Energy-saving boiler blowdown flash tank steam-water separation waste heat recovery device

Abstract

The application discloses an energy-saving boiler blowdown flash tank steam-water separation waste heat recovery device, which comprises a boiler body, a flash tank shell, an external heat exchanger, an umbrella-shaped liquid blocking assembly and a conical expansion type condensation heat exchange assembly. After the boiler blowdown water enters the flash tank shell, the rotary flow is formed and the steam-water separation is completed through the arc-shaped flow guide shell and the spiral flow guide plate. The liquid blowdown water exchanges heat with the inverted conical heat exchange pipe. The flash steam enters the upper heat exchange area through the perforated steam guide ring and exchanges heat with the conical expansion type heat exchange pipe group and the external expansion condensation heat exchange shell. The heat exchange medium in the external expansion condensation heat exchange shell drives the hydraulic paddle to rotate and drives the external steam guide fan blade to guide the flash steam flow through the magnetic transmission. The umbrella-shaped liquid blocking assembly is lifted by the gas phase pressure difference and drives the external expansion condensation heat exchange shell to vibrate through the vibration elastic element, promotes the condensate to fall off and backflow, and thus the liquid phase sensible heat and the gas phase condensation heat are recovered.

Description

Technical Field

[0001] This invention relates to the field of boiler energy saving and waste heat recovery technology, and in particular to an energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device. Background Technology

[0002] During boiler operation, high-temperature wastewater with high salt content needs to be discharged continuously or periodically. After the high-temperature and high-pressure wastewater enters the blowdown expansion tank, the pressure decreases, and part of the wastewater flashes to form steam, while the rest of the wastewater is discharged from the bottom of the expansion tank. Since both the flash steam and the liquid wastewater carry a lot of heat, direct discharge will not only waste energy but also increase the thermal pollution of the boiler room and the cooling load of subsequent drainage facilities. For example, Chinese Patent No. CN208536645U discloses a waste heat recovery system for boiler blowdown expansion tanks. It sends the waste steam and water from the expansion tank into a steam-liquid mixer, and then separates and recovers them in a liquid collection and separation tank. It can realize the utilization of waste heat from the blowdown steam. However, the waste heat recovery mainly relies on the direct mixing of steam and liquid outside the expansion tank and the supporting pipelines, without adjusting the distribution of flash steam and the retention of condensate inside the expansion tank.

[0003] However, existing waste heat recovery devices mostly use fixed expansion tanks, steam-water separators, and tubular heat exchangers. After flash steam enters the heat exchange area, it tends to concentrate and flow along channels with low resistance, preventing the peripheral or local heat exchange surfaces from fully participating in condensation heat exchange. At the same time, if the liquid film and droplets formed by flash steam condensation on the heat exchange surface cannot be discharged in time, it will increase the heat transfer resistance and may be re-entrained by the continuously rising airflow. Furthermore, as recorded in Chinese patent CN208536645U, existing serpentine coil-type waste steam heat exchange devices have problems such as low heat transfer coefficient, large required heat exchange area, and increased water-side resistance, indicating that fixed heat exchange structures do indeed have practical defects such as insufficient utilization of heat exchange area and high additional energy consumption.

[0004] The above-mentioned and existing related technologies often have the following drawbacks:

[0005] Because existing boiler blowdown expansion waste heat recovery devices typically introduce flash steam and high-temperature wastewater into fixed heat exchange structures for static recovery, the flow path of flash steam and the state of condensate discharge are difficult to adjust synchronously with the operating conditions when the blowdown flow fluctuates, resulting in uneven distribution of gas phase heat exchange, condensate retention or re-entrainment, and insufficient recovery of waste heat in both gas and liquid paths. Summary of the Invention

[0006] The technical problem to be solved by this invention is that the existing blowdown expansion tank adopts a fixed heat exchange structure, which causes uneven distribution of flash steam, condensate retention and insufficient waste heat recovery. To address this, we propose an energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device.

[0007] To achieve the above objectives, this application adopts the following technical solution: an energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device, comprising a boiler body, an expansion tank shell, an external heat exchanger, an umbrella-shaped liquid blocking component, and a conical expansion condensing heat exchanger component. The blowdown end of the boiler body is connected to the expansion tank shell. An inverted conical heat exchange tube is installed inside the expansion tank shell. The waste heat recovery side of the external heat exchanger is connected to the inverted conical heat exchange tube and the conical expansion condensing heat exchanger component, respectively. The inverted conical heat exchange tube is connected to the conical expansion heat exchange tube group, and the conical expansion heat exchange tube group is connected to the external heat exchanger.

[0008] The umbrella-shaped liquid blocking assembly is disposed between the inverted conical heat exchange tube and the conical expansion condenser heat exchange assembly and slides along the axial direction of the expansion vessel shell. The umbrella-shaped liquid blocking assembly has a perforated steam guide ring.

