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US 4,782,794 AGranted
Fuel injector system
AssigneeGeneral Electric Company
InventorsBertrand D. Hsu, Gary L. Leonard
Life of this patent
Estimating the term…
Abstract
A fuel injection system particularly adapted for injecting coal slurry fuels at high pressures includes an accumulator-type fuel injector which utilizes high-pressure pilot fuel as a purging fluid to prevent hard particles in the fuel from impeding the opening and closing movement of a needle valve, and as a hydraulic medium to hold the needle valve in its closed position. A fluid passage in the injector delivers an appropriately small amount of the ignition-aiding pilot fuel to an appropriate region of a chamber in the injector's nozzle so that at the beginning of each injection interval the first stratum of fuel to be discharged consists essentially of pilot fuel and thereafter mostly slurry fuel is injected.
Claims30
A system for injecting slurry fuel into a combustion chamber comprising:
- (a) an injector comprising:
- a housing defining a bore including a guide portion communicating with an accumulator chamber, said accumulator chamber having sufficient volume to store a predetermined amount of elastic energy in a slurry fuel having a given compressibility contained therein at a predetermined pressure, said housing having an inlet port and an outlet orifice communicating with said accumulator chamber;
- a movable needle valve extending through said bore and having a section thereof slidably disposed in said bore guide portion;
- control means associated with said needle valve for permitting external control of its movement between an open position wherein said outlet orifice is open and a closed position wherein said outlet orifice is blocked;
- and
- said housing further defining a purge chamber in a surface of said bore guide portion generally surrounding said needle valve section, and an aperture communicating with said purge chamber, the volume of said purge chamber being selected to be a predetermined relatively small percentage of the volume of said accumulator chamber;
- (b) first means connected to said inlet port and adapted to supply slurry fuel to said accumulator chamber;
- (c) second means for connecting said aperture to a supply of purging fluid;
- and
- (d) pumping means adapted to be connected to said first and second means and operative periodically to cause a charge of slurry fuel to be supplied by said first means to said accumulator chamber and concurrently to cause said second means to deliver a charge of purging fluid to said purge chamber at a pressure higher than the pressure of slurry fuel in said accumulator chamber.
7 more elements
In an improved system for periodically injecting fuel into a cylinder of a diesel engine having a crankshaft, which fuel comprises a mixture of coal and water:
- (a) an injector comprising:
- an assembly including a generally cylindrical, hollow nozzle portion adapted to project into a cylinder of the engine, an orifice in said nozzle portion, a pressure vessel connected to said nozzle portion, a first inlet port communicating with an accumulator chamber inside said vessel, a second relatively small chamber inside said nozzle portion adjacent to said orifice, a first fluid passage extending from said accumulator chamber to said second chamber, and a cylindrical guide portion defining a concentric bore in the assembly, said bore communicating at one end of said guide portion with said second chamber;
- a needle valve having a longitudinal section slidably disposed in the bore of the guide portion of said assembly for reciprocal movement between opened and closed positions, said needle valve also having means at one end thereof for blocking the discharge of fluid from said second chamber through said orifice whenever said needle valve is in its closed position;
- and
- control means associated with said needle valve for controlling its position;
- said assembly having a second inlet port and a second fluid passage extending from said second inlet port to the annular gap between said needle valve and said guide portion near said one end thereof;
- (b) first means connected to said first inlet port for supplying coal-water mixture to said accumulator chamber and, via said first fluid passage, to said second chamber;
- (c) second means for supplying purging fluid to said second inlet port and, via said second fluid passage and said annular gap, to said second chamber;
- (d) third means coupled to said control means and adapted to operate in synchronism with the rotation of the engine crankshaft to cause said needle valve periodically to move from opened to closed positions and alternately to permit needle valve movement from said closed position to said opened position in which said orifice is unblocked and fuel can discharge from the nozzle portion of said injector into the associated cylinder;
- and
- (e) periodically operative pumping means for causing said first means to deliver discrete, pressurized charges of coal-water mixture into said accumulator chamber while said needle valve is in its closed position;
- (f) the average pressure of the coal-water mixture in said accumulator chamber during each interval that said needle valve is closed being lower than the average pressure at which said purging fluid is supplied to said second inlet port, whereby there is a net flow of purging fluid through said annular gap and into said second chamber.
