Coal-fired unit blending combustion sludge rotary drying system based on internal combustion engine flue gas

Abstract

The invention relates to the field of municipal sludge drying and internal combustion engine flue gas utilization, in particular to a coal-fired unit blending combustion sludge rotary drying system based on internal combustion engine flue gas, which comprises an internal combustion engine, and high-temperature flue gas generated by the internal combustion engine is treated by a flue gas treatment module to form mixed flue gas; the mixed flue gas is used for treating wet sludge through the sludge treatment module to form dry sludge. Municipal sludge is dried by fully utilizing high-temperature flue gas drying waste heat of the internal combustion engine, the overall energy efficiency of the system can be improved, and the drying effect can be improved through the rotary dryer.

Description

Technical Field

[0001] The invention relates to the field of municipal sludge drying and internal combustion engine flue gas utilization, in particular to a sludge rotary drying system for coal-fired units based on internal combustion engine flue gas. Background Art

[0002] At present, the operating thermal efficiency of advanced large-scale gas internal combustion engines can reach more than 45%, but the temperature of the flue gas discharged is still as high as 300-500℃. If this part of the flue gas waste heat is not utilized, it will cause huge energy waste. The traditional method of recovering waste heat from internal combustion engine exhaust is to add a waste heat boiler to generate electricity using the generated steam, but because the parameters of the generated steam are not high, the power generation efficiency is very low. At the same time, the equipment investment for adding a waste heat boiler power generation system is very high, and the overall economic benefits are poor.

[0003] Most of my country's coal-fired power plants use pulverized coal combustion boilers. Coal for boiler combustion needs to be ground into fine coal powder by a pulverizer, and then hot air is used to carry the coal powder into the boiler for combustion. Nowadays, some coal-fired power plants around cities also burn municipal sludge. On the one hand, the problem of reducing the amount of municipal sludge is solved by incineration. On the other hand, municipal sludge also replaces part of the coal used in boilers, reducing carbon emissions. The municipal sludge produced by the sewage treatment plant is in a paste state with a water content of more than 80%. It cannot be mixed with pulverized coal and sent into the furnace. The municipal sludge must be dried. The traditional drying method is to use high-temperature steam generated by the boiler to remove moisture from the sludge, but this will consume additional steam from the boiler, resulting in a decrease in the power generation efficiency of the coal-fired power plant and affecting the economy of the entire power plant. Summary of the invention

[0004] In view of the above problems or problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the purpose of the present invention is to provide a sludge rotary drying system for coal-fired units based on internal combustion engine flue gas, which can solve the problem that internal combustion engine flue gas cannot be effectively utilized and the problem that sludge drying consumes boiler steam and reduces the power generation efficiency of coal-fired power plants.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a coal-fired unit sludge rotary drying system based on internal combustion engine flue gas, which includes an internal combustion engine, and the high-temperature flue gas generated by the internal combustion engine is treated by a flue gas treatment module to form a mixed flue gas; a sludge treatment module, and the mixed flue gas is treated by the sludge treatment module to form dry sludge.

[0007] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas described in the present invention, the flue gas treatment module includes a mixer and a thermostat, and the thermostat is electrically connected to the mixer.

[0008] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas described in the present invention, the high-temperature flue gas generated by the internal combustion engine enters the mixer and is adjusted by a temperature controller to form mixed flue gas.

[0009] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas described in the present invention, the sludge treatment module includes a fluidized bed dryer, a sludge digester and a filter press, and a pipeline is connected between the fluidized bed dryer, the sludge digester and the filter press.

[0010] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas described in the present invention, the wet sludge in the sludge digester is heated and drained by the mixed flue gas and then transported to the filter press by pipeline for dehydration.

[0011] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas described in the present invention, the wet sludge in the filter press is dehydrated to form dehydrated sludge, and the dehydrated sludge is transported to the fluidized bed dryer by pipeline.

[0012] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas described in the present invention, the dewatered sludge in the fluidized bed dryer is dried into dry sludge and then discharged.

[0013] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas of the present invention, the mixed flue gas discharged from the mixer is dried and dehydrated in the fluidized bed dryer.

