A hydrogen purification device for a steam turbine generator sealing oil system

Abstract

This utility model discloses a hydrogen purification device for a steam turbine generator sealing oil system, relating to the field of hydrogen purification technology. It includes a feed gas buffer tank and a desorbed gas treatment unit. The inlet of the feed gas buffer tank is connected to the generator hydrogen pipeline network, and the outlet of the feed gas buffer tank is connected to a feed gas pretreatment unit. The outlet of the feed gas pretreatment unit is connected to a PSA core purification unit, which is connected to a product hydrogen treatment unit. The desorbed gas treatment unit is connected to the PSA core purification unit. A feed gas regulating valve is installed on the pipeline connecting the feed gas buffer tank outlet to the feed gas pretreatment unit. The feed gas pretreatment unit includes a cyclone separator, a precision filter, and an adsorption dryer. By improving the pretreatment process, the damage of impurities to the adsorbent and the system is fundamentally reduced. The PSA circulation parameters are dynamically adjusted according to operating conditions to match feed gas fluctuations. A full-parameter monitoring system is established to provide early warning of faults and prevent problems from escalating.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen purification technology, specifically a hydrogen purification device for a steam turbine generator sealing oil system. Background Technology

[0002] Hydrogen is widely used as a cooling medium in steam turbine generator operation, and its purity directly affects the generator's cooling efficiency, operational safety, and equipment lifespan. Although the sealing oil system can prevent hydrogen leakage, the purity of hydrogen can still decrease due to moisture and air infiltration in the oil. The hydrogen purification unit is the core equipment used to remove impurities (mainly air, moisture, and oil vapor) from hydrogen and maintain high hydrogen purity (usually requiring ≥98% or higher). The adsorbent is the "heart" of the PSA unit, and its performance directly determines the purification efficiency. Common problems include decreased adsorption capacity, poisoning, and pulverization, which are the main reasons for substandard hydrogen purity and reduced recovery rate. The PSA unit relies on "pressure changes" to achieve adsorption and desorption. Abnormal fluctuations in pressure or flow rate will directly disrupt the cycle rhythm, leading to substandard purity or increased energy consumption. Utility Model Content

[0003] To address the above problems, this utility model provides a hydrogen purification device for a steam turbine generator sealing oil system, thus solving the aforementioned issues.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a hydrogen purification device for a steam turbine generator sealing oil system, comprising a raw material gas buffer tank and a desorption gas treatment unit. The inlet of the raw material gas buffer tank is connected to the generator hydrogen pipeline network, the outlet of the raw material gas buffer tank is connected to the raw material gas pretreatment unit, the outlet of the raw material gas pretreatment unit is connected to a PSA core purification unit, the PSA core purification unit is connected to a product hydrogen treatment unit, and the desorption gas treatment unit is connected to the PSA core purification unit.

[0005] Preferably, a raw gas regulating valve is installed on the pipeline connecting the outlet of the raw gas buffer tank to the raw gas pretreatment unit, and the raw gas pretreatment unit includes a cyclone separator, a precision filter, and an adsorption dryer.

[0006] Preferably, the PSA core purification unit includes a first adsorption tower and a second adsorption tower. Both the first and second adsorption towers are equipped with an inlet valve, an outlet valve, a desorption valve, a flushing valve, and a pressure equalization valve. The pressure equalization valve is used to connect the first and second adsorption towers. The first and second adsorption towers are filled with a mixed adsorbent of 13X molecular sieve and activated carbon.

[0007] Preferably, the product hydrogen processing unit includes a product hydrogen buffer tank, the outlet of which is connected to a generator hydrogen reuse pipeline, and an online hydrogen purity analyzer and a product hydrogen pressure regulating valve are installed between the outlet of the product hydrogen buffer tank and the generator hydrogen reuse pipeline.

