JP2009228991A - Boiler system and operating method of boiler system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of various problems caused by water treatment on a boiler side even when a boiler system is equipped with a water treating device or a portion of the water treating device having only a treating capacity smaller than a required treating capacity of a boiler at maximum load. <P>SOLUTION: This operating method of a boiler system A includes the water treating device 2 for treating raw water for boiler feed into boiler feed water and supplying to a water feed tank 11. The treating capacity of the whole water treating device or the portion 21 of the water treating device is made smaller than the required treating capacity of the boiler 10 at maximum load. A bypass line 30 for bypassing the device 21 having the reduced treating capacity is provided, a water flow valve 31 of the bypass line 30 is controlled by the water level of the water supply tank 11, and based on the deterioration of water quality of boiler feed water W3 caused by water passing through the water flow valve 31, at least one of a chemical injection amount from a chemical injection device 13 and a blow rate of can water W4 blown from the boiler 10 is controlled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a boiler system including a water treatment apparatus that processes boiler supply water for boiler supply and supplies the water to a water supply tank side, and an operation method of the boiler system.

  In a boiler system equipped with a boiler and a water treatment device for this boiler, boiler feed water from which impurities such as hardness are removed from raw water such as water, groundwater, and industrial water, and an oxygen scavenger is added to the boiler feed water. A boiler treatment agent such as a scale inhibitor or a canning agent is injected into the boiler.

  On the other hand, water treatment equipment that removes impurities from raw water uses soft water equipment that softens raw water (removes hardness components) to produce soft water, and filtration membranes such as nanofiltration membranes and reverse osmosis membranes. , A desalination apparatus for desalting raw water or soft water (for example, Patent Document 1 discloses a device using a nanofiltration membrane, Patent Document 2 discloses a reverse osmosis membrane), soft water or desalted water There is a deoxygenation device that performs deoxygenation treatment (for example, Patent Document 1 discloses a device for deoxygenating demineralized water).

JP 2005-288219 A Japanese Patent No. 3593723

  However, the conventional water treatment apparatus is designed so that water of a preset water quality can be supplied to the boiler side with respect to the amount of water supply (boiler load) required on the boiler side. For this reason, in a boiler system equipped with these water treatment devices, it is necessary to determine the treatment capacity of these water treatment devices in accordance with the maximum (peak) load of the boiler, and the treatment capacity of the water treatment device becomes excessive. There was a problem that it was easy. Note that the same can be said for a part of the water treatment apparatus.

  On the other hand, if a bypass line is provided and the water treatment device or a part of the treatment capacity of the water treatment device is made smaller than the amount of water supply required on the boiler side, the use of this bypass line causes a reduction in the quality of the boiler feed water, Boiler feed water quality cannot be kept constant. For this reason, in such a boiler system, the quality of the boiler can water greatly fluctuates, and various problems such as carryover, scale failure, and corrosion occur on the boiler side.

  In view of the above points, the present invention provides a water treatment device or a part of a water treatment device that has a treatment capacity smaller than the treatment ability required at the maximum load of the boiler. An object of the present invention is to provide a boiler system that does not cause various problems caused by processing, and a method for operating the boiler system.

  The invention according to claim 1 of the present invention is a method of operating a boiler system including a water treatment device that processes boiler supply water for boiler feed water and supplies the water to the feed water tank side, the water treatment device The entire or a part of the water treatment apparatus is made smaller than the treatment capacity required at the maximum load of the boiler, and the entire water treatment apparatus or a part of the water treatment apparatus with the reduced treatment capacity is bypassed. A bypass line is provided, and the water supply valve of the bypass line is controlled by the water level of the water supply tank, and at least based on the deterioration of the quality of the boiler water supply caused by the water passing through the water supply valve, Either the amount of the chemical solution injected from the boiler or the blow rate of the can water blown from the boiler is controlled.

