SRC Service Manual
Revision 02
Aug 2007
3.2.1 The Thermal Mass Concept
The purpose of the Coolant Circuit is to provide a dynamic “Thermal Mass” – that is a moving mass of
material with high
thermal retention – or
the capacity to absorb a significant quantity of heat without a
rapid rise in temperature.
The Thermal Mass consists of more than just the Coolant. All components of the system add to it’s
capacity to absorb heat, including:
•
the
Coolant,
•
the Coolant-to Refrigerant Heat Exchanger,
•
The Air-to-Coolant Heat Exchanger,
•
the Coolant Tank,
•
the inter-connecting piping of the coolant circuit, and
•
the Coolant Re-circulation Pump.
As the Coolant absorbs heat from the air, it disperses this heat throughout the Coolant Circuit, and
due to the significant mass of cold material to absorb this heat, the temperature rises very slowly.
The controls of the SRC dryer monitor the temperature of the Coolant in the Coolant Tank, and allow it
to fluctuate between an upper and lower limit.
When the temperature of the Coolant reaches the upper limit it turns the Refrigerant Compressor on,
and the resulting cooling effect in the Coolant-to-Refrigerant heat Exchanger, brings the Coolant
Temperature down.
When the temperature of the Coolant reaches the lower limit it turns the Refrigerant Compressor off,
and it’s temperature begins to rise again*.
The less the heat load in the incoming air, the less heat is transferred to the Coolant, the slower the
temperature rises, the less the refrigerant compressor needs to come on, and the lower the overall
power consumption.
* This is a simplified explanation. For full details on cycling operation please refer to Section 8.
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