Clean, efficient and stable ammonia humidification combustion power generation system and method

Abstract

The invention relates to a clean, efficient and stable ammonia humidification combustion power generation system and method, and belongs to the technical field of ammonia fuel clean and efficient combustion power generation. The ammonia fuel supply unit is used for providing fuel for the staged combustion chamber unit; the air supply unit is used for providing air for the staged combustion chamber unit; the oxygen supply unit is used for providing oxygen for the staged combustion chamber unit; the water supply unit provides water for the staged combustion chamber unit; the heat recovery unit recovers heat energy of the staged combustion chamber unit; and the staged combustion chamber unit does work to generate power. Water is adopted as a diluent, a humidification strategy far away from a flame root reaction area is adopted, the system mass flow rate is increased, the temperature of a combustion chamber is effectively restrained, the ammonia combustion power generation efficiency is improved, and meanwhile the thermal load of turbine machinery is reduced; ammonia oxygen-enriched on-duty flames are arranged at the roots of ammonia / air main flames, and the ignition characteristic of the ammonia flames and the stability of a power generation system are improved.

Description

Technical Field

[0001] The invention relates to an ammonia humidification combustion system and method, belonging to the technical field of clean and efficient combustion power generation of ammonia fuel. Background Art

[0002] The carbon emission problem caused by the electricity energy structure dominated by fossil fuels has seriously restricted the green development of the economy, and there is an urgent need to vigorously develop zero-carbon energy technology. Hydrogen production from renewable energy is a clean and efficient zero-carbon energy technology, but due to the difficulty and high cost of hydrogen storage and transportation technology, converting hydrogen into ammonia in the form of chemical energy storage is a potential sustainable energy development path. However, ammonia as a fuel has problems such as low flame speed, narrow flammability range, difficult ignition, and high NOx emissions, which limits the clean and efficient use of ammonia fuel.

[0003] In order to make ammonia fuel compatible with existing combustion power generation systems, the conventional method is to blend it with other active fuels such as hydrogen, natural gas, synthesis gas, coal, etc. Compared with blending active fuels, fuel preheating and oxygen-enriched combustion technology can significantly improve ammonia combustion activity while reducing blending process costs and achieving zero carbon emissions, while being compatible with existing industrial combustion systems.

[0004] The Brayton cycle is an important technical strategy for traditional gas turbine power generation systems. The key is that the combustion products directly do work, and high-power combustion may cause thermal overload problems in the working machinery. Water is the main product of ammonia combustion. The wet combustion strategy using it as a diluent can effectively control the ammonia combustion temperature, increase the system mass flow, and improve power generation efficiency.

[0005] Conventional carbon-based fuel combustion mainly produces thermal NOx, while NOx produced by ammonia combustion is mainly fuel NOx. Therefore, it is necessary to organize the injection strategy reasonably according to the combustion characteristics of ammonia. The staged combustion is adopted to make full use of the ammonia reduction characteristics to reduce NOx emissions, and the water dilution technology is combined to further reduce fuel NOx emissions and reduce thermal NOx generation.

[0006] Traditional wet combustion technology reduces flame temperature and thermal NOx by humidifying the oxidant. For example, the publication number is CN116517694A, and the name of the invention is gas turbine system. In its technical solution, the humidified air output by the humidification mechanism is mixed with the fuel gas, which not only increases the flow rate of the mixed working fluid entering the turbine mechanism, but also suppresses the generation of nitrogen oxides in the fuel gas, while improving the efficiency of the turbine mechanism. However, ammonia fuel has weaker fuel activity than conventional carbon-based fuels. Excessive humidification in an ammonia fuel mixture system will aggravate ammonia combustion instability, cause combustion instability phenomena such as blowout, and reduce combustion power generation efficiency and effective burnout rate. Ammonia flame stability is closely related to the flame root reaction zone, and a humidification strategy away from the root reaction zone needs to be adopted.

[0007] Therefore, there is an urgent need to propose a clean, efficient and stable ammonia humidified combustion power generation system and method to solve the above technical problems. Summary of the invention

[0008] In order to solve the above problems, a clean, efficient and stable ammonia humidified combustion power generation system and method is provided. A brief overview of the invention is given below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive overview of the invention. It is not intended to determine the key or important parts of the invention, nor is it intended to limit the scope of the invention.

[0009] The technical solution of the present invention:

[0010] A clean, efficient and stable ammonia humidified combustion power generation system, comprising:

[0011] Ammonia fuel supply unit: provides fuel for the staged combustion chamber unit;

[0012] Air supply unit: provides air for the staged combustion chamber unit;

[0013] Oxygen supply unit: provides oxygen to the staged combustion chamber unit;

[0014] Water supply unit: provides water for the staged combustion chamber unit;

[0015] Heat recovery unit: recover heat energy from staged combustion chamber unit;

[0016] Staged combustion chamber unit: The staged combustion chamber unit performs work to generate electricity.

