CN104826471A - Industrial boiler flow-guide-plate-type glass fiber reinforced plastic flue gas desulfuration column - Google Patents

Abstract

The invention relates to an industrial boiler deflector type FRP flue gas desulfurization tower, which includes a cylindrical tower, and the two ends of the cylindrical tower are respectively provided with a demister inlet and a flue gas inlet. A spray layer and three deflectors are arranged in sequence between the flue gas inlets. The deflectors are placed in sequence with a distance of 15 cm. The distance between the highest position of the uppermost deflector and the position of the flue gas inlet in the vertical direction is is 355cm, the spraying layer is provided with four layers, arranged vertically, and the interval between each layer is one meter, and a multi-tube variable device is arranged on each layer, and the multi-tube variable device includes an upper fine-mouth connection port and a lower coarse-mouth connection port and six branch pipe connections. Compared with the swirl plate tower and the deflector type desulfurization smoke tower, the present invention only needs a few deflector plates to produce the same spiral effect as the swirl plate, and cooperates with the desulfurization by spraying method, and has simple structure, low investment and operation and maintenance costs . Compared with adding the alkali pump, the multi-pipe variable device of the present invention has obvious cost savings, and the replacement of pipelines is convenient.

Description

Industrial Boiler Deflector Type FRP Desulfurization Smoke Tower

technical field

The invention belongs to the field of mechanical preparation, and in particular relates to an industrial boiler deflector type glass steel desulfurization smoke tower.

Background technique

The "integration of chimney tower" technology was defined in previous engineering practice as canceling the conventional boiler exhaust chimney, and combining the chimney and cooling tower into one, so that the cooling tower not only maintains the original cooling and heat dissipation function, but also replaces the chimney discharge Desulfurized boiler flue gas, this technology is only applicable to new large and medium-sized thermal power plants with cooling tower equipment.

For enterprises with small and medium-sized industrial boilers, because there is no cooling tower equipment, the integration of chimney and cooling tower cannot be realized, and the goal of cost reduction and efficiency increase is difficult to achieve. In the synchronous design of the flue gas desulfurization system of the new boiler unit or the flue gas desulfurization transformation process of the original boiler unit, by adopting the structural form of combining the desulfurization absorption tower and the boiler exhaust chimney into one, the "smoke tower integration" technology is given a brand new Definition. This type of smoke tower is made of glass fiber reinforced plastic, commonly known as glass fiber reinforced plastic (FRP or GRP), which is a composite material made of glass fiber and resin. The glass fiber provides strength and rigidity, and the resin provides chemical resistance and toughness. It is compatible with titanium. The steel plate is quite acid-resistant and anti-corrosion, and the insulation layer can be removed. It is especially suitable for the operating conditions of the wet chimney of the coal-fired power plant where desulfurization does not add GGH.

The working principle of the combined desulfurization absorption tower and chimney is that the flue gas from the coal-fired boiler first enters the absorption tower at the bottom through the induced draft fan. The gas is mixed to realize desulfurization, and the desulfurized flue gas is lifted through the top chimney and discharged to the atmosphere through the condensate recovery device at the top of the chimney.

Compared with the traditional desulfurization technology, the "smoke tower integration" technology has the following characteristics.

(1) Save the project area. In the overall layout of the system, there is no need to introduce the clean flue gas after the desulfurization reaction into the original old chimney, that is, there is no need to consider the direction of the clean flue gas flue after desulfurization, and the layout of the equipment can be arranged very compactly. Save over 20%.

(2) Reasonably optimize the system configuration and reduce project investment costs. Since the clean flue gas is directly discharged through the absorption tower, compared with the traditional desulfurization technology, the supporting flue gas baffle door, flue main material, flue insulation material and other equipment or materials are cancelled, which saves the initial investment cost, and to a certain extent It simplifies the operation control logic of the start and stop of the equipment in the system.

(3) Reduce the time cost and risk cost of original facility renovation. At present, domestic flue gas desulfurization projects generally do not have a flue gas heat exchanger (GGH). Therefore, new boiler units need anti-corrosion chimneys, and old units need to carry out anti-corrosion renovations on the original old chimneys.

