JP6651949B2 - SAMPLING DEVICE AND CONTROL METHOD OF SAMPLING DEVICE - Google Patents

Description

  The present invention relates to a sampling device for collecting sample water such as canned water and analyzing water quality in a power plant such as a thermal power plant, and a control method thereof.

  In power plants such as thermal power plants, water quality such as boiler can water and condensate is analyzed and water quality is adjusted based on the analysis results in order to prevent corrosion of plant components caused by water quality. . In order to perform such water quality analysis and water quality adjustment, a power generation plant is provided with a sampling device capable of collecting sample water at each point in the plant at one location and performing water quality analysis.

  Conventional sampling devices include a sample valve for collecting sample water such as canned water and condensate from a boiler, a supply valve for supplying the sample water collected by the sample valve to an electrode-type water quality analyzer, and a supply valve. An electrode-type water quality analyzer for analyzing the water quality of the sampled water with an analysis electrode, and a discharge valve for discharging the analyzed sample water from the electrode-type water quality analyzer are provided (for example, see Patent Document 1).

  An electrode-type water quality analyzer is an analyzer that immerses an analysis electrode having a working electrode and a reference electrode in sample water and analyzes the water quality of the sample water based on a potential difference generated between the working electrode and the reference electrode. For example, there are a pH meter, an electric conductivity meter and a hydrazine meter. When the electrode for analysis is deteriorated by drying, the accuracy of analysis is lowered and the response may be delayed. Therefore, it is necessary to immerse the electrode in pure water or sample water so as not to dry when not in use.

  In the sampler of Patent Document 1, when analyzing the water quality of the sample water, the sample valve, the supply valve, and the discharge valve are opened, and the water quality of the sample water is analyzed by the electrode type water quality analyzer. When the water quality analysis of the sample water is to be stopped, open the dummy water valve connected to the electrode type water quality analyzer, inject pure water, close the supply valve and the discharge valve, and insert the pure water into the electrode type water quality analyzer. Pure water is retained, and the electrode for analysis is immersed in pure water to prevent drying.

JP 2009-025101 A

  The sampling device supplies sample water to the electrode-type water quality analyzer at an appropriate timing during operation of the unit of the power plant, and also stores pure water in the electrode-type water quality analyzer at an appropriate time when the unit is stopped. There must be. However, in the sampler of Patent Literature 1, since the supply valve and the discharge valve are not automatically opened and closed, the supply valve and the discharge valve may not be opened and closed at an appropriate timing. In particular, if the supply of pure water or sample water to the electrode-type water quality analyzer is delayed when the operation of the power plant unit is stopped, the analysis electrodes are dried and deteriorated. If the analysis electrode is dried and deteriorated, it must be immersed in pure water or a pH standard solution for about half a day to one day to perform a drying countermeasure process, which takes time and costs.

  An object of the present invention is to provide a sampler and a control method of the sampler that can supply or retain sample water to the electrode type water quality analyzer at an appropriate timing according to the operation state of the power plant. I do.

In order to solve the above-mentioned problem, the invention according to claim 1 is a sample collection device that collects sample water of a power plant and analyzes the water quality of the sample water by an electrode type water quality analyzer. Valve for supplying water to the electrode-type water quality analyzer, a discharge valve for discharging the analyzed sample water from the electrode-type water quality analyzer, and an electrode-type water quality analysis by opening the supply and discharge valves when the power plant unit is operating. Control means for supplying the sample water to the meter, closing the supply valve and the discharge valve when the unit is stopped, allowing the sample water to stay in the electrode type water quality analyzer, and immersing the analysis electrode of the electrode type water quality analyzer in the sample water. A sample water collecting path for collecting the analyzed sample water as makeup water to be supplied to the boiler .

  According to the first aspect of the present invention, a sampler for collecting water sampled from a power plant and analyzing water quality includes an electrode-type water quality analyzer for analyzing the water quality of sampled water by an analysis electrode, and a sampled water sample. A supply valve for supplying water to the electrode type water quality analyzer, a discharge valve for discharging the analyzed sample water from the electrode type water quality analyzer, and control means for controlling the supply valve and the discharge valve are provided. The control means opens the supply valve and the discharge valve to supply the sample water to the electrode type water quality analyzer when the unit of the power plant is in operation, and closes the supply valve and the discharge valve to stop the electrode type water quality analyzer when the unit is stopped. The analysis electrode is immersed in the sample water to prevent deterioration due to drying.

