Low vibration throttling device for throttle-cycle refrigerators

A closed cycle refrigeration system for operation at a Pre-selected steady-state temperature T for cooling a load, comprising:

• a refrigerant mixture for operation at temperature T including at least one component that increases in flow resistance as its temperature decreases;
• a first throttle device connecting between a high pressure portion of said closed cycle system and a low pressure portion of said closed cycle system, said first throttle device including a high pressure inlet for said refrigerant and a low pressure outlet for said refrigerant, and a first flow restrictor in a first flow path between said inlet and outlet, said refrigerant flowing in said first flow path passing through said first flow restrictor, said refrigerant mixture in flowing through said first flow restrictor being increasingly restricted by increases in said flow resistance as said refrigerant is cooled toward temperature T,
• wherein said first flow restrictor becomes blocked to said refrigerant mixture at a temperature not exceeding said pre-selected temperature T.

A closed cycle refrigeration system for operation at a steady-state temperature T for cooling a load, comprising:

• a refrigerant mixture for operation at temperature T including at least one component that increases in flow resistance as its temperature decreases;
• a first throttle device connecting between a high pressure portion of said closed cycle system and a low pressure portion of said closed cycle system, said first throttle device including a high pressure inlet for said refrigerant and a low pressure outlet for said refrigerant, and a first flow restrictor in a first flow path between said inlet and outlet, said refrigerant flowing in said first flow path passing through said first flow restrictor, said refrigerant mixture in flowing through said first flow restrictor being increasingly restricted by increases in said flow resistance as said refrigerant is cooled toward temperature T, and
• a second throttle device in a second refrigerant flow path, said second flow path and second throttle device being in flow parallel with said first flow path and first flow throttle device, said second throttle device being dimensioned for performance at selected steady-state conditions of said refrigerant system.