White smoke elimination waste heat power generation device

Abstract

The present invention discloses a waste heat power generation device for eliminating white smoke, comprising a desulfurization tower and at least one waste heat treatment unit connected in sequence, the waste heat treatment unit comprising a flue gas cooling tower, a temperature-raising steam production unit and a steam generator set, the flue gas outlet of the desulfurization tower is connected to the flue gas inlet of the flue gas cooling tower, the first outlet of the flue gas cooling tower is connected to the heating end of the temperature-raising steam production unit, the heat source end of the steam generator set is connected to the hot water inlet of the flue gas cooling tower, and the hot water reflux end of the steam generator set is connected to the heat output end of the temperature-raising steam production unit. The present invention can condense and recycle water vapor in the flue gas, and adopts a combination of lithium bromide heat pump and membrane concentration to increase the low-grade heat in the flue gas to hot steam above 120 degrees Celsius, drive the steam generator set to generate electricity, and the hot water condensed by the steam generator set is sent to the flue gas heater at the outlet of the flue gas cooling tower to heat it to make it unsaturated hot flue gas, so as to achieve water saving, energy saving and white smoke elimination.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas treatment, and in particular to a white smoke waste heat power generation device. Background Art

[0002] At present, the exhaust temperature of coal-fired boilers and industrial furnaces is generally above 100°C. After desulfurization, the exhaust temperature of the flue gas is generally around 50 degrees. After desulfurization, the flue gas will take away a large amount of water vapor and heat, and eventually the chimney will have a white plume phenomenon. In addition, the large amount of waste heat generated by the flue gas, if directly discharged, will cause a waste of heat energy and pollute the environment. Summary of the invention

[0003] The present invention proposes a white smoke waste heat power generation device to solve the above technical problems.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A waste heat power generation device for eliminating white smoke comprises a desulfurization tower, a flue gas cooling tower and at least one waste heat treatment unit connected in sequence, the waste heat treatment unit comprises a temperature rising steam production unit, a steam generator unit and a second cooling tower connected in sequence, the flue gas outlet of the desulfurization tower is connected to the flue gas inlet of the flue gas cooling tower, a flue gas heater is provided in the internal space between the first outlet and the hot water inlet of the flue gas cooling tower, the first outlet of the flue gas cooling tower is connected to the heating end of the temperature rising steam production unit, the heat source end of the steam generator unit is connected to the hot water inlet of the flue gas cooling tower, the hot water return end of the steam generator unit is connected to the heat output end of the temperature rising steam production unit, and the second cooling tower outlet of the last waste heat treatment unit is connected to the flue gas heater of the flue gas cooling tower.

[0006] Preferably, the temperature-raising steam production unit includes a clean water buffer tank, an absorption liquid buffer tank, a membrane concentration unit and an evaporative absorption unit. The membrane concentration unit is connected to the clean water buffer tank and the absorption liquid buffer tank through pipelines, respectively, and the evaporative absorption unit is connected to the membrane concentration unit, the clean water buffer tank and the absorption liquid buffer tank through pipelines, respectively; the evaporative absorption unit is used to absorb the low-temperature steam from the flue gas cooling tower through the absorption liquid and release heat, and the membrane concentration unit is used to concentrate and regenerate the absorption liquid of the evaporative absorption unit.

[0007] Preferably, the evaporation and absorption unit comprises a primary evaporation and absorption unit, at least one intermediate evaporation and absorption unit, and a final evaporation and absorption unit arranged in sequence, wherein the primary evaporation and absorption unit, the intermediate evaporation and absorption unit, and the final evaporation and absorption unit respectively comprise an evaporator and an absorber, and the water supply end of each evaporator is connected to a clean water buffer tank; the steam inlet of the evaporator of the primary evaporation and absorption unit is connected to the first outlet of the flue gas cooling tower through a pipeline; the heat supply end of the evaporator of the intermediate evaporation and absorption unit is respectively connected to the heat output end of the absorber of the previous evaporation and absorption unit; the liquid supply ends of the absorbers of the primary evaporation and absorption unit and the intermediate evaporation and absorption unit are respectively connected to the liquid outlet end of the absorber of the next evaporation and absorption unit, the liquid supply end of the absorber of the final evaporation and absorption unit is connected to a membrane concentration unit, and the heat output end of the evaporator of the final evaporation and absorption unit is connected to the hot water reflux end of the steam generator set.

