Biomass gasifier jacketed circulating water heat recovery system coupled with steam boiler

Abstract

This utility model discloses a circulating water heat recovery system for a biomass gasifier jacket coupled with a steam boiler, relating to the field of biomass gasifier technology. The gasifier body has a water-cooled jacket, a circulating water outlet, and a circulating water inlet. The water inlet of the first heat exchange channel in the heat exchanger and the water inlet of the first heat exchange channel in the air preheater are both connected to the circulating water outlet; the water outlet of the first heat exchange channel and the water outlet of the first heat exchange channel are both connected to the circulating water inlet; the flue gas outlet of the biomass gas steam boiler is connected to the flue gas inlet of the energy-saving device; the water supply pump outlet is connected to the water inlet of the second heat exchange channel in the heat exchanger; the water outlet of the second heat exchange channel is connected to the water inlet of the water-cooled heat exchange pipeline in the energy-saving device; the blower outlet is connected to the second air inlet of the heat exchange channel in the air preheater, and the second air outlet of the heat exchange channel is connected to the air inlet of the biomass gas burner in the biomass gas steam boiler. This utility model realizes the coupling of the circulating water of the biomass gasifier with the water and air supply of the biomass gas boiler, reducing the boiler's gas consumption.

Description

Technical Field

[0001] This utility model relates to the field of biomass gasification furnace technology, and in particular to a biomass gasification furnace jacketed circulating water heat recovery system coupled with a steam boiler. Background Technology

[0002] Biomass energy, with its carbon neutrality and ability to ensure energy security, is increasingly being used by businesses to replace existing fossil fuels. Biomass gasification technology, which converts biomass into fuel gas, boasts wide applicability and environmental friendliness, making it a growing trend in biomass energy utilization in recent years. However, biomass gasification technology suffers from low thermal efficiency, thus necessitating improvements in the overall thermal efficiency of biomass gasification systems. Existing jacketed circulating water systems for biomass gasifiers still present numerous challenges.

[0003] Biomass is gasified into biomass fuel gas in a gasifier, which is then used in a biomass gas steam boiler to supply steam. However, in the field of biomass gasification combustion for steam supply, there are both gasifier systems and boiler systems. In particular, the gasifier jacket water circulation system and the gasifier system are independent of each other.

[0004] During operation, biomass gasifiers experience significant heat loss, resulting in a biomass gasification efficiency of no more than 75%. In contrast, direct-fired biomass boilers can achieve a thermal efficiency of 88%. Therefore, the overall thermal efficiency of biomass energy utilization technology, which involves gasifying biomass into fuel gas through a gasifier, is relatively low.

[0005] The gasifier body consists of two steel cylinders, an inner and an outer one, with a jacket space between them. Gasifier circulating water enters from the lower part of the jacket, absorbs heat from the inner cylinder of the gasifier body, and then flows out from the upper part of the jacket. This circulating water absorbs heat from the inner cylinder during gasifier operation, protecting the inner steel cylinder from high-temperature damage. However, the outlet temperature of the circulating water in the biomass gasifier jacket is 65-90℃, which is considered low-to-medium temperature waste heat within a steam supply energy station and cannot be directly supplied externally. Existing jacket circulating water systems typically use cooling towers or water tanks to dissipate the heat to the external environment, reducing the temperature to 45-55℃, resulting in wasted heat energy. This is a major factor contributing to the low gasification efficiency of biomass gasification systems.

[0006] The economizer in the biomass gas steam boiler system is cooled by room temperature water (20℃), which causes highly corrosive condensate to form in the economizer due to the high temperature flue gas from the boiler. This leads to corrosion of the economizer and a shorter lifespan.

[0007] Therefore, how to provide a jacketed circulating water heat recovery system for biomass gasifiers coupled with steam boilers, which can organically combine plate heat exchangers and air preheaters, so that the circulating water of biomass gasifiers can be coupled with the water and air supply of biomass gas boilers, can achieve the purpose of cooling the circulating water of gasifiers, and can also increase the temperature of boiler feedwater and air supply, thereby reducing boiler gas consumption and improving the overall thermal efficiency of biomass energy stations, is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0008] In view of this, the present invention proposes a biomass gasification furnace jacket circulating water heat recovery system coupled with a steam boiler, aiming to solve at least one of the above-mentioned technical problems.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] This utility model provides a biomass gasification furnace jacketed circulating water heat recovery system coupled with a steam boiler, including a gasification furnace body, a heat exchanger, an air preheater, a biomass gas steam boiler, an energy saver, a water supply pump, and a blower.

[0011] The gasifier body has a water-cooled jacket and a circulating water outlet and a circulating water inlet connected to the water-cooled jacket; the water inlet of the first heat exchange channel in the heat exchanger and the water inlet of the first heat exchange channel in the air preheater are both connected to the circulating water outlet through pipelines; the water outlet of the first heat exchange channel and the water outlet of the first heat exchange channel are both connected to the circulating water inlet through pipelines.

