CN206823458U - A kind of coal-burning power plant's energy-saving dedusting synergy cooperative intelligentization regulation and control remove white system - Google Patents

Abstract

The utility model relates to a coal-fired power plant energy-saving, dust-removing and efficiency-enhancing cooperative intelligent regulation and whitening removal system, which comprises sequentially connected desulfurization towers, flue gas phase change condensors, wet electrostatic multi-extractors, flue gas heating and whitening devices and Intelligent temperature adjustment system, flue gas phase change condensor, wet electrostatic multi-extractor are respectively connected to the drainage tank, the drainage tank is connected to the desulfurization tower and circulating water tank, and the circulating water tank is sprayed with the wet electrostatic multi-extractor through the self-cleaning filter The shower pipe and the flushing water pipe of the demister are connected. The utility model has high stability, low investment and operating costs, and a simple system; the water in the system can be reused to reduce the waste of water resources, and the low-grade steam of the boiler is used as a heat source, and the energy consumption is reduced by more than 10%. While the flue gas has high reliability and low cost, there is no obvious visible white mist emission, and at the same time, the removal efficiency of particulate matter is comprehensively improved by more than 20%, and the collaborative removal efficiency of gaseous SOx is increased by more than 10%.

Description

Coal-fired power plant energy-saving dust removal and efficiency synergy intelligent regulation and removal system

technical field

The utility model belongs to the technical field of coal-fired flue gas pollutant control, in particular to an energy-saving, dust-removing and efficiency-enhancing cooperative intelligent regulation and removal system for coal-fired power plants.

Background technique

With the promulgation of the "Notice on Printing and Distributing the Action Plan for Upgrading and Transformation of Coal Power Energy Conservation and Emission Reduction (2014-2020)" (Fagai Energy [2014] No. The emission concentration of air pollutants from coal has basically reached the emission limit of gas turbines (that is, under the condition of a reference oxygen content of 6%, the emission concentrations of soot, sulfur dioxide, and nitrogen oxides are not higher than 10, 35, and 50 mg/m3, respectively). The main technical route to achieve the ultra-low emission requirements of soot and sulfur dioxide is the integrated wet desulfurization and dust removal technology or the integrated wet desulfurization and dust removal + wet electric dust removal technology. At present, 93% of domestic thermal power plant systems adopt this kind of technology. After the flue gas from the coal-fired power plant is treated by the above process, the temperature of the flue gas will drop to 48-52°C, and it will be discharged through the high chimney. At this time, the flue gas is usually supersaturated wet flue gas, containing a large amount of water vapor and some condensed water. If the flue gas is discharged from the chimney mouth into the ambient air with a relatively low temperature, the amount of water vapor (saturated specific humidity) carried by the unit mass of dry air will decrease, and part of the water vapor in the flue gas will precipitate and condense into a tiny mist liquid. drop. When the diffusion speed of the flue gas is lower than the condensation speed, the water in the saturated state in the flue gas becomes supersaturated and condenses when it is cooled, resulting in a decrease in the lift height of the flue gas, which leads to the inability of the flue gas to dissipate quickly, especially due to the local temperature and air pressure. When it is relatively low or in the period of cloudy weather, a large amount of white smoke plume is likely to cause misunderstandings by the public, resulting in "visual pollution", which has a negative impact on the production and life of surrounding residents. At the same time, wet smoke takes away a large amount of water, causing water resources waste. Moreover, the white smoke is in a state of low temperature and high humidity, which will also lead to a decrease in the lift height of the smoke and a narrowing of the diffusion range, which will increase the concentration of pollutants in the surrounding perigee, resulting in "near-ground pollution".

In order to reduce the "visual pollution" and "near-ground pollution" caused by white smoke plumes, some power plants at home and abroad use flue gas heating devices to make the flue gas temperature reach a certain value before being discharged into the atmosphere by the chimney. The flue gas temperature should not be lower than 72°C (after adopting the EU standard in 2002, the discharge temperature of the flue gas should no longer be restricted to be higher than this temperature), the Japanese regulation is 90-110°C, and the British regulation is not lower than 80°C. Some power plants in my country use GGH to raise the exhaust gas temperature to about 80°C before discharging.

