A Deep Waste Heat Recovery and Carbon Neutralization System for Flue Gas from a Small Gas-Fired Boiler Room in an Automobile Factory

Abstract

This utility model discloses a deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory. The system includes a heat recovery subsystem and a filtration, compression, and purification subsystem connected to each other. The heat recovery subsystem includes a heat pipe waste heat recovery unit, a hot water circulation pump, an electric three-way regulating valve, a low-temperature water supply pipe, an inlet pipe, and an outlet pipe. Both the inlet and outlet of the heat pipe waste heat recovery unit are connected to flues. This utility model can reduce energy waste, improve the comprehensive energy utilization rate, reduce the overall energy consumption of the automobile factory, effectively reduce carbon dioxide emissions from boiler flue gas, help the automobile factory reduce carbon emissions, meet the goal of carbon neutrality, and has positive significance for environmental protection. It also helps enterprises cope with increasingly stringent environmental regulations and policy requirements.

Description

Technical Field

[0001] This utility model relates to the field of energy conservation and environmental protection technology, and in particular to a deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory. Background Technology

[0002] Under the policy framework of carbon peaking and carbon neutrality, all economic sectors are developing and adopting suitable energy-saving and emission-reduction technologies to ultimately achieve carbon neutrality. The automotive industry, in particular, which consumes a significant amount of heat energy and emits large amounts of carbon, especially needs to fundamentally seek carbon-neutral technological solutions. This patent aims to address small-scale gas-fired boiler rooms by reducing energy waste through deep waste heat recovery from flue gas and reducing carbon dioxide emissions from boiler flue gas through carbon capture, thereby achieving the goal of carbon neutrality.

[0003] The boiler room in an automobile factory is mainly used for preparing process hot water. The boilers are generally condensing, low-NOx gas-fired hot water boilers. Typically, the rated thermal power of a single boiler does not exceed 7000kW, and the total heat load does not exceed 14000kW.

[0004] The boiler is fueled by natural gas, primarily composed of alkanes, with methane being the most abundant. After combustion and heat exchange within the boiler, the natural gas is discharged into the atmosphere through the boiler chimney as flue gas at approximately 80°C. The main reaction equation for the complete combustion of natural gas under ignition conditions is as follows:

[0005] CH4 + 2O2 = CO2 + 2H2O

[0006] Methane + Oxygen → Carbon Dioxide + Water Vapor

[0007] The aforementioned boiler combustion heat exchange process fails to achieve carbon reduction or zero carbon emissions, and the emission of flue gas at 80°C represents a significant energy waste. Under the current dual-carbon policy framework, it is necessary to implement deep heat recovery and carbon recycling to achieve energy conservation, emission reduction, and carbon neutrality. Utility Model Content

[0008] To address the aforementioned problems, this invention provides a deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory.

[0009] To achieve the above objectives, this application provides the following technical solution:

[0010] A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory includes a heat recovery subsystem and a filtration, compression, and purification subsystem connected together. The heat recovery subsystem includes a heat pipe waste heat recovery unit, a hot water circulation pump, an electric three-way regulating valve, a low-temperature water supply pipe, an inlet pipe, and an outlet pipe. The inlet and outlet of the heat pipe waste heat recovery unit are both connected to a flue. The inlet of the electric three-way regulating valve is connected to the low-temperature water supply pipe, one outlet of the electric three-way regulating valve is connected to the inlet pipe, and the other outlet of the electric three-way regulating valve is connected to the water supply pipe. The outlet of the hot water circulation pump is connected to the water supply pipe. A first pipe connects the two systems; the inlet pipe is connected to the inlet of the heat pipe waste heat recovery unit; the outlet pipe is connected to the outlet of the heat pipe waste heat recovery unit, and the other end of the outlet pipe is connected to the inlet of the hot water circulation pump; the filtration, compression, and purification subsystem includes a flue gas filter, a compressor, and a pressure swing adsorber; the inlet of the flue gas filter is connected to a flue located at the outlet of the hot water circulation pump; a second pipe connects the outlet of the flue gas filter to the inlet of the compressor; a third pipe connects the outlet of the compressor to the inlet of the pressure swing adsorber; and a fourth pipe is provided at the outlet of the pressure swing adsorber.

