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: Provided herein are a heat engine system and a method for managing a working fluid in the heat engine system during an emergency shutdown. The heat engine system utilizes a working fluid (e.g., sc-CO2) contained within a working fluid circuit to absorb and transport heat. An inventory system is coupled to the working fluid circuit and configured to receive and store at least a portion of the working fluid in the working fluid circuit during an emergency shutdown process. An attemperation line is coupled to the working fluid circuit upstream one or more heat exchangers and configured to direct a portion of the working fluid flow around at least one or more heat exchangers, thereby managing the temperature of the working fluid in the working fluid circuit.

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.