JP4548907B2 - Operation method of high temperature filter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for operating a high-temperature filtration device that filters high-temperature water in, for example, a water supply system or a heater drain system in a power plant.
[0002]
[Prior art]
In a power plant or the like, high-temperature water of 100 ° C. or higher is sometimes filtered in a water supply system or a heater drain system, and it is necessary to use a heat-resistant filter that can withstand high-temperature water. Conventionally, use of a metal filter, a ceramic filter, or the like has been studied, but in recent years, use of a hydrophobic polymer filter has begun to be studied.
[0003]
Hydrophobic polymer filters have the property that once they are dried, they are hydrophobic and impervious to water and lose their filtration function. Therefore, for example, at the initial stage of water flow, the pressure on the secondary side of the filter is less than the saturated vapor pressure of the high-temperature water to be processed due to the filter differential pressure (filter pressure loss), the differential pressure of the high-temperature water treatment system or the water temperature. Then, the water to be treated changes into steam on the filter surface, the filter is dried, and the water treatment itself by the filter becomes impossible, and it may be impossible to collect the water filtered into the system. Once the hydrophobic polymer filter is dried, a chemical moistening operation is required to restore performance. Therefore, when applying a polymer filter, it is desirable to always adopt a condition in which the filter does not dry.
[0004]
On the other hand, metal filters and ceramic filters can be used even under temperature conditions of about 200 ° C such as heater drain water in power plants, but the iron removal performance is unstable, the differential pressure tends to increase, and elution It has problems such as being easy to get things out, and has not yet been fully introduced. In order to solve such a problem, application of a polymer filter is being studied, but the polymer filter has another problem as described above.
[0005]
Further, apart from the above-described problems related to the filter material, in general, a system for filtering high-temperature water often requires a basic precondition that steam is not generated in the system. This is required regardless of the material of the filter. In particular, when a polymer filter as described above is used, it is strongly desired not to generate steam from the viewpoint of ensuring the performance of the filter.
[0006]
[Problems to be solved by the invention]
Therefore, in view of the above problems and requirements, the object of the present invention is to allow a predetermined filtration process to be performed in a liquid state without changing high-temperature water into steam, and the water after the filtration process can be recovered appropriately. Another object of the present invention is to provide a method for operating a high-temperature filtration device.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the operation method of the high-temperature filtration device according to the present invention is the operation method of the high-temperature filtration device that filters high-temperature water, and a bypass passage that communicates the primary side and the secondary side of the high-temperature filtration device; A bypass valve capable of opening and closing the bypass passage, and an inlet-side on-off valve and an outlet-side on-off valve disposed on the inlet side and the outlet side of the high-speed filtration device, respectively, and a secondary of the filter provided in the high-temperature filtration device Side pressure and the pressure on the secondary side of the filter is saturated by opening the bypass valve when the pressure approaches a predetermined difference with respect to the saturated vapor pressure at the temperature. It consists of the method characterized by performing flow control of the water flow to a high temperature filtration apparatus so that it may be kept more than a vapor pressure.
[0008]
In this method, a bypass passage communicating the primary side and the secondary side of the high-temperature filtration device, and a bypass valve capable of opening and closing the bypass passage are provided to control the flow rate of water to the high-temperature filtration device and open and close the bypass valve. And thereby controlling the flow rate of water to the high-temperature filter so that the pressure on the secondary side of the filter is maintained at or above the saturated vapor pressure .
[0009]
Alternatively , the main tower of the high-temperature filtration device that normally filters high-temperature water is connected in parallel with the preliminary tower of the high-temperature filtration device, and the preliminary tower inlet-side opening and closing arranged respectively at the inlet side and the outlet side of the preliminary tower Valve and auxiliary tower outlet side opening / closing valve, auxiliary tower inlet side opening / closing valve, auxiliary tower inlet side bypass path communicating with the primary side and secondary side, and preliminary tower inlet side bypass capable of opening and closing the preliminary tower inlet side bypass path When the temperature and pressure on the secondary side of the filter in the main tower are detected, and the pressure approaches a predetermined difference with respect to the saturated vapor pressure at the temperature, the preliminary tower inlet side bypass valve And the auxiliary tower outlet side opening / closing valve is opened, and then the auxiliary tower inlet side opening / closing valve is opened and the auxiliary tower inlet side bypass valve is closed, and filtration is performed in the auxiliary tower. In addition to parallel water flow to the reserve tower As it carried out, whereby the pressure of the secondary side of the filter of the present tower can be made to flow control water passage into the tower so as to maintain on the saturated vapor pressure. If it does in this way, since the high temperature water which is to-be-processed water will always be filtered by the main tower and a preliminary | backup tower, the treated water filtered always will be sent out.
