A method and system for operating a cascaded organic Rankine cycle (ORC) system (100) utilizes two waste heat sources from a positive-displacement engine (106), resulting in increased efficiency of the engine (106) and the cascaded ORC system (100). A high temperature waste heat source from the positive-displacement engine (106) is used in a first ORC system (102) to vaporize a first working fluid (118). A low temperature waste heat source from the positive-displacement engine (106) is used in a second ORC system (104) to heat a second working fluid (130) to a temperature less than the vaporization temperature. The second working fluid (130) is then vaporized using heat from the first working fluid (118). In an exemplary embodiment, the positive-displacement engine (106) is a reciprocating engine. The high temperature waste heat source may be exhaust gas and the low temperature waste heat source may be jacket cooling water.

Cascaded organic rankine cycle (orc) system using waste heat from a reciprocating engine

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.

Heat Engine and Heat to Electricity Systems and Methods with Working Fluid Mass Management Control

A waste heat recovery system (10) includes at least two integrated rankine cycle systems (12, 14) coupled to at least two separate heat sources (18, 38, 40, 42, 44, 64, 78) having different temperatures. The first rankine cycle system (12) is coupled to a first heat source (18) and configured to circulate a first working fluid. The second rankine cycle system (14) is coupled to at least one second heat source and configured to circulate a second working fluid. The first and second working fluid are circulatable in heat exchange relationship through a cascading heat exchange unit (34) for condensation of the first working fluid in the first rankine cycle system (12) and evaporation of the second working fluid in the second rankine cycle system (14). At least one bypass unit (24, 58, 59, 65, 72, 80, 88, 96, 102, 108) is configured to divert at least a portion of the first working fluid to bypass the first evaporator (16), the first expander (30), the cascaded heat exchange unit (34), or combinations thereof; at least a portion of the second working fluid to bypass the second expander (46), the cascaded heat exchange unit (34), or combinations thereof.

Optimized system for recovering waste heat

A system for converting thermal energy to work. The system includes a working fluid circuit, and a precooler configured to receive the working fluid. The system also includes a compression stages and intercoolers. At least one of the precooler and the intercoolers is configured to receive a heat transfer medium from a high temperature ambient environment. The system also includes heat exchangers coupled to a source of heat and being configured to receive the working fluid. The system also includes turbines coupled to one or more of the heat exchangers and configured to receive heated working fluid therefrom. The system further includes recuperators fluidly coupled to the turbines, the precooler, the compressor, and at least one of the heat exchangers. The recuperators transfer heat from the working fluid downstream from the turbines, to the working fluid upstream from at least one of the heat exchangers.

Heat engine cycles for high ambient conditions

The present invention generally relates to a system that enables one to address various thermal management issues in advanced gas turbine engines. In one embodiment, the present invention relates to a method to extract heat from an air stream, utilize a significant fraction for on-board power generation, and reject a small quantity of heat to the fuel stream safely at, for example, a lower temperature. In another embodiment, the present invention relates to a method to extract heat from an air stream, utilize a significant fraction for on-board power generation, and reject a small quantity of heat to the fuel stream safely at, for example, a lower temperature with no potential air/fuel contact is disclosed.

System and method for managing thermal issues in gas turbine engines

In a waste heat recovery system wherein an organic rankine cycle system uses waste heat from the fluids of a reciprocating engine, provision is made to continue operation of the engine even during periods when the organic rankine cycle system is inoperative, by providing an auxiliary pump and a bypass for the refrigerant flow around the turbine. Provision is also made to divert the engine exhaust gases from the evaporator during such periods of operation. In one embodiment, the auxiliary pump is made to operate simultaneously with the primary pump during normal operations, thereby allowing the primary pump to operate at lower speeds with less likelihood of cavitation.

Organic rankine cycle system for use with a reciprocating engine

In a waste heat recovery system wherein a heat exchanger derives heat from an engine exhaust, a venturi is fluidly connected to an engine exhaust port so as to thereby increase the flow rate and reduce the pressure in a manifold which is fluidly connected between the venturis and the heat exchanger A fan is provided downstream of the heat exchanger to draw hot gases from the manifold, through the heat exchanger and discharge it to ambient But when the fan is not operating during periods in which the engine is operating, the lower pressure manifold will draw ambient air in through the fan and through the heat exchanger, with the ambient air then being entrained in the exhaust gases being discharged from an exhaust channel downstream of the venturi In one embodiment, a plurality of heat sources are provided with each having its own venturi connected to the common low pressure manifold

Duane Mccormick

Papers

Organic rankine cycle system for use with a reciprocating engine

Apparatus for extracting exhaust heat from waste heat sources while preventing backflow & corrosion