Search

CN-116516359-B - High-efficiency energy-saving electrolytic hydrogen production method

CN116516359BCN 116516359 BCN116516359 BCN 116516359BCN-116516359-B

Abstract

The application provides a high-efficiency energy-saving electrolytic hydrogen production method, which comprises an electrolytic tank, a separator, a vaporizer, a condenser, a raw water tank, a fresh water tank, a vacuum tank and a vacuum pump. Electrolyte is conveyed from the bottom of the separator to the upper side of the vaporizer to complete heat exchange and then flows back to the electrolytic tank from the vaporizer. Raw water enters from a condenser, is preheated by steam from a vaporizer, is discharged from the right side of the condenser, and a small part enters from the middle of the vaporizer, is vaporized under the vacuum effect after heat exchange with high-temperature electrolyte, and the vaporized steam enters into the left lower side of the condenser, is condensed into fresh water after heat exchange with the raw water, and flows into a fresh water tank from the right lower side of the condenser. The electrolytic hydrogen production method can realize separation and purification of raw material water without adding energy and a complex automatic control system, saves energy required by cooling the circulating electrolyte, has obvious energy-saving effect, and simultaneously greatly widens the raw material and application fields of hydrogen production.

Inventors

  • Kuang yun
  • LONG CHENGKUN
  • DAN ZHAOWANG
  • CHEN HAITAO
  • SUN HAORAN

Assignees

  • 深圳海氢科技有限公司

Dates

Publication Date
20260505
Application Date
20230413

Claims (10)

