Energy recycling device in field of hydrogen production through water electrolysis

Abstract

The utility model relates to an energy recycling device in the field of hydrogen production through water electrolysis. Alkali liquor is arranged in an electrolytic bath and used for absorbing heat generated in electrochemical reaction; the hot side of the first heat exchanger communicates with the electrolytic cell through a pipeline; the waste heat refrigeration equipment is communicated with the cold side of the first heat exchanger through a pipeline; the second heat exchanger is communicated with the first heat exchanger through a pipeline and is used for receiving the medium-temperature alkali liquor for cooling; the circulating cooling water system is communicated with the second heat exchanger through a pipeline; and the alkali liquor circulating pump is communicated with the second heat exchanger and the electrolytic bath through pipelines and is used for conveying the cooled low-temperature alkali liquor in the second heat exchanger into the electrolytic bath. According to the utility model, the heat energy in the alkali liquor is recycled and comprehensively utilized, so that the heat energy utilization efficiency of the water electrolysis hydrogen production system is improved, and the electric energy waste is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of water electrolysis hydrogen production, in particular to an energy recovery and utilization device in the field of water electrolysis hydrogen production. Background Art

[0002] During operation, water electrolysis hydrogen production systems generate a significant amount of waste heat while producing hydrogen, as the cell voltage within the electrolyzer is higher than the thermoneutral voltage of water molecules. While the cell voltage has been decreasing with advancements in cell structure, electrolysis technology, and diaphragm technology in alkaline water electrolyzers, 17%-20% of the electrical energy is still converted into waste heat. Therefore, the waste heat in the lye represents a significant thermal energy resource. Conventional water electrolysis hydrogen production systems utilize a circulating cooling water system to cool the lye. However, the high cooling water temperature of the circulating cooling water system cannot meet the chilled water requirements of the hydrogen purification and compression processes, necessitating the installation of power-consuming chilled water equipment, which increases electrical energy consumption. Utility Model Content

[0003] To this end, the technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an energy recovery and utilization device in the field of water electrolysis hydrogen production, which improves the thermal energy utilization efficiency of the water electrolysis hydrogen production system and reduces the waste of electric energy by recovering the heat energy in the alkaline solution for comprehensive utilization.

[0004] In order to solve the above technical problems, the utility model provides an energy recovery and utilization device in the field of water electrolysis hydrogen production, comprising: an electrolytic cell, a first heat exchanger, a second heat exchanger, an alkali solution circulation pump, a waste heat refrigeration device and a circulating cooling water system; wherein,

[0005] The electrolytic cell produces hydrogen through an electrochemical reaction, and an alkaline solution is provided in the electrolytic cell to absorb the heat generated in the electrochemical reaction;

[0006] a first heat exchanger, the hot side of which is connected to the electrolytic cell through a pipeline, for receiving the high-temperature alkali solution in the electrolytic cell and performing a temperature reduction treatment;

[0007] The waste heat refrigeration equipment is connected to the cold side of the first heat exchanger through a pipeline, and uses the heat energy received from the high-temperature alkali liquid as a heat source to produce low-temperature chilled water to cool the high-temperature alkali liquid to medium-temperature alkali liquid;

[0008] a second heat exchanger, which is connected to the first heat exchanger through a pipeline and is used to receive the medium-temperature alkali solution for cooling;

[0009] a circulating cooling water system, which is connected to the second heat exchanger through a pipeline and is used to cool the medium-temperature alkali liquid in the second heat exchanger to a low-temperature alkali liquid;

[0010] An alkali solution circulation pump is connected to the second heat exchanger and the electrolytic cell through a pipeline, and is used to transport the low-temperature alkali solution cooled in the second heat exchanger to the electrolytic cell.

[0011] In one embodiment of the present invention, the first heat exchanger is a plate heat exchanger, and the second heat exchanger is a shell and tube heat exchanger.

[0012] In one embodiment of the present utility model, the waste heat refrigeration equipment includes a refrigerant heating tank, a refrigerant vacuum evaporation tank, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger and a refrigerant circulation pump. The third heat exchanger and refrigerant are provided in the refrigerant heating tank, and the fourth heat exchanger is provided in the refrigerant vacuum evaporation tank; the refrigerant heating tank and the refrigerant vacuum evaporation tank are connected to the refrigerant circulation pump in sequence through the fifth heat exchanger.

