WO2018066366A1

WO2018066366A1 - Strainer cleaning device and method

Info

Publication number: WO2018066366A1
Application number: PCT/JP2017/034009
Authority: WO
Inventors: 大輝藤村
Original assignee: 三菱日立パワーシステムズ株式会社
Priority date: 2016-10-04
Filing date: 2017-09-21
Publication date: 2018-04-12
Also published as: JP2018058019A; JP6818495B2

Abstract

The present invention provides a strainer cleaning device and method comprising: a vent line (61) connected to an outlet-side chamber (54); a vent valve (62) provided in the vent line (61); a backwash line (63) connected to the outlet-side chamber (54) and capable of supplying cleaning water; a backwash valve (64) provided in the backwash line (63); a drain line (65) connected to an inlet-side chamber (53) and capable of discharging foreign matter; drain valves (66, 67) provided in the drain line (65); and a differential pressure generation device for adjusting pressure in the casing (51) to a pressure higher than that in the drain line (65).

Description

Strainer cleaning apparatus and method

The present invention relates to an apparatus and method for cleaning a strainer provided in a water supply system of a power plant.

For example, in a thermal power plant, steam is generated by burning fuel in a boiler, transferring heat energy of the generated combustion gas to boiler feed water to generate steam, and rotating the steam turbine with the steam, thereby rotating the steam turbine. The generator connected to the shaft is rotationally driven to generate electric power. Then, the steam that has been worked by rotating the steam turbine is condensed by heat exchange with cooling water and cooled by the condenser to be condensed water, and is returned to the boiler by the condensing water pump as water supply.

In such a boiler water supply system, since foreign matter such as rust is mixed in the circulation system of the water supply (steam), a strainer for removing foreign matter from the water supply (condensed water) is provided on the outlet side of the condenser. Then, since this strainer is clogged by foreign matter when used for a predetermined period, it is necessary to periodically clean the strainer. Generally, the strainer is cleaned by closing the inlet side and outlet side of the strainer and performing a backwashing process to spray wash water from the discharge side of the strainer to the screen, and removing it from the screen Foreign substances are discharged to the outside. As such a strainer cleaning apparatus, for example, there is one described in Patent Document 1 below.

Japanese Utility Model Publication No. 62-169276

By the way, before the strainer is cleaned, the internal condensate is drained and then a backwashing process is performed in which washing water is sprayed onto the screen. When draining the strainer, air is introduced from the vent line provided at the upper part of the strainer and drained from the drain line for drain provided at the lower part, but the condensate inside the strainer is discharged by its own weight against the pressure of the drain line Therefore, there is a problem that this drainage work takes a long time.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide a strainer cleaning apparatus and method for shortening the cleaning processing time.

In the strainer cleaning apparatus of the present invention for achieving the above object, the inside of the casing is divided into an inlet side chamber and an outlet side chamber by a screen, and a water supply line is connected to the inlet side chamber to provide an inlet valve. In the strainer in which the water supply line is connected to the outlet side chamber and the outlet valve is provided, a backwash line connected to the outlet side chamber and capable of supplying washing water, a backwash valve provided on the backwash line, the inlet A differential pressure generating device for adjusting the internal pressure of the casing higher than the pressure on the drain discharge side of the casing, the drain line connected to the drain discharge side of the side chamber and capable of discharging foreign matter, the drain valve provided on the drain line And.

Therefore, when the differential pressure generator adjusts the pressure to be higher than the pressure on the drain discharge side of the casing, the treated water in the casing flows to the drain discharge side to lower the water level in the casing. Here, when the backwash valve is opened to supply washing water from the backwash line to the outlet side chamber and the drain valve is opened, the foreign matter adhering to the strainer is removed, and the foreign matter is discharged from the inlet side chamber to the drain line Ru. That is, by adjusting the internal pressure of the casing to be higher than the pressure on the drain discharge side by the differential pressure generator, the treated water in the casing can be discharged at an early stage, and the processing time for cleaning the strainer is shortened. It can be improved.

In the strainer cleaning apparatus according to the present invention, the differential pressure generator includes a vent line connected to the outlet side chamber, a vent valve provided on the vent line, and a suction line connected to the drain discharge side of the outlet side chamber. And a suction valve provided in the suction line.

Therefore, when the suction valve is opened, suction force acts from the suction line to the outlet side chamber, the internal pressure of the casing becomes higher than the pressure of the suction line, and treated water in the casing can be rapidly flowed to the suction line. Water level can be lowered early.

In the apparatus for cleaning a strainer of the present invention, the water supply line is maintained at a vacuum pressure, and the suction line is connected upstream of the inlet valve in the water supply line, and the internal pressure of the suction line It is characterized by raising the internal pressure.

Therefore, simply by connecting the suction line to the water supply line maintained at the vacuum pressure, the treated water in the casing can be flowed to the suction line and the water level in the casing can be reduced early.

In the apparatus for cleaning a strainer according to the present invention, the suction line is connected to the drain line, and a first drain valve and a first drain valve are provided as the drain valve upstream and downstream of a connection portion of the drain line with the suction line. 2) It is characterized in that a drain valve is provided.

Therefore, by connecting the suction line to the drain line, after the water level in the casing is lowered, the backwash valve is opened to supply wash water from the backwash line to the outlet side chamber, and the first drain valve and the second drain valve When the drain valve is opened, the foreign matter adhering to the strainer can be discharged from the inlet side chamber to the drain line, and the treated water remaining in the suction line can also be discharged.

The apparatus for cleaning a strainer according to the present invention is characterized in that a water level detection and estimation device for detecting or estimating the water level in the casing is provided.

Therefore, since the water level detection and estimation device indicates that the water level in the casing is lowered, the suction valve can be closed and the backwash valve and the drain valve can be opened to continuously carry out drainage and foreign matter removal in the casing. .

In the strainer cleaning apparatus according to the present invention, a water level detection and estimation device for detecting or estimating the water level in the casing, and closing the suction valve when the water level in the casing falls to a predetermined water level set in advance A valve and a control device for opening the drain valve are provided.

Therefore, when the water level in the casing drops to a predetermined water level, the suction valve is closed and the backwash valve and the drain valve are opened, so that drainage and foreign matter removal in the casing can be performed continuously.

