Wind-solar power generation hydrogen production oxygen recovery liquefaction and air separation nitrogen production peak regulation coupling system

Abstract

The utility model provides an oxygen recovery liquefaction and air separation nitrogen preparation peak regulation coupling system for wind-solar power generation hydrogen production, which reasonably integrates hydrogen and oxygen products of a water electrolysis hydrogen production device and nitrogen products of an air separation nitrogen preparation device, realizes recovery of the oxygen products, and provides feed gas for a synthesis ammonia device at a stable nitrogen-hydrogen ratio. The device comprises an oxygen dehydrogenation drying unit, a liquefaction unit, an oxygen-nitrogen conversion unit and an oxygen-nitrogen storage unit, the liquefaction unit comprises a circulating nitrogen compressor, a first cooler, a high-temperature expansion machine, a second cooler, a low-temperature expansion machine, a third cooler, a main heat exchanger, a liquid oxygen subcooler, an oxygen liquefier and a first liquid oxygen separation tank; and the oxygen-nitrogen conversion unit comprises an oxygen-nitrogen heat exchanger and a second liquid oxygen separation tank.

Description

Technical Field

[0001] The utility model relates to an oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for hydrogen production by wind and solar power generation. Background Art

[0002] With the development of the hydrogen energy industry, we have been using wind and solar power generation, combined with water electrolysis to provide hydrogen, and air separation nitrogen production equipment to extract nitrogen. Hydrogen and nitrogen are used as synthetic ammonia raw materials to synthesize ammonia to meet the development needs of the green chemical industry.

[0003] Due to the intermittent and fluctuating nature of wind or solar power generation, the output of hydrogen produced by water electrolysis also fluctuates, and the demand for nitrogen, another raw gas required for synthetic ammonia, also fluctuates. It is usually required that the nitrogen production device can provide a load adjustment capacity of 30% to 120% to meet the uninterrupted production of synthetic ammonia. Oxygen, a byproduct of water electrolysis, is usually vented because its purity does not meet the standard, resulting in a waste of resources.

[0004] The raw nitrogen required for synthetic ammonia is generally extracted by cryogenic distillation. In order to adapt to the instability of hydrogen, the air separation nitrogen production unit needs to frequently perform variable load operation. Generally, it is required that the air separation unit uniformly increases the load from 30% to 105% in less than 2 hours, and the air separation unit uniformly decreases the load from 105% to 30% in less than 2 hours. The number of load adjustments of the air separation unit greater than 20% per year is greater than 2,000 times, and the number of load adjustments required per day is greater than 6 times. Higher requirements are placed on the stable and reliable operation of the air separation unit. Frequent load adjustments of the air separation nitrogen production unit will affect the purity and extraction rate of nitrogen. When operating at low load, the nitrogen production unit has low operating efficiency and high energy consumption.

[0005] During the peak period of wind and solar power generation, the hydrogen output is high, the oxygen products are high, and the corresponding demand for nitrogen products is also high. If the entire device is designed according to the peak period, the production load of the device will be obviously insufficient during the trough period, resulting in a waste of project investment and operating energy consumption.

[0006] The oxygen product recovery liquefaction also has the problem of oxygen product fluctuation and instability, and the liquefaction unit cannot operate stably and efficiently. The liquefaction unit is designed for the minimum output, and the excess oxygen needs to be vented, so the oxygen product cannot be fully recovered. Utility Model Content

[0007] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a coupling system for oxygen recovery and liquefaction and air separation nitrogen production peak regulation for hydrogen production from wind and solar power generation with a rational structural design, rationally integrate the hydrogen and oxygen products of the water electrolysis hydrogen production device and the nitrogen product of the air separation nitrogen production device, realize the recovery of oxygen products, and provide raw gas to the synthetic ammonia device with a stable nitrogen-hydrogen ratio.

[0008] The technical solution adopted by the utility model to solve the above problems is: an oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for hydrogen production by wind and solar power generation, characterized in that: it includes an oxygen dehydrogenation drying unit, a liquefaction unit, an oxygen-nitrogen conversion unit and an oxygen-nitrogen storage unit; the liquefaction unit includes a circulating nitrogen compressor, a first cooler, a high-temperature expander, a second cooler, a low-temperature expander, a third cooler, a main heat exchanger, a liquid oxygen subcooler, an oxygen liquefier and a first liquid oxygen separation tank; the oxygen-nitrogen conversion unit includes an oxygen-nitrogen heat exchanger and a second liquid oxygen separation tank;

