JP2011191194A - Quality measuring instrument of water and steam quality monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steam quality monitoring device capable of accurately measuring the quality of condensed water flowing through a flow cell using a dissolved oxygen concentration sensor or the like even if air is mixed in steam. <P>SOLUTION: In the steam quality monitoring device 1 constituted so that the condensed water W generated by cooling the air-containing steam S generated from a boiler 100 using a cooling device 2 is made to successively pass through a plurality of the flow cells 30a, 31a and 32a in a quality measuring instrument 3 of water and the quality of the condensed water W is measured by the measuring sensors 30b, 31b and 32b provided in the respective flow cells to monitor the quality of the steam S from which air is removed, the condensed water flow channel 33 of the outlet of the first flow cell 30a is branched into a downward flow channel 33c going toward the next flow cell 31a and an upward air venting flow channel 35a larger than the downward flow channel 33c in size and opened toward the atmosphere at the end side thereof. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a water quality measuring device for measuring the water quality of steam condensate containing a large amount of air. The present invention also relates to a vapor quality monitoring device that monitors the quality of steam excluding air by cooling the steam containing a large amount of air and measuring the quality of the condensed water generated at this time.

  The steam generated in the boiler is cooled by a cooling device, and the quality of the condensed water generated at this time is measured by a water quality measuring device, so that the quality of the steam, that is, the amount of impurities contained in the steam and the corrosiveness of the steam, etc. A vapor quality monitoring device that monitors (monitors) in real time is known (for example, Patent Document 1).

  In this vapor quality monitoring device, the condensed water obtained by cooling the sampled vapor by the cooling device is used as a flow cell for measuring the dissolved oxygen concentration in the water quality measurement device as described in Patent Document 1, for example. The quality of the steam is monitored by measuring the dissolved oxygen concentration, electrical conductivity, and pH value of the condensed water through a flow cell for measuring electrical conductivity and a flow cell for measuring pH. ing.

  By the way, in recent years, it has become the mainstream to install a plurality of small once-through boilers with a small amount of evaporation per can instead of a large water tube boiler or a flue tube boiler. In a boiler apparatus having a plurality of such boilers, it is rare that all the boilers operate at the same time. When the load is low, only some boilers are operated.

  In this case, when the pressure in the stop boiler is reduced to zero by gauge pressure, air enters the boiler through the vacuum breaker valve, but when this stop boiler becomes an operating boiler, a large amount of air is in the steam. It will be mixed.

  Therefore, the vapor quality monitoring device often monitors the quality of vapor mixed with a large amount of air. In this case, although a large amount of air exists in the condensed water, the quality of the vapor other than air is monitored by measuring the quality of the condensed water using a vapor quality monitoring device.

JP 2007-93128 A

  However, if there is a large amount of air in the condensed water, a large amount of air temporarily enters the flow cell, which reduces the flow rate of the condensed water in the flow cell and reduces the dissolved oxygen concentration and electrical conductivity of the condensed water. There was a problem that it could not be measured correctly.

  In addition, when a large amount of air is present in the condensed water, the flow cell for measuring the dissolved oxygen concentration becomes pressurized, which adversely affects the measurement of the dissolved oxygen concentration and the dissolved oxygen concentration cannot be measured correctly.

  The above problem also relates to a water quality measuring device that measures the water quality of the condensed water by measuring sensors provided in each flow cell by sequentially passing the condensed water of steam containing a large amount of air through a plurality of flow cells. It happens in the same way.

  In view of the above points, the present invention provides a water quality measurement device and a vapor quality monitoring device that can correctly measure the quality of condensed water flowing in a flow cell using a dissolved oxygen concentration sensor or the like even when air is mixed in the steam. The purpose is to provide.

  According to the first aspect of the present invention, the condensed water of steam containing air is sequentially passed through the plurality of flow cells, and the quality of the condensed water is measured by the measurement sensors provided in the respective flow cells. A water quality measurement device, wherein a condensate flow path at the outlet of the first flow cell has a downward flow path toward the next flow cell, and an upward air that is larger in size than the downward flow path and is open to the atmosphere at the end side. It is characterized in that it is branched into a discharge channel.

  When air is contained in the condensed water, if there is no air vent flow path, the condensed water that has exited the first flow cell goes to the next flow cell and descends in the downward flow path, so the air bubbles in the condensed water are light. It does not move with the condensed water, but collects near the outlet of the first flow cell. Then, the air bubbles sequentially enter the first flow cell to decrease the flow rate of the condensed water in the first flow cell and increase the pressure in the first flow cell by the amount that the flow of the condensed water is blocked. .