(4) Effectively reduce the daily energy consumption of the system. Because there is no need to clean the flue gas flue after desulfurization, the pressure loss of the desulfurization system can be effectively reduced by 500-700Pa, and the system can save more than 100 per hour of power consumption. .

(5) Widely applicable to small and medium-sized new construction and renovation projects. Through the organic combination of the main reaction process of wet desulfurization such as limestone-gypsum method, magnesium method, sodium method and seawater method, the "smoke tower integration" technology can be widely applied to small and medium-sized new construction and renovation projects, achieving reduced land occupation, The purpose of saving investment.

Although the "smoke tower integration" technology shows many advantages when it is used in the flue gas desulfurization of small and medium-sized coal-fired boilers, the existing "smoke tower integration" technology will face the impact of condensate precipitation if the wet flue gas is not dried A series of problems such as the surrounding environment, if limestone is used as the desulfurization reaction absorbent, the phenomenon of "gypsum rain" may appear around the plant area. In order to solve this problem, Wei Yu and others proposed to install an integrated chimney condensate recovery system, and the condensate recovery process is divided into three stages.

In the first stage, the saturated flue gas passes through the cyclone device to form a force in the normal direction of the flue gas flow, so that most of the condensed water flows to the inner wall of the chimney due to the combined force of the chimney uplift and the normal force; in the second stage, after passing the first stage The condensed water passes through the pores on the inner wall of the chimney, and returns to the inside of the absorption tower from the diversion pipe; in the third stage, a small amount of small particle size is lifted along the inner wall of the chimney to the top of the chimney and the condensed water is precipitated by contact with the external environment After passing through the top collecting device, the condensed water flows back to the absorption tower through the diversion pipeline for recycling. In addition, to meet increasingly stringent emission standards, further improvements in desulfurization efficiency are required. The reason is that most desulfurization towers of this technology use wet spray towers, and the flow field distribution of flue gas and slurry in the tower directly determines the mass transfer, heat transfer and reaction in the tower, especially the flow characteristics of flue gas directly affect To the determination of the geometric dimensions of the smoke tower, the number of nozzles in the tower, the type of nozzles and the arrangement of nozzles, etc.

The actual operation shows that the key factor affecting the efficiency of wet flue gas desulfurization is the complex flow field in the tower. For the spray tower, it is difficult to reveal the flow conditions in the tower only by the test, but the numerical simulation plays an important role in understanding the flue gas flow law and design of the spray tower. Wang Xu from North China Electric Power University carried out reasonable modeling and simplification of the large-scale desulfurization tower, and used the commercial software Fluent to conduct a two-dimensional numerical simulation of the empty tower of the wet desulfurization vertical spray tower. The calculation results show that the air velocity distribution of the empty tower flow field uneven. Lin Yongming from Zhejiang University, with the help of commercial Fluent software, carried out a numerical simulation of the flue gas flow field in the spray tower of the 300MW unit wet flue gas desulfurization system, and investigated in detail the influence of the geometric structure size and operating parameters on the flue gas flow field in the spray tower. The numerical simulation results show that the overall trend of the flue gas flow field in the spray tower is generally consistent, and the geometric structure size and operating parameters have a greater impact on the flue gas flow field in the tower. Zhao Zhe of Tsinghua University took the wet flue gas desulfurization spray tower of 300MW unit as the research object, and used the general software of computational fluid dynamics to simulate the internal two-phase flow field. When there was no spray, it was observed that the high-speed flue gas entered the tower body It directly impacts the tower wall opposite to the inlet flue, and after being blocked, it is forced to change its direction and deflect upwards, passing through 4 spray layers in sequence, and reaching the outlet section, forming an obvious high gas velocity zone within the entire tower body. The width accounts for about 1/3 of the tower diameter. In addition, due to the pressure constraint of the outlet section, part of the flue gas that reaches the outlet section flows back along the right tower wall, passes through four spray layers in turn, and then merges with the inlet high-speed flue gas. In this way, in the upper half of the entire tower Partially forms a large clockwise vortex.

The swirl tray is a jet tray, which has the characteristics of simultaneous dust removal and desulfurization, high load, low pressure drop, not easy to block, and wide operating flexibility. It is widely used in petroleum, chemical, light industry, and environmental protection. The air flow enters from the bottom of the blades, and the absorption liquid is evenly distributed to each blade from the top of the tray through the middle blind plate to form a thin liquid layer. The rotating upward air flow sprays the absorption liquid into fine droplets, which are thrown towards the tower under the action of centrifugal force. The wall forms a liquid ring, which flows to the sump under the action of gravity, and flows to the blind plate of the next tray through the downcomer.