[0014] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas of the present invention, the mixed flue gas after drying the dehydrated sludge in the fluidized bed dryer heats the wet sludge in the sludge digester.

[0015] As a preferred solution of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas of the present invention, the mixed flue gas after heating the wet sludge in the sludge digester is discharged to the outside of the sludge digester.

[0016] The beneficial effects of the present invention are as follows: the coal-fired unit sludge rotary drying system based on internal combustion engine flue gas described in the present invention can improve the overall energy efficiency of the system by making full use of the waste heat from the high-temperature flue gas drying of the internal combustion engine to dry the municipal sludge, and the drying effect can be improved through the rotary dryer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0018] Figure 1 It is a schematic diagram of the overall structure of the sludge rotary drying system for coal-fired units based on internal combustion engine flue gas. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0022] Example 1

[0023] Reference Figure 1 , which is the first embodiment of the present invention, provides a sludge rotary drying system for a coal-fired unit based on internal combustion engine flue gas, specifically comprising an internal combustion engine 100, wherein the high-temperature flue gas generated by the internal combustion engine 100 is treated by a flue gas treatment module 200 to form a mixed flue gas; and a sludge treatment module 300, wherein the mixed flue gas is treated by the sludge treatment module 300 to treat wet sludge to form dry sludge.

[0024] Furthermore, the flue gas treatment module 200 includes a mixer 201 and a temperature controller 202 , and the temperature controller 202 is electrically connected to the mixer 201 .

[0025] Furthermore, the high-temperature flue gas generated by the internal combustion engine 100 enters the mixer 201 and is regulated by the temperature controller 202 to form mixed flue gas.

[0026] Preferably, the temperature controller 202 adjusts the mixed flue gas to maintain the temperature between 180 and 220 degrees.

[0027] It needs to be explained that: the current advanced large-scale gas internal combustion engine can achieve a thermal efficiency of more than 45%, but the exhaust gas temperature is still as high as 300-500℃. If this part of the flue gas waste heat is not used, it will cause huge energy waste. The traditional method of recovering waste heat from internal combustion engine exhaust is to add a waste heat boiler to generate electricity using the generated steam, but because the parameters of the generated steam are not high, the power generation efficiency is very low. At the same time, the equipment investment for adding a waste heat boiler power generation system is very high, and the overall economic benefits are poor.

[0028] In response to these problems, the present invention uses a thermostat 202 to adjust the mixing ratio of high-temperature flue gas and cold air, so that the temperature of the mixed flue gas generated by the mixer 201 is maintained between 180 and 220 degrees. Compared with the flue gas directly generated by the internal combustion engine 100 at a temperature of up to 300 to 500 degrees Celsius, the mixed flue gas at this temperature is more stable and can efficiently recover heat energy through heat exchange equipment such as a heat recovery boiler or a heat exchanger. In addition, the mixed flue gas between 180 and 220 degrees has a smaller temperature difference with the surrounding environment, so the heat loss is less, which helps to more effectively preserve heat energy and improve the overall thermal energy utilization rate. At the same time, flue gas with a higher temperature (300 to 500 degrees Celsius) is prone to corrosion and wear in pipes and equipment, while the temperature of 180 to 220 degrees is lower, and the risk of damaging the equipment is relatively low, thereby extending the service life of the equipment.

[0029] In this embodiment, the specific temperature control logic for the mixed flue gas is as follows: the temperature of the mixed gas is adjusted by changing the flow rate of cold air and the exhaust gas of the internal combustion engine 100. The thermostat 202 monitors the exhaust temperature of the internal combustion engine and the ambient air temperature, adjusts the valve and monitors the temperature of the mixed flue gas to ensure that it is within the required range.

[0030] Example 2

[0031] Reference Figure 1 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0032] Furthermore, the sludge treatment module 300 includes a rotary dryer 301 , a sludge digester 302 and a filter press 303 , and pipelines are connected between the rotary dryer 301 , the sludge digester 302 and the filter press 303 .

