Waste heat utilization system of waste incineration power station integrating biomass gasification

Abstract

The invention discloses a waste incineration power station waste heat utilization system integrating biomass gasification, and relates to the field of biomass resource utilization and energy conservation and emission reduction, and the waste incineration power station waste heat utilization system integrating biomass gasification comprises a waste incineration boiler, a steam circulation generator set, a flue gas purification system and a biomass gasification and waste heat recovery coupling system. Exhaust gas of the turbine is conveyed to a condenser through a pipeline and condensed into water through the condenser, and the condenser is connected with a condensate pump through a pipeline. The flue gas purification tower receives flue gas discharged by the waste incineration boiler through a pipeline and purifies the flue gas, and the treated flue gas is connected with the bag-type dust collector through another pipeline for retreatment; the waste incineration boiler conveys gas to the biomass gasification furnace through a pipeline, and the biomass gasification furnace generates straw fuel gas and conveys the straw fuel gas to the cyclone separator through a pipeline. Compared with the prior art, the system has the advantages that the energy utilization efficiency is improved; the investment cost is reduced; the smoke exhaust loss is reduced; the economic benefit is improved.

Description

Technical Field

[0001] The present invention relates to the field of biomass resource utilization and energy conservation and emission reduction, and specifically refers to a waste heat utilization system of a garbage incineration power plant integrating biomass gasification. Background Art

[0002] As an effective way of waste disposal, waste incineration power generation has been widely used around the world in recent years. However, traditional waste incineration power generation systems have problems such as low energy efficiency, high cost investment, excessive exhaust loss resulting in low power generation efficiency, and poor economic benefits. Specifically, the high-temperature flue gas generated during the waste incineration process is often not fully utilized, resulting in a large amount of heat energy loss. At the same time, as a renewable energy source, biomass energy has a relatively single utilization method, and the heat source supply in the biomass gasification process also faces challenges.

[0003] In the prior art, there are some patents that attempt to combine biomass gasification with waste incineration power generation systems. For example, Patent No. CN201910318985.5 proposes a volume reduction and solidification treatment device and process for biomass gasification and reburning of waste combustion fly ash, but the system has problems such as low coupling between the biomass gasification process and the waste incineration power generation system and limited improvement in thermal energy utilization efficiency. In addition, Patent No. CN201620659837.1 proposes a biomass preparation RDF-5 smokeless incineration steam power generation system. Although it also involves the combined utilization of waste incineration and biomass energy, it still has deficiencies in waste heat recovery and system integration. Summary of the invention

[0004] In view of the problems of the current waste incineration power generation system, such as high cost investment, excessive smoke exhaust loss resulting in low power generation efficiency and poor economic benefits, the present invention proposes a waste incineration power plant waste heat utilization system integrating biomass gasification. The waste heat of the waste incineration power plant is combined with biomass gasification to effectively improve the energy utilization efficiency and economic benefits.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is: a waste heat utilization system of a garbage incineration power plant integrated with biomass gasification, including a garbage incineration boiler, a steam cycle generator set, a flue gas purification system, a biomass gasification and waste heat recovery coupling system, the steam cycle generator set is composed of a steam turbine, a condenser, a condensate pump, a regenerator, a deaerator, and a feed water pump. The steam turbine is provided with a plurality of pipeline interfaces, one pipeline interface of the steam turbine is connected to the condenser through a pipeline, the exhaust gas of the steam turbine is transported to the condenser through a pipeline, and is condensed into water by the condenser, and the condenser passes through The pipeline is connected to the condensate pump, and the condensate of the condenser is transported to the condensate pump through the pipeline; another pipeline interface of the steam turbine passes through the pipeline reheater, and the exhaust gas of the steam turbine is transported to the reheater by the pipeline to generate superheated steam, the reheater is connected to the deaerator through the pipeline, the superheated steam is transported to the deaerator through the pipeline, the superheated steam is transported to the deaerator through the pipeline, the deaerator removes oxygen and other gases dissolved in the superheated steam, the deaerator is connected to the feed water pump through the pipeline, the treated superheated steam is transported to the feed water pump through the pipeline, the feed water pump is connected to the steam drum through the pipeline to realize water circulation;

[0006] The flue gas purification system consists of a flue gas purification tower, a bag filter, a first-stage flue gas cooler, a second-stage flue gas cooler, and a smoke exhaust chimney. The flue gas purification tower receives the flue gas discharged from the waste incineration boiler through a pipeline and performs purification treatment. The treated flue gas is connected to the bag filter through another pipeline for re-treatment. The re-treated flue gas is transported to the first-stage flue gas cooler through a pipeline for treatment. The gas treated by the first-stage flue gas cooler is transported to the second-stage flue gas cooler through a pipeline for treatment. The treated gas is discharged through the smoke exhaust chimney connected to the second-stage flue gas cooler.

