294results about "Boiler water tubes" patented technology

The invention discloses a small micro-superheated steam through-flow type gas condensation boiler, belongs to the technical field of boilers, and solves the problems that the current small gas boiler is developed towards the high-efficiency, low-emission and compact direction, and particularly pays attention to waste heat recovery and steam quality control. Comprising an annular water chamber allowing water to enter, a combustion chamber arranged above the annular water chamber and an ultra-low nitrogen surface fiber combustor located above the combustion chamber and communicated with the combustion chamber, and an annular steam chamber is arranged above the combustion chamber. The ultra-low nitrogen surface fiber burner works to burn gas and raise the temperature, and the composite fin straight water pipe converts water in the water pipe into wet steam through efficient heat exchange of the spiral fins and enters the annular steam chamber. External water is injected into the annular water chamber through the finned tube group of the flue gas condenser and the connecting tube, and then enters the steam chamber through the straight tube. Wet steam in the steam chamber enters the superheater through an inlet pipe to form micro superheated steam. Combustion smoke is condensed and discharged after being filtered by a filter screen and subjected to heat exchange, and dryness of the combustion chamber is guaranteed.

The invention belongs to the technical field of fused salt energy storage, and particularly relates to a thermal power generating unit deep peak shaving system and method of a fused salt heat storage coupling high-temperature heat pump. In the high-generation time period of renewable energy sources, the load of a thermal power generating unit needs to be reduced, at the moment, a boiler operates at the lowest stable combustion load, a fused salt heat storage system is added, all main steam is extracted to enter the heat storage system to heat fused salt, a high-pressure cylinder of a steam turbine is stopped, and an intermediate-pressure cylinder and a low-pressure cylinder of the steam turbine operate under the low-load working condition; the output load of the unit only meets the plant power, and the load is not output to the power grid; in the load rising time period, heat stored by the fused salt heat storage system is used for generating steam in the unit load rising stage to increase the unit steam turbine load rising rate and peak power generation; the problems of operation safety and low energy grade in the unit peak regulation process are solved. In the peak period of electricity utilization, heat stored in the fused salt heat storage system is released into the unit, and the output load of the unit is rapidly increased. An outlet of the deaerator serves as a water taking point, part of supplied water is extracted to pass through the preheater, the evaporator and the superheater to generate high-temperature and high-pressure steam, the high-temperature and high-pressure steam enters a high-pressure cylinder of the steam turbine to do work, and therefore the output load of the steam turbine is rapidly increased. The invention provides a thermal power generating unit deep peak regulation system and method of a fused salt heat storage coupling high-temperature heat pump, and aims to realize deep peak regulation of a unit and power generation by absorbing renewable energy sources such as wind and light.

The invention provides an integrated vehicle-mounted steam-injection boiler with high maneuvering characteristics and a using method of the integrated vehicle-mounted steam-injection boiler. The integrated vehicle-mounted steam-injection boiler comprises a steam-injection boiler pressed assembly, an auxiliary system and a carrying tool, and the steam-injection boiler pressed assembly and the auxiliary system are arranged on the carrying tool; and the carrying tool is used for driving the steam-injection boiler compression assembly and the auxiliary system to move. The components are integrally arranged, so that the vehicle-mounted steam injection boiler can form a complete independent working unit from water supply to steam production, the dismounting workload in the steam injection transition and movement process is reduced, a carrying tool with a good suspension system is adopted, and the vehicle-mounted steam injection boiler is convenient to use. And the vehicle-mounted steam-injection boiler has good field driving capability and maneuverability.

A solid electric thermal storage superheated steam output system is provided. Through a high-temperature air duct, a superheated steam heat exchanger, a saturated steam heat exchanger and a water preheating heat exchanger, heat exchange is performed under the drive of a variable-frequency fan to finally generate superheated steam for use of a heat consumer. The water preheating heat exchanger is connected to a preheating steam tank, heat generated after the superheated steam heat exchanger and the saturated steam heat exchanger exchange heat is used to generate low-temperature steam for thermal deoxygenation of a deaerator, while water flows into a deaerator water tank through an overflow pipe. A superheated steam unit is a structural combination including a steam drum as a core, sets of superheated steam heat exchangers, saturated steam heat exchangers, water preheating heat exchangers and corresponding accessories. An overall combined superheated steam system includes multiple superheated steam units.