[0008] Preferably, the desorption gas treatment unit includes a desorption gas buffer tank, which is connected to the first adsorption tower and the second adsorption tower of the PSA core purification unit, and the desorption gas buffer tank is equipped with a flare fuel gas interface and a vacuum pump.

[0009] Preferably, both the first adsorption tower and the second adsorption tower are equipped with hydrogen leak detectors.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. Strengthen the pretreatment of raw gas to ensure that the impurity content is lower than the adsorbent tolerance threshold, such as sulfur <0.1ppm and heavy hydrocarbons <50ppm; optimize the airflow distribution: install an airflow distributor at the inlet of the adsorption tower to avoid high-speed airflow directly scouring the adsorbent bed; control the bed temperature: the adsorption temperature should not exceed 40℃ to avoid a decrease in adsorption capacity, and the regeneration temperature should not exceed the upper limit of the adsorbent tolerance, such as molecular sieve ≤200℃ and activated carbon ≤150℃.

[0011] 2. Reduce desorption pressure: Reduce the desorption pressure to 0.02-0.05 MPa absolute pressure to enhance the driving force for impurity desorption; Increase the proportion of flushing gas: Use 10%-15% of product hydrogen to backwash the bed to remove residual impurities; Extend regeneration time: While ensuring the throughput of the unit, extend the regeneration step time by 5%-10%, such as from 60s to 65s.

[0012] 3. When the adsorption capacity of the adsorbent decreases by more than 30%, such as when the hydrogen purity of the product drops from 99.99% to 99.9% or the bed pressure drop increases by more than 50%, the adsorbent needs to be replaced. When replacing, thoroughly clean the residual powder in the tower, purge with compressed air and wash with water to avoid contamination by the new adsorbent. Prioritize the use of anti-poisoning adsorbents, such as modified molecular sieves and sulfur-resistant activated carbon, to suit the working conditions of high-impurity feed gas.

[0013] 4. Add buffer facilities: Install a 10-20m³ raw gas buffer tank (100) at the PSA inlet to alleviate pressure fluctuations; Install pressure stabilizing valve / flow stabilizing valve: Install a self-regulating pressure stabilizing valve on the raw gas inlet pipeline to control pressure fluctuations ≤±0.05MPa and a mass flow controller to control flow fluctuations ≤±3%; Link upstream devices: Establish load interlock with upstream devices. When the upstream load changes by more than 10%, adjust the PSA processing capacity in advance, such as reducing the load by 5%, to avoid shock.

[0014] 5. Dynamically adjust adsorption time: The adsorption time is automatically adjusted by the PLC system according to the impurity content and flow rate of the feed gas. For example, if the feed gas flow rate increases by 10%, the adsorption time is extended by 8%. Optimize pressure equalization steps: Increase the number of pressure equalization steps, such as from 2 to 3, and slow down the pressure equalization speed, such as increasing the pressure equalization time from 10s to 15s, to avoid sudden changes in bed pressure. Adopt "multi-tower circulation": If the device is a PSA with 4 or more towers, adopt the "two-tower adsorption, two-tower regeneration" mode to reduce the load fluctuation of a single tower. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] The diagram is labeled as follows: 100, Raw material gas buffer tank; 200, Raw material gas pretreatment unit; 300, PSA core purification unit; 400, Product hydrogen treatment unit; 500, Desorbed gas treatment unit; 600, Control system; 700, Generator hydrogen pipeline. Detailed Implementation

[0017] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model.

