Hydrodesulfurization Unit Temperature Control for Fuel Cell Hydrogen Generators
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Solution Overview
Problem
The hydrodesulfurization unit in fuel cell systems experiences temperature fluctuations due to ambient temperature changes and catalytic degradation, leading to degraded desulfurization performance, which can result in the need to replace the entire hydrogen generator.
Innovation Solution
A hydrogen generator system that includes a hydrodesulfurization unit with a temperature control mechanism, using a desulfurization temperature detector and a controller to adjust the flow rate of air through a cooling passage to maintain the hydrodesulfurization unit within a proper temperature range, preventing overheating or overheating-related degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the hydrodesulfurization unit operates at high temperature to maintain desulfurization performance, then the desulfurization activity is improved, but the catalyst undergoes thermal degradation and sulfur accumulates on the adsorbent
Solution Approach 1:
The patent implements dynamic temperature control by adjusting the flow rate of cooling medium through the cooling passage based on detected temperature values. The control unit varies the cooling medium flow to maintain the hydrodesulfurization unit within the optimal temperature range of 200-300°C, preventing both thermal degradation and sulfur accumulation while ensuring continuous desulfurization performance.
Solution Approach 2:
The patent employs a feedback control mechanism where a temperature detector continuously monitors the temperature of the hydrodesulfurization unit and transmits this information to the control unit. The control unit processes this feedback and adjusts the cooling medium flow rate accordingly, creating a closed-loop control system that maintains stable operating conditions and prevents temperature-related degradation.
2Stability of the object's composition
If the hydrodesulfurization unit operates at low temperature to prevent thermal degradation, then catalyst stability is improved, but desulfurization activity decreases and sulfur compounds accumulate
Solution Approach 1:
The system dynamically adjusts the cooling medium flow rate to maintain the hydrodesulfurization unit within the optimal temperature range of 200-300°C. By preventing both excessive heat accumulation and unnecessary cooling, the system ensures catalyst stability while maintaining sufficient desulfurization activity through precise temperature control.
Solution Approach 2:
The patent controls the temperature parameter within the specific range of 200-300°C, which is the optimal range for balancing catalyst stability and desulfurization activity. This parameter control prevents thermal degradation while avoiding temperature drops that would reduce desulfurization performance or cause sulfur accumulation on the adsorbent.
3Ease of operation
If ambient temperature increases, then system operation is simplified, but the hydrodesulfurization unit temperature rises outside the proper range causing performance degradation
Solution Approach 1:
The patent implements preliminary anti-action by providing a cooling passage and cooling medium flow mechanism that counteracts the effect of ambient temperature increases. When the ambient temperature rises and threatens to push the unit temperature outside the proper range, the cooling system activates to prevent temperature excursions, thereby maintaining desulfurization performance without requiring manual intervention.
4Productivity
If reforming catalyst degradation increases hydrogen supply demand, then hydrogen production is improved, but the increased gas flow rate raises hydrodesulfurization unit temperature outside proper range
Solution Approach 1:
The feedback control mechanism monitors the temperature of the hydrodesulfurization unit and adjusts the cooling medium flow rate in response to temperature changes caused by increased gas flow. When reforming catalyst degradation requires higher hydrogen supply and consequently increases gas flow rate through the unit, the temperature detector detects the resulting temperature rise and the control unit increases cooling to maintain proper operating temperature.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively maintains the hydrodesulfurization unit at a stable temperature, suppressing performance degradation and reducing the need for frequent replacements of the hydrogen generator.
Implementation Method 1
a cooling passage through which at least a part of the air supplied from the air supply unit to the combustor flows, to cool the hydrodesulfurization unit
Implementation Method 2
a hydrodesulfurization unit which removes a sulfur component from the raw material through a hydrogenation reaction
Implementation Method 3
the generated hydrogen sulfide is adsorbed onto an adsorbent to be removed
Data Source
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AI summary
A hydrogen generator of the present invention comprises a reformer (9), a raw material supply unit (2) which supplies a raw material to the reformer (9), a combustor (10) which heats the reformer (9), an air supply unit (13) which supplies air to the combustor (10), a hydrodesulfurization unit (3) which removes a sulfur component from the raw material through a hydrogenation reaction, a heater which heats the hydrodesulfurization unit (3), a desulfurization temperature detector which detects a temperature of the hydrodesulfurization unit (3), a cooling passage (24) through which at least a part of the air supplied from the air supply unit (13) to the combustor (10) flows, to cool the hydrodesulfurization unit (3), and a controller (29) configured to perform control to cause a flow rate of the air supplied to the cooling passage (24) to be higher, when the temperature detected by the desulfurization temperature detector is higher a preset first temperature threshold than when the temperature is equal to or lower than the first temperature threshold.