[0012] The flue gas outlet of the biomass gas steam boiler is connected to the flue gas inlet of the economizer via a pipeline; the water outlet of the water supply pump is connected to the inlet of the second heat exchange channel in the heat exchanger via a pipeline; the outlet of the second heat exchange channel is connected to the inlet of the water-cooled heat exchange pipeline in the economizer used for heat exchange with flue gas via a pipeline; the blower outlet is connected to the inlet of the second heat exchange channel in the air preheater via a pipeline, and the outlet of the second heat exchange channel is connected to the air inlet of the biomass gas burner of the biomass gas steam boiler via a pipeline.

[0013] In the biomass gasification furnace jacketed circulating water heat recovery system of this utility model of coupled steam boiler, the water supply pump supplies softened water to the biomass gas steam boiler, and the blower supplies air to the biomass gas burner of the biomass gas steam boiler; medium heat exchange can occur between the first heat exchange channel and the second heat exchange channel in the heat exchanger; medium heat exchange can also occur between the first heat exchange channel and the second heat exchange channel in the air preheater. The high-temperature circulating water in the water-cooled jacket exchanges heat with the boiler's ambient temperature supply water through the heat exchanger, transferring heat from the jacketed circulating water to the boiler supply water, thus achieving the purpose of cooling the jacketed circulating water and simultaneously increasing the boiler supply water temperature, thereby reducing the fuel consumption for boiler heating water and improving boiler thermal efficiency. The high-temperature circulating water in the water-cooled jacket exchanges heat with the ambient air required by the biomass gas burner in the biomass gas steam boiler through the air preheater. The heat from the jacket circulating water is transferred to the boiler air, achieving the purpose of cooling the jacket circulating water and simultaneously increasing the temperature of the air entering the boiler. This reduces the fuel consumption for heating ambient air and improves the boiler's thermal efficiency. The coupling of these two pathways improves the system's regulation performance. The flow rate of the jacket circulating water entering the heat exchanger and air preheater can be adjusted according to the amount of softened water used in the boiler, maximizing the utilization of the jacket circulating water's heat. Furthermore, the boiler feedwater, heated after flowing through the heat exchanger, enters the economizer's water-cooled heat exchange pipes to continue exchanging heat with the boiler flue gas, further increasing the boiler feedwater temperature. Because the boiler feedwater entering the economizer's water-cooled heat exchange pipes is heated water after heat exchange, the generation of highly corrosive condensate from the boiler flue gas within the economizer is reduced, thus extending the economizer's service life. This invention combines a plate heat exchanger and an air preheater to couple the circulating water of the biomass gasifier with the water and air supply of the biomass gas boiler. This achieves both cooling of the circulating water in the gasifier and increasing the temperature of the boiler feedwater and air supply, thereby reducing boiler gas consumption and improving the overall thermal efficiency of the biomass energy station.

[0014] As a further improvement to the above technical solution, it also includes a circulating water pump and a pipeline assembly; the pipeline assembly includes a first pipeline and a second pipeline;

[0015] The inlet of the first heat exchange channel in the heat exchanger and the inlet of the first heat exchange channel in the air preheater are both connected to the circulating outlet through the first pipeline; the outlet of the first heat exchange channel and the outlet of the first heat exchange channel are both connected to the circulating inlet through the second pipeline; the circulating water pump is installed on the first pipeline or the second pipeline to drive the circulating water to perform circulating heat exchange.

[0016] The beneficial effects of the above technical solution are: the circulating water pump is used to drive and control the circulation speed of the circulating water in the water-cooled jacket, thereby achieving effective control of boiler water supply and air supply.

[0017] As a further improvement to the above technical solution, the first pipeline includes a first main pipeline, a first branch pipeline, and a second branch pipeline;

[0018] One end of the first main pipeline is connected to and communicates with the circulating water inlet, and the other end of the first main pipeline is connected to and communicates with one end of the first branch pipeline and the second branch pipeline. The other ends of the first branch pipeline and the second branch pipeline are connected to and communicate with the inlet of the first heat exchange channel and the inlet of the first heat exchange channel, respectively. The circulating water pump is installed on the first main pipeline. A valve is installed on the first branch pipeline, and a valve is installed on the second branch pipeline.

[0019] The beneficial effects of the above technical solution are: valve one is used to control the amount of circulating water entering the first heat exchange channel in the heat exchanger, thereby regulating the boiler water supply temperature; valve two is used to control the amount of circulating water entering the first heat exchange channel in the air preheater, thereby regulating the boiler air supply temperature; valve one and valve two, together with the circulating water pump, jointly regulate the boiler water and air supply, which can achieve flexible control.

[0020] As a further improvement to the above technical solution, a cooling tower is also included, wherein the circulating water outlet is connected to the water inlet of the cooling tower through a pipeline to drain water; and the water outlet of the cooling tower is connected to the circulating water inlet through a pipeline to return water.