The invention according to claim 2 is a sampler for collecting a sample water of a power plant and analyzing the water quality of the sample water by an electrode type water quality analyzer, and supplying the sampled water to the electrode type water quality analyzer. A supply valve, a discharge valve for discharging the analyzed sample water from the electrode type water quality analyzer, and a supply valve and a discharge valve that are open to supply the sample water to the electrode type water quality analyzer during unit operation of the power plant, When the unit is stopped, the supply valve and the discharge valve are closed to allow the sample water to stay in the electrode type water quality analyzer, and the control means for immersing the analysis electrode of the electrode type water quality analyzer in the sample water, and according to the operation status of the unit. and a supply pump is switched supply and supply stop of the sample water for the electrode type water analyzer, the control unit opens the supply valve and the discharge valve when the supply pump starts supplying the water sample supplied Pont There close the supply valve and the discharge valve when stopping the supply of the water sample.

The invention according to claim 3 is a sampler for collecting a sample water of a power plant and analyzing the water quality of the sample water by an electrode type water quality analyzer, and supplying the sampled water to the electrode type water quality analyzer. A supply valve, a discharge valve for discharging the analyzed sample water from the electrode type water quality analyzer, and a supply valve and a discharge valve that are open to supply the sample water to the electrode type water quality analyzer during unit operation of the power plant, When the unit is stopped, the supply valve and the discharge valve are closed to allow the sample water to stay in the electrode type water quality analyzer, and control means for immersing the analysis electrode of the electrode type water quality analyzer in the sample water is further provided. , A plurality of sample analysis systems including an electrode type water quality analyzer and a discharge valve, and the control means controls the plurality of sample water analysis systems in an integrated manner.

The invention according to claim 4 is a sample collection device that collects sample water from a power plant and analyzes the water quality of the sample water with an electrode type water quality analyzer, and supplies the collected sample water to the electrode type water quality analyzer. A supply valve, a discharge valve for discharging the analyzed sample water from the electrode type water quality analyzer, and a supply valve and a discharge valve that are open to supply the sample water to the electrode type water quality analyzer during unit operation of the power plant, When the unit is stopped, the supply valve and the discharge valve are closed to allow sample water to stay in the electrode type water quality analyzer, and control means for immersing the analysis electrode of the electrode type water quality analyzer in the sample water. The analyzer has an analysis tank for analyzing the sample water supplied from the supply valve by the analysis electrode, and a discharge tank that is connected to the analysis tank and discharges the analyzed sample water flowing from the analysis tank from the discharge valve. And.

  According to a fifth aspect of the present invention, in the sample collection device according to any one of the first to fourth aspects, the sample water is a liquid that requires water quality monitoring, such as boiler can water.

According to a sixth aspect of the present invention, there is provided a power supply plant, a supply valve for supplying collected sample water to the electrode type water quality analyzer, a discharge valve for discharging the analyzed sample water from the electrode type water quality analyzer, and a supply valve. And a control means for controlling the discharge valve, and a sample water recovery path for recovering the analyzed sample water , wherein the control means controls the power supply during unit operation of the power plant. Open the valve and discharge valve to supply sample water to the electrode type water quality analyzer.When the unit is stopped, close the supply valve and discharge valve to allow the sample water to stay in the electrode type water quality analyzer, and analyze the electrode type water quality analyzer. The sample electrode is immersed in the sample water, and the sample water recovery path collects the analyzed sample water as makeup water to be supplied to the boiler .

  According to the first and sixth aspects of the invention, the supply valve and the discharge valve are opened to supply the sample water to the electrode type water quality analyzer during the unit operation of the power plant, so that the plant configuration caused by the water quality of the sample water is provided. Accident of material corrosion can be prevented. In addition, when the unit is stopped, the supply valve and the discharge valve are closed, the sample water is retained in the electrode type water quality analyzer, and the analysis electrode is immersed in the sample water, so that the deterioration of the analysis electrode due to drying can be prevented. . Therefore, according to the sampling device of the present invention, even when the power plant unit is shut down for a long period of time, the electrode for analysis can be prevented from being dried. Will be able to use it. In addition, since it is not necessary to perform a measure for drying the analysis electrode at the start of the unit operation, the time and cost required for the measure can be reduced.

