JP2008229542A - Deoxygenation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the concentration of dissolved oxygen in treated water in a deoxidation system for reducing dissolved oxygen in supplied water. <P>SOLUTION: The deoxidation system includes a degassing device 1, a treated water tank 2 for storing the treated water produced in the degassing device 1, a loading device 3 using the treated water of the treated water tank 2 and a control means 4 for increasing the supply amount of water to be treated to the degassing device 1 accompanying the lowering of a water level on the basis of the water level data of the treated water tank 2. The control means 4 controls the supply amount of water to be treated so as to reduce it to a level lower than the supply amount only by the water level data on the basis of the treated water requiring amount data of the loading device 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a deoxygenation system that reduces dissolved oxygen in feed water.

  In the water supply system to the refrigeration equipment represented by the steam boiler, the exhaust gas boiler, the cooler, etc., in order to prevent the water contact portion of the refrigeration equipment from being corroded by dissolved oxygen in the feed water and damaging the refrigeration equipment. A deaerator is used.

  As the deaeration device, a large number of hollow fiber polymer membranes having a characteristic of permeating oxygen but not liquid are bundled and accommodated in a housing, and both ends of each polymer membrane are made of a resin agent. Dissolved oxygen contained in the liquid to be treated by supplying a liquid to be treated to one side of each polymer film and depressurizing the other side of each polymer film using a deoxygenation module having a sealed structure There is known a membrane type deaeration device having a configuration for reducing the above.

  A deoxygenation system using this type of membrane type deaerator is known from Patent Document 1. When the water level in the treated water tank is equal to or higher than the first set water level, this deoxygenation system performs a flow rate adjusting operation for adjusting the supply amount of the treated water according to the detected water level, and the water level in the treated water tank is the first. When the water level is equal to or lower than the second set water level that is lower than the set water level by a predetermined distance, the full amount supply operation is performed.

JP-A-10-28963

  Since the deoxygenation system of Patent Document 1 controls the supply amount of water to be treated based only on the water level information of the treated water tank, the water level information can be obtained even when the amount of treated water required by load equipment that changes in real time is small. Therefore, a high flow rate supply operation is performed. As a result, the dissolved oxygen concentration of the treated water supplied from the deaerator to the treated water tank increases.

  The problem to be solved by the present invention is to reduce the dissolved oxygen concentration of treated water.

  This invention was made in order to solve the said subject, and invention of Claim 1 is a deaeration apparatus, the treated water tank which stores the treated water produced | generated in this deaeration apparatus, and this A load device that uses the treated water in the treated water tank, and a control unit that increases the amount of treated water supplied to the deaeration device as the water level decreases based on the water level information of the treated water tank. In the oxygen system, the control unit performs control so that the supply amount is less than the supply amount based only on the water level information based on the required amount of treated water of the load device.

  The invention according to claim 2 is a deaeration device, a treated water tank that stores treated water generated by the deaerated device, a load device that uses treated water in the treated water tank, and the treated water. A deoxygenation system comprising control means for increasing the amount of water to be treated to be supplied to the deaeration device as the water level becomes lower based on the water level information of the tank, wherein the control means is configured to treat the load device. Based on water requirement information, when the treated water requirement is smaller than the set requirement, control is performed to make the supply amount smaller than the set supply amount set corresponding to the water level.

According to invention of Claim 1 or Claim 2, based on the treated water requirement amount information of the said load apparatus, even if the said water level is low, when the said treated water requirement amount is small, the control which reduces the said supply amount is carried out. Since it performs, compared with the system which does not perform control by the said treated water requirement information, the dissolved oxygen concentration of treated water can be reduced.

  Furthermore, the invention described in claim 3 is characterized in that, in claim 1 or 2, the control means performs a high flow rate operation at the start of operation of the deaeration device.

  According to the invention of claim 3, in addition to the effect of the invention of claim 1 or claim 2, it is possible to suppress the occurrence of clogging of the film due to low flow rate operation. .

  According to this invention, the dissolved oxygen concentration of treated water can be reduced.