In the strainer cleaning apparatus of the present invention, the differential pressure generating device is characterized by having a pressure line connected to the inlet side chamber or the outlet side chamber, and a pressure valve provided to the pressure line.

Therefore, when the pressurizing valve is opened, pressurizing force acts on the inlet side chamber from the pressurizing line, the internal pressure of the casing becomes higher than the pressure of the drain line, and the treated water in the casing can flow to the drain line. The water level in the casing can be reduced early simply by connecting a pressure line to the inlet side chamber.

In the strainer cleaning device according to the present invention, the pressurizing line is connected to a pressurizing device, and the internal pressure of the casing is made higher than the pressure of the drain line.

Therefore, only by connecting the pressurizing device to the pressurizing line, the treated water in the casing can be flowed to the drain line, and the water level in the casing can be reduced early.

In the strainer cleaning apparatus according to the present invention, the differential pressure generating device has a suction line connected to the pressure discharge device and the suction line connected to the drain side of the outlet side chamber, and suction provided to the suction line. And a valve, which is characterized in that the internal pressure of the casing is higher than the pressure of the suction line.

In the strainer cleaning apparatus according to the present invention, the water supply line is maintained at a vacuum pressure, and the suction line is connected upstream of the inlet valve in the water supply line.

In the strainer cleaning apparatus according to the present invention, there is provided a control device for closing the suction valve and opening the backwash valve and the drain valve when the water level in the casing falls to a predetermined water level set in advance. It is characterized.

In the strainer cleaning method according to the present invention, the inside of the casing is divided into an inlet side chamber and an outlet side chamber by a screen, and a water supply line is connected to the inlet side chamber to provide an inlet valve. In a strainer in which an outlet valve is provided, the steps of closing the inlet valve and the outlet valve, adjusting the internal pressure of the casing higher than the pressure on the drain discharge side of the casing, and Supplying flush water to the outlet side chamber and opening the drain line when the water level falls to a predetermined water level set in advance.

Therefore, by adjusting the internal pressure of the casing higher than the pressure on the drain discharge side of the casing, the treated water in the casing can be discharged early to the drain line, and the treatment time for cleaning the strainer is shortened and the treatment efficiency is improved. It can be improved.

According to the apparatus and method for cleaning a strainer of the present invention, the internal pressure of the casing is adjusted to be higher than the pressure on the drain discharge side, so the treated water in the casing can be discharged early, thereby shortening the cleaning processing time of the strainer. can do.

FIG. 1 is a schematic view showing a cleaning device of a strainer according to a first embodiment. FIG. 2 is a flowchart showing the method of cleaning the strainer according to the first embodiment. FIG. 3 is a schematic view showing a thermal power plant. FIG. 4 is a schematic view showing a cleaning device of a strainer according to a second embodiment. FIG. 5 is a flowchart showing a method of cleaning a strainer according to a second embodiment. FIG. 6 is a schematic view showing a strainer cleaning apparatus according to a third embodiment. FIG. 7 is a flowchart showing a method of cleaning a strainer according to a third embodiment.

Hereinafter, preferred embodiments of the apparatus and method for cleaning a strainer according to the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments, and in the case where there are a plurality of embodiments, the present invention also includes those configured by combining the respective embodiments.

First Embodiment
FIG. 3 is a schematic view showing a thermal power plant.

The thermal power plant according to the first embodiment burns fuel, generates steam with heat generated by combustion, and rotates a steam turbine with the produced steam to drive a generator connected to the steam turbine. It generates power.

As shown in FIG. 3, the thermal power plant 10 includes a boiler 11, a steam turbine 12, a condenser 13, a strainer 14, a condensate pump 15, a low pressure feed water heater 16, and a deaerator 17. , A high pressure feed water heater 18 and a generator 19.

For example, a conventional boiler is used for the boiler 11, and it is possible to burn pulverized coal as a fuel by a combustion burner and recover heat generated by this combustion using a furnace wall pipe 21 functioning as a heat transfer pipe . The steam turbine 12 has a high pressure turbine 22, an intermediate pressure turbine 23, and a low pressure turbine 24. The

turbines

22, 23, 24 are integrally rotatably connected by a rotor 25 serving as a rotation shaft.

In the high pressure turbine 22, the main steam line 26 from the furnace wall pipe 21 of the boiler 11 is connected to the inflow side, and the low temperature reheat steam line 27 leading to the reheater (not shown) of the boiler 11 is connected to the outflow side. It is done. The high pressure turbine 22 is rotated by the steam supplied from the main steam line 26 and discharges the used steam from the low temperature reheat steam line 27. The high pressure reheat steam line 28 from the reheater of the boiler 11 is connected to the inflow side of the intermediate pressure turbine 23, and the steam line 29 leading to the low pressure turbine 24 is connected to the outflow side. The medium pressure turbine 23 is rotated by the reheated steam supplied from the high temperature reheat steam line 28 and discharges the used steam from the steam line 29 toward the low pressure turbine 24. The steam line 29 is connected to the low pressure turbine 24 at the inflow side, and the condenser 13 is connected to the outflow side. The low pressure turbine 24 is rotated by the steam supplied from the steam line 29 and discharges the used steam to the condenser 13. In the generator 19, the rotations of the high pressure turbine 22, the intermediate pressure turbine 23, and the low pressure turbine 24 are transmitted through the rotor 25 and rotationally driven to generate electric power.

The condenser 13 condenses the steam discharged from the low pressure turbine 24 back to water (condensed water) by coming into contact with a cooling line through which the cooling water flows. The condensed water generated by the condenser 13 is supplied to the low pressure feed water heater 16 by the condensate pump 15 after the foreign matter is removed by the strainer 14. The first water supply line 31 connected to the outlet side of the condenser 13 is branched into two

branch lines

32 and 33, collected again to form a second water supply line 34, and connected to the furnace wall pipe 21 of the boiler 11 ing. The strainer 14 is composed of a first strainer 41 and a second strainer 42. The first strainer 41 is provided in the branch line 32, the inlet valve 43 is provided on the inflow side, and the outlet valve 44 is provided on the outflow side. The second strainer 42 is provided in the branch line 33, the inlet valve 45 is provided on the inflow side, and the outlet valve 46 is provided on the outflow side. In the drawing, the inlet valve 43 and the outlet valve 44 of the first strainer 41 are shown as being white in the drawing, and the inlet valve 45 and the outlet valve 46 of the second strainer 42 are shown as being black. It shows. That is, the first strainer 41 is in the water flowing state, and the second strainer 42 is in the water blocking state.

