Alkaline water electrolysis hydrogen production waste heat utilization system and method

Abstract

The present invention discloses an alkaline water electrolysis hydrogen production waste heat utilization system and method. The system includes: an electrolysis system for electrolyzing water to generate hydrogen to be processed and oxygen to be processed; a hydrogen processing system for processing the hydrogen to be processed to obtain hydrogen to be purified, and the hydrogen to be purified contains trace amounts of oxygen; an oxygen processing system for processing the oxygen to be processed to obtain clean oxygen; a circulation control pipeline for controlling the transmission of the caustic solution separated by the electrolysis system; a deoxidation system for reacting the trace amounts of oxygen and trace amounts of hydrogen in the hydrogen to be purified to obtain pure hydrogen and water; and a waste heat recovery system for connecting the circulation control pipeline and the deoxidation system to provide the waste heat of the caustic solution transmitted by the circulation control pipeline to the deoxidation system. The present invention utilizes the waste heat of the caustic solution after the electrolysis system in the deoxidation system through the waste heat recovery system to raise the temperature to remove the trace amounts of oxygen in the hydrogen to be purified, saving the additional heating electric energy of the deoxidation system and its supporting equipment, and simplifying the hydrogen deoxidation process.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen production systems, and more particularly to an alkaline water electrolysis hydrogen production waste heat utilization system and method. Background Art

[0002] With the popularization of environmental protection awareness, water electrolysis hydrogen has become the most popular hydrogen production method at present. The general technological process of alkaline water electrolysis hydrogen production waste heat utilization is as follows: 30% potassium hydroxide or 25% sodium hydroxide aqueous solution is used as the electrolyte, and the electrolyzer R usually operates under the condition of 80±5°C. Under the condition of passing direct current through the electrolyzer R, water is electrolyzed into H2 and O2, and together with the un-electrolyzed alkali solution, they respectively enter the hydrogen and oxygen gas-liquid separators in the gas-liquid post-treatment device. The separated gases are then washed and cooled. In the alkaline water electrolysis industry, oxygen is usually not used and is discharged into the atmosphere. Hydrogen is utilized, but the hydrogen after the above simple treatment has a relatively high water content and contains a small amount of oxygen.

[0003] In the water electrolysis hydrogen production industry, since a diaphragm is usually used to separate the anode and cathode in electrolyzed water, the hydrogen purity of the electrolyzed water usually contains hydrogen that meets the national standard requirements. However, the oxygen content in the hydrogen at this time is still too high for industrial use. Therefore, a catalyst is usually added in the deoxidation tower to remove trace oxygen. In order to meet the working conditions of the catalyst, in the traditional deoxidation process, an independent electric heating tube is required to heat the hydrogen. During the heating process, in order to well control the temperature of the hydrogen, a large amount of heat energy is consumed. The electric heating tube requires a supporting PLC logic control and its supporting intermediate relays, contactors, explosion-proof tubes, explosion-proof caps, thermocouples and other devices to control the heating temperature. Since related electrical equipment such as intermediate relays, contactors, and electric heating tubes are mostly consumable parts, they need to be frequently repaired and replaced, which increases the complexity, difficulty and cost of the entire hydrogen production. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this reason, the present invention provides an alkaline water electrolysis hydrogen production waste heat utilization system, which can utilize the waste heat of electrolyzed alkali solution to raise the temperature of the separated hydrogen, so that the heated hydrogen can react under the action of the catalyst in the deoxidation tower, without the need for an additional heater, that is, it saves the setting of the electric heating tube and makes the hydrogen production simpler.

[0005] The present invention also provides an alkaline water electrolysis hydrogen production waste heat utilization method.

[0006] In a first aspect, an embodiment of the present invention provides an alkaline water electrolysis hydrogen production waste heat utilization system, including:

[0007] An electrolysis system for electrolyzing water to generate hydrogen to be treated and oxygen to be treated;

[0008] A hydrogen treatment system for treating the hydrogen to be treated to obtain hydrogen to be purified, wherein the hydrogen to be purified contains trace amounts of oxygen;

[0009] An oxygen treatment system for treating the oxygen to be treated to obtain clean oxygen;

[0010] A circulation control pipeline for controlling the transmission of the lye separated by the electrolysis system;

[0011] A deoxidation system for reacting the trace amounts of oxygen and hydrogen in the hydrogen to be purified to obtain pure hydrogen and water;

[0012] A waste heat recovery system for connecting the circulation control pipeline and the deoxidation system to provide the waste heat of the lye transmitted by the circulation control pipeline to the deoxidation system.

