JPH06262198A - Water quality management method and water quality management chart for circulating water course system - Google Patents

Abstract

PURPOSE:To quantitatively recognize the ease (generation intensity) of rust and scale so that the operation of a water treating device can efficiently be made by managing water quality with the concns. of various kinds of ions in a circulating water course system and the fluctuation coefft. of the concentration multiple of a solute concn. as the index. CONSTITUTION:The measured values (a) of the concns. of various kinds of the ions and the solute in the circulating water course system entailing condensation of water and the measured values (b) of the various kinds of the ions and the solute in feed water to the circulating water course system are contrasted by each of the same kinds. The water quality is managed by defining the ratio of a standard deviation S at the concentration multiple X1 to the average concentration multiplex X which is the mean value of the concentration multiplex X1, i.e., fluctuation coefft. CV as an index if the ratio a/b of the measured values (a) to the measured values (b) is defined as the concentration multiplex X1 as the index. A vibrating magnetic field and electric field generator is used in such a manner that the fluctuation coefft. does not exceed 20%. This device is constituted by housing a 1/2 wavelength wire antenna 1 within a steel pipe 2, both ends 4, 4' of which are formed as an inlet and outlet for the water and connecting a high-frequency power source 3 to this antenna 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water quality control method and a water quality control table for a circulating water channel system.

[0002]

2. Description of the Related Art A circulating water channel system accompanied by water concentration, for example, cooling water from a cooling tower is pumped to a heat exchanger, and further circulating water channel to the cooling tower is pumped from a water softener through a water supply tank. Boiler system line that supplies water to the steam boiler, or non-circulating channel system that does not involve water concentration, for example, a drinking water supply line in a high-rise building that simply pumps water from a receiving tank to a high-level storage tank to supply water to each floor. Etc.,
In the line that sends water, or in heat exchangers, boilers, cooling towers,
Generation of rust and / or scale inside the water supply pipe has always been a problem.

Particularly, in a circulating water channel system such as a cooling tower-heat exchanger circulating system line and a boiler system line, circulating water is concentrated as water evaporates, so that various ion concentrations and solute concentrations are increased and rust and Scale is more likely to occur. J
IS-B8223 stipulates in detail the water quality control of a so-called steam circulation boiler, entitled "Water quality of boiler feed water and boiler water quality", in order to prevent rust and scale generation of the boiler. According to this, the upper (or upper and lower) limit concentrations of various components (ions and solutes) in feed water and boiler water are determined. For example, for boiler water of a round boiler, the heat transfer surface evaporation rate is 30 kg / m ² · h. The electrical conductivity of 60
00 (μs / cm) or less, M alkalinity is 100 to 80
It is defined as 0.

Although rust and scale can be temporarily suppressed if the JIS standards are complied with, it is not easy to completely contain each component within the specified range. That is, when a certain component is out of the specified range, various rust preventives, scale dispersants, clear cans and the like are generally used to keep it within the specified range. When a is contained in the specified range, another component b may be out of the specified range. In that case, in order to keep the component b in the specified range, further injection of the drug B is unavoidable. It lacks uniformity and logic, and tends to increase drug usage.
As described above, it is generally difficult to control the type and amount of the input drug, the running cost is high, and there is a problem in using a large amount of the drug for health reasons, such as drinking water.

On the other hand, in the circulating water system, it is preferable from the viewpoint of energy efficiency or thermal efficiency to suppress new water supply and maintain the concentration factor at a high level to some extent, but in the conventional water quality control method, rust and scale are generated. Therefore, there is no scale or index for judging whether or not there is no concern about increasing the concentration factor, and the timing of new water supply depends solely on the experience and intuition of the operator such as the cooling device or boiler. And decided the amount of water supply.

[0006]

[Problems to be Solved by the Invention] The regulation range for preventing rust and scale specified in JIS-B8223 is the regulation range for each individual component, which is the so-called total regulation value for the sum of each component. There is no such thing. If this overall regulation value can be found, it will be possible to make a quantitative judgment on the strength of rust / scale generation, and based on this judgment, regarding the type and amount of chemicals to be added to the circulating water system,
Alternatively, it should be possible to operate more uniformly and logically than before regarding the timing of new water supply and the amount of water supply to the circulating water system.

