Thermal power deep peak shaving system and method based on ammonia cracking hydrogen production coupling waste heat deep utilization

Abstract

The invention discloses a thermal power deep peak regulation system and method based on ammonia cracking hydrogen production coupling waste heat deep utilization, and relates to the field of thermal power generation, the thermal power deep peak regulation system comprises a gasifier, an ammonia cracking hydrogen production device, a cooler, a separator, an ammonia storage tank, an ammonia hydrogen storage system, a peak regulation combustor and a boiler. The waste heat of the thermal power boiler is utilized to gasify liquid ammonia to form gas ammonia, the ammonia cracking hydrogen production device utilizes medium-high temperature waste heat or electric energy and an ammonia cracking catalyst to crack part of ammonia gas to generate ammonia-hydrogen-nitrogen mixed gas, and the ammonia-hydrogen mixed gas is obtained through separation of the separator. The ammonia-hydrogen mixed gas and ammonia gas are mixed to generate mixed gas with different ammonia-hydrogen proportions, the mixed gas is stored in an ammonia-hydrogen storage tank, and the ammonia-hydrogen proportions used for the combustor are adjusted according to different loads to maintain stable combustion. Stable combustion of the combustor can be maintained under the low load, deep peak regulation of thermal power is achieved, waste heat of the thermal power can be deeply utilized, and the power generation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of energy technology, and in particular to a thermal power deep peak regulation system and method based on ammonia cracking hydrogen production coupled with deep utilization of waste heat. Background Art

[0002] Climate change is one of the main threats to the earth's environment. Carbon dioxide emitted into the atmosphere from fossil energy sources exacerbates global warming. Currently, the electricity and heat production industry accounts for the highest share of carbon emissions in the country.

[0003] In order to reduce carbon emissions from fossil energy, it is necessary to vigorously develop green new energy, including photovoltaics and wind power. The volatility, anti-peaking characteristics and large prediction errors of wind power increase the peak-to-valley difference of the power system, and put forward higher requirements on the peak-to-valley capacity of the power system. The capacity of thermal power units continues to increase, resulting in an increase in the low-load to high-load range of the units, and the performance of peak-to-valley power regulation has deteriorated. Especially during the nighttime peak-to-peak regulation of the units, the grid load is less than the minimum stable combustion load of the boiler, resulting in some energy waste. Therefore, deep peak regulation is required to meet the consumption of new energy and balance load fluctuations.

[0004] Ammonia, as a new type of carbon-free fuel for new energy consumption and energy storage, has the characteristics of high energy density, low storage and transportation costs, and high safety. Compared with coal, ammonia burns faster, and liquid ammonia has an energy density comparable to that of coal. In order to reduce carbon emissions from thermal power and achieve flexible peak regulation of thermal power, ammonia is used to replace coal for power generation, and is expected to replace coal to achieve deep peak regulation of thermal power. At present, there is an urgent need to achieve deep peak regulation in thermal power plants mixed with ammonia.

[0005] At present, the main technical approach for thermal power peak regulation is to add heat storage and heat release devices to the thermal power generation system to store the excess steam generated during the operation of the unit to achieve the purpose of peak regulation. In addition, the invention patent with application number CN202311703060.5 proposes an ammonia hydrogen production device and method based on exhaust gas enhanced combustion and cracking. This method is only used for ammonia cracking hydrogen production and does not involve thermal power peak regulation; the invention patent with application number CN202311541342.X proposes a "electrolysis hydrogen production + solid hydrogen storage" peak regulation and frequency regulation method, and solves the thorny problem of safe, low-cost, and large-capacity hydrogen storage through magnesium-based solid hydrogen storage equipment; the invention patent with application number CN202211161931.0 proposes a thermal power unit deep peak regulation device and method based on hydrogen ignition technology, and stores energy in hydrogen through a water electrolysis hydrogen production device, thereby improving the peak regulation capacity of thermal generators. However, the peak-shaving method of using water electrolysis to produce hydrogen for energy storage places extremely high demands on hydrogen storage equipment, with high storage costs. In addition, this method cannot make full use of the waste heat of thermal power generation and cannot improve the power generation efficiency of thermal power generation. Given that ammonia has higher energy density, lower storage and transportation costs, and higher safety than hydrogen, it has broader application prospects in the field of thermal power generation. It is urgent to achieve deep peak-shaving in ammonia-doped thermal power plants. Therefore, there is an urgent need for a thermal power deep peak-shaving technology that combines ammonia cracking to produce hydrogen with the utilization of thermal power waste heat. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a thermal power deep peak-shaving system and method based on ammonia cracking hydrogen production coupled with deep utilization of waste heat, so as to achieve deep peak-shaving of thermal power. The present invention utilizes the waste heat of the thermal power boiler to gasify liquid ammonia to form gaseous ammonia. The ammonia cracking hydrogen production device utilizes medium and high temperature waste heat or electric energy and an ammonia cracking catalyst to crack part of the ammonia to produce an ammonia-hydrogen-nitrogen mixed gas, which is separated by a separator to obtain an ammonia-hydrogen mixed gas. The ammonia-hydrogen mixed gas is mixed with ammonia to produce mixed gases with different ammonia-hydrogen ratios, which are stored in ammonia-hydrogen storage tanks respectively. The ammonia-hydrogen ratio used for the burner is adjusted according to different loads to maintain stable combustion. The present invention can not only maintain stable combustion of the burner under low load to achieve deep peak-shaving of thermal power, but also make deep use of thermal power waste heat to improve power generation efficiency.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A thermal power deep peak regulation method based on ammonia cracking hydrogen production coupled with deep utilization of waste heat, comprising:

