Biomass gas coupling coal-fired boiler peak shaving system and method thereof

Abstract

The application discloses a biomass gas coupling coal-fired boiler peak regulation system and a method thereof. The biomass gas coupling coal-fired boiler peak regulation system comprises a biomass gasifier, a gas storage tank, a heat exchanger and a coal-fired boiler system. The biomass gasifier is provided with an exhaust port. The biomass gasifier generates biomass gas and discharges the biomass gas through the exhaust port. The gas storage tank is provided with a gas storage inlet and a gas storage outlet. The gas storage tank is used for storing the biomass gas. The heat exchanger is formed with a first heat exchange flow channel and a second heat exchange flow channel which are isolated from each other and exchange heat with each other. One end of the second heat exchange flow channel is connected with the exhaust port, and the other end of the second heat exchange flow channel is connected with the gas storage inlet. The first heat exchange flow channel contains a heat exchange medium. The heat exchange medium cools the biomass gas in the second heat exchange flow channel. According to the biomass gas coupling coal-fired boiler peak regulation system, the rapid response of the unit load can be realized during the deep peak regulation, and the safety is improved.

Description

Technical Field

[0001] This invention relates to the fields of clean energy utilization and thermal power generation technology, and in particular to a biomass gas coupled coal-fired boiler peak shaving system and method thereof. Background Technology

[0002] Under the "dual carbon" target (carbon reduction and emission reduction), biomass gasification coupled with coal-fired power generation is an important technological path to reduce carbon emissions from coal-fired power plants. Current technologies typically feed the gas produced by biomass gasifiers directly or after simple purification into coal-fired boilers for co-combustion. However, this rigid coupling method has significant drawbacks: Coal-fired power units need to participate in deep grid peak shaving, requiring significant changes in boiler load. The operating characteristics of gasifiers make it difficult to synchronously and rapidly change loads, resulting in insufficient gas supply when the boiler is under low load, or insufficient gas supply when the boiler needs to rapidly increase load, thus limiting the speed and depth of peak shaving for the unit. Biomass fuels are diverse, and as a light fuel, biomass is prone to interruptions during transportation, leading to frequent start-ups and shutdowns of the gasifier or low efficiency and high energy consumption during low-load operation. In directly coupled systems, fluctuations in gas supply can affect boiler combustion stability.

[0003] Therefore, there is an urgent need for a device and method that can decouple biomass gasification from the instantaneous load of boiler combustion and improve system flexibility and safety. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, one objective of this invention is to propose a biomass gasification coupled coal-fired boiler peak-shaving system. This system connects a biomass gasifier to a gas storage tank, and the gas storage tank to a coal-fired boiler. When the biomass gasifier has excess capacity, the excess biomass is stored in the gas storage tank. When the coal-fired boiler needs to participate in rapid and deep peak-shaving of the power grid, the stored biomass gas is fed from the gas storage tank into the boiler for combustion to replace or supplement part of the coal, achieving rapid load response for the unit. Furthermore, by incorporating a heat exchanger, the cooling medium in the first heat exchange channel cools the biomass gas in the second heat exchange channel, improving the utilization efficiency of the biomass gas and the safety of system operation, and avoiding the risk of explosion due to excessively high biomass gas temperature.

[0005] The present invention also proposes a peak-shaving method for a biomass gas coupled with a coal-fired boiler using the above-mentioned biomass gas coupled with a coal-fired boiler peak-shaving system.

[0006] A biomass gas coupled coal-fired boiler peak-shaving system according to a first aspect of the present invention includes: a biomass gasifier having an exhaust port, the biomass gasifier generating biomass gas and discharging the biomass gas through the exhaust port; a gas storage tank having a gas storage inlet and a gas storage outlet, the gas storage tank being used to store biomass gas; a heat exchanger having a first heat exchange channel and a second heat exchange channel formed therein, which are mutually isolated and exchange heat with each other, one end of the second heat exchange channel being connected to the exhaust port, and the other end of the second heat exchange channel being connected to the gas storage inlet, the first heat exchange channel containing a heat exchange medium, the heat exchange medium cooling the biomass gas in the second heat exchange channel; and a coal-fired boiler system including a coal-fired boiler having a gas inlet connected to the gas storage outlet.

