JPS5851226B2 - Microwave oven - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a range switching device for a nuclear reactor power monitoring device used to measure the power of a nuclear reactor.

FIG. 1 shows a block diagram of a conventional range switching circuit.

In the figure, 1 is an ionization chamber for measuring the neutron flux of the nuclear reactor, 2 is a rotary switch for changing the range, 3 is an amplifier, 4 is a recorder, and 5 is a reactor safety circuit.

In nuclear reactors, neutron detection equipment is installed inside the reactor to measure the output.

In the above neutron detection equipment, when starting or stopping the reactor, the reactor output varies over a very wide range from several milliwatts to several tens of megawatts, so the operator must manually turn off the range switch (rotary switch). In addition, the output is monitored by a recorder 4.

Note that the recorder 4 is equipped with a limit switch that indicates the upper and lower limits of the output, and if the range switching is delayed and these limit values are exceeded, the reactor safety circuit 5 is activated.

In this case, when the upper limit of the recorder 4 is reached in each range, the reactor is scrammed (emergency shutdown).

Therefore, range switching operations during reactor startup and shutdown, including the possibility of rapid increases and decreases in output, require prompt and accurate operation to prevent the risk of reactor scram due to erroneous operation. It will be very burdensome for them.

In order to solve the above problems, the present invention prevents reactor scram caused by erroneous operation when switching ranges,
The present invention provides a reactor power monitoring device that reduces the burden on operators when switching ranges.

In order to achieve the above object, the present invention includes a comparator in addition to the conventional device, and compares the output signal from the recorder with upper and lower limit values set in the comparator.

This will cause an alarm indicator lamp (for example, an illuminated pushbutton switch that combines a lamp and a pushbutton switch) to flash when the output signal value exceeds the above limit value, indicating that a range change is necessary. Inform the operator.

The operator simply presses a flashing pushbutton switch to complete the operation, which changes the range, thereby avoiding reactor scrams caused by erroneous operation and reducing the burden on the operator.

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 2 shows a block diagram of a range switching device according to the invention.

In the figure, 1 is an ionization chamber that measures the neutron flux of the nuclear reactor, and 10 is a relay 20a.

20b...20n respectively operate range switching circuits, 11 is an amplifier, 12 is an indicator, and 13 is a comparator that compares the output of the reactor with a preset limit value.

Also 15a and 17a. 15b and 17b are illuminated pushbutton switches for upper and lower limits, respectively.
17a and 17b are each of the above-mentioned pushbuttons, and are an alarm display lamp that lights up when the reactor output exceeds the alarm level at a given level, and a pushbutton that the illuminated operator confirms and operates. These are switch contacts that operate respectively.

Furthermore, 18 is a left-right shift register that shifts left and right one bit at a time by opening and closing switch contacts 17a and 17b, 23 is a reactor safety circuit (trip circuit) that protects the reactor from erroneous operations by operators, and 24 is a nuclear reactor safety circuit (trip circuit). This is a blocking device that prevents range switching to prevent the furnace output from increasing beyond a predetermined range.

Below - As an example, if the reactor power is set to range switching circuit 10
The operation of this device will be explained when the device is in the range corresponding to the switching contact 10C.

In this state, 1'' is set in the digit 18c of the left-right shift register 18, and the contact 10c of the range switching circuit 10 is closed.

In addition, in the range switching block device 24, as will be described later, the switch 24 is
Suppose that b is closed.

Furthermore, in the comparator 13, the lower limit value is 10% and the upper limit value is 80%.
% and the trip level are respectively set to 90%.

Consider the case where the reactor output increases at this point.

In this case, when the reactor power reaches 80% or more, the ionization chamber 1 is added via the range switching circuit 10 and the amplifier 11.
The output signal of is compared with each limit value by a comparator 13,
The upper limit alarm signal 104a is connected to the AND gate circuit 16a.
At the same time, the ``HIGH'' alarm indicator lamp 15a blinks to notify the operator of the need to change the range.

As mentioned above, 15a and 15b are the display part and pushbutton of the illuminated pushbutton switch, and the operator presses the "HIGH" button on 15a.
``As the display lamp flashes, when the push button is pressed, the switch contact 17a closes, and the signal ``1'' is output to the AND gate 16.
sent to a.

On the other hand, the input signal 110 of the anime game N6a becomes "O" only when the digit 18b of the left-right shift register 1B becomes 1", so the signal level at this time is "II+".

The output of switch contact 17a is thus added as shift signal 106a to left-right shift register 18, and the contents of the left-right shift register are shifted one place to the right.

In other words, the content of 18c changes from "1" to ff O11,
The content of 18b changes from "091" to "1".

At this time, the output signal from the digit 18b is amplified by the amplifier 19b, operates the relay 20b, and closes the corresponding contact 10b of the range switching circuit 10.

On the other hand, the digit of register 18c changes to "O" and relay 2
0c is non-excited, so the contact 10c of the range switching circuit 10 is open.

The above operations complete range switching due to the reactor output exceeding the upper limit.

When the reactor output falls below the lower limit of a certain range, the lower limit alarm signal 104 from the comparator 13 is sent as described above.
b causes the "LOW" alarm indicator lamp 15b to flash, notifying the operator that it is time to change the range.

