| 摘要 |
<p>A cryogenic refrigerating machine adopting the Gifford MacMahon (GM) cycle wherein a rotary valve device (RV) for controlling the supply and discharge of refrigerant gas to/from a refrigerating machine (2) is rotated forwardly and/or reversely by means of reversibly motor (15), wherein a cooling mode operation for generating cold heat by virtue of adiabatic expansion is performed during forward rotation, while a temperature increasing mode operation for generating heat by virtue of adiabatic compression is performed during reverse rotation, and wherein the opening and closing timing of the rotary valve device (RV) relative to the reciprocating movement of displacers (3a, 3b) during forward reverse rotation is made different from that during reverse rotation so that optimum efficiency is obtained during the cooling mode and heating mode operations, respectively. As a result, it is possible to reduce time needed to heat the cooling portion in a cryogenic state of a room temperature without any particular equipment.</p> |
