Preparation device for sample water for water quality evaluation of boiler water

Abstract

To enhance reliability of water quality evaluation of boiler water in a boiler in operation.SOLUTION: A preparation device 200 for sample water includes a collection path 210 branched from a blow path 121 of boiler water extending from a boiler body 120. The high-temperature and high-pressure boiler water flowing in the collection path 210 from the blow path 121, in which generation of flash steam that causes water quality fluctuation is suppressed, passes through a decompressor 230 after being cooled in a cooler 220, and is stored in a water storage tank 240 open to the atmosphere. In the boiler water stored in the water storage tank 240, part of the water is supplied to a first analyzer 310 as it is as sample water through a water delivery path 250 and its pH is measured, and part of the water is supplied to a second analyzer 320 as sample water that is diluted with water for dilution supplied from a replenishing path 260 to the water storage tank 240 through the water delivery path 250 and its silica concentration is measured.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for preparing sample water for water quality evaluation, and more particularly to an apparatus for preparing sample water for evaluating the water quality of boiler water collected from an operating boiler using an analyzer. [Background technology]

[0002] A typical boiler system for supplying steam to load equipment such as a heat exchanger generates steam by heating the water fed to the boiler as boiler water, and supplies this steam to the load equipment through a steam path. Because the inside of a boiler is a high-temperature, high-pressure environment, the heat transfer surfaces of the water tubes that generate the steam can become corroded or scale can form on them due to the influence of various dissolved components in the feed water. Scale that forms on the heat transfer surfaces impedes heat transfer, reducing the operating efficiency of the boiler. Furthermore, corrosion of the heat transfer surfaces can damage the water tubes as it progresses, hindering the stable and continuous operation of the boiler.

[0003] Therefore, in the operation of a boiler system, calcium ions and magnesium ions that cause scale are usually removed from the water supplied to the boiler, and dissolved oxygen that causes corrosion is also removed, and various water treatment agents are added to the water supply and the concentration ratio of the boiler water is controlled to adjust the water quality of the boiler water, thereby suppressing the formation of scale and the progression of corrosion in the boiler. Here, since the water quality of the boiler water constantly changes during the operation of the boiler due to various factors such as fluctuations in the water quality of the raw water used for the feedwater and the amount of steam generated, it is ideal to evaluate the water quality of the boiler water in the operating boiler and, in light of the results, take necessary measures for the boiler water in a timely manner, such as selecting the water treatment agent to be added to the boiler feedwater, controlling the amount of addition, and controlling the blowing.

[0004] The water quality of boiler water is usually evaluated by collecting a portion of the boiler water from a boiler in operation and using the collected water as a sample with an analyzer suitable for the evaluation item. For example, Patent Document 1 discloses an analyzer in which the inlet side of a cooler is connected to an outlet for collecting high-temperature boiler water from a boiler and a water quality analyzer is connected to the outlet side of the cooler. The cooler used in this analyzer is a container with an opening at one end and a cooling fan at the other end, in which a metal tube having an inlet connected to the boiler water outlet and an outlet connected to the water quality analyzer is disposed, and the boiler water flowing from the inlet to the outlet in the metal tube is indirectly cooled by gas supplied by the cooling fan. The boiler water collected from the boiler in this analyzer is cooled to a predetermined temperature by the cooler and then supplied to the water quality analyzer, where it is analyzed.

[0005] Because the above-mentioned analyzer adjusts the flow rate at the inlet of the cooler, if cooling to a specified temperature is insufficient, flash steam will be generated in the boiler water moving from the outlet to the water quality analyzer, which may cause fluctuations in the water quality of the collected boiler water. If boiler water with fluctuating water quality is used as a sample and analyzed by a water quality analyzer, the results will be unreliable, and the measures taken for the boiler water based on the analysis results may be inappropriate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-241534 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to improve the reliability of evaluation of the water quality of boiler water in a boiler during operation. [Means for solving the problem]

[0008] The present invention relates to an apparatus for preparing sample water for evaluating the water quality of boiler water collected from an operating boiler using an analyzer. The preparation apparatus includes a boiler water collection path extending from the boiler, a boiler water cooler for the boiler water flowing through the collection path, a boiler water pressure reducer disposed on the collection path downstream of the cooler, a water tank open to the atmosphere for storing the boiler water from the pressure reducer, and a water supply path extending from the water tank for sending the sample water to the analyzer.