[0007] According to an embodiment of the present invention, a biomass gasification coupled with a coal-fired boiler peak-shaving system is configured by connecting a biomass gasifier to a gas storage tank, and connecting the gas storage tank to a coal-fired boiler. When the biomass gasifier has excess capacity, the excess biomass is stored in the gas storage tank. When the coal-fired boiler needs to participate in rapid and deep peak shaving of the power grid, the stored biomass gas is sent from the gas storage tank to the boiler for combustion to replace or supplement part of the coal, thereby achieving rapid response of the unit load. By setting up a heat exchanger, the cooling medium in the first heat exchange channel cools the biomass gas in the second heat exchange channel, thereby improving the utilization efficiency of the biomass gas and the safety of system operation, and avoiding the risk of explosion due to excessive temperature of the biomass gas.

[0008] According to some embodiments of the present invention, the coal-fired boiler system includes a condensate tank and a deaerator, the heat exchange medium includes condensate, the condensate tank is connected to one end of the first heat exchange channel and condensate is introduced into the first heat exchange channel, and the deaerator is connected to the other end of the first heat exchange channel and condensate in the first heat exchange channel is introduced into the deaerator.

[0009] According to some embodiments of the present invention, the system further includes a first connecting pipe, a second connecting pipe, a third connecting pipe, a gas supply pipe, and a manifold pipe. One end of the gas supply pipe is connected to the exhaust port, and the other end of the gas supply pipe is connected to one end of the manifold pipe. The end of the manifold pipe away from the gas supply pipe is connected to the gas inlet. A first valve is provided on the gas supply pipe. The exhaust port is connected to the heat exchanger through the first connecting pipe, the heat exchanger is connected to the gas storage inlet through the second connecting pipe, and the gas storage outlet is connected to the end of the manifold pipe away from the gas inlet through the third connecting pipe. A second valve is provided on the first connecting pipe.

[0010] According to some embodiments of the present invention, a third valve is provided on the second connecting pipeline; and / or, a fourth valve is provided on the third connecting pipeline.

[0011] According to some embodiments of the present invention, a remote monitoring and alarm system is also included. The remote monitoring and alarm system includes a control system, an alarm device, and multiple detection components. The detection components are respectively disposed on the first connecting pipeline, the second connecting pipeline, and the gas storage tank. The detection components detect the temperature, pressure, and composition of biomass gas in the pipeline or the gas storage tank. The control system and the multiple detection components are electrically connected. The control system is electrically connected to the alarm device. The control system controls the alarm device to sound an alarm based on the detection data of the detection components.

[0012] According to some embodiments of the present invention, the detection component includes a type K thermocouple that detects the temperature of biomass fuel gas; and / or, the detection component includes a component measuring element that measures the volume fractions of O2, CO, and CH4 in the biomass fuel gas.

[0013] According to some embodiments of the present invention, a pressurizing device is further included, which is connected in series in the second connecting pipeline, and the pressurizing device pressurizes the biomass gas in the second connecting pipeline and delivers it to the gas storage tank; and / or, a power device is further included, which is connected in series in the second connecting pipeline, and the power device drives the biomass gas in the second connecting pipeline to be delivered to the gas storage tank.

[0014] According to some embodiments of the present invention, the gas storage tank is provided with a safety valve, and the operating pressure of the safety valve is 2.2 MPa.

[0015] According to some embodiments of the present invention, a nitrogen generator is also included. The gas storage tank is provided with a nitrogen filling port and a gas dissipation port. The nitrogen filling port is located at the bottom of the gas storage tank and connected to the nitrogen generator. The gas dissipation port is located at the top of the gas storage tank and is provided with a fifth valve.

[0016] According to a second aspect of the present invention, a biomass gas-coupled coal-fired boiler peak-shaving method uses a biomass gas-coupled coal-fired boiler peak-shaving device according to a first aspect of the present invention to perform peak-shaving on the coal-fired boiler. The biomass gas-coupled coal-fired boiler peak-shaving method includes: the biomass gasifier generating biomass gas and discharging it through the exhaust port; the biomass gas entering the second heat exchange channel and exchanging heat with the heat exchange medium in the first heat exchange channel to cool the biomass gas; the biomass gas entering the gas storage tank for storage; and when the coal-fired boiler has a deep peak-shaving requirement, opening the gas storage outlet and introducing the biomass gas in the gas storage tank into the coal-fired boiler for combustion support.