[0013] The alkaline water electrolysis hydrogen production waste heat utilization system according to an embodiment of the present invention has at least the following beneficial effects: the waste heat of the lye remaining after the electrolysis system generates hydrogen to be treated and oxygen to be treated is recovered by the waste heat recovery system, and the waste heat recovery system utilizes the waste heat in the deoxidation system to rationally utilize the waste heat of the lye in the deoxidation system, so that the working environment of the deoxidation system meets the temperature of the catalyst reaction, thereby reacting the trace amounts of oxygen in the hydrogen to be purified. By using the waste heat of the lye to provide the working temperature of the deoxidation system, on the one hand, the additional heat of the deoxidation system is saved, and on the other hand, the deoxidation step of hydrogen is simplified, making the deoxidation of hydrogen simple.

[0014] An alkaline water electrolysis hydrogen production waste heat utilization system according to some other embodiments of the present invention further includes: a lye circulation system for connecting the circulation control pipeline to circulate the lye separated by the electrolysis system to the electrolysis system.

[0015] An alkaline water electrolysis hydrogen production waste heat utilization system according to some other embodiments of the present invention further includes: a waste heat utilization regulator for regulating the lye distribution amount of the waste heat recovery system.

[0016] An alkaline water electrolysis hydrogen production waste heat utilization system according to some other embodiments of the present invention, wherein the hydrogen treatment system includes:

[0017] A hydrogen scrubber for washing and removing trace amounts of lye in the hydrogen to be treated;

[0018] A first hydrogen cooler for cooling the hydrogen to be treated after washing;

[0019] A first hydrogen water separator for separating gas and water from the cooled hydrogen to be treated to separate trace amounts of water in the hydrogen to be treated to obtain water and the hydrogen to be purified;

[0020] Hydrogen drainer, used to drain water out of the system.

[0021] According to some other embodiments of the present invention, an alkaline water electrolysis hydrogen production waste heat utilization system, wherein the hydrogen to be purified is introduced into the waste heat recovery system, and the deoxidation system includes:

[0022] Deoxidation tower, used to react trace oxygen and trace hydrogen in the hydrogen to be purified passing through the waste heat recovery system to output hydrogen and water;

[0023] Second hydrogen cooler, used to cool the deoxidized hydrogen and water;

[0024] Second hydrogen water collector, used to separate the hydrogen and water, and the water is discharged through the hydrogen drainer;

[0025] First regulating valve, used to control and regulate the liquid level of the system, and discharge the hydrogen after ensuring the liquid level balance.

[0026] According to some other embodiments of the present invention, an alkaline water electrolysis hydrogen production waste heat utilization system, wherein the circulation control pipeline includes:

[0027] First connection pipeline, used to transport the alkali solution separated by the electrolysis system;

[0028] Second connection pipeline, used to connect the first connection pipeline;

[0029] Third connection pipeline, used to transport the alkali solution;

[0030] Several circulation control valves, used to control the flow and circulation of the alkali solution in the second connection pipeline;

[0031] Circulation pump, used to control the flow of the alkali solution and provide power for circulation;

[0032] The waste heat recovery system includes:

[0033] Fourth connection pipeline, used to transport a part of the alkali solution circulated by the circulation pump to the waste heat recovery system;

[0034] Fifth hydrogen treatment pipeline, used to transport the hydrogen to be purified separated by the first hydrogen water collector;

[0035] Hydrogen-alkali heat exchanger, used to receive the alkali solution input by the fourth connection pipeline and the hydrogen to be purified in the fifth hydrogen treatment pipeline, and the hydrogen to be purified is heated up after passing through the hydrogen-alkali heat exchanger;

[0036] Sixth hydrogen treatment pipeline, used to transport the heated hydrogen to be purified to the deoxidation tower.

[0037] An alkaline water electrolysis hydrogen production waste heat utilization system according to some other embodiments of the present invention, wherein the alkali liquid circulation system includes:

[0038] A fifth connecting pipeline for transporting the circulating alkali liquid;

[0039] A sixth connecting pipeline for connecting the fifth connecting pipeline and transporting the alkali liquid;

[0040] An alkali liquid cooler for cooling the alkali liquid transported by the fifth connecting pipeline and the alkali liquid transported by the sixth connecting pipeline;

[0041] A seventh connecting pipeline for transporting the cooled alkali liquid and at the same time for transporting the monitored alkali liquid to the electrolysis system;

[0042] An alkali liquid flowmeter for monitoring the flow rate of the alkali liquid.

