Strengthened anti-abrasion gravity assisted heat pipe flue gas waste heat utilization device

Abstract

The invention relates to the field of flue gas treatment and heat exchange, in particular to a reinforced anti-abrasion gravity assisted heat pipe flue gas waste heat utilization device which comprises a shell filled with flowing flue gas. The reinforced anti-abrasion gravity assisted heat pipe is located in the shell, and one end of the reinforced anti-abrasion gravity assisted heat pipe extends out of the shell and extends outwards. The cooling sleeve is arranged at the extending end of the reinforced anti-abrasion gravity assisted heat pipe in a sleeving manner; the partition plate is fixed to the extending position of the shell and the reinforced anti-abrasion gravity assisted heat pipe. Liquid from the liquid inlet box flows into one end of the cooling sleeve, and liquid at the other end of the cooling sleeve flows into the liquid outlet collecting box. The reinforced anti-abrasion gravity assisted heat pipe is adopted as a main heat exchange element, and heat transfer is achieved through phase change of working media at the two ends of the reinforced anti-abrasion gravity assisted heat pipe. Compared with a traditional tubular flue gas-water heat exchanger, heating medium water is completely separated from flue gas. And meanwhile, the heating medium water and the flue gas in the flue are doubly isolated by adopting the structure of the cooling sleeve and the partition plate, so that the hidden danger that the heating medium water flows into the flue is completely eradicated.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas treatment and heat exchange, and more particularly to a flue gas waste heat utilization device with enhanced wear-resistant gravity heat pipe. Background Art

[0002] In recent years, the flue gas waste heat utilization device arranged in the tail flue of the coal-fired unit has become a common energy-saving and environmental protection equipment. The flue gas waste heat utilization device is usually arranged in the flue after the air preheater and before the dust collector. Its main function is to reduce the exhaust temperature after the air preheater from 120℃-150℃ to about 90℃. The absorbed flue gas heat is heated by heat medium water according to the different needs of the power plant to heat the cold primary and secondary air, condensate water, and clean flue gas after desulfurization. It can improve the unit efficiency, save coal consumption, improve the corrosion and blockage problem of the cold end of the air preheater, and achieve the "whitening" of the chimney. At the same time, it can improve the dust removal efficiency of the electrostatic precipitator and the initial desulfurization of the flue gas, and reduce the amount of desulfurization water spray.

[0003] At present, most of the flue gas waste heat utilization devices used by various power plants are traditional tubular flue gas-water heat exchangers. The heat exchange tubes and heat medium water are located in the flue to directly exchange heat with the flue gas. Most traditional flue gas waste heat utilization devices have problems such as wear and corrosion. Due to its structural characteristics, if a heat exchange tube leaks, if it is not discovered and handled in time, the heat medium water will continue to leak into the flue gas, causing dust accumulation and hardening of the flue gas waste heat utilization device, aggravating leakage problems such as low-temperature corrosion, and in severe cases, even causing problems such as dust blockage and poor dust removal in the electrostatic precipitator, affecting the safe operation of the unit.

[0004] Therefore, how to provide a new type of flue gas waste heat utilization device that is different from the traditional structure to solve the problem of large amounts of heat medium water leaking into the flue affecting the safe operation of the unit, while at the same time improving the heat transfer efficiency and anti-wear performance, and improving the performance and life of the equipment, is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] To this end, the purpose of the present invention is to solve the problem that a large amount of heat medium water leaks into the flue of the traditional tubular flue gas-water heat exchanger, which affects the safe operation of the unit. At the same time, the heat transfer efficiency and anti-wear performance should be improved, and the performance and life of the equipment should be improved. A flue gas waste heat utilization device with enhanced anti-wear gravity heat pipe is proposed.

[0006] The specific scheme of the present invention includes:

[0007] a shell, the interior of which is filled with flowing smoke;

[0008] A reinforced anti-wear gravity heat pipe is located in the shell, one end of which extends out of the shell and extends outward;

[0009] A cooling sleeve, sleeved on the extended end of the enhanced anti-wear gravity heat pipe;

[0010] A partition plate is fixed to the shell and the extension of the enhanced anti-wear gravity heat pipe;

[0011] Wherein, the liquid from the liquid inlet tank flows into one end of the cooling jacket, and the liquid flows to the liquid outlet header at the other end.