[0011] The system is further configured to include a centralized control subsystem, which includes a central control host, a pressure transmitter, a pressure gauge, a temperature sensor, and a thermometer; pressure transmitters, pressure gauges, temperature sensors, and thermometers are installed at the lower half of both flues and the water supply pipeline; pressure gauges, temperature sensors, and thermometers are installed on both the inlet and outlet pipelines; and pressure transmitters and pressure gauges are installed on the second, third, and fourth pipelines.

[0012] The device is further configured such that a first automatic vent valve, a second automatic vent valve, and a safety valve are provided on the housing of the heat pipe waste heat recovery unit.

[0013] A further feature is provided: an automatic drain valve is provided at the lower part of the flue gas filter housing.

[0014] The setting is further configured such that the opening degree of the electric three-way regulating valve is controlled by a temperature sensor on the flue located at the outlet of the heat pipe waste heat recovery unit.

[0015] Further configuration: the shell material of the heat pipe waste heat recovery unit is stainless steel or carbon steel, and an external insulation layer is provided; the heat pipe of the heat pipe waste heat recovery unit is composed of a copper alloy shell and an internally filled heat-conducting medium, and is sealed after vacuuming.

[0016] Further configuration: The flue gas filter is a condensing filter, with the internal filter material made of high-efficiency borosilicate glass nanofibers and the outer shell made of stainless steel.

[0017] The compressor is further configured such that its rotor is made of stainless steel and its housing is made of carbon steel.

[0018] Further configuration: The pressure swing adsorber adopts a dual-tower structure, with its own vacuum pump group and automatic control microcomputer; both the dual towers and the vacuum pump are made of stainless steel.

[0019] Further configuration: The hot water circulation pump is made of cast iron or stainless steel.

[0020] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0021] 1. This utility model utilizes a heat pipe waste heat recovery device to fully exchange heat between the high-temperature flue gas discharged from the boiler and the water, effectively recovering a large amount of waste heat from the flue gas and heating the low-temperature water supply into usable hot water. This reduces energy waste, lowers the overall energy consumption of the automobile factory, and saves energy costs.

[0022] 2. This invention separates and purifies carbon dioxide from flue gas through a flue gas filter, compressor, and pressure swing adsorber in a filtration, compression, and purification subsystem. This effectively reduces carbon dioxide emissions from boiler flue gas, helping automobile factories lower their carbon emissions and achieving carbon neutrality goals.

[0023] 3. This utility model is equipped with a centralized control subsystem, which enables remote centralized control and real-time monitoring of system operation through a central control host and various sensors. It can automatically adjust equipment operating parameters; for example, the opening of the electric three-way regulating valve can be automatically adjusted according to the flue gas temperature, ensuring stable and efficient system operation.

[0024] 4. In this utility model, the shell material of the heat pipe waste heat recovery device is stainless steel or carbon steel, and an external insulation layer is set. The heat pipe is composed of a copper alloy shell and an internal heat-conducting medium. It is sealed after vacuuming and has good thermal conductivity and durability. The flue gas filter adopts a condensation filter, and the internal filter material is high-efficiency borosilicate glass nanofiber, which can effectively filter moisture and dust in the flue gas. The shell is made of stainless steel, which has strong corrosion resistance. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0027] Reference numerals: 1. Heat pipe waste heat recovery unit; 2. Hot water circulation pump; 3. Electric three-way regulating valve; 4. Low temperature water supply pipe; 5. Inlet pipe; 6. Outlet pipe; 7. Flue; 8. Water supply pipe; 9. First pipe; 10. Flue gas filter; 11. Compressor; 12. Pressure swing adsorption unit; 13. Second pipe; 14. Third pipe; 15. Central control unit; 16. Pressure transmitter; 17. Pressure gauge; 18. Temperature sensor; 19. Thermometer; 20. Fourth pipe; 21. First automatic exhaust valve; 22. Second automatic exhaust valve; 23. Safety valve; 24. Automatic drain valve. Detailed Implementation

