Dust collecting plate based on particle trap effect, new type of electrode matching and high-efficiency electrostatic precipitator

Abstract

The present invention relates to a dust collecting electrode plate, a new type of pole matching form and a high-efficiency electrostatic precipitator based on the particle trap effect. The dust collecting electrode plate is bent to form a plurality of raised folding plates and grooves, and a particle trap is formed at the groove. The dust collecting electrode plate and the new type of pole matching form matched with the multi-angle double-thorn electrode have low dust accumulation thickness and high field strength at the protrusion of the particle trap, and the particles at the protrusion are easy to enter the trap under the drag force of the airflow or the vibration. The dust accumulation thickness of the groove is high, but the field strength in the formed dust layer is low, which prevents the breakdown between particles and the interference with the discharge, increases the operating voltage working range, and cooperates with the intelligent vibration system to form an electrostatic precipitator. The present invention reduces secondary dusting, reduces the effective field strength loss of high specific resistance fly ash, and broadens the specific resistance application range and working temperature window of the electrostatic precipitator; it has the advantages of increasing the corona current, strengthening the charging of fine particles, and improving the dust removal efficiency, which can reduce the operating cost and has high industry applicability and operation reliability.

Description

Technical Field

[0001] The invention relates to the field of electrostatic precipitator environmental protection technology, and in particular to a dust collecting electrode plate based on a particle trap effect, a new electrode matching form and a high-efficiency electrostatic precipitator. Background Art

[0002] An electrostatic precipitator is a dust removal device that uses electricity to separate dust particles from gas. It is widely used in blast furnace tail gas dust removal in various industries and has the advantages of low energy consumption, low resistance, high dust removal efficiency and large flue gas processing volume. A conventional electrostatic precipitator, such as an electrostatic precipitator disclosed in patent number CN 103357504 B, includes a positive plate and a negative plate, wherein there is a gap between the positive plate and the negative plate, the positive plate is provided with a plurality of through holes to form a plurality of tubular positive electrodes, and the negative plate is correspondingly provided with a plurality of columnar negative electrodes, and the columnar negative electrodes are sleeved in the tubular positive electrode of the positive plate to form a plurality of tubular electrostatic precipitator units.

[0003] Traditional electrostatic precipitators can handle a limited number of types of dust. For example, in the power industry, SO3 will condense on the surface of particles in a low temperature range, changing the dielectric constant and resistivity of the particles, causing the charge of the particles and the removal efficiency to change. At the same time, as the dust collector is running, a certain thickness of dust will accumulate on the dust collecting plate. The dust accumulation will have an adverse effect on the stable discharge of the electrostatic precipitator, reducing the working efficiency of the dust collector, which is a major challenge faced by the electrostatic precipitator. The alkali metal content of glass furnace dust is high and corrosive. If this dusty flue gas passes directly through the SCR denitrification device, the alkali metal elements and trace element compounds in the fly ash will cause the SCR catalyst to be poisoned and deactivated, and at the same time reduce the service life of the SCR catalyst. In order to ensure the efficient and stable operation of the SCR system, it is necessary to remove particulate matter in the high-temperature flue gas before entering the SCR device. In order to improve the activity of the catalyst, the SCR system generally operates at a temperature of 320-450°C. Therefore, it is necessary to remove particulate matter at a temperature above 320-450°C to achieve high-temperature flue gas purification.

[0004] In order to improve the removal efficiency of fine particles by electrostatic precipitators, conventional electrostatic precipitators can alleviate the back corona problem caused by high resistivity dust by adding auxiliary electrodes to form a uniform electric field collection area. On this basis, C-type dust collecting plates and corrugated plate auxiliary electrodes are used. The dust layer formed by the accumulation on the surface of the conventional electrostatic precipitator plate will have an important impact on the capture of particles, and will have a completely different impact mechanism with the change of resistivity. For dust with too low resistivity, it is easy to jump on the dust collecting electrode, which is easy to form secondary dust and greatly reduce the efficiency of the dust collector; when the dust resistivity is too high and reaches the dust collecting electrode, the voltage in the dust layer increases, which weakens the spatial dust collecting field strength and significantly reduces the driving speed of the dust. In certain cases, it may even produce back corona, causing the dust collector to fail to operate normally. During the long-term operation of the electrostatic precipitator, as the ash on the dust collecting plates gradually accumulates, the thickness of the ash on the plates continues to increase, and the pressure drop on the ash layer increases accordingly. Therefore, it is necessary to remove the accumulated ash by vibrating the plates and wires. However, under certain complex working conditions, there are problems such as vibration and dust, which causes a significant drop in the capture efficiency. With the continuous improvement of particulate matter emission standards, the enhancement of particulate matter capture is the key to achieving further reductions in particulate matter emissions. Summary of the invention

[0005] The purpose of the present invention is to address the problems existing in existing electrostatic precipitators and to propose a dust collecting plate and a high-efficiency electrostatic precipitator based on the particle trap effect, which can broaden the applicable range of resistivity, increase corona current, strengthen the charging of fine particles, reduce airflow entrainment and secondary dust generated during vibration, and solve the problem of weakened electrode discharge characteristics and even back corona caused by the accumulation of dust layers.