[0009] The gasifier is provided with a liquid ammonia inlet and a gaseous ammonia outlet, and the gaseous ammonia outlet is connected to the ammonia cracking hydrogen production device and the ammonia storage tank through a pipeline;

[0010] Ammonia cracking hydrogen production device, using one or a combination of several technologies such as high temperature waste heat from thermal power generation, electric heating, plasma, fuel-rich combustion, and catalysts to crack all or part of ammonia into a mixture of ammonia, nitrogen, and hydrogen. The high temperature waste heat from thermal power generation is 150-900℃;

[0011] An ammonia storage tank, one end of which is connected to the gasifier ammonia outlet to store the ammonia produced by the gasifier, and the other end of which is connected to the ammonia hydrogen storage system and the peak-shaving burner respectively;

[0012] The ammonia-hydrogen storage system stores the ammonia-nitrogen-hydrogen mixed gas produced by the ammonia cracking hydrogen production device or the ammonia-hydrogen mixed gas after separation and purification, and stores ammonia from the ammonia storage tank, so as to store hydrogen at a certain ammonia-hydrogen ratio, and pass the ammonia-hydrogen mixed gas into the peak-shaving burner through a pipeline;

[0013] The peak-shaving burner uses hydrogen-ammonia mixture and preheated air to generate high-temperature flames and active components to ignite one or a combination of liquid ammonia, gaseous ammonia, coal, etc. to form a stable combustion flame to meet the requirements of stable combustion under low-load conditions of the boiler;

[0014] The boiler is equipped with one or a combination of peak-shaving burners, ammonia burners, ammonia-coal burners, and coal burners, and is at least equipped with a peak-shaving burner.

[0015] Furthermore, it also includes a cooler and a separator; the cooler is connected to the ammonia cracking hydrogen production device through a pipeline; the cooler is respectively connected to the separator and the ammonia storage tank through pipelines; the cooler absorbs heat through liquid ammonia gasification to cool the ammonia, nitrogen and hydrogen mixed gas produced by the ammonia cracking hydrogen production device; the separator separates the ammonia, nitrogen and hydrogen mixed gas to obtain an ammonia-hydrogen mixed gas, and connects it to the ammonia-hydrogen storage system through a pipeline.

[0016] Furthermore, the gasifier (1) utilizes low-temperature waste heat from thermal power generation, air at room temperature or electric heating to gasify the introduced liquid ammonia; the low-temperature waste heat from thermal power generation is 50-150°C.

[0017] Furthermore, the ammonia-hydrogen storage system includes a first ammonia-hydrogen storage tank, a second ammonia-hydrogen storage tank, and a third ammonia-hydrogen storage tank; the first ammonia-hydrogen storage tank, the second ammonia-hydrogen storage tank, and the third ammonia-hydrogen storage tank respectively store ammonia-hydrogen mixed gases in different proportions with the ratio of hydrogen to ammonia from high to low.

[0018] Furthermore, the peak-shaving burner includes an ammonia-hydrogen burner and an ammonia-hydrogen-coal burner; the ammonia-hydrogen burner and the ammonia-hydrogen-coal burner are burners that utilize ammonia-hydrogen to stabilize the flame to achieve deep peak-shaving of the boiler; the ammonia burner, the ammonia-coal burner, and the coal burner are burners that utilize ammonia, ammonia-coal, and coal combustion, respectively, and have poor flame stability.