An object of the present invention is to obtain an index indicating the rust and scale generation strength or an overall regulation value, and use it for water quality control of a circulating water channel system.

[0008]

According to the present invention, a measured value a of various ion and solute concentrations in a circulation channel system accompanied by water concentration is obtained.
And the measured values b of various ion and solute concentrations in the feed water for the circulating water channel system are compared for each same type, and the ratio a / b of the measured value a to the measured value b is the concentration factor X _i. Provided is a water quality management method for a circulating water channel system, which manages water quality using the ratio of the standard deviation S of the concentration factor X _{i to} the average value X bar of the concentration factor X _i , that is, the variation coefficient CV as an index.

[0009] The present invention is a measured value b and the measured value a with enumerating adjacent to each allogeneic ions and solutes, are indicated by the concentrated multiple X _i to the measured value a, and with the concentrated multiple X _i contrasted Provide a water quality control table that displays the average concentration multiple X bar at possible positions.

[0010]

The coefficient of variation indicates the degree of variation in the concentration factor of each ion and solute with respect to the average concentration factor (X bar). A large coefficient of variation means that ions and solutes react with each other and precipitate. Or indicates that a large amount is mixed in the steam. Therefore, by obtaining the coefficient of variation and using it as an index, it becomes possible to accurately grasp information regarding phenomena or changes in the circulating water channel system, and prevent rust and scale from occurring.

Further, by using the water quality control table of the present invention, it is possible to easily see how much the concentration factor of each ion and solute deviates from the average concentration factor (X bar) by plus or minus. The component or abnormal diluted component can be found at a glance, and water quality improvement measures corresponding to the abnormal component can be taken promptly and accurately. This water quality control table maximizes its practical value by using it together with the above water quality control method.

[0012]

[Example] The present inventor has found that the water quality control method for a circulating water channel system specified in JIS raises the ion concentration and the solute concentration (up and down).
Since the individual concentration values cannot be used as an index to show the susceptibility (occurrence intensity) of actual rust and scale only by limiting the limit, the idea was to compare each concentration value with the concentration value of the water supply. . That is, the ion concentration and solute concentration in the circulating water system, compared with the corresponding ion concentration and solute concentration of the feed water,
See how many times (concentration factor) it is.

If the water in the circulating water channel is concentrated in an ideal state, that is, if the ions and solutes in the water channel do not react with each other, do not precipitate, and do not mix in the steam, It should be the same multiple for ions and solutes (components). However, in reality, the concentration factor varies greatly depending on the component. Therefore, conversely, the fact that there is this variation can be said to indicate that some event is occurring in the circulation channel system. Based on this, the present inventor has conceived that the concentration multiple becomes a key point for water quality control, and has embodied it as a water quality control method.

A statistical method based on data is indispensable for accurately grasping the events occurring in the circulating water channel system, but in the conventional water quality management method of JIS, the statistical method cannot be adopted at all. There wasn't. This point concentration multiple is suitable for statistical processing, and as will be described below, information for making an accurate judgment regarding water quality management can be obtained.

In the present invention, measured values a of various ion concentrations and solute concentrations in a circulating water channel system accompanied by water concentration, such as a cooling tower-heat exchanger system line and a boiler system line, and water supply to the circulating water channel system. The measured values b of various ion concentrations and solute concentrations therein are measured. For stability and reliability of the coefficient of variation, it is desirable to measure as many kinds as possible, but it is recommended to measure, for example, the concentrations of the following 7 components.

(1) In the case of a circulating water channel system that does not use a water softener: conductivity, chloride ion, sulfate ion, M alkalinity, total hardness, silicate ion, evaporation residue

(2) In the case of a circulating water channel system using a water softener Conductivity, chloride ion, sulfate ion, M alkalinity, sodium ion, silicate ion, evaporation residue

In the case of the above (2), sodium ion is measured instead of the total hardness. This is because it is meaningless to measure the total hardness when using a water softener, and because the ion exchange resin contains sodium, it is necessary to monitor the ion concentration.

Although the sulfate ion and the sodium ion were not targeted for water quality control in the conventional JIS, the present inventor found that they were closely related to the generation of rust and scale, and the measurement target Added as.

