Cooperative control energy-saving optimization method and system for electrostatic precipitator

Abstract

The present invention aims at the problem that the power saving control of the precipitator in the prior art only considers the analysis of the electrical characteristics in the electric field of each electric field and controls them independently, but rarely considers the operating status of the entire system of the precipitator. A method and system for energy saving optimization of coordinated control of an electrostatic precipitator is proposed, including determining a number of electrostatic precipitator chambers according to the overall goal, and determining the smoke control sub-goal of each electrostatic precipitator chamber, setting the operation mode and related control parameters of each high-voltage power supply according to the flue gas conditions, and differentially allocating the rated output power and working mode of the high-voltage electric field in the same electrostatic precipitator chamber. Under the premise of ensuring that the smoke control sub-goal remains unchanged, the output power of each high-voltage electric field is automatically adjusted, and each high-voltage electric field can work in coordination with each other. The present invention performs systematic global deployment control on each high-voltage electric field in the electrostatic precipitator, and each high-voltage electric field can work in coordination with each other, and the dust removal energy consumption utilization rate is higher, thereby greatly improving the energy saving efficiency of the entire electrostatic precipitator.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrostatic precipitators, and in particular relates to a method and system for coordinated control and energy-saving optimization of electrostatic precipitators. Background Art

[0002] Experts and scholars at home and abroad and related manufacturers have conducted long-term research on the energy-saving optimization of dust collectors. Electrostatic precipitators have been partially applied in domestic power plants, but there are still many deficiencies in control theory, control means, control methods, control system performance and integrity, such as:

[0003] 1) Only the independent control of a single electric field is considered, and the overall operation optimization of the entire electric field coupling of the dust collector is rarely considered.

[0004] At present, the power saving control of many dust collectors only considers the analysis of the electrical characteristics of each electric field and controls them independently, but rarely considers the operation status of the entire system of the electrostatic precipitator, the operation impact of each electric field, and the characteristics of smoke, etc. Therefore, it is easy to emphasize the characteristics of each controller one-sidedly and pursue electric control transformation, but fail to grasp the real core content of its power saving.

[0005] 2) The control parameters and functions are not perfect, and it is impossible to flexibly adjust the control for variable and abnormal working conditions.

[0006] Many control parameters and functions in power saving control are still not perfect.

[0007] 3) Failure to establish an effective power supply concept for dust collectors

[0008] The concept of effective power supply for the electrostatic precipitator has not been established. In power-saving control, the power supply configuration, operation mode and operation parameters cannot be selected to ensure that the corresponding effective power supply is provided to each electric field of the entire electrostatic precipitator. Therefore, the optimal operation control mode cannot be achieved.

[0009] 4) The concept of anti-corona control needs to be improved

[0010] It is generally believed that the main reason for the occurrence of back corona in the electric field of the electrostatic precipitator is that the charge of the soot layer on the plate is not released in time and an electric field is formed locally. When the entire secondary voltage increases to a certain level, the electric field of the soot layer will be partially discharged or broken down. However, the power supply characteristics of the electrostatic precipitator are not the control characteristics of a simple circuit, and the electric field in the precipitator is not simply equivalent to a resistor-capacitor circuit, but a complex and changing electric field. Therefore, when overcoming back corona and reducing operating parameters, sometimes the effective power supply required in its electric field is also reduced, which sometimes greatly reduces the dust removal efficiency and increases the emission concentration. Therefore, one-sided emphasis on overcoming back corona and saving power control is sometimes harmful. Summary of the invention

[0011] In view of the problem that the power-saving control of the dust collector in the prior art only considers the electrical characteristics analysis within the electric field of each electric field and controls them independently, but rarely considers the overall system operation status of the electrostatic precipitator, the present invention proposes an electrostatic precipitator collaborative control energy-saving optimization method and system.

[0012] The invention object of the present invention is achieved through the following technical scheme: a method for energy-saving optimization of coordinated control of an electrostatic precipitator, comprising:

[0013] S01. Determine the total rated operating load of the electrostatic precipitator according to the smoke emission standards, the rated operating load of the power plant units, and the type of coal to be burned;

[0014] S02. The total output power of the electrostatic precipitator increases or decreases with the actual operating load of the power plant units and the changes in the type of coal burned;

[0015] S03, the electrostatic precipitator is composed of a plurality of electrostatic precipitator chambers with the same operating load, and each electrostatic precipitator chamber is composed of a plurality of high-voltage electric fields;

[0016] S04. The controller of the same electrostatic precipitator room allocates the output power and working mode of each high-voltage electric field differently, and automatically adjusts the output power of each high-voltage electric field under the premise of ensuring the smoke emission standard;

[0017] The automatic adjustment is to detect whether the actual operating load of the electrostatic precipitator chamber increases or decreases compared to the rated operating load:

[0018] When the actual operating load of the electrostatic precipitator room increases compared to the rated operating load, the output power of each high-voltage electric field in the electrostatic precipitator room will increase accordingly according to the differentiated distribution ratio.