[0010]
Further, in the pressure of the secondary side of the filter determines whether or not the saturated vapor pressure is to detect the temperature and pressure of the secondary side of the filter to determine the relationship between the saturated vapor pressure, the Based on the determination, the flow rate of water to the high-temperature filter is controlled .
[0011]
The high-temperature water targeted in the present invention is, for example, water having a water temperature of 100 ° C. or higher, and changes to steam when it falls below the saturated vapor pressure.
[0012]
In addition, although the flow control of the water flow to the high temperature filtration apparatus in the present invention can be performed using a flow control valve, the pressure loss due to the valve is suppressed as low as possible to suppress the pressure drop as a whole of the filter apparatus. Therefore, it is preferable to use a simple open / close valve in which the pressure loss of the valve itself is small.
[0013]
In the operation method of the high-temperature filtration device according to the present invention as described above, when the pressure on the secondary side of the filter decreases and approaches the saturated vapor pressure, the pressure is kept high so that the pressure is maintained at or above the saturated vapor pressure. The amount of water flow to the filtration device is suppressed. In the control of the water flow rate, when a bypass path is provided for the high-temperature filter device, the water flow rate to the high-temperature filter device is narrowed down and the rest is allowed to escape to the bypass channel. Also, when the main tower and the backup tower are connected in parallel, according to the pressure on the secondary side of the filter in the main tower, that is, when the pressure on the filter secondary side of the main tower approaches the saturated vapor pressure, The water flow to the tower should be performed in parallel, and the water flow to the main tower should be kept small. In the case of a system in which a bypass is provided, the pressure loss in the high-temperature filtration device, particularly the filter pressure loss, decreases as the amount of water flow to the high-temperature filtration device decreases. The pressure on the secondary side of the filter is reliably maintained at the saturated vapor pressure or higher. By maintaining the secondary side pressure at or above the saturated vapor pressure, generation of vapor on the filter surface is prevented, and consequently generation of vapor in the system is prevented. In addition, when the main tower and the backup tower are connected in parallel, when the pressure on the filter secondary side of the main tower drops and approaches the saturated vapor pressure, water flow to the backup tower is started and Since the amount of water flow can be kept small, the pressure loss in the main tower as a high-temperature filtration device can be kept small, the pressure on the secondary side of the filter is kept above the saturated vapor pressure, and steam is generated on the filter surface. Steam generation inside is prevented. In this method of connecting the main tower and the backup tower in parallel, after steam operation, the water flow is completely switched from the main tower to the backup tower, the main tower is disconnected from the filtration system, and the pressure on the filter secondary side of the main tower is reduced. The cause of the decrease can also be confirmed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a system of a high-temperature filtration device for carrying out the method according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a high-temperature water supply line, 2 denotes a water recovery line after filtration, and a high-temperature filtration device 3 is provided between the supply line 1 and the recovery line 2. On-off valves 4 and 5 are respectively provided on the inlet side and the outlet side of the high-temperature filtration device 3.
[0015]
In this embodiment, a filter 6 made of a hydrophobic polymer processed into a hollow fiber shape, a spiral shape, a pleat shape, or the like is disposed in the high temperature filtration device 3. As the format of the filter 6, other types can be adopted as will be described later.
[0016]
The high temperature filtration device 3 is provided with a temperature sensor 7 for detecting the temperature (T) on the secondary side of the filter 6 and a pressure sensor 8 for detecting the pressure (P). The detection signals from the temperature sensor 7 and the pressure sensor 8 are sent to the control device 9 and are used to determine whether or not the pressure on the secondary side of the filter 6 is maintained at or above the saturated vapor pressure.
[0017]
More precisely, between the primary side and the secondary side of the high-temperature filtration device 3, between the upstream side of the on-off valve 4 and the downstream side of the on-off valve 5, the primary side and the secondary side of the high-temperature filtration device 3 are located. A bypass path 10 that can communicate with the next side is provided. A bypass valve 11 that can open and close the bypass path 10 is provided in the bypass path 10. The bypass valve 11 of the bypass passage 10 is operated in conjunction with the control of water flow to the high temperature filtration device 3, that is, the opening / closing control of the opening / closing valves 4, 5.
