A kind of back pressure adaptive constant-flow nozzle
Technical field
The present invention relates to be used for the nozzle of liquid fuel injection system such as kerosene, diesel oil, gasoline, residual oil, can be applicable to injection system such as the energy, power, heating, Aero-Space propelling.
Background technology
The major function of nozzle is that liquid fuel is introduced the combustion chamber, controls its flow, makes liquid crushing become droplet.When designing nozzle, people only are concerned about its atomization in the past, have developed all kinds nozzle from atomizing type.The several types of widespread usage is at present: single flow nozzle (comprising jet nozzle, tack nozzle, diesel engine nozzle, scallop hole nozzle etc.), rotarytype injector, two-fluid spray nozzle (be divided into gas assist type nozzle and gas and blow the formula nozzle), rotating nozzle and other form nozzle (comprising supersonic nozzle, sound wave nozzle, EFI mouth etc.).
Common feature with top nozzle is, the hypothesis combustion chamber pressure is known and constant during design, and fuel flow rate is by storage tank pressure and orifice size decision.Yet in the real work, combustion chamber pressure does not always equal specified pressure, but within the specific limits fluctuation, particularly system start, the condition of changing a job and when closing, combustion chamber pressure is away from rated value, this moment, the plain nozzle discharge characteristic can't guarantee.
Summary of the invention
The technical problem to be solved in the present invention is, the defective that can't guarantee at prior art nozzle discharge characteristic when the back-pressure offrating, a kind of back pressure adaptive constant-flow nozzle is proposed, it need not external energy and drives, can adapt to back-pressure within the specific limits automatically changes, keep constant flow, and simple in structure, dependable performance.Technical solution of the present invention is, described back pressure adaptive constant-flow nozzle comprises sleeve, its design feature is, be provided with center-pole in the described sleeve, this center-pole rear portion is a cylindrical body and anterior be bullet, the bigger end of described bullet is positioned at jet expansion one side, the front end that is set with the annular space that forms between piston and this piston cavity and the described bullet on the described center-pole is communicated with described jet expansion and its rear end is communicated with passage front end in the described cylindrical body, this passage rear end is a fuel filler, between piston rear end and sleeve rear end spring is housed.
Below the present invention made further specify.
Referring to Fig. 1, the present invention includes sleeve 1, its design feature is, be provided with center-pole 10 in the described sleeve 1, these center-pole 10 rear portions are cylindrical body 4 and anterior be bullet 8, described bullet 8 bigger ends are positioned at jet expansion 9 one sides, the front end that is set with the annular space 7 that forms between piston 2 and this piston 2 inner chambers and the described bullet 8 on the described center-pole 10 is communicated with described jet expansion 9 and its rear end is communicated with passage 6 front ends in the described cylindrical body, these passage 6 rear ends are fuel filler 5, between piston 2 rear ends and sleeve 1 rear end spring 3 are housed.
The know-why of nozzle of the present invention is, liquid fuel enters the passage 6 of center-pole 10 according to Fig. 1 right side arrow direction by fuel filler 5, and the annular space (annulus) 7 that forms between the bullet 8 of piston 2 inner chambers and center-pole 10 again penetrates, and flow G is determined by following formula:
In the formula: C
dBe discharge coefficient; A is an orifice size; ρ is a liquid fuel density; p
0Be liquid fuel head stagnation pressure; P is the outlet back-pressure.
Piston 2, spring 3 assemblies change as sensing element induction back-pressure, by the dynamic balance of spring 3 with back-pressure, by spring 3 elastic compression amounts record back-pressure change amount, to act on simultaneously and directly pass to executing agency's piston 2, the change in location of piston 2 relative adjustment mechanism center-poles 10 causes the two slit to change, be that the nozzle orifice size changes, flow G equals design load all the time in maintenance (1) formula.
As known from the above, the present invention is a kind of back pressure adaptive constant-flow nozzle, it is compared with existing nozzle, need not the external energy driving and can adapt to back-pressure within the specific limits automatically to change, keep constant flow, and simple in structure, dependable performance can be widely used in injection system such as the energy, power, heating, Aero-Space propelling.
Description of drawings
Fig. 1 is the structural representation of an embodiment of the present invention.
In the drawings:
The 1-sleeve, the 2-piston, the 3-spring, the 4-cylindrical body, the 5-fuel filler,
The 6-passage, 7-annular space, 8-bullet, 9-jet expansion, 10-center-pole.
The specific embodiment
According to the back pressure adaptive constant-flow nozzle of figure and said structure, each member is made of equal metal material, and it is applied in the water reacting metal engine fuel, utilizes this nozzle that water is introduced the combustion chamber; The actual use shows, when combustion chamber pressure changes between 0.2MPa-0.55MPa, the discharge of back pressure adaptive constant-flow nozzle of the present invention of flowing through is constant near 0.035kg/s, worst error is 1.7%, and discharge is crossed the problem that senior general's flame is put out by water when having solved water reacting metal engine fuel effectively and changing a job condition.