[0009] In the preparation apparatus according to the present invention, for example, the cooler is a water-cooled heat exchanger and the pressure reducer is a constant flow valve.

[0010] The preparation apparatus according to the present invention further includes, for example, a circulation path that is branched off from the water supply path and communicates with the water tank.

[0011] In the preparation apparatus according to the present invention, the water tank is provided with, for example, a sensor on the upper portion for measuring the electrical conductivity of the stored boiler water.

[0012] The water tank includes, for example, a supply path for supplying dilution water for boiler water, and the supply path includes a control valve for switching between starting and stopping the supply of dilution water. In this case, the water tank includes, for example, a water volume control valve for controlling the amount of boiler water stored to a predetermined amount. The supply path also includes, for example, a metering tank for limiting the amount of dilution water supplied to the water tank to the predetermined amount.

[0013] Another aspect of the present invention relates to an apparatus for evaluating the quality of boiler water from a boiler in operation. The water quality evaluation apparatus includes a water quality analyzer connected to a water supply path extending from a water storage tank of the apparatus for preparing sample water for evaluating the quality of boiler water according to the present invention. Effect of the Invention

[0014] The sample water prepared by the apparatus for preparing sample water for evaluating the quality of boiler water according to the present invention allows the quality of boiler water in an operating boiler to be evaluated with high reliability by an analyzer.

[0015] The boiler water quality evaluation device according to the present invention can evaluate the quality of boiler water in an operating boiler with high reliability. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of a boiler system equipped with an embodiment of a water quality evaluation device for boiler water according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] An example of a boiler system including one embodiment of a boiler water quality evaluation device according to the present invention will be described with reference to Fig. 1. In the figure, the boiler system 1 mainly includes a boiler 10 and a boiler water quality evaluation device 20, and the boiler water quality evaluation device 20 mainly includes a sample water preparation device 200 used to evaluate the quality of boiler water from the boiler 10 in operation, and a water quality analyzer 300.

[0018] The boiler 10 is for supplying steam to a load device 110, which is steam-using equipment such as a heat exchanger, a steam kettle, a reboiler, or an autoclave, and is mainly equipped with a boiler body 120, a water supply device 130, and a chemical supply device 140.

[0019] The boiler body 120 has many water pipes (not shown) standing upright inside, stores the water supplied from the water supply device 130 as boiler water, and generates steam by heating this boiler water through the heat transfer surfaces of the water pipes. The boiler body 120 has a blow path 121 for discharging a portion of the boiler water, and this blow path 121 has a first control valve 122 for adjusting the amount of boiler water discharged. Furthermore, a steam supply pipe 123 that connects to the load device 110 extends from the upper part of the boiler body 120.

[0020] The water supply device 130 is for supplying feed water to be used as boiler water in the boiler body 120, and typically extends from a feed water tank (not shown) for storing feed water that has been treated to remove hardness components and dissolved oxygen from raw water supplied from a water source such as tap water, industrial water, or groundwater, and has a feed water path 131 that connects to the bottom of the boiler body 120. The feed water path 131 has a feed water pump (not shown) for sending the feed water stored in the feed water tank to the boiler body 120.

[0021] The chemical supply device 140 adds a water treatment agent to the feed water supplied from the water supply device 130 to the boiler body 120, and is capable of controlling the timing and amount of addition of the water treatment agent. As the water treatment agent, a pH adjuster, a scale dispersant, an anticorrosive agent, or the like is used. The pH adjuster adjusts the pH of the boiler water to an alkaline region to suppress corrosion in the boiler body 120, and for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is used. The scale dispersant seals hardness components remaining in the feed water to suppress the formation of scale in the boiler 120, and for example, a chelating agent such as ethylenediaminetetraacetic acid (EDTA) or a polymer compound such as a polyacrylic acid compound is used. The anticorrosive agent is for suppressing corrosion of water tubes and the like in the boiler body 120, and usually, an oxygen scavenger, a film forming agent, or the like is used. The oxygen scavenger is for removing dissolved oxygen remaining in the feed water, and for example, ascorbic acid, sulfite, or the like is used. The film-forming agent forms an anticorrosive film on water pipes, etc., and is, for example, a silicic acid-based compound such as silicon dioxide. The water treatment agent may be supplied individually from the chemical supply device 140 to the supply water, or may be supplied as a composite agent in which multiple types of water treatment agents are mixed in advance.