In order to fully diffuse the flue gas, prevent cold flue gas from sinking, and avoid flue corrosion caused by low temperature, the flue gas temperature is heated to about 80°C through GGH, which can improve the diffusion capacity of chimney exhaust while slowing down the corrosion of downstream equipment . However, GGH is easy to scale, block, and corrode. Once GGH scales and accumulates for a long time, it will lead to an increase in the thermal resistance between the heat exchange element and the flue gas, resulting in a decrease in heat exchange efficiency and increased corrosiveness to downstream equipment; at the same time As a result, the water consumption of the absorption tower increases, the booster fan works hard, increases the power consumption, increases the power consumption of the plant, and even causes the desulfurization system to stop operating.

Some domestic power plants use steam direct heating method or condensation method to achieve no white smoke emission. The direct steam heating method consumes a lot of energy, resulting in water loss, and has no corresponding deep removal effect on soot and SO _x . The saturated wet flue gas condensation method controls the phase change degree of the process through an external condensation source, and cooperates with a high-efficiency demister to effectively promote the condensation of fine particles and remove condensation. The method can reduce emissions, reduce water consumption, and consume less energy, but the corresponding The effect of white fog removal is greatly affected by the external ambient temperature. When the ambient temperature is low, the effect of white fog removal is not good. If the white fog is to be deeply resolved, the saturated wet flue gas needs to be further heated.

Chinese patent CN102980171A discloses a coal-fired boiler flue gas waste heat deep recovery utilization and flue gas condensation desulfurization and dust removal economizer, provides an economizer that utilizes the latent heat of vaporization of water vapor in flue gas, the patent involved The technology utilizes the latent heat of vaporization of part of the water vapor in the flue gas, but the water in the flue gas is not used by clean separation, and the effect of removing white smoke is not good.

Chinese patent CN104930539A discloses a flue gas recovery system of a coal-fired power plant and an energy-saving and water-saving ultra-clean discharge method. By adding a low-temperature economizer, a vacuum flash flash condensing device and a low-temperature heat pump heat exchange device, the flue gas can be saved, water-saving and reduced. However, if the exhaust gas temperature is between 30 and 40 °C, it is difficult to achieve no white smoke emission in areas with low ambient temperature, and the system is relatively complex, with high failure rate, large floor area, and difficult operation. Maintenance costs are high.

Utility model content

In order to make up for the deficiencies of the existing technology and improve the pollutant removal system of coal-fired power plants, the utility model provides a coal-fired power plant energy-saving, dust removal and efficiency synergistic intelligent control and whitening system, which is a high-reliability, low-cost, phase-change Condensation enhanced fine particulate matter, SOx and mist droplet efficient removal collaborative coal-fired power plant flue gas intelligent white mist removal system.

A coal-fired power plant energy-saving, dust removal and synergistic intelligent control and whitening system, the whitening system includes a desulfurization tower, a flue gas phase change coalescer, a wet electrostatic multi-extractor, a flue gas heating and whitening device, and an intelligent temperature adjustment system, the desulfurization tower is connected to the flue gas phase change condenser through the outlet flue of the desulfurization tower, and the flue gas phase change condenser is connected to the wet electrostatic multi-extractor through the outlet flue of the flue gas phase change condenser. The wet electrostatic multi-extractor is connected with the flue gas heating and whitening device, the flue gas heating and whitening device is connected with the chimney, and the intelligent temperature adjustment system is connected with the external air monitoring system and the flue gas heating and whitening device respectively .

Preferably, the flue gas phase change condenser includes a shell and a condensation heat exchange tube arranged in the shell, the condensation heat exchange tube is respectively connected with the cooling water inlet pipe and the cooling water outlet pipe, and the bottom of the shell The condensate collection pipe is connected to the drainage tank, the drainage tank is connected to the circulating water tank through the baffle, the drainage tank is connected to the desulfurization tower through the drainage pump, and the circulating water tank is connected to the self-cleaning filter through the circulating water pump , the self-cleaning filter communicates with the spraying water pipe of the wet electric demultiplexer and the flushing water pipe of the demister respectively.

Preferably, the condensing heat exchange tubes are connected in series, the direction is perpendicular to the flue gas flow, and are arranged in a staggered manner, the condensing heat exchange tubes are connected to the shell through sealing rings and metal parts, and the cooling water inlet pipe is connected to the The ends of the condensing heat exchange tubes are connected with row pipes and inserted into the bottom of the condensing heat exchange tubes, and the cooling water outlet pipe is connected with the first row of condensing heat exchange tubes.

Preferably, the wet electrostatic multi-disconnector communicates with the drainage tank through a drain pipe of the wet-type electrostatic multi-disconnector.