[0009] The oxygen dehydrogenation drying unit is connected to the hot runner inlet of the oxygen liquefier and the hot runner inlet of the oxygen-nitrogen heat exchanger respectively; the outlet of the circulating nitrogen compressor is connected to the inlet of the first cooler, the outlet of the first cooler is connected to the inlet of the boost end of the high-temperature expander, the outlet of the boost end of the high-temperature expander is connected to the inlet of the second cooler, the outlet of the second cooler is connected to the inlet of the boost end of the low-temperature expander, and the outlet of the boost end of the low-temperature expander is connected to the inlet of the third cooler; the outlet of the third cooler is respectively connected to the hot runner inlet of the main heat exchanger; The outlet is also connected to the hot runner inlet of the main heat exchanger, the hot runner outlet of the main heat exchanger is connected to the expansion end inlet of the high-temperature expander, the expansion end outlet of the high-temperature expander is connected to the cold runner inlet of the main heat exchanger, and the cold runner outlet of the main heat exchanger is connected to the inlet of the circulating nitrogen compressor; the hot runner outlet of the main heat exchanger is connected to the expansion end inlet of the low-temperature expander, the expansion end outlet of the low-temperature expander is connected to the cold runner inlet of the main heat exchanger, and the cold runner outlet of the main heat exchanger is connected to the inlet of the circulating nitrogen compressor; the hot runner outlet of the main heat exchanger is connected to the liquid oxygen subcooler The hot runner inlet is connected, and the hot runner outlet of the liquid oxygen supercooler is respectively connected to the cold runner inlet of the liquid oxygen supercooler, the liquid nitrogen storage tank, and the cold runner inlet of the oxygen liquefier; the cold runner outlet of the oxygen liquefier is connected to the inlet of the circulating nitrogen compressor; the cold runner outlet of the liquid oxygen supercooler is connected to the cold runner inlet of the main heat exchanger, and the cold runner outlet of the main heat exchanger is connected to the inlet of the circulating nitrogen compressor; the hot runner outlet of the oxygen liquefier is connected to the inlet of the first liquid oxygen separation tank, and the gas phase outlet of the first liquid oxygen separation tank is connected to the cold runner inlet of the oxygen liquefier, and the gas phase outlet of the first liquid oxygen separation tank is connected to the cold runner inlet of the oxygen liquefier. The liquid phase outlet of the separation tank is connected to the hot runner inlet of the liquid oxygen supercooler, and the hot runner outlet of the liquid oxygen supercooler is connected to the oxygen-nitrogen storage unit; the hot runner outlet of the oxygen-nitrogen heat exchanger is connected to the inlet of the second liquid oxygen separation tank, the gas phase outlet of the second liquid oxygen separation tank is connected to the cold runner inlet of the oxygen-nitrogen heat exchanger, the liquid phase outlet of the second liquid oxygen separation tank is connected to the hot runner inlet of the oxygen-nitrogen heat exchanger, and the hot runner outlet of the oxygen-nitrogen heat exchanger is connected to the oxygen-nitrogen storage unit; the oxygen-nitrogen storage unit is respectively connected to the cold runner inlet of the oxygen-nitrogen heat exchanger and the cold runner inlet of the liquid oxygen supercooler.

[0010] The oxygen dehydrogenation drying unit described in the utility model comprises an oxygen buffer tank, a circulation heater, an electric heater, a dehydrogenation reactor, a dehydrogenation cooler, a first gas-liquid separator, a main drying tower and a crude oxygen main pipe; the outlet of the oxygen buffer tank is connected to the shell-side inlet of the circulation heater, the shell-side outlet of the circulation heater is connected to the inlet of the electric heater, the outlet of the electric heater is connected to the inlet of the dehydrogenation reactor, the outlet of the dehydrogenation reactor is connected to the tube-side inlet of the circulation heater, the tube-side outlet of the circulation heater is connected to the shell-side inlet of the dehydrogenation cooler, the shell-side outlet of the dehydrogenation cooler is connected to the inlet of the first gas-liquid separator, the gas phase outlet of the first gas-liquid separator is connected to the inlet of the crude oxygen main pipe, and the outlet of the crude oxygen main pipe is connected to the inlet of the main drying tower; the outlet of the main drying tower is respectively connected to the hot runner inlet of the oxygen liquefier and the hot runner inlet of the oxygen-nitrogen heat exchanger.

[0011] The oxygen dehydrogenation drying unit described in the utility model also includes an auxiliary drying tower and a drying heater. The outlet of the crude oxygen main pipe is also connected to the inlet of the auxiliary drying tower, the outlet of the auxiliary drying tower is connected to the inlet of the drying heater, and the outlet of the drying heater is connected to the outlet of the main drying tower.

[0012] The oxygen dehydrogenation drying unit described in the utility model also includes a drying cooler and a second gas-liquid separator; the outlet of the crude oxygen main pipe is also connected to the inlet of the auxiliary drying tower, the outlet of the drying cooler is connected to the inlet of the second gas-liquid separator, and the outlet of the second gas-liquid separator is connected to the crude oxygen main pipe.

[0013] The oxygen-nitrogen storage unit described in the utility model comprises a liquid nitrogen storage tank and a liquid oxygen storage tank, the hot runner outlet of the liquid oxygen supercooler is connected to the inlet of the liquid nitrogen storage tank, the hot runner outlet of the liquid oxygen supercooler is connected to the inlet of the liquid oxygen storage tank, the hot runner outlet of the oxygen-nitrogen heat exchanger is connected to the inlet of the liquid oxygen storage tank, and the outlet of the liquid nitrogen storage tank is respectively connected to the cold runner inlet of the oxygen-nitrogen heat exchanger and the cold runner inlet of the liquid oxygen supercooler.

[0014] The hot runner outlet of the liquid oxygen supercooler described in the utility model is divided into three routes, the first route is connected to the cold runner inlet of the liquid oxygen supercooler through a first throttle valve, the second route is connected to the liquid nitrogen storage tank through a second throttle valve, and the third route is connected to the cold runner inlet of the oxygen liquefier through a third throttle valve.

