A heat pump power storage system and method coupling flue gas waste heat utilization and hydrogen fixation ammonia production

Abstract

The application discloses a kind of coupling flue gas waste heat utilization and hydrogen production ammonia heat pump power storage system and method, system includes solar heating device, electrolytic water hydrogen production device, synthetic ammonia device, heat pump circulating device, heat storage circulating device, organic rankine cycle and carbon capture circulating device, solar heating device, electrolytic water hydrogen production device, synthetic ammonia device, heat pump circulating device, heat storage circulating device, organic rankine cycle and carbon capture circulating device are sequentially connected between;By power drive, heat energy in flue gas waste heat is transferred to working medium, and then in the form of high-grade heat energy is stored, when the electric energy is needed, stored heat energy is converted back to electric energy, energy conversion and storage are realized, energy utilization efficiency is improved, and renewable energy utilization is supported, and balance power grid load, realize the technical effect of power grid peak shaving, flue gas waste heat recovery and utilization in thermal power plant, improve power plant power generation efficiency, reduce coal consumption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of heat pump electricity storage and waste heat utilization, and particularly relates to a heat pump electricity storage system and method coupling flue gas waste heat utilization and hydrogen fixation ammonia production. BACKGROUND

[0002] Under the "double carbon" target, renewable energy power generation technologies such as solar and wind energy are continuously developing. In this case, emerging energy storage technology is needed to enable stable operation of the power grid. The heat pump electricity storage system is a storage system that stores electrical energy in the form of high-grade heat and releases electrical energy through a power cycle. This technology is called by Professor Robert as a key technology for storing a large amount of energy in a carbon-neutral energy system.

[0003] This system is driven by electricity, which transfers heat energy from a low-temperature heat source to a working fluid, and then stores it in the form of high-grade heat. When electrical energy is needed, the stored heat energy is converted back into electrical energy. This process involves energy conversion and storage, aiming to improve energy utilization efficiency, support the use of renewable energy, and balance the load of the power grid.

[0004] Thermal power generation is one of the most common ways of generating electricity worldwide. Although it has played an important role in meeting the growing energy needs of humanity, this method of power generation also has the problems of low energy efficiency and serious environmental pollution. In particular, the problem of waste of waste heat resources has attracted widespread attention during the thermal power generation process. During thermal power generation, the high-temperature flue gas produced by fuel combustion contains a large amount of heat energy, and the heat energy of these flue gases is often not fully recovered and utilized before being discharged into the atmosphere.

[0005] Traditional waste heat utilization technologies, such as waste heat boilers and heat exchangers, have low efficiency under these low-temperature conditions, limiting the scope and efficiency of waste heat recovery. The application of these technologies often requires high initial investment and operating and maintenance costs, which may exceed the financial budget for many power generation companies, resulting in the lack of widespread application of these effective waste heat utilization technologies.

[0006] Physical energy storage is the most suitable large-scale electricity storage method for renewable energy power grid peak shaving, frequency regulation, valley filling, and emergency backup at the present stage; pumped storage and compressed air energy storage are typical large-scale energy storage technologies based on electrical energy → mechanical energy → electrical energy, with high round-trip efficiency and maturity, but their flexible application is limited by geographical factors; the heat pump electricity storage system based on heat pumps and organic Rankine cycles is an electricity storage technology based on electrical energy → thermal energy → electrical energy, with the advantages of not being limited by geographical conditions, large storage capacity, high efficiency, and long energy storage period.

[0007] For the existing standard, hydrogen is positioned as a dangerous chemical, and hydrogen production can only be carried out in a chemical industrial park, which increases transportation costs. Hydrogen is very active and has poor stability. After leakage, combustion and explosion are easy to occur. Under high temperature and high pressure, hydrogen can even penetrate very thick steel plates. Therefore, hydrogen storage and hydrogen energy transportation are major difficulties today. SUMMARY

[0008] The purpose of the present application is to provide a heat pump energy storage system and method coupling flue gas waste heat utilization and hydrogen fixation ammonia production to solve the technical defects of waste heat energy waste, energy storage limited by geographical factors, low energy utilization efficiency, hydrogen storage difficulty, power grid peak shaving and frequency modulation, and carbon capture difficulty in the prior art.

[0009] In order to achieve the above purpose, the following technical scheme is adopted:

[0010] In a first aspect, a heat pump energy storage system coupling flue gas waste heat utilization and hydrogen fixation ammonia production is provided, comprising: a solar heating device, a water electrolysis hydrogen production device, an ammonia synthesis device, a heat pump circulation device, a heat storage circulation device, an organic Rankine cycle and a carbon capture cycle device, the solar heating device, the water electrolysis hydrogen production device, the ammonia synthesis device, the heat pump circulation device, the heat storage circulation device, the organic Rankine cycle and the carbon capture cycle device are connected in sequence.

