The present disclosure relates to systems and methods that are useful in control of one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants, methods of starting power production plants, and methods of generating power with a power production plant wherein one or more control paths are utilized for automated control of at least one action. The present disclosure more particularly relates to power production plants, control systems for power production plants, and methods for startup of a power production plant.

An energy storage plant includes a casing for the storage of a working fluid other than atmospheric air, in a gaseous phase and in equilibrium of pressure with the atmosphere; a tank for the storage of said working fluid in a liquid or supercritical phase with a temperature close to the critical temperature; wherein said critical temperature is close to the ambient temperature. The plant is configured to carry out a closed thermodynamic cyclic transformation, first in one direction in a charge configuration and then in the opposite direction in a discharge configuration, between said casing and said tank; wherein in the charge configuration the plant stores heat and pressure and in the discharge configuration generates energy.

A plant for energy storage, comprises: a basin (2) for a work fluid having a critical temperature (T.sub.c) lower than 0°; a tank (3) configured to store the work fluid in at least partly liquid or super-critical phase with a storage temperature (T.sub.s) close to the critical temperature (T.sub.c); an expander (4); a compressor (5); an operating/drive machine (6) operatively connected to the expander (4) and to the compressor (5); a thermal store (8) operatively interposed between the compressor (5) and the tank (3) and between the tank (3) and the expander (4). The plant (1) is configured for actuating a Cyclic Thermodynamic Transformation (TTC) with the work fluid, first in a storage configuration and then in a discharge configuration. The thermal store (8), in the storage configuration, is configured for absorbing sensible heat and subsequently latent heat from the work fluid and, in the discharge configuration, it is configured for transferring latent heat and subsequently sensible heat to the work fluid.

Power and cooling systems including a drive system, a power generation unit, and a cooled fluid generation unit. A primary working fluid that is expanded within a turbine of the drive system and compressed within compressors in a closed-loop cycle. The power generation unit includes a generator and a heat source configured to heat the primary working fluid prior to injection into the turbine. T cooled fluid generation unit includes an ejector downstream of the compressors and a separator arranged downstream of the ejector and configured to separate liquid and gaseous portions of the primary working fluid. The gaseous portion is directed to the compressors and the liquid portion is directed to an evaporator heat exchanger to generate cooled fluid.

Direct-fired supercritical carbon dioxide (CO.sub.2) power cycle that generates hydrogen. More specifically, the discharge of a direct fired supercritical CO.sub.2 power cycle is converted to carbon dioxide and hydrogen where the hydrogen and/or carbon dioxide can be separated and stored/utilized in another application.

An apparatus for converting thermal energy into mechanical energy by a cycle, having a heat exchanger, a reservoir for an operating medium, a feed line, a turbine, and a return line having at least one recovery device is described. In order to also be able to utilize waste heat for the generation of electrical energy, the turbine is embodied as a disc rotor turbine. A method for converting thermal energy into mechanical energy in a cycle is also described, in which thermal energy is supplied to an operating medium in a reservoir, the operating medium evaporates and/or a pressure in the operating medium is increased, whereupon the operating medium releases energy in a turbine, after which the operating medium is returned to the reservoir.

It is provided a power generation model based on a transcritical cycle with an increasing-pressure endothermic process using CO.sub.2-based mixture working fluids for an enhanced geothermal system, including a geothermal water circulation, a mixture working fluid circulation and a cooling water circulation. A coaxial pipe-in-pipe downhole heat exchanger is provided in the mixture working fluid circulation. Innovations are reflected in that an increasing-pressure endothermic process is achieved due to making use of gravity and hence increase a heat quantity absorbed in a cycle, thereby improving power generation quantity of the cycle; and a binary mixture working fluid composed of CO.sub.2 and an organic working fluid is adopted to realize a transcritical power cycle with an increasing-pressure endothermic process and a decreasing-temperature exothermic process, thereby effectively reducing irreversibility of a heat transfer between a working fluid and a heat source and improving power cycle efficiency.

The present disclosure relates to systems and methods wherein a dilute hydrocarbon stream can be oxidized to impart added energy to a power production system. The oxidation can be carried out without substantial combustion of the hydrocarbons. In this manner, dilute hydrocarbon streams that would otherwise be required to undergo costly separation processes can be efficiently utilized for improving the power production system and method. Such systems and methods particularly can utilize dilute hydrocarbon stream including a significant amount of carbon dioxide, such as may be produced in hydrocarbon recovery process, such as enhanced oil recovery or conventional hydrocarbon recovery processes.

A system includes a pump for conveying a flow medium, an arrangement for converting the flow medium from a liquid state into a gaseous state, a turbomachine for converting the thermal energy of the flow medium into mechanical work, a condenser for condensing the gaseous flow medium into a liquid state, with a cooling unit for cooling the liquid flow medium being arranged upstream of the pump in order to reduce the compression work.

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.