JP2012083293A - Hot water quality measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water quality measurement device that cleans a water quality sensor with hot water obtained by eliminating ions without the provision of cleaning liquid from the outside of the device.SOLUTION: A hot water quality measurement device includes a water quality sensor 2 that measures the quality of hot water, and a deionization part 11 that produces deionized hot water by eliminating ions in the hot water. The hot water quality measurement device cleans the water quality sensor 2 with the deionized hot water.

Description

  The present invention relates to a hot water / water quality measuring apparatus having a mechanism for cleaning a water quality sensor that measures the quality of hot water having a high dissolved ion concentration.

Patent Document 1 includes an electrolytic cell that electrolyzes supplied water to ionized water having a predetermined pH value, a pH sensor disposed in a drainage channel of the electrolytic cell, and a sensor cleaning unit that cleans the pH sensor. The ion water generator provided with the pH sensor characterized by this is disclosed.

JP 2001-235443 A

  At a geothermal power plant, a mixed fluid of steam and hot water ejected from the underground is separated into steam and hot water by a gas-liquid separator, and then the steam is introduced into a turbine generator for geothermal power generation. Conventionally, hot water separated by a gas-liquid separator has been returned to the reduction well. In recent years, introduction of binary power generation in which high-temperature hot water that has not been used for power generation is used as a heat source and power is generated using a low-boiling point medium has been studied. In binary power generation, the temperature of hot water after use is further lowered, so that a scale source such as silica becomes supersaturated, and scale may be deposited. If a scale is deposited on the sensor of a pH meter or silica concentration meter, measurement may become impossible, measurement accuracy may deteriorate, and the response speed of the measuring device may slow. In order to remove this scale, the maintenance frequency has to be increased, and there has been a problem that maintenance costs increase.

  Therefore, sulfuric acid or the like is added to hot water to control the pH to about 5 to 6, and the maintenance rate is extended by reducing the polymerization rate of silica, thereby reducing maintenance costs. Since the quality of hot water changes from day to day, running sulfuric acid increases when sulfuric acid having a sufficient margin with respect to the range of change is constantly added, so that an optimal amount of sulfuric acid is required to be controlled. Therefore, the amount of sulfuric acid added is controlled based on the results of measuring the pH and silica concentration.

  However, when the sensor unit is manually cleaned, labor costs are incurred. Further, the method of physically rubbing off the dirt on the sensor part easily damages the sensor. Acid cleaning can remove stains from organic substances and substances that are highly soluble in acids, but it is difficult to wash substances that are poorly soluble in acids such as silica. Further, in the pH meter, it is necessary to sufficiently wash away the acid used for washing with pure water after the acid washing. Silica is easily dissolved by washing with alkali, but not only dirt but also a glass electrode is dissolved, which causes a problem that the life of the electrode is shortened. Moreover, it is necessary to wash away the alkali used for washing sufficiently. When acid or alkali is used for washing, it cannot be discharged directly into rivers or sewage, and waste liquid treatment such as neutralization is required, which increases costs. In addition, geothermal power plants are often installed in mountainous areas, and holding a large amount of pure water for sensor cleaning has a problem that it is not economical because of the transportation cost of pure water. The solubility of the scale due to the difference in pH of the cleaning liquid varies depending on the composition of the scale. For example, silica is easily dissolved in an alkaline solution, but calcium-based scale such as calcium carbonate is easily dissolved in an acidic solution.

  In the pH sensor of Patent Document 1, strong acidic water obtained by electrolyzing water in which ions are present is used as a cleaning solution. However, when the dissolved ion concentration is high, the ratio of the dissolved ion concentration to the saturated ion concentration increases, and There is a problem that the concentration difference that can contribute to dissolution of the scale attached to the sensor is small, or the ability to dissolve the scale is not available when the cleaning liquid is supersaturated.

  Since the present inventor can obtain solubility in both cases using pure water, if hot water from which ions have been removed is used as a washing liquid, the difference in concentration between the saturated solubility and the dissolved ion concentration can be increased, and the temperature can be increased. Focusing on the fact that the higher the saturation solubility is higher and the dissolution rate of the scale is accelerated, the present invention was created.

