RECIPROCATING COMPRESSOR WITH VAPOR INJECTION SYSTEM
A compressor assembly is provided and may include a compression cylinder and a compression piston disposed within the compression cylinder that compresses a vapor disposed within the compression cylinder from a suction pressure to a discharge pressure. The compressor assembly may additionally include a crankshaft that cycles the compression piston within the compression cylinder and an injection port in fluid communication with the compression cylinder that selectively communicates intermediate-pressure vapor at a pressure between the suction pressure vapor and the discharge pressure vapor to the compression cylinder. The injection port may communicate the intermediate-pressure vapor to the compression cylinder when the compression piston exposes the injection port and may be prevented from communicating the intermediate-pressure vapor to the compression cylinder when the compression piston blocks the injection port.
1 . A compressor assembly comprising:
a compression cylinder;
a compression piston disposed within said compression cylinder and operable to compress a vapor disposed within said compression cylinder from a suction pressure to a discharge pressure;
a crankshaft operable to cycle said compression piston within said compression cylinder; and
an injection port in fluid communication with said compression cylinder and operable to selectively communicate intermediate-pressure vapor at a pressure between said suction pressure vapor and said discharge pressure vapor to said compression cylinder, said injection port communicating said intermediate-pressure vapor to said compression cylinder when said compression piston exposes said injection port and prevented from communicating said intermediate-pressure vapor to said compression cylinder when said compression piston blocks said injection port.
2 . The compressor assembly of claim 1 , wherein said compression piston is movable within said compression cylinder between a top dead center (TDC) position and a bottom dead center (BDC) position, said compression piston exposing said injection port in said BDC position and blocking said injection port in said TDC position.
3 . The compressor of claim 2 , wherein said injection port is fully exposed when said compression piston is in said BDC position.
4 . The compressor of claim 2 , wherein said injection port is partially blocked by said compression piston when said compression piston is in said BDC position.
5 . The compressor of claim 2 , wherein said injection port includes at least two injection ports.
6 . The compressor of claim 5 , wherein said at least two injection ports are simultaneously exposed when said compression piston is in said BDC position.
7 . The compressor of claim 1 , further comprising a valve associated with said injection port, said valve operable to control passage of fluid from said injection port into said compression cylinder.
8 . The compressor of claim 7 , wherein said valve is a check valve that permits flow of said intermediate-pressure vapor into said compression cylinder and prevents flow of vapor from said compression cylinder into said injection port.
9 . The compressor of claim 7 , wherein said valve is an electronically controlled valve.
10 . The compressor of claim 9 , further comprising a controller in communication with said electronically controlled valve and operable to control said valve between an open state injecting said intermediate-pressure vapor into said compression cylinder and a closed state preventing injection of said intermediate-pressure vapor into said compression cylinder.
11 . A compressor assembly comprising:
a compression cylinder;
a compression piston disposed within said compression cylinder and operable to compress a vapor disposed within said compression cylinder from a suction pressure to a discharge pressure, said compression piston movable within said compression cylinder between a top dead center (TDC) position and a bottom dead center (BDC) position;
a crankshaft operable to cycle said compression piston within said compression cylinder; and
an injection port in fluid communication with said compression cylinder and operable to selectively communicate intermediate-pressure vapor at a pressure between said suction pressure vapor and said discharge pressure vapor to said compression cylinder, said injection port exposed by said compression piston when said compression piston is approaching said BDC position to permit communication of said inter-mediate pressure vapor into said compression cylinder.
12 . The compressor assembly of claim 11 , wherein said compression piston blocks said injection port in said TDC position to prevent communication of said intermediate-pressure vapor into said compression cylinder.
13 . The compressor of claim 11 , wherein said injection port is fully exposed when said compression piston is in said BDC position.
14 . The compressor of claim 11 , wherein said injection port is partially blocked by said compression piston when said compression piston is in said BDC position.
15 . The compressor of claim 11 , wherein said injection port includes at least two injection ports.
16 . The compressor of claim 15 , wherein said at least two injection ports are simultaneously exposed when said compression piston is in said BDC position.
17 . The compressor of claim 11 , further comprising a valve associated with said injection port, said valve operable to control passage of fluid from said injection port into said compression cylinder.
18 . The compressor of claim 17 , wherein said valve is a check valve that permits flow of said intermediate-pressure vapor into said compression cylinder and prevents flow of vapor from said compression cylinder into said injection port.
19 . The compressor of claim 17 , wherein said valve is an electronically controlled valve.
20 . The compressor of claim 19 , further comprising a controller in communication with said electronically controlled valve and operable to control said valve between an open state injecting said intermediate-pressure vapor into said compression cylinder and a closed state preventing injection of said intermediate-pressure vapor into said compression cylinder.