When the measured value a and the measured value b are obtained, next, a /
Calculate b (= concentration factor X _i ).

Here, the concentration factor of each component is expressed as follows: Component concentration factor Component concentration factor Conductivity X1 Total hardness X5 Chloride ion X2 (Na ion X5) Sulfate ion X3 Silicate ion X6 M Alkalinity X4 Evaporation Although it is possible to judge the water quality to some extent only by looking at the residue X7 concentration factor, by calculating the average concentration factor and the coefficient of variation, it is possible to make a drastically reliable and convenient water quality judgment.

To obtain the coefficient of variation, the standard deviation (S) is first obtained by the following equation.

S = √ {Σ (X _i −X bar) ² / (7-1)} (where i = 1, 2, 3, 4, 5, 6, 7) (X bar is the average concentration multiple) Represents.)

The coefficient of variation (CV%) is obtained by CV% = (S / X bar) × 100%.

The coefficient of variation indicates the degree of variation of each concentration factor with respect to the average concentration factor (X bar). A large coefficient of variation means that ions and solutes react with each other and precipitate, or in vapor. Indicates that a large amount is mixed in. Therefore, by obtaining the coefficient of variation, it is possible to accurately grasp information about the susceptibility (occurrence intensity) of rust and scale.

The present inventor has found that the coefficient of variation (CV%) expressed by (S / X bar) × 100% is 10% from many experimental examples.
Cooling water management is at its best when: no scale, corrosion or slime formation, at least about 2
It was found that 0% or less was acceptable, and it was found to be a strong standard for water quality management.

The water quality control method of the present invention is effective not only for preventing the formation of rust and scale, but also for improving energy efficiency. That is, if the coefficient of variation is within 20%, rust and scale are prevented from being generated in the circulating water channel system, so that the coefficient of variation is actively suppressed while observing the natural increase of the coefficient of variation or by a magnetic field electron field device or the like. While the coefficient of variation is within the range of about 20%, the energy efficiency of the boiler and the cooling device is improved by operating the boiler and the cooling device without new water supply until the average concentration multiple becomes maximum, thus saving water. Is also useful. According to the experiment, it was confirmed that the amount of water used can be reduced to 1/10 or less by increasing the concentration factor by 5.

It was also found that when the average concentration multiple is high, the elution of iron in the system is suppressed, and it is effective in stabilizing the coefficient of variation at a low level.

The coefficient of variation may exceed 20% due to a measurement error or an error when measuring the concentration multiple, despite the good water quality in which rust and scale are unlikely to occur. In this case, an abnormal value can be easily found by examining each enrichment factor, and therefore the abnormal value can be removed and recalculated. For example, in Example 2 below, it is found that the concentration factor of sulfate ion 10.0 is abnormally higher than the average concentration factor of 7.41. Since such a single abnormal value is theoretically unexplainable, it is considered that sulfate ions are mixed into the system due to some factor (for example, the effect of exhaust gas from a heavy oil-fired chimney in the vicinity). Therefore, a correct coefficient of variation can be obtained by excluding this abnormal value and recalculating.

Further, if each concentration factor is compared and examined in detail, it is clarified whether or not an abnormal value having a large deviation from the average concentration factor by ± is caused by a measurement error, an error, or another reason. Therefore, the judgment of water quality in the circulation channel system and measures for water quality improvement will be dramatically ensured.

Tables 1 and 2 show the results of experiments conducted in each case where the coefficient of variation is 20% or less and above. As is clear from the table, when the coefficient of variation exceeds 20%, the generation of rust and scale was observed, but when controlled to 20% or less, it was hardly observed.

Examples 1 and 2 of Tables 1 and 2
In order to control the coefficient of variation to 20% or less, an oscillating magnetic field electric field generator equipped with a linear antenna described later is used. In addition to this, in order to suppress the coefficient of variation, it is possible to employ various methods such as the use of a known boiler can or a reduction of the concentration factor by new water supply.

(Example 1 and Comparative Example 1) In Example 1, the coefficient of variation does not exceed 20% as shown in FIG.
The oscillating magnetic field electric field generator shown in is used. This device has a diameter of 3 mm and a length of about 500 in a steel tube 2 with a diameter of 10 cm.
A 1/2 wavelength line antenna 1 of mm stainless steel wire is accommodated,
This antenna 1 has about 30
Connected to 0MHz high frequency power supply 3, both ends of steel pipe 2, 4, 4 '
Is the entrance and exit of water.