[0021] The beneficial effects of the above technical solution are: the cooling tower serves as a backup cooling facility for the high-temperature circulating water in the jacket. When the biomass gas steam boiler is shut down or the load is low, the cooling tower is turned on to cool the high-temperature circulating water in the jacket, ensuring that the circulating water in the jacket can absorb the heat of the inner cylinder during the operation of the gasifier body, thus protecting the inner steel cylinder from high-temperature damage.

[0022] As a further improvement to the above technical solution, the pipeline assembly further includes a third pipeline, a fourth pipeline, and a fifth pipeline; one end of the third pipeline is connected to and communicates with the circulating water outlet, and the other end is connected to and communicates with the water inlet of the cooling tower; a valve three is installed on the first main pipeline corresponding to the circulating water pump and one end of the first main pipeline; one end of the fourth pipeline is connected to and communicates with the water outlet of the cooling tower, and the other end of the fourth pipeline is connected to and communicates with the position on the first main pipeline corresponding to the position between the circulating water pump and the valve three; one end of the fifth pipeline is connected to and communicates with the position on the first main pipeline corresponding to the position between the circulating water pump and the other end of the first main pipeline, and the other end of the fifth pipeline is connected to and communicates with the second pipeline; a valve four is installed on the fourth pipeline; and a valve five is installed on the fifth pipeline.

[0023] The beneficial effects of the above technical solution are as follows: When the biomass gas steam boiler is shut down, valves three, one and two can be closed, and valves four and five can be opened. The high-temperature circulating water output from the circulating water outlet enters the cooling tower for cooling through the third pipeline. Driven by the circulating water pump, the cooled circulating water flows back to the second pipeline through the outlet of the cooling tower, the fourth pipeline, the circulating water pump, and the fifth pipeline in sequence, and then returns to the water-cooled jacket through the circulating water inlet.

[0024] As a further improvement to the above technical solution, a water tank is also included, wherein the first inlet of the water tank is connected to and communicates with the circulating outlet for water storage; one end of the first main pipeline is connected to and communicates with the first outlet of the water tank; and one end of the third pipeline is connected to and communicates with the second outlet of the water tank.

[0025] The beneficial effects of the above technical solution are: the water tank serves as a temporary storage for high-temperature circulating water, ensuring sufficient and stable circulating water within the water-cooling jacket.

[0026] As a further improvement to the above technical solution, the water tank is provided with a second water inlet for replenishing circulating water.

[0027] The beneficial effect of the above technical solution is that when the water tank is not full, water can be added to the water tank through the second water inlet.

[0028] As a further improvement to the above technical solution, there are multiple circulating water pumps, which are connected in parallel.

[0029] The beneficial effects of the above technical solution are: the parallel setting of multiple circulating water pumps can improve the control flexibility of heat exchange efficiency, thereby adapting to various working conditions of steam boilers and biomass gasification furnaces.

[0030] As a further improvement to the above technical solution, the pipeline assembly further includes a sixth pipeline and a bypass pipeline; one end of the sixth pipeline is connected to and communicates with the outlet of the water supply pump, and the other end of the sixth pipeline is connected to and communicates with the inlet of the second heat exchange channel; a valve six is ​​installed on the sixth pipeline; one end of the bypass pipeline is connected to and communicates with the outlet of the water supply pump, and the other end of the bypass pipeline is connected to and communicates with the inlet of the water-cooled heat exchange pipeline inside the energy saver; a valve seven is installed on the bypass pipeline.

[0031] The beneficial effects of the above technical solution are as follows: During operation, the water supply pump drives the boiler feedwater to be transported sequentially through the sixth pipeline, the inlet of the second heat exchange channel in the heat exchanger, the pipeline, and the water-cooled heat exchange pipeline in the economizer to the biomass gas steam boiler; when the heat exchanger is closed, valve six is ​​closed and valve seven is opened, and the water supply pump drives the boiler feedwater to enter the water-cooled heat exchange pipeline in the economizer through the bypass pipeline, and then supply water to the boiler.

[0032] As a further improvement to the above technical solution, the inlet of the water supply pump is connected to the boiler softened water supply pipeline.

[0033] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a biomass gasification furnace jacketed circulating water heat recovery system coupled with a steam boiler, which has the following advantages and beneficial effects:

[0034] This invention, through the use of a heat exchanger and an air preheater, couples the circulating water of the biomass gasifier with the water and air supply of the biomass gas boiler. This not only achieves the purpose of cooling the circulating water in the gasifier but also increases the temperature of the boiler feedwater and air supply, thereby reducing boiler gas consumption and improving the overall thermal efficiency of the biomass energy station. The increased boiler feedwater temperature entering the economizer also reduces the formation of highly corrosive condensate from the boiler flue gas within the economizer, lowering the risk of economizer corrosion and extending its lifespan. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 This utility model presents a schematic diagram of the biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler.