[0006] In order to achieve the purpose, the technical solution provided by the present invention is:

[0007] The invention relates to a dust collecting electrode plate based on a particle trap effect, wherein a plurality of convex folding plates and grooves arranged at intervals are formed by bending, and particle traps are formed at the grooves.

[0008] The dust accumulation thickness at the protrusions of the particle trap is low and the field strength is high, so the particles at the protrusions can easily enter the trap under the drag of the airflow or the action of vibration; the dust accumulation thickness at the grooves is high, but the field strength in the dust layer formed here is low, which can effectively prevent breakdown between particles and interference with discharge, and increase the operating voltage working range; at the same time, since the field strength at the grooves is low, the electrostatic adhesion of the particles can be reduced, making it easy to vibrate and clean.

[0009] Preferably, the dust collecting electrode plate is also provided with a reinforcing folding plate, which can improve the transmission effect and distribution uniformity of the vibration force, reduce the vibration force loss, and help reduce the secondary dust caused by vibration.

[0010] Preferably, the cross section of the groove is an isosceles trapezoid, the width of the upper bottom surface of the cross section is 3 to 11 cm, the width of the lower bottom surface is 2 to 6 cm, the depth of the groove is 1 to 5 cm, and the angles between the two sides of the groove and the lower bottom surface of the groove are 100 to 135°.

[0011] The present invention relates to a new type of pole matching, comprising a plurality of dust collecting pole plates and a plurality of multi-angle double-thorn electrodes. The dust collecting pole plates are arranged at intervals, and the dust collecting pole plates are bent to form a plurality of spaced raised folding plates and grooves, and particle traps are formed at the grooves; the multi-angle double-thorn electrodes are spaced between adjacent dust collecting pole plates.

[0012] Preferably, the distance between the multi-angle double-puncture electrode and the dust collecting plate is 150-250 mm, and the distance between adjacent multi-angle double-puncture electrodes is 200-300 mm; the puncture length of the multi-angle double-puncture electrode is 5-15 mm, and the puncture angle is 15°-60°.

[0013] Preferably, for high specific resistivity dust, the multi-angle double-thorn electrode puncture length is 10-15 mm; for low specific resistivity dust, the multi-angle double-thorn electrode puncture length is 5-10 mm.

[0014] For high resistivity dust, the pole line uses a small-angle long-needle electrode to increase the dust collection field strength in the dust layer, effectively strengthen the capture, and inhibit the occurrence of back corona; for low resistivity dust, the pole line uses a large-angle short-needle electrode to inhibit the low resistivity particles from starting again on the pole plate and particle trap, reducing the decrease in particle capture efficiency caused by secondary dust. According to the requirements for different resistivity dust and particle control, the double-needle electrode and particle trap trapeze structure parameters are optimized to achieve efficient particle removal.

[0015] The invention relates to a high-efficiency electrostatic precipitator, comprising a plurality of groups of dust collecting plates, a plurality of multi-angle double-thorn electrodes and an intelligent vibration system; each group of dust collecting plates comprises a plurality of dust collecting plates arranged at intervals, at least one group of dust collecting plates is formed by bending to form a plurality of convex folding plates and grooves arranged at intervals, and particle traps are formed at the grooves; the multi-angle double-thorn electrodes are arranged at intervals between adjacent dust collecting plates; the intelligent vibration system cooperates with the dust collecting plates and is used to vibrate the dust collecting plates.

[0016] Preferably, the intelligent vibration system consists of an intelligent vibration module and a vibration device. The intelligent vibration module constructs a precise voltage drop prediction model based on the predicted value of the operating voltage reduction caused by dust layer accumulation, i.e., voltage drop. The vibration device is turned on when the voltage drop reaches a certain proportion.

[0017] Preferably, the specific steps of constructing the pressure drop accurate prediction model include:

[0018] 1) Based on online and historical data, establish a database of key equipment and parameters of the electrostatic precipitator covering flue gas parameters, electrostatic precipitator power supply parameters, and electrostatic precipitator body parameters;

[0019] 2) Based on the parameter database, a concentration gradient model of particulate matter along the flue gas flow direction is constructed;

[0020] 3) Based on the concentration gradient model of particulate matter along the flue gas flow direction, the accumulation rate of particulate matter on the plate surface is predicted to change with the airflow direction, the particle accumulation amount of the plate at the corresponding moment is obtained, and the plate particle accumulation thickness model is obtained according to the particle density;

[0021] 4) Combined with the particle resistivity parameters, the equivalent resistance of dust accumulation in the dust layer is established. By studying the dust layer resistance corresponding to each pole line of the electrostatic precipitator under different working conditions, a voltage drop proportional model is constructed;

[0022] 5) Calculate the pressure drop ratio according to the pressure drop ratio model, and start the vibration device when it exceeds the upper limit value;

[0023] 6) After vibrating for a period of time, repeat steps 1) to 5) and adjust the vibrating time.