[0015] One of the outlets of the liquid nitrogen storage tank of the utility model is connected to the cold flow channel inlet of the liquid oxygen supercooler through a liquid nitrogen feeding valve.

[0016] The hot runner outlet of the liquid oxygen supercooler of the utility model is connected with the inlet of the liquid oxygen storage tank after passing through the liquid oxygen delivery valve.

[0017] The outlet of the liquid nitrogen storage tank of the utility model is equipped with a liquid nitrogen backup pump.

[0018] The product outlet of the liquid oxygen storage tank of the utility model is equipped with a liquid oxygen car charging pump, and the product outlet of the liquid nitrogen storage tank is equipped with a liquid nitrogen car charging pump.

[0019] Compared with the prior art, the utility model has the following advantages and effects:

[0020] 1. Efficiently recycle oxygen, a byproduct of water electrolysis, to reduce resource waste and improve economic benefits;

[0021] 2. Through nitrogen peak-shaving management, a stable supply of nitrogen can be achieved to meet the needs of synthetic ammonia production.

[0022] 3. Combined with the liquefaction unit and the oxygen-nitrogen conversion unit, further peak regulation of nitrogen is carried out, and air separation nitrogen production always operates at high efficiency, reducing the number of frequent load adjustments, improving the utilization rate of nitrogen, and reducing the nitrogen emission rate;

[0023] 4. Through the coupling and intelligent scheduling between various systems, the collaborative work between modules can be achieved to improve the stability and economy of the entire system.

[0024] 5. The utility model combines wind and solar power generation to produce hydrogen, oxygen recovery, purification and liquefaction, and air separation to produce nitrogen for peak regulation. It efficiently recycles and utilizes oxygen, a by-product of water electrolysis, and uses a liquefaction device and an oxygen-nitrogen conversion device to perform nitrogen peak regulation. The nitrogen supply is adjusted according to changes in hydrogen production to meet the needs of synthetic ammonia production.

[0025] 6. After the recovered oxygen is dehydrogenated and dried by the dehydrogenation and drying purification device, the oxygen with a purity of 99.999% enters the liquefaction device. The liquefied oxygen is easy to store and transport, and the product transportation radius can reach 1,000 kilometers, which is highly economical. Liquefied oxygen can be used in many fields such as medicine, chemical industry, metallurgy, etc. to achieve efficient utilization of resources.

[0026] 7. The liquefaction device can produce liquid oxygen and liquid nitrogen products at the same time according to the supply of raw oxygen. During the low-peak period of hydrogen and nitrogen demand, the excess nitrogen can be liquefied and sold at the same time. During the peak period of hydrogen production, there may be a large amount of by-product oxygen production. At this time, the amount of nitrogen is insufficient. The liquid nitrogen can be pressurized and vaporized to transport the pipeline network, and the cold energy of the liquid nitrogen vaporization can be recycled to liquefy the excess oxygen into liquid oxygen.

[0027] 8. It can solve the problem of frequent load adjustment and compressor start and stop of air separation nitrogen making device, so that the air separation nitrogen making device can operate stably in the high efficiency range for a long time and avoid the problem of high energy consumption of air separation nitrogen making device when running at low load. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of an embodiment of the utility model.

[0029] Figure 2It is a schematic structural diagram of the oxygen dehydrogenation drying unit according to an embodiment of the utility model.

[0030] Figure 3 It is a structural schematic diagram of the liquefaction unit of an embodiment of the utility model.

[0031] Figure 4 It is a schematic diagram of the structure of the oxygen-nitrogen conversion unit of an embodiment of the utility model.

[0032] Figure 5 This is a schematic diagram of the structure of the oxygen and nitrogen storage unit according to an embodiment of the utility model. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are provided to explain the present invention, but the present invention is not limited to the following examples.

[0034] The embodiment of the utility model includes an oxygen dehydrogenation drying unit A, a liquefaction unit B, an oxygen-nitrogen conversion unit C and an oxygen-nitrogen storage unit D.

[0035] The oxygen dehydrogenation drying unit A includes an oxygen buffer tank 1, a circulation heater 2, an electric heater 3, a dehydrogenation reactor 4, a dehydrogenation cooler 5, a first gas-liquid separator 6, a main drying tower 7, an auxiliary drying tower 8, a drying heater 9, a drying cooler 10, a second gas-liquid separator 11 and a crude oxygen main pipe 29.

[0036] The outlet of the oxygen buffer tank 1 is connected to the shell side inlet of the circulation heater 2, the shell side outlet of the circulation heater 2 is connected to the inlet of the electric heater 3, the outlet of the electric heater 3 is connected to the inlet of the dehydrogenation reactor 4, the outlet of the dehydrogenation reactor 4 is connected to the tube side inlet of the circulation heater 2, the tube side outlet of the circulation heater 2 is connected to the shell side inlet of the dehydrogenation cooler 5, the shell side outlet of the dehydrogenation cooler 5 is connected to the inlet of the first gas-liquid separator 6, the gas phase outlet of the first gas-liquid separator 6 is connected to the inlet of the crude oxygen main pipe 29, the outlet of the crude oxygen main pipe 29 is divided into two routes, one route is connected to the inlet of the main drying tower 7 through a switching valve, and the other route is connected to the inlet of the auxiliary drying tower 8 through a switching valve; the outlet of the main drying tower 7 is divided into two routes, one route is connected to the hot runner inlet of the oxygen liquefier 20, and the other route is connected to the first hot runner inlet of the oxygen-nitrogen heat exchanger 22; the outlet of the auxiliary drying tower 8 is connected to the inlet of the drying heater 9, and the outlet of the drying heater 9 is connected to the outlet of the main drying tower 7 after switching the valve. The inlet of the main drying tower 7 is connected to the inlet of the dry cooler 10 through a switching valve, the outlet of the dry cooler 10 is connected to the inlet of the second gas-liquid separator 11, and the outlet of the second gas-liquid separator 11 is connected to the crude oxygen main pipe 29 through a switching valve.