[0011] The solar heating device is used to heat the flue gas, the water electrolysis hydrogen production device is used to produce hydrogen and oxygen by using the residual power of the power plant, and the heat pump circulation device is used to recover the heat of the flue gas and the heat released during the reaction of the ammonia synthesis device, and to improve the grade of low-grade heat source by driving the power to output high-temperature heat.

[0012] The heat storage circulation is used to store the high-temperature heat and supply the high-temperature heat to the organic Rankine cycle and the carbon capture cycle device.

[0013] Further, the water electrolysis hydrogen production device is used to receive the residual power of the power grid and obtain hydrogen and oxygen by electrolyzing water with the residual power of the power grid, and the oxygen is output as a byproduct.

[0014] Further, the ammonia synthesis device comprises an ammonia synthesis reactor, a first compressor and a first expander, the first inlet at the bottom of the ammonia synthesis reactor is connected with the first compressor, and the first outlet of the ammonia synthesis reactor is connected with the first expander.

[0015] Further, the heat pump circulation device comprises a second compressor, a first heat exchanger, a second expander, a throttle valve and a second heat exchanger, the second compressor is connected with the third outlet of the second heat exchanger, and the second compressor is also connected with the first inlet of the first heat exchanger.

[0016] The first outlet of the first heat exchanger is connected with the second expander, and the second expander is connected with the third inlet of the second heat exchanger through the throttling valve.

[0017] Further, the heat storage cycle device comprises a first tank, a third heat exchanger and a second tank, the first outlet of the first tank is connected with the first inlet of the third heat exchanger, and the first outlet of the third heat exchanger is connected with the second tank.

[0018] Further, the organic Rankine cycle comprises a third heat exchanger, a third expander, a fourth heat exchanger, a fourth expander, a first condenser and a water pump.

[0019] The third outlet of the third heat exchanger is connected with the third expander, the third expander is connected with the first inlet of the fourth heat exchanger, and the first outlet of the fourth heat exchanger is connected with the fourth expander.

[0020] The fourth expander is connected with the first condenser, and the first condenser is connected with the water pump.

[0021] Further, the water pump is connected with the third inlet of the third heat exchanger, and the second outlet of the fourth heat exchanger is connected with a second condenser.

[0022] Further, the carbon capture cycle device comprises a CO2 absorption tower, an absorbent regeneration tower, a third compressor and a fifth expander, the second outlet of the CO2 absorption tower is connected with the first inlet of the absorbent regeneration tower, and the second inlet of the CO2 absorption tower is connected with the first outlet of the absorbent regeneration tower.

[0023] Further, the third outlet of the absorbent regeneration tower is connected with the third compressor, and the fifth expander is also connected with the third compressor.

[0024] In a second aspect, a heat pump electricity storage method for coupling flue gas waste heat utilization carbon capture and hydrogen fixation ammonia production is provided, comprising:

[0025] Heating the medium-temperature flue gas to a medium-high temperature state, electrolyzing water by using an electrolytic water hydrogen production device to obtain hydrogen and oxygen;

[0026] Transporting the flue gas in the medium-high temperature state after heating to a synthetic ammonia device, so that the medium-high temperature flue gas preheats nitrogen, hydrogen and a mixed gas of nitrogen and hydrogen to obtain a low-temperature low-pressure mixed gas;

[0027] Carrying out catalytic reaction on the low-temperature low-pressure mixed gas, and changing the low-temperature low-pressure mixed gas into a low-temperature low-pressure working medium by using a heat pump cycle device to carry out heat exchange;

[0028] Changing the low-temperature low-pressure working medium into a low-temperature medium-pressure organic Rankine cycle working medium by using an organic Rankine cycle.

[0029] The low-temperature flue gas is converted into low-temperature and low-pressure carbon dioxide by the carbon capture circulation device, and is discharged as a product.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] 1. The heat energy in the flue gas waste heat is transferred to the working medium by electric power driving, and then stored in the form of high-grade heat energy. When electric energy is needed, the stored heat energy is converted back into electric energy, realizing energy conversion and storage, improving energy utilization efficiency, supporting the use of renewable energy, balancing the load of the power grid, and achieving the technical effect of power grid peak shaving. Secondly, by recycling the flue gas waste heat of the thermal power plant, the power generation efficiency of the power plant is improved by 0.1% to 0.5%, the standard coal consumption for power generation is reduced by 0.3% to 0.6%, and compared with the traditional flue gas recycling device, the waste heat power generation capacity can be increased by 5% to 20%. In addition, compared with the traditional system, the cost of the system is relatively lower than 5% to 12%, and the energy utilization efficiency is higher. The heat pump and organic Rankine cycle-based heat pump power storage system is a power storage technology based on electric energy-heat energy-electric energy, which has the advantages of not being limited by geographical conditions, large storage capacity, high efficiency, and long energy storage period.

[0032] 2. The water electrolysis hydrogen production device can receive and utilize the excess electricity in the power grid, which is usually generated during periods of low electricity demand. If not utilized, it may cause waste of energy. By electrolyzing water to produce hydrogen, the excess electricity is converted into hydrogen energy, realizing energy storage and reuse, and improving the overall energy utilization efficiency of the power grid.

