(1) All of the existing systems rely on solenoid valves to switch
between mechanical refrigeration and thermosyphon cooling.
In mild season when the outdoor temperature is neither
too high nor too low, the valves need to work and stop
frequently. This will greatly affect the lifetime of the valves
and the reliability of the whole system.
(2) Mechanical refrigeration and thermosyphon cannot work
simultaneously in existing systems. It means that when the
cooling capacity of the thermosyphon is not sufficient, the
system must work in the mechanical refrigeration mode and
the cooling capacity of the thermosyphon cannot be used.
This will reduce the working time of the thermosyphon
cooling and then reduce the energy-saving effect.