JPS6194118A - Temperature controller - Google Patents

Abstract

PURPOSE:To prevent the sodium freezing of a high-speed breeder with a simple constitution by adding a temperature-sensitive resistance element of positive characteristics to a material to be heated and giving the ON/OFF control signal to a switch device of an electric heater when a preheating controller has a fault. CONSTITUTION:A temperature detector 11 and an electric heater 12 are provided to a material to be heated such as a pipeline 10, etc., and a heat insulator 4 is added onto those detector 11 and the heater 12. The temperature PV of the pipeline 10 which is detected by the detector 11 is supplied to an estimation controller 19 and compared with a set temperature SV. Then the heater 12 is controlled via an ON/OFF control part 21 and a preheating power supply device 15. Here a heat-sensitive resistance element PTC13 of the positive temperature characteristics is added to the pipeline 10. The signal of the PTC13 is supplied to the device 15 for switching the power supply of the heater 12, and a relay 18 which is closed when the controller 19 has a fault is inserted to the PTC13. Thus the PTC13 performs the ON/OFF control to the heater 12 through the PTC13 to prevent the sodium freezing within the pipeline 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a temperature control device, particularly a humidity control device installed for preheating control of sodium equipment, piping, valves, etc. in a fast breeder reactor.

[Technical background of the invention and its problems] In fast breeder reactors, wave body storium is usually used as a coolant. Since sodium is solid at temperatures below 98°C, it is usually heated to above 200°C and used as liquid sodium. The sodium itself is heated in the Kumbh tank, but the parts that are filled and circulated with sodium, such as reactor containers, equipment, and piping, must be heated uniformly at a predetermined rate of change depending on the state of thorium filling. . In this case, an electric heater is usually used as the heating element 11.

The electric heater is energized in some cases by Nyristor firing angle control, but usually by on/off control using a switch.

Next, the configuration of a conventional temperature control device will be explained with reference to FIG. A temperature detector 2 and an electric heater 3 are installed on the heated object such as the piping 1, and a heat insulating material 4 is further installed on top of the temperature detector 2 and electric heater 3.
The temperature measurement IPV detected by the iF1 degree detection detector is input to the preheating control device 5 and is compared with the temperature setting value S■. Then, the declination value 5v-pv between the temperature setting value SV and the temperature measurement value P■ is inputted to the on-off control section 6, and an on-off control signal that turns on MV when SV≧pv and turns off M when sv<pv MV preheating power supply device 7
and connect the semiconductor type relay 5SR (Solid
5tate Relay) 8 is turned on and off.

The power supplied to the electric heater 3 is opened and closed in accordance with the on/off state of this relay 5SR8. Although FIG. 3 illustrates one temperature control loop, the temperature control 3D device normally inputs temperature measurement values PV from a plurality of temperature detectors 2 and controls a plurality of electric heaters 3.

Incidentally, a case is shown in which a microprocessor is used as the preheating control device 5, and the on/off control signal MV becomes the digital output 9 of the microprocessor. This digital output 9 is a 5SR8 stored in the preheating power supply device 7.
By turning on and off 5SR8, the power supplied to the electric heater 3 is opened and closed.

However, in the temperature control device configured as described above, if the preheating control device 5 breaks down, the digital output 9 will be lost, making it impossible to continue the preheating operation. In this case, especially in small-diameter pipes, the heat radiation is large, so the temperature decreases quickly, and there is a risk that sodium may freeze. Therefore, as a means to solve this problem, there are measures such as multiplexing the preheating control device 5 or providing a backup controller, but both methods have the problem of increasing the space and amount of materials. Another possible countermeasure is to forcibly apply power supplied to the electric heater 3 from the preheating power supply device 7, but since the signal from the temperature detector 2 is lost, there is no control, and vice versa. There is another problem, such as the possibility that the temperature of

[Purpose of Defense] The present invention has been made in view of the above circumstances, and its purpose is to maintain the temperature of heated objects such as piping by the preheating power supply device even when the preheating control device fails, thereby preventing the freezing of sodium. Temperature control 3D with simple configuration that can prevent
The goal is to provide equipment.

[Summary of the Invention] In order to achieve the above object, the present invention installs an electric heater and a temperature detector on an object to be heated, and performs preheating control on the temperature measurement value of the object to be heated detected by the temperature sensor. This temperature measurement value is input into the device and compared with a predetermined temperature set value, and an on/off control signal is given to open/close the electric heater according to the temperature difference. In the temperature control device, a heat-sensitive resistance element with a positive characteristic is further installed on the object to be heated, so that when the preheating control device fails, the object to be heated reaches a temperature that is below the temperature setting value or not below the temperature setting value. Then, the heat-sensitive resistance element changes accordingly to give an ON or OFF control signal to the switching device to maintain the temperature of the heated object at the temperature set value (as described in 1). The objects to be heated are the sodium equipment, piping, and valves of the fast breeder reactor.
Further, the heat-sensitive resistance element having positive temperature characteristics is a semiconductor having a composition such as barium titanate.