  According to the second aspect of the present invention, the supply valve and the discharge valve are controlled in accordance with the operation state of the supply pump for supplying and stopping the supply of the sample water, so that the sampling of the sample water is actually started. The supply and retention of the sample water to the electrode type water quality analyzer can be switched at the same timing or when the sampling of the sample water is stopped. Therefore, unnecessary supply and retention of the sample water to the electrode-type water quality analyzer can be prevented as compared with the case where the control is performed according to the operation state of the unit.

  According to the third aspect of the present invention, since a plurality of sample analysis systems can be controlled by the control means in a comprehensive manner, the type of the sample water is such as makeup water, canned water, condensate, generated steam, etc. Even in various cases, the analysis electrodes of each sample analysis system can be protected from drying.

  According to the invention as set forth in claim 4, the measuring tank in which the sample water of the electrode type water quality analyzer is retained, the analysis tank for analyzing the sample water with the analysis electrode, and the discharge valve for discharging the analyzed sample water. Since the sample water is separated from the discharge tank, the sample water leaks from the discharge tank due to a failure of the discharge valve when the sample water is retained in the electrode type water quality analyzer, for example. Since the leakage of the sample water from inside can be prevented, the deterioration of the analysis electrode due to drying can be prevented.

  According to the invention as set forth in claim 5, since the sample water can be applied to liquids requiring water quality monitoring such as boiler can water, it can be used for collecting and analyzing various types of sample water. Can be.

It is a schematic diagram showing composition of a thermal power plant. It is a schematic system diagram which shows the structure of a sampling device. It is the schematic which shows the structure of the pH meter for cans, the supply valve, and the discharge valve. It is a flowchart which shows the control procedure of a supply valve and a discharge valve.

  Hereinafter, the present invention will be described based on the illustrated embodiment.

  FIG. 1 is a schematic diagram illustrating a configuration of a thermal power plant (power generation plant) 1 including the sample collection device of the present invention. The thermal power plant 1 includes a plurality of units including a boiler 2, a turbine 3, a generator 4, a condenser 5, a sampling device 6, a unit computer (control means) 7, and the like.

  The boiler 2 heats makeup water using coal, oil, natural gas, or the like as fuel, and generates steam. The turbine 3 drives the generator 4 with the steam generated by the boiler 2 and causes the generator 4 to generate power. The condenser 5 condenses the steam discharged from the turbine 3 to generate condensed water, and supplies the generated condensed water to the boiler 2 as makeup water.

  The sampling device 6 samples the can water in the boiler 2 and the condensate of the condenser 5 as sample water and analyzes the water quality in order to prevent performance deterioration due to corrosion of facilities such as pipes and generation of scale. Still water and condensate are collected via sample valves 111 and 121. The unit computer 7 is a computer system that controls the entire thermal power plant 1 as a whole, and also controls the sampling device 6 as control means of the present invention. The sampling device 6 and the unit computer 7 protect the analysis electrodes of the pH meter (electrode water analyzer) in the sampling device 6 from drying when the unit is stopped for a long time.

  FIG. 2 is a schematic system diagram illustrating the configuration of the sample collection device 6. The sampling device 6 includes a cooling water supply channel 8A, a cooling water drain channel 8B, a sample water drain channel 9A, a sample water recovery channel 9B, and the like. The cooling water supply channel 8A and the cooling water drain channel 8B are pipes for supplying and draining cooling water used for cooling the sample water to a plurality of sample analysis systems. The sample water drain 9A is a pipe for draining the analyzed sample water toward the wastewater treatment device. The sample water collecting passage 9B is a pipe for collecting analyzed sample water as makeup water.

  The sampling device 6 includes a plurality of sample analysis systems, for example, a can water analysis system 11 and a condensate analysis system 12, for collecting and analyzing a plurality of types of sample water such as makeup water, canned water, and condensate. . The unit computer 7, which is a control means, controls the canned water analysis system 11 and the condensate analysis system 12 as a whole.