9 more elements
In an integrated pilot fuel system for periodically injecting, into a cylinder of a diesel engine having a crankshaft, a mixture of coal and water along with a pilot fuel that will aid ignition of the coal-water mixture:
- (a) an injector comprising:
- an assembly including a generally cylindrical, hollow nozzle portion adapted to project into a cylinder of the engine, an orifice in said nozzle portion, a chamber inside said nozzle portion adjacent to said orifice, a first inlet port, fluid passage means for connecting said first inlet port to said chamber, and a cylindrical guide portion defining a concentric bore in the assembly, said bore communicating with said chamber at one end of said guide portion in relatively close proximity to said orifice;
- a needle valve having a longitudinal section slidably disposed in the bore of the guide portion of said assembly for reciprocal movement between opened and closed positions, said needle valve also having means at one end thereof for blocking the discharge of fluid from said chamber through said orifice whenever said needle valve is in its closed position;
- and
- means for holding said needle valve in its closed position;
- said assembly having a second inlet port communicating with the annular gap between said needle valve and said guide portion;
- (b) first means connected to said first inlet port for supplying pressurized coal-water mixture to said chamber;
- (c) second means effective while said needle valve is in its closed position for supplying pressurized pilot fuel to said second inlet port and, via said annular gap, to said chamber;
- and
- (d) third means adapted to operate in synchronism with the rotation of the engine crankshaft for periodically initiating needle valve movement from said closed position to said opened position in which said orifice is unblocked and a combination of coal-water mixture and pilot fuel can discharge from said chamber through said orifice into the associated cylinder for a predetermined interval;
- (e) the average pressure in said chamber during each interval that said needle valve is closed being lower than the average pressure at which said pilot fuel is supplied to said second inlet port, whereby there is a net flow of pilot fuel through said annular gap and into said chamber;
- (f) said annular gap being sufficiently constricted to limit the amount of pilot fuel delivered to said chamber during each valve-closed interval to a relatively small fraction of the amount of each discharge of coal-water mixture and pilot fuel when the engine is running at full load.
9 more elements
In an integrated pilot fuel system for periodically injecting, into a cylinder of a diesel engine having a crankshaft, a mixture of coal and water along with a pilot fuel that will aid ignition of the coal-water mixture:
- (a) an injector comprising:
- an assembly including a generally cylindrical, hollow nozzle portion adapted to project into a cylinder of the engine, an orifice in said nozzle portion, a chamber inside said nozzle portion adjacent to said orifice, first and second inlet ports, fluid passage means for connecting said first inlet port to said chamber, a cylindrical guide portion defining a concentric bore in the assembly, and second fluid passage means for connecting said second inlet port to a region of said chamber in relatively close proximity to said orifice;
- a needle valve having a longitudinal section slidably disposed in the bore of the guide portion of said assembly for reciprocal movement between opened and closed positions, said needle valve also having means at one end thereof for blocking the discharge of fluid from said chamber through said orifice whenever said needle valve is in its closed position;
- and
- means for holding said needle valve in its closed position;
- (b) first means connected to said first inlet port for supplying pressurized coal-water mixture to said chamber;
- (c) second means effective while said needle valve is in its closed position for supplying pressurized pilot fuel to said second inlet port and, via said second fluid passage means, to said chamber;
- and
- (d) third means adapted to operate in synchronism with the rotation of the engine crankshaft for periodically initiating needle valve movement from said closed position to said opened position in which said orifice is unblocked and a combination of coal-water mixture and pilot fuel can discharge from said chamber through said orifice into the associated cylinder for a predetermined interval;
- (e) said second fluid passage means being sufficiently constricted to limit the amount of pilot fuel delivered to said chamber during each interval that said needle valve is closed to a relatively small fraction of the amount of each discharge of coal-water mixture and pilot fuel when the engine is running at full load;
- (f) the part of said first fluid passage means in communication with said chamber being dimensioned to ensure that a high concentration of pilot fuel will tend to accumulate in said chamber adjacent to said orifice during each valve-closed interval when the engine is running at full speed.
8 more elements
Dependencies are inferred from the claim text.