  In order to solve the above problems, the present invention has an object to provide a hot water / water quality measuring apparatus that can clean a water quality sensor without supplying cleaning liquid from the outside by washing the water quality sensor with hot water from which ions have been removed. To do.

  In order to solve the above problems, a hydrothermal water quality measuring apparatus according to the present invention includes a water quality sensor that measures the quality of hot water, and a deionization unit that generates deionized hot water by removing ions of the hot water. And the water quality sensor is washed with the deionized hot water.

  Moreover, in the hot water quality measuring device of the present invention, a water quality sensor provided in a main pipe through which the hot water flows, a deionization unit that generates deionized hot water by removing ions of the hot water, A branch pipe and a second switching valve are provided in the main pipe downstream from the water quality sensor, one end of the branch pipe is connected to the deionization section, and a first switching valve is provided in the main pipe upstream from the water quality sensor. A return pipe that connects the deionization unit and the first switching valve, and a circulation pump that circulates and distributes the deionized hot water between the water quality sensor and the deionization unit.

The hot water / water quality measuring apparatus according to the present invention further comprises a temperature regulator for heating or cooling the hot water before supplying the hot water to the deionization unit.
Moreover, the hydrothermal water quality measuring apparatus according to any one of the present invention is characterized in that the deionization part is an ion exchange resin.

Moreover, the hydrothermal water quality measuring apparatus according to any one of the present invention is characterized in that the deionization unit is an electric regeneration type deionization apparatus.
Moreover, the hot water / water quality measuring apparatus according to any one of the present invention is characterized in that the water quality sensor is a pH meter or a silica concentration meter.

  The hot water / water quality measuring apparatus according to any one of the present invention further includes a control unit that controls opening and closing of the first switching valve and the second switching valve and starting and stopping of the deionization unit. The water quality sensor is automatically cleaned periodically.

  ADVANTAGE OF THE INVENTION According to this invention, the water quality sensor which can wash | clean a water quality sensor without supplying a washing | cleaning liquid from the outside can be provided by wash | cleaning a water quality sensor with the hot water from which ion was removed.

1 is a schematic configuration diagram according to a first embodiment of the present invention. It is a schematic block diagram which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram which concerns on the 3rd Embodiment of this invention.

  Hereinafter, an embodiment of a hot water quality measuring apparatus according to the present invention will be described with reference to the drawings. About the same component, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted. In addition, this invention is not limited to the following embodiment, In the range which does not change the summary, it can implement suitably.

  A first embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a hot water quality measuring apparatus according to the first embodiment. The hot water quality measuring device of the present invention includes a water quality sensor 2 provided in a main pipe 1 through which hot water flows, a deionization unit 5 that generates deionized hot water by removing ions of the hot water, A branch pipe 7 and a second switching valve 4 are provided in the main pipe 1 on the downstream side of the water quality sensor 2, one end of the branch pipe is connected to the deionization unit 5, and the main pipe 1 on the upstream side of the water quality sensor 2. 1 is provided with a first switching valve 3 for circulating the deionized hot water between the water quality sensor 2 and the deionizing unit 5 through the return pipe 8 connecting the deionized unit 5 and the first switching valve 3. A circulation pump 6 to be provided. The type of the water quality sensor 2 is not limited, and may be a pH meter, a silica meter, or another water quality meter. In FIG. 1, a pH meter is used as an example. Although the electric conductivity meter 9 is not essential, it is more preferable to provide it from the viewpoint of checking the ion adsorption ability of the ion exchange resin of the deionization part 5. The ion exchange resin is stored in a removable cartridge, and when the ion adsorption capacity of the ion exchange resin is lowered, the ion exchange resin is replaced with a cartridge containing a new ion exchange resin. As the ion exchange resin, if the amount of the strongly acidic cation exchange resin and the strongly basic ion exchange resin is adjusted according to the quality of the hot water, the exchange frequency of the ion exchange resin can be reduced. It may be provided at a volume ratio of 1. The larger the capacity of the piping through which the deionized hot water circulates, the greater the load on the deionization section 5 and the shorter the exchange frequency of the ion exchange resin. Therefore, the running cost can be reduced by making this volume as small as possible. Can be reduced.