  The still water analysis system 11 is an analysis system for collecting and analyzing still water from the boiler 2, and includes a sample valve 111 for collecting still water from the boiler 2, a cooler 112, a supply pump 113, and a head vessel. 114, a supply valve 115, a pH meter 116 for still water, and a discharge valve 117.

  The cooler 112 is connected to the cooling water supply passage 8A and the cooling water drain passage 8B, and cools the can water supplied from the sample valve 111 with the cooling water. The supply pump 113 is a pump for supplying canned water to the pH meter 116 for canned water, and the supply of canned water and the stop of the supply are switched according to the operation state of the unit. The head vessel 114 applies a constant water pressure to the still water pH meter 116 to stabilize the flow rate of the can water.

  The supply valve 115 supplies canned water to the canned water pH meter 116, and the discharge valve 117 is a valve for discharging analyzed canned water from the canned water pH meter 116. The opening and closing of the supply valve 115 and the discharge valve 117 are controlled by the unit computer 7.

  As shown in FIG. 3 (A), a still water pH meter (electrode water quality analyzer) 116 is provided above the measuring tank 116a and a measuring tank 116a for storing the can water supplied from the supply valve 115. An analysis electrode 116c inserted through the opening 116b provided, a lid 116d for opening and closing the opening 116b, and a main body cover 116e covering the entire measuring tank 116a are provided.

  The measuring tank 116a is connected to the analyzing tank 116f for analyzing the can water supplied from the supply valve 115 by the analyzing electrode 116c, and the analyzed pipe which is connected to the analyzing tank 116f by the communicating portion 116g and flows from the analyzing tank 116f. A discharge tank 116h for discharging water from the discharge valve 117 is provided.

  The analysis electrode 116c includes a working electrode and a reference electrode (not shown), and is an analyzer that analyzes the pH (water quality) of the tube water based on a potential difference generated between the working electrode and the reference electrode. When the analysis electrode 116c is deteriorated by drying, the analysis accuracy may be reduced and the response may be delayed. Therefore, when the water pH meter 116 is not used, it is necessary to treat the electrode 116c for analysis so as not to dry.

  The unit computer 7 controls the opening and closing of the supply valve 115 and the discharge valve 117 according to the operation state of the supply pump 113, that is, the operation state of the unit. 117 is closed and the can water is retained in the measuring tank 116a. Then, the analysis electrode 116c is immersed in the retained can water to prevent the analysis electrode 116c from being deteriorated due to drying.

  The condensate analysis system 12 is an analysis system for collecting and analyzing condensate from the condenser 5 and, like the can water analysis system 11, a sample valve 121, a supply pump 123, a head vessel 124, and a supply valve. 125, a condensing pH meter 126, a discharge valve 127, and the like. Since these configurations are the same as those of the still water analysis system 11, detailed description will be omitted.

  Next, the operation of the sample collection device 6 and the unit computer 7 will be described with reference to the flowchart of FIG. When the supply pumps 113 and 123 operate (YES in step S1), that is, when the units start operating, the unit computer 7 sets the sample valves 111 and 121, the supply valves 115 and 125, and the discharge valves 117 and 127. Is opened (step S2). As a result, as shown in FIG. 3A, the still water and the condensate are supplied to the still water pH meter 116 and the condensate pH meter 126 by the supply pumps 113 and 123, respectively. Then, the pH of the still water and the condensate are analyzed by the condensate pH meter 126 (step S3). The analyzed can water and condensate are discharged to the sample water drain 9A via the discharge valves 117 and 127.

  When the supply pumps 113 and 123 are stopped (YES in step S4), that is, when the units stop operating, the unit computer 7 sets the sample valves 111 and 121, the supply valves 115 and 125, and the discharge valves 117 and 127. Is closed (step S5). As a result, as shown in FIG. 3B, the can water and the condensate are respectively retained in the measuring tanks 116a of the can water pH meter 116 and the condensate pH meter 126, and the analysis electrode 116c is immersed. Therefore, deterioration of the analysis electrode 116c due to drying can be prevented.

