What is subcooling? What is the difference between opening subcooling and closing subcooling? Which subcooling is greater?

The absolute value of the difference between the condensate temperature and the saturation temperature at the corresponding pressure is the degree of subcooling.

The valve opening subcooling refers to the absolute value of the difference between the valve opening temperature and the saturation temperature at the corresponding pressure.

Shut-off supercooling refers to the absolute value of the difference between the shut-off temperature and the saturation temperature at the corresponding pressure.

The subcooling at valve opening is greater than the subcooling at valve closing.