Graded heat supply hydrogen production and synthesis ammonia co-production system

Abstract

The utility model discloses a hydrogen production and ammonia synthesis co-production system with a graded heat supply function. The co-production system comprises an energy supply module, a fused salt heat exchange steam turbine power generation module, a hydrogen production and ammonia production module, a power storage module and a control module, the energy supply module is connected with the fused salt heat exchange steam turbine power generation module and the hydrogen and ammonia production module. The fused salt heat exchange steam turbine power generation module comprises a first heat exchanger, a second heat exchanger and a third heat exchanger which are connected in parallel; the hydrogen and ammonia production module comprises an SOEC unit, a deoxidation purification unit and an ammonia production unit which are connected in sequence, and first electric heating equipment is arranged on the SOEC unit; the first heat exchanger is used for providing high-temperature steam for the SOEC unit, the second heat exchanger is used for providing low-temperature steam for the deoxidation purification unit, and the second heat exchanger is used for providing medium-temperature steam for the ammonia production unit; the control module is electrically connected with and controls the energy supply module, the fused salt heat exchange steam turbine power generation module, the hydrogen and ammonia production module and the power storage module. Different grades of heat energy are provided through the fused salt heat exchange steam turbine power generation module, and the hydrogen production efficiency of the hydrogen production and ammonia production module and the heat efficiency of high-temperature fused salt are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of molten salt heat utilization, and specifically relates to a hydrogen production and ammonia synthesis cogeneration system with graded heating. Background Art

[0002] Solid oxide electrolyzer (SOEC) is a solid oxide fuel cell. In electrolysis mode, under external voltage and high temperature, it electrolyzes H2O to produce H2 and O2, thus converting electrical energy and thermal energy into chemical energy. Among various hydrogen production technologies, solid oxide electrolyzer (SOEC) has the highest energy conversion efficiency, but SOEC technology has the highest cost because the electrolysis reaction needs to occur in a high temperature environment.

[0003] In the existing technology, in order to reduce costs, photovoltaic power is used for electric heating to achieve heat supply, but photovoltaic power is intermittent, random and volatile, and the power grid has high requirements for the quality of grid-connected wind power and photovoltaic power, so a large amount of wind and solar power abandonment may occur; at the same time, photovoltaic power is only used for SOEC, and the heat medium is abandoned when the temperature is lower than the temperature required by SOEC, which has low thermal efficiency and a large amount of heat loss.

[0004] Alternatively, the existing technology also uses coal-fired boilers or other fossil fuels for heat supply, which not only requires the manufacture of related equipment and pipelines, greatly increasing production costs, but also consumes fossil energy and causes environmental pollution.

[0005] Based on this, SOEC is difficult to promote and apply due to the major defects in heating conditions. Utility Model Content

[0006] The utility model aims to provide a hydrogen production and ammonia synthesis co-production system with graded heat supply to solve the above problems existing in the prior art.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A hydrogen production and ammonia synthesis co-production system with staged heating, including an energy supply module, a molten salt heat exchange steam turbine power generation module, a hydrogen production and ammonia production module, a power storage module and a control module;

[0009] The energy supply module includes a photothermal heating unit and a photovoltaic power generation unit. The output end of the photothermal heating unit is connected to the molten salt heat exchange steam turbine power generation module, and the output end of the photovoltaic power generation unit is connected to the hydrogen and ammonia production module.

[0010] The molten salt heat exchange steam turbine power generation module comprises a first heat exchanger, a second heat exchanger and a third heat exchanger connected in parallel with each other;

[0011] The hydrogen and ammonia production module comprises a SOEC unit, a deoxygenation and purification unit and an ammonia production unit which are connected in sequence, and a first electric heating device is provided on the SOEC unit; a first heat exchanger is used to provide high-temperature steam for the SOEC unit, a second heat exchanger is used to provide low-temperature steam for the deoxygenation and purification unit, and a third heat exchanger is used to provide medium-temperature steam for the ammonia production unit;

[0012] The input end of the power storage module is electrically connected to the photovoltaic power generation unit and the molten salt heat exchange steam turbine power generation module, and the output end of the power storage module is electrically connected to the molten salt heat exchange steam turbine power generation module and the hydrogen and ammonia production module;

[0013] The control module is electrically connected to and controls the energy supply module, the molten salt heat exchange steam turbine power generation module, the hydrogen and ammonia production module and the power storage module.