  According to the present embodiment, the supply valves 115 and 125 and the discharge valves 117 and 127 are opened during the operation of the unit to supply canned water and condensed water to the pH meters 116 and 126, and the quality of the canned water and condensed water is analyzed. Therefore, it is possible to prevent a corrosion accident of the plant components due to the water quality of the canned water and the condensate. Further, when the unit is stopped, the supply valves 115 and 125 and the discharge valves 117 and 127 are closed to allow the water and condensate to stay in the pH meters 116 and 126, and the analysis electrode 116c is immersed in the water and condensate. Deterioration due to drying of the analysis electrode 116c can be reliably prevented. Therefore, even when the unit is stopped for a long period of time, drying of the analysis electrode 116c can be prevented, so that the pH meters 116 and 126 can be used immediately at the start of operation. In addition, since there is no need to perform a measure for drying the analysis electrode 116c at the start of the unit operation, the time and cost required for the measure can be reduced.

  Further, the supply valves 115 and 125 and the discharge valves 117 and 127 are controlled in accordance with the operation states of the supply pumps 113 and 123 for supplying and stopping the supply of the canned water and the condensate. The supply and retention of the sample water to the pH meters 116 and 126 can be switched at the timing when the collection is actually started or when the collection is stopped. Therefore, unnecessary supply and retention of the sample water to the pH meters 116 and 126 can be prevented as compared with the case where the control is performed according to the operation state of the unit.

  Further, since a plurality of sample analysis systems can be comprehensively controlled by the unit computer 7, each sample analysis system can be used even when the type of sample water is various such as makeup water, canned water, condensate water, generated steam, and the like. The analytical electrodes of the system can be protected from drying.

  Further, the measuring tanks of the pH meters 116 and 126 are divided into an analysis tank 116f for analyzing the sample water by the analysis electrode 116c and a discharge tank 116h for discharging the analyzed sample water. When the sample water is retained in the pH meters 116 and 126, even if the sample water leaks from the discharge tank 116h due to failure of the discharge valves 117 and 127, the sample water is prevented from leaking from the analysis tank 116f. Deterioration of the analysis electrode 116c due to drying can be prevented. Furthermore, since the present invention can be applied to liquids requiring water quality monitoring such as boiler can water as sample water, it can be used for collecting and analyzing various types of sample water.

  Although the embodiments of the present invention have been described in detail above, the specific configuration is not limited to the embodiments, and even if there is a design change or the like within a range not departing from the gist of the present invention, the present invention is not limited to the embodiments. include. For example, the opening and closing of the supply valves 115 and 125 and the discharge valves 117 and 127 are controlled in accordance with the operation status of the supply pumps 113 and 123. However, depending on the pressure of the sample water, the supply valve 115 may be used without using the supply pump. , 125 and the discharge valves 117, 127 can be supplied to the water quality analyzer simply by opening the same. Therefore, when the present invention is applied to a sample analysis system that does not use such a supply pump, the opening and closing of the supply valves 115 and 125 and the discharge valves 117 and 127 may be controlled according to the operation status of the unit.

  Although the pH meters 116 and 126 have been described as examples of the electrode type water quality analyzer, the present invention can be applied to an electric conductivity meter, a hydrazine meter, a silica / phosphoric acid meter, and the like. Furthermore, although the sample water is retained in the pH meters 116 and 126, pure water may be retained instead of the sample water. In this case, a tank for storing pure water and a valve for supplying pure water from the tank to the pH meters 116 and 126 are provided, and pure water is supplied after the sample water is discharged from the pH meters 116 and 126. As described above, the control may be performed by the unit calculator 7.

1 thermal power plant (power plant)
2 Boiler 6 Sampling device 7 Unit computer (control means)
11 Canned water analysis system (sample analysis system)
111 sample valve 113 supply pump 115 supply valve 116 pH meter for still water (electrode type water quality analyzer)
116c Analysis electrode 116f Analysis tank 116h Drain tank 117 Drain valve 12 Condensate analysis system (sample analysis system)
121 sample valve 123 supply pump 125 supply valve 126 condensate pH meter (electrode type water quality analyzer)
127 Discharge valve

Claims (6)

