JPS6057399B2 - Demineralizer group control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a demineralizer group control device, and more particularly, to one that controls the cycle of regeneration work in a condensate demineralizer in a nuclear power plant.

Water used in nuclear power plants must be maintained at a particularly high level of purity, and solids and ions in the inlet water are usually removed by a condensate demineralizer.

There are multiple condensate demineralizers installed, but one of them is on standby while it is in use. The one in the standby state is for continuous operation by switching when backflowing or regenerating the one in use.

Backflow is the process of cleaning the demineralizer with water when solid matter adheres to it and the differential pressure between the inlet and outlet increases. In addition, regeneration is an operation performed using chemicals when the amount of ions processed by the demineralizer increases and its performance deteriorates, and a backflow process is also performed. Here, the ion throughput is often determined by the product of the ion concentration difference at the inlet and outlet and the amount of water passing through the demineralizer. Regeneration is performed with sulfuric acid and caustic soda, and the regeneration waste liquid is sent to the liquid waste treatment system. Recycled waste liquid contains a large amount of sodium sulfate, so it is mainly treated with a concentrator. If the operating conditions of the power plant are maintained constant, the ion concentration of the condensate demineralizer inlet liquid will be constant, but if, for example, seawater for cooling is mixed in from the condenser, the inlet The ion concentration of the liquid increases.

In this case, the ion throughput of the demineralizer increases, the regeneration cycle becomes short, and furthermore, unless the operating method of the standby demineralizers is taken into account, it is conceivable that two or more demineralizers will be regenerated at the same time. Concentrators in liquid waste treatment systems typically have low throughput rates, and the combined waste generation not only requires significant effort, but may also delay the reclamation operation by several days.

To avoid this, there is a method of increasing the throughput of the concentrator. This method requires an increase in the heating boiler capacity and installation area, and also reduces the utilization rate during normal operation, making it difficult to achieve a significant increase. The present invention was developed in view of the above points, and it controls the operation of desalination equipment to prevent regeneration from occurring in two or more units at the same time, so that the regeneration work can be carried out smoothly, and the liquid waste treatment system can be operated efficiently. The purpose of the present invention is to provide a demineralizer control device that can perform the following steps. The present invention is based on Invention 1 Demineralizer group control device J (Japanese Patent Application No. 49-93421 (Japanese Patent Publication No. 47228)) by the same inventor.
This is an improvement to the operation method when seawater gets mixed in. When the ion concentration of the demineralizer inlet liquid becomes high, regeneration work becomes the main activity and backwashing work is no longer performed. in this case,
``The demineralizer with the second highest ion throughput in the demineralizer group is put on standby to delay regeneration, so that regeneration work does not overlap with two or more units. Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

Figure 1 shows the configuration of the main steam condensate system and regenerated waste liquid treatment system of a nuclear power plant.

The former system is constructed by sequentially connecting a nuclear reactor 1, a steam turbine 2, a condenser 4, a condensate demineralizer 5, 6, 1, and a feed water pump 8. The latter system is constructed by sequentially connecting a resin regenerating device 9, a waste liquid collection tank 10, and a waste liquid processing device 12. Furthermore, the former system has switching valves 14, 15, 1.
6, Flowmeter 17, 18, 19, Conductivity meter 20, 21, 2
2, 23, 24, and 25 are connected. The control device 26 connects the signal line 27 to the switching valve, flowmeter, and conductivity meter.
, 28, . . . 38. The conductivity meters 20, 21, 22, 23, 24, 25 are the condensate demineralizer 5
, 6 and 7 are used to detect the electrical conductivity on the inlet side and outlet side. Flowmeters 17, 18, and 19 are for detecting the processing flow rate. The control device 26 stores the states of the condensate demineralizers 5, 6, and 7 by comprehensively calculating the above detection results, and puts the demineralizer with the second highest ion throughput on standby. ．． It controls the operation. This control device 26
The switching valves 14, 15, and 16 are controlled by the output. A generator 3 is connected to the steam turbine 2. Next, the control device 26 will be explained based on FIG. 2.

The control device 26 includes timer devices 40, 41, an ion throughput calculation device 42, arithmetic devices 43, 44, . . . 49, and a valve switching device 50. Signal lines 30, 31, . . . , 38 are connected to the ion throughput calculation device 42, and signal lines 27, 28, 29 are connected to the valve switching device 50. Terminals 51, 52 and connection lines 53, 54 are connected to the computing devices 43, 46. Terminals 51 and 52 are a regeneration start ion processing amount set value and a set value for seawater contamination determination. Next, the effect will be explained.

The steam generated in the reactor 1 powers a steam turbine 2 and is then liquefied in a condenser 4, and this water is passed through a desalination machine 5.
, 6, 7.

Water is then supplied to the reactor 1. Water used in nuclear reactors must be purified to a particularly high degree of purity, and condensate desalination equipment 5,
In 6 and 7, ions and cladding in water are mainly Fe2O3.
However, in order to maintain the specified performance, the demineralizer 5
, 6, 7 is sent to a resin regenerating device 9 as appropriate for backwashing or regeneration work. When the amount of ions to be processed increases rapidly due to seawater contamination, etc., regeneration work becomes the main task. The waste liquid at this time is collected in a waste liquid collection tank 10, then purified in a waste liquid treatment device 12, and then sent to a condensate storage tank 13.
Next, the operation of the control device 26 will be explained. FIG. 2 shows the configuration of the control device 26, and FIG. 3 shows the operating procedure, which becomes a subprogram when executed by a control computer. Flow meters 17, 18, 19 and conductivity meters 20, 21, .
. . 25 are input to the Io7 throughput calculation device 42 via signal lines 30, 31, and 38.