  Although the temperature regulator 10 is provided in the middle of the branch pipe 7 that connects the second switching valve 4 and the deionization unit 5 in FIG. 1, it is not essential. However, when the temperature of the hot water flowing through the main pipe 1 is higher than the heat resistance temperature of the ion exchange resin of the deionization part 5, a temperature regulator 10 is provided to cool the hot water to a temperature lower than the heat resistance temperature of the ion exchange resin. . Many ion exchange resins have a heat-resistant temperature of about 50 ° C., so they are cooled to 50 ° C. or lower. As an example of the temperature regulator 10, it is good also as a structure which lengthens piping and cools piping with external air, it is good also as a structure which provides a fin in this piping and accelerates | stimulates heat transfer, and piping using a Peltier device May be cooled.

  When the temperature of the hot water flowing through the main pipe 1 is lower than the heat resistant temperature of the ion exchange resin of the deionization part 5, it is not essential to provide the temperature regulator 10, but the ion exchange resin of the deionization part 5 is not essential. It is desirable that the temperature be lower than the heat resistant temperature and as high as possible. This is because the concentration difference between the hot water saturation solubility and the dissolved ion concentration can be increased, and the higher temperature increases the saturation solubility and accelerates the dissolution rate of the scale.

  The control unit 16 is connected to the water quality sensor 2 and the electric conduction timepiece 9 through a signal line, and data is input to the control unit. Moreover, the control part 16 is electrically connected with the 1st switching valve 3, the 2nd switching valve 4, and the circulation pump 6, and the switching of the flow path of a valve and the flow volume of a circulation pump are controlled. The control unit 16 is not necessarily essential, and each device can be manually operated by a person. However, it is desirable that the control unit 16 automatically controls the device.

  Next, the operation of this apparatus will be described. At the time of water quality measurement by the water quality sensor 2, the first switching valve 3 and the second switching valve 4 are switched so that hot water flows only through the main pipe 1. When the measurement is completed, the first switching valve 3 and the second switching valve 4 are switched so that deionized hot water circulates between the water quality sensor 2 and the deionization unit 5 and flows therethrough.

  The determination of the end of cleaning may be a method in which the cleaning time is simply determined in advance by a timer (for example, measurement for 5 minutes, cleaning for 55 minutes), or when the indicated value of the conductivity meter 9 decreases and stabilizes, it is considered that the cleaning is completed. Control may be performed. When cleaning is completed, the first switching valve 3 and the second switching valve 4 are switched so that hot water flows only through the main pipe 1 to return the water quality sensor 2 to the measurement state, or the timing of the next measurement Stop water flow until.

  FIG. 2 is a schematic configuration diagram according to the second embodiment of the present invention. The second embodiment is an example in which the deionization unit 11 of the first embodiment is changed from an ion exchange resin to an electric regeneration type deionization apparatus (EDI). Hot water is introduced into a desalting chamber filled with an ion exchange resin (a mixed phase of a cation exchange resin and an anion exchange resin is generally used). The desalting chamber is provided between the cathode chamber 12 and the anode chamber 14, and a cation exchange membrane is provided between the cathode chamber and the desalting chamber, and an anion exchange membrane is provided between the anode chamber and the desalting chamber. is set up. The cathode chamber 12 is provided with a cathode, and the anode chamber 14 is provided with an anode. A pipe that connects one end of the cathode chamber 12 and the return pipe is provided, and a flow rate adjusting valve 17 is provided in the middle thereof. A pipe connecting the other end of the cathode chamber 12 and one end of the anode chamber is provided. A pipe for discharging the concentrate from the other end of the anode chamber is provided. The anode and the cathode are connected to a power source (not shown), and when a voltage is applied to the cathode and the anode according to a command from the control unit 16, the cation moves to the cathode and the anion moves to the anode, respectively. Ions such as chloride ions can be moved to the cathode chamber 12 and the anode chamber 14. The ion exchange resin in the desalting chamber is continuously regenerated by hydrogen ions and hydroxide ions generated by water electrolysis and ionization.

