Vacuum hot plate type low-temperature economizer

Abstract

This invention belongs to the field of heat exchange technology, and particularly relates to a vacuum hot plate type low-temperature economizer, comprising: a support frame; a plurality of vacuum heat exchange plates arranged in an array within the support frame; a first turbulence mechanism fixedly mounted on the side wall of the vacuum heat exchange plate parallel to the flue gas flow direction; heat exchange tubes fixedly mounted on the top of the vacuum heat exchange plate, with the inlet end of the heat exchange tubes fixedly connected to the top wall of the vacuum heat exchange plate, the outlet end of the heat exchange tubes located inside the vacuum heat exchange plate and close to the inner bottom wall of the vacuum heat exchange plate, and the outlet end of the heat exchange tubes located below the liquid surface of the heat exchange working fluid; and a heat exchange condensation mechanism fixedly sleeved on the outside of the heat exchange tubes, located above the insulation mechanism. This invention achieves efficient and stable recovery of flue gas waste heat through the synergistic effect of the vacuum heat exchange plate and the phase change working fluid, combined with the optimization of flue gas flow by the turbulence structure. It has advantages such as compact structure, strong heat exchange capacity, and reliable operation.

Description

Technical Field

[0001] This invention belongs to the field of heat exchange technology, and particularly relates to a vacuum hot plate type low-temperature economizer. Background Technology

[0002] Coal-fired power generation systems often generate a large amount of waste heat during the production process. If this heat energy is not properly recovered and utilized, it will lead to energy waste and a decrease in the efficiency of energy utilization.

[0003] Waste heat recovery technology can reduce coal consumption by recovering heat from flue gas, converting this waste heat energy into electricity, reducing energy waste, and simultaneously lowering pollutant emissions and alleviating environmental pressure. Developing waste heat recovery technologies to reduce operating costs, improve economic efficiency, and promote efficient, clean, and sustainable power production is a key approach that aligns with the current development theme of the energy industry.

[0004] Traditional finned tube flue gas heat exchangers face the wind directly, with the heat exchange tubes bearing the intense scouring and abrasion of flue gas dust particles. Furthermore, due to the high fin packing density and the often staggered arrangement of the tubes, there are numerous ash accumulation points and flow dead zones between the heat exchange tubes. This results in poor resistance to ash accumulation and blockage, making the heat exchanger prone to problems such as blockage, increased resistance, tube wall corrosion, and rupture and leakage. Consequently, it poses significant safety hazards and has a relatively short overall service life.

[0005] Therefore, a vacuum hot plate type low-temperature economizer needs to be designed to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a vacuum hot plate type low-temperature economizer to solve the above-mentioned problems.

[0007] To achieve the above objectives, the present invention provides the following solution: a vacuum hot plate type low-temperature economizer, comprising: a support frame; a plurality of vacuum heat exchange plates arranged in an array within the support frame, with gaps between adjacent vacuum heat exchange plates, the vacuum heat exchange plates being filled with a heat exchange medium; a first turbulence mechanism fixedly disposed on the side wall of the vacuum heat exchange plate parallel to the flue gas flow direction, the first turbulence mechanism being in communication with the interior of the vacuum heat exchange plate; a flow guiding mechanism fixedly disposed at the end of the vacuum heat exchange plate facing the flue gas flow; a heat insulation mechanism fixedly disposed at the top of the support frame; a heat exchange tube fixedly disposed at the top of the vacuum heat exchange plate, the inlet end of the heat exchange tube being fixedly connected to the top wall of the vacuum heat exchange plate, the outlet end of the heat exchange tube being located inside the vacuum heat exchange plate and close to the inner bottom wall of the vacuum heat exchange plate, the outlet end of the heat exchange tube being located below the liquid surface of the heat exchange medium; and a heat exchange condensation mechanism fixedly sleeved on the outside of the heat exchange tube, the heat exchange condensation mechanism being located above the heat insulation mechanism.

[0008] According to the present invention, a vacuum hot plate type low-temperature economizer includes a first turbulence mechanism comprising two end turbulence portions and a middle turbulence portion. The two end turbulence portions are respectively located at both ends of the side wall of the vacuum heat exchange plate parallel to the flue gas flow direction, and the middle turbulence portion is located in the middle of the side wall of the vacuum heat exchange plate parallel to the flue gas flow direction.