  In this invention, when the load on the boiler is low, the water flow valve in the bypass line is closed, and the water for boiler supply is processed by the water treatment device so as to have a predetermined water quality, and is supplied to the water supply tank. The In this case, on the boiler side, a predetermined amount of chemical solution is supplied to the boiler water supply line through a normal process according to the load of the boiler, that is, a chemical injection device, and can water with a predetermined blow rate is supplied from the boiler. Is blown. On the other hand, when the load of the boiler becomes larger than the treatment capacity of the water treatment device (or part of the water treatment device) provided with the bypass line, the level of the water supply tank decreases, but this level falls below a predetermined value. Then, the water flow valve is opened, and water that is not partly processed by the water treatment device (or part of the water treatment device) is supplied into the water supply tank, and the quality of the boiler feed water in the water supply tank is lowered. In this case, on the boiler side, in addition to the normal processing according to the load of the boiler, chemical solution injection and boiler boiler water are taken into consideration in consideration of the deterioration in the quality of the boiler feed water.

  That is, for example, when the water treatment apparatus (or part of the water treatment apparatus) provided with the bypass line is a desalination apparatus using a filtration membrane, the injection amount of the cleansing agent from the chemical injection device is reduced. In addition, the amount of scale inhibitor injected is increased and the blow rate of boiler can water is increased. When the water treatment apparatus (or part of the water treatment apparatus) provided with the bypass line is a deoxygenation apparatus, the injection of the deoxidizer from the chemical injection apparatus is started or the injection amount is Will be increased. The water flow valve may be controlled to be fully open and fully closed, and the opening degree of the water valve is controlled so that the flow rate of water in the bypass line can be continuously changed. Also good.

  According to a second aspect of the present invention, in the case of the first aspect of the present invention, the boiler supply water is softened softened water.

  According to a third aspect of the present invention, in the case of the first or second aspect of the present invention, the deterioration of the water quality of the boiler feed water is determined by the ratio of the water that has passed through the water flow valve in the boiler feed water. It is characterized by being.

  Invention of Claim 4 of this invention is a boiler system provided with the water treatment apparatus which processes the water for boiler supply for boiler feed water, and supplies it to the feed water tank side, Comprising: The said water treatment apparatus whole or the said A bypass line that bypasses the entire water treatment apparatus or a part of the water treatment apparatus that reduces the treatment capacity of a part of the water treatment apparatus to be smaller than the treatment capacity required at the maximum load of the boiler. And at least injecting a chemical solution from a chemical injection device based on the deterioration of the quality of boiler feed water caused by the water passing through the water flow valve while the water flow valve of the bypass line is controlled by the water level of the water supply tank. Control means for controlling either the amount or the blow rate of the can water blown from the boiler is provided.

  According to the first or fourth aspect of the present invention, even when the water supply valve of the bypass line is opened and the water quality of the boiler feedwater is lowered, the water supply from the chemical injection device is adapted to the water quality drop. By changing the amount of chemicals injected or changing the blow rate of the can water from the boiler, the value and fluctuation range of the impurity concentration in the can water are kept small and stabilized. There will be no problems such as corrosion. Therefore, in these inventions, even if the treatment capacity of the water treatment device (or part of the water treatment device) is smaller than the treatment ability required at the maximum load of the boiler, various problems caused by water treatment on the boiler side. Does not cause That is, in these inventions, it is not necessary to match the treatment capacity of the water treatment apparatus or the water treatment apparatus to the treatment capacity required at the maximum load of the boiler. It is possible to prevent a part from becoming excessive.

  According to the invention described in claim 2 of the present invention, water containing a hardness component does not flow into the water supply tank through the bypass line, so that a rapid increase in the blow rate of the can water and the amount of the chemical solution used can be suppressed. Can do.

  According to invention of Claim 3 of this invention, since the fall of the quality of boiler feedwater is judged by the ratio of the water which passed the water flow valve which occupies in boiler feedwater, the chemical | medical solution injection amount with respect to the fall of the quality of boiler feedwater It is possible to calculate in detail the increase and decrease of the can water blow rate.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a boiler system A according to an embodiment of the present invention.
As shown in FIG. 1, the boiler system A includes a boiler device 1, a water treatment device 2, and a bypass device 3.

  The boiler apparatus 1 is a generator of steam S, for example, two boilers 10 and 10 having the same capacity, a water supply tank (hot well tank) 11, and water supply pumps 12b and 12b in the water supply lines 12a and 12a. And a chemical injection for injecting a predetermined amount of a predetermined chemical solution into the water supply facilities 12 and 12 for supplying boiler water W3 from the water supply tank 11 to the two boilers 10 and 10 and the boiler water W3 in the water supply lines 12a and 12a. The apparatuses 13 and 13 and the can water blow apparatuses 14 and 14 for continuously blowing the can water W4 in each boiler 10 at a predetermined blow rate based on the water supply flow rate.

