CRYOGENIC FUEL SUPPLY SYSTEM FOR ENGINE

Abstract

The cryogenic fuel supply system for an engine is arranged in locomotive two sections connected by an inter-section connection for the purpose of transferring fuel from one section to the other. There is a cryogenic reservoir for storage of a liquefied cryogenic fuel, a positive-displacement high-pressure cryogenic pump, an oil heat-exchanger, a gas heat-exchanger, a gas mixer, a gas receiver, a fuel filter, a controlled gas metering unit, pipelines, valves, controlled valves, and a control unit. The cryogenic fuel supply system further includes an intermediate buffer arranged between the cryogenic reservoir and the positive-displacement high-pressure pump and connected to the cryogenic reservoir by pipelines and to the positive-displacement high-pressure cryogenic pump by a pipeline and two additional pipelines. The additional pipeline is used both for discharging excess cryogenic fuel from the pump to the intermediate buffer and for maintaining a required pressure in the intermediate buffer and the cryogenic reservoir.

Claims

1. A cryogenic fuel supply system for an engine, being arranged in two sections of a locomotive and comprising: a cryogenic reservoir for storage of liquefied cryogenic fuel, a positive-displacement high-pressure cryogenic pump, an oil heat-exchanger, a gas heat-exchanger, a gas mixer, a gas receiver, a fuel filter, a controlled gas metering unit, pipelines, valves, controlled valves, a control unit, and an intermediate buffer arranged between the cryogenic reservoir and the positive-displacement high-pressure cryogenic pump, said intermediate buffer being connected to the cryogenic reservoir by pipelines and to the positive-displacement high-pressure cryogenic pump by a pipeline and two additional pipelines; wherein the controlled valves are additionally installed on a pipeline going to the inlets of the oil heat-exchanger, the gas heat-exchanger and the gas mixer for the purpose of adjusting fuel supply to the gas receiver more finely and reliably; and wherein a cryogenic fuel supply pipeline is provided with an inter-section connection means for the purpose of transferring fuel from one section to the other.

2. The system, according to claim 1, wherein the intermediate buffer is installed at a minimum distance from the cryogenic reservoir and the positive-displacement high-pressure cryogenic pump.

3. The system, according to claim 1, wherein an additional pipeline, connecting an outlet of the positive-displacement high-pressure cryogenic pump with the intermediate buffer discharges excess cryogenic fuel from the pump to the intermediate buffer and maintains a required pressure in the intermediate buffer and the cryogenic reservoir.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0012] The FIGURE shows the functional layout of the proposed cryogenic fuel supply system for an engine.

DETAILED DESCRIPTION OF THE INVENTION

[0013] The cryogenic fuel supply system for an engine is arranged in the locomotive two sections 28, 29 connected by the inter-section connection means 4 and comprises: the cryogenic reservoir 1 for a liquefied cryogenic fuel; the intermediate buffer 2 serving for trouble-free operation of the positive-displacement high-pressure cryogenic pump 3 (hereinafter “the pump”); the pump 3 for adjusting and supplying a fuel to an engine 11; the oil heat-exchanger 5; the gas heat-exchanger 6; the gas mixer 7; the gas receiver 8; the fuel filter 9; the controlled gas metering unit 10; the engine 11; the controlled valves 12, 13, 14, 15, 16; the control unit 17; the valves 18, 19, 20, and 21 connected by the pipelines 22, 23, 24, 25 therebetween; the additional pipeline 26 connecting the cold end of the pump 3 with the intermediate buffer 2, the additional pipeline 27 connecting the outlet of the pump 3 with the intermediate buffer 2.

[0014] The cryogenic fuel supply system for an engine can be operated as follows.

[0015] The cryogenic fuel supply system operates under the control of the control unit 17 through which the pump 3, the controlled valves 12, 13, 14, 15, 16 and the controlled gas metering unit 10 are controlled.

[0016] A cryogenic fuel from the cryogenic reservoir 1, before the pump 3 is started, ensuring fuel adjustment and supply to the engine 11, is fed for cooling the intermediate buffer 2, the pipeline 22, the additional pipeline 26 and the pump 3, the valves 18, 19, 20, 21 being open and the controlled valve 12 being open, the other controlled valves being set at the “closed” position.

[0017] After the cryogenic fuel supply system is cooled, pressure is equalized in the cryogenic reservoir 1, the intermediate buffer 2, the gas receiver 8, the controlled valves 12 and 14 being open. The gas receiver 8 should have a certain volume and serves for providing a required fuel reserve if the operation mode of the engine 11 is changed, which improves operation reliability of the engine 11.

[0018] After pressure is equalized, the cryogenic pump 3 is started, and the engine 11 starts working after a preset pressure level is achieved in the gas receiver 8.

[0019] The use of the intermediate buffer 2, as arranged in the cryogenic fuel supply system, improves the performance of the pump 3 and reduces the risk of damage of the pump 3 due to discharge of gas bubbles forming in the pipeline 22 to the gas fraction in the intermediate buffer 2, as well as enables to make the cryogenic reservoir 1 removable, which provides the possibility of performing repairs and maintenance of a locomotive in the depot conditions without the necessity to drain and degas fuel from the cryogenic buffer 1, thus reducing time required for repairs and maintenance of a locomotive. The intermediate buffer 2 is arranged at a minimum distance from the pump 3 and the cryogenic reservoir 1, the pipelines 22 and 26 having a minimum length, which reduces time required for cooling and reduces consumption of a cryogenic fuel required for cooling.

[0020] When the operation mode of a locomotive is changed, an amount of a cryogenic fuel supplied to the engine 11, depending on power consumption of the engine 11, is changed by signals sent by the control unit 17 for changing rpm of the pump 3, the gas supply being finely metered by the controlled gas metering unit 10 and the controlled valves 14, 15, 16.

[0021] The controlled valves 14, 15, 16 are installed on the pipeline 24 going to the inlets of the oil heat-exchanger 5, the gas heat-exchanger 6 and the gas mixer 7, which valves ensure reliable bypass of a cryogenic fuel into the gas mixer 7 that maintains a preset fuel temperature, which further improves operation reliability of the fuel supply system for the engine 11.

[0022] The additional pipeline 26 with the controlled valve 13 is connected to the pump 3 and the intermediate buffer 2 and serves both for bypassing excess fuel when the engine 11 runs idle with the controlled valve 13 open, and for equalizing pressure between the cryogenic reservoir 1, the intermediate buffer 2 and the gas receiver 8 by compressed gas from the gas receiver 8 if pressure in the cryogenic reservoir drops below an allowable level when the controlled valves 12, 13, 14 are open and the pump 3 is not operated.

[0023] In order to ensure trouble-free operation of the cryogenic fuel supply system, the pipeline 23 is provided with the inter-section connection means 4 that is intended for supplying a cryogenic fuel from one section of a locomotive to the other.

[0024] After the engine 11 is stopped for speeding up the system transfer to the “storage” mode, gas from the gas receiver 8 is used.

[0025] The proposed cryogenic fuel supply system ensures stable operation of the engine 11 on liquefied natural gas and enables to reduce time required for preparing the cryogenic fuel supply system for operation and time required for its transfer to the “storage” mode.