[0022] The sample water preparation device 200 mainly comprises a sampling path 210, a cooler 220, a pressure reducer 230, a water storage tank 240, a water supply path 250, and a supply path 260 for dilution water.

[0023] The collection path 210 branches off from the blow path 121 at the upstream side of the first control valve 122, and has a second control valve 211 for adjusting the flow of boiler water from the boiler body 120.

[0024] The cooler 220 is a water-cooled heat exchanger, and includes a refrigerant jacket 221 that accommodates a portion of the collection path 210. The refrigerant jacket 221 includes an inlet path 212 equipped with a first on-off valve 213 for introducing cooling water as a refrigerant, and an outlet path 214 for discharging the introduced cooling water. The inlet path 212 branches off from a path that supplies raw water or soft water that has been treated to remove hardness components from raw water to the water supply device 130. The collection path 210 has a coil portion 223 formed in a portion accommodated within the refrigerant jacket 221, and a tip portion extends from the refrigerant jacket 221 to the water tank 240.

[0025] The pressure reducer 230 is a throttling mechanism arranged in the sampling path 210 between the refrigerant jacket 221 and the water tank 240, and is, for example, a constant flow valve or an orifice. However, it is preferable to use a constant flow valve because it is easier to stabilize the cooling capacity of the boiler water in the cooler 220, which is a water-cooled heat exchanger.

[0026] The water tank 240 is a container for storing the boiler water from the collection path 210, and is open to the atmosphere, and mainly includes a first overflow path 241, a drainage path 242, and a water amount adjustment path 243. The water tank 240 also includes a sensor 246 for measuring electrical conductivity at its upper portion. The sensor 246 is capable of measuring the electrical conductivity of the boiler water stored in the water tank 240 as well as the water temperature, and is capable of detecting that the boiler water has been stored up to a predetermined water level by a change in electrical conductivity.

[0027] The first overflow path 241 limits the amount of stored water by overflowing the boiler water when a certain amount or more of boiler water is supplied, and is connected to the discharge path 214 from the cooler 220. The drainage path 242 extends from the bottom of the water tank 240 and is connected to the discharge path 214 from the cooler 220, and has a second opening / closing valve 244 for controlling the discharge of the boiler water stored in the water tank 240. The water amount adjustment path 243 extends from between the bottom of the water tank 240 and the first overflow path 241 and is connected to the discharge path 214 from the cooler 220, and has a third opening / closing valve 245.

[0028] The water supply path 250 extends from near the bottom of the water tank 240 and is connected to the water quality analyzer 300, and has a pump 251 for pumping out the boiler water stored in the water tank 240. In addition, the water supply path 250 is branched off downstream of the pump 251 into a circulation path 252 whose tip is connected to the upper part of the water tank 240, and this circulation path 252 has a fourth opening / closing valve 253.

[0029] The dilution water supply path 260 has a main path 261 branching off from the cooling water inlet path 212 on the downstream side of the first on-off valve 213, and a sub-path 262 branching off from the main path 261. The main path 261 is provided with an activated carbon filter 263 and an ion exchange resin filter 264 arranged in series from the upstream side to the downstream side, and its tip is connected to a metering tank 265. In addition, the main path 261 has a fifth on-off valve 266 between the ion exchange resin filter 264 and the metering tank 265.

[0030] The metering tank 265 connected to the main passage 261 is capable of storing a predetermined amount of dilution water, and is provided with a second overflow passage 267 that allows the dilution water to overflow when the dilution water exceeds the predetermined amount, and a communication passage 268 that extends from the bottom to the storage tank 240. The second overflow passage 267 is connected to the discharge passage 214 from the cooler 220, and the communication passage 268 has a sixth opening / closing valve 269.