[0019] When the actual operating load of the electrostatic precipitator chamber decreases compared to the rated operating load, the output power of each high-voltage electric field in the electrostatic precipitator chamber is correspondingly reduced according to a differentiated distribution ratio, or one of the high-voltage electric fields in the electrostatic precipitator chamber is shut down.

[0020] An electrostatic precipitator coordinated control energy-saving optimization system includes a computer system that uses the above-mentioned optimization method to optimize the control of the electrostatic precipitator.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention carries out systematic global deployment control on each high-voltage electric field in the electrostatic precipitator, and each high-voltage electric field can operate in coordination with each other, so that the dust removal capacity of the entire electrostatic precipitator is more stable and the dust removal energy consumption utilization rate is higher, thereby greatly improving the energy saving efficiency of the entire electrostatic precipitator. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Flowchart of this optimization method;

[0024] Figure 2 This is a flow chart of automatic adjustment control of high voltage electric field in the same electrostatic precipitator chamber of the present invention;

[0025] Figure 3 The present invention is a power compensation control flow chart when the high-voltage electric field of the same electrostatic precipitator chamber operates abnormally. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings:

[0027] like Figure 1 , Figure 2 As shown, a coordinated control energy-saving optimization method for an electrostatic precipitator includes:

[0028] S01. Determine the total rated operating load of the electrostatic precipitator according to the smoke emission standards, the rated operating load of the power plant units, and the type of coal to be burned;

[0029] S02. The total output power of the electrostatic precipitator increases or decreases with the actual operating load of the power plant units and the changes in the type of coal burned;

[0030] S03, the electrostatic precipitator is composed of a plurality of electrostatic precipitator chambers with the same operating load, and each electrostatic precipitator chamber is composed of a plurality of high-voltage electric fields;

[0031] S04. The controller of the same electrostatic precipitator room allocates the output power and working mode of each high-voltage electric field differently, and automatically adjusts the output power of each high-voltage electric field under the premise of ensuring the smoke emission standard;

[0032] The automatic adjustment is to detect whether the actual operating load of the electrostatic precipitator chamber increases or decreases compared to the rated operating load:

[0033] When the actual operating load of the electrostatic precipitator room increases compared to the rated operating load, the output power of each high-voltage electric field in the electrostatic precipitator room will increase accordingly according to the differentiated distribution ratio.

[0034] When the actual operating load of the electrostatic precipitator chamber decreases compared to the rated operating load, wherein when the load reduction of the electrostatic precipitator chamber is less than the rated output power of each high-voltage electric field in the electrostatic precipitator chamber, the actual output power of each high-voltage electric field in the electrostatic precipitator chamber is correspondingly reduced according to the differentiated allocation ratio;

[0035] When the load reduction amount of the electrostatic precipitator chamber is equal to the high-voltage electric field with the minimum rated output power in the electrostatic precipitator chamber, the high-voltage electric field with the minimum rated output power in the electrostatic precipitator chamber is shut down;

[0036] When the load reduction of the electrostatic precipitator chamber is greater than the rated output power of any high-voltage electric field in the electrostatic precipitator chamber, the high-voltage electric field with the smallest rated output power in the electrostatic precipitator chamber will be shut down, and the output power of the remaining high-voltage electric fields will be further reduced according to the differentiated distribution ratio by the difference between the load reduction of the electrostatic precipitator chamber and the rated output power of the shut-down high-voltage electric field.

[0037] Take a 1000MW generator set with 100% full load power generation as an example: controlling the power consumption rate of the electrostatic precipitator system involves control parameters: the plant power consumption rate target value such as 0.15%, the real-time power consumption of the electrostatic precipitator system, the real-time power generation, and the unit load percentage to achieve the best coal-fired generator set standard.

[0038] The electrostatic precipitator has three chambers and five electric fields, and the rated configuration power is 160KW (80KV, 2.0A)*30=4800KW.

[0039] The target power consumption rate of the electrostatic precipitator plant is: 0.15%, that is, 1000MW*0.15%=1500KW.