[0037] The liquefaction unit B includes a circulating nitrogen compressor 12, a first cooler 13, a high temperature expander 14, a second cooler 15, a low temperature expander 16, a third cooler 17, a main heat exchanger 18, a liquid oxygen subcooler 19, an oxygen liquefier 20, and a first liquid oxygen separation tank 21. The main heat exchanger 18 has a first cold runner, a second cold runner, a first hot runner, a second hot runner, and a third hot runner. The liquid oxygen subcooler 19 has a cold runner, a first hot runner, and a second hot runner. The oxygen liquefier 20 has a first cold runner, a second cold runner, and a hot runner.

[0038] The nitrogen from the air separation peak shaving enters the inlet of the circulating nitrogen compressor 12, the outlet of the circulating nitrogen compressor 12 is connected to the inlet of the first cooler 13, the outlet of the first cooler 13 is connected to the inlet of the boost end of the high-temperature expander 14, the outlet of the boost end of the high-temperature expander 14 is connected to the inlet of the second cooler 15, the outlet of the second cooler 15 is connected to the inlet of the boost end of the low-temperature expander 16, and the outlet of the boost end of the low-temperature expander 16 is connected to the inlet of the third cooler 17. The outlet of the third cooler 17 is divided into two paths, one of which is connected to the inlet of the second hot runner of the main heat exchanger 18, and the other is connected to the inlet of the third hot runner of the main heat exchanger 18. The outlet of the first cooler 13 is also connected to the first hot runner inlet of the main heat exchanger 18, the first hot runner outlet of the main heat exchanger 18 is connected to the expansion end inlet of the high temperature expander 14, the expansion end outlet of the high temperature expander 14 is connected to the first cold runner inlet of the main heat exchanger 18, and the first cold runner outlet of the main heat exchanger 18 is connected to the inlet of the circulating nitrogen compressor 12. The second hot runner outlet of the main heat exchanger 18 is connected to the expansion end inlet of the low temperature expander 16, the expansion end outlet of the low temperature expander 16 is connected to the first cold runner inlet of the main heat exchanger 18, and the first cold runner outlet of the main heat exchanger 18 is connected to the inlet of the circulating nitrogen compressor 12. The third hot runner outlet of the main heat exchanger 18 is connected to the first hot runner inlet of the liquid oxygen subcooler 19. The first hot runner outlet of the liquid oxygen subcooler 19 is divided into three routes. The first route is connected to the cold runner inlet of the liquid oxygen subcooler 19 through the first throttle valve V04, the second route is connected to the inlet of the liquid nitrogen storage tank 24 through the second throttle valve V02, and the third route is connected to the first cold runner inlet of the oxygen liquefier 20 through the third throttle valve V05. The first cold runner outlet of the oxygen liquefier 20 is connected to the inlet of the circulating nitrogen compressor 12. After throttling, liquid nitrogen enters the first cold runner of the oxygen liquefier 20, exchanges heat with oxygen in the oxygen liquefier 20, is reheated into nitrogen, and returns to the circulating nitrogen compressor 12. The cold runner outlet of the liquid oxygen subcooler 19 is connected to the second cold runner inlet of the main heat exchanger 18, and the second cold runner outlet of the main heat exchanger 18 is connected to the inlet of the circulating nitrogen compressor 12.

[0039] The oxygen from the main drying tower 7 enters the first hot runner inlet of the oxygen liquefier 20, the first hot runner outlet of the oxygen liquefier 20 is connected to the inlet of the first liquid oxygen separation tank 21, the gas phase outlet of the first liquid oxygen separation tank 21 is connected to the second cold runner inlet of the oxygen liquefier 20, the second cold runner outlet of the oxygen liquefier 20 is used for venting, the liquid phase outlet of the first liquid oxygen separation tank 21 is connected to the second hot runner inlet of the liquid oxygen supercooler 19, and the second hot runner outlet of the liquid oxygen supercooler 19 is connected to the inlet of the liquid oxygen storage tank 27 through the liquid oxygen delivery valve V01.

[0040] The oxygen-nitrogen conversion unit C comprises an oxygen-nitrogen heat exchanger 22 and a second liquid oxygen separation tank 23; the oxygen-nitrogen heat exchanger 22 has a first cold flow channel, a second cold flow channel, a first hot flow channel and a second hot flow channel.