[0014] In one possible design, the molten salt heat exchange steam turbine power generation module includes a hot molten salt storage tank, a cold molten salt storage tank, a fourth heat exchanger and a steam turbine generator;

[0015] The hot molten salt storage tank and the cold molten salt storage tank are connected through a molten salt pipeline, and the molten salt pipeline passes through the solar thermal heating unit. The molten salt pipeline is provided with four branch pipes, and the four branch pipes pass through the first heat exchanger, the second heat exchanger, the third heat exchanger and the fourth heat exchanger respectively;

[0016] The first heat exchanger, the second heat exchanger and the third heat exchanger are all provided with a water supply pipe and a steam pipe, and the first heat exchanger, the second heat exchanger and the third heat exchanger respectively provide steam to the SOEC unit, the deoxygenation purification unit and the ammonia production unit through the steam pipe;

[0017] The fourth heat exchanger is connected to the steam turbine generator through the auxiliary steam pipe and the condensate pipe, and the output end of the steam turbine generator supplies power to the outside.

[0018] In a possible design, a second electric heating device is provided on the hot molten salt storage tank.

[0019] In one possible design, the input end of the power storage module is electrically connected to the steam turbine generator and the photovoltaic power generation unit, and the output end of the power storage module is electrically connected to the molten salt storage tank and the hydrogen and ammonia production module.

[0020] In a possible design, the control module includes a plurality of controllers, and controllers are provided at the input end of the power storage module, the output end of the power storage module and the auxiliary steam pipe.

[0021] In a possible design, the energy supply module further includes a wind power generation unit, and the wind power generation unit is connected in parallel with the photovoltaic power generation unit.

[0022] Beneficial effects:

[0023] The hierarchical heating system for hydrogen production and ammonia synthesis provides heat energy of different grades through the molten salt heat exchange steam turbine power generation module, thereby improving the hydrogen production efficiency of the hydrogen production and ammonia production modules and the thermal efficiency of high-temperature molten salt. Combined with photovoltaic power generation units, in areas with abundant wind and light resources such as deserts, the photovoltaic power station is coupled with efficient solid-state electrolysis hydrogen production and ammonia synthesis technology to aggregate intermittent and fluctuating photovoltaic power, thereby achieving the maximum efficient utilization of low-quality electricity and improving the local consumption of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The schematic diagram is a structural diagram of a hydrogen production and ammonia synthesis cogeneration system with staged heating.

[0025] In the figure:

[0026] 100, energy supply module; 110, solar thermal heating unit; 120, photovoltaic power generation unit; 200, molten salt heat exchange turbine power generation module; 201, first heat exchanger; 202, second heat exchanger; 203, third heat exchanger; 204, hot molten salt storage tank; 205, cold molten salt storage tank; 206, fourth heat exchanger; 207, steam turbine generator; 208, molten salt pipeline; 209, branch pipe; 210, water supply pipe; 211, steam pipe; 212, auxiliary steam pipe; 213, condensate pipe; 300, hydrogen and ammonia production module; 310, SOEC unit; 320, deoxygenation purification unit; 330, ammonia production unit; 400, power storage module; 500, controller. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the utility model will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the utility model, but does not constitute a limitation of the utility model.

[0028] Example:

[0029] like Figure 1 As shown, the hydrogen production and ammonia synthesis cogeneration system with staged heating includes an energy supply module 100, a molten salt heat exchange steam turbine power generation module 200, a hydrogen production and ammonia production module 300, a power storage module 400 and a control module;

[0030] The energy supply module 100 includes a photothermal heating unit 110 and a photovoltaic power generation unit 120. The output end of the photothermal heating unit 110 is connected to the molten salt heat exchange steam turbine power generation module 200, and the output end of the photovoltaic power generation unit 120 is connected to the hydrogen and ammonia production module 300.

