In accordance with at least one aspect of this disclosure, an actuation system for a guided munition, includes a reservoir disposed in a guided munition body housing a compressible fluid in a compressed state, a fluid path connecting the reservoir in fluid communication with a heat exchange volume, a throttling orifice disposed in the fluid path configured to expand the compressible fluid, and an actuation path connecting the heat exchange volume in fluid communication with a moveable component. The actuation path can be configured to supply pneumatic pressure to the moveable components.

The invention relates to an apparatus (112) and to a method (210) for generating cryogenic temperatures. The apparatus (112) comprises at least one cooling stage (111) which has a cold region (110) and a warm region (116), and a refrigerant mixture designed specifically for the cooling stage (111) is provided in the warm region (116), the refrigerant mixture having at least two components each having a different boiling temperature, and the cold region (110) comprises at least one cooling stage (111): - a first heat exchanger (122), which has a high-pressure side (120) to receive the refrigerant mixture at a high-pressure level from the warm region (116) of the cooling stage (111) and a low-pressure side (126) to deliver the refrigerant mixture to the warm region (116) of the cooling stage (111); - a first expansion device (136), which is designed for expansion and for cooling of the refrigerant mixture at a low-pressure level; - a second heat exchanger (148), which is designed for cooling and for partial condensation of a proportion of the refrigerant mixture located in a buffer volume (140), the buffer volume (140) being designed to limit the pressure exerted by the refrigerant mixture; and - a second expansion device (150), which is designed for separation of the buffer volume (140) from the low-pressure level of the cooling stage (111) or connection of the buffer volume (140) to said low-pressure level. The invention enables autonomous operation of the apparatus (112) and of the method (210) for generating cryogenic temperatures, in which each cooling stage (111) of the apparatus (112) can be filled with a pre-defined refrigerant mixture and can be permanently operated, and in particular in the cooling phase the refrigerating capacity can be increased, while incorrect distribution of the refrigerant of the relevant cooling stage (111) among parallel flow channels at the cold end of the first heat exchanger (122) can be prevented.

The invention relates to an apparatus (112) and to a method (210) for generating cryogenic temperatures. The apparatus (112) comprises at least one cooling stage (111) which has a cold region (110) and a warm region (116), and a refrigerant mixture designed specifically for the cooling stage (111) is provided in the warm region (116), the refrigerant mixture having at least two components each having a different boiling temperature, and the cold region (110) comprises at least one cooling stage (111): - a first heat exchanger (122), which has a high-pressure side (120) to receive the refrigerant mixture at a high-pressure level from the warm region (116) of the cooling stage (111) and a low-pressure side (126) to deliver the refrigerant mixture to the warm region (116) of the cooling stage (111); - a first expansion device (136), which is designed for expansion and for cooling of the refrigerant mixture at a low-pressure level; - a second heat exchanger (148), which is designed for cooling and for partial condensation of a proportion of the refrigerant mixture located in a buffer volume (140), the buffer volume (140) being designed to limit the pressure exerted by the refrigerant mixture; and - a second expansion device (150), which is designed for separation of the buffer volume (140) from the low-pressure level of the cooling stage (111) or connection of the buffer volume (140) to said low-pressure level. The invention enables autonomous operation of the apparatus (112) and of the method (210) for generating cryogenic temperatures, in which each cooling stage (111) of the apparatus (112) can be filled with a pre-defined refrigerant mixture and can be permanently operated, and in particular in the cooling phase the refrigerating capacity can be increased, while incorrect distribution of the refrigerant of the relevant cooling stage (111) among parallel flow channels at the cold end of the first heat exchanger (122) can be prevented.

A refrigeration system includes a rotary pressure exchanger fluidly coupled to a low pressure branch and a high pressure branch. The rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure branch, to receive the refrigerant at low pressure from the low pressure branch, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger includes the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger includes the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor.

A cryoprobe for cryotherapy, includes a working and a drain tube, welded together. The working tube has a first end, a distal end, an internal surface, an external surface, an inner diameter, and an outer diameter. The drain tube is placed concentrically in the working tube, and has an internal surface, an external surface, an inner diameter, an outer diameter, a first end connected to a first pressure supply, and a perforated second end which is proximate to the distal end of the working tube. The drain tube is welded to the working tube between the internal surface of the working tube and the external surface of the drain tube to manufacture a throttle perforation, in a manner which allows fluid to pass along the outer surface of the drain tube, expand at the distal end of the working tube, and drain through the drain tube.