[0041] The oxygen from the main drying tower 7 enters the first hot runner inlet of the oxygen-nitrogen heat exchanger 22, the first hot runner outlet of the oxygen-nitrogen heat exchanger 22 is connected to the inlet of the second liquid oxygen separation tank 23, the gas phase outlet of the second liquid oxygen separation tank 23 is connected to the second cold runner inlet of the oxygen-nitrogen heat exchanger 22, the liquid phase outlet of the second liquid oxygen separation tank 23 is connected to the second hot runner inlet of the oxygen-nitrogen heat exchanger 22, and the second hot runner outlet of the oxygen-nitrogen heat exchanger 22 is connected to the inlet of the liquid oxygen storage tank 27.

[0042] The oxygen and nitrogen storage unit D includes a liquid nitrogen storage tank 24, a liquid nitrogen backup pump 25, a liquid nitrogen charging pump 26, a liquid oxygen storage tank 27 and a liquid oxygen charging pump 28. The outlet of the liquid nitrogen storage tank 24 is divided into two routes, one route is connected to the first cold flow channel inlet of the oxygen and nitrogen heat exchanger 22, and the other route is connected to the cold flow channel inlet of the liquid oxygen subcooler 19 through the liquid nitrogen inlet valve V03; the outlet of the liquid nitrogen storage tank 24 is equipped with a liquid nitrogen backup pump 25. The product outlet of the liquid oxygen storage tank 27 is equipped with a liquid oxygen charging pump 28, and the product outlet of the liquid nitrogen storage tank 24 is equipped with a liquid nitrogen charging pump 26. The liquid nitrogen storage tank 24 can also store liquid nitrogen from the air separation nitrogen production device.

[0043] The main heat exchanger 18, the liquid oxygen subcooler 19, the oxygen liquefier 20 and the oxygen-nitrogen heat exchanger 22 are all vacuum brazed plate-fin heat exchangers.

[0044] The working method of the utility model comprises the following steps:

[0045] 1) The byproduct raw oxygen from the electrolyzer enters the oxygen buffer tank 1 for buffering, then enters the circulation heater 2, is reheated to a certain temperature by the reflux oxygen, and then further heated by the electric heater 3 before entering the dehydrogenation reactor 4 to remove hydrogen. Dehydrogenation adopts the principle of 2H2+O2=2H2O. The trace hydrogen in the oxygen reacts with the oxygen under the action of the dehydrogenation catalyst to achieve the purpose of dehydrogenation. The crude oxygen after dehydrogenation goes to the circulation heater 2 to heat the raw oxygen, and then enters the first gas-liquid separator 6 after being cooled by the dehydrogenation cooler 5 to separate the liquid water.

[0046] 2) The crude oxygen coming out of the first gas-liquid separator 6 enters the crude oxygen main pipe 29, and is first divided into two paths by a flow control regulating valve. One path goes directly to the main drying tower 7, where the adsorbent loaded therein adsorbs the moisture in the crude oxygen, so that the crude oxygen can be dried to obtain product oxygen; when one drying tower is saturated with H2O, it enters the regeneration process, and the drying tower that has been regenerated enters the adsorption process; the other path goes to the auxiliary drying tower 8 to participate in the regeneration of the main drying tower 7.

[0047] 21) The regeneration process of the drying tower is as follows:

[0048] a. Heating regeneration process:

[0049] The crude oxygen coming out of the crude oxygen main pipe 29 is separated into a part of gas for regeneration through a flow control regulating valve. The regenerated gas first enters the auxiliary drying tower 8 for drying to remove the H2O contained in it, and then is heated to 160-220°C by the drying heater 9, and then enters the main drying tower 7 through the outlet of the main drying tower 7 to heat the bed layer of the drying tower until the impurities such as H2O adsorbed in the bed layer are completely desorbed; the regenerated gas comes out from the inlet of the main drying tower 7, is cooled to 10-40°C by the drying cooler 10, and is separated by the drying separator 11, and then returns to the crude oxygen main pipe 29;

[0050] b.Cooling process:

[0051] The regenerated gas enters the main drying tower 7, and the main drying tower 7 is cooled and flushed until the temperature of the main drying tower 7 drops to 10-40°C, and the main drying tower 7 can carry out the next adsorption.

[0052] The gas coming out of the main drying tower 7 is heated by the drying heater 9 and then regenerated in the auxiliary drying tower 8. Then, it is cooled to 40°C by the drying cooler 10 and separated by the drying separator 11 before returning to the crude oxygen main pipe 29. The two drying towers alternately carry out the above adsorption and regeneration process to achieve continuous drying of the gas.

[0053] 4) According to the hydrogen and oxygen production of the electrolytic hydrogen production device and the demand for nitrogen in the pipeline network, the liquefaction unit, oxygen-nitrogen conversion unit and backup device can be selected to produce only liquid oxygen, produce both liquid oxygen and liquid nitrogen, produce only liquid nitrogen and vaporize liquid nitrogen to supply nitrogen.

[0054] 41) Only liquid oxygen production condition: The medium-pressure oxygen from the dehydrogenation drying and purification unit enters the oxygen liquefier 20 and is cooled to a certain temperature. It is then depressurized and throttled by a throttle valve. The oxygen is further purified by using the boiling point difference. The low-boiling hydrogen-containing flash vapor is recovered by the oxygen liquefier 20 and then discharged. The purified oxygen enters the liquid oxygen liquefaction subcooler 19 and is cooled by low-pressure and atmospheric-pressure liquid nitrogen to ~83K. After throttling, it is sent out of the cold box as a liquid oxygen product into the liquid oxygen storage tank 27, and then pressurized by the liquid oxygen filling pump 28 and sent to the tank truck.