The utility model belongs to the technical field of steam heaters, and discloses a steam heating pipeline and an instant electric steam heater, which comprise a pipe body, one end of the pipe body is provided with a water inlet port, and the other end of the pipe body is provided with a steam outlet port; the pipe body comprises a first spiral pipeline and a second spiral pipeline, and at least one part of the first spiral pipeline is inserted into the second spiral pipeline in parallel in a staggered mode. Through the first spiral pipeline and the second spiral pipeline, at least one part of the first spiral pipeline is inserted into the second spiral pipeline in a staggered and parallel mode, and heating pieces can be arranged in the intersection area and the non-intersection area of the first spiral pipeline and the second spiral pipeline. Heat of the heating piece can be fully transferred to the first spiral pipeline and the second spiral pipeline, water flow can flow through the first spiral pipeline and the second spiral pipeline respectively, the passing distance and the passing time of the water flow are longer, and the water flow can be fully heated and vaporized.

A system includes a heat exchanger having a plurality of tubes arranged in a tube bundle having opposite first and second sides, opposite third and fourth sides extending from the first side to the second side, and opposite fifth and sixth sides extending from the first side to the second side, wherein the fifth and sixth sides extend between the third and fourth sides. The heat exchanger further includes a plurality of external flow lanes extending across the tube bundle and between the fifth and sixth sides outside of the plurality of tubes. Each tube of the plurality of tubes comprises a plurality of tubing portions extending in opposite first and second directions between the first and second sides in a sequence, and each successive tubing portion in the sequence switches lanes between the plurality of external flow lanes relative to a preceding tubing portion.

To prevent dust from adhering to the interior of a boiler to protect the boiler.SOLUTION: A boiler includes: a heat radiation chamber having a heat transfer pipe which receives radiant heat of an exhaust gas circulating from a waste incinerator to generate steam, and a convective heat transfer chamber which overheats steam through heat exchange between the exhaust gas and the heat transfer pipe. The boiler has a plasma actuator, which generates airflow by an AC voltage being applied thereto, on a peripheral surface of the heat transfer pipe. Dust contained in the exhaust gas flows along the airflow generated by the plasma actuator. Thus, the structure can inhibit the dust contained in the exhaust gas from adhering to the heat transfer pipe and inhibit corrosion of the heat transfer pipe from being caused by the dust.SELECTED DRAWING: Figure 1

The system and method for preventing high-temperature corrosion of the boiler water-cooled wall provided by the present invention can spray the high-temperature and high-pressure air after the compressor is boosted and the heater is heated toward the water-cooled wall through the air duct, which can effectively penetrate the flue gas in the furnace and form a protective air film with good anti-corrosion effect on the water-cooled wall, and will not form a large degree of cooling in the furnace, thereby achieving the technical effect of improving the atmosphere near the water-cooled wall, preventing the water-cooled wall from high-temperature corrosion, and not affecting the performance of the boiler; the compressed air flow directed to the water-cooled wall can also purge the water-cooled wall to prevent the flame from scouring the water-cooled wall, and remove the accumulated dust and slag on the water-cooled wall; by setting a sensor to detect the concentration of oxygen, carbon monoxide and hydrogen sulfide in the atmosphere attached to the water-cooled wall, and then adjusting the opening of the regulating valve on the pipeline according to the detection value of the sensor through the controller, it is possible to monitor the atmosphere attached to the water-cooled wall online, and to reasonably optimize the amount of compressed air injected in real time, thereby improving the economy.

The utility model relates to the technical field of boilers, in particular to a low-nitrogen gas steam boiler which comprises a boiler body, two groups of water pipes are arranged in the boiler body and include an ascending pipe and a descending pipe, the descending pipe is located on the periphery of the ascending pipe, a gas distributor is arranged on one side of the ascending pipe, and a burner is installed on the side, facing the ascending pipe, of the gas distributor. A preheater is arranged on the outer side of the furnace body, one side of the furnace body is connected with a flue, a smoke pipe is vertically installed in the middle of the interior of the preheater, the top end of the smoke pipe is connected with the flue, and the bottom end of the smoke pipe is connected with a chimney. According to the low-nitrogen gas-steam boiler, the boiler body and the combustor are integrally designed, so that complicated structures such as a return smoke tube and a reversal chamber in a traditional boiler are omitted, the overall size of the boiler is greatly reduced, the weight is reduced accordingly, and the boiler is convenient to install and transport.

