阅读说明：本技术 一种利用烟气低温潜热的联合循环高效清洁发电装置及方法 (Combined-cycle efficient clean power generation device and method utilizing low-temperature latent heat of flue gas ) 是由 李硕 周贤 王长军 许世森 杨智 何宗伟 刘峻 潘晓伟 王瑞元 倪洋 于 2020-06-16 设计创作，主要内容包括：本发明提供的一种利用烟气低温潜热的联合循环高效清洁发电装置及方法,降低了联合循环余热锅炉排烟温度,大幅度回收了联合循环余热锅炉烟气余热,提高了能源利用效率,具有显著的经济效益；同时提高了进入燃气轮机燃烧室空气湿度,降低了氧气浓度,最终降低了燃烧室内燃烧温度,减小了燃烧高温区域,从而达到了降低NOx原始排放浓度和延长燃气轮机高温部件寿命的目的,加湿后的干空气进入燃气轮机后,提高了燃气轮机的比功,增加了燃气轮机的发电量；由于大幅度降低烟气温度,缓解了白色烟羽的视觉污染现象,回收的烟气凝结水可减小电厂水耗。(The combined-cycle efficient clean power generation device and method utilizing low-temperature latent heat of flue gas provided by the invention have the advantages that the flue gas temperature of the combined-cycle waste heat boiler is reduced, the flue gas waste heat of the combined-cycle waste heat boiler is greatly recovered, the energy utilization efficiency is improved, and the obvious economic benefit is realized; meanwhile, the humidity of air entering a combustion chamber of the gas turbine is improved, the oxygen concentration is reduced, the combustion temperature in the combustion chamber is finally reduced, and a combustion high-temperature area is reduced, so that the aims of reducing the original emission concentration of NOx and prolonging the service life of high-temperature parts of the gas turbine are fulfilled; as the temperature of the flue gas is greatly reduced, the visual pollution phenomenon of white smoke plume is relieved, and the water consumption of a power plant can be reduced by the recovered flue gas condensed water.)

1. A combined cycle efficient clean power generation device utilizing low-temperature latent heat of flue gas is characterized by comprising a gas turbine compressor (1), a gas turbine combustion chamber (2), a gas turbine (3), a waste heat boiler (4), a steam turbine (5), a flue gas condensation heat exchanger (7) and an air humidifier (9), wherein the gas turbine combustion chamber (2) is provided with a high-pressure air inlet which is connected with a high-pressure air outlet of the gas turbine compressor (1); a high-temperature high-pressure gas outlet is formed in the gas turbine combustion chamber (2), the high-temperature high-pressure gas outlet is connected with a gas turbine (3), and the gas turbine (3) is connected with a generator; a flue gas outlet of the gas turbine (3) is connected with a flue gas inlet of the waste heat boiler (4); a steam outlet arranged on the waste heat boiler (4) is connected with a steam turbine (5), and the steam turbine (5) is connected with a generator; a flue gas outlet of the waste heat boiler (4) is connected with a flue gas inlet of a flue gas condensation heat exchanger (7); an intermediate water outlet is formed in the bottom of the flue gas condensation heat exchanger (7) and is connected with an air humidifier (9); the top of the air humidifier (9) is provided with a wet air outlet which is connected with an air inlet of a gas turbine compressor (1); the bottom of the air humidifier (9) is provided with a dry air inlet.

2. The combined-cycle high-efficiency clean power generation device utilizing the low-temperature latent heat of the flue gas as claimed in claim 1, wherein a dead steam outlet is arranged on the steam turbine (5), and the dead steam outlet is connected with an inlet of a condenser (6); and a condensed water outlet of the condenser (6) is connected with a condensed water inlet of the waste heat boiler (4).

3. The combined-cycle high-efficiency clean power generation device utilizing the low-temperature latent heat of flue gas as claimed in claim 1, characterized in that the flue gas condensing heat exchanger (7) and the air humidifier (9) are in direct contact type structures.

