JPH08215680A - Desalting apparatus - Google Patents

Abstract

PURPOSE: To reduce the erroneous operation caused by the experience difference of an operator by attaching a water quality measuring device measuring a change in the quality of condensed water to the inlet of a condensed water desalting apparatus and detecting the fluctuations of inlet water quality at the time of the generation of a seawater leak to change over the operation system of a desalting column corresponding to a change in water quality. CONSTITUTION: A water quality measuring device 35 detects the fluctuations of the water quality at a condensed water inlet to transmit a signal to a control unit which in turn transmits a valve opening and closing signal to respective valves. That is, at first, the condensed water inlet and outlet valves 12d, 15d of a desalting column 13d standing by as a preparatory column are opened on the basis of signals 38d, 39d and the desalting column 13d is set to an H-OH type to start the supply of water. Next, the condensed water inlet and outlet valves 12a, 15a of the A-desalting column 13a large in integrated flow rate among desalting columns set to an NH4 type to permit water to pass are closed on the basis of signals 38a, 39a to stop the A-desalting tower 13a. Thereafter, a resin inlet valve 34a is opened by signals 46a, 46b and the H-OH type ion exchange resin 14e stored in a resin storage tank 32 to be held to a stand-by state is transferred to the A-desalting column 13a through a resin inlet pipe 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desalting apparatus for filling a desalting tower with a resin to remove impurities in a stock solution,
The present invention relates to a control device for changing the type of desalination device according to the quality of undiluted solution.

[0002]

2. Description of the Related Art For example, FIG.
Shown in In the figure, the steam generated in the boiler 1 rotates the steam turbine 2 and is condensed in the condenser 3 to be condensed water. After that, the condensate is boosted by the condensate pump 4 and purified by the condensate demineralizer 5, and then the condensate booster pump 6, the low pressure heater 7, the deaerator 8, the boiler feed water pump 9, the high pressure heater 1
After returning to 0, it is returned to the boiler 1 and becomes steam again for recycling.

Here, the water in the power generation equipment prevents damages caused by water quality such as corrosion and scale formation, and prevents accidents before they occur.
High water quality is required for highly efficient operation. For this reason, power generation equipment is equipped with a condensate demineralizer for the purpose of removing impurities. The condensate demineralizer comprises a desalination system shown in FIG. 4 and a regeneration system shown in FIG.

Condensed water whose pressure is increased by the condensate pump 4 is passed through the condensate inlet pipe 11 and the condensate inlet valves 12a to 12d to the ion exchange resins 14a to 14e in a mixed bed state of the cation exchange resin and the anion exchange resin. Lead to the packed desalting towers 13a-d. The ion exchange resins 14a to 14e remove impurities in the condensate according to the following principle.

Cation exchange resin

[0006]

Embedded image

Anion exchange resin

[0008]

Embedded image Here, R represents the matrix of the ion exchange resin, and Na + and Cl ⁻ were used as examples of impurities in the condensate.

For example, when the demineralization towers 13a to 13d are of four series, and three regular water passages and one tower preliminary operation are performed, at the time of resin regeneration,
When seawater leaks, the water flow is switched to the spare tower.

By passing water, impurities in the condensate are captured,
Ion exchange resins 14a to 14e having reduced ion exchange ability
Is transferred to the regeneration system shown in FIG. 5 and the cation exchange resin is regenerated with acid and the anion exchange resin is regenerated with alkali, and used again for purification of condensate. The regeneration principle of the ion exchange resin 14 is shown below.

Cation exchange resin

[0012]

Embedded image Anion exchange resin

[0013]

[Chemical 4] Here, R represents the matrix of the ion exchange resin, and sulfuric acid (H ₂ SO ₄ ) and caustic soda (NaOH) were used as examples of the acid and alkali.

When regenerating the ion exchange resins 14a to 14e having a reduced ion exchange capacity, the condensate inlet valve 12 and the condensate outlet valves 15a to 15d are opened to pass water to the preliminary column. The ion exchange resin 14 filled in the desalting towers 13a to 13d separated from the desalting system is transferred to the cation exchange resin 19 through the resin outlet pipe 18 by water and air. The ion exchange resins 14a to 14d transferred to the cation exchange resin 19 are separated into the anion exchange resin 20 and the cation exchange resin 21 by water and air from below, and the anion exchange resin 20 is transferred to the anion regeneration tower 24 in the anion exchange resin transfer pipe. Transfer via 22. Thereafter, the cation exchange resin 21 of the cation exchange resin 19 is the acid supplied from the acid inlet pipe 25, and the anion exchange resin 20 of the anion regeneration tower 24 is the alkali inlet pipe 27.
Each is regenerated by the alkali supplied from. The regenerated ion exchange resin is transferred to the resin storage tank 32 via the resin transfer pipe 31 and stands by until the next regeneration.