[0031] The sub-path 262 branches off from the main path 261 between the activated carbon filter 263 and the ion exchange resin filter 264 , has a seventh on-off valve 270 , and is connected to the storage tank 240 at its tip.

[0032] The water quality analyzer 300 includes a first analyzer 310 and a second analyzer 320 that are connected to the water supply path 250. The first analyzer 310 is a colorimeter for measuring the pH of the sample water, and the second analyzer 320 is a colorimeter for measuring the silica concentration of the sample water. These analyzers 310 and 320 have a cell (not shown) for storing the sample water. The first analyzer 310 and the second analyzer 320 each have a first inlet valve 311 and a second inlet valve 321 for introducing the sample water from the water supply path 250 into the cell, and each have a first waste water channel 312 and a second waste water channel 322 for discharging the sample in the cell. The first waste water channel 312 and the second waste water channel 322 are connected to the discharge channel 214 from the cooler 220.

[0033] The boiler system 1 includes a control device (not shown), which controls the operation of each part, thereby operating as follows.

[0034] In the boiler system 1, the boiler body 120 is supplied with feed water from a feed water tank via a feed water path 131 by a feed water pump. The boiler body 120 stores the supplied feed water as boiler water, and generates steam by heating the boiler water through the heat transfer surface of a water pipe. This steam is supplied to the load device 110 through the steam supply pipe 123. In this process, the feed water supplied to the boiler body 120 from the feed water path 131 is doped with a required chemical from the chemical supply device 140 at an appropriate time. In addition, since the boiler water is concentrated by the generation of steam, a part of the boiler water is discharged through the blow path 121 by appropriately opening and closing the first control valve 122.

[0035] While the boiler body 120 is operating, the boiler system 1 evaluates the water quality of the boiler water at appropriate times, and based on the evaluation results, controls the addition of chemicals to the feedwater from the chemical supply device 140, and controls the discharge of a portion of the boiler water through the blow path 121, thereby controlling the water quality of the boiler water to a state suitable for corrosion prevention and scale inhibition.

[0036] In the water quality evaluation of the boiler water, first, a part of the boiler water in a high-temperature and high-pressure state is collected from the boiler body 120, and sample water for evaluating the water quality is prepared from the collected boiler water. Here, by opening the first opening / closing valve 213, cooling water is continuously introduced into the refrigerant jacket 221 through the introduction path 212, and the inside of the refrigerant jacket 221 is filled with cooling water, and the cooling water pressed out from the refrigerant jacket 221 is continuously flowed to the discharge path 214. In this state, the second control valve 211 is controlled to send a part of the boiler water from the blow path 121 to the collection path 210. The boiler water sent to the collection path 210 is cooled by the cooling water in the refrigerant jacket 221 when passing through the coil part 223. The cooled high-pressure boiler water is reduced in pressure by passing through the pressure reducer 230, and is stored in the water tank 240. Here, the boiler water is usually cooled to a temperature of 40° C. or less, which is suitable for measurement by the water quality analyzer 300.

[0037] The boiler water flowing from the sampling path 210 into the water tank 240 is cooled and then depressurized, so that the generation of flash steam that causes fluctuations in water quality is suppressed. As a result, the boiler water stored in the water tank 240 is maintained at the same water quality as the boiler water in the boiler body 120, and is used as sample water for evaluating the water quality in the water quality analyzer 300.

[0038] In the evaluation of the quality of boiler water, if the amount of collected boiler water increases, it will affect the instantaneous energy loss and the operation control of the boiler body 120. Also, it is necessary to increase the amount of cooling water for cooling the boiler water in the cooler 220. Therefore, it is preferable to limit the amount of boiler water stored in the water tank 240 to the amount necessary for analysis by the water quality analyzer 300. Therefore, since the water tank 240 is provided with a sensor 246 for measuring electrical conductivity at its upper part, the rise in the water level in the water tank 240 due to the inflow of boiler water from the collection path 210 is detected in light of the change in electrical conductivity, and the closing timing of the second control valve 211 is controlled accordingly. As a result, the supply of boiler water to the water tank 240 is stopped, and the boiler water that flows into the water tank 240 above a predetermined water level overflows into the first overflow path 241. As a result, the amount of collected boiler water is not increased unnecessarily, and the necessary amount of boiler water is stored in the water tank 240.