[0009] According to the present invention, a vacuum hot plate type low temperature economizer includes an end turbulence section comprising a plurality of end turbulence shells, wherein the plurality of end turbulence shells are fixedly connected to the two ends of the side wall of the vacuum heat exchange plate parallel to the flue gas flow direction, and the end turbulence shells are in communication with the interior of the vacuum heat exchange plate.

[0010] According to the present invention, a vacuum hot plate type low-temperature economizer includes an intermediate turbulence section comprising a plurality of intermediate turbulence shells, wherein the plurality of intermediate turbulence shells are fixedly connected to the middle part of the side wall of the vacuum heat exchange plate parallel to the flue gas flow direction, and the intermediate turbulence shells are in communication with the interior of the vacuum heat exchange plate.

[0011] According to the present invention, a vacuum hot plate type low temperature economizer is provided, wherein the end turbulence shell and the middle turbulence shell are both inclined, the inclined low ends of the end turbulence shell and the inclined low ends of the middle turbulence shell are both facing the flue gas flow direction, and the inclination angle of the middle turbulence shell is greater than the inclination angle of the end turbulence shell.

[0012] According to the present invention, a vacuum hot plate type low-temperature economizer includes a heat exchange tube comprising a first vertical section, the bottom end of which is fixedly connected to the top wall of the vacuum heat exchange plate, the top end of which is fixedly connected to one end of a bent pipe section, the other end of which is fixedly connected to the top end of a second vertical section, the bottom end of which is located inside the vacuum heat exchange plate and close to the inner bottom wall of the vacuum heat exchange plate, the bottom end of which is located below the liquid surface of the heat exchange working fluid, and the heat exchange condensation mechanism is fixedly sleeved on the outside of the top end of the second vertical section.

[0013] According to the present invention, a vacuum hot plate type low temperature economizer is provided with a plurality of disturbance flow cavities at the top of the side wall of the second vertical section. The disturbance flow cavities are arranged in an array along the circumference and axial direction of the second vertical section, and the disturbance flow cavities are located within the heat exchange and condensation mechanism.

[0014] According to the present invention, a vacuum hot plate type low temperature economizer includes a heat exchange condensation mechanism comprising a plurality of heat exchange chambers. The heat exchange chambers are fixedly sleeved on the outer side of the top end of the second vertical section. Two adjacent heat exchange chambers are fixedly connected by a plurality of connecting pipes. The bottom end of the heat exchange chamber located on the outer side is fixedly connected to a water inlet pipe, and the top end of the heat exchange chamber located on the other outer side is fixedly connected to a water outlet pipe.

[0015] According to the present invention, a vacuum hot plate type low temperature economizer includes a flow guiding mechanism comprising a flow guiding platform with a triangular horizontal cross-section. The planar end of the flow guiding platform is fixedly connected to the end of the vacuum heat exchange plate near the flue gas inflow direction, and the tip of the flow guiding platform faces the flue gas inflow direction.

[0016] According to the present invention, a vacuum hot plate type low temperature economizer includes a support frame including a fixed plate, the bottom end of the vacuum heat exchange plate being fixedly connected to the top end of the fixed plate, a plurality of support plates being fixedly connected to the side wall of the fixed plate, the support plates being vertically arranged, and the heat insulation mechanism being fixedly connected to the top end of the support plates.

[0017] Compared with existing technologies, this invention has the following advantages and technical effects: By employing a vacuum heat exchange plate with an internally displacing heat exchange medium, this invention enables efficient heat exchange with high-temperature flue gas. When high-temperature flue gas flows through the vacuum heat exchange plate, the working medium inside the plate absorbs heat from the flue gas and undergoes a phase change, transforming from a liquid to a gaseous state, and then enters the connected heat exchange tubes. The gaseous working medium then flows to the heat exchange condensation mechanism, where it releases the heat it carries, achieving effective heat transfer. As heat is released, the working medium temperature decreases and undergoes another phase change, condensing into a liquid state, and finally flowing back into the vacuum heat exchange plate, thus forming a continuous, automatically circulating closed-loop heat exchange process.

[0018] To further enhance the heat exchange effect, this invention incorporates a first turbulence mechanism on the vacuum heat exchange plate. This mechanism turbulently flows the incoming high-temperature flue gas, breaking its laminar flow, increasing its turbulence, prolonging its residence time within the heat exchange area, and promoting heat exchange between the flue gas and the wall of the vacuum heat exchange plate. This design not only improves the overall system's heat exchange efficiency but also effectively enhances energy recovery and utilization, enabling the equipment to exhibit superior thermal performance during high-temperature flue gas waste heat recovery.