The condensate pump 15, the low pressure feed water heater 16, the deaerator 17 and the high pressure feed water heater 18 are provided in series in the second branch line 34. The low pressure feed water heater 16 heats the condensed water at a low pressure. The heated water is supplied from the low pressure feed water heater 16 to the deaerator 17. The deaerator 17 removes impurities such as dissolved oxygen and non-condensable gas (ammonia gas) from the condensed water supplied from the low pressure feed water heater 16. Deaerated water is supplied from the deaerator 17 toward the high pressure feed water heater 18. The high pressure feed water heater 18 heats the degassed condensate under high pressure. The heated condensate is supplied from the high pressure feed water heater 18 toward the furnace wall pipe 21 of the boiler 11 as the feed water.

In addition, the condenser 13 cools the steam used in the steam turbine 12 with cooling water and condenses it for condensation to reduce the volume to create a high vacuum state and improve the flow of the steam to make the turbine Improve the efficiency of Therefore, the vacuum state is maintained at least the condenser 13, the strainer 14, and the first water supply line 31, the

branch lines

32 and 33, and the second water supply line 34 to the condensate pump 15.

Therefore, in the thermal power plant 10, the water flowing in the furnace wall pipe 21 of the boiler 11 is heated by the internal flame to generate steam, and the generated steam is supplied to the steam turbine 12. The steam supplied to the steam turbine 12 flows through the high pressure turbine 22, the intermediate pressure turbine 23, and the low pressure turbine 24 in order and flows into the condenser 13. At this time, the steam turbine 12 is rotated by the flowed steam, so that the generator 19 is rotationally driven via the rotor 25, and the generator 19 generates electric power. The steam flowing into the condenser 13 is returned to the condensate by being condensed by the cooling line. The condensate condensed by the condenser 13 is subjected to the low pressure feed water heater 16, the deaerator 17 and the high pressure feed water heater 18 into the furnace wall pipe 21 of the boiler 11 after the foreign matter is removed by the strainer 14. Will be returned.

Here, although the strainer 14 will be described, since the first strainer 41 and the second strainer 42 constituting the strainer 14 are arranged in parallel between the

water supply lines

31 and 34 and have substantially the same configuration, The first strainer 41 will be described in detail. FIG. 1 is a schematic view showing a cleaning device of a strainer according to a first embodiment.

As shown in FIG. 1, the screen (mesh) 52 is disposed in an inclined state in the casing 51 so that the inside of the first strainer 41 is divided into an inlet side chamber 53 and an outlet side chamber 54. The inlet side chamber 53 is connected to the downstream end of the inlet line 32 a in the branch line 32, and the upstream end of the outlet line 32 b in the branch line 32 is connected to the outlet side chamber 54. The inlet line 32 a is provided with an inlet valve 43, and the outlet line 32 b is provided with an outlet valve 44.

In the casing 51, a vent line 61 is connected to the outlet side chamber 54, and a vent valve 62 is provided in the vent line 61. One end of the vent line 61 is open to the atmosphere, and the inside of the casing 51 is maintained in a sealed state by closing the vent valve 62, and the inside of the casing 51 is communicated to the atmosphere by opening the same. In addition. The vent line 61 may be connected to the inlet side chamber 53 of the casing 51.

In the casing 51, the backwash line 63 is connected to the outlet side chamber 54, and the backwash line 63 is provided with a backwash valve 64. One end of the backwashing line 63 is connected to the second water supply line 34 (see FIG. 3), and by opening the backwashing valve 64, the water supply of the second water supply line 34 is used as cleaning water in the outlet side chamber 54. Can be supplied. Further, in the casing 51, the drain line 65 is connected to the inlet side chamber 53, and the first drain valve 66 and the second drain valve 67 are provided in series in the drain line 65. The drain line 65 is connected at one end to a waste water treatment facility (not shown), and the treated water and wash water in the inlet side chamber 53 can be discharged to the waste water treatment facility by opening the

respective drain valves

66 and 67. it can.

Further, the first strainer 41 is provided with a differential pressure generating device which adjusts the internal pressure of the casing 51 higher than the pressure of the drain line 65. The differential pressure generator has a suction line 68 connected to the outlet side chamber 54 of the casing 51 and provided on the drain discharge side of the casing 51, and a vacuum valve (suction valve) 69 provided on the suction line 68. That is, one end of the suction line 68 is connected to the outlet side chamber 54 of the casing 51 and the other end is connected to the upstream side of the inlet valve 43 in the inlet line 32 a constituting the branch line 32. In this case, the suction line 68 is connected to the drain line 65, and the first drain valve 66 is provided on the upstream side (casing 51 side) of the connection portion of the drain line 65 with the suction line 68. A second drain valve 67 is provided on the side (the drainage treatment facility side). Further, the vacuum valve 69 is provided closer to the inlet line 32 a than the connecting portion of the suction line 68 with the drain line 65.

As described above, part of the condenser 13, the strainer 14, the condensate pump 15, the first water supply line 31, the

branch lines

32 and 33, and the second water supply line 34 is maintained at a vacuum pressure. Therefore, when the vent valve 62 is opened to open the outlet side chamber 54 to the atmosphere, and the vacuum valve 69 is opened to communicate the outlet side chamber 54 with the inlet line 32a by the suction line 68, the degree of vacuum of the inlet line 32a is the suction line It acts on the outlet side chamber 54 through 68. Then, in the casing 51 (outlet side chamber 54), the atmosphere is rapidly introduced from the vent line 61 to the inside, and the internal pressure of the casing 51 becomes higher than the pressure of the suction line 68 on the drain discharge side of the casing 51. The treated water inside is sucked to the inlet line 32 a side through the suction line 68, and the water level of the treated water in the casing 51 decreases rapidly.

The casing 51 is provided with a water level detection and estimation device that detects the water level inside. The water level detection and estimation apparatus includes a measurement line 70 having one end connected to the suction line 68 (the outlet side chamber 54), a water level gauge 71 connected to the end of the measurement line 70, and a measuring instrument provided on the measurement line 70. It has an on-off valve 72. The measuring line 70 may be directly connected to the outlet side chamber 54 instead of the suction line 68 at one end. Therefore, when the measuring instrument side open / close valve 72 is opened, the casing 51 and the water level gauge 71 communicate with each other through the suction line 68 and the measuring line 70, and the water level gauge 71 can measure the water level in the casing 51.