[0043] An alkaline water electrolysis hydrogen production waste heat utilization system according to some other embodiments of the present invention, wherein the waste heat utilization regulator is a regulating valve, and the regulating valve is arranged on the fifth connecting pipeline for regulating the dosage of the alkali liquid in the hydrogen-alkali heat exchanger.

[0044] In a second aspect, an embodiment of the present invention provides an alkaline water electrolysis hydrogen production waste heat utilization method, including:

[0045] The alkali liquid is electrolyzed in the electrolytic cell and then separated to obtain the hydrogen to be treated and the oxygen to be treated;

[0046] The oxygen to be treated is separated, washed, cooled, and drained to obtain clean oxygen;

[0047] The hydrogen to be treated is separated, washed, cooled, and drained to obtain the hydrogen to be purified;

[0048] The alkali liquid after electrolytic separation is circulated to the waste heat recovery system through a circulation control pipeline;

[0049] The waste heat recovery system passes the hydrogen to be purified into the hydrogen-alkali heat exchanger to heat up the hydrogen to be purified;

[0050] The heated hydrogen to be purified enters the deoxidation system, and the deoxidation system reacts hydrogen and oxygen in the hydrogen to be purified to obtain pure hydrogen and water.

[0051] The method for utilizing waste heat in alkaline water electrolysis hydrogen production according to an embodiment of the present invention has at least the following beneficial effects: The waste heat generated after electrolyzing the alkaline solution is utilized in the deoxygenation system through the waste heat recovery system, so that the working environment of the deoxygenation system meets the temperature for the catalyst reaction, thereby enabling the oxygen and hydrogen in the hydrogen to be purified to undergo a catalytic reaction to remove oxygen. By using the waste heat of the alkaline solution to provide the working temperature for the deoxygenation system, on the one hand, the additional heat and its auxiliary equipment of the deoxygenation system are saved, and on the other hand, the deoxygenation step of the hydrogen to be purified is simplified, making the deoxygenation of the hydrogen to be purified simple and easy.

[0052] According to another embodiment of the present invention, a method for utilizing waste heat in alkaline water electrolysis hydrogen production further includes:

[0053] The alkaline solution after electrolytic separation is cooled and then returned to the electrolytic cell. Brief Description of the Drawings

[0054] Figure 1 is a block diagram of a waste heat utilization system for alkaline water electrolysis hydrogen production according to an embodiment of the present invention;

[0055] Figure 2 is a schematic flow diagram of a waste heat utilization system for alkaline water electrolysis hydrogen production according to an embodiment of the present invention.

[0056] Reference Numerals: 100, electrolysis system; 200, hydrogen treatment system; 300, oxygen treatment system; 400, circulation control pipeline; 500, deoxygenation system; 600, waste heat recovery system; 700, alkaline solution circulation system; 800, waste heat utilization regulator; A1-1, first circulation control valve; A1-2, second circulation control valve; A1-3, third circulation control valve; A1-4, fourth circulation control valve; A2, regulating valve; E1, oxygen cooler; E2, first hydrogen cooler; E3, second hydrogen cooler; E4, alkaline solution cooler; E5, hydrogen-alkaline heat exchanger; V1, oxygen separator; V2, hydrogen separator; V3, oxygen scrubber; V4, hydrogen scrubber; V5, oxygen water collector; V6, first hydrogen water collector; V7, second hydrogen water collector; V8, oxygen drainer; V9, hydrogen drainer; Vg1, first regulating valve; Vg2, second regulating valve; P1, circulation pump; R1, deoxygenation tower; F1, alkaline solution flowmeter; K1, first connecting pipeline; K2, second connecting pipeline; K3, third connecting pipeline; K4, fourth connecting pipeline; K5, fifth connecting pipeline;

[0057] K6, the sixth connecting pipeline; K7, the seventh connecting pipeline; H1, the first hydrogen treatment pipeline; H2, the second hydrogen treatment pipeline; H3, the third hydrogen treatment pipeline; H4, the fourth hydrogen treatment pipeline; H5, the fifth hydrogen treatment pipeline; H6, the sixth hydrogen treatment pipeline; H7, the seventh hydrogen treatment pipeline; H8, the eighth hydrogen treatment pipeline; H9, the ninth hydrogen treatment pipeline; O1, the first oxygen treatment pipeline; O2, the second oxygen treatment pipeline; O3, the third oxygen treatment pipeline; O4, the fourth oxygen treatment pipeline; O5, the fifth oxygen treatment pipeline. Detailed implementation manners

[0058] The concept of the present invention and the technical effects produced will be clearly and completely described below in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present invention.