When the operator recognizes this and presses the push button 15b, contact 1
7b is closed, a shift signal 106b is applied to the left-right shift register 18, and its contents are shifted one place to the left, completing the range switching.

In this case, if switch contacts 17a and 17b were not provided, it would be possible to automatically switch the range when the reactor output reached the alarm level, but these contacts were forced to be provided for the following reasons. .

In other words, when the output fluctuates greatly, such as when starting or stopping the reactor, the operator presses the HIGH or LOW button and at the same time reads the indicator installed in the operation panel and confirms the output. The reason for this is to further enhance the safe operation of nuclear reactors.

Next, the block device 24 that prevents range switching will be explained.

Now, in the block device 24, the switch 24 is set by inserting a setting pin for preventing range switching.
Suppose that b is closed.

As a result, the signal 107 becomes "1".

When the reactor power increases and the digit 18b of the left-right shift register becomes "1'', the output 109 of the AND gate 25
The signal becomes '1'', which is inverted by the inverter 27, and the signal becomes '1''.
10 becomes "0'" and closes the AND gate 16a.

As a result, sending the shift signal 106a to the left-right shift register 18 is prohibited, and shifting in the right direction is prohibited.

Therefore, if the reactor output reaches 80% or more at the position of switching contact 10b of the range switching circuit, the operator
Even if the push button 53 is pressed and the switch contact 17a is closed, the range will not change.

Therefore, when the reactor output reaches the preset block level and increases further, the comparator 13 generates the trip signal 112 and the reactor safety circuit 23 is activated to trip the reactor and ensure safety. I will keep it.

Note that the trip signal 112 is generated when the HIGH alarm indicator lamp 15a is blinking in each range and the reactor output reaches the trip level set in that range without the operator paying attention to this.

Further, in this case, although the operator is notified of the necessity of changing the range only by blinking the alarm indicator lamp, it is also possible to add an alarm device such as a buzzer to this.

AND gates 16a, 16b, 15a.

If the alarm display lamp 15b is not displayed, the shift signal 106a is not displayed even if the push button is pressed.

106b from being sent to the left-right shift register 18.

Further, the initial value of the left-right shift register 18 is set by a reset signal 100.

This signal is sent by operating a reset switch (not shown) as described later, and as a result, the rightmost digit 18a of the left and right shift register 18 becomes "1", and the range is set to the highest position. .

FIG. 3 shows an operation panel incorporating the indicator 12, an alarm indicator lamp, an illuminated pushbutton switch consisting of pushbuttons 15a, 15b, and switch contacts 17a, 17b, and a block device 24 in FIG. 2.

In the figure, 200 is an indicator that displays the output value of the reactor, which is 10%.

The parts indicating 80% and 90% are marked with “L” respectively.
OW” HIGH” “TRP” are written.

In addition, 201 and 202 each have "LOW" on the surface.
and HIGH” are illuminated pushbutton switches with alarm indicator lamps and pushbuttons 15a and 1 shown in FIG.
5b and switch contacts 17a and 17b.

Reference numeral 203 denotes a projection display tube that displays the range, which is switched by the range switching circuit 10 shown in FIG. You can know the current reactor output value from.

204 shows a pin hole when the setting pin insertion method is used as a block device for range switching, and by inserting a setting pin to prevent switching into the pin hole corresponding to a predetermined range, high output beyond that range can be achieved. If the output increases further, the reactor will be scrammed.

Furthermore, 205 is a reset push button switch, which is incorporated into the indicator 12 in FIG.

As explained above, according to the present invention, when changing the range, the operator is notified of the operation, and the operator completes the range changing operation by simply pressing the displayed push button switch, and the operator receives instructions for changing the range. Since there is no need to take into account the instructions of the reactor, it is possible to prevent reactor scrams caused by erroneous operation and to greatly reduce the burden on operators when switching ranges.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional range switching circuit, FIG. 2 is a connection diagram of an embodiment of the present invention, and FIG. 3 is a front view of an operation panel. 1: Ionization chamber, 2: Rotary switch, 3: Amplifier, 4:
Recorder, 5: Reactor safety circuit, 10: Range switching circuit, 10a, 10b...10n: Switching contact, 1F = amplifier, 12: Indicator, 13: Comparator, 15
a: "HIGH" alarm indicator lamp and pushbutton, 15b = "LOW" alarm indicator lamp and pushbutton, 16a. 16b: AND gate, 17a, 17b: switch contact, 18: left-right shift register, 19a. 19b...19n: Amplifier, 20a, 20b.
...20n: Relay, 23: Reactor safety circuit, 2
4 Niblock device, 24a, 24b...24n
: Switch, 25: AND gate, 100: Reset output signal, 104a, 104b: Alarm signal, 106a
, 106b: Shift signal, 107: Block signal, 11
2 Nitrite signal, 200: Meter, 20L202: Illuminated push button switch, 203: Projection display tube, 204 Niblock bottle hole, 205: Reset push button switch.

Claims (1)

[Claims] 1. In an indicating device that requires range switching when the human power value reaches a predetermined limit value, a comparator that compares the input value with the limit value, and an indication when the input value exceeds the limit value in the comparator a display device for switching the range of the indicating device, a switch device for switching the range of the indicating device, and means for preventing the indicated range of the indicating device from being switched when the input value to the comparator does not exceed the limit value. A range switching device characterized by being provided with.