The invention discloses a low-grade
waste heat recovery and application technology. A special vacuum
heat pipe is introduced to the hot source end for collecting
waste heat, the vacuum
heat pipe extends towards a terminal user in an upward oblique-pulling mode, middle-end heat exchanging towers are built at certain intervals, the vacuum
heat pipe at the previous period transmits the
heat energy from the hot source end into the liquid in each middle-end heat exchanging
tower, another vacuum heat
pipe with the same specification material is additionally introduced in the heat exchanging
tower toabsorb the
heat energy of the liquid after heating, and
cascade heat energy transmission is conducted continuously in the same way; and during storing and using of the terminal, the long-distance transmission can be achieved through
cascade heat energy exchanging and transmission, the heat energy transmission of each heat
pipe is high in speed and less in
system energy consumption, a heat transmitting structure of each heat
pipe is simple and easy to operate, automatic and
continuous operation can be achieved, a screw-rod-type expansion power generator can still obtain higher internal efficiency under lower volume flow conditions, the fuel is not only saved, the secondary
utilization rate of the energy is improved, the environmental
pollution can also be reduced, and the energy using andconverting efficiency is high.