SU1277066A1 - Method of operation of internal combustion engine - Google Patents

Abstract

. The invention relates to engine-building and makes it possible to increase the efficiency and technical and operational performance of an engine in transient conditions by reducing the inertia of the regulation process .ff. Of fuel viscosity. When the engine is running, the fuel from the supply tank I is fed to the preheater 3 and to the bypass fuel line 6. In the preheater, the fuel is warmed up to the temperature 5-10 seconds higher than the level specified for the nominal mode by means of the regulating device 5. 20% of the fuel that is cooled. The heated and cooled streams are mixed in the required proportion, at which optimum fuel viscosity is provided. The latter is set by an extreme regulator from $ 8, which receives signals from the quality of the working process and L fuel temperature at the engine inlet. The impulses of the control of the retractor 8 are fed to an adjustable mixer 9. 3 ip. 1Fr Od O) O

Description

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.1277066

The invention relates to the automatic regulation of the operation of internal combustion engines and can be used in automatic control systems for the replenishment of internal combustion engines (two).

The aim of the invention is to increase fuel efficiency and technical performance of engine operation at transitional times by reducing the inertia of the process of adjusting the viscosity of the topiv, for which its viscosity, which ensures the highest quality combustion, automatically changes during transient conditions with minimal delay when the engine load changes .

Fig. 1 shows a possible 20 basic diagram of the device for implementing the proposed method in Fig. 2, a block diagram of an extremal controller;; Fig. 3 is an adjustment graph.

The device contains a fuel supply tank 1, fuel pumping pump 2, fuel heater 3, sensor 4 at the outlet of heater 3, regulator 5 of heater 3, bypass fuel line 6, fuel cooler 7, - extreme regulator 8 regulating body-mixer 9 and regulating body 10 cooling. The device works as follows.

The fuel priming pump 2 takes the fuel from the fuel supply distributor 1 and supplies it to the preheater 3 and to the bypass fuel line 6. In the preheater 3, the fuel is heated to a temperature higher than that which provides 45 (for a given fuel type) viscosity for engine operation at rated load. (This viscosity is minimally necessary from the operational point of view. The temperature of the fuel at the exit of the preheater 3 is measured by the temperature sensor 4, which acts on the regulator 5, which changes the amount of steam entering the heater 55.

Thus, two streams of fuel - preheated in the heater

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and having practically the same temperature as in the supply tank (without taking into account heat losses), are supplied to the regulating mixing body 9, where they are sewn in the necessary proportion, at which the optimum viscosity of the fuel is met, which corresponds to a certain operating condition m work two.

The optimum fuel viscosity is set by the extreme regulator 8, which constantly performs a comparison of the target value of the selected efficiency criterion; workflow (exhaust temperature) with actual. In the presence of a mismatch, the regulator 8 generates a regulating effect. The effect transmitted to the regulator-mixer 9. Due to the indicated features of the device, the duration of the viscosity control process is significantly reduced (due to the exclusion of the inertia of the fuel preheater) and is determined almost exclusively by the dynamic characteristics of the extreme regulator 8 and the regulator-mixer 9.

The extreme controller 8 contains an adjustable object 11, a sensitive element 12, a memory device 13, a comparison device; 14 and the actuator 15. In a typical operating case, the supply tank 1 receives fuel after the separator, and its temperature is close to that which provides the required minimum viscosity. In this case, the regulator-mixer 9 operates with a large gain factor, at which stable operation is not ensured.

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To prevent this, a fuel cooler 7 installation is provided. In this case, the heated and cooled fuel enters the regulator-mixer 9, and the mixer-regulator operates with a lower gain. Further, the adjustment process proceeds as indicated.

The optimal value of the flow of cooled fuel in terms of maximum technical and operational

The efficiency of the cooling system can be determined as follows.