[0024] Preferably, in the step 1), the established parameters of the electrostatic precipitator body include dust collecting area, electrode form, wire-plate distance, residence time, number of channels, and number of electric fields; the established flue gas parameters include inlet particulate matter concentration, inlet flue gas flow rate, and inlet flue gas volume; the established power supply device parameters mainly include primary voltage, secondary voltage, primary current, and secondary current.

[0025] In step 2), constructing a concentration gradient model of particulate matter along the flue gas flow direction specifically includes the following steps:

[0026] 2.1) Establishment of the prediction model C of the particle concentration at the inlet of the electrostatic precipitator based on the parameter database in ,

[0027]

[0028] Wherein, B is the amount of coal burned; η is the dust escape rate; Aar is the received ash content; Q is the flue gas flow rate;

[0029] 2.2) For a single electrostatic precipitator electric field, assuming that x=0 at the flue gas inlet, the particle removal amount of each micro-element length Δx along the x direction is predicted, and then the particle removal amount model of each micro-unit is constructed.

[0030]

[0031] At the entrance of the electric field, that is, when x = 0, C x＝0 =C in, when x = Δx, the amount of particulate matter removed is

[0032]

[0033] Where A is the specific dust collection area, l p is the length of the electrode plate, ω is the overall migration rate of particles in the flue gas, and C is the amount of particles removed;

[0034] 2.3) Based on the particle removal model, further construct the concentration gradient model of particulate matter along the flue gas flow direction

[0035]

[0036] Among them, Q is determined by the boiler load, and due to the continuous evolution of the particle size distribution along the x direction, the overall migration rate ω of the particles in the flue gas changes continuously.

[0037] The construction of the plate particle accumulation thickness model in step 3) includes the following steps:

[0038] 3.1) Obtain the accumulation rate of particles on the electrode along the x direction under different loads in the electric field of the electrostatic precipitator (%·s -1 ·Δx -1 ), the percentage of particles per second per unit length, where the percentage of particles is converted uniformly according to the average inlet particle concentration;

[0039] 3.2) Based on the accumulation rate of particles on the plate surface, a particle accumulation model at the corresponding time of the plate is constructed;

[0040] 3.3) Combined with the particle density along the flue gas flow in the electric field, the plate particle accumulation thickness model is obtained.

[0041]

[0042] Δh(x i ) is the dust accumulation height increment, H p is the plate height, t r Cumulative time after the last rapping, ρ p is the particle density.

[0043] The step 4) of constructing the pressure drop ratio model comprises the following steps:

[0044] 4.1) Combined with parameters such as particle resistivity, a prediction model for the equivalent resistance of dust accumulation in the dust layer is established. For pole line i, the equivalent resistance of the plate dust accumulation faced during the discharge process is the parallel value of the dust accumulation resistance on each microelement length.

[0045]

[0046] Rai is the dust accumulation resistance of electrode line i during discharge, d w-w is the epipolar spacing, ρ r is the particle specific resistance, Δh(j) is the particle layer thickness at position j, and x i is the boundary of the discharge area corresponding to the pole line i, x i+1 is the other side boundary of the discharge area corresponding to the pole line i;

[0047] 4.2) By simulating and calculating the dust layer resistance corresponding to each pole line of the electrostatic precipitator under different working conditions, combined with the current density of a single pole line of the electrostatic precipitator, the effective voltage ratio of the electrode line caused by the dust layer is simulated and calculated to form a voltage drop ratio model

[0048]

[0049] Ra is the equivalent total resistance of dust accumulation during the discharge process of the pole line, ρi is the current density of a single pole line, l is the length of the pole line, and U0 is the normal operating voltage.

[0050] In the step 5), when the pressure drop ratio exceeds the upper limit value of 10%, the rapping device is started and the rapping frequency is adjusted.

[0051] The particles in the flue gas enter the dust collecting space formed by the dust collecting electrode plate with the particle trap along the airflow direction. The multi-angle double-thorn electrode discharge charges the particles in the dust collecting space. Most of the particles enter the groove of the particle trap under the combined effect of airflow and electric field force, and only a small part of the particles are deposited on the raised folding plate of the particle trap, which significantly improves the capture efficiency of the particle trap groove; the groove of the particle trap can weaken the entrainment effect of the airflow in the dust layer, reduce the phenomenon of dust returning to the dust collecting space due to airflow entrainment, reduce the drag effect of the dust airflow, and make it difficult for the dust to start from the particle trap. When particles escape from the particle trap, the longer path increases the charge of the particles and increases the probability of the particles falling back into the particle trap, which can effectively prevent the particles from flying after vibration, thereby improving the particle capture efficiency; the dust accumulation thickness is low and the field strength is high at the raised folding plate of the particle trap, and the particles at the raised part are easy to enter the trap under the drag of the airflow or vibration; the dust accumulation thickness is high in the groove, but the field strength in the dust layer formed here is low, which can effectively prevent the breakdown between particles and the interference with the discharge, and increase the operating voltage working range; at the same time, due to the low field strength at the groove, the electrostatic adhesion of the particles can be reduced, making it easy to vibrate and clean.