The operating system for removing impurities in the condensate using H-type cation resin and OH-type anion exchange resin is H-O.
It is called H type. According to this method, not only impurities in the condensate but also NH ₄ + added to the condensate for pH adjustment will be removed by the ion exchange resin 14. Here, the ion selective adsorption of the cation exchange resin is
The higher the valence, the larger the valence, and when the valence is the same, the higher the valence, the larger.
l ³ +> Ca ² +> Mg ² +, Cu ² +, Mn ² +> K +, NH ₄ +
> Na +> H +.

In this H-OH type condensate demineralizer, NH ₄ + added for pH adjustment starts to leak to the outlet of the desalting tower, and at the same time, due to the ion selective adsorption property of the cation exchange resin, Na + leaks to the outlet of the desalting tower without being captured by the ion exchange resin. Therefore, in the case of the H-OH type condensate demineralizer, it was necessary to carry out the resin regeneration about once every 4 to 7 days.

On the other hand, a system using an NH ₄ type cation exchange resin and an OH type anion exchange resin is called an NH ₄ type condensate demineralizer. This method performs H-OH type operation, after the cationic resin has captured the NH ₄ + of condensate water is a method for passing without capturing the NH ₄ + was added for pH adjustment with a cation exchange resin. The reaction formula of the ion exchange resin is shown below.

Cation exchange resin

[0019]

Embedded image

The advantages of this NH ₄ type condensate demineralizer are as follows.

(1) Since the NH ₄ type condensate demineralizer does not capture NH ₄ + added to the condensate for pH adjustment, the regeneration frequency is about 30 days / time, which is higher than that of the H-OH type. Long.

(2) By means of (1), the amounts of reclaimed chemicals, reclaimed water, and reclaimed wastewater can be greatly reduced.

Therefore, as an example of the operation of the recent condensate demineralizer, two of the three operating towers are NH ₄ type condensate demineralizers, and one is H- In many cases, it is used as an OH type condensate demineralizer.

When a seawater leak occurs in the condenser, a large amount of Na + and Cl ⁻ flows into the plant.
When operating in a NH ₄ type condensate demineralizer, the cation exchange resin is NH ₄ type (R-NH ₄ ), and a large amount is obtained from the ion adsorption selectivity NH ₄ +> Na + of the cation exchange resin. The Na + that has flowed into the column cannot be captured by the cation exchange resin, and will leak into the treated water. The leaked Na + in the condensate causes corrosion of the components inside the power generation facility.

When a seawater leak occurs during operation with the NH ₄ type condensate desalination unit, water is passed as 3 towers H type, but the procedure is 1 tower H-in consideration of seawater leak. OH
Type, 2 tower NH ₄ type is as follows.

(1) Start passing water through the preliminary tower (H type).

(2) Among the NH ₄ type demineralization towers, the tower with the largest cumulative water flow is stopped and regenerated. After recycling, it is transferred to the resin storage tank for standby.

(3) The preliminary resin in the resin storage tank is transferred to the demineralization tower emptied in (2), and water is passed (H type).

(4) Stop the demineralization tower operating with the remaining NH ₄ type and regenerate. The resin waiting in the resin storage tank during the regeneration is transferred to the desalting tower to pass water (H type).

(5) The resin regenerated in (4) is transferred to the resin storage tank and stands by until the next resin regeneration.

(6) Hereinafter, the operation is similar to that of the H-OH type condensate demineralizer.

Conventionally, since the operator manually performed the above-mentioned device, there was a potential to affect the soundness of the plant due to an erroneous operation caused by a difference in experience of the operator.

Further, in the prior art, there is also a method of bypassing the condensate demineralizer according to the inlet water quality as the operation control of the condensate demineralizer depending on the inlet water quality of the condensate demineralizer. This method bypasses the condensate demineralizer when the water quality at the condensate demineralizer inlet is equal to or higher than the outlet water quality,
While it is intended to prevent the exchange capacity of the ion exchange resin from being consumed and to reduce the frequency of regeneration of the ion exchange resin, the outlet when the water quality of the inlet of the condensate demineralizer changes, such as when a seawater leak occurs. No consideration was given to methods for maintaining water quality.

A device related to this type of device is, for example, Japanese Patent Publication No. 2-13758.

[0035]

The condensate demineralizer is installed for the purpose of removing impurities in the condensate. However, when a seawater leak occurs in the condenser cooling pipe, the operation type of the demineralization tower is changed. NH ₄
Since it was manually switched from the type to the H-OH type in order, it had a potential to affect the soundness of the plant due to an erroneous operation caused by a difference in experience of operators.

Further, the inlet water quality of the condensate demineralizer is monitored,
There was also a method of bypassing the condensate desalination equipment depending on the inlet water quality, but operation control when the inlet water quality fluctuates like seawater leak was not considered.

