97results about "Boiler cleaning control devices" patented technology

The embodiment of the invention relates to the field of boiler ash removal, and provides an ash removal method and device for a solid waste incineration waste heat boiler, a terminal and a medium, and the method comprises the steps that smoke side parameters and working medium side parameters of a boiler heat exchanger are obtained; according to the flue gas side parameters, the heat exchange efficiency and the flue gas side pressure difference of the boiler heat exchanger are determined; acquiring historical ash deposition data of the boiler heat exchanger; constructing an ash deposition prediction model according to the historical ash deposition data, the heat exchange efficiency and the flue gas side pressure difference; according to the heat exchange efficiency and the flue gas side pressure difference, a real-time ash deposition index is determined through an ash deposition prediction model; and when the real-time ash deposition index is larger than an ash removal threshold value, an ash removal device is adopted to carry out ash removal operation on the solid waste incineration waste heat boiler, the ash deposition state of the boiler can be judged according to the real-time heat exchange efficiency and the smoke side pressure difference of the boiler heat exchanger, accurate ash removal is carried out on the boiler heat exchanger, the operation and maintenance cost is reduced, and the operation efficiency is improved. The production efficiency is improved.

The invention discloses a boiler blow-down water waste heat recovery control method, system and equipment and a medium. The method comprises the following steps that the current waste heat recovery efficiency eta of a waste heat recovery system is obtained; the current scaling coefficient R of a heat exchanger in the waste heat recovery system is obtained; according to the current waste heat recovery efficiency eta and the current scaling coefficient R, the heat transfer coefficient K of the heat exchanger is obtained; the current temperature T and the water quality concentration ratio C of the boiler are obtained; and inputting the heat transfer coefficient K, the current temperature T and the water quality concentration ratio C into a preset discharge capacity optimization model to obtain the optimal discharge capacity Q. The method has the advantages that the discharge capacity can be adaptively adjusted, and the boiler safety and waste heat recovery requirements can be balanced.

To provide a boiler low temperature state quick flushing method.SOLUTION: A boiler flushing device includes: an activation mechanism comprising a boiler body and a power assembly provided at the boiler body; a scale removal mechanism comprising a transmission assembly provided at the power assembly and a scale scraping assembly provided at the transmission assembly; and a uniform stirring mechanism comprising a fixed column provided at the boiler body, a limiting assembly provided at the fixed column, and a motion assembly provided at the limiting assembly. The scale removal mechanism allows a scale scraping brush to perform circular motion on an inner wall of the boiler body to scrape scales on the inner wall of the boiler body. A scraping member is provided on the inner wall of the boiler body and cleans the scale scraping brush. At the same time, the uniform stirring mechanism is provided on the fixed column to avoid the scraped scales from accumulating on a bottom part of the boiler body and being discharged from the boiler body with water flow through a drain pipe and allow cleaning to be performed more thoroughly.SELECTED DRAWING: Figure 2

The invention relates to the technical field of high-temperature gas cooled reactors and discloses a cleaning device which comprises a positioning assembly, a pushing assembly, a guiding assembly, a spray needle and a visual assembly, the positioning assembly comprises a connecting piece capable of moving in any direction of the X-axis direction, the Y-axis direction, the Z-axis direction and the Z-axis circumferential direction, the pushing assembly is connected with the connecting piece, and the guiding assembly is connected with the visual assembly. The pushing assembly comprises a moving part capable of moving in the Z-axis direction, the guiding assembly is connected with the pushing assembly and comprises a guiding hole, the guiding assembly can be connected with any to-be-cleaned assembly and enables the guiding hole to be communicated with a working cavity of the to-be-cleaned assembly, the spraying needle is arranged on the moving part, and the moving part can drive the spraying needle to penetrate through the guiding hole and be inserted into the working cavity. The spray needle can spray out a cleaning medium to clean the working cavity, the visual assembly comprises a camera, and the camera can observe the state of the spray needle. The cleaning device provided by the embodiment of the invention can be used for quickly positioning and cleaning the tubular parts such as the throttling assembly, so that the manpower is saved.