[0018] Please see Figure 1 A hydrogen purification device for a steam turbine generator sealing oil system includes a raw gas buffer tank 100, a desorption gas treatment unit 500, and a control system 600. The inlet of the raw gas buffer tank 100 is connected to the generator hydrogen pipeline network 700. The raw gas buffer tank 100 is used to stabilize the upstream gas pressure, such as in a steam turbine generator hydrogen system, and to alleviate pressure fluctuations. It has a volume of 10-20 m³. The outlet of the raw gas buffer tank 100 is connected to a raw gas pretreatment unit 200. The raw gas pretreatment unit 200 includes a cyclone separator, a precision filter, and an adsorption dryer. The raw gas pretreatment unit 200 removes oil mist, dust, and moisture from the raw gas through a three-stage treatment process. A cyclone separator, a precision filter, and an adsorption dryer are connected in series. The cyclone separator removes dust / oil droplets with a diameter ≥10μm. The precision filter uses a 1-5μm filter element to remove fine oil mist. The adsorption dryer uses alumina / molecular sieves to reduce the dew point to below -40℃. A raw material gas regulating valve is installed on the pipeline connecting the outlet of the raw material gas buffer tank 100 to the raw material gas pretreatment unit 200. The raw material gas regulating valve is V1. The control system 600 includes a PLC control cabinet with a touch screen, which connects to all programmable valves and sensors (pressure, temperature, purity) to achieve cyclic timing control (e.g., adsorption 180s → pressure equalization 30s → desorption 150s → rinsing 30s).

[0019] Please see Figure 1The outlet of the raw gas pretreatment unit 200 is connected to the PSA core purification unit 300. The PSA core purification unit 300 includes a first adsorption tower and a second adsorption tower. Both the first and second adsorption towers are equipped with an inlet valve, an outlet valve, a desorption valve, a flushing valve, and a pressure equalization valve. The pressure equalization valve is used to connect the first and second adsorption towers. The first and second adsorption towers are filled with a mixed adsorbent of 13X molecular sieve and activated carbon. In order to distinguish the inlet valve, outlet valve, desorption valve, flushing valve, and pressure equalization valve on the first and second adsorption towers, the first adsorption tower has an inlet valve V2, an outlet valve V3, a desorption valve V4, a flushing valve V9, and a pressure equalization valve V5, and the second adsorption tower has an inlet valve V6, an outlet valve V7, a desorption valve V8, and a flushing valve V11. The first and second adsorption towers work alternately and cyclically. One tower adsorbs and produces hydrogen, while the other tower regenerates and restores its adsorption capacity. The PLC controls the timing switching of the programmable valves to achieve continuous hydrogen production. The standard cycle time is 360 seconds, which can be adjusted according to the purity of the raw gas. The operation of the first and second adsorption towers is divided into four stages: Phase 1: Adsorption in the first adsorption tower, regeneration in the second adsorption tower, 180 seconds; The first adsorption tower is an adsorption tower: airflow direction: the raw gas passes through the raw gas pretreatment unit 200 → the inlet valve V2 is opened → the bottom of the first adsorption tower → flows upward through the adsorbent layer, impurities are adsorbed → pure hydrogen from the top of the first adsorption tower → the outlet valve V3 is opened → the product hydrogen buffer tank; the pressure inside the first adsorption tower is maintained at 0.8~1.2MPa adsorption pressure, and the adsorbent is in a stable state before "saturation adsorption".

[0020] The second adsorption tower is a regeneration tower: airflow direction: impurities adsorbed in the second adsorption tower need to be desorbed → first open the desorption valve V8 → the pressure inside the second adsorption tower drops to 0.02~0.05MPa absolute pressure, vacuum desorption → impurities are discharged into the desorption gas unit with the airflow; at the same time, the flushing valve V11 is opened → a small amount of pure hydrogen, about 5%~10% of product hydrogen, flows back into the second adsorption tower to flush away residual impurities and enhance regeneration; the temperature inside the second adsorption tower drops slightly due to the endothermic effect of desorption, which needs to be monitored by a temperature sensor to avoid excessively low temperatures that could cause moisture condensation; Phase 2: Equalization, 30 seconds; Reduce pressure fluctuations to protect valves and recover high-pressure pure hydrogen to increase yield; Valve status: The inlet valve V2 and outlet valve V3 of the first adsorption tower, and the desorption valve V8 and flushing valve V11 of the second adsorption tower are all closed → the pressure equalization valve V5 is opened; Airflow direction: Pure hydrogen in the first adsorption tower (high pressure, 0.8~1.2MPa) → pressure equalization valve V5 → second adsorption tower (low pressure, 0.02~0.05MPa) → pressure of the first and second adsorption towers is balanced to 0.4~0.6MPa; Phase 3: Adsorption in the second adsorption tower, regeneration in the first adsorption tower, 150 seconds; The second adsorption tower is an adsorption tower with the following airflow direction: raw material gas → open inlet valve V6 → bottom of the second adsorption tower → adsorbent layer (adsorbing impurities) → pure hydrogen → open outlet valve V7 → product hydrogen buffer tank; key conditions: consistent with the adsorption stage of the first adsorption tower, maintaining an adsorption pressure of 0.8~1.2MPa to ensure stable purity of product hydrogen.