[0059] In the description of the present invention, if it involves orientation description, such as "upper", "lower", "front", "rear", "left", "right", etc., the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention. If a certain feature is referred to as "set", "fixed", "connected", "installed" on another feature, it can be directly set, fixed, connected, installed on another feature, or indirectly set, fixed, connected, installed on another feature.

[0060] In the description of the embodiments of the present invention, if it involves "several", its meaning is more than one; if it involves "multiple", its meaning is more than two; if it involves "greater than", "less than", "exceeding", it should be understood as not including the number itself; if it involves "above", "below", "within", it should be understood as including the number itself. If it involves "first", "second", it should be understood as used to distinguish technical features, rather than indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0061] Refer to Figure 1, showing a module block diagram of a waste heat utilization system for alkaline water electrolysis hydrogen production in an embodiment of the present invention. An embodiment of the present invention discloses a waste heat utilization system for alkaline water electrolysis hydrogen production, including: an electrolysis system 100, a hydrogen treatment system 200, an oxygen treatment system 300, a circulation control system, a deoxidation system 500, and a waste heat recovery system 600; the electrolysis system 100 is used for electrolyzing an alkaline solution to generate hydrogen to be processed and oxygen to be processed; the hydrogen treatment system 200 is used for processing the hydrogen to be processed to obtain hydrogen to be purified; the oxygen treatment system 300 is used for processing the oxygen to be processed to obtain clean oxygen; the circulation control pipeline 400 is used for controlling the transmission of the alkaline solution separated by the electrolysis system 100; the deoxidation system 500 is used for reacting the oxygen and hydrogen in the hydrogen to be purified to obtain pure hydrogen and water; the waste heat recovery system 600 is used for connecting the circulation control pipeline 400 and the deoxidation system 500 to provide the waste heat of the alkaline solution transmitted by the circulation control pipeline 400 into the deoxidation system 500. After the electrolysis system 100 generates hydrogen to be processed and oxygen to be processed, the oxygen treatment system 300 processes the oxygen to be processed to obtain clean oxygen and discharges it. The hydrogen obtained after the hydrogen treatment system 200 processes the hydrogen to be processed contains trace amounts of oxygen, so hydrogen to be purified is obtained. The deoxidation system 500 removes the oxygen in the hydrogen to be purified by heating the oxygen and hydrogen with a catalyst to generate water. Since the deoxidation system 500 requires high temperature to react hydrogen and oxygen, the waste heat recovery system 600 recovers the heat of the alkaline solution after the electrolysis system 100 generates hydrogen to be processed and oxygen to be processed and provides it to the deoxidation system 500. Therefore, additional heat provided to the deoxidation system 500 is saved, and the original heat of the alkaline solution can be recycled, so as to save the setting of heating equipment and corresponding control equipment for the deoxidation system 500 and simplify the processing procedure of the entire hydrogen production system.

[0062] Since the processes of water electrolysis for hydrogen and oxygen production are exothermic reactions, in order to maintain the normal operation of the system, an alkaline solution cooler is usually set up to take away the heat with cooling water, control the circulating temperature of the alkaline solution, and maintain the continuous operation of the equipment. Now, the heat generated by water electrolysis for hydrogen and oxygen production is applied to the deoxidation process, which not only saves the setting of the alkaline solution cooler but also saves the heating equipment used for deoxidation.

[0063] In some embodiments, refer to Figure 1 and Figure 2, the electrolysis system 100 includes: an electrolytic cell R, a hydrogen separator V2, and an oxygen separator V1. The electrolytic cell R is used to electrolyze an alkaline solution to generate hydrogen to be processed and oxygen to be processed. However, the hydrogen to be processed and the oxygen to be processed generated by the electrolytic cell R are respectively mixed with the lye. The hydrogen separator V2 is used to normally separate the hydrogen to be processed and the lye to generate the hydrogen to be processed, and the oxygen separator V1 is used to normally separate the oxygen to be processed and the lye to generate the oxygen to be processed. To ensure the normal operation of the system, half of the volume in the hydrogen separator V2 and the oxygen separator V1 is lye.