  The boiler 10 generates steam t of several t / hr, for example. Since the two boilers 10 and 10 are operated simultaneously, the maximum load of these boilers 10 and 10 is the sum of the two cans. The amount of water supply to each boiler 10 is measured by a flow meter (not shown), and the water supply flow rate signal is transmitted to a control device 32 (described later) of the bypass device 3.

  The water supply tank 11 stores a boiler feed water W1 by a predetermined amount, and has a level switch 11a that emits a signal according to a predetermined water level in the water supply tank 11.

  The chemical injection device 13 includes a chemical injection tank 13a having an interior divided into three parts, three chemical injection pumps 13b, 13b, 13b whose discharge amount can be changed, and pipes. In the chemical injection tank 13a, for example, a cleaning agent, a scale inhibitor, and an oxygen scavenger are stored, and each of these chemical liquids is injected into the boiler feed water W3 by the chemical injection pump 13b. . This chemical injection device 13 controls the discharge amount of each chemical injection pump 13b based on the signal from the bypass device 3, and injects a predetermined amount of three chemical solutions into the water supply lines 12a and 12a.

  The can water blower 14 is composed of a blow valve 14a capable of controlling the flow rate, piping and the like. The can water blowing device 14 adjusts the opening degree of the blow valve 14a based on the signal from the bypass device 3, and the can water W4 in the boiler 10 is supplied by a predetermined amount at a predetermined blow rate based on the feed water flow rate. Blow continuously.

  The water treatment device 2 treats raw water W0 such as tap water, groundwater, and industrial water from which suspended solids and the like are removed so as to become a boiler feed water W3, and supplies it to the feed water tank 11 of the boiler device 2. Is. The water treatment device 2 includes a water softening device 20 and a desalination device 21 using a filtration membrane provided on the downstream side of the water softening device 20.

  The water softener 20 includes a water softener, a soft water tank, a pump, and the like. In the water softener 20, the raw water W0 to which a predetermined water pressure is applied is softened (removed hardness component) by a water softener to obtain soft water W1, which is then stored in a soft water tank and stored in the soft water tank. The soft water W1 is pumped out. The water softener 20 has a processing capacity required at the time of maximum load of the two boilers 10 and 10.

  The desalinator 21 removes the salts in the soft water W1 using a reverse osmosis membrane, and includes a reverse osmosis membrane separator 21a, a guard filter 21b, a water feed pump 21c, and a heat exchanger 21d. ing. This desalination apparatus 21 has only a processing capacity of, for example, 50% (the processing capacity at the maximum load of one boiler 10) of the processing capacity required at the maximum load of the two boilers 10, 10. . The guard filter 21b and the heat exchanger 21d are pretreatment devices for the reverse-centered membrane separation device 21a, and the water feed pump 21c is for operating / stopping the desalination device 21.

  The bypass device 3 includes a bypass line 30 that bypasses the desalination device 21 between the outlet of the soft water device 20 and the water supply tank 11 by piping, an opening / closing valve 31 that serves as a water flow valve that opens and closes the bypass line 30, and water supply It has a control device 32 as a control means for controlling the level of the tank 11 and controlling the medicine injection device 14 and the blow device 14.

  The size of the bypass line 30 can at least cover the amount of water supplied at the maximum load of one boiler 10. The on-off valve 31 is controlled at two positions, fully open and fully closed. When the on-off valve 31 is open, the flow rate of the soft water W1 flowing through the on-off valve 31 is considered to be substantially constant. The opening / closing valve 31 is controlled to be opened / closed by a control device 32 and transmits an open / close signal to the control device 32.

  The control device 32 includes a level control unit 32a that performs level control of the water supply tank 11 by open / close control of the open / close valve 31 and ON / OFF control of the water supply pump 21c, water quality of the boiler feed water W3, and feed water flow rate to each boiler 10. And a chemical injection blow control unit 32b that controls the amount of the chemical liquid injected from the chemical injection device 14 and the amount of blown water W4 from the boiler 10 by the blow device 14.

