Cooling system for automotive engine or the like

Claim 2

In an internal combustion engine having a combustion chamber; a radiator; a coolant jacket in which coolant is boiled and the vapour produced fed to said radiator for condensation therein; a reservoir containing coolant; a first conduit leading from said radiator to said coolant jacket, said first conduit including a pump for returning liquid coolant from said radiator said said coolant jacket and a first valve, said first valve having an open position wherein fluid can flow therethrough and a closed position wherein fluid is prevented from passing therethrough to said coolant jacket; a second conduit which communicates with said reservoir at one one end thereof and which communicates with said coolant jacket at the other end thereof, said second conduit including a second valve having an open position and a closed position; a third conduit which communicates at one end thereof with said reservoir and which communicates at the other end thereof with one of said radiator and said first conduit at a location between said pump and said radiator, said third conduit including a third valve, said third valve having an open position and a closed position; and a control circuit for controlling the operation of said pump, first, second and third valves.

Claim 3

An engine as claimed in claim 1, further comprising a fourth conduit which leads from the highest point of one of said coolant jacket and said radiator to said reservoir, said fourth conduit including a fourth valve therein which controls fluid communication between said reservoir and said highest point of said one of said coolant jacket and said radiator.

Claim 4

An engine as claimed in claim 2, further comprising a first level sensor, said first level sensor being disposed in said coolant jacket at a first predetermined level which is higher than said combustion chamber, said contol circuit being responsive to the output of said first level sensor in a manner to energize said pump in manner which maintains the level of liquid coolant in said coolant jacket at said first level.

Claim 5

An engine as claimed in claim 3, further comprising: a temperature sensor, said temperature sensor sensing the temperature of the liquid coolant in said coolant jacket; and a device for varying the rate of condensation of the coolant vapour in said radiator; said control circuit being responsive to said temperature sensor in a manner to induce said device to increase the rate of condensation in said radiator upon the temperature of the liquid coolant within said coolant jacket exceeding a target level.

Claim 6

An engine as claimed in claim 4, further comprising a small tank at the bottom of said radiator for collecting condensed coolant; and a second level sensor disposed in said tank for sensing the level of liquid coolant at a second predetermined level.

Claim 7

An engine as claimed in claim 5, further comprising a third level sensor, said third level sensor being disposed at said highest point of said one of said coolant jacket and said radiator and arranged to indicate the level of liquid coolant reaching same when the engine is stopped.

Claim 8

An engine as claimed in claim 6, wherein said control circuit includes a microprocessor, said microprocessor being arranged to receive data inputs from said first, second and third level sensors and said temperature sensor, said microprocessor being arranged to, in accordance with the inputs, operate said pump, said device and said first, second, third and fourth valves in manner to perform: a non-condensible matter purge operation wherein excess coolant is pumped into said coolant jacket and said radiator to the point of overfilling same and thus displacing any non-condensible matter out through said fourth valve and said fourth conduit; a cold start operation wherein excess coolant in said coolant jacket and said radiator are displaced out to said reservoir by the pressure developed when said coolant is heated by the heat produced when the engine operates; a normal operation wherein said coolant jacket and radiator are fluidly separated from said reservoir and said device is controlled in a manner to control the rate of condensation in said radiator and thus control the pressure within said coolant jacket and radiator in a manner to control the boiling point of said coolant; an overcooled control operation wherein, if the engine becomes excessively cooled, said radiator is partially filled with liquid coolant to reduce the amout of heat which may be released to the ambient atmosphere by said radiator; and a system shutdown operation wherein the coolant in said coolant jacket is allowed to cool before communication between said reservoir and said coolant jacket is established whereby a negative pressure which develops in said coolant jacket and radiator inducts coolant from said reservoir and fills said coolant jacket and radiator with liquid coolant.