[0039] In addition, the conductivity and temperature of the boiler water stored in the water tank 240 are measured by a sensor 246, and if the water quality is too low for the water quality analyzer 300 or if the cooling is insufficient, the second opening / closing valve 244 is opened and the water is discharged through the drainage path 242.

[0040] When a predetermined amount of boiler water is stored in the water tank 240, the fourth on-off valve 253 is opened and the pump 251 is operated. As a result, the boiler water stored in the water tank 240 is sent from the water supply path 250 to the circulation path 252 and returned to the water tank 240. As a result, the boiler water is circulated and agitated, thereby improving the homogeneity of the water quality in the water tank 240. Here, the homogeneity of the water quality can be confirmed based on the stability of the conductivity measured by the sensor 246. This suppresses the influence of measurement errors and the like caused by supplying non-homogeneous sample water to the water quality analyzer 300, and improves the accuracy of the water quality evaluation. After the conductivity of the boiler water measured by the sensor 246 becomes stable, the pump 251 is stopped and the fourth on-off valve 253 is closed to stop the circulation of the boiler water.

[0041] When measuring the pH of boiler water using sample water stored in the water tank 240, the first inlet valve 311 is opened and the sample water is introduced from the water tank 240 through the water supply path 250 into the cell of the first analyzer 310. The first analyzer 310 is then operated to measure the pH of the sample water. The sample water in the cell is discharged through the first waste water channel 312.

[0042] On the other hand, when measuring the silica concentration of boiler water, if the boiler water stored in the water tank 240 is used as the sample water as is, the silica concentration of the boiler water is usually relatively high, and there is a possibility that it will greatly exceed the measurement range of the second analyzer 320 or that the measurement accuracy will be impaired. Therefore, the boiler water is diluted to the required ratio in the water tank 240 and used as the sample water.

[0043] In diluting the boiler water, the fifth on-off valve 266 is opened while the first on-off valve 213 is kept open, and cooling water from the introduction passage 212 is supplied as dilution water to the main passage 261 of the supply passage 260. The dilution water supplied to the main passage 261 is purified by passing through an activated carbon filter 263 and an ion exchange resin filter 264 in this order, and flows into the metering tank 265. Here, the dilution water that flows into the metering tank 265 above a predetermined water level overflows into the second overflow passage 267. As a result, a predetermined amount of dilution water is stored in the metering tank 265.

[0044] Next, in the water tank 240, the third on-off valve 245 is opened, and a part of the boiler water is discharged from the water tank 240 through the water amount adjustment path 243. As a result, the water level of the boiler water in the water tank 240 drops, and the amount of boiler water remaining in the water tank 240 is adjusted. Next, the sixth on-off valve 269 is opened, and the entire amount of dilution water is supplied from the metering tank 265 to the water tank 240 through the communication path 268. As a result, the boiler water in the water tank 240 is diluted with the dilution water and prepared as sample water suitable for measurement by the second analyzer 320. Here, the residual amount of the boiler water in the water tank 240 is adjusted to a predetermined amount by the water amount adjustment path 243, and the boiler water is diluted by supplying a predetermined amount of dilution water stored in the metering tank 265, so that the required dilution ratio can be controlled with high accuracy. In addition, when diluting to a required ratio, the amount of boiler water in the water tank 240 is reduced and diluted with dilution water, so that the amount of dilution water used can be reduced.

[0045] The sample water prepared by diluting the boiler water in the water tank 240 is circulated through the circulation path 252 by opening the fourth open valve 253 again and operating the pump 251, and is thereby stirred and homogenized. The homogeneity of the sample water prepared here can be confirmed based on the stability of the electrical conductivity measured by the sensor 246. This suppresses the influence of measurement errors and the like caused by diluting the sample water, and improves the accuracy of the water quality evaluation. When measuring the silica concentration of the boiler water, the second introduction valve 321 is opened and the sample water is introduced from the water tank 240 through the water supply path 250 into the cell of the second analyzer 320. The second analyzer 320 is then operated to measure the silica concentration of the sample water. The silica concentration of the boiler water can be calculated based on the silica concentration measured for the sample water and the dilution ratio of the boiler water. The sample water in the cell is discharged through the second waste water channel 322.