[0007] The biomass gasification and waste heat recovery coupling system consists of a biomass gasifier, a cyclone separator, and a synthesis gas cooler. The waste incineration boiler transports gas to the biomass gasifier through a pipeline. The biomass gasifier generates straw gas and transports it to the cyclone separator through a pipeline. The cyclone separator processes the input straw gas and separates the ash. The cyclone separator is connected to the synthesis gas cooler through a pipeline. The gas treated by the cyclone separator is input into the synthesis gas cooler for further processing and output synthesis gas. The synthesis gas is transported to the waste incineration boiler through a pipeline to realize gas energy supply.

[0008] Furthermore, the steam turbine is coaxially connected to the generator, and the outlet of the steam turbine is connected to the condenser, condensate pump, regenerator, deaerator, and feed water pump in sequence. The final exhaust steam of the steam turbine enters the condenser, the regenerator, and the deaerator respectively use extraction steam matching the steam turbine pressure as heat sources, and the regenerator drain outlet is connected to the deaerator inlet.

[0009] Furthermore, the tail flue gas pipeline of the waste incineration boiler is connected to the flue gas purification tower and the bag dust collector, and the flue gas passes through in sequence; the bag dust collector outlet pipeline is connected to the flue gas inlet of the first-stage flue gas cooler, the condensate inlet of the first-stage flue gas cooler is connected to the regenerator outlet, and the condensate outlet is connected to the deaerator inlet; the flue gas outlet of the first-stage flue gas cooler is connected to the flue gas inlet of the second-stage flue gas cooler, the gas inlet of the second-stage flue gas cooler is introduced into the air, and the gas outlet is connected to the inlet of the biomass gasification furnace.

[0010] Furthermore, a portion of the high-temperature flue gas generated by the waste incineration boiler is extracted as a heat source for the biomass gasifier. The gas will be heated by the second-stage flue gas cooler and then sent to the biomass gasifier. At the same time, a portion of the synthesis gas in the synthesis cooler is sent to the furnace of the waste incineration boiler for combustion.

[0011] The advantages of the present invention compared with the prior art are: (1) improving energy utilization efficiency: by high-intensity coupling of the biomass gasification system and the waste incineration power generation system, the high-temperature flue gas generated by the waste incineration is fully utilized as the heat source for biomass gasification, and the waste heat is used to heat condensate and air, thereby effectively improving energy utilization efficiency; (2) reducing investment costs: by optimizing the system structure and integration method, the number of equipment and the floor area are reduced, thereby reducing investment costs; (3) reducing exhaust losses: by setting up a flue gas purification system and a two-stage flue gas cooler, the exhaust temperature is effectively reduced, thereby reducing exhaust losses; (4) improving economic benefits: by improving energy utilization efficiency and reducing investment costs, the system of the present invention has higher economic benefits and market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The schematic diagram of the structure is a waste heat utilization system of a garbage incineration power plant integrating biomass gasification.

[0013] As shown in the figure: 1-waste incineration boiler; 2-biomass gasification furnace; 3-cyclone separator; 4-synthesis gas cooler; 5-steam drum; 6-flue gas purifier; 7-bag dust collector; 8-second stage flue gas cooler; 9-exhaust chimney; 10-steam turbine; 11-condenser; 12-condensate pump; 13-regenerator; 14-first stage flue gas cooler; 15-deaerator; 16-feedwater pump; 17-generator. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0015] Embodiment 1

[0016] like Figure 1As shown, this embodiment provides a waste heat utilization system of a waste incineration power plant integrated with biomass gasification, which mainly includes a waste incineration boiler 1, a steam cycle generator set, a flue gas purification system, a biomass gasification and waste heat recovery coupling system, etc. The steam cycle generator set mainly includes a steam turbine 10, a condenser 11, a condensate pump 12, a regenerative heater 13, a first-stage flue gas cooler 14, a deaerator 15, and a feed water pump 16; the flue gas purification system mainly includes a flue gas purification tower 6, a bag filter 7, a first-stage flue gas cooler 14, a second-stage flue gas cooler 8, and a smoke exhaust chimney 9; the biomass gasification and waste heat recovery coupling system mainly includes a biomass gasifier 2, a cyclone separator 3, and a synthesis gas cooler 4.

