JP2968901B2 - Makeup water production equipment for power plants - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing makeup water for steam turbines of thermal power plants or nuclear power plants, and more particularly to an apparatus for producing makeup water from which organochlorine compounds have been removed.

[0002]

2. Description of the Related Art In a conventional make-up water production system for a steam turbine, removal of organic compounds, especially organic chlorine compounds, is carried out by the following method.
For example, some volatile substances such as trihalomethane are subjected to aeration in a decarbonation tower or vacuum deaeration tower, and some non-volatile substances such as humic acid and pesticides are aggregated and precipitated, filtered, activated carbon adsorption and ion exchange. Has been removed. But,
The conventional make-up water production apparatus cannot completely remove these organic compounds and organic chlorine compounds, and has a TOC of 30 to 50.
About ppb and about 5 to 10 ppb of organic chlorine such as trihalomethane remain, which causes various problems. For example, in a PWR-type nuclear power plant, if chlorine ions are contained in the condensed water of the turbine, it causes stress corrosion cracking of stainless steel in the steam generator. Therefore, it is desirable to remove chlorine ions as much as possible.

[0003] Further, if an organic chlorine compound is contained in makeup water, it is decomposed by a steam generator to generate chlorine ions, thus causing the above problem. Furthermore, organic substances are also decomposed into organic acids such as carboxylic acids, so that it is better not to include them.

On the other hand, by using a reverse osmosis membrane device,
General organic compounds can be removed, but low molecular organic chlorine compounds such as trihalomethane cannot be removed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to supply a replenishing water for a power plant capable of supplying make-up water having an extremely low content of an organic chlorine compound. It is to provide a water production device.

[0006]

In order to achieve the above object, the present invention comprises an ultraviolet oxidizer and an ion exchange device connected to each other. Low molecular content in pre-treated water by irradiating ultraviolet rays
A steam tank configured to send a chlorine compound to an ion exchange device after being decomposed, remove the decomposition products of the decomposition by the ion exchange device, and take out makeup water from the ion exchange device .
Oh those related to power plants supply water production apparatus for a turbine
In addition, the present invention comprises an ion exchanger, an ultraviolet oxidizer, and a non-regenerative ion exchanger, which are sequentially connected, and supplies pretreated water to the ion exchanger to remove ions in the pretreated water. Then, it is sent to an ultraviolet oxidizer, where it is irradiated with ultraviolet rays to decompose the low-molecular-weight organic chlorine compounds, and then the decomposition products are removed by a non-regeneration type ion exchange device, and makeup water is taken out from the non-regeneration type ion exchange device. Steam configured as
Those about the power plant makeup water production apparatus for a gas turbine.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flow chart showing one embodiment of the present invention incorporated in a PWR type nuclear power plant. A portion surrounded by a two-dot chain line a in the drawing shows the configuration of one embodiment of the present invention. ing.

In the drawing, reference numeral 2 denotes a nuclear reactor, 4 denotes a steam generator, 6 denotes a turbine, 8 denotes a generator, 10 denotes a condenser, 12 denotes a condensate filtration device, 14 denotes a condensate desalination device, and 16 denotes a feedwater pump. It is.

[0010] The steam generated by the steam generator 4 is supplied to a turbine 6.
Is operated, the condensate is condensed by the condenser 10 and returned to the steam generator 4, but the condensate is gradually dissipated and reduced over a long period of operation. The reduced amount of the condensed water is supplemented by the makeup water in the makeup water tank 18.

An embodiment of the makeup water producing apparatus of the present invention will be described below.

In FIG. 1, reference numeral 20 denotes a pretreatment device, which supplies industrial water, well water, etc., as a raw material for making-up water, to a coagulating sedimentation device, a filtration device, a two-bed, three-column type pure water production device. And the like, and is pretreated by a conventional method.

The pretreated water thus pretreated is sent to the ultraviolet oxidizer 22. In addition, a reverse osmosis membrane device can be installed as necessary at the subsequent stage of the pretreatment device.

The pre-treated water is irradiated with ultraviolet rays to decompose organic compounds containing organic chlorine compounds contained in the pre-treated water into organic acids, carbonic acid, chloride ions and the like. As an ultraviolet lamp for irradiating ultraviolet rays, the main wavelengths of the generated ultraviolet rays are 365 nm, 254 nm, and (185 nm , respectively).
Although three types of ultraviolet lamps ( +254 nm ) are manufactured, a so-called low-pressure ultraviolet lamp having a main wavelength of ( 185 nm + 254 nm ) is suitable for further decomposing low-concentration organic substances such as makeup water. .

