초록 ▼

The invention provides a system and a method for generating high pressure hydrogen that is able to efficiently and safely generate hydrogen by only the electrolysis of water even when using electric power generated by a frequently varying natural energy, such as sunlight, without using any compresso

The invention provides a system and a method for generating high pressure hydrogen that is able to efficiently and safely generate hydrogen by only the electrolysis of water even when using electric power generated by a frequently varying natural energy, such as sunlight, without using any compressors. The system comprises an electrolysis cell using polyelectrolyte membranes, particularly a double-polarity multi-layered type electrolysis cell having a specified structure disposed in a vessel for storing generated hydrogen, preferably for storing cooled hydrogen under a high pressure hydrogen atmosphere. High pressure hydrogen is generated by electrolysis of pure water using the electrolysis cell by suppressing the pressure applied to the cell to a pressure below the pressure resistance of the cell using a differential pressure sensor and pressure controller.

대표청구항 ▼

What is claimed is: 1. A system for generating high pressure hydrogen by direct electrolysis of pure water using an electrolysis cell comprising polyelectrolyte membranes, wherein an electrolysis cell disposed in hydrogen gas generated and stored in a high pressure vessel that serves as a storage t

What is claimed is: 1. A system for generating high pressure hydrogen by direct electrolysis of pure water using an electrolysis cell comprising polyelectrolyte membranes, wherein an electrolysis cell disposed in hydrogen gas generated and stored in a high pressure vessel that serves as a storage tank of hydrogen generated and electrolysis pure water stored in another high pressure vessel that communicates with the electrolysis cell and serves as a storage tank of oxygen generated, wherein the system has pressure control means for controlling a differential pressure between the inner pressure of the high pressure vessel for storing hydrogen and the inner pressure of the high pressure vessel for storing oxygen to a pressure below the pressure resistance of the electrolysis cell, wherein the pressure control means is provided for adjusting the differential pressure to a pressure below the pressure resistance of the electrolysis cell by allowing pure water to be transferred by switching the valves in the vessels connected to pipe lines communicating with the pure water in the respective high pressure vessels, and wherein the pressure control means has a differential pressure gauge which is comprising: a cylinder of a non-magnetic material having both ends sealed with elastic bellows disposed in the axial direction by the pressures of respective high pressure vessels and filled with an inert fluid; a main unit comprising an internal magnetic body provided in close contact with the inner surface of the cylinder and an external magnetic body provided in close contact with the outer surface of the cylinder; and a sensor for sensing the differential pressure based on the position of the external magnetic body that changes by elastic deformation of the bellows. 2. The system for generating high pressure hydrogen according to claim 1, wherein the pipe lines communicating with the pure water in the high pressure vessels comprise two pipes of a pipe line having a valve provided in the high pressure vessel for storing hydrogen and a pipe line having a valve provided in the high pressure vessel for storing oxygen. 3. The system for generating high pressure hydrogen according to claim 2, wherein the valves have a triangular discharge port. 4. The system for generating high pressure hydrogen according to claim 1, wherein the sensor comprises a light shielding plate interlocked with the external magnetic body, an aperture plate having an opening shielded with the light shielding plate, and a photoelectric meter for converting luminous energy permeating through the opening into electric signals. 5. The system for generating high pressure hydrogen according to claim 1, wherein the sensor comprises a slider sliding on an electric resistor by being interlocked with the external magnetic body. 6. System for generating high pressure hydrogen by direct electrolysis of pure water using an electrolysis cell comprising polyelectrolyte membranes, wherein an electrolysis cell disposed in hydrogen gas generated and stored in a high pressure vessel that serves as a storage tank of hydrogen generated and electrolysis pure water stored in another high pressure vessel that communicates with the electrolysis cell and serves as a storage tank of oxygen generated, wherein the system has pressure control means for controlling a differential pressure between the inner pressure of the high pressure vessel for storing hydrogen and the inner pressure of the high pressure vessel for storing oxygen to a pressure below the pressure resistance of the electrolysis cell, wherein the pressure control means is provided in the pipe line communicating with pure water in respective high pressure vessels and adjusts the pressure of the vessels with a pressure controller containing a slider sliding in response to the differential pressure of pure water in respective high pressure vessels, and wherein the pressure controller has a main unit and a position sensor for sensing the position of an external slider, and adjusts the pressure of high pressure vessels by allowing pure water in the respective high pressure vessels to move, and the main unit comprising: a hollow cylinder made of a non-magnetic material with one end communicating with the pure water in the high pressure vessel for storing hydrogen and the other end communicating with the pure water in the high pressure vessel for storing oxygen; an internal slider made of a magnetic material for blocking the pure water and sliding in close contact with an inner surface of the hollow cylinder; and an external slider made of a magnetic material and sliding in close contact with the outer surface of the hollow cylinder. 