To stabilize the water quality of boiler water in a boiler, thereby preventing the generation of carry-over in which a large amount of boiler water is mixed into generated stream, corrosion of each part of a can body, and an overheat state of a heat transfer surface due to the adhesion of scale to a can wall surface.SOLUTION: A method of stabilizing the water quality of boiler water in a boiler is provided. A water supply pump for supplying the boiler water to the boiler is intermittently operated. Whenever the water supply pump is intermittently operated, blow operation for discharging the boiler water to the outside of a can is performed.SELECTED DRAWING: Figure 2

The application discloses a chemical cleaning liquid level control system and method for a power station boiler, which comprises a water storage tank, a differential pressure liquid level transmitter, a liquid level interlocking controller, a drainage electric valve, a cleaning water inlet valve, a cleaning backwater pipeline, a cleaning water inlet pipeline and a circulating cleaning system; the water storage tank, the cleaning backwater pipeline, the circulating cleaning system and the cleaning water inlet pipeline are sequentially connected to form a circulating pipeline; the cleaning backwater pipeline is further connected to a drainage system at a water outlet end; the liquid level steam side communication pipe and the liquid level water side communication pipe of the water storage tank are both connected to the differential pressure liquid level transmitter; the drainage electric valve is arranged at the water outlet end of the cleaning backwater pipeline and is connected to the drainage system; and the input end of the liquid level interlocking controller is electrically connected to the differential pressure liquid level transmitter, and the output end is connected to the drainage electric valve. The application solves the problems of high equipment failure rate, high human error rate, unreliable control measures and high labor intensity of personnel in the conventional chemical cleaning liquid level control technology.

To provide a heat transfer surface cleaning system capable of making proper cleaning capacity act on a thickness of a deposit adhering to a heat transfer surface.SOLUTION: A heat transfer surface cleaning system comprises: an infrared camera that measures a surface temperature of a heat transfer surface by photographing the heat transfer surface exposed inside the boiler; a thermometer that measures a gas temperature in an internal space of the boiler; a cleaning device that cleans the heat transfer surface by injecting cleaning fluid; and a controller that controls an injection amount of the cleaning fluid. The controller performs machine learning of outputting the injection amount, acquiring state values including the measured surface temperature of the heat transfer surface and the gas temperature, acquiring a post-cleaning gas temperature measured by the thermometer after cleaning is performed by the cleaning device based on the injection amount, calculating a reward based on the post-cleaning gas temperature, and determining the injection amount to be output at current state values based on the injection amount, a state amount and the reward.SELECTED DRAWING: Figure 5

The utility model relates to efficient scaling-free steam generator equipment, and relates to the related technical field of steam heating. The device comprises a furnace body, a heating assembly, a liquid inlet pipeline, a sealing plate, an exhaust port, a descaling agent storage barrel, a descaling agent spraying unit, an ultrasonic generation device and a waste discharge pipeline. According to the efficient scaling-free steam generator equipment, a descaling agent in the descaling agent storage barrel is injected into the furnace body through the descaling agent spraying unit, stubborn scale is softened, and the descaling agent generates high-frequency vibration through the ultrasonic generating device; dirt on the inner wall of the furnace body and the periphery of the heating assembly can be softened and fall off due to high-frequency vibration of the descaling agent and is discharged through the waste discharge pipeline, and therefore the descaling efficiency of the furnace body and the heating assembly is effectively guaranteed.