From the equation of warmth balance

t (c + g -

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- the resulting temperature of the mixture of fuel (hereinafter, see the notation in figure 1); - temperature of the heated and cooled 15 fuel, respectively; - mass of heated and cooled fuel, respectively.

as typical values 20, T -, T, with 1, G KG ,,

t (1 + kb)

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With extreme limits of change

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temperatures of cooled fuel T., taken from the standpoint of choosing the optimal ratio between the flow rate and the degree of cooling of the fuel, after substituting the initial values, we get:

, 00 iiO: Iil0.55K). ..20; (one)

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Thus, the mass of the cooled fuel can be accepted for specified conditions within 20–25% of the mass of the heated fuel, or, equivalently, 15–20% of the total consumption, of fuel to the engine 16.

The principle of action of the extreme regulator is as follows (Fig, 2, 3).

In general, the characteristics of adjustable objects can have a minimum or maximum. The external speed characteristic of a diesel engine has a maximum torque, and the load characteristics have a minimum specific fuel consumption. In connection with this, more and more such applications have been created and are now - SAR, which themselves (automatically) look for the extremum of the characteristics

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and support the operation of the regulated object in the extremum mode.

There are several ways to create extreme controllers. One of the possible functional schemes has the following form (figure 2).

In such systems, the sensing element measures the variable Y (in this case, the exhaust gas temperature, which is uniquely related and characterizes the specific fuel consumption). This value of the regulated value is compared with the comparison device with the value of the regulated value recorded in the previous measurement and stored in the storage device.

If the new value of the regulated value is less (or more) than the previous one, an appropriate signal is given to the actuator, as a result of which the actuator generates the effect of the corresponding sign, aimed at eliminating the mismatch between the previous and current values of the controlled variable.

Thus, the system of extreme regulation automatically finds the extremum of the function and maintains the operation mode of the object corresponding to this extremum.

As can be seen from Fig. 3, with the same deviation of the regulable value (g g and T) (points A and B) from the optimum value (point C) in one case it is necessary to increase and B to reduce the viscosity of the fuel by another. The optimum value of the fuel viscosity is determined by the shape of the combustion chamber, the design of the fuel apparatus, the fuel grade, and a number of other factors, and is approximately 2 U (Engler).

Claims (1)