[0033] 3. The first compressor is responsible for compressing the raw gas to a pressure range suitable for ammonia synthesis. The compressed gas has a higher energy density, which is beneficial for full reaction in the ammonia synthesis reactor, thereby improving the efficiency of ammonia synthesis. The first expander is used to recover the high-pressure energy in the outlet gas of the ammonia synthesis reactor and convert it into mechanical energy or electric energy, which can be used to drive other equipment or supply the power grid, realizing efficient energy utilization.

[0034] 4. The second compressor compresses the low-temperature and low-pressure heat source gas into high-temperature and high-pressure gas, improving the grade of the heat source. The high-temperature and high-pressure gas releases heat in the first heat exchanger to heat the working medium, realizing heat energy conversion.

[0035] 5. The first tank body serves as a heat energy storage unit, which can store heat energy from external heat sources or heat pump systems. Through the first outlet, the heat energy can be transported to the third heat exchanger for further processing. Secondly, the heat storage process can be carried out during off-peak hours or low-cost periods, thereby optimizing energy utilization and cost-effectiveness. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0037] Figure 1 The schematic diagram of the heat pump electricity storage system provided by the present application for coupling flue gas waste heat utilization and hydrogen fixation ammonia production;

[0038] Figure 2 The schematic diagram of the ammonia synthesis device in the heat pump electricity storage system provided by the present application for coupling flue gas waste heat utilization and hydrogen fixation ammonia production;

[0039] Figure 3 The flow chart of the heat pump electricity storage method provided by the present application for coupling flue gas waste heat utilization and hydrogen fixation ammonia production;

[0040] 1, solar heater; 2, ammonia synthesis reactor; 3, first compressor; 4, water electrolysis hydrogen production device; 5, first expander; 6, first valve; 7, second compressor; 8, first heat exchanger; 9, second expander; 10, throttling valve; 11, second heat exchanger; 12, first tank body; 13, third heat exchanger; 14, second tank body; 15, second valve; 16, third valve; 17, third expander; 18, fourth heat exchanger; 19, fourth expander; 20, first condenser; 21, water pump; 22, second condenser; 23, gas separator; 24, CO2 absorption tower; 25, absorbent regeneration tower; 26, third compressor; 27, fifth expander; 28, ammonia synthesis reactor second inlet valve; 29, ammonia synthesis reactor first inlet valve; 30, first air blower; 31, ammonia synthesis reactor first valve; 32, first spiral heat exchanger; 33, ammonia synthesis reactor second valve; 34, ammonia synthesis reactor third valve; 35, second air blower; 36, ammonia synthesis reactor fourth valve; 37, second spiral heat exchanger; 38, ammonia synthesis reactor fifth valve; 39, ammonia synthesis reactor sixth valve; 40, ammonia synthesis reactor seventh valve; 41, first mesh heat exchanger; 42, third spiral heat exchanger; 43, ammonia synthesis reactor first outlet valve; 44, second mesh heat exchanger; 45, third mesh heat exchanger; 46, fourth mesh heat exchanger; 47, fifth mesh heat exchanger. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0043] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0044] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0045] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0046] The conventional waste heat utilization technologies, such as waste heat boiler and heat exchanger, have low efficiency under these low temperature conditions, which limits the range and efficiency of waste heat recovery, and the application of these technologies often requires high initial investment and operation and maintenance costs, which may exceed the financial budget for many power generation enterprises, thereby resulting in that these effective waste heat utilization technologies are not widely applied.

[0047] Physical energy storage is the most suitable large-scale electricity storage method for renewable energy grid peak shaving, frequency modulation, valley filling and emergency backup at present; pumped storage and compressed air energy storage are typical large-scale energy storage technologies based on electric energy-mechanical energy-electric energy, which have high round-trip efficiency and maturity, but their flexible application is limited by geographical factors; and the heat pump electricity storage system composed of heat pumps and organic Rankine cycles is an electricity storage technology based on electric energy-thermal energy-electric energy, which has the advantages of not being limited by geographical conditions, large storage capacity, high efficiency and long energy storage period.

[0048] For the existing standard, hydrogen is classified as a hazardous chemical, and hydrogen production can only be carried out in a chemical park, which increases transportation costs. Hydrogen is very active and has very poor stability, and after leakage, it is easy to cause combustion and explosion. Under high temperature and high pressure, hydrogen can even penetrate very thick steel plates. Therefore, hydrogen storage and hydrogen energy transportation are major problems today.

[0049] In order to solve the above technical defects, the inventors provide a heat pump electricity storage system and method coupling flue gas waste heat utilization and hydrogen storage ammonia production.