[0013] In one embodiment of the present invention, the third heat exchanger and the fourth heat exchanger are both fin-type heat exchangers.

[0014] In one embodiment of the present invention, the fifth heat exchanger is a condenser, which is used to convert the refrigerant from gas to liquid.

[0015] In one embodiment of the present invention, the second heat exchanger includes a shell side and a tube side, the shell side is connected to the first heat exchanger through a pipeline for receiving medium-temperature alkali solution; the tube side is connected to the circulating cooling water system through a pipeline.

[0016] In one embodiment of the present invention, the circulating cooling water system comprises:

[0017] a sixth heat exchanger, connected to the second heat exchanger through pipelines, for initially cooling the high-temperature water flowing out of the second heat exchanger;

[0018] a seventh heat exchanger, which is connected to the sixth heat exchanger through a pipeline and is used to further cool the medium-temperature water flowing out of the sixth heat exchanger;

[0019] an external circulation water spraying system, configured to spray water onto the outside of the seventh heat exchanger to cool the seventh heat exchanger, so that the water in the seventh heat exchanger is cooled to low-temperature cold water;

[0020] An external circulation water reservoir is connected to the external circulation water spraying system through an external circulation pump; the external circulation water reservoir is used to collect water falling from the external circulation water spraying system and supply water to the external circulation water spraying system through the external circulation pump.

[0021] In one embodiment of the present invention, the sixth heat exchanger is an air heat exchanger.

[0022] In one embodiment of the present invention, the seventh heat exchanger is a coil heat exchanger.

[0023] In one embodiment of the present invention, the alkali solution circulation flow rate in the alkali solution circulation pump is 5~100m 3 / h.

[0024] In one embodiment of the present invention, the waste heat refrigeration equipment is connected to the hydrogen purification system and the hydrogen compression system to provide low-temperature chilled water therefor.

[0025] The above technical solution of the utility model has the following beneficial effects compared with the prior art:

[0026] The utility model discloses a heat energy recovery and utilization device in the field of water electrolysis hydrogen production, which recovers the heat energy in the alkaline solution in the electrolytic cell as the power source of the waste heat refrigeration equipment for waste heat refrigeration, thereby replacing the power-consuming chilled water equipment in the hydrogen purification process and the hydrogen compression process, improving the heat energy utilization efficiency of the water electrolysis hydrogen production system and reducing the power consumption of the water electrolysis hydrogen production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to make the content of the utility model easier to understand, the utility model is further described in detail below based on the specific embodiments of the utility model and in conjunction with the accompanying drawings, wherein

[0028] Figure 1 This is a structural diagram of a heat energy recovery and utilization device in the field of water electrolysis hydrogen production in a preferred embodiment of the present utility model;

[0029] Figure 2 yes Figure 1 The schematic structural diagram of the waste heat refrigeration equipment of the heat energy recovery and utilization device in the field of water electrolysis hydrogen production is shown;

[0030] Figure 3 yes Figure 1 The circulating cooling water system of the heat energy recovery and utilization device in the field of water electrolysis hydrogen production shown;

[0031] Explanation of the reference numerals in the specification: 1. electrolytic cell; 2. first heat exchanger; 3. second heat exchanger; 4. alkali solution circulation pump; 5. waste heat refrigeration equipment; 6. hydrogen purification system; 7. hydrogen compression system; 8. circulating cooling water system; 1.1. high-temperature alkali solution; 1.2. medium-temperature alkali solution; 1.3. low-temperature alkali solution; 1.4. low-temperature liquid water; 1.5. high-temperature liquid water; 1.6. low-temperature chilled water; 1.7. high-temperature chilled water; 1.8. low-temperature cold water; 1.9. high-temperature water; 2.1. refrigerant heating tank; 2.2. third heat exchanger; 2.3. refrigerant vacuum evaporation tank; 2.4. fourth heat exchanger; 2.5. fifth heat exchanger; 2.6. refrigerant circulation pump; 3.1. sixth heat exchanger; 3.2. external circulation water spray system; 3.3. seventh heat exchanger; 3.4. external circulation water reservoir; 3.5. external circulation pump. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0033] Reference Figure 1 As shown, the energy recovery and utilization device in the field of water electrolysis hydrogen production described in the present invention includes: an electrolytic cell 1, a first heat exchanger 2, a second heat exchanger 3, an alkali solution circulation pump 4, a waste heat refrigeration device 5 and a circulating cooling water system 8; wherein,