[0017] The steam turbine 10 is coaxially connected to the generator 17, and the outlet of the steam turbine 10 is connected to the condenser 11, the condensate pump 12, the regenerative heater 13, the first-stage flue gas cooler 14, the deaerator 15, and the feed water pump 16 in sequence. The exhaust steam of the last stage of the steam turbine 10 enters the condenser, and the regenerative heater 13 and the deaerator 15 use the extraction steam matching the pressure of the steam turbine 10 as the heat source, and the outlet of the regenerative heater 13 is connected to the inlet of the deaerator 15 step by step.

[0018] The flue gas pipeline at the tail end of the boiler 1 is connected to the flue gas purification tower 6 and the bag-type dust collector 7, and the flue gas passes through them in sequence; the outlet pipeline of the bag-type dust collector 7 is connected to the flue gas inlet of the first-stage flue gas cooler 14, the condensate inlet of the first-stage flue gas cooler 14 is connected to the outlet of the regenerative heater 13, and the condensate outlet is connected to the inlet of the deaerator 15; the flue gas outlet of the first-stage flue gas cooler 14 is connected to the flue gas inlet of the second-stage flue gas cooler 8, the gas inlet of the second-stage flue gas cooler 8 is introduced into the air, and the gas outlet is connected to the inlet of the biomass gasifier 2.

[0019] A portion of the high-temperature flue gas generated by waste incineration is extracted as a heat source for biomass gasification, and the air heated by the second-stage flue gas cooler 8 is sent to the biomass gasifier 2, while a portion of the synthesis gas in the synthesis cooler 4 is sent to the furnace of the waste incineration boiler 1 for combustion.

[0020] Specifically, the key components of this device include:

[0021] (1) Waste incineration boiler 1

[0022] The waste incineration boiler is of traditional design, with a high-temperature incineration chamber, a flue gas outlet and a superheated steam outlet. Its interior is made of high-temperature resistant and corrosion-resistant materials to adapt to the high temperature and corrosive gases generated during the waste incineration process. The input waste is incinerated at high temperature to produce superheated steam and high-temperature flue gas. The superheated steam is used to drive the steam turbine to generate electricity, and the high-temperature flue gas is used for subsequent flue gas purification and biomass gasification processes. The superheated steam outlet is connected to the steam turbine 10 through a pipeline, and the flue gas outlet is connected to the flue gas purification tower 6 through a pipeline.

[0023] (2) Steam turbine 10 and power generation system

[0024] The steam turbine is a multi-stage design, including a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder, and each cylinder section is provided with a steam extraction port. The generator 17 is coaxially connected to the steam turbine. The steam turbine uses the expansion of superheated steam to drive the generator to generate electricity. At the same time, part of the steam is extracted from different sections of the steam turbine to heat the deaerator 15 and the regenerative heater 13. The steam turbine is connected to the condenser 11, the condensate pump 12, the regenerator 13, the deaerator 15 and the feed water pump 16 through pipelines to form a steam cycle. The generator 17 is coaxially connected to the steam turbine to achieve electrical energy output.

[0025] (3) Flue gas purification system

[0026] The flue gas purification tower 6 adopts a multi-stage spray and packing layer design to remove particulate matter and harmful gases in the flue gas. The bag filter 7 adopts high-efficiency bag filter materials to further remove fine particulate matter in the flue gas. The first-stage flue gas cooler 14 and the second-stage flue gas cooler 8 are both shell and tube heat exchangers, which are used to reduce the flue gas temperature and recover waste heat. The flue gas discharged from the waste incineration boiler is purified to reduce its emission concentration and temperature. The flue gas purification tower 6 is connected to the flue gas outlet of the waste incineration boiler 1 through a pipeline, and the bag filter 7 is connected to the outlet of the flue gas purification tower 6. The first-stage flue gas cooler 14 is connected to the outlet of the bag filter 7, and the second-stage flue gas cooler 8 is connected to the outlet of the first-stage flue gas cooler 14.