[0040] The power consumption rate target can be set according to the specific situation of the project. For example, the accurate change of the real-time value of environmental protection emissions should also be used as a control parameter. Under the power consumption rate target of 0.15%, the differentiated allocation schemes and indicators of each high-voltage electric field are as follows in Table 1:

[0041] Table 1 Differentiated distribution schemes of high voltage electric fields in electrostatic precipitators

[0042]

[0043] The boiler load in this embodiment is 100%, and the boiler load cannot be increased. Therefore, taking the boiler load reduced to 80% as an example, the power generation of the electric field is 1000MW*80%=800MW, and the target value of the electric power consumption rate of the electrostatic precipitator plant: 0.15% remains unchanged, then the power used for the electrostatic precipitator becomes 800MW*0.15%=1200KW. The actual standard output power distribution of each high-voltage electric field of the electrostatic precipitator should be reduced accordingly, as shown in Table 2:

[0044] Table 2 Actual power output of each high voltage electric field of the electrostatic precipitator after reducing the power output according to the differentiated distribution ratio

[0045]

[0046] Comparing Table 2 with Table 1, it can be seen that the total operating standard power of the electrostatic precipitator room is reduced by 50KW, which is greater than the total operating power of the three or four electric fields in the electrostatic precipitator room. Under the premise of meeting the smoke emission standards, the three or four electric fields can be shut down to achieve the purpose of energy saving. As shown in Table 3:

[0047] Table 3 Automatic allocation scheme of each high-voltage electric field in the electrostatic precipitator room when the total operating standard power reduction of the electrostatic precipitator room is greater than the rated output power of one of the high-voltage electric fields in the electrostatic precipitator room

[0048]

[0049] In order to ensure the safety of smoke and dust emissions and meet smoke and dust emission standards, the high-voltage electric field in the same electrostatic precipitator room must ensure that at least 3 or more high-voltage electric fields are operating simultaneously.

[0050] like Figure 3 As shown, when one of the high-voltage electric fields in the same electrostatic precipitator room has an abnormal operation and cannot maintain the set output power, the other high-voltage electric fields in the same electrostatic precipitator room will compensate for the lost power according to the pre-set priority of the high-voltage electric field. The steps of power compensation are as follows: compare the difference between the actual output power of the high-voltage electric field and the set target power, query the remaining high-voltage electric fields in the same electrostatic precipitator room according to the priority to see if there is power loss. If the actual output power of the high-voltage electric field is the same as the set target power, the high-voltage electric field with the first priority will increase the output power, and the power difference of the high-voltage electric field that cannot output to the set target power will be compensated. If the actual output power of the first-priority high-voltage electric field queried according to the priority has power loss, the high-voltage electric field with the second priority will be queried according to the priority until the power difference is compensated. The power compensation of the faulty electric field by each normal operating electric field in the same electrostatic precipitator room is set according to a certain priority. The setting of the priority level can be determined according to the distance between the high-voltage electric field and the flue gas inlet, and the high-voltage electric field closest to the flue gas inlet is the first priority. The electric fields are arranged in order of first and last levels, such as: when the high voltage electric field of electric field one is abnormal, compensation is made according to the priority order of two-three-four-five; when the high voltage electric field of electric field two is abnormal, compensation is made according to the priority order of one-three-four-five, and so on.

[0051] Taking the power output of the high-voltage electric field in Table 1 as an example, when the No. 1 high-voltage electric field in the electrostatic precipitator room A is unable to output the target set power value due to operating conditions, the No. 2 electric field with the highest priority will compensate for the power output of the No. 1 electric field through system calculation. The power distribution after power compensation is shown in Table 4:

[0052] Table 4 High voltage electric field power compensation scheme for electrostatic precipitator chamber A

[0053]

[0054] The priority setting can also be sorted according to the cumulative operating time of the electric field, and the electric field with the shortest cumulative operating time has the highest priority.

[0055] An electrostatic precipitator coordinated control energy-saving optimization system includes a computer system that uses the above-mentioned optimization method to optimize the control of the electrostatic precipitator.

