CN109925839A - It is a kind of to utilize fume afterheat deep condensation demister system - Google Patents

Abstract

Fume afterheat deep condensation demister system is utilized the invention discloses a kind of, generation room, desulfurizing tower and vaporization chamber including being sequentially connected setting, further include condenser and absorber；Room and vaporization chamber and condenser between both occurs and absorber collectively forms the utilizing waste heat for refrigeration circulatory system；Indoor be equipped with occurs, heat exchanger occurs, flue gas is occurred in the chamber of room by passing through in generation heat exchanger also filled with refrigerant-absorbent solution；Evaporating heat exchanger is equipped in vaporization chamber, flue gas is by passing through elimination supersaturation water steam and reducing smoke temperature in evaporating heat exchanger.The present invention produces cold source using industrial low-quality waste heat, it is adaptable, stability is high, smaller by seasonal effect, and the cold energy produced is used for the deep condensation to wet flue gas after desulfurization, it is white to achieve the effect that chimney demisting disappears, can be widely applied to station boiler and the wet plume of Industrial Boiler chimney is administered.

Description

A deep condensation and demisting system using waste heat of flue gas

technical field

The invention relates to the technical field of plume treatment of chimneys of utility boilers and industrial boilers, in particular to a deep condensation and demisting system utilizing the residual heat of flue gas.

Background technique

In response to the national requirements for environmental protection of coal-fired power plants, power plant boilers or industrial boilers usually discharge flue gas to the chimney after desulfurization and denitrification. Since most of the currently used desulfurization methods are wet desulfurization, supersaturated wet flue gas is discharged to the chimney. The flue gas is directly discharged into the atmosphere through the chimney, and is in contact with the ambient air with a lower temperature. During the cooling process of the flue gas, the supersaturated water vapor contained in the flue gas condenses into water droplets, which refract and scatter the light, so that the chimney will cause the flue gas to refract and scatter. The outlet forms a misty white or grey plume.

The formation of wet plumes not only causes visual pollution and environmental pollution, worsens the urban landscape, but also aggravates the formation of smog. The de-fogging and whitening of the chimneys of thermal power plants should not only achieve environmental benefits in terms of urban landscape, but also collect dust particles, sulfates, nitrates, etc. contained in the flue gas, which greatly improves the efficiency of dust removal, desulfurization and denitrification.

Coal-fired power plants control environmental pollution while effectively utilizing energy. In industrial production, waste heat recovery and utilization is an important way to improve the economical operation of power plants and save fuel. There are various waste heats in the production process of thermal power plants, such as waste heat of flue gas. Usually, the air preheater and economizer of industrial boilers use the heat of flue gas to heat the air and feed water required for combustion. The waste heat of the flue gas is rarely reused. There are various energy levels of waste heat in the thermal system of coal-fired power plants. Choosing a suitable waste heat utilization site plays a crucial role in improving energy utilization efficiency.

At present, for the treatment of wet plumes in chimneys, three solutions have been summarized from the formation mechanism of wet plumes: flue gas heating method, flue gas cooling and condensation method, and flue gas condensation and reheating method. Combined with industrial waste heat utilization technology, the method of using low-quality waste heat as a heat source to produce a cold source in an absorption refrigeration cycle can provide a new solution for the control of wet plumes in coal-fired power plants.

The invention patent of Bulletin No. CN109045953A discloses a flue gas cooling, cooling, condensation, dehumidification, decontamination, reheating and whitening system, which consists of a flue gas deep cooler, a flue gas condensing heat exchanger, a flue gas reheater and a cold source. The flue gas deep cooling process provides a heat source for flue gas reheating, heats the main condensate water, and reduces the flue gas temperature at the outlet of the desulfurization tower; the flue gas condensation process can heat the main condensate water, provide a heat source for the heat pump, recover water resources, and reduce the humidity of flue gas. The flue gas reheating process reduces the relative humidity of the exhaust smoke and eliminates white smoke visually. The system innovates the structure of the condensing heat exchanger, uses 316L instead of fluorine plastics, titanium alloys, etc., introduces a mechanical ventilation brine tower and an intelligent control system, reduces the cost and energy consumption of the device and system, and visually eliminates white smoke. The waste heat in the flue gas can remove more than 50% of PM2.5, SO ₃ and more than 15% of NO _x , taking into account both environmental benefits and economic benefits.

However, the above technical solutions still have the defects of insufficient fog elimination, poor energy saving and environmental protection effects, and low energy utilization rate.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a deep condensation demisting system utilizing the residual heat of flue gas.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

A deep condensation and demisting system utilizing the residual heat of flue gas comprises a generating chamber, a desulfurizing tower and an evaporation chamber which are connected in sequence, and also includes a condenser and an absorber; a condenser and an absorber between the generating chamber and the evaporation chamber and the two Together they form a waste heat refrigeration cycle system;

A generating heat exchanger is arranged in the generating chamber, the flue gas passes through the generating heat exchanger, and the chamber of the generating chamber is also filled with a refrigerant-absorbent solution;

An evaporative heat exchanger is arranged in the evaporation chamber, and the flue gas passes through the evaporative heat exchanger to eliminate supersaturated water vapor and reduce the temperature of the smoke, and a liquid distributor for spraying to the evaporative heat exchanger is arranged on the top of the evaporation chamber;

The top of the generating chamber is connected with a high-pressure refrigeration steam pipeline, the high-pressure refrigeration steam pipeline is connected with the steam inlet of the condenser, and the liquid outlet of the condenser is connected with the liquid distributor in the evaporation chamber through the refrigerant pipeline. Equipped with an expansion valve; the bottom of the generating chamber is connected with a refrigerant-absorbent concentrated solution transportation pipeline, and the refrigerant-absorbent concentrated solution transportation pipeline is connected with the inlet of the liquid distributor of the absorber;

The upper part of the evaporation chamber is also connected with a low-pressure refrigerant vapor pipeline. The low-pressure refrigerant vapor pipeline is connected with the vapor inlet of the absorber. The low-pressure refrigerant vapor entering the absorber is absorbed by the refrigerant-absorbent concentrated solution and forms below the absorber. Refrigerant-absorbent dilute solution; an absorber solution outlet is arranged at the bottom of the absorber, and the absorber solution outlet is connected to the generating chamber through a refrigerant-absorbent dilute solution conveying pipeline.

The evaporative heat exchangers are respectively provided with condensed water outlets, the condensed water outlets are connected to the water collection tank through a guide pipe, and the condensed water on the flue gas side is introduced into the water collection tank through the guide pipe.

The refrigerant-absorbent concentrated solution conveying pipeline is equipped with a solution circulating pump.

The refrigerant-absorbent dilute solution conveying pipeline is equipped with a solution circulating pump.

The absorber and the condenser share the cooling water pipeline. The cooling water pipeline first passes through the condenser and then enters the absorber. The cooling water in the cooling water pipeline is provided by the cooling tower, and the cooling water flows out through the cooling tower and then passes through the cooling water pipeline. Then return to the cooling tower.

The desulfurization tower is a wet flue gas desulfurization structure. The bottom of the desulfurization tower is provided with a slurry pool at the bottom of the tower. A pipeline heat exchanger is arranged between the pipeline and the return part of the cooling water pipeline for heat exchange.

A dust collector is also arranged between the generating chamber and the desulfurization tower.

Beneficial effects of the present invention:

1. The present invention is based on the combination of industrial low-quality waste heat refrigeration and wet flue gas defogging and whitening treatment, and utilizes industrial low-quality waste heat to produce cold energy for the effective treatment of wet plumes in coal-fired power plants, so as to achieve both environmental protection work. The purpose of effectively utilizing industrial waste heat is required.

The invention utilizes industrial low-quality waste heat to produce cold source, and the produced cold energy is used to deeply condense the wet flue gas after desulfurization, so as to achieve the effect of removing fog and whitening of the chimney, and can be widely used in power station boilers and industrial boiler chimney humidification. Smoke plume control, and the recovery and utilization of flue gas waste heat is realized.

The invention uses the low-quality waste heat of flue gas as heat source drive, uses absorption refrigeration to produce cold energy, is used for condensation of wet flue gas after desulfurization, collects water vapor in supersaturated wet flue gas, and realizes effective utilization of low-quality waste heat, and Complete the task of exhausting smoke, defogging and eliminating whitening.

2. The present invention adopts the flue gas cooling and condensation method, which has a remarkable effect of removing fog and whitening, which not only saves energy and reduces production costs, but also fully and effectively utilizes industrial waste heat to control the wet plume in the industrial production of power station boilers and coal-fired power plants. Innovative technical solutions.

Different from the traditional flue gas cooling and condensing method, the present invention loads the waste heat of low-quality flue gas in industrial production for refrigeration, and uses the obtained cold energy to replace the cooling water in the traditional flue gas cooling, which is beneficial to eliminating the wetness after desulfurization and denitrification of power station boilers or industrial boilers. The colored plume produced by the flue gas has a more significant effect.

3. The technical solution of the present invention has strong adaptability and high stability, and the absorption refrigeration method that carries industrial waste heat as a heat source is less affected by seasons.

4. The design of the present invention is concise and clear. It is the combined application of industrial waste heat recovery, absorption refrigeration and flue gas de-fogging and whitening. It can realize the integration of industrial energy saving and whitening, and it is easy to implement and install. It only needs to be based on the original equipment of the boiler. A refrigeration cycle system can be installed on it.

5. From the perspective of effectively utilizing industrial waste heat, the present invention utilizes the absorption refrigeration cycle to produce cold energy, which is used to condense the supersaturated wet flue gas at the tail of the boiler, eliminate supersaturated water vapor in the flue gas, and achieve industrial pollution control. The purpose of chimney defogging and whitening.

Description of drawings

FIG. 1 is a schematic diagram of a system according to an embodiment of the present invention.

The reference numerals of the parts in the figure: 1—desulfurization tower; 2—dust collector; 3—generating chamber; 4—condenser; 5—absorption chamber; 6—evaporation chamber; 7—desulfurization tower slurry spray device; 8— Cooling tower; 9—expansion valve; 10—direct slurry circulation pump; 11—pipeline heat exchanger; 12—corona wire; 13—electrode plate; 14—indirect slurry circulation pump; 15—ash treatment device; 16— Concentrated solution pool; 17—solution circulation pump; 18—refrigerant-absorbent concentrated solution delivery pipeline; 19—liquid distributor; 20—cooling water circulation pump; 21—refrigerant pipeline; 22—lead pipe; 23—collection Pool; 24—smoke exhaust channel; 25—solution circulation pump; 26—high pressure refrigeration steam pipeline.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention. In Figure 1, the arrow A is the flue gas inlet, and the arrow B is the flue gas outlet.

As shown in FIG. 1 , a deep condensation and demisting system utilizing the residual heat of flue gas in this embodiment includes a generating chamber 3, a dust collector 2, a desulfurization tower 1 and an evaporation chamber 6 connected in sequence, and also includes a condenser 4 and an absorption chamber 6. The generator chamber 3 and the evaporation chamber 6 and the condenser 4 and the absorber 5 between them together constitute a waste heat refrigeration cycle system.

The generating chamber 3 is provided with a generating heat exchanger, the flue gas passes through the generating heat exchanger, and the cavity of the generating chamber 3 is also filled with a refrigerant-absorbent solution. The flue gas inlet and outlet pipes of the generating chamber 3 are subjected to anti-wear and anti-corrosion treatment.

The precipitator 2 is an electrostatic precipitator. The flue gas enters the precipitator 2 after being cooled by the heat exchanger in the generating room. A strong electric field is generated by the corona line 12 to charge the dust in the flue gas. The plate 13 adsorbs and settles to achieve the purpose of dust removal. The bottom of the dust collector 2 is also provided with an ash treatment device.

The desulfurization tower 1 is a wet flue gas desulfurization structure. The flue gas after dust removal enters the desulfurization tower 1 for flue gas desulfurization treatment. Flue gas wet desulfurization desulfurization is currently a widely used desulfurization method with remarkable effect.

The bottom of the desulfurization tower 1 is provided with a slurry pool at the bottom of the tower. The slurry pool at the bottom of the tower is connected by a slurry circulation pipeline to a desulfurization tower slurry spray device 7 located at the upper part of the desulfurization tower. The slurry circulation pipeline is also provided with a direct slurry circulation pump 10, Indirect slurry circulation pump 14 . The desulfurization tower 1 is also provided with a desulfurization wastewater discharge pipeline and a treatment device.

An evaporation heat exchanger is arranged in the evaporation chamber 6, and the flue gas passes through the evaporation heat exchanger to eliminate supersaturated water vapor and reduce the smoke temperature, and the top of the evaporation chamber is provided with a liquid distributor for spraying to the evaporation heat exchanger. The size of the evaporative heat exchanger is determined by the actual size of the evaporating chamber and the amount of smoke exhausted. The evaporative heat exchanger can be composed of a single heat exchange structure or multiple heat exchange structures, and the heat exchange surface is subjected to enhanced heat exchange and anti-wear and anti-corrosion treatment.

The wet flue gas after desulfurization contains a large amount of supersaturated water vapor, which is the fundamental reason for the formation of fog-like plumes from the chimney exhaust of thermal power plants. In the present invention, after the wet flue gas enters the flue gas exhaust passage 24 and before it is introduced into the chimney, an absorption refrigeration evaporation chamber 6 is added. It is used to condense the wet flue gas and recover the supersaturated water vapor in the flue gas. After the flue gas is condensed in the evaporation chamber 6, the absolute moisture content in the flue gas can be reduced, and the moisture content of the flue gas can be guaranteed. During the cooling process of the flue gas passing through the chimney, it is always lower than the saturated moisture content value to ensure that the flue gas is always lower than the saturated moisture content. The water vapor is always in the gas phase, and there will be no phase change to separate out condensed water.

The waste heat refrigeration cycle system is a closed cycle, which does not involve mixing of working medium, which is convenient for precise control and can achieve better refrigeration effect. Since the refrigeration cycle is a closed cycle, there can be various refrigerant-absorbent pairs in the refrigeration cycle. According to an embodiment of the present invention, water is used as the refrigerant and lithium bromide solution is used as the absorbent.

The top of the generating chamber 3 is connected with a high-pressure refrigeration steam pipeline 26, the high-pressure refrigeration steam pipeline 26 is connected with the steam inlet of the condenser 4, and the liquid outlet of the condenser 4 and the liquid distributor in the evaporation chamber 6 pass through the refrigerant pipe Road 21 is connected, and an expansion valve 9 is arranged on the refrigerant pipeline. A concentrated solution pool 16 is formed at the bottom of the generating chamber 3, and the concentrated solution pool 16 is connected with a refrigerant-absorbent concentrated solution delivery pipeline 18, and the refrigerant-absorbent concentrated solution delivery pipeline is connected with the inlet of the liquid distributor 19 of the absorber 5, A solution circulation pump 17 is arranged on the refrigerant-absorbent concentrated solution conveying pipeline 18 .

The upper part of the evaporation chamber 6 is also connected with a low-pressure refrigerant vapor pipeline, and the low-pressure refrigerant vapor pipeline is connected with the vapor inlet of the absorber 5, and the low-pressure refrigerant vapor entering the absorber 5 is absorbed by the refrigerant-absorbent concentrated solution, and is absorbed in the absorber 5. A refrigerant-absorbent dilute solution is formed below the absorber; the absorber 5 is provided with an absorber solution outlet at the bottom, and the absorber solution outlet is connected to the generation chamber 3 through a refrigerant-absorbent dilute solution delivery pipeline, and the refrigerant-absorbent dilute solution is transported The pipe is equipped with a solution circulating pump 25 .

In this embodiment, the absorber 5 and the condenser 4 share the cooling water pipeline. The cooling water pipeline first passes through the condenser 4 and then enters the absorber 5. The cooling water in the cooling water pipeline is provided by the cooling tower 8, and the cooling water is cooled by After the tower 8 flows out, it passes through the cooling water pipeline, and then returns to the cooling tower 8. A cooling water circulating pump 20 is provided on the cooling water pipeline.

In this embodiment, a pipeline heat exchanger 11 is provided between the slurry circulation pipeline and the return portion of the cooling water pipeline for heat exchange, so as to complete the cooling of the slurry circulation pipeline by the cooling water.

The working principle of the waste heat refrigeration cycle system in the present invention is as follows: the dilute lithium bromide solution in the absorption chamber 5 is transported to the generation chamber 3 by the solution circulation pump 25, and the refrigerant in the solution is evaporated by the heat of the waste heat of the flue gas in the generation chamber 3, High-pressure refrigeration steam is formed, the evaporated high-pressure refrigeration steam enters the condenser 4, and the unevaporated solution is collected in the solution pool 16 at the bottom of the generating chamber 3 to form a refrigerant-absorbent concentrated solution, which is depressurized by the expansion valve and then transported to the absorption chamber The liquid distributor 19 at the top of 5, the sprayed refrigerant-absorbent concentrated solution absorbs the low-pressure refrigerant vapor from the evaporation chamber 6, and the concentrated solution is taken away by the cooling device in the absorption chamber 5 to absorb the low-pressure refrigerant vapor. The generated heat turns the refrigerant-absorbent solution that has absorbed the refrigerant vapor into a dilute solution, which is then transported to the generation chamber 3 by the solution circulation pump 25; the high-pressure refrigeration vapor entering the condenser 4 is condensed into a refrigerant liquid by the cooling water , and then expanded to a low pressure state through the expansion valve 9, and then sent to the liquid distributor of the evaporation chamber 6 and sprayed to the heat exchange heat exchanger in the evaporation chamber 6 to absorb the heat of the wet and hot flue gas after desulfurization, and the wet flue gas is cooled and condensed. The refrigerant heats up and evaporates to form low-pressure refrigerant vapor, and the condensed water on the flue gas side is introduced into the water collection tank 23 through the guide pipe 22 and is treated and recycled together with the water in the slurry tank at the bottom of the desulfurization tower 1. Low-pressure refrigeration is generated in the evaporation chamber 6 The agent vapor passes into the absorption chamber 5, is absorbed by the refrigerant-absorbent concentrated solution to form a dilute solution, returns to the initial state, and completes the cycle.

Based on the combination of industrial low-quality waste heat refrigeration and wet flue gas defogging and whitening treatment, the invention utilizes industrial low-quality waste heat to produce cold energy, which is used for the effective treatment of wet smoke plumes in coal-fired power plants, so as to meet the requirements of environmental protection work and meet the requirements of environmental protection. The purpose of effectively utilizing industrial waste heat.

The invention utilizes industrial low-quality waste heat to prepare a cold source, has strong adaptability, high stability, and is less affected by seasons, and the prepared cold energy is used to deeply condense the wet flue gas after desulfurization, so as to achieve de-fogging and whitening of the chimney. It can be widely used in power station boiler and industrial boiler chimney wet plume treatment, and realize the recovery and utilization of flue gas waste heat.

The invention uses the low-quality waste heat of flue gas as heat source drive, and uses absorption refrigeration to produce cold energy, which is used for condensation of wet flue gas after desulfurization, and collects water vapor in supersaturated wet flue gas, so as to realize the effective utilization of low-quality waste heat, and Complete the task of exhausting smoke, defogging and eliminating whitening.

The invention adopts the flue gas cooling and condensation method, and has remarkable effect of removing fog and whitening, which not only saves energy and reduces production cost, but also fully and effectively utilizes industrial waste heat, and proposes an innovative method for the treatment of wet smoke plumes in the industrial production of power station boilers and coal-fired power plants. technical solution.

Different from the traditional flue gas cooling and condensation method, the present application uses the waste heat of low-quality flue gas in industrial production for refrigeration, and uses the obtained cold energy to replace the cooling water in the traditional flue gas cooling, which is beneficial to eliminating the wetness after desulfurization and denitrification of power station boilers or industrial boilers. The colored plume produced by the flue gas has a more significant effect.

From the perspective of effectively utilizing industrial waste heat, the invention utilizes an absorption refrigeration cycle to produce cold energy, which is used to condense the supersaturated wet flue gas at the tail of the boiler, eliminate supersaturated water vapor in the flue gas, and achieve chimney removal in industrial pollution control. The purpose of fog elimination.

The design of the invention is concise and clear, and it is used for the combined application of industrial waste heat recovery, absorption refrigeration and flue gas de-fogging and whitening, which can realize the integration of industrial energy saving and whitening, and is easy to implement and install. A waste heat refrigeration cycle system can be installed.

The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced without departing from the Any modification or partial replacement of the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims (7)

1. a deep condensation demisting system utilizing the residual heat of flue gas, it is characterized in that: comprise generation chamber, desulfurization tower and evaporation chamber that are connected and set successively, also comprise condenser and absorber; Between generation chamber and evaporation chamber and both The condenser and absorber together constitute the waste heat refrigeration cycle system; A generating heat exchanger is arranged in the generating chamber, the flue gas passes through the generating heat exchanger, and the chamber of the generating chamber is also filled with a refrigerant-absorbent solution; An evaporative heat exchanger is arranged in the evaporation chamber, and the flue gas passes through the evaporative heat exchanger to eliminate supersaturated water vapor and reduce the temperature of the smoke, and a liquid distributor for spraying to the evaporative heat exchanger is arranged on the top of the evaporation chamber; The top of the generating chamber is connected with a high-pressure refrigeration steam pipeline, the high-pressure refrigeration steam pipeline is connected with the steam inlet of the condenser, and the liquid outlet of the condenser is connected with the liquid distributor in the evaporation chamber through the refrigerant pipeline. Equipped with an expansion valve; the bottom of the generating chamber is connected with a refrigerant-absorbent concentrated solution transportation pipeline, and the refrigerant-absorbent concentrated solution transportation pipeline is connected with the inlet of the liquid distributor of the absorber; The upper part of the evaporation chamber is also connected with a low-pressure refrigerant vapor pipeline. The low-pressure refrigerant vapor pipeline is connected with the vapor inlet of the absorber. The low-pressure refrigerant vapor entering the absorber is absorbed by the refrigerant-absorbent concentrated solution and forms below the absorber. Refrigerant-absorbent dilute solution; an absorber solution outlet is arranged at the bottom of the absorber, and the absorber solution outlet is connected to the generating chamber through a refrigerant-absorbent dilute solution conveying pipeline. 2. The deep condensation and demisting system utilizing the residual heat of flue gas according to claim 1, characterized in that: the evaporative heat exchanger is respectively provided with a condensed water outlet, and the condensed water outlet is connected to a water collecting tank through a guide pipe , and the condensed water on the flue gas side is introduced into the collection tank through the guide pipe. 3 . The deep condensation demisting system utilizing the residual heat of flue gas according to claim 1 , wherein a solution circulation pump is arranged on the refrigerant-absorbent concentrated solution conveying pipeline. 4 . 4 . The deep condensation demisting system utilizing the residual heat of flue gas according to claim 1 , wherein a solution circulation pump is arranged on the refrigerant-absorbent dilute solution conveying pipeline. 5 . 5. The deep condensation and demisting system utilizing the residual heat of flue gas according to any one of claims 1-4, wherein the absorber and the condenser share a cooling water pipeline, and the cooling water pipeline passes through the condenser first. Then enter the absorber, the cooling water in the cooling water pipeline is provided by the cooling tower, the cooling water flows out through the cooling tower and then passes through the cooling water pipeline, and then returns to the cooling tower. 6. A kind of deep condensation demisting system utilizing flue gas waste heat according to claim 5, it is characterized in that: described desulfurization tower is wet flue gas desulfurization structure, the bottom of desulfurization tower is provided with tower bottom slurry pool, tower bottom The slurry tank is connected by the slurry circulation pipeline to the desulfurization tower slurry spray device located at the upper part of the desulfurization tower, and a pipeline heat exchanger is arranged between the slurry circulation pipeline and the reflux part of the cooling water pipeline for heat exchange. 7 . The deep condensation and demisting system using the residual heat of flue gas according to claim 6 , wherein a dust collector is further provided between the generating chamber and the desulfurization tower. 8 .