System for coupling biomass gasifier with thermal power plant
By coupling a biomass gasification furnace with a thermal power plant system, and utilizing equipment such as drying, gasification, steam boilers, and air preheaters, efficient power generation of biomass and thermal power plants is achieved, solving the problem of high carbon emissions in traditional thermal power plants and improving thermal energy utilization efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HEPU ENERGY ENVIRONMENTAL TECHNOLOGY CO LTD
- Filing Date
- 2025-05-15
- Publication Date
- 2026-05-05
AI Technical Summary
Traditional coal-fired power plants are mainly coal-fired, resulting in high carbon emissions. Existing biomass gasification and coal-fired power plant coupling methods mostly adopt simple co-firing, which have problems such as small scale, low efficiency and poor economic performance. How to fully couple biomass power generation with coal-fired power plants to reduce carbon emissions and insufficient heat energy utilization is a key question.
Design a biomass gasification furnace coupled with a thermal power plant system, including a drying device, a biomass gasification furnace, a steam boiler, an air preheater, and a heat exchanger. The system produces fuel gas by drying biomass materials, and generates electricity by coupling the heat from the fuel gas and flue gas. The system also utilizes thermal energy in a gradient manner to produce steam and activated carbon, thereby reducing carbon emissions.
It has achieved efficient coupling power generation between biomass gasification furnace and traditional power plant boiler and main steam turbine, which has reduced carbon emissions, improved thermal energy utilization efficiency, and reduced carbon emissions from coal-fired power plants.
Smart Images
Figure CN224199333U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of biomass and coal-fired power generation, specifically relating to a system of a biomass gasifier coupled with a thermal power plant. Background Technology
[0002] Traditional coal-fired power plants primarily use coal, resulting in high carbon emissions and facing severe environmental pressures. Biomass energy, as a renewable energy source, can convert biomass into combustible gas (syngas) through gasification technology. However, relying solely on biomass gasification for power generation suffers from small scale, low efficiency, and poor economic viability. Current technologies often couple biomass gasification with coal-fired power plants using simple co-firing methods (such as directly feeding biomass into the boiler), but these methods have the following drawbacks:
[0003] How to fully couple biomass power generation with thermal power plants to reduce carbon emissions and fully utilize thermal energy has become a concern for technical personnel. Utility Model Content
[0004] (I) Purpose of the utility model
[0005] The purpose of this invention is to provide a system for coupling a biomass gasification furnace with a thermal power plant, so as to reduce carbon emissions from the thermal power plant and make full use of thermal energy.
[0006] (II) Technical Solution
[0007] To address the aforementioned problems, the first aspect of this utility model provides a system for coupling a biomass gasification furnace with a thermal power plant, the thermal power plant comprising a power plant boiler, a main steam turbine, and a generator, including:
[0008] Drying equipment used for drying biomass materials;
[0009] A biomass gasification furnace is used to produce fuel gas from the dried biomass material.
[0010] A steam boiler has its gas inlet connected to the gas outlet of the biomass gasification furnace for burning gas to produce steam; the steam boiler is equipped with a heat exchanger; the inlet of the heat exchanger's heat absorption section is connected to the condensate pipeline of the main steam turbine, and the outlet of the heat exchanger's heat absorption section is connected to the main steam turbine or power plant boiler, for heating the condensate in the condensate pipeline into steam and supplying it to the main steam turbine or power plant boiler;
[0011] An air preheater, connected to the steam boiler, is used to preheat air from the flue gas of the steam boiler and to supply the preheated air to the steam boiler.
[0012] Furthermore, the flue gas outlet of the steam boiler is equipped with a first flue gas pipeline;
[0013] The heat exchanger's heat release section is configured on the furnace of the steam boiler and / or on the first flue gas pipeline.
[0014] Furthermore, the inlet of the heat release section of the air preheater is connected to the outlet of the first flue gas pipeline, and the outlet of the heat release section of the air preheater is connected to the chimney; the inlet of the heat absorption section of the air preheater is connected to the outside air, and the outlet of the heat absorption section of the air preheater is connected to the air inlet of the steam boiler.
[0015] Furthermore, the power plant boiler is equipped with a reheater, the steam outlet of which is connected to the steam inlet of the intermediate-pressure cylinder of the main turbine through a reheat hot section pipeline; the steam inlet of which is connected to the return steam outlet of the high-pressure cylinder of the main turbine through a reheat cold section pipeline.
