Abstract: Aspects of the invention disclosed herein generally provide a heat engine system, a turbopump system, and methods for lubricating a turbopump while generating energy. The systems and methods provide proper lubrication and cooling to turbomachinery components by controlling pressures applied to a thrust bearing in the turbopump. The applied pressure on the thrust bearing may be controlled by a turbopump back-pressure regulator valve adjusted to maintain proper pressures within bearing pockets disposed on two opposing surfaces of the thrust bearing. Pocket pressure ratios, such as a turbine-side pocket pressure ratio (P1) and a pump-side pocket pressure ratio (P2), may be monitored and adjusted by a process control system. In order to prevent damage to the thrust bearing, the systems and methods may utilize advanced control theory of sliding mode, the multi-variables of the pocket pressure ratios P1 and P2, and regulating the bearing fluid to maintain a supercritical state.

Abstract: Systems and methods are provided for charging a pumped thermal energy storage (“PTES”) system. A system may include a compressor or pump configured to circulate a working fluid within a fluid circuit, wherein the working fluid enters the pump at a first pressure and exits at a second pressure; a first heat exchanger through which the working fluid circulates in use; a second heat exchanger through which the working fluid circulates in use; a third heat exchanger through which the working fluid circulates in use, a turbine positioned between the first heat exchanger and the second heat exchanger, configured to expand the working fluid to the first pressure; a high temperature reservoir connected to the first heat exchanger; a low temperature reservoir connected to the second heat exchanger, and a waste heat reservoir connected to the third heat exchanger.

Abstract: Provided herein are heat engine systems and methods for transforming energy, such as generating mechanical energy and/or electrical energy from thermal energy. The heat engine systems may have one of several different configurations of a working fluid circuit. One configuration of the heat engine system contains at least four heat exchangers and at least three recuperators sequentially disposed on a high pressure side of the working fluid circuit between a system pump and an expander. Another configuration of the heat engine system contains a low-temperature heat exchanger and a recuperator disposed upstream of a split flowpath and downstream of a recombined flowpath in the high pressure side of the working fluid circuit.

Abstract: Systems and methods are provided for generating electricity via a pumped thermal energy storage (“PTES”) system. A system may include a pump configured to circulate a working fluid within a fluid circuit, wherein the working fluid enters the pump at a first pressure and exits at a second pressure; a first heat exchanger; a second heat exchanger; a turbine positioned between the first heat exchanger and the second heat exchanger, configured to expand a first portion of the working fluid to the first pressure; a heat rejection heat exchanger configured to remove thermal energy from a second portion of the working fluid; a high temperature reservoir connected to the first heat exchanger; and a low temperature reservoir connected to the second heat exchanger.

Abstract: Aspects of the invention disclosed herein generally provide a heat engine system, a turbopump system, and methods for lubricating a turbopump while generating energy. The systems and methods provide proper lubrication and cooling to turbomachinery components by controlling pressures applied to a thrust bearing in the turbopump. The applied pressure on the thrust bearing may be controlled by a turbopump back-pressure regulator valve adjusted to maintain proper pressures within bearing pockets disposed on two opposing surfaces of the thrust bearing. Pocket pressure ratios, such as a turbine-side pocket pressure ratio (P1) and a pump-side pocket pressure ratio (P2), may be monitored and adjusted by a process control system. In order to prevent damage to the thrust bearing, the systems and methods may utilize advanced control theory of sliding mode, the multi-variables of the pocket pressure ratios P1 and P2, and regulating the bearing fluid to maintain a supercritical state.

Abstract: A turbopump system includes a pump portion including a housing having a pressure release passageway disposed therein. The pump portion is disposed between a high pressure side and a low pressure side of a working fluid circuit. A drive turbine is coupled to the pump portion and configured to drive the pump portion to enable the pump portion to circulate a working fluid through the working fluid circuit. A pressure release valve is fluidly coupled to the pressure release passageway and configured to be positioned in an opened position to enable pressure to be released through the pressure release passageway and in a closed position to disable pressure from being released through the pressure release passageway.