[0019] In summary, this invention achieves efficient and stable recovery of waste heat from flue gas by combining the synergistic effect of the vacuum heat exchange plate and the phase change working fluid with the optimization of flue gas flow through the turbulence structure. It has the advantages of compact structure, strong heat exchange capacity and reliable operation. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the entire invention. Figure 1 .

[0022] Figure 2 This is a schematic diagram of the entire invention. Figure 2 .

[0023] Figure 3 This is a cross-sectional view of the vacuum heat exchange plate of the present invention.

[0024] Among them, 1. fixed plate; 2. support plate; 3. heat insulation plate; 4. vacuum heat exchange plate; 5. end turbulence shell; 6. middle turbulence shell; 7. guide platform; 8. heat exchange tube; 9. heat exchange cavity; 10. water inlet pipe; 11. connecting pipe; 12. water outlet pipe; 13. turbulence cavity. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Reference Figures 1 to 3 As shown, the present invention provides a vacuum hot plate type low-temperature economizer, comprising: a support frame; a plurality of vacuum heat exchange plates 4 arranged in an array within the support frame, with gaps between adjacent vacuum heat exchange plates 4, and the vacuum heat exchange plates 4 filled with a heat exchange medium; a first turbulence mechanism fixedly disposed on the side wall of the vacuum heat exchange plate 4 parallel to the flue gas flow direction, and communicating with the interior of the vacuum heat exchange plate 4; a flow guiding mechanism fixedly disposed at the end of the vacuum heat exchange plate 4 facing the flue gas flow; a heat insulation mechanism fixedly disposed at the top of the support frame; a heat exchange tube 8 fixedly disposed at the top of the vacuum heat exchange plate 4, with the inlet end of the heat exchange tube 8 fixedly communicating with the top wall of the vacuum heat exchange plate 4, the outlet end of the heat exchange tube 8 located inside the vacuum heat exchange plate 4 and close to the inner bottom wall of the vacuum heat exchange plate 4, and the outlet end of the heat exchange tube 8 located below the liquid surface of the heat exchange medium; and a heat exchange condensation mechanism fixedly sleeved on the outside of the heat exchange tube 8, located above the heat insulation mechanism.

[0028] Furthermore, the first turbulence mechanism includes two end turbulence sections and one middle turbulence section. The two end turbulence sections are located at the two ends of the side wall of the vacuum heat exchange plate 4 parallel to the flue gas flow direction, respectively, and the middle turbulence section is located in the middle of the side wall of the vacuum heat exchange plate 4 parallel to the flue gas flow direction.

[0029] Furthermore, the end turbulence section includes several end turbulence shells 5, which are fixedly connected to the two ends of the side wall of the vacuum heat exchange plate 4 that are parallel to the flue gas flow direction, and the end turbulence shells 5 are internally connected to the vacuum heat exchange plate 4.

[0030] Furthermore, the intermediate turbulence section includes several intermediate turbulence shells 6, which are fixedly connected to the middle of the side wall of the vacuum heat exchange plate 4 parallel to the flue gas flow direction, and the intermediate turbulence shells 6 are internally connected to the vacuum heat exchange plate 4.

[0031] Furthermore, both the end spoiler shell 5 and the middle spoiler shell 6 are inclined, with the lower inclined ends of the end spoiler shell 5 and the middle spoiler shell 6 facing the flue gas flow direction, and the inclination angle of the middle spoiler shell 6 being greater than that of the end spoiler shell 5.

[0032] The end-stage turbulence section occupies 15%-20% of the inlet length of the vacuum heat exchange plate 4. The inclination angle of the end-stage turbulence shell 5 can be selected from 20° to 30°, forming low-angle, sparse "guide corrugations." This layout has the effects of uniform gas supply and scour control. Uniform gas supply is manifested in the low-angle, sparse corrugations providing a low-resistance flow path for high-speed steam, allowing it to be quickly and evenly distributed across the entire width of the plate, avoiding flow dead zones or short circuits. Scour control is manifested in the gentle corrugated structure avoiding the generation of excessive turbulence at the inlet.