[0017] Preferably: the staged combustion chamber unit includes a staged combustion chamber, a secondary injector, a primary injector, a duty flame premixing chamber and a main flame premixing chamber, and the secondary injector, the primary injector, the duty flame premixing chamber and the main flame premixing chamber are arranged in sequence from right to left in the staged combustion chamber unit, and the staged combustion chamber is connected to the turbine generator.

[0018] Preferably: the number of main flame premixing chambers is one, the number of secondary injectors, primary injectors and duty flame premixing chambers are two each, and the secondary injectors, primary injectors and duty flame premixing chambers are symmetrically arranged.

[0019] Preferably: the ammonia fuel supply unit comprises a liquid ammonia storage tank, an ammonia booster pump and a shell side of a liquid ammonia evaporator, the liquid ammonia storage tank, the ammonia booster pump and the shell side inlet of the liquid ammonia evaporator are connected in sequence, and the secondary injector, the primary injector, the duty flame premixing chamber and the main flame premixing chamber are all connected to the shell side outlet of the liquid ammonia evaporator.

[0020] Preferably: the air supply unit includes an air compressor, a shell side of an air preheater, an air booster pump, an on-duty air compressor and an on-duty air booster pump; the air compressor, the air booster pump and the shell side inlet of the air preheater are connected in sequence; the secondary injector, the primary injector and the main flame premixing chamber are all connected to the shell side outlet of the air preheater; the on-duty air compressor, the on-duty air booster pump and the on-duty flame premixing chamber are connected in sequence.

[0021] Preferably, the oxygen supply unit comprises an oxygen storage tank, an oxygen compressor and an oxygen booster pump, and the oxygen storage tank, the oxygen compressor, the oxygen booster pump and the on-duty flame premixing chamber are connected in sequence.

[0022] Preferably: the water supply unit includes a hot water storage tank and a first water suction pump, the secondary ejector and the primary ejector are connected to the hot water storage tank outlet through the first water suction pump; the hot water storage tank is connected to a water quality detector to monitor the ammonia concentration in the storage tank water in real time online.

[0023] Preferably: the heat recovery unit includes a normal temperature water storage tank, a flue gas cooling heat exchanger, a second water suction pump, a pipe side of an air preheater, a compressor, and a pipe side of a liquid ammonia evaporator; the outlet of the staged combustion chamber, a turbine power generation machine, a pipe side of a liquid ammonia evaporator, a compressor, a pipe side of an air preheater, and a flue gas cooling heat exchanger are connected in sequence; the normal temperature water storage tank, a second water suction pump, a flue gas cooling heat exchanger, and an inlet of a hot water storage tank are connected.

[0024] Preferably: it also includes a first regulating valve, a second regulating valve, a third regulating valve, a fourth regulating valve, a fifth regulating valve, a sixth regulating valve, a seventh regulating valve, an eighth regulating valve, a tenth regulating valve, an eleventh regulating valve, a twelfth regulating valve and a thirteenth regulating valve, the liquid ammonia evaporator is connected to the inlets of the corresponding secondary injector, the primary injector, the main flame premixing chamber and the duty flame premixing chamber through the eleventh regulating valve, the tenth regulating valve, the sixth regulating valve and the fourth regulating valve respectively, the air preheater is connected to the inlets of the corresponding secondary injector, the primary injector, the main flame premixing chamber and the duty flame premixing chamber through the eighth regulating valve, the seventh regulating valve, the fifth regulating valve and the thirteenth regulating valve respectively, the oxygen booster pump is connected to the inlet of the duty flame premixing chamber through the first regulating valve, the first water suction pump is connected to the corresponding secondary injector and the primary injector through the third regulating valve and the second regulating valve respectively, and the second water suction pump is connected to the flue gas cooling heat exchanger through the twelfth regulating valve.

[0025] A clean, efficient and stable ammonia humidified combustion method, using a clean, efficient and stable ammonia humidified combustion power generation system, comprising the following steps:

[0026] In the duty flame premixing chamber at the root of the main flame, an ammonia-oxygen-enriched system is used to form the duty flame, which serves as a continuous ignition source at the root of the ammonia main flame, preventing the main flame from being blown out and improving system instability;

[0027] During system operation, the combustion organization mode can be switched between fuel staged organization mode and air staged organization mode, and the primary injector and the secondary injector are far away from the main flame root reaction zone;

[0028] In the fuel staged organization mode, the main flame premixing chamber is a lean combustion system. The primary injector sprays ammonia fuel and water mist, and the excess ammonia fuel is used to reduce NOx and reduce the heat load of the combustion chamber. The secondary injector sprays air and water mist, and the excess air consumes the remaining ammonia fuel.

[0029] In the air staged organization mode, the main flame premixing chamber is a rich combustion system. The primary injector sprays air and water mist to consume the remaining ammonia fuel and reduce the heat load of the combustion chamber through excess air; the secondary injector sprays ammonia fuel and water mist to reduce NOx through excess ammonia fuel.