[0055] The medium-pressure nitrogen from the air separation nitrogen production device is combined after decompression and enters the circulating nitrogen compressor 12 for pressurization. After being cooled by the first cooler 13, it is divided into two streams. One stream is cooled by the main heat exchanger 18 and enters the expansion end of the high-temperature expander 14, expands to ~0.52MpaG, and is reheated by the main heat exchanger 18 and then exits the cold box and returns to the inlet of the circulating nitrogen compressor 12; the other stream is cooled by the supercharging end of the high-temperature expander 14, the second cooler 15, the supercharging end of the low-temperature turbine expander 16 and the third cooler 17, and then is divided into two paths, one of which is cooled by the main heat exchanger 18. Then it enters the expansion end of the cryogenic expander 16, expands to ~0.52Mpa, and is reheated by the main heat exchanger 18 before leaving the cold box and returning to the inlet of the circulating nitrogen compressor 12; the other nitrogen is liquefied by the main heat exchanger 18, throttled into the liquid oxygen subcooler 19, and is subcooled by the reflux liquid nitrogen and is divided into two parts. A small part is combined with the supplementary liquid nitrogen from the liquid nitrogen storage tank, and then enters the liquid oxygen subcooler 19 as a liquefied cold source for liquid oxygen subcooling, and most of it enters the oxygen liquefier 20 for heat exchange with oxygen, and after reheating, it exits the device and returns to the inlet of the circulating nitrogen compressor 12.

[0056] A stream of liquid nitrogen from the liquid nitrogen storage tank 24 is used as liquid oxygen for subcooling, and the low-pressure liquid nitrogen is reheated and then returned to the inlet of the circulating nitrogen compressor 12 from the device to supplement the sealing nitrogen of the system.

[0057] 42) Working condition of producing liquid oxygen and liquid nitrogen simultaneously: When the amount of raw oxygen is insufficient, a portion of the liquid nitrogen product can be sent to the liquid nitrogen storage tank 24 by closing the liquid nitrogen feed valve V03 and adjusting the opening of the third throttle valve V05, the second throttle valve V02 and the first throttle valve V04.

[0058] The medium-pressure nitrogen from the air separation nitrogen production device is combined after decompression and enters the circulating nitrogen compressor 12 for pressurization. After being cooled by the first cooler 13, it is divided into two streams. One stream is cooled by the main heat exchanger 18 and enters the expansion end of the high-temperature expander 14, expands to ~0.52MpaG, and is reheated by the main heat exchanger 18 before leaving the cold box and returning to the inlet of the circulating nitrogen compressor 12; the other stream is cooled by the supercharging end of the high-temperature expander 14, the second cooler 15, the supercharging end of the low-temperature turbine expander 16 and the third cooler 17, and then is divided into two paths. One path is cooled by the main heat exchanger 18 and enters the low The expansion end of the warm expander 16 is expanded to ~0.52Mpa, and after being reheated by the main heat exchanger 18, it is discharged from the cold box and returned to the inlet of the circulating nitrogen compressor 12; the other nitrogen is liquefied by the main heat exchanger 18, throttled into the liquid oxygen subcooler 19, and is subcooled by the reflux liquid nitrogen and is divided into three parts, one part enters the liquid oxygen subcooler 19 as a liquefied cold source for liquid oxygen subcooling, one part passes through the throttle valve V02 and is sent to the liquid nitrogen storage tank 24 as a liquid nitrogen product, and the remaining part enters the oxygen liquefier 20 for heat exchange with oxygen, and after being reheated, it exits the device and returns to the inlet of the circulating nitrogen compressor 12.

[0059] 43) Only liquid nitrogen production condition: by closing the raw oxygen inlet valve and the liquid oxygen outlet valve V01, closing the liquid nitrogen inlet valve V03, adjusting the opening of the second throttle valve V02 and the first throttle valve V04, the nitrogen of the air separation unit can be converted into liquid nitrogen product and sent to the liquid nitrogen storage tank 24.

[0060] The medium-pressure nitrogen from the air separation nitrogen production device is combined after decompression and enters the circulating nitrogen compressor 12 for pressurization. After being cooled by the first cooler 13, it is divided into two streams. One stream is cooled by the main heat exchanger 18 and enters the expansion end of the high-temperature expander 14, expands to ~0.52MpaG, and is reheated by the main heat exchanger 18 and then exits the cold box and returns to the inlet of the circulating nitrogen compressor 12; the other stream is cooled by the supercharging end of the high-temperature expander 14, the second cooler 15, the supercharging end of the low-temperature turbine expander 16 and the third cooler 17, and then is divided into two paths, one of which is cooled by the main heat exchanger 18 and the other is cooled by the supercharging end of the high-temperature expander 14, the second cooler 15, the supercharging end of the low-temperature turbine expander 16 and the third cooler 17, and then is divided into two paths. After cooling, 18 enters the expansion end of the cryogenic expander 16, expands to ~0.52Mpa, and is reheated by the main heat exchanger 18 before leaving the cold box and returning to the inlet of the circulating nitrogen compressor 12; the other nitrogen is liquefied by the main heat exchanger 18, throttled into the liquid oxygen subcooler 19, and is subcooled by the reflux liquid nitrogen and is divided into two parts, one part enters the liquid oxygen subcooler 19 as a liquefied cold source for liquid oxygen subcooling, and after reheating, it leaves the device and returns to the inlet of the circulating nitrogen compressor 12; the other part passes through the second throttle valve V02 and is sent to the liquid nitrogen storage tank 24 as a liquid nitrogen product.