[0017] According to an embodiment of the present invention, the biomass gas coupled with coal-fired boiler peak shaving method stores biomass gas in a gas storage tank. When the coal-fired boiler has a deep peak shaving requirement, the biomass gas in the gas storage tank is introduced into the coal-fired boiler for combustion assistance, replacing or supplementing part of the coal, thereby achieving rapid response of the unit load and meeting the unit's peak shaving requirements. By allowing the biomass gas to enter the second heat exchange channel, it exchanges heat with the heat exchange medium in the first heat exchange channel, and the biomass gas cools down, improving the utilization efficiency of the biomass gas and the safety of system operation, and avoiding the risk of explosion due to excessively high temperature of the biomass gas.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a peak-shaving system for a biomass gas coupled with a coal-fired boiler, according to some embodiments of the present invention.

[0020] Figure label: 100. Biomass-fired gas coupled with coal-fired boiler peak-shaving system; 1. Biomass gasification furnace; 11. Exhaust port; 2. Gas storage tank; 21. Gas inlet; 22. Gas outlet; 23. Safety valve; 24. Nitrogen filling port; 25. Ventilation port; 26. Nitrogen generator; 3. Heat exchanger; 31. First heat exchange channel; 32. Second heat exchange channel; 4. Coal-fired boiler system; 41. Coal-fired boiler; 411. Gas inlet; 42. Condensate tank; 43. Deaerator; 51. First connecting pipeline; 52. Second connecting pipeline; 53. Third connecting pipeline; 54. Air supply pipeline; 55. Manifold pipeline; 61. First valve; 62. Second valve; 63. Third valve; 64. Fourth valve; 65. Fifth valve; 66. Power unit; 7. Remote monitoring and alarm system; 71. Control system; 72. Detection component. Detailed Implementation

[0021] Embodiments of the present invention 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] The following is for reference. Figure 1 A peak-shaving system for a biomass-fired gas coupled with a coal-fired boiler, according to an embodiment of the present invention, is described.

[0023] Reference Figure 1 According to a first aspect of the present invention, a biomass gasification coupled coal-fired boiler peak-shaving system 100 includes: a biomass gasifier 1, a gas storage tank 2, a heat exchanger 3, and a coal-fired boiler system 4.

[0024] The biomass gasifier 1 is equipped with an exhaust port 11, through which it generates biomass gas and discharges it. The gas storage tank 2 is equipped with a gas inlet 21 and a gas outlet 22, and is used to store the biomass gas. The heat exchanger 3 contains a first heat exchange channel 31 and a second heat exchange channel 32 that are isolated from each other but exchange heat. One end of the second heat exchange channel 32 is connected to the exhaust port 11, and the other end is connected to the gas inlet 21. The first heat exchange channel 31 contains a heat exchange medium that cools the biomass gas in the second heat exchange channel 32. The coal-fired boiler system 4 includes a coal-fired boiler 41, which is equipped with a gas inlet 411 connected to the gas outlet 22.

[0025] After biomass gas is generated in the biomass gasifier 1, it is discharged from the exhaust port 11 and then enters the second heat exchange channel 32 of the heat exchanger 3. In this channel, the gas undergoes indirect heat exchange with the heat exchange medium in the first heat exchange channel 31. After the temperature decreases, it is sent out from the other end of the second heat exchange channel 32 and enters the gas storage tank 2 through the gas storage inlet 21 for storage. When the coal-fired boiler system 4 is running, the stored gas is output from the gas storage outlet 22 and sent through the pipeline to the gas inlet 411 of the coal-fired boiler 41, and finally enters the furnace of the coal-fired boiler 41 to participate in combustion.

[0026] For example, gas storage tank 2 is well sealed, and the tank body is placed in a cool place, with no open flames allowed within a 5m radius around it. Gas storage tank 2 is a pressure vessel, designed to withstand pressures of 0.5-2.0MPa, serving as a buffer and energy storage unit for biomass gas.