[0050] The present application will be described in further detail below with reference to the accompanying drawings:

[0051] As Figures 1-2As shown, the first aspect of the embodiment of the present application provides a heat pump power storage system coupling flue gas waste heat utilization and hydrogen production for ammonia synthesis, comprising a solar heating device, a water electrolysis hydrogen production device 4, an ammonia synthesis device, a heat pump circulation device, a heat storage circulation device, an organic Rankine cycle and a carbon capture circulation device, which are connected in sequence; wherein the solar heating device is preferably a solar heater 1 for heating the flue gas, the water electrolysis hydrogen production device 4 is used to produce hydrogen and oxygen by using the surplus power of the power plant, the heat pump circulation device is used to recover the heat of the flue gas and the heat released during the reaction of the ammonia synthesis device, and the low-grade heat source is lifted in grade by driving the heat pump circulation device with electricity to output high-temperature heat; the heat storage circulation is used to store the high-temperature heat output by the heat pump circulation device, and supply the high-temperature heat to the organic Rankine cycle and the carbon capture circulation device when needed, the organic Rankine cycle converts the heat energy stored in the heat storage circulation device into electricity; the carbon capture circulation includes an adsorption process and a desorption process, the adsorption process is used to capture carbon dioxide in the low-temperature flue gas, and the desorption process is used to regenerate the saturated adsorption material by heating with the high-temperature heat obtained in the heat storage circulation, to realize the regeneration of the adsorption material and produce high-purity carbon dioxide, which can be used as raw material for production. In addition, the released carbon dioxide has high heat, which can be compressed and used for turbine power generation. In the application process, the system uses medium-temperature flue gas as carbon source and heat source, and uses the surplus power of the power plant as power source, uses the surplus power of the power plant to drive the compressor and produce hydrogen, the medium-temperature flue gas is further heated to be used as heat source for ammonia synthesis reaction, so that hydrogen and nitrogen are converted into ammonia, solving the problem of hydrogen storage. In the charging process, the heat of flue gas waste heat and chemical reaction is recovered as low-grade heat source of heat pump circulation, and the heat is lifted in grade by heat pump circulation driven by surplus power, and stored in high-temperature storage tank; in the discharging process, the stored heat energy is converted into electricity by organic Rankine cycle, and the heat of the mixed gas generated by the ammonia synthesis reaction is further recovered by the regenerator. The desorption process of the carbon capture circulation is driven by the heat stored in the high-temperature storage tank, and the whole process uses heat storage as an intermediate process, realizing low-cost, high-density and long-time storage of electric energy, effectively solving the problems encountered in energy transformation and the demand for grid peak regulation; and the coupled carbon capture system uses the heat in the high-level storage tank to solve the problem of high carbon dioxide content in the flue gas, the "electricity-heat-electricity" in the system has high round-trip efficiency, realizes comprehensive utilization of electricity and heat, and has high comprehensive energy utilization efficiency. The surplus electricity of the thermal power plant is used to electrolyze water to produce hydrogen, and then the hydrogen is used to produce ammonia with cheap nitrogen through ammonia synthesis reaction, so that the hydrogen is stored and transported in the form of ammonia, solving the problem of hydrogen storage. The reaction heat of the chemical reaction is utilized in stages, so that the temperature of the heat source is increased by 17% to 33%, and the high-temperature and high-pressure ammonia gas generated by the reaction is used for turbine power generation, fully utilizing the heat energy.Finally, the carbon dioxide with high content in the flue gas of the thermal power plant is captured, and the heat in the high-temperature heat tank is used to regenerate the capture material, realizing the separation of carbon dioxide, and obtaining high-purity carbon dioxide.

[0052] As shown in Figure 1 The water electrolysis hydrogen production device 4 is used to receive the grid surplus electricity and obtain hydrogen and oxygen by electrolyzing water through the grid surplus electricity, wherein the hydrogen participates in the subsequent reaction, and the oxygen is output as a byproduct. The ammonia synthesis device includes an ammonia synthesis reactor 2, a first compressor 3 and a first expander 5. The hydrogen enters the first compressor 3 from the inlet after being mixed with nitrogen in a ratio slightly less than 1:3 through a pipeline, the outlet of the first compressor 3 is connected with the first inlet at the bottom of the ammonia synthesis reactor 2, and the first outlet of the ammonia synthesis reactor 2 is connected with the first expander 5. The outlet of the solar heater 1 is connected with the second inlet at the bottom of the ammonia synthesis reactor 2, and the second outlet of the ammonia synthesis reactor 2 is connected with the second heat exchanger 11. The first inlet of the ammonia synthesis reactor 2 is connected with the first outlet of the ammonia synthesis reactor 2 through the first spiral heat exchanger 32, the second spiral heat exchanger 37 and the third spiral heat exchanger 42. The second inlet of the ammonia synthesis reactor 2 is connected with the second outlet thereof through a preheating chamber. The reaction chamber of the ammonia synthesis reactor 2 has a third outlet and a third inlet. The third outlet and the third inlet of the ammonia synthesis reactor 2 are connected through the second heat exchanger 11.