The control device 73 is connected to the inlet valve 43, the outlet valve 44, the vent valve 62, the backwash valve 64, the first drain valve 66, the second drain valve 67, the vacuum valve 69, the water level gauge 71, and the measuring instrument side open / close valve 72 And a control signal from an external operating device (not shown) can be input. The controller 73 controls the inlet valve 43, the outlet valve 44, the vent valve 62, the backwash valve 64, the first drain valve 66, and the second drain valve 67 according to the control signal from the operating device and the detection result of the water level gauge 71. The vacuum valve 69 and the measuring instrument side open / close valve 72 can be controlled to open and close.

For example, by closing the inlet valve 43 and the outlet valve 44 in the first strainer 41 and opening the vent valve 62, the vacuum valve 69, and the measuring device side on-off valve 72, the treated water in the casing 51 is discharged. When the water level in the casing 51 measured by the water level gauge 71 falls to a predetermined level set in advance, that is, when the treated water in the casing 51 disappears, the controller 73 closes the vacuum valve 69 and reversely The wash valve 64 and each

drain valve

66, 67 are opened. That is, the discharge operation of the treated water in the casing 51 and the foreign material removal and discharge operation from the screen 52 are continuously performed.

Here, a method of cleaning the first strainer 41 by the cleaning device of the strainer of the first embodiment will be described. FIG. 2 is a flowchart showing the method of cleaning the strainer according to the first embodiment.

In the strainer cleaning method according to the first embodiment, a step of closing the inlet valve 43 and the outlet valve 44, a step of opening the outlet side chamber 54 to the atmosphere, and a suction line 68 connected the internal pressure of the casing 51 to the outlet side chamber 54. And adjusting the pressure in the casing 51 to a predetermined level, and supplying drain water to the outlet side chamber 54 and opening the drain line 65.

Specifically, as shown in FIG. 3, the first water supply line 31 connected to the condenser 13 is branched into

branch lines

32 and 33, and the inlet valve 43 and the first strainer 41 are branched to the branch line 32. And an outlet valve 44, and the branch line 33 is provided with an inlet valve 45, a second strainer 42, and an outlet valve 46. Therefore, the first strainer 41 and the second strainer 42 are alternately used by alternately opening and closing the

inlet valves

43, 45 and the

outlet valves

44, 46. Here, the case where the second strainer 42 is cleaned and in the standby state and the first strainer 41 in use is cleaned in the standby state will be described. The vent valve 62, the first drain valve 66, the second drain valve 67, the vacuum valve 69, and the measuring device side open / close valve 72 are closed in the use state of the strainer, that is, the water flowing state.

In the method of cleaning the strainer according to the first embodiment, in step S11, the inlet valve 45 and the outlet valve 46 of the second strainer 42 on the standby side are opened to supply water to the second strainer 42, and cleaning is performed in step S12. The inlet valve 43 and the outlet valve 44 of the first (in use) first strainer 41 are closed to stop water flow to the first strainer 41. Then, as shown in FIGS. 1 and 2, in step S13, the vent valve 62 is opened to open the outlet side chamber 54 of the casing 51 to the atmosphere, whereby the inside of the casing 51 (inlet side chamber 53 and outlet side chamber 54) Introduce ambient air to

In step S14, the measuring instrument side open / close valve 72 is opened to connect the casing 51 (outlet side chamber 54) and the water level gauge 71, and the water level gauge 71 can measure the water level of the treated water in the casing 51. Then, in step S15, the vacuum valve 69 is opened, and the outlet side chamber 54 and the inlet line 32a are communicated by the suction line 68. Then, the degree of vacuum of the inlet line 32 a acts on the outlet side chamber 54 through the suction line 68, and the pressure of the outlet side chamber 54 becomes relatively higher than the pressure of the suction line 68. Therefore, when the treated water in the outlet side chamber 54 flows from the suction line 68 to the inlet line 32a, the water level in the casing 51 decreases. In addition, since the treated water in the outlet side chamber 54 is filtered water that has been filtered through the screen 52, even if it flows into the inlet line 32a, the condensate does not become dirty.

The control device 73 grasps the water level of the treated water in the casing 51 measured by the water level meter 71, and determines in step S16 whether the water level in the casing 51 has dropped to a predetermined water level. There is. Here, if it is determined that the water level in casing 51 has not dropped to the predetermined water level (No), this process is continued, and if it is determined that the water level in casing 51 has dropped to the predetermined water level (Yes), step Transfer to S17. In step S17, the vacuum valve 69 is closed to shut off the communication between the outlet side chamber 54 and the inlet line 32a by the suction line 68, and in step S18, the measuring device side on-off valve 72 is closed. Stop measuring the water level of the treated water.

Then, in step S19, the first drain valve 66 and the second drain valve 67 are opened, so that drainage of the treated water in the casing 51 from the inlet side chamber 53 by the drain line 65 is enabled. Further, in step S20, by opening the backwash valve 64, the water supply of the second water supply line 34 is supplied as wash water into the outlet side chamber 54. Then, the water supplied from the backwash line 63 into the outlet side chamber 54 is sprayed to the surface on the outlet side chamber 54 side of the screen 52 by a nozzle not shown, and adheres to the surface on the inlet side chamber 53 side in the screen 52 Foreign substances are removed. Then, the foreign matter removed from the screen 52 flows from the inlet side chamber 53 into the drain line 65 together with the water supply, and is discharged to the drainage treatment facility to be treated.

In step S21, it is determined whether a predetermined time set in advance has passed since the backwash valve 64 was opened. The predetermined time is the cleaning time of the screen 52, and the cleaning time capable of removing most foreign matter from the screen 52 is confirmed in advance by experiment or the like. Here, if it is determined (No) that the predetermined time has not elapsed since the opening of the backwashing valve 64, this process is continued, and it is determined that the predetermined time has elapsed since the opening of the backwashing valve 64 ( If yes, the process proceeds to step S22.