[0061] 44) Liquid nitrogen vaporization nitrogen supply conditions: When the oxygen supply exceeds the design value of the liquefaction unit, the excess medium-pressure oxygen from the dehydrogenation drying and purification unit can be fed into the oxygen-nitrogen conversion unit C. The oxygen-nitrogen conversion unit C can convert the excess oxygen into liquid oxygen products and vaporize the liquid nitrogen into medium-pressure nitrogen to make up for the insufficient nitrogen consumption.

[0062] The medium-pressure oxygen from the dehydrogenation drying and purification device 7 enters the first hot runner of the oxygen-nitrogen heat exchanger 22 and is cooled to ~105K by liquid nitrogen; the saturated medium-pressure liquid oxygen enters the second liquid oxygen separation tank 23 after being depressurized and throttled by the throttle valve, and the second liquid oxygen separation tank 23 further purifies the liquid oxygen; in the second liquid oxygen separation tank 23, due to the pressure drop, the low-boiling point components in the liquid oxygen, such as hydrogen and nitrogen, will flash into a gas phase, and the gas phase outlet enters the second cold runner of the oxygen-nitrogen heat exchanger 22, recovers the cold in the oxygen-nitrogen heat exchanger 22, and then is discharged from the high place of the cold box. The liquid oxygen coming out of the second liquid oxygen separation tank 23 enters the second hot runner of the oxygen-nitrogen heat exchanger 22, is further supercooled to ~83K in the oxygen-nitrogen heat exchanger 22, and is sent to the liquid oxygen storage tank 27 as a liquid oxygen product.

[0063] The liquid nitrogen from the liquid nitrogen storage tank 24 is pressurized by the liquid nitrogen pump 25 and enters the first cold flow channel of the oxygen-nitrogen heat exchanger 22 to provide cooling capacity for oxygen liquefaction. The liquid nitrogen is reheated in the oxygen-nitrogen heat exchanger 22 to become medium-pressure nitrogen at room temperature and is sent to the nitrogen pipeline network as peak-shaving nitrogen.

[0064] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the utility model. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the utility model are included in the protection scope of the utility model patent. Technicians in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.

Claims

1. A wind-solar power generation hydrogen production oxygen recovery liquefaction and air separation nitrogen production peak regulation coupling system, characterized by: It includes an oxygen dehydrogenation drying unit, a liquefaction unit, an oxygen-nitrogen conversion unit and an oxygen-nitrogen storage unit; the liquefaction unit includes a circulating nitrogen compressor, a first cooler, a high-temperature expander, a second cooler, a low-temperature expander, a third cooler, a main heat exchanger, a liquid oxygen subcooler, an oxygen liquefier and a first liquid oxygen separation tank; the oxygen-nitrogen conversion unit includes an oxygen-nitrogen heat exchanger and a second liquid oxygen separation tank; The oxygen dehydrogenation drying unit is connected to the hot runner inlet of the oxygen liquefier and the hot runner inlet of the oxygen-nitrogen heat exchanger respectively; the outlet of the circulating nitrogen compressor is connected to the inlet of the first cooler, the outlet of the first cooler is connected to the inlet of the boost end of the high-temperature expander, the outlet of the boost end of the high-temperature expander is connected to the inlet of the second cooler, the outlet of the second cooler is connected to the inlet of the boost end of the low-temperature expander, and the outlet of the boost end of the low-temperature expander is connected to the inlet of the third cooler; the outlet of the third cooler is respectively connected to the hot runner inlet of the main heat exchanger; The outlet is also connected to the hot runner inlet of the main heat exchanger, the hot runner outlet of the main heat exchanger is connected to the expansion end inlet of the high-temperature expander, the expansion end outlet of the high-temperature expander is connected to the cold runner inlet of the main heat exchanger, and the cold runner outlet of the main heat exchanger is connected to the inlet of the circulating nitrogen compressor; the hot runner outlet of the main heat exchanger is connected to the expansion end inlet of the low-temperature expander, the expansion end outlet of the low-temperature expander is connected to the cold runner inlet of the main heat exchanger, and the cold runner outlet of the main heat exchanger is connected to the inlet of the circulating nitrogen compressor; the hot runner outlet of the main heat exchanger is connected to the liquid oxygen subcooler The hot runner inlet is connected, and the hot runner outlet of the liquid oxygen supercooler is respectively connected to the cold runner inlet of the liquid oxygen supercooler, the liquid nitrogen storage tank, and the cold runner inlet of the oxygen liquefier; the cold runner outlet of the oxygen liquefier is connected to the inlet of the circulating nitrogen compressor; the cold runner outlet of the liquid oxygen supercooler is connected to the cold runner inlet of the main heat exchanger, and the cold runner outlet of the main heat exchanger is connected to the inlet of the circulating nitrogen compressor; the hot runner outlet of the oxygen liquefier is connected to the inlet of the first liquid oxygen separation tank, and the gas phase outlet of the first liquid oxygen separation tank is connected to the cold runner inlet of the oxygen liquefier, and the gas phase outlet of the first liquid oxygen separation tank is connected to the cold runner inlet of the oxygen liquefier. The liquid phase outlet of the separation tank is connected to the hot runner inlet of the liquid oxygen supercooler, and the hot runner outlet of the liquid oxygen supercooler is connected to the oxygen-nitrogen storage unit; the hot runner outlet of the oxygen-nitrogen heat exchanger is connected to the inlet of the second liquid oxygen separation tank, the gas phase outlet of the second liquid oxygen separation tank is connected to the cold runner inlet of the oxygen-nitrogen heat exchanger, the liquid phase outlet of the second liquid oxygen separation tank is connected to the hot runner inlet of the oxygen-nitrogen heat exchanger, and the hot runner outlet of the oxygen-nitrogen heat exchanger is connected to the oxygen-nitrogen storage unit; the oxygen-nitrogen storage unit is respectively connected to the cold runner inlet of the oxygen-nitrogen heat exchanger and the cold runner inlet of the liquid oxygen supercooler.