[0052] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0053] 1. The dust collecting electrode plate involved in the present invention is formed into a plurality of spaced-apart raised folding plates and grooves by bending, and the grooves are the particle traps. The dust accumulation thickness at the raised folding plates is low and the field strength is high, and the particles at the raised folding plates are easy to enter the traps under the drag of the airflow or the action of vibration; the dust accumulation thickness in the grooves is high, and a relatively low field strength can be formed in the dust layer to prevent the breakdown between particles and the interference with the discharge, and increase the operating voltage working range; at the same time, the low electric field strength grooves formed can reduce the electrostatic adhesion of the particles, and are easy to vibrate and clean.

[0054] 2. The present invention can replace the puncture angle of the multi-angle double-puncture electrode according to the size of the specific resistance, and expand the applicable scope of the specific resistance by changing the matching relationship between the multi-angle double-puncture electrode and the particle trap electrode plate, thereby broadening the industry applicability.

[0055] 3. The dust collecting plate in the present invention is also provided with a reinforced folding plate, and the intelligent vibration system is connected to the reinforced folding plate, which can improve the distribution uniformity and transmission capacity of the vibration force and reduce the secondary dust generated by the vibration.

[0056] 4. The present invention adopts an intelligent vibration system in combination with a particle trap structure to effectively prevent particles from flying after vibration; at the same time, real-time intelligent vibration is realized based on the pressure drop ratio prediction model in the intelligent vibration system, thereby reducing the dust layer from having a greater impact on the electrode discharge characteristics, thereby strengthening the charge and achieving an improvement in dust removal efficiency.

[0057] 5. The present invention uses a dust collecting plate with a particle trap, which can effectively increase the dust collecting area compared to the traditional dust collecting plate, while reducing the floor space of the entire electrostatic precipitator equipment; the dust collecting plate can be selectively arranged in different electric fields of the electrostatic precipitator according to the dust collecting effect. For example, if it is arranged in the final electric field, a particle trap with a relatively low field strength is formed, which reduces the electrostatic adhesion of the particles and is easy to vibrate and clean; at the same time, a particle trap is formed in the low-speed area to reduce the secondary dust caused by airflow entrainment. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the structure of the dust collecting plate based on the particle trap effect;

[0059] Figure 2 It is a schematic diagram of a new type of electrode matching based on the particle trap effect, which is a dust collecting electrode plate and a multi-angle double-thorn electrode;

[0060] Figure 3 It is a top view of the multi-angle double-thorn electrode;

[0061] Figure 4 This is a schematic diagram of the structure of a high-efficiency electrostatic precipitator having a particle trap dust collecting plate in the final electric field of Example 3;

[0062] Figure 5This is a schematic diagram of the structure of the dust collecting electrode plate with a particle trap in Example 3 (for low specific resistivity dust);

[0063] Figure 6 is a top view of the multi-angle double-thorn electrode of Example 3;

[0064] Figure 7 Control flow chart of intelligent rapping system;

[0065] Figure 8 It is a structural diagram of a high-efficiency electrostatic precipitator with particle trap dust collecting plates in the first and last electric fields;

[0066] Fig. 9 This is a schematic diagram of the structure of the dust collecting electrode plate with a particle trap in the fourth embodiment (for high specific resistivity dust);

[0067] Fig.10 is a top view of the multi-angle double-thorn electrode of Example 4;

[0068] Fig.11 It is a schematic diagram of the optional multi-angle double-thorn electrode polar lines. DETAILED DESCRIPTION

[0069] In order to deepen the understanding of the present invention, the embodiments of the present invention are described in detail with reference to the accompanying drawings. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods are given, but the protection scope of the present invention is not limited to the following embodiments.

[0070] Example 1

[0071] Combined with Figure 1 As shown, this embodiment relates to a dust collecting plate 1 based on the particle trap effect, wherein the dust collecting plate 1 is formed by bending to form a plurality of spaced convex folding plates 4 and grooves 5, and a particle trap is formed at the grooves 5. The cross section of the groove 5 is an isosceles trapezoid, the width of the upper bottom surface of the cross section is 3 to 11 cm, the width of the lower bottom surface is 2 to 6 cm, the depth of the groove 5 is 1 to 5 cm, and the angles between the two sides of the groove 5 and the lower bottom surface of the groove 5 are 100 to 135 degrees. The dust collecting plate 1 is also provided with a reinforcing folding plate 3, which is arranged at both ends of the dust collecting plate 1.