  Next, an embodiment of the present invention will be described. This invention suppresses corrosion in refrigeration equipment such as steam boilers, exhaust gas boilers, and coolers, prevents red water from being generated in water supply piping of buildings, condominiums, etc., or improves the efficiency of ultrasonic cleaning in parts cleaning equipment at semiconductor manufacturing plants, etc. This is preferably carried out in a deoxygenation system using a membrane type deaeration device used for the above purpose. This deoxygenation system can be referred to as a degassing system.

  An embodiment of the present invention includes a deaeration device, a treated water tank that stores treated water generated by the deaerated device, a load device that uses treated water in the treated water tank, and the treated water tank. A deoxygenation system comprising a control means for increasing the amount of water to be treated to be supplied to the deaeration device as the water level becomes lower based on water level information, wherein the control means is a request for treated water from the load device. It is a deoxygenation system characterized by performing control which makes the said supply amount smaller than the supply amount only by the said water level information based on quantity information.

  In this deoxygenation system, the control means performs control to increase the supply amount of water to be treated to the deaeration device as the water level becomes low as basic first control. In addition to the first control, the control means additionally performs a control as a second control to make the supply amount smaller than the supply amount based only on the water level information based on the treated water requirement amount information of the load device. Do. By performing this second control, the amount of treated water supplied to the treated water tank can be reduced, and the dissolved oxygen concentration of treated water is reduced compared to a system that does not perform the second control. The

  Next, each component of this embodiment will be described. The deaerator is a membrane type deaerator, a so-called membrane type deaerator using a gas permeable membrane or a gas separation membrane, and is not limited to a specific structure. This membrane-type deaeration device forms a gas permeable membrane into a tubular, hollow fiber-like, pleated, spiral-like (spread-like) shape, etc., and is housed in an appropriate container in this state to constitute one component. It is used as a so-called membrane module. This deaeration device has a characteristic that the dissolved oxygen concentration of the treated water is lowered when the supply amount of the treated water is reduced.

  The inside of the membrane module is divided into a liquid phase side and a gas phase side, and on the liquid phase side, water to be treated (also referred to as raw water, well water, tap water, various industries) A treated water supply line having a feed water pump for supplying water (including water, other liquid products, etc.) and a treated water supply line for supplying a treated water tank for storing treated water after deaeration treatment are connected .

On the gas phase side, a vacuum suction line is connected to a decompression means for vacuum suction in the compartment. Then, in the process of circulating the water to be treated in the membrane module, by vacuum suction through the gas permeable membrane, the dissolved gas in the water to be treated is sucked and removed, and the degassed treated water is removed from the treated water supply line. It is configured to supply to the treated water tank. The decompression means is preferably a water ring vacuum pump.

  One or a plurality of deaeration devices are used in relation to the amount of treated water (maximum capacity) and the required amount of treated water (maximum capacity) of load equipment. In the case of a plurality of units, they are used in parallel with each other.

  The load device is preferably a cooling / heating device represented by a steam boiler, a hot water boiler, an exhaust gas boiler, a cooler, etc., but is not limited to this, and is disposed in a building such as a building or a condominium. Water supply equipment, semiconductor manufacturing plant parts washing equipment, food equipment and food related equipment.

  The control means is preferably a controller provided separately from a controller provided in the deaeration device, but may be a controller of the deaeration device. When there are a plurality of the deaeration devices, the controllers of the deaeration devices are connected to each other through a signal line or a network so as to be able to communicate with each other without providing a separate controller. It is configured to control each deaeration device by exchanging signals between them, or to control by a controller that takes in the signal of the controller of each deaeration device and controls the load device be able to.

  The control by the control means is executed by a pre-stored processing procedure. This treatment procedure is based on the water level information of the treated water tank, and is a first control (referred to as basic control) that increases the amount of treated water supplied to the deaeration device as the water level becomes lower. And a control program for performing second control (which can be referred to as additional control) for making the supply amount smaller than the supply amount based only on the water level information, based on the treated water requirement amount information of the load device. . The second control is preferably configured to be performed with a condition that the water level of the treated water tank is equal to or higher than a set value.

