Abstract: A thermodynamic system and method for performing work includes a working fluid and a fluid pump for pumping the working fluid through a cycle. A thermal input supplies heat to the working fluid. An expansion device downstream of the thermal input converts at least the heat of the working fluid to useful work. A heat exchanger downstream of the expansion device has a first portion to transfer heat from downstream said expansion device to a second portion at or upstream of said thermal input. A conversion device expands the working fluid with constant enthalpy from a higher to a lower pressure.

Abstract: A thermodynamic system and method for performing work includes a working fluid and a fluid pump for pumping the working fluid through a cycle. A thermal input supplies heat to the working fluid. An expansion device downstream of the thermal input converts at least the heat of the working fluid to useful work. A heat exchanger downstream of the expansion device has a first portion to transfer heat from downstream said expansion device to a second portion at or upstream of said thermal input. A conversion device expands the working fluid with constant enthalpy from a higher to a lower pressure.

Abstract: A thermodynamic system and method for performing work includes a working fluid and a fluid pump for pumping the working fluid through a cycle. A thermal input supplies heat to the working fluid. An expansion device downstream of the thermal input converts at least the heat of the working fluid to useful work. A heat exchanger downstream of the expansion device has a first portion to transfer heat from downstream said expansion device to a second portion at or upstream of said thermal input. A conversion device expands the working fluid with constant enthalpy from a higher to a lower pressure. The conversion device may be part of a heat pump pumping heat from one portion of said working fluid to another portion of the working fluid.

Abstract: A thermodynamic system and method of producing useful work includes providing a working fluid and a fluid pump, or compressor, for pumping the working fluid in a cycle. A thermal input is provided for supplying heat to the working fluid. An expansion device downstream of the thermal input converts motion of the working fluid to useful work. A heat pump is provided. A number of different means of implementing the heat pump are presented, including direct transfer of working fluid mass flow. The heat pump pumps heat from one portion of the working fluid to another portion of the working fluid. For some applications, a regenerator, or recuperator, may be used to transfer heat from a high temperature portion of the working fluid to a lower temperature portion.

Abstract: A thermodynamic system and method of producing useful work includes providing a working fluid and a fluid pump, or compressor, for pumping the working fluid in a cycle. A thermal input is provided for supplying heat to the working fluid. An expansion device downstream of the thermal input converts motion of the working fluid to useful work. A heat pump is provided. A number of different means of implementing the heat pump are presented, including direct transfer of working fluid mass flow. The heat pump pumps heat from one portion of the working fluid to another portion of the working fluid. For some applications, a regenerator, or recuperator, may be used to transfer heat from a high temperature portion of the working fluid to a lower temperature portion.

Abstract: A method of converting a diesel engine to a natural gas engine comprising inserting a spark plug into a diesel fuel injector opening in a cylinder head; installing a throttle body on the diesel engine; installing a throttle body adaptor between a throttle body and an intake manifold of said diesel engine; and modifying a piston, whereby the compression ratio of said piston is decreased during operation of said piston. The method also includes installation of a waste gate and waste gate adaptor and a timing mask.

Abstract: A kit and method for converting a compression ignition diesel engine into a spark ignition natural gas engine is disclosed. The kit includes a throttle body, a fuel management system, a timing module, a means for reducing a compression ratio of a piston in the diesel engine, and a means for providing a spark in a cylinder of the natural gas engine. The method includes the steps of providing a diesel engine, machining one or more cylinder heads on the diesel engine to accept one or more spark plugs, machining a top surface of one or more pistons of the diesel engine to increase the volume of the one or more combustion chambers when the one or more pistons are located at top dead center in the diesel engine, providing a fuel management system to deliver the air/fuel mixture to the one or more combustion chambers, and providing a timing module to monitor the position of one or more camshafts on the diesel engine and provide piston position information to the fuel management system.

Abstract: In a time and temperature controlled defrost cycle for a heat pump system, defrost cycles are controlled by two variables: elapsed time since the last defrost cycle, and the refrigerant temperature in the outdoor coil. The elapsed time variable for the first defrost cycle after power-up is set less than the elapsed time variable required for subsequent defrost cycles. Thus, the system is not vulnerable to planned cyclical power outages if the power outage cycle time is less than the elapsed time variable required between regular defrost cycles.

Abstract: A method for the separation of gaseous mixtures such as air and for producing medium purity oxygen, comprising compressing the gaseous mixture in a first compressor to about 3.9-4.