Multiple fuel system for internal combustion engines

A method for managing the delivery of fuel to an internal combustion engine of a vehicle, comprising the steps of:

• filling a main tank of said vehicle with a predetermined amount of regular fuel having an intermediate research octane number (IRON);
• controllably delivering IRON fuel from said main tank to an on-board separation (OBS) unit of said vehicle, said OBS unit being operable for separating said IRON fuel into a high research octane number (HRON) fuel and a low research octane number (LRON) fuel, higher and lower than said IRON fuel, respectively;
• delivering HRON fuel from said OBS unit to an HRON tank of said vehicle;
• monitoring the operational requirements of said engine at any given time;
• controllably and selectively delivering either HRON fuel from said HRON tank, or LRON fuel directly from said OBS unit, or a mixture thereof to said engine, in response to said monitoring step;
• measuring the HRON fuel level in said HRON tank;
• controlling both the production of said HRON and LRON fuels by said OBS unit, and the consumption of these fuels by said engine, in response to both said HRON level measuring step, and to said monitoring step, whenever the level of fuel in said HRON tank is within predetermined limits;
• and
• controlling the production and consumption of HRON and LRON fuels in accordance with a predetermined algorithm, whenever the level of fuel in said HRON tank decreases to a predetermined low limit.

In a motorized vehicle including a main fuel tank, an on-board separation (OBS) unit, a high research octane number (HRON) fuel tank, and an internal combustion engine, a method for selectively delivering fuel from one or a combination of said main tank, OBS unit, and HRON tank to said engine, comprising the steps of:

• filling said main tank with a predetermined amount of fuel having an intermediate research octane number (IRON);
• controllably delivering fuel from said main tank to said OBS unit;
• operating said OBS unit to produce an HRON grade fuel, and a low research octane number LRON fuel;
• delivering said HRON fuel from said OBS unit to said HRON tank;
• controllably delivering said LRON fuel in a retentate stream directly from said OBS unit to said engine in a first mode of operation;
• controllably delivering HRON fuel from said HRON tank to said engine in a second mode of operation;
• sensing the level of HRON fuel in said HRON tank;
• controllably delivering HRON fuel from said OBS unit to said main tank, in response to said level sensing step, at times that said HRON tank is filled to a predetermined level with HRON fuel;
• controllably recycling HRON fuel from said HRON tank to said OBS unit, in response to said level sensing step, at times that said HRON tank is filled to a predetermined level;
• limiting the delivery of LRON fuel in said retentate stream to said main tank;
• controllably delivering IRON fuel from said main tank to said engine in a third mode of operation;
• and
• controlling the production of HRON and LRON fuels by said OBS unit both in response to said level sensing step, and to match the demand for these fuels by said engine at any given time.

A vehicle mounted fuel management system for delivering individually and/or in different mixtures a plurality of different grades of RON fuel to an associated internal combustion engine, comprising:

• a main tank for containing a fuel having an intermediate research octane number (IRON);
• an on-board separation (OBS) unit receptive of IRON fuel, said OBS unit being operable for separating said IRON fuel into at least a high research octane number (HRON) fuel, and a low research number (LRON) fuel, higher and lower than said IRON fuel, respectively;
• flow control means for feeding IRON fuel from said main tank to said OBS unit;
• an HRON tank for receiving and containing HRON fuel from said OBS unit;
• means for measuring the level of HRON fuel in said HRON tank;
• means for controllably and selectively delivering either HRON fuel from said HRON tank, or LRON fuel directly from said OBS unit, or a mixture thereof to said engine, in response to both said level measuring means, and the operational requirements of said engine at any given time;
• and
• means for controlling the speed of said flow control means to obtain a feed rate of said IRON fuel to said OBS unit, to control the latter's production of HRON and LRON fuels to match the demand for these fuels by said engine at any given time.

A method for managing the delivery of fuel to an internal combustion engine of a vehicle, comprising the steps of:

• filling a main tank of said vehicle with a predetermined amount of regular fuel having an intermediate autoignition temperature (IAT);
• controllably delivering IAT fuel from said main tank to an on-board separation (OBS) unit of said vehicle, said OBS unit being operable for separating said IAT fuel into a high autoignition temperature (HAT) fuel and a low autoignition temperature (LAT) fuel, higher and lower than said IAT fuel, respectively;
• delivering LAT fuel from said OBS unit to an LAT tank of said vehicle;
• monitoring the operational requirements of said engine at any given time;
• controllably and selectively delivering either LAT fuel from said LAT tank, or HAT fuel directly from said OBS unit, or a mixture thereof to said engine, in response to said monitoring step;
• measuring the LAT fuel level in said LAT tank;
• controlling both the production of said LAT and HAT fuels by said OBS unit, and the consumption of these fuels by said engine, in response to both said LAT level measuring step, and to said monitoring step, whenever the level of fuel in said LAT tank is within predetermined limits;
• and
• controlling the production and consumption of LAT and HAT fuels in accordance with a predetermined algorithm, whenever the level of fuel in said LAT tank is not within predetermined limits.

In a motorized vehicle including a main fuel tank, an on-board separation (OBS) unit, a low autoignition temperature (LAT) fuel tank, and an internal combustion engine, a method for selectively delivering fuel from one or a combination of said main tank, OBS unit, and LAT tank to said engine, comprising the steps of:

• filling said main tank with a predetermined amount of fuel having an intermediate autoignition temperature (IAT);
• controllably delivering fuel from said main tank to said OBS unit;
• operating said OBS unit to produce an LAT grade fuel, and a high autoignition temperature (HAT) fuel;
• delivering said LAT fuel from said OBS unit to said LAT tank;
• controllably delivering said HAT fuel in a retentate stream directly from said OBS unit to said engine in a first mode of operation;
• controllably delivering LAT fuel from said LAT tank to said engine in a second mode of operation;
• sensing the level of LAT fuel in said LAT tank;
• controllably delivering LAT fuel from said OBS unit to said main tank, in response to said level sensing step, at times that said LAT tank is filled to a predetermined level with LAT fuel;
• controllably recycling LAT fuel from said LAT tank to said OBS unit, in response to said level sensing step, at times that said LAT tank is filled to a predetermined level;
• limiting the delivery of HAT fuel in said retentate stream to said main tank;
• controllably delivering IAT fuel from said main tank to said engine in a third mode of operation;
• and
• controlling the production of LAT and HAT fuels by said OBS unit both in response to said level sensing step, and to match the demand for these fuels by said engine at any given time.

A vehicle mounted fuel management system for delivering individually and/or in different mixtures a plurality of different grades of fuel each designated in terms of autoignition temperature to an associated internal combustion engine, comprising:

• a main tank for containing a fuel having an intermediate autoignition temperature (IAT);
• an on-board separation (OBS) unit receptive of IAT fuel, said OBS unit being operable for separating said IAT fuel into at least a low autoignition temperature (LAT) fuel, and a high autoignition temperature (HAT) fuel, lower and higher than said IAT fuel, respectively;
• flow control means for feeding IAT fuel from said main tank to said OBS unit;
• an LAT tank for receiving and containing LAT fuel from said OBS unit;
• means for measuring the level of LAT fuel in said LAT tank;
• means for controllably and selectively delivering either LAT fuel from said LAT tank, or HAT fuel directly from said OBS unit, or a mixture thereof to said engine, in response to both said level measuring means, and the operational requirements of said engine at any given time;
• and
• means for controlling the speed of said flow control means to obtain a feed rate of said IAT fuel to said OBS unit, to control the latter's production of LAT and HAT fuels to match the demand for these fuels by said engine at any given time.