A cryoprobe for cryotherapy, includes a working and a drain tube, welded together. The working tube has a first end, a distal end, an internal surface, an external surface, an inner diameter, and an outer diameter. The drain tube is placed concentrically in the working tube, and has an internal surface, an external surface, an inner diameter, an outer diameter, a first end connected to a first pressure supply, and a perforated second end which is proximate to the distal end of the working tube. The drain tube is welded to the working tube between the internal surface of the working tube and the external surface of the drain tube to manufacture a throttle perforation, in a manner which allows fluid to pass along the outer surface of the drain tube, expand at the distal end of the working tube, and drain through the drain tube.

There is provided refrigeration system (1) and method for remote cooling of a thermal load having a first portion (27) and a second portion (25). The system comprises a cold source (4) having a first cooling stage (5) and a second cooling stage (6), the temperature of the first cooling stage being higher than the temperature of the second cooling stage. The system also comprises a cryogen circuit for circulation of a cryogen flow in a closed cycle, the closed cycle being thermally coupled to the cold source. The system further comprises a compressor (7) for compressing and circulating the cryogen flow in the cryogen circuit. The cryogen circuit comprises a first conduit for thermally connecting the first cooling stage of the cold source to the first portion of the thermal load so as to cool said first portion towards the temperature of the first cooling stage, and a second conduit for thermally connecting the second cooling stage of the cold source to the second portion of the thermal load so as to cool said second portion to wards the temperature of the second cooling stage. The cryogen flow in the system is a sub-cooled or saturated liquid, two phase, saturated or overheated, supercritical gas helium flow.

There is provided refrigeration system (1) and method for remote cooling of a thermal load having a first portion (27) and a second portion (25). The system comprises a cold source (4) having a first cooling stage (5) and a second cooling stage (6), the temperature of the first cooling stage being higher than the temperature of the second cooling stage. The system also comprises a cryogen circuit for circulation of a cryogen flow in a closed cycle, the closed cycle being thermally coupled to the cold source. The system further comprises a compressor (7) for compressing and circulating the cryogen flow in the cryogen circuit. The cryogen circuit comprises a first conduit for thermally connecting the first cooling stage of the cold source to the first portion of the thermal load so as to cool said first portion towards the temperature of the first cooling stage, and a second conduit for thermally connecting the second cooling stage of the cold source to the second portion of the thermal load so as to cool said second portion to wards the temperature of the second cooling stage. The cryogen flow in the system is a sub-cooled or saturated liquid, two phase, saturated or overheated, supercritical gas helium flow.

Systems and methods of continuous cooling at cryogenic temperatures. One exemplary aspect involves a refrigeration system that includes: a chamber adapted to hold liquid and gaseous coolant received from a cooling pot; a first adsorption pump having an inlet end in fluid communication with the chamber, the first adsorption pump configured to capture gas from the liquid and gaseous coolant when the first adsorption pump is enabled; a second adsorption pump having an inlet end in fluid communication with the chamber, the second adsorption pump configured to capture gas from the liquid and gaseous coolant when the second adsorption pump is enabled; a means for desorbing the gas captured by the first adsorption pump; and a means for desorbing the gas captured by the second adsorption pump.

A heat exchanger for use with a refrigeration device having a FPA disposed therein being comprised of a polymeric composite mesh material having a hot end and a cold end and defining an array of weft capillaries interwoven with a perpendicular array of warp strands. The array of weft capillaries may include a plurality of high pressure inlet capillaries for channeling and distributing high pressure gas from an inlet at the hot end to a Joule-Thomson orifice at the cold end, a plurality of low pressure outlet capillaries for channeling and distributing high pressure gas from a Joule-Thomson orifice to an outlet of the heat exchanger, and a plurality of low thermal conductivity fibers interspersed between the high pressure inlet capillaries and the low pressure outlet capillaries. In example embodiments. the array of warp strands comprises at least one or more of carbon fibers, copper fibers or glass fibers.