Power generating apparatus and operation method thereof

Abstract

Provided is a power generating apparatus capable of using power generated by a heat engine in combination with power of a driving source provided separately from the heat engine. In order to prevent a problem caused when activating and stopping the apparatus, the apparatus of the present invention includes a rotary machine driving source which generates a rotational driving force for a rotary machine and a heat engine which drives the rotary machine in cooperation with the rotary machine driving source, wherein the heat engine includes an expander which expands an evaporated working medium so as to generate a rotational driving force, the expander is provided with a bypass pipe which causes a working medium inlet of the expander to communicate with a working medium outlet thereof, and the bypass pipe is provided with an on-off valve which opens and closes the bypass pipe.

What is claimed is: 
     
         1 . A power generating apparatus comprising:
 a rotary machine driving source which generates a rotational driving force for a rotary machine; and   a heat engine which drives the rotary machine in corporation with the rotary machine driving source,   wherein the heat engine includes an expander which expands an evaporated working medium so as to generate a rotational driving force,   wherein the expander is provided with a bypass pipe which causes a working medium inlet of the expander to communicate with a working medium outlet thereof, and   wherein the bypass pipe is provided with an on-off valve which opens and closes the bypass pipe.   
     
     
         2 . The power generating apparatus according to  claim 1 , further comprising:
 a control device which controls an opening and closing operation of the on-off valve,   wherein when activating the rotary machine driving source and the heat engine, the control device performs control which opens the on-off valve so that the working medium flows into the bypass pipe, activates the rotary machine driving source, and closes the on-off valve when it is determined that the working medium flowing into the expander is evaporated.   
     
     
         3 . The power generating apparatus according to  claim 2 , further comprising:
 a suction pressure detector which detects a suction pressure of the expander,   wherein the control device determines that the working medium flowing into the expander is evaporated when a pressure value detected by the suction pressure detector becomes a predetermined pressure value or more.   
     
     
         4 . The power generating apparatus according to  claim 2 , further comprising:
 a suction pressure detector which detects a suction pressure of the expander; and   an discharge pressure detector which detects an discharge pressure of the expander,   wherein the control device determines that the working medium flowing into the expander is evaporated when a differential pressure between a pressure value detected by the suction pressure detector and a pressure value detected by the discharge pressure detector becomes a predetermined value or more.   
     
     
         5 . The power generating apparatus according to  claim 2 ,
 wherein the rotary machine is a gas compressor,   wherein the power generating apparatus further comprises a temperature detector which detects an exhaust gas temperature of the gas compressor, and   wherein the control device determines that the working medium flowing into the expander is evaporated when a temperature value detected by the temperature detector becomes a predetermined temperature value or more.   
     
     
         6 . The power generating apparatus according to  claim 2 ,
 wherein the control device includes a time measuring unit which measures an elapse time from the activation of the rotary machine driving source, and   wherein the control device determines that the working medium flowing into the expander is evaporated when the elapse time detected by the time measuring unit becomes a predetermined time or more.   
     
     
         7 . The power generating apparatus according to  claim 1 , further comprising:
 a control device which controls an opening and closing operation of the on-off valve,   wherein when stopping the rotary machine driving source and the heat engine, the control device performs control which opens the on-off valve so that the working medium flows into the bypass pipe and the driving operation of the expander is stopped.   
     
     
         8 . The power generating apparatus according to  claim 1 , further comprising:
 a control device which controls an opening and closing operation of the on-off valve,   wherein when the rotary machine driving source is stopped under the state where the rotary machine driving source and the heat engine are normally operated, the control device performs control which opens the on-off valve so that the working medium flows into the bypass pipe and the driving operation of the expander is stopped.   
     
     
         9 . The power generating apparatus according to  claim 1 ,
 wherein the rotary machine is a compressor which compresses a gas supplied thereto in a high pressure state and the rotary machine driving source is a motor, and   wherein heat of a high-pressure gas produced by the compressor is used as a heat source for a working medium in an evaporator of the heat engine.   
     
     
         10 . The power generating apparatus according to  claim 1 ,
 wherein the rotary machine driving source is a second expander which generates power by expanding a heating medium as steam, and   wherein an evaporator of the heat engine heats and evaporates the working medium by the heating medium expanded by the second expander.   
     
     
         11 . The power generating apparatus according to  claim 10 , further comprising:
 a first shaft portion which is connected to a rotary shaft of the heat engine;   a second shaft portion which is connected to a rotary shaft of the second expander; and   a coupling portion which couples the first shaft portion and the second shaft portion to each other so that a driving force is transmitted through the coupled shaft portions,   wherein the coupling portion is configured as a speed increasing and decreasing mechanism which is provided between the first shaft portion and the second shaft portion so as to change a rotation speed.   
     
     
         12 . The power generating apparatus according to  claim 10 ,
 wherein water used in a condenser of the heat engine or water condensed from the steam in the evaporator of the heat engine is supplied as lubricant to a bearing of the rotary shaft of the second expander.   
     
     
         13 . The power generating apparatus according to  claim 1 , further comprising:
 a first shaft portion which is connected to a rotary shaft of the heat engine;   a second shaft portion which is connected to a rotary shaft of the rotary machine driving source; and   a coupling portion which couples the first shaft portion and the second shaft portion to each other so that a driving force is transmitted through the coupled shaft portions,   wherein at least one of the first shaft portion and the second shaft portion is accommodated inside a hermetic body, and   wherein the coupling portion is configured as a magnetic coupling which magnetically couples the first shaft portion and the second shaft portion to each other.   
     
     
         14 . A method of operating the power generating apparatus according to  claim 1 ,
 wherein when activating the heat engine and the rotary machine driving source, the on-off valve is opened so as to cause the working medium to flow into the bypass pipe, the heat engine and the rotary machine driving source are activated, and the on-off valve of the bypass pipe is closed when it is determined that the working medium flowing into the expander is evaporated, and   wherein when stopping the heat engine and the rotary machine driving source, the on-off valve is opened so as to cause the working medium to flow into the bypass pipe and the driving operation of the expander is stopped.   
     
     
         15 . The method of operating the power generating apparatus according to  claim 1 ,
 wherein when the rotary machine driving source is stopped under the state where the rotary machine driving source is normally operated, the on-off valve is opened so as to cause the working medium to flow into the bypass pipe and the driving operation of the expander is stopped.