Tight temperature control at a thermal load with a two phase pumped loop, optionally augmented with a vapor compression cycle

A thermal management system for dissipating a thermal load during operation of an apparatus;

• the thermal management system comprising a two-phase pump loop (TPPL) and a primary vapor cycle system (p-VCS) that are configured to use the same coolant and to be in fluid communication through a vapor/liquid receiver;
• wherein the TPPL comprises:
• the vapor/liquid receiver configured to store the coolant;
• a pump configured to force the coolant to flow throughout the TPPL;
• an evaporator configured to absorb heat (QABSORBED) from the apparatus, the evaporator having an inlet and an outlet;
• and
• a valve (V1) having a control set point set at a first pressure (P1set) measured downstream of the evaporator, the P1set set to achieve an evaporator exit pressure that is the saturation pressure (PH) of the coolant at a predetermined target exit temperature from the evaporator;
• wherein the p-VCS comprises:
• the vapor/liquid receiver configured to store the coolant;
• a condenser configured so that the coolant releases heat (QREJECTED) in order to remove heat (QREJECTED) from the thermal management system;
• a first compressor;
• a valve (V2) having a control set point set at a second pressure (P2set) to prevent the vapor/liquid receiver pressure from going to a pressure/temperature that is lower than a predetermined value (PL);
• a controller configured to control the set points of V1 and V2;
• wherein the controller is configured to set P1set so as to provide a predetermined temperature at the outlet of the evaporator and the controller is configured to vary P2set so as to maintain the pressure in the vapor/liquid receiver at or above PL;
• a valve (V3) configured to act as an expansion valve;
• the V3 having a control set point set to maintain a predetermined pressure at an outlet of the compressor;
• and
• one or more recuperators configured with a condenser exit flow or hot gas bypass flow to prevent any coolant in liquid form from entering the compressor;
• wherein V2 is configured to allow a portion of the coolant exiting the compressor to flow back into the vapor/liquid receiver in order to prevent overcooling of the vapor/liquid receiver while allowing the compressor to continue to run.

A thermal management system for dissipating a thermal load during operation of an apparatus;

• the thermal management system comprising a two-phase pump loop (TPPL) and a vapor cycle system (VCS) configured to use the same coolant;
• the TPPL comprising:
• a vapor/liquid receiver configured to store a coolant;
• a pump configured to force the coolant to flow throughout the TPPL;
• the flow of coolant being a flow of a liquid or a two-phase flow that includes a vapor/liquid mixture;
• an evaporator configured to absorb heat (QABSORBED) from the apparatus, the evaporator comprising an inlet and an outlet;
• and
• a valve (V1) configured to regulate a pressure at or after an outlet of the evaporator, the V1 having a control set point set at a first pressure (P1set) to achieve an evaporator exit pressure that is the saturation pressure (PH) of the coolant at a predetermined exit temperature from the evaporator;
• wherein the TPPL is configured to cool the thermal load with tight control of the temperature of the coolant that is cooling the apparatus.