[0027] Preferably, the gas storage tank 2 is designed to withstand a pressure of 0.8-1.2 MPa.

[0028] For example, the gas storage tank 2 is made of high-strength carbon steel with a wall thickness of 2.5-3mm to ensure compressive strength and corrosion resistance.

[0029] For example, the gas storage tank 2 is covered with an insulation device.

[0030] For example, heat exchanger 3 includes a heat exchanger 3 shell and heat exchanger 3 cooling tubes. The heat exchanger 3 cooling tubes are disposed in the heat exchanger 3 shell and define a first heat exchange channel 31 and a second heat exchange channel 32. The heat exchanger 3 cooling tubes are made of stainless steel C304, with an outer diameter of 16-30 mm and a wall thickness of 0.5-0.8 mm.

[0031] By installing a gas storage tank 2 between the biomass gasifier 1 and the coal-fired boiler 41, the gas storage tank 2 can quickly release a large amount of gas, allowing the boiler to rapidly increase fuel input, greatly shortening the unit's load response time, and allowing the boiler to operate at lower loads, thereby improving the unit's deep peak-shaving capacity. This ensures that the biomass gasifier 1 can operate continuously and at full load under optimal conditions, improving gasification efficiency and economic benefits. Furthermore, storing surplus biomass gas avoids waste and maximizes the utilization of renewable energy.

[0032] Furthermore, gas storage tank 2 can be directly connected to existing biomass gasification coupling projects, which is convenient and cost-effective for modification.

[0033] By installing a heat exchanger 3 between the biomass gasifier 1 and the gas storage tank 2, the cooling medium in the first heat exchange channel 31 of the heat exchanger 3 cools down the biomass gas in the second heat exchange channel 32, which improves the utilization efficiency of biomass gas and the safety of system operation, avoids the risk of explosion of biomass gas due to excessive temperature, and keeps the storage temperature of biomass gas in the gas storage tank 2 below the ignition point, preventing it from deflagration in the gas storage tank 2 and ensuring the overall safety of the system.

[0034] According to an embodiment of the present invention, the biomass gasification gas coupled with a coal-fired boiler peak shaving system 100 connects a biomass gasifier 1 to a gas storage tank 2, and connects the gas storage tank 2 to a coal-fired boiler 41. When the biomass gasifier 1 has excess capacity, the excess biomass is stored in the gas storage tank 2. When the coal-fired boiler 41 needs to participate in rapid and deep peak shaving of the power grid, the stored biomass gas is sent from the gas storage tank 2 into the boiler for combustion to replace or supplement part of the coal, thereby achieving rapid response of the unit load. By setting up a heat exchanger 3, the cooling medium in the first heat exchange channel 31 cools the biomass gas in the second heat exchange channel 32, thereby improving the utilization efficiency of the biomass gas and the safety of system operation, and avoiding the risk of explosion due to excessive temperature of the biomass gas.

[0035] Reference Figure 1 According to some embodiments of the present invention, the coal-fired boiler system 4 includes a condensate tank 42 and a deaerator 43. The heat exchange medium includes condensate. The condensate tank 42 is connected to one end of the first heat exchange channel 31 and condensate is introduced into the first heat exchange channel 31. The deaerator 43 is connected to the other end of the first heat exchange channel 31 and condensate in the first heat exchange channel 31 is introduced into the deaerator 43.

[0036] By pumping water from the condensate tank 42 in the coal-fired boiler system 4 and passing the condensate from the condensate tank 42 into the first heat exchange channel 31 to cool the biomass gas in the second heat exchange channel 32, no additional cooling medium is required, reducing costs and making full use of the water resources in the coal-fired boiler system 4, thus saving energy.

[0037] By introducing water from the second heat exchange channel 32 into the deaerator 43, water loss in the water circulation of the coal-fired boiler system 4 is reduced. On the other hand, the temperature of the condensate after heat exchange in the first heat exchange channel 31 rises, i.e., biomass gas heats the condensate, which can improve the efficiency of the deaerator 43 and enhance the benefits of the coal-fired boiler system 4.

[0038] For example, the condensate in the first heat exchange channel 31 and the biomass gas in the second heat exchange channel 32 flow in opposite directions to improve heat exchange efficiency.