[0072] Example 2

[0073] Combined with Figure 2As shown, a new type of pole matching involved in this embodiment includes two dust collecting pole plates 1 and a plurality of multi-angle double-thorn electrodes 6. The dust collecting pole plates 1 are arranged at intervals, and the dust collecting pole plates 1 are formed by bending to form a plurality of spaced raised folding plates 4 and grooves 5, and a particle trap is formed at the groove 5. The cross section of the groove 5 is an isosceles trapezoid, the width of the upper bottom surface of the cross section is 3 to 11 cm, the width of the lower bottom surface is 2 to 6 cm, the depth of the groove 5 is 1 to 5 cm, and the angles between the two sides of the groove 5 and the lower bottom surface of the groove 5 are 100 to 135°. The dust collecting electrode plate 1 is also provided with a strengthening folding plate 3, which is arranged at both ends of the dust collecting electrode plate 1; the multi-angle double-thorn electrode 6 is arranged between adjacent dust collecting electrode plates 1, the distance between the multi-angle double-thorn electrode 6 and the dust collecting electrode plate is 150-250mm, and the distance between adjacent multi-angle double-thorn electrodes is 200-300mm; the multi-angle double-thorn electrode needle puncture length is 5-15mm, and the needle puncture angle can be selected between 15° and 60°, such as Fig.11 As shown, multi-angle double-needle electrode acupuncture 6 with acupuncture angles of 15°, 30°, 45° and 60° is given.

[0074] Example 3

[0075] Based on a power plant with a capacity of 1000MW, the particle size range of flue gas particles is measured to be 0.01-0.1μm, and the maximum stable ash concentration of the dust removal device is set to 30g / m 3 , particle specific resistance ρ r =2×10 12 Ω·cm, which is a low resistivity particle. A dry electrostatic precipitator is used to efficiently remove fine particles.

[0076] Combined with Figure 4 As shown, it is the electric field layout diagram and the vibration control structure diagram of the high-efficiency electrostatic precipitator with the particle trap dust collecting plate in Example 3, wherein the dust collecting plate 1 with the particle trap is only arranged in the fourth electric field of the high-efficiency electrostatic precipitator, i.e., the final electric field.

[0077] Combined with Figure 4 As shown, the high-efficiency electrostatic precipitator involved in this embodiment includes four groups of dust collecting plates 1, multiple multi-angle double-thorn electrodes 6 and an intelligent vibration system 7; each group of dust collecting plates 1 includes three dust collecting plates 1 arranged at intervals, wherein the fourth group of dust collecting plates 1 is formed by bending to form convex folding plates 4 and grooves 5 arranged at intervals, and particle traps 2 are formed at the grooves 5, and the particle traps 2 on two adjacent dust collecting plates 1 with particle traps 2 are arranged alternately. Figure 5 As shown, the distance between the two dust electrodes 1 is 300 mm, the depth of the particle trap 2 is 10 mm, and the angle between the two sides of the trapezoidal groove 5 and the bottom surface of the groove is 120°.

[0078] Combined with Figures 4 to 6As shown, the multi-angle double-thorn electrode 6 is arranged between the upper and lower adjacent dust collecting plates 1 and cooperates with the dust collecting plates 1; Fig.11 As shown, the puncture angle of the multi-angle double-thorn electrode 6 can be selected between 15° and 60°. In this embodiment, the distance between the multi-angle double-thorn electrode 6 and the dust collecting plate 1 with the particle trap 2 is 150 mm, the distance between adjacent multi-angle double-thorn electrodes 6 is 240 mm, the puncture length of the multi-angle double-thorn electrode is 15 mm, and the puncture angle is 30°, which is suitable for dust removal of low resistivity dust.

[0079] Combined with Figure 4 As shown, the intelligent vibration system 7 cooperates with the dust collecting plate 1 and is used to vibrate the dust collecting plate; wherein, the dust collecting plate 1 with the particle trap 2 is also provided with a reinforcing folding plate 3, and the intelligent vibration system 7 is connected to the reinforcing folding plate 3. The reinforcing folding plate 3 can improve the transmission effect and distribution uniformity of the vibration force, reduce the vibration force loss, and help reduce the secondary dust caused by vibration. The intelligent vibration system 7 is based on the particle removal mechanism of the electrostatic precipitator, establishes a concentration gradient model of the particles along the flue gas flow direction, calculates and predicts the ash accumulation thickness of the plate during the vibration cycle, and combines parameters such as the particle resistivity to predict the value of the operating voltage reduction caused by the accumulation of the dust layer, that is, the voltage drop, to form a precise prediction model for the voltage drop. When the voltage drop reaches a certain proportion, the vibration device is turned on, and combined with the attached Figure 7 As shown, the intelligent vibration system builds a pressure drop accurate prediction model for adjusting the vibration time and realizing intelligent vibration. The specific steps of building the pressure drop accurate prediction model include:

[0080] 1) Based on online and historical data, a database of key equipment and parameters of electrostatic precipitators is established, covering flue gas parameters, parameters of power supply devices of electrostatic precipitators, and parameters of the electrostatic precipitator body. The established parameters of the electrostatic precipitator body include dust collection area, electrode form, wire-plate distance, residence time, number of channels, and number of electric fields. The established flue gas parameters include inlet particulate matter concentration, inlet flue gas flow rate, and inlet flue gas volume. The established power supply device parameters mainly include primary voltage, secondary voltage, primary current, and secondary current.

