Heat removal and heat energy storage system for magnesium hydride hydrogen charging and discharging reactor

Abstract

The utility model relates to the technical field of chemical reaction heat storage, and provides a magnesium hydride hydrogen charging and discharging reactor heat taking and heat energy storage system which comprises a magnesium hydride reactor, a heat conduction oil system and an organic Rankine power generation unit. The magnesium hydride reactor comprises a U-shaped tube heat exchanger and a hydrogen inlet and outlet pipeline; mg / MgH2 is arranged on the shell pass side of the U-shaped tube heat exchanger; the shell pass side of the U-shaped tube heat exchanger is connected with a hydrogen inlet and outlet pipeline; the heat-conducting oil system comprises a heat-conducting oil furnace, an oil conveying pipe and a first oil return pipe; the oil conveying pipe and the first oil return pipe are connected with the tube pass side of the U-shaped tube heat exchanger; the oil conveying pipe and the first oil return pipe are connected with the heat-conducting oil furnace; the organic Rankine power generation unit comprises an evaporator, an organic Rankine turbine, a working medium pump, a second oil return pipe and a third oil return pipe. According to the Mg / MgH2 reversible reaction device, heat generated in the Mg / MgH2 reversible reaction process can be taken through the organic Rankine power generation unit, and energy waste is greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical reaction heat storage, in particular to a heat extraction and heat energy storage system for a magnesium hydride hydrogen charging and discharging reactor. Background Art

[0002] During the hydrogen charging process of the reversible reaction Mg / MgH2, a large amount of heat energy is generated. The existing heat extraction methods include direct heat dissipation through the outer surface in the air, external heat extraction with a jacketed heat transfer oil, internal heat extraction with a coiled heat transfer oil pipe, and internal heat extraction with a heat exchange tube heat transfer oil. After the heat transfer oil extracts heat, it is cooled by air cooling and then circulated.

[0003] After heat extraction by the existing methods, the heat is dissipated into the air, resulting in a large amount of resource waste; and in these heat exchange methods, heat exchange is finally carried out through air, so the heat exchange efficiency cannot be guaranteed, and the temperature in the magnesium hydride reactor cannot be accurately controlled, which will affect the hydrogen charging process. Summary of the Utility Model

[0004] The utility model mainly solves the technical problems that in the existing heat extraction methods, the heat is dissipated into the air after heat extraction, resulting in a large amount of resource waste and the heat exchange efficiency cannot be guaranteed by air heat exchange. The utility model provides a heat extraction and heat energy storage system for a magnesium hydride hydrogen charging and discharging reactor, which can extract the heat generated in the reversible reaction process of Mg / MgH2 through an organic Rankine power generation unit for power generation of the organic Rankine power generation unit, and the generated electricity can be stored and used, greatly reducing energy waste; and after using the organic Rankine power generation unit for heat extraction, the heat exchange amount can be accurately controlled to ensure that the temperature of the magnesium hydride reactor can be accurately controlled.

[0005] The utility model provides a heat extraction and heat energy storage system for a magnesium hydride hydrogen charging and discharging reactor, comprising: a magnesium hydride reactor, a heat transfer oil system and an organic Rankine power generation unit;

[0006] The magnesium hydride reactor comprises: a U-shaped tube heat exchanger and a hydrogen inlet and outlet pipeline;

[0007] Mg / MgH2 is installed on the shell side of the U-shaped tube heat exchanger; the shell side of the U-shaped tube heat exchanger is connected to the hydrogen inlet and outlet pipeline;

[0008] The heat transfer oil system comprises: a heat transfer oil furnace, an oil pipeline and a first return oil pipeline;

[0009] The oil pipeline and the first return oil pipeline are connected to the tube side of the U-shaped tube heat exchanger;

[0010] The oil pipeline and the first return oil pipeline are connected to the heat transfer oil furnace; the heat transfer oil furnace stores heat transfer oil;

[0011] The organic Rankine power generation unit includes: an evaporator, an organic Rankine turbine, a condenser, a working fluid pump, a second oil return pipe, and a third oil return pipe;

[0012] The evaporator is connected to the first oil return pipe through the second oil return pipe; the evaporator is connected to the oil delivery pipe through the third oil return pipe;

[0013] The gas outlet of the evaporator is connected to the organic Rankine turbine, the organic Rankine turbine is connected to the gas inlet of the condenser, the liquid outlet of the condenser is connected to the working fluid pump, and the working fluid pump is connected to the liquid inlet of the evaporator.

[0014] Preferably, a heat transfer oil circulation pump is provided on the oil delivery pipe.

[0015] Preferably, a first stop valve and a second heat transfer oil thermocouple are provided on the first oil return pipe;

[0016] A second stop valve is provided on the second oil return pipe;

[0017] A third stop valve and a first heat transfer oil thermocouple are provided on the third oil return pipe.