  When the water level of the water supply tank 11 reaches the high level H by the signal from the level switch 11a, the level control unit 32a stops the water pump 21c to stop the operation of the desalination apparatus 21 and the water in the water supply tank 11 When a predetermined time (for example, 15 minutes) elapses after the level becomes high level H, the water supply pump 21c is moved to operate the desalination apparatus 21. Of course, the level control part 32a similarly operates the desalination apparatus 21 also when the water level of the water supply tank 11 reaches the low level H before the predetermined time. When the water level of the water supply tank 11 reaches a low level L by a signal from the level switch 11a, the level control unit 32a opens the on-off valve 31 and uses the bypass line 30 to supply the soft water W1 to the water supply tank 11. When the water level of the water supply tank 11 reaches the high level H, the on-off valve 31 is closed and the supply of the soft water W1 using the bypass line 30 to the water supply tank 11 is stopped.

  When the boiler feed water W3 in the feed water tank 11 is filled with the desalted water W2 processed by the desalting device 21, the medicinal blow control unit 32b controls the medicating device 13 to adjust the amount of water supplied. A chemical solution (cleaning agent, scale inhibitor, oxygen scavenger) of a certain injection rate (hereinafter referred to as a standard injection rate) is injected in an amount corresponding to the feed water flow rate of each boiler 10, and a can water blower 14 is provided. By controlling, the can water W4 is continuously blown from each boiler 10 by an amount corresponding to the feed water flow rate of each boiler 10 at a standard blow rate (for example, 5%).

  In addition, when the on-off valve 31 is opened and the soft water W1 is mixed with the boiler feed water W3 in the feed water tank 11 and the water quality of the boiler feed water W3 is lowered, the medicinal blow control unit 32b opens the boiler feed water W3. In accordance with the ratio of the soft water W1, the injection ratio of the predetermined chemical solution is changed (increased or decreased) from the standard one, and the blow rate by the can water blowing device 14 is increased from the standard one.

  That is, the medicinal blow control unit 32b reduces the injection rate of the cleansing agent in consideration of the increase in the alkalinity of the boiler feed water W3 as the proportion of the soft water W1 in the boiler feed water W3 increases. Considering the adhesion of scale due to mixing of hardness components, the injection rate of scale inhibitor is increased. In this case, it is not necessary to change the injection ratio of the oxygen scavenger. In addition, the chemical injection blow control unit 32b takes into consideration that the impurity concentration in the boiler can water W4 increases as the ratio of the soft water W1 in the boiler feed water W3 increases, and sets the blow rate to a standard value (5 %).

  Here, if the flow rate of the soft water W1 flowing in the on-off valve 31 is constant, the ratio of the soft water W1 in the boiler feed water W3 increases abruptly to some extent after the on-off valve 31 is opened, and after a certain time has elapsed (boiler When the feed water W3 is sufficiently stirred, the maximum value is obtained when the on-off valve 31 is closed, and this maximum state is maintained even after the on-off valve 31 is closed (when the on-off valve 31 is closed, the desalination apparatus 21 Operation is also stopped). Then, the ratio of the soft water W1 in the boiler feed water W3 starts to decrease when the on-off valve 31 is closed and a certain time elapses and the desalination apparatus 21 is operated again. ) Therefore, in consideration of such a change in the ratio of the soft water W1 in the boiler feed water W3, the chemical injection blow control unit 32b applies a predetermined chemical solution (cleaning agent and scale inhibitor) to the chemical injection device 13. While changing the injection ratio, the blow rate was increased from the standard value (5%) for the can water blowing device 14 and then decreased to the standard value.

Next, operational effects of the boiler system A will be described.
When the total load of the two boilers 10, 10 is low, the water supply to each boiler 10 can be covered by the desalinator 21, so that the water supply tank 11 is filled with the desalted water W 2, and each boiler 10 Is supplied with demineralized water W2 as boiler feed water W3. For this reason, the chemical injection blow control unit 32b of the control device 32 sets the injection ratio of the chemical solution as a standard, and controls the two chemical injection devices 13 and 13 to control each chemical solution (cleaning agent, scale inhibitor, removal agent). Oxygen agent) is injected into each water supply line 12a of each boiler 10 at a standard injection rate and according to the water supply flow rate of each boiler 10. Moreover, the chemical | medical agent blow control part 32b sets the blow rate of the can water W4 as a standard, controls the two can water blow apparatuses 14 and 14, and is the standard blow rate, and the feed water flow rate of each boiler 10 Accordingly, the can water W4 is blown from each boiler 10.

