SOLID FREEZER

To defrost a low-temperature side heat exchanger while avoiding increase in size and complication of a solid freezer.SOLUTION: A solid freezer (1) performs heating operation and defrosting operation. In the defrosting operation, frost adhering to a second heat exchanger (17) is removed during the heating operation. A solid refrigerant substance (12) includes a plurality of substances (12a to 12e) having different temperatures at which a calorific effect is maximum. The plurality of substances (12a to 12e) are arranged along an internal flow path (13) in descending order of temperature. In the defrosting operation, a conveyance direction of a heat medium in the internal flow path (13) with respect to a phase of force field fluctuation is switched to an opposite direction to that in the heating operation.SELECTED DRAWING: Figure 5 【課題】固体冷凍装置の大型化や複雑化を回避しつつ低温側熱交換器の除霜を行えるようにする。【解決手段】固体冷凍装置（1）は、加熱運転と、デフロスト運転とを行う。デフロスト運転では、加熱運転で第２熱交換器（17）に付着した霜を取り除く。固体冷媒物質（12）は、熱量効果が最大となる温度が異なる複数の物質（12a～12e）を含み、前記複数の物質（12a～12e）は、内部流路（13）に沿って前記温度の高低順に配置される。デフロスト運転において、力場変動の位相に対する内部流路（13）における熱媒体の搬送方向を、加熱運転とは反対向きに切り替える。【選択図】図５