[0016] The heat exchanger's heat absorption section outlet is connected to the reheat hot section pipeline, the reheat cold section pipeline, and the low-pressure cylinder of the main steam turbine, respectively, for the steam boiler to transport the produced steam to the reheat hot section, the reheat cold section, or the low-pressure cylinder according to the pressure and temperature of the steam.
[0017] Furthermore, the biomass gasification furnace is also used to prepare activated carbon using the biomass material and air or steam.
[0018] Furthermore, the outlet of the heat exchanger's heat absorption section is also connected to the steam inlet of the biomass gasifier to provide the required steam to the biomass gasifier.
[0019] Furthermore, the outlet of the heat absorption section of the air preheater is connected to the air inlet of the biomass gasifier, and is used to preheat the air required for the biomass gasifier to produce activated carbon.
[0020] Furthermore, the biomass gasification furnace is equipped with an activated carbon flue gas outlet and an activated carbon outlet;
[0021] The activated carbon flue gas outlet is connected to the drying device and is used to dry the biomass material using the activated carbon flue gas generated during the preparation of activated carbon.
[0022] Furthermore, a gas fan is provided between the gas outlet of the biomass gasifier and the gas inlet of the steam boiler.
[0023] Furthermore, the condensate pipeline is located downstream of the steam outlet of the low-pressure cylinder of the main steam turbine, and the condensate pipeline is sequentially equipped with a condenser, a condensate pump, a low-pressure heater, and a deaerator.
[0024] The heat exchanger’s absorber section inlet is connected to the condensate pipeline downstream of the deaerator, and a feed water pump is provided between the heat exchanger’s absorber section inlet and the condensate pipeline.
[0025] (III) Beneficial Effects
[0026] The above-mentioned technical solution of this utility model has the following beneficial technical effects:
[0027] In this application, biomass materials are gasified in a biomass gasifier to produce fuel gas; a steam boiler burns the fuel gas and exchanges heat with condensate downstream of the main steam turbine to produce steam, which is then supplied to the power generation system of a thermal power plant; an air preheater utilizes the residual heat in the flue gas to preheat the air required by the steam boiler. This achieves coupled power generation between the biomass gasifier and a traditional power plant boiler and main steam turbine, and utilizes the heat from the flue gas generated by the combustion of the fuel gas in a gradient manner; in addition to CO, the fuel gas also contains hydrogen, reducing carbon emissions compared to traditional coal-fired power plants. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the structure of a biomass gasification furnace coupled with a thermal power plant in one embodiment of this application;
[0029] Figure label:
[0030] 1. High-pressure cylinder; 2. Medium-pressure cylinder; 3. Low-pressure cylinder; 4. Condenser; 5. Condensation pump; 6. Low-pressure heater; 7. Deaerator; 8. Chimney; 10. Drying device; 11. Biomass gasifier; 12. Steam boiler; 13. Air preheater; 14. Heat exchanger; 15. Feed water pump; 16. Gas fan; G. Generator.
[0031] 17. Condensate pipeline; 18. Reheat hot section pipeline; 19. Reheat cold section pipeline; 20. First flue gas pipeline; 21. Second flue gas pipeline; 22. Pressure regulating and temperature regulating device. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.
[0033] Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0034] like Figure 1As shown, one embodiment of this application proposes a system for a biomass gasification furnace coupled to a thermal power plant, the thermal power plant having a conventional power plant boiler (not shown) that burns coal to produce main steam, a main steam turbine, and a generator G, including:
[0035] The drying device 10 is used to dry biomass materials; optionally, the system is also equipped with a biomass crushing device or a granulation device. The biomass materials are transported to the drying device 10 for drying after being crushed or granulated.
[0036] Biomass gasifier 11 is used to produce fuel gas from dried biomass materials.
[0037] The gas inlet of the steam boiler 12 is connected to the gas outlet of the biomass gasifier 11 for burning gas to produce steam.
[0038] The steam boiler 12 is equipped with a heat exchanger 14. Gas is burned in the furnace of the steam boiler 12, and the generated flue gas is discharged through the first flue gas pipe 20. Optionally, the heat-releasing section of the heat exchanger 14 is located on the furnace. Optionally, since the flue gas near the end of the first flue gas pipe 20 connected to the flue gas outlet of the steam boiler 12 has a higher temperature, the heat-releasing section of the heat exchanger 14 can be configured separately on the furnace or on the first flue gas pipe 20, or both. The inlet of the heat-absorbing section of the heat exchanger 14 is connected to the condensate pipe 17 of the main steam turbine, and the outlet of the heat-absorbing section of the heat exchanger 14 is connected to the main steam turbine or power plant boiler, used to heat the condensate in the condensate pipe 17 into steam and supply it to the main steam turbine or power plant boiler.
