CN203836997U - Various-contaminant high-efficiency cooperative removing integrated system - Google Patents

Abstract

The utility model relates to a various-contaminant high-efficiency cooperative removing integrated system. The emission values of main smoke contaminants such as smoke, SO2, NOX, mercury and SO3 are lowered, and the requirement of the fuel gas unit emission standard is met. According to the technical scheme, the system comprises an SCR reactor, low-low-temperature dust removing equipment, a desulfurizing absorption tower and a wet type electrostatic dust removing device, an inlet of the SCR reactor is connected with a boiler tail portion smoke channel smoke outlet after low-nitrogen combustion transforming, SCR denitration catalysts are modified catalysts which can improve the performance for oxidizing elemental mercury, an inlet of the low-low-temperature dust removing equipment is connected with an outlet of the SCR reactor, the low-low-temperature dust removing equipment is used for dust removing and SO3 removing, an inlet of the desulfurizing absorption tower is connected with an outlet of the low-low-temperature dust removing equipment, the desulfurizing absorption tower is used for desulfurizing and dust removing, an inlet of the wet type electrostatic dust removing device is connected with an outlet of the desulfurizing absorption tower, an outlet of the wet type electrostatic dust removing device is connected to a chimney through temperature rising equipment, and the wet type electrostatic dust removing device is used for dust removing and removing of gypsum fogdrop, mercury and SO3. The various-contaminant high-efficiency cooperative removing integrated system is used in the field of atmospheric pollution prevention.

Description

Integrated system for efficient and collaborative removal of various pollutants

technical field

The utility model relates to an integrated system for efficiently synergistically removing various pollutants, and is mainly applicable to the technical field of air pollution prevention and control.

Background technique

There are triple pressures in my country's current energy situation, namely, the pressure of continuous growth in energy demand, the pressure of continuously increasing environmental protection requirements in energy utilization, and the pressure of energy supply security. How to find a balance point among these triple pressures and jointly solve them reasonably and appropriately The problem is a very urgent and necessary work.

my country's coal-based energy consumption structure will hardly change fundamentally for a long period of time in the future. A large amount of soot, sulfur dioxide (SO ₂ ), nitrogen oxides (NO _X ) and heavy metals and other pollutants produced during coal combustion are also fine particulate matter (PM _2.5 ) and its precursors such as SO ₂ , NO One of the most important sources of atmospheric pollutants such as _X , these pollutants have serious threats to the environment and public health.

As of the end of 2012, my country's coal-fired power plants consumed about 1.855 billion tons of coal, accounting for 52.8% of the country's total coal consumption, making it the largest coal-consuming household. In September 2011, the Ministry of Environmental Protection and the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China jointly issued the most stringent "Emission Standards of Air Pollutants for Thermal Power Plants" (GB13223-2011), requiring that by July 2014, coal-fired boilers should meet: Mercury and its compounds 0.03mg/Nm ³ , soot 30mg/Nm ³ , sulfur dioxide 200 (existing units)/100 (newly built units) mg/Nm ³ , nitrogen oxides 100 mg/Nm ³ ; emissions in key areas The standard is 20mg/Nm ³ for smoke and 50mg/Nm ³ for sulfur dioxide, and the pressure on environmental protection of coal-fired units has further increased.

In addition to smoke, SO ₂ , NO _X and other main flue gas pollutants and _Hg mentioned in the new standard, SO ₃ , a pollutant with a small concentration, has also attracted widespread attention. SO ₃ is extremely corrosive, It not only causes pollution to the environment, but also brings great hidden dangers to the safe operation of power plants. Although the concentration of SO ₃ in the flue gas emissions of coal-fired power plants is low, the absolute amount of emissions is relatively large, which cannot be ignored. The United States has related emissions Standards were promulgated, the most stringent state standard is 0.6mg/Nm ³ , but there is no relevant standard in China.

my country's energy structure determines that the structure of the coal-based power industry is difficult to change in the short term. Coal-fired units are currently the safest and most reliable way to generate electricity. Moreover, my country's economy is developing rapidly and the demand for electricity is strong. To solve these problems at the same time, only The clean and efficient centralized consumption and treatment of coal-fired electricity can further remove various pollutants from coal-fired units so that they can reach the emission level of gas turbine units, which can simultaneously solve the aforementioned triple pressures.

Contents of the invention

The technical problem to be solved by the utility model is to provide an integrated system for the efficient and collaborative removal of various pollutants in view of the above existing problems, and to integrate and improve the efficiency of various pollutant removal technologies to effectively reduce smoke and dust (including PM2.5), SO ₂ , NO _X , mercury and SO ₃ and other main flue gas pollutant emission values, and make it meet the purpose of gas unit emission standards.

