Controlled and variable gas phase shifting cryocooler

Abstract

Cryocoolers, including coolers, heaters, and heat pumps each having a first stage and a second stage, are modified with controlled and variable gas phase shifting devices for controlling gas pressure and mass flow between volumes of the first and second stages for improving the efficiency and temperature range of expander cryocoolers such as displacer cryocoolers using controlled valves as flow impedance devices and pulse tube cryocoolers using inertance gaps as flow inertia devices, for maximizing cooling between the first and second stages.

1 . A cryocooler a first volume and a second volume, the cryocooler comprising,
 a first stage defining a first volume for containing gas at a first temperature and first pressure, and   a second stage defining a second volume for containing the gas at a second temperature and second pressure, and   a gas phase shifting device between the first volume and the second volume,   the gas phase shifting device providing a pressure and temperature phase difference between the first volume and the second volume, and   a controller for controlling the gas phase shifting device for controlling the pressure and temperature phase difference between the first volume and the second volume.   
   
   
       2 . The cryocooler of  claim 1  wherein,
 the cryocooler is selected from a group consisting of coolers, heaters, and heat pumps.   
   
   
       3 . The cryocooler of  claim 1  wherein,
 gas mass flow in the first volume exit is in phase with the gas pressure.   
   
   
       4 . The cryocooler of  claim 1  wherein,
 the cryocooler is a displacer cryocooler,   the first stage is a moving first heat exchanger, and   the second stage is a moving second heat exchanger.   
   
   
       5 . The cryocooler of  claim 1  wherein,
 the cryocooler comprises a compressor,   the cryocooler is a displacer cryocooler,   the first stage is a moving first heat exchanger,   the second stage is a moving second heat exchanger, and   the moving first heat exchanger and the second stage heat exchanger are portions of a porous piston driving gas pressure and mass flow from a compressor.   
   
   
       6 . The cryocooler of  claim 1  wherein
 the cryocooler is a pulse tube cryocooler,   the gas phase shifting device is an inertance gap,   the first stage comprising stationary heat exchanger and an exit volume as the first volume,   the second stage comprises a pulse tube, the gas phase shifting device, and a reservoir volume, and   the reservoir volume is the second volume.   
   
   
       7 . The cryocooler of  claim 1  wherein
 the cryocooler comprises a compressor,   the cryocooler is a pulse tube cryocooler,   the gas phase shifting device is an inertance gap,   the first stage comprising stationary heat exchanger and an exit volume as the first volume,   the second stage comprises a pulse tube, the gas phase shifting device, and a reservoir volume, the reservoir volume being the second volume, and   the compressor injects gas through the stationary heat exchanger and exit volume and through the pulse tube and through the inertance gap and into the reservoir.   
   
   
       8 . The cryocooler of  claim 1  wherein,
 the cryocooler is a displacer cryocooler,   the gas phase shifting device is a flow impedance device, and   the flow impedance device is controlled by the controller.   
   
   
       9 . The cryocooler of  claim 1  wherein,
 the cryocooler is a displacer cryocooler,   the gas phase shifting device is a valve, and   the valve is controlled by the controller.   
   
   
       10 . The cryocooler of  claim 1  wherein,
 the cryocooler is a displacer cryocooler,   the gas phase shifting device is an orifice, and   the orifice is controlled by the controller.   
   
   
       11 . The cryocooler of  claim 1  wherein,
 the cryocooler is a displacer cryocooler,   the gas phase shifting device is a flow inertance device, and   the flow inertance device is controlled by the controller.   
   
   
       12 . The cryocooler of  claim 1  wherein,
 the cryocooler is a displacer cryocooler,   the gas phase shifting device is an inertance gap, and   the inertance gap is controlled by the controller.   
   
   
       13 . The cryocooler of  claim 1  wherein,
 the cryocooler is selected from the group consisting of displacer cryocoolers and pulse tube cryocoolers, and   the gas phase shifting device is selected from the group consisting of flow impedance devices and flow inertance devices.   
   
   
       14 . The cryocooler of  claim 1  wherein,
 the cryocooler is a pulse tube cryocooler,   the gas phase shifting device is a flow inertance device, and   the flow inertance device is controlled by the controller.   
   
   
       15 . The cryocooler of  claim 1  wherein,
 the cryocooler is a pulse tube cryocooler,   the gas phase shifting device is an inertance gap, and   the inertance gap device is controlled by the controller.   
   
   
       16 . The cryocooler of  claim 1  wherein,
 the cryocooler is a pulse tube cryocooler,   the gas phase shifting device is an inertance gap, and   a dimension of the inertance gap is controlled by a motor controlled by the controller.   
   
   
       17 . The cryocooler of  claim 1  wherein,
 the cryocooler is a pulse tube cryocooler,   the gas phase shifting device is an inertance gap, a dimension of the inertance gap is controlled by a motor being controlled by the controller, and   the motor is selected from the group consisting of electromechanical motors and thermal motors.   
   
   
       18 . The cryocooler of  claim 1  wherein,
 the cryocooler is a pulse tube cryocooler,   the gas phase shifting device is an inertance gap, a dimension of the inertance gap is controlled by a motor being controlled by the controller, the dimension being selected from the group consisting of width, length, and thickness, and   the motor is selected from the group consisting of electromechanical motors and thermal motors.   
   
   
       19 . The cryocooler of  claim 1  wherein,
 the controller controls the gas phase shifting device over time for time varying the pressure and temperature phase difference between the first volume and the second volume.