[0037] In the diagram: 1. Gasifier body; 101. Water-cooled jacket; 102. Circulating water outlet; 103. Circulating water inlet; 2. Heat exchanger; 3. Air preheater; 4. Biomass gas steam boiler; 41. Biomass gas burner; 411. Air inlet; 412. Biomass gas inlet; 5. Eco-friendly device; 51. Flue gas duct; 52. Water inlet of water-cooled heat exchanger pipe; 53. Water outlet of water-cooled heat exchanger pipe; 6. Water supply pump; 7. Blower; 71. Air duct; 8. Circulating water pump; 9. Piping components; 91. First pipeline; 911. First main pipeline; 912. First branch pipeline; 913. Second branch pipeline; 92. Second pipeline; 93. Third pipeline; 94. Fourth pipeline; 95. Fifth pipeline; 96. Sixth pipeline; 97. Bypass pipeline; 98. Softened water supply pipeline; 10. Cooling tower; 11. Valve 1; 12. Valve 2; 13. Valve 3; 14. Valve 4; 15. Valve 5; 16. Valve 6; 17. Valve 7; 18. Water tank. Detailed Implementation

[0038] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0039] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this utility model.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between 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.

[0042] According to the embodiments of this utility model, such as Figure 1 As shown, the biomass gasifier jacketed circulating water heat recovery system coupled with the steam boiler includes: gasifier body 1, heat exchanger 2, air preheater 3, biomass gas steam boiler 4, economizer 5, water supply pump 6, and blower 7.

[0043] The gasifier body 1 has a water-cooled jacket 101 and a circulating water outlet 102 and a circulating water inlet 103 connected to the water-cooled jacket 101; the water inlet of the first heat exchange channel in the heat exchanger 2 and the water inlet of the first heat exchange channel in the air preheater 3 are both connected to the circulating water outlet 102 through pipelines; the water outlet of the first heat exchange channel and the water outlet of the first heat exchange channel are both connected to the circulating water inlet 103 through pipelines.

[0044] The flue gas outlet of the biomass gas steam boiler 4 is connected to the flue gas inlet of the economizer 5 through the flue gas pipe 51; the water outlet of the water pump 6 is connected to the water inlet of the second heat exchange channel in the heat exchanger 2 through the pipe; the water outlet of the second heat exchange channel is connected to the water inlet 52 of the water-cooled heat exchange pipe in the economizer 5 used for heat exchange with the flue gas through the pipe; the air outlet of the blower 7 is connected to the air inlet of the second heat exchange channel in the air preheater 3 through the air pipe 71, and the air outlet of the second heat exchange channel is connected to the air inlet 411 of the biomass gas burner 41 of the biomass gas steam boiler 4 through the air pipe 71.

[0045] In this embodiment, when the biomass gasification furnace jacket circulating water heat recovery system of the coupled steam boiler is in use, the water supply pump 6 is used to supply softened water to the biomass gas steam boiler 4, and the blower 7 is used to supply air to the biomass gas burner 41 of the biomass gas steam boiler 4; medium heat exchange can be carried out between the first heat exchange channel and the second heat exchange channel in the heat exchanger 2; medium heat exchange can be carried out between the first heat exchange channel and the second heat exchange channel in the air preheater 3. The high-temperature circulating water in the water-cooled jacket 101 exchanges heat with the boiler's ambient temperature supply water through the heat exchanger 2, and the heat of the jacket circulating water is transferred to the boiler supply water, realizing the purpose of cooling the jacket circulating water in the water-cooled jacket 101, while increasing the boiler supply water temperature, thereby reducing the fuel consumption of the boiler heating water and improving the boiler thermal efficiency. The high-temperature circulating water inside the water-cooled jacket 101 exchanges heat with the ambient air required by the biomass gas burner 41 of the biomass gas steam boiler 4 through the air preheater 3. The heat of the jacket circulating water is transferred to the boiler air, achieving the purpose of cooling the jacket circulating water inside the water-cooled jacket 101, while simultaneously increasing the temperature of the air entering the boiler. This reduces the fuel consumption for heating ambient air in the boiler and improves the boiler's thermal efficiency. The coupling of these two pathways improves the system's regulation performance. The amount of jacket circulating water entering the heat exchanger 2 and the air preheater 3 can be adjusted according to the amount of softened water used in the boiler, maximizing the utilization of the jacket circulating water's heat. In addition, the boiler feedwater, which has been heated after flowing through the heat exchanger 2, enters the water-cooled heat exchange pipeline of the economizer 5 to continue exchanging heat with the boiler flue gas, further increasing the boiler feedwater temperature. Because the boiler feedwater entering the water-cooled heat exchange pipeline of the economizer 5 is heated water after heat exchange in the heat exchanger 2, the generation of highly corrosive condensate from the boiler flue gas in the economizer can be reduced, thereby increasing the service life of the economizer 5. This heat recovery system organically combines a plate heat exchanger and an air preheater to couple the circulating water of the biomass gasifier with the water and air supply of the biomass gas boiler. This achieves both cooling of the circulating water in the gasifier and increasing the temperature of the boiler feedwater and air supply, thereby reducing boiler gas consumption and improving the overall thermal efficiency of the biomass energy station.

