Gas-liquid treatment system capable of stably operating in wide load fluctuation range
By installing level gauges and temperature detectors in the water electrolysis hydrogen production system, combined with nitrogen charging valves and cooling systems, the problems of level deviation and gas purity under wide load fluctuations in the water electrolysis hydrogen production system were solved, achieving stable system operation and efficient gas purity control.
Patent Information
- Application Number
- CN202510948596.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2025-10-31
AI Technical Summary
The electrolysis hydrogen production system suffers from unstable operation due to issues such as liquid level deviation and substandard gas purity in the gas-liquid processing module under wide load fluctuations.
By installing level gauges and temperature detectors on the hydrogen separator and oxygen separator, combined with nitrogen filling valves and cooling systems, the liquid level and temperature can be regulated to achieve stable system operation.
It achieves stable operation within a wide load fluctuation range, avoids extreme conditions, improves system stability and gas purity, and expands the equipment's applicability.
Smart Images
Figure CN120866845A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of water electrolysis for hydrogen production technology, specifically to a gas-liquid processing system that can operate stably under a wide load fluctuation range. Background Technology
[0003] Hydrogen production via water electrolysis is gradually developing towards large-scale and intensive operations. The green electricity required for hydrogen production via water electrolysis mainly comes from wind or solar power, which is subject to significant fluctuations. The process includes an electrolysis module, a gas-liquid processing module, and a purification module, among which the gas-liquid processing module has relatively poor shock resistance. To improve system stability, the gas-liquid processing module needs to be improved to possess adaptive adjustment capabilities.
[0004] System fluctuations affect the gas-liquid treatment module primarily in two ways: First, there's the discrepancy in liquid levels on both the hydrogen and oxygen sides. If one side's level is too high, alkali solution will spray out from the outlet on that side; if one side's level is too low, alkali solution is easily drawn into the circulating pump and flows back into the electrolyzer, causing hydrogen and oxygen to mix. Second, the gas purity may not meet standards. Gas purity is mainly affected by the outlet temperature of the gas-liquid treatment module. Higher outlet gas temperatures result in higher alkali content in the gas, which is detrimental to subsequent purification processes. Summary of the Invention
[0006] To address the aforementioned technical problems, this invention provides a gas-liquid processing system that can operate stably under a wide load fluctuation range, capable of adjusting the liquid levels on both the hydrogen and oxygen sides to ensure normal equipment operation.
[0007] The technical solution is as follows: a gas-liquid treatment system capable of stable operation under a wide load fluctuation range, comprising an electrolytic cell, the outlet of which is connected to a hydrogen separator and an oxygen separator arranged in parallel; the outlet of the hydrogen separator is connected to the inlet of a hydrogen heat exchanger; the outlet of the oxygen separator is connected to the inlet of an oxygen heat exchanger; the inlet of the hydrogen heat exchanger is connected to a hydrogen scrubbing tower; the outlet of the hydrogen scrubbing tower is connected to a hydrogen outlet pipe; the inlet of the oxygen heat exchanger is connected to an oxygen scrubbing tower; and the outlet of the oxygen scrubbing tower is connected to an oxygen outlet pipe. The system is characterized in that level gauges are installed on both the hydrogen and oxygen separators; both the hydrogen and oxygen separators are connected to nitrogen purging pipes; nitrogen purging pipes are equipped with nitrogen purging valves and connected to a nitrogen source; temperature detectors are installed on the hydrogen-side connection pipes between the hydrogen heat exchanger and the hydrogen scrubbing tower, and on the oxygen-side connection pipes between the oxygen heat exchanger and the oxygen scrubbing tower; and the temperature detectors are connected to the cooling system controlling the hydrogen and oxygen heat exchangers.
[0008] A further feature is that when the threshold range of the liquid level deviation between the hydrogen separator and the oxygen separator is within ±50mm, the opening of the hydrogen outlet pipe or the oxygen outlet pipe is adjusted to balance the liquid level; when the threshold range of the liquid level deviation between the hydrogen separator and the oxygen separator exceeds ±50mm, the nitrogen valve is opened to stabilize the liquid level. When the temperature detector detects an increase in the gas outlet temperature, it increases the opening of the cooling water regulating valve in the cooling system, thereby increasing the flow rate of cooling water and thus reducing the gas outlet temperature of the hydrogen heat exchanger and the oxygen heat exchanger.