[0019] Furthermore, after the gasifier gasifies the liquid ammonia, it is passed into the ammonia cracking hydrogen production device and the ammonia storage tank respectively; the ammonia cracking hydrogen production device cracks ammonia to form a mixed gas of ammonia, nitrogen and hydrogen, and passes the cracked mixed gas into the cooler, or passes the cracked mixed gas into the ammonia hydrogen storage system through a pipeline; the cooler uses liquid ammonia to cool the mixed gas produced by the ammonia cracking hydrogen production device, and the cooled mixed gas is passed into the separator, and the gasified liquid ammonia is passed into the ammonia storage tank; the separator separates ammonia and hydrogen from the mixed gas, and passes the ammonia hydrogen mixed gas into the ammonia hydrogen storage system; the ammonia storage tank passes ammonia into the ammonia hydrogen storage system; the ammonia hydrogen storage system passes the hydrogen ammonia mixed gas into the peak-shaving burner at a certain flow rate according to the peak-shaving depth of thermal power generation and the boiler power. The peak-shaving burner is installed on the boiler, and the flame generated maintains the stable combustion of the boiler at low load.

[0020] Furthermore, the peak-shaving burner includes three operating modes: mode one, mode two and mode three; in mode one, the power of the ammonia cracking hydrogen production device is high, and the volumes of the first ammonia hydrogen storage tank, the second ammonia hydrogen storage tank and the third ammonia hydrogen storage tank are relatively small. When the thermal power is at its peak, the ammonia cracking hydrogen production device, the cooler and the separator are turned off, and the gasifier is turned on to use the low-temperature waste heat to gasify the liquid ammonia to produce ammonia gas, which is then introduced into the peak-shaving burner for combustion. When the thermal power is at its trough, the gasifier, the ammonia cracking hydrogen production device, the cooler and the separator are turned on to produce an ammonia-hydrogen mixed gas, and different proportions of the ammonia-hydrogen mixed gas are provided to the peak-shaving burner according to the boiler power to achieve stable combustion at low load of the boiler.

[0021] Furthermore, in mode 2, the power of the ammonia cracking hydrogen production device is moderate, and the volumes of the first ammonia hydrogen storage tank, the second ammonia hydrogen storage tank, and the third ammonia hydrogen storage tank are moderate. When thermal power is at a peak, the gasifier, the ammonia cracking hydrogen production device, the cooler, and the separator are turned on to generate an ammonia hydrogen mixture, and the hydrogen ammonia mixture is stored in the first ammonia hydrogen storage tank, the second ammonia hydrogen storage tank, and the third ammonia hydrogen storage tank. After the storage tanks are full, the ammonia cracking hydrogen production device, the cooler, the separator, and the gasifier are turned off, and ammonia generated by gasifying liquid ammonia with low-temperature waste heat is passed into the peak-shaving burner for combustion. When thermal power is at a trough, the gasifier, the ammonia cracking hydrogen production device, the cooler, and the separator are turned on to generate an ammonia hydrogen mixture, which is passed into the first ammonia hydrogen storage tank, the second ammonia hydrogen storage tank, and the third ammonia hydrogen storage tank, and different proportions of ammonia hydrogen mixture are provided to the peak-shaving burner according to the boiler power to achieve stable combustion of the boiler at low load;

[0022] Furthermore, in mode three, the power of the ammonia cracking hydrogen production device is low, the volumes of the first ammonia-hydrogen storage tank, the second ammonia-hydrogen storage tank, and the third ammonia-hydrogen storage tank are the largest, the gasifier, the ammonia cracking hydrogen production device, the cooler, and the separator operate all day to produce an ammonia-hydrogen mixture, which is stored in the first ammonia-hydrogen storage tank, the second ammonia-hydrogen storage tank, and the third ammonia-hydrogen storage tank. When thermal power is at its peak, the ammonia produced by the gasifier is passed into the peak-shaving burner for combustion. When thermal power is at its trough, the first ammonia-hydrogen storage tank, the second ammonia-hydrogen storage tank, and the third ammonia-hydrogen storage tank provide different proportions of ammonia-hydrogen mixture to the peak-shaving burner according to the boiler power, thereby achieving stable combustion of the boiler at low load.

[0023] Furthermore, ammonia and hydrogen are mixed and stored in a storage tank in a certain ratio to avoid hydrogen embrittlement and reduce the risk of hydrogen storage.

