SU1191759A1 - Method of determining power of internal combustion engine mechanical loss - Google Patents

Description

The invention relates to measuring equipment and can be used to determine the power of mechanical losses of the engine Internal

combustion, for example, when searching for 5

malfunctions causing low engine fuel efficiency.

The purpose of the invention is to improve the accuracy and reduce the complexity,

The drawing shows graphs explaining the method.

Traffic shows dependencies of indicator efficiency P ·, consumption

** 1 <s

fuel C _t , and rotational speed sweat effective engine power Νθ.

The essence of the method lies in the fact that at a constant rotational speed between the indicator 'power Ν · and the fuel consumption C _t there is ^ 0 proportional relationship:

where C is a constant multiplier depending on the design features of the engine;

£ · - indicator efficiency, 30

The presence of this dependence

allows you to determine the power of mechanical losses Ν _Μ fuel consumption. at idle Ο _Τχ , effective power Νρ and the corresponding '35

fuel consumption (P _t , To eliminate the error associated with the dependence of the indicator efficiency · ·. on the effective power _ε , the fuel consumption must be measured at such an effective power M _e , at which the indicator efficiency r? is equal to the indicator efficiency idle stroke at a given frequency of rotation n ^.

Indicator efficiency within 45 of the regular branch of the characteristic is weakly dependent on the load. Initially, as the engine power increases, it increases slightly, and then begins to gradually decrease, and, 50

As can be seen from the above, in FIG. I · of the graph £ = Γ (Νθ), within the indicated limits there is a point for which?! ~? ΐχ · ^er P Y ^la-valued characteristics of tractor and combine 55 diesels, this point is at the HA fire rate corresponding to 70-80 percent of the nominal power of a diesel engine.

And since the nature of the flow curve = Ρ (Νθ) at n = const practically does not depend on the technical condition of the engine, for the engine of a given brand the value ^ equal to _χ always corresponds to the same load level relative to the nominal power of the engine.

The proposed method is implemented as follows.

Preliminary for this type of engine, a functional dependence is established> ?, = Ρ (Ν _β ) at the nominal rotation frequency η and a given value is determined from this dependence, at which y ·.

In addition, for a given type of engine, a predetermined rotation frequency n ^ is preliminarily set, at which the power of mechanical losses is subsequently determined. To do this, when the engine is idling, the nominal speed of rotation n ₍₁ , and then with the same position of the engine control lever, the engine is loaded to the specified power ,θ, ^ and the steady-state rotational frequency is taken as η y.

Power mechanical losses on a particular engine is determined as follows.

Start and warm up the engine to a normal thermal mode.

Set the nominal frequency of rotation of n _(| at idle.

When the position of the engine control lever is unchanged, the engine is loaded until the set rotational speed is reached n ^ and the effective power N is measured.

In order to get η2 at Ν ₆ ^., Adjust the frequency of rotation of idling by the expression

^Nn

. ^{P u} from to

where η. - corrected time ^A QA

rotational speed of idling.

Using the engine control lever set obtained

the value of ηχ load the engine to

achieve a given speed

η and measure the fuel consumption C _t ,

about

3

) 191759

four

corresponding to the specified power value

The engine is unloaded and, when operating at idle speed, the speed limit is reduced until it is reached by influencing the engine control lever and the fuel consumption is measured

But the value of 6 _Τχ , C _m ^ iY _{e> is} determined by the power of mechanical losses N from the expression

^T e ^T L

Claims (2)

THE METHOD OF DETERMINING THE POWER OF THE MECHANICAL LOSSES OF THE ENGINE IS INTERNAL »ITS COMBUSTION, is that _? that fuel consumption is measured when the engine is running at a given constant rotational speed at idle and with known effective power, with subsequent determination by the power of mechanical losses, about tl and h ayuschy sya by the fact that, In order to improve accuracy and reduce the complexity of the determination, a functional relationship between the indicator efficiency and effective power is established for this type of engine beforehand at a given constant Rotation frequency, and this relationship determines the value of the known effective power corresponding to the indicator efficiency value equal to the indicator efficiency at idle and the power of mechanical losses is determined from the expression ' ^T x m Where power loss; given effective power; fuel consumption, respectively, at idle and at a given effective power. <19) 5C "and 1191759 > one 1191759 2