Dual-Expansion Refrigeration Cycle for Higher Heating Capacity

The patent divides the heating process into two stages by introducing two expansion mechanisms. The first expansion mechanism creates a first expansion state with lower pressure and temperature, allowing greater temperature difference with the sub-refrigerant for enhanced heat exchange. The second expansion mechanism then creates the final expansion state. This segmentation enables the main refrigerant to absorb more heat from the sub-refrigerant in the first stage, thereby increasing heating capacity while reducing the total heat-exchange amount required.

The patent changes the pressure and temperature parameters of the main refrigerant by introducing a first expansion mechanism before the sub-usage-side heat exchanger. This first expansion reduces the refrigerant's pressure and temperature, creating a larger temperature difference with the sub-refrigerant during heating operation. By adjusting these parameters, the system optimizes heat transfer efficiency and increases heating capacity without requiring excessive heat-exchange amount.

The first expansion mechanism serves multiple functions: it decompresses the main refrigerant before the sub-usage-side heat exchanger to increase temperature difference for heating, and it also prepares the refrigerant for efficient heat exchange during cooling operation. By designing this component to fulfill multiple roles, the patent reduces the need for separate dedicated components, thereby managing system complexity while achieving the desired temperature difference improvement.

The patent employs controllable expansion mechanisms that can dynamically adjust their operation based on whether the system is in heating or cooling mode. The first expansion mechanism is activated selectively to provide the necessary pressure reduction and temperature difference during heating operations, while remaining inactive or bypassed during cooling operations. This dynamic control allows the system to maintain simplicity by only activating additional components when needed.