4. The combined-cycle high-efficiency cleaning power generation device utilizing the low-temperature latent heat of flue gas as claimed in claim 1, wherein a first demister (12), a first liquid distribution layer (11) and a first spraying layer (10) are arranged in the inner cavity of the flue gas condensing heat exchanger (7) from top to bottom in sequence; and a flue gas inlet of the flue gas condensation heat exchanger (7) is arranged below the first spraying layer (10).

5. The combined cycle high-efficiency clean power generation device utilizing the low-temperature latent heat of flue gas as claimed in claim 1, wherein a condensed water storage tank is arranged at the bottom of the flue gas condensation heat exchanger (7), and a condensed water outlet is formed in the condensed water storage tank; the condensed water storage tank is arranged below the flue gas inlet.

6. The combined-cycle high-efficiency clean power generation device utilizing the low-temperature latent heat of flue gas as claimed in claim 1, characterized in that the top of the flue gas condensing heat exchanger (7) is provided with a low-temperature flue gas outlet, and the low-temperature flue gas outlet is connected with a chimney (8).

7. The combined-cycle high-efficiency clean power generation device using the low-temperature latent heat of flue gas as claimed in claim 1, wherein a second demister (15), a second liquid distribution layer (14) and a second spraying layer (13) are arranged in the inner cavity of the air humidifier (9) from top to bottom in sequence; and an intermediate water outlet of the air humidifier (9) is arranged below the second spraying layer (13).

8. A combined-cycle high-efficiency clean power generation method utilizing low-temperature latent heat of flue gas, which is characterized in that the combined-cycle high-efficiency clean power generation device utilizing low-temperature latent heat of flue gas based on any one of claims 1 to 7 comprises the following steps:

the natural gas is subjected to combustion reaction with high-pressure air compressed by a gas compressor (1) of the gas turbine in a combustion chamber (2) of the gas turbine to form high-temperature and high-pressure gas, the high-temperature and high-pressure gas is sent to a turbine (3) of the gas turbine to push the turbine (3) of the gas turbine to rotate, so that the conversion of heat energy to mechanical energy is realized, and the turbine (3) of the gas turbine drives a generator to realize the conversion of the mechanical energy to electric energy;

the high-temperature flue gas discharged by the gas turbine (3) is sent to a waste heat boiler (4), the waste heat of the flue gas is recovered by the waste heat boiler (4), and high-temperature and high-pressure water vapor is generated; the steam is sent into a steam turbine (5) and drives a generator to output electric energy;

the flue gas at the outlet of the waste heat boiler (4) is sent into a flue gas condensation heat exchanger (7), and exchanges heat with intermediate water in the flue gas condensation heat exchanger (7) and is cooled to be below the dew point of the water; the intermediate water is heated and then sent into an air humidifier (9) to perform a countercurrent heat and mass transfer process with dry and cold air, and the intermediate water is cooled;

the dry and cold air forms wet air and is sent into a compressor (1) of the gas turbine.

Technical Field

The invention belongs to the field of thermal power generation energy conservation and emission reduction, and particularly relates to a combined-cycle efficient clean power generation device and method utilizing low-temperature latent heat of flue gas.

Background

The flue gas after the combustion of the natural gas contains a large amount of water vapor, the proportion of the latent heat of vaporization of the water vapor in the flue gas to the high-order heating value of the natural gas reaches 10-11%, and the latent heat of the existing natural gas flue gas is basically not utilized and is directly discharged into the environment. In addition, water vapor in the natural gas flue gas is directly discharged into the atmosphere, so that water loss is caused, a white smoke plume phenomenon is formed, and landscape pollution is caused. The deep recycling of the flue gas waste heat including the latent heat of condensation of water vapor is of great significance to energy conservation and pollutant discharge reduction. The deep utilization technology of the flue gas waste heat is characterized in that a condensing heat exchanger is additionally arranged on a tail flue, high-humidity flue gas and intermediate water exchange heat efficiently in the heat exchanger, the flue gas is cooled and condensed rapidly, and most of water vapor is removed and then sent into a chimney. After the intermediate water exchanging heat with the flue gas is heated, an additional heat source can be provided for the combined cycle.