[0018] Preferably, an electric heater is installed in the heat transfer oil furnace.

[0019] Preferably, a filter, a hydrogen flow meter, a pneumatic control valve, a coil air cooler, a hydrogen pump, and a hydrogen compressor are sequentially provided on the hydrogen inlet and outlet pipeline.

[0020] Preferably, a branch is provided between the coil air cooler and the hydrogen pump to connect a nitrogen purging device; a branch is provided between the pneumatic control valve and the coil air cooler to connect a hydrogen source.

[0021] Preferably, the organic Rankine turbine is connected to a storage battery.

[0022] Preferably, a second control valve is provided between the gas outlet of the evaporator and the organic Rankine turbine.

[0023] Preferably, a first control valve is provided on the pipeline between the working fluid pump and the liquid inlet of the evaporator.

[0024] The utility model provides a heat extraction and thermal energy storage system for a magnesium hydride hydrogen charging and discharging reactor, which utilizes a reversible reaction Mg / MgH2 hydrogen storage system to achieve effective use of thermal energy. Thermal oil is used as a heat exchange medium in the process. The Mg / MgH2 system combined with an organic Rankine power generation unit can achieve effective, safe and convenient storage of hydrogen energy, and can also achieve effective use of heat for continuous power generation. In the process of hydrogen energy storage, electrical energy storage is achieved by the way, avoiding the waste of thermal energy, and after combining with the organic Rankine power generation unit, by controlling the evaporation amount and temperature of the evaporator working fluid, compared with ordinary air-cooled heat exchange, the temperature of the thermal oil can be more accurately controlled, so as to more accurately control the temperature of the reversible reaction Mg / MgH2, make the reaction more stable, and avoid uncontrollable over-temperature during the reaction process.

[0025] Compared with traditional liquid hydrogen storage and high-pressure gaseous hydrogen storage, the Mg / MgH2 system for hydrogen storage has the advantages of high hydrogen storage density, good safety, and mild charging and discharging conditions. Mg / MgH2 hydrogen storage does not require high-pressure equipment, and has lower requirements for components such as containers and valves, which reduces initial investment, costs, and failure rates. Mg / MgH2 hydrogen storage also has the advantages of long storage time and low leakage, which can better ensure the safety and stable supply of hydrogen energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The utility model provides a schematic diagram of the composition of a heat extraction and thermal energy storage system of a magnesium hydride hydrogen charging and discharging reactor.

[0027] Figure numerals: 1. U-tube heat exchanger; 2. U-tube heat exchanger thermocouple; 3. filter; 4. pneumatic control valve; 5. hydrogen flowmeter; 6. coil air cooler; 7. nitrogen purge device; 8. hydrogen pump; 9. hydrogen compressor; 10. electric heater; 11. thermal oil furnace; 12. thermal oil circulation pump; 13. first thermal oil thermocouple; 14. first stop valve; 15. second stop valve; 16. third stop valve; 17. oil pipeline; 18. first return oil pipe; 19. second return oil pipe; 20. third return oil pipe; 21. organic Rankine turbine; 22. evaporator; 23. condenser; 24. working fluid pump; 25. battery; 26. first control valve; 27. second control valve; 28. hydrogen inlet and outlet pipelines; 29. ​​hydrogen source; 30. second thermal oil thermocouple. DETAILED DESCRIPTION

[0028] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model and are not intended to limit the present utility model. Additionally, it should be noted that for the convenience of description, only the parts related to the present utility model rather than all the content are shown in the drawings.

[0029] As Figure 1 shown, a heat extraction and thermal energy storage system for a magnesium hydride hydrogen charging and discharging reactor provided by an embodiment of the present utility model includes: a magnesium hydride reactor, a heat transfer oil system, and an organic Rankine power generation unit.

[0030] The magnesium hydride reactor includes: a U-tube heat exchanger 1 and a hydrogen inlet and outlet pipeline 28; Mg / MgH2 is installed on the shell side of the U-tube heat exchanger 1; the shell side of the U-tube heat exchanger 1 is connected to the hydrogen inlet and outlet pipeline 28; the hydrogen inlet and outlet pipeline 28 is connected to a hydrogen source 29.

[0031] A filter 3, a hydrogen flowmeter 5, a pneumatic control valve 4, a coil air cooler 6, a hydrogen pump 8, and a hydrogen compressor 9 are sequentially provided on the hydrogen inlet and outlet pipeline 28. A branch is provided between the coil air cooler 6 and the hydrogen pump 8 and is connected to a nitrogen purging device 7; a branch is provided between the pneumatic control valve 4 and the coil air cooler 6 and is connected to the hydrogen source 29.

[0032] The heat transfer oil system includes: a heat transfer oil furnace 11, an oil pipeline 17, and a first oil return pipeline 18.