[0033] The intermediate turbulence section accounts for 60%-70% of the intermediate length of the vacuum heat exchange plate 4. The tilt angle of the intermediate turbulence shell 6 can be selected from 60° to 70°, forming a high-angle, dense "guide ripple", which has the effect of maximizing the heat transfer coefficient and enhancing the surface area.

[0034] Furthermore, the heat exchange tube 8 includes a first vertical section, the bottom end of which is fixedly connected to the top wall of the vacuum heat exchange plate 4, the top end of which is fixedly connected to one end of a bent tube section, the other end of which is fixedly connected to the top end of a second vertical section, the bottom end of which is located inside the vacuum heat exchange plate 4 and close to the inner bottom wall of the vacuum heat exchange plate 4, the bottom end of which is located below the liquid surface of the heat exchange working fluid, and the heat exchange condensation mechanism is fixedly sleeved outside the top end of the second vertical section.

[0035] Furthermore, a disturbance flow cavity 13 is provided at the top of the side wall of the second vertical section. The disturbance flow cavity 13 is arranged in an array along the circumference and axial direction of the second vertical section, and the disturbance flow cavity 13 is located inside the heat exchange and condensation mechanism.

[0036] After the heat transfer medium that transforms into vapor enters the second vertical section through the bend section from the first vertical section, it gradually condenses and the flow rate decreases, causing the condensate film on the inner wall of the second vertical section to thicken and become the main thermal resistance. Therefore, a turbulent flow cavity 13 is designed at the top of the second vertical section. The turbulent flow cavity 13 can generate rotation and eddies in the condensed fluid, effectively destroying the condensate film and increasing the heat transfer coefficient of the heat transfer medium to near the limit level.

[0037] Furthermore, the heat exchange and condensation mechanism includes several heat exchange chambers 9, which are fixedly sleeved on the outer side of the top end of the second vertical section. Two adjacent heat exchange chambers 9 are fixedly connected by several connecting pipes 11. The bottom end of the outer heat exchange chamber 9 is fixedly connected to a water inlet pipe 10, and the top end of the other outer heat exchange chamber 9 is fixedly connected to a water outlet pipe 12.

[0038] The array of heat exchange tubes 8 along the direction of flue gas flow is a transverse array, and the array of heat exchange tubes 8 perpendicular to the direction of flue gas flow is a longitudinal array. The heat exchange chamber 9 is fixedly sleeved on the outside of the heat exchange tubes 8 in the longitudinal array.

[0039] The heat exchange medium is stored in the vacuum heat exchange plate 4 in liquid form. After exchanging heat with the flue gas, it changes from liquid to gas and enters the first vertical section of the heat exchange tube 8. Then, it enters the second vertical section through the bend section and exchanges heat with the condensate flowing into the heat exchange chamber 9, changing back to liquid. It then flows back into the vacuum heat exchange plate 4. The bottom of the second vertical section is below the liquid surface of the heat exchange medium, which prevents the gaseous heat exchange medium from entering the second vertical section and ensures that the gaseous medium completely enters the first vertical section.

[0040] Furthermore, the flow guiding mechanism includes a flow guiding platform 7, the horizontal cross-section of which is triangular. The planar end of the flow guiding platform 7 is fixedly connected to the end of the vacuum heat exchange plate 4 near the flue gas inflow direction, and the tip of the flow guiding platform 7 faces the flue gas inflow direction.

[0041] The guide platform 7 guides the flue gas to ensure that it enters the gap between the vacuum heat exchange plates 4.

[0042] Furthermore, the support frame includes a fixed plate 1, the bottom end of the vacuum heat exchange plate 4 is fixedly connected to the top end of the fixed plate 1, and several support plates 2 are fixedly connected to the side wall of the fixed plate 1. The support plates 2 are vertically arranged, and the heat insulation mechanism is fixedly connected to the top end of the support plate 2.

[0043] The heat insulation mechanism includes a heat insulation plate 3. On the one hand, the heat insulation plate 3 ensures that the heat exchange process between the flue gas and the heat exchange medium takes place in the vacuum heat exchange plate 4. On the other hand, it can prevent condensate from dripping onto the surface of the vacuum heat exchange plate 4 and causing corrosion if leakage occurs in the heat exchange cavity 9.

[0044] The specific working process of this invention is as follows: This invention is mainly used to reduce the temperature of flue gas emitted from industrial boilers or kilns, recover heat, and improve the overall thermal efficiency of the system. Its core innovation lies in using a vacuum heat exchange plate array internally filled with a phase change working fluid as the main heat exchange element. Combined with a unique turbulence, flow guidance, and condensation structure, it achieves efficient and uniform heat exchange between the flue gas side and the working fluid side, and effectively solves problems such as condensation corrosion, flow dead zones, and thermal resistance.