[0039] The air preheater 13 is used to preheat air using the flue gas from the steam boiler 13 and supply the preheated air to the steam boiler.
[0040] In this application, biomass materials are gasified in a biomass gasifier 11 to produce fuel gas. High-temperature flue gas generated by the combustion of the fuel gas in a steam boiler 12 exchanges heat with the condensate in the condensate pipe 17 of the main steam turbine to produce steam. This steam is supplied to the power plant's power generation system (power plant boiler or main steam turbine). The remaining heat in the flue gas after heat exchange is used in an air preheater 13 to preheat the air required by the biomass gasifier 11. This achieves coupled power generation between the biomass gasifier 11 and a traditional power plant boiler and main steam turbine, and utilizes the heat from the combustion of the fuel gas in a gradient manner. In addition to CO, the fuel gas also contains hydrogen, reducing carbon emissions compared to traditional coal-fired power plants.
[0041] Specifically, the drying device 10 in this application can be an existing biomass fuel dryer, capable of drying the moisture content of the biomass material to below 20%. Biomass materials include sawdust, bamboo shavings, crop straw, tree leaves and stems, etc. The biomass fuel dryer can be a drum type, having an outer shell and a rotating drum inside the shell. Multiple spiral lifting plates are arranged along the inner wall of the rotating drum. As the rotating drum rotates, the material is continuously lifted by the lifting plates at one end of the drum and dried under the action of hot air. With the rotation of the rotating drum and the cooperation of the spiral lifting plates, the dried biomass material is spiraled out from the other end of the rotating drum. The dried biomass material can be transported to the biomass gasifier 11 by a transport vehicle, or it can be directly transported to the biomass gasifier 11 via a conveyor belt located between the drying device 10 and the biomass gasifier 11. Optionally, the drying device 10 is located inside the biomass gasifier 11.
[0042] The biomass gasifier 11 in this application can be any existing biomass gasifier 11 that can produce both fuel gas and activated carbon. It can convert all of the biomass material into fuel gas, or partially into activated carbon, as needed. Optionally, the main structure and principle of an existing biomass gasifier 11 are as follows: a pyrolysis gasification reactor and an activation reactor are arranged vertically and can be opened and closed, and there are required material inlet, air inlet, steam inlet, fuel gas outlet, activated carbon outlet, and activated carbon flue gas outlet.
[0043] The pyrolysis-gasification reactor has a connected pyrolysis zone and a gasification zone. Biomass undergoes low-oxygen combustion and pyrolysis in the pyrolysis zone to produce tar and pyrolysis gas. This tar and pyrolysis gas are then introduced into the gasification zone, where they undergo cracking, oxidation, and reduction reactions to produce fuel gas containing CO and H2. The heat released during the low-oxygen combustion of biomass during oxidation provides some heat for the pyrolysis process and subsequent activation processes. The pyrolysis-gasification reactor can also use an airflow (inert gas / air or steam) to suspend and agitate the material, allowing it to flow sequentially through the pyrolysis and gasification zones. The temperature in the pyrolysis zone is controlled between 300 and 700°C, where biomass is pyrolyzed under oxygen-deficient or low-oxygen conditions to produce unactivated carbon matrix. The gasification zone introduces a limited amount of oxygen or steam into the carbon matrix to produce fuel gas. The chemical transformations involved mainly include:
[0044] C+H2O→CO+H2; C+CO2→2CO.
[0045] The activation reactor is located below the pyrolysis gasification reactor. When the steam boiler 12 requires a larger amount of fuel gas, the pyrolysis gasification reactor and the activation reactor are closed. When the steam boiler 12 requires a smaller amount of fuel gas, the pyrolysis gasification reactor and the activation reactor are opened, allowing some of the carbon matrix produced by the pyrolysis gasification reactor to enter the activation reactor from its bottom. Then, the pyrolysis gasification reactor and the activation reactor are closed. High-temperature steam (800-900℃) or air is introduced into the activation reactor, and the pores of the carbon matrix are expanded through an oxidation reaction to obtain activated carbon. The activated carbon can be sold as an adsorbent. The main chemical transformation involved is: C + H₂O → CO + H₂ (pore formation).