The controller 73 closes the backwash valve 64 in step S22, closes the first drain valve 66 and the second drain valve 67 in step S23, and closes the vent valve 62 in step S24. Then, in step S25, a balance valve (not shown) provided between the outlet side chamber 54 and the outlet valve 44 and connected to the condenser 13 is opened to remove the air in the casing 51 to make a vacuum state. . Thereafter, by opening the inlet valve 43, the casing 51 is filled with condensed water and preparation for water passage is made.

As described above, in the strainer cleaning apparatus according to the first embodiment, the vent line 61 connected to the outlet side chamber 54, the vent valve 62 provided on the vent line 61, and the outlet side chamber 54 are connected to wash water. A backwash line 63 which can be supplied, a backwash valve 64 provided in the backwash line 63, a drain line 65 connected to the inlet side chamber 53 capable of discharging foreign substances, and a

drain valve

66, 67 provided in the drain line 65 And a differential pressure generator for adjusting the internal pressure of the casing 51 higher than the pressure of the suction line 68.

Therefore, when the outlet side chamber 54 is opened to the atmosphere by the vent valve 62 and the internal pressure of the casing 51 is adjusted to be higher than the pressure of the suction line 68 by the differential pressure generator, the treated water in the casing 51 is It flows and the water level in casing 51 falls. Thereafter, when the water level reaches a predetermined level, the vacuum valve 69 is closed and the backwash valve 64 is opened to supply flush water from the backwash line 63 to the outlet side chamber 54 and open the

drain valves

66 and 67, The foreign matter adhering to the screen 52 is removed, and the foreign matter is discharged from the inlet side chamber 53 to the drain line 65. That is, by adjusting the internal pressure of the casing 51 higher than the pressure of the suction line 68 by the differential pressure generator, the treated water in the casing 51 can be discharged to the suction line 68 at an early stage. Can be shortened to improve processing efficiency. Further, since the cleaning process time of the strainer 14 can be shortened, the strainer 14 (41, 42) can be coped with a small size by increasing the number of times of alternately cleaning the

respective strainers

41, 42, so the manufacturing cost Can be reduced.

In the strainer cleaning apparatus according to the first embodiment, as a differential pressure generator, a vent line 61 connected to the outlet side chamber 54, a vent valve 62 provided on the vent line 61, a suction line 68, and a suction line 68 are provided. And a vacuum valve 69. Therefore, when the vacuum valve 69 is opened, a suction force acts from the suction line 68 to the outlet side chamber 54, the internal pressure of the casing 51 becomes higher than the pressure of the suction line 68, and the treated water in the casing 51 is rapidly applied to the suction line 68. The water level in the casing 51 can be reduced early.

In the strainer cleaning apparatus according to the first embodiment, the first water supply line 31 is maintained at a vacuum pressure, and the suction line 68 is connected to the inlet line 32 a on the upstream side of the inlet valve 43 in the first water supply line 31. . Therefore, only by connecting the suction line 68 to the inlet line 32a maintained at the vacuum pressure, the treated water in the casing 51 can be flowed to the suction line 68, and the water level in the casing 51 can be lowered early.

In the strainer cleaning apparatus according to the first embodiment, the suction line 68 is connected to the drain line 65, and the first drain valve 66 and the second drain are connected upstream and downstream of a connection portion of the drain line 65 with the suction line 68, respectively. A valve 67 is provided. Therefore, after the water level in the casing 51 is lowered, the vacuum valve 69 is closed, and then the backwash valve 64 is opened to supply flush water from the backwash line 63 to the outlet side chamber 54 and the first drain valve 66 and When the second drain valve 67 is opened, the foreign matter adhering to the screen 52 is discharged from the inlet side chamber 53 to the drain line 65, and the treated water remaining in the suction line 68 can also be discharged.

In the strainer cleaning apparatus according to the first embodiment, the water level detection / estimation device for detecting or estimating the water level in the casing 51 and the vacuum valve 69 are closed when the water level in the casing 51 falls to a predetermined water level set in advance. A controller 73 for opening the backwash valve 64 and the

drain valves

66 and 67 is provided. Therefore, when the water level in the casing 51 drops to a predetermined water level, the drainage in the casing 51 and the removal of foreign matter are continuously performed in order to close the vacuum valve 69 and open the backwash valve 64 and the

drain valves

66 and 67. be able to.

In the strainer cleaning method according to the first embodiment, the steps of closing the inlet valve 43 and the outlet valve 44, opening the outlet side chamber 54 to the atmosphere, and connecting the internal pressure of the casing 51 to the inlet side chamber 53 Adjusting the pressure higher than the pressure of the suction line 68, and supplying the cleaning water to the outlet side chamber 54 and opening the drain line 65 when the water level in the casing 51 falls to a predetermined level previously set. ing.

Therefore, by adjusting the internal pressure of the casing 51 higher than the pressure of the suction line 68 connected to the outlet side chamber 54, the treated water in the casing 51 can be discharged to the suction line 68 at an early stage. , 42) can be shortened to improve the processing efficiency.

In the first embodiment described above, the measurement line 70, the water level gauge 71, and the measuring device side open / close valve 72 are provided as the water level detection / estimation device for detecting the water level inside the casing 51, but this configuration is limited It is not a thing. For example, after the inlet valve 43 and the outlet valve 44 are closed and the vent valve 62 and the vacuum valve 69 are opened, the time when the water level in the casing 51 falls to a predetermined water level is measured in advance by experiment or the like. Then, the control device 73 closes the vacuum valve 69 and opens the backwash valve 64 and the

drain valves

66 and 67 when a predetermined time elapses after the vent valve 62 and the vacuum valve 69 are opened. Good.

Second Embodiment
FIG. 4 is a schematic view showing a strainer cleaning apparatus according to the second embodiment, and FIG. 5 is a flowchart showing a strainer cleaning method according to the second embodiment. The members having the same functions as those in the above-described embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

In the second embodiment, as shown in FIG. 4, in the casing 51, the vent line 61 is connected to the outlet side chamber 54, and the vent valve 62 is provided. In the casing 51, a backwash line 63 is connected to the outlet side chamber 54, and a backwash valve 64 is provided. In the casing 51, a drain line 65 is connected to the inlet side chamber 53, and a drain valve 66 is provided.

