Method and device for converting surplus energy on distillation tower top into electric energy

The invention relates to a method and device for converting surplus energy on the distillation tower top into electric energy. The gas-phase surplus energy on the distillation tower top is made full use of, another working medium having heat transfer temperature difference with the gas-phase surplus energy is adopted for heat transfer, and energy needed for evaporation and expansion is provided for the working medium. The device is mainly composed of a distillation tower, a phase-change heat removal device, a heat removal material flow condenser, a heat removal material flow circulation pump, a generator, a distillation tower condensate receiving tank, a distillation tower condensate conveying pump and the like. The gas-phase surplus energy on the distillation tower top cooled by air and water originally is fully recycled and converted into electric energy, and energy recovery and utilization are achieved in the process. According to the method and device, the gas-phase surplus energy which can not be recycled easily on the distillation tower top can be made full use of, heat energy is converted into mechanical energy and then is converted into electric energy, and the energy of a distillation device can be utilized and recycled to the maximum extent. The method and device have the advantages of being simple in technological process, low in equipment investment, convenient to operate and capable of fully recycling the gas-phase surplus energy on the tower top.