| 摘要 |
<p>An energy recovery, pressure reducing system (30 or 50) for reducing high pressure gas in a transmission pipeline (13A) to a lower pressure in a consumer pipeline (18A) includes a primary pressure regulator or regulating valve (17A or 17B) having an adjustable flow control opening, the pressure regulating valve (17A or 17B) being selectively connectable between the transmission and consumer pipelines (13A and 18A) for throttling the high pressure gas and producing low pressure gas when the primary pressure regulator or regulating valve (17A or 17B) connects the pipelines. A bypass line (45 or 51) shunts the primary pressure regulator or regulating valve for connecting the pipelines when the primary pressure regulating valve is disconnected from the pipelines. The bypass line includes an expander system having at least one expander (31, 101, or EXP) for expanding the high pressure gas in the gas transmission pipeline (13A) and producing work and lower pressure gas that is supplied to the consumer pipeline (18A). Preferably, a generator (33 or G) is coupled to the expander (31, 101, or EXP) for converting work produced by the expander (31, 101, or EXP) to electricity which is supplied to an electrical load. A fast acting, selectively adjustable pressure regulator or regulating valve apparatus (41 or 17B) is connected in parallel with the expander system. Finally, a control system (47 or 58) is provided, responsive to a reduction in flow through the expander system for rapidly switching the apparatus from a non-operational state in which no gas is transmitted between the transmission and the consumer pipelines (13A and 18A), to an operational state in which high pressure gas is throttled to the lower pressure in the consumer pipeline (18A) and transmitted thereto. <IMAGE> <IMAGE> <IMAGE> <IMAGE></p> |
