Expander systems for harnessing energy from pressurized fluid flow

A system, comprising:

• a reciprocating expander, comprising:
• a piston disposed in a chamber;
• a crankshaft;
• a connector rod coupled between the piston and the crankshaft and configured to transfer torque to the crankshaft in response to movement of the piston in the chamber;
• and
• a fluid inlet and a fluid outlet on one side of the piston,
• wherein the reciprocating expander is configured to receive fluid at a first pressure and to output the fluid at a second pressure, the second pressure being lower than the first pressure;
• and
• a compressor connected to the reciprocating expander, wherein the compressor receives operating power from the reciprocating expander to compress another fluid stream.

A system, comprising:

• a reciprocating expander comprising a first reciprocating expander stage and a second reciprocating expander stage,
• wherein the first reciprocating expander stage has a first fluid inlet and a first fluid outlet, and the second reciprocating expander stage has a second fluid inlet and a second fluid outlet;
• a heat exchanger coupled between the first fluid outlet and the second fluid inlet, wherein the heat exchanger is configured to raise the temperature of gas flowing from the first fluid outlet to the second fluid inlet via heat exchange with ambient air or another fluid
• a first flowpath coupled to the reciprocating expander for providing gas from a wellbore to the reciprocating expander;
• and
• a second flowpath coupled to the reciprocating expander for providing gas from the reciprocating expander to downstream equipment at a second pressure.

A system, comprising:

• an expander;
• a compressor coupled to the expander and configured to receive operating power from the expander;
• a generator coupled to the expander and configured to generate electricity via rotation of the generator by the expander;
• and
• one or more components of electrolysis equipment coupled to the generator and configured to receive the electricity from the generator and to generate hydrogen gas via the electricity, wherein:
• the electrolysis equipment is coupled to the compressor for inputting the hydrogen gas generated via the electrolysis equipment into the compressor, and
• the compressor compresses the hydrogen gas.