JPH01218612A - Controller for filters - Google Patents

Abstract

PURPOSE:To stabilize a filtration performance by making flow rates through individual condensate filters differ stepwise one another from the beginning of an operation and by changing them automatically in sequence. CONSTITUTION:Flow rate controlling devices 2a-2d for changing flow rates through respective filters 1a-1d, pressure drop detecting devices 3a-3d for detecting pressure drops between inlets and outlets of respective filters, pressure drop setting device 4 for sending out a signal when a detected pressure drop exceeds a prescribed value and an alarm device 5 for sending out an alarm when a pressure drop signal reaches a set value are installed. An adder 7 adds up signals from a plurality of flow rate detecting devices 6a-6d, and a controller 8 sends out signals for individual filters after multiplying respective biases stepwise to a deviation from an average of the outputs from the adder 7 to a set value of flow rate given by others. Furthermore, a signal selection device 10 not only repeats these output signals from the device 8 but also stops them and changes the biases according to the input signals from the device 4, and higher value priority circuits 11a-11d controls the flow rate controlling devices 2a-2d according to respective higher values between the output signals from the device 10 and the device 4.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention is intended to appropriately control the cleaning timing of a plurality of filters during operation in a condensate filtration system used in, for example, a nuclear power plant. The invention relates to a device that controls the

(Prior art) In conventional condensate filtration systems in nuclear power plants, etc., multiple filters are operated simultaneously in parallel, and the filters in each series are controlled so that their water flow rates are approximately equal. Also, in order to prevent the continuous flow of condensate from being interrupted during the regeneration operation of the filter, a bypass line is installed for passing water at a flow rate of one or more filters. However, the adhesion of substances to each filter,
Because it varies depending on the plant operating conditions, filter piping, etc., each filter does not have a regular cleaning period, and if the pressure difference between the inlet and outlet of the filter exceeds the specified value within each series. An operating method was used in which an alarm was displayed, the operator took the filter out of operation, regenerated it by cleaning, and then put it back into operation.

(Problem to be Solved by the Invention) However, in the conventional method described above, as shown in the characteristic diagram of FIG. This happens from time to time, and if each purification process is carried out, it becomes difficult to secure a predetermined condensate flow rate, and in some cases, the filtration operation may be temporarily interrupted. Therefore, operators must constantly monitor the differential pressures of a large number of filters, which places a heavy burden on the operators.

[Structure of the invention] (Means for solving the problem) A plurality of filters are installed in parallel, and this control device includes a flow rate detection means, a flow rate adjustment means for changing the amount of water flowing through the filters, A differential pressure detection means that detects the differential pressure between the inlet and outlet of the filter, a differential pressure setting means that issues a signal when these signals exceed a predetermined value, and an alarm that issues an alarm when the differential pressure signal reaches the set value. An alarm means for issuing an alarm, an adder for adding up the signals from the plurality of flow rate detection means, and a bias is applied in stages to the deviation between the average of this output and the flow rate set value given by the others, and the difference is determined for each filter. a signal selection means for relaying these output signals and stopping the output signals and sequentially changing the bias setting by a pano signal from the differential pressure setting means; A high value priority circuit is provided for controlling the flow rate adjusting means based on the high value of the signal with the differential pressure setting means.

(Function) Since the water flow rates of multiple filters are gradually different from the beginning, the amount of matter to be removed, that is, the time for purification and regeneration is reached, is naturally determined in a predetermined order, and the time for regeneration is also determined. The operator will be notified. Even after switching to the standby unit, the water flow rate is automatically set for each filter in the correct order, and the water flow rate of the filtration system is also adjusted, so there is no need to worry about large fluctuations in the processing function of the filtration system. Since this does not occur and the regeneration timings do not overlap, there is no need to interrupt operation.

(Example) An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram, in which flow control valves 2a to 2d for adjusting the water flow rate are connected in series to each of a plurality of condensate filters 1a to 1d, and connected in parallel to each other. Condensate filter 1a-1
Differential pressure transmitters 3a to 3 for detecting pressure differences at the input and outlet of d.
d, and input this output signal to the signal converter 4 and alarm setting device 5. The signal converter 4 connects each condensate filter 1a to 1
The signal selection device 1 selects only the signal exceeding the set value within the differential pressure of d.
0 and is output to the high value signal priority circuits 11a to 11b. Flow rate transmitters 6a to 6d are installed at the inlets of the condensate filters 1a to 1d, respectively.
are connected to measure the flow rate, and these output signals are output to the flow rate adder 7.

The signal added by the flow rate adder 7 is manually input to the flow rate regulator 8,
The deviation from the averaged and separately given flow rate setting value 9 is applied with a bias set in advance in stages, and each is applied to the signal selection device 1.
Output to 0. The signal) selection device 10 outputs these signals to the high value signal priority circuits 11a to 11d, respectively, or receives a signal from the signal converter 4 indicating that the differential pressure exceeds the set value. ~1d high value signal priority circuits 11a~11
It has the function of stopping the signal to d and sequentially changing the distribution of bias signals. High value signal priority circuit 11
a to 11d input the output of the signal selection device 10 and the signal from the signal converter 4, select one of the high value signals, and select the flow rate control valve? Electropneumatic converters 12a to 12 that drive a to 2d
Output to d. An alarm display 13 is connected to the alarm setting device 5, and when the differential pressure signal input exceeds a set value, the alarm display 13 issues an alarm. The inlets and outlets of the condensate filters 1a to 1d are provided with artificial valves and outlet valves (not shown), cleaning piping for regeneration operation, on-off valves, and the like. The configuration in which there are four condensate filters 1a to 1d has been described above; however,
In this case, normally the three condensate filters 1a to 1C are in operation, and one condensate filter 1d is kept on standby as a standby with its population valve and outlet valve closed.