  More specifically, the second control is a setting in which the supply amount is set in correspondence with the water level when the required amount of treated water is smaller than the set required amount based on the required amount of processed water information of the load device. This control is less than the supply amount.

  The treated water requirement amount information is information on the secondary side of the treated water tank, and can be referred to as direct information on the load device side or load information on the load device. As this treated water requirement amount information, when the load device is a steam boiler, it is preferably header pressure information or combustion state information of the boiler, but is not limited thereto. The combustion state information is, for example, a boiler capable of switching between low combustion and high combustion, and a high combustion operation excessive state (high load) when the ratio of the operation time of the high combustion operation in the past fixed time exceeds a set value. When the ratio of the operation time of the high combustion operation in the past fixed time is less than the set value, it can be determined that the state is the low combustion operation excessive state (low load state).

When the water level information of the water pipe of the boiler is the treated water requirement information, it is determined that the load is low when the water pipe level exceeds a set value, and is determined to be high load when the water pipe level is less than the set value. To be configured. Further, when the operation time information of the boiler is the treated water request information, the operation time in the past fixed time is calculated, and when (operation time / previous fixed time)> 0.5, it is determined as the high load operation state. However, when (operating time / previous fixed time) <0.5, it can be configured to determine the low-load operating state. Further, in the case where the amount of steam used is the above-mentioned treated water requirement information, it is determined that the operation state is a high load when steam supply amount per unit time> boiler capacity / 2, and steam supply amount per unit time <boiler capacity / 2. At this time, it can be configured to determine the low-load operation state. Furthermore, as treated water request information, it can be set as the operating time information of the feed water pump to the boiler, or the makeup water information to the boiler.

  The control of the supply amount of the water to be treated to the deaerator will be described. This supply amount control is performed by the flow rate adjusting means, and can be stepwise flow rate control or continuous flow rate control. When this stage control is performed in two stages of a high flow rate and a low flow rate, when the high flow rate is set to 100% of the supply amount of the water to be treated, the low flow rate is preferably set to a supply amount of 50 to 60%. However, the present invention is not limited to this. Further, the flow rate control stage is not limited to two stages, but can be configured to control to three or more stages such as high flow rate, medium flow rate, and low flow rate.

  The flow rate adjusting means for performing two-stage flow rate control is configured such that a first valve and a second valve are connected in parallel to a deaeration module of the deaeration device, and the first valve and the second valve are connected to each other. By opening and closing, the flow rate can be increased by opening both valves, and the flow rate can be decreased by closing the first valve. However, the present invention is not limited to this. That is, rather than providing the first valve and the second valve with a flow rate adjusting function, a second valve and a flow rate adjusting member are connected in parallel with the first valve, and flow control is performed by opening and closing these valves. be able to. The first valve and the second valve are preferably provided in the deaeration device, but may be provided outside the deaeration device.

  Moreover, a feed water pump can be provided with respect to the said deaeration apparatus, and it can comprise so that control of a high flow rate and a low flow rate may be performed by controlling the rotation speed of the said feed water pump.

  When there are a plurality of the deaeration devices, the supply amount (water flow rate) control of the water to be treated to the deaeration device is controlled so that all the supply amounts of the water to be treated are the same. It can be set as control which varies the supply amount to. In this case, the two-stage flow rate adjusting means may be configured to provide the first valve and the second valve for each deaeration device or to provide the water supply pump. In the case of using the water supply pump, the flow rate can be adjusted by providing a common water supply pump for a plurality or all of the deaeration devices, or by providing a water supply pump for each deaeration device.

  Furthermore, in this embodiment, it is preferable that the deaeration device perform a high flow rate operation (when the high flow rate is a rated operation, it can be referred to as a rated load operation) at the start of the operation of the deaeration device. It is configured to perform clogging prevention control. This is for the following reason. The deoxygenation system of this embodiment controls the supply amount of the water to be treated to the low flow rate side as described above. As a result, the deaeration device is likely to be clogged. Therefore, clogging can be suppressed by performing a high flow rate operation at the start of operation of the deaeration device. Instead of the high flow rate operation at the start of the operation, the high flow rate operation is performed when the duration of the low flow rate operation reaches a predetermined time, or the high flow rate operation is periodically performed at a predetermined time interval such as a fixed time interval. Can be configured.