It is an object of the present invention to provide the same treatment when switching the operation type of the desalting tower when the water quality of the inlet changes, such as when a sea water leak occurs, regardless of the difference in the experience of operators. .

[0038]

In order to achieve the above object, the present invention provides a water quality measuring device for measuring a change in condensate water quality at the inlet of the condensate demineralizer, and changes in the inlet water quality when a seawater leak occurs. It was possible to switch the operation type of the desalination tower according to changes in the water quality at the inlet of the condensate desalination device.

[0039]

Operation When the inlet water quality is abnormal, such as when a seawater leak occurs, the desalting tower operation type switching control is performed by the water quality measuring device installed for monitoring the inlet water quality of the condensate demineralizer. As a result, it becomes possible to automatically open and close the condensate inlet / outlet valve of the desalting tower, the ion exchange resin transfer pipe, the valves installed in the acid and alkali inlet pipes, etc. to perform the resin transfer regeneration.

[0040]

EXAMPLE An example of the present invention will be described below.

The technical contents described above do not change. That is, the steam generated in the boiler 1 is sent to the steam turbine 2, condensed in the condenser 3, and then condensed in the condensate demineralizer 5.
There is no change in the basic configuration that is purified by and returned to the boiler 1.

In addition, the condensate shown in FIG.
From the dewatering tower 13 filled with the ion exchange resin 14 through the condensate inlet valve 12 to purify the condensate, and FIG.
Ion exchange resin 14 with reduced ion exchange capacity
Is transferred to the cation exchange resin 19 via the resin outlet valve 17 and the resin outlet pipe 18, and is separated into the anion exchange resin 20 and the cation exchange resin 21 by water and air, and the anion exchange resin 20 is replaced with the anion exchange resin inlet valve 23 and the anion. The cation exchange resin 19 is transferred to the anion regeneration tower 24 through the exchange resin transfer pipe 22, and the cation exchange resin 19 is regenerated with an acid and the anion exchange resin 20 is regenerated with an alkali.
The configuration of the regeneration system that transfers to 2 and stands by does not change.

Here, the difference from the prior art is that a condensate demineralizer condensate water quality measuring device 35 is installed at the condensate inlet of the condensate demineralizer, and the operation type of the demineralizer tower is automatically generated by this signal. That is what made it possible to do.

The embodiment shown in FIG. 1 is applied to a condensate demineralizer of a thermal power generation facility, and the structure is such that four desalting towers are used and three towers are regularly used (two towers NH ₄ type water passage). , 1 tower H type water flow), and 1 tower spare is explained as an example (NH ₄
It is assumed that the integrated flow rate of the desalting tower 13a and the desalting tower 13b passing through the mold is large in the desalting tower 13a. Also, in FIG.
The corresponding flow is summarized. ).

For example, when the condensate quality changes, for example, when a seawater leak occurs, a large amount of Na + and Cl ⁻ flows into the condensate, so that the electric conductivity of the condensate demineralizer inlet increases.

The water quality measuring device 35 at the inlet of the condensate demineralizer, which has detected that the water quality of the condensate inlet has changed, transmits the signal 36 to the controller 37. Control device 37 that received the signal
Transmits a valve opening / closing signal to each valve.

First, the desalting tower 1 which was on standby as a spare tower
The condensate inlet valve 12d and the condensate outlet valve 15d of 3d are opened by the signals 38d and 39d from the control device 37, and the demineralization tower 13d starts flowing water in the H-OH type.

Next, from the controller 37, the condensate inlet valve 12a and the condensate outlet valve 15a of the A desalting tower 13a, which has a large integrated flow rate, among the desalting towers that have been passing water of NH ₄ type, are controlled by the controller 37. Signal of
It is closed by 38a and 39a, and the A desalting tower 13a is stopped.

Here, the H-OH type water tower is the desalting tower 13
c and the desalting tower 13d, the NH ₄ type water tower is the desalting tower 13
b. In this operating state, Na + contained in the condensate
1/3 of the impurities such as will leak,
It is necessary to use another tower H-OH type operation.

Therefore, it is necessary to regenerate the ion-exchange resin 14a filled in the A desalting tower 13a to make it into an H-OH type. In order to regenerate the ion exchange resin 14a of the A desalting tower 13a, the resin outlet valve 17a is opened by the signal 40a from the control device 37, and transferred to the cation exchange resin 19 via the resin outlet pipe 18.

After that, the resin inlet valve 34a is opened by the signal 46 from the controller 37, and the resin inlet pipe 33 is opened.
The H-OH type ion exchange resin 14e, which was in the standby state after being filled in the resin storage tank 32, is transferred to the A desalting tower 13a.