The effects of the above configuration will be described. Condensate filter 1a
The amount of water flowing through each of the third bases of ~1C is detected by flow rate transmitters 68~6C, summed by flow rate adder 7, and calculated by flow rate regulator 8.
is man-powered. The flow rate regulator 8 outputs a signal @3 to the plate selection device 10 based on the deviation between the average of this signal and the flow rate setting value 9.
For example, a bias corresponding to the flow rate control valve openings such that the flow rates of the condensate filters 1a, lb, and 1C become 90%, 80%, and 70%, respectively, is applied to the two signals. Normally, the signal from the flow rate regulator 8 enters the electro-pneumatic converters 12a to 12c via the high value signal priority circuits 11a to 11c, and flows through the flow rate control valve 2a.
Adjust the opening degrees of ~2c to 90%, 80%, and 70% settings, respectively. Note that the flow rate control valve 2d is closed because there is no signal from the signal selection device 10, and no condensate flows to the condensate filter 1d, so signals from the flow rate transmitter 6d and the differential pressure transmitter 3d are also generated. do not.

When filtering condensate, etc., the amount of substances to be removed is proportional to the amount of water flowing through, so first, a large amount of substances to be removed is accumulated in the condensate filter 1a set at 90%, and the differential pressure becomes high. This is signal converter 4
When the differential pressure exceeds the set value, the signal converter 4 outputs a signal indicating that the differential pressure of the condensate filter 1a is exceeded to the signal selection device 10 and the high value signal priority circuit 11a.

As a result, the signal selection device 10 selects the high value signal priority circuit 11a.
For the high value signal priority circuits 11b and 110, the bias signals are changed to 90% and 80%, and a signal with a bias of 70% is output to the high value signal priority circuit 11d. Therefore, the flow control valve 2a becomes 100% open, and the opening signals to the flow control valves 2b and 2C12d are output with biases of 90%, 80%, and 70%, respectively. Note that even if the operating number of condensate filters or the respective flow rates change, the flow rate transmitters 6a to 6d, the flow rate adder 7, and the flow rate regulator 8
Adjust the condensate flow rate to the specified value. Therefore, since the flow rate control valve 2a is fully opened, the flow rate of the other condensate filters 1b and 1C decreases, so the flow rate of the condensate filter 1a increases compared to before, and as a result, the flow rate of the condensate filter i1a increases. The amount of trapped material increases, the differential pressure becomes higher, and the regeneration operation time is brought forward.

When the differential pressure reaches the set value of the alarm setting device 5, the alarm indicator 13
issues an alarm and notifies the operator that the regeneration period of the condensate filter 1a has arrived.

When the operator confirms the need for purification and regeneration operation, the operator closes the artificial valve and outlet valve (not shown) of the condensate filter 1a, disconnects it from the filtration system, and performs the regeneration operation, and also closes the inlet valve and outlet valve of the spare condensate filter 1d. Open the valve and incorporate it into the filtration system □
Set it to operating condition. As a result, the differential pressure signal of the condensate filter 1a stops, and the condensate filter 1d is connected to the other condensate filters 1b, 1.
It is operated at a flow rate with a bias of 70% and a bias of 90% and 80% of c.

Figure 2 is a characteristic diagram showing the operation pattern, and each condensate filter 1
For a to 1d, the timings at which the differential pressure reaches the upper limit do not match with each other, and naturally the regeneration operations are performed at approximately equal intervals. Therefore, there will be no reduction in the total processing capacity of the filtration system or interruption of operation due to concentration of regeneration periods.

[Effects of the Invention] According to the present invention, the flow rates for each condensate filter at the same time are made different in stages from the beginning of operation, and this is automatically switched sequentially, so that the reserve equipment can be used. In addition to the application, the regeneration times of the condensate filters do not coincide with each other, and the intervals between regeneration operations are approximately unified, so the filtration function is stabilized and reliability is improved, and the operation, regeneration, Maintenance management can be carried out in a planned manner and has the effect of reducing the burden on operators.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is a characteristic diagram of an operating pattern, and FIG. 3 is a characteristic diagram of an operating pattern of a conventional device. 1a to 1d...Condensate filter 2a to 2d...Flow rate control valves 3a to 3d...Differential pressure transmitter 4...Signal converter 5...Alarm setting device 6...
・Flow rate transmitter 7...Signal adder 8...Flow rate regulator 9...Flow rate setting value 10...Signal selection device 11a-11d...High value signal priority circuit 13...Alarm indicator

Claims (1)

[Claims] In a control device that performs parallel simultaneous operation of a plurality of filters for filtering waste liquid, turbine condensate, etc., a flow rate detection means;
A flow rate adjustment means that changes the amount of water flowing through the filter, a differential pressure detection means that detects the differential pressure between the inlet and outlet of the filter, a differential pressure setting means that issues a signal when this signal exceeds a predetermined value, an alarm means that issues an alarm when the pressure signal reaches a set value; an adder that adds the signals from the plurality of flow rate detection means;
A regulator that outputs a signal for each filter by applying a bias in stages to the deviation between the average of this output and a flow rate setting value given from another, and a regulator that relays these output signals and the differential pressure setting means. and a signal selection means for stopping the output signal and changing the bias setting in response to an input signal from the differential pressure setting means, and a high value priority circuit for controlling the flow rate adjustment means based on the high value of the signal between this output signal and the differential pressure setting means. A filter control device characterized by variable control of cleaning timing of a filter.