[0031] The molten salt heat exchange steam turbine power generation module 200 includes a first heat exchanger 201, a second heat exchanger 202 and a third heat exchanger 203 connected in parallel with each other;

[0032] The hydrogen and ammonia production module 300 includes a SOEC unit 310, a deoxygenation and purification unit 320, and an ammonia production unit 330 connected in sequence, and the SOEC unit 310 is provided with a first electric heating device; the first heat exchanger 201 is used to provide high-temperature steam for the SOEC unit 310, the second heat exchanger 202 is used to provide low-temperature steam for the deoxygenation and purification unit 320, and the second heat exchanger 202 is used to provide medium-temperature steam for the ammonia production unit 330;

[0033] The input end of the power storage module 400 is electrically connected to the photovoltaic power generation unit 120 and the molten salt heat exchange steam turbine power generation module 200, and the output end of the power storage module 400 is electrically connected to the molten salt heat exchange steam turbine power generation module 200 and the hydrogen and ammonia production module 300;

[0034] The control module is electrically connected to and controls the energy supply module 100 , the molten salt heat exchange steam turbine power generation module 200 , the hydrogen and ammonia production module 300 and the power storage module 400 .

[0035] Among them, the utilization of solar energy and wind energy is realized through the photothermal heating unit 110 and the photovoltaic power generation unit 120. The photothermal heating unit 110 realizes heating, and the photovoltaic power generation unit 120 realizes power supply. Specifically, the hot molten salt heat exchange steam turbine power generation module 200 is provided with molten salt. The photothermal heating unit 110 heats the molten salt, and the hot molten salt is transported to the first heat exchanger 201 for heat exchange, thereby inputting heat into the hydrogen and ammonia production module 300, which not only realizes heating, but also improves the quality of heating. Similarly, the photovoltaic power generation unit 120 uses solar energy to generate electricity, avoids the use of fossil fuels for heating, and also realizes the maximum efficient utilization of low-quality electric energy, which helps to overcome the defects of intermittent, random and volatile photovoltaic electricity.

[0036] In addition, an electricity storage module 400 is provided. During the peak period of the operation of the solar thermal heating unit 110 and the photovoltaic power generation unit 120, excess heat and electricity are stored in the electricity storage module 400 in the form of chemical energy. During the trough period of the operation of the solar thermal heating unit 110 and the photovoltaic power generation unit 120, the electricity storage module 400 supplies energy so that the hydrogen and ammonia production module 300 can maintain high working efficiency for a long time.

[0037] As for power supply, the photovoltaic power generation unit 120 and the power storage module 400 cooperate with each other to achieve the aggregation and efficient use of photovoltaic power, solving the problem of unstable energy supply caused by the intermittent, random and volatile nature of photovoltaic power aggregation in the existing technology, helping to achieve long-term stable power supply and avoiding the phenomenon of large-scale wind and solar power abandonment.

[0038] For heating, the molten salt heat exchange steam turbine power generation module 200 uses molten salt as a medium to convert the solar energy absorbed by the solar thermal heating unit 110 into thermal energy, thereby providing heat for the hydrogen and ammonia production module 300. Molten salt has the advantages of a wide liquid temperature, a large heat storage temperature difference, a high heat storage density, good heat transfer performance, a stable working state, and low cost, and is suitable for large-scale heat storage.

[0039] Furthermore, the molten salt heat exchanger steam turbine power generation module 200 includes a first heat exchanger 201, a second heat exchanger 202 and a third heat exchanger 203 which are connected in parallel. On the one hand, high-temperature, medium-temperature and low-temperature steam are generated respectively through the three heat exchangers, which are then supplied to the three functional units of the hydrogen and ammonia production module 300 respectively. On the other hand, the parallel connection improves the independence of the heat exchangers, reduces mutual interference, and ensures that all heat exchangers will not be unable to supply steam normally due to abnormal function of a certain heat exchanger.