[0018]
The method according to the present invention is carried out as follows using the system of the high-temperature filtration device configured as described above.
At normal times, the bypass valve 11 of the bypass passage 10 is closed, the on-off valves 4 and 5 are fully opened, and the supplied high-temperature water passes through the high-temperature filter 3 and is filtered by the filter 6. In this filtration process, the pressure on the secondary side of the filter 6 is reduced as compared with the pressure on the supply side due to the pressure loss caused by the high-temperature water passing through the filter 6. Therefore, if this pressure loss is large, the degree of decrease in the pressure on the secondary side of the filter 6 increases, and the pressure may become equal to or lower than the saturated vapor pressure.
[0019]
The pressure on the secondary side of the filter 6 is directly detected by the pressure sensor 8, and the saturated vapor pressure is calculated by the control device 9 or stored in advance as the saturated vapor pressure corresponding to the temperature detected by the temperature sensor 7 at that time. Read from the diagram. Then, the control device 9 determines whether or not the detected pressure on the secondary side of the filter 6 by the pressure sensor 8 is equal to or higher than the saturated vapor pressure and how much difference there is between the saturated vapor pressure. Is calculated.
[0020]
In this embodiment, when the pressure detected by the pressure sensor 8 approaches a predetermined difference with respect to the saturated vapor pressure, the bypass valve 11 is opened first, the bypass passage 10 is opened, and then the valves 4, 5 are opened. Is squeezed. Since the pressure loss in the bypass passage 10 is small, most of the supplied high-temperature water flows through the bypass passage 10 and the rest passes through the high-temperature filtration device 3. By reducing the flow rate passing through the high temperature filtration device 3, the pressure loss (pressure drop) due to the passage through the high temperature filtration device 3 is greatly reduced, and the pressure on the secondary side of the filter 6 is less than the saturated vapor pressure. And generation of steam is reliably prevented. Further, since the generation of steam on the secondary side of the filter 6 is prevented, no steam is generated in the treated water recovered through the recovery line 2, and the generation of steam in the system is reliably prevented.
[0021]
In addition, when the cause of the pressure drop on the secondary side of the filter 6 is due to clogging of the filter 6 and it is determined that the filter 6 has reached the replacement or regeneration time, the valves 4 and 5 are completely closed. The filter 6 may be replaced in a state where the entire amount of high-temperature water is passed through the bypass passage 10.
[0022]
In the first embodiment, the filter 6 is a hydrophobic polymer filter processed into a hollow fiber shape, a spiral shape, a pleat shape, or the like, but other types of filters can be used. For example, as in a filtration desalination apparatus used in nuclear power plants and the like, it is possible to use a hydrophobic polymer resin powdered and pre-coated on a filter element. Alternatively, filtration can be performed by forming a filter layer with a filter medium made of granular material such as sand or ion exchange resin, such as a sand filtration device or a condensate demineralization device. For example, a hydrophobic polymer can be prepared into a granular material having an appropriate particle size, and a filter medium can be formed from the granular material to perform filtration.
[0023]
FIG. 2 shows a system of a high-temperature filtration device for carrying out the method according to the second embodiment of the present invention, and shows a case where the filter is composed of a filter layer 21 using hydrophobic polymer particles. ing. In this embodiment, because of the configuration of the filter layer 21, FIG. 2 is displayed with the top and bottom reversed compared to FIG. 1, but the basic configuration other than the filter layer 21 portion is the same as the embodiment shown in FIG. Therefore, about the same component part, description is abbreviate | omitted by attaching | subjecting the same code | symbol which attached | subjected FIG. 2 to FIG.
[0024]
3 and 4 show a system of a high-temperature filtration device for carrying out the method according to the third and fourth embodiments of the present invention. In these embodiments, in addition to preventing the generation of steam, consideration is also given to preventing the occurrence of problems in the temperature rising process at the start of system operation.
