High-temperature flue gas utilization system and power generation system

Abstract

The utility model relates to the technical field of flue gas recovery, in particular to a high-temperature flue gas utilization system and a power generation system. Comprising a heat supply unit, a first treatment part which is connected with the heat supply unit and receives smoke cooled by the heat supply unit, and a second treatment part which is connected with the heat supply unit and receives high-temperature smoke of the heat supply unit. Wherein the first processing piece is communicated with the second processing piece, and the first processing piece provides part of raw materials for the second processing piece. The sludge drying device has the beneficial effects that sludge drying and one-time hot air replacement are realized by utilizing high-temperature flue gas of the internal combustion engine. The energy utilization efficiency of the internal combustion engine is improved, meanwhile, consumption of high-temperature steam is reduced, the sludge blending combustion proportion of the boiler is increased, and the power generation efficiency of the system is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of flue gas recovery, in particular to a high-temperature flue gas utilization system and a power generation system. Background Art

[0002] Currently, advanced large-scale gas-fired internal combustion engines can achieve operating thermal efficiencies exceeding 45%, but the exhaust gas temperature remains as high as 300-500°C. If this waste heat is not utilized, it results in significant energy waste. Traditionally, waste heat recovery from internal combustion engine exhaust involves adding a waste heat boiler (WHB) to generate steam for power generation. However, due to the low steam parameters, the power generation efficiency is very low. Furthermore, the equipment investment required to add a WHB power generation system is high, resulting in poor overall economic benefits.

[0003] Most coal-fired power plants in my country use pulverized coal-fired boilers. To burn coal in the boilers, the coal is ground into fine powder in a pulverizer, then carried by hot air into the boiler for combustion. Some coal-fired power plants near cities now also use sewage sludge as a fuel. This incineration not only reduces the amount of municipal sewage sludge required for disposal, but also replaces some of the coal used in the boilers, reducing carbon emissions. The sludge produced by sewage treatment plants is in a paste-like form with a moisture content exceeding 80%. This makes it difficult to mix it with pulverized coal and feed it into the furnace, requiring drying. Traditional drying methods use high-temperature steam generated by boilers to remove moisture from the sludge, but this consumes additional steam, resulting in a decrease in the power generation efficiency of the coal-fired power plant and impacting the overall economic viability of the plant.

[0004] Therefore, we proposed a high-temperature flue gas utilization system. Utility Model Content

[0005] In view of the above-mentioned technical problem that the utilization rate of high-temperature flue gas discharged by existing internal combustion engines is insufficient, the present utility model is proposed.

[0006] The utility model aims to provide a high-temperature flue gas utilization system, which aims to solve the problem of insufficient utilization rate of high-temperature flue gas discharged by internal combustion engines.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a high-temperature flue gas utilization system, which includes a heating unit, a first processing component connected to the heating unit and receiving the flue gas after cooling down from the heating unit, and a second processing component connected to the heating unit and receiving the high-temperature flue gas from the heating unit; wherein, the first processing component is connected to the second processing component, and the first processing component provides part of the raw materials for the second processing component.

[0008] As a preferred solution of the high-temperature flue gas utilization system of the utility model, the heating unit includes at least one internal combustion engine and a booster fan connected to the high-temperature exhaust pipe of the internal combustion engine, and the booster fan is used to increase the high-temperature flue gas discharged by the internal combustion engine.

[0009] As a preferred solution of the high-temperature flue gas utilization system of the present invention, the first processing component includes a sludge dryer, the sludge dryer air inlet pipe is connected to the water heater, and the water heater air inlet pipe is connected to the booster fan flue gas exhaust pipe.

[0010] As an optimal solution of the high-temperature flue gas utilization system of the present invention, a boiler feed water pipe is provided inside the feed water heater, and the high-temperature flue gas discharged by the internal combustion engine is cooled by heat exchange in the feed water heater and then filled into the sludge dryer through the exhaust pipe to dry the sludge.

[0011] As a preferred solution of the high-temperature flue gas utilization system of the present invention, a first regulating valve is provided between the booster fan and the feed water heater, and a second regulating valve is provided between the feed water heater and the sludge dryer.

