System for preheating biomass raw materials in heating funnel by utilizing waste heat of boiler flue gas

Abstract

The utility model discloses a system for preheating a biomass raw material in a heating funnel by utilizing waste heat of boiler flue gas. The system comprises a gasification furnace, a biomass gas boiler, a flue gas heat exchanger and an air heat exchanger, a heating funnel is arranged at the top of the gasifier; the gas inlet end of the biomass gas boiler is communicated with the gas outlet end of the gasification furnace; a biomass gas pipeline is connected between the gasification furnace and the biomass gas boiler, and a first induced draft fan is arranged on the biomass gas pipeline; the gas inlet end of the flue gas heat exchanger is communicated with the gas outlet end of the biomass gas boiler; the gas outlet end of the biomass gas boiler is connected with a chimney through a flue gas channel, a second induced draft fan is arranged on the flue gas channel, and the chimney is communicated with a gas inlet of the flue gas heat exchanger; a circulating water pipeline is connected between the air heat exchanger and the flue gas heat exchanger, and water in the flue gas heat exchanger flows back into the flue gas heat exchanger after passing through the air heat exchanger; and the hot air outlet end of the air heat exchanger is communicated with the heating funnel. The flue gas waste heat recycling device can recycle flue gas waste heat.

Description

Technical Field

[0001] This utility model relates to the field of flue gas waste heat utilization technology, and more specifically to a system for preheating biomass raw materials in a hopper using boiler flue gas waste heat. Background Technology

[0002] Biomass is a green, zero-carbon, and renewable energy source, and its applications are gradually diversifying against the backdrop of global energy transition and sustainable development. Especially during the shift from subsidy-driven to market-driven growth, non-electric sectors such as biomass gasification for heating have become important development directions. Biomass gasification technology involves pyrolyzing biomass raw materials (such as wood chips, bamboo, rice husks, fruit shells, and other agricultural and forestry waste) at high temperatures to produce combustible gases for heating or power generation.

[0003] Currently, biomass gasification is utilized by producing gas in a biomass gasifier, which is then burned in a biomass gas boiler for heating. The flue gas produced by the boiler undergoes heat recovery through economizers and energy-saving devices, with the recovered heat primarily used for preheating the boiler's feedwater or burner air. However, even after these treatments, the flue gas emission temperature remains around 150℃, meaning a significant amount of heat energy in the flue gas is not fully utilized, resulting in substantial energy waste.

[0004] Therefore, developing a system that can recover and utilize waste heat from boiler flue gas to preheat biomass feedstock in a hopper is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the present invention provides a system for recovering and utilizing waste heat from boiler flue gas to preheat biomass raw materials in a hopper.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A system that utilizes waste heat from boiler flue gas to preheat biomass feedstock in a heating funnel includes:

[0008] A gasifier, wherein a heating funnel is provided on the top of the gasifier;

[0009] A biomass gas boiler, wherein the inlet end of the biomass gas boiler is connected to the outlet end of the gasifier; a biomass gas pipeline is connected between the gasifier and the biomass gas boiler, and a first induced draft fan is installed on the biomass gas pipeline.

[0010] The flue gas heat exchanger is connected with the gas outlet end of the biomass gas boiler, and the gas outlet end of the biomass gas boiler is connected with a chimney through a flue gas channel, wherein a second induced draft fan is arranged on the flue gas channel, and the chimney is connected with the air inlet of the flue gas heat exchanger.

[0011] The air heat exchanger is connected with the flue gas heat exchanger through a circulating water pipeline, and the water in the flue gas heat exchanger flows through the air heat exchanger and then returns to the flue gas heat exchanger, and the hot air outlet end of the air heat exchanger is connected with the heating hopper.

[0012] The biomass gas boiler flue gas waste heat is used to preheat the biomass raw material, the heat energy in the flue gas can be effectively recovered, the energy waste is reduced, the temperature of the biomass raw material is increased, the subsequent gasification process is accelerated, the gasification furnace gas production efficiency is improved, and the energy efficient utilization and energy saving and emission reduction are realized.

[0013] Preferably, the gasification furnace is connected with a blower.

[0014] Preferably, the outside of the heating hopper is provided with a feeding conveyor belt, and the conveying end of the feeding conveyor belt extends into the inside of the heating hopper. The feeding conveyor belt conveys the biomass raw material into the heating hopper for preliminary heating.

[0015] Preferably, the bottom of the heating hopper is provided with a spiral feeder.

