CN-116202340-B - Spiral double-preheating heat exchanger suitable for pure oxygen combustion system

CN116202340BCN 116202340 BCN116202340 BCN 116202340BCN-116202340-B

Abstract

The invention relates to a spiral double-preheating heat exchanger suitable for a pure oxygen combustion system, which comprises a heat exchanger outer shell and a cleaning mechanism for cleaning parts in the heat exchanger outer shell, wherein four layers of spiral heat exchange tubes are arranged in the heat exchanger outer shell and are uniformly distributed on a circumference from inside to outside, a plurality of overhauling flushing preformed holes are formed in the outer side wall of the heat exchanger outer shell, a high-temperature flue gas inlet and a low-temperature flue gas outlet are respectively formed in the positions, close to two ends, of the outer side wall of the heat exchanger outer shell, the high-temperature flue gas inlet is connected with a flue gas inlet pipe, the low-temperature flue gas outlet is connected with the flue gas inlet pipe through a pipeline, the overhauling flushing preformed holes are communicated with the cleaning mechanism through a water pipe, an ash removing mechanism is arranged on the flue gas inlet pipe, and the cleaning mechanism can drive the ash removing mechanism to filter flue gas entering the heat exchanger outer shell to remove smoke. The spiral double-preheating heat exchanger suitable for the pure oxygen combustion system enables flame type and combustion conditions of subsequent combustion to be more stable.

Inventors

YOU SHUHUAI
MAO LIN
LAN CONG
ZHOU PING
CHE BO
LI QUANYI
BAI ZHENGHAO

Assignees

湖南钟鼎热工科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20230215

Claims (6)

