Improvement in methods of supercharging an engine, preferably a diesel engine in such supercharged engines, and in supercharging units for such engines

Claim 1

A method of supercharging an internal combustion engine of the expansible chamber type having a turbo-compressor system with at least one compressor and at least one turbine for driving the compressor, said engine having a combustion chamber system connected between the outlet of said compressor and the inlet of said turbine having an airflow capacity which varies as a function of engine r.p.m. and load, said method comprising the steps of: a. directly communicating the outlet of said compressor with the turbine inlet by connecting a bypass passageway between said outlet and inlet in parallel airflow relation with the engine combustion chamber system; b. establishing a substantially constant total airflow capacity between the compressor outlet and the turbine inlet for any given compressor outlet pressure by providing an airflow capacity in said bypass passageway adequate to automatically responsively compensate for the variations in the airflow capacity of the engine combustion chamber system caused by engine r.p.m. and load variations whereby the pressure difference, if any, between the compressor outlet and turbine inlet is generally independent of the ratio of the flow rate of the air traversing said bypass passageway to the total airflow delivered from said compressor; c. matching said turbo-compressor system to the total airflow capacity of said engine combustion chamber system and of said bypass passageway such that the plot of the ratio of the compressor output pressure to the compressor input pressure versus the airflow delivered by the compressor, during self-sustaining operation of said turbo-compressor system and conjoint operation of the engine under its own power in response to any variation in engine load and r.p.m. within the complete operating range of the engine, lies at least within a narrow area approximating a predetermined curve located in a high yield area generally near to, but which does not exceed, the surge line characteristic of the compressor; and d. operating the engine under its own power and simultaneously operating the turbo-compressor system in a self-sustaining mode so as to deliver air from said compressor to said engine combustion chamber system and to said bypass passageway such that the aforementioned plot of the matched turbo-compressor lies within said narrow area.

Claim 2

A method of supercharging an internal combustion engine of the expansible chamber type having a turbo-compressor system with at least one compressor and at least one turbine for driving the compressor, said engine having a combustion chamber system connected between the outlet of said compressor and the inlet of said turbine having an airflow capacity which varies as a function of engine r.p.m. and load, said method comprising the steps of: a. directly communicating the outlet of said compressor with the turbine inlet by connecting a bypass passageway between said outlet and inlet in parallel airflow relation with the engine combustion chamber system; b. establishing a substantially constant total airflow capacity between the compressor outlet and the turbine inlet for any given compressor outlet pressure by providing an airflow capacity in said bypass passageway adequate to automatically responsively compensate for the variations in the airflow capacity of the engine combustion chamber system caused by engine r.p.m. and load variations whereby the pressure difference, if any, between the compressor outlet and turbine inlet is generally independent of the ratio of the flow rate of the air traversing said bypass passageway to the total airflow delivered from said compressor; c. matching said turbo-compressor system to the total airflow capacity of said engine combustion chamber system and of said bypass passageway such that the plot of the ratio of the compressor output pressure to the compressor input pressure versus the airflow delivered by the compressor, during self-sustaining operation of said turbo-compressor system and conjoint operation of the engine under its own power in response to any variation in engine load and r.p.m. within the complete operating range of the engine, lies at least within a narrow area approximating a predetermined curve located in a high yield area generally near to, but which does not exceed, the surge line characteristic of the compressor; and d. operating the engine under its own power and simultaneously operating the turbo-compressor system in a self-sustaining mode so as to deliver air from said compressor to said engine combustion chamber system and to said bypass passageway such that the aforementioned plot of the matched turbo-compressor lies within said narrow area.