The first strainer 41 is provided with a differential pressure generator that adjusts the internal pressure of the casing 51 higher than the pressure of the drain line 65. The differential pressure generator has a pressure line 81 connected to the backwash line 63, and a pressure valve 82 and a pressure pump (pressure device) 83 provided on the pressure line 81. That is, one end of the pressurizing line 81 is connected to the outlet side chamber 54 side of the backwashing valve 64 in the backwashing line 63, and the pressurizing valve 82 and the pressurizing pump 83 are provided. In this case, the pressure line 81 may be directly connected to the outlet side chamber 54 or may be connected to the inlet side chamber 53. Moreover, although the pressurization pump 83 was applied as a pressurization apparatus here, if there exists a pressurization air line in a plant, you may connect the pressurization line 81 to this pressurization air line.

Therefore, when the pressurizing valve 82 is opened and the pressurizing pump 83 is driven, pressurized air is supplied to the outlet side chamber 54 through the pressurizing line 81 and the backwash line 63. Then, since the vent valve 62 is closed, the internal pressure of the casing 51 becomes higher than the pressure of the drain line 65 by the pressurized air being supplied from the pressurizing line 81 to the casing 51 (the outlet side chamber 54) .

The control device 73 is connected to the inlet valve 43, the outlet valve 44, the vent valve 62, the backwash valve 64, the drain valve 66, and the pressurizing valve 82, and receives control signals from an external operating device (not shown). It is possible. The controller 73 can control the opening and closing of the inlet valve 43, the outlet valve 44, the vent valve 62, the backwash valve 64, the drain valve 66, and the pressurizing valve 82 in accordance with a control signal from the operating device.

Here, a method of cleaning the first strainer 41 by the apparatus for cleaning a strainer of the second embodiment will be described. In the use state of the strainer, that is, in the water flowing state, the vent valve 62, the backwash valve 64, the drain valve 66, and the pressurizing valve 82 are closed.

In the method of cleaning the strainer according to the second embodiment, as shown in FIGS. 3 and 5, in step S31, the inlet valve 45 and the outlet valve 46 of the second strainer 42 on the standby side are opened to the second strainer 42. Water is supplied, and in step S32, the inlet valve 43 and the outlet valve 44 of the first strainer 41 on the cleaning side (in use) are closed to stop the water supply to the first strainer 41.

In step S33, the drain valve 66 is opened to allow the drain line 65 to discharge the treated water in the casing 51 from the inlet side chamber 53. Then, in step S34, the pressurizing valve 82 is opened and the pressurizing pump 83 is driven to supply pressurized air to the outlet side chamber 54 through the pressurizing line 81 and the backwash line 63. Then, the pressure in the outlet side chamber 54 of the casing 51 becomes relatively higher than the pressure in the drain line 65. Therefore, when the treated water in the casing 51 is discharged from the inlet side chamber 53 by the drain line 65, the water level in the casing 51 decreases.

In step S35, it is determined whether or not a predetermined time set in advance has elapsed since the pressurizing valve 82 was opened. The predetermined time is a discharge time during which the treated water in the casing 51 is discharged, and is previously confirmed by an experiment or the like. Here, if it is determined that the predetermined time has not elapsed since the pressurization valve 82 was opened (No), this process is continued, and it is determined that the predetermined time has elapsed since the pressurization valve 82 was opened (Yes) Then, the process proceeds to step S36. In step S36, the pressurizing valve 82 is closed and the driving of the pressurizing pump 83 is stopped.

Then, in step S37, by opening the backwash valve 64, the water supply of the second water supply line 34 is supplied as wash water into the outlet side chamber 54. Then, the water supplied from the backwash line 63 into the outlet side chamber 54 is sprayed to the surface on the outlet side chamber 54 side of the screen 52 by a nozzle not shown, and adheres to the surface on the inlet side chamber 53 side in the screen 52 Foreign substances are removed.

In step S38, it is determined whether or not a predetermined time (washing time) set in advance has passed after the backwashing valve 64 is opened. Here, if it is determined (No) that the predetermined time has not elapsed since the opening of the backwashing valve 64, this process is continued, and it is determined that the predetermined time has elapsed since the opening of the backwashing valve 64 ( If yes, the process moves to step S39. The controller 73 closes the backwash valve 64 in step S39, and opens the vent valve 62 in step S40. Thereby, the foreign matter removed from the screen 52 flows from the inlet side chamber 53 to the drain line 65 together with the washing water, and is discharged to the drainage treatment facility to be treated. Next, in step S41, it is determined whether or not the opening time of the vent valve 62 has passed a preset predetermined time suitable for discharging the foreign matter and the water supply. If it is determined (No) that the predetermined time has not elapsed since the vent valve 62 was opened, this process is continued, and if it is determined (Yes) that the predetermined time has elapsed, the vent valve 62 is determined in step S42. Is closed, and the drain valve 66 is closed in step S43. Then, in step S44, a balance valve (not shown) provided between the outlet side chamber 54 and the outlet valve 44 and connected to the condenser 13 is opened to remove the air in the casing 51 to make it into a vacuum state. . Thereafter, by opening the inlet valve 43, the casing 51 is filled with condensed water and preparation for water passage is made.

As described above, in the strainer cleaning apparatus according to the second embodiment, the pressure line 81 connected to the outlet side chamber 54 and the pressure valve 82 provided on the pressure line 81 are provided as a differential pressure generator. There is.

Therefore, when the pressurizing valve 82 is opened in a state where the drain line 65 is opened by the drain valve 66, the internal pressure of the casing 51 becomes higher than the pressure of the drain line 65 by supplying pressurized air into the casing 51, The treated water in the casing 51 flows to the drain line 65, and the water level in the casing 51 decreases. Here, when the backwashing valve 64 is opened and washing water is supplied from the backwashing line 63 to the outlet side chamber 54, the foreign matter adhering to the screen 52 is removed, and the foreign matter is discharged from the inlet side chamber 53 to the drain line 65. Ru. That is, by adjusting the internal pressure of the casing 51 higher than the pressure of the drain line 65 by the pressurized air from the pressurizing line 81, the treated water in the casing 51 can be discharged to the drain line 65 at an early stage, and the strainer The processing time can be improved by shortening the cleaning process time of 14. Further, the water level in the casing 51 can be reduced early by only connecting the pressure line 81 to the outlet side chamber 54.