7. The system for generating high pressure hydrogen according to claim 6, wherein the hollow cylinder has buffer means as well as flow passageways at both ends thereof, which provide for flowing pure water through the passageways when the internal slider slides to one of both ends of the cylinder. 8. The system for generating high pressure hydrogen according to claim 6, wherein the hollow cylinder has buffer means as well as switches at both ends thereof, which provide for switching a shutoff valve provided in the pipe line for flowing pure water when internal slider slides to one of both ends of the cylinder. 9. The system for generating high pressure hydrogen according to claim 6, wherein the hollow cylinder has a net volume equal to or smaller than the smaller one of either the volume of hydrogen stored in the high pressure vessel for storing hydrogen or the volume of oxygen stored in the high pressure vessel for storing oxygen. 10. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the pressure control means is provided for adjusting the inner pressure of the high pressure vessel for storing hydrogen to be a little lower than the inner pressure of the high pressure vessel for storing oxygen. 11. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the pressure control means is provided for measuring the pressures of respective high pressure vessels and adjusting the differential pressure to a pressure below the pressure resistance of the electrolysis cell by discharging hydrogen or oxygen through valves provided at respective high pressure vessels being switched based on the measured values. 12. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the system has a heat exchanger provided outside the high pressure vessel for cooling the generated hydrogen. 13. The system for generating high pressure hydrogen according to claim 12, wherein the high pressure vessel for storing hydrogen and the heat exchanger provided at the outside of the high pressure vessel are connected with a hydrogen cooling pipe line comprising a plurality of branched fine tubes branched in the high pressure vessel. 14. The system for generating high pressure hydrogen according to claim 13, wherein each of the fine tubes are held and plumbed at a center of a core and hermetically fixed in through-holes tapered from the inside toward the outside of side walls constituting the respective high pressure vessels. 15. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the system has heat exchangers in the passageway of the pipe line for feeding the pure water for electrolysis to the electrolysis cell and/or in the passageway of the pipe line for returning the pure water from the electrolysis cell, and the heat exchangers are provided for controlling the temperatures of the pure water supplied to the electrolysis cell and/or the pure water returned from the electrolysis cell, or preventing the pure water from freezing. 16. The system for generating high pressure hydrogen according to claim 15, wherein the pipe line for the returned pure water comprises a plurality of branched fine tubes in the high pressure vessel for storing hydrogen. 17. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the system has a plurality of cooling fine tubes, disposed within the high pressure vessel for storing hydrogen and/or high pressure vessel for storing oxygen, for controlling the temperatures of stored hydrogen and/or oxygen and pure water, or for preventing pure water from freezing. 18. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the high pressure vessel for storing oxygen houses a water feed pump for feeding pure electrolysis water stored in the vessel to the electrolysis cell, and a motor for driving the water feed pump. 19. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the high pressure vessel for storing oxygen is furnished with volume control means for controlling the volume of pure water stored in the high pressure vessel to be larger than the volume of the high pressure vessel for storing hydrogen, and for controlling the volume of oxygen to be 4% or less of the volume of the high pressure vessel for storing hydrogen. 20. The system for generating high pressure hydrogen according to claim 19, wherein the volume control means comprises at least a level meter for measuring the surface of pure water filled in the high pressure vessel for storing oxygen, and a needle valve interlocking with the level meter, and the level meter is provided for controlling the surface of the pure water so that the volume of oxygen collected in the high pressure vessel for storing oxygen becomes 4% or less of the volume of the high pressure vessel for storing hydrogen. 21. The system for generating high pressure hydrogen according to claim 20, wherein the level meter comprises metal electrodes electrically insulated from each other and fixed to a brace, and a resistance meter for measuring the electrical resistance between the electrodes and the high pressure vessel. 