Since the deionization tower 13a was filled with the ion exchange resin 14e which was in a standby state as a spare, the condensate inlet valve 12a and the condensate outlet valve 15a were opened by the signals 38a and 39a from the control device 37. , H for the desalting tower 13a
-OH type starts water flow.

After the A-demineralization tower 13a starts to collect water in the H-OH type, the condensate inlet valve 12b and the condensate exit valve 15b of the remaining desalting tower 13b during the NH ₄ type operation are signaled from the controller 37.
It is opened by 38b and 39b, and the desalting tower 13b is stopped.

From the above, the desalting towers 13a, 13 in operation
The c and 13d3 towers are all H-OH type operation, and the water quality at the outlet of the condensate demineralizer can be maintained.

After operating the three operating towers in the H-OH type, the ion exchange resin 14a and the desalting tower 13b in the regeneration system are used.
The ion exchange resin 14b of No. 1 is regenerated. This reproduction method remains unchanged. That is, the cation exchange resin 19
After the ion exchange resin 14a transferred to the water is separated into the anion exchange resin 20 and the cation exchange resin 21 by water and air due to the difference in specific gravity, the upper anion exchange resin 20 is passed through the anion exchange resin transfer pipe 22 to the anion regeneration tower 24. In the cation exchange resin 19, the acid inlet valve 26 is opened and the acid is injected through the acid inlet pipe 25 to regenerate the cation exchange resin 21. Similarly, in the anion regeneration tower 24,
The alkali inlet valve 28 is opened and alkali is injected through the alkali inlet pipe 27 to regenerate the anion exchange resin 20.

The cation exchange resin 21 which has been regenerated is transferred to the resin storage tank 32 through the resin transfer pipe 31 by opening the cation exchange resin outlet valve 29. Similarly, the anion exchange resin 20 after the regeneration is replaced with the anion exchange resin outlet valve 30.
Is opened and the resin is transferred to the resin storage tank 32 through the resin transfer pipe 31.

The ion exchange resin transferred to the resin storage tank 32 stands by until the next regeneration.

According to the present embodiment, when the inlet water quality changes, such as when a seawater leak occurs, the condensate demineralizer operation type control can be automatically performed, the outlet water quality can be maintained, and the equipment in the plant can be corroded. Factors can be reduced.

Further, there is an effect such that the erroneous operation potential due to the difference in the experience of the operator is reduced and the burden on the operator is lightened.

[0060]

EFFECTS OF THE INVENTION According to the present invention, it is possible to automatically switch the operation type of the desalination device when the quality of the inlet water changes, such as when a seawater leak occurs, by a water quality measuring device installed at the inlet of the desalination device. As a result, it is possible to reduce erroneous operations due to differences in operator experience, and to ensure the integrity of the plant when the quality of inlet water deteriorates, such as when a seawater leak occurs.
Reduce the burden on operators.

[Brief description of drawings]

FIG. 1 is a system diagram of a condensate demineralizer capable of automatically switching operation types by a condensate demineralizer measuring device.

FIG. 2 is a flowchart of a condensate desalination apparatus when the water quality of the inlet changes.

FIG. 3 is a schematic system diagram of thermal power generation equipment.

FIG. 4 is a desalination system diagram of a condensate demineralizer.

FIG. 5 is a regeneration system diagram of the condensate demineralizer.

[Explanation of symbols]

11 ... Condensate inlet pipe, 12a-d ... Condensate inlet valve, 13a-
d ... desalting tower, 14a to e ... ion exchange resin, 15a to d
... condensate outlet valve, 16 ... condensate outlet pipe, 17a-d ... resin outlet valve, 18 ... resin outlet pipe, 19 ... cation exchange resin, 2
0 ... Anion exchange resin, 21 ... Cation exchange resin, 22
... anion exchange resin transfer pipe, 23 ... anion exchange resin inlet valve, 24 ... anion regeneration tower, 25 ... acid inlet pipe, 26 ...
Acid inlet valve, 27 ... Alkali inlet pipe, 28 ... Alkali inlet valve, 29 ... Cation exchange resin outlet valve, 30 ... Anion exchange resin outlet valve, 31 ... Resin transfer pipe, 32 ... Resin storage tank, 3
3 ... Resin inlet pipe, 34a-d ... Resin inlet valve, 35 ... Water quality measuring device, 37 ... Control device.

Claims (2)

[Claims] 1. A desalting apparatus having a desalting tower filled with an ion exchange resin, and having a function of removing impurities in a stock solution by the resin filling the desalting tower, wherein the water quality at the outlet of the desalting tower The desalination apparatus is characterized in that the operation type of the desalination tower is switched according to the quality of the undiluted solution in order to keep the value below the standard value. 2. The desalination apparatus according to claim 1, wherein a water quality measuring device is provided at the inlet of the desalting tower, and the operation type of the desalting tower is switched according to the water quality at the inlet of the desalting tower.