[0012] As a preferred solution of the high-temperature flue gas utilization system of the present invention, the second processing component includes a coal mill, the coal mill air intake pipe is connected to the high-temperature exhaust pipe of the booster fan, and a third regulating valve is provided between the coal mill air intake pipe and the high-temperature exhaust pipe of the booster fan.

[0013] As a preferred solution of the high-temperature flue gas utilization system of the utility model, the coal mill is connected to the boiler, the coal mill air intake pipeline is connected to the feedwater heater exhaust pipeline, and a fourth regulating valve is provided between the coal mill air intake pipeline and the feedwater heater exhaust pipeline.

[0014] As a preferred solution of the high-temperature flue gas utilization system of the present invention, the coal mill air inlet pipeline is further connected with a boiler primary fan, and an air preheater is connected between the boiler primary fan and the coal mill.

[0015] As a preferred solution of the high-temperature flue gas utilization system of the utility model, the air preheater is used to heat the flue gas discharged by the primary fan of the boiler, the pulverized coal is mixed with the dried sludge by the pulverizer, and the mixed pulverized coal is transported into the boiler furnace for combustion in combination with the flue gas discharged by the air preheater, the internal combustion engine and the feed water heater.

[0016] The utility model also provides the following technical solution: a power generation system, including a high-temperature flue gas utilization system.

[0017] The beneficial effects of this new high-temperature flue gas utilization system include utilizing the high-temperature flue gas from the internal combustion engine to dry sludge and replace primary hot air. This not only improves the energy efficiency of the internal combustion engine, but also reduces high-temperature steam consumption, increases the proportion of sludge mixed with the boiler, and improves the system's power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of 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 work.

[0019] Figure 1 This is the overall system diagram of the high-temperature flue gas utilization system in the present utility model. DETAILED DESCRIPTION

[0020] 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 with reference to the accompanying drawings.

[0021] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. 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.

[0022] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout 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.

[0023] Example 1, reference Figure 1 , which is the first embodiment of the present utility model, provides a high-temperature flue gas utilization system, including a heating unit 100, a first processing unit 200 connected to the heating unit 100 and receiving the flue gas after cooling from the heating unit 100, and a second processing unit 300 connected to the heating unit 100 and receiving the high-temperature flue gas from the heating unit 100.

[0024] The first processing component 200 is connected to the second processing component 300 , and the first processing component 200 provides part of the raw materials for the second processing component 300 .

[0025] Preferably, the heating unit 100 generates heat energy by burning fuel, converts the heat energy into mechanical energy, and then converts it into electrical energy through a generator; the high-temperature flue gas generated by the burning of fuel by the heating component 100 passes through a high-temperature exhaust pipe, and after heat exchange, the cooled flue gas is connected to the first treatment element 200 through a pipe, and in the first treatment element 200, the wet sludge in the city is treated and dried.

[0026] Preferably, the wet sludge passes through the first treatment element 200 and is treated with the flue gas after cooling to become dry sludge. The sludge in the first treatment element 200 is transported to the second treatment element 300 and mixed with the coal powder in the second treatment element 300, replacing part of the boiler coal and reducing carbon emissions.

[0027] Furthermore, the high-temperature flue gas generated by burning fuel in the heating component 100 is directly introduced into the second treatment component 300 through the high-temperature exhaust pipe, and the mixture of coal powder and dry sludge in the second treatment component 300 is transported to the boiler furnace for combustion through the waste heat of the high-temperature flue gas.

[0028] In summary, utilizing the high-temperature flue gas from the heating unit 100 to achieve sludge drying and primary hot air replacement not only improves the energy utilization efficiency of the internal combustion engine, but also reduces the consumption of high-temperature steam, increases the proportion of sludge mixed combustion in the boiler, and improves the power generation efficiency of the system.

[0029] Example 2, reference Figure 1 This is the second embodiment of the present invention, which further provides a high-temperature flue gas utilization system. It includes a heating unit 100 including at least one internal combustion engine 101 and a booster fan 102 connected to the high-temperature exhaust pipe of the internal combustion engine 101.

[0030] Preferably, the heating component 100 in the present invention mainly refers to multiple internal combustion engines 101; the multiple internal combustion engines 101 connect the high-temperature flue gas generated by burning fuel through a high-temperature flue gas pipeline, and transport the high-temperature flue gas to the next unit through a booster fan 102.