[0040] The hydrogen and ammonia production module 300 adds a deoxygenation purification unit 320 and an ammonia production unit 330 on the basis of the SOEC unit 310, synthesizes ammonia on the basis of hydrogen production, and realizes the co-production of hydrogen production and ammonia synthesis. Specifically, the operating temperature of SOEC is 500-850°C, the operating temperature of deoxygenation purification is 250-300°C, the operating temperature of hydrogen synthesis ammonia is 300-500°C, and the heat of the solar thermal heating unit 110 is supplied to the molten salt heat exchange steam turbine power generation module 200, which generates high-temperature, medium-temperature and low-temperature steam through three heat exchanges.

[0041] Therefore, the molten salt heat exchange steam turbine power generation module 200 can provide high-temperature steam to the SOEC unit 310, low-temperature steam to the deoxygenation purification unit 320, and medium-temperature steam to the ammonia production unit 330, except that the temperature of the high-temperature steam is 500-550°C, and a first electric heating device needs to be set in the SOEC unit 310 for temperature supplement. Both the medium-temperature steam and the low-temperature steam can meet the temperature requirements of the corresponding units.

[0042] Based on this, the molten salt heat exchange steam turbine power generation module 200 not only realizes the heat supply to the hydrogen and ammonia production module 300, but also improves the independence of the three heat exchangers in parallel, reduces the impact of faults on the molten salt heat exchange steam turbine power generation module 200, and helps to improve the smoothness of system operation. It not only meets the needs of the hydrogen and ammonia production modules 300 for different levels of heat, but also improves the energy supply efficiency of the solar thermal heating unit 110, while improving the efficiency of hydrogen production and ammonia synthesis.

[0043] In addition, each functional module is controlled by a control module to realize automatic operation of the hydrogen production and ammonia synthesis cogeneration system with graded heating, thereby improving the degree of automation and intelligence.

[0044] In this embodiment, the molten salt heat exchange steam turbine power generation module 200 includes a hot molten salt storage tank 204, a cold molten salt storage tank 205, a fourth heat exchanger 206 and a steam turbine generator 207;

[0045] The hot molten salt storage tank 204 and the cold molten salt storage tank 205 are connected by a molten salt pipeline 208, and the molten salt pipeline 208 passes through the photothermal heating unit 110. The molten salt pipeline 208 is provided with four branch pipes 209, and the four branch pipes 209 pass through the first heat exchanger 201, the second heat exchanger 202, the third heat exchanger 203 and the fourth heat exchanger 206 respectively;

[0046] The first heat exchanger 201, the second heat exchanger 202 and the third heat exchanger 203 are all provided with a water supply pipe 210 and a steam pipe 211. The first heat exchanger 201, the second heat exchanger 202 and the third heat exchanger 203 respectively provide steam to the SOEC unit 310, the deoxygenation purification unit 320 and the ammonia production unit 330 through the steam pipe 211;

[0047] The fourth heat exchanger 206 is connected to the steam turbine generator 207 through the auxiliary steam pipe 212 and the condensate pipe 213, and the output end of the steam turbine generator 207 supplies power to the outside.

[0048] Based on the above design scheme, the hot molten salt storage tank 204 contains heated liquid molten salt to achieve heat storage. When supplying heat to the outside, the hot molten salt is first transported to the first heat exchanger 201 to generate high-temperature steam, and the hot molten salt is transported to the third heat exchanger 203 again to generate medium-temperature steam. The hot molten salt is finally transported to the second heat exchanger 202 to generate low-temperature steam. Further, in the order of the first heat exchanger 201, the third heat exchanger 203 to the second heat exchanger 202, the hot molten salt delivery amount decreases successively, thereby generating high-temperature, medium-temperature and low-temperature steam respectively.