[0046] Specifically, the gasifier body 1 is a biomass gasifier used to generate biomass gas. The flue gas outlet of the economizer 5 is connected to an external chimney via a flue gas pipe 51; the water outlet 53 of the water-cooled heat exchange pipe of the economizer 5 is connected to the inlet of the feedwater system of the biomass gas steam boiler 4 via a pipe. The biomass gas burner 41 is installed at the end of the biomass gas steam boiler 4; the biomass gas outlet of the gasifier body 1 is connected via a pipe to the biomass gas inlet 412 of the biomass gas burner 41 of the biomass gas steam boiler 4, so as to transport the biomass gas generated by the gasifier body 1 to the biomass gas steam boiler 4 for gas supply.

[0047] In some embodiments, the system further includes a circulating water pump 8 and a piping assembly 9; the piping assembly 9 includes a first pipe 91 and a second pipe 92.

[0048] The inlet of the first heat exchange channel in heat exchanger 2 and the inlet of the first heat exchange channel in air preheater 3 are both connected to the circulating outlet 102 through the first pipe 91; the outlet of the first heat exchange channel and the outlet of the first heat exchange channel are both connected to the circulating inlet 103 through the second pipe 92; the circulating water pump 8 is installed on the first pipe 91 or the second pipe 92 to drive the circulating water to circulate and exchange heat.

[0049] The circulating water pump 8 is used to drive and control the circulation speed of the circulating water in the water-cooled jacket 101, thereby achieving effective control of the boiler water supply and air supply.

[0050] In some embodiments, the first pipeline 91 includes a first main pipeline 911, a first branch pipeline 912, and a second branch pipeline 913;

[0051] One end of the first main pipeline 911 is connected to and connected to the circulating water inlet 103, and the other end of the first main pipeline 911 is connected to and connected to one end of the first branch pipeline 912 and the second branch pipeline 913. The other ends of the first branch pipeline 912 and the second branch pipeline 913 are connected to and connected to the inlet of the first heat exchange channel and the inlet of the first heat exchange channel, respectively. The circulating water pump 8 is installed on the first main pipeline 911. A valve 11 is installed on the first branch pipeline 912, and a valve 2 12 is installed on the second branch pipeline 913.

[0052] Valve 11 is used to control the amount of circulating water entering the first heat exchange channel in heat exchanger 2, thereby regulating the boiler water supply temperature; Valve 22 is used to control the amount of circulating water entering the first heat exchange channel in air preheater 3, thereby regulating the boiler air supply temperature; Valve 11 and Valve 22, together with circulating water pump 8, jointly regulate the boiler water and air supply, enabling flexible control.

[0053] In some embodiments, a cooling tower 10 is also included, with a circulating water outlet 102 connected to the water inlet of the cooling tower 10 via a pipeline for draining water; and the water outlet of the cooling tower 10 connected to the circulating water inlet 103 via a pipeline for returning water.

[0054] Cooling tower 10 serves as a backup cooling facility for the high-temperature circulating water in the jacket. When the biomass gas steam boiler 4 is shut down or the load is low, cooling tower 10 is turned on to cool the high-temperature circulating water in the jacket 101, ensuring that the circulating water in the jacket can absorb the heat of the inner cylinder during the operation of the gasifier body 1, and protecting the inner steel cylinder from high-temperature damage.

[0055] In some embodiments, the piping assembly 9 further includes a third pipe 93, a fourth pipe 94, and a fifth pipe 95; one end of the third pipe 93 is connected to and communicates with the circulating water outlet 102, and the other end is connected to and communicates with the water inlet of the cooling tower 10; a valve 13 is installed on the first main pipe 911 between the circulating water pump 8 and one end of the first main pipe 911; one end of the fourth pipe 94 is connected to and communicates with the water outlet of the cooling tower 10, and the other end of the fourth pipe 94 is connected to and communicates with the position on the first main pipe 911 between the circulating water pump 8 and the valve 13; one end of the fifth pipe 95 is connected to and communicates with the position on the first main pipe 911 between the circulating water pump 8 and the other end of the first main pipe 911, and the other end of the fifth pipe 95 is connected to and communicates with the second pipe 92; a valve 14 is installed on the fourth pipe 94; and a valve 15 is installed on the fifth pipe 95.