[0056] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for energy-saving optimization of coordinated control of an electrostatic precipitator, characterized in that: include: S01. Determine the total rated operating load of the electrostatic precipitator according to the smoke emission standards, the rated operating load of the power plant units, and the type of coal to be burned; S02. The total output power of the electrostatic precipitator increases or decreases with the actual operating load of the power plant units and the changes in the type of coal burned; S03, the electrostatic precipitator is composed of a plurality of electrostatic precipitator chambers with the same operating load, and each electrostatic precipitator chamber is composed of a plurality of high-voltage electric fields; S04. The controller of the same electrostatic precipitator room allocates the output power and working mode of each high-voltage electric field differently, and automatically adjusts the output power of each high-voltage electric field under the premise of ensuring the smoke emission standard; The automatic adjustment is to detect whether the actual operating load of the electrostatic precipitator chamber increases or decreases compared to the rated operating load: When the actual operating load of the electrostatic precipitator room increases compared to the rated operating load, the output power of each high-voltage electric field in the electrostatic precipitator room will increase accordingly according to the differentiated distribution ratio. When the actual operating load of the electrostatic precipitator chamber is reduced compared to the rated operating load, the output power of each high-voltage electric field in the electrostatic precipitator chamber is correspondingly reduced according to the differentiated allocation ratio, or one of the high-voltage electric fields in the electrostatic precipitator chamber is shut down; When the actual operating load of the electrostatic precipitator chamber is reduced compared to the rated operating load, the load reduction of the electrostatic precipitator chamber is compared with the rated output power of each high-voltage electric field in the electrostatic precipitator chamber: When the load reduction of the electrostatic precipitator chamber is less than the rated output power of each high-voltage electric field in the electrostatic precipitator chamber, the actual output power of each high-voltage electric field in the electrostatic precipitator chamber is reduced accordingly according to the differentiated allocation ratio; When the load reduction amount of the electrostatic precipitator chamber is equal to the high-voltage electric field with the minimum rated output power in the electrostatic precipitator chamber, the high-voltage electric field with the minimum rated output power in the electrostatic precipitator chamber is shut down; When the load reduction of the electrostatic precipitator chamber is greater than the rated output power of any high-voltage electric field in the electrostatic precipitator chamber, the high-voltage electric field with the smallest rated output power in the electrostatic precipitator chamber will be shut down, and the output power of the remaining high-voltage electric fields will be further reduced according to the differentiated distribution ratio by the difference between the load reduction of the electrostatic precipitator chamber and the rated output power of the shut-down high-voltage electric field.

2. The electrostatic precipitator coordinated control energy-saving optimization method according to claim 1 is characterized in that: The differentiated allocation is that the rated output power of each high-voltage electric field in the same electrostatic precipitator chamber is set according to the percentage of the full load power of the high-voltage electric field, and the rated output power of each high-voltage electric field is set independently and has different sizes.

3. The method for energy-saving optimization of coordinated control of an electrostatic precipitator according to claim 1, characterized in that: The automatic adjustment in step S04 also includes that when one of the high-voltage electric fields in the same electrostatic precipitator room has an abnormal operation and cannot maintain the set output power, the other high-voltage electric fields in the same electrostatic precipitator room will compensate for the lost power according to the pre-set priority of the high-voltage electric field. The steps for power compensation are as follows: compare the difference between the actual output power of the high-voltage electric field and the set target power, and query the remaining high-voltage electric fields in the same electrostatic precipitator room according to the priority to see whether there is power loss. If the actual output power of the high-voltage electric field is the same as the set target power, the high-voltage electric field with the first priority will increase the output power, and power compensation will be performed for the power difference of the high-voltage electric field that cannot output to the set target power. If the actual output power of the high-voltage electric field of the first priority queried according to the priority has power loss, the high-voltage electric field of the second priority will be queried according to the priority until the power difference is compensated.

4. The method for energy-saving optimization of coordinated control of an electrostatic precipitator according to claim 3 is characterized in that: If the compensation power of one high-voltage electric field cannot meet the lost power, two or more high-voltage electric fields are enabled in sequence according to the priority to compensate for the lost power.

5. The electrostatic precipitator coordinated control energy-saving optimization method according to claim 3 or 4, characterized in that: The priority is determined according to the distance between the high-voltage electric field and the smoke inlet, and the high-voltage electric field closest to the smoke inlet has the first priority.

6. The method for energy-saving optimization of coordinated control of an electrostatic precipitator according to claim 3 or 4, characterized in that: The priority is determined according to the accumulated operation time of the high-voltage electric field, and the high-voltage electric field with the shortest accumulated operation time has the first priority.

7. An electrostatic precipitator coordinated control energy-saving optimization system, characterized in that: A computer system comprising a computer system for optimizing and controlling an electrostatic precipitator using any of the optimization methods described in claims 1 to 6.

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