In addition, the concentration of NOx formed in natural gas during combustion is primarily affected by temperature, and thermal NOx emissions increase exponentially with increasing temperature. After steam or water is injected into combustion air of the gas turbine, the generation of thermal NOx in the combustion process can be reduced after wet air enters the gas turbine. Studies have shown that diffusion combustion and premixed combustion NOx emissions are reduced by 38.8% and 12.2%, respectively, when the air moisture content is increased to 15g/kg compared to dry air combustion. In addition, after the humidity of combustion air of the gas turbine is improved, the specific work of the gas turbine can be improved, and therefore the power generation power of the gas turbine is improved.

Disclosure of Invention

The invention aims to provide a combined-cycle efficient clean power generation device and method utilizing low-temperature latent heat of flue gas, and the defect of resource waste in the prior art is overcome.

In order to achieve the purpose, the invention adopts the technical scheme that:

the invention provides a combined cycle high-efficiency clean power generation device utilizing low-temperature latent heat of flue gas, which comprises a gas turbine compressor, a gas turbine combustion chamber, a gas turbine, a waste heat boiler, a steam turbine, a flue gas condensation heat exchanger and an air humidifier, wherein the gas turbine combustion chamber is provided with a high-pressure air inlet which is connected with a high-pressure air outlet of the gas turbine compressor; the gas turbine combustion chamber is provided with a high-temperature high-pressure gas outlet which is connected with a gas turbine, and the gas turbine is connected with a generator; a flue gas outlet of the gas turbine is connected with a flue gas inlet of the waste heat boiler; a steam outlet arranged on the waste heat boiler is connected with a steam turbine, and the steam turbine is connected with a generator; the flue gas outlet of the waste heat boiler is connected with the flue gas inlet of the flue gas condensation heat exchanger; the bottom of the flue gas condensation heat exchanger is provided with an intermediate water outlet which is connected with an air humidifier; the top of the air humidifier is provided with a wet air outlet, and the wet air outlet is connected with an air inlet of a gas turbine compressor; the bottom of the air humidifier is provided with a dry air inlet.

Preferably, the steam turbine is provided with a waste steam outlet, and the waste steam outlet is connected with an inlet of the condenser; and a condensed water outlet of the condenser is connected with a condensed water inlet of the waste heat boiler.

Preferably, the flue gas condensing heat exchanger and the air humidifier are both in a direct contact structure.

Preferably, a first demister, a first liquid distribution layer and a first spraying layer are sequentially arranged in an inner cavity of the flue gas condensation heat exchanger from top to bottom; and a flue gas inlet of the flue gas condensation heat exchanger is arranged below the first spraying layer.

Preferably, a condensed water storage tank is arranged at the bottom of the flue gas condensing heat exchanger, and a condensed water outlet is formed in the condensed water storage tank; the condensed water storage tank is arranged below the flue gas inlet.

Preferably, a low-temperature flue gas outlet is formed in the top of the flue gas condensation heat exchanger, and the low-temperature flue gas outlet is connected with a chimney.

Preferably, a second demister, a second liquid distribution layer and a second spraying layer are sequentially arranged in the inner cavity of the air humidifier from top to bottom; and an intermediate water outlet of the air humidifier is arranged below the second spraying layer.

