Coffee machine with dynamic flow and temperature control

The patent extracts the temperature maintenance function from a large boiler system and implements it through a smaller boiler combined with PID control and preheating elements. The temperature control function is separated from the water storage function, allowing a compact boiler design that maintains temperature stability through active control rather than thermal mass.

The patent changes the temperature control parameters from粗放式 (coarse) thermostat control to precise PID control with setpoints optimized for different brewing types. This allows a smaller boiler to achieve the same temperature stability as a larger boiler would provide through thermal mass alone.

The patent transitions from a static fixed-pressure pump system to a dynamic pump control system that adjusts pressure and flow rate based on real-time brewing parameters. The pump speed and pressure are dynamically adjusted during the brewing process to maintain optimal flow rates through the coffee puck, enabling precise control while managing complexity through electronic control.

The patent implements feedback control where flow rate sensors monitor the actual flow through the coffee puck and feed this information back to the pump controller. This closed-loop control allows the system to automatically adjust pump output to maintain precise flow rates, compensating for variations in coffee puck resistance without requiring complex mechanical pressure regulation.

The patent replaces mechanical thermostat control with electronic PID temperature control. The mechanical bimetallic strip or mercury switch of traditional thermostats is substituted with electronic temperature sensors and microcontroller-based PID algorithms, enabling precise temperature regulation while managing complexity through integrated control circuits.

The patent implements preheating elements that prepare the water and brewing components to the target temperature before the main brewing cycle begins. This preliminary heating action reduces the temperature control burden on the main heating element during brewing, allowing more precise temperature maintenance with a simpler control system.

The patent implements periodic flushing cycles where water is circulated through the boiler and heating elements at intervals to prevent scale buildup. The system alternates between brewing cycles and maintenance flushing cycles, reducing chemical deposition while maintaining brewing efficiency. This periodic action disrupts the accumulation process without compromising the high temperature and pressure conditions needed for efficient brewing.

The patent converts the harmful effect of high temperature and pressure-induced chemical activity into a benefit by using the same conditions to flush and clean the system periodically. The high-velocity water flow during flushing cycles removes deposits that form during brewing, transforming the potentially harmful chemical activity into a self-cleaning mechanism.