[0053] The heat pump circulation device includes a second compressor 7, a first heat exchanger 8, a second expander 9, a throttle valve 10 and a second heat exchanger 11. The first and second inlets of the second heat exchanger 11 are respectively connected to the second outlet and the third outlet of the ammonia synthesis reactor 2, the first outlet of the second heat exchanger 11 is connected to the first inlet of the CO2 absorption tower 24, the second compressor 7 is connected to the third outlet of the second heat exchanger 11, and the second compressor 7 is also connected to the first inlet of the first heat exchanger 8; the first outlet of the first heat exchanger 8 is connected to the second expander 9, the second expander 9 is connected to the third inlet of the second heat exchanger 11 through the throttle valve 10, the first inlet and the first outlet of the second heat exchanger 11 are connected; the second inlet and the second outlet of the second heat exchanger 11 are connected. The heat storage cycle device includes a first heat exchanger 8, a first tank 12, a third heat exchanger 13, and a second tank 14. The second inlet of the first heat exchanger 8 is connected to the first expander 5 via a first valve 6, and the third outlet of the first heat exchanger 8 is connected to the first inlet of the first tank 12; the first outlet of the first tank 12 is connected to the first inlet of the third heat exchanger 13; the first outlet of the third heat exchanger 13 is connected to the second tank 14; the second tank 14 is connected to the third inlet of the first heat exchanger 8; the second outlet of the first heat exchanger 8 is connected to the second condenser 22; the first inlet of the first heat exchanger 8 is connected to the first outlet; the second outlet of the first heat exchanger 8 is connected to the second inlet; the third outlet of the first heat exchanger 8 is connected to the third inlet. The first inlet of the third heat exchanger 13 is connected to the first outlet.

[0054] The organic Rankine cycle includes a third heat exchanger 13, a third expander 17, a fourth heat exchanger 18, a fourth expander 19, a first condenser 20 and a water pump 21; the second inlet of the third heat exchanger 13 is connected to the first expander 5 through the second valve 15, the second outlet of the third heat exchanger 13 is connected to the second condenser 22, and the third outlet of the third heat exchanger 13 is connected to the third expander 17; the third expander 17 is connected to the first inlet of the fourth heat exchanger 18; the first outlet of the fourth heat exchanger 18 is connected to the fourth expander 19, and the fourth expander 19 is connected to the first condenser 2 0; the first condenser 20 is connected to the water pump 21; the water pump 21 is connected to the third inlet of the third heat exchanger 13; the second inlet of the fourth heat exchanger 18 is connected to the first expander 5 through the third valve 16; the second outlet of the fourth heat exchanger 18 is connected to the second condenser 22, and the second condenser 22 is connected to the gas separator 23; the second inlet of the third heat exchanger 13 is connected to the second outlet; the third inlet and the third outlet of the third heat exchanger 13 are connected; the first inlet and the first outlet of the fourth heat exchanger 18 are connected; the second inlet and the second outlet of the fourth heat exchanger 18 are connected.

[0055] The carbon capture cycle device comprises a CO2 absorption tower 24, an absorbent regeneration tower 25, a third compressor 26 and a fifth expander 27, the first outlet of the CO2 absorption tower 24 is connected with the first inlet; the second outlet of the CO2 absorption tower 24 is connected with the second inlet. The second outlet of the CO2 absorption tower 24 is connected with the first inlet of the absorbent regeneration tower 25; the second inlet of the CO2 absorption tower 24 is connected with the first outlet of the absorbent regeneration tower 25; the second inlet of the absorbent regeneration tower 25 is connected with the second outlet of the first tank body 12; the second outlet of the absorbent regeneration tower 25 is connected with the second inlet of the first tank body 12; the third compressor 26 is connected with the third outlet of the absorbent regeneration tower 25; the fifth expander 27 is connected with the third compressor 26.