  In the present invention, an upward air vent channel having a size larger than the downward channel is provided at the inlet of the downward channel on the first flow cell outlet side. Condensed water contained therein is discharged while the internal air bubbles rise in the upper air vent channel, and only the condensed water enters the next flow cell through the downward channel. Therefore, there is no accumulation of air on the outlet side of the first flow cell, and air accumulates in the first flow cell, reducing the flow rate of condensed water in the first flow cell or pressurizing the first flow cell. There is no end to it. The same applies to the subsequent flow cells.

  According to a second aspect of the present invention, in the case of the first aspect of the present invention, the air vent channel is connected to the condensed water discharge channel at the final flow cell outlet, and the upper part of the air vent channel Further, it is characterized in that an air release portion extending upward is provided.

  Condensed water is stored at a certain height in the air vent channel according to the pressure balance in the condensate channel, but the air bubbles rising in the condensed water burst when it exits the condensed water. , The surrounding condensed water is scattered around. In the present invention, the air vent channel is connected to the condensed water discharge channel for discharging the measured condensed water, and the condensed water scattered when the air bubbles burst is allowed to escape to the condensed water discharge channel side. In this case, since the atmosphere release portion extends upward from the upper part of the air vent channel, the condensed water does not scatter through the atmosphere release portion.

  According to a third aspect of the present invention, the steam containing air generated from the boiler is cooled by using a cooling device, and the generated condensed water is sequentially passed through a plurality of flow cells in the water quality measuring device. A vapor quality monitoring device that measures the quality of condensed water by a measurement sensor provided in each flow cell and monitors the quality of the vapor excluding the air, the condensed water flow path at the first flow cell outlet, It is characterized in that it is branched into a downward flow path toward the next flow cell and an upward air vent flow path having a size larger than this downward flow path and having an end portion open to the atmosphere.

  According to a fourth aspect of the present invention, in the case of the third aspect of the present invention, the air vent channel is connected to the condensed water discharge channel at the final flow cell outlet, and the upper part of the air vent channel. Further, it is characterized in that an air release portion extending upward is provided.

  According to the first aspect of the present invention, even if air is mixed in the steam, the air bubbles in the condensed water are not collected in the first flow cell, etc. For example, the dissolved oxygen concentration sensor provided in the first flow cell can be used to correctly measure the dissolved oxygen concentration of the condensed water, and provided in the subsequent flow cell. The electrical conductivity sensor and pH value of the condensed water can be correctly measured using the electrical conductivity sensor and pH sensor.

  According to the invention described in claim 2 of the present invention, the condensed water scattered by the bursting of air bubbles in the condensed water can be guided from the air vent channel to the condensed water discharge channel, so that the condensed water is scattered outside. Can be prevented.

  According to the invention described in claim 3 of the present invention, even if air is contained in the steam, the water quality can be appropriately measured by the water quality measuring device, so that the quality of the steam excluding air is properly monitored. can do.

  According to invention of Claim 4 of this invention, since the scattering of the condensed water from a water quality measuring apparatus can be prevented, the quality of a vapor | steam can be monitored safely.

It is a figure which shows the flow of a vapor | steam and condensed water in the vapor quality monitoring apparatus which concerns on one embodiment of this invention. It is a figure which shows the effect | action of an air vent flow path, (a) shows the case where the air vent flow path is not provided, (b) shows the case where the air vent flow path is provided.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a vapor quality monitoring apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the steam quality monitoring device 1 includes a cooling device 2, a water quality measuring device 3, a flow rate adjusting valve 4 for condensed water W, a flow rate adjusting valve 5 for cooling water C, and a steam line 6. , The condensed water line 7, the condensed water discharge line 8, the cooling water supply line 9, the cooling water discharge line 10 and the like.

  In addition, the boiler apparatus 100 by which the quality of the steam S is monitored by this steam quality monitoring apparatus 1 is comprised from the small through-flow boiler 100a of 4 cans with small evaporation amount, for example, as shown in FIG. ing. In this boiler apparatus 100, an operation is performed in which the stop boilers are sequentially changed by a constant rotation with the three cans of the small once-through boiler 100a as the operating boiler and the one can of the small once-through boiler 100a as the stop boiler. The steam S from the boiler device 100 is sent to the demand department in the factory via the steam header 101.

