Air preheater based on offshore oilfield flue gas waste heat recovery and reutilization

Abstract

The utility model provides an air preheater based on offshore oilfield flue gas waste heat recovery and reutilization, which relates to the technical field of flue gas waste heat recovery and comprises a heat exchange cylinder, a plurality of uniformly distributed heat exchange tubes are arranged in the heat exchange cylinder along the length direction, and a first partition plate and a second partition plate are arranged in the heat exchange cylinder from an air inlet end to an air outlet end. The first partition plate and the second partition plate divide the interior of the heat exchange barrel into a first heat exchange area, a second heat exchange area and a third heat exchange area in the air flowing direction. Heat of high-temperature flue gas can be effectively absorbed through three times of heat exchange of cold air to be subjected to heat exchange, most of air in the first heat exchange area rises to the high position from the low end through the air through holes in the first partition plate and the second partition plate, most of air entering the second heat exchange area falls to the low position from the high end, and therefore heat exchange efficiency is improved. Most of the air entering the third heat exchange area rises from the low end to the high end, and the heat exchange effect can be further improved through the change of the air circulation path.

Description

Technical Field

[0001] The utility model relates to the technical field of flue gas waste heat recovery, in particular to an air preheater based on the recovery and reuse of flue gas waste heat in offshore oil fields. Background Art

[0002] Offshore oil fields refer to oil and gas fields located in the ocean, which are usually located on the continental shelf or in deeper waters. Offshore oil development usually refers to activities such as oil exploration, extraction, storage and transportation in the ocean. The development and production of these oil fields require special facilities and technologies. Offshore oil field flue gas refers to the waste gas generated during offshore oil field operations, especially after burning fuel (usually diesel, heavy oil or natural gas) in power stations, heating furnaces or other combustion equipment. These flue gases usually contain a large amount of heat energy, as well as some pollutants such as sulfur dioxide (SO2), nitrogen oxides (NO x ), particulate matter (PM) and other harmful substances.

[0003] A large amount of high-temperature flue gas is emitted from power stations or other industrial processes on offshore oil production platforms, and these flue gases contain considerable energy. The flue gas outlet temperature of the offshore platform boiler is about 240°C, and the flue gas quality is relatively good. If the flue gas is directly discharged into the atmosphere, it will cause a large amount of heat energy loss. In order to focus on energy saving and consumption reduction, an air preheater based on the recovery and reuse of waste heat from offshore oilfield flue gas is proposed. Utility Model Content

[0004] In order to solve the above deficiencies in the prior art, the utility model proposes an air preheater based on the recovery and reuse of waste heat from offshore oilfield flue gas.

[0005] The technical solution of the present utility model is achieved as follows:

[0006] Air preheater based on offshore oilfield flue gas waste heat recovery and reuse, including:

[0007] A heat exchange cylinder, wherein a first mounting cover and a second mounting cover are symmetrically mounted at both ends of the heat exchange cylinder, the first mounting cover is connected to a flue gas inlet pipe, and the second mounting cover is connected to a flue gas outlet pipe;

[0008] A plurality of evenly distributed heat exchange tubes are provided inside the heat exchange tube along the length direction, and both ends of the heat exchange tubes extend to the outside of the heat exchange tube. A first partition and a second partition are provided inside the heat exchange tube from the air inlet end to the air outlet end. The first partition and the second partition divide the interior of the heat exchange tube into a first heat exchange zone, a second heat exchange zone and a third heat exchange zone along the air flow direction, and a plurality of air holes are equidistantly provided on the first partition and the second partition from top to bottom.

[0009] Preferably, the lengths of the air holes on the first partition plate increase sequentially from bottom to top, and the lengths of the air holes on the second partition plate decrease sequentially from bottom to top.

[0010] Preferably, the bottom ends of the first mounting cover and the second mounting cover are integrally formed with a convex edge, and a solid sedimentation trough is opened inside the first mounting cover and the second mounting cover at the position of the convex edge, and the bottom end of the solid sedimentation trough is connected to a slag discharge pipe.