[0008] Preferably, the evaporation absorption unit further comprises an absorption liquid heat exchanger, the absorption liquid heat exchanger of the primary evaporation absorption unit is respectively connected to the absorption liquid buffer tank, the membrane concentration unit, the liquid outlet of the primary evaporation absorption unit absorber and the absorption liquid heat exchanger of the next evaporation absorption unit, the absorption liquid heat exchanger of each intermediate evaporation absorption unit is respectively connected to the liquid supply end of the previous evaporation absorption unit absorber, the absorption liquid heat exchanger of the previous evaporation absorption unit, the liquid outlet of the same evaporation absorption unit absorber, and the absorption liquid heat exchanger of the next evaporation absorption unit, and the absorption liquid heat exchanger of the final evaporation absorption unit is respectively connected to the liquid supply end of the previous evaporation absorption unit absorber, the absorption liquid heat exchanger of the previous evaporation absorption unit, the liquid outlet of the same evaporation absorption unit absorber, and the liquid supply end of the same evaporation absorption unit absorber.

[0009] Preferably, the membrane concentration unit comprises a membrane assembly and a cooler, and the membrane assembly is connected to the cooler and then respectively connected to a clean water buffer tank and an absorption liquid buffer tank through pipelines.

[0010] Preferably, the steam generator set is an ORC waste heat generator set.

[0011] Preferably, the absorption liquid is an aqueous solution of lithium bromide, lithium chloride or a compound formed by lithium bromide and ammonia.

[0012] Preferably, when there is more than one waste heat treatment unit, the waste heat treatment units are connected in series.

[0013] Compared with the prior art, the present invention reduces the flue gas temperature from 50°C to 20°C (it can be reduced to below 10°C as required) so that the water vapor in the flue gas is condensed and collected for reuse, so as to achieve the purpose of water saving; the cooling process is achieved by a combination of a lithium bromide heat pump and a membrane concentration, and the low-grade heat in the flue gas is increased to hot steam above 120 degrees Celsius through a heating module; the generated steam is then used to drive an ORC generator set to generate electricity, so as to achieve the purpose of energy saving; the steam is condensed into hot water above 100°C after passing through the ORC unit, and the hot water is then sent to the flue gas heater at the outlet of the flue gas cooling tower to heat the flue gas to make it unsaturated hot flue gas, so as to achieve the purpose of eliminating white smoke. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the white smoke waste heat power generation device of the present invention.

[0015] In the figure, 1-desulfurization tower, 2-flue gas cooling tower, 3-heating steam production unit, 5-steam generator unit, 6-second cooling tower, 11-flue gas inlet, 12-water tank, 13-sprayer, 14-first demister, 21-flue gas heater, 22-second demister, 23-second sprayer, 24-second water tank, 31-primary evaporator, 32-secondary evaporator, 33-tertiary evaporator, 34-final evaporator, 35-primary absorber, 36-secondary absorber Receiver, 37-tertiary absorber, 38-final absorber, 39-clean water buffer tank, 40-absorption liquid buffer tank, 41-membrane assembly, 42-cooler, 43-primary absorption liquid heat exchanger, 44-secondary absorption liquid heat exchanger, 45-tertiary absorption liquid heat exchanger, 46-final absorption liquid heat exchanger, 51-hot water tank, 52-evaporator, 53-reheater, 54-liquid storage tank, 55-condenser, 56-first-stage expander, 57-secondary expander, 58-generator. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below in conjunction with the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0017] The terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "the" and "the" used in the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0018] like Figure 1As shown, a waste heat power generation device for eliminating white smoke comprises a desulfurization tower 1, a flue gas cooling tower 2 and at least one waste heat treatment unit connected in sequence, wherein the waste heat treatment unit comprises a temperature rising steam production unit 3, a steam generator unit 5 and a second cooling tower 6 connected in sequence, the flue gas outlet of the desulfurization tower 1 is connected to the flue gas inlet of the flue gas cooling tower 2, a flue gas heater 21 is arranged in the internal space between the first outlet and the hot water inlet of the flue gas cooling tower 2, the first outlet of the flue gas cooling tower 2 is connected to the heating end of the temperature rising steam production unit 3, the heat source end of the steam generator unit 5 is connected to the hot water inlet of the flue gas cooling tower 2, the hot water reflux end of the steam generator unit 5 is connected to the heat output end of the temperature rising steam production unit 3, and the outlet of the second cooling tower 6 of the last waste heat treatment unit is connected to the flue gas heater 21 of the flue gas cooling tower 2.