[0024] Furthermore, by absorbing the low-temperature waste heat from thermal power with liquid ammonia and producing ammonia after gasification, the waste heat from thermal power is fully utilized, thus improving the power generation efficiency of thermal power.

[0025] Furthermore, the boiler peak load regulation includes the following process:

[0026] 1). When the boiler operates at a power of more than 40-50%, the ammonia-hydrogen burner and the ammonia-hydrogen-coal burner operate at the minimum power or stop operating, and the ammonia burner, the ammonia-coal burner and the coal burner operate at the appropriate power according to the boiler power requirements;

[0027] 2). When the boiler operates at a power lower than 40-50%, the ammonia hydrogen burner and ammonia hydrogen coal burner operate at a suitable power and ammonia hydrogen ratio to meet the needs of stable operation of the boiler at low load. The ammonia burner, ammonia coal burner and coal burner operate at a suitable power according to the boiler power requirements.

[0028] The beneficial effects of the present invention are:

[0029] The present invention utilizes liquid ammonia gasification to absorb low-temperature waste heat from thermal power generation, thereby improving thermal power generation efficiency; the gasified ammonia is introduced into a burner, thereby enhancing combustion stability; an ammonia cracking hydrogen production device is used to crack ammonia to produce hydrogen, and different proportions of hydrogen-ammonia mixed gases are introduced into a peak-shaving burner according to the boiler power, thereby ensuring stable combustion of the boiler under low load and realizing deep peak-shaving of thermal power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of an example of a thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat according to the present invention;

[0031] Figure 2 This is a schematic diagram of Example 2 of a thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat according to the present invention;

[0032] Figure 3 It is a schematic diagram of the burner type used in a thermal power deep peak regulation method based on ammonia cracking hydrogen production coupled with deep utilization of waste heat of the present invention;

[0033] In the figure, the reference numbers are: 1-gasifier; 2-ammonia cracking hydrogen production device; 3-cooler; 4-separator; 5-ammonia storage tank; 6-ammonia hydrogen storage system; 6-1-first ammonia hydrogen storage tank; 6-2-second ammonia hydrogen storage tank; 6-3-third ammonia hydrogen storage tank; 7-peak shaving burner; 7-1-ammonia hydrogen burner; 7-2-ammonia hydrogen coal burner; 8-boiler; 8-1-ammonia burner; 8-2-ammonia coal burner; 8-3-coal burner. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0035] According to two embodiments of the present invention, Figure 1-3 As shown, a thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat,

[0036] It comprises a gasifier 1, which is provided with a liquid ammonia inlet and a gas ammonia outlet, and the gas ammonia outlet is connected to an ammonia cracking hydrogen production device 2 and an ammonia storage tank 5 through a pipeline;

[0037] Ammonia cracking hydrogen production device 2, using the combination of high temperature waste heat from thermal power, plasma, rich fuel combustion, and catalyst technology to crack all or part of ammonia into ammonia, nitrogen, and hydrogen mixed gas. The high temperature waste heat from thermal power is 150-900°C;

[0038] An ammonia storage tank 5, one end of which is connected to the ammonia outlet of the gasifier 1 to store the ammonia produced by the gasifier 1, and the other end of which is connected to the ammonia hydrogen storage system 6 and the peak-shaving burner 7 respectively;

[0039] The ammonia-hydrogen storage system 6 stores the ammonia-nitrogen-hydrogen mixed gas produced by the ammonia cracking hydrogen production device 2 or the ammonia-hydrogen mixed gas after separation and purification, and stores the ammonia from the ammonia storage tank 5, so as to store hydrogen at a certain ammonia-hydrogen ratio, and pass the ammonia-hydrogen mixed gas into the peak-shaving burner 7 through a pipeline;

[0040] The peak-shaving burner 7 uses hydrogen-ammonia mixed gas and preheated air to generate high-temperature flames and active components, igniting the liquid ammonia and coal combined fuel to form a stable combustion flame to meet the stable combustion of the boiler 8 under low load conditions;

[0041] The boiler 8 is equipped with a peak-shaving burner 7, an ammonia burner 8-1, and a coal burner 8-3.

[0042] It also includes a cooler 3 and a separator 4; the cooler 3 is connected to the ammonia cracking hydrogen production device 2 through a pipeline; the cooler 3 is respectively connected to the separator 4 and the ammonia storage tank 5 through pipelines; the cooler 3 absorbs heat through liquid ammonia gasification to cool the ammonia, nitrogen and hydrogen mixed gas produced by the ammonia cracking hydrogen production device 2; the separator 4 separates the ammonia, nitrogen and hydrogen mixed gas to obtain an ammonia-hydrogen mixed gas, and connects it to the ammonia-hydrogen storage system 6 through a pipeline.