As a preference, the flue gas heating and whitening device includes a low-grade steam inlet main pipe, a low-grade steam inlet branch pipe, a flue gas heating and whitening device heat exchange tube, a flue gas heating and whitening device outer frame channel steel, and a flue gas heating and whitening device. Rib plate inside the device, low-grade steam outlet branch pipe, and low-grade steam outlet main pipe. The pipes are respectively connected with the low-grade steam inlet branch pipe and the low-grade steam outlet branch pipe, the low-grade steam inlet branch pipe is connected with the low-grade steam inlet main pipe, and the low-grade steam outlet branch pipe is connected with the low-grade steam outlet main pipe; The high-grade steam inlet main pipe is connected with the low-grade steam boiler in the factory area, and the intelligent temperature adjustment system is connected with the low-grade steam inlet main pipe.

The material of the condensing heat exchange tube in the utility model adopts fluorine plastic, the material of the shell part in contact with the flue gas is selected from SAF2205, and the external material of the shell is selected from 20# steel; the surface of the anode tube in the wet electrostatic multi-disconnector is coated with epoxy resin Or polytetrafluoroethylene, the surface of the anode tube is modified to achieve the function of hydrophilicity and non-contamination; the material of the low-grade steam tube in the flue gas heating and whitening device is SAF2205.

The beneficial effects of the utility model are:

(1) The flue gas phase change condenser uses the industrial water of the power plant as the cold source, and uses the condensate collection pipe to collect the condensed liquid water. The collected condensed liquid water is enough for the flushing of the desulfurization tower demister or the spraying water of the wet electrostatic demister , realize the reuse of water resources;

(2) At the same time, the condensed liquid film produced on the surface of the condensing heat exchange tube absorbs and absorbs SOx and fine particles in the flue gas, so as to realize the deep purification of the flue gas;

(3) After the wet flue gas passes through the phase change coalescer, the temperature decreases and the flue gas flow rate decreases, which promotes the condensation and growth of fine particles and the charging of particles, and comprehensively improves the particle removal efficiency of the wet electrostatic multi-extractor by more than 20%, and the gaseous SOx synergy The removal efficiency is increased by more than 10%;

(4) The condensed and dehumidified wet flue gas is reheated by the steam heat exchanger. Under the condition of ensuring the lowest energy consumption, the intelligent temperature adjustment system is used according to the external environmental parameters (humidity, temperature, wind speed) to convert the flue gas The temperature of the gas is raised to the temperature where it is most easy to diffuse, so as to realize the "no white" emission of the flue gas; the flue gas after reheating is an undersaturated wet flue gas, which can slow down the corrosion of the subsequent flue and chimney;

(5) The heat source of the flue gas heating and whitening device adopts low-grade boiler steam, and the flue gas after cooling and condensing is low-saturated wet flue gas, and the energy consumption of reheating is smaller than that of direct heating of saturated wet flue gas and steam consumption. The energy consumption is reduced by more than 10%, and the energy saving effect is good;

(6) The phase change coalescer contains condensed water separation measures to avoid the "secondary entrainment" of condensed water, and at the same time reduce the water loss caused by smoke exhaust, and has a better water-saving effect in water-deficient areas;

(7) The utility model has high stability. Compared with other whitening systems, the investment and operation costs are low, and the system is simple; the intelligent temperature adjustment system is used to adjust the exhaust gas temperature according to the external environment parameters (humidity, temperature, wind speed) to realize the smoke removal. The air lift height and diffusion are better, there is no obvious visible white mist discharge and the energy consumption is the lowest; the water in the system can be reused to reduce the waste of water resources.

Description of drawings

Fig. 1 is the structural representation of the whitening system of the present utility model;

Fig. 2 is a structural schematic diagram of the flue gas heating and whitening device of the present invention.

detailed description

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments, but the scope of protection of the utility model is not limited thereto.

Referring to Fig. 1 and Fig. 2, a coal-fired power plant energy-saving, dust removal and efficiency synergistic intelligent control whitening system, the whitening system includes a desulfurization tower 1, a flue gas phase change coalescer 4, a wet electrostatic multi-extractor 7, a flue gas Gas heating and whitening device 8 and intelligent temperature adjustment system 31, the desulfurization tower 1 communicates with the flue gas phase-change condenser 4 through the outlet flue 2 of the desulfurization tower, and the flue gas phase-change condenser 4 passes through the flue gas phase The outlet flue 6 of the variable condensator is connected with the wet electrostatic multi-extractor 7, and the wet electrostatic multi-extractor 7 is connected with the flue gas heating and whitening device 8, and the flue gas heating and whitening device 8 is connected with the chimney 21 , the intelligent temperature regulation system 31 is connected with the outside air monitoring system 20 and the flue gas heating and whitening device 8 respectively. The outside atmosphere monitoring system 20 is set above the chimney 21 to monitor the outside environment parameters, and use the intelligent temperature regulation system according to the outside environment parameters (humidity, temperature, wind speed) to increase the temperature of the flue gas to the temperature that is most likely to diffuse, so as to realize the smoke emission. "White-free" emissions of air.