[0031] The booster fan 102 is used to increase the high-temperature flue gas discharged by the internal combustion engine 101 .

[0032] The first treatment unit 200 includes a sludge dryer 201 , an air inlet pipe of the sludge dryer 201 is connected to a feedwater heater 202 , and an air inlet pipe of the feedwater heater 202 is connected to a flue gas exhaust pipe of the booster fan 102 .

[0033] The high-temperature flue gas generated by the internal combustion engine 1101 is divided into two paths after passing through the booster fan 102. This embodiment mainly describes the first path.

[0034] The first high-temperature flue gas passes through the feed water heat exchanger 202 to initially recover waste heat, and after cooling, enters the sludge dryer 201 to dry the wet sludge, and finally the cooled flue gas is discharged.

[0035] A boiler feed water pipe 202a is provided inside the feed water heater 202. The high temperature flue gas discharged by the internal combustion engine 101 is cooled by heat exchange in the feed water heater 202 and then fed into the sludge dryer 201 through the exhaust pipe to dry the sludge.

[0036] After the water in the boiler feed water pipe 202a enters the water accumulation heat exchanger 202, it exchanges heat with the high-temperature flue gas generated by the internal combustion engine 101, reducing the temperature of the high-temperature flue gas. The cooled flue gas is then passed through the sludge dryer 201 to dry the wet sludge therein.

[0037] Preferably, the temperature of the high-temperature flue gas passing through the outlet of the feedwater heat exchanger 202 is 180-220°C, preferably 200°C.

[0038] Preferably, the flue gas temperature at the outlet of the sludge dryer 201 is 80-100°C, preferably 90°C.

[0039] A first regulating valve 203 is provided between the booster fan 102 and the feed water heater 202 , and a second regulating valve 204 is provided between the feed water heater 202 and the sludge dryer 201 .

[0040] The first flue gas regulating valve 203 is used to adjust the flue gas flow entering the first path, thereby controlling the flue gas flow entering the feed water heater 202. At the same time, by adjusting the boiler feed water flow, the flue gas temperature at the outlet of the feed water heater 202 is controlled to 180-220°C, preferably 200°C.

[0041] The second regulating valve 204 is used to adjust the flue gas flow rate entering the sludge dryer 4, thereby controlling the flue gas temperature at the outlet of the sludge dryer 4 to be 80-100°C, preferably 90°C.

[0042] In summary, this embodiment shows the first flow direction of the exhaust gas from the internal combustion engine 101. The first high-temperature flue gas passes through the feed water heat exchanger 202 to initially recover waste heat, and after cooling, enters the sludge dryer 201 to dry the wet sludge, and finally the cooled flue gas is discharged.

[0043] Example 3, reference Figure 1This is the third embodiment of the present invention, further providing a high-temperature flue gas utilization system. This embodiment includes a second processing unit 300, including a coal mill 301. The coal mill 301 air intake pipeline is connected to the high-temperature exhaust pipe of the booster fan 102. A third regulating valve 304 is installed between the coal mill 301 air intake pipeline and the high-temperature exhaust pipe of the booster fan 102. The coal mill 301 air intake pipeline is also connected to the boiler primary fan 303, and an air preheater 302 is connected between the boiler primary fan 303 and the coal mill 301.

[0044] This embodiment shows the second flow direction of the flue gas discharged from the internal combustion engine 101. After the high-temperature flue gas generated by the internal combustion engine 101 passes through the booster fan 102, it is regulated by the third regulating valve 304 and combined with the flue gas heated by the boiler primary fan 303 through the air preheater 302. The two are then transported together into the pulverizer 301. The above is the second flow direction of the high-temperature flue gas.

[0045] The coal mill 301 is connected to the boiler 306 , and the air inlet pipeline of the coal mill 301 is connected to the exhaust pipeline of the feedwater heater 202 . A fourth regulating valve 305 is provided between the air inlet pipeline of the coal mill 301 and the exhaust pipeline of the feedwater heater 202 .