[0009] The conical expansion condensing heat exchange assembly includes an annular heat exchange collector shell fixed inside the expansion vessel shell and multiple outward expansion condensing heat exchange shells arranged circumferentially along the annular heat exchange collector shell. The outward expansion condensing heat exchange shells are connected to the annular heat exchange collector shell through an elastic sealing connection section. The outward expansion condensing heat exchange shells are provided with a folded-back heat exchange channel and a hydraulic steam guide rotating assembly driven by the heat exchange medium in the folded-back heat exchange channel. The hydraulic steam guide rotating assembly includes a hydraulic blade and a steam guide fan blade located outside the outward expansion condensing heat exchange shell. The hydraulic blade and the steam guide fan blade are magnetically driven through the outward expansion condensing heat exchange shell.

[0010] A vibrating elastic element connects the umbrella-shaped liquid-blocking assembly to the externally expanded condenser heat exchange shell.

[0011] Preferably, a sewage inlet pipe connected to the sewage discharge end of the boiler body is provided on one side of the expansion vessel shell, and an arc-shaped guide shell corresponding to the outlet of the sewage inlet pipe is provided inside the expansion vessel shell. The arc-shaped guide shell is set with a wider inlet and a narrower outlet along the flow direction of the sewage discharge, and a spiral guide plate is provided on the outer side of the outlet of the arc-shaped guide shell.

[0012] Preferably, a bottom drain pipe is provided at the bottom of the expansion vessel shell, and an excess gas discharge port is provided at the position of the expansion vessel shell above the cone-expansion condensing heat exchange component.

[0013] Preferably, the waste heat recovery side of the external heat exchanger is connected to the inlet of the inverted conical heat exchange tube through connecting pipe three, and is connected to the liquid supply area of ​​the annular heat exchange manifold through connecting pipe one. The heat exchange medium outlet of the conical heat exchange tube group and the return flow area of ​​the annular heat exchange manifold are both connected to the waste heat recovery side of the external heat exchanger through connecting pipe two.

[0014] Preferably, the heat-using side of the external heat exchanger is connected to the heat-using equipment through a connecting pipe four. The connecting pipe four is provided with a water supply channel and a water return channel that are separated from each other. The water supply channel connects the outlet of the heat-using side of the external heat exchanger with the inlet of the heat-using equipment, and the water return channel connects the outlet of the heat-using equipment with the inlet of the heat-using side of the external heat exchanger.

[0015] Preferably, the inverted conical heat exchange tube is composed of a spiral coil that is wider at the top and narrower at the bottom. The upper end of the inverted conical heat exchange tube is connected to the lower end of the conical expansion heat exchange tube assembly through an upwardly extending tube section. The conical expansion heat exchange tube assembly includes multiple conical expansion heat exchange branch pipes arranged at intervals along the circumference. The multiple conical expansion heat exchange branch pipes are arranged to expand outward from the bottom up and are connected to the heat exchange medium outlet.

[0016] Preferably, the umbrella-shaped liquid blocking assembly includes an umbrella-shaped liquid blocking shell, a perforated steam guide ring fixed to the upper part of the umbrella-shaped liquid blocking shell, and a central sleeve hole opened in the middle of the perforated steam guide ring. The umbrella-shaped liquid blocking shell is narrower at the top and wider at the bottom, and a liquid drainage gap is formed between the outer edge of the umbrella-shaped liquid blocking shell and the inner wall of the expansion container shell.

[0017] Preferably, a central guide sleeve is fixedly installed on the outer side of the upwardly extending section of the inverted conical heat exchange tube. An annular groove with a sliding stroke along its axial direction is opened on the outer periphery of the central guide sleeve. The perforated steam guide ring is sleeved on the outer side of the central guide sleeve through the central sleeve hole, and the inner edge of the central sleeve hole is slidably disposed in the annular groove.

[0018] Preferably, the inner wall of the expansion container shell is provided with multiple sets of vertical guide grooves, and the outer side of the umbrella-shaped liquid blocking shell is provided with an elastic guide component corresponding to the vertical guide groove. The elastic guide component includes a guide slider that is slidably disposed in the vertical guide groove, a groove opening blocking plate that blocks the opening of the vertical guide groove, a guide telescopic rod, and a return spring sleeved on the outer side of the guide telescopic rod. The groove opening blocking plate is fixedly connected to the umbrella-shaped liquid blocking shell.

[0019] Preferably, the perforated steam guide ring has multiple sets of inclined steam guide holes in the annular area outside the central sleeve hole. The multiple sets of inclined steam guide holes are arranged at intervals along the circumference of the perforated steam guide ring, and the axis of each inclined steam guide hole is inclined toward the heat exchange gap between the conical expansion heat exchange tube group and the outer expansion condenser heat exchange shell.

[0020] Preferably, each expanded condensing heat exchange shell is provided with a flow channel baffle, which divides the internal space of the expanded condensing heat exchange shell into a descending flow channel and an ascending flow channel. The lower end of the flow channel baffle and the bottom of the expanded condensing heat exchange shell form a bottom connection port that connects the descending flow channel and the ascending flow channel.

[0021] The hydraulic steam-guiding rotating assembly includes a hydraulic impeller located at the bottom connection port or the heat exchange medium turning position, a steam-guiding fan blade located on the outside of the expanded condensing heat exchange shell, and an inner magnetic component and an outer magnetic component connected to the hydraulic impeller and the steam-guiding fan blade respectively. The inner magnetic component and the outer magnetic component are located on both sides of the shell wall of the expanded condensing heat exchange shell respectively.

