Abstract: A pair of organic Rankine cycle systems (20, 25) are combined and their respective organic working fluids are chosen such that the organic working fluid of the first organic Rankine cycle is condensed at a condensation temperature that is well above the boiling point of the organic working fluid of the second organic Rankine style system, and a single common heat exchanger (23) is used for both the condenser of the first organic Rankine cycle system and the evaporator of the second organic Rankine cycle system. A preferred organic working fluid of the first system is toluene and that of the second organic working fluid is R245fa.

Abstract: A pair of organic Rankine cycle systems (20, 25) are combined and their respective organic working fluids are chosen such that the organic working fluid of the first organic Rankine cycle is condensed at a condensation temperature that is well above the boiling point of the organic working fluid of the second organic Rankine style system, and a single common heat exchanger (23) is used for both the condenser of the first organic Rankine cycle system and the evaporator of the second organic Rankine cycle system. A preferred organic working fluid of the first system is toluene and that of the second organic working fluid is R245fa.

Abstract: Turbulators are disclosed for use in a high-stage generator for an exhaust-fired absorption chiller/heater. The turbulators are designed to minimize pressure drop across the turbulator, and thus minimize the efficiency loss to the exhaust source. One turbulator design has a number of flanges extending at a non-normal angle to a central web. Further, some of the flanges have cutout portions. The overall turbulator design is intended to minimize wake downstream of the turbulator blades, which could otherwise cause undesirable pressure drop. A second turbulator design incorporates flanges that extend at a normal angle relative to the central web, but wherein the flanges have a non-rectangular cross-sectional shape. Again, the goal of the turbulator designs here is to minimize wake, and potential pressure drop.

Abstract: A control for controlling the amount of heated fluid entering the inlet of the driving heat source for a refrigerant absorption cycle is controlled to vary the relative amount of heated fluid entering the driving heat source inlet, and being dumped to atmosphere. Preferably, a diverter valve is utilized such that a first valve body (40) communicates the flow into the driving heat source inlet, and moves in opposition to a second valve body (46) controlling the flow through the exhaust. The two valves bodies (40, 46) are preferably mechanically linked. Since the heated fluid is not allowed to enter the refrigerant absorption cycle as its drive heating source, no additional hardware and control for dumping excess heat is necessary within the refrigerant absorption cycle. A computer control preferably drives the first valve to a precise position and the linkage ensures the second valve is also received at a precise position.

Abstract: A machine designed as a centrifugal compressor is applied as an organic rankine cycle turbine by operating the machine in reverse. In order to accommodate the higher pressures when operating as a turbine, a suitable refrigerant is chosen such that the pressures and temperatures are maintained within established limits. Such an adaptation of existing, relatively inexpensive equipment to an application that may be otherwise uneconomical, allows for the convenient and economical use of energy that would be otherwise lost by waste heat to the atmosphere.

Abstract: A machine designed as a centrifugal compressor is applied as an organic rankine cycle turbine by operating the machine in reverse. In order to accommodate the higher pressures when operating as a turbine, a suitable refrigerant is chosen such that the pressures and temperatures are maintained within established limits. Such an adaptation of existing, relatively inexpensive equipment to an application that may be otherwise uneconomical, allows for the convenient and economical use of energy that would be otherwise lost by waste heat to the atmosphere.

Abstract: Turbulators are disclosed for use in a high-stage generator for an exhaust-fired absorption chiller/heater. The turbulators are designed to minimize pressure drop across the turbulator, and thus minimize the efficiency loss to the exhaust source. One turbulator design has a number of flanges extending at a non-normal angle to a central web. Further, some of the flanges have cutout portions. The overall turbulator design is intended to minimize wake downstream of the turbulator blades, which could otherwise cause undesirable pressure drop. A second turbulator design incorporates flanges that extend at a normal angle relative to the central web, but wherein the flanges have a non-rectangular cross-sectional shape. Again, the goal of the turbulator designs here is to minimize wake, and potential pressure drop.

Abstract: This application discloses a control logic for maintaining a proper solution concentration within an absorption chiller. Further, safeguards are added to a system control to ensure robust operation when operated in a co-generation application with a heat source such as a micro-turbine, a reciprocating engine, etc. In such applications, in proper management of the heat flow into the chiller from such sources can result in crystallization of the absorption solution, which would be undesirable. Inventive control logic works to minimize such occurrences.