[0011] Preferably, slag guiding slopes are fixed at both ends of the interior of the solid sedimentation tank, and the end of the slag guiding slope close to the center of the solid sedimentation tank is lower.

[0012] Preferably, the first partition plate and the second partition plate are further provided with holes for the heat exchange tubes to pass through.

[0013] Preferably, the lower end surface of the heat exchange tube and one end close to the flue gas inlet pipe is connected to the air inlet pipe, and the upper end surface of the heat exchange tube and one end close to the flue gas outlet pipe is connected to the air outlet pipe.

[0014] Preferably, a heat pipe bundle is further provided inside the heat exchange cylinder and outside the heat exchange tube.

[0015] Preferably, a filter is installed inside the first installation cover and the second installation cover and at one end close to the heat exchange tube.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. When the present invention is in use, through the arrangement of the first partition, the second partition and the air through-holes, the cold air to be heat-exchanged first enters the first heat exchange zone for a heat exchange, then undergoes a second heat exchange in the second heat exchange zone, and then undergoes a third heat exchange in the third heat exchange zone. The three heat exchanges can effectively absorb the heat of the high-temperature flue gas and improve the heat exchange effect. Among them, the arrangement of the air through-holes on the first partition and the second partition makes most of the air in the first heat exchange zone rise from the low end to the high end first, and most of the air entering the second heat exchange zone first descend from the high end to the low end, and most of the air entering the third heat exchange zone first rise from the low end to the high end. The change of the air flow path can further increase the heat exchange effect.

[0018] 2. When the utility model is in use, through the arrangement of the solid sedimentation trough, the slag discharge pipe and the slag guiding slope, after the high-temperature flue gas is introduced from the flue gas inlet pipe, the solid sedimentation trough can be used to collect the settled solid impurities both before and after the heat exchange. The collected solid impurities slide down through the slag guiding slope and can be discharged from the slag discharge pipe. In addition, the filter screen can block the solid impurities, which is conducive to the faster sedimentation of the solid impurities and can reduce the sedimentation of solid impurities in the heat exchange tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 This is a schematic diagram of the explosion structure of the utility model;

[0021] Figure 2 This is a schematic diagram of the appearance structure of the utility model;

[0022] Figure 3 This is a schematic structural diagram of the second mounting cover of the utility model;

[0023] Figure 4 This is a schematic cross-sectional view of the heat exchange tube of the present invention;

[0024] Figure 5 This is a schematic diagram of the explosion structure of the first partition and the second partition of the utility model;

[0025] Figure 6 This is a structural diagram of the second mounting cover of the utility model when the filter is installed.

[0026] In the figure: 1. Heat exchange tube; 2. First mounting cover; 3. Second mounting cover; 4. Flue gas inlet pipe; 5. Flue gas outlet pipe; 6. Air inlet pipe; 7. Air outlet pipe; 8. Heat exchange tube; 9. Raised edge; 10. Solid sedimentation trough; 11. Slag guide slope; 12. Slag discharge pipe; 13. First partition; 14. Second partition; 15. Perforation; 16. Air through hole; 17. Filter; 18. Heat pipe bundle. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] The utility model provides Figure 1-Figure 2The air preheater based on the recovery and reuse of waste heat from offshore oilfield flue gas shown in the figure comprises a heat exchange tube 1, a first mounting cover 2 and a second mounting cover 3 are symmetrically installed at both ends of the heat exchange tube 1, the flue gas inlet end of the first mounting cover 2 is connected to the flue gas inlet pipe 4, and the flue gas outlet end of the second mounting cover 3 is connected to the flue gas outlet pipe 5, the lower end surface of the heat exchange tube 1 and one end close to the flue gas inlet pipe 4 is connected to the air inlet pipe 6, and the upper end surface of the heat exchange tube 1 and one end close to the flue gas outlet pipe 5 is connected to the air outlet pipe 7, a plurality of evenly distributed heat exchange tubes 8 are provided inside the heat exchange tube 1 and along the length direction, the heat exchange tube 8 is preferably provided in a plurality of rows from top to bottom, and a plurality of heat exchange tubes 8 are equidistantly provided in each row, and both ends of the heat exchange tube 8 extend to the outside of the heat exchange tube 1, and there is also a heat exchange tube 8 inside the heat exchange tube 1 and on the periphery of the heat exchange tube 8. A heat pipe bundle 18 is provided. This heat pipe bundle 18 is a heat transfer element that transfers heat through the phase change of its internal working fluid. The heated side of the heat pipe bundle 18 absorbs exhaust heat and transfers the heat to the working fluid (liquid) within the tube. After absorbing heat, the working fluid evaporates and boils, transforming into steam. Under the action of the pressure difference, the steam rises to the heat release side and condenses into liquid, releasing latent heat of vaporization. The heat is transferred to the cold fluid on the heat release side. The condensed liquid flows back to the heated side by gravity. Because the interior of the heat pipe bundle 18 is evacuated, the working fluid evaporates and boils easily. The heat pipe bundle 18 starts up quickly and has a series of advantages, such as extremely high thermal conductivity, good isothermal properties, the heat transfer area on the hot and cold sides can be arbitrarily changed, long-distance heat transfer is possible, temperature control is possible, and adaptability to various ambient temperatures is possible.