[0043] The ammonia-hydrogen storage system 6 includes a first ammonia-hydrogen storage tank 6-1, a second ammonia-hydrogen storage tank 6-2, and a third ammonia-hydrogen storage tank 6-3; the first ammonia-hydrogen storage tank 6-1, the second ammonia-hydrogen storage tank 6-2, and the third ammonia-hydrogen storage tank 6-3 respectively store ammonia-hydrogen mixed gases in different proportions with the ratio of hydrogen to ammonia from high to low.

[0044] The gasifier 1 utilizes low-temperature waste heat (50-150° C.) from thermal power to gasify the introduced liquid ammonia, thereby improving the waste heat utilization rate and the total enthalpy of ammonia, and further improving the power generation efficiency of thermal power.

[0045] The ammonia cracking hydrogen production device 2 uses the high temperature waste heat (150-900°C) of thermal power to preheat ammonia, and then uses plasma to assist ammonia rich combustion, combined with an ammonia cracking catalyst to produce a hydrogen, ammonia, nitrogen and hydrogen mixed gas, thereby improving the reaction activity and combustion stability of the fuel, and ensuring that the boiler operates stably at low load without flameout during deep peak regulation.

[0046] The peak-shaving burner 7 includes an ammonia-hydrogen burner 7-1 and an ammonia-hydrogen-coal burner 7-2; the ammonia-hydrogen burner 7-1 and the ammonia-hydrogen-coal burner 7-2 use hydrogen-ammonia mixed gas and preheated air to generate high-temperature flames and active components, ignite liquid ammonia and coal combined fuel to form a stable combustion flame, so as to achieve stable combustion and safe operation of the boiler 8 under low load; one of the ammonia-hydrogen burner 7-1 and the ammonia-hydrogen-coal burner 7-2 is selected for use as needed. The ammonia burner 8-1, the ammonia-coal burner 8-2 and the coal burner 8-3 are burners that use ammonia, ammonia-coal and coal combustion respectively, and have poor flame stability.

[0047] After the gasifier 1 gasifies the liquid ammonia introduced, it is introduced into the ammonia cracking hydrogen production device 2 and the ammonia storage tank 5 respectively; the ammonia cracking hydrogen production device 2 cracks ammonia to form a mixed gas of ammonia, nitrogen and hydrogen, and the cracked mixed gas is introduced into the cooler 3; the cooler 3 uses liquid ammonia to cool the mixed gas produced by the ammonia cracking hydrogen production device 2, and the cooled mixed gas is introduced into the separator 4, and the gasified liquid ammonia is introduced into the ammonia storage tank 5; the separator 4 separates ammonia and hydrogen from the mixed gas, and the ammonia and hydrogen mixed gas is introduced into the ammonia and hydrogen storage system 6; the ammonia storage tank 5 introduces ammonia into the ammonia and hydrogen storage system 6; the ammonia and hydrogen storage system 6 introduces the hydrogen and ammonia mixed gas into the peak-shaving burner 7 at a certain flow rate according to the peak-shaving depth of thermal power generation and the boiler power. The peak-shaving burner 7 is installed on the boiler, and the flame generated maintains the low-load stable combustion of the boiler 8.

[0048] The peak-shaving burner 7 includes three operating modes: mode 1, mode 2 and mode 3; in mode 1, the power of the ammonia cracking hydrogen production device 2 is high, and the volumes of the first ammonia hydrogen storage tank 6-1, the second ammonia hydrogen storage tank 6-2, and the third ammonia hydrogen storage tank 6-3 are relatively small. When the thermal power is at a peak, the ammonia cracking hydrogen production device 2, the cooler 3, and the separator 4 are closed, and the gasifier 1 is opened to use the low-temperature waste heat to gasify the liquid ammonia to produce ammonia gas, which is then introduced into the peak-shaving burner 7 for combustion. When the thermal power is at a trough, the gasifier 1, the ammonia cracking hydrogen production device 2, the cooler 3, and the separator 4 are opened to produce an ammonia-hydrogen mixed gas, and different proportions of the ammonia-hydrogen mixed gas are provided to the peak-shaving burner 7 according to the boiler power to achieve stable combustion of the boiler at low load.