  When the water level of the water supply tank 11 reaches the high level H, the level control unit 32a stops the water pump 21c and stops the operation of the desalinator 21, and then operates the water pump 21c after a certain time has elapsed. Then, the operation of the desalination apparatus 21 is started. In addition, if the water level of the water supply tank 11 reaches the low level L before reaching the predetermined time, the level control unit 32a operates the water supply pump 21c to start the operation of the desalination apparatus 21.

  Further, when the total load of the two boilers 10 and 10 rises and the supply amount of the desalted water W2 by the desalinator 21 falls below the amount required by the total load of the two cans 10 and 10, water supply The water level of the tank 11 falls. When the water level of the water supply tank 11 reaches the low level L, the level control unit 32 a opens the on-off valve 31 of the bypass line 30 that bypasses the desalination apparatus 21 and supplies the soft water W1 into the water supply tank 11. . Thereby, in the feed water tank 11, mixing of the desalted water W2 and the soft water W1 occurs, and the water quality of the boiler feed water W3 starts to deteriorate.

  On the other hand, the chemical injection blow control unit 32b calculates the ratio of the soft water W1 in the boiler feed water W3 along with the change in the ratio of the soft water W1 in the boiler feed water W3 after the opening / closing valve 31 is opened. Corresponding to the ratio of the soft water W1 in the boiler feed water W3, the injection ratio of the chemical solution from the chemical injection device 13 and the blow rate of the can water W4 from the can water blow device 14 are calculated. And the chemical injection blow control part 32b is based on the calculated injection | pouring ratio of the chemical | medical solution, the blow rate of the can water W4, and the water supply flow volume to each boiler 10, and supplies the chemical injection apparatus 13 to the water supply line 12a of each boiler 10. Then, a predetermined amount of the chemical solution is injected via the boiler water, and the can water W4 of each boiler 10 is blown with a predetermined blow amount via the can water blowing device 14.

  When the liquid level in the water supply tank 11 rises to the high level H, the level control unit 32a closes the on-off valve 31 and stops the flow of the soft water W1 into the water supply tank 11. In this case, the level control unit 32a stops the water pump 21c and stops the operation of the desalination apparatus 21 and the like, so the ratio of the soft water W1 in the boiler feed water W3 does not change thereafter, and the chemical injection blow control unit 32b The chemical injection device 13 and the can water blowing device 14 are controlled under the same conditions as when the on-off valve 31 is closed. Thereafter, when the demineralizer 21 is operated after a certain period of time, the ratio of the soft water W1 in the boiler feed water W3 decreases. Therefore, the chemical injection blow control unit 32b corresponds to the ratio of the soft water W1 in the boiler water supply W3 in the water supply tank 11 and the injection ratio of the chemical solution from the chemical injection device 13 and the can water from the can water blow device 14. The blow rate of W4 is calculated, and the chemical injection device 13 and the can water blow device 14 are controlled as described above.

  As described above, in this boiler system A, the on-off valve 31 of the bypass line 30 that bypasses the desalination apparatus 21 is opened, the soft water W1 is caused to flow into the feed water tank 11, and the boiler feed water W3 in the feed water tank 11 is large. Even if the water quality is lowered (water quality fluctuation), the operation state of the chemical injection device 13 and the can water blowing device 14 is changed in response to the water quality decline (water quality fluctuation). The value and fluctuation range of the impurity concentration can be reduced and stabilized, and there is no inconvenience such as carryover, scale failure, and corrosion on the boiler 10 side. For this reason, in this boiler system A, the treatment capacity of a part of the water treatment apparatus 2 (desalination apparatus 21) that produces the boiler feed water W3 can be sufficiently smaller than the treatment capacity required at the maximum load of the boilers 10 and 10. The water treatment device 2 can be effectively prevented from becoming excessive.