[0030] After combustion, the flue gas flows out from the staged combustion chamber and generates electricity through a turbine generator; the high-temperature flue gas is used as the heating medium in the liquid ammonia evaporator, the flue gas is compressed and heated up again by the compressor, the flue gas passes through the air preheater, and the flue gas is cooled by the flue gas cooling heat exchanger. The cooling water in the flue gas cooling heat exchanger comes from the normal temperature water storage tank and is pumped to the direct heat exchange device through the second water suction pump to perform direct contact cooling on the flue gas. After cooling, the moisture and gas phase are separated; the gas phase is directly discharged, and the cooling water that absorbs heat is stored in the hot water storage tank as a water source for spraying; the concentration of ammonia dissolved in water in the hot water storage tank is monitored online by a water quality detector, and the ammonia spraying amount of the primary injector and the secondary injector is adjusted based on the real-time monitoring of the ammonia concentration.

[0031] The present invention has the following beneficial effects:

[0032] The ammonia humidified combustion power generation system proposed in the present invention uses liquid ammonia as fuel, air and oxygen as oxidants, and the combustion system is a zero-carbon system with no carbon emissions.

[0033] The present invention uses preheating of ammonia fuel and air to improve the activity of ammonia fuel, thereby increasing the ammonia combustion rate and flame stability;

[0034] The present invention uses water as a diluent, which increases the system mass flow and effectively suppresses the combustion chamber temperature, thereby improving the ammonia combustion power generation efficiency and reducing the turbine mechanical heat load; adopts a humidification strategy away from the root of the ammonia flame, and sets an ammonia oxygen-enriched duty flame at the root of the ammonia / air main flame to improve the ignition characteristics and flame stability of the ammonia flame;

[0035] The flue gas after the turbine of the present invention is used as the heat source for evaporation of liquid ammonia and preheating of air, and the waste heat of the flue gas is recovered into the liquid water diluent, thereby reducing the energy consumption of the heat cycle;

[0036] The present invention can effectively reduce NOx emissions and inhibit the escape of unburned ammonia by adjusting the hierarchical organization mode of the combustion chamber, thereby achieving ultra-low NOx emissions and no denitration equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of a clean, efficient and stable ammonia humidified combustion power generation system.

[0038] In the figure: 1- oxygen storage tank, 2- oxygen compressor, 3- oxygen booster pump, 4- hot water storage tank, 5- normal temperature water storage tank, 6- liquid ammonia storage tank, 7- flue gas cooling heat exchanger, 8- second water suction pump, 9- air compressor, 10- ammonia booster pump, 11- first water suction pump, 12- air preheater, 13- compressor, 14- air booster pump, 15- liquid ammonia evaporator, 16- turbine power generation machinery, 17- staged combustion chamber, 18- secondary injection Injector, 19-primary injector, 20-duty flame premixing chamber, 21-main flame premixing chamber, 22-first regulating valve, 23-second regulating valve, 24-third regulating valve, 25-fourth regulating valve, 26-fifth regulating valve, 27-sixth regulating valve, 28-seventh regulating valve, 29-eighth regulating valve, 30-tenth regulating valve, 31-eleventh regulating valve, 32-twelfth regulating valve, 33-water quality detector, 34-thirteenth regulating valve. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0040] Specific implementation method 1: Combination Figure 1 This embodiment is described as a clean, efficient and stable ammonia humidification combustion power generation system, comprising:

[0041] Staged combustion chamber unit: one or more staged injection channels are arranged in the staged combustion chamber to achieve water mixing, fuel staged or oxidant staged; the number of staged injection channels for water, fuel and oxidant is at least two respectively, and the staged injection channels for water, fuel and oxidant are independent of each other;

[0042] The staged combustion chamber unit includes a staged combustion chamber 17, a secondary injector 18, a primary injector 19, a duty flame premixing chamber 20 and a main flame premixing chamber 21. The staged combustion chamber unit is provided with the secondary injector 18, the primary injector 19, the duty flame premixing chamber 20 and the main flame premixing chamber 21 in sequence from right to left. The staged combustion chamber 17 is connected to a turbine generator 16.

[0043] The number of the main flame premixing chamber 21 is one, the right end of the staged combustion chamber 17 is the staged combustion chamber outlet, the left end of the staged combustion chamber 17 is provided with the main flame premixing chamber 21, the outlet center of the main flame premixing chamber is provided at the horizontal center line (central axis) of the staged combustion chamber 17, the outlet of the main flame premixing chamber includes a plurality of nozzles arranged in an array, the number of the secondary injectors 18, the primary injectors 19, and the duty flame premixing chamber 20 are all two, and the secondary injectors 18, the primary injectors 19, and the duty flame premixing chamber 20 are symmetrically arranged along the axial center (central axis) of the combustion chamber;

[0044] Ammonia fuel supply unit: Ammonia fuel is extracted and pressurized by an ammonia booster pump 10, and high-pressure liquid ammonia exchanges heat with the flue gas after the turbine to evaporate and form high-pressure ammonia gas;

