Gas turbine engines are described. The gas turbine engines includes a compressor section, a combustor section, a turbine section, and a nozzle section. The compressor section, the combustor section, the turbine section, and the nozzle section define a core flow path that expels through the nozzle section. A cooling duct is provided that is separate from the core flow path. A waste heat recovery system is arranged with a heat rejection heat exchanger arranged within the cooling duct and a blower is arranged within the cooling duct and configured to generate a pressure drop across the heat rejection heat exchanger.

A supercritical carbon dioxide power generation Brayton cycle system and method that employs an alternate heat recuperation method and apparatus that utilizes switched banks of bead filled tanks to accumulate and recover the thermal energy of the two streams of working fluid in such a way that the variable thermal properties of the supercritical carbon dioxide can be accommodated without significant loss of thermal efficiency.

A method for converting thermal energy into mechanical energy in a thermodynamic cycle includes placing a thermal energy source in thermal communication with a heat exchanger arranged in a working fluid circuit containing a working fluid (e.g., sc-CO2) and having a high pressure side and a low pressure side. The method also includes regulating an amount of working fluid within the working fluid circuit via a mass management system having a working fluid vessel, pumping the working fluid through the working fluid circuit, and expanding the working fluid to generate mechanical energy. The method further includes directing the working fluid away from the expander through the working fluid circuit, controlling a flow of the working fluid in a supercritical state from the high pressure side to the working fluid vessel, and controlling a flow of the working fluid from the working fluid vessel to the low pressure side.

The present disclosure is directed to heat recovery systems that employ two or more organic Rankine cycle (ORC) units disposed in series. According to certain embodiments, each ORC unit includes an evaporator that heats an organic working fluid, a turbine generator set that expands the working fluid to generate electricity, a condenser that cools the working fluid, and a pump that returns the working fluid to the evaporator. The heating fluid is directed through each evaporator to heat the working fluid circulating within each ORC unit, and the cooling fluid is directed through each condenser to cool the working fluid circulating within each ORC unit. The heating fluid and the cooling fluid flow through the ORC units in series in the same or opposite directions.

A unique method and ternary cycle process that captures heat from low temperature sources currently considered not commercially usable to produce electricity and desalinate water. In one cycle a novel flash tower operating at vacuum pressure causes a fraction of low temperature water to flash into steam. The steam passes to an indirect heat exchanger with a circulating refrigerating agent such as CO.sub.2, which condenses the steam on its outside surfaces to produce desalinated water product. The steam heat of condensation vaporizes the refrigerating agent, which is part of a binary refrigerate cycle that uniquely conditions it for turbine expansion to produce electricity in a connected electric generator.

This invention refers to an installation for the generation of mechanical energy using a Combined Power Cycle which comprises, at least; means to implement a closed or semi-closed regenerative constituent Brayton cycle which uses water as thermal fluid, means to implement at least one Rankine cycle, the constituent basic Rankine cycle, interconnected with the regenerative constituent Brayton cycle, and a heat pump (UAX) which makes up a closed circuit that regenerates the regenerative constituent Brayton cycle;
as well as the procedure for generating energy through the use of the cited installation.

Systems and methods for converting energy are provided. In one aspect, the system includes a closed cycle engine defining a cold side. The system also includes a bottoming-cycle loop. A pump is operable to move a working fluid along the bottoming-cycle loop. A cold side heat exchanger is positioned along the bottoming-cycle loop in a heat exchange relationship with the cold side of the closed cycle engine. A constant density heat exchanger is positioned along the bottoming-cycle loop downstream of the cold side heat exchanger and upstream of an expansion device. The constant density heat exchanger is operable to hold a volume of the working fluid flowing therethrough at constant density while increasing, via a heat source, the temperature and pressure of the working fluid. The expansion device receives the working fluid at elevated temperature and pressure and extracts thermal energy from the working fluid to produce work.

Aspects of the invention provided herein include heat engine systems, methods for generating electricity, and methods for starting a turbo pump. In some configurations, the heat engine system contains a start pump and a turbo pump disposed in series along a working fluid circuit and configured to circulate a working fluid within the working fluid circuit. The start pump may have a pump portion coupled to a motor-driven portion and the turbo pump may have a pump portion coupled to a drive turbine. In one configuration, the pump portion of the start pump is fluidly coupled to the working fluid circuit downstream of and in series with the pump portion of the turbo pump. In another configuration, the pump portion of the start pump is fluidly coupled to the working fluid circuit upstream of and in series with the pump portion of the turbo pump.

Systems and methods are provided for regenerating a bed containing absorbed and/or adsorbed CO.sub.2 using a low value steam stream. The steam stream can have a pressure of 10 kPa-a to 50 kPa-a and a temperature of 46° C. to 81° C. The steam stream can be used to displace CO.sub.2 from the bed, resulting in formation of a low pressure stream including water vapor and CO.sub.2. The stream containing water vapor and CO.sub.2 is then passed through a liquid ring pump that includes an associated ring cooler. The ring pump provides the suction necessary to draw the low value steam stream through the bed to displace the CO.sub.2. Due to the nature of operation of the liquid ring pump, the majority of water in the steam containing H.sub.2O and CO.sub.2 can be removed within the liquid ring pump, resulting in production of a stream comprising 90 vol % or more of CO.sub.2 at a pressure of 90 kPa-a or more. An example of a bed that can be regenerated using a low value steam stream is a bed that corresponds to a liquid amine that is coated on/covering/impregnated into a porous solid, so that the liquid amine remains substantially in place during a cycle of sorption and desorption of CO.sub.2.

Techniques for cogeneration of heat and power are disclosed. A cogeneration system includes: a conduit loop configured to carry a working fluid using a Rankine cycle; a valve system disposed along the conduit loop, including valves configured to manage flow of the working fluid through a chamber; a backflow vapor line disposed along the conduit loop, configured to direct working fluid in a gaseous state to the chamber, such that the working fluid in the gaseous state displaces working fluid in a liquid state in the chamber and the working fluid in the liquid state advances through the conduit loop without requiring a mechanical pump; and a heat exchanger disposed along the conduit loop, configured to extract heat from the working fluid and direct the heat to a practical use.