[0049] In mode 2, the power of the ammonia cracking hydrogen production device 2 is moderate, and the volumes of the first ammonia hydrogen storage tank 6-1, the second ammonia hydrogen storage tank 6-2, and the third ammonia hydrogen storage tank 6-3 are moderate. When the thermal power is at its peak, the gasifier 1, the ammonia cracking hydrogen production device 2, the cooler 3, and the separator 4 are turned on to generate ammonia hydrogen mixed gas, and the hydrogen ammonia mixed gas is stored in the first ammonia hydrogen storage tank 6, the second ammonia hydrogen storage tank 7, and the third ammonia hydrogen storage tank 8 until the storage tanks are full, and then the ammonia cracking hydrogen production device 2, the cooler 3, and the separator 4 are turned on to generate ammonia hydrogen mixed gas. The ammonia generated by gasifying liquid ammonia with low-temperature waste heat is introduced into the peak-shaving burner 7 for combustion. When the thermal power is at a trough, the gasifier 1, the ammonia cracking hydrogen production device 2, the cooler 3, and the separator 4 are turned on to generate an ammonia-hydrogen mixed gas, which is introduced into the first ammonia-hydrogen storage tank 6-1, the second ammonia-hydrogen storage tank 6-2, and the third ammonia-hydrogen storage tank 6-3. Different proportions of ammonia-hydrogen mixed gas are provided to the peak-shaving burner 7 according to the boiler power to achieve stable combustion of the boiler at low load.

[0050] In mode three, the power of the ammonia cracking hydrogen production device 2 is low, the first ammonia hydrogen storage tank 6-1, the second ammonia hydrogen storage tank 6-2, and the third ammonia hydrogen storage tank 6-3 have large volumes, the gasifier 1, the ammonia cracking hydrogen production device 2, the cooler 3, and the separator 4 operate all day to produce an ammonia-hydrogen mixture, which is stored in the first ammonia hydrogen storage tank 6-1, the second ammonia hydrogen storage tank 6-2, and the third ammonia hydrogen storage tank 6-3. When thermal power is at its peak, the ammonia produced by the gasifier 1 is passed into the burner 9 for combustion. When thermal power is at its trough, the first ammonia hydrogen storage tank 6-1, the second ammonia hydrogen storage tank 6-2, and the third ammonia hydrogen storage tank 6-3 provide different proportions of ammonia-hydrogen mixture to the peak-shaving burner 7 according to the boiler power, so as to achieve stable combustion of the boiler at low load.

[0051] After ammonia and hydrogen are mixed, they are stored in a storage tank at a certain ratio to avoid hydrogen embrittlement and reduce the risk of hydrogen storage. Liquid ammonia absorbs the low-temperature waste heat of thermal power and produces ammonia after gasification, which makes full use of the waste heat of thermal power and improves the power generation efficiency of thermal power.

[0052] The boiler 8 is equipped with an ammonia-hydrogen burner 7-1 and an ammonia-coal burner 8-2; the ammonia-hydrogen burner 7-1 uses ammonia-hydrogen to achieve flame stabilization and ignites the fuel introduced by the ammonia-coal burner 8-2, thereby achieving deep peak regulation of the boiler; the ammonia-coal burner 8-2 is a burner that uses ammonia-coal combustion and has poor flame stability.

[0053] The peak load regulation of the boiler 8 includes the following process:

[0054] 1. When the boiler 8 operates at a power of more than 40-50%, the ammonia-hydrogen burner 7-1 stops operating, and the ammonia-coal burner 8-2 operates at a suitable power according to the power requirement of the boiler 8;

[0055] 2. When the boiler 8 operates at a power lower than 40-50%, the ammonia-hydrogen burner 7-1 operates at a suitable power and ammonia-hydrogen ratio to meet the needs of stable operation of the boiler 8 at low load, and the ammonia-coal burner 8-2 operates at a suitable power according to the power requirements of the boiler 8.