Abstract: Systems and methods are provided for controlling the pressure of a working fluid at an inlet of a main pressurization device of a heat engine system. The heat engine system may include a control system and a working fluid circuit including a waste heat exchanger, an expansion device, a recuperator, a main pressurization device, and a heat exchanger assembly. The heat exchanger assembly may include a plurality of gas-cooled heat exchangers configured to transfer thermal energy from the working fluid to a cooling medium, a plurality of fans configured to direct the cooling medium into contact with the gas-cooled heat exchangers, and a plurality of drivers, each driver configured to drive a respective fan. The control system may be communicatively coupled to the heat exchanger assembly and configured to modulate a rotational speed of at least one fan to regulate a pressure of the working fluid at the inlet.

Abstract: Aspects of the invention generally provide a heat engine system and a method for activating a turbopump within the heat engine system during a start-up process. The heat engine system utilizes a working fluid circulated within a working fluid circuit for capturing thermal energy. In one exemplary aspect, a start-up process for a turbopump in the heat engine system is provided such that the turbopump achieves self-sustained operation in a supercritical Rankine cycle. Bypass and check valves of a start pump and the turbopump, a drive turbine throttle valve, and other valves, lines, or pumps within the working fluid circuit are controlled during the turbopump start-up process. A process control system may utilize advanced control techniques of the control sequence to provide a successful start-up process of the turbopump without over pressurizing the working fluid circuit or damaging the turbopump via low bearing pressure.

Abstract: Provided herein is a heat engine system and a method for transforming energy, such as generating mechanical energy and/or electrical energy from thermal energy. The heat engine system may have one of several different configurations of a mass management system (MMS) fluidly coupled to a working fluid circuit. The MMS may be utilized to control the amount of working fluid added to, contained within, or removed from the working fluid circuit. The MMS may contain a mass control tank, an inventory transfer line, and system/tank transfer valves. The MMS may contain a transfer pump fluidly coupled to the inventory transfer line and configured to control the pressure in the inventory transfer line. The MMS may have two or more transfer lines, such as an inventory return line and valve, and an inventory supply line and valve.

Abstract: A heat engine system and a method for cooling a fluid stream in thermal communication with the heat engine system are provided. The heat engine system may include a working fluid circuit configured to flow a working fluid therethrough, and a cooling circuit in fluid communication with the working fluid circuit and configured to flow the working fluid therethrough. The cooling circuit may include an evaporator in fluid communication with the working fluid circuit and configured to be in fluid communication with the fluid stream. The evaporator may be further configured to receive a second portion of the working fluid from the working fluid circuit and to transfer thermal energy from the fluid stream to the second portion of the working fluid.

Abstract: A method includes controlling a bearing fluid supply system to provide the bearing fluid to a hydrostatic bearing of the turbopump assembly. The bearing fluid includes a supercritical working fluid. The method also includes receiving data corresponding to a pressure of the bearing fluid measured at or near a bearing fluid drain fluidly coupled to the hydrostatic bearing, determining a thermodynamic state of the bearing fluid at or near the bearing fluid drain based at least in part on the received data, and controlling a backpressure regulation valve to throttle the backpressure regulation valve between an opened position and a closed position to regulate a backpressure in a bearing fluid discharge line to maintain the bearing fluid in a supercritical state in the hydrostatic bearing and/or at or near the bearing fluid drain.

Abstract: Systems and methods for controlling a heat engine system are provided. One method includes initiating flow of a working fluid through a working fluid circuit having a high pressure side and a low pressure side by controlling a pump to pressurize and circulate the working fluid through the working fluid circuit and determining a configuration of the working fluid circuit by determining which of a plurality of waste heat exchangers and which of a plurality of recuperators to position in the high pressure side of the working fluid circuit. The method also includes determining, based on the determined configuration of the working fluid circuit, for each of a plurality of valves, whether to position each respective valve in an opened position, a closed position, or a partially opened position and actuating each of the plurality of valves to the determined opened position, closed position, or partially opened position.