[0025]
In the third embodiment shown in FIG. 3, a bypass passage 31 and a bypass valve 32 are provided for the opening / closing valve 4 on the inlet side of the high-temperature filtration device 3. It consists of a narrow valve with a small channel. At the start of water flow to the high temperature filtration device 3, the temperature of the entire high temperature filtration device 3 has not been raised yet, so that the temperature rises gradually in order to avoid sudden temperature rise and the occurrence of inconveniences such as a seal portion. It is hoped that Therefore, when the water flow starts, the on-off valve 4 is closed, the bypass valve 32 is opened, and the high-temperature filter 3 is gradually warmed by passing high-temperature water at a small flow rate, and the high-temperature filter 3 is heated to a predetermined temperature. When this is done, the on-off valve 4 is opened and the bypass valve 32 is closed, and water is introduced into the high-temperature filtration device 3 at a predetermined flow rate. In this way, it is possible to prevent the occurrence of inconvenience in the temperature raising process at the start of water flow. Control for keeping the pressure on the secondary side of the filter 6 at or above the saturated vapor pressure may be performed in the same manner as in the first embodiment.
[0026]
In the 4th embodiment shown in FIG. 4, the filter layer 21 is formed from the granular material of hydrophobic polymer. Similarly, a bypass passage 31 and a bypass valve 32 are provided for the opening / closing valve 4 on the inlet side of the high-temperature filtration device 3. As in the third embodiment, the operation at the start of water flow may be performed in the same manner as in the second embodiment described above to keep the pressure on the secondary side of the filter 21 at or above the saturated vapor pressure.
[0027]
FIG. 5 shows a system of a high temperature filtration device for carrying out the method according to the fifth embodiment of the present invention. In this embodiment, no bypass path is provided, and an apparatus equivalent to that shown in the third embodiment in FIG. In other words, a preliminary tower 3b is connected in parallel to the main tower 3a as a high-temperature filtration device that filters high-temperature water at normal times, and the main tower 3a is connected to the main tower 3a according to the pressure on the secondary side of the filter 6 in the main tower 3a. In addition to the water flow, the water flow to the preliminary tower 3b can be performed in parallel.
[0028]
More specifically, at the beginning of water flow, as in the third embodiment, the valve 32 is opened to allow water to flow through the bypass passage 31 of the valve at a relatively small flow rate, the valve 5 is opened, and the main tower 3a. When the temperature of the main tower 3a rises, the valve 4 is opened, the valve 32 is closed and water is passed through, and normal filtration is performed. When the pressure on the secondary side of the filter 6 in the main tower 3a decreases and approaches the saturated vapor pressure (that is, when the differential pressure of the filter 6 increases to a predetermined level or more), the valve 42 on the side of the preliminary tower 3b is opened to open the valve Water is passed through the bypass passage 41 at a relatively small flow rate, and the valve 43 is opened to start filtration in the preliminary tower 3b. When the temperature of the preliminary tower 3b rises, the valve 44 is opened and the valve 42 is closed. Water is used, and normal filtration is performed in the preliminary tower 3b. In this state, both the main tower 3a and the standby tower 3b are in a normal filtration state. However, since water is passed through both the towers 3a and 3b in parallel, the amount of water passing through the main tower 3a is greatly reduced. The pressure loss of the filter 6 is significantly reduced, and it is prevented from reaching the saturated vapor pressure, and the generation of steam on the secondary side surface of the filter 6 and in the system is prevented.
[0029]
After switching to this parallel water flow, the differential pressure of the filter 6 in the main tower 3a increased by closing the valves 4 and 5 on the main tower 3a side and completely disconnecting the main tower 3a from the filtration system. The cause can be confirmed.
[0030]
In the fifth embodiment shown in FIG. 5, the control device is not shown. However, as in each of the above-described embodiments, the control device is provided to start the water flow of the spare tower 3b and switch to the spare tower 3b. Can also be performed automatically. Further, in the fifth embodiment shown in FIG. 5, the bypass path 10 in each of the above-described embodiments is not provided. However, for emergency measures, etc., the same as in each of the above-described embodiments. A common bypass passage 10 and a bypass valve 11 may be provided for the tower 3a and the spare tower 3b.
[0031]
In FIG. 5, the main tower 3a and the spare tower 3b are shown separately. However, since both towers 3a and 3b and their auxiliary facilities may be basically the same, either one is the main tower and the other is the spare tower. It can be operated as a tower.
[0032]
Further, in each of the embodiments described above, a hydrophobic polymer is used for each filter, regardless of the type, but the present invention is also applicable when a metal filter or a ceramic filter is used. Even when a metal filter or a ceramic filter is used, the generation of steam on the secondary side of the filter is prevented by applying the operation method according to the present invention, and consequently the generation of steam in the system is prevented. Is done.