[0027] (4) Biomass gasification and waste heat recovery coupling system

[0028] The biomass gasifier 2 is designed with a fixed bed or a fluidized bed, and is used to gasify the biomass raw material into straw gas. The cyclone separator 3 is used to separate the ash from the straw gas. The syngas cooler 4 is used to cool and purify the straw gas and output the syngas. The high-temperature flue gas generated by the incineration of garbage is used as a heat source to carry out the biomass gasification process to generate straw gas. After the straw gas is purified, part of it is used for combustion in the garbage incineration boiler, and part of it is used for other purposes such as gas-fired power generation and heating. The garbage incineration boiler 1 transports the high-temperature flue gas as a heat source to the biomass gasifier 2 through a pipeline. The straw gas generated by the biomass gasifier 2 is connected to the cyclone separator 3 through a pipeline, and the cyclone separator 3 is then connected to the syngas cooler 4 through a pipeline. Part of the syngas output by the syngas cooler 4 is returned to the furnace of the garbage incineration boiler 1 through a pipeline for combustion.

[0029] Embodiment 2

[0030] Based on the first embodiment, Figure 1As shown, the working mode of this device is: the superheated steam from the waste incineration boiler 1 enters the steam turbine 10 to expand and do work, driving the generator 17 to generate electricity, and at the same time, part of the steam is extracted from different sections of the steam turbine to heat the deaerator 15 and the regenerative heater 13. The high-temperature flue gas coming out of the tail of the waste incineration boiler 1 passes through the flue gas purification tower 6 and the bag filter 7 in turn to reduce its temperature. Then the flue gas enters the first-stage flue gas cooler 14, exchanges heat with the condensed water flowing out of the regenerative heater 13, heats the condensed water, and the heated condensed water is merged into the inlet pipeline of the deaerator 15. At this time, the flue gas temperature will drop again. The flue gas enters the second-stage flue gas cooler 8 to heat the air, and the heated air is sent to the biomass gasifier 2.

[0031] Specifically, when the garbage is incinerated and steam is generated, the garbage is put into the garbage incineration boiler 1 for incineration, generating superheated steam and high-temperature flue gas. The superheated steam enters the steam turbine 10 through the pipeline to expand and do work, driving the generator 17 to generate electricity.

[0032] During flue gas purification and waste heat recovery, high-temperature flue gas is discharged from the flue gas outlet of the waste incineration boiler 1, and is purified by the flue gas purification tower 6 and the bag filter 7 in sequence. The purified flue gas enters the first-stage flue gas cooler 14 and exchanges heat with the condensed water flowing out of the regenerative heater 13 to reduce the flue gas temperature and recover waste heat. The flue gas continues to enter the second-stage flue gas cooler 8 to heat the air, and the heated air is sent to the biomass gasifier 2 as a heat source.

[0033] When biomass is gasified and syngas is used, in the biomass gasifier 2, high-temperature flue gas is used as a heat source to carry out the biomass gasification process and generate straw gas. After the straw gas passes through the cyclone separator 3 to separate the ash and slag, it enters the syngas cooler 4 for cooling and purification. Part of the treated syngas is returned to the furnace of the waste incineration boiler 1 for combustion, and part is used for other purposes.

[0034] During the steam cycle and power generation, the steam turbine 10 extracts part of the steam from different sections to heat the deaerator 15 and the regenerative heater 13. After being pressurized by the condensate pump 12, the condensate enters the regenerative heater 13 and the deaerator 15 for heating and deoxygenation. The treated condensate is sent to the steam drum 5 through the feed water pump 16 to form a steam cycle.

[0035] It can be seen that this device realizes the effective utilization of the waste heat of flue gas from the waste incineration power plant. The circulating water that absorbs the heat of the waste incineration boiler exhaust gas is used to flow into the deaerator, which effectively reduces the high-quality steam used for extraction and heat recovery to heat the condensate, so that more high-quality steam can be used for work, effectively reducing the heat loss of exhaust gas and improving the power generation efficiency of the steam turbine. The air passes through the second-stage flue gas cooler and is heated to 50-60°C by the flue gas. The heated air is sent into the biomass gasifier, and part of the synthesis gas is sent back to the boiler, which strengthens the boiler combustion and reasonably utilizes the waste heat in the tail flue gas within a reasonable temperature range.