[0056] The second inlet of the ammonia synthesis reactor 2 is connected with the outlet of the solar heater 1 through an ammonia synthesis reactor second inlet valve 28; the first inlet of the ammonia synthesis reactor 2 is connected with the outlet of the first compressor 3 through an ammonia synthesis reactor first inlet valve 29; the first outlet of the ammonia synthesis reactor 2 is connected with the inlet of the first expander 5 through an ammonia synthesis reactor first outlet valve 43; the ammonia synthesis reactor second inlet valve 28 is connected with the first spiral heat exchanger 32; the first spiral heat exchanger 32 is connected with the second spiral heat exchanger 37 through an ammonia synthesis reactor third valve 34; the second spiral heat exchanger 37 is connected with the third spiral heat exchanger 42 through an ammonia synthesis reactor sixth valve 39; the second spiral heat exchanger 37 is also connected with the second outlet through an ammonia synthesis reactor seventh valve 40; the ammonia synthesis reactor second inlet valve 28 is connected with the first reaction bin; the first reaction bin is connected with the second reaction bin through an ammonia synthesis reactor second valve 33; the second reaction bin is connected with the third reaction bin through an ammonia synthesis reactor fifth valve 38; the third reaction bin is connected with the ammonia synthesis reactor first outlet valve 43 through an ammonia synthesis reactor first outlet valve 43; the first reaction bin is provided with a first air blower 30, an ammonia synthesis reactor first valve 31, a fourth mesh heat exchanger 46 and a fifth mesh heat exchanger 47; the inlet of the first air blower 30 is connected with the ammonia synthesis reactor first valve 31, which is located at the upper part of the first reaction bin, and the outlet is located at the bottom of the first reaction bin. The second reaction bin is provided with a third mesh heat exchanger 45 and a first mesh heat exchanger 41; the outlet of the second air blower 35 is located at the bottom of the second reaction bin. The third reaction bin is provided with a second mesh heat exchanger 44; the inlet of the second air blower 35 is connected with the upper part of the third reaction bin through an ammonia synthesis reactor fourth valve 36; the third mesh heat exchanger 45 is connected with the fourth mesh heat exchanger 46; the second mesh heat exchanger 44 is connected with the fifth mesh heat exchanger 47; the bottom of the second reaction bin is connected with the top of the third reaction bin through the second air blower 35 and the ammonia synthesis reactor fourth valve 36. The absorption medium of the CO2 absorption tower 24 absorbs carbon dioxide at 100-200 degrees and releases carbon dioxide at 400-500 degrees, and the material can be selected from MgO / POL-PPH3 adsorbent or CdO-MgO adsorbent.

[0057] The inlet flue gas of the ammonia synthesis reactor 2 is preheated by a spiral pipeline to the mixed gas in the cabin, a gas circulation device is arranged in the preheating chamber, at least two reaction chambers are arranged, a heat removal device is arranged before all the reaction chambers except the last one, and the two reaction chambers are taken as an example, the heat removal device corresponds to the third outlet and the third inlet of the ammonia synthesis reactor 2; when the current reaction chamber reaches the reaction limit of the current temperature, the valve between the reaction chambers is opened to make the mixed gas enter the next reaction chamber; the catalyst in the reaction chamber is attached to the flue gas pipeline in a net structure; the catalyst can be selected from an iron catalyst medium, which requires 100-300 bar, or a sodium alloy, which can react at normal pressure. The heat removal device is a net structure and contains a heat-absorbing medium located in the reaction chamber. When the reaction temperature is measured to be above 400 degrees, the valve is opened to make the cooling liquid flow to absorb heat and maintain a certain temperature.

[0058] In a second aspect, the embodiment provides a heat pump electricity storage method for coupling flue gas waste heat utilization, carbon capture and hydrogen storage ammonia production, as shown in the formula (I): Figure 3 The formula (I) comprises the following steps:

[0059] S101, heating the medium-temperature flue gas to a medium-high temperature state, electrolyzing water by using an electrolytic water hydrogen production device to obtain hydrogen and oxygen; exemplarily, the medium-temperature flue gas is heated to a medium-high temperature state by a solar heater 1, and the electrolytic water hydrogen production device 4 electrolyzes water to obtain hydrogen and oxygen, wherein the oxygen is output as a byproduct, and the hydrogen is compressed to a high-pressure state by a first compressor 3 to enter an ammonia synthesis reactor 2 together with an external nitrogen source.

[0060] S102, delivering the flue gas in the medium-high temperature state after heating to a synthetic ammonia device to preheat the medium-high temperature flue gas to nitrogen, hydrogen and a mixed gas of nitrogen and hydrogen to obtain a low-temperature and low-pressure mixed gas; exemplarily, the medium-high temperature flue gas is preheated to a mixed gas of nitrogen and hydrogen, all of which are in a medium-high temperature state, and then enters the ammonia synthesis reactor 2. Due to heat release in the reaction, the product ammonia gas and the original medium-high temperature flue gas are both in a high temperature state. Because the reaction is reversible, the product ammonia gas contains nitrogen and hydrogen. In order to make the ammonia gas production high enough, a two-time reaction method is adopted, and a regenerative tube is used to exchange heat with a second heat exchanger 11. The high-temperature and high-pressure product mixed gas enters a first expander 5, becomes a high-temperature and low-pressure product mixed gas after generating electricity, and then enters a fourth heat exchanger 18 through a third valve 16 to exchange heat with an organic Rankine cycle working medium. The product mixed gas can enter a first heat exchanger 8 through a first valve 6 to exchange heat with a heat storage cycle working medium, or enter a third heat exchanger 13 through a second valve 15 to exchange heat with an organic Rankine cycle working medium according to the temperature, and finally obtain a low-temperature and low-pressure product mixed gas. After passing through a second condenser 22 and a gas separator 23, the product mixed gas obtains product ammonia gas and raw materials of nitrogen and hydrogen, wherein the nitrogen and hydrogen are returned to the first compressor 3 for reuse.