[0039] For example, the temperature of the biomass gas discharged from the second heat exchange channel 32 is controlled to not exceed 90°C under rated operating conditions. This prevents the condensate from overheating and causing the gas to expand in volume.

[0040] Reference Figure 1 According to some embodiments of the present invention, the system further includes a first connecting pipe 51, a second connecting pipe 52, a third connecting pipe 53, a gas supply pipe 54, and a manifold pipe 55. One end of the gas supply pipe 54 is connected to the exhaust port 11, and the other end of the gas supply pipe 54 is connected to one end of the manifold pipe 55. The end of the manifold pipe 55 away from the gas supply pipe 54 is connected to the gas inlet 411. A first valve 61 is provided on the gas supply pipe 54. The exhaust port 11 is connected to the heat exchanger 3 through the first connecting pipe 51. The heat exchanger 3 is connected to the gas storage inlet 21 through the second connecting pipe 52. The gas storage outlet 22 is connected to the end of the manifold pipe 55 away from the gas inlet 411 through the third connecting pipe 53. A second valve 62 is provided on the first connecting pipe 51.

[0041] For example, insulation devices are installed on the first connecting pipe 51, the second connecting pipe 52, the third connecting pipe 53, the gas supply pipe 54, and the manifold pipe 55.

[0042] The biomass gas produced by biomass gasifier 1 flows out from exhaust port 11, and a portion of the biomass gas flows along the following path: Figure 1As shown by the solid arrows, biomass gas flows through the first connecting pipe 51 into the heat exchanger 3 for cooling. The cooled gas then flows through the second connecting pipe 52 to the gas inlet 21 of the gas storage tank 2, where it is finally stored. When the coal-fired boiler 41 needs to use biomass gas, the gas is discharged from the gas outlet 22 and flows through the third connecting pipe 53 into the manifold 55, from where it is delivered to the gas inlet 411 of the coal-fired boiler 41, thus ensuring a stable gas supply. The flow path of another portion of the biomass gas is as follows... Figure 1 As shown by the dashed arrow, biomass gas flows directly from the exhaust port 11 into the gas supply pipeline 54. The gas supply pipeline 54 is used as a bypass channel to directly guide the gas to the manifold 55. Then, without cooling and storage, it is directly transported to the gas inlet 411 of the coal-fired boiler 41 through the manifold 55 to realize the direct combustion utilization of hot gas.

[0043] By setting the first valve 61 and the second valve 62, the operating conditions can be switched. For example, when the coal-fired boiler 41 does not require gas replenishment, the first valve 61 can be opened and the second valve 62 closed, allowing the biomass gas to enter the heat exchanger 3 for cooling through the first connecting pipe 51, and then enter the gas storage tank 2 for storage through the second connecting pipe 52. When the coal-fired boiler 41 requires gas replenishment, the first valve 61 can be closed and the second valve 62 opened, allowing the biomass gas to directly enter the manifold pipe 55 through the gas replenishment pipe 54 to replenish the coal-fired boiler 41. At the same time, the gas storage outlet 22 can be opened to allow the biomass gas in the gas storage tank 2 to enter the manifold pipe 55 through the third connecting pipe 53 to replenish the coal-fired boiler 41, making the gas replenishment of the coal-fired boiler 41 more sufficient.

[0044] For example, the first valve 61 and the second valve 62 can be flow valves. This allows the opening of the first valve 61 and the second valve 62 to be adjusted according to the actual operating conditions of the coal-fired boiler 41, thereby adjusting the ratio of biomass gas directly fed into the coal-fired boiler 41 to biomass gas stored in the gas storage tank 2, and thus adjusting the flow rate of biomass gas used to supplement fuel to the coal-fired boiler 41.

[0045] Reference Figure 1 According to some embodiments of the present invention, a third valve 63 is provided on the second connecting pipe 52. By providing the third valve 63 on the second connecting pipe 52, the connection between the heat exchanger 3 and the gas storage tank 2 can be controlled independently. When the heat exchanger 3 or the gas storage tank 2 is damaged, relevant personnel can close the third valve 63 to carry out repairs on the heat exchanger 3 or the gas storage tank 2, making the maintenance and repair of the heat exchanger 3 or the gas storage tank 2 more convenient.