[0056] When the biomass gas steam boiler 4 is shut down, valves 13, 11, and 12 can be closed, and valves 14 and 15 can be opened. The high-temperature circulating water output from the circulating outlet 102 enters the cooling tower 10 for cooling through the third pipeline 93. Driven by the circulating water pump 8, the cooled circulating water flows back to the second pipeline 92 through the outlet of the cooling tower 10, the fourth pipeline 94, the circulating water pump 8, and the fifth pipeline 95, and then returns to the water-cooled jacket 101 through the circulating inlet 103.

[0057] In some embodiments, the system further includes a water tank 18, with a first inlet 181 connected to and communicating with a circulation outlet 102 for water storage; a first main pipeline 911 connected to and communicating with a first outlet 182 of the water tank 18; and a third pipeline 93 connected to and communicating with a second outlet 183 of the water tank 18.

[0058] The water tank 18 serves as a temporary storage for high-temperature circulating water, ensuring sufficient and stable circulating water within the water-cooled jacket 101.

[0059] In some embodiments, the water tank 18 is provided with a second inlet 184 for replenishing circulating water.

[0060] The second water inlet 184 of the water tank 18 is located at the top of the water tank 18. When the water storage in the water tank 18 is insufficient, water can be added to the water tank 18 through the second water inlet 184.

[0061] The circulating water outlet 102 is located at the upper part of the water-cooling jacket 101, and the circulating water inlet 103 is located at the lower part of the water-cooling jacket 101; the first water inlet of the water tank 18 is located at the upper part of the water tank 18; the circulating water outlet 102 is connected to the water tank 18 through a pipeline to input the output high-temperature circulating water into the water tank 18. The first water outlet of the water tank 18 is located at the lower part of the water tank 18; the second water outlet of the water tank 18 is located at the upper part of the water tank 18.

[0062] In some embodiments, there are multiple circulating water pumps 8, which are connected in parallel via pipelines.

[0063] The parallel connection of multiple circulating water pumps (8 in total) can improve the control flexibility of heat exchange efficiency, thereby adapting to various working conditions of steam boilers and biomass gasification furnaces.

[0064] Specifically, heat exchanger 2 can be a plate heat exchanger; two circulating water pumps 8 can be installed in parallel.

[0065] In some embodiments, the piping assembly 9 further includes a sixth pipe 96 and a bypass pipe 97; one end of the sixth pipe 96 is connected to and communicates with the outlet of the water supply pump 6, and the other end of the sixth pipe 96 is connected to and communicates with the inlet of the second heat exchange channel; a valve 16 is installed on the sixth pipe 96; one end of the bypass pipe 97 is connected to and communicates with the outlet of the water supply pump 6, and the other end of the bypass pipe 97 is connected to and communicates with the inlet of the water-cooled heat exchange pipe inside the energy saver 5; a valve 17 is installed on the bypass pipe 97.

[0066] During operation, the water supply pump 6 drives the boiler feedwater to be delivered sequentially through the sixth pipeline 96, the inlet of the second heat exchange channel in the heat exchanger 2, the pipeline, and the water-cooled heat exchange pipeline in the economizer 5 to the biomass gas steam boiler 4. When the heat exchanger 2 is closed, valve 6 16 is closed and valve 7 17 is opened. The water supply pump 6 drives the boiler feedwater to enter the water-cooled heat exchange pipeline in the economizer 5 through the bypass pipeline 97, and then supplies water to the boiler.

[0067] In some embodiments, the inlet of the water supply pump 6 is connected to the boiler softened water supply pipeline 98.

[0068] Specifically, the water supply pump 6 can be a deaerator; there can be multiple water supply pumps 6; multiple water supply pumps 6 are connected in parallel through pipelines.

[0069] In some embodiments, the operation method of the biomass gasification furnace jacket circulating water heat recovery system coupled to a steam boiler includes:

[0070] Operating Mode 1: High-temperature circulating water at 65-90℃ in the water-cooled jacket 101 enters the water tank 18 through the circulating outlet 102. Valve 4 14 is closed, and valve 3 13 is open. The circulating water in the water tank 18 is drawn into the first main pipeline 911 by the circulating water pump 8. Valve 1 11 is open, valve 2 12 is open, and valve 5 15 is closed. The circulating water in the first main pipeline 911 is pressurized by the circulating water pump 8 and then splits into two pipelines to enter the subsequent equipment: one pipeline enters the heat exchanger 2 and the 15-25℃ ambient temperature boiler through the first branch pipeline 912. The feedwater (normal boiler feedwater is generally around 20℃) exchanges heat to cool the jacketed circulating water to 45-55℃, and then flows back to the water-cooled jacket 101 for reuse. Another path, via the second branch pipe 913, enters the air preheater 3 to exchange heat with 15-25℃ normal temperature air (normal air is generally around 20℃). The heat is transferred to the normal temperature air through the air preheater 3, and the circulating water cooled to 60-85℃ merges with the first path of cooled circulating water through a pipe and enters the bottom of the water-cooled jacket 101 through the circulating water inlet 103. Through water cooling and air cooling, the high-temperature circulating water inside the water-cooled jacket 101 is cooled.