[0081] 2) Based on the parameter database, a concentration gradient model of particulate matter along the flue gas flow direction is constructed. The specific steps are as follows:

[0082] 2.1) Establishment of the prediction model C of the particle concentration at the inlet of the electrostatic precipitator based on the parameter database in ,

[0083]

[0084] Wherein, B is the amount of coal burned; η is the dust escape rate; Aar is the received ash content; Q is the flue gas flow rate;

[0085] 2.2) For a single electrostatic precipitator electric field, assuming that x=0 at the flue gas inlet, the particle removal amount of each micro-element length Δx along the x direction is predicted, and then the particle removal amount model of each micro-unit is constructed.

[0086]

[0087] At the entrance of the electric field, that is, when x = 0, C x＝0 =C in , when x = Δx, the amount of particulate matter removed is

[0088]

[0089] Where A is the specific dust collection area, l p is the length of the electrode plate, ω is the overall migration rate of particles in the flue gas, and C is the amount of particles removed;

[0090] 2.3) Based on the particle removal model, further construct the concentration gradient model of particulate matter along the flue gas flow direction

[0091]

[0092] Among them, Q is determined by the boiler load, and due to the continuous evolution of the particle size distribution along the x direction, the overall migration rate ω of the particles in the flue gas changes continuously.

[0093] 3) Based on the concentration gradient model of particulate matter along the flue gas flow direction, the variation law of the accumulation rate of particulate matter on the plate surface with the airflow direction is predicted, the particle accumulation amount of the plate at the corresponding moment is obtained, and according to the particle density, the plate particle accumulation thickness model is obtained. The specific steps are as follows:

[0094] 3.1) Obtain the accumulation rate of particles on the electrode along the x direction under different loads in the electric field of the electrostatic precipitator (%·s -1 ·Δx -1 ), the percentage of particles per second per unit length, where the percentage of particles is converted uniformly according to the average inlet particle concentration;

[0095] 3.2) Based on the accumulation rate of particles on the plate surface, a particle accumulation model at the corresponding time of the plate is constructed;

[0096] 3.3) Combined with the particle density along the flue gas flow in the electric field, the plate particle accumulation thickness model is obtained.

[0097]

[0098] Δh(x i ) is the dust accumulation height increment, H p is the plate height, t r Cumulative time after the last rapping, ρp is the particle density;

[0099] 4) Combined with the particle resistivity parameters, the equivalent resistance of dust accumulation in the dust layer is established. By studying the dust layer resistance corresponding to each pole line of the electrostatic precipitator under different working conditions, a voltage drop proportional model is constructed. The specific steps are as follows:

[0100] 4.1) Combined with parameters such as particle resistivity, a prediction model for the equivalent resistance of dust accumulation in the dust layer is established. For pole line i, the equivalent resistance of the plate dust accumulation faced during the discharge process is the parallel value of the dust accumulation resistance on each microelement length.

[0101]

[0102] Ra i is the dust accumulation resistance of electrode line i during discharge, d w-w is the epipolar spacing, ρ r is the particle specific resistance, Δh(j) is the particle layer thickness at position j, and x i is the boundary of the discharge area corresponding to the pole line i, x i+1 is the other side boundary of the discharge area corresponding to the pole line i;

[0103] 4.2) By simulating and calculating the dust layer resistance corresponding to each pole line of the electrostatic precipitator under different working conditions, combined with the current density of a single pole line of the electrostatic precipitator, the effective voltage ratio of the electrode line caused by the dust layer is simulated and calculated to form a voltage drop ratio model

[0104]

[0105] Ra is the equivalent total resistance of dust accumulation during the discharge process of the pole line, ρi is the current density of a single pole line, l is the length of the pole line, and U0 is the normal operating voltage.

[0106] 5) Calculate the pressure drop ratio according to the pressure drop ratio model, and start the vibration device when it exceeds the upper limit value by 10%;

[0107] 6) After vibrating for a period of time, repeat steps 1) to 5) and adjust the vibrating time. The final vibrating time is adjusted to 300 to 350 seconds.

[0108] The working principle of the high-efficiency electrostatic precipitator involved in the present invention is as follows: the particles in the flue gas enter the dust collecting space formed by the dust collecting electrode plate 1 with the particle trap along the airflow direction, the multi-angle double-thorn electrode 6 discharges to charge the particles in the dust collecting space, most of the particles enter the groove 5 of the particle trap 2 under the combined effect of airflow and electric field force, and part of the particles enter the raised folding plate 4 of the particle trap 2, and after a certain time interval, the particles accumulate in the groove 3 and the raised folding plate 4; the raised folding plate 4 has a low dust accumulation thickness and a high field strength, and the particles at the raised folding plate 4 are easy to enter the particle trap 2 formed by the groove 5 under the drag of the airflow or the vibration; the groove 5 reduces the entrainment effect of the airflow, avoids the particles from returning to the dust collecting space, and at the same time reduces the drag of the airflow and effectively prevents the particles from starting from the trap of the groove 5 after vibration, causing secondary dust, thereby improving the capture efficiency of the particles.