[0045] The ammonia fuel supply unit includes a liquid ammonia storage tank 6, an ammonia booster pump 10 and a shell side of a liquid ammonia evaporator 15. The shell side inlets of the liquid ammonia storage tank 6, the ammonia booster pump 10 and the liquid ammonia evaporator 15 are connected in sequence, and the secondary injector 18, the primary injector 19, the on-duty flame premixing chamber 20 and the main flame premixing chamber 21 are all connected to the shell side outlet of the liquid ammonia evaporator 15; the high-pressure ammonia is divided into four paths before entering the staged combustion chamber, one path of ammonia enters the main flame premixing chamber of the combustion chamber as the main fuel, one path of ammonia enters the on-duty flame premixing chamber as the combustion-supporting fuel, and the other two paths enter the staged injection channels in the combustion chamber as regulating fuels;

[0046] Air supply unit: air is extracted and pressurized by the air booster pump 14, and the high-pressure air exchanges heat with the flue gas after the turbine to form preheated air. The preheating of ammonia fuel and air can effectively improve the activity of ammonia fuel, and enhance the ammonia combustion rate and flame stability;

[0047] The air supply unit comprises an air compressor 9, a shell side of an air preheater 12 and an air booster pump 14. The air compressor 9, the air booster pump 14 and the shell side inlet of the air preheater 12 are connected in sequence. The secondary injector 18, the primary injector 19, the duty flame premixing chamber 20 and the main flame premixing chamber 21 are all connected to the shell side outlet of the air preheater 12. The high-pressure air is divided into four paths before entering the staged combustion chamber. One path of air enters the main flame premixing chamber of the combustion chamber as the main oxidant, one path of air enters the duty flame premixing chamber of the combustion chamber as the duty flame oxidant, and the other two paths enter the staged injection channels in the combustion chamber as the regulating oxidants.

[0048] High-pressure ammonia and high-pressure air are mixed in the main flame premixing chamber of the staged combustion chamber, and burn in the combustion zone to form a main flame; the main flame is ejected from an independent nozzle or an array nozzle; high-pressure oxygen enters the duty flame premixing chamber of the staged combustion chamber as a combustion-supporting fuel, and high-pressure ammonia, high-pressure oxygen and high-pressure air are mixed in the duty flame premixing chamber, and form a duty flame at the root of the main flame to stabilize the main flame, and the molar fraction ratio of oxygen to oxidant is 21% to 100%; the duty flame nozzles are an even number, symmetrically arranged along the axial center of the combustion chamber, and the jet direction of the duty flame is perpendicular to the jet direction of the main flame;

[0049] Oxygen supply unit: oxygen comes from the oxygen storage tank 1, the oxygen is pressurized by the oxygen compressor 2, and then secondary pressurized by the oxygen booster pump 3 to form high-pressure oxygen;

[0050] The oxygen supply unit comprises an oxygen storage tank 1, an oxygen compressor 2 and an oxygen booster pump 3, and the oxygen storage tank 1, the oxygen compressor 2, the oxygen booster pump 3 and the duty flame premixing chamber 20 are connected in sequence;

[0051] Water supply unit: Water as a diluent enters the staged injection channel in the staged combustion chamber, and the water is sprayed into the staged combustion chamber in the form of a spray;

[0052] The water-dilution graded injection channel is set away from the flame root reaction zone to reduce the inhibitory effect of water dilution on flame stability. The number of water-dilution graded injection channels is at least two, which are respectively set near the flame high temperature zone and the post-flame zone near the end of the flame length; the flame length is defined by temperature, optical means, etc. The flame high temperature zone is located more than 5 times the nozzle diameter from the nozzle outlet and within the flame length corresponding to the minimum system operating power; the post-flame zone is located above the flame length corresponding to the maximum system operating power and before the smoke outlet of the combustion chamber;

[0053] The graded injection channel located in the high-temperature zone of the flame sprays water to cool the flame once, reducing NOx emissions and the heat load of the combustion chamber; the graded injection channel located in the rear flame zone sprays water to cool the flame twice, controlling the flue gas temperature not to exceed the heat load of the working machinery (such as turbine blades) and improving the system mass flow rate;

[0054] The water supply unit includes a hot water storage tank 4 and a first water suction pump 11, and the secondary ejector 18 and the primary ejector 19 are both connected to the outlet of the hot water storage tank 4 through the first water suction pump 11;

[0055] Ammonia fuel is stored in a liquid ammonia storage tank, oxygen is stored in an oxygen storage tank, water is stored in a normal temperature water storage tank and a hot water storage tank respectively, and air comes directly from the environment;

[0056] Heat recovery unit: The high-temperature flue gas generated by combustion drives the generator to generate electricity through the turbine work machine. The flue gas after the turbine work is used for liquid ammonia gasification and air preheating;

