Extracting heat from very hot, dry rocks presents a more difficult problem: the rocks must be fractured to permit the circulationof water, and the water must be provided artificially.
Air circulation carries product heat and the heat which penetrates the walls, floors, and ceiling of the trailer to the refrigeration unit where it can be removed.
空气在循环过程中会带走农产品本身的热量，也会带走那些从门、地板和拖车的顶部渗透进来的热量。
3
Reciprocating compressors can produce the work a lot ofheat, so in working circulation cooling process between need to set.