Various organic substances are decomposed by the irradiation of ultraviolet rays as described above. In particular, trihalomethanes such as trichloromethane and dichlorobromomethane, and other trichloroethylene, tetrachloroethylene, 1,1,1,2
Low molecular weight organic chlorine compounds such as 1-trichloroethane are efficiently decomposed. General organic compounds can be removed to some extent with a reverse osmosis membrane device, but organic chlorine compounds such as trihalomethane are difficult to remove with a reverse osmosis membrane device. According to the apparatus of the present invention, a feature is that trihalomethane, which is difficult to remove with a reverse osmosis membrane apparatus, can also be removed.

The irradiation water irradiated with the ultraviolet light is then supplied to an ion exchange device 24 disposed downstream of the ultraviolet oxidation device 22.
Where the chlorine ions, organic acids, carbonic acid, and the like in the irradiation water generated by the ultraviolet irradiation are removed.

The ion exchange apparatus has been conventionally used in the production of make-up water, and has a mixed bed type ion exchange apparatus of an anion exchange resin and a cation exchange resin, which has a regeneration facility as an incidental equipment, a cation exchange column and an anion exchange resin. Use a so-called pure water production device such as a double bed ion exchange device comprising an exchange column (the order of the cation exchange column and the anion exchange column is not limited), or use a non-regenerative mixed bed type without regeneration equipment Although an ion exchange device is preferably used, a single bed ion exchange device having an anion exchange column alone may be used in some cases.

The content of the organic compounds of water and the various ions described above which are taken out through the ion exchanger is extremely low.
This water is sent to the make-up water tank 18 as make-up water, and thereafter sent to the condenser 10 as needed, as described above, to be used for making up the condensed water.

[0019] In the above embodiment has been described with reference to PWR type nuclear power plant as a power plant, but not limited to, BWR nuclear power plant, and is used as well to the thermal power plant.

FIG. 2 shows another embodiment of the present invention. An example of the configuration is shown in a region surrounded by a two-dot chain line a in the figure.

In this embodiment, the pretreated water pretreated by the pretreatment device 20 is first sent to the ion exchange device 26. The ion exchange device 26 may be the same as that conventionally used for the production of makeup water, and may be a mixed-bed ion exchange device in which an anion exchange resin and a cation exchange resin are appropriately mixed, a cation exchange column and an anion exchange column. A double-bed ion exchange apparatus having a regeneration facility is used.

The deionized water from which ions in the pretreatment water have been removed by the above-mentioned ion exchange device is then sent to the ultraviolet oxidizing device 22.
Is irradiated with ultraviolet rays to decompose an organic compound containing an organic chlorine compound to generate chlorine ions, organic acids, carbonic acid, etc., and the configuration of the ultraviolet oxidizing apparatus 22 is the same as that of the above-described embodiment. .

The irradiation water irradiated with the ultraviolet rays then flows into a non-regeneration type ion exchange device 28. This exchange device 28
Is a so-called cartridge polisher in which a mixed resin of a cation exchange resin and an anion exchange resin that has been regenerated outside in advance is filled in a tower. This is a non-regeneration type ion exchange device that is used by exchanging it. When the irradiation water passes through the inside of the apparatus 28, decomposition products in the irradiation water can be removed, and anion and cations are removed so that treated water having a predetermined Na / Cl molar ratio can be obtained. A resin filled with a resin having an adjusted ion exchange resin composition is preferable. In this case, the molar ratio of Na / Cl is preferably set in a range of 0.5 ± 0.2. By doing so, corrosion in the condensate circulation path can be effectively prevented. This effect is particularly significant in PWR power plants.

The treated water from which decomposition products such as chlorine ions and carbonic acid have been removed by the non-regenerating ion exchange device 28 and the molar ratio of Na / Cl has been adjusted is then sent to the makeup water tank 18 and thereafter. It is used to supply condensate water as described above.

Hereinafter, the present invention will be described in detail with reference to examples.

[0026]

【Example】

Example 1 Pretreated water sent from a pretreatment device was treated with a reverse osmosis membrane device to obtain permeated water, and the obtained permeated water was sent to an ultraviolet oxidation device at a flow rate of 80 m ³ / h, where 0.35 kWh / After irradiation with ultraviolet light of m ^3, the mixture was passed through a regeneration-type mixed-bed type ion exchange apparatus having regeneration equipment. The mixed bed type ion exchange apparatus was a mixture of a strongly acidic cation exchange resin Amberlite (registered trademark) 200CT and a strongly basic anion exchange resin Amberlite IRA-900 at a volume ratio of 1: 1. The components contained in the outlet water of the ion exchange device were analyzed to obtain the results shown in Table 1 (Example 1).

For comparison, the results of analysis performed in exactly the same manner except that the ultraviolet light was not passed through the ultraviolet oxidation apparatus are shown in Table 1 (Comparative Example).

