temperature measurement section 10 includes a temperature measurement element using, for example, a sheath type thermocouple.

That is, as is clear from the figure, a pair of thermocouples 12 are built inside the sheath II of this sheath type thermocouple. Further, in the figure, reference numeral 13 indicates the sheath 11 at high temperature.
This is a so-called well used for protection from high pressure, vibration, etc. Reference numeral 14 is a connector of the sheath type thermocouple, and reference numeral 15 is a head portion of the connector 14.

FIG. 1 shows a block diagram of a temperature measurement system according to the present invention. For example, the sheath type thermocouples 2 to 2 (here, "n" is 2 or more) described above are fixedly arranged at predetermined locations in the furnace 1. Converters 3 to 3 are provided in the head portions of these plurality of sheath type thermocouples 2 to 2, respectively. These converters 3-3 have A inside them.
It has a built-in /D converter and converts the output of the thermocouple, which is a temperature measuring element, into a digital signal and outputs it to its output terminal.

These converters 3 to 3 are connected to an optical cable 4, which is a single data transmission cable, and connected to an instrumentation panel 5 provided in a central control room. For this reason, these converters 3 to 3 have a built-in optical signal converter for converting the digital signal into an optical signal, and the optical output signal is connected to the optical cable 4 through a photocoupler or the like. and serial transmission. Moreover, not only one-way transmission of the output method but also bi-directional transmission in which the converters 3 to 3 . . . are controlled by commands from the CPU of the instrumentation panel 50 is also possible.

On the other hand, the instrumentation panel 5 in the central control room is equipped with a digital computer, which inputs the digital signal output to the optical cable 4 and performs predetermined calculations to measure the temperature of each part of the furnace l. At the same time, the measured value is displayed on the instrumentation panel 5. Further, in the figure, reference numeral 6 denotes a so-called power cable for supplying the necessary power to the plurality of sheathed thermocouples 2 to 2 and their converters 3 to 3.

According to the temperature measurement system described above, when the plurality of sheathed thermocouples 2 to 2 and their converters 3 to 3 are arranged in each part of the furnace 1, the number of cables to be wired is as follows.
As is clear from the above explanation, only two cables, the optical cable 4 for transmitting the optical signal converted into a digital signal and the electric cable 6 for power supply, are required, making the wiring extremely simple. costs can be significantly reduced. In addition, the thermoelectromotive force, which is the output from the sheathed thermocouples 2 to 2, which are temperature measuring elements, is converted into a digital signal by an A/D converter provided inside each of the converters 3 to 3, and is transmitted. Therefore, even if the temperature measuring point of the furnace 1 and the instrumentation panel 5 are far apart, there is no problem of deterioration of measurement accuracy due to the transmission path.

Next, FIG. 3 shows a temperature measurement system which is another embodiment of the present invention. In the temperature measurement system according to this other embodiment, as is clear from the figure, the plurality of sheathed heat transfer pairs 2-2 fixedly arranged in the furnace l in which the temperature at various locations is to be measured are at least two or more. divided into groups,
Each of these groups is provided with its own input/output processing circuits 7 to 7 (here, "i" is an integer of 2 or more). These input/output processing circuits 7 to 7 are arranged near temperature measurement points at various locations in the furnace 1, and input the outputs from the converters 3 to 3 of the sheathed heat transfer pairs 2 to 2 connected to each of them. , for example, an input processing processor that performs predetermined pre-calculations, such as engineering units, and then internally transmits the data to the digital computer of the instrumentation panel 5 in the central control room. It is advantageous that such input processing circuits 7 to 7 are provided one by one near the sheathed heat transfer pairs 2 to 2 that are relatively gathered in one place.

In addition, the temperature measurement system according to another embodiment shown in FIG. Since the information is later transmitted to the digital computer in the 81-mounted board 5 in the central control room, it is significantly advantageous in its degree of integration compared to the embodiment shown in FIG. 1 above. Furthermore, in this FIG. 3, the parts indicated by the same reference numerals as the constituent parts shown in the above-mentioned FIG. 1 indicate the same constituent parts.

In the explanation of the above embodiments, a thermocouple was mainly described as the temperature measuring element, but the present invention is not limited to this, for example, a temperature measuring resistor whose resistance value changes with temperature change. Similar effects can be obtained by using the body. Further, it goes without saying that the other constituent parts are not necessarily limited to those shown in the above-described embodiments, and may be any other components that perform the same functions as these.

[Effects of the Invention] As is clear from the above description, according to the present invention, even if the distance between the temperature measurement point and the arithmetic processing unit becomes large and the signal transmission path becomes long, the measurement accuracy is not adversely affected. This provides an excellent effect in that a temperature measurement system can be provided that does not cause problems and can sufficiently reduce costs such as wiring work.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the structure of a temperature measurement system that is an embodiment of the present invention, and FIG. 2 is a perspective view including a partial cross section showing a WIM of a temperature measurement unit used in the temperature measurement system.
FIG. 3 is a block diagram showing the structure of a temperature measurement system according to another embodiment of the present invention. ■...Furnace 2~2...Sheath type heat transfer pair 3~3...
・Converter 4... Optical cable 5... Instrumentation panel 6.
...Electric cable 7-7...Input/output processing circuit patent applicant Sukegawa Electric Industry Co., Ltd. Agent Patent attorney Kazuyoshi Hojo'$, 2 Figures

Claims (1)

[Claims] (1) In a temperature measuring device comprising a plurality of temperature measuring elements whose electrical characteristics change due to temperature changes and a temperature conversion means that converts the change in the electrical characteristics of these temperature measuring elements into a temperature measurement signal, A temperature measuring device characterized in that each of the plurality of temperature measuring elements is provided with an A/D converter, and these A/D converters are connected to a central processing unit via a single data transmission cable. measurement system.