[0033] Furthermore, the dewatered sludge in the rotary dryer 301 is dried into dry sludge and then discharged.

[0034] It should be noted that the sludge dryer is mainly used to dehydrate and dry the sludge generated during the sewage treatment process. Its main functions include: reducing the volume of sludge to facilitate transportation and treatment; reducing treatment costs and improving the economic efficiency of the sewage treatment system; increasing the calorific value of the dried sludge so that it can be used for incineration to generate electricity or as fuel; improving the stability of the sludge, reducing pathogens and odor, and improving environmental friendliness; and facilitating subsequent incineration, composting and other treatments. This makes the sludge dryer play an important role in the sewage treatment system and significantly improves the overall treatment efficiency.

[0035] In this embodiment, the sludge dryer adopts a rotary method to fully increase the mixing of high-temperature flue gas and dehydrated sludge and improve the drying effect. The rotary dryer is arranged at an angle of 15 degrees to the horizontal to ensure that the sludge stays in the rotary dryer for no less than 10 minutes; a tube bundle is arranged in the rotary dryer, and the high-temperature exhaust gas of the internal combustion gas flows through the tube bundle.

[0036] It needs to be explained that some coal-fired power plants around cities nowadays also burn municipal sludge. On the one hand, the incineration solves the problem of reducing the amount of municipal sludge. On the other hand, municipal sludge also replaces part of the coal used in boilers, reducing carbon emissions. The municipal sludge produced by the sewage treatment plant is in a paste state with a water content of more than 80%. It cannot be mixed with coal powder and sent into the furnace. The municipal sludge must be dried. The traditional drying method is to use high-temperature steam generated by the boiler to remove moisture from the sludge, but this will consume additional steam from the boiler, resulting in a decrease in the power generation efficiency of the coal-fired power plant, affecting the economy of the entire power plant.

[0037] Furthermore, the mixed flue gas discharged from the mixer 201 is dried and dehydrated into sludge in the rotary dryer 301 .

[0038] Furthermore, the mixed flue gas after drying the dehydrated sludge in the rotary dryer 301 heats the wet sludge in the sludge digester 302 .

[0039] In view of these problems, the present invention utilizes mixed flue gas to dry the dehydrated sludge, and can directly utilize the heat energy of the mixed flue gas, thus avoiding the consumption of high-temperature steam in the original technology.

[0040] Example 3

[0041] Reference Figure 1 , which is the third embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0042] Furthermore, the wet sludge in the sludge digester 302 is heated and drained by the mixed flue gas, and then transported to the filter press 303 through a pipeline for dehydration.

[0043] It should be noted that a sludge digester is a device used to treat sludge generated during sewage treatment. Its main functions include: decomposing organic matter through microorganisms, significantly reducing the volume of sludge for subsequent treatment and disposal; improving the stability of sludge, reducing corruption, odor and pathogen content; recycling the generated biogas for power generation, heating or as fuel to achieve resource reuse; reducing degradable organic matter and pathogens, thereby reducing the impact on the environment; and releasing nutrients (such as nitrogen and phosphorus) that can be used for soil improvement or as fertilizer. Overall, sludge digesters effectively improve treatment efficiency in sewage treatment systems and promote resource recovery and environmental protection.

[0044] In this embodiment, by using the mixed flue gas after the dewatered sludge is dried to heat the wet sludge, the thermal energy of the mixed flue gas can be further utilized; the wet sludge is heated by the mixed flue gas, which can cause the water in the cell walls of the wet sludge to overflow; the moisture in the wet sludge is discharged in advance, so that the dewatered sludge entering the rotary dryer 301 has a lower moisture content, thereby making the drying of the dewatered sludge more thorough.

[0045] Furthermore, the wet sludge in the filter press 303 is dehydrated to form dehydrated sludge, and the dehydrated sludge is transported to the rotary dryer 301 through a pipeline.

[0046] It should be noted that the filter press 303 is a device for solid-liquid separation, which is widely used in water treatment, mining, chemical industry, food, pharmaceutical and other industrial fields. Its main function is to separate liquid from solid by applying pressure to achieve the purpose of dehydration and concentration.