[0012] According to the technical solution of the present invention, the part of the enhanced anti-wear gravity heat pipe located in the shell is arranged vertically or inclined.

[0013] According to the technical solution of the present invention, a closed cavity is formed inside the enhanced anti-wear gravity heat pipe, and the working medium filled in the cavity is distilled water.

[0014] According to the technical solution of the present invention, the working mass of the filling in the enhanced anti-wear gravity heat pipe is calculated and determined according to its gradient along the direction of the flue gas flow.

[0015] According to the technical solution of the present invention, after the reinforced anti-wear gravity heat pipe is filled with working fluid, a certain vacuum degree is drawn.

[0016] According to the technical solution of the present invention, the working fluid contains nanofluid.

[0017] According to the technical solution of the present invention, the reinforced anti-wear gravity heat pipe includes a plurality of pipes, each of which is an independent structure and each of which is correspondingly connected to the cooling jacket.

[0018] According to the technical solution of the present invention, reinforcing ribs are provided on both sides of each of the reinforced anti-wear gravity heat pipes along the flue gas flow direction.

[0019] According to the technical solution of the present invention, the reinforcing ribs are rectangular reinforcing ribs or trapezoidal reinforcing ribs.

[0020] According to the technical solution of the present invention, the liquid inlet box is located in the direction of the smoke outlet, and after the liquid enters the cooling sleeve, it is in a cross-countercurrent with the smoke direction.

[0021] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention adopts a reinforced anti-wear gravity heat pipe as the main heat exchange element, and realizes heat transfer through the phase change of the working medium at both ends of the reinforced anti-wear gravity heat pipe. Compared with the traditional tubular flue gas-water heat exchanger, the heat medium water (cooling water) and the flue gas are completely separated. At the same time, the structure of cooling jacket plus partition is adopted to double isolate the heat medium water (cooling water) and the flue gas in the flue, completely eliminating the hidden danger of heat medium water (cooling water) flowing into the flue.

[0023] Each enhanced anti-wear gravity heat pipe in the present invention is an independent heat exchange element. Even if an individual enhanced anti-wear gravity heat pipe leaks due to local wear and other reasons, only a trace amount of working fluid inside the heat pipe leaks into the flue. This trace amount of working fluid will be quickly evaporated by the flue gas and will not affect the safe operation of the unit. At the same time, the failure of a small number of enhanced anti-wear gravity heat pipes will not affect the normal operation of other heat pipes, and there will be no problem of dust accumulation and hardening in a traditional tubular flue gas-water heat exchanger if a heat exchange tube leaks and is not discovered and handled in time, thereby aggravating the low-temperature corrosion.

[0024] The main forms of traditional heat exchange tubes include round tubes, oval tubes, spiral fin tubes, H-shaped fin tubes, etc. Due to the working characteristics of gravity heat pipes, gravity heat pipes need to be arranged vertically or obliquely. If traditional spiral fin tubes or H-shaped fin tubes are used, their expansion surfaces will form steps, causing serious dust accumulation on the heating surface, thereby affecting the heat exchange performance of the heat pipe. However, round tubes and oval tubes have the disadvantages of low heat exchange efficiency, relatively large equipment space and investment. The present invention arranges reinforcing ribs on both sides of the enhanced anti-wear gravity heat pipe along the flue gas flow direction, which can deflect the flue gas to a certain extent, reduce the direct scouring of the flue gas on the enhanced anti-wear gravity heat pipe itself, and improve the anti-wear performance and service life of the enhanced anti-wear gravity heat pipe. At the same time, the heat transfer efficiency of the enhanced anti-wear gravity heat pipe can be improved, and the layout space requirements of the flue gas waste heat utilization device can be reduced.

[0025] At the same time, since the flue of the flue gas waste heat utilization device in a thermal power plant is usually large, the length of the reinforced anti-wear gravity heat pipe is long, usually 7 to 10 meters. After the reinforcement ribs are set, the stiffness of the reinforced anti-wear gravity heat pipe itself can be improved and the vibration of the reinforced anti-wear gravity heat pipe during operation can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the structure of a device for utilizing flue gas waste heat by a reinforced anti-wear gravity heat pipe provided by the present invention;

[0028] Figure 2 The schematic diagram of the structure of a single reinforced anti-wear gravity heat pipe is shown;

[0029] Figure 3 for Figure 2 A cross-sectional view showing a structural schematic diagram of a reinforcing rib plate;