[0046] The steam boiler 12 in this application can be any existing boiler capable of producing steam by burning gas.
[0047] In one embodiment of this application, the air preheater 13 includes: a shell and a tube bundle; the tube bundle is disposed inside the shell, and air inlets and air outlets at both ends of the tube bundle extend outside the shell, with the air inlets communicating with the outside air; the shell has a flue gas inlet and a flue gas outlet. The flue gas inlet of the air preheater 13 is connected to the outlet of the first flue gas pipeline 20, and the accommodating space formed by the outer wall of the tube bundle and the inner wall of the shell is used to circulate flue gas and preheat the air using the flue gas; the preheated air is supplied to the biomass gasifier 11 and the steam boiler 12.
[0048] Specifically, the inlet (flue gas inlet) of the heat release section of the air preheater 13 is connected to the outlet of the first flue gas pipeline 20, and the outlet (flue gas outlet) of the heat release section of the air preheater 13 is connected to the chimney 8; the inlet (air inlet) of the heat absorption section of the air preheater 13 is connected to the outside air, and the outlet (air outlet) of the heat absorption section of the air preheater 13 is connected to the air inlet of the steam boiler 12.
[0049] In one embodiment, a reheater (not shown) is provided on a conventional power plant boiler. The steam outlet of the reheater is connected to the steam inlet of the intermediate-pressure cylinder 2 of the main turbine through a reheat hot section pipeline 18. The steam inlet of the reheater is connected to the return steam outlet (or extraction steam outlet) of the high-pressure cylinder 1 of the main turbine through a reheat cold section pipeline 19.
[0050] The outlet of the heat exchanger 14's absorption section is connected to the reheat hot section pipeline 18, the reheat cold section pipeline 19, and the low-pressure cylinder 3 of the main steam turbine, respectively (these three connections are...). Figure 1 (Not shown in the image) The pressure and temperature of the produced steam can be adjusted by the pressure and temperature regulating device 22 located at the outlet of the heat absorption section of the heat exchanger 14, and then transported to the hot section of the reheater (temperature above 500°C), the cold section of the reheater (temperature around 300°C), or the low-pressure cylinder 3.
[0051] In one embodiment, when the steam boiler 12 requires a small amount of fuel gas, the biomass gasifier 11 is also used to prepare activated carbon using biomass materials, air, and steam. In the biomass gasification and activated carbon preparation process, the products, in addition to CO, include H2 and activated carbon. The CO and H2 are used for combustion, and the activated carbon is used as a fuel or adsorbent, effectively reducing carbon emissions from the power plant.
[0052] Preferably, the outlet of the heat exchanger 14 is also connected to the steam inlet of the biomass gasifier 11 to provide the steam required for the biomass gasifier 11 to produce activated carbon.
[0053] Preferably, the outlet of the heat absorption section of the air preheater 13 is connected to the air inlet of the biomass gasifier 11 to preheat the air required for the preparation of activated carbon in the biomass gasifier 11, and further utilize the heat of the flue gas in a gradient manner.
[0054] Furthermore, the biomass gasifier 11 generates activated carbon flue gas during activated carbon preparation. This flue gas primarily contains CO and H2; therefore, the biomass gasifier 11 is equipped with both an activated carbon flue gas outlet and an activated carbon outlet. Activated carbon is removed from the activated carbon outlet and stored. The activated carbon flue gas outlet is located on the outer shell of the activation reaction chamber and is connected to the drying device 10 via a second flue gas pipeline 21. The activated carbon flue gas generated during activated carbon preparation, along with hot air, is used to dry the biomass material.
[0055] The flue gas from the steam boiler 12, after being cooled by the air preheater 13, can be directly sent to the existing chimney 8 of the power plant for treatment and discharge, or it can be treated separately by the tail-end environmental protection device and then discharged into the atmosphere through another chimney. Optionally, the flue gas discharged from the drying device 10 for drying biomass materials can be treated in the same way.
[0056] Preferably, a gas fan 16 is provided between the gas outlet of the biomass gasifier 11 and the gas inlet of the steam boiler 12.
[0057] Furthermore, the condensate pipeline 17 is located downstream of the steam outlet of the low-pressure cylinder 3 of the main steam turbine; the condensate pipeline 17 is sequentially equipped with a condenser 4, a condensate pump 5, a low-pressure heater 6, and a deaerator 7.