[0047] It needs to be explained that many coal-fired power plants use pulverized coal combustion boilers. The coal needs to be ground into fine powder by a pulverizer, and then hot air is used to send the pulverized coal into the boiler for combustion.

[0048] It should be noted that feeding dry sludge into a coal mill and mixing it with coal for grinding and co-combustion can make efficient use of resources. This method combines the organic matter and heat energy in the sludge with coal powder, which can reduce the emission and treatment costs of sludge, while reducing fuel costs. In addition, optimizing the combustion process helps to improve the uniformity and stability of combustion, improve the efficiency of heat energy conversion, thereby reducing environmental pollution and the emission of unburned substances. Co-combustion can also significantly reduce dependence on landfills, promote resource recycling, and conform to the concept of sustainable development.

[0049] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only several embodiments are described in detail in this disclosure, it should be easily understood by the personnel referring to this disclosure that many modifications are possible (for example, the size, scale, structure, shape and ratio of various elements, and parameter values ​​(for example, temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of a plurality of parts or elements, the position of the element can be inverted or otherwise changed, and the property or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method step can be changed or reordered according to alternative embodiments. Therefore, the present invention is not limited to specific embodiments, but extends to a variety of modifications still falling within the scope of the appended claims.

[0050] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but for those of ordinary skill having the benefit of this disclosure, the development effort will be a routine task of design, fabrication, and production without undue experimentation.

[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A coal-fired unit sludge rotary drying system based on internal combustion engine flue gas, characterized by: include, An internal combustion engine (100), wherein high-temperature flue gas generated by the internal combustion engine (100) is processed by a flue gas processing module (200) to form mixed flue gas; The mixed flue gas is processed by the sludge processing module (300) to process the wet sludge to form dry sludge.

2. The sludge rotary drying system for coal-fired units based on internal combustion engine flue gas according to claim 1 is characterized by: The flue gas treatment module (200) comprises a mixer (201) and a temperature controller (202), and the temperature controller (202) is electrically connected to the mixer (201).

3. The rotary drying system for sludge mixed with coal-fired units based on internal combustion engine flue gas according to claim 2 is characterized by: The high-temperature flue gas generated by the internal combustion engine (100) enters the mixer (201) and is regulated by the temperature controller (202) so that the high-temperature flue gas and air are mixed to form mixed flue gas.

4. The sludge rotary drying system for coal-fired units based on internal combustion engine flue gas according to claim 3 is characterized by: The sludge treatment module (300) comprises a rotary dryer (301), a sludge digester (302) and a filter press (303), and pipelines are connected between the rotary dryer (301), the sludge digester (302) and the filter press (303).

5. The sludge rotary drying system for coal-fired units based on internal combustion engine flue gas according to claim 4 is characterized by: The wet sludge in the sludge digester (302) is heated and drained by the mixed flue gas, and then transported to the filter press (303) through a pipeline for dehydration.

6. The rotary drying system for sludge mixed with coal-fired units based on internal combustion engine flue gas according to claim 5 is characterized by: The wet sludge in the filter press (303) is dehydrated to form dehydrated sludge, which is then transported to the rotary dryer (301) through a pipeline.

7. The sludge rotary drying system for coal-fired units based on internal combustion engine flue gas according to claim 6 is characterized by: The dewatered sludge in the rotary dryer (301) is dried into dry sludge and then discharged.

8. The sludge rotary drying system for coal-fired units based on internal combustion engine flue gas according to claim 7 is characterized by: The mixed flue gas discharged from the mixer (201) is dried and dehydrated into sludge in the rotary dryer (301).

9. The rotary drying system for coal-fired units using internal combustion engine flue gas according to claim 8 is characterized by: The mixed flue gas after drying the dewatered sludge in the rotary dryer (301) heats the wet sludge in the sludge digester (302).

10. The sludge rotary drying system for coal-fired units based on internal combustion engine flue gas according to claim 9, characterized in that: The mixed flue gas after the wet sludge is heated in the sludge digester (302) is discharged to the outside of the sludge digester (302).

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