[0064] The oxygen treatment system 300 includes: an oxygen scrubber V3, an oxygen cooler E1, an oxygen water collector V5, an oxygen drain V8, and a second regulating valve Vg2. The oxygen scrubber V3 and the oxygen separator V1 are connected by a second oxygen treatment pipeline O2. The oxygen to be processed flows into the oxygen scrubber V3 through the second oxygen treatment pipeline O2. The oxygen scrubber V3 is used to wash the trace lye in the oxygen to be processed clean. The oxygen cooler E1 and the oxygen scrubber V3 are connected by a third oxygen treatment pipeline O3. The washed oxygen to be processed passes through the oxygen cooler E1. The oxygen cooler E1 is used to cool the washed oxygen to be processed so as to condense the moisture in the oxygen. The oxygen cooler E1 and the oxygen water collector V5 are connected by a fourth oxygen treatment pipeline O4, and the oxygen water collector V5 and the oxygen drain V8 are connected. The oxygen water collector V5 is used to separate the oxygen and trace water in the oxygen to be processed. The water separated by the oxygen water collector V5 is discharged through the oxygen drain V8. A fifth oxygen treatment pipeline O5 is connected between the oxygen water collector V5 and the second regulating valve Vg2. The oxygen separated by the water collector flows through the fifth oxygen treatment pipeline O5 to the second regulating valve Vg2, and the oxygen is discharged after the system pressure is adjusted by the second regulating valve Vg2. The oxygen to be processed after electrolysis is washed, cooled, and water is separated by the oxygen scrubber V3, the oxygen cooler E1, the oxygen water collector V5, the oxygen drain V8, and the second regulating valve Vg2 to discharge clean oxygen.

[0065] The hydrogen processing system 200 includes: a hydrogen scrubber V4, a first hydrogen cooler E2, a first hydrogen water collector V6, and a hydrogen drain V9. Since the hydrogen carries trace amounts of alkali and oxygen, the hydrogen scrubber V4 is used to wash and remove the trace alkali in the hydrogen gas; the first hydrogen cooler E2 is used to cool the washed hydrogen to condense the moisture in the hydrogen; the first hydrogen water collector V6 is used to separate the cooled hydrogen into gas and water to separate the trace water in the hydrogen to obtain water and hydrogen to be purified; the hydrogen drain V9 is used to discharge the water. The hydrogen to be processed is obtained after separating the alkali solution by the hydrogen separator V2, and a second hydrogen processing pipeline H2 is connected between the hydrogen separator V2 and the hydrogen scrubber V4. The hydrogen to be processed flows through the second hydrogen processing pipeline H2 to the hydrogen scrubber V4 to wash away the trace alkali solution. The hydrogen scrubber V4 and the first hydrogen cooler E2 are connected with a third hydrogen processing pipeline H3. The washed hydrogen to be processed flows through the third hydrogen processing pipeline H3 to the first hydrogen cooler E2 for cooling. The first hydrogen cooler E2 and the first hydrogen water collector V6 are connected with a fourth hydrogen processing pipeline H4. The cooled hydrogen flows through the fourth hydrogen processing pipeline H4 to the first hydrogen water collector V6 to separate the trace moisture in the hydrogen to be processed to obtain hydrogen to be purified. The separated water is discharged through the hydrogen drain V9. The trace alkali solution and trace water in the hydrogen to be processed are removed by the hydrogen scrubber V4, the first hydrogen cooler E2, the first hydrogen water collector V6, and the hydrogen drain V9 to obtain hydrogen to be purified containing trace oxygen.

[0066] The circulation control pipeline 400 includes: a first connection pipeline K1, a second connection pipeline K2, a third connection pipeline K3, a fifth connection pipeline K5, a seventh connection pipeline K7, a circulation control valve, and a circulation pump P1. The hydrogen separator V2 and the oxygen separator V1 are connected to the first connection pipeline K1, and the first connection pipeline K1 is connected to the second connection pipeline K2 so that the lye separated by the hydrogen separator V2 and the oxygen separator V1 flows through the first connection pipeline K1 to the second connection pipeline K2. The setting of several circulation control valves can control the stable circulation of the lye through the circulation pump P1. In this embodiment, four circulation control valves are provided and are respectively defined as a first circulation control valve A1-1, a second circulation control valve A1-2, a third circulation control valve A1-3, and a fourth circulation control valve A1-4. Among them, the first circulation control valve A1-1 is provided on the second connection pipeline K2. The second circulation control valve A1-2 and the third circulation control valve A1-3 are respectively provided in front of and behind the circulation pump P1, and the fourth circulation control valve A1-4 is provided for the external connection of the second connection pipeline K2. Among them, the first circulation control valve A1-1 is closed and the fourth circulation control valve A1-4 is opened to inject lye into the system before the system starts; the first circulation control valve A1-1 is opened and the fourth circulation control valve A1-4 is closed for the lye circulation after the system is started. The second circulation control valve A1-2 is provided in front of the circulating lye pump P1, and the third circulation control valve A1-3 is provided behind the circulating lye pump P1. When the circulating lye pump P1 fails and needs to be removed for maintenance, the third circulation control valve A1-3 and the second circulation control valve A1-2 are closed to control the valves. Another function of the third circulation control valve A1-3 control valve is to adjust the total lye circulation volume. The circulation pump P1 provides power for the lye to flow through.