1. The spiral double-preheating heat exchanger suitable for the pure oxygen combustion system comprises a heat exchanger outer shell (1) and is characterized by further comprising: a cleaning mechanism for cleaning the internal components of the heat exchanger outer shell (1); four layers of spiral heat exchange tubes (3) are arranged in the heat exchanger outer shell (1), and the layers of spiral heat exchange tubes (3) are uniformly distributed on a circumference from inside to outside; A plurality of overhaul flushing preformed holes (2) are formed in the outer side wall of the heat exchanger outer shell (1), a high-temperature flue gas inlet (12) and a low-temperature flue gas outlet (13) are respectively formed in positions, close to two ends, of the outer side wall of the heat exchanger outer shell (1), the high-temperature flue gas inlet (12) is connected with a flue gas inlet pipe (21), the low-temperature flue gas outlet (13) is connected through a pipeline, the overhaul flushing preformed holes (2) are communicated with a cleaning mechanism through a water pipe I (20), an ash removing mechanism is arranged on the flue gas inlet pipe (21), and the cleaning mechanism can drive the ash removing mechanism to filter and remove smoke dust from flue gas entering the heat exchanger outer shell (1); The plurality of overhaul flushing preformed holes (2) are uniformly distributed on the outer side wall of the heat exchanger outer shell (1), the cleaning mechanism comprises a clean water tank (32), a pump water wheel (31) and a frame plate (42) are fixed on the clean water tank (32), a first water pipe (20) is fixed and communicated with the side wall of the pump water wheel (31), a sliding rail (43) is fixed on the frame plate (42), a sliding seat (44) is connected onto the sliding rail (43) in a sliding manner, a motor (46) is fixed onto the sliding seat (44), a second gear (45) is coaxially and fixedly connected onto an output shaft of the motor (46), a third gear (47) is coaxially and fixedly connected onto an impeller shaft of the pump water wheel (31), and the second gear (45) can be meshed and connected with the third gear (47); The low-temperature flue gas outlet (13) is connected with the inlet end of the three-way joint (15), two outlet ends of the three-way joint (15) are respectively connected with the flue gas exhaust pipe (18) and the drain pipe (19), one end of the three-way joint (15) close to the flue gas exhaust pipe (18) is connected with the first electromagnetic valve (16), one end of the three-way joint (15) close to the drain pipe (19) is connected with the second electromagnetic valve (17), a filter cylinder (33) is fixed in the clean water tank (32), the drain pipe (19) is communicated with the interior of the filter cylinder (33), a bottom plate of the clean water tank (32) is connected with the second water pipe (35), one end of an impeller shaft of the pump water wheel (31) far away from the third gear (47) penetrates through the top wall of the clean water tank (32) and is positioned in the filter cylinder (33), one end of the impeller shaft positioned in the filter cylinder (33) is fixedly provided with a scraping plate (34), a bracket two (27) is fixedly arranged on the bracket (42), a piston of the cylinder (28) is fixedly connected with a connecting rod (41), the piston of the cylinder (41) is fixedly connected with the connecting rod (41), the upper end (41) and the lower end (41) of the piston is fixedly connected with the rack (30) in parallel with the slide seat (30), the valve rod of the butterfly valve (22) is coaxially and fixedly connected with a first gear (29), and the first gear (29) is meshed with a rack (30); The ash removal mechanism comprises a filtering dense net (23) fixed on the inner wall of the smoke inlet pipe (21), the filtering dense net (23) is obliquely arranged, the impact surface of the filtering dense net (23) and smoke is downwards arranged, an ash discharge cylinder (24) is fixed on the outer side wall of the smoke inlet pipe (21), the ash discharge cylinder (24) is communicated with one side of the smoke inlet pipe (21) where the filtering dense net (23) impacts smoke, a plug (48) is fixed at the end part of the rack (30), the plug (48) can plug the outlet end of the ash discharge cylinder (24), a first bracket (26) is fixed on the first bracket (42), a fluted disc (40) is fixedly connected with the second bracket (45) in a rotating manner, a pin rod (39) is fixed on the fluted disc (40) at a position far away from the center of a circle, a sliding sleeve (37) is penetrated and fixedly connected on the side wall of the ash discharge cylinder (24), a sliding rod (25) is inserted in the sliding sleeve (37) in a sliding manner, the sliding rod (25) is connected with the sliding rod (25) in a sliding manner, and the two hammer heads (36) are connected with the sliding trolley (38) in a sliding manner, and the sliding trolley (38) is connected with the sliding rod (38) in a sliding manner, and the sliding trolley (36) is connected with the sliding rod (36) in a sliding manner.
2. The spiral double-preheating heat exchanger suitable for the pure oxygen combustion system according to claim 1, wherein four layers of the spiral heat exchange tubes (3) are arranged from inside to outside, wherein four tubes are arranged on a first layer, six tubes are arranged on a second layer, six tubes are arranged on a third layer, eight tubes are arranged on a fourth layer, the spiral length of the tubes is sequentially increased from inside to outside, so that the four layers of the spiral heat exchange tubes (3) form a vortex structure in a cavity, smoke passes through gaps of the tubes, the four layers of the spiral heat exchange tubes (3) are arranged from inside to outside, the first layer of spiral lines and the third layer of spiral lines are arranged anticlockwise, and the second layer of spiral lines and the fourth layer of spiral lines are arranged anticlockwise.
3. The spiral double-preheating heat exchanger suitable for the pure oxygen combustion system according to claim 1, wherein the two ports of the heat exchanger outer shell (1) are respectively fixed with spiral pipe fixing clamping plates (4), and the two ports of the spiral heat exchange pipe (3) respectively penetrate through and are welded on the corresponding spiral pipe fixing clamping plates (4).
4. A spiral double-preheating heat exchanger suitable for a pure oxygen combustion system is characterized in that a gas separation shell (6) is arranged on one side, away from a heat exchanger outer shell (1), of a spiral pipe fixing clamp plate (4), the end portion of a spiral heat exchange pipe (3) is communicated with the inside of the corresponding gas separation shell (6), the gas separation shell (6) is fixedly connected with the corresponding spiral pipe fixing clamp plate (4) and a port of the heat exchanger outer shell (1) through a flange and a plurality of bolt assemblies, and sealing rings (14) are arranged on end faces connected with the bolt assemblies, so that gas leakage is prevented, economic effects are guaranteed, and safety accidents are prevented.
5. The spiral double-preheating heat exchanger suitable for a pure oxygen combustion system according to claim 4, wherein a flow separation plate (5) is fixed inside the gas separation shell (6), the gas separation shell (6) is divided into an oxygen fluid domain and a fuel gas fluid domain by the flow separation plate (5), a low-temperature oxygen inlet air channel (8) and a low-temperature fuel gas inlet air channel (9) are fixedly connected to the gas separation shell (6) close to a low-temperature flue gas outlet (13), the low-temperature oxygen inlet air channel (8) is communicated with the oxygen fluid domain, the low-temperature fuel gas inlet air channel (9) is communicated with the fuel gas fluid domain, a high-temperature oxygen outlet air channel (10) and a high-temperature fuel gas outlet air channel (11) are fixedly connected to the gas separation shell (6) close to a high-temperature flue gas inlet (12), the high-temperature oxygen outlet air channel (10) is communicated with the oxygen fluid domain, and the high-temperature fuel gas outlet air channel (11) is communicated with the fuel gas fluid domain.
6. The spiral double-preheating heat exchanger suitable for the pure oxygen combustion system according to claim 5, wherein the low-temperature oxygen air inlet duct (8) and the low-temperature fuel gas air inlet duct (9) are respectively provided with a spring type energy accumulator (7) so as to reduce vibration of the spiral heat exchange tube (3) caused by fluid impact due to pressure and flow adjustment.

