Echogen Power Systems Inc. | Date: 2014-08-27
Embodiments of the invention generally provide a heat engine system, a mass management system (MMS), and a method for regulating pressure in the heat engine system while generating electricity. In one embodiment, the MMS contains a tank fluidly coupled to a pump, a turbine, a heat exchanger, an offload terminal, and a working fluid contained in the tank at a storage pressure. The working fluid may be at a system pressure proximal an outlet of the heat exchanger, at a low-side pressure proximal a pump inlet, and at a high-side pressure proximal a pump outlet. The MMS contains a controller communicably coupled to a valve between the tank and the heat exchanger outlet, a valve between the tank and the pump inlet, a valve between the tank and the pump outlet, and a valve between the tank and the offload terminal.
Echogen Power Systems Inc. | Date: 2015-05-08
A system including a seal cartridge is provided. The seal cartridge includes a housing defining a passageway that receives a driveshaft. A dry gas seal is circumferentially disposed about the passageway within the housing at a first axial location along the housing. A magnetic liquid seal is circumferentially disposed about the passageway within the housing at a second axial location along the housing. A fluid leakage cavity is formed between the dry gas seal at the first axial location and the magnetic liquid seal at the second axial location. An extraction port is disposed in the housing and enables recovery of a leaked fluid from the fluid leakage cavity.
Echogen Power Systems Inc. | Date: 2015-07-16
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.
Echogen Power Systems Inc. | Date: 2015-07-20
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-CO_(2)). 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.
Echogen Power Systems Inc. | Date: 2014-01-27
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-CO_(2)) 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.
Echogen Power Systems Inc. | Date: 2014-09-03
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.
Echogen Power Systems Inc. | Date: 2014-03-12
A heat engine system and a method for generating electrical energy from the heat engine system are provided. The method includes circulating via a turbo pump a working fluid within a working fluid circuit of the heat engine system. The method also includes transferring thermal energy from a heat source stream to the working fluid by at least a primary heat exchanger, feeding the working fluid into a power turbine and converting the thermal energy from the working fluid to mechanical energy, and converting the mechanical energy into electrical energy by a generator coupled to the power turbine. At least one valve operatively coupled to a control system is modulated in order to synchronize the generator with an electrical grid. A generator breaker is closed such that the generator and electrical grid are electrically coupled and the electrical energy is supplied to the electrical grid.
Echogen Power Systems Inc. | Date: 2014-09-03
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.
Echogen Power Systems Inc. | Date: 2014-03-13
Provided herein are a heat engine system and a method for generating energy, such as transforming thermal energy into mechanical energy and/or electrical energy. The heat engine system may have a single charging pump for efficiently implementing at least two independent tasks. The charging pump may be utilized to remove working fluid (e.g., CO2) from and/or to add working fluid into a working fluid circuit during inventory control of the working fluid. The charging pump may be utilized to transfer or otherwise deliver the working fluid as a cooling agent to bearings contained within a bearing housing of a system component during a startup process. The heat engine system may also have a mass control tank utilized with the charging pump and configured to receive, store, and distribute the working fluid.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2016
Supercritical carbon dioxide (sCO2) power cycles offer higher thermodynamic efficiency than both traditional and advanced steam Rankine cycles. One of the significant, but rarely recognized challenges of this type of cycle is the need to actively manage the fluid inventory within the primary power cycle loop to properly control the inlet pressure to the compressor/pump(s). Without inventory management, changes in operating state due to ambient temperature, source temperature, or source heat flow result in uncontrolled variation in the inlet state to the compression devices, leading to substantial performance loss, or even physical damage to the fluid impellers. Echogen has significant experience in the operational control of megawatt-class sCO2 power cycles, and has developed control algorithms with demonstrated effectiveness in control of compressor/pump inlet pressure over a wide range of operating conditions. However, the primary method for fluid addition to the main loop is transfer of lower pressure liquid CO2 into the main loop using positive displacement pumps due to the high head and relatively low flow needed for this service. Currently-available commercial pumps of this type and capacity are generally of the plunger type. While effective and efficient, the sliding seals represent an objectionable fluid leak source, and a large component of the maintenance burden of the cycle. Traditional centrifugal pumps require a large number of stages to develop the high head needed for the fluid transfer service. As a result, they have a low overall efficiency, and require a large physical footprint. Alternatively, regenerative pumps allow for a much higher head with fewer stages. However, few commercial versions of this pump style exist, and none combine the regenerative impeller with the near-zero leakage requirement for the sCO2 application. We propose the development of a purpose-designed sCO2 “transfer pump,” which satisfies the high head, low-to-moderate flow, and zero leakage requirements of the present application. The Phase I program would include the design, fabrication and test of a subscale version of this pump. The design tools and parametric relationships derived during the Phase I program would then be used in a Phase II effort to design a full-scale version of the pump for commercial service. Key Words: Supercritical CO2, power cycles, regenerative pump