[0009] By adopting this invention, nitrogen can be introduced through a nitrogen-filling valve to regulate the liquid level balance of the hydrogen separator and oxygen separator. This allows the gas-liquid treatment system to effectively regulate and control the liquid level balance of the hydrogen separator and oxygen separator throughout the entire process, avoiding extreme conditions and effectively improving system stability. Furthermore, temperature control is added. By detecting the gas temperature with a temperature detector, the cooling water flow rate of the cooling system can be controlled, resulting in a lower and more stable gas outlet temperature compared to existing processes. This reduces the alkaline content in the outlet gas, increases gas purity, and ensures stable operation of the water electrolysis hydrogen production equipment under a wide load fluctuation range, thus broadening the applicability of the water electrolysis hydrogen production equipment. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the system of the present invention. Detailed Implementation
[0011] See Figure 1 As shown, it includes an electrolytic cell 1, a nitrogen source 2, a cooling water regulating valve 3, a hydrogen separator 4, an oxygen separator 5, a hydrogen heat exchanger 6, an oxygen heat exchanger 7, a hydrogen scrubber 8, an oxygen scrubber 9, a hydrogen-side regulating valve 10, an oxygen-side regulating valve 11, a hydrogen-side nitrogen charging valve 12, an oxygen-side nitrogen charging valve 13, a hydrogen-side temperature detector 14, and an oxygen-side temperature detector 15.
[0012] Hydrogen separator 4 and oxygen separator 5 are connected in parallel to electrolyzer 1. The outlet of hydrogen separator 4 is connected to hydrogen heat exchanger 6, and the outlet of oxygen separator 5 is connected to oxygen heat exchanger 7. The gas outlet of hydrogen heat exchanger 6 is connected to hydrogen scrubber 8, and the gas outlet of oxygen heat exchanger 7 is connected to oxygen scrubber 9. A hydrogen-side regulating valve 10 is installed on the hydrogen outlet pipe of hydrogen scrubber 8, and an oxygen-side regulating valve 11 is installed on the oxygen outlet pipe of oxygen scrubber 9. A cooling water regulating valve 3 is installed on the cooling water inlet pipe from the utility system. The outlet of cooling water regulating valve 3 is divided into two paths, which enter hydrogen heat exchanger 6 and oxygen heat exchanger 7 respectively. The cooling water outlet pipes of hydrogen heat exchanger 6 and oxygen heat exchanger 7 are merged and flow back to the utility system. Nitrogen from nitrogen source 2 is divided into two paths, which enter hydrogen separator 4 and oxygen separator 5 through hydrogen-side nitrogen charging valve 12 and oxygen-side nitrogen charging valve 13 respectively. A hydrogen-side temperature detector 14 is installed on the connecting pipe between the hydrogen heat exchanger 6 and the hydrogen scrubber 8, and an oxygen-side temperature detector 15 is installed on the connecting pipe between the oxygen heat exchanger 7 and the oxygen scrubber 9.
[0013] In electrolytic cell 1, the alkaline solution is electrolyzed to generate hydrogen and oxygen, which then enter hydrogen separator 4 and oxygen separator 5, respectively, to separate the gases from the alkaline solution. The separated hydrogen and oxygen then enter hydrogen heat exchanger 6 and oxygen heat exchanger 7, respectively, to cool the gases to 50°C. The cooled hydrogen and oxygen then enter hydrogen scrubber 8 and oxygen scrubber 9, respectively, to clean the alkaline solution from the gases and further cool them, ensuring the quality of the outlet gas.
[0014] Operating Condition 1: The threshold range of the liquid level difference between hydrogen separator 4 and oxygen separator 5 fluctuates within ±50mm. When the liquid level of hydrogen separator 4 is higher than that of oxygen separator 5, the opening of hydrogen-side regulating valve 10 is reduced; when the liquid level of hydrogen separator 4 is lower than that of oxygen separator 5, the opening of hydrogen-side regulating valve 10 is increased to control the liquid level balance of the separators.
[0015] Operating Condition 2: The threshold range of the liquid level difference between hydrogen separator 4 and oxygen separator 5 exceeds ±50mm. When the liquid level in hydrogen separator 4 is higher than that in oxygen separator 5, open the nitrogen charging valve 12 on the hydrogen side until the liquid level is balanced; when the liquid level in hydrogen separator 4 is lower than that in oxygen separator 5, open the nitrogen charging valve 13 on the oxygen side until the liquid level is balanced. This achieves effective regulation of the liquid level difference between hydrogen separator 4 and oxygen separator 5 throughout the entire process, ensuring stable and efficient system operation.