  As shown in FIG. 1, the cooling device 2 cools the steam S from the boiler 100 with cooling water C and converts it into condensed water W for water quality measurement, and includes a heat transfer tube in the casing 20. The heat exchange part 21 is accommodated. The cooling water supply line 9 is connected to the casing 20 on the condensed water outlet side of the heat exchange unit 21, and the cooling water discharge line 10 is connected to the casing 20 on the steam inlet side of the heat exchange unit 21. Further, the steam line 6 is connected to the steam S inlet side of the heat exchange unit 21, and the condensed water line 7 is connected to the condensed water W outlet side of the heat exchange unit 21.

  In the cooling device 2, the flow rate of the cooling water C is controlled by the flow rate adjusting valve 5 provided in the cooling water supply line 9, and the temperature of the condensed water W becomes a predetermined temperature suitable for water quality measurement. Have been adjusted so that.

  As shown in FIG. 1, the water quality measuring device 3 sequentially passes the condensed water W through a plurality of flow cells, and various water qualities of the condensed water W, for example, dissolved by the measurement sensor provided in each flow cell. The oxygen concentration (DO), electrical conductivity (EC), and pH value are measured. As shown in FIG. 1, the water quality measuring instrument 3 includes a dissolved oxygen concentration meter 30 in which a dissolved oxygen concentration sensor 30b is provided in the first first flow cell 30a, and an electric conduction in the next second flow cell 31a. The electrical conductivity meter 31 provided with the rate sensor 31b, the pH meter 32 provided with the pH sensor 32b in the last third flow cell 32a, the dissolved oxygen concentration meter 30 and the electrical conductivity meter 31 are connected. A condensate water flow path 33, and a condensate water flow path 34 connecting the electric conductivity meter 31 and the pH meter 32.

  Here, the condensed water W flows into the inside from the lower side of each flow cell 30a, 30b, 30c, and is discharged | emitted from the upper side of each flow cell 30a, 30b, 30c. For this reason, the condensed water line 7 is connected to the lower part of the 1st flow cell 30a, and the condensed water discharge line 8 is connected to the upper part of the 3rd flow cell 32a. The condensed water flow path 33 connected to the upper part of the first flow cell 30a and the lower part of the second flow cell 31a has a downward flow path part 33c that descends between the horizontal flow path parts 33a and 33b. The condensed water channel 34 connected to the upper part of the flow cell 31a and the upper part of the third flow cell 32a also has a downward channel part that descends between the horizontal channel parts. In addition, the flow path diameter of the condensed water flow paths 33 and 34 is formed so that an internal diameter may be 4.0 mm.

  In addition, as shown in FIG. 1, the water quality measuring device 3 includes a condensed water flow path 34 between the first flow cell 30a and the second flow cell 31a so as to straddle the electric conductivity meter 31 and the pH meter 32. An air vent channel 35 for connecting the condensed water discharge line 8 at the outlet of the third flow cell 32a is provided. The air vent channel 35 has an upward channel part 35a that rises vertically, a horizontal channel part 35b that follows, and a downward channel part 35c that descends thereafter, and is formed in a substantially (U) shape. The flow path diameter is formed to be 8 mm, which is sufficiently larger than the condensed water flow paths 33 and 34. The air vent channel 35 is connected such that the lower end of the upward channel part 35a forms a (T) shape directly above the downward channel part 33c of the condensed water channel 33, and the lower end of the downward channel part 35c. Are connected so as to form a (T) shape directly above the descending portion of the condensed water discharge line 8.

  Condensed water W is accumulated in the upward flow path portion 35a of the air vent flow path 35 by a certain height due to the pressure balance in the condensed water flow path 33, as shown in FIG. Therefore, the upward flow path part 35a is raised to such a height that the internal condensed water W does not flow into the condensed water discharge line 8 side. Further, an air release portion 35d whose upper portion is bent 90 degrees upward is formed in the horizontal flow passage portion 35b on the upper side of the air vent flow passage 35, and an air release hole is formed on one end side thereof. Yes.

  The steam line 6 is a cooling device for the steam S on the boiler device 100 side, specifically, from the side of the branch pipe 103 next to the pressure gauge 102 provided in the steam header 101 of the boiler device 100 as shown in FIG. 2 is a steam flow path for taking in the gas. The steam line 6 has a flow path diameter of 4 mm.