[0019] The desulfurization tower 1 is a tower-shaped structure, and the inner cavity is composed of the flue gas outlet, the first demister 14, the sprayer 13 and the water tank 12 from top to bottom. The flue gas inlet 11 is opened on the side wall, and the second outlet for flue gas discharge is set at the top opening. The flue gas cooling tower 2 is also a tower-shaped structure, and the inner cavity is composed of the flue gas heater 21, the second demister 22, the second sprayer 23 and the second water tank 24 from top to bottom. The first outlet is set at the outlet end of the flue gas heater 21, and the hot water inlet is set on the side wall between the second sprayer 23 and the second water tank 24. When there are more than one waste heat treatment units, the waste heat treatment units are connected in series.

[0020] The heating steam production unit 3 includes a clean water buffer tank 39, an absorption liquid buffer tank 40, a membrane concentration unit and an evaporation absorption unit. The membrane concentration unit is connected to the clean water buffer tank 39 and the absorption liquid buffer tank 40 through pipelines, and the evaporation absorption unit is connected to the membrane concentration unit, the clean water buffer tank 39 and the absorption liquid buffer tank 40 through pipelines; the evaporation absorption unit is used to absorb the low-temperature steam from the flue gas cooling tower 2 through the absorption liquid and release heat, and the membrane concentration unit is used to concentrate and regenerate the absorption liquid of the evaporation absorption unit.

[0021] The evaporation and absorption unit comprises a primary evaporation and absorption unit, at least one intermediate evaporation and absorption unit, and a final evaporation and absorption unit which are arranged in sequence. The primary evaporation and absorption unit, the intermediate evaporation and absorption unit, and the final evaporation and absorption unit respectively comprise an evaporator and an absorber, and the water supply end of each evaporator is connected to a clean water buffer tank; the steam inlet of the evaporator of the primary evaporation and absorption unit is connected to the first outlet of the flue gas cooling tower through a pipeline; the heat supply end of the evaporator of the intermediate evaporation and absorption unit is respectively connected to the heat output end of the absorber of the previous evaporation and absorption unit; the liquid supply ends of the absorbers of the primary evaporation and absorption unit and the intermediate evaporation and absorption unit are respectively connected to the liquid outlet end of the absorber of the next evaporation and absorption unit, the liquid supply end of the absorber of the final evaporation and absorption unit is connected to a membrane concentration unit, and the heat output end of the evaporator of the final evaporation and absorption unit is connected to the hot water reflux end of the steam generator set. Figure 1 In the middle are two intermediate-stage evaporation absorption units.

[0022] In order to maintain thermal balance, the evaporation and absorption unit may also include an absorption liquid heat exchanger. The absorption liquid heat exchanger of the primary evaporation and absorption unit is respectively connected to the absorption liquid buffer tank 40, the membrane concentration unit, the liquid outlet end of the primary evaporation and absorption unit absorber and the absorption liquid heat exchanger of the next evaporation and absorption unit. The absorption liquid heat exchangers of each intermediate evaporation and absorption unit are respectively connected to the liquid supply end of the absorber of the previous evaporation and absorption unit, the absorption liquid heat exchanger of the previous evaporation and absorption unit, the liquid outlet end of the absorber of the same evaporation and absorption unit, and the absorption liquid heat exchanger of the final evaporation and absorption unit is respectively connected to the liquid supply end of the absorber of the previous evaporation and absorption unit, the absorption liquid heat exchanger of the previous evaporation and absorption unit, the liquid outlet end of the absorber of the same evaporation and absorption unit, and the liquid supply end of the absorber of the same evaporation and absorption unit.

[0023] The absorbent heat exchanger can be used to exchange heat between the dilute absorbent solution flowing out of each stage of absorbent and the concentrated absorbent solution concentrated and regenerated by the membrane concentration unit. In this way, the dilute absorbent solution is preheated before concentration, and the concentrated absorbent solution is cooled before returning.

[0024] Here, the membrane concentration unit includes a membrane assembly 41 and a cooler 42. The membrane assembly 41 is connected to the cooler 42 and then connected to the clean water buffer tank 39 and the absorption liquid buffer tank 40 through pipelines. To ensure the installation and operation of the membrane assembly, the membrane assembly 41 has certain requirements for the operating temperature, and the temperature cannot be too high. The cooler 42 can exchange heat between the high-temperature dilute solution to be treated and the low-temperature clean water produced by the membrane assembly 41 to ensure the maximum thermal efficiency of the system. The absorption liquid can be an aqueous solution of lithium bromide, lithium chloride, or a compound formed by lithium bromide and ammonia.

