A waste incineration flue gas waste heat supply device and system of smoke tower in one

Abstract

The application discloses a waste incineration flue gas waste heat heating device and system, which is used for purifying and recycling waste heat of flue gas discharged from a waste heat boiler. The device comprises a low-temperature coal economizer, a flue gas purification unit, a spray tower and an external heat exchanger. The low-temperature coal economizer is used for heat exchange between flue gas and circulating heat network water to reduce the temperature of the flue gas. The flue gas purification unit is used for purifying the flue gas. The spray tower is used for heat exchange between the flue gas and spray water. The external heat exchanger is used for heat exchange between the spray water in the external heat exchanger and heat user heat network water to supply heat to the outside. A flue gas reheater is used for heat exchange between the flue gas and the circulating heat network water to increase the temperature of the flue gas. After the flue gas is heated and increased in temperature in the flue gas reheater, the flue gas enters the flue gas cooling tower and is discharged to the atmosphere through the flue gas cooling tower. According to the waste incineration flue gas waste heat heating device and system, most of the sensible heat and latent heat in the flue gas can be recycled, the water content of the flue gas and the power loss of an induced draft fan are reduced, and the heat utilization rate is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste incineration flue gas waste heat utilization, in particular to a waste incineration flue gas waste heat supply device and system with a combined tower. BACKGROUND

[0002] With the release of the Action Plan for Carbon Peak by 2030, the green and low-carbon economic development model has become the mainstream of today's world development, and waste harmless treatment is also one of the important ways to achieve the green "double carbon" goal. At present, waste harmless treatment mainly includes incineration treatment, which can eliminate a large number of harmful bacteria and toxic substances in waste and effectively control secondary pollution after high-temperature incineration; the volume of waste can be reduced by more than 90% and the weight can be reduced by more than 80% after incineration; the heat energy generated after waste incineration can be used for power generation and heating, realizing the comprehensive utilization of resources; waste incineration treatment has the advantages of land saving, fast processing speed, good reduction effect, controllable pollution emission, relatively small environmental impact, and high energy utilization rate, and is a treatment method that meets the principles of waste treatment "harmless, reduction, and resource utilization".

[0003] At present, there are two common situations in the waste incineration power plant flue gas waste heat utilization: (1) the outlet flue gas temperature of the boiler is too high (as high as 220-240℃ or even higher), the boiler exhaust heat loss is large, and the heat utilization rate is low; (2) the flue gas emission temperature is too high and the water content is high (as high as about 28%), most of the latent heat and sensible heat of the flue gas is lost, and the flue gas waste heat is not effectively recovered and utilized.

[0004] Therefore, in order to solve the above problems, it is necessary to propose a waste incineration flue gas waste heat supply device and system with a combined tower. SUMMARY

[0005] A series of simplified concepts are introduced in the summary section, which will be further described in detail in the specific embodiment section. The summary section of the present application does not mean to attempt to limit the key features and necessary technical features of the claimed technical solution, nor does it attempt to determine the protection scope of the claimed technical solution.

[0006] The application provides a waste incineration flue gas waste heat supply device of smoke tower integration, which is used for purifying and recycling the flue gas discharged from a waste heat boiler, and comprises a low-temperature economizer, a flue gas purification unit, a spray tower, an external heat exchanger and a flue gas reheater.

[0007] The flue gas purification unit comprises a semi-dry deacidification tower, which is communicated with the low-temperature economizer and used for deacidifying the flue gas entering the semi-dry deacidification tower.

[0008] The flue gas purification unit further comprises a bag-type dust collector, which is communicated with the semi-dry deacidification tower and used for dust removal of the flue gas entering the bag-type dust collector to remove the particulate matters in the flue gas.

[0009] The flue gas purification unit further comprises an activated carbon sprayer, which sprays activated carbon into the pipeline connecting the semi-dry deacidification tower and the bag-type dust collector to remove dioxins in the flue gas.

[0010] The flue gas purification unit further comprises a dry method sprayer, which sprays deacidification substances into the pipeline connecting the semi-dry deacidification tower and the bag-type dust collector to remove acid gases in the flue gas.