[0045] The equipment mainly consists of a support frame, a vacuum heat exchange plate array, a first turbulence mechanism, a flow guiding mechanism, a heat insulation mechanism, and a condensation and reflux system composed of heat exchange tubes and a heat exchange condensation mechanism. Its basic working process is as follows: low-temperature flue gas flows through the gaps between the vacuum heat exchange plates, exchanging heat with the working fluid inside the plates; the working fluid absorbs heat and evaporates; the generated steam rises into the heat exchange tubes and is condensed into liquid by the cooling medium in the heat exchange condensation mechanism; the condensate flows back to the bottom of the vacuum heat exchange plates by gravity, completing a closed loop. The entire process utilizes the latent heat of phase change of the working fluid for efficient heat transfer.

[0046] The flue gas enters the economizer area under the action of the induced draft fan. It first encounters a flow guiding mechanism fixed to the flue gas-facing end of the vacuum heat exchange plates. This mechanism consists of a flow guide platform with a horizontal triangular cross-section. Its tip faces the flue gas, smoothly "splitting" the incoming flow and guiding it to the gap inlet between each vacuum heat exchange plate. This design avoids the flue gas directly impacting the plate ends, preventing eddies and increased resistance, and ensures that the flue gas can enter each flow channel uniformly, laying the foundation for subsequent uniform heat exchange. The triangular structure of the flow guide platform effectively reduces inlet resistance and prevents flow separation of the flue gas at the inlet.

[0047] After entering the narrow flow channel formed by adjacent vacuum heat exchange plates, the flue gas undergoes convective heat exchange with the outer wall of the vacuum heat exchange plates. The interior of the vacuum heat exchange plates is evacuated and filled with a low-boiling-point heat exchange working fluid. When the flue gas flows through the plate wall, heat is transferred to the working fluid through the plate wall, causing the liquid working fluid at the bottom of the plate to boil and generate steam. Because the interior of the plate is a vacuum environment, the boiling point of the working fluid is significantly reduced, and it can undergo a violent phase change and evaporate even at relatively low flue gas temperatures, absorbing a large amount of latent heat of vaporization. This makes the heat exchange efficiency much higher than that of conventional indirect heat exchangers.

[0048] In this process, the first turbulence mechanism fixed to the side wall of the vacuum heat exchange plate plays a crucial role. This mechanism is not a simple rib, but a carefully designed functional structure that communicates with the inside of the plate, consisting of an end turbulence section and a middle turbulence section.

[0049] End-section turbulence: Located near the inlet of the flow channel, occupying 15%-20% of the plate length, it consists of end-section turbulence shells with a small inclination angle (20°-30°). Its main function is "guidance" rather than "strong disturbance". The low-angle, sparse arrangement provides a low-resistance flow channel for the high-speed steam evaporating from inside the plate, promoting the rapid and uniform distribution of steam across the entire width of the plate, avoiding localized overheating or heat transfer dead zones caused by concentrated steam rising in one area. At the same time, the gentle corrugated structure provides moderate disturbance to the flue gas flow, enhancing heat transfer in the inlet section while avoiding excessive turbulence and pressure drop, achieving "uniform gas supply" and "controlled scouring" of the plate inlet section.

[0050] The intermediate turbulence section occupies the main part of the plate length (60%-70%) and is composed of relatively dense intermediate turbulence shells with a large tilt angle (60°-70°). This area is the heat transfer enhancement zone. The high-angle, dense corrugations significantly increase the heat transfer area and generate strong turbulence in the flue gas flow, disrupting the laminar sublayer of the flue gas and greatly enhancing the convective heat transfer coefficient on the flue gas side. At the same time, the interior of these turbulence shells is also connected to the steam chamber inside the plate, which helps the smooth flow of steam and further promotes the uniformity of plate wall temperature. The gradient design of the intermediate and end turbulence sections achieves a smooth transition from uniform guidance at the inlet to enhanced heat transfer in the main body, making the entire heat transfer process efficient and with controllable resistance.

[0051] The steam generated within the vacuum heat exchange plate, due to its decreased density, naturally rises and collects in the steam space at the top of the plate. The inlet of the first vertical section of the heat exchange tube is located at the top of this steam space. Under the influence of the pressure difference, the steam enters the first vertical section, then flows through the bend section, turns downward, and enters the second vertical section.