[0046] The boiler system 1 controls the amount of required chemicals added to the feed water from the chemical supply device 140 and the amount of boiler water blown from the boiler body 120 in accordance with the pH and silica concentration of the boiler water evaluated by the water quality analyzer 300 and the conductivity of the boiler water measured by the sensor 246, thereby controlling the water quality of the boiler water.

[0047] The pH and silica concentration of the boiler water evaluated by the water quality analyzer 300 are not measured on boiler waters individually collected from the boiler body 120 with a time lag for each evaluation, but are measured on sample waters distributed from boiler waters collected all at once from the boiler body 120 without a time lag, and therefore accurately reflect each evaluation item at the time the boiler water was collected, making them highly reliable. Therefore, when the boiler 10 is a multi-tube once-through boiler (a special circulation boiler defined in the Japanese Industrial Standards (JIS)) in which the water quality of the boiler water fluctuates significantly, the boiler system 1 equipped with the water quality evaluation device 20 is particularly effective in water quality management for suppressing scale and corrosion in the multi-tube once-through boiler.

[0048] In the boiler system 1, the quality of the boiler water can also be controlled in light of fluctuations in the quality of the raw water. In this case, the first on-off valve 213 of the supply path 260 is opened, and the seventh on-off valve 270 of the sub-path 262 is opened. As a result, the raw water used as cooling water flows into the sub-path 262 of the supply path 260 and is supplied to the water tank 240. The quality of the raw water stored in the water tank 240 is then analyzed by the water quality analyzer 300, and in light of the results, the amount of a required chemical added from the chemical supply device 140 to the feed water and the amount of boiler water blown from the boiler body 120 are controlled, thereby controlling the quality of the boiler water.

[0049] In the above-mentioned boiler system 1, the boiler water quality evaluation device 20 can be modified in various ways. For example, the following modifications are possible. (1) The cooler 220 is preferably a water-cooled heat exchanger as used in the above embodiment, since it can stably cool the boiler water flowing through the collection path 210 in a short time by using low-temperature cooling water. However, it can be changed to an air-cooled type or a type using another refrigerant as long as it can sufficiently cool the boiler water flowing through the collection path 210. Since the installation environment of the boiler 10 and the preparation device 200 is often high temperature, when an air-cooled heat exchanger is used as the cooler 220, if air that has become hot due to the surrounding environment is used as the refrigerant, the cooling capacity for the high-temperature boiler water may be insufficient. In addition, if the cooling capacity is insufficient or becomes unstable, the sensor 246 installed in the water tank 240 may lose the measurement accuracy of the conductivity due to its temperature dependency. Therefore, when an air-cooled type is used as the cooler 220, it is preferable to consider the temperature management and control of the air used as the refrigerant.

[0050] (2) In order to facilitate highly accurate adjustment to the required water volume by discharging a portion of the water from the water volume adjustment path 243 when diluting the boiler water, the water tank 240 can be designed to have a small internal cross-sectional area for the predetermined water level portion, so that subtle fluctuations in the water level are less likely to be reflected in the water volume. Also, in order to store a predetermined amount of dilution water with high accuracy, the metering tank 265 can be designed to have a small internal cross-sectional area for the predetermined water level portion corresponding to the second overflow path 267, so that subtle fluctuations in the water level are less likely to be reflected in the water volume.

[0051] (3) In the above embodiment, the water quality analyzer 300 is equipped with two analyzers, one for measuring pH and the other for measuring silica concentration, but the evaluation items of water quality are not limited to pH and silica concentration, and may be, for example, the concentrations of various chemicals added to the water supply from the chemical supply device 140 or dissolved components such as chloride ions contained in the raw water. The water quality analyzer 300 may also be equipped with three or more analyzers to measure three or more types of water quality items. (4) If the water quality evaluation items by each analyzer provided in the water quality analyzer 300 do not require dilution of the boiler water, or if there is no need to analyze the quality of the raw water by the water quality analyzer 300, the relevant elements in the supply path 260 can be omitted as appropriate.