[0011] The waste incineration flue gas waste heat supply device of smoke tower integration further comprises an induced draft fan, which is arranged between the flue gas reheater and the flue gas cooling tower and used for sucking the flue gas into the flue gas cooling tower.

[0012] The flue gas reheater comprises a fluoroplastic heat exchanger or an ND steel heat exchanger.

[0013] Illustratively, the spray tower is provided with a sprayer for spraying the spray water and a demisting device for removing liquid water from the flue gas.

[0014] Illustratively, the external heat exchanger comprises a plate heat exchanger, a tube heat exchanger or an absorption heat pump.

[0015] A smoke-tower-combined waste incineration flue gas waste heat supply system comprises the smoke-tower-combined waste incineration flue gas waste heat supply device.

[0016] The present application has the following beneficial effects:

[0017] By arranging the low-temperature coal economizer and the circulating heat network water, the flue gas temperature at the outlet of the waste heat boiler is reduced, and the heat absorbed by the circulating heat network water is used for the flue gas reheater. By arranging the spray tower, the flue gas discharged from the bag-type dust collector is directly contacted with the spray water for heat exchange, so that the flue gas temperature is reduced. By arranging the external heat exchanger, the heat absorbed by the spray water is used for heating the heat network return water for external heat supply. By arranging the exhaust gas cooling tower, the flue gas at a lower temperature at the outlet of the flue gas reheater is discharged into the atmosphere by the wet hot air in the cooling tower, so that the lifting height of the flue gas is improved. By adopting the scheme of the present application, the latent heat and the sensible heat of the waste incineration flue gas are both utilized, and the safety and the economy are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] The following drawings of the present application are hereby incorporated into the present application as a part of the present application for understanding the present application. The embodiments of the present application and the description thereof shown in the drawings are used to explain the principles of the present application.

[0019] In the drawings:

[0020] Figure 1 A structural schematic diagram of a smoke-tower-combined waste incineration power plant flue gas waste heat supply device according to an embodiment of the present application is shown.

[0021] Explanation of reference signs:

[0022] 1 waste heat boiler 2 low-temperature coal economizer

[0023] 3 semi-dry deacidification tower 4 dry method sprayer

[0024] 5 activated carbon sprayer 6 bag-type dust collector

[0025] 7 spray tower 8 flue gas reheater

[0026] 9 induced draft fan 10 exhaust gas cooling tower

[0027] 11 external heat exchanger

[0028] 100 smoke-tower-combined waste incineration flue gas waste heat supply device DETAILED DESCRIPTION

[0029] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, some technical features well known in the art are not described to avoid confusion with the present invention.

[0030] To thoroughly understand the embodiments of the present application, detailed structures will be provided in the following description. Obviously, the implementation of the embodiments of the present application is not limited to the specific details familiar to those skilled in the art. The preferred embodiments of the present application are described in detail below, but in addition to these detailed descriptions, the present application may also have other embodiments.

[0031] The following combination Figure 1 A detailed description is given of a waste incineration flue gas waste heat heating device with an integrated chimney and tower according to one embodiment of the present application.

[0032] like Figure 1 As shown, the waste incineration flue gas waste heat heating device 100 with integrated smoke tower provided in this embodiment includes: a waste heat boiler 1, a low-temperature economizer 2, a semi-dry deacidification tower 3, a dry ejector 4, an activated carbon ejector 5, a bag dust collector 6, a spray tower 7, a flue gas reheater 8, an induced draft fan 9, an exhaust cooling tower 10, and an external heat exchanger 11.

[0033] The flue gas inlet end of the low-temperature economizer 2 is connected to the tail heating surface of the waste heat boiler 1. After the flue gas enters the low-temperature economizer 2, it exchanges heat with the circulating hot water in the low-temperature economizer 2 to reduce the temperature. The water side of the flue gas reheater 8 is connected to the water side of the low-temperature economizer 2. A circulating hot water network is provided between the low-temperature economizer 2 and the flue gas reheater 8. After the flue gas enters the flue gas reheater 8, it exchanges heat with the circulating hot water network to increase the temperature.