Description

Spiral double-preheating heat exchanger suitable for pure oxygen combustion system Technical Field The invention relates to a spiral double-preheating heat exchanger suitable for a pure oxygen combustion system, which is mainly used for flue gas heat exchange and waste heat recovery of the pure oxygen combustion system in petrochemical industry and metallurgical industry. The method can also be used for flue gas heat exchange and waste heat recovery of a common combustion system. Background At present, the combustion systems used in the industries of petrochemical industry, metallurgical industry and the like are quite many, after fuel is combusted in a boiler, generated flue gas contains a large amount of unutilized waste heat, and the waste heat in the flue gas can be recovered by using a heat exchanger, so that higher energy conversion efficiency is realized, and the purposes of energy conservation and emission reduction are achieved. As combustion technology is updated and iterated, pure oxygen combustion will become increasingly popular with cleaner features. Compared with the common combustion, the pure oxygen combustion hardly generates nitrogen oxides and sulfur oxides, the smoke quantity generated by the combustion is greatly reduced, and the pure oxygen combustion can realize more efficient and environment-friendly combustion. The highest theoretical flame temperature of pure oxygen combustion can reach 2700 ℃, and the smoke exhaust temperature can reach 950 ℃ under the condition that refractory materials are not paved on the furnace wall. Compared with the traditional heat exchanger, the pure oxygen combustion flue gas recovery problem has higher requirements on heat exchange efficiency. Most of the prior flue gas heat exchangers can only perform heat exchange between two gases, namely heating fuel gas, but the fuel gas and oxygen are heated simultaneously, so that the combustion is more stable and sufficient. The flushing and oxidation of the inner tubes of the heat exchanger by the unconsumed oxygen in the flue gas will affect the performance and life of the heat exchanger, and most spiral wound heat exchangers do not currently provide a solution for the cleaning of the interior. In pure oxygen combustion systems, the combustion conditions are monitored and dynamically adjusted in real time, and the main oxygen and fuel gas pipelines need to face pressure and flow changes and fluctuation. The fluctuation of the pressure and the flow of the main pipeline and the startup and shutdown of the system can cause fluid impact on the 3-spiral heat exchange pipe, the damage is not controlled, the metal fatigue of an internal structure can be caused after long-time use, and the service life of the equipment is shortened. In order to solve the problems, the invention discloses a spiral double-preheating heat exchanger suitable for a pure oxygen combustion system. Disclosure of Invention The invention aims to provide a spiral double-preheating heat exchanger suitable for a pure oxygen combustion system, so as to solve the problems in the background art. In order to achieve the purpose, the invention provides the technical scheme that the spiral double-preheating heat exchanger suitable for the pure oxygen combustion system comprises a heat exchanger shell body and further comprises: a cleaning mechanism for cleaning the internal components of the heat exchanger outer shell; Four layers of spiral heat exchange tubes are arranged in the heat exchanger shell, and the spiral heat exchange tubes of each layer are uniformly distributed on one circumference from inside to outside; a plurality of overhauling and flushing preformed holes are formed in the outer side wall of the heat exchanger outer shell, a high-temperature flue gas inlet and a low-temperature flue gas outlet are respectively formed in positions, close to two ends, of the outer side wall of the heat exchanger outer shell, the high-temperature flue gas inlet is connected with a flue gas inlet pipe, the low-temperature flue gas outlet is connected through a pipeline, the overhauling and flushing preformed holes are communicated with a cleaning mechanism through a water pipe, an ash removing mechanism is arranged on the flue gas inlet pipe, and the cleaning mechanism can drive the ash removing mechanism to filter and remove smoke dust from flue gas entering the heat exchanger outer shell. Preferably, four layers of spiral heat exchange tubes are formed by arranging four tubes from inside to outside on a first layer, arranging six tubes on a second layer, arranging six tubes on a third layer, arranging eight tubes on a fourth layer, and sequentially increasing the spiral length of the tubes from inside to outside, so that a vortex structure is formed in a cavity by the four layers of spiral heat exchange tubes, flue gas passes through gaps of the tubes, the four layers of spiral heat exchange tubes are arranged from inside to outside, the spiral lines o