[0025] The number of the intermediate-stage evaporation absorption units can be set according to actual needs. Here, an example with two intermediate-stage evaporation absorption units (ie, a secondary evaporation absorption unit and a tertiary evaporation absorption unit) is used for introduction.

[0026] The high-temperature raw flue gas from the coal-fired boiler (industrial furnace) passes through the desulfurization tower 1 for desulfurization, dust removal and demisting, and then enters the flue gas cooling tower. After entering the cooling tower, the flue gas is cooled by spraying coolant (water, etc.). The flue gas is cooled to below 20 degrees after passing through the second sprayer 24, and the heat in the flue gas can be transferred to the coolant. After the coolant absorbs the heat in the flue gas, the temperature rises, and then the heated coolant is transported to the evaporation absorption unit for cooling. After cooling and cooling, the coolant is transported to the cooling tower again to spray the flue gas to absorb the heat of the flue gas.

[0027] In the primary evaporator 31, the water in the clean water buffer tank 14 is continuously transported to the primary evaporator 31 through the evaporation pump, continuously absorbing the heat released by the condensation of the secondary steam from the separator and continuously evaporating into water vapor. The water vapor in the primary evaporator 31 is transported to the primary absorber 35 through a pipeline, and the water vapor in the primary absorber 35 is continuously absorbed by the absorption liquid sprayed from the secondary absorber 36 and releases heat. After the absorption liquid absorbs the water vapor, the concentration continues to decrease, and the ability to absorb water vapor continues to decrease. The absorption liquid dilute solution is transported to the absorption liquid buffer tank 15 through a pipeline. In the primary absorber 35, the water vapor is absorbed by the absorption liquid and continuously releases heat, and this heat is transported to the secondary evaporator 32 through the heat conduction device. In the secondary evaporator 32, the water in the clean water buffer tank 14 is continuously transported to the secondary evaporator 32 through the evaporation pump and continuously absorbs the heat transported from the primary absorber 35 and continuously evaporates into water vapor. At this time, the steam temperature generated by the secondary evaporator 32 is much higher than the steam temperature generated by the primary evaporator 31.

[0028] The functions of the secondary evaporator 32, the secondary absorber 36, the tertiary evaporator 33, and the tertiary absorber 37 are similar. The number of the intermediate evaporators and absorbers is not limited to two.

[0029] The water vapor in the final evaporator 34 is transported to the final absorber 38 through a pipeline. In the final absorber 38, the water vapor is continuously absorbed by the concentrated absorption liquid solution transported after being concentrated by the membrane assembly 41 and releases heat. After the concentrated absorption liquid solution absorbs the water vapor, its concentration decreases to a certain extent. The absorption liquid is transported to the previous absorber to absorb water vapor at a relatively lower temperature.

[0030] The heating steam production unit 3 is a membrane concentrated lithium bromide heat pump. When the absorption liquid is a lithium bromide concentrated solution, the concentration can be set to 50% to 66%, which can be selected according to different needs. The heat released by cooling the lithium bromide solution with water is absorbed and heated by the 4-effect (four-stage evaporation absorption unit) to produce steam of about 150 degrees, which can be used for power generation or other purposes.

[0031] The steam generator set 5 may be an ORC waste heat generator set, which includes an evaporator 52, a reheater 53, a primary expander 56, a secondary expander 57, a generator 58, a condenser 55, a liquid storage tank 54, and a hot water tank 51, etc., and the connection method is as follows: Figure 1 As the thermal efficiency of an ORC generator set is generally only about 10%, one or more groups of steam generating units 3 and steam generator sets 5 can be connected in series after the ORC unit to increase the thermal efficiency to more than 50% or even higher.

[0032] The steam produced by the steam production unit 3 is first supplied to the ORC waste heat generator unit for power generation. After power generation, the steam is condensed into hot water. The hot water can be used to heat the low-temperature flue gas because it still has a certain amount of heat, so that the flue gas becomes unsaturated flue gas from the top, achieving the purpose of eliminating white smoke. The steam at about 150 degrees is cooled to hot water above 100 degrees after passing through the ORC waste heat generator unit, and then the hot water is transported to the flue gas heater 21 at the top of the flue gas cooling tower 2 to heat the flue gas, so that the flue gas temperature is raised to above 60 degrees, achieving the purpose of eliminating white smoke. The hot water after heating the flue gas is cooled to below 80 degrees, and then transported to the evaporation absorption unit to produce steam.

[0033] The lithium bromide solution after absorbing water vapor becomes diluted and is transported to the membrane assembly 41. The lithium bromide solution is concentrated by membrane separation technology and then transported back to the evaporation absorption unit to absorb water vapor. The separated clean water is transported back to the evaporation absorption unit for evaporation.