[0052] (5) In the above-described embodiment, boiler water is collected from the boiler body 120 through the blow path 121. However, the boiler water may be collected to the collection path 210 through a path provided in the boiler body 120 separate from the blow path 121.

[0053] (6) In the above-described embodiment, the activated carbon filter 263 and the ion exchange resin filter 264 in the supply path 261 can be omitted as appropriate. That is, in the above-described embodiment, desalted water treated with the activated carbon filter 263 and the ion exchange resin filter 264 is used as the dilution water, but raw water used as cooling water to be supplied to the supply path 261 or soft water obtained by removing hardness components from the raw water may be used as the dilution water as it is. In this case, when the dilution water also includes the target water quality evaluation items related to the boiler water, the water quality of the dilution water can be evaluated in advance and the analysis results of the sample water can be corrected in light of the results to evaluate the water quality of the boiler water.

[0054] (7) In the above embodiment, the dilution of the boiler water is controlled with high precision by supplying the dilution water stored in the metering tank 265 to the boiler water in the water tank 240 adjusted to a predetermined amount, but the boiler water may be diluted while measuring the conductivity with the sensor 246. That is, the supply of dilution water to the boiler water is controlled so that the conductivity of the boiler water before dilution is equivalent to the required dilution ratio, and the boiler water can be diluted with high precision. In this case, for example, the metering tank 265, the communication path 268, and the sixth opening / closing valve 269 are omitted, and the tip of the main path 261 is set to directly connect to the water tank 240. [Explanation of symbols]

[0055] 10. Boiler 20 Water quality evaluation device 200 Preparation equipment 210 Collection route 220 Cooler 230 Pressure reducer 240 Water Tank 243 Water flow control route 245 Third opening and closing valve 246 Sensors 250 Water Supply Route 252 Circulation Route 260 Supply Route 265 Measuring tank 269 ​​6th opening and closing valve 300 water quality analyzer

Claims

1. An apparatus for preparing sample water for evaluating the water quality of boiler water collected from an operating boiler using an analyzer, comprising: A boiler water collection path extending from the boiler; A cooler for the boiler water flowing through the collection path; A pressure reducer for the boiler water is disposed in the collection path downstream of the cooler; a water tank open to the atmosphere for storing the boiler water from the pressure reducer; a water supply path extending from the water tank for supplying the sample water to the analyzer; A sample water preparation device for evaluating the water quality of boiler water.

2. 2. The apparatus for preparing sample water for evaluating the quality of boiler water according to claim 1, wherein the cooler is a water-cooled heat exchanger and the pressure reducer is a constant flow valve.

3. 2. The apparatus for preparing sample water for evaluating the quality of boiler water according to claim 1, further comprising a circulation path that is branched off from said water supply path and communicates with said water tank.

4. 2. The apparatus for preparing sample water for evaluating the quality of boiler water according to claim 1, wherein the water tank is provided with a sensor at an upper portion thereof for measuring the electrical conductivity of the stored boiler water.

5. The apparatus for preparing sample water for evaluating the water quality of boiler water as described in claim 4, wherein the water tank is provided with a supply path for supplying water for diluting the boiler water, and the supply path has a control valve for switching between starting and stopping the supply of the water for dilution.

6. 6. The apparatus for preparing sample water for evaluating the quality of boiler water according to claim 5, wherein the water tank is provided with a water volume regulating valve for controlling the amount of the boiler water stored therein to a predetermined amount.

7. 7. The apparatus for preparing sample water for evaluating the quality of boiler water according to claim 6, wherein the supply path has a metering tank for limiting the amount of the dilution water supplied to the water tank to a predetermined amount.

8. An apparatus for evaluating the quality of boiler water from a boiler in operation, using the apparatus for preparing sample water for evaluating the quality of boiler water according to any one of claims 1 to 7, a water quality analyzer connected to the water supply path of the conditioning device; Boiler water quality evaluation device.

Images