[0046] Preferably, the fourth regulating valve 305 further controls the flue gas flow in the first path, thereby controlling the flue gas flow entering the feed water heater 202, and controlling the flue gas temperature entering the sludge dryer 201. When the flue gas flow in the first path is too large, the fourth regulating valve 305 is opened to allow the flue gas to enter the second path, and to be combined with the flue gas in the second path and sent into the coal mill 301 together.

[0047] The air preheater 302 is used to heat the flue gas exhausted by the boiler primary fan 303. The pulverizer 301 mixes the pulverized coal with the dried sludge, and then combines the flue gas exhausted by the air preheater 302, the internal combustion engine 101 and the feedwater heater 202 to transport the mixed pulverized coal into the furnace of the boiler 306 for combustion.

[0048] In summary, this embodiment shows the second flow direction of the flue gas discharged from the internal combustion engine 101. After the high-temperature flue gas generated by the internal combustion engine 101 passes through the booster fan 102, it is adjusted by the third regulating valve 304 and combined with the flue gas heated by the boiler primary fan 303 through the air preheater 302. The two are transported together into the pulverizer 301, and the mixed coal powder and dry sludge are transported into the furnace of the boiler 306 for combustion. This not only improves the energy utilization efficiency of the internal combustion engine, but also reduces the consumption of high-temperature steam, increases the proportion of sludge mixed in the boiler, and improves the power generation efficiency of the system.

[0049] Example 4, reference Figure 1 , which is the fourth embodiment of the present utility model, and this embodiment further provides a high-temperature flue gas utilization system.

[0050] For illustration, consider a coupled system consisting of a 600MW coal-fired unit's boiler and fourteen 18MW internal combustion engines. Internal combustion engine 101 represents a combination of one or more internal combustion engines. At full load, the high-temperature exhaust temperature of internal combustion engine 101 is 370°C. The exhaust gases from multiple internal combustion engines 101 are combined and enter a high-temperature exhaust duct, which is connected to the inlet of booster fan 102. After pressurization, the high-temperature flue gas is divided into two paths. The first path of high-temperature flue gas passes through feedwater heat exchanger 202 for initial waste heat recovery. By adjusting the boiler feedwater flow rate, the flue gas temperature at the outlet of feedwater heat exchanger 202 is controlled at approximately 200°C. The flue gas at the outlet of feedwater heat exchanger 202 enters sludge dryer 201 to dry the wet sludge. Finally, the flue gas temperature is reduced to approximately 90°C before being discharged. In the second path, the pressurized high-temperature flue gas is mixed with the flue gas at the outlet of the feed water heat exchanger 202, and then mixed with the air heated by the boiler primary fan 303 and sent to the air preheater 302, and then sent to the pulverizer 301; the dry sludge produced by the sludge dryer 201 is also sent to the pulverizer 301 to be mixed with the coal and ground together; the mixture of the high-temperature flue gas of the internal combustion engine and the hot primary air is used to transport the coal powder into the boiler chamber for combustion.

[0051] The fuel consumption of a 600MW coal-fired unit is about 300 tons per hour. By using high-temperature flue gas from an internal combustion engine to dry sludge, 15% of dry sludge can be mixed in. In addition, about 70% of the waste heat from the internal combustion engine flue gas can be recovered, saving a total of 70 tons of coal consumption and reducing carbon dioxide emissions by 180 tons per hour. The economic and environmental benefits are significant.

[0052] In summary, this flue gas utilization system fully utilizes the waste heat from the high-temperature flue gas of the internal combustion engine to dry the sludge, while also using the high-temperature flue gas to replace the boiler's primary hot air for conveying pulverized coal, thereby improving the system's overall energy efficiency. By efficiently utilizing the waste heat from the internal combustion engine flue gas, 70% of the waste heat can be recovered. Furthermore, using the high-temperature flue gas of the internal combustion engine to dry the sludge reduces steam consumption by 0.8 tons per ton of sludge dried, and each ton of dried sludge burned replaces 0.4 tons of coal. Combined, these two factors reduce coal consumption by 0.5 tons for every ton of sludge burned in a coal-fired boiler.