[0109] Example 4

[0110] Based on a power plant with a capacity of 1000MW, the same flue gas conditions and arrangement of particle trap plates as in Example 3 were adopted, i.e., the particle size range of flue gas particles was 0.01-0.1 μm, and the maximum stable ash concentration of the dust removal device was set to 30 g / m 3 , particle specific resistance ρ r =2×10 12 Ω·cm, the particle trap plate is arranged in the final electric field, the operating voltage of the electrostatic precipitator is 60kV, and ordinary mechanical vibration and intelligent vibration are adopted for the third electric field plate and the fourth electric field plate respectively to explore the effect of the intelligent vibration system of the present invention. Table 1 is a comparison table of the effects of ordinary vibration and intelligent vibration.

[0111] Table 1

[0112]

[0113] The normal vibration interval is 300s, and the vibration is performed three times every 300s; the operating voltage of the intelligent vibration input is U0=60kV. When the dust collecting plate is a normal parallel plate, the particle concentration after the first normal vibration is 50.8mg / m 3 After intelligent vibration, the particle concentration is 42.5mg / m 3 After the second normal vibration, the particle concentration was 48.6 mg / m 3 After intelligent vibration, the particle concentration is 40.2mg / m 3 When the dust collecting plate is a plate with a particle trap, the particle concentration after the first ordinary vibration is 45.6 mg / m 3 After intelligent vibration, the particle concentration is 26.5mg / m 3 After the second normal vibration, the particle concentration was 42.3 mg / m 3After intelligent vibration, the particle concentration is 23.8mg / m 3 It can be seen that the electrode plates with particle traps can improve the removal efficiency of the electrostatic precipitator, but the removal effect is not obvious when combined with ordinary vibration. The use of an intelligent vibration system to vibrate the electrode plates with particle traps can often achieve a vibration effect similar to that of two vibration cycles of ordinary vibration within one vibration cycle. Therefore, it is necessary to use intelligent vibration in the present invention.

[0114] Example 5

[0115] Based on a power plant with a capacity of 1000MW, the particle size range of flue gas is measured to be 0.1-1μm, and the particle concentration at the inlet of the dust removal device is set to 30g / m 3 , particle specific resistance ρ r =1.25×10 6 Ω·cm, which is a low resistivity particle. A dry electrostatic precipitator is used to achieve efficient removal of fine particles.

[0116] Combined with Figure 8 As shown, the electric field layout diagram and vibration control structure diagram of the high-efficiency electrostatic precipitator with particle trap dust collecting plate. The dust collecting plate 1 with particle trap is arranged in the first electric field and the fourth electric field, i.e. the first and last electric fields of the high-efficiency electrostatic precipitator.

[0117] Combined with Figure 8 As shown, the difference between this embodiment and embodiment 3 is that: the high-efficiency electrostatic precipitator involved in this embodiment includes four groups of dust collecting electrode plates 1, multiple multi-angle double-thorn electrodes 6 and an intelligent vibration system 7; each group of dust collecting electrode plates 1 includes three spaced dust collecting electrode plates 1, wherein the first and fourth groups of dust collecting electrode plates 1 are formed by bending to form spaced raised folding plates 4 and grooves 5, and particle traps 2 are formed at the grooves 5, and the particle traps 2 on two adjacent dust collecting electrode plates 1 with particle traps 2 are staggered.

[0118] Combined with Fig. 9 As shown, in this embodiment, the dust collecting plate 1 with the particle trap 2 is 15m high and the width between the dust collecting plates is 300mm. The particle trap groove 5 is an isosceles trapezoidal structure, the upper bottom width of the particle trap groove 5 is 30mm, and the lower bottom width is 20mm; the particle trap groove 5 is 12mm deep; the angle between the two sides of the trapezoid of the groove 5 and the lower bottom of the groove is 105°. Fig.10 As shown, the distance between the multi-angle double-thorn electrode 6 and the dust collecting electrode plate 1 with a particle trap is 150 mm, and the distance between adjacent electrodes is 240 mm; the multi-angle double-thorn electrode has a puncture length of 10 mm and a puncture angle of 60°, which is suitable for dust removal of high resistivity dust.

[0119] The present invention is described in detail above in conjunction with the embodiments, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A high-efficiency electrostatic precipitator, characterized in that: It includes several groups of dust collecting plates, several multi-angle double-thorn electrodes and an intelligent vibration system; each group of dust collecting plates includes a plurality of spaced dust collecting plates, at least one group of dust collecting plates is formed by bending to form a plurality of spaced raised folding plates and grooves, and particle traps are formed at the grooves; the multi-angle double-thorn electrodes are spaced between adjacent dust collecting plates; the intelligent vibration system cooperates with the dust collecting plates to vibrate the dust collecting plates; for high specific resistivity dust, the multi-angle double-thorn electrode needle puncture length is 10 to 15 mm; for low specific resistivity dust, the multi-angle double-thorn electrode needle puncture length is 5 to 10 mm; The intelligent vibration system consists of an intelligent vibration module and a vibration device. The intelligent vibration module constructs a precise voltage drop prediction model based on the predicted value of the operating voltage reduction caused by dust layer accumulation, i.e., voltage drop. The vibration device is turned on when the voltage drop reaches a certain proportion.