[0028] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] Example

[0032] Reference Figure 1 This utility model discloses a deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory, which includes a heat recovery subsystem, a filtration, compression and purification subsystem and a centralized control subsystem.

[0033] The heat recovery subsystem includes a heat pipe waste heat recovery unit 1, a hot water circulation pump 2, an electric three-way regulating valve 3, a low-temperature water supply pipe 84, an inlet pipe 5, and an outlet pipe 6. The heat pipe waste heat recovery unit 1 has a flue 7 connected to both its air inlet and outlet. The inlet of the electric three-way regulating valve 3 is connected to the low-temperature water supply pipe 84. One outlet of the electric three-way regulating valve 3 is connected to the inlet pipe 5, and the other outlet of the electric three-way regulating valve 3 is connected to the water supply pipe 8. The outlet of the hot water circulation pump 2 is connected to the water supply pipe 8 via a first pipe 9. The inlet pipe 5 is connected to the inlet of the heat pipe waste heat recovery unit 1. The outlet pipe 6 is connected to the outlet of the heat pipe waste heat recovery unit 1, and the other end of the outlet pipe 6 is connected to the inlet of the hot water circulation pump 2.

[0034] The filtration, compression, and purification subsystem includes a flue gas filter 10, a compressor 11, and a pressure swing adsorber 12. The inlet of the flue gas filter 10 is connected to the flue 7 at the outlet of the hot water circulation pump 2. A second pipe 13 connects the outlet of the flue gas filter 10 to the inlet of the compressor 11. A third pipe 14 connects the outlet of the compressor 11 to the inlet of the pressure swing adsorber 12. A fourth pipe 20 is provided at the outlet of the pressure swing adsorber 12.

[0035] The centralized control subsystem includes a central control host 15, a pressure transmitter 16, a pressure gauge 17, a temperature sensor 18, and a thermometer 19. Pressure transmitters 16, pressure gauges 17, temperature sensors 18, and thermometers 19 are installed at the lower sections of the two flues 7 and the water supply pipe 8; pressure gauges 17, temperature sensors 18, and thermometers 19 are installed on the inlet pipe 5 and the outlet pipe 6; and pressure transmitters 16 and pressure gauges 17 are installed on the second pipe 13, the third pipe 14, and the fourth pipe 20.

[0036] The heat pipe waste heat recovery unit 1 is provided with a first automatic exhaust valve 21, a second automatic exhaust valve 22, and a safety valve 23; the flue gas filter 10 is provided with an automatic drain valve 24 at the bottom of its housing.

[0037] In this embodiment, the opening of the electric three-way regulating valve 3 is controlled by the temperature sensor 18 on the flue 7 located at the outlet of the heat pipe waste heat recovery unit 1.

[0038] Pressure transmitters 16 and pressure gauges 17 are installed before and after the flue gas filter 10 to compare the pressure values ​​before and after to determine whether the flue gas filter 10 is clogged and to remind users to clean or replace the filter element. The automatic drain valve 24 installed on it can automatically drain the water adsorbed and collected inside to prevent equipment failure.

[0039] Pressure transmitters 16 and pressure gauges 17 are installed on the pipe sections before and after the compressor 11 and the pressure swing adsorber 12 (including the second pipe 13, the third pipe 14 and the fourth pipe 20) to monitor the flue gas and carbon dioxide pressure in real time.