[0057] The heat recovery unit comprises a normal temperature water storage tank 5, a flue gas cooling heat exchanger 7, a second water suction pump 8, a tube side of an air preheater 12, a compressor 13 and a tube side of a liquid ammonia evaporator 15, an outlet of a staged combustion chamber 17, a turbine generator 16, a tube side of a liquid ammonia evaporator 15, a compressor 13, a tube side of an air preheater 12 and a flue gas cooling heat exchanger 7 are connected in sequence, and a normal temperature water storage tank 5, a second water suction pump 8, a flue gas cooling heat exchanger 7 and an inlet of a hot water storage tank 4 are connected; The water in the water storage tank exchanges heat with the flue gas after the turbine through a centrifugal pump, and the water in the flue gas and the water after heat exchange enter the hot water storage tank together, and the gas in the flue gas can be discharged directly; the hot water storage tank 4 has insulation measures, and the water in the hot water storage tank enters the staged combustion chamber after passing through the booster pump, and liquid water is used as the heat carrier to realize the recovery of flue gas waste heat; the ammonia concentration dissolved in the water in the hot water storage tank 4 is monitored online by a water quality detector, and the ammonia injection amount of the primary / secondary injector is adjusted based on the real-time monitoring of the ammonia concentration.

[0058] The control valve 14 also includes a first regulating valve 22, a second regulating valve 23, a third regulating valve 24, a fourth regulating valve 25, a fifth regulating valve 26, a sixth regulating valve 27, a seventh regulating valve 28, an eighth regulating valve 29, a tenth regulating valve 30, an eleventh regulating valve 31, a twelfth regulating valve 32 and a thirteenth regulating valve. The regulating valves are electric regulating valves. The liquid ammonia evaporator 15 is connected to the inlets of the corresponding secondary injectors 18, the primary injectors 19, the main flame premixing chamber 21 and the duty flame premixing chamber 20 through the eleventh regulating valve 31, the tenth regulating valve 30, the sixth regulating valve 27 and the fourth regulating valve 25 respectively. The air preheater 12 is connected to the corresponding secondary injectors 18, the primary injectors 19, the main flame premixing chamber 21 and the duty flame premixing chamber 20 through the eighth regulating valve 29, the seventh regulating valve 28, the fifth regulating valve 26 and the thirteenth regulating valve 34 respectively. The inlet of the premixing chamber 21 and the duty flame premixing chamber 20 are connected, the oxygen booster pump 3 is connected to the inlet of the duty flame premixing chamber 20 through the first regulating valve 22, the first water suction pump 11 is connected to the corresponding secondary injector 18 and the primary injector 19 through the third regulating valve 24 and the second regulating valve 23 respectively, and the second water suction pump 8 is connected to the flue gas cooling heat exchanger 7 through the twelfth regulating valve 32; the fuel flow (thermal power), equivalence ratio, water dilution ratio and hierarchical organization mode and other operating parameters are adjusted by electric regulating valve control; the hierarchical organization mode can be adjusted according to actual conditions; the number of hierarchical injection channels of fuel and oxidant is at least two respectively, so that the area near the root of the main flame-the high temperature zone of the flame-the rear flame zone forms a hierarchical organization mode of lean combustion-rich combustion-lean combustion or rich combustion-lean combustion-rich combustion in sequence;

[0059] Since water dilution under lean conditions may aggravate NOx emissions, while water dilution under rich conditions may promote NOx reduction; the water ratio is controlled within a lower range when the local equivalence ratio of the combustion chamber is under lean conditions, and the water ratio is controlled within a higher range when the local equivalence ratio of the combustion chamber is under rich conditions;

[0060] The ammonia humidified combustion power generation system proposed in the present invention uses liquid ammonia as fuel and air and oxygen as oxidants. The combustion system is a zero-carbon system with zero carbon emissions. Preheating of ammonia fuel and air is used to improve the activity of ammonia fuel, thereby increasing the ammonia combustion rate and flame stability. Water is used as a diluent to increase the system mass flow and effectively suppress the combustion chamber temperature, thereby increasing the ammonia combustion power generation efficiency while reducing the turbine mechanical heat load. An ammonia oxygen-enriched duty flame is set at the root of the ammonia / air main flame to improve the ignition characteristics and flame stability of the ammonia flame. The flue gas after the turbine is used as the heat source for liquid ammonia evaporation and air preheating, and the flue gas waste heat is recovered into the liquid water diluent, thereby reducing the energy consumption of the thermal cycle. By adjusting the hierarchical organization of the combustion chamber, NOx emissions can be effectively reduced and the escape of unburned ammonia can be suppressed, and it is expected to achieve ultra-low NOx emissions and no denitrification equipment.