[0058] The inlet of the heat exchanger 14's absorber section is connected to the condensate pipeline 17 downstream of the deaerator 7. A feedwater pump 15 is installed between the inlet of the heat exchanger 14's absorber section and the condensate pipeline 17 to use the condensate in the condensate pipeline 17 as feedwater for the heat exchanger 14. Preferably, a portion of the condensate in the condensate pipeline 17 enters the heat exchanger 14, while the other portion flows into the main feedwater of the power plant boiler and enters the power plant boiler.
[0059] In addition, the biomass gasification furnace coupled to the thermal power plant system in this application also involves some pipelines for controlling air, flue gas, water, steam, etc., as well as control devices for the opening and closing of the pipelines, flow rate, pressure and temperature, which will not be described here.
[0060] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A system for coupling a biomass gasifier (11) to a thermal power plant, the thermal power plant having a power plant boiler, a main steam turbine, and a generator (G), characterized in that, include: Drying device (10) is used for drying biomass materials; A biomass gasifier (11) is used to produce fuel gas from the dried biomass material; A steam boiler (12) has its gas inlet connected to the gas outlet of the biomass gasifier (11) for burning gas to produce steam; the steam boiler (12) is equipped with a heat exchanger (14); the inlet of the heat exchanger (14) is connected to the condensate pipeline (17) of the main steam turbine, and the outlet of the heat exchanger (14) is connected to the main steam turbine or power plant boiler for heating the condensate in the condensate pipeline (17) into steam and supplying it to the main steam turbine or power plant boiler; An air preheater (13) is connected to the steam boiler (12) and is used to preheat air using the flue gas from the steam boiler (12) and to supply the preheated air to the steam boiler.
2. The system according to claim 1, wherein, The flue gas outlet of the steam boiler (12) is provided with a first flue gas pipeline (20); The heat exchanger (14) has its heat release section located inside the furnace of the steam boiler (12) and / or located on the first flue gas pipeline (20).
3. The system according to claim 2, wherein, The inlet of the heat release section of the air preheater (13) is connected to the outlet of the first flue gas pipeline (20), and the outlet of the heat release section of the air preheater (13) is connected to the chimney (8); the inlet of the heat absorption section of the air preheater (13) is connected to the outside air, and the outlet of the heat absorption section of the air preheater (13) is connected to the air inlet of the steam boiler (12).
4. The system according to claim 1, wherein, The power plant boiler is equipped with a reheater, and the steam outlet of the reheater is connected to the steam inlet of the intermediate pressure cylinder (2) of the main steam turbine through the reheat hot section pipeline (18); the steam inlet of the reheater is connected to the return steam outlet of the high pressure cylinder (1) of the main steam turbine through the reheat cold section pipeline (19). The heat exchanger (14) has its heat absorption section outlet connected to the reheat hot section pipeline (18), the reheat cold section pipeline (19), and the low-pressure cylinder (3) of the main steam turbine, respectively, so that the steam boiler (12) can transport the steam produced to the reheat hot section, the reheat cold section, or the low-pressure cylinder (3) according to the pressure and temperature of the steam produced.
5. The system according to claim 1, wherein, The biomass gasifier (11) is also used to prepare activated carbon using the biomass material and air or steam.
6. The system according to claim 5, wherein, The heat exchanger (14) has its heat absorption section outlet connected to the steam inlet of the biomass gasifier (11) to provide the required steam to the biomass gasifier (11).
7. The system according to claim 5, wherein, The outlet of the heat absorption section of the air preheater (13) is connected to the air inlet of the biomass gasifier (11) to preheat the air required for the biomass gasifier (11) to prepare activated carbon.
8. The system according to claim 7, wherein, The biomass gasifier (11) is equipped with an activated carbon flue gas outlet and an activated carbon outlet; The activated carbon flue gas outlet is connected to the drying device (10) and is used to dry the biomass material using the activated carbon flue gas generated during the preparation of activated carbon.
9. The system according to claim 1, wherein, A gas blower (16) is provided between the gas outlet of the biomass gasifier (11) and the gas inlet of the steam boiler (12).
10. The system according to claim 1, wherein, The condensate pipeline (17) is located downstream of the steam outlet of the low-pressure cylinder (3) of the main steam turbine. The condensate pipeline (17) is provided with a condenser (4), a condensate pump (5), a low-pressure heater (6), and a deaerator (7) in sequence. The heat exchanger (14) has its heat absorption section inlet connected to the condensate pipeline (17) downstream of the deaerator (7), and a water supply pump (15) is provided between the heat exchanger (14) heat absorption section inlet and the condensate pipeline (17).