(paal. The invention relates to the automatic regulation of the operation of internal combustion engines and can be used in the automatic regulation of the viscosity of the fuel of internal combustion engines (two). The aim of the invention is to increase the fuel economy and technical performance indicators of the engine during transient conditions by reducing the inertia the process of adjusting the viscosity of a fuel, for which its viscosity, which ensures the highest quality combustion, is automatically changed to driving modes with minimal delay when the engine load changes. Figure 1 shows a possible schematic diagram of the device for implementing the proposed method in Figure 2 is a block diagram of the extreme regulator; Figure 3 shows the adjustment schedule. 1, fuel priming pump 2, fuel preheater 3, temperature sensor 4 at the outlet of the preheater 3, regulator 5 of the preheater 3, bypass fuel line 6, fuel cooler 7, - extreme regulator 8, Body 9 that mixes body 9 and cooling regulator 10. The device works as follows. The fuel priming pump 2 takes the fuel from the supply dytern 1 and supplies it to the preheater 3 and to the bypass fuel line 6. In the preheater 3, the fuel is heated to a temperature higher than that which the engine requires at nominal load. (This viscosity is the minimum required from the operational point of view. The fuel temperature at the outlet of heater 3 is measured by temperature sensor 4, which acts on regulator 5, which changes the amount of steam entering the heater 3. Thus, two streams fuel - heated in the preheater 6 and having practically the same temperature as in the supply tank (without taking into account heat losses), goes to the regulating body-mixer 9, where they are sewn; The optimum viscosity of the fuel corresponding to the specific operating conditions of operation is two. The optimum viscosity of the fuel is set by the extreme regulator 8, which constantly compares the set value of the selected efficiency criterion; the working process (exhaust temperature) with the actual one. torus 8 generates a regulatory action transmitted to the regulatory body-mixer 9. Due to the specified features of the device, the duration of The viscosity control sss is significantly reduced (by eliminating the inertia of the fuel preheater) and is determined almost exclusively by the dynamic characteristics of the extreme regulator 8 and the regulator-mixer 9. Extreme regulator 8 contains an adjustable object 11, a sensitive element 12, a storage device 13, comparing device; 14 and the actuator 15. In a typical operating case, the supply tank 1 receives fuel after the separator, and its temperature is close to that which provides the required minimum viscosity. In this case, the regulating organ mixer 9 operates with a high gain factor, at which the system does not provide stable operation. 1 To prevent this, a fuel cooler 7 installation is provided. In this case, the heated and cooled fuel enters the regulator-mixer 9, and the mixer-regulator operates with a lower gain. Further, the adjustment process proceeds as indicated. The optimum value of the flow of cooled fuel in terms of the maximum technical and operational efficiency of the cooling system can be determined as follows. From the heat balance equation t (c + g - x: ..Ii, -L: lL.-I: L., Where T °, is the resultant temperature of the fuel mixture (hereinafter, see the symbols in figure 1) T and T are the temperatures of the heated and cooled fuels, respectively, G. and G are the masses of the heated and cooled fuels, respectively.Take as typical TCM values 1-т, Т -, Т, Зр-Б С, at 1, G KG, we get: t (1 + kb) -1 With extreme limits of temperature variation of the cooled fuel T. taken from the standpoint of choosing the optimal ratio between the flow rate and the degree of cooling of the fuel, after Application source the quantities, we obtain, 00 iiO: Iil0.55K). ..20; (1, 00.1i ° - | liO- 5 i; K.-0.25. (2 Thus, the mass of the cooled fuel can be accepted for the specified conditions within 20-25% of the mass of the heated fuel, or, However, 15–20% of the total fuel consumption per engine 16. The principle of the extreme controller is as follows (Fig. 2, 3). In general, the characteristics of adjustable objects can have a minimum or a maximum. torque, and load characteristics - a minimum of specific fuel consumption. In connection with this, Today, such CAPs, which automatically (automatically) search for the extremum of their characteristics and support the operation of a controlled object in the extremum mode, are now and there are several ways to create extreme regulators. One of the possible functional diagrams is as follows (Fig. 2) In such systems, the sensing element measures the variable Y (in this case, the exhaust gas temperature, which is uniquely related and characterizes the specific fuel consumption). This value of the regulated value is compared with the comparison device with the value of the regulated value recorded in the previous measurement and stored in the storage device. If the new value of the regulated value is less (or more) than the previous one, an appropriate signal is given to the actuator, as a result of which the actuator generates the effect of the corresponding sign, aimed at eliminating the mismatch between the previous and current values of the controlled variable. Thus, the system of extreme regulation automatically finds the extremum of the function and maintains the operation mode of the object corresponding to this extremum. As can be seen from Fig. 3, with the same deviation of the regulated value (g g and T) (points A and B) from the optimal value (point C) in one case it is necessary to increase, and B another to reduce the viscosity of the fuel. The optimum value of the fuel viscosity is determined by the shape of the combustion chamber, the design of the fuel apparatus, the fuel grade and a number of other factors and is approximately 2E (Engler). The method of operation of an internal combustion engine, in which, during operation of the engine, fuel is fed from the feed tank through a fuel preheater, is measured; The quality factor of the working process of the crucible and the temperature of the fuel on the course of the engine, send signals of measured parameters to the extreme regulator, with which they generate impulses to control the temperature of the fuel, about root and so that, in order to increase fuel efficiency and technical performance of the engine at transients by reducing the inertia of the process of adjusting the viscosity of the fuel, measure the fuel temperature at the outlet of the preheater and maintain 12 W. gjue.2 6 its above set / ut nominal level - using a regulating device, bypass 20-25 fuel past the fuel preheater, cool the bypass fuel to a predetermined level, mix the heated and cooled fuel in the adjustable mixer, and control pulses of the extreme regulator serve on an adjustable mixer.