[0016] Preferably, a circulating water pump is arranged on the circulating water pipeline. Through the connection of the circulating water pump, the flue gas heat exchanger, the air heat exchanger and the fan, the circulating water is used to absorb the flue gas waste heat, and the heat is transferred to the air, and finally the hot air is sent into the furnace top heating hopper to preheat the biomass raw material. This process fully utilizes the waste heat in the flue gas, and improves the energy utilization efficiency.

[0017] Preferably, the air inlet of the air heat exchanger is connected with a fan, and the air outlet is connected with an air duct, and the air duct is connected with the heating hopper.

[0018] Preferably, an air exhaust hole is arranged in the side wall of the heating hopper. The air exhaust hole can exhaust the gas in the heating hopper, so that the hot air in the heating hopper is in convection heat exchange with the biomass raw material, thereby realizing the preheating of the biomass raw material.

[0019] Preferably, a redirection roller is arranged in the heating hopper, and the feeding conveyor belt is arranged outside the redirection roller.

[0020] Compared with the prior art, the system for preheating and heating the biomass raw material in the heating hopper by using the flue gas waste heat of the boiler has the beneficial effects that:

[0021] (1) The biomass raw material is preheated by using the flue gas waste heat of the biomass gas boiler, the heat energy not fully utilized in the flue gas is effectively recycled and reused, the energy utilization efficiency is significantly improved, and energy waste is reduced.

[0022] (2) Meanwhile, the temperature of the preheated biomass raw material is increased, the subsequent gasification process is accelerated, the gas production efficiency of the gasification furnace is improved, and the operation performance of the whole system is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only a part of the embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the provided drawings.

[0024] Figure 1 The system provided by the present application is a structural schematic view.

[0025] In the figure,

[0026] 1-gasification furnace; 2-heating hopper; 3-biomass gas boiler; 4-flue gas heat exchanger; 5-air heat exchanger; 6-circulating water pipeline; 7-feeding conveyor belt; 8-biomass gas pipeline; 9-first induced draft fan; 10-flue gas passage; 11-chimney; 12-second induced draft fan; 13-circulating water pump; 14-fan; 15-air duct; 16-spiral material feeder; 17-blast fan; 18-reversing roller. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the present application.

[0028] The system for preheating and heating the biomass raw material in the heating hopper by using the flue gas waste heat of the boiler is disclosed in the embodiments of the present application, which comprises:

[0029] The gasification furnace 1 is provided with the heating hopper 2 at the top of the furnace 1.

[0030] The biomass gas boiler 3 is connected with the gasification furnace 1 through a biomass gas pipeline 8, and the first induced draft fan 9 is arranged on the biomass gas pipeline 8.

[0031] The flue gas heat exchanger 4 is connected with the biomass gas boiler 3 through a flue gas passage 10, and the second induced draft fan 12 is arranged on the flue gas passage 10.

[0032] The air heat exchanger 5 is connected with the flue gas heat exchanger 4 through a circulating water pipeline 6, and the water in the flue gas heat exchanger 4 flows through the air heat exchanger 5 and then returns to the flue gas heat exchanger 4.

[0033] In order to further optimize the above technical scheme, the gasification furnace 1 can be a fixed bed updraft gasification furnace; the biomass gas boiler 3 can be a steam boiler, and the steam supply parameter is determined according to the actual demand of the heat user; the biomass gas boiler 3 can be a hot water boiler, and the hot water supply parameter is determined according to the actual demand of the heat user.

[0034] In order to further optimize the above technical scheme, the gasification furnace 1 is connected with the air blower 17. The biomass raw material and the air are dried, pyrolyzed, oxidized and reduced in the gasification furnace 1 to generate biomass gas; the air blower 17 provides power to send the air into the gasification furnace 1 to participate in the gasification process.

[0035] In order to further optimize the above technical scheme, the feeding conveyor belt 7 is arranged outside the heating hopper 2, and the conveying end of the feeding conveyor belt 7 extends into the inside of the heating hopper 2.

[0036] In order to further optimize the above technical scheme, the bottom of the heating hopper 2 is provided with the screw feeder 16. The screw feeder 16 can uniformly add the biomass material into the gasification furnace 1.

[0037] In order to further optimize the above technical scheme, the SNCR reactor, the SCR reactor, the economizer and the energy-saving device are arranged in sequence on the flue gas passage 10 between the biomass gas boiler 3 and the second induced draft fan 12, and the desulfurization and dust removal device is arranged at the bottom of the chimney 11. The SNCR reactor, the SCR reactor and the desulfurization and dust removal device can treat the flue gas, so that the flue gas at the flue gas outlet of the flue gas heat exchanger 4 can be directly discharged into the atmosphere.

[0038] In order to further optimize the above technical scheme, the flue gas heat exchanger 4 and the air heat exchanger 5 are both tube-shell heat exchangers.

