The present invention provides a multi-stage
heat pump drying unit parallel
system, including a plurality of dryers arranged in parallel and a main
engine room shared by the plurality of dryers, the dryers are divided into a pair of
drying chambers, a return
air chamber arranged between the pair of
drying chambers, and a buffer chamber, the side walls of the return
air chamber adjacent to each drying chamber are provided with a shunt structure connected to the drying chamber, a circulating fan and a condenser are arranged in the return
air chamber, a return air valve and an exhaust air valve are arranged on the side walls adjacent to the return air chamber and the buffer chamber, respectively, a first
fresh air valve is arranged on the top wall of the buffer chamber; the exhaust air valve is connected to the exhaust duct of the main
engine room through the buffer chamber, and the return air valve is directly connected to the main
engine room through the buffer chamber; a plurality of
heat pump units are arranged in the main engine room, and a second
fresh air valve and a dehumidification valve fan
assembly are arranged on the side walls of the main engine room. The present invention can solve the technical problems that the performance of the
heat pump system is low under low temperature conditions in cold areas in winter and the energy efficiency of the closed-loop circulation heat pump drying
system is relatively low under high temperature conditions in summer.