[0040] In this embodiment, the first automatic exhaust valve 21, the second automatic exhaust valve 22, and the safety valve 23 are used to prevent the heat pipe waste heat recovery unit 1 from operating under overpressure and to automatically discharge internal gas and eliminate gas resistance.

[0041] The hot water circulation pump 2 can be frequency-controlled according to the pressure changes of the hot water at the terminal, so as to save energy. In this utility model, the equipment, temperature signal and pressure signal are all connected to the central control host 15, which can realize remote centralized control.

[0042] In this embodiment, the shell of the heat pipe waste heat recovery unit 1 is made of stainless steel or carbon steel, and an external centrifugal glass wool insulation layer is provided. The heat pipe consists of a copper alloy shell and is filled with a heat-conducting medium with exceptional thermal activity and sensitivity (such as acetone, ammonia, alcohol, etc.), and is divided into 10 sections. -3 ~10 -6 It is formed by vacuum sealing.

[0043] The flue gas filter 10 is a condensing filter, with high-efficiency borosilicate glass nanofiber as the internal filter material and stainless steel as the outer shell.

[0044] The rotor of compressor 11 is made of stainless steel, while the casing can be made of carbon steel.

[0045] The pressure swing adsorber 12 adopts a dual-tower structure, with its own vacuum pump and automatic control microcomputer. It sequentially undergoes adsorption, pressure equalization drop, vacuuming, and pressure equalization rise at different times. Both the dual towers and the vacuum pump are made of stainless steel, which is a conventional technology in the field. Therefore, its working principle and internal structure will not be described in detail here.

[0046] The hot water circulation pump 2 is made of cast iron or stainless steel.

[0047] This utility model applies to small gas-fired boiler room systems in automobile factories. It should be noted that this utility model also applies to gas-fired boiler rooms where the rated thermal power of a single boiler is no more than kW and the total heat load is no more than kW.

[0048] The working principle and beneficial effects of this utility model are as follows:

[0049] The flue gas discharged from the boiler enters the heat pipe waste heat recovery unit 1 for gas-water heat exchange after the pressure and temperature are detected by the pressure transmitter 16 and temperature sensor 18 in the flue 7. After being cooled by heat exchange in the heat pipe waste heat recovery unit 1, the flue gas enters the flue gas filter 10 after the pressure and temperature are detected in the flue 7 again, where the moisture and dust are filtered out. Then it enters the compressor 11 for pressurization. After being pressurized to a suitable pressure, it enters the pressure swing adsorber 12, where the pressure swing adsorber 12 separates and purifies the carbon dioxide in the flue gas, and the rest is discharged as waste gas.

[0050] During this process, low-temperature water flows through the low-temperature water supply pipe 84 and then through the electric three-way regulating valve 3. The temperature sensor 18 on the flue 7 at the outlet of the heat pipe waste heat recovery unit 1 adjusts the opening and closing degree of the electric three-way regulating valve 3 according to the flue gas temperature detected by the heat pipe waste heat recovery unit 1, thereby adjusting the water supply flow rate. This results in part of the water supply entering the heat pipe waste heat recovery unit 1 and part flowing through the water supply pipe 8, merging with the circulating water flowing out of the hot water circulation pump 2 through the first pipe 9. This ensures that the mixed water reaches the set temperature and is then supplied to the required hot water unit.