Although the theory that the coefficient of variation is suppressed by the oscillating magnetic field is not always clear, the present inventor has made the following hypothesis. That is, SiH _{4 has} a natural frequency of 2191 ν / cm or 914 ν / cm, and when silicic acid is placed in an oscillating magnetic field field, four electrons of silicon M electron nuclei are activated based on the resonance theory. The siloxane bond (—Si—O—Si—) polymerizes in a two-dimensional or three-dimensional manner, and this polymer combines with various inorganic and organic ions to increase the solubility of the corresponding component and reduce the coefficient of variation. Of.

In the first embodiment, as shown in FIG.
In the water supply system of No. 3, the oscillating magnetic field electric field generator 15 was attached to the water supply tank 11, and the water in the tank 11 was pumped to circulate in the apparatus 15. As the supply water, soft water having the composition shown in Table 1 was used, and 1 W of electric power was output to the oscillating magnetic field electric field generator, and the current of the linear antenna was 1
The flow rate of the treated water in the device was set to 0 mA and the flow rate to the treated water was set to 15 m ³ / hour.

The boiler water supply operation was continued until the electric conductivity of the soft water, which was initially 150 μs / cm, became 1960 μs / cm, at which point the water in the water supply tank was sampled and analyzed. The results are shown in Table 1.

As a comparative example, similar to the example, except that the oscillating magnetic field electric field generator 15 was not used, a commercially available boiler agent was used instead, and the boiler water supply operation was continued up to the conductivity of 1710 μs / cm for sampling. The results of water analysis are shown in Table 1 for water quality management.

[0038]

[Table 1]

Continue the boiler operation with the conductivity as a guide,
After 6 months, the state of generation of rust and scale in the boiler and piping was examined, and in the case of Example 1, almost no rust and scale were observed, but in the case of Comparative Example 1, considerable rust and scale were found. Admitted. In Comparative Example 1, the concentration factor of sulfate ion was 1.40 as compared with the average concentration factor of 10.04.
0 is extremely low, which causes an increase in the coefficient of variation, and
It is considered that the difference in concentration factor of silicate ions was generated in the can as a silica-based hard scale.

Thus, according to the water quality control table of the present invention,
It is possible to see at a glance what the concentration factor is abnormally high or low, and therefore it is possible to take swiftly and appropriately measures for improving the water quality corresponding to the ions and solutes having abnormal concentrations.

The measurement of each parameter in Table 1 is as follows.
According to JISKO101, ph is glass electrode method, chlorine ion is ion electrode method, sulfate ion is barium chromate method, M alkalinity is acid consumption method, Na ion is ion electrode method, silicate ion is all silica, evaporation The residue was measured gravimetrically.

(Example 2 and Comparative Example 2) An oscillating magnetic field field generator using the same linear antenna as that used in Example 1 (output power 1 W, linear antenna current 10 m)
(A, about 300 MHz) was located at position 9 in the circulating cooling water system line in FIG. 2, that is, between the heat exchanger 7 and the cooling tower lower part 5. Industrial water having a composition shown in Table 2 (no water softener) was used as make-up water, and the operation was performed with the conductivity as a guide. The flow rate in the device 9 of the present invention is set to 50 m ³ / hour.
Was done. On the other hand, for comparison, the same operation was performed in parallel without using the device of the present invention. Water conductivity is about 830μ
The water quality control table 2 shows the results of sampling and analysis of the circulating water of both when it reached about s / cm.

[0043]

[Table 2]

In Example 2, the coefficient of variation was somewhat higher than 20% (it is considered that the exhaust gas in the air had an influence because the concentration factor of sulfate ion was abnormally high). A considerable effect was observed for the prevention of occurrence.
In addition, when it is carried out in a normal environment in which the sulfate ion concentration is close to the average value, the average concentration factor when the device of the present invention is used is 7.05 and the standard deviation is 1.
16, the coefficient of variation was 16.4%.

The concentration factor is preferably 3 or less in order to reduce the mixture of SOx from the outside.