The utility model relates to the technical field of sulfuric acid waste heat recovery, in particular to a tube bundle slideway device of a sulfuric acid HRS steam generator. Comprising a plurality of supporting plates arranged in parallel, mounting grooves are formed in the middles of the upper ends and the lower ends of the supporting plates correspondingly, rollers are arranged in the mounting grooves in the lower ends, mounting plates are arranged on the left sides and the right sides of the rollers correspondingly, and the lower ends of the rollers abut against sliding rails; angle steel sliding rails are arranged on the left side and the right side of the sliding rail respectively, and the supporting angle steel located in the angle steel groove at the lower end is pressed on the angle steel sliding rails. Compared with the prior art, the structure is simple, the performance is reliable, when the tube bundle of the HRS steam generator is installed in or drawn out of the shell, through rolling friction of the rollers, sliding friction of the left and right angle steel rails and guiding, the workload of installing or drawing out the tube bundle is greatly reduced, and deformation or damage caused by overlarge stress of the tube bundle is also avoided.

To improve heat exchange efficiency between a first fluid within heat transfer pipes and a second fluid at the outer side of the heat transfer pipes.SOLUTION: A heat exchanger includes: a pipe body formed with a passage to which a first fluid is supplied; a pair of partition plates which are disposed spaced apart from each other in an extension direction of the pipe body and define a closed space at a part of the passage; multiple heat transfer pipes which extend in the extension direction so as to penetrate through the pair of partition plates and arranged spaced apart from each other; a supply part which may supply a second fluid from the outside of the pipe body to the closed space; a discharge part which may discharge the second fluid in the closed space to the outside; and a passage formation part in which multiple small passage parts are formed between the heat transfer pipes located adjacent to each other with the closest spacing formed therebetween of the multiple heat transfer pipes. The second fluid circulates between the multiple heat transfer pipes so as to flow in an opposite direction of a circulation direction of the first fluid in the closed space. The multiple small passage parts are disposed at positions different from each other when viewed from a position where the discharge part is placed in the extension direction.SELECTED DRAWING: Figure 1

The utility model provides an anti-blocking device for oxide skin at the elbow of a U-shaped pipe on a high-temperature heating surface of a boiler, which belongs to the technical field of power station boiler experiments and comprises an inlet header and an outlet header, and a plurality of heat exchange pipes are connected between the inlet header and the outlet header. An oxide skin anti-blocking mechanism is mounted at an elbow of the heat exchange pipe and comprises an oxide skin anti-blocking device with a triangular outer contour, and a plurality of anti-blocking device inlet pipes and a plurality of anti-blocking gas outlet pipes which are mounted on the two sides of the oxide skin anti-blocking device respectively; and the plurality of anti-blocking device inlet pipes and the plurality of anti-blocking gas outlet pipes are connected with the heat exchange pipe. Theoretical simulation calculation shows that the oxide skin anti-blocking mechanism with the contour in the shape of an equilateral triangle is additionally arranged at the elbow of the U-shaped pipe, so that oxide skin particles are obviously and stably deposited at the lower right corner of the oxide skin collecting mechanism in the shape of the equilateral triangle, and the problem of oxide skin blocking at the elbow of the U-shaped pipe is effectively avoided; and the problem of blockage caused by falling of an oxide film in the pipe is well solved.

The invention provides a supercritical circulating fluidized bed unit dry and wet state automatic conversion and whole-course water supply control system and method, and belongs to the technical field of automatic control. The problems of low automatic input rate, complex and difficult wet state control strategy, large dry and wet state conversion disturbance, load control breakpoints and the like in once-through boiler feed water control in the deep peak regulation coordinated variable load process of the unit are solved; the main steam flow is corrected by introducing the enthalpy value of the last-stage superheater and the enthalpy value of the outlet of the separator on the basis of a self-balancing water supply control strategy, the heat released / absorbed by the boiler is dynamically reflected, the balance of the heat load and the evaporation capacity of the boiler is guaranteed, and meanwhile the boiler bed temperature and the wall temperature of a certain area of the boiler are corrected in real time; according to the method, the same set of control strategy is adopted for water supply control in the dry state and the wet state of the boiler, and switching and transformation of water supply control modes are not needed. Meanwhile, power control and dry-wet state conversion control are combined, and continuous power control in the dry-wet state conversion process is achieved.