The flue gas phase change condenser includes a shell 30 and a condensation heat exchange tube 28 arranged in the shell. The condensation heat exchange tube 28 is connected to the cooling water inlet pipe 5 and the cooling water outlet pipe 3 respectively. The shell The bottom of the body is connected to the drainage tank 9 through the condensate collecting pipe 16, the drainage tank 9 is connected to the circulating water tank 10 through the baffle plate, the drainage tank 9 is connected to the desulfurization tower 1 through the drainage pump 14, and the circulating water tank 10 The circulating water pump 11 communicates with the self-cleaning filter 12, and the self-cleaning filter 12 communicates with the spraying water pipe 13 of the wet electric demultiplexer and the flushing water pipe 17 of the demister respectively. The wet electrostatic multi-disconnector 7 communicates with the drainage box 9 through the wet electrostatic multi-disconnector drainage pipe 15 .

The condensing heat exchange tubes 28 are connected in series, the direction is perpendicular to the flue gas flow, and are arranged in a staggered manner. The condensing heat exchange tubes are connected to the shell through sealing rings and metal parts. In the form of a serpentine tube, one end of the condensing heat exchange tube is a closed structure, and the other end is a flange structure. The cooling water inlet pipe 5 is connected with the end row pipe of the condensing heat exchange tube and inserted into the bottom of the condensing heat exchange tube to distribute the condensed water to the heat exchange tubes of the last row; the cooling water outlet pipe 3 is connected to the first row of condensing heat exchange tubes. The heat exchange tubes are connected to collect the exchange water flowing out of the heat exchange tubes. The exchange water can be used as water for the limestone pulping system to increase the solubility of limestone and increase the absorption and mass transfer rate of the desulfurization system.

The flue gas heating and whitening device includes a low-grade steam inlet main pipe 25, a low-grade steam inlet branch pipe 22, a flue gas heating and whitening device heat exchange tube 29, a flue gas heating and whitening device outer frame channel steel 23, and a flue gas heating and whitening device. Rib plate 24 inside the whitening device, low-grade steam outlet branch pipe 26, low-grade steam outlet main pipe 27, the heat exchange pipe 29 of the flue gas heating and whitening device is arranged in the channel steel 23 of the outer frame of the flue gas heating and whitening device, and the flue gas The heat exchange pipe 29 of the heating and whitening device is connected with the low-grade steam inlet branch pipe 22 and the low-grade steam outlet branch pipe 26 respectively, and the low-grade steam inlet branch pipe 22 is connected with the low-grade steam inlet main pipe 25, and the low-grade steam outlet branch pipe 26 It is connected with the low-grade steam outlet main pipe 27; the low-grade steam inlet main pipe 25 is connected with the low-grade steam boiler 18 in the factory area, and the intelligent temperature adjustment system 31 is connected with the low-grade steam inlet main pipe 25. The heat exchange tubes of the flue gas heating and whitening device are arranged horizontally, and the direction is perpendicular to the flue gas flow direction, and the two sides of the low-grade steam outlet branch pipe are fixed with tube plates.

The material of the condensing heat exchange tube in the utility model adopts fluorine plastic, the material of the shell part in contact with the flue gas is selected from SAF2205, and the external material of the shell is selected from 20# steel; the surface of the anode tube in the wet electrostatic multi-disconnector is coated with epoxy resin Or polytetrafluoroethylene, the surface of the anode tube is modified to achieve the function of hydrophilicity and non-contamination; the material of the low-grade steam tube in the flue gas heating and whitening device is SAF2205.

