CN203464803U - Anti-corrosion anti-scale high-efficiency flue gas waste heat recovery device - Google Patents

Abstract

The utility model discloses an anti-corrosion and anti-scaling high-efficiency flue gas waste heat recovery device, which belongs to the field of energy utilization devices. The heat exchange device is to pass both sides of the finned tube through the positioning holes of the side shell, and the finned tube and the side shell are flexibly sealed by a high-temperature resistant rubber ring, and then the upper and lower shells are connected to the side shell to form a heat exchanger. Heater shell, specifically, high-efficiency heat exchange devices that use high thermal conductivity filled composite materials to recover various boiler flue gas waste heat can prevent low-temperature acid dew corrosion of flue gas, and can reduce or remove dust accumulation on the surface of the heat exchanger Fouling. It has comprehensive properties such as acid dew corrosion resistance, not easy to scale, good thermal conductivity, and easy processing and molding, which solves the problem of low-temperature acid dew corrosion in flue gas waste heat recovery. The easy-to-disassemble combined shell is used to facilitate the maintenance of the heat exchanger and the replacement of the finned tube unit. The overall heat exchanger adopts a modular structure, and the size can be adjusted in three directions to meet different air duct sizes and replacements. Caloric requirements.

Description

A high-efficiency flue gas waste heat recovery device with anti-corrosion and anti-scaling

technical field

The utility model belongs to the field of energy utilization devices, in particular to an anti-corrosion and anti-scaling high-efficiency flue gas waste heat recovery device. Specifically, the high-efficiency heat exchange device that uses special composite materials to recover various boiler flue gas waste heat can prevent low-temperature acid dew corrosion of flue gas, and can reduce or remove ash and scale on the surface of the heat exchanger. the

Background technique

Boiler flue gas contains a certain amount of sulfur dioxide and sulfur trioxide, which combine with water vapor in the flue gas to form sulfuric acid vapor, and its condensation temperature is called the acid dew point of the flue gas. When the temperature of the heating surface at the rear of the boiler is lower than the acid dew point of the flue gas, a sulfuric acid solution will form on the surface. the

When the metal heat exchanger is used for flue gas waste heat recovery, in order to prevent acid dew corrosion, the exhaust gas temperature is designed at 120-140°C. Considering the decrease in heat transfer coefficient caused by the pollution of the heating surface during operation, the actual exhaust gas temperature is mostly 140-180°C ℃, the exhaust heat loss leads to a lot of energy waste. On the other hand, high exhaust gas temperature will increase the water consumption of flue gas desulfurization. This is because wet desulfurization requires the temperature of flue gas entering the desulfurization tower to be 80°C, and the use of water spraying to reduce the temperature of high-temperature flue gas requires a lot of cooling. water. the

If corrosion-resistant heat exchange equipment is used to recover the waste heat of the flue gas, the limitation of corrosion can be overcome, and the exhaust temperature of the flue gas can be reduced from at least 120°C to 80°C. According to the existing research results, for every 16-20°C decrease in the exhaust gas temperature of large boilers, the thermal efficiency of the boilers will increase by 1%. Therefore, using corrosion-resistant heat recovery equipment to reduce the exhaust gas temperature at 40°C, the boiler efficiency can be increased by 2-3%, and the comprehensive energy utilization efficiency can be significantly improved. At the same time, it can save the amount of cooling water required for spraying water to cool down, achieving the double effect of energy saving and water saving. the

There are two main methods of flue gas anti-corrosion: metal heat exchangers coated with corrosion-resistant coatings and heat exchangers using corrosion-resistant materials. For the method of coating the metal surface with a corrosion-resistant coating, it is difficult for the coating to completely cover the surface of the heat exchanger, and the coating is susceptible to thermal stress and comes off. For heat exchangers made of corrosion-resistant materials, fluoroplastic heat exchangers are widely used, but because fluoroplastics are difficult to process and have low thermal conductivity, the heat transfer performance of fluoroplastic heat exchangers is weak, and they are limited to thin-walled thin tubes. However, in practical applications, there are problems such as difficult sealing, difficult fixing of tube bundles, easy blockage, and large flow resistance. the