He Sicheng of Changzhou University et al. numerically simulated the velocity and pressure drop of the gas phase flow field in the swirling plate tower, and pointed out that the axial and radial velocity of the flue gas in the tower has an important influence on the gas-liquid heat and mass transfer, while the deflector type FRP The desulfurization tower has similar axial and radial flue gas velocities to those in the swirling plate tower.

For the spray layer, the insufficient liquid supply pressure of the high-level spray layer leads to problems such as the inability of the lye to fully react with the sulfur-containing flue gas, and the poor atomization effect of the droplets. At present, the solution to this problem is to install a liquid supply pump and adopt a mesh arrangement The pipe layout method is expensive for small equipment; and the pipe is blocked, so it is not easy to replace the pipe. The shortcoming of prior art mainly shows as following aspects:

1) In the current "smoke tower integration" type desulfurization chimney, after the flue gas enters the tower body, it directly impacts the tower wall opposite to the inlet flue, and is forced to change direction and deflect upward after being blocked. In the entire tower body, the flue gas deflects , forming an obvious high-speed gas zone, the high-speed gas zone reduces the uniformity of the smoke flow field, thereby reducing the contact time and contact area between the smoke and the spray liquid. The plate improves the uniformity of the flue gas flow field in the tower, avoids the phenomenon of high gas velocity bands, prolongs the contact time between the flue gas and the liquid droplets, and increases the contact area between the flue gas and the spray liquid;

2) For the "tower-in-one" type desulfurization chimney, the condensate recovery system proposed by Wei Yu et al. needs to process pores on the tower wall, which is cumbersome and reduces the strength of the chimney. The cleaning work brings difficulties. In addition, it is necessary to install a swirl device, which has a complex structure. In view of such shortcomings, the use of deflector drainage can replace the swirl device on the one hand, and on the other hand, the mature and efficient The demister replaces the condensate recovery device, and at the same time, due to the spiral rise of the wet flue gas, the centrifugal force generated by the radial velocity makes the liquid droplets with large mass hit the wall and fall to the waste liquid pool, reducing the water content of the wet flue gas;

3) Most of the fouling in the desulfurization system is on the inner wall of the tower, nozzles, nozzles, nozzles and other parts. The discontinuous deflectors are arranged intermittently and arranged at high and low levels to reduce the accumulation of liquid and fouling. The radial temperature of the absorption tower is distributed in a way that the center is higher and the wall side is lower. In this case, the solid particulate matter carried in the flue gas is easy to collide with the wall of the absorption tower and cause scaling. The deflector proposed by the present invention makes the flue gas produce a spiral upward movement effect, and the radial velocity of the flue gas helps the high-temperature flue gas at the center to mix and transfer heat with the low-temperature flue gas around, so that the temperature of the flue gas in the tower is uniform and effective. Reduce scaling problems caused by too low temperature. In addition, due to the scouring effect of the flue gas moving in the radial direction on the tower wall, nozzle, etc., it helps to clean the scale layer on the surface of the components;

4) In the spray tower commonly used at present, the flue gas hits the wall and moves upwards, and the spiral effect is weak. However, the deflector type desulfurization flue gas tower proposed by the present invention has a strong flue gas spiral effect, and has the effect of simultaneous dust removal and desulfurization. The purpose of secondary dust removal can reduce or even eliminate the investment and operating costs of dust removal devices; in addition, He Sicheng of Changzhou University et al. have numerically simulated the velocity and pressure drop of the gas phase flow field in the swirl plate tower, and pointed out that the flue gas tangential velocity in the tower It reflects the speed of the fluid rotating in the swirl plate tower, reflects the size of the centrifugal force, and is also a key factor for whether the gas-liquid mass transfer and absorption can be fully carried out. Tang Yongzhi from Southeast University, etc. conducted a three-dimensional numerical simulation of the flow field of the spray tower empty tower and pointed out that the rotating and rising flue gas has a high degree of turbulence, which is conducive to the good mixing of gas and liquid and can improve the desulfurization efficiency. The deflector type FRP flue gas desulfurization tower also has the same spiral air flow as in the swirl plate tower, so it shows the above-mentioned advantages.

