Pre-Stage Flux Chiller
The Pre-Stage Flux Chiller is a component used aboard Federation Constitution Class starships during the late 23rd century, located on both the port and starboard side of a vessel.
These components must be activated prior to the departure of a vessel from spacedock moorings. Their used before the activation of the ship's Pre-Stage Flux Chambers. (Star Trek II: The Wrath of Khan)
It is likely that these are high powerered heat-exchangers used to supercool plasma coolant for the Warp Coils. This is the first stage of the cooling cycle prior to the coolant circulating into the Pre-Stage Flux Chiller.
Other components in the Cooling cycle are likely to include the Pre-Stage Flux Chamber, the Main Stage Flux Chiller and the Main Stage Flux Chamber.
The most likely activation sequence is as follows:
- Activate Pre-Stage Flux Chillers
- Activate Pre-Stage Flux Chambers
- Activate Main Stage Flux Chillers
- Activate Main Stage Flux Chambers
Because it is mentioned that these devices must be activated prior to disengaging from dock, it is likely that during docking with a spacedock that either they are not needed and therefore left deactivated, or that the Space dock, provides a service that mimics the function of these components.
Additionally one can extrapolate that the Chambers act as tanks, most likely holding the Plasma Coolant. In a manner similar to a heat exchanger, the Pre-Stage Chillers and Chambers most likely act as pre-coolers to reduce the workload of the Main chillers and chambers. The coolant most likely resides in the cooling system, perhaps stored in the Chambers, prior to being run through the warp coils and returned to the Pre Stage chiller and Chambers. After they have left the Pre-Stage, they then flow to the Main Stage Chiller and Chambers before returning to the coils for heat absorption.
- The fact that there are separate port and starboard components suggests that these might be located in the engine Nacelle, but there is no direct evidence for this.