[0053] Example 5, reference Figure 1 , the utility model provides a power generation system, including a high-temperature flue gas utilization system; the use of this new internal combustion engine exhaust high-temperature flue gas utilization system in the power generation system can significantly improve energy utilization efficiency, reduce energy waste and carbon emissions, reduce operating costs, and at the same time increase sludge treatment capacity, improve economic benefits and environmental friendliness, enhance system flexibility and stability, promote cogeneration of heat and power, and improve the technical level and market competitiveness of power plants.

[0054] It is important to note that the construction and arrangement of the present application shown in a number of different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, colors, directional changes, etc.) without departing substantially from the novel teachings and advantages of the subject matter described in this application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature or number or position of the discrete elements may be altered or changed. Therefore, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also an equivalent structure. Without departing from the scope of the present invention, other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0055] Additionally, in order to provide a concise description of example embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0056] It will be appreciated that in the development of any actual embodiment, 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 will, for those of ordinary skill having the benefit of this disclosure, be a routine undertaking of design, fabrication, and production without undue experimentation.

[0057] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. 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, and all of these should be included in the scope of the claims of the present invention.

Claims

1. A high-temperature flue gas utilization system, characterized by: include, a heating unit (100), a first processing unit (200) connected to the heating unit (100) and receiving the flue gas after cooling from the heating unit (100); and a second processing unit (300) connected to the heating unit (100) and receiving high-temperature flue gas from the heating unit (100); The first processing part (200) is connected to the second processing part (300), and the first processing part (200) provides part of the raw materials for the second processing part (300).

2. The high-temperature flue gas utilization system according to claim 1, characterized in that: The heating unit (100) comprises at least one internal combustion engine (101) and a booster fan (102) connected to a high-temperature exhaust pipe of the internal combustion engine (101), wherein the booster fan (102) is used to increase the high-temperature flue gas discharged by the internal combustion engine (101).

3. The high-temperature flue gas utilization system according to claim 2, characterized in that: The first processing unit (200) includes a sludge dryer (201), an air intake pipe of the sludge dryer (201) is connected to a feedwater heater (202), and an air intake pipe of the feedwater heater (202) is connected to a flue gas exhaust pipe of the booster fan (102).

4. The high-temperature flue gas utilization system according to claim 3, characterized in that: A boiler water supply pipe (202a) is provided inside the water supply heater (202). The high-temperature flue gas discharged by the internal combustion engine (101) is cooled by heat exchange in the water supply heater (202) and then fed into the sludge dryer (201) through the exhaust pipe to dry the sludge.

5. The high-temperature flue gas utilization system according to claim 4, characterized in that: A first regulating valve (203) is provided between the booster fan (102) and the feedwater heater (202), and a second regulating valve (204) is provided between the feedwater heater (202) and the sludge dryer (201).

6. The high-temperature flue gas utilization system according to claim 5, characterized in that: The second processing unit (300) includes a coal mill (301), an air intake pipe of the coal mill (301) is connected to a high-temperature exhaust pipe of the booster fan (102), and a third regulating valve (304) is provided between the air intake pipe of the coal mill (301) and the high-temperature exhaust pipe of the booster fan (102).

7. The high-temperature flue gas utilization system according to claim 6, characterized in that: The coal mill (301) is connected to the boiler (306), the coal mill (301) air intake pipeline is communicated with the feedwater heater (202) exhaust pipeline, and a fourth regulating valve (305) is provided between the coal mill (301) air intake pipeline and the feedwater heater (202) exhaust pipeline.

8. The high-temperature flue gas utilization system according to claim 7, characterized in that: The coal mill (301) is also connected to a boiler primary fan (303) on its air inlet pipeline, and an air preheater (302) is connected between the boiler primary fan (303) and the coal mill (301).

9. The high-temperature flue gas utilization system according to claim 8, characterized in that: The air preheater (302) is used to heat the flue gas discharged by the primary fan (303) of the boiler. The coal mill (301) mixes the pulverized coal with the dried sludge, and then combines the flue gas discharged by the air preheater (302), the internal combustion engine (101) and the feed water heater (202) to transport the mixed pulverized coal into the furnace of the boiler (306) for combustion.

10. A power generation system, characterized in that: It comprises the high-temperature flue gas utilization system described in any one of claims 1 to 9.

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