Here, the difference in conductivity between the inlet and outlet sides of each demineralizer is multiplied by the flow rate and added to the past value to obtain the integrated value of the ion throughput. When converting the amount of treated ions into calcium carbonate, the relationship shown in FIG. 4 is used to correct the amount. This is step A in FIG. The calculation results are sent to arithmetic units 43, 44, and 45 via a switch 41 operated by a signal from a timer 40 that generates a signal at a constant cycle. Arithmetic unit 4
In 3, the playback start time is predicted as follows, and the signal line 5 is
Output to 3. In FIG. 5, it is assumed that the current time is PO, and the ion throughputs of the demineralizers 1 and 2 are Ql and Q2. P
Suppose seawater contamination occurs in step 1, and if this situation continues,
The reproduction start time is time point P2 after t1. When using a computer, it can be calculated by statistically processing data from the past few days. This is step B. Arithmetic device 44
Now, calculate the changes in the ion throughput of each desalter and find the average value. This is step C. The arithmetic unit 46 compares the set value E<5i and makes the following determination. This is step D. b<ξ Normal operation,
No seawater contamination, etc. i≧ξ Seawater contamination, etc. is possible.

If i<ε, a signal is sent to 54 to leave the demineralizer operating as is, and if i≧ε, a signal is sent to arithmetic units 48, 49.

The arithmetic unit 48 calculates the leakage amount of seawater or the like from the conductivity and flow rate and outputs it to the signal line -53. This is step E. The arithmetic unit 45 selects the demineralizer with the second largest ion throughput in the demineralizer group, and in step F, the arithmetic unit 49 determines whether or not it is on standby. This is step G
It is. When it is on standby, it is output to the signal line 54 and the demineralizer continues to operate, but when it is in use, it is output to the signal line 54, but when it is in use, it is output to the signal line 54.
sends a signal to put it on standby. This is step H. Note that the standby state of the demineralizers can be established by checking the flow rate of each demineralizer, and is performed by the arithmetic unit 47. Next, an example of controlling the operation of the four condensate demineralizers 1, 1, 2, and 2 will be described with reference to FIG.

In the figure, TA is the time required for reproduction, and T8 is the period at which the operation of the present invention is performed. Specifically, the timer 40 in FIG.
is the period at which a signal is issued to the switch 41. Now, in the initial stage of operation of condensate demineralizer 1,■,■,■,
Consider the case where the ion throughput of , ■ is almost equal. Bl,
At points B2 and B3, the demineralizer with the second highest ion throughput is on standby. At point A1, the ion processing amount of the demineralizer 1 reaches the regeneration start amount Rt, and the demineralizer 1 enters a standby state for regeneration. Furthermore, at point B, the desalter with the second highest ion throughput is placed on standby. By repeating the above operations, the conventional situation in which the demineralizers 1, 1, 2, had to be intensively re-extracted near the A1 point is dispersed to Al, to A8.

Although backwashing is not shown in the characteristics shown in Figure 6,
This is because when seawater is mixed in, the main activity is regeneration work, and the regeneration work also includes a backwashing process. In the embodiment, there are three condensate demineralizers 5, 6, and 7, but even if this number changes depending on the power plant, the present invention can be implemented according to the number.

According to the present invention, the regeneration timing of the desalter is dispersed even when seawater is mixed in, so the regeneration work can be carried out smoothly.

Furthermore, since the timing of resin regeneration can be determined, operations can be carried out efficiently, such as by preparing for acceptance in advance.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the system of a nuclear power plant, Fig. 2 is a block diagram showing the control device of the present invention, Fig. 3 is an explanatory diagram showing its operation, and Figs. 4 and 5 are each arithmetic device. FIG. 6 is an explanatory diagram of the operating characteristics of the control device. 5...Condensate demineralizer, 14...Switching valve,
17...Flowmeter, 20...Conductivity meter, 23
... Conductivity meter, 26 ... Control device, 42
...Ion throughput calculation device, 43-49...
... Arithmetic device, 50 ... Valve switching device.

Claims (1)

[Scope of Claims] 1. A plurality of condensate demineralizers, a switching valve provided at the inlet of each demineralizer to switch its use, and a switching valve provided between each demineralizer and the switching valve. a conductivity meter and a flow meter, a conductivity meter provided at the outlet of each demineralizer, and the conductivity meter,
The demineralizer is characterized by comprising a control device that calculates each output of the flowmeter and switches and controls the switching valve so that the demineralizer with the second highest ion throughput is placed on standby based on the calculated output. Salt ware group control device. 2. In the apparatus according to claim 1, the control device comprises a device that calculates the ion throughput of each demineralizer based on the conductivity and flow rate of the inlet and outlet liquids of each demineralizer, and a device that calculates the ion throughput of each demineralizer per unit time. The demineralizer is characterized in that it is comprised of a device for determining the increased amount of ion processing and comparing it with a set amount, and a device for placing the demineralizer with the second highest ion throughput in the demineralizer group in a standby state. Salt ware group control device.