  In addition, the processing capacity of a part of the water treatment apparatus 2 (desalination apparatus 21) is made smaller than the processing capacity required at the maximum load of the boilers 10 and 10, and the processing capacity (desalination apparatus 21) is reduced. ), The on-off valve 31 of the bypass line 30 is controlled by the water level of the water supply tank 11, and the water quality of the boiler feed water W3 caused by opening the on-off valve 31 is reduced. In the operation method of the boiler system A that controls the injection amount of the chemical solution from the chemical injection device 13 and the blow rate of the can water W4 from the boiler 10, the same effect as in the case of the boiler system A can be obtained. .

  In addition, the water treatment apparatus 2 does not have the soft water apparatus 20, and may be only the desalination apparatus 21, or may not have the desalination apparatus 21 and may be only the soft water apparatus 20. . In this case, since the boiler feed water W3 having a large hardness component is supplied into the feed water tank 11 through the bypass line 30, a scale failure or the like is likely to occur on the boiler 10 side. For this reason, in this case, the injection amount of the scale inhibitor is increased in the chemical injection device 13, and the blow rate is greatly increased in the can water blowing device 14.

  Moreover, the water treatment apparatus 2 may have a deoxygenation apparatus. When the bypass line 30 is provided in the oxygen removal apparatus, boiler feed water W3 having a large amount of dissolved oxygen is supplied into the feed water tank 11 through the bypass line 30. For this reason, in this case, injection of the oxygen scavenger is started in the chemical injection device 13, or the injection amount of the oxygen scavenger is increased.

  Furthermore, the desalting apparatus 21 may be of other types besides those using a filtration membrane such as a reverse osmosis membrane or a nanofiltration membrane.

  Further, the bypass line 30 may be provided not only in a part of the water treatment apparatus (may be a plurality of places) but also in the entire water treatment apparatus.

  Furthermore, the valve opening / closing signal output from the opening / closing valve 31 to the chemical injection blow control unit 32b may be output from the level control unit 32a to the chemical injection blow control unit 32b.

  Further, the water flow valve (open / close valve 31) may be capable of controlling the flow rate of the soft water W1 flowing through the bypass line 30 according to the opening of the valve. For example, when the water level of the water supply tank 11 is low level L, the valve opening degree of the water flow valve (open / close valve 31) is increased so that a large amount of soft water W1 flows through the bypass line 30. When the water level approaches the high level L, the valve opening degree of the water flow valve (open / close valve 31) may be reduced so that only a small amount of soft water W1 flows through the bypass line 30. In this case, a flow meter is provided in the bypass line 30 and the amount of soft water W1 passing through the on-off valve 31 is measured by this flow meter. Based on this measured value, the chemical injection blow control unit 32b is supplied with the boiler feed water W3. The ratio of the soft water W1 may be calculated.

  Furthermore, the water supply line 12a of the boiler 10 is provided with a measuring instrument (for example, an electric conductivity meter or a dissolved oxygen meter) that can measure the water quality of the boiler water supply W3. The chemical injection blow control unit 32b is based on the opening / closing of the on-off valve 31. Thus, instead of calculating the ratio of the soft water W1 in the boiler feed water W3, the chemical injection device 13 and the can water blowing device 14 may be controlled based on the output of the measuring instrument.

Next, the test results using the actual machine for the boiler system A will be described below.
The average water quality of the raw water W0, the soft water W1, and the demineralized water W2 in the water treatment apparatus 2 is shown in FIG. The total load of the two boilers 10, 10, that is, the total water supply amount varies greatly between daytime and nighttime as shown in FIG. 3. Considering the peak load of the two cans 10 and 10, from FIG. 3, the water treatment device 2 is required to have a treatment capacity of 25 t / hr or more. 12 t / hr.

  The chemical injection device 13 injects only the cleansing agent. When the on-off valve 31 is opened and until a certain time has elapsed after the on-off valve 31 is closed, the medicine injection device 13 has a normal amount of discharge of the cleansing agent from the medicine injection pump 13b (boiler 10). In the case where only the desalted water W2 is supplied).

  The can water blowing device 14 includes a blow bypass valve beside the blow valve 14a in order to easily perform opening / closing control of the blow valve 14a. In the normal case (when desalted water W2 is used for boiler feed water W3), this can water blowing device 14 is controlled to blow 5% of can water W4 using the blow valve 14a, and is opened and closed. The blow bypass valve is also opened when the valve 31 is open and until the on-off valve 31 is closed, and control is performed so that 7% of the canned water W4 is blown by the blow valve 14a and the blow bypass valve. Is done.