5) Lin Yongming of Zhejiang University found through the numerical simulation of the wet spray tower that the flow field between the flue gas demister and the top spray layer changed from no vortex to two vortices, and the flue gas was close to The wall becomes more serious, which may cause blockage and scaling of the demister. The spiral rising flue gas produced by the deflector in the present invention not only rectifies the flue gas, but also uniforms the flue gas pressure in the direction of the cross section, which is beneficial Help demister dehydration work;

6) In the multi-layer spray desulfurization device, a certain spray pressure needs to be maintained when the spray liquid passes through the outlet of the nozzle. Due to the large cross-sectional area of the spray layer, it is necessary to ensure that the pressure is above a certain value, usually by changing the tube The diameter method is used to realize the equal pressure value of each part of the main pipe. What the pipe diameter joint adopts is the existing different diameter pipe on the market, also known as the big and small head, different diameter straight through. This is one of the chemical pipe fittings, used for the connection between two pipes with different diameters. For small-scale desulfurization devices, the cost is relatively high if the network arrangement is adopted, and a large number of liquid supply pumps need to be configured.

The existing variable devices generally only have 3 or 4 connections, that is, the number of pipes connected on the same level is limited. In a small desulfurization system, it is difficult to maintain equal pressure and uniform spraying, and more main pipes are required. It is more complicated, and it is inconvenient to install and replace a single pipe.

Contents of the invention

The present invention overcomes the deficiencies of the prior art and proposes a deflector-type FRP desulfurization smoke tower for industrial boilers. The multi-tube variable joints of the desulfurization smoke tower are arranged in a small desulfurization device combined with deflectors, which can evenly spray desulfurization The lye can fully combine the spray liquid and the flue gas, and has a greater coverage, while saving the use of the liquid supply pump and simplifying the pipeline arrangement. the

Technical scheme of the present invention is:

An industrial boiler deflector type FRP desulfurization flue tower, comprising a cylindrical tower, the two ends of the cylindrical tower are respectively provided with a demister inlet and a flue gas inlet, and the demister inlet and the flue gas inlet A spray layer and three deflectors are arranged in sequence, and the deflectors are placed in sequence with a distance of 15 cm. The distance between the highest position of the uppermost deflector and the position of the flue gas inlet in the vertical direction is 355 cm. The spraying layer is provided with four layers, arranged vertically, and the interval between each layer is one meter, and a multi-pipe variable device is arranged on each layer, and the multi-tube variable device includes an upper fine port connection, a lower coarse port connection and six The branch pipe connection port, the upper thin port connection port is located above the lower coarse port connection port, the branch pipe connection port is located between the upper fine port connection port and the lower coarse port connection port, the branch pipe connection port is connected to a spray branch pipe, each branch pipe The angle between them is 60°, and the spiral nozzle is arranged at the end of the spray branch pipe, and the upper thin-mouth connection port, the lower thick-mouth connection port and the six branch pipe connection ports are connected to each other.

The beneficial effects of the present invention are:

(1) Compared with the swirl plate tower and the deflector type desulfurization flue tower, the present invention only needs a few deflector plates to produce the same spiral effect as the swirl plate, and cooperates with the spray desulfurization method, which has a simple structure, low investment and operation Low maintenance.

(2) Compared with the addition of alkali pumps, the cost savings of the multi-tube variable device of the present invention is obvious. Pipe replacement is easy.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is the structural representation of installation angle model of the present invention;

Fig. 2 is a schematic diagram of the shape of the deflector of the present invention;

Fig. 3 is a schematic diagram of the shape of the spray layer of the present invention;

Fig. 4 is a structural representation of the present invention;

Fig. 5 is a schematic diagram of the overall structure of the multi-tube variable device of the present invention;

Fig. 6 is a top view of the multi-tube deformer of the present invention.

In the figure: 1. The inlet of the demister; 2. The spray layer; 3. The inlet of the flue gas; 4. The high-efficiency demister; , Bottom rough mouth connection port; 9, tower tube.