[0034] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present invention are indicated by the claims of the present application.

[0035] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A white smoke waste heat power generation device, characterized in that: It comprises a desulfurization tower, a flue gas cooling tower and at least one waste heat treatment unit connected in sequence, wherein the waste heat treatment unit comprises a temperature-raising steam production unit, a steam generator unit and a second cooling tower connected in sequence, the flue gas outlet of the desulfurization tower is connected to the flue gas inlet of the flue gas cooling tower, a flue gas heater is arranged in the internal space between the first outlet and the hot water inlet of the flue gas cooling tower, the first outlet of the flue gas cooling tower is connected to the heating end of the temperature-raising steam production unit, the hot water return end of the steam generator unit is connected to the hot water inlet of the flue gas cooling tower, the hot water return end of the steam generator unit is connected to the heat output end of the temperature-raising steam production unit, and the second cooling tower outlet of the last waste heat treatment unit is connected to the flue gas heater of the flue gas cooling tower; The temperature-raising steam production unit comprises a clean water buffer tank, an absorption liquid buffer tank, a membrane concentration unit and an evaporation absorption unit. The membrane concentration unit is connected to the clean water buffer tank and the absorption liquid buffer tank through pipelines, respectively. The evaporation absorption unit is connected to the membrane concentration unit, the clean water buffer tank and the absorption liquid buffer tank through pipelines, respectively. The evaporation absorption unit is used to absorb the low-temperature steam from the flue gas cooling tower through the absorption liquid and release heat. The membrane concentration unit is used to concentrate and regenerate the absorption liquid of the evaporation absorption unit. The evaporation and absorption unit comprises a primary evaporation and absorption unit, at least one intermediate evaporation and absorption unit, and a final evaporation and absorption unit arranged in sequence, wherein the primary evaporation and absorption unit, the intermediate evaporation and absorption unit, and the final evaporation and absorption unit respectively comprise an evaporator and an absorber, and the water supply end of each evaporator is connected to a clean water buffer tank; the steam inlet of the evaporator of the primary evaporation and absorption unit is connected to the first outlet of the flue gas cooling tower through a pipeline; the heat supply end of the evaporator of the intermediate evaporation and absorption unit is respectively connected to the heat output end of the absorber of the previous evaporation and absorption unit; the liquid supply ends of the absorbers of the primary evaporation and absorption unit and the intermediate evaporation and absorption unit are respectively connected to the liquid outlet end of the absorber of the next evaporation and absorption unit, the liquid supply end of the absorber of the final evaporation and absorption unit is connected to a membrane concentration unit, and the heat output end of the evaporator of the final evaporation and absorption unit is connected to a hot water reflux end of a steam generator set; The evaporation absorption unit also includes an absorption liquid heat exchanger, the absorption liquid heat exchanger of the primary evaporation absorption unit is respectively connected to the absorption liquid buffer tank, the membrane concentration unit, the liquid outlet end of the primary evaporation absorption unit absorber and the absorption liquid heat exchanger of the next evaporation absorption unit, the absorption liquid heat exchanger of each intermediate evaporation absorption unit is respectively connected to the liquid supply end of the previous evaporation absorption unit absorber, the absorption liquid heat exchanger of the previous evaporation absorption unit, the liquid outlet end of the same-level evaporation absorption unit absorber, and the absorption liquid heat exchanger of the next evaporation absorption unit, and the absorption liquid heat exchanger of the final evaporation absorption unit is respectively connected to the liquid supply end of the previous evaporation absorption unit absorber, the absorption liquid heat exchanger of the previous evaporation absorption unit, the liquid outlet end of the same-level evaporation absorption unit absorber, and the liquid supply end of the same-level evaporation absorption unit absorber; The membrane concentration unit comprises a membrane assembly and a cooler. The membrane assembly is connected to the cooler and then respectively connected to a clean water buffer tank and an absorption liquid buffer tank through pipelines.

2. The white smoke waste heat power generation device according to claim 1, characterized in that: The steam generator set is an ORC waste heat generator set.

3. The white smoke waste heat power generation device according to claim 1 or 2, characterized in that: The absorption liquid is an aqueous solution of lithium bromide, lithium chloride or a compound formed by lithium bromide and ammonia.

4. The white smoke waste heat power generation device according to claim 1 or 2, characterized in that: When there is more than one waste heat treatment unit, the waste heat treatment units are connected in series.

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