Claim 10

A method of operating a supercharged internal combustion engine of the compression ignition type which is subject to speed and load variations and which is supercharged by an associated turbine-compressor supercharger wherein the turbine drives the compressor such that the supercharger drive is mechanically independent of the engine, said engine having an air intake communicating with the compressor output and an exhaust conduit communicating with the turbine inlet and a gas flow path from the compressor to the turbine in bypass relation to said engine intake, said method comprising the steps of: a. maintaining the rotational speed of the turbine-compressor supercharger, at least when engine is running under its own power, at or above a minimum threshold speed sufficient to cause the compressor to deliver air to the engine at correlated minimum temperature and pressure conditions high enough such that, when said air is compressed by said engine from a point at or near the beginning of the intake phase of the cycle of said engine to a point at or near the end of the compression phase of said cycle, self-ignition of fuel in the engine is produced, said minimum threshold speed having a fixed value for an engine having a given compression ratio, said minimum threshold speed being lower for an engine having a higher compression ratio and being higher for an engine having a lower compression ratio with all other conditions affecting self-ignition being constant; b. operating said engine under its own power over a varying speed and load range while continuously supplying air from the compressor to the engine intake at or above said correlated minimum temperature and pressure conditions; c. automatically maintaining the air flow capacity of said bypass gas flow path at a value correlated with that of said engine such that the combined air flow capacity of the parallel air flow paths provided by said engine and said bypass gas flow path remains substantially constant for any given compressor outlet pressure regardless of the rate of change of speed and load conditions of said engine; and d. driving the turbine at least after being started solely by sufficiently heating gases admitted to the turbine so as to operate said turbine-compressor supercharger in a high yield mode at or near its characteristic surge line whereby surging of said compressor is prevented despite sudden variations in the airflow capacity of the engine induced by variations in the load and speed conditions of the engine.

Claim 11

A method of operating a supercharged internal combustion engine of the compression ignition type which is subject to speed and load variations and which is supercharged by an associated turbine-compressor supercharger wherein the turbine drives the compressor such that the supercharger drive is mechanically independent of the engine, said engine having an air intake communicating with the compressor output and an exhaust conduit communicating with the turbine inlet and a gas flow path from the compressor to the turbine in bypass relation to said engine intake, said method comprising the steps of: a. maintaining the rotational speed of the turbine-compressor supercharger, at least when engine is running under its own power, at or above a minimum threshold speed sufficient to cause the compressor to deliver air to the engine at correlated minimum temperature and pressure conditions high enough such that, when said air is compressed by said engine from a point at or near the beginning of the intake phase of the cycle of said engine to a point at or near the end of the compression phase of said cycle, self-ignition of fuel in the engine is produced, said minimum threshold speed having a fixed value for an engine having a given compression ratio, said minimum threshold speed being lower for an engine having a higher compression ratio and being higher for an engine having a lower compression ratio with all other conditions affecting self-ignition being constant; b. operating said engine under its own power over a varying speed and load range while continuously supplying air from the compressor to the engine intake at or above said correlated minimum temperature and pressure conditions; c. automatically maintaining the air flow capacity of said bypass gas flow path at a value correlated with that of said engine such that the combined air flow capacity of the parallel air flow paths provided by said engine and said bypass gas flow path remains substantially constant for any given compressor outlet pressure regardless of the rate of change of speed and load conditions of said engine; and d. driving the turbine at least after being started solely by sufficiently heating gases admitted to the turbine so as to operate said turbine-compressor supercharger in a high yield mode at or near its characteristic surge line whereby surging of said compressor is prevented despite sudden variations in the airflow capacity of the engine induced by variations in the load and speed conditions of the engine.

Claim 12

A method of supercharging an internal combustion engine of the expansible chamber type having a turbo-compressor with at least one compressor and at least one turbine for driving the compressor, said engine having a combustion chamber system connected between said compressor and said turbine, and a bypass passageway communicating with the outlet of said compressor and with the turbine inlet in parallel air flow relation with the engine combustion chamber system, said method comprising the steps of: a. operating the turbocompressor so as to deliver air from said compressor to said engine combustion chamber system and to said bypass passageway; b. simultaneously operating the engine under its own power; c. controlling the pressure difference between the compressor outlet and the turbine inlet by maintaining a sufficient air flow capacity in the bypass passageway so as to permit the entire air flow output of the compressor to pass through said bypass passgeway both when the engine is stationary and when the engine is running under varying conditions of load and speed such that for a given pressure ratio of the compressor or for a given power output of the engine the air flow delivery of said compressor remains generally constant regardless of the rotary speed and load conditions of said engine; and d. simultaneously operating said compressor such that a plot of the pressure ratio versus the air flow delivery of said compressor is generally along a line generally parallel to and sufficiently near its surge line to optimize the efficiency of said compressor.