  When this clogging prevention operation is applied to a system using a plurality of deaeration devices, not all the deaeration devices to be operated at a high flow rate at the start of operation, but a part (one or a plurality). Rotating the degassing device that operates at a high flow rate can prevent clogging of the specific degassing device.

  Embodiment 1 of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a deoxygenation system according to the first embodiment, FIG. 2 is a time chart illustrating control of the supply amount of water to be treated according to the first embodiment, and FIG. It is a flowchart explaining the principal part of the control procedure of Example 1.

(Configuration of Example 1)
The deoxygenation system according to Example 1 includes three first to third degassing devices 1A, 1B, and 1C having the same configuration and connected in parallel to each other (for example, the maximum capacity of each degassing device is 5.0 t / h)), a treated water tank 2 for storing treated water generated by the degassed apparatus 1, and load equipment using treated water in the treated water tank 2 6 steam boilers 3, 3,... (For example, the maximum capacity of each steam boiler is 2.5 t / h), the water level information of the treated water tank 2 and the treatment of the steam boilers 3, 3,. A first controller 4 that controls the operating state of each deaeration device 1 based on the required water amount information is provided as a main part.

  The deaerator 1 is connected to a water softener 5 and a water line to be treated (hereinafter, the line can be referred to as a path or a flow path) 6, 6,. The degassing devices 1 and the treated water tank 2 are connected by first treated water lines 7, 7,... For supplying treated water from the degassing devices 1.

  The steam boilers 3 are connected in parallel to each other, and are connected to the treated water tank 2 by second treated water lines 8, 8,... For supplying treated water from the degassing devices 1. Further, each steam boiler 3 is connected to steam use equipment (not shown) by first steam lines 9, 9,..., A steam header 10, and a second steam line 11.

  The deaeration apparatus 1 is a membrane type deaeration apparatus having a known configuration, and a membrane module (not shown) as a deaeration means for deaeration treatment of supplied water to be treated, and a vacuum inside the membrane module A water-sealed vacuum pump (not shown) for suction is provided. The membrane module is configured as a hollow fiber gas permeable membrane (not shown) contained in a container, and the inside of the membrane module is partitioned into a liquid phase side and a gas phase side by a gas permeable membrane. The membrane module is connected to the water lines 6 to be treated on the liquid phase side, and to the water-sealed vacuum pump via a vacuum suction line (not shown) on the gas phase side. ing. Accordingly, in the flow of the water to be treated in the membrane module, the inside of the membrane module is vacuum-sucked through the gas-permeable membrane by the water-sealed vacuum pump, and the dissolved gas in the water to be treated is sucked and removed, and degassed. The treated water is supplied to the treated water tank 2 via the first treated water supply lines 7.

  The deaerators 1A, 1B, and 1C have flow rate adjusting means for controlling the amount of water to be treated to the membrane module to a high flow rate of 100% water flow and a low flow rate of 50% water flow. The flow rate adjusting device 12 is incorporated. The flow rate adjusting device 12 includes a first valve 13 and a second valve 14 connected in parallel to each other. The first valve 13 and the second valve 14 are opened to increase the flow rate. By closing 13 and opening the second valve 14, the low flow rate is set. In the first embodiment, the flow rate adjustment function is achieved by opening and closing the first valve 13 and the second valve 14.

  Next, the control configuration of the first embodiment will be described. Each deaeration device 1A, 1B, 1C includes a second controller 15 as an individual controller for controlling each first valve 13, each second valve 14, each water ring vacuum pump, and the like. The first controller 4 is stored in advance based on the water level information of the water level sensor 16 provided in the treated water tank 2 and the steam boiler 3, 3,... 3), the deaerators 1A, 1B, and 1C are controlled to operate at a high flow rate, a low flow rate, and stop by sending a command to each second controller 15. The deaeration control program is based on the water level information of the treated water tank 2, the first control for increasing the supply amount of the treated water to the deaeration device 1 as the water level becomes lower, and the boiler 3 A control program for performing second control for making the supply amount smaller than the supply amount based only on the water level information based on the treated water requirement amount information;

In the first embodiment, the treated water requirement amount information includes the steam header 10 as shown in FIG.
It is the combustion state information resulting from the pressure fluctuation inside. That is, when the ratio of the operation time of the high combustion operation in the past fixed time exceeds the set value, it is determined as a high combustion operation excessive state (high load state) and the first control is performed. In addition, when the ratio of the operation time of the high combustion operation in the past fixed time is less than the set value, it is determined that the low combustion operation is excessive (low load state) and the second control is performed.

