Tecogen, Inc.

Joseph B Gehret

Robert Panora

Jean Roy

Ranson Roser

Jian Wen

Ahmed Fouad Ghoniem

A hybrid power-generator system includes an engine, an electric generator, first and second rectifiers, first and second DC-DC voltage converters, a DC bus, an inverter, and one or more controllers. The system provides a unique method of joining two power sources such that the relative proportion utilized can be changed to any value seamlessly, such as to avoid daily and/or seasonal variations in utility charges. Since the AC output portion of the circuit is independent of the utility grid, power can be supplied at variable frequencies to motor loads with significant positive impacts in load efficiency. Power increases required by the load(s) that occur rapidly can utilize the electrical grid to assist for the brief transient, allowing the engine, which is maintained at a fixed and wide-open-throttle position, to continue operation and in a more gradual process to resume its blend target for power generation.

Hybrid power system with electric generator and auxiliary power source

An exhaust aftertreatment system includes a first stage catalytic converter, a second stage catalytic converter, and a conduit extending from the first stage catalytic converter to the second stage catalytic converter. The conduit passes through an exhaust gas intercooler, between the first and second stage catalytic converts, that reduces the temperature of the exhaust to about 300&#xb0; F. to about 500&#xb0; F. Air is ejected into the exhaust conduit to increase the oxygen concentration in the exhaust before it passes through the second stage catalytic converter. The air can be ejected from an air ejection conduit that extends to an engine charger compressor or a compressed air conduit that extends from the engine charger compressor, such as a turbo charger and/or a supercharger, to the engine. A gas particulate filter can be disposed in the exhaust conduit or it can be integrated with the second stage catalytic converter, for example as a catalyzed gas particulate filter.

Dual stage internal combustion engine aftertreatment system using exhaust gas intercooling and charger driven air ejector

A system and method for controlling an internal combustion engine and electrical inverter system for powering a load, including controlling the operation of a spark-ignited internal combustion engine prime mover used in generation of electrical power by way of a generator. A microprocessor (e.g., DSP) controlled circuit taking engine speed input from an engine speed signal is used to control the operation of the internal combustion engine prime mover so that it is preferably operated substantially at wide open throttle.

Internal combustion engine controller

An assembly and method for reducing nitrogen oxides, carbon monoxide, hydrocarbons and hydrogen gas in exhausts of internal combustion engines and simultaneously generating electrical power, wherein the exhaust is acted upon in a first stage catalytic converter and is at least in part passed through a thermoelectric generator for production of electrical power. The exhausts are thereafter directed to a second stage catalytic converter.

Assembly and method for reducing nitrogen oxides, carbon monoxide, hydrocarbons and hydrogen gas in exhausts of internal combustion engines and producing an electrical output

A system for reducing ammonia in exhaust gas generated from a lean burn internal combustion engine includes an oxidation catalyst, a selective reduction catalyst (SCR), a cooling unit, and a three-way catalyst. Exhaust gas generated by the engine passes through the oxidation catalyst to oxidize carbon monoxide from the exhaust gas to form carbon dioxide. Nitrous oxide (NOx) compounds in the exhaust gas are reduced in the SCR to form nitrogen and water. The exhaust gas is then cooled in a cooling unit and then passed over the three-way catalyst. The three-way catalyst causes ammonia in the cooled exhaust stream to react to form less harmful compounds, such as nitrogen and water.

Assembly and method for reducing ammonia in exhaust of internal combustion engines

An assembly and method for reducing nitrogen oxides, carbon monoxide and hydrocarbons in exhausts of internal combustion engines, wherein the exhaust is acted upon in a first stage catalytic converter. A first portion of the first stage catalytic converter output is cooled and a second portion of the catalytic converter output is not cooled. The cooled and not cooled exhausts are united and directed to a second stage catalytic converter. Air is injected into a selected one of (1) the not cooled exhaust prior to the juncture thereof with the cooled exhaust, and (2) the combined cooled and not cooled exhausts after the juncture thereof.

Assembly and method for reducing nitrogen oxides, carbon monoxide and hydrocarbons in exhausts of internal combustion engines

A method for controlling internal combustion engine emissions, including the steps of reading signals from sensors in an engine exhaust manifold and catalytic converter exhaust, an upstream one of the sensors being provided with an air-fuel mixture setpoint, comparing signal values with previous average values and automatically adjusting the air-fuel mixture set point to vary the fuel mixture fed to the engine.

Method for controlling internal combustion engine emissions

A combined heat and AC power generating system is disclosed having black start capability for the full time, simultaneous production of both electricity and heat. Heat generated within the system is captured and used for heating applications such as heating building air and tap water. The power generating system comprises an engine, generator, rectifier, variable frequency drive inverter, and inverter control electronics. The system provides improved efficiency and prolonged engine life by always operating the engine with its throttle fully open to obtain maximum efficiency and the engine is normally operated near its stall point. In this operating state the inverter control electronics adjust the power output from the inverter to control the speed of the engine. This is done by increasing the power output from the inverter when the power drawn by the load decreases. This causes the engine to operate closer to its stall point and it slows down. The power from the inverter is decreased when the power drawn by the load increases. This causes the engine to operate further from its stall point and it speeds up. The slight power changes to facilitate this operation will always be drawn from or distributed to the electric utility grid so there is no wasted power. The inverter control electronics are responsive to signals from loads such as refrigeration loads to cause the frequency of the inverter output to change to permit the refrigeration load to operate more efficiently.

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Lynnfield, MA, United States of America

Joseph B Gehret