The application relates to a boiler container, which comprises a container with a containing cavity, a plurality of openings in communication with the containing cavity, an inner wall of the container provided with a reflecting layer, and an outer wall of the container provided with a heat insulation layer; a plurality of boilers, at least one of which is arranged in the opening, and any two adjacent boilers are communicated through at least one heat transfer pipe, the heat transfer pipe is arranged in the containing cavity, and the reflecting layer is used for reflecting heat radiated outward by the heat transfer pipe to the heat transfer pipe. As known from the above, the boiler container in the embodiment can reduce the heat dissipation of the heat transfer pipe, reduce the heat energy loss of the boiler container, increase the number of the heat transfer pipes, and guarantee the energy conversion efficiency of the boiler container.

The invention discloses a water-cooled wall intermediate header flow distribution system of an ultra-supercritical coal-fired unit, which comprises an intermediate header and a collection header, a three-stage adjustable throttling orifice plate is arranged in an inlet pipeline of the intermediate header, a plurality of groups of cyclone flow deflectors are arranged in the intermediate header, the intermediate header is communicated with the collection header through a plurality of branch pipes, and the branch pipes are communicated with the collection header. The inlet of each branch pipe is provided with a Venturi pipe, and the outlet of each branch pipe is provided with a sensor probe of the control unit; the three-stage adjustable throttling orifice plate and the cyclone flow deflector are respectively in transmission connection with respective actuating mechanisms, and all the actuating mechanisms are in signal connection with the control unit. The invention further discloses a water-cooled wall intermediate header flow distribution method of the ultra-supercritical coal-fired unit. The invention belongs to the technical field of ultra-supercritical coal-fired power generation, and solves the problem that in the prior art, due to the limitation of structural design, the wide load range adjustment requirement cannot be met.

A boiler water treatment device and treatment method are provided that prevent carbon dioxide in the atmosphere from mixing with water in a tank. [Solution] A water supply tank 7 is provided which receives pure water from a pure water tank 2 and condensate from a condensate tank 4, and nitrogen gas is supplied from a nitrogen gas source 8 to the pure water tank 2, the condensate tank 4, and the water supply tank 7. Water from the water supply tank 7 is supplied to a boiler, and is passed through an OH-type anion exchange resin tower 17 or 18 by switching using valves 15a, 16a. Treated water from the OH-type anion exchange resin tower 17 or 18 is returned to the water supply tank 7.

To provide a repair method of a hanging panel which enables easy repairing of the hanging panel, and to provide a hanging pipe alignment tool.SOLUTION: A hanging panel has a plurality of hanging pipes 14 arranged in a horizontal direction and is supported hanging from above. A repair method for repairing the hanging panel includes: an attachment step in which a hanging pipe alignment tool 2, including a plurality of sandwiching parts 3 each of which is arranged over the hanging pipes and sandwiches the hanging pipes from one side and the other side in a depth direction orthogonal to a vertical direction and an arrangement direction, is used and the sandwiching parts are attached to the upper side and the lower side of an area A to be repaired (a repaired area) of the hanging panel; and a repair step in which the hanging panel is repaired in the repaired area.SELECTED DRAWING: Figure 1

A system includes a heat exchanger having a plurality of tubes arranged in a tube bundle having opposite first and second sides, opposite third and fourth sides extending from the first side to the second side, and opposite fifth and sixth sides extending from the first side to the second side, wherein the fifth and sixth sides extend between the third and fourth sides. The heat exchanger further includes a plurality of external flow lanes extending across the tube bundle and between the fifth and sixth sides outside of the plurality of tubes. Each tube of the plurality of tubes comprises a plurality of tubing portions extending in opposite first and second directions between the first and second sides in a sequence, and each or at least one successive tubing portion in the sequence switches lanes between the plurality of external flow lanes relative to a preceding tubing portion.

The present invention relates to a supercritical or ultra-supercritical boiler rapid strengthening working medium side energy supply system in the field of energy technology, comprising: a circulating water circuit matched with the boiler, which is connected with an input pipeline and an output pipeline; a steam-water separator, which is connected to the output pipeline of the circulating water circuit; a water storage tank, which is connected to the steam-water separator; a high-temperature boiler water energy storage device with a storage chamber; an openable and closable energy storage pipeline, wherein the steam chamber of the steam-water separator and the liquid chamber of the water storage tank are connected to the input side of the high-temperature boiler water energy storage device through the energy storage pipeline; an openable and closable energy release pipeline, wherein the energy release side of the high-temperature boiler water energy storage device is connected to the input pipeline of the circulating water circuit through the energy release pipeline. The ultra-supercritical boiler rapid peak regulation and variable load response capability can be strengthened from the working medium side.