[0067] The waste heat recovery system 600 includes: a fourth connection pipeline K4, a fifth hydrogen treatment pipeline H5, a hydrogen-alkali heat exchanger E5, a sixth hydrogen treatment pipeline H6, and a sixth connection pipeline K6; the fourth connection pipeline K4 is used to transport part of the lye utilized by the circulation pump P1; the fifth hydrogen treatment pipeline H5 is used to transport the hydrogen to be purified separated by the first hydrogen water collector V6 to the hydrogen-alkali heat exchanger E5; the hydrogen-alkali heat exchanger E5 is used to receive the lye input by the fourth connection pipeline K4 and the hydrogen to be purified in the fifth hydrogen treatment pipeline H5, and the hydrogen to be purified is heated up after passing through the hydrogen-alkali heat exchanger E5; the sixth hydrogen treatment pipeline H6 is used to transport the heated hydrogen to be purified to the deoxidation system 500, and the sixth treatment pipeline is used to transport the lye flowing out of the hydrogen-alkali heat exchanger E5 to the lye cooler E4. Since the separated lye is generally between 85°C and 90°C, and the hydrogen utilizes the waste heat of the lye to achieve its own temperature increase after passing through the hydrogen-alkali heat exchanger E5, the temperature can be raised to about 85°C. The hydrogen to be purified after the temperature increase flows through the sixth hydrogen treatment pipeline H6 to the deoxidation system 500 for deoxidation. The hydrogen to be purified is heated up through the hydrogen-alkali heat exchanger E5 to recycle the waste heat of the lye and achieve the energy-saving and environmental protection effect of waste heat utilization.

[0068] The deoxidization system 500 includes: a deoxidization tower R1, a second hydrogen cooler E3, a second hydrogen water collector V7, and a first regulating valve Vg1; the deoxidization tower R1 is used to react oxygen and hydrogen in the hydrogen to be purified passing through the waste heat recovery system 600 to output hydrogen and water; the second hydrogen cooler E3 is used to cool the deoxidized hydrogen and water; the second hydrogen water collector V7 is used to separate hydrogen and water, and the water is discharged through the hydrogen drain V9; the first regulating valve Vg1 is used to output the hydrogen after controlling the liquid level balance of the separator out of this system. A seventh hydrogen treatment pipeline H7 is provided between the deoxidization tower R1 and the second hydrogen cooler E3, an eighth hydrogen treatment pipeline H8 is connected between the second hydrogen cooler E3 and the second hydrogen water collector V7, and a ninth hydrogen treatment pipeline H9 is connected between the second hydrogen water collector V7 and the first regulating valve Vg1. Since a catalyst is provided in the deoxidization tower R1, the condition required for the hydrogen-oxygen reaction by the catalyst is that the working temperature of the catalyst is above 60 °C, and the hydrogen to be purified uses the waste heat of the lye to raise its own temperature to about 85 °C through the hydrogen-alkali heat exchanger E5. The hydrogen to be purified after the temperature is raised enters the deoxidization tower R1. Since the hydrogen to be purified meets the starting temperature of the catalyst after heating, the hydrogen and trace oxygen in the hydrogen to be purified react to form water in the deoxidization tower R1. Since the hydrogen-oxygen reaction is an exothermic reaction, the temperature in the deoxidization tower R1 is raised again, further promoting the catalytic reaction. The hydrogen after the reaction is mixed with water vapor and enters the second hydrogen cooler E3 through the seventh hydrogen treatment pipeline H7. The hydrogen after cooling is subjected to gas-liquid separation in the second hydrogen water collector V7. The separated water is discharged through the hydrogen drain V9, and the hydrogen flows to the first regulating valve Vg1 through the ninth hydrogen treatment pipeline H9. The first regulating valve Vg1 adjusts the liquid level balance and then outputs the hydrogen out of this system. By using the waste heat of the lye to carry out a heating reaction in the deoxidization tower R1, an additional heating device is saved to provide a high-temperature environment. On the one hand, the setting of the heating device and the electric energy consumed by it are saved, and the procurement and maintenance of the corresponding equipment are reduced. On the other hand, the operation of the hydrogen-oxygen reaction is simplified.