A combined-cycle efficient clean power generation method utilizing low-temperature latent heat of flue gas is based on the combined-cycle efficient clean power generation device utilizing the low-temperature latent heat of the flue gas, and comprises the following steps:

the natural gas is subjected to combustion reaction with high-pressure air compressed by a gas compressor of the gas turbine in a combustion chamber of the gas turbine to form high-temperature and high-pressure gas, the high-temperature and high-pressure gas is sent to a turbine of the gas turbine to push the turbine of the gas turbine to rotate, so that the conversion of heat energy to mechanical energy is realized, and the turbine of the gas turbine drives a generator to realize the conversion of the mechanical energy to electric energy;

the method comprises the following steps that high-temperature flue gas exhausted by a turbine of a gas turbine is sent to a waste heat boiler, waste heat of the flue gas is recovered by the waste heat boiler, and high-temperature and high-pressure water vapor is generated; the steam is sent into a steam turbine and drives a generator to output electric energy;

the flue gas at the outlet of the waste heat boiler is sent into a flue gas condensation heat exchanger, exchanges heat with intermediate water in the flue gas condensation heat exchanger and is cooled to be below the water dew point; the intermediate water is heated and then sent into an air humidifier to perform a countercurrent heat and mass transfer process with dry and cold air, and the intermediate water is cooled; the dry and cold air forms wet air and is sent into a compressor of the gas turbine.

Compared with the prior art, the invention has the beneficial effects that:

the combined-cycle efficient clean power generation device and method utilizing low-temperature latent heat of flue gas provided by the invention have the advantages that the flue gas temperature of the combined-cycle waste heat boiler is reduced, the flue gas waste heat of the combined-cycle waste heat boiler is greatly recovered, the energy utilization efficiency is improved, and the obvious economic benefit is realized; meanwhile, the humidity of air entering a combustion chamber of the gas turbine is improved, the oxygen concentration is reduced, the combustion temperature in the combustion chamber is finally reduced, and a combustion high-temperature area is reduced, so that the aims of reducing the original emission concentration of NOx and prolonging the service life of high-temperature parts of the gas turbine are fulfilled; as the temperature of the flue gas is greatly reduced, the visual pollution phenomenon of white smoke plume is relieved, and the water consumption of a power plant can be reduced by the recovered flue gas condensed water.

Furthermore, the direct contact structure of the flue gas condensation heat exchanger and the air humidifier ensures that the intermediate water dilutes impurities in the flue gas, the requirement on corrosion resistance of the heat exchanger material is low, and the flue gas resistance can be controlled within an acceptable range.

Drawings

Fig. 1 is a schematic structural view of a power generation device according to the present invention.

Detailed Description

The invention mainly aims to provide a combined-cycle efficient clean power generation device and a combined-cycle efficient clean power generation method utilizing low-temperature latent heat of flue gas. The heated intermediate water is sent into a direct contact type air humidifier arranged at the inlet of the gas compressor of the gas turbine to perform a countercurrent heat and mass transfer process with dry and cold air, so that the air humidity and temperature are improved. The technology related by the system is mature and reliable, the energy utilization efficiency can be effectively improved, the flue gas condensate water is recovered, the original emission concentration of NOx is reduced, the phenomenon of white smoke plume visual pollution is relieved, and the system has remarkable economic benefit and environmental protection benefit.

The combined-cycle efficient clean power generation device comprises a gas turbine compressor 1, a gas turbine combustion chamber 2, a gas turbine 3, a waste heat boiler 4, a steam turbine 5, a condenser 6, a direct-contact flue gas condensing heat exchanger 7, a chimney 8, a direct-contact air humidifier 9, a first spraying layer 10, a first liquid distribution layer 11, a first demister 12, a second spraying layer 13, a second liquid distribution layer 14, a second demister 15, a second water pump 16 and a first water pump 17, wherein the gas turbine combustion chamber 2 is provided with a high-pressure air inlet which is connected with a high-pressure air outlet of the gas turbine compressor 1; the gas turbine combustion chamber 2 is provided with a high-temperature high-pressure gas outlet which is connected with the gas turbine 3 to push the gas turbine 3 to rotate.

The gas turbine 3 is connected to an electric generator.

A flue gas outlet of the gas turbine 3 is connected with a flue gas inlet of the waste heat boiler 4; and a steam outlet arranged on the waste heat boiler 4 is connected with a steam turbine 5, and the steam turbine 5 is connected with a generator.