An ideal flue gas heat recovery device should not only have good corrosion resistance, but also have excellent heat transfer performance, including strengthening the heat transfer on the flue gas side and reducing the thermal resistance caused by dust accumulation and scaling during operation . the

Utility model content

The purpose of this utility model is to provide an anti-corrosion and anti-scaling efficient flue gas waste heat recovery device, which is characterized in that the structure of the heat exchange device is that the two sides of the fin tube 1 pass through the positioning holes of the side shell 3, and the The tube 1 and the side shell 3 are flexibly sealed by a high-temperature-resistant rubber ring 4, and then the upper and lower shells 2 are connected to the side shell 3 to form a heat exchanger shell, and the finned tubes 1 are arranged horizontally in the heat exchanger shell , arranged vertically and regularly; and on both sides of the heat exchanger shell, the ends of the two finned tubes in each horizontal row of finned tubes are sealed and connected with semicircular elastic pressure-resistant elbows 5 to form a row of channels, and finally , each of the channel openings arranged vertically on both sides of the heat exchanger shell is communicated with a connecting pipe 6 . the

The size of the heat exchanger shell in the three-dimensional direction of space changes to suit the size of the boiler flue, and the length of the finned tubes 1 in the X direction and the number of rows of the finned tubes 1 in the Y direction in the XY plane are determined according to the size of the flue. The number of fins increases proportionally with the length of the tube, and the number of columns of the heat exchanger in the Z direction is determined according to the size of the flue in the Z direction and the actual required heat exchange area. the

The number of rows and the number of rows of finned tubes 1 arranged in the shell of the heat exchanger are equal or different. the

The multiple heat exchanger shells are connected in series through the flange holes on their sides, or fixed with the boiler flue. the

The material of the finned tube is a high thermal conductivity filled composite material, the base material of the composite material is nylon, polyolefin, polyphenylene sulfide plastic material, or rubber material, or ceramic material, and graphite is filled inside these base materials Alkenes, carbon nanotubes, carbon fibers, metal particles and metal compound particles to improve the thermal conductivity of composite materials. the

The high-temperature-resistant rubber ring is an I-shaped structure, and is stuck in the fixing hole of the finned tube of the side housing 3 . the

The finned tube and the housing are flexibly sealed, and the finned tubes are flexibly connected to each other. The finned tube can move 1-10 mm along the tube length to provide mechanical disturbance and remove dust and scale during operation. the

The fin pitch of the finned tubes and the arrangement of the finned tubes are such that the fin pitch is between 1-15 mm, the finned tubes are arranged in parallel or forked rows, and the pitch is 0.5-3 times the diameter of the finned tubes. the

Beneficial effects of the utility model: (1) The anti-corrosion and anti-scaling composite material heat exchange device adopts the form of a finned tube heat exchanger, the fluid inside the tube is water, and the fluid between the fins outside the tube is smoke, which solves the problem of Corrosion of low-temperature acid dew in flue gas waste heat recovery; (2) The composite material used in this device has high thermal conductivity and can effectively transfer heat. Eliminate the damage of flue gas temperature fluctuations to finned tubes; (3) adopt fin structure to strengthen flue gas side heat exchange and improve heat recovery efficiency; (4) optimize fin spacing and finned tube arrangement according to fuel types to reduce operating (5) The flexible seal between the finned tube and the shell, the flexible connection between the finned tubes, the finned tube can move along the length of the tube, provide mechanical disturbance, and remove the ash during operation Scaling; (6) The heat exchanger shell is composed of detachable modules, and part of the shell can be disassembled according to cleaning needs, and the finned tube unit can be cleaned and replaced; (7) The heat exchanger adopts a modular structure as a whole, The size can be adjusted in three directions to meet the requirements of different air duct sizes and heat transfer. the