[0046] Reference Figure 1According to some embodiments of the present invention, a fourth valve 64 is provided on the third connecting pipe 53. By providing a fourth valve 64 on the third connecting pipe 53, the connection between the gas storage tank 2 and the coal-fired boiler 41 can be controlled independently. When the gas storage tank 2 does not need to replenish biomass fuel gas for the coal-fired boiler 41, the fourth valve 64 can be closed to prevent the biomass fuel gas in the gas storage tank 2 from leaking into the third connecting pipe 53.

[0047] Reference Figure 1 According to some embodiments of the present invention, a remote monitoring and alarm system 7 is also included. The remote monitoring and alarm system 7 includes a control system 71, an alarm device, and multiple detection components 72. The detection components 72 are respectively disposed on the first connecting pipe 51, the second connecting pipe 52, and the gas storage tank 2. The detection components 72 detect the temperature, pressure, and composition of the biomass gas in the pipes or the gas storage tank 2. The control system 71 and the multiple detection components 72 are electrically connected. The control system 71 is electrically connected to the alarm device. The control system 71 controls the alarm device to sound an alarm based on the detection data of the detection components 72.

[0048] For example, a detection component 72 is connected in series on the first connecting pipe 51 to detect the temperature and pressure of the biomass gas inside the first connecting pipe 51; a detection component 72 is connected in series on the second connecting pipe 52 to detect the temperature and pressure of the biomass gas inside the second connecting pipe 52; a detection component 72 is installed on the tank body of the gas storage tank 2 to detect the temperature, pressure and composition of the biomass gas inside the gas storage tank 2.

[0049] For example, the control system 71 includes cards and a data acquisition console.

[0050] For example, the remote monitoring alarm system 7 also includes a communication cable, and the detection component 72 is connected to the control system 71 via the communication cable.

[0051] The control system 71 averages the temperature values ​​detected by multiple detection components 72 and uses this average temperature value to determine the temperature of the biomass gas. The control system 71 also averages the pressure values ​​detected by multiple detection components 72 and uses this average temperature value to determine the pressure of the biomass gas.

[0052] For example, the temperature warning value of the gas storage tank 2 is 100℃, the pressure warning value is 2.0MPa, and the O2 concentration warning value is 1%. When the detection component 72 detects that the temperature of the gas storage tank 2 exceeds 100℃, or the detection component 72 detects that the pressure exceeds 2.0MPa, or the detection component 72 detects that the oxygen concentration exceeds 1%, the control system 71 controls the alarm device to sound an alarm.

[0053] When the temperature or pressure of the biomass gas is too high, the control system 71 activates the alarm device to reduce the risk of explosions and other hazards. The remote monitoring and alarm system 7 enables online early warning, reducing the cost of manual inspections and improving the timeliness and accuracy of monitoring, thus ensuring the overall safety and stability of the system.

[0054] According to some embodiments of the present invention, the detection component 72 includes a K-type thermocouple that detects the temperature of biomass gas. By setting the K-type thermocouple to detect the temperature of biomass gas, the temperature of biomass gas is monitored, and the data is transmitted to the control system 71. This provides timely warnings when the temperature of the biomass gas is too high, reducing the occurrence of hazards such as explosions.

[0055] According to some embodiments of the present invention, the detection component 72 includes a component measuring element that measures the volume fractions of O2, CO, and CH4 in biomass fuel gas. For example, the component measuring element includes a spectrometer.

[0056] According to some embodiments of the present invention, a pressurizing device is also included, which is connected in series in the second connecting pipeline 52. The pressurizing device pressurizes the biomass gas in the second connecting pipeline 52 and delivers it to the gas storage tank 2. By connecting the pressurizing device in series in the second connecting pipeline 52 and pressurizing the biomass gas in the second connecting pipeline 52 and delivering it to the gas storage tank 2, the gas storage tank 2 can hold more biomass gas, thus providing a sufficient supply of biomass gas during subsequent peak shaving of the coal-fired boiler 41.