[0030] Figure 4for Figure 2 The cross-sectional view shows the structural schematic diagram of another reinforcing rib. DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0032] Since most of the flue gas waste heat utilization devices used in various power plants are traditional tubular flue gas-water heat exchangers. The heat exchange tubes and heat medium water are located in the flue and directly exchange heat with the flue gas, which may cause problems such as wear and corrosion. Due to its structural characteristics, if a heat exchange tube leaks, if it is not discovered and handled in time, the heat medium water will continue to leak into the flue gas, causing dust accumulation and hardening in the flue gas waste heat utilization device, aggravating leakage problems such as low-temperature corrosion, and in severe cases, even causing problems such as dust blockage and poor dust removal in the electrostatic precipitator, affecting the safe operation of the unit.

[0033] In view of this, the technical solution of the present invention provides a flue gas waste heat utilization device with enhanced wear resistance gravity heat pipe, which solves the problem of unit safety affected by large amounts of heat medium water leakage, and at the same time, has the advantages of high efficiency heat transfer and high wear resistance, so as to replace the traditional flue gas waste heat utilization device. Figure 1 , including: a shell 1, which is filled with flowing flue gas, and the shell 1 can be welded with steel plates; a reinforced anti-wear gravity heat pipe 2 is located in the shell 1, and one end of the reinforced anti-wear gravity heat pipe 2 extends out of the shell 1 and extends outward; a cooling sleeve 5 is sleeved on the extended end of the reinforced anti-wear gravity heat pipe 2; a partition 3 is fixed to the shell 1 and the extended part of the reinforced anti-wear gravity heat pipe 2 to separate the heat medium water (cooling water) from the flue gas, and the extended part is filled with insulation cotton; wherein, one end of the cooling sleeve 5 flows into the liquid from the liquid inlet box 4, and the other end of the liquid flows to the liquid outlet header 6.

[0034] Advantageously, the portion of the enhanced anti-wear gravity heat pipe 2 located inside the shell 1 is arranged vertically or inclined.

[0035] According to the attached Figure 1 The schematic orientation (the following description of the present invention is based on the attached Figure 1 The orientation is described as the main orientation), which can be understood as: the flue gas flows through the shell 1, the enhanced anti-wear gravity heat pipe 2 is arranged vertically or obliquely, the lower end of the enhanced anti-wear gravity heat pipe 2 is located inside the shell 1, and the cooling jacket 5 is arranged outside the upper end of the enhanced anti-wear gravity heat pipe 2. The heat medium water (air-cooled water) enters the cooling jacket 5 from the liquid inlet tank 4, and finally flows out through the liquid outlet header 6.

[0036] See attached Figure 2 A closed cavity is formed inside the enhanced anti-wear gravity heat pipe 2, and the working medium filled in the cavity is distilled water.

[0037] After the flue gas flows through the lower end of the enhanced anti-wear gravity heat pipe 2, the internal working medium absorbs heat and undergoes phase change (evaporation and boiling) to become water vapor. The water vapor flows to the upper end of the enhanced anti-wear gravity heat pipe 2 under the action of the pressure difference, and the steam condenses into liquid water after heat exchange with the heat medium water in the cooling jacket 5. The liquid water flows back to the lower end of the enhanced anti-wear gravity heat pipe 2 under the driving action of gravity and performs the next working medium cycle.

[0038] In a specific embodiment of the present invention, the enhanced anti-wear gravity heat pipe 2 includes a plurality of pipes, each of which is an independent structure, and an extension portion of each pipe is correspondingly connected to the cooling jacket 5 .

[0039] The outer ends (extended ends) of the upper ends of adjacent reinforced anti-wear gravity heat pipes 2 are connected to the cooling jacket 5 through connecting pipes, and the heat medium water flows completely inside the cooling jacket 5. The structure of the cooling jacket 5 plus the partition 3 can double isolate the heat medium water and the flue gas in the flue, completely preventing the heat medium water from flowing into the flue and affecting the safe operation of the unit.

