Pump operated cooling system using cold fuel

Claim 2

In combination: a gas turbine engine; an electronic computer operatively connected to the engine to sense various engine parameters; a fuel tank adapted to contain fuel for the engine; a first impeller pump having an inlet and an outlet for respectively receiving fuel from the tank and discharging fuel; a second impeller pump having an inlet and an outlet; a heat exchanger connected to the computer to withdraw heat therefrom, the heat exchanger being fluidly connected to the outlet of the first impeller pump to receive a cooling flow therefrom and the inlet of the second impeller pump to discharge the flow heated by the computer thereto; a bypass duct in parallel with the heat exchanger fluidly interconnecting the outlet of the first impeller pump and the inlet of the second impeller pump to provide an additional flow path from the outlet of the first impeller pump to the inlet of the second impeller pump; valve means responsive to a predetermined pressure differential between the outlet of the first impeller pump and the inlet of the second impeller pump to control flow in the bypass duct such that a sufficient pressure rise for charging the inlet of the second impeller pump is assured; a positive displacement pump having an inlet fluidly connected to the outlet of the second impeller pump and an outlet for directing a pressurized flow to the engine; means drivingly interconnecting the first impeller pump and the second impeller pump; and means drivingly connecting the first impeller pump, the second impeller pump and the positive displacement pump to the engine.

Claim 3

The combination, as defined in claim 1, wherein the first impeller pump consists essentially of an inducer having a helical blade, and wherein the second impeller pump comprises a centrifugal impeller.

Claim 4

The combination, as defined in claim 2, further including: a metering device operatively connected to the computer so as to be controlled in accordance with the parameters sensed thereby and to the outlet of the positive displacement pump for delivering a metered flow of fuel to the engine.

Claim 5

The combination, as defined in claim 2, further including: an insulating material interposed between the first impeller pump and the second impeller pump to prevent heat transfer therebetween.

Claim 6

In combination: an engine; a heat generating device for controlling the engine; a source of fuel for the engine; a first housing portion having an inlet for receiving fuel from the source and an outlet for discharging the fuel; an inducer, having a helical blade, mounted in the first housing portion between the inlet and the outlet thereof such that the blade is adapted to provide a pressure rise at the outlet; a heat exchanger connected to the device to withdraw heat therefrom, the heat exchanger being fluidly connected to the outlet of the first housing portion to receive a flow of cooling fuel; a second housing portion having an inlet fluidly connected to the heat changer to receive the fuel heated therein and an outlet for discharging the heated fuel; an impeller mounted in the second housing portion between the inlet and the outlet thereof for supplying fuel to the engine; a shaft drivingly interconnecting the inducer and the impeller; means to drivingly connect the inducer and the impeller to the engine; an insulating material interposed between the first housing portion and the second housing portion to prevent heat transfer therebetween; a bypass duct in parallel with the heat exchanger fluidly interconnecting the outlet of the first housing portion and the inlet of the second housing portion to provide an additional flow path from the outlet of the first housing portion to the inlet of the second housing portion; and valve means responsive to a predetermined pressure differential between the outlet of the first housing portion and the inlet of the second housing portion to control flow in the bypass duct such that a sufficient pressure rise for charging the inlet of the second housing portion is assured.

Claim 7

In combination: an engine; a heat generating device for controlling the engine; a source of fuel for the engine; a first housing portion having an inlet for receiving fuel from the source and an outlet for discharging the fuel; an inducer, having a helical blade, mounted in the first housing portion between the inlet and the outlet thereof such that the blade is adapted to provide a pressure rise at the outlet; a heat exchanger connected to the device to withdraw heat therefrom, the heat exchanger being fluidly connected to the outlet of the first housing portion to receive a flow of cooling fuel; a second housing portion having an inlet fluidly connected to the heat changer to receive the fuel heated therein and an outlet for discharging the heated fuel; an impeller mounted in the second housing portion between the inlet and the outlet thereof for supplying fuel to the engine; a shaft drivingly interconnecting the inducer and the impeller; means to drivingly connect the inducer and the impeller to the engine; an insulating material interposed between the first housing portion and the second housing portion to prevent heat transfer therebetween; a bypass duct in parallel with the heat exchanger fluidly interconnecting the outlet of the first housing portion and the inlet of the second housing portion to provide an additional flow path from the outlet of the first housing portion to the inlet of the second housing portion; and valve means responsive to a predetermined pressure differential between the outlet of the first housing portion and the inlet of the second housing portion to control flow in the bypass duct such that a sufficient pressure rise for charging the inlet of the second housing portion is assured.

Claim 8

The combination, as defined in claim 5, further including: a positive displacement pump having an inlet and an outlet, the inlet of the positive displacement pump being fluidly connected to the outlet of the second housing portion to receive the output flow thereof; means drivingly connecting the positive displacement pump to the engine; and a metering device fluidly connected to the outlet of the positive displacement pump to receive a flow of fuel therefrom and fluidly connected to the engine to deliver a metered flow of fuel thereto, the metering device being operatively connected to the heat generating device so as to be controlled thereby.

Claim 9

The combination, as defined in claim 6, wherein the impeller is a centrifugal impeller, and the inducer is an axial inducer; and wherein the heat generating device is an electronic computer adapted to sense various engine parameters.