2. The oxygen recovery liquefaction and air separation nitrogen peak-shaving coupling system for hydrogen production by wind and solar power generation according to claim 1 is characterized by: The oxygen dehydrogenation drying unit comprises an oxygen buffer tank, a circulation heater, an electric heater, a dehydrogenation reactor, a dehydrogenation cooler, a first gas-liquid separator, a main drying tower and a crude oxygen main pipe; the outlet of the oxygen buffer tank is connected to the shell-side inlet of the circulation heater, the shell-side outlet of the circulation heater is connected to the inlet of the electric heater, the outlet of the electric heater is connected to the inlet of the dehydrogenation reactor, the outlet of the dehydrogenation reactor is connected to the tube-side inlet of the circulation heater, the tube-side outlet of the circulation heater is connected to the shell-side inlet of the dehydrogenation cooler, the shell-side outlet of the dehydrogenation cooler is connected to the inlet of the first gas-liquid separator, the gas phase outlet of the first gas-liquid separator is connected to the inlet of the crude oxygen main pipe, and the outlet of the crude oxygen main pipe is connected to the inlet of the main drying tower; the outlet of the main drying tower is respectively connected to the hot runner inlet of the oxygen liquefier and the hot runner inlet of the oxygen-nitrogen heat exchanger.

3. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for wind and solar power generation hydrogen production according to claim 2 is characterized by: The oxygen dehydrogenation drying unit also includes an auxiliary drying tower and a drying heater. The outlet of the crude oxygen main pipe is also connected to the inlet of the auxiliary drying tower, the outlet of the auxiliary drying tower is connected to the inlet of the drying heater, and the outlet of the drying heater is connected to the outlet of the main drying tower.

4. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for hydrogen production by wind and solar power generation according to claim 3 is characterized by: The oxygen dehydrogenation drying unit also includes a drying cooler and a second gas-liquid separator; the outlet of the crude oxygen main pipe is also connected to the inlet of the auxiliary drying tower, the outlet of the drying cooler is connected to the inlet of the second gas-liquid separator, and the outlet of the second gas-liquid separator is connected to the crude oxygen main pipe.

5. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for wind and solar power generation hydrogen production according to claim 1 is characterized by: The oxygen-nitrogen storage unit comprises a liquid nitrogen storage tank and a liquid oxygen storage tank, the hot runner outlet of the liquid oxygen supercooler is connected to the inlet of the liquid nitrogen storage tank, the hot runner outlet of the liquid oxygen supercooler is connected to the inlet of the liquid oxygen storage tank, the hot runner outlet of the oxygen-nitrogen heat exchanger is connected to the inlet of the liquid oxygen storage tank, and the outlet of the liquid nitrogen storage tank is respectively connected to the cold runner inlet of the oxygen-nitrogen heat exchanger and the cold runner inlet of the liquid oxygen supercooler.

6. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for hydrogen production by wind and solar power generation according to claim 1 is characterized by: The hot runner outlet of the liquid oxygen subcooler is divided into three routes, the first route is connected to the cold runner inlet of the liquid oxygen subcooler through a first throttle valve, the second route is connected to the liquid nitrogen storage tank through a second throttle valve, and the third route is connected to the cold runner inlet of the oxygen liquefier through a third throttle valve.

7. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for wind and solar power generation hydrogen production according to claim 1 is characterized by: One of the outlets of the liquid nitrogen storage tank is connected to the cold channel inlet of the liquid oxygen supercooler through a liquid nitrogen inlet valve.

8. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for hydrogen production by wind and solar power generation according to claim 1 is characterized by: The hot runner outlet of the liquid oxygen subcooler is connected to the inlet of the liquid oxygen storage tank through a liquid oxygen delivery valve.

9. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for hydrogen production by wind and solar power generation according to claim 5 is characterized by: The outlet of the liquid nitrogen storage tank is equipped with a liquid nitrogen backup pump.

10. The oxygen recovery liquefaction and air separation nitrogen peak regulation coupling system for wind and solar power generation hydrogen production according to claim 5 is characterized by: The product outlet of the liquid oxygen storage tank is equipped with a liquid oxygen filling pump, and the product outlet of the liquid nitrogen storage tank is equipped with a liquid nitrogen filling pump.

Images