  As a method of compensating for the decrease in the liquid volume due to the concentrated liquid being discharged to the outside, the pipe is branched from the main pipe 1 on the upstream side of the first switching valve 3, and the upstream side of the deionization unit 11 or the temperature regulator 10. There is a method of connecting to the branch pipe 7 on the upstream side.

As another method, there is a method in which the first switching valve 3 is adjusted so as to supply hot water as raw water in the direction a-b by the flow rate of the concentrated liquid.
As another method, a buffer tank (not shown) may be provided in the middle of the branch pipe, and hot water larger than the amount of the concentrated liquid discharged to the outside by the deionization unit 11 may be stored. In this case, the following procedure is performed. After the measurement is completed, the first switching valve 3 is switched to flow in the a-b direction, and the second switching valve 4 is switched to flow in the a-c direction. The circulation pump 6 is started and hot water is stored in the buffer tank. A water level gauge is provided in the buffer tank, and when the water level gauge reaches the upper limit value, the first switching valve 3 is switched to flow in the cb direction, and deionized hot water is circulated in the same manner as described above. Let At this time, the water level in the buffer tank decreases by the amount of liquid discharged as the concentrated liquid. When the water level gauge reaches the lower limit value, the first switching valve 3 is caused to flow in the direction a-b, and hot water is stored again in the buffer tank.

  FIG. 3 is a schematic configuration diagram according to the third embodiment of the present invention. With respect to the content described in the second embodiment, an output unit of an ultrasonic generator is provided at a position facing a portion of the water quality sensor 2 that contacts the hot water, and the water quality sensor 2 is irradiated with ultrasonic waves to obtain pure water. The cleaning effect by is further enhanced. This installation of the ultrasonic generator can also be applied to the first embodiment.

DESCRIPTION OF SYMBOLS 1 Main piping 2 Water quality sensor 3 1st switching valve 4 2nd switching valve 5 Deionization part (ion exchange cartridge)
6 Circulation pump 7 Branch piping 8 Return piping 9 Electrical conductivity meter 10 Temperature regulator 11 Deionization part (electric regeneration type deionization device)
DESCRIPTION OF SYMBOLS 12 Cathode chamber 13 Desalination chamber 14 Anode chamber 15 Ultrasonic generator 16 Control part 17 Flow control valve

Claims (7)

  A water quality sensor for measuring the quality of the hot water; and a deionization unit for generating deionized hot water by removing ions of the hot water, wherein the water quality sensor is washed with the deionized hot water. Hot water quality measuring device.   The hot water / water quality measuring apparatus according to claim 1, wherein a water quality sensor is provided in a main pipe through which the hot water flows, and a deionization unit that generates deionized hot water by removing ions of the hot water. The branch pipe and the second switching valve are provided in the main pipe downstream from the water quality sensor, one end of the branch pipe is connected to the deionization section, and the first switch valve is provided in the main pipe upstream from the water quality sensor. And a return pipe for connecting the deionization part and the first switching valve, and a circulation pump for circulating the deionized hot water between the water quality sensor and the deionization part. Water quality measuring device.   The hydrothermal water quality measurement apparatus according to claim 1 or 2, further comprising a temperature regulator that heats or cools the hot water before supplying the hot water to the deionization unit. apparatus.   The hot water / water quality measuring apparatus according to claim 1, wherein the deionization part is an ion exchange resin.   The hot water / water quality measuring apparatus according to claim 1, wherein the deionizing unit is an electric regeneration type deionizing apparatus.   The hot water / water quality measuring apparatus according to claim 1, wherein the water quality sensor is a pH meter or a silica concentration meter.   The hot water and water quality measuring apparatus according to any one of claims 1 to 6, further comprising: a control unit that controls opening and closing of the first switching valve and the second switching valve and starting and stopping of the deionization unit. And a hot water quality measuring device that automatically cleans the water quality sensor periodically.

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