[0033] The oil pipeline 17 and the first oil return pipeline 18 are connected to the tube side of the U-tube heat exchanger 1. The oil pipeline 17 and the first oil return pipeline 18 are connected to the heat transfer oil furnace 11 to form a heat transfer oil circulation loop. A heat transfer oil circulation pump 12 is provided on the oil pipeline 17. Heat transfer oil is stored in the heat transfer oil furnace 11; an electric heater 10 is installed in the heat transfer oil furnace 11 for heating the heat transfer oil.

[0034] A first stop valve 14 and a second heat transfer oil thermocouple 30 are provided on the first oil return pipeline 18; a second stop valve 15 is provided on the second oil return pipeline 19; a third stop valve 16 and a first heat transfer oil thermocouple 13 are provided on the third oil return pipeline 20.

[0035] The organic Rankine power generation unit includes: an evaporator 22, an organic Rankine turbine 21, a condenser 23, a working fluid pump 24, a second oil return pipeline 19, and a third oil return pipeline 20.

[0036] The evaporator 22 is connected to the first oil return pipe 18 through the second oil return pipe 19, and the evaporator 22 is connected to the oil delivery pipe 17 through the third oil return pipe 20 to form a heat transfer oil circuit. The gas outlet of the evaporator 22 is connected to the organic Rankine turbine 21, and a second control valve 27 is provided between the gas outlet of the evaporator 22 and the organic Rankine turbine 21. The organic Rankine turbine 21 is connected to the storage battery 25. The organic Rankine turbine 21 is connected to the inlet of the condenser 23, the liquid outlet of the condenser 23 is connected to the working fluid pump 24, and the working fluid pump 24 is connected to the inlet of the evaporator 22 to form a working fluid circuit. A first control valve 26 is provided in the pipeline between the working fluid pump 24 and the inlet of the evaporator 22.

[0037] The working process of the heat extraction and heat energy storage system of the magnesium hydride charge and discharge hydrogen reactor of the present utility model:

[0038] The shell side of the U-shaped tube heat exchanger 1 in the magnesium hydride reactor is filled with Mg / MgH2, and the heat transfer oil flows on the tube side for heat exchange. Mg can undergo a hydrogen absorption reaction at a temperature of 120-300 °C, absorb a large amount of hydrogen, and generate MgH2, and the hydrogen absorption reaction will release a large amount of heat.

[0039] During the process of Mg reacting with H2 to generate MgH2, hydrogen is provided by the hydrogen source 29 and enters the shell side of the U-shaped tube heat exchanger 1 through the pneumatic control valve 4, the hydrogen flowmeter 5, and the filter 3. The flow rate of hydrogen is controlled by the pneumatic control valve 4 and recorded by the hydrogen flowmeter 5. The heat transfer oil in the heat transfer oil furnace 11 is heated to the initial start-up reaction temperature of 120 °C - 300 °C by the electric heater 10, and the heated heat transfer oil is input into the tube side of the U-shaped tube heat exchanger 1 by the heat transfer oil circulation pump 12 to heat Mg and hydrogen to the reaction temperature to start the hydrogen absorption reaction. After the hydrogen absorption reaction starts, a large amount of heat is generated. When the temperature is detected to reach a certain value by the U-shaped tube heat exchanger thermocouple 2 and the first heat transfer oil thermocouple 13, the first stop valve 14 is closed, the heat transfer oil electric heater 10 is closed, and the second stop valve 15 and the third stop valve 16 are opened; the heat transfer oil enters the tube side of the evaporator 22 through the second oil return pipe 19. The working fluid on the shell side of the evaporator 22 is heated and vaporized and expanded by the heat transfer oil on the tube side. The working fluid forms a high-temperature and high-pressure gas and enters the organic Rankine turbine 21 for power generation, and the generated electricity is stored in the storage battery 25. The high-temperature and high-pressure working fluid gas that has consumed part of the energy enters the condenser 23 and is cooled and liquefied by the cooling water in the condenser 23 and returns to the shell side of the evaporator 22 through the working fluid pump 24 for circulation.

[0040] After being cooled, the heat-conducting oil flows out from the outlet on the tube side of the evaporator 22, enters the third oil return pipe 20, and forms a cycle through the third stop valve 16 and the heat-conducting oil circulation pump 12 into the tube side of the U-shaped tube heat exchanger 1. The temperature of the heat-conducting oil monitored by the first heat-conducting oil thermocouple 13 and the reaction temperature monitored by the U-shaped tube heat exchanger thermocouple 2 are jointly fed back to control the opening degree of the pneumatic control valve 4, and the reaction temperature in the U-shaped tube heat exchanger 1 is controlled.