[0034] The flue gas purification unit is connected to the low-temperature economizer 2 and is used to purify the flue gas discharged from the waste heat boiler 1. After the flue gas is treated by the flue gas purification unit, the temperature of the flue gas is approximately 140°C-150°C. In this embodiment, the flue gas purification unit includes a semi-dry deacidification tower 3, a dry ejector 4, an activated carbon ejector 5, and a bag filter 6.

[0035] The inlet of the semi-dry deacidification tower 3 is connected to the flue gas side outlet of the low-temperature economizer 2, and is used to deacidify the flue gas entering the semi-dry deacidification tower 3 to remove acidic gases in the flue gas, such as SO2, HCl, and HF gas, and reduce the temperature of the flue gas to ensure that the temperature entering the bag filter 6 is around 150°C to extend the service life of the bag filter 6. The semi-dry deacidification tower 3 uses a semi-dry reaction for deacidification.

[0036] The dry injection device 4 is used to inject deacidification substances into the pipeline connecting the semi-dry deacidification tower 3 and the bag-type dust collector 6, so as to remove the acid gases in the flue gas. For example, the dry injection device 4 can inject dry lime into the pipeline connecting the semi-dry deacidification tower 3 and the bag-type dust collector 6, so as to deacidify the flue gas by the reaction between the dry lime and the acid gases in the flue gas. It should be understood that in the present embodiment, the acid gases in the flue gas are mainly removed by the semi-dry deacidification tower 3, and the dry injection device 4 is used to deacidify the flue gas when the semi-dry deacidification tower 3 is under maintenance or failure, or is used to be started when there are more acid gases in the flue gas, so as to better remove the acid gases in the flue gas.

[0037] The activated carbon injection device 5 is used to inject activated carbon into the pipeline connecting the semi-dry deacidification tower 3 and the dust collector 6, so as to remove dioxins in the flue gas.

[0038] The bag-type dust collector 6 is connected to the semi-dry deacidification tower 3 through a communication pipeline, and is used to remove particulate matters in the flue gas entering the bag-type dust collector 6.

[0039] The flue gas side inlet of the spray tower 7 is connected to the bag-type dust collector 6, and the flue gas outlet is connected to the flue gas reheater 8. The flue gas directly contacts with the spray water sprayed by the spray tower 7 after entering the spray tower, so as to further reduce the temperature. The spray tower 7 is provided with an injector for spraying the spray water and a demisting device for removing the liquid water in the flue gas at the outlet of the spray tower 7.

[0040] The flue gas side of the flue gas reheater 8 is connected to the spray tower 7 and the induced draft fan 9, and the water side of the flue gas reheater 8 is connected to the water side of the low-temperature economizer 2. A circulating heat network water circulation flow is arranged between the low-temperature economizer 2 and the flue gas reheater 8. The flue gas is heated by the circulating heat network water after entering the flue gas reheater 8, so as to increase the temperature. The flue gas reheater 8 includes a fluoroplastic heat exchanger or an ND steel heat exchanger, so as to prevent low-temperature corrosion.

[0041] The induced draft fan 9 is arranged between the flue gas reheater 8 and the flue gas cooling tower 10, and is used to draw the flue gas into the flue gas cooling tower.

[0042] The external heat exchanger 11 is connected to the water side of the spray tower 7. The spray water circulates between the spray tower 7 and the external heat exchanger 11. The spray tower 7 is used as the heat supply end of the external heat exchanger 11. The external heat exchanger 11 is connected to the heat user heat network water pipe network system. The external heat exchanger is used to heat the spray water in the external heat exchanger by the heat user heat network water, so as to supply heat to the heat user. The external heat exchanger 11 includes a plate heat exchanger, a tube heat exchanger or an absorption heat pump.