The steam turbine 5 is provided with a waste steam outlet which is connected with an inlet of a condenser 6; and a condensed water outlet of the condenser 6 is connected with a condensed water inlet of the waste heat boiler 4.

And a flue gas outlet of the waste heat boiler 4 is connected with a flue gas inlet of the direct contact type flue gas condensation heat exchanger 7.

A first demister 12, a first liquid distribution layer 11 and a first spraying layer 10 are sequentially arranged in an inner cavity of the direct contact type flue gas condensation heat exchanger 7 from top to bottom; the flue gas inlet of the direct contact type flue gas condensation heat exchanger 7 is arranged below the first spraying layer 10.

And a condensed water storage tank is arranged at the bottom of the direct contact type flue gas condensation heat exchanger 7, and a condensed water outlet is formed in the condensed water storage tank.

The condensed water storage tank is arranged below the flue gas inlet.

The top of the direct contact type flue gas condensation heat exchanger 7 is provided with a low-temperature flue gas outlet which is connected with a chimney 8.

The bottom of the direct contact type flue gas condensation heat exchanger 7 is provided with an intermediate water outlet, and the intermediate water outlet is connected with a direct contact type air humidifier 9 through a first water pump 17.

And a second demister 15, a second liquid distribution layer 14 and a second spraying layer 13 are sequentially arranged in the inner cavity of the direct contact type air humidifier 9 from top to bottom.

An intermediate water outlet is formed in the bottom of the direct contact type air humidifier 9 and is connected with an intermediate water inlet formed in the top of the direct contact type flue gas condensation heat exchanger 7 through a second water pump 16.

The bottom of the direct contact air humidifier 9 is provided with a dry air inlet.

The top of the direct contact type air humidifier 9 is provided with a wet air outlet, and the wet air outlet is connected with an air inlet of the gas turbine compressor 1.

The working process is as follows:

the natural gas is subjected to a combustion reaction with high-pressure air compressed by the gas compressor 1 of the gas turbine in the gas turbine combustion chamber 2 to form high-temperature and high-pressure gas, the high-temperature and high-pressure gas is sent to the gas turbine 3 to push the gas turbine 3 to rotate, so that the conversion of heat energy to mechanical energy is realized, and the gas turbine 3 drives the generator to realize the conversion of the mechanical energy to electric energy.

The flue gas with higher temperature discharged by the gas turbine 3 is sent to a waste heat boiler 4, the waste heat of the flue gas is recovered by the waste heat boiler 4, and high-temperature and high-pressure steam is generated; the steam is sent to the steam turbine 5 and drives the generator to output electric energy.

And the exhaust steam discharged by the steam turbine 5 is sent to a condenser 6, condensed water is formed in the condenser 6, and then the condensed water is sent to the waste heat boiler 4 to continuously recover the waste heat of the flue gas.

The flue gas at the outlet of the waste heat boiler 4 is sent into the direct contact type flue gas condensation heat exchanger 7, and sequentially passes through the first spraying layer 10, the first liquid distribution layer 11 and the first demister 12 in the direct contact type flue gas condensation heat exchanger 7, exchanges heat with intermediate water, cools down to below a water dew point, and simultaneously discharges condensed water.

The low-temperature flue gas at the outlet of the direct contact type flue gas condensation heat exchanger 7 is directly sent into a chimney 8 and is discharged into the atmosphere; after the temperature of the intermediate water is raised, the intermediate water is sent into the direct contact type air humidifier 9 by the first water pump 17 to perform a countercurrent heat and mass transfer process with the dry and cold air, so that the air humidity and temperature are improved.

The dry and cold air passes through the second spraying layer 13, the second liquid distribution layer 14 and the second demister 15 in sequence to form wet air, and the wet air is sent into the gas turbine compressor 1.

The intermediate water is pumped to the cooling water inlet of the direct contact type flue gas condensation heat exchanger 7 by a second water pump 16 after being cooled.