The present application relates to a kind of alkali recovery furnace water washing process, the process includes the following steps: step one: after alkali recovery furnace shutdown, open disc valve, plug valve and hearth furnace door, carry out hearth cooling;Step two: after cold furnace, washing water is pumped to alkali recovery furnace soot blower by feed water pump, by soot blower flushes the surface of heat exchange element, and the slagging and coking material therein is cleaned up completely;Washing waste water is recycled by dissolving tank and venting tank;Step three: after washing furnace, by hot air into air supply system, air draft system exhaust, dry hearth and heat exchange element;Step four: after drying furnace, in chute pouring castable, repair the part that is washed away by combustion melt and washing water, a kind of alkali recovery furnace water washing process designed by the present application can conveniently clean ash and remove coke with high efficiency, good effect, can effectively guarantee the cleanliness of heat exchange element, improve alkali recovery furnace operating efficiency.

The invention relates to the technical field of steam generators and discloses a method for cleaning a throttling assembly of a steam generator, which comprises the following steps: S1, a control system selects the throttling assembly according to the position information of the selected throttling assembly; s2, the positioning module is controlled to be in butt joint with the interface; S3, a flushing needle is controlled to be inserted into a channel by a preset depth along a positioning hole; S4, a pump station is controlled to supply a cleaning medium to the flushing needle, the flushing needle is controlled to withdraw in the axial direction of the channel, and in the withdrawing process, the flushing needle is driven by the mobile platform to move; the flushing needle can continuously rotate around the axis of the flushing needle, S5, the flushing needle is controlled to completely retreat from the channel, and S6, the control system controls the moving platform to drive the cleaning module to return to the initial position, and the steps are repeatedly executed till all the selected throttling assemblies are cleaned. According to the cleaning method for the throttling assembly of the steam generator, the throttling assembly of the steam generator can be rapidly positioned and cleaned.

The invention provides a cleaning system for a throttling assembly of a high-temperature gas cooled reactor steam generator, and relates to the technical field of cleaning equipment for throttling assemblys.The cleaning system comprises a machine base, a mechanical arm, a positioning device and a cleaning device, and the mechanical arm is arranged on the machine base; the positioning device and the cleaning device are both arranged on the mechanical arm, the mechanical arm can adjust the positions of the positioning device and the cleaning device relative to a throttling assembly to be cleaned, and the positioning device is used for positioning the position of the throttling assembly to be cleaned; the cleaning device comprises at least one of a hole cleaning mechanism and a cavity cleaning mechanism, the hole cleaning mechanism is used for cleaning throttling holes of the to-be-cleaned throttling assembly, and the cavity cleaning mechanism is used for cleaning the inner circumferential wall of the to-be-cleaned throttling assembly. According to the cleaning device, the position of the to-be-cleaned throttling assembly can be accurately positioned, so that the cleaning device can accurately reach the to-be-cleaned throttling assembly to clean the to-be-cleaned throttling assembly, and the cleaning effect and efficiency are improved.

To provide a dust removal system and a dust removal method, which can more reliably remove dust from within a combustor.SOLUTION: A dust removal system comprises two shock wave generation devices each configured so as to generate a shock wave for removing dust in a combustor. The two shock wave generation devices each include: a chamber configured so as to be filled with a mixture containing a fuel and an oxidizing agent; an ignition device for igniting the mixture in the chamber; and a launch unit for using a detonation wave produced by the ignition by the ignition device to launch a shock wave into the combustor. The two shock wave generation devices are arranged so that two shock waves respectively launched from the two launch units reinforce one another due to interference. The dust removal system further comprises an ignition control unit configured so as to send, to each of the two ignition devices, an ignition command for starting ignition.SELECTED DRAWING: Figure 1

The present invention is a method for feeding a chemical to a steam system that controls the injection of a water treatment chemical to the steam system, the method being for feeding a chemical to the steam system that comprises: a pressure sensor, a temperature sensor, or a steam trap as a steam circulation detection means provided to the steam system; and a chemical feed pump for injecting the water treatment chemical to the steam system, said steam system controlling the injection of the water treatment chemical by means of the chemical feed pump in accordance with the steam circulation detection status of the steam circulation detection means.