The technical solution adopted by the utility model is: an integrated system for efficient and coordinated removal of multiple pollutants, which is characterized in that it includes:

The SCR reactor, whose inlet is connected to the smoke outlet of the boiler tail flue modified by low-nitrogen combustion, and the SCR denitrification catalyst adopts a modified catalyst that can improve the oxidation performance of zero-valent mercury;

Low-temperature dedusting equipment, the inlet of which is connected to the outlet of the SCR reactor for dedusting and removal of SO ₃ ;

Desulfurization absorption tower, the inlet of which is connected to the outlet of low-temperature dust removal equipment, used for desulfurization and dust removal;

Wet electrostatic precipitator, its inlet is connected with the outlet of the desulfurization absorption tower, and the outlet is connected to the chimney through the heating equipment, which is used for dust removal, removal of gypsum droplets, mercury and SO ₃ .

The low and low temperature dust removal equipment includes a tubular heat exchanger and a low and low temperature electrostatic precipitator, wherein the inlet of the cooling section of the tubular heat exchanger is connected to the outlet of the SCR reactor, and the outlet is connected to the inlet of the low and low temperature electrostatic precipitator.

The heating device is a heating section of a tubular heat exchanger.

The beneficial effects of the utility model are: 1. The utility model organically integrates the SCR reactor, low and low temperature dust removal equipment, desulfurization absorption tower and wet electrostatic precipitator through pipeline optimization and arrangement optimization, and improves the pollution of each technology itself. At the same time, the pollutant removal efficiency of the integrated system technology has reached a new height, which can remove a variety of major pollutants at one time, and meet the emission standards of natural gas gas turbine units: the emission of smoke and dust concentration is less than 5mg /Nm ³ , SO ₂ emission concentration lower than 35mg/Nm ³ , NO _X emission concentration lower than 45mg/Nm ³ , and H _g emission concentration lower than 0.003mg/Nm ³ (only one tenth of the national standard ), the SO ₃ emission concentration is lower than 5mg/Nm ³ (there is no domestic standard), and the full-load denitrification, elimination of "white smoke" and gypsum rain are realized. 2. Integrate multiple devices. Through device integration, the compatibility and matching degree between devices can be improved. The addition of other devices can improve the efficiency of a single device, and also make the possible side effects of a single device decontamination possible. Eliminated by other equipment, such as the SO ₃ generated by oxidation in the SCR reactor can be removed by low-temperature dust removal equipment and wet electrostatic precipitator, and the gypsum droplets brought out of the desulfurization absorption tower can be removed by the downstream wet electrostatic precipitator, etc. , prevent various foreseeable side effects, improve equipment operation safety and life, and realize real ultra-low emission of pollutants. 3. Through reasonable order arrangement and layout, optimize pipeline planning and connection, make various equipments organically integrated, improve overall efficiency, and reduce operating costs. For example, the operating cost of renovation projects is only 0.015 yuan/kwh, and the operating cost of new projects is only 0.01 Yuan/kwh. 4. Each equipment generally mainly removes certain pollutants, and at the same time can remove other pollutants to a certain extent. The utility model rationally distributes the removal of the same pollutant by different equipment through the organic integration, overall planning and arrangement optimization of the equipment. The removal ratio can achieve the maximum pollutant removal effect at the minimum cost. 5. The utility model can remove multiple pollutants at one time. Compared with multiple removal projects for a single pollutant, the investment cost and construction time can be saved, and the overall planning can reduce the occupied space. 6. It is applicable to all kinds of coal-fired units, and can be adjusted according to the conditions and requirements of the units (reduce the number of equipment or change the connection sequence of equipment) to achieve the best effect and wider adaptability. 7. Adopt high-efficiency tubular heat exchanger, use its cooling section to cool down the flue gas entering the low-low temperature dust collector, and use its heating section to heat up the flue gas output from the wet electrostatic precipitator, which simplifies the structure and improves the efficiency efficiency.

Description of drawings

Fig. 1 is a structural diagram of the utility model.

Detailed ways

For the first time, the utility model organically integrates the international mainstream advanced technologies of denitrification, desulfurization, dust removal and removal of trace pollutants. The matching and compatibility of several technologies are good, and they can cooperate with each other and organically integrate into a variety of pollution An integrated system for efficient and collaborative removal of matter, and innovatively proposed the use of this system to make the main pollutants of coal-fired power plants meet the emission standards of gas turbine units.