[0061] Specific implementation method 2: Combination Figure 1 The present embodiment is described. A clean, efficient and stable ammonia humidification combustion method of the present embodiment adopts a clean, efficient and stable ammonia humidification combustion power generation system, including an ammonia fuel supply unit, an air supply unit, a water supply unit, an oxygen supply unit, a heat recovery unit and a staged combustion chamber unit;

[0062] In the ammonia fuel supply unit, liquid ammonia fuel is stored in a liquid ammonia storage tank 6; an ammonia booster pump 10 extracts liquid ammonia fuel from the liquid ammonia storage tank 6 to form high-pressure liquid ammonia; the high-pressure liquid ammonia enters the liquid ammonia evaporator 15, and the high-pressure liquid ammonia absorbs heat and is converted into ammonia gas; the liquid ammonia evaporator 15 is an indirect heat exchange device, and the heating medium in the indirect heat exchange device is high-temperature flue gas, and the temperature of the ammonia gas after the liquid ammonia evaporates is 20-300°C; the ammonia gas is divided into four routes to enter the staged combustion chamber 17, one route of ammonia gas enters the main flame premixing chamber 21 as the main fuel, one route of ammonia gas enters the duty flame premixing chamber 20 as the combustion-supporting fuel, and the other two routes enter the primary injector 19 and the secondary injector 18 in the staged injection channel in the combustion chamber as the regulating fuel;

[0063] In the air supply unit, the air comes from the environment; after dust removal, the air passes through the air compressor 9 and the air booster pump 14 to form high-pressure air; the high-pressure air enters the air preheater 12, which is an indirect heat exchange device. The heating medium in the indirect heat exchange device is high-temperature flue gas, and the temperature of the air after preheating is 120-400°C; the air is divided into four routes to enter the staged combustion chamber 17, one route of air enters the main flame premixing chamber 21 as the main oxidant, one route of air enters the duty flame premixing chamber 20 as the duty flame oxidant, and the other two routes enter the primary injector 19 and the secondary injector 18 in the staged injection channel in the combustion chamber as the regulating oxidant; an ammonia-air mixture is formed in the main flame premixing chamber 21, and an ammonia / air main flame is formed in the staged combustion chamber 17;

[0064] In the water supply unit, the water suction pump 11 extracts the hot water in the hot water storage tank 4 to form high-pressure liquid water; the liquid water enters the staged combustion chamber 17 from the primary injector 19 and the secondary injector 18 in the form of a spray; the ammonia concentration dissolved in the water in the hot water storage tank 4 is monitored online by a water quality detector, and the ammonia spraying amount of the primary injector 19 and the secondary injector 18 is adjusted based on the real-time monitoring of the ammonia concentration.

[0065] In the oxygen supply unit, oxygen is stored in an oxygen storage tank 1; the oxygen compressor 2 pressurizes the oxygen to high-pressure oxygen, and the oxygen booster pump 3 further increases the pressure of the high-pressure oxygen; oxygen enters the duty flame premixing chamber 20 as a combustion-supporting oxidant, and the thirteenth regulating valve is controlled to control the molar fraction of oxygen in the oxidant to be greater than 50%, and an ammonia-enriched oxygen mixture is formed in the duty flame premixing chamber 20; the ammonia-pure oxygen mixture has an equivalent ratio of 0.7 to 0.9, and the duty flame has a fast combustion speed and high stability under this equivalent ratio; an ammonia-pure oxygen duty flame is formed near the root of the main flame in the staged combustion chamber 17, which is used to stabilize the ammonia / air main flame; there are two duty flame premixing chambers 20, which are symmetrically arranged along the axial center of the combustion chamber, and the jet direction of the duty flame is perpendicular to the jet direction of the main flame;

[0066] In the staged combustion chamber unit, there is one main flame premixing chamber 21, and the main flame is ejected by an array nozzle. The maximum pressure of the staged combustion chamber 17 is less than 4MPa; the primary injector 19 and the secondary injector 18 are arranged symmetrically along the central axis of the combustion chamber, and at least two groups of injectors are used along the axial direction of the combustion chamber; the staged injection channels of water, fuel and air adopt a coaxial jet structure, the fuel channel is located in the outer channel, the air channel is located in the central channel, and the water channel is located between the fuel channel and the air channel, which can cool the outer channel and the central channel at the same time to inhibit nozzle ablation;

[0067] The primary injector 19 and the secondary injector 18 are arranged away from the flame root reaction zone, and are arranged in the post-flame zone near the flame high temperature zone and the end of the flame length respectively; the flame length is defined by temperature, the flame high temperature zone is located at a distance of more than 5 times the nozzle diameter from the nozzle outlet, and within the flame length corresponding to the minimum system operating power; the post-flame zone is located above the flame length corresponding to the maximum system operating power and before the smoke outlet of the combustion chamber;

[0068] A clean, efficient and stable ammonia humidified combustion method comprises the following steps:

[0069] In the fuel staged organization mode, the main flame premixing chamber 21 is a lean combustion system, the primary injector 19 injects ammonia fuel and water mist, and reduces NOx and reduces the heat load of the combustion chamber through excess ammonia fuel; the secondary injector 18 injects air and water mist, and consumes the remaining ammonia fuel through excess air;

[0070] In the air staged organization mode, the main flame premixing chamber 21 is a rich combustion system, the primary injector 19 injects air and water mist, consumes the remaining ammonia fuel through excess air and reduces the heat load of the combustion chamber; the secondary injector 18 injects ammonia fuel and water mist, and reduces NOx through excess ammonia fuel;