This invention relates to a sootblower arrangement for a boiler / furnace, comprising a base frame (10), a moveable carriage (14) supported by the frame (10), a motor (2) for moving the carriage (14), a lance tube (11) mounted on the carriage (14) to be insertable into and retractable from the boiler / furnace, said lance tube (11) having at least one nozzle (12), and a steam feed tube (50, 51) connected to the lance tube (11) for feeding sootblowing steam to be ejected through said at least one nozzle (12) into the boiler / furnace, said steam feed tube (50, 51) having a first valve (3) for admitting steam through said at least one nozzle (12), when the carriage with the lance tube (11) is in an active position, i.e. during retraction and / or introduction of the lance tube (11), wherein there is arranged an adjustment arrangement (7) including a movable member (70), arranged to be movable between a first and a second end position, which movable member (70) is mechanically connected by means of a pivot device (75) to a control member (32) arranged to move / position a closure means (30) of said valve (3) into an open or closed position, facilitating closure of said valve (3) also when the lance tube (11) is in its activated position, w h e r e i n said adjustment arrangement (7) includes adjustment arrangement (7) includes an adjustable member (76) that by means of a second power mechanism (78) arranged to operate independently in relation to said first power mechanism (71),and arranged to position said pivot device (75) in at least one intermediate position between said first and second end positions.

The invention provides a generator set waste heat utilization system and a control method, and relates to the technical field of efficient utilization of industrial waste heat, by establishing a continuous blow-down water vaporization proportion correction calculation formula and introducing a continuous blow-down sewage waste heat coefficient, high, medium and low states of continuous blow-down sewage waste heat are calculated, and the continuous blow-down water vaporization proportion correction calculation formula is established. Whether a low-pressure cylinder of the generator set exhausts air to supplement a heat source or not and whether an intermediate heat exchanger is used for achieving primary heating of heating return water are judged, efficient recovery of waste heat of the generator set in a generator and an evaporator of the lithium bromide heat pump unit is achieved through a waste heat utilization system and a control method, and it is guaranteed that the heating return water reaches the common heating required temperature; the impact on the waste heat utilization system caused by changes of the continuous sewage discharge rate, continuous sewage thermal parameters and the like is avoided, the discharged sewage waste heat is recycled to be used for the heating system, and the operation stability and reliability of the heating system using the discharged sewage waste heat are improved.

The invention discloses a steam generation device for waste heat utilization of an ES fiber production heat conduction oil system, and relates to the technical field of waste heat recovery in textile fiber production. The device comprises a heat exchanger and a steam generator, the steam generator is arranged at the top of the heat exchanger, and a heat conducting plate is arranged at the top of the heat exchanger; a knocking mechanism is arranged in an inner cavity of the steam generator. The knocking hammer is used for periodically knocking the heat-conducting plate at high frequency, so that the scale generates fatigue cracks and is crushed, the floating cleaning brush supported by the spring is adaptively attached to the surface of the heat-conducting plate, crushed scale is thoroughly removed, stubborn scale on the surface of the heat-conducting plate can be effectively crushed and removed, the scale on the surface of the heat-conducting plate is timely removed, and the heat conduction performance of the heat-conducting plate is recovered; the energy loss is reduced, the steam generation efficiency is improved, the production energy consumption is reduced, the cleaning time is short, the effect is good, the problem of long time consumption of manual cleaning is avoided, and the equipment operation continuity is remarkably improved.

The start-up time of a power generation unit having a steam generator, a steam turbine rotated by steam generated by the steam generator, a condenser that cools and condenses exhaust steam from the steam turbine to produce condensed water, and a vacuum pump that sucks and discharges non-condensable gases in the condenser is shortened. [Solution] The system comprises a start-up preparation step for preparing to start up the power generation unit 1, a water quality improvement execution step for gradually executing each process of the water quality improvement process for improving the water quality within the equipment to be improved, including the condenser 4 and the once-through boiler 7 as a steam generating device, and an ignition step for preparing the once-through boiler 7 for ignition and then igniting the boiler, and the operation of increasing the vacuum of the condenser 4 is reserved in the water quality improvement execution step and is performed in the ignition preparation step of the ignition step.