The saturated wet flue gas at the outlet of the desulfurization tower of the utility model passes through the flue gas phase change condenser, the liquid water condensed in the saturated wet flue gas and the free water carried are separated and collected, and the gaseous SOx and particulate matter (fine particles) in the flue gas are washed at the same time particulate matter, SO ₃ and other condensable particulate matter and mist droplets containing soluble salt), use the drainage tank to collect filtered liquid water, and the liquid water is filtered through a self-cleaning filter to remove fine particles carried in the liquid water, and the liquid water can be used for desulfurization The flushing water of the tower demister or the wet electrostatic multi-extractor realizes the reuse of water resources; the high-humidity flue gas undergoes phase change condensation after passing through the phase change condenser, which promotes the growth of fine particles and condensable particles; The high-humidity flue gas after condensation treatment is passed through the wet electric multi-extractor to strengthen the efficient and coordinated removal of fine particles, SO ₃ and other condensable particles, and mist droplets containing soluble salts; the low-grade steam of the boiler is used to cool the condensation Heating and heating the wet flue gas after deep desulfurization, dust removal and dehumidification; using the intelligent temperature adjustment system to adjust the steam supply of the flue gas heating device according to the external environmental parameters (humidity, temperature, wind speed), and then intelligently adjust the exhaust gas temperature to realize the flue gas High reliability and low cost energy consumption "no white fog" emission.

Claims (5)

1. a kind of coal-burning power plant's energy-saving dedusting synergy cooperative intelligentization regulation and control remove white system, it is characterised in that：It is described to remove white system White device and Intelligent thermoregulation system, institute are removed including the more de- device of desulfurizing tower, flue gas phase transformation knockouts, wet electrostatic, flue gas heating State desulfurizing tower by desulfurizing tower exhaust pass with flue gas phase transformation knockouts to be connected, the flue gas phase transformation knockouts passes through Gas phase Smoke Become knockouts exhaust pass with the more de- device of wet electrostatic to be connected, the more de- device of the wet electrostatic removes white device phase with flue gas heating Connection, the flue gas heating are connected except white device with chimney, and the Intelligent thermoregulation system monitors with ambient atmosphere respectively is System is with flue gas heating except white device is connected.

2. coal-burning power plant's energy-saving dedusting synergy cooperative intelligentization regulation and control according to claim 1 remove white system, its feature exists In：The flue gas phase transformation knockouts includes housing and the condensing heat-exchanging pipe being arranged in housing, the condensing heat-exchanging pipe difference It is connected with cooling water inlet pipe, cooling water outlet pipe, the housing bottom is connected by condensate collector tube with discharge casing, The discharge casing is connected by baffle plate with cyclic water tank, and the discharge casing is connected by draining pump with desulfurizing tower, the circulation Water tank is connected by water circulating pump with self-cleaning filter, and the self-cleaning filter takes off device shower waters more with wet electricity respectively Pipe, mist eliminator flushing water pipe are connected.

3. coal-burning power plant's energy-saving dedusting synergy cooperative intelligentization regulation and control according to claim 2 remove white system, its feature exists In：The condensing heat-exchanging pipe is serially connected, and direction is vertical with flue gas flow direction, and is in interlaced arrangement, the condensing heat-exchanging pipe and shell It is connected between body by sealing ring, metalwork, the cooling water inlet pipe is connected and inserted cold with condensing heat-exchanging pipe end comb The bottom of solidifying heat exchanger tube, the cooling water outlet pipe are connected with first row condensing heat-exchanging pipe.

4. coal-burning power plant's energy-saving dedusting synergy cooperative intelligentization regulation and control according to claim 1 remove white system, its feature exists In：The more de- device of the wet electrostatic is connected by the more de- device drainpipe of wet electrostatic with discharge casing.

5. coal-burning power plant's energy-saving dedusting synergy cooperative intelligentization regulation and control according to claim 1 remove white system, its feature exists In：The flue gas heating includes low-grade steam inlet house steward, low-grade steam inlet branch pipe, flue gas heating except white except white device Device heat exchanger tube, flue gas heating are except white device housing rack slot steel, flue gas heating are except white device inner reinforced plate, low-grade steam (vapor) outlet branch Pipe, low-grade steam (vapor) outlet house steward, the flue gas heating remove white device housing frame except white device heat exchanger tube is arranged on flue gas heating In channel-section steel, flue gas heating is connected with low-grade steam inlet branch pipe, low-grade steam (vapor) outlet branch pipe respectively except white device heat exchanger tube Logical, the low-grade steam inlet branch pipe is connected with low-grade steam inlet house steward, low-grade steam (vapor) outlet branch pipe and low product Position steam (vapor) outlet house steward is connected；The low-grade steam inlet house steward is connected with plant area low-grade steam boiler, the intelligence Thermoregulating system can be changed with low-grade steam inlet house steward to be connected.