[0016] Operating Condition 3: When hydrogen-side temperature detector 14 and oxygen-side temperature detector 15 detect that the outlet temperatures of hydrogen and oxygen at hydrogen heat exchanger 6 and oxygen heat exchanger 7 are respectively higher than the set value of 50°C, the opening of cooling water regulating valve 3 is increased until the gas temperature drops to 50°C. If the outlet temperatures of hydrogen heat exchanger 6 and oxygen heat exchanger 7 are lower than the set value of 50°C, the opening of cooling water regulating valve 3 is decreased until the gas temperature returns to 50°C, saving cooling water consumption. Conversely, if the load on the gas-liquid processing system increases, the cooling capacity required to lower the gas to the set temperature also increases accordingly, thus requiring an increase in the opening of cooling water regulating valve 3; conversely, the opening of cooling water regulating valve 3 is decreased. However, the load on the gas-liquid processing system can be reflected in hydrogen-side temperature detector 14 and oxygen-side temperature detector 15, thus ensuring that the gas-liquid processing system can operate stably under a wide load fluctuation range, effectively reducing the outlet temperatures of hydrogen and oxygen at hydrogen heat exchanger 6 and oxygen heat exchanger 7, respectively.
[0017] The formula for calculating the area of a heat exchanger is as follows: Q=W 气 c p气 ΔT 气 = W 水 c p水 ΔT 水 = KSΔT m It can be seen that if the outlet temperature of the gas in the heat exchanger is reduced, the temperature difference ΔT of the gas needs to be increased. 气 At gas flow rate W 气 Under certain conditions, the heat exchange rate Q increases. If the cooling water temperature difference ΔT 水 If it remains unchanged, then the cooling water flow rate W needs to be increased. 水 The heat exchange area S of the heat exchangers is used to meet the heat exchange requirements for gas cooling. In a conventional gas-liquid processing system, the temperature is approximately 65°C. To lower the gas outlet temperature of the gas-liquid processor, a temperature detector is added to the gas outlets of both the hydrogen and oxygen heat exchangers, controlling the cooling water regulating valves. If the temperature detector detects an increase in the gas outlet temperature, the control system increases the opening of the cooling water regulating valve, increasing the cooling water flow rate and thus lowering the gas outlet temperature of the hydrogen and oxygen heat exchangers. Simultaneously, the heat exchange area of the hydrogen and oxygen heat exchangers is increased, resulting in a hydrogen outlet temperature of approximately 50°C, a reduction of about 15°C compared to the original process. Under this temperature difference, the alkali content in every 1000 standard cubic meters of hydrogen is reduced by approximately 1.33 kg / h, effectively reducing the alkali content in the gas outlet gas of the gas-liquid processing module. The presence of temperature detectors and cooling water regulating valves allows the gas temperature at the outlets of the hydrogen cooler and oxygen cooler to be stabilized at the set value, thus enabling more accurate and efficient control of the gas temperature. This makes the system more flexible and adjustable, and better adaptable to fluctuations.
Claims
1. A gas-liquid processing system capable of stable operation under a wide load fluctuation range, comprising an electrolytic cell, the outlet of which is connected to a hydrogen separator and an oxygen separator arranged in parallel; the outlet of the hydrogen separator is connected to the inlet of a hydrogen heat exchanger; the outlet of the oxygen separator is connected to the inlet of an oxygen heat exchanger; the inlet of the hydrogen heat exchanger is connected to a hydrogen scrubbing tower; the outlet of the hydrogen scrubbing tower is connected to a hydrogen outlet pipe; the inlet of the oxygen heat exchanger is connected to an oxygen scrubbing tower; and the outlet of the oxygen scrubbing tower is connected to an oxygen outlet pipe, characterized in that... The hydrogen separator and the oxygen separator are each equipped with a level gauge. Both the hydrogen separator and the oxygen separator are connected to a nitrogen filling pipe. The nitrogen filling pipe is equipped with a nitrogen filling valve and connected to a nitrogen source. Temperature detectors are installed on the hydrogen side connection pipe between the hydrogen heat exchanger and the hydrogen scrubber, and on the oxygen side connection pipe between the oxygen heat exchanger and the oxygen scrubber. The temperature detectors are connected to the cooling system that controls the hydrogen heat exchanger and the oxygen heat exchanger.
2. The gas-liquid processing system according to claim 1, which can operate stably under a wide load fluctuation range, is characterized in that, When the liquid level deviation between the hydrogen separator and the oxygen separator is within ±50mm, adjust the opening of the hydrogen outlet pipe or the oxygen outlet pipe to balance the liquid level; when the liquid level deviation between the hydrogen separator and the oxygen separator exceeds ±50mm, open the nitrogen valve to stabilize the liquid level.
3. The gas-liquid processing system according to claim 1, which can operate stably under a wide load fluctuation range, is characterized in that, When the temperature detector detects an increase in the gas outlet temperature, it increases the opening of the cooling water regulating valve in the cooling system, thereby increasing the flow rate of cooling water and thus reducing the gas outlet temperature of the hydrogen heat exchanger and the oxygen heat exchanger.