[0043] The operation process of the smoke-tower combined waste incineration flue gas waste heat supply device 100 according to the present embodiment is as follows: the high-temperature flue gas of 220-240℃ or even higher temperature from the outlet of the waste heat boiler 1 is subjected to heat exchange with the circulating heat network water (about 130℃) through the low-temperature economizer 2, and the flue gas temperature is reduced to about 180℃; the heat-absorbed circulating heat network water (150-160℃) enters the flue gas reheater 8 through a pipeline, and is re-entered into the low-temperature economizer 2 to be subjected to heat exchange with the high-temperature flue gas after heat release; the flue gas (about 180℃) of reduced temperature from the outlet of the low-temperature economizer 2 is sequentially entered into the semi-dry deacidification tower 3, the dry method ejector 4, the activated carbon ejector 5 and the bag-type dust collector 6, and is sequentially subjected to deacidification, dioxin removal and dust removal, and the flue gas temperature from the outlet of the bag-type dust collector 6 is 140-150℃; the flue gas is subjected to direct contact heat exchange with the spray water sprayed from the ejector at the upper part of the spray tower 7 from bottom to top, and the flue gas temperature is reduced to 30-60℃ after heat exchange; the spray water absorbed heat from the spray tower 7 is delivered to the external heat exchanger 11 through a pump (not shown) to be subjected to heat exchange with the heat network return water, and the heat network return water is heated; the heat-released spray water is then returned to the ejector of the spray tower 7, and is subjected to direct contact heat exchange with the flue gas after spraying; the flue gas is then passed through the mist removal device arranged at the upper part of the spray tower 7 to remove the liquid water in the flue gas at the outlet of the spray tower 7; the low-temperature flue gas of 30-60℃ discharged from the mist removal device of the spray tower 7 is subjected to heat exchange with the heat-absorbed circulating heat network water (150-160℃) in the flue gas reheater 8, and the flue gas temperature at the outlet of the flue gas reheater 8 is 80-100℃; and then the flue gas is sent into the exhaust gas cooling tower 10 through the induced draft fan 9, and is discharged into the atmosphere under the push of the hot and humid air inside and outside the exhaust gas cooling tower 10.

[0044] By arranging the spray tower 7, the flue gas of 140-150℃ from the outlet of the bag-type dust collector 6 is directly subjected to heat exchange with the cooling water, and the flue gas temperature is reduced to 30-60℃ (the temperature is selected according to the external heat demand); by arranging the external heat exchanger 11 (such as a plate heat exchanger, a tube heat exchanger or a heat pump), the heat absorbed by the spray water is used to heat the heat network return water for external heat supply; by arranging the flue gas reheater 8, the flue gas from the outlet of the spray tower 7 is raised to 80-100℃ (the temperature depends on the flue gas temperature from the outlet of the spray tower 7 and the flue gas temperature from the outlet of the waste heat boiler 1); by arranging the low-temperature economizer 2 and the circulating heat network water (temperature 130-160℃), the flue gas temperature from the outlet of the waste heat boiler 1 is reduced to about 180℃, and the heat absorbed by the circulating heat network water is used for the flue gas reheater 8; and by arranging the exhaust gas cooling tower 10, the flue gas of lower temperature from the outlet of the flue gas reheater 8 is discharged into the atmosphere through the exhaust gas cooling tower 10 under the push of the hot and humid air inside the exhaust gas cooling tower 10, and the flue gas lifting height is improved. By adopting the scheme of the present application, the latent heat and the sensible heat of the waste incineration flue gas are both utilized, and the safety and the economy are improved.

[0045] The smoke tower combined waste incineration power plant flue gas waste heat supply device and system according to the present application has the following advantages:

[0046] 1. Deeply recycling waste incineration flue gas waste heat, the lowest water content of the discharged flue gas is reduced to 8%, most of the sensible heat and latent heat in the flue gas is recycled, and the thermal utilization rate of the power plant is greatly improved.

[0047] 2. By setting the flue gas reheater and the low-temperature economizer, the low-temperature flue gas at the outlet of the spray tower is warmed to an appropriate temperature without consuming high-quality steam, and the thermal utilization rate of the power plant is further improved.

[0048] 3. By setting the flue gas cooling tower, the flue gas with lower water content and lower temperature is discharged to the atmosphere, which can improve the diffusion effect of pollutants in the flue gas and reduce the power loss of the induced draft fan, and is economical.

[0049] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used herein, the term "set" can mean that a component is directly attached to another component, or that a component is attached to another component through an intermediate component. The features described in one embodiment herein can be applied to another embodiment, either alone or in combination with other features, unless the features are not applicable to the other embodiment or are otherwise stated.