[0040] Each enhanced anti-wear gravity heat pipe 2 is an independent heat exchange element. In actual operation, even if an individual enhanced anti-wear gravity heat pipe 2 leaks due to local wear and other reasons, only a trace amount of working fluid inside the heat pipe leaks into the flue. This trace amount of working fluid will be quickly evaporated by the flue gas and will not affect the safe operation of the electrostatic precipitator and the unit. At the same time, the failure of a small number of heat pipes will not affect the normal operation of other heat pipes, nor will there be a problem of dust accumulation and hardening in a traditional tubular flue gas-water heat exchanger if a heat exchange tube leaks and is not discovered and handled in time, which will aggravate low-temperature corrosion and affect the service life of the flue gas waste heat utilization device.

[0041] In a preferred embodiment of the present invention, see the attached Figure 1 and 2 On the basis of several vertically or obliquely arranged reinforced anti-wear gravity heat pipes, along the flue gas flow direction, both sides of each of the reinforced anti-wear gravity heat pipes 2 are provided with reinforcing ribs, wherein the arrow indicates the flue gas flow direction. The stiffness, heat exchange performance and anti-wear performance of the reinforced anti-wear gravity heat pipe 2 can be improved. At the same time, compared with traditional spiral fins and H-shaped fins, there is no dust accumulation problem.

[0042] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0043] Specifically, see Appendix Figure 3 and 4 , the reinforcing rib is a rectangular reinforcing rib 21 or a trapezoidal reinforcing rib 22. The "rectangular" and "trapezoidal" in the present invention mainly refer to the cross-sectional shape of the reinforcing rib. Figure 3 and Figure 4 The arrow in the figure indicates the direction of smoke flow.

[0044] In other embodiments of the present invention, the liquid inlet box 4 is located in the direction of the smoke outlet, and after the liquid enters the cooling jacket 5, it is in a cross-countercurrent with the smoke direction.

[0045] In the present invention Figure 1 middle, Indicates the direction of smoke flow. Indicates the cooling liquid flow direction.

[0046] In the present invention, the internal cavity of the enhanced anti-wear gravity heat pipe 2 is pickled and passivated, and a corrosion inhibitor is added to the internal working fluid (distilled water) of the enhanced anti-wear gravity heat pipe 2 to reduce the generation of non-condensable gases and improve the service life and performance of the enhanced anti-wear gravity heat pipe 2.

[0047] The interior of the enhanced anti-wear gravity heat pipe 2 is airtight, and a certain amount of working fluid is pre-filled inside, and then evacuated to a slight vacuum. The amount of working fluid filled inside the enhanced anti-wear gravity heat pipe 2 is calculated separately according to the gradient along the flue gas flow direction. If the flue gas waste heat utilization device of the enhanced anti-wear gravity heat pipe 2 is designed to be divided into a high-temperature section and a low-temperature section along the flue gas flow direction, the amount of working fluid filled inside the enhanced anti-wear gravity heat pipe 2 is calculated separately according to the different working characteristics of the high-temperature section and the low-temperature section. So that the heat exchange performance of each enhanced anti-wear gravity heat pipe 2 is closer to the theoretical performance upper limit. After the working fluid is filled, each enhanced anti-wear gravity heat pipe 2 is evacuated to a certain slight vacuum, and the vacuum degree is calculated and determined based on different working characteristics. Then the enhanced anti-wear gravity heat pipe 2 is sealed, and an appropriate amount of nanofluid is added to the internal working fluid to improve the heat exchange performance of the gravity heat pipe.

[0048] During operation, after the flue gas enters the shell 1, it flows through the lower end of the enhanced anti-wear gravity heat pipe 2. The working fluid inside the enhanced anti-wear gravity heat pipe 2 absorbs the heat of the flue gas and undergoes a phase change (evaporation and boiling) to become water vapor. The water vapor flows to the upper end of the enhanced anti-wear gravity heat pipe 2 under the action of the pressure difference. After the steam exchanges heat with the heat medium water in the cooling sleeve 5, it condenses into liquid water and releases heat to the heat medium water. The liquid water flows back to the lower end of the enhanced anti-wear gravity heat pipe 2 under the driving force of gravity, and repeats the next working fluid cycle. Through this working fluid cycle consisting of a continuous phase change process, the heat in the flue gas is continuously transferred to the heat medium water.