[0021] The first adsorption tower is a regeneration tower: airflow direction: open desorption valve V4 → the pressure of the first adsorption tower drops to 0.02~0.05MPa → impurities are discharged; at the same time, open flushing valve V9 → a small amount of pure hydrogen backwashes the first adsorption tower; key state: after regeneration, the adsorbent in the first adsorption tower restores its adsorption capacity, preparing for the next round of adsorption.

[0022] Phase 4: Secondary pressure equalization, optional, 30 seconds; If the raw gas has a high impurity content, such as a hydrogen purity of <90%, a "secondary pressure equalization" process can be added: close the inlet valve V6 and outlet valve V7 of the second adsorption tower and the desorption valve V4 and flushing valve V9 of the first adsorption tower → open the pressure equalization valve V5 → high-pressure pure hydrogen from the second adsorption tower flows into the first adsorption tower → after pressure balance, the next cycle of "adsorption in the first adsorption tower and regeneration in the second adsorption tower" begins; this further improves the pure hydrogen recovery rate from 85%~90% to 92%~95%.

[0023] Please see Figure 1 The PSA core purification unit 300 is connected to a product hydrogen processing unit 400. The product hydrogen processing unit 400 includes a product hydrogen buffer tank. The outlet of the product hydrogen buffer tank is connected to a generator hydrogen reuse pipeline. An online hydrogen purity analyzer and a product hydrogen pressure regulating valve are installed between the outlet of the product hydrogen buffer tank and the generator hydrogen reuse pipeline. The purity is monitored in real time, and the threshold of the online hydrogen purity analyzer is ≥99.9%. The product hydrogen pressure regulating valve is a V10 type, controlling the outlet pressure to match the generator hydrogen pressure. The desorbed gas processing unit 500 is connected to the PSA core purification unit 300. The processing unit 500 includes a desorption gas buffer tank, which is connected to the first adsorption tower and the second adsorption tower of the PSA core purification unit 300. The desorption gas buffer tank is equipped with a flare fuel gas interface and a vacuum pump. The desorption gas buffer tank collects N2, O2, etc. desorbed from the first adsorption tower or the second adsorption tower. If the hydrogen content of the desorption gas is ≥5%, the flare fuel gas interface can be connected to the fuel gas pipeline; otherwise, it is vented through flare combustion. If vacuum desorption is performed, the vacuum pump reduces the desorption pressure to 0.02-0.05 MPa absolute pressure. Both the first adsorption tower and the second adsorption tower are equipped with hydrogen leak detectors.

[0024] Furthermore, 50mm ceramic balls are laid at the bottom of the first and second adsorption towers, adsorbent is loaded in the middle, and 20mm wire mesh is laid at the top; adsorbent replacement interfaces with flange covers are added next to the first and second adsorption towers, and they are replaced every 3-5 years. The PSA core purification unit 300 needs to be used in conjunction with the raw gas pretreatment unit 200 to remove oil and water and prevent adsorbent poisoning; a bed temperature sensor is added at the outlet of the second adsorption tower to monitor the regeneration temperature and avoid exceeding 200°C.