[0029] As can be seen from the above, during specific use, the air to be heat exchanged is introduced from the air inlet pipe 6, and the high-temperature flue gas from the offshore oil field is introduced from the flue gas inlet pipe 4. The flue gas inlet pipe 4 enters the heat exchange pipe 8 and passes through it, and is finally discharged from the flue gas outlet pipe 5. In the process of air flowing from the air inlet pipe 6 to the air outlet pipe 7, the high-temperature flue gas in the heat exchange pipe 8 can heat it, so as to preheat the combustion air entering the boiler. The high-temperature air entering the boiler can save fuel, which not only improves the thermal efficiency of the boiler but also reduces pollution to the environment, saves energy, and achieves comprehensive energy utilization of the boiler itself.

[0030] refer to Figure 4-Figure 5 As shown, a first partition 13 and a second partition 14 are provided inside the heat exchange tube 1 from the air inlet end to the air outlet end. The first partition 13 and the second partition 14 divide the interior of the heat exchange tube 1 into a first heat exchange zone, a second heat exchange zone and a third heat exchange zone along the air flow direction, and a plurality of air holes 16 are equidistantly provided on the first partition 13 and the second partition 14 from top to bottom. The length of the air holes 16 on the first partition 13 increases from bottom to top, and the length of the air holes 16 on the second partition 14 decreases from bottom to top.

[0031] Through the above technical solution:

[0032] During use, after the cold air to be heat exchanged enters the air inlet pipe 6, it first enters the first heat exchange zone for a heat exchange, and then the air passes through the first partition 13 and enters the second heat exchange zone for a second heat exchange, and then the air enters the third heat exchange zone for a third heat exchange. The three heat exchanges enable the air to effectively absorb the heat of the high-temperature flue gas and improve the heat exchange effect.

[0033] Among them, the arrangement of the air holes 16 on the first partition 13 and the second partition 14 makes most of the air in the first heat exchange zone first rise from the low end to the high end, and most of the air entering the second heat exchange zone first descend from the high end to the low end, and most of the air entering the third heat exchange zone first rise from the low end to the high end. The change in the air circulation path can increase its heat exchange effect.

[0034] Furthermore, the first partition plate 13 and the second partition plate 14 are provided with through holes 15 for the heat exchange tube 8 to pass through. The heat exchange tube 8 is installed through the through holes 15 , and the connection between the heat exchange tube 8 and the through holes 15 is sealed.

[0035] In addition, reference Figure 3 and Figure 6 As shown, the bottom ends of the first mounting cover 2 and the second mounting cover 3 are integrally formed with a convex edge 9, and a solid sedimentation trough 10 is opened inside the first mounting cover 2 and the second mounting cover 3 and at the position of the convex edge 9. The bottom end of the solid sedimentation trough 10 is connected to a slag discharge pipe 12, and a valve is installed on the slag discharge pipe 12. Slag guiding slopes 11 are fixed at both ends of the interior of the solid sedimentation trough 10, and the end of the slag guiding slope 11 close to the center of the solid sedimentation trough 10 is lower.