[0049] In the present invention, reinforcing ribs are provided on both sides of the reinforced anti-wear gravity heat pipe 2. After the flue gas flows through the rectangular reinforcing ribs 21 or the trapezoidal reinforcing ribs 22, it turns to a certain extent, thereby reducing the direct scouring of the flue gas on the reinforced anti-wear gravity heat pipe 2 itself, and improving the anti-wear performance and service life of the reinforced anti-wear gravity heat pipe 2. Compared with traditional spiral fin tubes and H-shaped fin tubes, this structure does not have the problem of dust accumulation. Compared with conventional round tubes and elliptical tubes, it can also improve the heat transfer efficiency of the gravity heat pipe, and reduce the layout space and investment cost of the flue gas waste heat utilization device. At the same time, since the length of the gravity heat pipe required for the flue gas waste heat utilization device of a coal-fired power plant is usually long, usually 7 to 10 meters, the provision of this reinforcing rib can improve the rigidity of the gravity heat pipe itself and reduce the vibration of the gravity heat pipe during operation.

[0050] In the actual engineering project, the present invention can select which reinforcing rib to use based on the actual coal combustion and flue gas characteristics. In the present invention, the cross-section of the rib is preferably a rectangular structure or a trapezoidal structure.

[0051] In the present invention, the shell 1, the enhanced anti-wear gravity heat pipe 2, and the partition 3 are welded and sealed. The upper and lower ends of the cooling sleeve 5 and the outer wall surface of the upper end of the enhanced anti-wear gravity heat pipe 2 are welded and sealed by manual argon arc welding, the connection between the two cooling sleeves 5 is welded and sealed by manual argon arc welding, and the cooling sleeve 5 and the liquid inlet box 4 and the liquid outlet header 6 are welded and sealed by manual argon arc welding to ensure the sealing of the heat medium water.

[0052] The embodiments of the present invention have obvious advantages over traditional tubular flue gas-water heat exchangers in terms of operational safety, wear resistance, service life, etc., and are suitable for use as a new type of heat exchange device for recovering waste heat from flue gas in the tail flue of a coal-fired unit.

[0053] The enhanced anti-wear gravity heat pipe flue gas waste heat utilization device provided by the present invention can be used as a separate module unit. The whole system can include multiple module units of the present invention. Isolation valves can be set on the corresponding coolant circuits between the module units, thereby facilitating transportation, assembly, inspection and maintenance. Multiple module units can be assembled on site by welding.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0055] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A device for utilizing flue gas waste heat from a reinforced anti-wear gravity heat pipe, characterized in that: include: A shell (1) filled with flowing smoke; A reinforced anti-wear gravity heat pipe (2) is located in the shell (1), one end of which extends out of the shell (1) and extends outward; A cooling sleeve (5) is sleeved on the extended end of the enhanced anti-wear gravity heat pipe (2); A partition (3) is fixed to the extension of the shell (1) and the enhanced anti-wear gravity heat pipe (2); Wherein, liquid from the liquid inlet tank (4) flows into one end of the cooling jacket (5), and liquid flows to the liquid outlet header (6) at the other end.

2. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 1 is characterized in that: The part of the enhanced anti-wear gravity heat pipe (2) located inside the shell (1) is arranged vertically or inclined.

3. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 1 is characterized in that: A closed cavity is formed inside the enhanced anti-wear gravity heat pipe (2), and the working medium filled in the cavity is distilled water.

4. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 3 is characterized in that: The working mass filled in the enhanced anti-wear gravity heat pipe (2) is calculated and determined according to its gradient along the direction of the flue gas flow.

5. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 4 is characterized in that: After the enhanced anti-wear gravity heat pipe (2) is filled with working fluid, a certain vacuum degree is drawn.

6. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 3 is characterized in that: The working fluid contains nanofluid.

7. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 1 is characterized in that: The enhanced anti-wear gravity heat pipe (2) comprises a plurality of pipes, each of which is an independent structure and each of which is correspondingly connected to the cooling jacket (5).

8. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 7 is characterized in that: Along the flow direction of the flue gas, both sides of each of the reinforced anti-wear gravity heat pipes (2) are provided with reinforcing ribs.

9. The enhanced wear-resistant gravity heat pipe flue gas waste heat utilization device according to claim 8, characterized in that: The reinforcing ribs are rectangular reinforcing ribs (21) or trapezoidal reinforcing ribs (22).

10. A device for utilizing flue gas waste heat of a reinforced anti-wear gravity heat pipe according to any one of claims 1 to 9, characterized in that: The liquid inlet box (4) is located in the direction of the smoke outlet, and after the liquid enters the cooling jacket (5), it is in a cross-countercurrent flow with the smoke direction.

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