[0069] In some embodiments, an alkaline water electrolysis hydrogen production waste heat utilization system further includes: a lye circulation system 700 and a waste heat utilization regulator 800. The lye circulation system 700 is used to connect to the circulation control pipeline 400 to input the lye separated by the electrolysis system 100 into the electrolysis system 100 again. The waste heat utilization regulator 800 is used to adjust the lye distribution amount between the waste heat recovery system 600 and the lye circulation system 700. Through the lye circulation system 700, the lye of the hydrogen separator V2 and the oxygen separator V1 flows back to the electrolytic cell R again, so that the lye can continue to decompose into hydrogen and oxygen. Through the waste heat utilization regulator 800, the distribution amount flowing into the hydrogen-alkali heat exchanger E5 is distributed to achieve reasonable distribution. It can not only enable hydrogen to use the waste heat of the lye to raise the temperature, but also ensure that the lye continues to decompose under the action of the lye cooler E4 to control the system working temperature.

[0070] In some embodiments, the lye circulation system 700 includes: a fifth connection pipeline K5, a lye cooler E4, a sixth connection pipeline K6, a lye flowmeter F1, and a seventh connection pipeline K7; the fifth connection pipeline K5 is used to transport the lye circulated by the circulation pump P1; the lye cooler E4 is used to centrally cool a part of the lye transported by the fifth connection pipeline K5 and a part of the lye flowing through the sixth connection pipeline K6 after flowing through the hydrogen-lye heat exchanger E5; the seventh connection pipeline K7 is used to transport the cooled lye; the lye flowmeter F1 is used to monitor the flow rate of the lye; at the same time, the seventh connection pipeline K7 is used to transport the monitored lye to the electrolysis system 100. The lye is centrally cooled after flowing through the lye cooler E4 through the sixth connection pipeline K6 and the fifth connection pipeline K5, and the lye cooler E4 cools the lye to the requirements of the process system under the action of externally introduced cooling water. The lye is distributed by the waste heat utilization regulator 800, and then the distributed lye flows through the hydrogen-lye heat exchanger E5 through the sixth connection pipeline K6 and then flows into the lye cooler E4 and then flows to the lye flowmeter F1 for system monitoring, and then the lye flows back to the electrolytic cell R through the seventh connection pipeline K7 so that the circulating lye can continue to electrolyze hydrogen and oxygen.

[0071] The waste heat utilization regulator 800 is a regulating valve A2, and the regulating valve A2 is arranged on the fifth connection pipeline K5 to regulate the distribution amount of the lye in the hydrogen-lye heat exchanger E5 to ensure that the temperature of the hydrogen to be treated can reach about 85°C. A sixth connection pipeline K6 is connected between the hydrogen-lye heat exchanger E5 and the lye cooler E4 to flow the lye in the hydrogen-lye heat exchanger E5 to the lye cooler E4 through the sixth connection pipeline K6, and after controlling the total lye temperature, it flows back to the electrolytic cell R. The distribution amount of the lye in the hydrogen-lye heat exchanger E5 is regulated by the regulating valve A2 to achieve reasonable distribution.

[0072] In some embodiments, the present invention discloses a method for utilizing waste heat in alkaline water electrolysis for hydrogen production, including:

[0073] After electrolysis in the electrolytic cell, the lye is separated to obtain hydrogen to be treated and oxygen to be treated;

[0074] The oxygen to be treated is obtained as clean oxygen after separation, washing, cooling, and drainage treatment;

[0075] The hydrogen to be treated is obtained as hydrogen to be purified after separation, washing, cooling, and drainage;

[0076] The lye after electrolytic separation is circulated to the waste heat recovery system through the circulation control pipeline;

[0077] The waste heat recovery system passes the hydrogen to be purified into the hydrogen-lye heat exchanger to raise the temperature of the hydrogen to be purified;

[0078] The hydrogen to be purified after temperature rise enters the deoxygenation system, where the hydrogen and oxygen in the hydrogen to be purified react to obtain pure hydrogen and water. The waste heat of the alkaline solution in the waste heat recovery system is utilized in the deoxygenation system to provide a high-temperature working environment so that the catalyst can reach the starting temperature for operation. In order to recycle the waste heat of the alkaline solution, on the one hand, it saves the additional electric heating equipment, supporting explosion-proof equipment and the consumed electric energy of the deoxygenation system, and on the other hand, it simplifies the steps of hydrogen deoxygenation and makes hydrogen deoxygenation easier.

[0079] A method for utilizing waste heat in alkaline water electrolysis hydrogen production further includes: cooling the alkaline solution after electrolytic separation and then recycling it to the electrolytic cell.