[0039] In order to further optimize the above technical scheme, the circulating water pipeline 6 is provided with a circulating water pump 13.

[0040] In order to further optimize the above technical scheme, the air inlet of the air heat exchanger 5 is connected with a fan 14, and the air outlet is connected with an air duct 15, which is communicated with the heating hopper 2.

[0041] In order to further optimize the above technical scheme, the sidewall of the heating hopper 2 is provided with an air exhaust hole.

[0042] In order to further optimize the above technical scheme, the heating hopper 2 is provided with a redirection roller 18, and the feeding conveying belt 7 is arranged outside the redirection roller 18, so that the feeding conveying belt 7 changes the conveying direction at the redirection roller 18, and the biomass material is conveniently fed into the heating hopper 2.

[0043] Working principle:

[0044] The gasification furnace 1 is gasified, and the generated biomass gas enters the biomass gas boiler 3 through the biomass gas pipeline 8 and the first induced draft fan 9, the flue gas generated by the biomass gas boiler 3 enters the flue gas heat exchanger 4 through the chimney 11, the flue gas heats the circulating water in the flue gas heat exchanger 4, the heated circulating water is transported to the air heat exchanger 5 through the flue gas heat exchanger 4 outlet pipeline, in the air heat exchanger 5, the heated circulating water transmits heat to the air, and the cooled circulating water enters the flue gas heat exchanger 4 through the circulating water pump 13 to continue the circulation.

[0045] The high-temperature heat source of the air heat exchanger 5 is the heated circulating water, and the low-temperature heat source is the heated air, the fan 14 provides power to transport the air to the air heat exchanger 5 through the fan outlet air duct, the air absorbs the heat of the circulating water in the air heat exchanger 5 to be heated, and the heated air enters the heating hopper 2 at the top of the furnace through the air duct 15 and is discharged through the air vent arranged on the inner side of the heating hopper 2, so as to preheat the biomass raw material in the heating hopper 2 at the top of the furnace in the form of convection heat exchange.

[0046] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0047] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for preheating of biomass feedstock in a heating hopper using boiler flue gas waste heat, characterized in that, The utility model relates to a biomass gasification system, which comprises: a gasification furnace, a heating hopper being arranged on the top of the gasification furnace; a biomass gas boiler, an air inlet of the biomass gas boiler being communicated with an air outlet of the gasification furnace; a biomass gas pipeline being connected between the gasification furnace and the biomass gas boiler, and a first air blower being arranged on the biomass gas pipeline; a flue gas heat exchanger, an air inlet of the flue gas heat exchanger being communicated with an air outlet of the biomass gas boiler; a chimney being connected to the air outlet of the biomass gas boiler through a flue gas channel, a second air blower being arranged on the flue gas channel, and the chimney being communicated with an air inlet of the flue gas heat exchanger; an air heat exchanger, a circulating water pipeline being connected between the air heat exchanger and the flue gas heat exchanger, water in the flue gas heat exchanger flowing through the air heat exchanger and then back flowing into the flue gas heat exchanger; and a hot air outlet of the air heat exchanger being communicated with the heating hopper.

2. The system for preheating the biomass feedstock in the hopper using the waste heat of the boiler flue gas as claimed in claim 1, wherein, The gasification furnace is connected with a blower.

3. The system for preheating of the biomass feedstock in the hopper using the waste heat of the boiler flue gases as claimed in claim 1 wherein, An external part of the heating hopper is provided with a feeding conveyor belt, and a conveying end of the feeding conveyor belt extends into an internal part of the heating hopper.

4. The system for preheating the biomass feedstock in the hopper using the waste heat of the boiler flue gases as claimed in claim 3 wherein, A spiral feeder is arranged at the bottom of the heating hopper.

5. The system for preheating of the biomass feedstock in the hopper using the waste heat of the boiler flue gases as claimed in claim 1 wherein, A circulating water pump is arranged on the circulating water pipeline.

6. The system for preheating of the biomass feedstock in the hopper using the waste heat of the boiler flue gases as claimed in claim 1 wherein, An air inlet of the air heat exchanger is connected with a fan, and an air outlet is connected with an air duct, the air duct being communicated with the heating hopper.

7. The system for preheating of the biomass feedstock in the hopper using the waste heat of the boiler flue gases as claimed in claim 6 wherein, An air exhaust hole is arranged on a side wall of the heating hopper.

8. The system for preheating of the biomass feedstock in the hopper using the waste heat of the boiler flue gases as claimed in claim 3 wherein, A redirection roller is arranged in the heating hopper, and the feeding conveyor belt is arranged outside the redirection roller.

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