[0034] The electrolytic cell 1 produces hydrogen through an electrochemical reaction, and an alkaline solution is provided in the electrolytic cell 1 to absorb the heat generated in the electrochemical reaction;

[0035] A first heat exchanger 2, whose hot side is connected to the electrolytic cell 1 through a pipeline, is used to receive the high-temperature alkali solution 1.1 in the electrolytic cell 1 for cooling; the first heat exchanger 2 is a plate heat exchanger or a shell and tube heat exchanger;

[0036] The waste heat refrigeration device 5 is connected to the cold side of the first heat exchanger 2 through a pipeline, and uses the heat energy received from the high-temperature alkali solution 1.1 as a heat source to produce low-temperature chilled water 1.6 to cool the high-temperature alkali solution 1.1 to medium-temperature alkali solution 1.2;

[0037] The second heat exchanger 3 is connected to the first heat exchanger 2 through a pipeline and is used to receive the medium-temperature alkali solution 1.2 and cool it down; the second heat exchanger 3 is a shell and tube heat exchanger;

[0038] a circulating cooling water system 8, which is connected to the second heat exchanger 3 via a pipeline and is used to cool the medium-temperature alkali solution 1.2 in the second heat exchanger 3 to a low-temperature alkali solution 1.3;

[0039] The alkali liquid circulation pump 4 is connected to the second heat exchanger 3 and the electrolytic cell 1 through a pipeline, and is used to transport the low-temperature alkali liquid 1.3 cooled in the second heat exchanger 3 to the electrolytic cell 1. The alkali liquid circulation flow rate in the alkali liquid circulation pump 4 is 5~100m 3 / h.

[0040] Preferably, the second heat exchanger 3 includes a shell side and a tube side, the shell side is connected to the first heat exchanger 2 through a pipeline for receiving the medium-temperature alkali solution 1.2; the cold side and the hot side of the tube side are respectively connected to the circulating cooling water system 8 through pipelines.

[0041] The electrolyzer 1 is the main device that uses electrical energy to produce hydrogen through electrochemical reactions. During the process of producing hydrogen, since the voltage of the small chamber exceeds the thermoneutral voltage of water electrolysis for hydrogen production (i.e., the voltage at which the heat released and the heat absorbed during the electrochemical reaction are in equilibrium), the electrolyzer 1 will generate a large amount of waste heat. This waste heat is absorbed by the alkaline solution circulating through the electrolyzer 1; the temperature of the low-temperature alkaline solution 1.3 is raised from 35-60°C to the high-temperature alkaline solution 1.1, which has a temperature of 80-98°C; the low-temperature liquid water 1.4 on the cold side of the first heat exchanger 2 exchanges heat with the high-temperature alkaline solution 1.1 on the hot side, and the low-temperature liquid water 1.4 at 40-70°C is heated to 1.1. The alkali liquid heats up the temperature to high-temperature liquid water 1.5 at 80-93°C, while the high-temperature alkali liquid 1.1 at 80-98°C is cooled down to medium-temperature alkali liquid 1.2 at 60-80°C. The low-temperature cold water 1.8 in the second heat exchanger 3 exchanges heat with the medium-temperature alkali liquid 1.2, and the low-temperature cold water 1.8 at 30-38°C is heated by the alkali liquid to high-temperature water 1.9 at 35-45°C, while the medium-temperature alkali liquid 1.2 at 60-80°C is cooled down to low-temperature alkali liquid 1.3 at 35-60°C.