In the strainer cleaning apparatus according to the second embodiment, the pressure line 81 is provided with a pressure pump 83 as a pressure device. Therefore, only by providing the pressurizing pump 83 in the pressurizing line 81, the treated water in the casing 51 can be flowed to the drain line 65, and the water level in the casing 51 can be reduced early.

Third Embodiment
FIG. 6 is a schematic view showing a strainer cleaning apparatus according to the third embodiment, and FIG. 7 is a flowchart showing a strainer cleaning method according to the third embodiment. The members having the same functions as those in the above-described embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

In the third embodiment, as shown in FIG. 6, in the casing 51, a vent line 61 is connected to the outlet side chamber 54, and a vent valve 62 is provided in the vent line 61. In the casing 51, the backwash line 63 is connected to the outlet side chamber 54, and the backwash line 63 is provided with a backwash valve 64. In the casing 51, a drain line 65 is connected to the inlet side chamber 53, and a first drain valve 66 and a second drain valve 67 are provided in series in the drain line 65.

The first strainer 41 is provided with a differential pressure generator that adjusts the internal pressure of the casing 51 higher than the pressure of the drain line 65. The differential pressure generator has a pressure line 81 connected to the backwash line 63 and a pressure valve 82 and a pressure pump 83 provided on the pressure line 81. Further, the differential pressure generator has a suction line 68 connected to the outlet side chamber 54 of the casing 51 and a vacuum valve 69 provided in the suction line 68.

Here, a method of cleaning the first strainer 41 by the apparatus for cleaning a strainer of the third embodiment will be described. In the use state of the strainer, that is, in the water flowing state, the vent valve 62, the backwash valve 64, the first drain valve 66, the second drain valve 67, the vacuum valve 69, the measuring instrument side on-off valve 72, and the pressurizing valve 82 It is closed.

In the method of cleaning the strainer according to the third embodiment, as shown in FIGS. 3 and 7, in step S 51, the inlet valve 45 and the outlet valve 46 of the second strainer 42 on the standby side are opened to the second strainer 42. Water is supplied, and in step S52, the inlet valve 43 and the outlet valve 44 of the first strainer 41 on the cleaning side (in use) are closed to stop the water supply to the first strainer 41.

In step S53, the pressurizing valve 82 is opened and the pressurizing pump 83 is driven to supply pressurized air to the outlet side chamber 54 through the pressurizing line 81 and the backwash line 63. Further, in step S54, the measuring instrument side open / close valve 72 is opened to communicate the casing 51 (outlet side chamber 54) with the water level gauge 71, and the water level gauge 71 can measure the water level of the treated water. Then, in step S55, the vacuum valve 69 is opened, and the outlet side chamber 54 and the inlet line 32a are communicated by the suction line 68.

Then, the pressurized air is supplied to the outlet side chamber 54, whereby the pressure in the outlet side chamber 54 of the casing 51 becomes high. In addition, the pressure of the outlet side chamber 54 of the casing 51 is also increased by the degree of vacuum of the inlet line 32 a acting on the outlet side chamber 54 through the suction line 68. As a result, the pressure in the outlet side chamber 54 of the casing 51 becomes relatively higher than the pressure in the suction line 68. Therefore, when the treated water in the outlet side chamber 54 flows from the suction line 68 to the inlet line 32a, the water level in the casing 51 is rapidly reduced.

At step S56, control device 73 determines whether the water level in casing 51 has dropped to a predetermined water level. Here, if it is determined that the water level in casing 51 has not dropped to the predetermined water level (No), this process is continued, and if it is determined that the water level in casing 51 has dropped to the predetermined water level (Yes), step Transfer to S57. In step S57, the pressurizing valve 82 is closed and the driving of the pressurizing pump 83 is stopped. Further, in step S58, the vacuum valve 69 is closed to shut off the communication between the outlet side chamber 54 and the inlet line 32a by the suction line 68, and in step S59, the measuring device side on-off valve 72 is closed. Stop measuring the level of treated water in 51.

Then, in step S60, the first drain valve 66 and the second drain valve 67 are opened to allow the drain line 65 to discharge the treated water in the casing 51 from the inlet side chamber 53. Further, in step S61, by opening the backwash valve 64, the water supply of the second water supply line 34 is supplied as wash water into the outlet side chamber 54. Then, the water supplied from the backwash line 63 into the outlet side chamber 54 is sprayed to the surface on the outlet side chamber 54 side of the screen 52 by a nozzle not shown, and adheres to the surface on the inlet side chamber 53 side in the screen 52 Foreign substances are removed.

In step S62, it is determined whether a predetermined time set in advance has passed since the backwash valve 64 was opened. Here, if it is determined (No) that the predetermined time has not elapsed since the opening of the backwashing valve 64, this process is continued, and it is determined that the predetermined time has elapsed since the opening of the backwashing valve 64 ( If yes, the process moves to step S63. The control device 73 closes the backwash valve 64 in step S63, and opens the vent valve 62 in step S64. Thereby, the foreign matter removed from the screen 52 flows from the inlet side chamber 53 to the drain line 65 together with the washing water, and is discharged to the drainage treatment facility to be treated. Next, in step S65, it is determined whether the opening time of the vent valve 62 has passed a predetermined time set in advance that is appropriate for discharging the foreign matter and the water supply. If it is determined (No) that the predetermined time has not elapsed since the vent valve 62 was opened, this process is continued, and if it is determined (Yes) that the predetermined time has elapsed, the vent valve 62 is determined in step S66. Are closed, and the first drain valve 66 and the second drain valve 67 are closed in step S67. Then, in step S68, the air in the casing 51 is removed to be in a vacuum state by opening a balance valve (not shown) provided between the outlet side chamber 54 and the outlet valve 44 and connected to the condenser 13. . Thereafter, by opening the inlet valve 43, the casing 51 is filled with condensed water and preparation for water passage is made.

As described above, in the strainer cleaning apparatus according to the third embodiment, the suction line 68 connected to the outlet side chamber 54 and the vacuum valve 69 provided on the suction line 68 are provided as a differential pressure generating device, and the outlet A pressure line 81 connected to the side chamber 54 and a pressure valve 82 provided on the pressure line 81 are provided.

Therefore, by adjusting the internal pressure of the casing 51 higher than the pressure of the suction line 68 by the pressurized air from the pressure line 81 and the suction force of the suction line 68, the treated water in the casing 51 can be made into the suction line early. It is possible to discharge and shorten the cleaning processing time of the strainer 14 to improve the processing efficiency.