As shown in Figure 1, the system of this embodiment includes:

SCR reactor 1, the inlet of which is connected to the smoke outlet of boiler 5 tail flue; wherein boiler 5 is modified by low-nitrogen combustion, combined with SCR (selective catalytic reduction) denitrification technology, so that the denitrification efficiency of the whole system reaches more than 90%; In addition, the SCR denitrification catalyst is modified to oxidize zero-valent mercury and improve the mercury removal efficiency of downstream equipment;

Low-low temperature dust removal equipment 2, including high-efficiency tubular heat exchanger 2-1 and low-low temperature electric precipitator 2-2, and using high-frequency power supply, wherein the inlet of the cooling section of high-efficiency tubular heat exchanger 2-1 is connected to the SCR reactor 1 is connected to the outlet, and the outlet is connected to the inlet of the low-temperature electrostatic precipitator 2-2. The equipment has high dust removal efficiency, low power consumption and operation cost, the dust removal efficiency can reach more than 99.9%, and the SO ₃ removal efficiency can reach more than 80%;

The desulfurization absorption tower 3, whose inlet is connected with the outlet of the low and low temperature electrostatic precipitator 2-2, is used for desulfurization and dust removal; in this embodiment, desulfurization and efficiency improvement are carried out by adding a current equalizing efficiency disc, a desulfurization synergistic ring, and desulfurization additives. , can make the desulfurization efficiency of the whole system reach more than 98%, and have a dust removal efficiency of more than 50%;

The wet electrostatic precipitator 4 has its inlet connected to the outlet of the desulfurization absorption tower 3, and the outlet is connected to the chimney 6 after passing through the heating section of the high-efficiency tubular heat exchanger 2-1, which can achieve a deep dust removal effect and effectively remove gypsum droplets. And it has a high removal effect on mercury and SO ₃ , and the dust removal efficiency and SO ₃ removal efficiency can reach more than 70%.

In this embodiment, the SCR reactor 1, the low and low temperature dust removal equipment 2, the desulfurization absorption tower 3 and the wet electrostatic precipitator 4 form an organic whole through mutual connection and cooperation and the reasonable distribution of the removal ratio of various pollutants, and the NO _x , soot (including PM2.5), SO ₂ , SO ₃ and mercury are gradually removed, so that the main pollutant content in the final outlet flue gas reaches the gas turbine standard.

The integrated system of the utility model has been applied to the 2×1000MW unit of Zheneng Jiahua Power Generation Co., Ltd., which is a renovation project. As shown in Figure 1, the integrated system consists of SCR reactor 1 (equipped with a layer of modified catalyst), two-stage high-efficiency tubular heat exchanger 2-1 plus low and low temperature electrostatic precipitator 2-2, desulfurization absorption tower 3 and wet Composed of 4 electrostatic precipitators, the flue gas composition at the outlet meets the requirements of: the emission concentration of smoke and dust is lower than 5mg/Nm ³ , the emission concentration of SO ₂ is lower than 35mg/Nm ³ , and the emission concentration of NOX is lower than 45mg/Nm ³ , and at the same time, the emission of H _g is realized The concentration is less than 0.003mg/Nm ³ , the SO ₃ emission concentration is less than 5mg/Nm ³ , and full-load denitrification is realized, the temperature of the flue gas at the outlet reaches above 80°C, and the phenomenon of "white smoke" and gypsum rain is eliminated.

The project started construction in August 2013 and is scheduled to be completed in June 2014. At that time, it will be the first integrated demonstration project of ultra-low emission technology of flue gas pollutants for coal-fired power plants with a capacity of one million kilowatts in China. After completion, it is expected to reduce smoke and dust emissions by 880 tons/year, SO ₂ emissions by 2,524 tons/year, NO _X emissions by 642 tons/year, and SO ₃ emissions by 1,109 tons/year for the two million units. The investment cost is about 420 million yuan, and the operating cost is 0.015 yuan/KWh.

Claims (3)

1. the efficient cooperation-removal integrated system of multiple pollutant, is characterized in that it comprises:

SCR reactor (1), its entrance is connected with the outlet flue through the improved boiler of low nitrogen burning (5) back-end ductwork, and SCR denitrating catalyst adopts can improve the modified catalyst to the oxidation susceptibility of nonvalent mercury;

Low temperature cleaner (2), its entrance is connected with the outlet of SCR reactor (1), for dedusting with remove SO ₃;

Desulfuration absorbing tower (3), its entrance is connected with the outlet of low temperature cleaner (2), for desulfurization and dedusting;

Wet cottrell (4), its entrance is connected with the outlet of desulfuration absorbing tower (3), and outlet is connected to chimney (6) through heating device, for dedusting, removes gypsum droplet, mercury and SO ₃.

2. the efficient cooperation-removal integrated system of multiple pollutant according to claim 1, it is characterized in that: described low temperature cleaner (2) comprises pipe heat exchanger (2-1) and low low temp. electric deduster (2-2), wherein the entrance of pipe heat exchanger (2-1) temperature descending section is connected with SCR reactor (1) outlet, and outlet is connected with low low temp. electric deduster (2-2) entrance.

3. the efficient cooperation-removal integrated system of multiple pollutant according to claim 2, is characterized in that: described heating device is the intensification section of pipe heat exchanger (2-1).