[0042] like Figure 2 As shown, the waste heat refrigeration device 5 includes a refrigerant heating tank 2.1, a third heat exchanger 2.2, a refrigerant vacuum evaporation tank 2.3, a fourth heat exchanger 2.4, a fifth heat exchanger 2.5, and a refrigerant circulation pump 2.6. The third heat exchanger 2.2 and refrigerant are disposed in the refrigerant heating tank 2.1, and the fourth heat exchanger 2.4 is disposed in the refrigerant vacuum evaporation tank 2.3. The refrigerant heating tank 2.1 and the refrigerant vacuum evaporation tank 2.3 are connected in sequence via the fifth heat exchanger 2.5 and the refrigerant circulation pump 2.6.

[0043] Preferably, the third heat exchanger 2.2 and the fourth heat exchanger 2.4 are both finned heat exchangers. The fifth heat exchanger 2.5 is a condenser, which is used to convert the refrigerant from gas to liquid.

[0044] The refrigeration principle of the waste heat refrigeration equipment in this embodiment is as follows: high-temperature liquid water 1.5 flows into the third heat exchanger 2.2 in the refrigerant heating tank 2.1, heating the low-temperature refrigerant to a high-temperature refrigerant. The high-temperature refrigerant then flows from the refrigerant heating tank 2.1 into the refrigerant vacuum evaporator 2.3. The high-temperature refrigerant evaporates and becomes gaseous under a vacuum environment. During this process, the high-temperature refrigerant absorbs a large amount of heat, causing the high-temperature chilled water 1.7 in the fourth heat exchanger 2.4 to cool to low-temperature chilled water 1.6. The gaseous refrigerant in the refrigerant vacuum evaporator 2.3 passes through the fifth heat exchanger 2.5 and becomes liquid refrigerant. The refrigerant circulation pump 2.6 then circulates the liquid refrigerant to the refrigerant heating tank 2.1.

[0045] like Figure 3 As shown, the circulating cooling water system 8 in this embodiment includes:

[0046] a sixth heat exchanger 3.1, connected to the second heat exchanger 3 through pipelines, for initially cooling the high-temperature water 1.9 flowing out of the second heat exchanger 3;

[0047] The seventh heat exchanger 3.3 is connected to the sixth heat exchanger 3.1 through a pipeline and is used to further cool the medium-temperature water flowing out of the third heat exchanger 3.1;

[0048] an external circulation water spraying system 3.2 for spraying water onto the outside of the seventh heat exchanger 3.3 to cool the seventh heat exchanger 3.3, so that the water in the seventh heat exchanger 3.3 is cooled to low-temperature cold water 1.8;

[0049] The external circulating water reservoir 3.4 is connected to the external circulating water spraying system 3.2 through the external circulating pump 3.5; the external circulating water reservoir 3.4 is used to collect the water falling from the external circulating water spraying system 3.4 and supply water to the external circulating water spraying system 3.2 through the external circulating pump 3.5.

[0050] Preferably, the sixth heat exchanger 3.1 is an air heat exchanger.

[0051] Preferably, the seventh heat exchanger 3.3 is a coil heat exchanger.

[0052] The circulating cooling water system 8 based on the above-described mechanism cools high-temperature water 1.9, which has been heated by the alkali solution in the second heat exchanger 3 and has a temperature of 35-45°C. High-temperature water 1.9 first passes through the sixth heat exchanger 3.1, where it is initially cooled by the atmosphere and becomes medium-temperature water. It then enters the seventh heat exchanger 3.3, where it undergoes heat exchange with the external circulation spray water system 3.2, cooling the medium-temperature water to low-temperature cold water 1.8, which has a temperature of 30-38°C. A portion of the external circulation spray water on the surface of the seventh heat exchanger 3.3 absorbs heat due to evaporation, resulting in cooling. The remaining spray water is heated and flows to the external circulation water reservoir 3.4. It then passes through the external circulation pump 3.5 and re-enters the external circulation water spray system 3.2, thus repeating the cycle.