As shown in FIG. 1, the oscillating magnetic field electric field is preferably made of stainless steel, steel conductor or copper conductor, and the linear antenna 1 having a predetermined length, that is, 250 mm or 500 mm and 1000 mm is accommodated in the steel pipe 2. About 300
High frequency power supply of Mhz (wavelength about 1m) is connected, output power of the power supply is 0.5 to 1W, linear antenna current is 10m.
It is given as A. The water to be treated is the steel pipe 2
It is made to flow in one direction through the entrances and exits 4 and 4'provided in.

The wavelength shortening rate is given by the permittivity of water and the permittivity of the waterproof insulating coat (for example, polyethylene), and the actual length of the antenna is shortened.

The introduction flow rate of the water to be treated is 0.2 to 200 m ³
It is selected within the range of / hour. The diameter of the steel pipe depends on the amount of water treated and the flow rate, but is usually about 5 to 20 cm. By doing so, an electric field strength of 500 μV / m or less is given at a distance of 3 m from the linear antenna, effective water treatment is possible, and an optimum oscillating magnetic field field that does not conflict with the Radio Law is obtained. Given.

[0049]

As described above, according to the present invention, the water quality is controlled by using the coefficient of variation of the concentration multiple of the various ion concentrations and the solute concentration in the circulating water channel as an index, so that the susceptibility to rust and scale (generation strength) is determined. For the first time, it becomes possible to quantitatively grasp, enabling efficient and accurate operation of various water treatment devices, minimizing the amount of use of boiler cans, and supplying water to boilers, etc. Can accurately grasp the water supply timing and water supply amount, and therefore can effectively and surely prevent the generation of rust and scale, and can significantly improve the life of the boiler and the cooling device.

Also, while confirming that the coefficient of variation is less than or equal to the predetermined value, the average concentration factor can be safely increased to the upper limit value without new water supply, so that the energy efficiency of the boiler and the cooling device is remarkably improved. It is possible,
In addition, significant water savings will be possible.

Further, by using the water quality control table of the present invention, it is possible to see at a glance the ions and solutes whose concentration factor is abnormally separated from the average concentration factor in the plus or minus direction. Can be taken quickly and accurately.

[Brief description of drawings]

FIG. 1A is a device using a quarter-wave antenna,
(B) is a device using a 1/2 wavelength antenna, (C) is 1
A device that uses a wavelength antenna.

FIG. 2 is a water route diagram when the present invention is applied to a circulating cooling water system.

FIG. 3 is a water channel diagram when the present invention is applied to a water supply system of a steam boiler.

[Explanation of symbols]

 1 ... Antenna 3 ... High frequency power supply 7 ... Heat exchanger 8 ... Cooling tower upper part 10 ... Water softener 11 ... Water tank 13 ... Steam boiler 14 ... Pump

Claims (6)

[Claims] 1. A measurement value a of various ions and solute concentrations in a circulating water channel system accompanied by water concentration and a measurement value b of various ions and solute concentrations in feed water to the circulation water channel system, for each same type. contrast, and when the ratio a / b for the measured value b of the measurement values a and concentration multiple X _i, with respect to the average concentration multiple X bar the is an average value of the concentration multiples X _i, the standard deviation of the concentration multiples X _i A water quality management method for a circulation channel system, which manages water quality using the ratio of S, that is, the coefficient of variation CV as an index. 2. The water quality control method for a circulating water channel system according to claim 1, wherein the water quality is controlled on the basis of the coefficient of variation CV = about 20%. 3. The water quality control according to claim 1, wherein the measured values a and b include measured values of conductivity, chloride ion, sulfate ion, M alkalinity, total hardness, silicate ion, and evaporation residue. Method. 4. The measured values a and b include measured values of conductivity, chlorine ion, sulfate ion, M alkalinity, silicate ion, evaporation residue, and sodium ion.
Or the water quality management method described in 2. And wherein said measurement values a measured value b with enumerating adjacent to each allogeneic ions and solutes, are indicated by the concentrated multiple X _i to the measured value a, and can be compared position and the concentrated multiple X _i A water quality management table in which the average concentration factor X bar is displayed on the. 6. The water quality management table according to claim 5, wherein the coefficient of variation CV is displayed at a position where it can be compared with the concentration multiple X _i and the average concentration multiple X bar.