[0052] The heat exchange and condensation mechanism is crucial for the working fluid circulation. This mechanism consists of multiple heat exchange chambers mounted at the top of the second vertical section. Adjacent heat exchange chambers are connected in series via connecting pipes. The external cooling medium enters from the inlet pipe on one side, flows through all heat exchange chambers, and exits from the outlet pipe on the other side. When high-temperature steam flows downwards within the second vertical pipe, its heat is transferred through the pipe wall to the cooling water flowing counter-currently or cross-currently within the heat exchange chambers. The steam, releasing heat, begins to condense into a liquid film that adheres to the inner wall of the pipe. As condensation progresses, the liquid film gradually thickens. Due to its much lower thermal conductivity than the metal pipe wall, this film forms the main thermal resistance.

[0053] To overcome this thermal resistance, turbulence cavities are arranged in a circumferential and axial array on the top sidewall of the second vertical section. When the vapor-liquid two-phase flow passes through these raised cavity structures, the flow state is strongly disturbed, generating rotation and eddies. This disturbance effectively tears apart and thins the condensate film adhering to the pipe wall, significantly reducing the condensation thermal resistance and raising the heat transfer coefficient on the condensation side to near its limit, ensuring the high efficiency of the condensation process. The fully condensed liquid working fluid continues to flow downward along the second vertical section.

[0054] The bottom outlet of the second vertical section extends below the liquid working fluid level at the bottom of the vacuum heat exchange plate. This "liquid seal" design is crucial: firstly, it ensures that the condensate flows smoothly back to the storage area by gravity to participate in the next evaporation cycle; secondly, and more importantly, it effectively prevents uncondensed steam in the vacuum heat exchange plate from directly entering the second vertical section, forcing all generated steam to rise through the first vertical section and undergo a complete condensation process, ensuring the integrity of the phase change cycle and heat exchange efficiency. The heat released during condensation is ultimately carried away by the cooling water in the heat exchange chamber, achieving heat recovery from the flue gas.

[0055] The support frame provides robust mechanical support for the entire equipment. The insulation mechanism is fixed to the top of the support frame, located between the vacuum heat exchanger plate array and the upper heat exchange condensation mechanism. It serves a dual protection function: firstly, it reduces radial heat loss between the high-temperature flue gas area and the upper condensation mechanism, ensuring that heat exchange primarily occurs along the designed heat exchange path; secondly, it provides a crucial safety barrier for the lower vacuum heat exchanger plates. In the event of a leak in the upper heat exchange chamber or connecting pipes, condensate will drip onto the insulation plate, rather than directly onto the relatively cooler vacuum heat exchanger plate wall, thus avoiding potential corrosion or stress damage caused by localized rapid cooling.

[0056] This invention achieves efficient, safe, and reliable recovery of waste heat from low-temperature flue gas through the principles of vacuum phase change, a gradient-designed turbulence mechanism, efficient condensate film disruption technology, and a rational system layout. Its working process is a continuous, closed, and self-driven phase change cycle: working fluid inside the flue gas heating plate → working fluid evaporation → steam rising and condensing → condensate recirculation. Each component is meticulously designed and optimized, working collaboratively to ensure the equipment's excellent performance in enhancing heat transfer, reducing resistance, creating a uniform flow field, and preventing corrosion, ultimately achieving significant energy savings and reduced consumption.

[0057] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0058] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A vacuum hot plate type low-temperature economizer, characterized in that, include: Support frame; Several vacuum heat exchange plates (4) are arranged in an array in the support frame, with a gap between two adjacent vacuum heat exchange plates (4), and the vacuum heat exchange plates (4) are filled with heat exchange working fluid. The first turbulence mechanism is fixedly installed on the side wall of the vacuum heat exchange plate (4) parallel to the flue gas flow direction, and the first turbulence mechanism is connected to the inside of the vacuum heat exchange plate (4). A flow guiding mechanism is fixedly installed at the end of the vacuum heat exchange plate (4) facing the flue gas flow; The heat insulation mechanism is fixedly installed at the top of the support frame; A heat exchange tube (8) is fixedly installed at the top of the vacuum heat exchange plate (4). The inlet end of the heat exchange tube (8) is fixedly connected to the top wall of the vacuum heat exchange plate (4). The outlet end of the heat exchange tube (8) is located inside the vacuum heat exchange plate (4) and close to the inner bottom wall of the vacuum heat exchange plate (4). The outlet end of the heat exchange tube (8) is located below the liquid surface of the heat exchange medium. The heat exchange condensation mechanism is fixedly sleeved on the outside of the heat exchange tube (8), and the heat exchange condensation mechanism is located above the heat insulation mechanism.