  FIG. 4 shows a comparison of the change in the electrical conductivity of the canned water W4 for the boiler system A that controls the blow rate in two stages, for example, and the boiler system in which the blow rate is constant at the maximum value (7%). is there. When the blow rate is constant (7%), the electrical conductivity of the canned water W4 is as small as 290 mS / m for the average value but fluctuates greatly as 230 to 400 mS / m for each value (open / close valve). When the valve 31 is opened, it rises and when the valve 31 is closed, the total blow amount for two days is 81.7 t. In the boiler system A that controls the blow rate in two steps, the electrical conductivity of the canned water W4 is as large as 340 mS / m for the average value, but the fluctuation range is small as 300 to 350 mS / m for each value. Thus, the total blow amount for 2 days is also 74.7 t. In the case of this boiler system A, the electrical conductivity of the can water W4 increases, but the fluctuation range can be suppressed small, and problems such as carryover, scale failure, corrosion, etc. caused by water treatment on the boilers 10 and 10 side. The amount of blow could be reduced by 3.5 tons (8.5%) per day.

  In the test using the actual machine, two chemical injection devices were prepared, and when the boiler feed water W3 was only the desalted water W2, and when the open / close valve 31 was opened and the soft water W1 was added to the boiler feed water W3, Although these two chemical injection devices were properly used, the control of the two chemical injection devices was also successful in this case, and the value of the anticorrosive component in the boiler feed water W3 did not decrease.

It is a figure which shows the flow of the boiler system which concerns on one embodiment of this invention. It is a figure which shows the quality of raw | natural water, soft water, and desalted water in the water treatment apparatus 2 used by the test using a real machine. . It is a figure which shows the change of the amount of water supply of the boiler of 2 cans used by the test using a real machine, the change of the amount of water holding of a water supply tank, the state of operation / stop of a desalination apparatus, and the state of opening and closing of an on-off valve. Changes in electrical conductivity in the can water when the blow rate of the can water is controlled in two stages (5% and 7%) and constant at the maximum value (7%) in the test using the actual machine. It is a graph to show.

Explanation of symbols

2 Water treatment device 10 Boiler 11 Water supply tank 13 Chemical injection device 14 Can water blow device 30 Bypass line 31 On-off valve (water flow valve)
32 Controller A Boiler system W1 Soft water W
W3 boiler water supply W4 can water

Claims (4)

A boiler system operation method comprising a water treatment device for treating boiler supply water for boiler feed water and supplying the water to the feed water tank side,
The entire water treatment apparatus or a part of the water treatment apparatus has a treatment capacity smaller than the treatment capacity required at the maximum load of the boiler, and the treatment capacity of the entire water treatment apparatus or the water treatment apparatus is reduced. By providing a bypass line that bypasses a part, the water flow valve of this bypass line is controlled by the water level of the water supply tank,
And controlling at least one of the chemical solution injection amount from the chemical injection device and the blow rate of the can water blown from the boiler based on the deterioration of the quality of the boiler feed water caused by the water passing through the water flow valve. The operation method of the boiler system characterized by this.   The boiler system operation method according to claim 1, wherein the boiler supply water is softened softened water.   The method for operating a boiler system according to claim 1 or 2, wherein a deterioration in water quality of the boiler feed water is determined by a ratio of water that has passed through the water flow valve in the boiler feed water. A boiler system comprising a water treatment device that processes boiler supply water for boiler supply and supplies the water to the water supply tank side,
The entire water treatment apparatus or a part of the water treatment apparatus is made smaller than the treatment capacity required at the maximum load of the boiler, and the whole water treatment apparatus or one of the water treatment apparatuses is reduced in this treatment capacity. A bypass line is provided to bypass the section,
And while controlling the water flow valve of the bypass line by the water level of the water supply tank, and based on the deterioration of the quality of boiler feed water caused by the water that has passed through the water flow valve, at least the amount of chemical liquid injected from the chemical injection device and A boiler system comprising a control means for controlling one of blow rates of can water blown from a boiler.

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