[0022] Preferably, the annular heat exchange manifold is fixedly connected to the expansion vessel shell through multiple sets of fixed connecting plates. Multiple outward expansion condensing heat exchange shells are arranged at intervals along the circumference of the annular heat exchange manifold. Multiple vibrating elastic elements correspond one-to-one with multiple outward expansion condensing heat exchange shells. The vibrating elastic elements are bent or corrugated, with one end connected to the umbrella-shaped liquid blocking shell and the other end connected to the lower part of the corresponding outward expansion condensing heat exchange shell.

[0023] The technical effects and advantages of this invention are as follows:

[0024] In this invention, when the device is in operation, boiler wastewater enters the expansion tank shell and undergoes expansion, pressure reduction, and steam-water separation. The liquid wastewater contacts the inverted conical heat exchange tubes and releases sensible heat. The separated flash steam passes through an axially sliding umbrella-shaped liquid-blocking assembly and enters the conical expansion condensation heat exchange area. It contacts the conical expansion heat exchange tube assembly and multiple outer expansion condensation heat exchange shells arranged circumferentially along the annular heat exchange manifold shell and condenses, releasing heat. When the heat exchange medium in the outer expansion condensation heat exchange shell flows along the folded heat exchange channel, it drives the hydraulic impeller to rotate. The hydraulic impeller drives the outer steam guide fan blades to rotate magnetically through the shell wall, continuously guiding the flash steam to each heat exchange gap and reducing airflow short-circuiting. With local stagnation, when the instantaneous flash evaporation increases, the gas phase pressure difference drives the umbrella-shaped liquid blocking component to rise and fall slightly. The umbrella-shaped liquid blocking component drives the outer expansion condensation heat exchange shell to vibrate slightly through the vibrating elastic element, causing the condensate film attached to the heat exchange surface to coalesce and fall off and flow back in time. Thus, without adding an independent electric drive mechanism, the sensible heat recovery of wastewater, flash steam diversion and condensation, airflow fluctuation buffering and condensation surface vibration dehydration are linked together, which can improve the utilization of waste heat in the gas and liquid phases, reduce the heat transfer resistance formed by the condensate film, reduce secondary entrainment of condensate and heat exchange dead zone, and improve the heat exchange stability of the device under the condition of fluctuating wastewater discharge. Attached Figure Description

[0025] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts:

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 2 ;

[0028] Figure 3 This is a schematic diagram of the external structure of the waste heat recovery device for wastewater discharge expansion according to the present invention;

[0029] Figure 4 This is a schematic diagram of the internal structure of the expansion container shell of the present invention;

[0030] Figure 5This is a schematic diagram of the assembly structure of the expansion container shell and internal components of the present invention;

[0031] Figure 6 This is a schematic diagram of the umbrella-shaped liquid-blocking assembly structure of the present invention;

[0032] Figure 7 For the present invention Figure 6 A partially enlarged structural schematic diagram of the elastic guide component in Figure A;

[0033] Figure 8 This is a schematic diagram of the assembly structure of the conical expansion condenser heat exchanger and the inverted conical heat exchange tube of the present invention;

[0034] Figure 9 This is an exploded structural diagram of the conical expansion heat exchanger tube assembly and the conical expansion condenser heat exchanger component of the present invention.

[0035] Figure 10 This is a schematic diagram of the externally expanded condenser heat exchange shell structure of the present invention;

[0036] Figure 11 This is a schematic diagram of the internal flow channel structure of the externally expanded condensing heat exchange shell of the present invention.

[0037] Legend: 1. Boiler body; 2. Waste heat recovery device for blowdown expansion; 21. Expansion tank shell; 211. Blowdown inlet pipe; 212. Waste gas outlet; 213. Arc-shaped guide shell; 214. Spiral guide plate; 215. Vertical guide groove; 22. Bottom blowdown pipe; 23. External heat exchanger; 231. Connecting pipe four; 232. Connecting pipe three; 233. Connecting pipe one; 234. Connecting pipe two; 235. Inverted conical heat exchanger tube; 236. Conical expansion heat exchanger tube assembly; 2361. Conical expansion heat exchanger branch pipe; 2362. Heat exchange medium outlet; 24. Umbrella-shaped liquid blocking assembly. Components; 241, Umbrella-shaped liquid-blocking shell; 242, Perforated steam guide ring; 243, Central sleeve hole; 244, Elastic guide assembly; 2441, Guide slider; 2442, Slot baffle; 2443, Guide telescopic rod; 2444, Return spring; 245, Central guide sleeve; 2451, Annular groove; 25, Conical expansion condensing heat exchange assembly; 251, Annular heat exchange manifold shell; 252, Fixed connecting plate; 253, Outward expansion condensing heat exchange shell; 254, Hydraulic steam guide rotating assembly; 255, Flow channel baffle; 2551, Bottom connecting port; 26, Vibrating elastic component. Detailed Implementation

[0038] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0039] See attached document Figure 1-11 As shown, this embodiment provides an energy-saving boiler blowdown expansion container steam-water separation waste heat recovery device, including a boiler body 1 and a blowdown expansion waste heat recovery device 2. The blowdown expansion waste heat recovery device 2 includes an expansion container shell 21, a bottom blowdown pipe 22, an external heat exchanger 23, an umbrella-shaped liquid blocking assembly 24, and a cone-expansion condensing heat exchange assembly 25. The blowdown end of the boiler body 1 is connected to the expansion container shell 21 through a blowdown inlet pipe 211, so that the high-temperature and high-pressure blowdown water discharged during boiler operation can enter the expansion container shell 21 to complete expansion and pressure reduction, steam-water separation, and waste heat recovery.