Claims

1. A thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat, characterized in that: include: The gasifier (1) is provided with a liquid ammonia inlet and a gaseous ammonia outlet, and the gaseous ammonia outlet is connected to the ammonia cracking hydrogen production device (2) and the ammonia storage tank (5) through a pipeline; The ammonia cracking hydrogen production device (2) utilizes one or a combination of several technologies, such as high temperature waste heat from thermal power generation, electric heating, plasma, fuel-rich combustion, and catalysts, to crack all or part of the ammonia into a mixed gas of ammonia, nitrogen, and hydrogen, wherein the high temperature waste heat from thermal power generation is 150-900° C.; An ammonia storage tank (5) has one end connected to the ammonia outlet of the gasifier (1) to store ammonia generated by the gasifier (1), and the other end connected to an ammonia-hydrogen storage system (6) and a peak-shaving burner (7) respectively; an ammonia-hydrogen storage system (6) for storing a mixed gas of ammonia, nitrogen and hydrogen produced by the ammonia cracking hydrogen production device (2) or a mixed gas of ammonia and hydrogen after separation and purification, and for storing ammonia from an ammonia storage tank (5) to store hydrogen at a certain ammonia-hydrogen ratio, and for passing the mixed gas of ammonia and hydrogen into a peak-shaving burner (7) through a pipeline; The peak-shaving burner (7) uses hydrogen-ammonia mixed gas and preheated air to generate high-temperature flames and active components, igniting one or a combination of liquid ammonia, gaseous ammonia, coal to form a stable combustion flame to meet the stable combustion of the boiler (8) under low load conditions; The boiler (8) is equipped with one or a combination of a peak-shaving burner (7), an ammonia burner (8-1), an ammonia-coal burner (8-2), and a coal burner (8-3), and is at least equipped with the peak-shaving burner (7).

2. According to claim 1, a thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat is characterized by: The invention also comprises a cooler (3) and a separator (4); the cooler (3) is connected to the ammonia cracking hydrogen production device (2) through a pipeline; the cooler (3) is respectively connected to the separator (4) and the ammonia storage tank (5) through pipelines; the cooler (3) absorbs heat through liquid ammonia gasification to cool the ammonia, nitrogen and hydrogen mixed gas produced by the ammonia cracking hydrogen production device (2); the separator (4) separates the ammonia, nitrogen and hydrogen mixed gas into an ammonia-hydrogen mixed gas, and connects the mixed gas to the ammonia-hydrogen storage system (6) through a pipeline.

3. According to claim 1, a thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat is characterized by: The gasifier (1) utilizes low-temperature waste heat from thermal power generation, air at room temperature or electric heating to gasify the introduced liquid ammonia; the low-temperature waste heat from thermal power generation is 50-150°C.

4. According to claim 1, a thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat is characterized by: The ammonia-hydrogen storage system (6) comprises a first ammonia-hydrogen storage tank (6-1), a second ammonia-hydrogen storage tank (6-2), and a third ammonia-hydrogen storage tank (6-3); the first ammonia-hydrogen storage tank (6-1), the second ammonia-hydrogen storage tank (6-2), and the third ammonia-hydrogen storage tank (6-3) respectively store ammonia-hydrogen mixed gases in different proportions in a descending order of hydrogen-ammonia ratio.

5. According to claim 1, a thermal power deep peak regulation system based on ammonia cracking hydrogen production coupled with deep utilization of waste heat is characterized by: The peak-shaving burner (7) comprises an ammonia-hydrogen burner (7-1) and an ammonia-hydrogen-coal burner (7-2); the ammonia-hydrogen burner (7-1) and the ammonia-hydrogen-coal burner (7-2) are burners that utilize ammonia-hydrogen to stabilize the flame to achieve deep peak-shaving of the boiler; the ammonia burner (8-1), the ammonia-coal burner (8-2) and the coal burner (8-3) are burners that utilize ammonia, ammonia-coal and coal combustion respectively and have poor flame stability.

6. A thermal power deep peak regulation method based on ammonia cracking hydrogen production coupled with deep utilization of waste heat, characterized by: The gasifier (1) gasifies the introduced liquid ammonia and then introduces it into the ammonia cracking hydrogen production device (2) and the ammonia storage tank (5) respectively; the ammonia cracking hydrogen production device (2) cracks the ammonia to form an ammonia, nitrogen and hydrogen mixed gas, and introduces the cracked mixed gas into the cooler (3), or introduces the cracked mixed gas into the ammonia hydrogen storage system (6) through a pipeline; the cooler (3) uses liquid ammonia to cool the mixed gas generated by the ammonia cracking hydrogen production device (2), and the cooled mixed gas is introduced into the separator (4), and the gas The liquid ammonia after chemical treatment is introduced into an ammonia storage tank (5); the separator (4) separates ammonia and hydrogen from the mixed gas, and introduces the ammonia-hydrogen mixed gas into an ammonia-hydrogen storage system (6); the ammonia storage tank (5) introduces ammonia into the ammonia-hydrogen storage system (6); the ammonia-hydrogen storage system (6) introduces the hydrogen-ammonia mixed gas into a peak-shaving burner (7) at a certain flow rate according to the peak-shaving depth of thermal power generation and the boiler power; the peak-shaving burner (7) is installed on the boiler, and the flame generated maintains the low-load stable combustion of the boiler (8).