[0071] Operating Mode 2: Valve 6 (16) is open, valve 7 (17) is closed. Softened boiler water (generally around 20℃) is pressurized by water supply pump 6 and enters the second heat exchange channel of heat exchanger 2 to absorb heat from the high-temperature circulating water (generally 65-90℃). After the softened water temperature rises by about 40℃, it enters the water-cooled heat exchange pipeline of economizer 5 to continue exchanging heat with the boiler flue gas and raising its temperature. (The purpose of reheating the softened water is to prevent the high-temperature boiler flue gas from condensing in the economizer and producing highly corrosive condensate).

[0072] Working mode 3: Normal temperature air (generally around 20℃) is pressurized by the blower 7 of the boiler system and enters the heat exchange channel 2 of the air preheater 3 to absorb heat from the high temperature circulating water (65-90℃). The air, heated to 50-60℃, enters the biomass gas burner 41 of the biomass gas steam boiler 4 and is mixed and burned with biomass gas.

[0073] Working Mode 4: When there is a brief period without steam supply, i.e. when the biomass gas steam boiler 4 is temporarily shut down, the gasifier needs to be shut down. Valve 3 13 is closed, valve 4 14 is opened, valve 5 15 is opened, valve 1 11 and valve 2 12 are closed, the cooling tower 10 is started, and the 65-90℃ high-temperature circulating water output from the circulating water outlet 102 of the water-cooled jacket 101 enters the cooling tower 10 for cooling through the second water outlet at the top of the water tank 18. After the circulating water is cooled to 45-55℃, it is pressurized by the circulating water pump 8 and re-enters the water-cooled jacket 101 for reuse.

[0074] Operating mode 5: When heat exchanger 2 is not working, valve 6 16 is closed and valve 7 17 is open. The softened water for the normal temperature boiler goes directly to the downstream equipment through the bypass pipeline 97 where valve 7 17 is located.

[0075] In some embodiments, the gasifier jacket circulating water flow rate is 40t / h, which is supplied by a boiler with a steam capacity of 25t / h. When the steam load is 20t / h, the boiler feedwater flow rate is 20t / h. The jacket circulating water enters the gasifier jacket at a temperature of 45°C. After absorbing heat from the inner cylinder of the gasifier, it is heated to 65°C and flows out of the gasifier jacket. All of it enters the plate heat exchanger, where the heat is transferred to the boiler feedwater to cool it down to 45°C. At the same time, the boiler feedwater temperature is increased from 20°C to 59°C, and the boiler efficiency can be increased by 1%.

[0076] In some embodiments, the gasifier jacket circulating water flow rate is 40t / h, and the steam load is 25t / h. When the steam load is 20t / h, the boiler blast volume is 13000Nm³. 3 / h, the jacketed circulating water enters the gasifier jacket at a temperature of 45℃. After absorbing heat from the inner cylinder of the gasifier, it rises to 65℃ and flows out of the gasifier jacket. All of it enters the air preheater, where the heat is transferred to the boiler air and then cooled to 52℃. At the same time, the boiler air temperature rises from 20℃ to 59℃, which can improve the boiler efficiency by 1.3%.

[0077] In some embodiments, the steam supply capacity of the gasifier jacket is 12t / h, and the steam flow rate of the gasifier jacket is 10t / h. When the steam load is 10t / h, the boiler feedwater flow rate is 10t / h. The temperature of the jacket circulating water entering the gasifier jacket is 40°C. After absorbing heat from the inner cylinder of the gasifier, it is heated to 80°C and flows out of the gasifier jacket. All of it enters the plate heat exchanger, where the heat is transferred to the boiler feedwater to cool it down to 40°C. At the same time, the boiler feedwater temperature is increased from 20°C to 59°C, and the boiler efficiency can be increased by 1%.

[0078] In some embodiments, the gasifier jacket circulating water flow rate is 10t / h, and the steam load is 12t / h. When the steam load is 10t / h, the boiler blast volume is 6700 Nm³. 3 / h, the jacketed circulating water enters the gasifier jacket at a temperature of 40℃. After absorbing heat from the inner cylinder of the gasifier, it rises to 80℃ and flows out of the gasifier jacket. All of it enters the air preheater, where the heat is transferred to the boiler air and then cooled to 40℃. At the same time, the boiler air temperature rises from 20℃ to 78℃, which can improve the boiler efficiency by 1.9%.