  The condensed water line 7 is a condensed water flow path for sending the condensed water W from the cooling device 2 to the water quality measuring device 3, and a flow rate adjusting valve 4 is provided in the middle. The steam line 6 has a flow path diameter of 4 mm. The flow rate adjusting valve 4 controls the flow rate of the condensed water W sent to the water quality measuring device 3 to a predetermined flow rate suitable for measurement.

  The condensed water discharge line 8 is a condensed water discharge channel for discharging the measured condensed water W discharged from the water quality measuring device 3 to the outside. It has become.

  In the steam quality monitoring device 1, the steam S on the boiler 100 side taken in through the steam line 6 is cooled by the cooling device 2 and converted into condensed water W. The condensed water W is sent to the water quality measuring device 3 through the condensed water line 7, and the first flow cell 30 a, the condensed water flow channel 33, the second flow cell 31 a, the condensed water flow channel 34, the first in the water quality measuring device 3. 3 is sent to the condensed water discharge line 8 through the flow cell 32a. The condensed water W is measured by the dissolved oxygen concentration sensor 30b while passing through the first flow cell 30a, and the electrical conductivity is measured by the conductivity sensor 31b while passing through the second flow cell 31a. During the passage through the third flow cell 32a, the pH value is measured by the pH sensor 32b. And the quality of the vapor | steam S from the boiler apparatus 100 is monitored by the dissolved oxygen concentration of the measured condensed water W, an electrical conductivity, and pH value.

  On the other hand, in the boiler apparatus 100, an operation is performed in which one of the small once-through boilers 100a is a stop boiler among the four cans of the once-through boiler 100a, and this stop boiler is replaced by a fixed rotation. However, because this stop boiler is introduced with air through the vacuum breaker valve due to a drop in the steam pressure during stoppage, when this stop boiler becomes an operation boiler, it is temporary. A large amount of air is mixed in the steam S.

  Next, in the case where a large amount of air is mixed in the steam S, the operational effects of the water quality measuring device 3 when the quality of the steam S is monitored by the steam quality monitoring device 1 will be described with reference to FIG. explain.

  Here, as shown in FIG. 2, in the dissolved oxygen concentration meter 30, the first flow cell 30a is formed in a concave shape having an inlet portion H1 in the lower portion and an outlet portion H2 in the upper portion and opened upward. The oxygen concentration sensor 30b is formed in a shape in which a sensor part B2 is provided at the lower end of a rod-like part B1 extending downward from the collar part B3. In order to attach the dissolved oxygen concentration sensor 30b to the first flow cell 30a, the rod-like portion B1 may be inserted into the first flow cell 30a so as to cover the rib portion B3 of the dissolved oxygen concentration sensor 30b.

  FIG. 2A shows a state in the dissolved oxygen concentration meter 30 and in the condensed water channel 33 when the air vent channel 35 is not provided on the condensed water channel 33 side of the water quality measuring device 3. .

  When a large amount of air A is contained in the condensed water W, if there is no air vent channel 35, the condensed water W that has exited the first first flow cell 30a is directed to the next second flow cell 31a, and therefore the condensed water channel 33. When the downward flow path portion 33c is lowered, the air bubbles A1 in the condensed water W are light and therefore do not move with the condensed water W, and as shown in FIG. 2A, the outlet portion of the first flow cell 30a. It collects in the horizontal flow path part 33a near H2. The air bubbles A1 sequentially enter the first flow cell 30a to reduce the flow rate of the condensed water W in the first flow cell 30a and to block the flow of the condensed water W. Increase pressure. For this reason, the dissolved oxygen concentration meter 30 cannot accurately measure the dissolved oxygen concentration.

  FIG. 2B shows the dissolved oxygen concentration meter 30, the air vent channel 35, and the condensate channel 33 in the case where the air vent channel 35 is provided on the condensate channel 33 side of the water quality measuring device 3. Indicates the state.

  When the air vent channel 35 is provided on the condensate channel 33 side, the condensed water W including the air bubbles A1 heading from the first flow cell 30a to the downward channel part 33c of the condensate channel 33 is converted into the internal air bubbles A1. Rises in the upward flow path portion 35a of the upper air vent flow path 35 and is discharged, and only the condensed water W passes through the downward flow path section 33c and enters the next second flow cell 31a. In particular, since the air vent channel 35 has a larger diameter than the condensed water channel 33, the air bubbles A1 in the condensed water W easily move to the air vent channel 35 side with less channel resistance. To do. Therefore, the accumulation of air A does not occur on the outlet H2 side of the first flow cell 30a, the air A accumulates in the first flow cell 30a, and the flow rate of the condensed water W in the first flow cell 30a decreases. The first flow cell 30a is not pressurized. The same applies to the second flow cell 31a and the like later. Therefore, in this water quality measuring device 3, the dissolved oxygen concentration of the condensed water W can be accurately measured by the dissolved oxygen concentration meter 30, and the electrical conductivity and the like of the condensed water W can be accurately measured by the electrical conductivity meter 31 and the like.

