摘要 |
A steam supply system is provided for use in conjunction with both a superposed turbine driven by a steam boiler and a process chamber. The steam boiler operates at a pressure above that needed for consumption in the process chamber and uses highly purified water. The process chamber can use steam which has been generated from relatively low purity water and may be any steam consuming process, such as in one embodiment coal gasification, not requiring that the water be returned for re-use as steam. Energy remaining in the high purity steam after it leaves the superposed turbine is used in a condensing reboiler to heat the water into steam for the process chamber. The two fluids are kept essentially isolated from contact with each other in the condensing reboiler, and the high purity water is pumped back to the high pressure boiler in a closed loop system. The use of high purity water to produce high pressure steam provides protection to the superposed turbine from fouling and damage, thereby extending both its operating range and useful life. |