Abstract: Heat engine systems having selectively configurable working fluid circuits are provided. One heat engine system includes a pump that circulates a working fluid through a working fluid circuit and an expander that receives the working fluid from a high pressure side of the working fluid circuit and converts a pressure drop in the working fluid to mechanical energy. A plurality of waste heat exchangers are each selectively positioned in or isolated from the high pressure side. A plurality of recuperators are each selectively positioned in or isolated from the high pressure side and the low pressure side. A plurality of valves are actuated to enable selective control over which of the plurality of waste heat exchangers is positioned in the high pressure side, which of the plurality of recuperators is positioned in the high pressure side, and which of the plurality of recuperators is positioned in the low pressure side.

Abstract: Aspects of the invention disclosed herein generally provide heat engine systems and methods for generating electricity. In one configuration, a heat engine system contains a working fluid circuit having high and low pressure sides and containing a working fluid (e.g., sc-CO2). The system further contains a power turbine configured to convert thermal energy to mechanical energy, a motor-generator configured to convert the mechanical energy into electricity, and a pump configured to circulate the working fluid within the working fluid circuit. The system further contains a heat exchanger configured to transfer thermal energy from a heat source stream to the working fluid, a recuperator configured to transfer thermal energy from the low pressure side to the high pressure side of the working fluid circuit, and a condenser (e.g., air- or fluid-cooled) configured to remove thermal energy from the working fluid within the low pressure side of the working fluid circuit.

Abstract: 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.

Abstract: Embodiments of the invention generally provide a heat engine system, a method for generating electricity, and an algorithm for controlling the heat engine system which are configured to efficiently transform thermal energy of a waste heat stream into electricity. In one embodiment, the heat engine system utilizes a working fluid (e.g., sc-CO2) within a working fluid circuit for absorbing the thermal energy that is transformed to mechanical energy by a turbine and electrical energy by a generator. The heat engine system further contains a control system operatively connected to the working fluid circuit and enabled to monitor and control parameters of the heat engine system by manipulating a power turbine throttle valve to adjust the flow of the working fluid. A control algorithm containing multiple system controllers may be utilized by the control system to adjust the power turbine throttle valve while maximizing efficiency of the heat engine system.

Abstract: Provided herein are heat engine systems and methods for starting such systems and generating electricity while avoiding damage to one or more system components. A provided heat engine system maintains a working fluid (e.g., sc-CO2) within the low pressure side of a working fluid circuit in a liquid-type state, such as a supercritical state, during a startup procedure. Additionally, a bypass system is provided for routing the working fluid around one or more heat exchangers during startup to avoid overheating of system components.

Abstract: Aspects of the disclosure generally provide a heat engine system and a method for regulating a pressure and an amount of a working fluid in a working fluid circuit during a thermodynamic cycle. A mass management system may be employed to regulate the working fluid circulating throughout the working fluid circuit. The mass management systems may have a mass control tank fluidly coupled to the working fluid circuit at one or more strategically-located tie-in points. A heat exchanger coil may be used in conjunction with the mass control tank to regulate the temperature of the fluid within the mass control tank, and thereby determine whether working fluid is either extracted from or injected into the working fluid circuit. Regulating the pressure and amount of working fluid in the working fluid circuit selectively increases or decreases the suction pressure of the pump to increase system efficiency.

Abstract: The present invention generally relates to a system that enables one to both: (i) address various thermal management issues (e.g., inlet air cooling) in gas turbines, gas turbine engines, industrial process equipment and/or internal combustion engines; and (ii) yield a supercritical fluid-based heat engine. In one embodiment, the present invention utilizes at least one working fluid selected from ammonia, carbon dioxide, nitrogen, or other suitable working fluid medium. In another embodiment, the present invention utilizes carbon dioxide or ammonia as a working fluid to achieve a system that enables one to address inlet cooling issues in a gas turbine, internal combustion engine or other industrial application while also yielding a supercritical fluid based heat engine as a second cycle using the waste heat from the gas turbine and/or internal combustion engine to create a combined power cycle.

Abstract: Aspects of the disclosure generally provide a heat engine system with a working fluid circuit and a method for starting a turbopump disposed in the working fluid circuit. The turbopump has a main pump and may be started and ramped-up using a starter pump arranged in parallel with the main pump of the turbopump. Once the turbopump reaches a self-sustaining speed of operation, a series of valves may be manipulated to deactivate the starter pump and direct additional working fluid to a power turbine for generating electrical power.