[0041] During the process of hydrogen release from MgH2, the heat-conducting oil in the heat-conducting oil furnace 11 is heated by the electric heater 10 to the reaction temperature of 120°C - 300°C. The first stop valve 14 is opened, and the second stop valve 15 and the third stop valve 16 are closed. The heated heat-conducting oil is input into the tube side of the U-shaped tube heat exchanger 1 by the heat-conducting oil circulation pump 12. The reaction continuously absorbs heat, and the electric heater 10 continuously heats. The heat-conducting oil returns to the heat-conducting oil furnace 11 through the first oil return pipe 18 to form a cycle. The temperature of the heat-conducting oil monitored by the second heat-conducting oil thermocouple 30 and the reaction temperature monitored by the U-shaped tube heat exchanger thermocouple 2 jointly feed back to control the power of the electric heater 10, and then control the reaction temperature in the U-shaped tube heat exchanger 1 to make the reaction proceed under the optimal temperature conditions. After reaching the appropriate reaction temperature, MgH2 continuously decomposes and absorbs heat to generate Mg and H2. The H2 is pumped out by the hydrogen pump 8. The H2 passes through the filter 3 to prevent dust from being carried out with the gas, is cooled by the coil air cooler 6, and enters the hydrogen storage tank after being compressed by the hydrogen compressor 9.

[0042] After the hydrogenation or dehydrogenation reaction ends, the residual unreacted H2 is pumped out and evacuated to a safe place through the hydrogen pump 8 to prevent the accumulation of H2; nitrogen is blown into the U-shaped tube heat exchanger 1 through the nitrogen purging device 7, and then the nitrogen is pumped out through the hydrogen pump 8 again, repeating twice; then the U-shaped tube heat exchanger 1 is filled with nitrogen for gas protection.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: modifications made to the technical solutions recorded in the foregoing embodiments, or equivalent replacements of some or all of the technical features therein, do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat extraction and thermal energy storage system for a magnesium hydride charging and discharging hydrogen reactor, characterized in that: include: Magnesium hydride reactor, thermal oil system and organic Rankine power generation unit; The magnesium hydride reactor comprises: a U-tube heat exchanger (1) and a hydrogen inlet and outlet pipeline (28); The shell side of the U-tube heat exchanger (1) is filled with Mg / MgH2; the shell side of the U-tube heat exchanger (1) is connected to the hydrogen inlet and outlet pipeline (28); The heat transfer oil system comprises: a heat transfer oil furnace (11), an oil delivery pipe (17) and a first oil return pipe (18); The oil delivery pipe (17) and the first oil return pipe (18) are connected to the tube side of the U-tube heat exchanger (1); The oil delivery pipe (17) and the first oil return pipe (18) are connected to the thermal oil furnace (11); the thermal oil furnace (11) stores thermal oil; The organic Rankine power generation unit comprises: an evaporator (22), an organic Rankine turbine (21), a condenser (23), a working fluid pump (24), a second oil return pipe (19) and a third oil return pipe (20); The evaporator (22) is connected to the first oil return pipe (18) via the second oil return pipe (19); the evaporator (22) is connected to the oil delivery pipe (17) via the third oil return pipe (20); The air outlet of the evaporator (22) is connected to the organic Rankine turbine (21), the organic Rankine turbine (21) is connected to the air inlet of the condenser (23), the liquid outlet of the condenser (23) is connected to the working fluid pump (24), and the working fluid pump (24) is connected to the liquid inlet of the evaporator (22).

2. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 1 is characterized in that: The oil delivery pipe (17) is provided with a heat transfer oil circulation pump (12).

3. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 1 is characterized in that: The first oil return pipe (18) is provided with a first stop valve (14) and a second heat transfer oil thermocouple (30); A second stop valve (15) is provided on the second oil return pipe (19); The third oil return pipe (20) is provided with a third stop valve (16) and a first heat transfer oil thermocouple (13).

4. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 1, characterized in that: An electric heater (10) is installed in the thermal oil furnace (11).

5. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 1, characterized in that: The hydrogen inlet and outlet pipeline (28) is provided with a filter (3), a hydrogen flow meter (5), a pneumatic control valve (4), a coil-type air cooler (6), a hydrogen pump (8), and a hydrogen compressor (9) in sequence.

6. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 5, characterized in that: A branch is provided between the coil-type air cooler (6) and the hydrogen pump (8) and connected to a nitrogen purge device (7); a branch is provided between the pneumatic control valve (4) and the coil-type air cooler (6) and connected to a hydrogen source (29).

7. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 1, characterized in that: The organic Rankine turbine (21) is connected to a battery (25).

8. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 7, characterized in that: A second control valve (27) is arranged between the gas outlet of the evaporator (22) and the organic Rankine turbine (21).

9. The heat extraction and thermal energy storage system of the magnesium hydride charging and discharging reactor according to claim 8, characterized in that: A first control valve (26) is provided in the pipeline between the working fluid pump (24) and the liquid inlet of the evaporator (22).

Images