  1. 1. The electrolytic hydrogen production method is characterized by using an efficient and energy-saving electrolytic hydrogen production system, wherein the electrolytic hydrogen production system comprises an electrolytic tank (1), a separator (2), a circulating pump (3), a vaporizer (4), a condenser (5), a raw water tank (6), a fresh water tank (7), a vacuum pump (8) and a vacuum tank (9); The electrolytic tank outlet (1-2) at the upper side of the electrolytic tank (1) is communicated with the separator inlet (2-1) at the upper side of the separator (2) through a gas-liquid pipeline (11), and the separator outlet (2-2) at the bottom of the separator (2) is communicated with the circulating pump inlet (3-1) of the circulating pump (3) through a separated electrolyte pipeline (12); The circulating pump outlet (3-2) of the circulating pump (3) is communicated with the vaporizer heating pipe inlet (4-1) at the upper side of the vaporizer (4) through a cooling electrolyte pipeline (13), and the vaporizer heating pipe outlet (4-2) at the lower side of the vaporizer (4) is communicated with the electrolytic tank inlet (1-1) at the lower side of the electrolytic tank (1) through a backflow electrolyte pipeline (14); The evaporator steam outlet (4-4) at the top of the evaporator (4) is communicated with the condenser shell side inlet (5-1) at the left lower side of the condenser (5) through a steam pipeline (17), and the condenser shell side outlet (5-2) at the right lower side of the condenser (5) is communicated with the fresh water tank (7) through a fresh water pipeline (18); The raw material water pipeline (15) is connected to a condenser pipeline inlet (5-3) at the left end of the condenser (5), a condenser pipeline outlet (5-4) at the right end of the condenser (5) is communicated with a vaporizer raw material inlet (4-3) at the middle part of the vaporizer (4) through a hot water pipeline (16), the condenser pipeline outlet (5-4) at the right end of the condenser (5) is also communicated with the raw water tank (6) through a hot water pipeline upstream part (16-1) and a waste water pipeline (19) in sequence, a vaporizer raffinate outlet (4-5) at the bottom of the vaporizer (4) is communicated to a waste water pipeline (19) through a vaporizer raffinate outlet pipeline (23), the joint of the vaporizer outlet pipeline (23) and the waste water pipeline (19) is the upper end of the vaporizer raffinate outlet pipeline (23), and the upper end of the vaporizer outlet pipeline (23) is lower than the lower end of the hot water pipeline upstream part (16-1); The condenser vacuum outlet (5-5) at the right upper side of the condenser (5) is communicated with the upper inlet of the vacuum tank (9) through a first vacuum pipeline (21), and the lower outlet of the vacuum tank (9) is communicated with the inlet of the vacuum pump (8) through a second vacuum pipeline (22); The electrolytic hydrogen production method comprises the following steps: Generating hydrogen and oxygen by the electrolyte after the electrolysis of the electrolytic tank (1), enabling a high-temperature gas-liquid mixture containing the electrolyte and the hydrogen or a high-temperature gas-liquid mixture containing the electrolyte and the oxygen to flow into the separator (2) from the outlet (1-2) of the electrolytic tank through the gas-liquid pipeline (11) and the inlet (2-1) of the separator, and discharging the separated gas from the top of the separator (2); The separated high-temperature electrolyte sequentially passes through the separated electrolyte pipeline (12), the circulating pump (3), the cooling electrolyte pipeline (13) and the vaporizer heating pipe inlet (4-1) from the separator outlet (2-2), the electrolyte which completes heat exchange with raw water in the vaporizer (4) and is cooled down sequentially passes through the reflux electrolyte pipeline (14) and the electrolytic tank inlet (1-1) from the vaporizer heating pipe outlet (4-2) to the electrolytic tank (1), and the raw water in the vaporizer (4) and the high-temperature electrolyte in the heating pipe of the vaporizer (4) generate steam under the action of vacuum after heat exchange, and sequentially passes through the vaporizer steam outlet (4-4), the steam pipeline (17) and the condenser shell side inlet (5-1) to enter the shell side of the condenser (5); Raw water input from the outside enters a tube side of the condenser (5) through the raw water pipeline (15) and the condenser tube side inlet (5-3), the raw water is preheated by steam in the shell side of the condenser (5) and then discharged from the condenser tube side outlet (5-4), a part of discharged raw water enters the vaporizer (4) through the hot water pipeline (16) and the vaporizer raw water inlet (4-3), and then is vaporized under the vacuum effect to generate steam after heat exchange with high-temperature electrolyte of a heating tube of the vaporizer (4), and most of discharged raw water flows into the raw water tank (6) through the upstream part (16-1) of the hot water pipeline and the wastewater pipeline (19) in sequence; after heat exchange is completed between steam in the shell side of the condenser (5) and raw water in the tube side, most of the steam is condensed into fresh water and automatically flows into the fresh water tank (7) through a shell side outlet (5-2) of the condenser and a fresh water pipeline (18) in sequence; a small part of unvaporized raw water in the vaporizer (4) is discharged into the bottom of the raw water tank (6) through a vaporizer raffinate outlet (4-5), a vaporizer raffinate outlet pipeline (23) and a wastewater pipeline (19) in sequence; A small amount of steam in the shell side of the condenser (5) is sucked from the vacuum outlet (5-5) of the condenser into the vacuum tank (9), condensed into water and then discharged from the lower outlet of the vacuum tank (9) through the vacuum pump (8).
  2. 2. The electrolytic hydrogen production method according to claim 1, wherein the waste water pipe (19) is connected to the hot water pipe upstream portion (16-1) at a position higher than the vaporizer raw material inlet (4-3), and the vaporizer raffinate outlet (4-5) is lower than the vaporizer raw material inlet (4-3).
  3. 3. The electrolytic hydrogen production method according to claim 1, wherein the difference in height between the top of the vaporizer raffinate outlet pipe (23) and the liquid level of the raw water tank (6) is >5m; the height difference between the lowest part of the condenser (5) and the liquid level of the fresh water tank (7) is more than 5m.
  4. 4. The electrolytic hydrogen production method according to claim 1, wherein a valve is provided at the raw material inlet (4-3) of the carburetor.
  5. 5. The electrolytic hydrogen production method according to claim 1, wherein the vaporizer (4) is of a vertical design and is divided into three sections, namely an upper section, a middle section and a lower section; The upper part is an expansion section for vaporization separation and steam delivery; The middle section is a heating section and is used for circulating electrolyte and raw water to enter and complete heat exchange or electric heating and heat preservation of the electrolyte before starting electrolysis; the lower section is a residual liquid section and is used for collecting and discharging residual liquid after raw material water separation.
  6. 6. The electrolytic hydrogen production method according to claim 1, wherein an insulating layer is arranged on the outer surface of the vaporizer (4) or the separator (2) to prevent heat loss during starting up and stopping and pressure maintaining, and an electric heating device is arranged in the vaporizer (4) or the separator (2) and is used for providing heat during starting up or stopping and pressure maintaining so as to raise the temperature of the electrolytic system as soon as possible.
  7. 7. The electrolytic hydrogen production method according to claim 1, wherein when the system is initially operated, the vacuum pump (8) is turned on, so that the vaporizer (4), the condenser (5) shell side, the vacuum tank (9), a hot water pipe (16), a steam pipe (17), a fresh water pipe (18), a waste water pipe (19), and a vaporizer raffinate outlet pipe (23) are in a vacuum state; raw water is pre-stored in the raw water tank (6), and part of the raw water rises into the fresh water pipeline (18) to form a water column so as to balance the external atmospheric pressure, namely, the lower end of the fresh water pipeline (18) is always kept below the liquid level of the raw water tank (6); Fresh water is pre-stored in the fresh water tank (7), and part of the fresh water rises in the waste water pipeline (19) to form a water column so as to balance the external atmospheric pressure, namely, the lower end of the fresh water pipeline (18) is always kept below the liquid level of the raw water tank (6); in the running process of the system, the vacuum pump (8) is closed, vacuum is consumed in the vaporizer (4) through vaporization, vacuum is generated in the shell side of the condenser (5) through condensation, and the continuous maintenance of the vacuum state in the vaporizer (4) and the shell side of the condenser (5) is realized.
  8. 8. The electrolytic hydrogen production method according to claim 1, characterized in that the vaporization temperature in the vaporizer (4) is reduced by increasing the vacuum in the vaporizer (4) and the condenser (5) shell side.
  9. 9. The electrolytic hydrogen production method according to claim 1, wherein not only inorganic salts, microorganisms and mechanical impurities in raw water but also low-boiling components and non-condensable gases are separated by increasing the heating vaporization of the vaporizer (4) and the condensation of the condenser (5) and the vacuum suction of the vacuum pump (8).
  10. 10. The electrolytic hydrogen production method according to claim 6, wherein the electric heating means of the vaporizer (4) or the separator (2) is turned on during start-up warm-up or shut-down pressure-maintaining to supply heat to raise the temperature of the electrolysis system as soon as possible.