The invention belongs to the technical field of boiler furnace cleaning control, and particularly discloses a boiler furnace cleaning control system based on CCD imaging recognition, which comprises an image acquisition module, a pollution recognition module, a grade confirmation module, a cleaning control module, a residue analysis module and a feedback control terminal, according to the invention, through surface texture features such as thickness, color and texture in the visual image, contour type determination and area calculation of ash deposition and coking are realized, the problem of lack of visual monitoring at present is solved, key parameters such as ash deposition coverage rate and coking thickness are acquired in real time, quantitative data support is provided for subsequent cleaning control, and the method is suitable for popularization and application. And meanwhile, the pollution level is dynamically upgraded by combining the temperature characteristic of the infrared thermodynamic diagram based on the analysis of the coking thickness and the ash deposition coverage rate, so that the cleaning efficiency is improved, and the risk of equipment overtemperature caused by the misjudgment of the pollution level is avoided through the fusion analysis of the infrared temperature data and the visual characteristic.

Disclosed is a method of pre-operational cleaning of water and steam systems in a combined cycle power plant (1, 1') including a gas turbine engine (2), a steam turbine system (4), a condenser (6), and a heat recovery steam generator HRSG (3). The method comprises: performing a pre-operational initial flushing and chemical cleaning operation on the water and steam system of the finally constructed combined cycle power plant (1, 1'); firing the gas turbine engine (2) and commissioning the gas turbine engine (2); and, while the gas turbine engine (2) is being commissioned, performing a validation steam blow procedure including a steam blow operation, wherein steam is generated in the HRSG (3) and blown at high velocities, temperatures and cleaning force ratio conditions through a portion of a closed flow circuit for cleaning steam-carrying parts of the HRSG (3) and steam lines (39-51) connecting the HRSG (3) to the steam turbine system (4), wherein the steam is routed to bypass the steam turbine system (4) via operational bypass lines (52-54), without using any temporary piping, and is discharged to the condenser (6); and monitoring and validating cleanliness of selected steam blown steam lines (39-54). A combined cycle power plant (1, 1') arranged for performing such a pre-operational cleaning is also disclosed.

The invention discloses a steam pocket device for removing reaction heat and generating steam, and belongs to the technical field of chemical equipment. The device comprises a steam pocket and a tubular reactor, the tubular reactor is communicated with the steam pocket through a conveying pipeline, reaction heat generated in the reaction process can be transferred to the steam pocket, and heat absorption and cyclic utilization are achieved. A water level detector is arranged in the steam pocket and comprises a monitoring floating ball and a control part, the monitoring floating ball can monitor the water level depth of waste water, and the control part can control the sewage discharge pipeline to discharge sewage when the water level reaches an early warning line; an adjusting piece is arranged between a high water level detection piece and a low water level detection piece in the control part, and the water level control interval can be flexibly adjusted; secondly, efficient recovery of reaction heat and resource utilization of steam are achieved, and accurate water level control and comprehensive water quality management functions are achieved; the pH value of water is adaptively adjusted, the steam extraction efficiency is greatly improved, and a large amount of scale is prevented from appearing in the steam pocket.

Obtained is a multi-pipe once-through boiler with which it is possible to suppress ash residue from adhering within a combustion chamber when reclaimed oil (waste oil) is used as a combustion gas for generating consumption steam.　A multi-pipe once-through boiler configured to retrieve consumption steam, wherein the multi-pipe once-through boiler comprises a plurality of nozzles (50, 60, 70) that use reclaimed oil as fuel and that are installed in order to spray steam onto the surfaces of an inner-side water pipe row (3) and an outer-side water pipe row (4), and a spray control device (85) that controls the time for which steam is sprayed from the nozzles, whereby consumption steam is fed back and intermittently sprayed during operation of the multi-pipe once-through boiler (100), and ash residue is suppressed from adhering to the surfaces of the water pipe rows due to combustion of the reclaimed oil resulting from use of the reclaimed oil.