To provide a method for forming a functional self-fluxing alloy coating, capable of exhibiting excellent wear resistance, corrosion resistance and lubricity and suppressing the suppression effect of the adhesion and deposition of ash (clinker) for a long period of time.SOLUTION: A method for forming a functional self-fluxing alloy coating comprises: the thermal spray coating formation step of forming a self-fluxing alloy thermal spray coating on the surface of a base material; the lubricant composition impregnation step; the drying step of drying the thermal spray coating including the impregnated lubricant composition to remove the solvent and form a thermal spray coating including the solid lubricant particles; and the self-fluxing alloy remelting step of heating the thermal spray coating including the solid lubricant particles to remelt the self-fluxing alloy.SELECTED DRAWING: Figure 1

The invention discloses the technical field of waste heat boilers, and particularly relates to a method for preventing overtemperature of the bottom of a waste heat boiler and a desuperheater, the method comprises a main body mechanism, the main body mechanism comprises a pipe body and connecting flanges, and the connecting flanges are arranged at the two ends of the pipe body; the cooling mechanism is arranged on the pipe body, the cooling mechanism comprises a water feeding assembly, a sensing assembly, a power assembly and a control assembly, the water feeding assembly is used for feeding liquid into the pipe body, and the sensing assembly is used for sensing the temperature change in the pipe body; the sensing assembly is matched with the power assembly to control the flow of liquid in the pipe body through the control assembly, the change of the temperature of steam in the pipe body can be detected by arranging the sensing assembly on the water supply pipe, and the flow of cooling water is quickly responded and automatically adjusted according to the temperature change through the matching of the power assembly and the control assembly. The requirement of manual intervention is reduced, and the operation difficulty and the maintenance cost are reduced.

The utility model discloses a protection device for a heating surface pipeline of a power plant boiler, and relates to the technical field of boiler equipment. According to the technical scheme, the protective device comprises a first protective body, a second protective body and a third protective body, one end of the first protective body and one end of the second protective body are connected together, and the other end of the first protective body and the other end of the second protective body are fixedly connected together through the third protective body. The assembled protection device can comprehensively protect a plurality of pipes which cannot be protected by a conventional semicircular anti-abrasion tile due to space limitation in the tail flue of the boiler, so that heating surface pipelines are prevented from being abraded by flue gas fly ash and being damaged by blowing of steam of a soot blower.

The invention discloses a deep peak shaving device for a coal power unit and an operation method.The deep peak shaving device comprises the coal power unit, a high-pressure bypass and a low-pressure bypass, the coal power unit comprises a boiler, a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder, and a superheater outlet of the boiler is connected with a steam inlet of the high-pressure cylinder through a main steam pipeline; the main steam pipeline is communicated with a heat control system, a temperature and pressure reducer system is arranged on the main steam pipeline, a plurality of branch steam pipelines are arranged on the main steam pipeline on one side of the temperature and pressure reducer system, and a first stop valve and a first electric valve are arranged on each branch steam pipeline. The branch steam pipelines are connected with the heat control system, and a plurality of drainage pipelines are arranged on the main steam pipeline on the other side of the temperature and pressure reducer. According to the invention, the cost investment is greatly reduced, the main steam heat supply transformation is realized while the deep peak regulation operation transformation of the lowest rated load is realized, and the external heat supply capability is greatly improved.

The present invention discloses a control method for preventing oxide scale shedding from the heating surface during peak-shaving startup and shutdown of a coal-fired unit. By controlling the rate of change of steam temperature and pressure during startup and shutdown, sudden changes in steam and wall temperatures are prevented. The method also adjusts the opening of the boiler's additional air and fuel air dampers to control the flue gas temperature at the furnace outlet and prevent overheating and dry burning of the heating surface. The method also adjusts the opening of the high-pressure bypass to control the steam flow rate on the heating surface and prevent sudden changes in superheated steam temperature. During turbine run-up and generator grid connection, the method adjusts the reheat flue gas damper to prevent a sudden rise in reheated steam temperature. During shutdown, the method controls the superheat after the desuperheater to prevent water plugging in the superheater. Thus, without upgrading or renovating the heating surface materials, and only by optimizing the operation control method, it is possible to achieve a state where oxide scale is not detected on the heating surface throttle orifices and the bottom of the U-bend within a single maintenance cycle, and tube bursts are avoided.