7. A thermal power deep peak regulation method based on ammonia cracking hydrogen production coupled with deep utilization of waste heat according to claim 6, characterized in that: The peak-shaving burner (7) includes three operation modes: mode 1, mode 2 and mode 3. In mode 1, the power of the ammonia cracking hydrogen production device (2) is high, and the volumes of the first ammonia hydrogen storage tank (6-1), the second ammonia hydrogen storage tank (6-2) and the third ammonia hydrogen storage tank (6-3) are relatively small. When the thermal power is at a peak, the ammonia cracking hydrogen production device (2), the cooler (3) and the separator (4) are closed, and the gasifier (1) is opened to gasify liquid ammonia using low-temperature waste heat to generate ammonia gas, which is then introduced into the peak-shaving burner (7) for combustion. When the thermal power is at a trough, the gasifier (1), the ammonia cracking hydrogen production device (2), the cooler (3) and the separator (4) are opened to generate ammonia hydrogen mixed gas, and different proportions of ammonia hydrogen mixed gas are provided to the peak-shaving burner (7) according to the boiler power, so as to achieve stable combustion of the boiler at low load. In mode 2, the power of the ammonia cracking hydrogen production device (2) is moderate, and the volumes of the first ammonia hydrogen storage tank (6-1), the second ammonia hydrogen storage tank (6-2), and the third ammonia hydrogen storage tank (6-3) are moderate. When thermal power is at its peak, the gasifier (1), the ammonia cracking hydrogen production device (2), the cooler (3), and the separator (4) are turned on to generate ammonia hydrogen mixed gas, which is then stored in the first ammonia hydrogen storage tank (6-1), the second ammonia hydrogen storage tank (6-2), and the third ammonia hydrogen storage tank (6-3) until the storage tanks are full, and then the ammonia cracking hydrogen production device (2) is turned off. , cooler (3), separator (4), gasifier (1), ammonia gas generated by gasifying liquid ammonia with low-temperature waste heat is introduced into the peak-shaving burner (7) for combustion; when thermal power is at a trough, the gasifier (1), ammonia cracking hydrogen production device (2), cooler (3), separator (4) are turned on to generate ammonia-hydrogen mixed gas, which is introduced into the first ammonia-hydrogen storage tank (6-1), the second ammonia-hydrogen storage tank (6-2), and the third ammonia-hydrogen storage tank (6-3); and ammonia-hydrogen mixed gas of different proportions is provided to the peak-shaving burner (7) according to the boiler power, so as to realize stable combustion of the boiler at low load; In mode three, the power of the ammonia cracking hydrogen production device (2) is low, the first ammonia hydrogen storage tank (6-1), the second ammonia hydrogen storage tank (6-2), and the third ammonia hydrogen storage tank (6-3) have the largest volumes, the gasifier (1), the ammonia cracking hydrogen production device (2), the cooler (3), and the separator (4) operate all day to produce ammonia hydrogen mixed gas, which is stored in the first ammonia hydrogen storage tank (6-1), the second ammonia hydrogen storage tank (6-2), and the third ammonia hydrogen storage tank (6-3). When the thermal power is at its peak, the ammonia produced by the gasifier (1) is passed into the peak-shaving burner (7) for combustion. When the thermal power is at its trough, the first ammonia hydrogen storage tank (6-1), the second ammonia hydrogen storage tank (6-2), and the third ammonia hydrogen storage tank (6-3) provide the peak-shaving burner (7) with ammonia hydrogen mixed gas in different proportions according to the boiler power, thereby achieving stable combustion of the boiler at low load.

8. A thermal power deep peak regulation method based on ammonia cracking hydrogen production coupled with deep utilization of waste heat according to claim 6, characterized in that: The peak load regulation of the boiler (8) comprises the following process: 1) When the boiler operates at a power of more than 40-50%, the peak-shaving burner (7) operates at the minimum power or stops operating, and the ammonia burner (8-1), the ammonia-coal burner (8-2), and the coal burner (8-3) operate at appropriate power according to the power requirements of the boiler (8); 2) When the boiler operates at a power lower than 40-50%, the peak-shaving burner (7) operates at an appropriate power and ammonia-hydrogen ratio to meet the needs of stable operation of the boiler at low load, and the ammonia burner (8-1), ammonia-coal burner (8-2), and coal burner (8-3) operate at appropriate power according to the power requirements of the boiler (8).

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