[0040] The external heat exchanger 23 is located on the outside of the expansion vessel shell 21. The waste heat recovery side of the external heat exchanger 23 delivers heat exchange medium to the inverted conical heat exchange tube 235 through the connecting pipe three 232, and delivers heat exchange medium to the conical expansion condensing heat exchange assembly 25 through the connecting pipe one 233. After the heat exchange medium absorbs heat, it returns to the external heat exchanger 23 through the connecting pipe two 234. The heat-using side of the external heat exchanger 23 is connected to the equipment that needs to be heated through the connecting pipe four 231. The connecting pipe four 231 has a water supply channel and a water return channel that are separated from each other. The water supply channel is used to send the heat-absorbing heat-using medium to the heat-using equipment, and the water return channel is used to send the heat-releasing heat-using medium back to the external heat exchanger 23, thus forming a complete heat-using side circulation.

[0041] The bottom of the expansion vessel shell 21 is provided with a bottom drain pipe 22, and the top of the expansion vessel shell 21 is provided with a residual gas discharge port 212. The bottom drain pipe 22 is used to discharge liquid wastewater after the waste heat recovery is completed. The residual gas discharge port 212 is used to discharge flash steam and non-condensable gases that have not been completely condensed. The residual gas discharge port 212 can be connected to a pressure regulating valve or a safety relief pipeline to prevent the internal pressure of the expansion vessel shell 21 from continuously increasing and affecting the boiler blowdown and steam-water separation process.

[0042] An arc-shaped guide shell 213 corresponding to the outlet of the sewage inlet pipe 211 is provided on the inner side of the expansion vessel shell 21. The arc-shaped guide shell 213 is arranged in a form with a wider inlet and a narrower outlet along the flow direction of the sewage. A spiral guide plate 214 is provided on the outer side of the outlet of the arc-shaped guide shell 213. After the high-temperature sewage enters through the sewage inlet pipe 211, it is first blocked and deflected by the arc-shaped guide shell 213, and then guided by the spiral guide plate 214 into a water flow that rotates and moves downward along the inner wall of the expansion vessel shell 21, thereby avoiding the high-speed sewage from directly impacting the heat exchange components inside the expansion vessel shell 21.

[0043] After the high-temperature and high-pressure wastewater enters the expansion vessel shell 21, the pressure decreases. Some of the water quickly flashes to form steam. The wastewater that does not flash and the larger droplets entrained in the steam move towards the periphery and lower part of the expansion vessel shell 21 under the action of centrifugal force, inertia and gravity. The flash steam moves towards the middle and upper part of the expansion vessel shell 21. Thus, a flow relationship is formed in the expansion vessel shell 21 where the liquid flows outward and downward and the steam flows inward and upward.

[0044] An inverted conical heat exchange tube 235 is provided at the lower end of the interior of the expansion vessel shell 21. The inverted conical heat exchange tube 235 is composed of a spirally coiled tube body and is wider at the top and narrower at the bottom. Its shape is adapted to the downward flow area of ​​the liquid wastewater, so that the high-temperature wastewater can continuously flow through the outside of the inverted conical heat exchange tube 235 when it moves around the inner wall of the expansion vessel shell 21. The connecting pipe 232 sends the heat exchange medium into the inverted conical heat exchange tube 235. The heat exchange medium flows in the tube and absorbs the sensible heat of the high-temperature wastewater through the tube wall.

[0045] The upper end of the inverted conical heat exchange tube 235 extends upward and connects to the conical expansion heat exchange tube assembly 236. The conical expansion heat exchange tube assembly 236 includes multiple conical expansion heat exchange branch tubes 2361 arranged circumferentially. The multiple conical expansion heat exchange branch tubes 2361 together form a heat exchange structure that expands outward at the upper end. The heat exchange medium outlet 2362 of the conical expansion heat exchange tube assembly 236 is connected to the external heat exchanger 23 through the connecting pipe 234, so that the heat exchange medium that has initially absorbed heat through the inverted conical heat exchange tube 235 continues to enter the conical expansion heat exchange tube assembly 236 and further absorbs the heat released when the upper flash steam condenses.

[0046] An umbrella-shaped liquid blocking assembly 24 is provided in the middle of the expansion vessel shell 21. The umbrella-shaped liquid blocking assembly 24 includes an umbrella-shaped liquid blocking shell 241, a perforated steam guide ring 242 disposed on the upper part of the umbrella-shaped liquid blocking shell 241, and a central sleeve hole 243 opened in the middle of the perforated steam guide ring 242. The umbrella-shaped liquid blocking shell 241 is tapered with a narrow upper part and a wide lower part. The inclined surface of the umbrella-shaped liquid blocking shell 241 is used to receive the liquid droplets moving upward with the flash vapor, so that the liquid droplets flow outward along the umbrella-shaped liquid blocking shell 241.