[0028]

[Table 1] * Both are below the lower limit of measurement. As shown in Table 1, according to the apparatus of the present invention, the amount of organic substances and organic chlorine compounds in the makeup water could be reduced to below the lower limit of measurement. Examples 2 and 3 The pretreatment water sent from the pretreatment device was supplied at a flow rate of 100 m ³ / h.
, And water is passed through a regenerative mixed-bed ion exchanger, and then the obtained pure water is sent to an ultraviolet oxidizer, where it is 0.35 kW.
h / m ³ of ultraviolet light was applied. The regenerative ion exchange apparatus is a strongly acidic cation exchange resin Amberlite 2
00CT and strongly basic anion exchange resin Amberlite I
RA-900 was mixed at a volume ratio of 1: 1. Next, the irradiation water irradiated with ultraviolet rays is divided into two parts, and one of the two parts is filled with a mixed resin of an H-type cation exchange resin and an OH-type anion exchange resin whose ionic composition is not particularly adjusted. Water is passed through a non-regenerative mixed-bed ion exchange apparatus (Example 2), and the other part of the irradiated water is 0.1% (equivalent%, hereinafter the same) of the H-type resin content of the Na-type resin. Is 99.9%, and the content of the strongly acidic cation exchange resin whose ionic composition is adjusted and the OH type resin is 96.0.
% Of a non-regenerating mixed bed type ion for adjusting a molar ratio, which is filled with a mixed resin with a strongly basic anion exchange resin whose ionic composition is adjusted so that the content of Cl-type resin is 4.0%. Water was passed through the exchange device (Example 3).

The ion exchange resin used in the above two types of non-regenerative ion exchangers was the same as that of the regenerative ion exchangers in both cases.
00CT (strongly acidic cation exchange resin) and Amberlite IRA-900 (strongly basic anion exchange resin)
The mixing ratio of both resins was (cation exchange resin: anion exchange resin) = 9: 10 (volume ratio) in each case.

Table 2 shows the results of water quality analysis of the outlet water of the above two types of non-regenerative mixed-bed type ion exchangers.

[0031]

[Table 2] * In each case, it is below the lower limit of measurement. As shown in Table 2, both Examples 2 and 3 were able to reduce the amount of organic substances and organic chlorine compounds in the makeup water to below the lower limit of measurement. In addition, as a non-regenerative ion exchange device,
A cation exchange resin and a mixed resin in which the ionic composition of the anion exchange resin has been adjusted in advance so as to obtain outlet water (treated water) having a predetermined Na / Cl molar ratio are prepared. When a regenerative ion exchange device was used (Example 3), the amount of organic substances and organic chlorine compounds was reduced to the lower limit of measurement or lower, and the Na / Cl molar ratio was reduced to a predetermined value (0.5
Makeup water adjusted to ± 0.2) could be obtained.

[0032]

According to the present invention, low-molecular-weight organic chlorine compounds such as trihalomethane, which are difficult to remove by the conventional method, can be efficiently removed. Corrosion of the circulation path of the condensate of the power plant caused by ions can be prevented.

[Brief description of the drawings]

FIG. 1 is a flow diagram of a nuclear power plant incorporating one embodiment of the present invention.

FIG. 2 is a flowchart showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 22 UV oxidation device 24 Ion exchange device 26 Ion exchange device 28 Non-regenerative ion exchange device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C02F 1/32 C02F 1/32 1/42 1/42 A 1/58 CDV 1/58 CDVA (58) Investigated field (Int. Cl. ⁶ , DB name) C02F 9/00 502-504 C02F 1/32 C02F 1/42 C02F 1/58

Claims (2)

(57) [Claims] 1. An ultraviolet oxidizing device and an ion exchange device are connected to each other, and the pretreated water is supplied to the ultraviolet oxidizing device and irradiated with ultraviolet light, whereby low-molecular-weight components in the pretreated water are provided.
A steam tank configured to send a chlorine compound to an ion exchange device after being decomposed, remove the decomposition products of the decomposition by the ion exchange device, and take out makeup water from the ion exchange device .
-A make- up water production system for power plants for bins . 2. An ion exchange device, an ultraviolet oxidation device,
A non-regenerating type ion exchange device is connected in series, and the pretreatment water is supplied to the ion exchange device to remove ions in the pretreatment water, and then sent to an ultraviolet oxidation device where it is irradiated with ultraviolet rays to emit low-molecular A steam tank configured to decompose an organochlorine compound , then remove decomposition products by a non-regenerative ion exchanger, and take out makeup water from the non-regenerative ion exchanger .
-A make- up water production system for power plants for bins .