A sampler for collecting the sample water of the power plant and analyzing the water quality of the sample water with an electrode type water quality analyzer,
A supply valve for supplying the sampled water to the electrode type water quality analyzer,
A discharge valve for discharging the analyzed sample water from the electrode-type water quality analyzer,
At the time of unit operation of the power plant, the supply valve and the discharge valve are opened to supply the sample water to the electrode type water quality analyzer, and when the unit is stopped, the supply valve and the discharge valve are closed and the electrode type water quality analysis is performed. Control means for retaining the sample water in the meter, and immersing the analysis electrode of the electrode-type water quality analyzer in the sample water,
A sample water collection path for collecting the analyzed sample water that has been analyzed, as makeup water to be supplied to the boiler,
A sampling device characterized by comprising: A sampler for collecting the sample water of the power plant and analyzing the water quality of the sample water with an electrode type water quality analyzer,
A supply valve for supplying the sampled water to the electrode type water quality analyzer,
A discharge valve for discharging the analyzed sample water from the electrode-type water quality analyzer,
At the time of unit operation of the power plant, the supply valve and the discharge valve are opened to supply the sample water to the electrode type water quality analyzer, and when the unit is stopped, the supply valve and the discharge valve are closed and the electrode type water quality analysis is performed. Control means for retaining the sample water in the meter, and immersing the analysis electrode of the electrode type water quality analyzer in the sample water,
E Bei and a supply pump is switched supply and supply stop of the sample water for the electrode type water analyzer according to the operating conditions of the unit,
The control unit opens the supply valve and the discharge valve when the supply pump starts supplying the sample water, and closes the supply valve and the discharge valve when the supply pump stops supplying the sample water.
Specimen collection device that be characterized in that. A sampler for collecting the sample water of the power plant and analyzing the water quality of the sample water with an electrode type water quality analyzer,
A supply valve for supplying the sampled water to the electrode type water quality analyzer,
A discharge valve for discharging the analyzed sample water from the electrode-type water quality analyzer,
At the time of unit operation of the power plant, the supply valve and the discharge valve are opened to supply the sample water to the electrode type water quality analyzer, and when the unit is stopped, the supply valve and the discharge valve are closed and the electrode type water quality analysis is performed. Control means for retaining the sample water in the meter and immersing the analysis electrode of the electrode-type water quality analyzer in the sample water,
Furthermore, a plurality of the sample analysis systems including the supply valve, the electrode-type water quality analyzer and the discharge valve are provided, and the control unit controls the plurality of the sample analysis systems in an integrated manner.
Specimen collection device that be characterized in that. A sampler for collecting the sample water of the power plant and analyzing the water quality of the sample water with an electrode type water quality analyzer,
A supply valve for supplying the sampled water to the electrode type water quality analyzer,
A discharge valve for discharging the analyzed sample water from the electrode-type water quality analyzer,
At the time of unit operation of the power plant, the supply valve and the discharge valve are opened to supply the sample water to the electrode type water quality analyzer, and when the unit is stopped, the supply valve and the discharge valve are closed and the electrode type water quality analysis is performed. Control means for retaining the sample water in the meter and immersing the analysis electrode of the electrode-type water quality analyzer in the sample water,
The electrode-type water quality analyzer is an analysis tank for analyzing the sample water supplied from the supply valve by the analysis electrode, and is connected to the analysis tank, and analyzes the analyzed sample water flowing from the analysis tank. A discharge tank for discharging from the discharge valve;
Specimen collection device you comprising: a. The sample water is a liquid that requires water quality monitoring, including boiler can water,
The sampling device according to any one of claims 1 to 4, wherein: A power supply plant, a supply valve for supplying the collected sample water to the electrode type water quality analyzer, a discharge valve for discharging the analyzed sample water from the electrode type water quality analyzer, and controlling the supply valve and the discharge valve. Control means, a sample water collecting path for collecting the analyzed sample water that has been analyzed, a control method of a sample collection device comprising:
The control means opens the supply valve and the discharge valve to supply the sample water to the electrode type water quality analyzer during unit operation of the power plant, and closes the supply valve and the discharge valve when the unit is stopped. The sample water is retained in the electrode type water quality analyzer, and the analysis electrode of the electrode type water quality analyzer is immersed in the sample water .
The sample water recovery path collects the analyzed sample water that has been analyzed as makeup water to be supplied to the boiler.
A method for controlling a sampling device, comprising:

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