[0047] A central guide sleeve 245 is fixedly installed on the outer side of the upward-extending section of the inverted conical heat exchange tube 235. An annular groove 2451 is opened on the outer periphery of the central guide sleeve 245. The perforated steam guide ring 242 is sleeved on the outer side of the central guide sleeve 245 through the central sleeve hole 243, and the inner edge of the central sleeve hole 243 is slidably disposed in the annular groove 2451. Thus, the central sleeve hole 243 is only used to realize the sleeve, guidance and axial limit between the perforated steam guide ring 242 and the central guide sleeve 245, and does not serve as a flow channel for flash steam.

[0048] Multiple sets of inclined steam guide holes are provided on the perforated steam guide ring 242. Each inclined steam guide hole is distributed circumferentially along the perforated steam guide ring 242 and is inclined toward the outer area where the conical expansion condensing heat exchange assembly 25 is located. The flash steam that has undergone preliminary liquid removal mainly enters the gas phase area above the umbrella-shaped liquid blocking assembly 24 through the inclined steam guide holes, and diffuses toward the location of the conical expansion heat exchange tube group 236 and the outer expansion condensing heat exchange shell 253 under the guidance of the inclined steam guide holes, thereby reducing the short-circuiting phenomenon of the flash steam being discharged directly upward along the center of the expansion vessel shell 21.

[0049] A drain gap is formed between the outer edge of the umbrella-shaped liquid blocking shell 241 and the inner wall of the expansion vessel shell 21. The liquid droplets trapped by the umbrella-shaped liquid blocking shell 241 and the condensate generated by the upper heat exchange structure flow along the inclined surface of the umbrella-shaped liquid blocking shell 241 to the drain gap and fall back into the liquid phase region. This drain gap mainly undertakes the function of liquid reflux and does not serve as the main rising channel for flash vapor, thereby reducing the continuous collision and secondary entrainment of rising vapor and falling liquid in the same narrow position.

[0050] The inner wall of the expansion container shell 21 has multiple sets of vertical guide grooves 215. The outer side of the umbrella-shaped liquid blocking shell 241 is provided with an elastic guide component 244 corresponding to the vertical guide grooves 215. The elastic guide component 244 includes a guide slider 2441 slidably disposed in the vertical guide groove 215, a groove blocking plate 2442 blocking the opening of the vertical guide groove 215, a guide telescopic rod 2443, and a return spring 2444 disposed on the outer side of the guide telescopic rod 2443. The guide slider 2441 and the central guide sleeve 245 together restrict the movement direction of the umbrella-shaped liquid blocking component 24, so that the umbrella-shaped liquid blocking component 24 can move up and down slightly along the axial direction of the expansion container shell 21 without easily deflecting.

[0051] The slot baffle 2442 is fixedly connected to the umbrella-shaped liquid blocking shell 241 and moves synchronously with the umbrella-shaped liquid blocking assembly 24, so that the opening of the vertical guide groove 215 is still blocked when the umbrella-shaped liquid blocking assembly 24 moves up and down, so as to reduce the entry of liquid wastewater, scale and impurities into the vertical guide groove 215 and affect the normal sliding of the guide slider 2441. The reset spring 2444 is used to buffer the instantaneous gas impact on the umbrella-shaped liquid blocking assembly 24 and push the umbrella-shaped liquid blocking assembly 24 to reset after the pressure difference between the upper and lower parts decreases.

[0052] The total flow area of ​​each inclined steam guide hole on the perforated steam guide ring 242 is set according to the flash steam flow rate under normal boiler blowdown conditions. When the boiler blowdown volume or blowdown pressure increases for a short time, the instantaneously generated flash steam cannot immediately pass through all the inclined steam guide holes. The pressure below the umbrella-shaped liquid blocking assembly 24 increases for a short time and forms a pressure difference with the area above it. This pressure difference pushes the umbrella-shaped liquid blocking assembly 24 to move upward against the elastic force of the return spring 2444 and the vibrating elastic element 26. The inner edge of the perforated steam guide ring 242 slides upward along the annular groove 2451 in sync.

[0053] When the umbrella-shaped liquid blocking assembly 24 moves upward, it can temporarily increase the buffer space below it and absorb part of the instantaneous airflow impact. However, the area of ​​the central sleeve hole 243 and the total flow area of ​​the inclined steam guide hole do not change with the movement process. After the flash vapor gradually enters the gas phase region through the inclined steam guide hole, the pressure difference between the upper and lower sides of the umbrella-shaped liquid blocking assembly 24 decreases. The reset spring 2444 and the vibrating elastic element 26 release elastic potential energy and drive the umbrella-shaped liquid blocking assembly 24 to reset downward.

[0054] The conical expansion condensing heat exchange assembly 25 is disposed above the umbrella-shaped liquid blocking assembly 24. The conical expansion condensing heat exchange assembly 25 includes an annular heat exchange manifold 251, a fixed connecting plate 252, multiple sets of outward expansion condensing heat exchange manifolds 253, a hydraulic steam guiding rotating assembly 254, and a flow channel baffle 255. The annular heat exchange manifold 251 is fixedly connected to the expansion container shell 21 through multiple sets of fixed connecting plates 252, so that the annular heat exchange manifold 251 remains fixed during the operation of the device.