[0051] This invention utilizes a heat pipe waste heat recovery unit 1 to perform full gas-water heat exchange on the high-temperature flue gas discharged from the boiler, effectively recovering a large amount of waste heat from the flue gas and heating the low-temperature water supply into usable hot water, reducing energy waste, improving the comprehensive energy utilization rate, reducing the overall energy consumption of the automobile factory, and saving energy costs. Through the flue gas filter 10, compressor 11, and pressure swing adsorption unit 12 in the filtration, compression, and purification subsystem, carbon dioxide in the flue gas is separated and purified, effectively reducing carbon dioxide emissions from the boiler flue gas, which helps the automobile factory reduce carbon emissions, meets the goal of carbon neutrality, has positive significance for environmental protection, and is also conducive to enterprises to cope with increasingly stringent environmental regulations and policy requirements.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory, characterized in that, The system includes a heat recovery subsystem and a filtration, compression, and purification subsystem connected together. The heat recovery subsystem includes a heat pipe waste heat recovery unit (1), a hot water circulation pump (2), an electric three-way regulating valve (3), a low-temperature water supply pipe (8)(4), an inlet pipe (5), and an outlet pipe (6). The air inlet and outlet of the heat pipe waste heat recovery unit (1) are both connected to a flue (7). The inlet of the electric three-way regulating valve (3) is connected to the low-temperature water supply pipe (8)(4), one outlet of the electric three-way regulating valve (3) is connected to the inlet pipe (5), and the other outlet of the electric three-way regulating valve (3) is connected to the water supply pipe (8). A first pipe (9) connects the outlet of the hot water circulation pump (2) to the water supply pipe (8). The inlet pipe (5) is connected to the heat pipe. The inlet of the waste heat recovery unit (1) is connected; the outlet pipe (6) is connected to the outlet of the heat pipe waste heat recovery unit (1), and the other end of the outlet pipe (6) is connected to the inlet of the hot water circulation pump (2); the filtration, compression and purification subsystem includes a flue gas filter (10), a compressor (11), and a pressure swing adsorber (12); the inlet of the flue gas filter (10) is connected to the flue (7) located at the outlet of the hot water circulation pump (2); a second pipe (13) is connected between the outlet of the flue gas filter (10) and the inlet of the compressor (11); a third pipe (14) is connected between the outlet of the compressor (11) and the inlet of the pressure swing adsorber (12); and a fourth pipe (20) is provided at the outlet of the pressure swing adsorber (12).

2. The deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, It also includes a centralized control subsystem, which includes a central control host (15), a pressure transmitter (16), a pressure gauge (17), a temperature sensor (18), and a thermometer (19); a pressure transmitter (16), a pressure gauge (17), a temperature sensor (18), and a thermometer (19) are installed at the lower half of the two flues (7) and the water supply pipe (8); a pressure gauge (17), a temperature sensor (18), and a thermometer (19) are installed on the inlet pipe (5) and the outlet pipe (6); a pressure transmitter (16) and a pressure gauge (17) are installed on the second pipe (13), the third pipe (14), and the fourth pipe (20).

3. The deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, The heat pipe waste heat recovery unit (1) is equipped with a first automatic exhaust valve (21), a second automatic exhaust valve (22), and a safety valve (23).

4. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory, as described in claim 1, is characterized in that... An automatic drain valve (24) is provided at the lower part of the housing of the flue gas filter (10).

5. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, The opening degree of the electric three-way regulating valve (3) is controlled by a temperature sensor (18) on the flue (7) located at the outlet of the heat pipe waste heat recovery unit (1).

6. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, The shell of the heat pipe waste heat recovery unit (1) is made of stainless steel or carbon steel and is provided with an external insulation layer; the heat pipe of the heat pipe waste heat recovery unit (1) is composed of a copper alloy shell and a heat-conducting medium filled inside, and is sealed after vacuuming.

7. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, The flue gas filter (10) is a coagulation filter, with high-efficiency borosilicate glass nanofiber as the internal filter material and stainless steel as the external shell.

8. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, The rotor of the compressor (11) is made of stainless steel, and the casing is made of carbon steel.

9. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, The pressure swing adsorber (12) adopts a dual-tower structure and comes with its own vacuum pump group and automatic control microcomputer; both the dual towers and the vacuum pump are made of stainless steel.

10. A deep waste heat recovery and carbon neutralization system for flue gas from a small gas-fired boiler room in an automobile factory according to claim 1, characterized in that, The hot water circulation pump (2) is made of cast iron or stainless steel.

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