[0049] At the same time, the first heat exchanger 201, the second heat exchanger 202 and the third heat exchanger 203 are all provided with a water supply pipe 210, and the water supply is ensured through the water supply pipe 210. The hot molten salt exchanges heat with water and generates steam, which also ensures the steam supply of the hydrogen and ammonia production module 300. The steam enters the corresponding unit of the hydrogen and ammonia production module 300 through the steam pipe 211.

[0050] On the basis of satisfying the heat supply of the hydrogen and ammonia production module 300, if there is excess heat, part of the hot molten salt is transported to the fourth heat exchanger 206, and steam is provided to the steam turbine generator 207 through the fourth heat exchanger 206, thereby driving the steam turbine generator 207 to work and generate electricity. Based on this, the effective utilization of excess heat is achieved, the abandoned heat is minimized, and the utilization rate of heat is improved. On the contrary, if there is no excess heat, the heat supply of the first heat exchanger 201, the second heat exchanger 202 and the third heat exchanger 203 should be guaranteed first, and the hot molten salt does not need to be transported to the fourth heat exchanger 206.

[0051] In a possible implementation, a second electric heating device is provided on the hot molten salt storage tank 204. Based on the above design scheme, when the photothermal heating unit 110 is insufficiently supplied with heat, in order to ensure that the heating of the hydrogen and ammonia production module 300 meets the production requirements. At this time, the second electric heating device is started and the heat is supplemented by electric heating; it is easy to understand that the power supply of the second electric heating device can be selected from the photovoltaic power generation unit 120, the power storage module 400 or the mains system.

[0052] In this embodiment, the input end of the power storage module 400 is electrically connected to the steam turbine generator 207 and the photovoltaic power generation unit 120, and the output end of the power storage module 400 is electrically connected to the hot molten salt storage tank 204 and the hydrogen and ammonia production module 300. Based on the above design scheme, the power generation unit 240 uses the excess heat of the photothermal heating unit 110 to generate electricity, which can not only power the hydrogen and ammonia production module 300, but also be stored in the power storage module 400. Similarly, the excess electricity of the photovoltaic power generation unit 120 can also be stored in the power storage module 400.

[0053] When the solar thermal heating unit 110 does not provide sufficient heat and / or the photovoltaic power generation unit 120 does not provide sufficient power, the power storage module 400 supplies power to the molten salt storage to supplement heat, and the power storage module 400 supplies power to the hydrogen and ammonia production module 300 to supplement electricity, thereby ensuring that the hydrogen and ammonia production module 300 can operate efficiently.

[0054] In a possible implementation, the control module includes a plurality of controllers 500, and the controllers 500 are provided at the input end of the power storage module 400, the output end of the power storage module 400, and the auxiliary steam pipe 212. Based on the above design, the controller 500 is used to control the power storage and power supply of the power storage module 400 and the power generation of the power generation unit 240, and the maximum degree of coordinated control is achieved on the basis of ensuring power supply and heat supply, so that the molten salt cascade wind and solar power generation hydrogen synthesis ammonia cogeneration system can operate stably and efficiently.

[0055] It is easy to understand that the controller 500 can be any suitable commercially available model.

[0056] In this embodiment, the energy supply module 100 also includes a wind power generation unit, and the wind power generation unit is connected in parallel with the photovoltaic power generation unit 120. Based on the above design scheme, the photovoltaic power generation unit 120 uses solar energy to generate electricity, and the wind power generation unit uses wind power to generate electricity. It is easy to understand that in areas with abundant solar and thermal resources, the photovoltaic power generation unit 120 is preferred to supply power, and conversely, in areas with abundant wind resources, the wind power generation unit is preferred to supply power. That is, one of the wind power generation unit and the photovoltaic power generation unit 120 is selected to supply power; further, if both wind and photovoltaic power are unstable, both can be selected to be used at the same time to improve the stability of power supply.

[0057] Considering that the hydrogen production and ammonia synthesis cogeneration system with graded heating is preferably used in areas with abundant solar thermal resources, the energy supply module 100 preferably uses a photovoltaic power generation unit 120 .