Claim 13

A method of supercharging an internal combustion engine of the expansible chamber type having a turbo-compressor with at least one compressor and at least one turbine for driving the compressor, said engine having a combustion chamber system connected between said compressor and said turbine, and a bypass passageway communicating with the outlet of said compressor and with the turbine inlet in parallel air flow relation with the engine combustion chamber system, said method comprising the steps of: a. operating the turbocompressor so as to deliver air from said compressor to said engine combustion chamber system and to said bypass passageway; b. simultaneously operating the engine under its own power; c. controlling the pressure difference between the compressor outlet and the turbine inlet by maintaining a sufficient air flow capacity in the bypass passageway so as to permit the entire air flow output of the compressor to pass through said bypass passgeway both when the engine is stationary and when the engine is running under varying conditions of load and speed such that for a given pressure ratio of the compressor or for a given power output of the engine the air flow delivery of said compressor remains generally constant regardless of the rotary speed and load conditions of said engine; and d. simultaneously operating said compressor such that a plot of the pressure ratio versus the air flow delivery of said compressor is generally along a line generally parallel to and sufficiently near its surge line to optimize the efficiency of said compressor.

Claim 15

A method of supercharging an internal combustion engine of the expansible chamber type having a turbocompressor with at least one compressor and at least one turbine for driving the compressor, said engine having a combustion chamber system connected between said compressor and said turbine, and a bypass passageway communicating with the outlet of said compressor and with the turbine inlet in parallel air flow relation with the engine combustion chamber system, said method comprising the steps of: a. operating the turbocompressor so as to deliver air from said compressor to said engine combustion chamber system and to said bypass passageway with the compressor outlet pressure exceeding turbine inlet pressure; b. simultaneously operating the engine under its own power and admitting exhaust gases from the engine combustion chamber system to the turbine; c. generating hot gases as necessary externally of and separately from the burning of fuel in the engine combustion chamber and admitting the same along with the engine exhaust gases to the turbine to provide a supply of motive gases having sufficient temperature to cause the turbocompressor to operate in a self-sustaining mode; d. maintaining in said bypass passageway an air flow capacity responsive to any variation in the air flow capacity of said engine combustion chamber system caused by variations in engine load and r.p.m. such that the total air flow capacity provided by said bypass passageway and engine combustion chamber system is substantially constant for any given compressor outlet pressure whereby any appreciable pressure difference developed in the air passing through the bypass passageway toward said turbine is generally independent of the ratio of the flow rate of the air traversing said bypass passageway to to the total air flow delivered from said compressor and whereby for a given pressure ratio of the compressor the air flow delivery of said compressor remains generally constant regardless of the rotary speed and load conditions of said engine; and e. simultaneously operating said compressor such that a plot of the pressure ratio versus the air flow delivery of said compressor is generally within a narrow area generally parallel to its surge line.

Claim 16

A method of supercharging an internal combustion engine of the expansible chamber type having a turbocompressor with at least one compressor and at least one turbine for driving the compressor, said engine having a combustion chamber system connected between said compressor and said turbine, and a bypass passageway communicating with the outlet of said compressor and with the turbine inlet in parallel air flow relation with the engine combustion chamber system, said method comprising the steps of: a. operating the turbocompressor so as to deliver air from said compressor to said engine combustion chamber system and to said bypass passageway with the compressor outlet pressure exceeding turbine inlet pressure; b. simultaneously operating the engine under its own power and admitting exhaust gases from the engine combustion chamber system to the turbine; c. generating hot gases as necessary externally of and separately from the burning of fuel in the engine combustion chamber and admitting the same along with the engine exhaust gases to the turbine to provide a supply of motive gases having sufficient temperature to cause the turbocompressor to operate in a self-sustaining mode; d. maintaining in said bypass passageway an air flow capacity responsive to any variation in the air flow capacity of said engine combustion chamber system caused by variations in engine load and r.p.m. such that the total air flow capacity provided by said bypass passageway and engine combustion chamber system is substantially constant for any given compressor outlet pressure whereby any appreciable pressure difference developed in the air passing through the bypass passageway toward said turbine is generally independent of the ratio of the flow rate of the air traversing said bypass passageway to to the total air flow delivered from said compressor and whereby for a given pressure ratio of the compressor the air flow delivery of said compressor remains generally constant regardless of the rotary speed and load conditions of said engine; and e. simultaneously operating said compressor such that a plot of the pressure ratio versus the air flow delivery of said compressor is generally within a narrow area generally parallel to its surge line.