Sumitomo SRDK Series - Page 44

OPERATION MANUAL Sumitomo Heavy Industries, Ltd.
SRDK Series CRYOCOOLER 15
1-3 THEORY OF OPERATION
The refrigerator operates as follows;
PRESSURE BUILD-UP
With the displacer at the bottom of the cylinder and the
outlet valve closes and the inlet valve opens, increasing
the pressure level in the system. Fluid will be led
through the inlet valve to fill the regenerator and the
space above the displacer, volume 1.
INTAKE STROKE
With the inlet valve open, the displacer is moved from the
bottom to the top of the cylinder. This displaces high
pressure fluid from the space above the displacer,
volume 1, through the regenerator, to the space below
the displacer, volume 2. In passing through the
regenerator, the gas cools causing the pressure to
decrease and further gas to enter the system to maintain
the maximum cycle pressure.
PRESSURE RELEASE AND EXPANSION
With the displacer at the top of the cylinder, the inlet
valve closes and outlet valve opens. Fluid escapes and
the pressure will decrease. The drop in pressure
causes a reduction in the gas temperature level. The
temperature decrease of gas in the bottom cylinder
space, volume 2, is the useful refrigeration process of
the cycle.
EXHAUST STROKE
With outlet valve open, the displacer moves from the top
to bottom of the cylinder, displacing fluid from volume
2(below) to volume 1, above the displacer. As it flows
through the regenerator, the fluid is heated to near
ambient temperature by the matrix. This process, can
be produced the cool in the matrix ready for the gas
entering in the succeeding cycle.
Displacer
Regenerator
Inlet Valve
Outlet Valve
Compressor
Volume 2
Volume 1
INTAKE STROKE
PRESSURE RELEASE AND EXPANSION
EXHAUST STROKE
PRESSURE BUILD-UP
Figure 1.3 PRINCIPLE OF GM CYCLE