[0058] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydrogen production and ammonia synthesis cogeneration system with staged heating, characterized in that: It comprises an energy supply module (100), a molten salt heat exchange steam turbine power generation module (200), a hydrogen and ammonia production module (300), a power storage module (400) and a control module; The energy supply module (100) comprises a photothermal heating unit (110) and a photovoltaic power generation unit (120), wherein the output end of the photothermal heating unit (110) is connected to a molten salt heat exchange steam turbine power generation module (200), and the output end of the photovoltaic power generation unit (120) is connected to a hydrogen and ammonia production module (300); The molten salt heat exchange steam turbine power generation module (200) comprises a first heat exchanger (201), a second heat exchanger (202) and a third heat exchanger (203) which are connected in parallel with each other; The hydrogen and ammonia production module (300) comprises a SOEC unit (310), a deoxygenation and purification unit (320) and an ammonia production unit (330) which are connected in sequence, wherein the SOEC unit (310) is provided with a first electric heating device; the first heat exchanger (201) is used to provide high-temperature steam for the SOEC unit (310), the second heat exchanger (202) is used to provide low-temperature steam for the deoxygenation and purification unit (320), and the second heat exchanger (202) is used to provide medium-temperature steam for the ammonia production unit (330); The input end of the power storage module (400) is electrically connected to the photovoltaic power generation unit (120) and the molten salt heat exchange steam turbine power generation module (200), and the output end of the power storage module (400) is electrically connected to the molten salt heat exchange steam turbine power generation module (200) and the hydrogen and ammonia production module (300). The control module is electrically connected to and controls the energy supply module (100), the molten salt heat exchange steam turbine power generation module (200), the hydrogen and ammonia production module (300), and the power storage module (400).

2. The hydrogen production and ammonia synthesis co-production system with hierarchical heating according to claim 1 is characterized in that: The molten salt heat exchange steam turbine power generation module (200) comprises a hot molten salt storage tank (204), a cold molten salt storage tank (205), a fourth heat exchanger (206) and a steam turbine generator (207); The hot molten salt storage tank (204) and the cold molten salt storage tank (205) are connected via a molten salt pipeline (208), and the molten salt pipeline (208) passes through the photothermal heating unit (110). The molten salt pipeline (208) is provided with four branch pipes (209), and the four branch pipes (209) respectively pass through the first heat exchanger (201), the second heat exchanger (202), the third heat exchanger (203) and the fourth heat exchanger (206); The first heat exchanger (201), the second heat exchanger (202) and the third heat exchanger (203) are all provided with a water supply pipe (210) and a steam pipe (211), and the first heat exchanger (201), the second heat exchanger (202) and the third heat exchanger (203) respectively provide steam to the SOEC unit (310), the deoxygenation purification unit (320) and the ammonia production unit (330) through the steam pipe (211); The fourth heat exchanger (206) is connected to the steam turbine generator (207) via the auxiliary steam pipe (212) and the condensate pipe (213), and the output end of the steam turbine generator (207) supplies power to the outside.

3. The hydrogen production and ammonia synthesis co-production system with hierarchical heating according to claim 2 is characterized in that: The hot molten salt storage tank (204) is provided with a second electric heating device.

4. The hydrogen production and ammonia synthesis co-production system with hierarchical heating according to claim 2 is characterized in that: The input end of the power storage module (400) is electrically connected to the steam turbine generator (207) and the photovoltaic power generation unit (120), and the output end of the power storage module (400) is electrically connected to the hot molten salt storage tank (204) and the hydrogen and ammonia production module (300).

5. The hydrogen production and ammonia synthesis co-production system with hierarchical heating according to claim 4 is characterized in that: The control module comprises a plurality of controllers (500), and the input end of the power storage module (400), the output end of the power storage module (400) and the auxiliary steam pipe (212) are all provided with the controllers (500).

6. The hydrogen production and ammonia synthesis co-production system with hierarchical heating according to claim 1 is characterized in that: The energy supply module (100) further comprises a wind power generation unit, which is connected in parallel with the photovoltaic power generation unit (120).

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