  On the other hand, as shown in FIG. 2B, since the condensed water W is stored up to a certain height in the upward flow path portion 35a of the air vent flow path 35, it rises in the upward flow path portion 35a. The air bubbles A1 to be ruptured when coming out of the condensed water W, and the surrounding condensed water W is scattered around. For this reason, in this water quality measuring device 3, the other end side of the air vent channel 35 is connected to the condensed water discharge line 8, and the condensed water W scattered when the air bubbles A1 burst is recovered in the condensed water discharge line 8. To ensure safety. In addition, since the air release part 35d of the air vent channel 35 is provided so as to extend upward from the horizontal channel part 35b and the upper end is bent by 90 degrees, the condensed water W jumps out from the air release part 35d. There is no.

  As described above, since the steam quality monitoring device 1 has a large amount of air A in the steam S, the water quality measuring device 3 has a large amount of air bubbles A1 in the condensed water W. The condensate flow path 33 at the outlet of the first flow cell 30a, which is the first flow cell, has a downward flow path 33c toward the next second flow cell 31a and a size larger than the downward flow path 33c, and the end side is open to the atmosphere. The air bubbles A1 in the condensed water W are discharged to the outside from the air vent channel 35, and the air bubbles A1 are discharged from the condensed water channel 33. It is not stored in the horizontal flow path portion 33a or the first flow cell 30a. For this reason, in this steam quality monitoring device 1, even when the steam S has a large amount of air A, the water quality measuring device 3 can accurately measure the water quality of the condensed water W, and the quality of the steam S excluding the air A can be measured. Can be monitored accurately.

  Moreover, in this vapor quality monitoring apparatus 1, while connecting the air vent flow path 35 to the condensed water discharge line 8 of the 3rd flow cell 32a exit which is the last flow cell, the upper part of this air vent flow path 35, ie, horizontal Since the air opening part 35c extending upward is provided in the flow path part 35b, even if the air bubbles A1 in the air vent flow path 35 burst inside and cause the condensed water W to scatter, the scattered condensed water W The condensed water discharge line 8 can be safely discharged without discharging to the outside.

  Note that the vapor quality monitoring device 1 is not a water-cooled cooling device, but may have an air-cooling cooling device that forcibly cools the steam S and the condensed water W by air in the atmosphere. Of course.

1 Steam quality monitoring device 2 Cooling device 3 Water quality measuring device 8 Condensate drain line (Condensate drain)
30a First flow cell (first flow cell)
30b Second flow cell (next flow cell)
30c 3rd flow cell (last flow cell)
33 Condensed water flow path 33c Downward flow path part 35 Air vent flow path 35d Atmospheric release part A Air S Steam W Condensed water

Claims (4)

A water quality measuring device that measures the quality of this condensed water by a measurement sensor provided in each flow cell by sequentially passing condensed water of steam containing air through a plurality of flow cells,
The condensed water flow path at the first flow cell outlet is branched into a downward flow path toward the next flow cell and an upward air vent flow path that is larger in size than the downward flow path and that is open to the atmosphere at the end side. Water quality measuring device characterized by that.   2. The air vent channel is connected to a condensate discharge channel at the final flow cell outlet, and an air opening portion extending upward is provided above the air vent channel. Water quality measuring device. The steam generated from the boiler is cooled using a cooling device, and the resulting condensed water is sequentially passed through a plurality of flow cells in the water quality measuring device so that the water quality of the condensed water is provided in each flow cell. A vapor quality monitoring device that monitors the quality of the vapor, excluding the air, measured by a measurement sensor,
The condensed water flow path at the first flow cell outlet is branched into a downward flow path toward the next flow cell and an upward air vent flow path that is larger in size than the downward flow path and that is open to the atmosphere at the end side. Vapor quality monitoring device characterized by that.   4. The air vent channel is connected to a condensate discharge channel at the final flow cell outlet, and an air opening portion extending upward is provided at an upper portion of the air vent channel. Vapor quality monitoring device.

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