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Frequency rotation regulator of the direct action

Frequency rotation regulator of the direct action is such a regulator, in which the replacement of the control device is performed by sensitive element efforts, directly connected with it. On fig. 5.2 the structural scheme of regulator, which is considered, static characteristic and functional diagram of the regulator are given.

 

 

 

Fig 5.2.Frequency rotation regulator of the direct action

1 – executive bond lever; 2 – dosing needle (control unit); 3 –driving roller-spring; 4, 5 – bearing; 6 –plug; 7 – centrifugal weight (sensitive element) ; 8 – executive rod connection; 9 – spring of set up device; 10 – bush; 11 – lever; a – structural scheme of regulator; b–static characteristic; c –functional diagram of regulator

As it is evident from the structural scheme, SE of regulator 7 during the rotation with speed, which is proportional to the engine rotor frequency rotation n, pick up centrifugal force, axial component Fâ.öof which displaces rod 8, connected via lever 1with dosing fuel burner 2. Rod and dosing burner position is determined by equation of centrifugal force component and spring contraction force 9.

 

For setting up the regulator for another rotation frequency it’s necessary to change previous spring contaction 9, achieved by replacement of moving bush 10, which is connected to lever gear 11 by rail-joint clutch. Interaction of direct action regulator elements and set up device is shown on the functional diagram (see fig 5.2. c).

Functional diagram is conventional image of speed rotation regulator, where conventionally depictedelements of the regulator that are the part of it, the connection between them and between governing body.Feature of the scheme is that the function comparison element CE and executiveconnection performed by the same detail, and, specifically, by the rod 8.

Let’s consider the static properties of direct action regulator, analyzing characteristics of the necessary fuel consumption depending on frequency rotation for several different external conditions, which is characterized, for example, different temperature of the environment.

On the fig. 5.2 b curve 1 corresponds to necessary fuel consumption at environment temperature Ò*í0,

and curve 3 – at temperature Ò*í1. Moreover Ò*í1 > Ò*í0.At steady-state mode at a given position of SD regulator is adjusted on frequency rotor rotation position n0, for which at Ò*í0 conditions meets the fuel supply requirements Gï0.

With increasing of ambient temperature by reducing the density of air decreases also the time of the compressor motor rotor resistance. So, given frequency of rotation n0in conditions Ò*í1must correspond to less fuel consumptionGï2. Reducing of Gïin regulator is carried out by changing of position of dosing burner DB. For Gïreducing DB 2 issinking.

 

Due to the presence of a direct mechanical connection, which is present between burner 2 and rod 8, changing of position DB necessarily accompanied by an efforts changing of previous spring 9 tightening.



That’s why efforts from centrifugal weights, that balances the spring force 9, also will differ from the original value, and. Because of it, new ascertained valuen1 will differ from initialn0. In accordance with this in process air temperature changing to the value Ò*í1 and fuel consumption by line 2 at ascertained mode the direct action regulator will maintain the rotation frequency n1, that exceeds the initial valuen0 at some value Dn, which is the static control error. Accordingly, fuel consumption Gï1also will exceed value Gï2.

Should be added, that regulator operation conditions will be similar to conditions at reducing of ambient air pressure.

Thereby the frequency rotation regulator of direct action is static, i.e. by principle of action it cannot exactly maintain given rotation frequency at ambient conditions changes.

The wider range of changes in external conditions, the greater static error of frequency rotation regulation will be.

Advantages:

· frequency rotation regulator of direct action is stable by construction;

· it has a good dynamic characteristic, which allows you to get aperiodic processes with small time controlling.

 

Disadvantages:

· frequency rotation regulator of direct action has static errors at frequency rotation controlling. For this reason the frequency rotation regulator of direct action is called static regulators

· this regulator cannot be used on engines with high fuel consumption, for replacement CD of which it’s necessaryconsiderable effort.

 

Frequency rotation regulator of direct action is used in low-power GTU (GTE) with little fuel consumption, at exploitation of which wide ambient condition changes aren’t stipulated.

 


Date: 2015-02-16; view: 899


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