[0050] The present application has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and illustration, and are not intended to limit the present application to the scope of the described embodiments. In addition, those skilled in the art can understand that the present application is not limited to the above embodiments, and more various modifications and modifications can be made according to the teachings of the present application, which all fall within the scope of the present application. The scope of protection of the present application is defined by the attached claims and their equivalent scope.

Claims

1. A waste incineration flue gas waste heat heating device with a combined chimney and tower, used for purifying and recovering waste heat from flue gas discharged from a waste heat boiler, wherein the temperature of the flue gas discharged from the waste heat boiler is not less than 220°C, and the flue gas contains particulate matter, dioxins, and acidic gases, and is characterized in that: include: A low-temperature economizer, wherein the low-temperature economizer is connected to the waste heat boiler. After the flue gas enters the low-temperature economizer, it exchanges heat with the circulating hot water in the low-temperature economizer to reduce the temperature. The temperature of the circulating hot water after the heat exchange is 150°C to 160°C, and the temperature of the flue gas is 180°C. A flue gas purification unit, the flue gas purification unit being connected to the low-temperature economizer and being used to purify the flue gas after cooling, wherein the temperature of the flue gas after being treated by the flue gas purification unit is 140° C. to 150° C.; A spray tower, the spray tower being connected to the flue gas purification unit. After the flue gas enters the spray tower, it directly exchanges heat with the spray water sprayed by the spray tower to further reduce the temperature to 30°C to 60°C; an external heat exchanger, the external heat exchanger being in communication with the spray tower, the spray water circulating between the spray tower and the external heat exchanger, the external heat exchanger being used to exchange heat between the spray water in the external heat exchanger and water from a heat user's heating network to supply heat externally; A flue gas reheater, wherein the flue gas reheater is connected to the spray tower and the low-temperature economizer, and the circulating hot water circulates between the low-temperature economizer and the flue gas reheater. After the flue gas enters the flue gas reheater, it exchanges heat with the circulating hot water to raise the temperature to 80°C to 100°C; The smoke exhaust cooling tower is connected to the smoke reheater. The smoke enters the smoke exhaust cooling tower after heat exchange and temperature increase in the smoke reheater, and is discharged into the atmosphere through the smoke exhaust cooling tower.

2. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 1 is characterized in that: The flue gas purification unit comprises: A semi-dry deacidification tower is connected to the low-temperature economizer and is used for deacidifying the flue gas entering the semi-dry deacidification tower.

3. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 2 is characterized in that: The flue gas purification unit further comprises: A bag dust collector is connected to the semi-dry deacidification tower and is used to remove dust from the flue gas entering the bag dust collector to remove particulate matter in the flue gas.

4. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 3 is characterized in that: The flue gas purification unit further comprises: The activated carbon injector is used to inject activated carbon into the pipeline connecting the semi-dry deacidification tower and the bag filter to remove dioxins in the flue gas.

5. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 3 is characterized in that: The flue gas purification unit further comprises: The dry ejector is used to eject deacidification material into the pipeline connecting the semi-dry deacidification tower and the bag filter to remove acidic gas in the flue gas.

6. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 1 is characterized in that: Also includes: An induced draft fan is arranged between the flue gas reheater and the flue gas cooling tower, and is used to draw the flue gas into the flue gas cooling tower.

7. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 1 is characterized in that: The flue gas reheater includes a fluoroplastic heat exchanger or an ND steel heat exchanger.

8. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 1 is characterized in that: The spray tower is provided with an ejector and a demisting device, wherein the ejector is used for spraying spray water and the demisting device is used for removing liquid water in the flue gas.

9. The waste incineration flue gas waste heat heating device with integrated chimney and tower according to claim 1 is characterized in that: The external heat exchanger includes: a plate heat exchanger, a tube heat exchanger or an absorption heat pump.

10. A waste incineration flue gas waste heat heating system with integrated chimney and tower, characterized in that: It comprises a waste incineration flue gas waste heat heating device integrated with a smoke tower according to any one of claims 1-9.

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