| 摘要 |
Conversion of heat from high-temperature off-gases into useful work is accomplished with a process having first and second stages. The first stage comprises i) passing feed water through a counterflow feed water preheater which is heated by off-gas, to form preheated feed water; ii) converting the preheated feed water into steam in a steam boiler which is heated by off-gas; iii) superheating the steam in a steam superheater which is heated by off-gas; iv) passing the superheated steam into a steam expander which allows expansion of the superheated steam, thus producing shaft work to operate a first machine, and exhausting low pressure steam; v) feeding the low pressure steam through a steam condenser to form condensed feed water; and vi) pumping the feed water through a counterflow fluorocarbon working fluid preheater before passing the feed water through the first stage again starting at step. The second stage comprises a) passing liquid fluorocarbon working fluid, e.g. HCFC, through the fluorocarbon working fluid preheater to preheat the liquid fluorocarbon working fluid; b) passing the preheated liquid fluorocarbon working fluid into a separator, from where liquid fluorocarbon working fluid passes through a heat exchanger in the steam condenser thus converting some of the liquid fluorocarbon into gaseous fluorocarbon, whence the mixed liquid and gas is returned to the separator in which the gas is separated from the liquid fluorocarbon; c) superheating the gaseous fluorocarbon working fluid in a gaseous fluorocarbon superheater which is heated by off-gas; d) passing the superheated gaseous fluorocarbon working fluid through a fluorocarbon expander which allows expansion of the superheated gaseous fluorocarbon working fluid, thus producing low pressure gaseous fluorocarbon working fluid and producing shaft work to drive a second machine; e) feeding the low pressure gaseous fluorocarbon working fluid through a fluorocarbon condenser to give up its latent heat and form liquid fluorocarbon working fluid; and f) pumping the liquid fluorocarbon working fluid through the second stage again, starting at step a). Heat is provided to the process by passing high temperature off-gas, e.g. 350 to 1100.degree.C off-gas, in sequence through the steam superheater, the water boiler, the fluorocarbon superheater and the feed water heater.
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