[0057] Reference Figure 1 According to some embodiments of the present invention, a power unit 66 is also included. The power unit 66 is connected in series in the second connecting pipeline 52, and the power unit 66 drives the biomass gas in the second connecting pipeline 52 to be transported to the gas storage tank 2. By providing the power unit 66, the power unit 66 can drive the biomass gas in the second connecting pipeline 52 to be transported to the gas storage tank 2, so that the generated biomass gas can be stored as soon as possible and avoids accumulation in the pipeline.

[0058] For example, the power unit 66 includes a gas compressor that provides power to draw biomass gas from the biomass gasifier 1 to the gas storage tank 2 for compression and storage. The gas compressor operates in a medium temperature range of 0~150℃.

[0059] Reference Figure 1 According to some embodiments of the present invention, a safety valve 23 is provided on the gas storage tank 2, and the operating pressure of the safety valve 23 is 2.2 MPa. By providing a safety valve 23 on the gas storage tank 2, the safety valve 23 can automatically open to release gas when the gas pressure in the gas storage tank 2 exceeds 2.2 MPa, thereby preventing the gas pressure in the gas storage tank 2 from becoming too high and causing danger.

[0060] Reference Figure 1 According to some embodiments of the present invention, a nitrogen generator 26 is also included. The gas storage tank 2 is provided with a nitrogen filling port 24 and a gas dissipation port 25. The nitrogen filling port 24 is located at the bottom of the gas storage tank 2 and is connected to the nitrogen generator 26. The gas dissipation port 25 is located at the top of the gas storage tank 2, and a fifth valve 65 is provided at the gas dissipation port 25.

[0061] Since biomass gas contains combustible components, when maintenance, long-term shutdown, or emptying of the gas storage tank 2 is required, nitrogen can be introduced into the tank through the nitrogen filling port 24 at the bottom of the tank by the nitrogen generator 26, and the gas can be discharged through the top vent 25 by opening the fifth valve 65. This displacement method utilizes the inert properties of nitrogen to completely dilute and displace the remaining combustible gas in the tank, thereby effectively reducing the concentration of biomass gas in the tank, preventing the formation of explosive gas mixtures, eliminating the risk of fire and explosion, and ensuring system safety.

[0062] For example, the nitrogen generator 26 includes a standard nitrogen cylinder with 99.999% purity.

[0063] According to a second aspect embodiment of the present invention, a peak-shaving method for a biomass-gas coupled coal-fired boiler 41 is used to regulate the peak load of the coal-fired boiler 41 using a peak-shaving device according to a first aspect embodiment of the present invention. The peak-shaving method for the biomass-gas coupled coal-fired boiler 41 includes: The biomass gasifier 1 generates biomass gas and discharges it through the exhaust port 11.

[0064] Biomass gas enters the second heat exchange channel 32 and exchanges heat with the heat exchange medium in the first heat exchange channel 31, thereby cooling the biomass gas.

[0065] Biomass gas is stored in storage tank 2.

[0066] When the coal-fired boiler 41 has a deep peak shaving requirement, the gas storage outlet 22 is opened, and the biomass gas in the gas storage tank 2 is introduced into the coal-fired boiler 41 for combustion assistance.

[0067] According to the peak-shaving method of biomass gas coupled with coal-fired boiler 41 according to an embodiment of the present invention, biomass gas is stored in gas storage tank 2. When the coal-fired boiler 41 has a deep peak-shaving demand, the biomass gas in gas storage tank 2 is introduced into the coal-fired boiler 41 for combustion assistance to replace or supplement part of the coal, thereby achieving rapid response of unit load and meeting the peak-shaving demand of the unit. By allowing biomass gas to enter the second heat exchange channel 32, heat exchange occurs with the heat exchange medium in the first heat exchange channel 31, and the biomass gas is cooled down, thereby improving the utilization efficiency of biomass gas and the safety of system operation, and avoiding the risk of explosion due to excessive temperature of biomass gas.

[0068] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0069] In the description of this invention, "first feature" and "second feature" may include one or more of the features.

[0070] In the description of this invention, "a plurality of" means two or more.

[0071] In the description of this invention, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0072] In the description of this invention, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature.

[0073] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "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 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.