In the second and third embodiments described above, the vent valve 62 is opened for a predetermined time after the backwash valve 64 is closed, but the backwash valve 64 is opened after the pressurizing valve 82 is closed. The vent valve 62 may be closed after a predetermined time has elapsed after the vent valve 62 has been opened and the backwash valve 64 has been closed. According to this configuration, the opening time of the vent valve 62 can be further shortened.

Further, in the second and third embodiments described above, the vent valve 62 is opened and drained from the drain line 65 in order to drain out the foreign matter and flush water generated by the backwash line 63. After cleaning by the backwash line 63 without providing the vent line 61 and the vent valve 62, that is, after closing the backwash valve 64, the pressure valve 82 is opened, and pressure from the pressure line 81 causes foreign matter The washing water may be discharged. As a result, it is possible to discharge the foreign matter and the washing water more quickly than the discharge by the vent line 61.

Further, in the above-described first to third embodiments, automatic control is performed by the control device 73. However, manual control may be performed.

In the first to third embodiments described above, the first water supply line 31 connected to the condenser 13 is branched into two

branch lines

32 and 33, and the inlet valve 43 and the first strainer 41 are connected to the branch line 32. The outlet valve 44 is provided, and the inlet valve 45, the second strainer 42, and the outlet valve 46 are provided in the branch line 33. However, the number of branches is not limited to two and may be three or more.

In the first to third embodiments described above, the strainer cleaning apparatus and method of the present invention have been described as applied to the water supply system of a thermal power plant, but the water supply system of a nuclear power plant or a geothermal power plant, or It can also be applied to other water supply systems.

DESCRIPTION OF SYMBOLS 10 thermal power generation plant 11 boiler 12 steam turbine 13 condenser 14 strainer 15 condensate pump 16 low pressure feed water heater 17 deaerator 18 high pressure feed water heater 19 generator 31

1st feed line

32, 33 branch line

32a inlet line

32b Outlet line 34 second water supply line 41 first strainer 42

second strainer

43, 45

inlet valve

44, 46 outlet valve 51 casing 52 screen (mesh)
53 inlet side chamber 54 outlet side chamber 61 vent line 62 vent valve 63 backwash line 64 backwash valve 65 drain line 66 first drain valve 67 second drain valve 68 suction line (differential pressure generator)
69 Vacuum valve (suction valve, differential pressure generator)
70 Measurement line 71 Water level gauge 72 Measuring device side open / close valve 73 Control device 81 Pressurization line (differential pressure generator)
82 Pressure valve (differential pressure generator)
83 Pressure pump (differential pressure generator, pressure device)

Claims

In a strainer in which the interior of the casing is partitioned by a screen into an inlet side chamber and an outlet side chamber, a water supply line is connected to the inlet side chamber to provide an inlet valve, and a water supply line is connected to the outlet side chamber to provide an outlet valve;
A backwash line connected to the outlet side chamber and capable of supplying washing water;
A backwash valve provided in the backwash line;
A drain line connected to the drain discharge side of the inlet side chamber for discharging foreign substances;
A drain valve provided in the drain line;
A differential pressure generator for adjusting the internal pressure of the casing higher than the pressure on the drain discharge side of the casing;
An apparatus for cleaning a strainer, comprising:
The differential pressure generator includes a vent line connected to the outlet side chamber, a vent valve provided on the vent line, a suction line connected to the drain discharge side of the outlet side chamber, and suction provided on the suction line. The strainer cleaning apparatus according to claim 1, further comprising a valve.
The water supply line is maintained at a vacuum pressure, and the suction line is connected upstream of the inlet valve in the water supply line, and the internal pressure of the casing is made higher than the internal pressure of the suction line. The strainer cleaning device according to claim 2.
The suction line is connected to the drain line, and a first drain valve and a second drain valve are respectively provided as the drain valve on the upstream side and the downstream side of the connection portion of the drain line with the suction line. The strainer cleaning apparatus according to claim 3, wherein
5. The strainer cleaning device according to claim 3, further comprising a water level detection and estimation device that detects or estimates the water level in the casing.
A water level detection and estimation device for detecting or estimating the water level in the casing, and a control for closing the suction valve and opening the backwash valve and the drain valve when the water level in the casing falls to a predetermined water level set in advance The strainer cleaning apparatus according to claim 3 or 4, wherein an apparatus is provided.
The strainer cleaning device according to claim 1, wherein the differential pressure generating device includes a pressurizing line connected to the inlet side chamber or the outlet side chamber, and a pressurizing valve provided to the pressurizing line. .
The strainer cleaning apparatus according to claim 7, wherein the pressure line is connected to a pressure device, and the internal pressure of the casing is higher than the pressure of the drain line.
The differential pressure generator has a suction line connected to the drain side of the outlet chamber and the suction line connected to the pressure device, and a suction valve provided on the suction line, the suction line 8. The strainer cleaning apparatus according to claim 7, wherein the internal pressure of the casing is made higher than the pressure of.
The strainer cleaning apparatus according to claim 9, wherein the water supply line is maintained at a vacuum pressure, and the suction line is connected upstream of the inlet valve in the water supply line.
The suction line is connected to the drain line, and a first drain valve and a second drain valve are respectively provided as the drain valve on the upstream side and the downstream side of the connection portion of the drain line with the suction line. 11. The strainer cleaning apparatus according to claim 10, wherein
The strainer washing apparatus according to any one of claims 9 to 11, further comprising a water level detection and estimation device that detects or estimates the water level in the casing.
13. The control device according to claim 12, further comprising: a controller that closes the suction valve and opens the backwash valve and the drain valve when the water level in the casing falls to a predetermined water level set in advance. Strainer cleaning device.
The inside of the casing is divided by a screen into an inlet side chamber and an outlet side chamber, a water supply line is connected to the inlet side chamber to provide an inlet valve, and a strainer is connected to the outlet side chamber and the water supply line is connected to provide an outlet valve. ,
Closing the inlet valve and the outlet valve;
Adjusting the internal pressure of the casing higher than the pressure on the drain discharge side of the casing;
Supplying flush water to the outlet side chamber and opening the drain line when the water level in the casing falls to a predetermined level previously set;
A method of cleaning a strainer, comprising: