CN118239550A

CN118239550A - High-salt water and high-humidity flue gas cooperative treatment system and method

Info

Publication number: CN118239550A
Application number: CN202310942811.2A
Authority: CN
Inventors: 高境; 李艳萍; 高迪
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-07-28
Filing date: 2023-07-28
Publication date: 2024-06-25
Also published as: CN220555645U

Abstract

The invention discloses a high-salinity water and high-humidity flue gas cooperative treatment system which comprises a high-salinity water source, a heat transfer decontamination device, a high-salinity water cooling concentration device and a concentration liquid pool which are sequentially connected, wherein the heat transfer decontamination device is used for transferring the waste heat of the high-humidity flue gas to the high-salinity water and removing pollutants in the high-humidity flue gas.

Description

High-salt water and high-humidity flue gas cooperative treatment system and method

Cross Reference to Related Applications

The present invention claims priority to chinese patent application No. 2022, 7, 28, 202210897745.7, entitled "high brine and high humidity flue gas co-processing system and method", which is incorporated herein by reference in its entirety.

Technical Field

The invention relates to a co-processing system and a method for high-salinity water and high-humidity flue gas.

Background

Along with the promotion of water conservation consciousness and environmental protection consciousness in China, a plurality of factories running coal-fired boilers require the design of zero emission of wastewater of the whole factory. In order to meet the normal operation of the desulfurization system and the material balance in the system, desulfurization wastewater is required to be discharged. The desulfurization waste water has high salt content, has the characteristics of high corrosion, easy scaling and the like, and cannot be recycled. In addition, the final waste liquid generated in the water treatment links of the industries such as sea water desalination, steel, chemical industry and the like is mostly high-salt water similar to desulfurization waste water, and cannot be recycled.

The existing high-salt water zero-emission process route at home and abroad is generally divided into 4 steps: 1, a high-salt water pretreatment unit; 2a high brine concentration unit; 3 concentrating the water crystallization unit; and 4, disposing of solid waste. According to the technical route, 95% of the wastewater is converted into pure water which can be recycled, the rest is dried and crystallized into solid particles, and then the product sale or the reprocessing as waste is determined according to the component purity of the solid particles.

Disclosure of Invention

The invention provides a high-humidity flue gas and high-salt water cooperative treatment system and a method. The system and the method can heat the high-salt water by utilizing the waste heat of the high-humidity flue gas, and cooperatively realize the concentration and crystallization of the high-salt water, the water recovery, the high-purity salt extraction and the removal of pollutants in the high-humidity flue gas. In particular, the system and the method can carry out cooperative treatment on the high-humidity flue gas and high-salt water after a coal-fired, gas-fired boiler or an industrial kiln. The high-salt water is mainly desulfurization wastewater generated by a coal-fired boiler, and can also comprise seawater, waste liquid generated by other water treatment links and aqueous solution obtained after various salts are dissolved. The invention is suitable for the treatment of high-salt water in the fields of electric power, sea water desalination, papermaking, chemical industry, steel and the like. High brine is highly corrosive and difficult to apply industrially, and seawater in nature is typically high brine.

The first aspect of the invention relates to a high-salt water and high-humidity flue gas cooperative treatment system, which comprises a high-salt water source, a heat transfer decontamination device, a high-salt water cooling concentration device and a concentration liquid pool which are connected in sequence, wherein the heat transfer decontamination device is used for transferring the waste heat of the high-humidity flue gas to the high-salt water and removing pollutants in the high-humidity flue gas.

In some embodiments, the concentrate tank includes a water outlet connected to the heat transfer decontamination device.

In some embodiments, the air outlet of the cooling concentration device is connected to the flue.

In some embodiments, the system further comprises a fan and an airflow ejector disposed in the flue, and the air outlet of the cooling concentration device, the fan and the airflow ejector inlet are connected in sequence.

In some embodiments, the heat transfer decontamination device comprises a flue gas condenser arranged in a high-humidity flue gas flue, the high-salt water source is connected with a working fluid inlet of the flue gas condenser, and a working fluid outlet of the flue gas condenser is connected with a water inlet of the cooling concentration device.

In some embodiments, the heat transfer decontamination device comprises a first heat transfer device and a second heat transfer device connected, wherein the first heat transfer device is used for transferring the waste heat of the high humidity flue gas to the heat medium, and the second heat transfer device is used for transferring the heat from the heat medium to the high brine.

In some embodiments, the first heat transfer device is a spray device or a flue gas condenser and the second heat transfer device is a second heat exchanger or a heat pump.

In some embodiments, the system further comprises a condensate collection device for collecting condensate formed during the high humidity flue gas cool down process.

In some embodiments, the system further comprises a heating device connected between the heat transfer decontamination device and the cooling concentration device for further heating the high brine.

In some embodiments, the heating device is a hot water heater, an electric heater, or a steam heater, or the heating device is a flue heat exchanger disposed in a high temperature flue gas flue that has a higher flue temperature than the high humidity flue gas.

In some embodiments, the flue gas condenser or the second heat transfer device in contact with the high brine is made of a corrosion resistant material.

In some embodiments, the corrosion resistant material is stainless steel, titanium, thermally conductive plastic, fluoroplastic, or enamel.

In some embodiments, the system includes more than one set of cooling concentration devices and concentrate reservoirs, each set connected in parallel or in series.

In some embodiments, a slag scooper is disposed within the concentrate tank for scooping up the crystallized salt.

In some embodiments, the system further comprises a salt ion concentration detection device for detecting the ion concentration in the concentrated high brine in the concentrate pond.

In some embodiments, the system further comprises a conditioning device disposed between the high brine source and the heat transfer decontamination device for adjusting the ion concentration in the high brine to be treated.

Another aspect of the invention provides a method of co-processing high brine and high humidity flue gas, the method comprising:

(1) Heating high-salt water to be treated by utilizing the waste heat of the high-humidity flue gas and simultaneously removing pollutants in the high-humidity flue gas;

(2) And enabling the heated high-salt water to enter a cooling concentration device for cooling and concentrating, and then entering a concentrated solution tank.

In some embodiments, the method further comprises crystallizing the concentrated high brine in a concentrate pond to precipitate a crystalline salt.

In some embodiments, the high humidity flue gas is a flue gas after wet desulfurization treatment.

In some embodiments, the high humidity flue gas is a flue gas having a relative humidity above 80%.

In some embodiments, the regimen further comprises subjecting part or all of the concentrated high brine in the concentrate pond to step (1) and step (2) again as at least a portion of the high brine to be treated.

In some embodiments, the humid air exiting the cooling concentration device is introduced into the flue to mix with the flue gas.

In some embodiments, the wet air discharged from the cooling concentration device is pressurized and accelerated by a fan and then enters the flue as an injection air flow.

In some embodiments, step (1) comprises passing the high humidity flue gas through a flue gas condenser in heat exchange with the high brine.

In some embodiments, step (1) comprises transferring the waste heat of the high humidity flue gas to the high brine via a heat medium.

In some embodiments, step (1) comprises heating a heating medium with a high humidity flue gas via a first heat transfer device, and subsequently transferring heat of the heating medium to the high brine via a second heat transfer device.

In some embodiments, the method further comprises collecting condensed water formed by the cooling of the high humidity flue gas.

In some embodiments, the high brine that absorbs the heat of the high humidity flue gas is reheated prior to entering the cooling and concentrating device.

In some embodiments, the reheating is by a hot water source heater, a steam source heater, or an electric heater; or through a flue heat exchanger arranged in a high-temperature flue gas flue.

In some embodiments, when the high brine in the concentrate pond is concentrated to some extent, it is removed, in whole or in part, for further salification or other use.

In some embodiments, the method further comprises pre-conditioning the high brine to be treated to adjust the type and concentration of salts therein.

In some embodiments, the conditioning comprises removing a portion of the calcium ions in the high brine to be treated.

In some embodiments, the conditioning comprises reducing the calcium ion concentration in the high salt water to be treated to no more than 20mg/L.

In some embodiments, the conditioning comprises removing some or all of the sulfate ions in the high brine to be treated.

In some embodiments, the conditioning comprises reducing the concentration of sulfate ions in the high brine to be treated below a concentration threshold that causes the concentration of one or more sulfates in the high brine to be below its saturation concentration at a particular concentration ratio and lowest possible operating temperature.

In some embodiments, the conditioning comprises reducing the sulfate ion concentration in the high salt water to be treated to no more than 6000mg/L.

In some embodiments, the crystalline salt is a high purity first order precipitated crystalline salt.

In some embodiments, the first sequentially precipitated crystalline salt is a sodium chloride crystalline salt.

In some embodiments, the method further comprises detecting the concentration of ions in the concentrated high brine in the concentrate pond and withdrawing the crystallized salt or concentrated high brine from the concentrate pond before the second sequentially precipitated crystallized salt reaches the saturation concentration.

In some embodiments, the high brine in the treatment system or the method is obtained from a waste salt dissolved in water or other high brine.

Drawings

Fig. 1 is a schematic diagram of a first embodiment of the high brine and high humidity flue gas co-treatment system and process of the present invention.

Fig. 2 is a schematic diagram of a second embodiment of the high brine and high humidity flue gas co-treatment system and process of the present invention.

Fig. 3 is a schematic diagram of a third embodiment of the high brine and high humidity flue gas co-treatment system and process of the present invention.

Detailed description of the preferred embodiments

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The connection of two devices or components includes the case where other devices and other components are also present therebetween. For example, two devices or two components may have tubing or other devices between them. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art in a specific case.

The terms "first," "second," and the like in the present invention are used merely for distinguishing between different components and devices and do not imply that the components or devices have a particular structure. When the name of a "second" component is used, the "second" may be considered a part of its name, not meaning that there must be a "first" component corresponding thereto.

In the present invention, when "%" is mentioned, it means mass/mass% unless otherwise specified.

In the present invention, when referring to the temperature unit "degrees", it refers to degrees celsius if not specifically stated.

The invention relates to a co-processing system and a method for high-humidity flue gas and high-salt water. The system and the method can achieve the effects of utilizing the waste heat of the high-humidity flue gas, recovering the moisture, purifying the salt, reducing the emission of atmospheric pollutants, realizing the zero emission of high-salinity water and the like.

The cooperative processing method comprises the following steps: and heating the high-salt water to be treated by utilizing the waste heat of the high-humidity flue gas, removing pollutants in the high-humidity flue gas while carrying out heat transfer and cooling on the high-humidity flue gas, enabling the heated high-salt water to enter a cooling concentration device, and cooling and concentrating by contacting with air and then entering a concentration liquid pool. The high-humidity flue gas can be cooled by a flue gas condenser to form a large amount of condensed water or can be sprayed by hot medium water, pollutants in the high-humidity flue gas can be removed by flushing, absorbing and or adsorbing mechanisms in the condensing process or the spraying process, dust in the flue gas, escaped slurry liquid drops, SO ₂ and other pollutants can be removed by the condensed water or the spraying water, and the peripheral air quality of a factory is improved. The concentrated high-salt water can be used for precipitating crystalline salt in a concentrated liquid pool, for example, the crystalline salt can be stably precipitated in the concentrated liquid pool and is precipitated at the bottom, and the precipitated crystalline salt can be high-purity crystalline salt. "high purity crystalline salt" refers to a crystalline salt of relatively high purity, such as not less than 90%, not less than 91%, not less than 92%, not less than 93%, not less than 94%, not less than 95%, not less than 96%, not less than 97%, not less than 98% or not less than 99% pure; those skilled in the art are aware of the high purity criteria of different crystalline salts, e.g., for sodium chloride, "high purity" may refer to a purity of not less than 97.2%. In some embodiments, the concentrated high brine in the concentrate pond may also be used for other purposes, such as for dry ash conditioning, etc.

In order to realize the treatment method, the invention provides a cooperative treatment system, which comprises a high-salt water source, a heat transfer decontamination device, a cooling concentration device and a concentration liquid pool which are sequentially connected; the heat transfer decontamination device is used for transferring the waste heat of the high-humidity flue gas to the high-salt water, forming condensed water and removing pollutants in the flue gas.

The heat transfer decontamination device in the invention is a device which can cool high-humidity flue gas, heat high-salt water and remove pollutants in the flue gas through flushing, absorbing and/or adsorbing mechanisms. In some embodiments, the heat transfer decontamination device may remove contaminants by flushing, absorbing and/or adsorbing the contaminants with condensed water formed by condensation of the high-humidity flue gas or spray water used to spray the high-humidity flue gas to cool the high-humidity flue gas.

The high brine to be treated from the high brine source enters the heat transfer decontamination device where it absorbs the heat of the high humidity flue gas, thereby being heated. The heat transfer decontamination device is connected with the cooling concentration device so that the heated high-salt water can enter the cooling concentration device for cooling and concentration. The heat transfer decontamination device may be connected to the cooling concentration device by any suitable means, for example, the high brine outlet of the heat transfer decontamination device may be connected to the water inlet of the cooling concentration device. The heated high-salt water is heat-exchanged with cold air as a heat source in the cooling concentration device, the temperature thereof is lowered, and the moisture therein is evaporated, thereby being concentrated and cooled. The concentrated liquid pool is connected with the water outlet of the cooling concentration device so as to contain high-salt water flowing out of the cooling concentration device. In some embodiments, the concentrate pond may also provide the necessary environment for stable crystallization and precipitation of concentrated high brine.

As used herein, "high brine" may also be referred to as "high salt wastewater," and generally refers to wastewater produced in industrial processes that has a relatively high salt content, including, but not limited to, power plant desulfurization wastewater, salt-containing waste streams produced in other industries (e.g., desalination, iron and steel, chemical, etc.), aqueous solutions of dissolved seawater or waste salts, and treatment fluids after treatment (e.g., concentration treatment) thereof. The term "waste salt" refers to solid waste containing inorganic salt as a main component, such as various waste residues, dust, etc. discharged during industrial production; the byproduct crystalline salt produced in industrial production is generally called waste salt in the field, and mainly comes from a plurality of industries such as pesticides, pharmacy, fine chemical industry, printing and dyeing and the like. The term "high brine source" refers to a source of high brine to be treated in the present invention, such as any device or apparatus that produces, contains, or otherwise receives high brine. The term "high brine to be treated" in the present invention refers to any high brine to be treated by the co-treatment system of the present invention and also includes concentrated high brine that has been treated by the co-treatment system of the present invention for one or more cycles but has also been re-entered into the co-treatment system of the present invention for treatment. The temperature of the high brine to be treated is typically lower than the flue gas temperature of the high wet flue gas, for example, may be about 10 to about 30 degrees lower than the flue gas temperature of the high wet flue gas. In some aspects, the temperature of the high brine to be treated (e.g., the high brine temperature at the inlet of the heat transfer decontamination device) may be, for example, about 10 degrees to about 40 degrees, such as about 15 degrees to about 35 degrees, such as about 20 degrees to about 30 degrees. In some embodiments, the treated high brine may include desulfurization waste water and other industrial waste salts/waste water, including mixtures of desulfurization waste water and other industrial waste salts/waste water, or high brine obtained after desulfurization waste water is mixed with other industrial waste salts/waste water and pretreated.

As used herein, "high humidity flue gas" refers to flue gas having a relative humidity above 50%, above 60%, above 70%, above 80% or above 90%, such as near saturated wet flue gas. Due to the lower temperature of the flue gas, the waste heatThe lower the value (quality), the lower the thermal price and the better the economics for treating high brine. The high-humidity flue gas is preferably flue gas subjected to wet desulfurization spray treatment or high-humidity flue gas formed by cooling the flue gas. The flue gas temperature of the high humidity flue gas described herein may be no more than 60 ℃, preferably no more than 55 ℃, for example may be about 45 ℃ to 55 ℃. The waste heat of the high humidity flue gas may also be referred to as the heat of the high humidity flue gas. The flue gas can be flue gas generated by combustion in industries such as power plants, steel, chemical industry, garbage incineration and the like. The high-humidity flue gas can be near-saturation wet flue gas formed by slurry spraying or cooling after combustion in industries such as power plants, steel, chemical industry, garbage incineration and the like.

As used herein, "low temperature", "cold" and "high temperature", "hot" do not refer to temperatures below or above a particular temperature, but rather are relative concepts. A low temperature fluid or cold fluid refers to a fluid that is at a lower temperature than the other fluid, e.g., a lower temperature fluid, while a high temperature fluid or hot fluid refers to a fluid that is at a higher temperature than the other fluid, e.g., a higher temperature than the low temperature fluid.

As used herein, "fluid" includes various forms of liquids and gases such as water, high brine, flue gas, air, and other fluids that may be used as heat exchange media. The term "heat exchange medium" as used herein may also be referred to as a "heat medium" or a "working fluid" of a heat exchanger, and refers to a gas or liquid that can absorb and release heat. The term "circulating water" as used herein refers to the heat exchange medium, typically water or an aqueous solution, that is circulated through the system. In the present invention, high brine may be used as the circulating water. In the invention, the heat transfer decontamination device can heat the high-salt water by using the heat of the high-humidity flue gas, but does not exclude the heat of other sources from heating the high-salt water.

In the method of the invention, the waste heat of the high humidity flue gas can be directly transferred to the high brine (direct heat transfer scheme) or indirectly transferred to the high brine through another heat medium (indirect heat transfer scheme).

In a direct heat transfer scheme, a dividing wall heat exchanger, such as a flue gas condenser, may be used to transfer the waste heat of the high humidity flue gas to the high brine, i.e., to exchange heat with the high humidity flue gas through the flue gas condenser. Correspondingly, the heat transfer decontamination device comprises a flue gas condenser, a high-salt water source is connected with a working fluid inlet of the flue gas condenser, and a working fluid outlet of the flue gas condenser (namely a high-salt water outlet of the heat transfer decontamination device in a direct heat transfer scheme) is connected with a water inlet of the cooling concentration device. The heat of the high-humidity flue gas can be transferred to the working fluid through heat exchange when the high-humidity flue gas passes through the flue gas condenser. The high-humidity flue gas can be condensed to form a large amount of condensed water on the outer surface of the flue gas condenser, and the condensed water can wash, absorb and/or adsorb pollutants in the high-humidity flue gas SO as to remove the pollutants, for example, dust, liquid drops and acid gas in the flue gas can be obviously removed in the condensation process and the falling of the condensed water, and when the flue gas condenser is of a high-density finned tube structure, fine particulate matters such as condensable particulate matters and vapor-state pollutants such as SO ₃, heavy metals and VOC can be also obviously removed. The flue gas condensers can be one group, two groups or more groups, and the flue gas condensers of each group can be connected in series or in parallel.

The term "flue gas condenser" as used herein refers to a flue heat exchanger disposed in a high humidity flue gas flue. When the high-humidity flue gas is cooled by the flue gas condenser, the water vapor contained in the high-humidity flue gas can be condensed into water. The flue gas condenser is a dividing wall type heat exchanger. The flue gas condenser may be any form of heat exchanger, for example a tube heat exchanger or a plate heat exchanger or the like, preferably a finned tube heat exchanger.

As used herein, "high-humidity flue gas duct" refers to the flue of the high-humidity flue gas section, i.e., the flue gas in the section of flue is high-humidity flue gas. The high-humidity flue gas flue can be a flue after the desulfurizing tower, such as a connecting flue between any two of the desulfurizing tower, the wet electric dust collector and the chimney.

In the indirect heat transfer scheme, the waste heat of the high-humidity flue gas is transferred to a heating medium, and then the heating medium transfers the heat to high-salinity water.

The transfer of the waste heat of the high humidity flue gas to the heating medium may be performed by any suitable method, for example by direct contact heat exchange (e.g. spraying) or non-contact heat exchange (e.g. dividing wall heat exchange), such as by a hybrid heat exchanger, a regenerative heat exchanger or a dividing wall heat exchanger. In some embodiments, the waste heat of the high-humidity flue gas is transferred to the heat medium through the flue gas condenser, namely the heat medium is used as working fluid of the flue gas condenser, and the heat medium exchanges heat with the high-humidity flue gas and absorbs heat to raise temperature. In some embodiments, the waste heat of the high humidity flue gas is transferred to the heating medium by spraying, i.e. the high humidity flue gas is sprayed with the heating medium, and the high humidity flue gas heat is extracted, at which time the spraying can be performed using a hybrid heat exchanger.

The transfer of heat from the heating medium to the high brine may be carried out by any suitable method, for example by means of a further heat exchanger and/or heat pump.

The temperature of the high-humidity flue gas after desulfurization is about 50 ℃, and the high-salt water inlet/outlet temperature of the flue gas condenser is controlled to be about 20-30 ℃ so that the economical efficiency is better. The high-temperature and low-temperature air at the cooling concentration device directly influences the evaporation capacity of high-salt water, when the temperature difference between the high-salt water and the air is small or even no temperature difference exists in high temperature and high humidity in summer, the air humidity is high, when the temperature of the air wet bulb is close to or higher than the temperature of the high-salt water, the water is difficult to evaporate or cannot evaporate, the high-salt water is difficult to realize cooling, and when the high-salt water circularly flows in the flue gas condenser, the absorbed heat is less, so that the normal operation of a system is influenced. In order to solve the problem, the water temperature of the high-salinity water can be increased by arranging the heat pump, so that the system can be ensured to be capable of normally taking heat in high-temperature and high-humidity weather.

A "heat pump" as described herein is a device that is capable of flowing heat from a low temperature object to a high temperature object. The heat pump in the invention can be an absorption heat pump, a compression heat pump or other devices capable of realizing the heat pump function.

Based on the above considerations, in some embodiments of the invention, the heat of the heating medium is extracted by a heat pump and transferred to the high brine. In some embodiments, the working fluid of the heat pump absorbs heat from the heating medium in the evaporator section (or absorber section) and transfers heat to the high brine in the condenser section to heat the high brine. The temperature of the high-salt water heated by the heat pump can exceed the temperature of the air wet bulb by more than 1 ℃,2 ℃,3 ℃,5 ℃ or 10 ℃, so that the high-salt water can still be largely evaporated when the environmental temperature and humidity are high.

The indirect heat transfer scheme can be realized through two or more heat transfer devices, firstly, the waste heat of the high-humidity flue gas is transferred to the heat medium through the first heat transfer device, and then the heat of the heat medium is extracted through the second heat transfer device or the other heat transfer devices and transferred to the high-salt water. The high brine outlet of the second heat transfer device or the high brine outlet of the end heat transfer device of the two or more heat transfer devices (i.e., the high brine outlet of the heat transfer decontamination device in the indirect heat transfer scheme) is connected to the water inlet of the cooling concentration device.

The first heat transfer device may be a hybrid heat exchanger, a regenerative heat exchanger, or a divided wall heat exchanger. The first heat transfer device may be disposed in a high humidity flue gas duct. In some embodiments, the first heat transfer device is a hybrid heat exchanger, such as a spray device. The high-humidity flue gas can be sprayed by using a heating medium in the spraying device, and the heat of the high-humidity flue gas is transferred to the heating medium through direct contact heat exchange. In some embodiments, the first heat transfer device is a flue gas condenser, and the heating medium is used as a working fluid of the flue gas condenser, exchanges heat with high-humidity flue gas and absorbs heat to raise temperature. The first heat transfer means is in one or more groups, which may be connected in series and/or parallel, wherein each group of heat transfer means may be independently selected from a flue gas condenser and a shower. In some embodiments, the first heat transfer means may comprise one or more sets of flue gas condensers and/or one or more sets of spray devices,

The second heat transfer device may be a heat pump or a second heat exchanger, which may be a hybrid heat exchanger, a regenerative heat exchanger or a dividing wall heat exchanger. In some embodiments, the second heat transfer device is a heat pump, the high salt water source, the condensing section of the heat pump, the cooling and concentrating device and the concentrate pond are connected in sequence, and the first heat transfer device is connected with the evaporating section of the heat pump. In some embodiments, the high brine source is connected to the heat pump condensing section inlet, the heat pump condensing section outlet is connected to the water inlet of the cooling concentration device, and the heat medium outlet of the first heat transfer device is connected to the heat pump evaporating section inlet. In some embodiments, the heat medium can circulate in the heat pump evaporator end and the first heat transfer device to absorb and release heat repeatedly, in which case the heat pump evaporator end outlet is connected to the heat medium inlet of the first heat transfer device.

In some preferred embodiments, the waste heat of the high-humidity flue gas is transferred to the heating medium through the flue gas condenser, and then the heat of the heating medium is extracted by the heat pump and transferred to the high-salt water, i.e. the waste heat of the high-humidity flue gas can be transferred to the high-salt water by using the combination of the flue gas condenser and the heat pump. Correspondingly, the heat transfer decontamination device comprises a flue gas condenser and a heat pump.

In other preferred embodiments, the waste heat of the high humidity flue gas is transferred to the heating medium by spraying, and then the heat of the heating medium is extracted by the heat pump and transferred to the high brine, i.e. the waste heat of the high humidity flue gas can be transferred to the high brine by using a combination of the spraying device and the heat pump. Correspondingly, the heat transfer decontamination device comprises a spraying device and a heat pump. The spraying device can be a hybrid heat exchanger arranged in a high-humidity flue gas flue.

The "hybrid heat exchanger" as used herein is a heat exchanger that exchanges heat by direct contact and mixing of cold and hot fluids, also known as a contact heat exchanger.

As used herein, a "regenerative heat exchanger" refers to a heat exchanger that exchanges heat by alternately flowing cold and hot fluids across the surface of a regenerator (packing) in a regenerator.

As used herein, "dividing wall heat exchanger" refers to a heat exchanger in which cold and hot fluids are separated by a solid dividing wall and heat exchange occurs through the dividing wall, also known as a surface heat exchanger.

The system cold source is ambient air, the temperature difference of the air in summer and in winter is larger, the flue gas condensers (16 layers) with the same scale and the high-humidity flue gas (120 ten thousand cubic meters and 52 degrees) are calculated, the ambient temperature is about 30 degrees in summer, the high-salt water temperature is about 35-40 degrees, the high-temperature flue gas can only be cooled by 3 degrees, 15MW heat is provided, 16t/h high-salt water is treated, the ambient temperature is about 5 degrees in winter, the high-salt water temperature is 15-25 degrees, the high-humidity flue gas can be cooled by 8 degrees, 33MW heat is provided, 41t/h high-salt water is treated, and the difference of waste heat is generated.

For example, in some embodiments, a second heat pump may be added to the co-processing system, after the heat of the high-humidity flue gas is obtained by using the first heat transfer device, a part of the heat is heated by the second heat pump, for example, after the heat of the high-humidity flue gas is absorbed by the heat medium by using the first heat transfer device, a part of the heat medium enters the first heat pump as the second heat transfer device, the heat of the part of the heat medium is absorbed by the heat pump and transferred to the high-salt water, and another part of the heat medium enters the second heat pump, and the heat of the part of the heat medium is absorbed by the second heat pump and transferred to heating water for heating in winter; the amount of heat medium entering the heat pump as the second heat transfer means and the amount of heat medium entering the second heat pump can be adjusted.

In other embodiments, the co-processing system includes two or more sets of first heat transfer devices and a heat pump as the second heat transfer devices. The two or more sets of first heat transfer means may be connected in series or in parallel. The two or more groups of first heat transfer devices can be divided into two parts, in winter, one part of the first heat transfer devices takes high-salt water as working fluid, so that the high-salt water absorbs the heat of high-humidity smoke and then heats up, the high-salt water enters a cooling and concentrating device for cooling and concentrating, the other part of the first heat transfer devices takes heating medium as working fluid, the heating medium absorbs the heat of high-humidity smoke and heats up, and then the heat of the heated heating medium is extracted by a heat pump and is transmitted to heating water for heating in winter; in summer, the two parts of the first heat transfer devices take high-salt water as working fluid, so that the high-salt water absorbs the heat of the high-humidity flue gas and then heats up, and then enters the cooling concentration device for cooling and concentrating. In some embodiments, the two or more sets of working fluid inlets of the first heat transfer device are connected to the heat medium conduit and the working fluid outlets thereof are connected to the heat pump evaporator section, and at least a portion of the working fluid inlets of the first heat transfer device are also connected to a source of high brine and the working fluid outlets thereof are also connected to a cooling concentrate device spray liquid inlet; the inlet of the evaporation section of the heat pump is connected with a heat medium pipeline of the first heat transfer device, and the condensation section is respectively communicated with a high-salt water source and a heating water pipe. Valves which can be opened and closed can be arranged on connecting pipelines between the devices so as to control the pipelines to be opened or closed, and therefore, different working modes in winter and summer can be realized through switching of the valves.

In order to prevent corrosion of the heat exchanger and the pipes by the high brine, the flue gas condenser or the second heat transfer device in contact with the high brine may also be made of a corrosion resistant material, for example, a metal material or a non-metal material, wherein the metal material may be titanium or stainless steel, such as 316l,2205, etc., and the non-metal material may be a heat conducting plastic, fluoroplastic, enamel, etc.

To prevent corrosion, corrosion inhibitors may also be added to the high brine to be treated. The corrosion inhibitor may be a conventional corrosion inhibitor in the art, for example, an inorganic corrosion inhibitor such as nitrite, silicate, etc.; organic corrosion inhibitors such as phosphonates, benzotriazoles and the like; and/or polymeric corrosion inhibitors such as polyethylenes, POCA, and the like.

In the invention, condensed water is formed and showered off in the cooling process of the high-humidity flue gas. The condensed water can be collected by arranging a water outlet at the bottom of the high-humidity flue gas flue. Accordingly, the co-processing system of the present invention may further comprise a condensed water collecting device for collecting the condensed water. The condensed water collected has low salt content, and can be used as process makeup water or raw water of boiler makeup water.

In the invention, when the flue gas condenser is used in the process of transferring the waste heat of the high-humidity flue gas to the high-salt water, because the high-humidity flue gas is nearly saturated wet flue gas, a large amount of condensed water is formed in the flue gas and on the outer surface of the flue gas condenser when the temperature of the high-humidity flue gas is reduced, and the condensed water can be dropped and can be collected. On the premise of the same heat exchange quantity, the condensation water quantity on the surface of the flue gas condenser is larger than the water vapor quantity evaporated in the cooling and concentrating device, and the water recovery benefit is better. In addition, the high-humidity flue gas is condensed on the outer surface of the flue gas condenser to form a large amount of condensed water, and the condensed water can wash, absorb and/or adsorb pollutants in the high-humidity flue gas SO as to remove the pollutants, for example, dust, liquid drops and acid gases in the flue gas can be obviously removed in the condensation process and the spraying of the condensed water, and when the flue gas condenser is of a high-density finned tube structure, fine particles such as condensable particles and vapor-state pollutants such as SO ₃, heavy metals and VOC (volatile organic compounds) can be obviously removed, and the pollutant emission reduction amount greatly exceeds the amount of drips in the air discharged by the cooling concentration device.

In the present invention, it should be appreciated that the temperature of the heating medium in the high brine or indirect heat transfer scheme should be lower than the temperature of the high humidity flue gas. In some embodiments, the temperature of the high brine prior to absorbing the heat of the high humidity flue gas is in the range of about 15 ℃ to about 35 ℃, such as may be in the range of about 15 ℃ to about 20 ℃. In some embodiments, the temperature of the heating medium in the indirect heat transfer scheme prior to absorbing the heat of the high humidity flue gas is in the range of about 15 ℃ to about 35 ℃, such as may be in the range of about 15 ℃ to about 20 ℃.

In some embodiments, the high salt water absorbs heat from the high humidity flue gas and is warmed up before entering the cooling and concentrating device for spraying, so that a large enough temperature difference is ensured to maintain the evaporation of the high salt water.

The further heating may use a hot water source heater, a steam source heater or a power source heater, or the high salt water may be further heated by the heat of the high temperature flue gas through a flue heat exchanger.

Thus, in some embodiments, the co-processing system of the present invention further comprises a heating means located between the heat transfer decontamination means and the cooling concentration means for further heating the high brine. The heating device can be a hot water source heater, a steam source heater or a power source heater or a flue heat exchanger arranged in a high-temperature flue gas flue.

As used herein, "stack heat exchanger" refers to a heat exchanger disposed in a stack. The flue may refer to any flue gas channel, such as a connecting flue between any two of an economizer, an SCR denitration system, an air preheater, a dust remover, a desulfurizing tower, a wet electric precipitator, and a chimney.

As used herein, "high temperature flue gas" does not refer to flue gas temperatures above a particular temperature, but rather to flue gas temperatures above the high humidity.

When the high-temperature flue gas heat is utilized to further heat the high-salt water through the flue heat exchanger, the flue heat exchanger is arranged in the high-temperature flue gas flue and can be one or more flue heat exchangers connected in series or in parallel, the high-salt water outlet of the heat transfer decontamination device is connected with the working fluid inlet of the flue heat exchanger, and the working fluid outlet of the flue heat exchanger is connected with the spray liquid inlet of the cooling concentration device. As used herein, "high temperature flue gas stack" means that the flue gas in the stack is a high temperature flue gas as defined herein having a temperature higher than the high humidity flue gas. In some embodiments, the flue heat exchanger is disposed in the flue before the flue gas inlet of the flue gas condenser.

In the invention, the cooling concentration device is used for enabling the heated high-salt water to be in contact with dry and cold air, thereby reducing the temperature and concentrating. The heated high-salt water is contacted with dry and cold air in a cooling concentration device, so that the water in the high-salt water is evaporated, the high-salt water is cooled and concentrated, and the concentrated high-salt water enters a concentration liquid tank. The dry and cold air is warmed up and absorbed with water vapor to become damp and hot air, which is discharged from the cooling and concentrating device. Correspondingly, the cooling concentration device is communicated with the concentrated liquid pool, so that the concentrated high-salt water can enter the concentrated liquid pool. In some embodiments, the cooling concentration device includes a water inlet and a water outlet, an air inlet and an air outlet. The heated high-salt water can enter the cooling concentration device from the water inlet, and the cooled and concentrated high-salt water is discharged to the concentrated liquid pool from the water outlet. The dry air enters the cooling concentration device from the air inlet, absorbs water vapor and discharges the heated wet and hot air from the air outlet. In some embodiments, the cooling concentration device further comprises a fan disposed before/after the air inlet/outlet to drive the air flow. The cooling and concentrating device can be any device capable of cooling liquid by utilizing the contact of low-temperature air (i.e. dry and cold air) and high-temperature liquid, and the principle is that the high-temperature liquid is contacted with flowing air to perform cold and heat exchange to generate steam, and the steam volatilizes to take away heat to achieve the purpose of cooling, wherein the contact of the air and the liquid is direct. Such devices are well known to those skilled in the art, such as open cooling towers, in which a high temperature liquid is sprayed directly onto the surface of a packing (e.g., a heat sink material), in direct contact with air and in heat exchange relationship therewith, a portion of the water in the high temperature liquid is vaporized to water vapor, and the heat is discharged into the air together; or a bubbling tower, which discharges the air from the high-temperature liquid after absorbing heat and humidifying by bubbling the air into the heated high-temperature liquid. The equipment can be used as a cooling concentration device in the invention, and when the cooling concentration device is an open cooling tower, the heated high-salt water is used as high-temperature spraying liquid to spray the filler; in the case where the cooling and concentrating device is a bubble column, air is bubbled into the heated high brine.

The top of the cooling concentration device can be provided with a water receiver for collecting escaped high-salt liquid drops. The cooled and concentrated high-salt water enters a concentrated solution tank, and can be sent to a heat transfer decontamination device by a circulating pump to absorb heat again.

As used herein, "dry cold air" and "hot humid air" do not refer to air having a temperature and humidity above or below a certain level, but rather refer to the relative degree of temperature and humidity that allows it to achieve a desired objective during the process. For example, "dry and cold air" in a cooling and concentrating device that exchanges heat with high brine refers to air having a lower temperature and relative humidity so as to be able to cool the high brine and absorb water vapor from the high brine, and "hot and humid air" refers to air having a higher temperature and humidity than the dry and cold air prior to contact with the high brine. As used herein, "high temperature liquid" does not mean that the temperature of the liquid is above a certain value, when it is used to cool a concentrating device, it means that the temperature of the liquid is above the air with which it is in contact.

The cooling and concentrating device outlet air contains a certain amount of fine water drops called drips. When high salt water is used as the spray liquid, the floating drops contain high concentration of salt and other toxic and harmful substances, so that air pollution is formed.

In some embodiments, the humid air exiting the cooling and condensing unit may be introduced into the boiler air inlet and into the boiler as combustion air, and the heat absorbed by the exhaust air may be further recycled within the boiler. In some embodiments, humid air exiting the cooling concentration device may be introduced into the flue. The position of the wet air discharged from the cooling concentration device, which is introduced into the flue, can be any section of flue between the boiler and the chimney, such as a flue before the inlet of the flue gas condenser, a flue at the inlet of the flue gas condenser or a flue at the outlet of the flue gas, so as to further reduce the temperature and the humidity of the flue gas, recover moisture and weaken or even eliminate the phenomenon of white smoke at the outlet of the chimney. In some embodiments, the humid air exiting the cooling concentration device may be introduced into the high humidity flue gas duct to be mixed with the high humidity flue gas. Because the temperature of the discharged air of the cooling concentration device is lower than that of the high-humidity flue gas, a large amount of water is condensed into liquid drops after the cooling concentration device is mixed with the high-humidity flue gas, the effect of flushing the mixed flue gas can be achieved, and air pollutants such as drips, particles, SO ₂ and the like in the mixed flue gas can be removed, and meanwhile, the effect of removing drips in the air discharged by the cooling concentration device is also achieved.

Accordingly, in the co-processing system of the present invention, the cooling concentrator air outlet may be connected to a flue, such as a high humidity flue gas flue. A fan may be provided between the cooling and concentrating device air outlet and the flue to deliver humid air exiting the cooling and concentrating device to the high humidity flue. In some embodiments, the humid air exiting the cooling concentration device may be introduced into a flue at the inlet of the flue gas condenser. When multiple sets of flue gas condensers are included in the co-processing apparatus, the inlet of the flue gas condenser may be the inlet of any one of the sets of flue gas condensers. In some embodiments, the cooling concentrator air outlet is connected to a flue at the flue gas inlet of the flue gas condenser. After the air discharged by the cooling concentration device is mixed into high-humidity smoke, the temperature is further reduced by the smoke condenser, a large amount of liquid drops are formed in the mixed smoke, and the removal efficiency of the mixed smoke and the atmospheric pollutants is higher.

In some embodiments, an air flow ejector can be arranged in a flue (such as a high-humidity flue), an inlet of the air flow ejector is connected with an outlet of a fan, air enters the air flow ejector after being pressurized and accelerated by the fan, and the flow speed of the ejected air flow is higher than the wind speed of the high-humidity flue gas and can be 1.5 times, 2 times, 3 times or 4 times of the wind speed of the high-humidity flue gas, so that the air pressure/wind speed of the high-humidity flue gas is improved, and the problem that the pressure head of a booster fan of a current power plant is generally insufficient and the high-load operation of a boiler is influenced is solved. The air may be chilled concentrator outlet air. In some embodiments, the location of the airflow eductor is upstream of the flue gas inlet of the heat transfer decontamination device.

As used herein, "injection" is the mixing of two streams of different pressures in the same direction to form a fluid of intermediate pressure. In the ventilation device, the ejector can be used for forming main power of the air duct, so that uninterrupted air flow is realized. As the flue gas treatment equipment is increased, the wind resistance of the outlet flue of the boiler is larger and larger, the wind resistance is mainly offset by the booster fan, but the pressure head limit value of the axial flow booster fan applied by the main flow is 9000Pa, the pressure heads of a plurality of units of booster fans reach the limit value, and when the high-load operation is carried out, the flue resistance greatly exceeds the limit value, and the fan booster transformation can not be carried out any more, so that the stable operation can only be maintained under the low-load working condition. In this case, the pressurization of the flue gas can be realized by injecting high-pressure air flow.

The concentrated solution tank is usually positioned at the lower part of the cooling concentration device and used for collecting concentrated high-salt water. The cooling concentration device and the cooling concentration device can be connected through a pipeline or not. The concentrate tank is used for storing concentrated high-salt water. The concentrated high-salt water can be further subjected to salt separation crystallization, and can also be used for quenching slag, regulating humidity of dry ash and the like.

In the synergistic treatment system, the cooling concentration device and the concentration liquid tank can be one or more groups, and the groups can be connected in series or in parallel, or in a combination of series and parallel so as to realize the great reduction of the water temperature of the high brine, or in a parallel connection relationship so as to realize the cooling treatment of a larger amount of high brine.

When the high-salt water is concentrated to a certain degree, the salt in the high-salt water can be crystallized and separated out at the place with the lowest temperature of the circulating system (normally in a concentrated liquid tank). In some embodiments, the concentrated high brine may crystallize salt in a concentrate pond adapted to stabilize the salt in the concentrated high brine therein from crystallization and precipitation. The part of the crystallized salt can be fished out, dried and reused as industrial salt. The residual small amount of mixed salt solution (1/10-1/20 of the original high salt wastewater) can be continuously subjected to salt separation crystallization through other salt separation devices, and can also be used for production links such as slag quenching, dry ash humidity control and the like. Thereby realizing the high-purity salt extraction and zero emission of the high-salt water.

The solubility and concentration of different salts contained in the high-salt water in the aqueous solution are different, the solubility of each salt is also different at different working temperatures, the crystallization of different salts is sequentially carried out, the crystallization of a single salt in a concentrated liquid pond can be realized by monitoring the ion concentration in the high-salt water, and the crystallization is stopped (for example, concentrated high-salt water or crystallized salt is removed) before the concentration of other salts reaches the saturation concentration, so that the high-purity crystallized salt is obtained. The order of precipitation in the concentrate reservoirs may vary depending on the type and concentration of salts contained in the high brine from different sources, but it will be appreciated that one skilled in the art may calculate the order of precipitation of the various salts by combining the concentration of the different salts contained in the high brine with the solubility and operating temperature, e.g., as the high brine concentration increases, the first salt precipitated may be referred to as a first order salt and the second salt precipitated may be referred to as a second order salt.

The co-processing method of the present invention may further comprise determining the order of precipitation of salts in the high brine in the concentrate pond, allowing the salts precipitated in the first order to crystallize in said concentrate pond, and monitoring the concentration of different salt ions in the concentrate pond, taking out concentrated high brine or crystallized salts before the salts precipitated in the second order reach their saturation concentration, and collecting the high purity salts precipitated in the first order. The co-processing system of the present invention may further comprise a salt ion concentration detection means for detecting or monitoring the salt ion concentration in the concentrate reservoir, in particular the ion concentration of the salt precipitated in the second sequence. The method of the present invention may further comprise scooping up the crystallized salt, such as a high purity single crystallized salt, in a concentrate pond. Accordingly, the system of the present invention may include a slag extractor disposed within the concentrate tank for extracting the crystallized salt.

In some embodiments, all or part of the concentrated high brine in the concentrate pond may be reintroduced into the heat transfer decontamination apparatus, again with the heat absorbed to raise the temperature, repeating the heat exchange cycle and further concentrating. At this time, the high brine may be used as circulating water in the entire system. Concentrated high brine in the concentrate pond can be reintroduced into the heat transfer decontamination device by a circulation pump. Accordingly, in the co-processing system of the present invention, the concentrate tank includes a water outlet in communication with the heat transfer decontamination device. The co-processing system of the present invention may further comprise a circulation pump provided on a line between the concentrate tank and the heat transfer decontamination device such that a water outlet of the concentrate tank communicates with the heat transfer decontamination device through the circulation pump.

In order to reduce the interference of the water outlet process on the crystallization and precipitation of the high-salt water concentrate in the concentrate pool, the water outlet and the water intake can be arranged at an upper position of the concentrate pool.

In some embodiments, all or part of the concentrated high-salt water in the concentrated solution tank can be reintroduced into the water inlet of the cooling concentration device, and the high-salt water is mixed with low-temperature air again for cooling and further concentration.

It should be understood that the concentrated high brine in the concentrated tank may also be mixed with other sources of high brine, industrial waste salt, and then enter the heat transfer decontamination device with adjustable flow.

In some embodiments, when the concentrated high brine in the concentrate pond is concentrated to some extent, it can be removed, in whole or in part, for further salt separation or other use. It should be understood that the term "to a certain extent" means that the salt concentration of one or more of the concentrated high brine reaches or approaches a certain threshold value, which does not mean a certain concentration, but can be determined manually according to the actual situation and the actual requirements. For example, when the skilled artisan deems that one or more of the salts in the concentrated high brine reaches a certain concentration, continuing the concentration by the method of the present invention is less efficient and uneconomical, at which point the concentration may be set as a threshold. For another example, when one or more salts in the concentrated high brine reach a certain concentration that makes the concentrated high brine suitable for other uses, the concentration may be set as a threshold. In some embodiments, the threshold is a saturation concentration value for a particular salt.

In the invention, the high-salt water to be treated can be pretreated, including solid matter removal, heavy metal removal and/or tempering. The tempering includes adjusting the type and concentration of the salt content to improve the quality, purity, and/or avoid clogging of the piping system by salt crystals. To avoid clogging of the pipe system by salt crystals, the conditioning may include reducing the concentration of ions in the high brine to be treated that may clog the pipe system. The salts which may clog the pipe system may be, for example, salts which are present in the high-salt water to be treated in a relatively high amount and/or salts whose solubility varies greatly with temperature, such as sulfates. To increase the purity of the high-salt water crystalline salt, to obtain a high-purity crystalline salt, the tempering may include reducing the ion concentration of other salts than the desired crystalline salt (i.e., the salt precipitated in the first order, or the desired high-purity crystalline salt) in the high-salt water to be treated and/or adjusting the pH of the high-salt water, etc., for example, when the desired crystalline salt is sodium chloride, the tempering may include reducing the concentration of magnesium ions, calcium ions, and/or sulfate ions in the high-salt water to be treated. The system treatment system of the present invention may further comprise a conditioning device for conditioning the high brine to be treated. The conditioning device is adapted to receive high brine to be treated and to add reagents for conditioning, non-limiting examples of which include a sedimentation tank. The conditioning device is arranged in front of the heat transfer decontamination device, and the high-salt water to be treated flowing out of the conditioning device flows into the heat transfer decontamination device.

Taking desulfurization wastewater of a power plant as an example, the cations in the salt are mainly magnesium ions, calcium ions or sodium ions, and the anions are mainly sulfate radicals and chloride ions.

From the existing desulfurization wastewater quality report, the concentration of calcium ions is generally 600-1200mg/L, the concentration is lower due to the influence of the solubility of calcium sulfate, and calcium ions are increased in the desulfurization wastewater concentration process, such as sulfate radicals, carbonate radicals and hydroxide radicals in solution, can be combined with the calcium ions, and the scale is precipitated in a pipeline.

The concentration of magnesium ions in the desulfurization wastewater is high and can reach 5000-11000mg/L, magnesium sulfate can be largely dissolved in water, but magnesium carbonate and magnesium hydroxide can form precipitation to block a pipeline system.

The concentration of sulfate ions in the desulfurization wastewater is higher, even higher than the concentration of chloride ions, can reach 10000-50000mg/L, the solubility of sulfate is greatly changed along with the change of temperature, the solubility is high at high temperature, the solubility is low at low temperature, for example, sodium sulfate, the solubility is 9.5g/100g of water at 10 ℃, the solubility is 20.5g/100g of water at 20 ℃, and the solubility is 40.8g/100g of water at 30 ℃.

When the desulfurization waste water is concentrated, the concentration of magnesium sulfate and sodium sulfate gradually rises, when the working temperature of the heat exchange system is greatly different from the ambient temperature, the temperature of the solution is reduced under the influence of the fluctuation of the ambient temperature, and at the moment, the magnesium sulfate and the sodium sulfate can be greatly precipitated and condensed due to the reduction of the temperature of the solution to block a pipeline.

Taking desulfurization wastewater of a certain power plant as an example, the salt composition is as follows:

Solubility meter for main salt of desulfurization waste water

After removing calcium ions, the desulfurization wastewater is concentrated, the working temperature of the solution is circulated between 20 and 30 ℃, and the calculation shows that when the concentration ratio is 5.8 times, sodium sulfate in the 20-degree concentrated solution is saturated and can be analyzed, and if the environmental temperature is slightly reduced at this time, a large amount of sodium sulfate decahydrate can be separated out, so that a pipeline is blocked.

For calcium ions, the conditioning may include removing some or all of the calcium ions, for example by adding a substance (e.g., carbonate) that reacts with the calcium ions to form a precipitate. In some embodiments, sodium carbonate may be added to remove calcium ions, which may allow for the removal of calcium ions while increasing the sodium chloride concentration of the high brine to facilitate the extraction of high purity sodium chloride crystalline salts using sodium chloride as the salt to be precipitated in the first order. The amount of the carbonate added, such as sodium carbonate, is not particularly limited, and may be suitable for removing part of calcium ions or may be suitable for removing all calcium ions. The calcium carbonate precipitate may be removed by methods well known in the art, for example by precipitation or by rotary screen. In some embodiments, the conditioning comprises reducing the concentration of calcium ions to no more than 20mg/L.

For magnesium ions, the conditioning may include removing some or all of the magnesium ions therein or adjusting the pH to be acidic, for example, adjusting the pH to 7.0 or less, 6.5 or less, or 6.0 or less. Removal of magnesium ions may be performed by adding a substance capable of reacting with magnesium ions to form a precipitate, for example, removal of Mg ions may be performed by adding a base to form a poorly soluble magnesium hydroxide precipitate. The magnesium hydroxide precipitate may be removed by methods well known in the art, such as by precipitation or by rotary screen.

In some embodiments, one or more alkaline substances of calcium oxide, calcium hydroxide and sodium hydroxide can be added into the high-salt water to be treated to form indissolvable magnesium hydroxide precipitate, then sodium carbonate is added into the indissolvable magnesium hydroxide precipitate to form calcium carbonate precipitate, calcium and magnesium ions in the high-salt water are removed, and meanwhile, the concentration and purity of sodium chloride in the high-salt water can be improved, so that the sodium chloride is taken as a salt precipitated in a first sequence, and high-purity sodium chloride crystal salt is obtained. The amount of calcium oxide, calcium hydroxide, sodium hydroxide and sodium carbonate added is not particularly limited, and may be suitable for removing part of calcium and magnesium ions, and may be suitable for removing all of calcium and magnesium ions.

For sulfate ions, the conditioning may include removal of all or part of the sulfate ions to reduce the sulfate ion concentration to avoid sulfate crystallization out from clogging the tubing during concentration. The sulfate ion concentration may be removed by adding to the high brine a substance capable of reacting with sulfate ions to form a precipitate, such as a calcium salt (calcium chloride and/or calcium hydroxide), an aluminum salt and/or a barium salt, and the like, to form a sulfate precipitate. In some embodiments, a portion of the sulfate ions may be removed, i.e., sulfate in the high brine is reduced below a concentration threshold such that at a particular concentration ratio and minimum operating temperature, the sulfate (e.g., one, two or more of magnesium sulfate, sodium sulfate, calcium sulfate, and potassium sulfate, such as magnesium sulfate and/or sodium sulfate) does not reach a saturation concentration in the concentrated high brine. For example, in some embodiments, the concentration threshold is calculated as: concentration threshold = saturation concentration (or solubility) of a particular sulfate at the lowest possible operating temperature/concentration ratio. In this case, an expensive barium salt is not required, and a calcium salt such as calcium hydroxide or calcium chloride may be used to react with sulfate to form a precipitate of calcium sulfate which is hardly soluble in water, and the sulfate may be reduced to the above concentration threshold. In addition, if sodium chloride is used as a target crystallization salt, the concentration of sulfate ions is reduced, so that precipitation of sodium sulfate can be avoided, and the purity of the crystallization sodium chloride is ensured. In some embodiments, the conditioning may include reducing the concentration of sulfate ions to no more than 6000mg/L, such as no more than 5000mg/L, no more than 4000mg/L, or no more than 2000mg/L.

The concentration thresholds may be determined for one or more sulfates, with the lowest of the concentration thresholds of each sulfate being taken as the final concentration threshold when it is desired that neither sulfate nor sulfate reach a saturation concentration.

The calculation of the concentration threshold value can be described by taking the following cases as examples: the normal working temperature of the high-salt water is between 20 and 30 ℃, the concentration ratio is 10 times, the environment temperature is the lowest 10 ℃, wherein the saturated concentration of sodium sulfate corresponding to 10 ℃ is 9.5g/100g, the concentration of sulfate ions corresponding to the sodium sulfate is about 95000mg/l, the concentration of sulfate ions in the desulfurization wastewater is 64230mg/l, the concentration of sulfate ions in the desulfurization wastewater is processed to be lower than 6423mg/l, the normal working of the high-salt water at the concentration ratio of 10 times can be ensured, the solution temperature is 20 to 30 ℃, and sodium sulfate crystallization can not be separated out even if the working temperature of the solution fluctuates to about 10 ℃ under the influence of the environment temperature. In this case, barium salt is not needed, calcium salt such as calcium hydroxide or calcium chloride is used to react with sulfate to generate calcium sulfate precipitate which is indissolvable in water, the sulfate can be reduced to 1800mg/l, and the subsequent concentration process is ensured that sodium sulfate is not crystallized even if the temperature of the solution is reduced to 10 ℃, so that the purity of the crystallized sodium chloride is ensured.

As used herein, "concentration ratio" refers to the ratio of the volume of the high brine before concentration to the volume after concentration. The concentration ratio can be set according to actual production requirements and can be 5-10 times, and engineering personnel can determine other working parameters in the system according to the set concentration ratio. When sodium chloride crystals are required to be separated out from the concentrated solution pond, the concentration ratio is not lower than the saturated concentration of sodium chloride divided by the concentration value of sodium chloride in high-salt water, and is usually more than 10 times, the larger the NaCl crystallization amount is, the higher the concentration ratio is, and the lower the corresponding sulfate concentration threshold value is.

As used herein, "minimum possible operating temperature" refers to the environment in which high brine is located and the minimum temperature that may be experienced during operation. In some embodiments, the lowest possible operating temperature of the high brine is equivalent to the ambient temperature (or atmospheric temperature), where the lowest possible operating temperature is the lowest value of the ambient temperature.

It should be understood that any one, any two or three of the tempering of calcium ions, magnesium ions, sulfate ions may be selected and performed in any order. In some embodiments, conditioning may be performed first for sulfate ions and/or magnesium ions, and then for calcium ions.

In some embodiments, the temperature differential during high brine operation may also be reduced by any or all of the following measures to avoid sulfate precipitation:

(1) The medium-temperature flue gas and the low-temperature flue gas, such as clean flue gas (the flue gas temperature is about 50 ℃) after a desulfurizing tower are selected, and the condensing and cooling are carried out by a cooling and condensing device, so that the temperature difference between the inlet temperature and the outlet temperature of the cooling and condensing device and the ambient temperature is reduced, and a large amount of precipitation of magnesium sulfate, sodium sulfate and the like due to high-salt water cooling is avoided.

(2) The heat preservation treatment is carried out on the equipment such as the pipeline, the pump, the valve and the like in the system so as to ensure the stability of the high-salt water temperature in the pipeline.

The invention includes, but is not limited to, the following benefits: (1) The invention heats the high brine by utilizing the waste heat of the high-humidity flue gas, especially the waste heat of the high-humidity flue gas after desulfurization (only about 50 degrees, which is generally considered to have no recycling value), then carries out evaporative cooling on the high brine in a cooling concentration device, and concentrates the high brine, thereby finally realizing salt crystallization and precipitation, and having the lowest overall treatment cost of only 3-8 yuan/ton of high brine. (2) The invention realizes the separation of salt by using the crystallization of supersaturated salt solution, and the obtained crystalline salt has high purity and can be reused as industrial salt. (3) The crystallized high-salt concentrated solution is only 1/10-1/20 of the high-salt wastewater before treatment, can be used for production links such as dry ash humidifying, slag quenching and the like, can be further concentrated for crystallization, and has no solid waste. (4) When the high-salt wastewater is treated by utilizing the high-humidity flue gas waste heat, the amount of flue gas condensate water is higher than the evaporation water amount in the cooling concentration device, the salt content in the condensate water is very low, the water quality is excellent, and the water-saving benefit is good. (5) The high-humidity flue gas is cooled by the flue gas condenser to form a large amount of condensed water or is sprayed by hot medium water, and the condensed water or the spraying can remove dust, escaped slurry liquid drops, SO ₂ and other pollutants in the flue gas, SO that the pollution of the drips added in the cooling concentration device can be greatly counteracted.

The invention relates in particular to the following solutions:

Scheme 1. High brine and high wet flue gas co-processing system, including high brine source, heat transfer decontamination plant, high brine cooling enrichment facility and the concentrate pond that link to each other in proper order, heat transfer decontamination plant is used for giving high brine with high wet flue gas waste heat transfer, gets rid of the pollutant in the high wet flue gas simultaneously.

The system of claim 1, wherein the concentrate tank comprises a water outlet coupled to the heat transfer decontamination device.

Scheme 3. The system of scheme 1 or 2 wherein the air outlet of the cooling concentrator is connected to the flue.

Scheme 4. The system of scheme 3 wherein the system further comprises a fan and an air flow ejector disposed in the flue, the air outlet of the cooling concentration device, the fan and the air flow ejector inlet are connected in sequence.

The system of any of claims 1-4, wherein the heat transfer decontamination device comprises a flue gas condenser disposed in a high humidity flue gas flue, the high salt water source is connected to a working fluid inlet of the flue gas condenser, and a working fluid outlet of the flue gas condenser is connected to a water inlet of the cooling concentration device.

The system of any of claims 1-4, wherein the heat transfer decontamination device comprises a first heat transfer device and a second heat transfer device coupled, wherein the first heat transfer device is configured to transfer the waste heat of the high humidity flue gas to a heat medium, and the second heat transfer device is configured to transfer heat from the heat medium to the high brine.

The system of claim 6, wherein the first heat transfer device is a spray device or a flue gas condenser and the second heat transfer device is a second heat exchanger or a heat pump.

The system of any one of claims 1-7, further comprising a condensate collection device for collecting condensate formed during the cooling of the high humidity flue gas.

The system of any one of claims 1-8, further comprising a heating device coupled between the heat transfer decontamination device and the cooling concentration device for further heating the high brine.

The system of claim 9, wherein the heating device is a hot water heater, an electric heater, or a steam heater, or the heating device is a flue heat exchanger disposed in a high temperature flue gas flue, and the high temperature flue gas has a higher flue gas temperature than the high humidity flue gas.

Scheme 11. The system of any one of schemes 5-10 wherein the flue gas condenser or the second heat transfer device in contact with the high brine is made of a corrosion resistant material.

Scheme 12. The system of scheme 11 wherein the corrosion resistant material is stainless steel, titanium, thermally conductive plastic, fluoroplastic, or enamel.

The system of any one of claims 1-12, wherein more than one set of cooling concentration device and concentrate tank are included, each set being connected in parallel or in series.

Scheme 14. The system of any one of schemes 1-13 wherein a slag extractor is provided in the concentrate tank for extracting the crystalline salt.

The system of any one of claims 1-14, further comprising a salt ion concentration detection device for detecting the concentration of ions in the concentrated high brine in the concentrate pond.

The system of any one of claims 1-15, further comprising a conditioning device disposed between the high brine source and the heat transfer decontamination device for adjusting the concentration of ions in the high brine to be treated.

Scheme 17. High brine and high humidity flue gas co-treatment method, the method comprises:

The method of claim 17, wherein the method further comprises crystallizing the concentrated high brine in a liquid concentrate pond to precipitate a crystalline salt.

The method of claim 17 or 18, wherein the high humidity flue gas is a flue gas having a relative humidity of 80% or greater.

The method of any one of claims 17-19, wherein step (1) and step (2) are performed again with part or all of the concentrated high brine in the concentrate pond as at least a portion of the high brine to be treated.

The method of any one of claims 17-20 wherein the humid air exiting the cooling and concentrating device is introduced into the flue to mix with the flue gas.

The method of claim 21, wherein the humid air exiting the cooling concentrator is forced up by a fan and enters the flue as an induced draft.

The method of any one of claims 17-22, wherein step (1) comprises passing the high humidity flue gas through a flue gas condenser in heat exchange relationship with the high brine.

The method of any one of claims 17-22, wherein step (1) comprises transferring waste heat from the high humidity flue gas to the high brine via a heat medium.

The method of claim 24, wherein step (1) comprises heating the heating medium with the high humidity flue gas via a first heat transfer device, and subsequently transferring heat from the heating medium to the high brine via a second heat transfer device.

The method of claim 25, wherein the first heat transfer device is a spray device or a flue gas condenser and the second heat transfer device is a second heat exchanger or a heat pump.

The method of any one of claims 17-26, further comprising collecting condensed water formed by the cooling of the high humidity flue gas.

The method of any one of claims 17-27 wherein the high brine that absorbs heat from the high humidity flue gas is reheated prior to entering the cooling concentrator.

The method of claim 28, wherein the reheating is by a hot water source heater, a steam source heater, or an electric heater; or through a flue heat exchanger arranged in a high-temperature flue gas flue.

The method of any one of claims 17-29, wherein when the high brine in the concentrate pond is concentrated to a certain extent, all or part is removed for further salt separation treatment or for other uses.

Scheme 31. The method of any one of schemes 17-30 further comprising pre-conditioning the high brine to be treated to adjust the type and concentration of salts therein.

The method of claim 31, wherein the conditioning comprises removing a portion of the calcium ions in the high brine to be treated.

Scheme 33. The method of scheme 32 wherein said conditioning comprises reducing the concentration of calcium ions in the high salt water to be treated to no more than 20mg/L.

Scheme 34 the method of any one of schemes 31-33 wherein said conditioning comprises removing some or all of the sulfate ions in the high brine to be treated.

The method of claim 34, wherein the conditioning comprises reducing the concentration of sulfate ions in the high brine to be treated below a concentration threshold that causes the concentration of one or more sulfate salts in the high brine to be below its saturation concentration at a particular concentration ratio and lowest possible operating temperature.

Scheme 36. The method of scheme 34 or 35 wherein said conditioning comprises reducing the sulfate ion concentration in the high brine to be treated to no more than 6000mg/L.

The method of any one of claims 17-36, wherein the crystalline salt is a high purity first order precipitated crystalline salt.

The method of claim 37, wherein the first sequentially precipitated crystalline salt is sodium chloride crystalline salt.

The method of claim 37 or 38, further comprising detecting the concentration of ions in the concentrated brine in the concentrate pool, and withdrawing the crystallized salt or concentrated brine from the concentrate pool before the second sequentially precipitated crystallized salt reaches the saturation concentration.

Scheme 40. The treatment system of any one of schemes 1-16 or the method of any one of schemes 17-39, wherein the high brine is obtained from a waste salt dissolved in water or other high brine.

The objects, technical solutions and advantages of the present invention will become more apparent by the following detailed description of the present invention with reference to the accompanying drawings. It should be understood that the description is only illustrative and is not intended to limit the scope of the invention. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention.

The schematic diagram of the first embodiment of the high-salt water and high-humidity flue gas co-treatment system and the co-treatment process of the invention is shown in fig. 1, the system comprises a flue gas condenser, a cooling concentration device and a concentration liquid pool which are sequentially connected, the concentration liquid pool is communicated with the flue gas condenser through a circulating pump, and the flue gas condenser is positioned in a rear flue of a desulfurizing tower. The technological process is as follows: the high-humidity flue gas is cooled by a flue gas condenser, pollutants in the flue gas are removed, the flue gas is discharged from a chimney, the high-humidity flue gas is condensed on the surface of the flue gas condenser to form condensate, and the condensate can be recovered. The high brine enters the flue gas condenser through the circulating pump to serve as working fluid, the temperature is raised after the waste heat of the high-humidity flue gas is absorbed, the high brine enters the cooling concentration device, the high brine is contacted with air in the cooling concentration device to realize cooling and concentration of the high brine, the air is raised in temperature and is discharged into the atmosphere after absorbing water vapor, the concentrated high brine enters the concentrated liquid pond, and the concentrated high brine in the concentrated liquid pond enters the flue gas condenser through the circulating pump to perform circulating heat exchange. When the high-salt water is concentrated to a certain extent, the salt content exceeds the saturated concentration, and the crystalline salt is precipitated in the concentrated solution tank. The residual high-salt water concentrated solution can be used for the production links of dry ash humidifying, slag quenching and the like, or further concentrate salt.

Referring to fig. 2, a schematic diagram of a second embodiment of the high-salt water and high-humidity flue gas co-treatment system and the co-treatment process of the invention is shown, the system comprises a second flue gas condenser, a first flue gas condenser, a cooling concentration device and a concentration liquid pool which are sequentially connected, the concentration liquid pool is communicated with the flue gas condenser through a circulating pump, the first flue gas condenser and the second flue gas condenser are positioned in a rear flue of a desulfurizing tower, and the first flue gas condenser is positioned in a flue before a flue gas inlet of the second flue gas condenser (namely, flue gas firstly passes through the first flue gas condenser and then passes through the second flue gas condenser). The technological process is as follows: cooling the high-humidity flue gas sequentially through a first flue gas condenser and a second flue gas condenser, removing pollutants in the high-humidity flue gas, discharging the high-humidity flue gas from a chimney, condensing the high-humidity flue gas on the surface of the flue gas condenser to form condensate, and recovering the condensate; the high-salt water sequentially enters a second flue gas condenser and a first flue gas condenser through a circulating pump to serve as working fluid, absorbs the residual heat of high-humidity flue gas, then heats, enters a cooling concentration device, contacts with air in the cooling concentration device to realize high-salt water cooling and concentration, heats the air, absorbs water vapor, is introduced into a flue between the first flue gas condenser and the second flue gas condenser to be mixed with the flue gas, and then passes through the first flue gas condenser; the concentrated high-brine enters a concentrated solution tank, and the concentrated high-brine in the concentrated solution tank enters a flue gas condenser through a circulating pump for circulating heat exchange. When the high-salt water is concentrated to a certain extent, the salt content exceeds the saturated concentration, and the crystalline salt is precipitated in the concentrated solution tank. The remaining high salt concentrate can be used for dry ash conditioning.

The schematic diagram of the third embodiment of the high-salt water and high-humidity flue gas co-treatment system and the co-treatment process of the invention is shown in fig. 3, the system comprises a spray device, a heat pump, a cooling concentration device and a concentrated liquid pool, wherein a condensation section of the heat pump, the cooling concentration device and the concentrated liquid pool are sequentially connected, the concentrated liquid pool is communicated with the condensation section of the heat pump through a circulating pump, an inlet of the spray device and a spray water recovery outlet are connected with an evaporation section of the heat pump, and the spray device is positioned in a rear clean flue of a desulfurizing tower. The technological process is as follows: the high-humidity flue gas is sprayed and cooled in a clean flue through hot medium water, pollutants in the flue gas are removed, the flue gas is discharged from a chimney, the high-humidity flue gas is cooled to form condensate, and the condensate is mixed into spray water to be recovered; the heat medium water absorbs the heat of the high-humidity flue gas while the clean flue sprays, and after the temperature is raised, the heat medium water is collected and enters the evaporation section of the heat pump, and the heat medium water is cooled after the heat pump absorbs the heat and returns to the clean flue spraying device; the high-salt water enters a heat pump condensation section through a circulating pump, heats up after absorbing heat provided by the heat pump, then enters a cooling concentration device, contacts with air in the cooling concentration device to realize high-salt water cooling and concentration, heats up the air and absorbs water vapor, then discharges the air into the atmosphere, the concentrated high-salt water enters a concentrated solution tank, and the concentrated high-salt water in the concentrated solution tank enters the heat pump condensation section through the circulating pump for circulating heat exchange. When the high-salt water is concentrated to a certain extent, the salt content exceeds the saturated concentration, and the crystalline salt is precipitated in the concentrated solution tank. The remaining high brine concentrate may be further dried in a dryer and/or used for dry ash conditioning.

Case one: by using the system and the process shown in FIG. 1,4 300MW coal-fired units are used in a power plant, the flue gas quantity of one 300MW coal-fired boiler is 120 ten thousand m ³/h, the temperature of the desulfurized saturated wet flue gas is 51 ℃, a group of flue gas condensers are arranged in a flue after desulfurization, 16 tons of high-salt water is produced in the wet desulfurization system per hour, and the chloride ion concentration is 1% (10000 PPM). Firstly, pretreating high-salt water, sequentially adding calcium hydroxide and sodium carbonate, flocculating and precipitating, removing solid substances in the wastewater, reducing the concentration of calcium ions to below 20mg/mL, reducing the concentration of sulfate ions to below 6000mg/mL, adjusting the pH value to about 6.5, entering a flue gas condenser as circulating water, wherein the temperature is 20 ℃, the circulating water quantity is 1500t/h, the saturated wet flue gas is reduced by 3 ℃, the heat quantity of 16MWh is discharged, meanwhile, about 20t/h of condensed water is separated out in a flue, dust and acid gas and steam pollutants in the flue gas are removed through flushing, absorbing, adsorbing and other mechanisms in the condensed water leaching process, collecting the 20t/h of condensed water as raw water of boiler make-up water, heating the high-salt water from 20 ℃ to 30 ℃, then pumping the high-salt water into an open cooling tower, mixing with the risen air, evaporating about 15t/h of water, cooling the high-salt water to 20 ℃, settling to a concentrated liquid pool, and carrying out heat exchange in the flue gas condenser again through a circulating pump. The cooling concentration device is internally provided with a water collector for removing high-salt water drops carried in the air. After circulation for a period of time, the concentration of sodium chloride in the high-salt water is supersaturated and then is separated out stably, the high-purity sodium chloride is taken out by a slag dragging machine at regular intervals, the high-purity sodium chloride is sold according to industrial salt after dehydration, and the residual concentrated salt water is taken out from a concentrated solution tank for humidifying dry ash, wherein the residual concentrated salt water is less than 1 ton/h.

Case two: the system and the process shown in the figure 1 are used, 4 300MW coal-fired units are used in a power plant, the flue gas quantity of a 300MW coal-fired boiler is 120 ten thousand m ³/h, the temperature of saturated wet flue gas after desulfurization is 51 ℃, a group of flue gas condenser wet methods are arranged in a flue after desulfurization, 16 tons of high-salt water is produced in total by the desulfurization system per hour, then a proper amount of waste salt (the main components are sodium, calcium and magnesium ions and sulfate radicals and chloride radicals) in the coal chemical industry is dissolved in the high-salt water, the concentration of Cl ions is controlled to be not more than 5 percent, pretreatment is carried out, heavy metals in the high-salt water are removed, calcium oxide and sodium carbonate are added, flocculation precipitation is carried out, the concentration of calcium ions is reduced to below 20mg/mL, the concentration of sulfate ions is reduced to below 6000mg/mL, the pretreated high-salt water is taken as circulating water to enter a flue gas condenser, the temperature is 20 ℃, the circulating water quantity is 1300t/h, saturated wet flue gas is cooled to 3 ℃, 16MWh of heat is discharged, meanwhile, about 20t/h of condensed water is separated out in a flue, dust, acid gas, vaporous pollutants in the flue gas are removed through flushing, absorption, adsorption and other mechanisms in the process of pouring down the condensed water, the 20t/h of condensed water is collected as raw water of boiler makeup water, the high-salt water is heated from 20 ℃ to 30 ℃, and then is pumped into an open cooling tower to be mixed with rising air, about 15t/h of water is evaporated, the high-salt water is cooled to 20 ℃, is settled into a concentrated liquid pool, and enters the flue heat exchanger again through a circulating pump to exchange heat. After circulating for a period of time, after the NaCl concentration in the high-salt water is supersaturated, salt is separated out in the concentrated solution tank, when the salt is accumulated to a certain amount, the salt is fished out by a slag scooping machine and dried, wherein the NaCl purity exceeds 98 percent, and the salt can be sold as industrial salt. And taking the residual concentrated salt solution out of the concentrated solution pond for dry ash humidifying or further salt separating treatment.

Case three: the system and the process shown in the figure 2 are used, 4 300MW coal-fired units are used in a power plant, the flue gas quantity of a 300MW coal-fired boiler is 120 ten thousand m ³/h, the temperature of the flue gas after desulfurization is 51 ℃, two groups of flue gas condensers (a first flue gas condenser and a second flue gas condenser respectively) are arranged in series in a flue gas channel after desulfurization, 16 tons of high-salt water is produced in total per hour by the desulfurization system, the chloride ion concentration is 1% (10000 PPM), the high-salt water is subjected to pretreatment, heavy metals in the high-salt water are removed, calcium oxide and sodium carbonate are added, flocculation precipitation is carried out, the calcium ion concentration is reduced to below 20mg/mL, the sulfate ion concentration is reduced to below 5000mg/mL, the temperature is 20 ℃, the circulating water quantity is reduced to 1500t/h, the saturated wet flue gas is reduced to 3 ℃, 16 h heat is released, meanwhile, about 20t/h of condensate water is precipitated in the flue gas channel, the condensate water is removed by scouring, absorption, adsorption and the like, the raw water and the vapor state pollutants are collected as the boiler make-up water, the high-salt water is taken as the high-salt water, the high-salt water is heated up to 30 ℃ to about 30 ℃ through a high-temperature pond, and is cooled to about 15 ℃ by an open-type cooling tower, and is cooled to be cooled to the high-temperature, and then enters the condensate pump, cooled to the high-temperature, and enters the circulating water to be cooled to about 15 g, and cooled to the temperature. The cooling concentration device is internally provided with a water collector for removing high-salt water drops carried in the air. After circulating for a period of time, the NaCl concentration in the high-salt water is supersaturated and separated out, the remaining strong brine is less than 1 ton/h, and the strong brine is taken out from the concentrated solution tank and used for dry ash humidifying. The high-humidity air discharged by the cooling concentration device is introduced between the first flue gas condenser and the second flue gas condenser, is mixed with the high-humidity flue gas, is cooled through the second flue gas condenser, is separated out by a large amount of water, further removes dust, drips, SO ₂ and other atmospheric pollutants in the mixed flue gas, and has 60% removal efficiency on drips in the high-humidity air.

Case four: the system and the process shown in the figure 1 are used in a power plant, a 300MW coal-fired boiler is used in the power plant, the flue gas volume is 120 ten thousand m ³/h, the temperature of the desulfurized flue gas is 51 ℃, a group of flue gas condensers are arranged in a flue after desulfurization, seawater is used as circulating water to enter the flue gas condensers, the temperature of the seawater is 18 ℃, the circulating water volume is 7500t/h, saturated wet flue gas is reduced to 35 ℃, 60MWh of heat is discharged, 70t/h of condensed water is separated out in the flue at the same time, dust, acid gas and steam-state pollutants in the flue gas are removed through flushing, absorbing, adsorbing and other mechanisms in the condensed water falling process, the 70t/h of condensed water is collected for other purposes, the seawater is heated from 18 ℃ to 25 ℃, then is pumped into a cooling concentration device, atomized spraying is mixed with the heated up air, the 70t/h of water is evaporated, the high-salt water is cooled to 18 ℃, and is settled into a concentrated solution pool, and then enters the flue gas condensers for heat exchange through a circulating pump. After circulating for a period of time, after the NaCl concentration in the high-salt water is supersaturated, salt is separated out in the concentrated solution tank, when the salt is accumulated to a certain amount, the salt is fished out by a slag scooping machine and dried, wherein the purity of the sodium chloride exceeds 98%, and the sodium chloride can be sold as industrial salt.

Case five: the system and the process shown in the figure 3 are used, 4 300MW coal-fired units are used in a power plant, the flue gas quantity of a 300MW coal-fired boiler is 120 ten thousand m ³/h, the flue gas temperature after desulfurization is 51 ℃, a group of spraying devices are arranged in a flue after desulfurization, 16 tons of high-salt wastewater is generated in the desulfurization system in each hour, then a proper amount of waste salt (the main components are sodium, calcium and magnesium ions and sulfate radicals and chloride radicals) in the coal chemical industry is dissolved in high-salt water, the concentration of Cl ions is controlled to be not more than 5%, common desalted water is used as circulating heat medium water to contact and exchange heat with the high-humidity flue gas through the spraying devices, the temperature of the circulating heat medium water is 15 ℃, the water quantity is 700t/h, the saturated wet flue gas is reduced by 1.5 ℃, 7MWh heat is released, 8t/h condensed water is simultaneously precipitated in the flue gas, dust in the flue gas is removed through flushing, absorbing, steam-state pollutants are removed in the spraying process of the heat medium water, the circulating heat medium water is heated from 15 ℃ to 25 ℃, the temperature is pumped through an absorption heat pump evaporation section after the circulating heat medium water is heated, the circulating heat medium water is pumped to the temperature is reduced to 15 ℃, and the circulating heat medium water is returned to the circulating pump device. The high-salt water passes through the condensing section of the heat pump, the circulation volume of the high-salt water is 700 tons per hour, the inlet temperature is 40 ℃, the temperature is raised to 50 ℃ through the heating of the heat pump, the high-salt water is pumped into the cooling concentration device, the atomization spraying and the rising air are mixed, the water at 15t/h is evaporated, the temperature of the high-salt water is reduced to 40 ℃, the high-salt water is settled into the concentration liquid pool, and the high-salt water enters the heat pump again through the circulating pump for heat exchange. After circulating for a period of time, after the concentration of sodium chloride in the high-salt wastewater is close to saturation, salt begins to be separated out in a concentrated solution pond, when the salt is accumulated to a certain amount, the salt is fished out by a slag scooping machine and dried, wherein the purity of the sodium chloride exceeds 98 percent, the sodium chloride can be sold as industrial salt, and the residual concentrated solution is used for regulating the humidity of dry ash.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explanation of the principles of the present invention and are in no way limiting of the invention. Accordingly, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present invention should be included in the scope of the present invention. Furthermore, the appended claims are intended to cover all such changes and modifications that fall within the scope and boundary of the appended claims, or equivalents of such scope and boundary.

Claims

1. The high-salinity water and high-humidity flue gas cooperative treatment system comprises a high-salinity water source, a heat transfer decontamination device, a high-salinity water cooling concentration device and a concentration liquid pool which are sequentially connected, wherein the heat transfer decontamination device is used for transferring high-humidity flue gas waste heat to the high-salinity water and removing pollutants in the high-humidity flue gas.

2. The system of claim 1, wherein:

the heat transfer decontamination device comprises a flue gas condenser arranged in a high-humidity flue gas flue, the high-salt water source is connected with a working fluid inlet of the flue gas condenser, and a working fluid outlet of the flue gas condenser is connected with a water inlet of the cooling concentration device; or alternatively

The heat transfer decontamination device comprises a first heat transfer device and a second heat transfer device which are connected, wherein the first heat transfer device is used for transferring the waste heat of the high-humidity flue gas to a heating medium, and the second heat transfer device is used for transferring heat from the heating medium to high-salinity water.

3. The system of claim 1 or 2, further comprising a condensate collection device for collecting condensate formed during the cooling of the high humidity flue gas.

4. A system as claimed in any one of claims 1 to 3 wherein a slag extractor is provided in the concentrate tank for extracting the crystallised salt.

5. The system of any one of claims 1-4, further comprising a conditioning device disposed between the high brine source and the heat transfer decontamination device for adjusting the concentration of ions in the high brine to be treated.

6. A method for the synergistic treatment of high brine and high humidity flue gas, the method comprising:

7. The method of claim 6, wherein the method further comprises crystallizing the concentrated high brine in a concentrate pond to precipitate a crystalline salt.

8. The method of claim 6 or 7, wherein step (1) comprises:

heat exchanging the high-humidity flue gas with the high-salt water through a flue gas condenser; or alternatively

And the waste heat of the high-humidity flue gas is transferred to the high-salt water through a heating medium.

9. The method of any one of claims 6-8, further comprising pre-conditioning the high brine to be treated, adjusting the type and concentration of salts therein, wherein the conditioning comprises removing some or all of the sulfate ions in the high brine to be treated.

10. The treatment system of any one of claims 1-5 or the method of any one of claims 6-9, wherein the high brine is obtained from waste salt after dissolution in water or other high brine.