[0061] S103, the low-temperature and low-pressure mixed gas is subjected to catalytic reaction and heat exchange by using a heat pump circulation device to become a low-temperature and low-pressure working medium; for example, the high-pressure hydrogen-nitrogen mixed gas enters a first reaction chamber through an ammonia synthesis reactor first inlet valve 29. The medium-high-temperature flue gas enters a first spiral heat exchanger 32 through an ammonia synthesis reactor second inlet valve 28. Here, the high-pressure hydrogen-nitrogen mixed gas exchanges heat with the medium-high-temperature flue gas to become medium-high-temperature and high-pressure hydrogen-nitrogen mixed gas. The first air blower 30 and the ammonia synthesis reactor first valve 31 are opened to make the upper high-temperature gas and the lower low-temperature gas circulate to be sufficiently heated. After being heated to a certain extent, the ammonia synthesis reactor second valve 33 and the ammonia synthesis reactor third valve 34 are opened, the medium-high-temperature flue gas enters a second spiral heat exchanger 37, and the medium-high-temperature and high-pressure hydrogen-nitrogen mixed gas enters a second reaction chamber. At this time, the first catalytic reaction is carried out, and the heat released is absorbed by the first mesh heat exchanger 41 to keep the reaction temperature stable. The excess heat is absorbed by the third mesh heat exchanger 45 to enter the first reaction chamber for heat exchange. In this process, the medium-high-temperature flue gas absorbs heat to become high-temperature flue gas, and part of the hydrogen and nitrogen is not fully reacted. The gas in the reaction chamber is a mixed gas of nitrogen, hydrogen and ammonia. During the reaction, the ammonia synthesis reactor seventh valve 40 can be opened to make the high-temperature flue gas discharge, or the ammonia synthesis reactor sixth valve 39 can be opened to make the high-temperature flue gas enter the third spiral heat exchanger 42 according to the temperature of the flue gas. After a period of reaction, the ammonia synthesis reactor fifth valve 38 is opened, and the mixed gas in the second reaction chamber enters the third reaction chamber. The heat of the mixed gas is further absorbed by the second mesh heat exchanger 44, and the temperature is maintained by the high-temperature flue gas in the third spiral heat exchanger 42. To make the reaction more sufficient, the second air blower 35 and the ammonia synthesis reactor fourth valve 36 are opened to make the mixed gas circulate between the second reaction chamber and the third reaction chamber; after complete reaction, the ammonia synthesis reactor first outlet valve 43 is opened to obtain the product mixed gas.

[0062] The high-temperature flue gas enters the second heat exchanger 11 to exchange heat with the working medium of the heat pump circulation to become medium-low-temperature flue gas, which enters the CO2 absorption tower 24. The circulating working medium becomes medium-high-temperature, and is compressed to a high-temperature and high-pressure state by the second compressor 7. Then, the working medium exchanges heat with the working medium in the heat storage circulation in the first heat exchanger 8. The working medium of the heat pump circulation becomes low-temperature and high-pressure, and then enters the second expander 9 to generate electricity. After passing through the throttle valve 10, the working medium becomes low-temperature and low-pressure working medium.

[0063] S104, the low-temperature and low-pressure working medium is changed into a low-temperature and medium-pressure organic Rankine cycle working medium by the organic Rankine cycle; exemplarily, the high-temperature heat storage working medium which is heat-exchanged in the first heat exchanger 8 enters the first tank body 12, and is heat-exchanged with the organic Rankine cycle working medium in the third heat exchanger 13 when necessary, and the heat storage working medium changes into low-temperature and enters the second tank body 14. In the organic Rankine cycle, the high-temperature and high-pressure organic Rankine cycle working medium after heat exchange passes through the third expander 17, changes into a medium-temperature and low-pressure organic Rankine cycle working medium, and changes into a high-temperature and high-pressure organic Rankine cycle working medium after heat exchange with the high-temperature product mixed gas in the fourth heat exchanger 18, and the product mixed gas changes into a medium-temperature and low-temperature. The organic Rankine cycle working medium changes into a medium-temperature and low-pressure organic Rankine cycle working medium after passing through the fourth expander 19, and changes into a low-temperature and medium-pressure organic Rankine cycle working medium after passing through the first condenser 20 and the water pump 21.

[0064] S105, the low-temperature and low-pressure working medium is changed into a low-temperature and medium-pressure organic Rankine cycle working medium by the organic Rankine cycle; exemplarily, the high-temperature heat storage working medium which is heat-exchanged in the first heat exchanger 8 enters the first tank body 12, and is heat-exchanged with the organic Rankine cycle working medium in the third heat exchanger 13 when necessary, and the heat storage working medium changes into low-temperature and enters the second tank body 14. In the organic Rankine cycle, the high-temperature and high-pressure organic Rankine cycle working medium after heat exchange passes through the third expander 17, changes into a medium-temperature and low-pressure organic Rankine cycle working medium, and changes into a high-temperature and high-pressure organic Rankine cycle working medium after heat exchange with the high-temperature product mixed gas in the fourth heat exchanger 18, and the product mixed gas changes into a medium-temperature and low-temperature. The organic Rankine cycle working medium changes into a medium-temperature and low-pressure organic Rankine cycle working medium after passing through the fourth expander 19, and changes into a low-temperature and medium-pressure organic Rankine cycle working medium after passing through the first condenser 20 and the water pump 21.