[0036] The above shows and describes the basic principles and main features of the present invention and the advantages of the invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A waste heat utilization system for a waste incineration power plant with biomass gasification, comprising a waste incineration boiler (1), a steam cycle generator set, a flue gas purification system, and a biomass gasification and waste heat recovery coupling system, characterized in that: The steam cycle generator set is composed of a steam turbine (10), a condenser (11), a condensate pump (12), a regenerator (13), a deaerator (15), and a feed water pump (16); the steam turbine (10) is provided with a plurality of pipeline interfaces; one pipeline interface of the steam turbine (10) is connected to the condenser (11) via a pipeline; the exhaust gas of the steam turbine (10) is transported to the condenser (11) via a pipeline and condensed into water by the condenser (11); the condenser (11) is connected to the condensate pump (12) via a pipeline; the condensed water of the condenser (11) is transported to the condensate pump (12) via a pipeline; the steam turbine (10) Another pipeline interface is connected to the pipeline reheater (13), the exhaust gas of the steam turbine (10) is transported to the reheater (13) through the pipeline to generate superheated steam, the reheater (13) is connected to the deaerator (15) through the pipeline, the superheated steam is transported to the deaerator (15) through the pipeline, the superheated steam is transported to the deaerator (15) through the pipeline, the deaerator (15) removes oxygen and other gases dissolved in the superheated steam, the deaerator (15) is connected to the feed water pump (16) through the pipeline, the treated superheated steam is transported to the feed water pump (16) through the pipeline, the feed water pump (16) is connected to the steam drum (5) through the pipeline, and the water circulation is realized; The flue gas purification system is composed of a flue gas purification tower (6), a bag filter (7), a first-stage flue gas cooler (14), a second-stage flue gas cooler (8), and a smoke exhaust chimney (9). The flue gas purification tower (6) receives the flue gas discharged from the waste incineration boiler (1) through a pipeline and performs purification treatment. The treated flue gas is connected to the bag filter (7) through another pipeline for re-treatment. The re-treated flue gas is transported to the first-stage flue gas cooler (14) through a pipeline for treatment. The gas treated by the first-stage flue gas cooler (14) is transported to the second-stage flue gas cooler (8) through a pipeline for treatment. The treated gas is discharged through the smoke exhaust chimney (9) connected to the second-stage flue gas cooler (8); The biomass gasification and waste heat recovery coupling system is composed of a biomass gasifier (2), a cyclone separator (3), and a synthesis gas cooler (4). The waste incineration boiler (1) transmits gas to the biomass gasifier (2) through a pipeline. The biomass gasifier (2) generates straw gas and transmits it to the cyclone separator (3) through a pipeline. The cyclone separator (3) processes the input straw gas and separates ash. The cyclone separator (3) is connected to the synthesis gas cooler (4) through a pipeline. The gas processed by the cyclone separator (3) is input into the synthesis gas cooler (4) for reprocessing and outputting synthesis gas. The synthesis gas is transmitted to the waste incineration boiler (1) through a pipeline to realize gas energy supply.

2. The waste heat utilization system of a waste incineration power plant integrated with biomass gasification according to claim 1 is characterized by: The steam turbine (10) is coaxially connected to the generator (17); the outlet of the steam turbine (10) is connected to the condenser (11), the condensate pump (12), the regenerator (13), the deaerator (15), and the feed water pump (16) in sequence; the final exhaust steam of the steam turbine (10) enters the condenser, the regenerator (13), and the deaerator (15), respectively using extraction steam matching the pressure of the steam turbine (10) as a heat source; the drain outlet of the regenerator (13) is connected to the inlet of the deaerator (15).

3. The waste heat utilization system of a waste incineration power plant integrated with material gasification according to claim 1 is characterized in that: The tail flue gas pipeline of the waste incineration boiler (1) is connected to the flue gas purification tower (6) and the bag filter (7), and the flue gas passes through them in sequence; the outlet pipeline of the bag filter (7) is connected to the flue gas inlet of the first-stage flue gas cooler (14), the condensate inlet of the first-stage flue gas cooler (14) is connected to the outlet of the regenerator (13), and the condensate outlet is connected to the inlet of the deaerator (15); the flue gas outlet of the first-stage flue gas cooler (14) is connected to the flue gas inlet of the second-stage flue gas cooler (8), the gas inlet of the second-stage flue gas cooler (8) is introduced with air, and the gas outlet is connected to the inlet of the biomass gasification furnace (2).

4. The waste heat utilization system of a waste incineration power plant integrated with material gasification according to claim 1 is characterized in that: A portion of the high-temperature flue gas generated by the waste incineration boiler (1) is extracted as a heat source for the biomass gasifier (2). The gas is heated by a second-stage flue gas cooler (8) and then fed into the biomass gasifier (2). At the same time, a portion of the synthesis gas in the synthesis cooler (4) is fed into the furnace of the waste incineration boiler (1) for combustion.

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