[0033]
【The invention's effect】
As described above, according to the operation method of the high-temperature filtration device of the present invention, the high-temperature water can be reliably filtered in a liquid state without changing the high-temperature water into steam, and the water after the filtration is appropriately recovered. be able to.
[Brief description of the drawings]
FIG. 1 is an equipment diagram including a high-temperature filtration device for carrying out a method according to a first embodiment of the present invention.
FIG. 2 is an equipment diagram including a high-temperature filtration device for carrying out a method according to a second embodiment of the present invention.
FIG. 3 is an equipment diagram including a high-temperature filtration device for carrying out a method according to a third embodiment of the present invention.
FIG. 4 is an equipment diagram including a high-temperature filtration device for carrying out a method according to a fourth embodiment of the present invention.
FIG. 5 is an equipment diagram including a high-temperature filtration device for carrying out a method according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High temperature water supply line 2 Water recovery line after filtration 3 High temperature filtration device 3a Main tower 3b as a high temperature filtration device Preliminary tower 4 Inlet side on / off valve 5 Outlet side on / off valve 6, 21 Filter 7 Temperature sensor 8 Pressure sensor DESCRIPTION OF SYMBOLS 9 Control apparatus 10 Bypass path 11 Bypass valve 31 Bypass path 32 in high temperature filter inlet side Bypass valve 41 in high temperature filter inlet side Bypass path 42 in preliminary tower inlet side Bypass valve 43 in preliminary tower inlet side Preliminary tower outlet side opening / closing valve 44 Preliminary tower entrance side open / close valve

Claims (5)

In an operation method of a high-temperature filtration device for filtering high-temperature water , a bypass passage communicating the primary side and secondary side of the high-temperature filtration device, a bypass valve capable of opening and closing the bypass passage, and an inlet side and an outlet of a high-speed filtration device An inlet-side on-off valve and an outlet-side on-off valve respectively disposed on the side, and detects the temperature and pressure on the secondary side of the filter provided in the high-temperature filter, and the pressure becomes the saturated vapor pressure at the above temperature. On the other hand, the flow rate control of water flow to the high-temperature filtration device is performed so that the pressure on the secondary side of the filter is maintained at the saturated vapor pressure or higher by opening the bypass valve when approaching a predetermined difference set in advance. A method for operating a high-temperature filtration device, characterized in that: The high temperature filtration according to claim 1, wherein when the pressure approaches a predetermined difference with respect to the saturated vapor pressure at the temperature, the bypass valve is first opened, and then the inlet side on-off valve and the outlet side on-off valve are throttled. How to operate the device. In the operation method of the high-temperature filtration device for filtering high-temperature water, a high-temperature filter preparatory tower is connected in parallel to the main tower of the high- temperature filtration device that normally filters high-temperature water, and the preparatory tower inlet side and Preliminary tower inlet side opening / closing valve and auxiliary tower outlet side opening / closing valve respectively arranged on the outlet side, a preliminary tower inlet side opening / closing valve, a preliminary tower inlet side bypass passage communicating the primary side and secondary side, and the preliminary tower inlet A bypass column inlet side bypass valve capable of opening and closing the side bypass passage, detecting the temperature and pressure on the secondary side of the filter in the main column , and the pressure is determined in advance with respect to the saturated vapor pressure at the temperature When the difference is approached, the spare tower inlet bypass valve and spare tower outlet open / close valve are opened, and then the spare tower inlet open / close valve is opened and the spare tower inlet bypass valve is closed and filtered in the spare tower. Is done , Have rows in parallel water flow to a spare column in addition to the water passage to the tower, so that the pressure on the secondary side of the filter is kept on the saturated vapor pressure, the water flow to the hot filtration unit A method for operating a high-temperature filtration device, characterized by performing flow rate control . The operation method of the high-temperature filtration apparatus according to claim 3 , wherein after the preliminary tower inlet side bypass valve and the preliminary tower outlet side opening / closing valve are opened, the preliminary tower inlet side opening / closing valve is opened when the temperature of the preliminary tower rises .   The operation method of the high temperature filtration apparatus in any one of Claims 1 thru | or 4 whose water temperature of the high temperature water filtered is 100 degreeC or more.

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