[0065] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit the scope of protection, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: the skilled person in the art can still make various changes, modifications or equivalent replacements to the specific embodiments of the application after reading the present application, but these changes, modifications or equivalent replacements are all within the protection scope of the claims of the application to be approved.

Claims

1. A heat pump power storage system that couples flue gas waste heat utilization with solid hydrogen production to ammonia, characterized in that: include: A solar heating device, a water electrolysis hydrogen production device, an ammonia synthesis device, a heat pump circulation device, a heat storage circulation device, an organic Rankine cycle, and a carbon capture circulation device, wherein the solar heating device, the water electrolysis hydrogen production device, the ammonia synthesis device, the heat pump circulation device, the heat storage circulation device, the organic Rankine cycle, and the carbon capture circulation device are connected in sequence; The solar heating device is used to heat the flue gas, the water electrolysis hydrogen production device is used to produce hydrogen and oxygen using the surplus electricity of the power plant, and the heat pump circulation device is used to recover the flue gas heat and the heat released during the reaction of the ammonia synthesis device, and to improve the quality of the low-level heat source through electric drive to output high-temperature heat; The heat storage cycle is used to store the high-temperature heat and supply the high-temperature heat to the organic Rankine cycle and the carbon capture cycle device; The ammonia synthesis device includes an ammonia synthesis reactor, a first compressor and a first expander, wherein the first inlet at the bottom of the ammonia synthesis reactor is connected to the first compressor, and the first outlet of the ammonia synthesis reactor is connected to the first expander; The organic Rankine cycle includes a third heat exchanger, a third expander, a fourth heat exchanger, a fourth expander, a first condenser and a water pump; The third outlet of the third heat exchanger is connected to the third expander, the third expander is connected to the first inlet of the fourth heat exchanger, and the first outlet of the fourth heat exchanger is connected to the fourth expander; The fourth expander is connected to the first condenser, and the first condenser is connected to the water pump; The carbon capture cycle device includes a CO2 absorption tower, an absorbent regeneration tower, a third compressor and a fifth expander. The second outlet of the CO2 absorption tower is connected to the first inlet of the absorbent regeneration tower, and the second inlet of the CO2 absorption tower is connected to the first outlet of the absorbent regeneration tower.

2. The system according to claim 1, wherein: The water electrolysis hydrogen production device is used to receive surplus electricity from the power grid and electrolyze water using the surplus electricity from the power grid to obtain hydrogen and oxygen, with the oxygen being output as a by-product.

3. The system according to claim 1, wherein: The heat pump circulation device includes a second compressor, a first heat exchanger, a second expander, a throttle valve and a second heat exchanger, wherein the second compressor is connected to the third outlet of the second heat exchanger, and the second compressor is also connected to the first inlet of the first heat exchanger; The first outlet of the first heat exchanger is connected to the second expander, and the second expander is connected to the third inlet of the second heat exchanger through the throttle valve.

4. The system according to claim 1, wherein: The heat storage cycle device includes a first tank body, a third heat exchanger and a second tank body. The first outlet of the first tank body is connected to the first inlet of the third heat exchanger, and the first outlet of the third heat exchanger is connected to the second tank body.

5. The system according to claim 1, wherein: The water pump is connected to the third inlet of the third heat exchanger, and the second outlet of the fourth heat exchanger is connected to the second condenser.

6. The system according to claim 1, wherein: The third outlet of the absorbent regeneration tower is connected to the third compressor, and the fifth expander is also connected to the third compressor.

7. A heat pump power storage method that couples flue gas waste heat utilization, carbon capture, and solid hydrogen production to ammonia, characterized in that: The method is performed using the system according to any one of claims 1 to 6, comprising: The medium-temperature flue gas is heated to a medium-high temperature state, and water is electrolyzed using a water electrolysis hydrogen production device to obtain hydrogen and oxygen; The heated flue gas in a medium-high temperature state is transported to a synthetic ammonia device, so that the medium-high temperature flue gas preheats the nitrogen, hydrogen, and the mixed gas of nitrogen and hydrogen to obtain a low-temperature and low-pressure mixed gas; The low-temperature and low-pressure mixed gas is subjected to a catalytic reaction and converted into a low-temperature and low-pressure working fluid after heat exchange using a heat pump circulation device; Converting the low-temperature and low-pressure working fluid into a low-temperature and medium-pressure organic Rankine cycle working fluid through an organic Rankine cycle; The low-temperature flue gas is converted into low-temperature, low-pressure carbon dioxide through a carbon capture circulation device and discharged as a product.

Images