Abstract: 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.

Abstract: A prime mover (28) in a heat recovery system drives an induction generator (8) which feeds power to a utility grid (9) through a breaker (10) but also powers a load including auxiliary induction motors (11, 12). To provide acceptable waveform and power factor, the auxiliary equipment is driven through IGBT switched bridge converters (13) by DC voltage (15) generated by an IGBT switched bridge converter (13a), instead of three-phase diode rectifiers (16). The switched bridge converter controller (14a) is responsive to a system process controller (23a) which causes the switched bridge controller (13a) to be driven in response to the voltage (26) and current (27) on the generator bus (17). This eliminates the need for harmonic filters (18) and power factor capacitors (20) while improving the quality of the power generated. The controller (23a) trips the breaker if the voltage, frequency or power factor is out of limits.

Abstract: In order to effectively extract the waste heat from a reciprocating engine, the normal heat exchanger components of an engine are replaced with one or more heat exchangers which have the motive fluid of an organic rankine cycle system flowing therethrough. With the heat transfer in the plurality of heat exchangers, the engine is maintained at a reasonable cool temperature and the extracted heat is supplied to an ORC turbine to generate power. The heat is derived from a plurality of sources within the reciprocating engine, and at least two of those sources have their fluids passing through the same heat exchanger. In one embodiment, the engine coolant and the engine lubricant pass through the heat exchanger in the same direction, and the ORC motive fluid passes therethrough in a counterflow relationship.

Abstract: A power conversion system which uses a plurality of transistors to convert DC power to AC power is made more efficient by the use of liquid refrigerant to cool the transistors. A plurality of passages are formed in a cold plate on which the transistors are mounted, and liquid refrigerant is flashed into the passages to cool the cold plate and the transistors. The liquid refrigerant can by derived from a condenser from an organic rankine cycle or a vapor compression cycle.

Abstract: A power conversion system which uses a plurality of transistors to convert DC power to AC power is made more efficient by the use of liquid refrigerant to cool the transistors. A plurality of passages are formed in a cold plate on which the transistors are mounted, and liquid refrigerant is flashed into the passages to cool the cold plate and the transistors. The liquid refrigerant can by derived from a condenser from an organic rankine cycle or a vapor compression cycle.

Abstract: 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.

Abstract: This application discloses a control logic for maintaining a proper solution concentration within an absorption chiller. Further, safeguards are added to a system control to ensure robust operation when operated in a co-generation application with a heat source such as a micro-turbine, a reciprocating engine, etc. In such applications, in proper management of the heat flow into the chiller from such sources can result in crystallization of the absorption solution, which would be undesirable. Inventive control logic works to minimize such occurrences.

Abstract: An absorption chiller system has an efficient start-up control that monitors system condition, and in particular the absorption solution temperature. The system limits the amount of heat delivered into the absorption chiller generator, to provide a gradual rise in the absorption solution temperature at start-up. In this manner, undesirable noise vibration and rapid thermal expansion, which may have occurred in the past is reduced or eliminated.

Abstract: In a Rankine cycle system wherein a vapor generator receives heat from exhaust gases, provision is made to avoid overheating of the refrigerant during ORC system shut down while at the same time preventing condensation of those gases within the vapor generator when its temperature drops below a threshold temperature by diverting the flow of hot gases to ambient and to thereby draw ambient air through the vapor generator in the process. In one embodiment, a bistable ejector is adjustable between one position, in which the hot gases flow through the vapor generator, to another position wherein the gases are diverted away from the vapor generator. Another embodiment provides for a fixed valve ejector with a bias towards discharging to ambient, but with a fan on the downstream side of said vapor generator for overcoming this bias.

Abstract: An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor.

Abstract: 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.

Abstract: In a Rankine cycle system wherein a vapor generator receives heat from exhaust gases, provision is made to avoid overheating of the refrigerant during ORC system shut down while at the same time preventing condensation of those gases within the vapor generator when its temperature drops below a threshold temperature by diverting the flow of hot gases to ambient and to thereby draw ambient air through the vapor generator in the process. In one embodiment, a bistable ejector is adjustable between one position, in which the hot gases flow through the vapor generator, to another position wherein the gases are diverted away from the vapor generator. Another embodiment provides for a fixed valve ejector with a bias towards discharging to ambient, but with a fan on the downstream side of said vapor generator for overcoming this bias.