  The water level sensor 16 is configured to detect the water level using water pressure, is installed near the bottom of the treated water tank 2, detects the water level of the treated water in the treated water tank 2, and this detection signal Is output to the first controller 4.

  In addition, the deaeration control program includes a clogging prevention program for preventing clogging of each deaeration device 1 as shown in FIG. This clogging prevention program is a control for performing a high flow rate operation at the start of operation of the present deaeration system. The determination of the start of the operation of the system is based on a command from the first controller 4 such as a system operation start operation of the operation operation switch 23 attached to the first controller 4 or a control of each deaeration device 1. Based on. Further, the high flow rate operation can perform all of the deaeration device 1 at the same time.

  Each steam boiler 3 is a third control that individually performs three-position combustion control of high combustion, low combustion, and shutdown and feed water pump (not shown) control for supplying treated water to each steam boiler 3. Each third controller 17 is connected to a fourth controller 18 that controls the number of boilers. And the said 4th controller 18 is comprised so that the number control of the said steam boilers 3, 3, ... may be performed with the boiler control program memorize | stored previously based on the steam demand amount from the said steam use installation. The boiler control program can be a well-known program, for example, a pressure sensor 19 for detecting the pressure of the steam header 10 is provided for the required steam amount, and the steam boilers 3, 3,. The program sets the number of units in operation. In the first embodiment, the plurality of steam boilers 3, 3,... Simultaneously perform stop, low combustion, and high combustion according to the detected pressure.

  In the first embodiment, the raw water supply line 20 for supplying raw water to the water softener 5 is provided with a hardness sensor 21 for detecting the hardness of the raw water and a temperature sensor 22 for detecting the temperature of the raw water, and detection by these sensors. A signal is input to the first controller 4 to control each deaeration device 1. In addition, the raw | natural water supply line 20 or the pump system (illustration omitted) for pumping raw | natural water to the said water softener 5 is provided in the upstream.

(Operation of Example 1)
Next, the operation of the deoxygenation system according to Example 1 will be described. First, the raw water supplied from the raw water supply line 20 is softened by ion exchange in the water softener 5. This soft water is supplied to the deaeration device 1 through the first treated water line 6 as treated water. The treated water generated by deaeration is supplied to the treated water tank 2 through the second treated water line 7 and stored therein.

  With reference to FIG. 2, the operation of each steam boiler 3 causes the pressure in the steam header 10 to change as indicated by line D in FIG. The combustion state of the steam boiler 3 changes as indicated by line E, and the required amount of treated water for the steam boilers 3, 3,. An amount of treated water corresponding to the required amount of treated water is supplied from the treated water tank 2 to each steam boiler 3 required. As a result, the supply of treated water to each steam boiler 3 causes the water level in the treated water tank 2 to fluctuate like an F line. The first controller 4 performs a clogging prevention operation and controls the amount of treated water supplied to the deaeration device 1 based on the water level and the amount of treated water supplied.

  Referring to FIG. 3, when it is determined in S1 that the operation of the system is started, the process proceeds to S2, and each first valve 13 and each second valve 14 of each deaeration device 1A, 1B, 1C is opened. Then, high flow operation (100% water flow) is performed. By this clogging prevention operation, a high flow rate operation is always performed at the start of system operation, so that clogging can be reduced despite the fact that the amount of water to be treated is suppressed by the second control.

  If NO is determined in S <b> 1, the process proceeds to S <b> 3, and the first control and the second control, which are control of the treated water supply amount, are performed. The control of the treated water supply amount will be described based on FIGS. 2 and 3 in comparison with the proportionality not considering the treated water requirement amount information (not performing the second control).