[0053] During the process of hydrogen production by water electrolysis, the hydrogen purification system 6 and the hydrogen compression system 7 both require low-temperature chilled water 1.6 at a temperature of 7-20°C. By connecting the waste heat refrigeration equipment in this embodiment to the hydrogen purification system 6 and the hydrogen compression system 7 to provide them with low-temperature chilled water 1.6, the waste heat refrigeration equipment is used to replace the power-consuming chilled water equipment of the hydrogen purification process and the hydrogen compression process, thereby greatly reducing the power consumption of the water electrolysis hydrogen production system.

[0054] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An energy recovery and utilization device in the field of water electrolysis hydrogen production, characterized by: include: Electrolytic cell, first heat exchanger, second heat exchanger, alkali solution circulation pump, waste heat refrigeration equipment and circulating cooling water system; wherein, The electrolytic cell produces hydrogen through an electrochemical reaction, and an alkaline solution is provided in the electrolytic cell to absorb the heat generated in the electrochemical reaction; a first heat exchanger, the hot side of which is connected to the electrolytic cell through a pipeline, for receiving the high-temperature alkali solution in the electrolytic cell and performing a cooling treatment; The waste heat refrigeration equipment is connected to the cold side of the first heat exchanger through a pipeline, and uses the heat energy received from the high-temperature alkali liquid as a heat source to produce low-temperature chilled water to cool the high-temperature alkali liquid to medium-temperature alkali liquid; a second heat exchanger, which is connected to the first heat exchanger through a pipeline and is used to receive the medium-temperature alkali solution for cooling; a circulating cooling water system, which is connected to the second heat exchanger through a pipeline and is used to cool the medium-temperature alkali liquid in the second heat exchanger to a low-temperature alkali liquid; An alkali solution circulation pump is connected to the second heat exchanger and the electrolytic cell through a pipeline, and is used to transport the low-temperature alkali solution cooled in the second heat exchanger to the electrolytic cell.

2. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 1, characterized in that: The first heat exchanger is a plate heat exchanger or a shell and tube heat exchanger, and the second heat exchanger is a shell and tube heat exchanger.

3. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 1, characterized in that: The waste heat refrigeration equipment includes a refrigerant heating tank, a refrigerant vacuum evaporation tank, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger and a refrigerant circulation pump. The third heat exchanger and refrigerant are provided in the refrigerant heating tank, and the fourth heat exchanger is provided in the refrigerant vacuum evaporation tank; the refrigerant heating tank and the refrigerant vacuum evaporation tank are connected in sequence through the fifth heat exchanger and the refrigerant circulation pump.

4. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 3, characterized in that: The third heat exchanger and the fourth heat exchanger are both fin-type heat exchangers.

5. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 3, characterized in that: The fifth heat exchanger is a condenser, which is used to convert the refrigerant from gas to liquid.

6. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 1, characterized in that: The second heat exchanger includes a shell side and a tube side. The shell side is connected to the first heat exchanger through a pipeline for receiving medium-temperature alkali solution; the tube side is connected to a circulating cooling water system through a pipeline.

7. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 6, characterized in that: The circulating cooling water system comprises: A sixth heat exchanger, respectively, connected to the second heat exchanger through a pipe, for initially cooling the high-temperature water flowing out of the second heat exchanger; the sixth heat exchanger is an air heat exchanger; a seventh heat exchanger, which is connected to the sixth heat exchanger through a pipeline and is used to further cool the medium-temperature water flowing out of the sixth heat exchanger; an external circulation water spraying system, configured to spray water onto the outside of the seventh heat exchanger to cool the seventh heat exchanger, so that the water in the seventh heat exchanger is cooled to low-temperature cold water; An external circulation water reservoir is connected to the external circulation water spraying system through an external circulation pump; the external circulation water reservoir is used to collect water falling from the external circulation water spraying system and supply water to the external circulation water spraying system through the external circulation pump.

8. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 7, characterized in that: The seventh heat exchanger is a coil heat exchanger.

9. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 1, characterized in that: The alkali solution circulation flow rate in the alkali solution circulation pump is 5~100m 3 / h.

10. The energy recovery and utilization device in the field of water electrolysis hydrogen production according to claim 1, characterized in that: The waste heat refrigeration equipment is connected to the hydrogen purification system and the hydrogen compression system to provide them with low-temperature chilled water.

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