To provide a method of pre-operational cleaning of water and steam systems in combined cycle power plants.SOLUTION: Provided is a method comprising: performing a pre-operational initial flushing and chemical cleaning operation on a water and steam system of a combined cycle power plant (1); starting a gas turbine engine (2) and test-driving it; and performing a validation steam blow procedure including a steam blow operation during test-driving of the gas turbine engine, wherein steam is generated in an HRSG (3), the steam is flowed to a part of a closed flow circuit, and steam-carrying components of the HRSG and steam lines (39-51) connecting the HRSG to a steam turbine system (4) are cleaned, wherein the steam is routed to bypass the steam turbine system via operational bypass lines (52-54), without using any temporary piping, and is discharged to a condenser (6); and monitoring and validating cleanliness of selected steam-blown steam lines (39-54).SELECTED DRAWING: Figure 1

The invention provides a high-temperature gas cooled reactor steam generator throttling assembly cleaning system and method.The high-temperature gas cooled reactor steam generator throttling assembly cleaning system comprises a cleaning water storage tank, a water conveying pipe, a water conveying pump and a spray gun, and the cleaning water storage tank is provided with a first containing cavity and a first water outlet communicated with the first containing cavity; the first accommodating cavity is used for accommodating demineralized water; the first end of the water conveying pipe communicates with the first water outlet. The water conveying pump is connected to the water conveying pipe in series to pressurize demineralized water in the water conveying pipe. The spray gun is provided with a water supply channel and water spraying holes, the water supply channel communicates with the second end of the water conveying pipe, and the water spraying holes are suitable for communicating with the water supply channel and can spray high-pressure demineralized water towards the inner cavity of the throttling assembly. The inner cavity of the throttling assembly can be washed through high-pressure demineralized water, so that water scale, sediment or other foreign matter in the inner cavity can be effectively cleaned, the cleaning effect on the throttling assembly is ensured, and cleaning operation is simple and convenient.

The invention relates to a coal-fired boiler water-cooled wall area coking condition real-time monitoring and cleaning device which is characterized by comprising a monitoring system, a controller and a cleaning system, and the monitoring system is used for collecting the wall temperature of a boiler water-cooled wall and the smoke temperature in a hearth in real time; the controller is in communication connection with the monitoring system and is used for calculating a heat transfer coefficient based on the wall temperature and the smoke temperature and judging the coking condition of the water-cooled wall area according to the heat transfer coefficient; the cleaning system is in communication connection with the controller and is used for responding to an instruction of the controller to execute cleaning operation; the cleaning operation comprises the steps of adjusting the opening degree of a secondary air adjusting baffle to slow down coking and starting a steam soot blowing system to remove the coking, and real-time monitoring and intelligent cleaning of the coking of the water cooling wall of the coal-fired boiler are achieved.

The invention provides a thermal generator set low-quality heat comprehensive utilization system and a control method, and relates to the technical field of thermal generator sets, the thermal generator set low-quality heat comprehensive utilization system comprises a regular drainage pool, a boiler regular drainage flash tank, a stainless steel water tank, a linkage control assembly, a heat recycling end and an overflow pipe. Through sequential treatment of the regular drainage pool, the boiler regular drainage flash tank and the stainless steel water tank, stable storage and pretreatment of high-temperature and high-pressure wastewater are achieved, and by means of real-time monitoring and threshold value control of a temperature sensor and a liquid level meter, it is ensured that only the wastewater meeting the heat utilization condition is recycled to the heat supply urban network water return main pipe and the bath water pool, and the heat utilization efficiency is improved. Ineffective conveying of low-quality heat is avoided, the overflow risk caused by the fact that the stainless steel water tank is full of water is effectively prevented through the arrangement of the overflow pipe, directional recovery and efficient utilization of the low-quality heat of the thermal generator set are achieved through the whole system, heat energy waste caused by traditional direct emission is reduced, and the steam production cost is reduced. And the energy utilization efficiency of the unit is improved.