2. The high-efficiency electrostatic precipitator according to claim 1, characterized in that: The specific steps of constructing the pressure drop accurate prediction model include: 1) Based on online and historical data, establish a database of key equipment and parameters of the electrostatic precipitator covering flue gas parameters, electrostatic precipitator power supply parameters, and electrostatic precipitator body parameters; 2) Based on the parameter database, a concentration gradient model of particulate matter along the flue gas flow direction is constructed; 3) Based on the concentration gradient model of particulate matter along the flue gas flow direction, the accumulation rate of particulate matter on the plate surface is predicted to change with the airflow direction, the particle accumulation amount of the plate at the corresponding moment is obtained, and the plate particle accumulation thickness model is obtained according to the particle density; 4) Combined with the particle resistivity parameters, the equivalent resistance of dust accumulation in the dust layer is established. By studying the dust layer resistance corresponding to each pole line of the electrostatic precipitator under different working conditions, a voltage drop proportional model is constructed; 5) Calculate the pressure drop ratio according to the pressure drop ratio model, and start the vibration device when it exceeds the upper limit value; 6) After vibrating for a period of time, repeat steps 1) to 5) and adjust the vibrating time.

3. The high-efficiency electrostatic precipitator according to claim 2, characterized in that: In the step 1), the established electrostatic precipitator body parameters include dust collection area, electrode form, wire-plate distance, residence time, number of channels, and number of electric fields; the established flue gas parameters include inlet particulate matter concentration, inlet flue gas flow rate, and inlet flue gas volume; the established power supply device parameters mainly include primary voltage, secondary voltage, primary current, and secondary current; In step 2), constructing a concentration gradient model of particulate matter along the flue gas flow direction specifically includes the following steps: 2.1) Establishment of the prediction model C of the particle concentration at the inlet of the electrostatic precipitator based on the parameter database in , Wherein, B is the amount of coal burned; η is the dust escape rate; Aar is the received ash content; Q is the flue gas flow rate; 2.2) For a single electrostatic precipitator electric field, assuming that x=0 at the flue gas inlet, the particle removal amount of each micro-element length Δx along the x direction is predicted, and then the particle removal amount model of each micro-unit is constructed. At the entrance of the electric field, that is, when x = 0, C x＝0 =C in , when x = Δx, the amount of particulate matter removed is Where A is the specific dust collection area, l p is the length of the electrode plate, ω is the overall migration rate of particles in the flue gas, and C is the amount of particles removed; 2.3) Based on the particle removal model, further construct the concentration gradient model of particulate matter along the flue gas flow direction Among them, Q is determined by the boiler load, and due to the continuous evolution of the particle size distribution along the x direction, the overall migration rate ω of the particles in the flue gas changes continuously; The construction of the plate particle accumulation thickness model in step 3) includes the following steps: 3.1) Obtain the accumulation rate of particles on the electrode along the x direction under different loads in the electric field of the electrostatic precipitator (%·s -1 ·Δx -1 ), the percentage of particles per second per unit length, where the percentage of particles is converted uniformly according to the average inlet particle concentration; 3.2) Based on the accumulation rate of particles on the plate surface, a particle accumulation model at the corresponding time of the plate is constructed; 3.3) Combined with the particle density along the flue gas flow in the electric field, the plate particle accumulation thickness model is obtained. Δh(x i ) is the dust accumulation height increment, H p is the plate height, t r Cumulative time after the last rapping, ρ p is the particle density; The step 4) of constructing the pressure drop ratio model comprises the following steps: 4.1) Combined with parameters such as particle resistivity, a prediction model for the equivalent resistance of dust accumulation in the dust layer is established. For pole line i, the equivalent resistance of the plate dust accumulation faced during the discharge process is the parallel value of the dust accumulation resistance on each microelement length. Ra i is the dust accumulation resistance of electrode line i during discharge, d w-w is the epipolar spacing, ρ r is the particle specific resistance, Δh(j) is the particle layer thickness at position j, and x i is the boundary of the discharge area corresponding to the pole line i, x i+1 is the other side boundary of the discharge area corresponding to the pole line i; 4.2) By simulating and calculating the dust layer resistance corresponding to each pole line of the electrostatic precipitator under different working conditions, combined with the current density of a single pole line of the electrostatic precipitator, the effective voltage ratio of the electrode line caused by the dust layer is simulated and calculated to form a voltage drop ratio model Ra is the equivalent total resistance of dust accumulation during the discharge process of the pole line, ρi is the current density of a single pole line, l is the length of the pole line, and U0 is the normal operating voltage; In the step 5), when the pressure drop ratio exceeds the upper limit value of 10%, the rapping device is started and the rapping frequency is adjusted.

4. The high-efficiency electrostatic precipitator according to claim 1, characterized in that: The dust collecting electrode plate is also provided with a reinforcing folding plate.

5. The high-efficiency electrostatic precipitator according to claim 1, characterized in that: The cross section of the groove is an isosceles trapezoid, the width of the upper bottom surface of the cross section is 3-11 cm, the width of the lower bottom surface is 2-6 cm, the depth of the groove is 1-5 cm, and the angles between the two sides of the groove and the lower bottom surface of the groove are 100-135 degrees.

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