The invention provides a sectional
evaporation-compression vapor compression
heat pump, belonging to the technical field of residual-heat utilization and
heat pump /
refrigeration. The vapor compression
heat pump aims at overcoming the defects of a vapor compressor provided with a single
evaporator when a residual-heat medium has large temperature variation range, and provides a vapor compression
machine set which comprises more than two compressors, more than two evaporators, a condenser, a
throttle valve and the like and realizes sectional
evaporation-compression; low temperature section
evaporation-compression can be realized by the low temperature
evaporator and the first compressor; high temperature section evaporation-compression can be realized by the high temperature
evaporator and the second compressor; the residual-heat medium firstly flows through heating
refrigerant liquid of the high temperature evaporator to become
refrigerant vapor to be provided for the second compressor, and then flows through heating
refrigerant liquid of the low temperature evaporator to become refrigerant vapor to be provided for the first compressor after the temperature is lowered, the first compressor provides the refrigerant vapor for the condenser or the second compressor; and the heat of the heated medium is absorbed by the condenser when the medium flows through the condenser. The sectional evaporation-compression vapor compression heat pump reduces residual-
heat transmission temperature difference, improves the
performance index of the
machine set, and can reduce the
power consumption of the
machine set when the residual-heat medium has large temperature variation range.