The application discloses a boiler automatic blowdown mechanism, which comprises a boiler body, a water inlet pipe is arranged on the upper end of the boiler body, a funnel-shaped bottom is arranged on the lower end of the boiler body, a water outlet pipe is arranged on the lower end of the funnel-shaped bottom, and an electric control valve is arranged on the water outlet pipe; a plurality of support frames are arranged on the slope of the funnel-shaped bottom, a detection chamber is fixed on the support frames, the detection chamber is suspendedly fixed in the boiler body, and the detection chamber is located above the funnel-shaped bottom; when dirt on the side wall of the boiler body is cleaned, the water in the boiler body becomes turbid gradually, the inner detector and the outer detector are set as turbidity detectors, the turbidity of the water can be determined by the loss degree of the emitted signal and the received signal, when the water is very turbid, the inner detector and the outer detector are controlled by the controller to open the electric control valve, and the cleaned sewage is directly discharged to the outside, so that the automatic blowdown function of the boiler is realized.

The present invention relates to the field of automation control technology, and particularly to a water quality control method and system for a once-through boiler. The method includes the following steps: collecting liquid sensing signals and temperature sensing signals in the once-through boiler; performing preliminary liquid resistance value calculation processing according to the liquid sensing signals to generate preliminary liquid resistance value data; performing temperature compensation-based liquid resistance value correction processing on the preliminary liquid resistance value data based on the temperature sensing signals to generate liquid resistance value data; performing the water supply operation of the feed water pump of the once-through boiler; performing immediate analysis processing of the liquid conductivity and dissolved solids concentration on the liquid resistance value data according to the water supply operation of the feed water pump to respectively obtain an immediate liquid conductivity signal and immediate dissolved solids concentration data; and performing the sewage discharge control operation of the once-through boiler according to the immediate liquid conductivity signal and the immediate dissolved solids concentration data. The present invention realizes intelligent and efficient water quality sewage discharge control by analyzing the water quality characteristics of the once-through boiler.

To provide a control system which enables reduction of a water circulation pipe clean-up process in a gas-gas heater device 200.SOLUTION: At a control system of a water circulation pipe 4 clean up process in a gas-gas heater device 200, including a heat recovery device 2 configured to recover heat from exhaust gas of a boiler 71, a heater 3 which increases a temperature of a process gas, and the water circulation pipe 4 located between the heat recovery device 2 and the heater 3, in a flushing process of the water circulation pipe 4, drainage tank draining control means 102 of an information processing device 1 controls drainage tank draining means 46 so that a water level of a drainage tank 52 received by drainage tank water level receiving means 104 is maintained at a level lower than a setting value. Further, water circulation control means 105 of the information processing device 1 controls a water supply valve 47 and circulation water draining means 45 so that a water storage amount of a circulation water tank 51 received by circulation water tank water storage amount receiving means 103 is maintained in a predetermined amount or larger amount and the water level of the drainage tank 52 received by the drainage tank water level receiving means 104 becomes lower than a predetermined value.SELECTED DRAWING: Figure 7

The purpose of the present invention is to effectively reduce the corrosion fatigue of an evaporating tube in a boiler which occurs in association with a corrosive environment or repeated application of stress due to the presence of scales. A method for reducing the corrosion fatigue of an evaporating tube in a boiler, in which each of the concentration of chloride ions and the concentration of sulfate ions in the boiler water is managed at 10 mg / L or less. It is preferred to manage each of the concentration of chloride ions and the concentration of sulfate ions in boiler water by subjecting boiler feed water to a desalination treatment with an ion exchange device, a reverse osmosis membrane device or an electrodeionization device or by increasing the collection rate of boiler condensed water.