Solar-assisted ocean temperature difference energy based cooling, heating, power and fresh water poly-generation system

The invention belongs to the technical field of efficient conversion of low-grade heat sources, and provides a solar-assisted ocean temperature difference energy based cooling, heating, power and fresh water poly-generation system. By means of the system, ocean surface warm seawater subjected to solar heat collection is used as a heat source to heat and vaporize a low-boiling-point working medium discharged from a working medium pump, and meanwhile the seawater subjected to heat exchange enters a single-pole flash tank to be subjected to flash evaporation to generate fresh water. The vaporized working medium enters an expansion machine to do work, dead steam exhausted from the expansion machine enters a flow divider, the flow divider divides the dead steam into two paths, and one path provides heat for working fluid of an ejector in an ejection refrigeration sub-cycle; and the other path provides heat for a working medium in a steam compression heat pump sub-cycle, so that after the working medium is vaporize