[0079] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0080] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A biomass gasification furnace jacketed circulating water heat recovery system coupled with a steam boiler, characterized in that, It includes a gasifier body (1), a heat exchanger (2), an air preheater (3), a biomass gas steam boiler (4), an energy saver (5), a water supply pump (6), and a blower (7); The gasifier body (1) has a water-cooled jacket (101) and a circulating water outlet (102) and a circulating water inlet (103) connected to the water-cooled jacket (101); the water inlet of the first heat exchange channel in the heat exchanger (2) and the water inlet of the first heat exchange channel in the air preheater (3) are both connected to the circulating water outlet (102) through pipelines; the water outlet of the first heat exchange channel and the water outlet of the first heat exchange channel are both connected to the circulating water inlet (103) through pipelines. The flue gas outlet of the biomass gas steam boiler (4) is connected to the flue gas inlet of the energy saver (5) through a pipeline; the outlet of the water pump (6) is connected to the inlet of the second heat exchange channel in the heat exchanger (2) through a pipeline; the outlet of the second heat exchange channel is connected to the inlet of the water-cooled heat exchange pipeline in the energy saver (5) for heat exchange with the flue gas through a pipeline; the outlet of the blower (7) is connected to the inlet of the second heat exchange channel in the air preheater (3) through a pipeline, and the outlet of the second heat exchange channel is connected to the air inlet of the biomass gas burner of the biomass gas steam boiler (4) through a pipeline.

2. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 1, characterized in that, It also includes a circulating water pump (8) and a piping assembly (9); the piping assembly (9) includes a first pipe (91) and a second pipe (92); The inlet of the first heat exchange channel in the heat exchanger (2) and the inlet of the first heat exchange channel in the air preheater (3) are both connected to the circulating outlet (102) through the first pipeline (91); the outlet of the first heat exchange channel and the outlet of the first heat exchange channel are both connected to the circulating inlet (103) through the second pipeline (92); the circulating water pump (8) is installed on the first pipeline (91) or the second pipeline (92) to drive the circulating water to circulate and exchange heat.

3. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 2, characterized in that, The first pipeline (91) includes a first main pipeline (911), a first branch pipeline (912), and a second branch pipeline (913); One end of the first main pipeline (911) is connected to and communicates with the circulating water inlet (103), and the other end of the first main pipeline (911) is connected to and communicates with one end of the first branch pipeline (912) and the second branch pipeline (913). The other ends of the first branch pipeline (912) and the second branch pipeline (913) are connected to and communicate with the inlet of the first heat exchange channel and the inlet of the first heat exchange channel. The circulating water pump (8) is installed on the first main pipeline (911). A valve (11) is installed on the first branch pipeline (912), and a valve (12) is installed on the second branch pipeline (913).

4. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 3, characterized in that, It also includes a cooling tower (10), wherein the circulating water outlet (102) is connected to the water inlet of the cooling tower (10) through a pipeline to drain water; and the water outlet of the cooling tower (10) is connected to the circulating water inlet (103) through a pipeline to return water.

5. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 4, characterized in that, The piping assembly (9) further includes a third pipe (93), a fourth pipe (94), and a fifth pipe (95); one end of the third pipe (93) is connected to and communicates with the circulating water outlet (102), and the other end is connected to and communicates with the water inlet of the cooling tower (10); a valve three (13) is installed on the first main pipe (911) corresponding to the circulating water pump (8) and one end of the first main pipe (911); one end of the fourth pipe (94) is connected to and communicates with the water outlet of the cooling tower (10), and the fourth pipe (94) The other end is connected and connected to the first main pipeline (911) at the position between the circulating water pump (8) and the valve three (13); one end of the fifth pipeline (95) is connected and connected to the first main pipeline (911) at the position between the circulating water pump (8) and the other end of the first main pipeline (911), and the other end of the fifth pipeline (95) is connected and connected to the second pipeline (92); valve four (14) is installed on the fourth pipeline (94); valve five (15) is installed on the fifth pipeline (95).

6. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 5, characterized in that, It also includes a water tank (18), the first inlet of which is connected to and communicates with the circulating outlet (102) for water storage; one end of the first main pipeline (911) is connected to and communicates with the first outlet of the water tank (18); and one end of the third pipeline (93) is connected to and communicates with the second outlet of the water tank (18).

7. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 6, characterized in that, The water tank (18) is provided with a second inlet for replenishing circulating water.

8. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 2, characterized in that, There are multiple circulating water pumps (8), and the multiple circulating water pumps (8) are arranged in parallel.

9. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 2, characterized in that, The piping assembly (9) also includes a sixth pipe (96) and a bypass pipe (97); one end of the sixth pipe (96) is connected to and communicates with the outlet of the water supply pump (6), and the other end of the sixth pipe (96) is connected to and communicates with the inlet of the second heat exchange channel; a valve six (16) is installed on the sixth pipe (96); one end of the bypass pipe (97) is connected to and communicates with the outlet of the water supply pump (6), and the other end of the bypass pipe (97) is connected to and communicates with the inlet of the water-cooled heat exchange pipe inside the energy saver (5); a valve seven (17) is installed on the bypass pipe (97).

10. The biomass gasification furnace jacketed circulating water heat recovery system for a coupled steam boiler according to claim 9, characterized in that, The inlet of the water supply pump (6) is connected to the boiler softened water supply pipeline.

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