Description of drawings

Fig. 1 is a three-dimensional view of a corrosion-resistant high-efficiency flue gas waste heat recovery device with a shell. The heat exchange device adopts the arrangement of finned tubes 1 in a row, which is an example arrangement of 3×3 rows on the YZ plane perpendicular to the finned tubes 1 . the

Figure 2 is a schematic diagram of the parts of the heat exchange device, in which a is a schematic diagram of the shape of the upper and lower shells; b is a schematic diagram of the shape of the finned tube; c is a schematic diagram of the shape of the side shell. the

Fig. 3 is a structural diagram of the heat exchanger shell. the

Figure 4 is a cross-sectional view of the flexible seal between the finned tube and the side shell through a high-temperature-resistant rubber ring. the

Detailed ways

The utility model provides an anti-corrosion and anti-scaling high-efficiency flue gas waste heat recovery device, which will be described below in conjunction with the accompanying drawings. the

Fig. 1 is a three-dimensional view of a corrosion-resistant high-efficiency flue gas waste heat recovery device with a shell. The structure of the heat exchange device is that both sides of the finned tube 1 pass through the positioning holes of the side shell 3, and the finned tube 1 and the side shell 3 are flexibly sealed by a high-temperature-resistant rubber ring 4, as shown in the figure. The high-temperature rubber ring is an I-shaped structure, and is stuck in the fixing hole of the 3-finned tube of the side shell. Then the upper and lower shells 2 are connected with the side shells 3 to form a heat exchanger shell, and the finned tubes 1 are regularly arranged in horizontal rows and vertical columns in the heat exchanger shell; and on both sides of the heat exchanger shell, each horizontal row The ends of the two finned tubes in the finned tubes are sealed and connected with semicircular elastic pressure-resistant elbows 5 to form a row of channels. The connecting pipe 6 communicates. the

Figure 2 is a schematic diagram of the parts of the heat exchange device, in which a is a schematic diagram of the shape of the upper and lower shells; b is a schematic diagram of the shape of the finned tube; c is a schematic diagram of the shape of the side shell. Among them, 1 is a finned tube, and the shape of the fin is rectangular; 2 is the upper and lower shells, and the upper and lower shells 2 are flanging structures around the flat plate, and the flanging on the front and rear sides are air duct flanges, and flange holes 7, The flanges on the left and right sides are orifice plates connected with the side shell 3; 3 is the side shell, which is a flange structure on both sides of the flat plate, wherein the flanges on the front and rear sides are air duct flanges, and flange holes 7 are provided. The two ends are orifice plates connected with the upper and lower shells 2; the positioning holes of the finned tubes 1 are distributed on the side shell 3. the

Fig. 3 is a structural diagram of the heat exchanger shell. The heat exchanger shell consists of upper and lower shells 2 and side shells 3 . The size of the heat exchanger shell in the three-dimensional direction of space changes to suit the size of the boiler flue, and the length of the finned tube 1 in the X direction and the number of rows of the finned tube 1 in the Y direction in the XY plane are determined according to the size of the flue. The number of fins increases proportionally with the length of the tube, and the number of columns of the heat exchanger in the Z direction is determined according to the size of the flue in the Z direction and the actual required heat exchange area. The number of rows and columns of finned tubes 1 in the heat exchanger shell is equal or different, as shown in Figure 1, the heat exchange device adopts the form of arranged finned tubes 1 in a row, on the YZ plane perpendicular to the finned tubes 1 is an example arrangement of 3x3 rows. the

The material of the finned tube is a high thermal conductivity filled composite material, the base material of the composite material is nylon, polyolefin, polyphenylene sulfide plastic material, or rubber material, or ceramic material, and graphite is filled inside these base materials Alkenes, carbon nanotubes, carbon fibers, metal particles and metal compound particles to improve the thermal conductivity of composite materials. the