  Referring to FIG. 2, assuming that the water level of the treated water tank 2 has changed as indicated by the F line, the control based on the proportionality is performed as follows. That is, when the water level of the treated water tank 2 cuts the first water level L at the start of water supply that sets the start of water flow, the deaeration device 1 opens the first valve 13 and the second valve 14 of each device. Then, high flow operation (100% water flow) is performed. When the water level rises to the second water level M, only the first valve 13 is closed and a low flow rate operation (50% water flow) is performed. When the water level rises to the third water level H, the first valve 13 and the second valve 14 are closed to stop water flow.

  The above is the control that does not consider the treated water requirement information, but in the first embodiment, the control considering the treated water requirement information is performed. That is, in S3, when it is determined that the combustion state of the steam boiler 3 is a high combustion excessive state of E rays, that is, a low combustion excessive state, the process proceeds to S4 and the treated water requirement information is not taken into consideration. The first control that is control is performed. This treated water supply amount control of the first control is indicated by the H line.

  If it is determined in S3 that the low combustion excessive state is detected, the process proceeds to S5 and the second control is performed. Referring to the F line and the H line, when the water level of the treated water tank 2 cuts the first water level L that sets the start of water flow, the deaeration device 1 opens only the first valve 13 of each device. Then, low-flow operation (50% water flow) is performed. Then, even if the water level rises to the second water level M, the low flow rate operation is continued, and after the water level rises to the third water level H, a set time elapses or the water level in the treated water tank 2 reaches the second water level M. When the set water level is higher and lower than the third water level H, the first valve 13 and the second valve 14 are closed to stop water flow.

  Thus, compared with the control which does not consider the said treated water requirement amount information, the to-be-treated water supply amount to the said deaeration apparatus 1 is made into a low flow volume, and reduces only for the time enclosed with the dashed-dotted line J. Become. As a result, the dissolved oxygen concentration of the treated water supplied to the treated water tank 2 decreases. Further, as shown by the one-dot chain line K, by extending the low flow rate operation, the flow rate is reduced by the first control so that the supply amount to the treated water tank 2 is not insufficient.

  Thus, in this Example 1, since said 2nd control is performed, compared with the system which does not perform said 2nd control, reducing the dissolved oxygen concentration of the treated water stored in said treated water tank 2 Can do.

  This invention is not limited to the said Example 1, The said deaeration apparatus 1 can be comprised by 1 unit | set instead of multiple units | sets. Further, the steam boiler 3 can be one instead of a plurality, and the operation control pattern of the plurality is not limited to the first embodiment. Furthermore, the number of the deaeration devices 1 and the configuration of the flow rate adjustment device 12 can be variously changed.

1 is a schematic configuration diagram of a deoxygenation system according to Embodiment 1 of the present invention. It is a figure explaining the control operation of the same Example 1. FIG. It is a figure explaining the principal part control procedure of the Example 1. FIG.

Explanation of symbols

1, 1A, 1B, 1C Deaerator 2 Treated water tank 3 Steam boiler (loading equipment)
4 Controller (control means)

Claims (3)

A degassing device, a treated water tank for storing treated water generated by the degassing device, a load device using treated water in the treated water tank, and the water level based on the water level information of the treated water tank. A deoxygenation system comprising control means for increasing the amount of water to be treated to be supplied to the deaeration device as it decreases,
The said control means performs the control which makes the said supply amount smaller than the supply amount only by the said water level information based on the required amount information of the treated water of the said load apparatus. A degassing device, a treated water tank for storing treated water generated by the degassing device, a load device using treated water in the treated water tank, and the water level based on the water level information of the treated water tank. A deoxygenation system comprising control means for increasing the amount of water to be treated to be supplied to the deaeration device as it decreases,
The control unit is configured to control the supply amount to be smaller than a set supply amount set corresponding to the water level when the treated water request amount is smaller than a set request amount based on the treated water request amount information of the load device. Deoxygenation system characterized by performing.   3. The deoxygenation system according to claim 1, wherein the control unit performs a high flow rate operation at the start of operation of the deaeration device.

Images