2. The vacuum hot plate type low-temperature economizer according to claim 1, characterized in that, The first turbulence mechanism includes two end turbulence parts and one middle turbulence part. The two end turbulence parts are located at the two ends of the side wall of the vacuum heat exchange plate (4) parallel to the flue gas flow direction, and the middle turbulence part is located in the middle of the side wall of the vacuum heat exchange plate (4) parallel to the flue gas flow direction.

3. A vacuum hot plate type low-temperature economizer according to claim 2, characterized in that, The end turbulence section includes a plurality of end turbulence shells (5), and the plurality of end turbulence shells (5) are fixedly connected to the two ends of the side wall of the vacuum heat exchange plate (4) parallel to the flue gas flow direction. The end turbulence shells (5) are in communication with the interior of the vacuum heat exchange plate (4).

4. A vacuum hot plate type low-temperature economizer according to claim 3, characterized in that, The intermediate turbulence section includes several intermediate turbulence shells (6), and the several intermediate turbulence shells (6) are fixedly connected to the middle of the side wall of the vacuum heat exchange plate (4) parallel to the flue gas flow direction. The intermediate turbulence shells (6) are in communication with the interior of the vacuum heat exchange plate (4).

5. A vacuum hot plate type low-temperature economizer according to claim 4, characterized in that, Both the end spoiler shell (5) and the middle spoiler shell (6) are inclined. The inclined lower ends of the end spoiler shell (5) and the inclined lower ends of the middle spoiler shell (6) are both facing the flue gas flow direction. The inclination angle of the middle spoiler shell (6) is greater than that of the end spoiler shell (5).

6. A vacuum hot plate type low-temperature economizer according to claim 1, characterized in that, The heat exchange tube (8) includes a first vertical section, the bottom end of which is fixedly connected to the top wall of the vacuum heat exchange plate (4), the top end of which is fixedly connected to one end of a bent tube section, the other end of which is fixedly connected to the top end of a second vertical section, the bottom end of which is located inside the vacuum heat exchange plate (4) and close to the inner bottom wall of the vacuum heat exchange plate (4), the bottom end of which is located below the liquid surface of the heat exchange medium, and the heat exchange condensation mechanism is fixedly sleeved on the outside of the top end of the second vertical section.

7. A vacuum hot plate type low-temperature economizer according to claim 6, characterized in that, The top of the side wall of the second vertical section is provided with a disturbance flow cavity (13), and a plurality of disturbance flow cavities (13) are arranged in an array along the circumference and axial direction of the second vertical section. The disturbance flow cavity (13) is located in the heat exchange and condensation mechanism.

8. A vacuum hot plate type low-temperature economizer according to claim 6, characterized in that, The heat exchange and condensation mechanism includes several heat exchange chambers (9). The heat exchange chambers (9) are fixedly sleeved on the outer side of the top end of the second vertical section. Two adjacent heat exchange chambers (9) are fixedly connected through several connecting pipes (11). The bottom end of the heat exchange chamber (9) located on the outer side is fixedly connected to a water inlet pipe (10), and the top end of the heat exchange chamber (9) located on the other outer side is fixedly connected to a water outlet pipe (12).

9. A vacuum hot plate type low-temperature economizer according to claim 1, characterized in that, The flow guiding mechanism includes a flow guiding platform (7), the horizontal cross section of which is triangular. The planar end of the flow guiding platform (7) is fixedly connected to the end of the vacuum heat exchange plate (4) near the flue gas flow direction, and the tip of the flow guiding platform (7) faces the flue gas flow direction.

10. A vacuum hot plate type low-temperature economizer according to claim 1, characterized in that, The support frame includes a fixed plate (1), the bottom end of the vacuum heat exchange plate (4) is fixedly connected to the top end of the fixed plate (1), and a number of support plates (2) are fixedly connected to the side wall of the fixed plate (1). The support plates (2) are vertically arranged, and the heat insulation mechanism is fixedly connected to the top end of the support plate (2).

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