The working principle of the device is: the anti-corrosion and anti-fouling composite material heat exchange device adopts the form of finned tube heat exchanger, the fluid inside the tube is water, and the fluid between the outer fins of the tube is flue gas; The flow between the plates, the water flows inside the tube, and the two are generally counter-currently arranged. The high thermal conductivity composite material can effectively transfer heat, and the fin structure strengthens the heat transfer on the flue gas side. The heat of the flue gas is transferred to the water in the pipe, the temperature of the flue gas gradually decreases from the inlet to the outlet, and the temperature of the water gradually increases from the inlet to the outlet. The operating temperature range of the finned tubes is from room temperature to 200°C, which not only covers all temperature ranges for flue gas waste heat recovery, but also effectively prevents thermal shock from damaging the finned tubes when flue gas temperature fluctuates. The finned tube and the shell are flexibly sealed, and the finned tubes are flexibly connected to each other. The finned tube can move 1-10mm along the tube length to provide mechanical disturbance and remove dust and scale during operation. The finned tubes should adjust the fin spacing and the arrangement of the finned tubes according to the fuel type and composition of the boiler, wherein the fin spacing is between 1 and 15mm, and the finned tubes are arranged in parallel or forked rows, and the spacing is 0.5 to 3 times the diameter of the sheet tube. the

When dust and fouling problems occur during operation, due to the flexible seal between the finned tube and the shell and the flexible connection between the finned tubes, the finned tube can move 1-10 mm along the tube length, providing mechanical Disturbance to remove fouling during operation. In addition, the heat exchanger shell is composed of detachable modules, and part of the shell can be disassembled to clean and replace the finned tube unit according to the cleaning needs. the

Claims (6)

1. An anti-corrosion and anti-fouling high-efficiency flue gas waste heat recovery device, characterized in that the structure of the heat exchange device is that the two sides of the finned tube (1) pass through the positioning holes of the side shell (3), and the finned tube (1) and the side shell (3) are flexibly sealed by a high-temperature-resistant rubber ring (4), and then the upper and lower shells (2) are connected to the side shell (3) to form a heat exchanger shell. The finned tubes (1) in the shell are regularly arranged in horizontal and vertical columns; and on both sides of the heat exchanger shell, the ends of the two finned tubes in each horizontal row of finned tubes are semicircular elastic pressure-resistant elbows (5) Sealed connection to form a row of channels, and finally, connect the vertically arranged channel openings on both sides of the heat exchanger shell with a connecting pipe (6). the 2. An anti-corrosion and anti-fouling high-efficiency flue gas waste heat recovery device according to claim 1, characterized in that the number of rows and columns of finned tubes (1) arranged in the heat exchanger shell are equal or different . the 3. An anti-corrosion and anti-fouling anti-fouling high-efficiency flue gas waste heat recovery device according to claim 1, characterized in that the plurality of heat exchanger shells are connected in series through flange holes on their sides, or are fixed to the boiler flue. the 4. An anti-corrosion and anti-fouling high-efficiency flue gas waste heat recovery device according to claim 1, characterized in that the high-temperature-resistant rubber ring is an I-shaped structure, which is fixed on the finned tube of the side shell (3) inside the hole. the 5. An anti-corrosion and anti-fouling high-efficiency flue gas waste heat recovery device according to claim 1, characterized in that the finned tube and the shell are flexibly sealed, the finned tubes are connected flexibly, and the finned tube The pipe can move 1-10mm along the length of the pipe to provide mechanical disturbance and remove the fouling during operation. the 6. An anti-corrosion and anti-fouling high-efficiency flue gas waste heat recovery device according to claim 1, characterized in that the fin spacing of the finned tubes and the arrangement of the finned tubes are such that the fin spacing is between 1 and 15 mm , The finned tubes are arranged in parallel or forked rows, and the spacing is 0.5 to 3 times the diameter of the finned tubes. the

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