The utility model belongs to a boiler main steam pipeline in the technical field of power generation systems. The main steam pipeline comprises a first pipeline assembly (1) and a second pipeline assembly (2), a first pipeline assembly flange (3) is arranged at one end of the first pipeline assembly (1), a second pipeline assembly flange (4) is arranged at one end of the second pipeline assembly (2), a communicating part is connected between the first pipeline assembly flange (3) and the second pipeline assembly flange (4), and the communicating part comprises a connecting straight pipe (5) and a connecting bent pipe (6). According to the main steam pipeline of the boiler, after a superheater of the boiler is replaced, purging can be conveniently carried out, relevant parts do not need to be disassembled, and operation convenience is improved.

A method of installing a liner assembly for pipeline repair or reinforcement includes: pulling a prepared liner assembly into position in the pipeline, the liner assembly including an outer tubular liner and an inner inflatable bladder positioned longitudinally within the tubular liner, the tubular liner being wetted with a curable compound; introducing fluid into the inflatable bladder so that the inflatable bladder expands to bring the tubular liner into firm contact with an interior surface of the pipeline; flowing the fluid continuously through the bladder and discharging the fluid into the pipeline, while maintaining the liner assembly in an inflated condition for a time period sufficient for the tubular liner to cure; and deflating the inflatable bladder and retrieving at least a portion of the liner assembly from the pipeline.

To provide a furnace wall in which corrosion is less likely to occur in a water-cooled wall even when components contained in furnace gas permeate through a refractory material.SOLUTION: A furnace wall 111 of a gasification furnace comprises: a water-cooled wall 112 having a plurality of heat transfer tubes 112a; a protective film 113 provided on a surface of the water-cooled wall 112 and having higher corrosion resistance than the water-cooled wall 112; and a protective material 114 provided on a surface of the protective film 113. The protective material 114 may contain slag generated in the gasification furnace.SELECTED DRAWING: Figure 3

To provide a heat exchanger which is suitable for recovering heat from a flow medium in a flow layer boiler.SOLUTION: A heat exchanger (10) has: first and second heat exchanger tubes (810, 820); and first and second supply chambers (310, 320) configured to supply a flow medium to the first and second heat exchanger tubes (810, 820) respectively. The first heat exchanger tube (810) is disposed on a first side surface of a plane (P) intersecting with the first supply chamber (310), and the second heat exchanger tube (820) is disposed on a second side surface of the plane (P). The first supply chamber (310) is configured to supply the flow medium to the second supply chamber (320).SELECTED DRAWING: Figure 2

This boiler water treatment device is provided with a water supply tank (7) that receives pure water from a pure water tank (2) and condensed water from a condensed water tank (4), wherein nitrogen gas is supplied from a nitrogen gas source (8) to the pure water tank (2), the condensed water tank (4), and the water supply tank (7). Supply water from the water supply tank (7) is supplied to a boiler and is also switched by valves (15a, 16a) and passed through an OH-type anion exchange resin tower (17) or (18). Treated water from the OH-type anion exchange resin tower (17) or (18) is returned to the water supply tank (7).

The invention discloses a supercritical gas-fired boiler based on tower type arrangement and a thermal optimization control method, and relates to the field of supercritical gas-fired boilers, the supercritical gas-fired boiler comprises a hearth, a burner, a water cooling wall, a heating surface in the boiler, a header outside the boiler, an economizer and a tubular air preheater. The periphery of the hearth is wrapped by an ash bucket water-cooled wall, a spiral tube coil water-cooled wall and a vertical tube coil water-cooled wall, in-furnace heating surfaces are sequentially arranged in the smoke flowing direction and are suspended through in-furnace suspension tubes, and an out-furnace collecting box is suspended through out-furnace suspension tubes; the economizer is divided into an upper stage and a lower stage, is arranged by adopting sequential tube bundles and is provided with a bypass, and a denitration reactor is arranged between the upper stage and the lower stage; the suspension pipe is made of high-strength alloy steel, a working medium flows in the suspension pipe, and a heating surface and related parts are made of alloy materials with adaptive performance. The invention has the technical effects of high safety of the wall temperature of the heated surface, small deviation, small occupied area, low smoke, wind, steam and water resistance, smooth expansion system, adaption to the rapid variable load requirement, excellent environmental protection property, reliable operation and the like.