22. The system for generating high pressure hydrogen according to claim 20, wherein the level meter comprises a cylindrical electrode having a rod-shaped electrode at the center. 23. The system for generating high pressure hydrogen according to claim 22, wherein the level meter also comprises a rod-shaped reference electrode covered with an electrically insulated cylinder except the tip thereof, and a cylindrical reference electrode having the rod-shaped reference electrode at the center thereof. 24. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the high pressure vessel for storing oxygen is furnished with a pure water replenishing equipment composed of a circulation system comprising a pure water storage tank for replenishing consumed pure water, an ion-exchanger tower and a pure water replenishing tank. 25. The system for generating high pressure hydrogen according to claim 24, wherein the pure water replenishing equipment comprises the pure water replenishing tank, a feed pipe line and a pipe line for returning oxygen and pure water, the pure water replenishing tank being disposed so that pure water stored therein is able to be supplied gravitationally to the high pressure vessel for storing oxygen and so as to be able to accept oxygen in the high pressure vessel for storing oxygen, the feed pipe line being disposed between the pure water storage tank and pure water replenishing tank so that pure water in the pure water storage tank is supplied to the pure water replenishing tank through the ion-exchanger tower, and the pipe line for returning oxygen and pure water being disposed between the pure water storage tank and pure water replenishing tank so that high pressure oxygen in the pure water storage tank is able to be discharged through a filter provided in the pure water replenishing tank, pure water in the pure water replenishing tank being circulated until pure water resumes a prescribed resistivity. 26. The system for generating high pressure hydrogen according to claim 1 or 6, wherein the electrolysis cell is a double-polarity multi-layered electrolysis cell manufactured by laminating a plurality of double-polarity electrodes comprising polyelectrolyte membranes having catalytic layers formed on both surfaces thereof and porous electrodes in contact with both surfaces of the polyelectrolyte membrane, the double-polarity electrolysis cell being disposed on a mounting table in the high pressure vessel so as to be compressed with compression jigs from above the table. 27. The system for generating high pressure hydrogen according to claim 26, wherein the electrolysis cell is a double-polarity multi-layered electrolysis cell having double-polarity electrodes comprising a pure water feed passageway formed at the center of the double polarity electrode. 28. The system for generating high pressure hydrogen according to claim 26, wherein the electrolysis cell is a double-polarity multi-layered electrolysis cell comprising a pure water feed passageway formed at the center of the double polarity electrode with a discharge port of oxygen and pure water at the anode side of each double-polarity electrode and a discharge port for directly discharging hydrogen and pure water into the high pressure vessel formed at the cathode side, and oxygen and pure water discharge passageways being vertically formed at the outer circumference of each double-polarity electrode so as to contact the oxygen and pure water discharge port. 29. The system for generating high pressure hydrogen according to claim 26, wherein the shape of the double-polarity electrodes is a disk. 30. The system for generating high pressure hydrogen according to claim 26, wherein the polyelectrolyte membrane is fixed to the double-polarity electrode with a sheet of seal member interposed at the outer circumference of the polyelectrolyte membrane. 31. The system for generating high pressure hydrogen according to claim 30, wherein the sheet of seal member is formed of a material thinner and harder than the polyelectrolyte membrane. 32. The system for generating high pressure hydrogen according to claim 26, wherein the compressed double-polarity multi-layered electrolysis cells are disposed to form a cascade. 33. The system for generating high pressure hydrogen according to claim 26, wherein the table for mounting the electrolysis cell comprises a pure water feed port for feeding pure water to the pure water feed passageway. 34. The system for generating high pressure hydrogen according to claim 26, wherein one end of the compression jig is fixed and held on an inner wall of the high pressure vessel. 35. The system for generating high pressure hydrogen according to claim 26, wherein the compression jig comprises a main unit of the jig fixed at an upper part of the electrolysis cell, a spring accommodated within the main unit of the jig, and a press screw with one end held in the high pressure vessel in order to energize the spring. 36. The system for generating high pressure hydrogen according to claim 26, wherein the double-polarity electrodes are laminated in a vertical direction with the top face serving as an anode and the bottom face serving as a cathode. 37. The system for generating high pressure hydrogen according to claim 26, wherein the porous electrode is fixed within the electrolysis cell by welding. 38. The system for generating high pressure hydrogen according to claim 26, wherein the electrolysis cell comprises the porous electrode having a polished surface in contact with the polyelectrolyte membrane.