ACT has developed an efficient, compact vapor compression system (VCS) that can handle very high pulsed heat loads including those from high-energy lasers and other non-lethal directed energy weapon systems.  Our vapor compression system is unique in that it incorporates thermal energy storage within the system, which in turn enables the system size, weight and power (SWaP) to be substantially reduced.   Peak heat loads are rapidly stored in the latent heat of a phase change material (PCM) and dissipated at a slower rate during longer recharge periods.  In effect, the thermal energy storage “dampens” the heat load that must be handled by the vapor compression system.

At ACT, particular attention has been given to the design, fabrication and testing of the heat exchanger (HX) that incorporates the phase change material.  It has been designed to efficiently transfer large amounts of heat from a liquid coolant into the PCM where it is temporarily stored before being dissipated by the system.

A top-level schematic of a vapor compression system is shown below (left) along with a schematic of a representative pulsed heat load profile (right).  The red area represents the transient high peak loads that need to be managed and the blue region shows the much lower heat load that is taken up by a VCS having thermal energy storage.

Figure 1:  (Left) A schematic of a vapor compression system with integrated thermal energy storage; (Right) A representative transient thermal energy profile showing that the use of thermal energy storage dampens the heat loads that need to be managed by the vapor compression system.

At present, ACT is developing these systems for both ground and air-based platforms.  For more information, contact ACT.