[0036] In addition, a filter screen 17 is installed inside the first installation cover 2 and the second installation cover 3 and at one end close to the heat exchange tube 1 .

[0037] Through the above technical solution:

[0038] During use, after high-temperature flue gas enters from the flue gas inlet pipe 4, some solid impurities settle and fall into the solid sedimentation tank 10. By opening the valve regularly, the collected solid impurities can slide down through the slag guide slope 11 and be discharged from the slag discharge pipe 12.

[0039] Wherein, both the first installation cover 2 and the second installation cover 3 are provided with a solid sedimentation tank 10, which can realize the collection of solid impurities sedimentation before and after heat exchange.

[0040] In addition, by providing the filter 17, solid impurities can be effectively blocked, which is conducive to faster sedimentation of solid impurities and can reduce the sedimentation of solid impurities in the heat exchange tube 8, preventing the inner wall of the heat exchange tube 8 from being clogged by solid impurities.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Air preheater based on recovery and reuse of waste heat from offshore oilfield flue gas, characterized in that: include: A heat exchange cylinder (1), wherein a first mounting cover (2) and a second mounting cover (3) are symmetrically mounted at both ends of the heat exchange cylinder (1), the first mounting cover (2) is connected to a flue gas inlet pipe (4), and the second mounting cover (3) is connected to a flue gas outlet pipe (5); The interior of the heat exchange tube (1) is provided with a plurality of evenly distributed heat exchange tubes (8) along the length direction, both ends of the heat exchange tubes (8) extend to the outside of the heat exchange tube (1), and the interior of the heat exchange tube (1) is provided with a first partition (13) and a second partition (14) from the air inlet end to the air outlet end, the first partition (13) and the second partition (14) divide the interior of the heat exchange tube (1) into a first heat exchange zone, a second heat exchange zone and a third heat exchange zone along the air flow direction, and a plurality of air through holes (16) are evenly spaced from top to bottom on the first partition (13) and the second partition (14).

2. The air preheater based on offshore oilfield flue gas waste heat recovery and reuse according to claim 1 is characterized in that: The lengths of the air holes (16) on the first partition plate (13) increase sequentially from bottom to top, and the lengths of the air holes (16) on the second partition plate (14) decrease sequentially from bottom to top.

3. The air preheater based on offshore oilfield flue gas waste heat recovery and reuse according to claim 1 is characterized in that: The bottom ends of the first mounting cover (2) and the second mounting cover (3) are both integrally formed with a convex edge (9), and a solid deposition trough (10) is provided inside the first mounting cover (2) and the second mounting cover (3) and located at the position of the convex edge (9), and the bottom end of the solid deposition trough (10) is connected to a slag discharge pipe (12).

4. The air preheater based on offshore oilfield flue gas waste heat recovery and reuse according to claim 3 is characterized in that: Slag guiding slopes (11) are fixed at both ends of the interior of the solid sedimentation tank (10), and the end of the slag guiding slope (11) close to the center of the solid sedimentation tank (10) is lower.

5. The air preheater based on offshore oilfield flue gas waste heat recovery and reuse according to claim 1 is characterized in that: The first partition plate (13) and the second partition plate (14) are also provided with through holes (15) for the heat exchange tubes (8) to pass through.

6. The air preheater based on offshore oilfield flue gas waste heat recovery and reuse according to claim 1 is characterized in that: An air inlet pipe (6) is connected to the lower end surface of the heat exchange tube (1) and one end close to the flue gas inlet pipe (4), and an air outlet pipe (7) is connected to the upper end surface of the heat exchange tube (1) and one end close to the flue gas outlet pipe (5).

7. The air preheater based on offshore oilfield flue gas waste heat recovery and reuse according to claim 1 is characterized in that: A heat pipe bundle (18) is further provided inside the heat exchange cylinder (1) and outside the heat exchange tube (8).

8. The air preheater based on offshore oilfield flue gas waste heat recovery and reuse according to claim 1 is characterized in that: A filter screen (17) is installed inside the first installation cover (2) and the second installation cover (3) and at one end close to the heat exchange cylinder (1).

Images