RU2495277C2 - Device for defining high-pressure nozzle and pipeline effective flow section - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed method consists in forcing the fuel through tested nozzle (of fuel line) for preset controlled time interval. Initial air pressure is created by charging hydropneumatic accumulator on feeding the fuel therein for air compression. Here, compressed air makes the fuel flow through tested nozzle (or fuel line) in pressure drop in hydropneumatic accumulator from initial value to preset final magnitude.

EFFECT: higher accuracy of determination.

Description

The invention relates to the field of engine manufacturing and can be mainly used in testing fuel equipment of diesel engines.

A known method of determining the effective flow area of nozzles and high pressure fuel lines [Patent No. 2030625 of the Russian Federation. The method of determining the internal volume of the fuel line and device for its implementation / B.P. Udalov, A.P. Wuhanov. - No. 4891277; Application 11/17/1990; Publ. 03/10/1995, Bull. No. 7], which consists in displacing fuel from the air from the channel of the tested fuel line (or nozzle) into a measuring tank pre-filled with fuel. In this case, the volume (quantity) of fuel passing through the fuel line will correspond to the volume (amount) of air displaced from the tested fuel line (or nozzle) for a certain time under constant static pressure.

The disadvantage of this method is the low accuracy of determining the effective flow area of nozzles and fuel pipelines of high pressure due to the difficulty of ensuring constant pressure during the test.

The closest in technical essence is a method for determining the effective flow area of nozzles and high pressure fuel lines [Ukhanov A., Chernyakov A. Selection of reference nozzles and fuel lines // Rural mechanic. - 2004. - No. 2. - S.12-13], which consists in passing the recommended mass amount of fuel through the test nozzle (or fuel line) under constant pressure for a controlled time.

The disadvantage of this method is the low accuracy of determining the effective flow area of nozzles and fuel pipelines of high pressure due to the difficulty of ensuring constant pressure during the test.

The present invention is aimed at eliminating this drawback and the following technical result was obtained from its use: improving the accuracy of determining the effective flow area of nozzles and high pressure fuel lines.

The specified technical result is achieved through the use of a method for determining the effective cross-section of nozzles and high pressure fuel lines, which consists in passing fuel through the tested nozzle (or fuel line) under pressure for a controlled time, and the initial air pressure is provided by charging the hydro-pneumatic accumulator by compressing air when fuel is supplied to it , when the hydropneumatic accumulator is discharged under the action of compressed air pressure, fuel passes through the tested nozzle y (fuel-wire) time for the air pressure drop from a predetermined initial gidropnevmoakkumulyatore to a predetermined end, wherein the effective flow cross-section (μf) is calculated in the following sequence:

- determine the mass of air (m) in the hydropneumatic accumulator

m = ρ _in · V, kg,

where ρ _in - the density of air, kg / m ³ ; V is the volume of the hydropneumatic accumulator, m ³ .

- determine the volume of compressed air (V ₁ ) in the hydropneumatic accumulator

, $$V_{\mathrm{one}}=\frac{m\cdot R\cdot T}{P_{\mathrm{one}}},{\text{m}}^{\text{3}}$$

,

where R is the universal gas constant of air, J / kg · K;

T is the temperature of the compressed air in the hydropneumatic accumulator, K;

.P ₁ - the initial air pressure in the hydro-pneumatic accumulator, $$P\mathrm{but}=\frac{N}{m^2}=\frac{\mathrm{to}g}{m\cdot {\mathrm{from}}^2}$$

.

- determine the effective flow area

, $$\mu f=\frac{V_{\mathrm{one}}\cdot \left(\sqrt{P_{\mathrm{one}}}-\sqrt{P_2}\right)\cdot \sqrt{2{\rho }_t}}{P_{\mathrm{one}}\cdot t}\cdot {10}^3,{\text{mm}}^{\text{2}}$$

,

where µ is the flow coefficient;

f is the area of the transverse channel of the nozzle (fuel line), m ² ;

ρ _t - density of fuel spilled through the nozzle (fuel line) at a given temperature, kg / m ³ ;

;P ₂ - final air pressure in the hydro-pneumatic accumulator, $$P\mathrm{but}=\frac{N}{m^2}=\frac{\mathrm{to}g}{m\cdot {\mathrm{from}}^2}$$

;

t is the time of air pressure drop in the hydropneumatic accumulator from a given initial to a given final, s.

For example, if V ₁ = 202 · 10 ^-6 m ³ , t = 7c,

, $$P_{\mathrm{one}}=5\text{MPa}=\text{5}\cdot {\text{10}}^{\text{6}}\frac{\mathrm{to}g}{m\cdot {\mathrm{from}}^2}$$

,

$$P_2=\mathrm{one}\text{MPa}=\text{one}\cdot {\text{10}}^{\text{6}}\frac{\mathrm{to}g}{m\cdot {\mathrm{from}}^2},$$

ρ _t = 830 kg / m ³ , then for the nozzle

. $$\mu f=\frac{202\cdot {10}^{-6}\cdot \left(\sqrt{5}-\sqrt{\mathrm{one}}\right)\cdot {10}^6\cdot \sqrt{2\cdot 830}}{5\cdot {10}^6\cdot 7}\cdot {10}^3=0.29{\text{mm}}^{\text{2}}$$

.

Claims (1)

A method for determining the effective cross section of nozzles and high pressure fuel lines, which consists in passing fuel through a test nozzle (or fuel line) under pressure for a controlled time, characterized in that the initial air pressure is provided by charging the hydropneumatic accumulator by compressing the air when fuel is supplied to it, when the hydropneumatic accumulator is discharged Under the influence of compressed air pressure, fuel passes through the test nozzle (fuel line) during the time of air pressure drop in a hydropneumatic accumulator from a given initial to a given final, while the effective cross-section (µf) is calculated in the following sequence:
determine the mass of air (m) in the hydropneumatic accumulator
m = ρ _in · V, kg,
where ρ _in - the density of air, kg / m ³ ;
V is the volume of the hydropneumatic accumulator, m ³ ,
determine the volume of compressed air (V ₁ ) in the hydropneumatic accumulator
$$V_{\mathrm{one}}=\frac{m\cdot R\cdot T}{P_{\mathrm{one}}},{\text{m}}^{\text{3}},$$

where R is the universal gas constant of air, J / kg · K;
T is the temperature of the compressed air in the hydropneumatic accumulator, K;
P ₁ - the initial air pressure in the hydropneumatic accumulator, $$P\mathrm{but}=\frac{N}{m^2}=\frac{\mathrm{to}g}{m\cdot {\mathrm{from}}^2},$$

determine effective cross-section
$$\mu f=\frac{V_{\mathrm{one}}\cdot \left(\sqrt{P_{\mathrm{one}}}-\sqrt{P_2}\right)\cdot \sqrt{2{\rho }_t}}{P_{\mathrm{one}}\cdot t}\cdot {10}^3,{\text{mm}}^{\text{2}},$$

where µ is the flow coefficient;
f is the area of the transverse channel of the nozzle (fuel line), m ² ;
ρ _t - density of fuel spilled through the nozzle (fuel line), kg / m ³ ;
P ₂ - final air pressure in the hydro-pneumatic accumulator, $$P\mathrm{but}=\frac{N}{m^2}=\frac{\mathrm{to}g}{m\cdot {\mathrm{from}}^2}$$

;
t is the pressure drop time from the initial to the final value, s.