[0071] The maximum temperature of the staged combustion chamber 17 is controlled to be less than 1600°C, and the flue gas temperature at the outlet of the staged combustion chamber 17 is 800-1400°C, which does not exceed the heat load of the working machine (such as turbine blades); the equivalence ratio in the main flame premixing chamber is 0.6-1.4, the molar fraction ratio of the water mist injection is 0-60%, the maximum system power is greater than 8MW, and the maximum net electrical efficiency is greater than 55%;

[0072] After combustion, the flue gas flows out from the staged combustion chamber 17 and passes through the turbine generator 16 to generate electricity; after the turbine works, the flue gas temperature is 200-700°C, and is mainly a mixture of nitrogen, oxygen and water; the high-temperature flue gas is used as the heating medium in the liquid ammonia evaporator 15, and the ammonia temperature is 20-300°C after the liquid ammonia evaporates; the flue gas temperature is 100-300°C after passing through the liquid ammonia evaporator 15; the flue gas is compressed and heated twice by the compressor 13, and the temperature is raised to 200-700°C; the flue gas passes through the air preheater 12, and the air temperature after preheating is 120-400°C, and the flue gas temperature is 100-200°C; the flue gas is cooled by the flue gas cooling heat exchanger 7, and the flue gas cooling heat exchanger 7 is used to cool the flue gas. The cooling water in the heat exchanger 7 comes from the normal temperature water storage tank 5, and is pumped to the direct heat exchange device 7 through the second water suction pump 8 to cool the flue gas. After the flue gas is cooled, the water is condensed and separated from the gas phase; the gas phase is directly discharged, and the NOx emission in the gas phase is less than 50ppmv@15%O2; the cooling water temperature is 10-35°C, and the temperature of the cooling water and the condensed water in the flue gas after heat exchange is 30-80°C; the cooling water that absorbs heat and the condensed water in the flue gas are stored in the hot water storage tank 4 as a water source for spraying water to reduce the heat energy loss of the system; the concentration of ammonia dissolved in water in the hot water storage tank 4 is monitored online by a water quality detector, and the ammonia spraying amount of the primary injector 19 and the secondary injector 18 is adjusted based on the real-time monitoring of the ammonia concentration;

[0073] By controlling the electric regulating valve, the fuel flow (thermal power), equivalence ratio, water dilution ratio and combustion stage organization mode can be controlled. By closing the eighth regulating valve 29 and the seventh regulating valve 28, fuel stage can be achieved by controlling the eleventh regulating valve 31 and the tenth regulating valve 30; by closing the eleventh regulating valve 31 and the tenth regulating valve 30, air stage can be achieved by controlling the seventh regulating valve 28 and the eighth regulating valve 29; by controlling the third regulating valve 24 and the second regulating valve 23, the water dilution ratio can be controlled and the combustion chamber temperature can be adjusted.

[0074] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A clean, efficient and stable ammonia humidification combustion power generation system, characterized by: include: Ammonia fuel supply unit: provides fuel for the staged combustion chamber unit; Air supply unit: provides air for the staged combustion chamber unit; Oxygen supply unit: provides oxygen to the staged combustion chamber unit; Water supply unit: provides water for the staged combustion chamber unit; Heat recovery unit: recover heat energy from staged combustion chamber unit; Staged combustion chamber unit: The staged combustion chamber unit performs work to generate electricity.

2. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 1, characterized in that: The staged combustion chamber unit comprises a staged combustion chamber (17), a secondary injector (18), a primary injector (19), a duty flame premixing chamber (20) and a main flame premixing chamber (21); the secondary injector (18), the primary injector (19), the duty flame premixing chamber (20) and the main flame premixing chamber (21) are arranged in sequence in the staged combustion chamber unit; the staged combustion chamber (17) is connected to a turbine generator (16).

3. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 2, characterized in that: The number of the main flame premixing chamber (21) is one, the number of the secondary injectors (18), the primary injectors (19), and the duty flame premixing chamber (20) are two, and the secondary injectors (18), the primary injectors (19), and the duty flame premixing chamber (20) are symmetrically arranged.

4. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 2, characterized in that: The ammonia fuel supply unit comprises a liquid ammonia storage tank (6), an ammonia booster pump (10) and a liquid ammonia evaporator (15); the liquid ammonia storage tank (6), the ammonia booster pump (10) and the liquid ammonia evaporator (15) are connected in sequence; the secondary injector (18), the primary injector (19), the duty flame premixing chamber (20) and the main flame premixing chamber (21) are all connected to the liquid ammonia evaporator (15).

5. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 4, characterized in that: The air supply unit comprises an air compressor (9), an air preheater (12) and an air booster pump (14); the air compressor (9), the air booster pump (14) and the air preheater (12) are connected in sequence; the secondary injector (18), the primary injector (19), the duty flame premixing chamber (20) and the main flame premixing chamber (21) are all connected to the air preheater (12).

6. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 5, characterized in that: The oxygen supply unit comprises an oxygen storage tank (1), an oxygen compressor (2) and an oxygen booster pump (3), and the oxygen storage tank (1), the oxygen compressor (2), the oxygen booster pump (3) and the duty flame premixing chamber (20) are connected in sequence.

7. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 6, characterized in that: The water supply unit comprises a hot water storage tank (4) and a first water suction pump (11); the secondary ejector (18) and the primary ejector (19) are both connected to the hot water storage tank (4) via the first water suction pump (11); and the water quality detector (33) is connected to the hot water storage tank (4).

8. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 7, characterized in that: The heat recovery unit comprises a normal temperature water storage tank (5), a flue gas cooling heat exchanger (7), a second water suction pump (8), an air preheater (12), a compressor (13) and a liquid ammonia evaporator (15); a staged combustion chamber (17), a turbine power generation machine (16), a liquid ammonia evaporator (15), a compressor (13), an air preheater (12) and a flue gas cooling heat exchanger (7) are connected in sequence; and a normal temperature water storage tank (5), a second water suction pump (8), a flue gas cooling heat exchanger (7) and a hot water storage tank (4) are connected.

9. A clean, efficient and stable ammonia humidified combustion power generation system according to claim 8, characterized in that: The liquid ammonia evaporator (15) further comprises a first regulating valve (22), a second regulating valve (23), a third regulating valve (24), a fourth regulating valve (25), a fifth regulating valve (26), a sixth regulating valve (27), a seventh regulating valve (28), an eighth regulating valve (29), a tenth regulating valve (30), an eleventh regulating valve (31), a twelfth regulating valve (32) and a thirteenth regulating valve (33). The liquid ammonia evaporator (15) is connected to the secondary injector (18), the primary injector (19), the main flame premixing chamber (21) and the duty flame premixing chamber (20) respectively through the eleventh regulating valve (31), the tenth regulating valve (30), the sixth regulating valve (27) and the fourth regulating valve (25). The air preheater (12) is connected to the inlet of the secondary injector (18), the primary injector (19) and the main flame premixing chamber (21) through the eighth regulating valve (29), the seventh regulating valve (28), the fifth regulating valve (26) and the thirteenth regulating valve (34), respectively; the oxygen booster pump (3) is connected to the inlet of the duty flame premixing chamber (20) through the first regulating valve (22); the first water suction pump (11) is connected to the secondary injector (18) and the primary injector (19) through the third regulating valve (24) and the second regulating valve (23), respectively; the second water suction pump (8) is connected to the flue gas cooling heat exchanger (7) through the twelfth regulating valve (32).

10. A clean, efficient and stable ammonia humidification combustion method, characterized in that: The clean, efficient and stable ammonia humidified combustion power generation system according to claim 8 or 9 comprises the following steps: In the duty flame premixing chamber (20) at the root of the main flame, an ammonia-oxygen-enriched system is used to form a duty flame, which serves as a continuous ignition source at the root of the ammonia main flame, thereby preventing the main flame from being blown out and improving system instability; During the operation of the system, the combustion organization mode can be switched between a fuel staging organization mode and an air staging organization mode, and the primary injector (19) and the secondary injector (18) are far away from the main flame root reaction zone; In the fuel staged organization mode, the main flame premixing chamber (21) is a lean combustion system, the primary injector (19) injects ammonia fuel and water mist, and the excess ammonia fuel is used to reduce NOx and reduce the heat load of the combustion chamber; the secondary injector (18) injects air and water mist, and the excess air is used to consume the remaining ammonia fuel; In the air staged organization mode, the main flame premixing chamber (21) is a rich combustion system, the primary injector (19) injects air and water mist, and the excess air consumes the remaining ammonia fuel and reduces the heat load of the combustion chamber; the secondary injector (18) injects ammonia fuel and water mist, and the excess ammonia fuel reduces NOx; After combustion, the flue gas flows out from the staged combustion chamber (17) and generates electricity through the turbine generator (16); the high-temperature flue gas is used as the heating medium in the liquid ammonia evaporator (15); the flue gas is compressed and heated up again through the compressor (13); the flue gas is heat exchanged through the air preheater (12); the flue gas is cooled through the flue gas cooling heat exchanger (7); the cooling water in the flue gas cooling heat exchanger (7) comes from the normal temperature water storage tank (5) and is pumped to the direct heat exchange device through the second water suction pump (8) to cool the flue gas; after the flue gas is cooled, the water condenses and separates from the gas phase; the gas phase is directly discharged, and the cooling water that absorbs heat and the condensed water in the flue gas are stored in the hot water storage tank (4) as a water source for spraying; the concentration of ammonia dissolved in water in the hot water storage tank (4) is monitored online by a water quality detector, and the ammonia spraying amount of the primary injector (19) and the secondary injector (18) is adjusted based on the real-time monitoring of the ammonia concentration.

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