[0080] Among them, the specific working process of a method for utilizing waste heat in alkaline water electrolysis hydrogen production refers to a waste heat utilization system for alkaline water electrolysis hydrogen production, which will not be elaborated here.

[0081] The embodiments of the present invention have been described in detail above with reference to the drawings. However, the present invention is not limited to the above embodiments. Various changes can be made without departing from the gist of the present invention within the knowledge scope of those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. An alkaline water electrolysis hydrogen production waste heat utilization system, characterized in that, Including: An electrolysis system for electrolyzing water to generate hydrogen to be processed and oxygen to be processed; A hydrogen processing system for processing the hydrogen to be processed to obtain hydrogen to be purified, wherein the hydrogen to be purified contains trace amounts of oxygen; wherein, the hydrogen processing system includes a first hydrogen water collector for separating the cooled hydrogen to be processed into gas and water to separate trace amounts of water in the hydrogen to be processed to obtain water and the hydrogen to be purified; An oxygen processing system for processing the oxygen to be processed to obtain clean oxygen; A circulation control pipeline for controlling the transmission of the lye separated by the electrolysis system; wherein, the circulation control pipeline includes a circulation pump for controlling the circulation of the lye and providing power for circulation; A deoxidation system for reacting trace amounts of oxygen and trace amounts of hydrogen in the hydrogen to be purified to obtain pure hydrogen and water; A waste heat recovery system for connecting the circulation control pipeline and the deoxidation system to provide the waste heat of the lye transmitted by the circulation control pipeline to the deoxidation system; The deoxidation system includes: A deoxidation tower for reacting trace amounts of oxygen and trace amounts of hydrogen in the hydrogen to be purified passing through the waste heat recovery system to output hydrogen and water; The waste heat recovery system includes: A fourth connection pipeline for transmitting a part of the lye circulated by the circulation pump to the waste heat recovery system; A fifth hydrogen processing pipeline for transmitting the hydrogen to be purified separated by the first hydrogen water collector; A hydrogen-lye heat exchanger for receiving the lye input by the fourth connection pipeline and the hydrogen to be purified in the fifth hydrogen processing pipeline, and the hydrogen to be purified is heated up after passing through the hydrogen-lye heat exchanger; A sixth hydrogen processing pipeline for transmitting the heated hydrogen to be purified to the deoxidation tower.

2. The alkaline water electrolysis hydrogen production waste heat utilization system according to claim 1, characterized in that, It further includes: A lye circulation system for connecting the circulation control pipeline to circulate the lye separated by the electrolysis system to the electrolysis system.

3. The alkaline water electrolysis hydrogen production waste heat utilization system according to claim 2, wherein, It further includes: A waste heat utilization regulator for regulating the lye distribution amount of the waste heat recovery system.

4. The alkaline water electrolysis hydrogen production waste heat utilization system according to claim 3, characterized in that, The hydrogen processing system further includes: A hydrogen scrubber for washing and removing trace amounts of lye in the hydrogen to be processed; A first hydrogen cooler for cooling the washed hydrogen to be processed; A hydrogen drainer for discharging water out of the system.

5. The alkaline water electrolysis hydrogen production waste heat utilization system according to claim 4, characterized in that, The hydrogen to be purified is introduced into the waste heat recovery system, and the deoxidation system further includes: A second hydrogen cooler for cooling the deoxidized hydrogen and water; A second hydrogen water collector for separating the hydrogen and water, and the water is discharged through the hydrogen drainer; A first regulating valve for controlling and regulating the liquid level of the system, and discharging the hydrogen after ensuring the liquid level balance.

6. A method for utilizing the waste heat of alkaline water electrolysis for hydrogen production, characterized in that, Including: The lye is electrolyzed in the electrolytic cell and then separated to obtain hydrogen to be processed and oxygen to be processed; The oxygen to be processed is separated, washed, cooled, and drained to obtain clean oxygen; The hydrogen to be processed is separated, washed, cooled, and drained to obtain hydrogen to be purified; The lye after electrolytic separation is circulated to the waste heat recovery system through the circulation control pipeline; The waste heat recovery system introduces the hydrogen to be purified into the hydrogen-lye heat exchanger to heat up the hydrogen to be purified; The heated hydrogen to be purified enters the deoxidization system, where the hydrogen and oxygen in the hydrogen to be purified react to obtain pure hydrogen and water.

7. The method for utilizing waste heat in alkaline water electrolysis hydrogen production according to claim 6, wherein It also includes: The lye after electrolytic separation is cooled and then refluxed to the electrolytic cell.

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