Fuel supply system for alternative fuel
AssigneeDenso Corporation
InventorsMasaaki Kato, Satoru Sasaki, Hisaharu Takeuchi
Life of this patent
Estimating the term…
Abstract
A fuel supply apparatus is provided which works to supply fuel such as a dimethly ether used as an alternative to a typical fuel for an internal combustion engine. The fuel supply apparatus includes a high-pressure pump working to feed the to injectors from a fuel tank through a common rail, a fuel return line, and a compressor working to add to a back pressure higher than a vapor pressure of the fuel to the return line. The addition of the back pressure higher than the vapor pressure of the fuel facilitates liquidizing of the fuel. This results in a decrease in leakage of the fuel, which improves the efficiency of burning of the fuel and ensures the startability and drivability of the engine.
Claims25
An alternative fuel supply apparatus for an internal combustion engine comprising:
- a high-pressure pump working to feed a fuel which is susceptible to vaporization to injectors from a fuel tank through a common rail under a given high pressure;
- a return line including a first line and a second line which extend from said high-pressure pump to the fuel tank;
- a pressurizing mechanism disposed in the first line of said return line to add a back pressure higher than a vapor pressure of the fuel to the first line;
- and
- a selector to selectively communicate one of (1) the fuel tank and the first line through said pressurizing mechanism (2) the fuel tank and second line, based on a pressure of the fuel within said return line.
An alternative fuel supply apparatus for an internal combustion engine comprising:
- a high-pressure pump connected to a fuel tank through a feed pump, a fuel cooler, and a fuel filter, the fuel tank storing therein a vaporable fuel under pressure higher than a vapor pressure of the fuel;
- a common rail within which the fuel supplied from the fuel tank through said high-pressure pump is stored at a given high pressure, said common rail being connected to injectors working to inject the fuel into the engine;
- a pressure limiter installed in said common rail to set a maximum pressure within said common rail;
- a fuel return line returning fuel relieved from said common rail through said pressure limiter and fuel flowing out of said high-pressure pump to the fuel tank;
- and
- a fuel selector valve, a purge tank, a compressor, and a fuel cooler installed in said fuel return line in this order.
An alternative fuel supply apparatus for an internal combustion engine comprising:
- a high-pressure pump working to feed a fuel which is susceptible to vaporization to injectors from a fuel tank through a common rail under a given high pressure;
- a return line extending from said high-pressure pump to the fuel tank;
- and
- a pressurizing mechanism working to add to said return line a back pressure higher than a vapor pressure of the fuel,
- wherein said high-pressure pump includes a pump chamber to which the fuel from the feed pump is inputted through a fuel gallery at a feed pressure, a plunger reciprocating within a plunger chamber formed within a cylinder to pressurize the fuel within the pump chamber and inject the pressurized fuel into the engine through a discharge valve and each of the injectors, a higher-pressure leakage line, and a lower-pressure leakage line, the higher-pressure and lower-pressure leakage lines working to withdraw the fuel leaking out of the pump chamber through a gap between the plunger and the plunger chamber following reciprocating motion of the plunger.
Dependencies are inferred from the claim text.