Description

High-efficiency energy-saving electrolytic hydrogen production method Technical Field The invention belongs to the technical field of hydrogen production by water electrolysis, and particularly relates to a high-efficiency and energy-saving hydrogen production method by electrolysis. Background In the current hydrogen production system by water electrolysis, the process for producing hydrogen by electrolysis of the alkaline solution prepared by pure water has particularly high purity requirement on the pure water, and the purification cost of the pure water is particularly high, so that the cost of hydrogen production by electrolysis is higher. In the electrolysis process, part of electric energy is directly consumed to generate a large amount of heat, a large amount of circulating cooling water is needed to be adopted to circularly cool electrolyte, and particularly, a large amount of heat is also needed to be consumed in the starting heating process or the stopping pressure maintaining process. Disclosure of Invention In order to solve at least one technical problem, the application reduces the temperature of the circulating electrolyte by reducing the pressure in vacuum to ensure that the vaporization boiling point of raw material water is far lower than the temperature of the circulating electrolyte and realizing heat exchange by vaporizing the raw material water by heat generated in the electrolysis process. The steam obtained after vaporization preheats raw water and condenses into fresh water which can be directly used for electrolysis, so that the manufacturing cost of the water for electrolysis is reduced, the production cost of hydrogen is reduced, the cooling energy of circulating electrolyte is saved, and the raw material and application field of hydrogen production are greatly widened. By adding electric heating and heat preservation measures in the electrolyte circulation process, heat is provided in the starting heating or stopping pressure maintaining process so as to raise the temperature of the electrolysis system as soon as possible. The first aspect of the invention provides an efficient and energy-saving electrolytic hydrogen production system, which comprises an electrolytic tank 1, a separator 2, a circulating pump 3, a vaporizer 4, a condenser 5, a raw water tank 6, a fresh water tank 7, a vacuum pump 8 and a vacuum tank 9; The electrolysis bath outlet 1-2 on the upper side of the electrolysis bath 1 is communicated with the separator inlet 2-1 on the upper side of the separator 2 through a gas-liquid pipeline 11, and the separator outlet 2-2 on the bottom of the separator 2 is communicated with the circulating pump inlet 3-1 of the circulating pump 3 through a separated electrolyte pipeline 12; The circulating pump outlet 3-2 of the circulating pump 3 is communicated with the vaporizer heating pipe inlet 4-1 at the upper side of the vaporizer 4 through a cooling electrolyte pipeline 13, and the vaporizer heating pipe outlet 4-2 at the lower side of the vaporizer 4 is communicated with the electrolytic tank inlet 1-1 at the lower side of the electrolytic tank 1 through a reflux electrolyte pipeline 14; The vaporizer steam outlet 4-4 at the top of the vaporizer 4 is communicated with the condenser shell side inlet 5-1 at the left lower side of the condenser 5 through a steam pipeline 17, and the condenser shell side outlet 5-2 at the right lower side of the condenser 5 is communicated with the fresh water tank 7 through a fresh water pipeline 18; The raw material water pipeline 15 is connected to a condenser tube inlet 5-3 at the left end of the condenser 5, a condenser tube outlet 5-4 at the right end of the condenser 5 is communicated with a vaporizer raw material inlet 4-3 at the middle part of the vaporizer 4 through a hot water pipeline 16, the condenser tube outlet 5-4 at the right end of the condenser 5 is also communicated with the raw water tank 6 through a hot water pipeline upstream part 16-1 and a waste water pipeline 19 in turn, a vaporizer raffinate outlet 4-5 at the bottom of the vaporizer 4 is communicated with the waste water pipeline 19 through a vaporizer raffinate outlet pipeline 23, the joint of the vaporizer raffinate outlet pipeline 23 and the waste water pipeline 19 is the upper end of the vaporizer raffinate outlet pipeline 23, and the upper end of the vaporizer raffinate outlet pipeline 23 is lower than the lower end of the hot water pipeline upstream part 16-1; the condenser vacuum outlet 5-5 on the right upper side of the condenser 5 is communicated with the upper inlet of the vacuum tank 9 through a first vacuum pipeline 21, and the lower outlet of the vacuum tank 9 is communicated with the inlet of the vacuum pump 8 through a second vacuum pipeline 22. Preferably, the separator 2 is an oxygen gas-liquid separator or a hydrogen gas-liquid separator. Thus the top of the separator 2 is vented to oxygen or hydrogen. Preferably, the waste line 19 is connected