The precise hydrogen supply control system of the hydrogen-rich gas boiler is the core of ensuring its efficient and safe operation. It achieves precise control of hydrogen flow rate, pressure, and mixing ratio through multi-dimensional technology collaboration. Based on a sensor network, this system combines intelligent algorithms and actuators to form a closed-loop control system, ensuring dynamic matching between hydrogen supply and boiler load.
Hydrogen flow control is the primary step in precise supply. The hydrogen-rich gas boiler employs a high-precision mass flow controller, whose core component is a thermal or Coriolis flow sensor. This sensor monitors hydrogen mass flow rate in real time and dynamically adjusts the opening of a PID control valve. When the boiler load changes, the control system quickly corrects the hydrogen flow rate setpoint based on steam pressure or temperature signals. For example, when the load increases, the system synchronously increases the hydrogen supply while simultaneously using feedforward control to predict fuel demand and avoid combustion fluctuations caused by delays. Furthermore, the flow controller incorporates temperature and pressure compensation algorithms to eliminate the influence of environmental factors on metering accuracy, ensuring that the deviation between the hydrogen supply and the theoretical value is kept within a minimal range.
Stable control of hydrogen pressure is equally crucial. The hydrogen-rich gas boiler's gas supply system is equipped with a multi-stage pressure regulating device, including an inlet filter pressure regulating valve, a safety shut-off valve, and an outlet proportional regulating valve. The pressure regulating valve maintains a constant hydrogen inlet pressure through a spring-diaphragm structure, preventing fluctuations in gas source pressure from affecting combustion stability. The safety shut-off valve employs a dual-valve series design; when the pressure exceeds a safety threshold, both the main and auxiliary valves close simultaneously, cutting off the hydrogen supply. The proportional regulating valve dynamically adjusts the outlet pressure according to the boiler load, ensuring that the hydrogen and air mix at the optimal dynamic pressure ratio. For example, under low-load conditions, the system reduces the hydrogen pressure to minimize the risk of backfire, while simultaneously adjusting the air supply through air pressure linkage to maintain combustion efficiency.
The hydrogen-air mixing ratio directly affects combustion completeness. The hydrogen-rich gas boiler uses premixed combustion technology, achieving efficient mixing of the gas and liquid phases through a swirl-type or Venturi mixer. The mixer is equipped with guide vanes or retractable nozzles to ensure that hydrogen and air form a uniform premixed gas before entering the combustion chamber. The control system adjusts the ratio of hydrogen and air flow rates in real time based on these signals to ensure the hydrogen concentration in the mixture remains within a safe combustion range. For example, when the hydrogen concentration approaches the lower explosive limit, the system automatically increases the air supply to dilute the mixture; when the concentration is too low, it reduces the air supply to maintain combustion intensity. Furthermore, some boilers are equipped with laser-induced fluorescence or infrared absorption spectroscopy analyzers to monitor the mixture composition online, providing feedback for the control system to make corrections.
Dynamic optimization of the combustion process relies on intelligent algorithms. The control system of the hydrogen-rich gas boiler integrates a PLC or DCS platform, achieving multi-variable coordinated regulation through model predictive control algorithms. Based on the boiler's thermodynamic model and combined with historical operating data, the algorithm predicts the hydrogen supply demand under different loads and generates optimal control commands. For example, under variable load conditions, the system adjusts the hydrogen flow rate and air ratio in advance to avoid efficiency reduction or excessive emissions caused by combustion fluctuations. Simultaneously, the control system has a built-in fault diagnosis module that monitors sensor signals, actuator status, and combustion parameters in real time. When an anomaly is detected, it automatically triggers protection mechanisms, such as emergency shutdown and nitrogen purging, to ensure equipment safety.
A robust safety protection system ensures precise hydrogen supply. The hydrogen pipeline of the hydrogen-rich gas boiler is equipped with multiple safety devices, including a hydrogen leak detector, pressure switch, and flame detector. The leak detector uses electrochemical or semiconductor sensors to detect even extremely low concentrations of hydrogen leakage. When the concentration exceeds a set value, the hydrogen supply is immediately cut off and an alarm is triggered. The pressure switch provides both high-pressure and low-pressure protection; high pressure prevents overpressure in the pipeline, while low pressure prevents backfire. The flame detector monitors the combustion status using ultraviolet or infrared sensors. When the flame extinguishes, the hydrogen valve is automatically closed, and a nitrogen purging procedure is executed to remove residual hydrogen from the pipeline.
The precise hydrogen supply control system of the hydrogen-rich gas boiler achieves high efficiency, stability, and safety in hydrogen supply through dynamic regulation of flow rate, pressure, and ratio, combined with intelligent algorithms and safety protection measures. This provides reliable technical support for the industrial application of hydrogen-rich gas boilers.
