Systems and methods for venting a pressurized fluid used as a fuel in an engine

An engine system, comprising:

• an engine configured to combust a gaseous fuel;
• a fuel feed line used to provide the gaseous fuel to the engine;
• a fuel shutoff valve configured to, when closed, isolate the gaseous fuel from the fuel feed line;
• a fuel feed vent valve configured to, when open, vent a first volume of the fuel feed line from the fuel shutoff valve to the fuel feed vent valve;
• a first gas shutoff valve and a second gas shutoff valve downstream of the first gas shutoff valve, wherein the first gas shutoff valve or the second gas shutoff valve is configured to, when closed, isolate the first volume of the fuel feed line from the fuel shutoff valve to the first gas shutoff valve or the second gas shutoff valve;
• an isolation vent valve configured to, when open, vent a second volume of the fuel feed line from the second gas shutoff valve to a plurality of gas admission valves of the engine;
• and
• an engine purge controller comprising:
• a memory storing computer-executable instructions;
• and
• a processor in communication with the memory, the computer-executable instructions causing the processor to perform acts comprising:
• receiving, at the engine purge controller, a shutdown notice;
• issuing, by the engine purge controller, a fuel connection signal to cause the fuel shutoff valve to close;
• issuing, by the engine purge controller, a first gas shutoff valve signal to cause the first gas shutoff valve to close;
• issuing, by the engine purge controller, a second gas shutoff valve signal to cause the second gas shutoff valve to close;
• issuing, by the engine purge controller, a first vent valve signal to cause the fuel feed vent valve to open to vent the first volume of the fuel feed line;
• and
• issuing, by the engine purge controller, a second vent valve signal to cause the isolation vent valve to open to vent the second volume;
• waiting a predetermined period of time after issuing the first gas shutoff valve signal;
• and
• issuing the second gas shutoff valve signal after the predetermined period of time.

A non-transitory computer-readable media storing computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• receiving, at an engine purge controller, a shutdown notice to shut down an engine of an engine system, the engine system comprising:
• the engine configured to combust a gaseous fuel;
• a fuel feed line used to provide the gaseous fuel to the engine;
• a fuel shutoff valve configured to, when closed, isolate the gaseous fuel from the fuel feed line;
• a fuel feed vent valve configured to, when open, vent a first volume of the fuel feed line from the fuel shutoff valve to the fuel feed vent valve;
• a first gas shutoff valve and a second gas shutoff valve downstream of the first gas shutoff valve, wherein the first gas shutoff valve or the second gas shutoff valve is configured to, when closed, isolate the first volume of the fuel feed line from the fuel shutoff valve to the first gas shutoff valve or the second gas shutoff valve;
• and
• an isolation vent valve configured to, when open, vent a second volume of the fuel feed line from the second gas shutoff valve to a plurality of gas admission valves of the engine;
• issuing, by the engine purge controller, a fuel connection signal to cause the fuel shutoff valve to close;
• issuing, by the engine purge controller, a first gas shutoff valve signal to cause the first gas shutoff valve to close;
• issuing, by the engine purge controller, a second gas shutoff valve signal to cause the second gas shutoff valve to close;
• issuing, by the engine purge controller, a first vent valve signal to cause the fuel feed vent valve to open to vent the first volume of the fuel feed line;
• issuing, by the engine purge controller, a second vent valve signal to cause the isolation vent valve to open to vent the second volume;
• receiving, by the engine purge controller, a pressure signal from a pressure detector indicating that a pressure in a volume of the fuel feed line is below a predetermined pressure;
• and
• issuing the second gas shutoff valve signal.