[0055] Multiple sets of outward-expanding condensing heat exchange shells 253 are arranged circumferentially along the annular heat exchange manifold 251. The upper end of the outward-expanding condensing heat exchange shell 253 is connected to the annular heat exchange manifold 251 through an elastic sealing connection section that can withstand small deformations. This allows the heat exchange medium transported by the connecting pipe 233 to be distributed from the annular heat exchange manifold 251 to each outward-expanding condensing heat exchange shell 253. At the same time, it allows the outward-expanding condensing heat exchange shell 253 to vibrate slightly relative to the fixed annular heat exchange manifold 251.

[0056] Each set of externally expanded condensing heat exchange shells 253 is equipped with a flow channel baffle 255. The flow channel baffle 255 divides the internal space of the externally expanded condensing heat exchange shell 253 into adjacent descending flow channels and ascending flow channels. A bottom connection port 2551 is reserved between the lower end of the flow channel baffle 255 and the bottom of the externally expanded condensing heat exchange shell 253. The heat exchange medium flows downward from the descending flow channel, turns through the bottom connection port 2551 and enters the ascending flow channel, and then returns to the return area of ​​the annular heat exchange collector shell 251 through the ascending flow channel, and finally flows back to the external heat exchanger 23 through the connecting pipe 234.

[0057] The flow channel baffle 255 prevents the heat exchange medium entering the expanded condenser heat exchange shell 253 from flowing directly from the inlet to the outlet. Instead, it forms a reversible flow along the descending flow channel, the bottom connecting port 2551, and the ascending flow channel, thereby extending the residence path of the heat exchange medium in the gas phase heat exchange area and enabling different positions of the expanded condenser heat exchange shell 253 to participate in heat exchange.

[0058] The hydraulic steam-guiding rotating assembly 254 includes a hydraulic impeller disposed inside the expanded condensing heat exchange shell 253, a steam-guiding fan blade disposed outside the expanded condensing heat exchange shell 253, and a magnetic drive assembly disposed between the hydraulic impeller and the steam-guiding fan blade. The hydraulic impeller is disposed at a position where the flow direction of the heat exchange medium changes or the flow velocity is high. The hydraulic impeller is connected to the inner magnetic component of the magnetic drive assembly, and the steam-guiding fan blade is connected to the outer magnetic component of the magnetic drive assembly. The inner and outer magnetic components are sealed and separated by the non-magnetic shell wall of the expanded condensing heat exchange shell 253 itself.

[0059] When the heat exchange medium enters the rising channel from the descending channel through the bottom connecting port 2551, it impacts the hydraulic impeller and drives it to rotate. The hydraulic impeller drives the outer steam guide fan blades to rotate synchronously through the magnetic drive assembly. Since the magnetic drive assembly does not need to be equipped with a rotating shaft and shaft hole that penetrates the outer condenser heat exchange shell 253, it can reduce the possibility of heat exchange medium leakage from the rotating connection position and reduce the impact of shaft seal wear on the operational stability of the device under high temperature environment.

[0060] After the steam guide fan blades rotate, they radially guide the flash steam in the gas phase region, causing the flash steam that enters the gas phase region through the inclined steam guide holes to flow towards the heat exchange gap between the conical expansion heat exchange tube group 236 and each external expansion condensation heat exchange shell 253, increasing the contact opportunity between the flash steam and the heat exchange surface and reducing the occurrence of stagnant dead zones around the gas phase region.

[0061] After the flash steam has a low contact temperature, it condenses and releases heat in the conical expansion heat exchange tube group 236 and the external expansion condensing heat exchange shell 253. The heat exchange medium in the conical expansion heat exchange tube group 236 absorbs the sensible heat from the liquid phase region and the condensation heat from the gas phase region. The heat exchange medium in the external expansion condensing heat exchange shell 253 mainly absorbs the heat released during the condensation of the flash steam. The two heat exchange media return to the external heat exchanger 23 through the second connecting pipe 234, and then transfer the recovered heat to the heat-using equipment connected to the fourth connecting pipe 231.

[0062] The vapor phase condensation heat and liquid phase sensible heat vary with the boiler blowdown pressure, blowdown volume, flash evaporation ratio, and blowdown temperature. The two heat exchange branches recover waste heat from their respective areas. The actual magnitude of the vapor phase condensation heat and liquid phase sensible heat is related to the boiler blowdown pressure, blowdown volume, flash evaporation ratio, liquid blowdown temperature, and the flow rate of the heat exchange medium in the two heat exchange branches. The flow rates in connecting pipe 232 and connecting pipe 233 can be distributed according to the liquid phase temperature and vapor phase pressure to adapt the liquid phase sensible heat recovery capacity and vapor phase condensation heat recovery capacity to the actual operating conditions.