Detailed ways

Referring to Fig. 1 to Fig. 6, the present invention includes a cylindrical tower 9, and the two ends of the cylindrical tower 9 are respectively provided with a demister inlet 1 and a flue gas inlet 3, and between the demister inlet 1 and the A spray layer 2 and three deflectors 5 are sequentially arranged between the flue gas inlets 3, and the deflectors 5 are placed in sequence with a distance of 15 cm. The distance between the positions in the vertical direction is 355cm, and the spray layer 2 is provided with four layers, which are vertically arranged, and the interval between each layer is one meter, and a multi-tube variable device is arranged on each layer, and the multi-tube variable device includes The thin-mouth connection port 6, the lower thick-mouth connection port 8 and six branch pipe connection ports 7, the upper thin-mouth connection port 6 is located above the lower thick-mouth connection port 8, and the branch pipe connection port 7 is located at the upper thin-mouth connection port 6 and the lower thick-mouth connection port Between the connection ports 8, the branch pipe connection port 7 is connected to a spray branch pipe, and a spiral nozzle is arranged at the end of the spray branch pipe. The upper thin-mouth connection port 6, the lower thick-mouth connection port 8 and the six branch pipe connection ports 7 are connected . As shown in Figure 1, three deflectors 5 are inlaid in the tower, all of which are 100cm in height and rotated 180°. The widths of the deflectors 5 from bottom to top are 62, 62, and 55 cm respectively. 5 The spacing in the vertical direction is 15cm, and there is an overlapping part of 10-20° in the horizontal direction. The starting point of the installation position of the first deflector 5 is directly opposite to the flue gas inlet 3, and the height is 25 cm from the vertical height above the flue. At the position of 7m to 12m, four spray layers 2 are arranged at an even interval of 1m, and six spray branch pipes are arranged in each layer. The device is shown in Figure 2 and Figure 3. working principle:

(1) As shown in Figure 4, the flue gas to be treated enters the desulfurization flue gas tower according to the present invention from the flue gas inlet 3, and after being diverted by the deflector 5, the flue gas moves upward in a spiral, and the flue gas sprayed out from the spray layer 2 The slurry contact is desulfurized and purified, and the purified flue gas continues to move upwards, enters the high-efficiency demister 4 in the air flow stabilization section (uniform air flow, no spiral effect) and is discharged to the atmosphere. The water collected by the high-efficiency demister 4 is combined with desulfurization The waste liquid will drop to the waste liquid pool together.

The present invention adopts the multi-pipe variable section to effectively solve the above-mentioned problems: ①Through hydraulic calculation, according to the connection of variable-diameter pipelines in the vertical direction, the diameter of the main pipeline becomes smaller, so that the four spray layers can maintain a certain outlet pressure; ②Six spray pipes are arranged between each spray layer in a radial arrangement, which can fully and evenly mix the desulfurization slurry and flue gas; Strength; ④ If the pipe is blocked or damaged, it is convenient to replace a single pipe.

The multi-tube variable device is shown in Figure 5. In the figure, the upper thin-mouth connection port 6 is connected to the upper thinner main pipe, the lower thick-mouth connection port 8 is connected to the lower thicker main pipe, and the extension of the branch pipe connection port 7 is connected to each branch pipe. . Fig. 6 is a top view of the multi-tube deformer, and the angles between the branch tubes are all 60°.

Claims (1)

1. An industrial boiler deflector type FRP flue gas desulfurization tower is characterized in that: it comprises a cylindrical tower, and the two ends of the cylindrical tower are respectively provided with a demister inlet and a flue gas inlet. A spray layer and three deflectors are arranged in sequence between the inlet of the device and the flue gas inlet. The deflectors are placed in sequence with a distance of 15 cm. The highest position of the uppermost deflector is vertical to the position of the flue gas inlet. The spacing in the direction is 355cm. The spray layer is provided with four layers, which are arranged vertically. Coarse connection port and six branch pipe connection ports, the upper thin port connection is located above the lower coarse connection port, the branch pipe connection port is located between the upper thin port connection and the lower coarse connection port, and the branch pipe connection port is connected The angle between each branch pipe is 60°, and the spiral nozzle is arranged at the end of the spray branch pipe, and the upper thin-mouth connection port, the lower thick-mouth connection port and the six branch pipe connection ports are connected to each other.