A multi-stage gas compression system useful at the production site and at central collection points, having an energy efficient and effective intercooler system. The system includes a reciprocating compressor having a plurality of compressor valves and cylinders configured in series to provide staged compression to the natural gas. Coupled with the compressor are an inlet port for receiving natural gas to be compressed, and an outlet port for delivering compressed fluid from the compressor to a discharge line, to the transmission pipeline or storage. Facilitating transmission and intercooling of the natural gas between cylinders are a plurality of pipes, each pipe in close proximity with an intercooler. The rate of cooling of the intercooler is determined by a control system coupled therewith, including a temperature sensor positioned within pipe proximal to the intercooler, and means to compare the temperature measured by the temperature sensor and an optimal temperature or temperature range, and determine appropriate levels of cooling provided by the intercooler.

A compound engine assembly for use as an auxiliary power unit for an aircraft and including an engine core with internal combustion engine(s), a compressor having an outlet in fluid communication with an engine core inlet, a bleed conduit in fluid communication with the compressor outlet through a bleed air valve, and a turbine section having an inlet in fluid communication with the engine core outlet and configured to compound power with the engine core. The turbine section may include a first stage turbine having an inlet in fluid communication with the engine core outlet and a second stage turbine having an inlet in fluid communication the first stage turbine outlet. A method of providing compressed air and electrical power to an aircraft is also discussed.

A gas turbine engine has a compressor section with a low pressure compressor and a high pressure compressor having a downstream end. A cooling air system includes a tap from a location upstream of the downstream most location. The tap passes air to a boost compressor, and the boost compressor passes the air back to a location to be cooled. The boost compressor is driven by a shaft in the engine through an epicyclic gear system. A speed control changes the relative speed between an input and an output to the epicyclic gear system.

A gas turbine engine has a compressor section with a low pressure compressor and a high pressure compressor having a downstream end. A cooling air system includes a tap from a location upstream of the downstream most location. The tap passes air to a boost compressor, and the boost compressor passes the air back to a location to be cooled. The boost compressor is driven by a shaft in the engine through an epicyclic gear system. A speed control changes the relative speed between an input and an output to the epicyclic gear system.

A compressor system includes a compressor having a discharge port; and a shell and tube heat exchanger fluidly coupled to the discharge port. The heat exchanger includes a shell and a tube bundle disposed inside the shell. The shell includes a first flat portion extending along a longitudinal axis of the shell from a first end of the shell to a second end of the shell, and a second flat portion parallel to the first flat portion and extending along the longitudinal axis between the first end and the second end. The tube bundle is positioned between the first flat portion and the second flat portion, and extends along the longitudinal axis between the first end of the shell and the second end of the shell.

A gas turbine engine has a compressor section with a low pressure compressor and a high pressure compressor having a downstream end. A cooling air system includes a tap from a location upstream of the downstream most location. The tap passes air to a boost compressor, and the boost compressor passes the air back to a location to be cooled. The boost compressor is driven by a shaft in the engine through an epicyclic gear system. A speed control changes the relative speed between an input and an output to the epicyclic gear system.

A compound engine assembly for use as an auxiliary power unit for an aircraft and including an engine core with internal combustion engine(s), a compressor having an outlet in fluid communication with an engine core inlet, a bleed conduit in fluid communication with the compressor outlet through a bleed air valve, and a turbine section having an inlet in fluid communication with the engine core outlet and configured to compound power with the engine core. The turbine section may include a first stage turbine having an inlet in fluid communication with the engine core outlet and a second stage turbine having an inlet in fluid communication the first stage turbine outlet. A method of providing compressed air and electrical power to an aircraft is also discussed.

A compound engine assembly for use as an auxiliary power unit for an aircraft and including an engine core with internal combustion engine(s), a compressor having an outlet in fluid communication with an engine core inlet, a bleed conduit in fluid communication with the compressor outlet through a bleed air valve, and a turbine section having an inlet in fluid communication with the engine core outlet and configured to compound power with the engine core. The turbine section may include a first stage turbine having an inlet in fluid communication with the engine core outlet and a second stage turbine having an inlet in fluid communication the first stage turbine outlet. A method of providing compressed air and electrical power to an aircraft is also discussed.

A compressor system includes a compressor having a discharge port; and a shell and tube heat exchanger fluidly coupled to the discharge port. The heat exchanger includes a shell and a tube bundle disposed inside the shell. The shell includes a first flat portion extending along a longitudinal axis of the shell from a first end of the shell to a second end of the shell, and a second flat portion parallel to the first flat portion and extending along the longitudinal axis between the first end and the second end. The tube bundle is positioned between the first flat portion and the second flat portion, and extends along the longitudinal axis between the first end of the shell and the second end of the shell.

A multi-stage gas compression system useful at the production site and at central collection points, having an energy efficient and effective intercooler system. The system includes a reciprocating compressor having a plurality of compressor valves and cylinders configured in series to provide staged compression to the natural gas. Coupled with the compressor are an inlet port for receiving natural gas to be compressed, and an outlet port for delivering compressed fluid from the compressor to a discharge line, to the transmission pipeline or storage. Facilitating transmission and intercooling of the natural gas between cylinders are a plurality of pipes, each pipe in close proximity with an intercooler. The rate of cooling of the intercooler is determined by a control system coupled therewith, including a temperature sensor positioned within pipe proximal to the intercooler, and means to compare the temperature measured by the temperature sensor and an optimal temperature or temperature range, and determine appropriate levels of cooling provided by the intercooler.