[0025] Add a self-regulating pressure valve next to the raw gas regulating valve of the first adsorption tower, with pressure fluctuation ≤ ±0.05MPa”; add a pressure transmitter to the top of the raw gas buffer tank 100, connect it to the PLC, and set up an overpressure alarm. Corresponding to raw material gas buffer tank 100 and control system 600; add mass flow controller to raw material gas pipeline, flow fluctuation ≤±3%, and adjust adsorption time in conjunction with PLC; Add a valve position feedback sensor next to each programmable valve, and trigger an alarm with a switching delay of ≤0.1s; add a redundant PLC module next to the PLC control cabinet, with dual PLC redundancy to avoid program loss. Corresponding to PSA core purification unit 300 and control system 600; add a gas source filter with 5μm precision to the valve gas source pipeline, and clean it every 3 months; The feed gas pretreatment unit 200 is refined into three-stage filtration: a cyclone separator to remove impurities ≥10μm, a precision filter with a 1μm filter element, pressure difference checked every week, dryer dew point ≤-40℃, and adsorbent replaced every 3 months. Corresponding to the raw gas pretreatment unit 200; add a dew point meter at the dryer outlet, connect to PLC, and trigger an alarm if the value exceeds the limit; add an oil content detector at the precision filter outlet, with an oil content ≤0.1mg / m³.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hydrogen purification device for a steam turbine generator sealing oil system, characterized in that: It includes a raw gas buffer tank (100) and a desorption gas treatment unit (500). The inlet of the raw gas buffer tank (100) is connected to the generator hydrogen pipeline (700), and the outlet of the raw gas buffer tank (100) is connected to the raw gas pretreatment unit (200). The outlet of the raw gas pretreatment unit (200) is connected to the PSA core purification unit (300). The PSA core purification unit (300) is connected to the product hydrogen treatment unit (400). The desorption gas treatment unit (500) is connected to the PSA core purification unit (300).

2. The hydrogen purification device for a steam turbine generator sealing oil system according to claim 1, characterized in that: A raw material gas regulating valve is installed on the pipeline connecting the outlet of the raw material gas buffer tank (100) to the raw material gas pretreatment unit (200). The raw material gas pretreatment unit (200) includes a cyclone separator, a precision filter, and an adsorption dryer.

3. The hydrogen purification device for a steam turbine generator sealing oil system according to claim 1, characterized in that: The PSA core purification unit (300) includes a first adsorption tower and a second adsorption tower. Both the first adsorption tower and the second adsorption tower are equipped with an inlet valve, an outlet valve, a desorption valve, a flushing valve, and a pressure equalization valve. The pressure equalization valve is used to connect the first adsorption tower and the second adsorption tower. The first adsorption tower and the second adsorption tower are filled with a mixed adsorbent of 13X molecular sieve and activated carbon.

4. The hydrogen purification device for a steam turbine generator sealing oil system according to claim 1, characterized in that: The product hydrogen processing unit (400) includes a product hydrogen buffer tank, the outlet of which is connected to a generator hydrogen recycling pipeline, and an online hydrogen purity analyzer and a product hydrogen pressure regulating valve are installed between the outlet of the product hydrogen buffer tank and the generator hydrogen recycling pipeline.

5. The hydrogen purification device for a steam turbine generator sealing oil system according to claim 1, characterized in that: The desorption gas processing unit (500) includes a desorption gas buffer tank, which is connected to the first adsorption tower and the second adsorption tower of the PSA core purification unit (300). The desorption gas buffer tank is equipped with a flare fuel gas interface and a vacuum pump.

6. The hydrogen purification device for a steam turbine generator sealing oil system according to claim 3, characterized in that: Both the first and second adsorption towers are equipped with hydrogen leak detectors.

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