[0074] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A biomass-gas coupled coal-fired boiler peak-shaving system, characterized in that, include: A biomass gasifier is provided with an exhaust port, wherein the biomass gasifier produces biomass gas and discharges the biomass gas through the exhaust port; A gas storage tank is provided with a gas inlet and a gas outlet, and the gas storage tank is used to store biomass fuel gas. The heat exchanger has a first heat exchange channel and a second heat exchange channel that are isolated from each other and exchange heat with each other. One end of the second heat exchange channel is connected to the exhaust port and the other end of the second heat exchange channel is connected to the gas storage inlet. The first heat exchange channel contains a heat exchange medium, which cools the biomass gas in the second heat exchange channel. A coal-fired boiler system includes a coal-fired boiler, wherein the coal-fired boiler is provided with a gas inlet, and the gas inlet is connected to the gas storage outlet.

2. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 1, characterized in that, The coal-fired boiler system includes a condensate tank and a deaerator. The heat exchange medium includes condensate. The condensate tank is connected to one end of the first heat exchange channel and condensate is introduced into the first heat exchange channel. The deaerator is connected to the other end of the first heat exchange channel and condensate in the first heat exchange channel is introduced into the deaerator.

3. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 1, characterized in that, It also includes a first connecting pipe, a second connecting pipe, a third connecting pipe, a gas supply pipe, and a manifold pipe. One end of the gas supply pipe is connected to the exhaust port, and the other end of the gas supply pipe is connected to one end of the manifold pipe. The end of the manifold pipe away from the gas supply pipe is connected to the gas inlet. A first valve is provided on the gas supply pipe. The exhaust port is connected to the heat exchanger via the first connecting pipe, the heat exchanger is connected to the gas storage inlet via the second connecting pipe, and the gas storage outlet is connected to the end of the manifold away from the gas inlet via the third connecting pipe. A second valve is provided on the first connecting pipe.

4. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 3, characterized in that, The second connecting pipe is provided with a third valve; and / or, the third connecting pipe is provided with a fourth valve.

5. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 3, characterized in that, It also includes a remote monitoring and alarm system, which includes a control system, an alarm device, and multiple detection components. The detection components are respectively installed on the first connecting pipeline, the second connecting pipeline, and the gas storage tank. The detection components detect the temperature, pressure, and composition of biomass gas in the pipeline or the gas storage tank. The control system and the multiple detection components are electrically connected. The control system is electrically connected to the alarm device. The control system controls the alarm device to sound an alarm based on the detection data of the detection components.

6. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 5, characterized in that, The detection component includes a type K thermocouple for detecting the temperature of biomass gas; and / or, the detection component includes a component measuring element for measuring the volume fractions of O2, CO, and CH4 in the biomass gas.

7. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 3, characterized in that, It also includes a pressurizing device, which is connected in series in the second connecting pipeline. The pressurizing device pressurizes the biomass gas in the second connecting pipeline and delivers it to the gas storage tank. And / or, it also includes a power unit connected in series in the second connecting pipeline, the power unit driving the biomass gas in the second connecting pipeline to be transported to the gas storage tank.

8. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 1, characterized in that, The gas storage tank is equipped with a safety valve, and the operating pressure of the safety valve is 2.2 MPa.

9. The biomass-gas coupled coal-fired boiler peak-shaving system according to claim 1, characterized in that, It also includes a nitrogen generator. The gas storage tank is provided with a nitrogen filling port and a gas dissipation port. The nitrogen filling port is located at the bottom of the gas storage tank and is connected to the nitrogen generator. The gas dissipation port is located at the top of the gas storage tank and is provided with a fifth valve.

10. A method for peak shaving in a biomass-gas coupled coal-fired boiler, characterized in that, The peak-shaving device for a biomass-fired gas coupled with a coal-fired boiler according to any one of claims 1-9 is used to regulate the peak load of the coal-fired boiler, and the peak-shaving method for the biomass-fired gas coupled with a coal-fired boiler includes: The biomass gasifier generates biomass gas and discharges it through the exhaust port. Biomass gas enters the second heat exchange channel and exchanges heat with the heat exchange medium in the first heat exchange channel, thus cooling the biomass gas. Biomass gas is stored in the gas storage tank; When the coal-fired boiler has a deep peak-shaving requirement, the gas outlet of the gas storage tank is opened, and the biomass gas in the gas storage tank is introduced into the coal-fired boiler for combustion assistance.

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