[Embodiments of the invention] An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a circuit configuration diagram of an embodiment of the present invention. As shown in the figure, in addition to a temperature detector 11 and an electric heater 12, a temperature detector 11 and an electric heater 12 are installed on objects to be heated such as piping 10. A heat-sensitive resistance element (p
ositive T cmperatureCoef
ficient Thermistor, hereafter PT
(referred to as C) 13 is installed, and the top thereof is covered with a heat insulating material 14. PTC13 is a semiconductor having a composition such as barium titanate, and has characteristics having a curve as shown in FIG. In other words, in the same figure, the PTC characteristic curve is expressed by the temperature T on the horizontal axis and the resistance R on the vertical axis, where the lower the temperature, the lower the resistance, and the lower the temperature, the lower the resistance, and the lower the temperature, the lower the resistance.
It has a characteristic that the resistance increases rapidly when S is exceeded. The signal of PTC13 is input to preheating power supply unit: G15,
Through the diode 16 to prevent current from flowing in, S
It is connected to the input side of R17, and has a +M configuration that can open and close the power supply for the electric heater 12. And PTC
13 is connected in series with a relay 18, which opens when the preheating control device 19 fails. Moreover, the temperature measurement 1itf P V detected by the temperature detector 11 is
It is input to the preheating control device 19 and compared with the temperature set value SV. The subtraction value 5v-pv is the on-off control unit 2.
1, and the following on/off control signal MV is output. In other words, if S≧PV, MV is on, and SV<P
In the case of V, the on/off control signal MV, in which MV is turned off, is input to the preheating power supply device 15, which turns on and off the semiconductor type relay 5SR17, opens and closes the power supply supplied to the electric heater 12, and changes the temperature of the heated object such as the piping 10. It is configured to maintain the set value S■.

Next, the operation of this embodiment will be explained.

During preheating operation of the fast breeder reactor, objects to be heated such as sodium equipment, valves, piping 10, etc. are heated to a predetermined temperature by the electric heater 12 as described above. Here, preheating control device 1
If 9 fails, the digital output 20 will be lost. The preheating control device 19 is a microprocessor self-diagnosis i! ! A failure is detected by i, etc., and the relay 18 of the preheating power supply device 15 is closed. On the other hand, since the SSR 17 is turned off, no power is supplied to the electric heater, and the temperature of the pipe 10 and the like decreases. At this point, the temperature of the pipe 10, etc. is Ts in Figure 4.
Because of the above, the resistance of PTC13 is large, so P
No current flows through T C13. However, when the temperature of the piping 10, etc. further decreases to TS, the resistance of the PTC 13 rapidly decreases and current flows through the circuit including the PTC 13, so the 5SR17 turns on and the electric heater 12
Electricity will be supplied to the When electric power is supplied to the electric heater 12 and the temperature of the piping 10 etc. rises and the temperature exceeds Ts, the resistance of the PTC 13 increases rapidly, so no current flows through the PTC 13, and the S S
R17 is turned off. Therefore, the power to the electric heater 12 is cut off, and the temperature of the pipe 10 and the like decreases. In this way, when the preheating control device 19 fails, the PTC13
By this function, the temperature of the pipe 10'6 is maintained at the temperature TS, and freezing of sodium is prevented.

Here, as the PTC 13, it is necessary to select an element whose temperature Ts is somewhat higher than the freezing temperature of sodium.

In addition, according to this embodiment, the desired purpose can be achieved by adding only the PTC 13 and its cables to the conventional temperature control device, so compared to multiplexing the preheating control device 19, etc. It is very easy and economical.

Furthermore, the PTC 13 has both the capabilities of a detector and a controller, and the temperature of the pipe 10'8 is maintained at a substantially constant temperature, providing good controllability.

In addition, although the above embodiment describes the case where a microprocessor is used as the preheating control device, it can be similarly applied to the case where an analog controller is used. Although the explanation is given for the case where SSR is used, it goes without saying that it can be similarly applied even when an electromagnetic contactor is used.

[Effects of the Invention] As explained above, according to the temperature control device of the present invention,
Even in the event of a failure of the preheating control device, the sodium equipment, piping, valves, etc. in the high-speed Y1 breeder furnace can be maintained, and freezing of sodium can be prevented. Moreover, since it is only necessary to add the PTC and its cables to the equipment for this purpose, it is possible to achieve the excellent effects of a simple 14-side configuration and very good controllability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a dimensional diagram showing the characteristics of PTC, and FIG. 3 is a block diagram of a conventional temperature control device. 10...Piping 11...Temperature detector 12...Electric heater 13...PTC 14...Material 15...Preheating power supply device 16...Diode 17...5SR 18. ...Relay 19...Preheating control device: C゛1 21...On-off control section (7317) Agent: Patent attorney Noriyuki Chika (and 1 others)
Figure 1 D 14 Figure 2

Claims (3)

[Claims] (1) An electric heater and a temperature detector are installed on the object to be heated, and the temperature measurement value of the object to be heated detected by the temperature detector is inputted to the preheating control device and predetermined as the temperature measurement value. In the temperature control device, the temperature control device is configured to perform a comparison operation with a temperature set value obtained by the heating process, and to apply an on/off control signal to the opening/closing device of the electric heater according to the temperature difference. A heat-sensitive resistance element is installed, and when the preheating control device malfunctions and the temperature of the object to be heated falls below or below the temperature setting value, the heat-sensitive resistance element changes accordingly to turn on or off. A temperature control device characterized in that the temperature control device is configured to maintain the temperature of the object to be heated at the temperature setting value by applying a control signal to the opening/closing device. (2) The objects to be heated are fast breeder reactor sodium equipment, piping,
The temperature control device according to claim 1, which is a valve. (3) The temperature control device according to claim 1, wherein the heat-sensitive resistance element having positive temperature characteristics is a semiconductor having a composition such as barium titanate.