[0063] A vibrating elastic element 26 is connected between the umbrella-shaped liquid blocking shell 241 and multiple sets of outward expansion condensing heat exchange shells 253. One end of the vibrating elastic element 26 is connected to the umbrella-shaped liquid blocking shell 241, and the other end is connected to the lower part of the corresponding outward expansion condensing heat exchange shell 253. The vibrating elastic element 26 adopts a bending or corrugated structure that can produce elastic bending and rebound, so that when the umbrella-shaped liquid blocking assembly 24 moves up and down, it can apply a slight reciprocating vibration to the outward expansion condensing heat exchange shell 253.

[0064] When the instantaneous flash evaporation increases and pushes the umbrella-shaped liquid blocking assembly 24 upward, the vibrating elastic element 26 is bent or compressed under force and stores elastic potential energy. At the same time, it causes the outward expansion condensing heat exchange shell 253 to vibrate slightly relative to the fixed annular heat exchange manifold 251. When the gas phase pressure recovers and the umbrella-shaped liquid blocking assembly 24 returns to its downward position, the vibrating elastic element 26 rebounds and causes the outward expansion condensing heat exchange shell 253 to vibrate again. Therefore, the conical expansion condensing heat exchange assembly 25 does not vibrate as a whole, and the fixed connecting plate 252 and the annular heat exchange manifold 251 remain fixed.

[0065] Slight vibration of the externally expanded condenser heat exchange shell 253 can cause the condensate film attached to its outer surface to fluctuate and gradually coalesce into larger droplets. Under the action of gravity and vibration inertia, the droplets detach from the heat exchange surface and fall onto the umbrella-shaped liquid blocking shell 241, and then return to the liquid phase region through the drain gap, thereby reducing the situation where a thick condensate film covers the heat exchange surface for a long time, which would increase the heat transfer resistance.

[0066] The up-and-down movement of the umbrella-shaped liquid blocking assembly 24 can also buffer the direct impact of instantaneous flash steam on the upper heat exchange structure. The vibration of the umbrella-shaped liquid blocking shell 241 itself can promote the flow of liquid on its surface to the outer drainage gap. The vibration of the outward expansion condensation heat exchange shell 253 can renew the gas phase boundary layer near the heat exchange surface and reduce the long-term adhesion of salt, scale and impurities. At the same time, the condensate that falls off quickly is not easily rolled up again by the rotating steam guide fan blades, thereby reducing the impact of secondary entrainment of condensate on the steam-water separation effect.

[0067] When the device is running continuously, the boiler wastewater forms a rotating flow under the action of the arc-shaped flow guide shell 213 and the spiral flow guide plate 214 and completes the initial steam-water separation. The liquid wastewater exchanges heat with the inverted conical heat exchange tube 235 in the liquid phase region. After the flash steam is deliquescent by the umbrella-shaped liquid blocking shell 241, it enters the gas phase region through the inclined steam guide hole on the perforated steam guide ring 242 and exchanges heat with the conical expansion heat exchange tube group 236 and the outward expansion condensing heat exchange shell 253. The flow of the heat exchange medium simultaneously drives the hydraulic steam guide rotating component 254 to guide the flow of flash steam. The instantaneous change in gas phase pressure pushes the umbrella-shaped liquid blocking component 24 to rise and fall and promotes the condensate to fall off through the vibrating elastic element 26. Thus, a linkage working relationship is formed between steam-water separation, gas-liquid dual-path waste heat recovery, flash steam guidance and condensate removal.

[0068] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. An energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device, characterized in that, The system includes a boiler body, an expansion tank shell, an external heat exchanger, an umbrella-shaped liquid-blocking assembly, and a conical expansion condensing heat exchanger assembly. The blowdown end of the boiler body is connected to the expansion tank shell. An inverted conical heat exchange tube is installed inside the expansion tank shell. The waste heat recovery side of the external heat exchanger is connected to both the inverted conical heat exchange tube and the conical expansion condensing heat exchanger assembly. The inverted conical heat exchange tube is connected to the conical expansion heat exchange tube assembly, and the conical expansion heat exchange tube assembly is connected to the external heat exchanger. The umbrella-shaped liquid blocking assembly is disposed between the inverted conical heat exchange tube and the conical expansion condenser heat exchange assembly and slides along the axial direction of the expansion vessel shell. The umbrella-shaped liquid blocking assembly has a perforated steam guide ring. The conical expansion condensing heat exchange assembly includes an annular heat exchange collector shell fixed inside the expansion vessel shell and a plurality of outward expansion condensing heat exchange shells arranged circumferentially along the annular heat exchange collector shell. The outward expansion condensing heat exchange shells are connected to the annular heat exchange collector shell through an elastic sealing connection section. The outward expansion condensing heat exchange shells are provided with a folded-back heat exchange channel and a hydraulic steam guide rotating assembly driven by the heat exchange medium in the folded-back heat exchange channel. The hydraulic steam guide rotating assembly includes a hydraulic blade and a steam guide fan blade located outside the outward expansion condensing heat exchange shell. The hydraulic blade and the steam guide fan blade are magnetically driven through the outward expansion condensing heat exchange shell. A vibrating elastic element connects the umbrella-shaped liquid-blocking assembly to the externally expanded condensing heat exchange shell.

2. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 1, characterized in that, A sewage inlet pipe is provided on one side of the expansion container shell, which is connected to the sewage discharge end of the boiler body. An arc-shaped guide shell is provided inside the expansion container shell, which corresponds to the outlet of the sewage inlet pipe. The arc-shaped guide shell is wide at the inlet and narrow at the outlet along the flow direction of the sewage. A spiral guide plate is provided on the outer side of the outlet of the arc-shaped guide shell.

3. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 2, characterized in that, The bottom of the expansion container shell is provided with a bottom drain pipe, and the expansion container shell is provided with a residual gas discharge port located above the cone-expansion condensing heat exchange assembly.

4. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 1, characterized in that, The waste heat recovery side of the external heat exchanger is connected to the inlet of the inverted conical heat exchange tube through connecting pipe three, and is connected to the liquid supply area of ​​the annular heat exchange manifold through connecting pipe one. The heat exchange medium outlet of the conical heat exchange tube group and the return flow area of ​​the annular heat exchange manifold are both connected to the waste heat recovery side of the external heat exchanger through connecting pipe two.

5. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 4, characterized in that, The heat-using side of the external heat exchanger is connected to the heat-using equipment through a connecting pipe four. The connecting pipe four is provided with a water supply channel and a water return channel that are separated from each other. The water supply channel connects the outlet of the heat-using side of the external heat exchanger with the inlet of the heat-using equipment, and the water return channel connects the outlet of the heat-using equipment with the inlet of the heat-using side of the external heat exchanger.

6. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 4, characterized in that, The inverted conical heat exchange tube is composed of a spiral coil that is wider at the top and narrower at the bottom. The upper end of the inverted conical heat exchange tube is connected to the lower end of the conical expansion heat exchange tube assembly through an upwardly extending tube section. The conical expansion heat exchange tube assembly includes multiple conical expansion heat exchange branch pipes arranged at intervals along the circumference. The multiple conical expansion heat exchange branch pipes are arranged to expand outward from bottom to top and are connected to the heat exchange medium outlet.

7. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 1, characterized in that, The umbrella-shaped liquid blocking assembly includes an umbrella-shaped liquid blocking shell, a perforated steam guide ring fixed to the upper part of the umbrella-shaped liquid blocking shell, and a central sleeve hole opened in the middle of the perforated steam guide ring. The umbrella-shaped liquid blocking shell is narrower at the top and wider at the bottom, and a liquid drainage gap is formed between the outer edge of the umbrella-shaped liquid blocking shell and the inner wall of the expansion container shell.

8. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 7, characterized in that, The upper end of the inverted conical heat exchange tube is provided with an upwardly extending tube section. A central guide sleeve is fixedly provided on the outer side of the tube section. An annular groove with a sliding stroke along its axial direction is opened on the outer periphery of the central guide sleeve. The perforated steam guide ring is sleeved on the outer side of the central guide sleeve through the central sleeve hole. The inner edge of the central sleeve hole is slidably disposed in the annular groove.

9. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 8, characterized in that, The inner wall of the expansion container shell has multiple sets of vertical guide grooves. The outer side of the umbrella-shaped liquid-blocking shell is provided with an elastic guide component corresponding to the vertical guide groove. The elastic guide component includes a guide slider that is slidably disposed in the vertical guide groove, a groove opening blocking plate that blocks the opening of the vertical guide groove, a guide telescopic rod, and a return spring sleeved on the outer side of the guide telescopic rod. The groove opening blocking plate is fixedly connected to the umbrella-shaped liquid-blocking shell.

10. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 8, characterized in that, The perforated steam guide ring has multiple sets of inclined steam guide holes in the annular area outside the central sleeve hole. The multiple sets of inclined steam guide holes are arranged at intervals along the circumference of the perforated steam guide ring, and the axis of each inclined steam guide hole is inclined toward the heat exchange gap between the conical expansion heat exchange tube group and the outer expansion condensation heat exchange shell.

11. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 7, characterized in that, Each of the externally expanded condensing heat exchange shells is provided with a flow channel baffle, which divides the internal space of the externally expanded condensing heat exchange shell into a descending flow channel and an ascending flow channel. The lower end of the flow channel baffle and the bottom of the externally expanded condensing heat exchange shell form a bottom connection port that connects the descending flow channel and the ascending flow channel. The hydraulic steam-guiding rotating assembly includes a hydraulic impeller, which is rotatably disposed within the descending flow channel and the ascending flow channel, and located on the path through which the heat exchange medium flows; it also includes a steam-guiding fan blade disposed on the outside of the expanded condensing heat exchange shell, and an inner magnetic component and an outer magnetic component respectively connected to the hydraulic impeller and the steam-guiding fan blade, the inner magnetic component and the outer magnetic component being located on both sides of the shell wall of the expanded condensing heat exchange shell.

12. The energy-saving boiler blowdown expansion tank steam-water separation waste heat recovery device according to claim 11, characterized in that, The annular heat exchange manifold is fixedly connected to the expansion vessel shell through multiple sets of fixed connecting plates. Multiple external expansion condensation heat exchange shells are arranged at intervals along the circumference of the annular heat exchange manifold. Multiple vibrating elastic elements correspond one-to-one with multiple external expansion condensation heat exchange shells. The vibrating elastic elements are bent or corrugated, with one end connected to the umbrella-shaped liquid blocking shell and the other end connected to the lower part of the corresponding external expansion condensation heat exchange shell.

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