RU2546909C2 - Control method of fuel parameters in fuel feed system of multifuel engine (versions) - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to engine building industry and can be used at stationary plants at operation of an engine on different types of fuel, namely on oil. The invention proposes a control method of fuel parameters in a fuel feed system of a multifuel engine, which consists in the fact that the engine start is performed on standard fuel; then, non-standard fuel is supplied to the engine by means of an injection pump (IP) (6); pressure of non-standard fuel is controlled in a make-up engine line by changing IP rotation speed and temperature of non-standard fuel is controlled at the inlet of fuel boost pump (FBP) (10) located at the inlet of the high pressure fuel pump (HPFP) of the engine by heating or cooling of excess non-standard fuel that is fed from HPFP to the inlet of FBP (10) or IP (6).

EFFECT: possibility of controlling fuel parameters by changing its pressure and temperature at engine operation on fuels with a wide range of viscosities; exclusion of a possibility of mixing standard and non-standard fuel when switching-over the make-up line from one type of fuel to another and simplification of a fuel feed system.

4 cl, 2 dwg

Description

The invention relates to the field of engine building and can be used in stationary installations when the engine is running on various grades of fuel, in particular oil.

A known fuel system that ensures the operation of the engine in multi-fuel mode: diesel fuel (at start-up and at low engine speeds) and viscous fuel (in the main operating modes). The transition from diesel to viscous fuel is carried out automatically with increasing engine speed. The logical device, depending on the operational parameters, controls the advance of fuel supply to the engine cylinders, according to a given optimal law. When operating on viscous fuel (heavy fuel), the logic device, based on the signal from the temperature sensor of the nozzle atomizer, includes a thermoelectric cooler, the cold junctions of which are cooled by convective heat exchange of the atomizer nozzle (see RF Patent No. 2131536 F02M 43/00, published June 10, 1999) .

This fuel system has certain limitations in terms of controlling the parameters of the fuel at the engine inlet.

A multi-fuel marine engine system is known, the use of which allows to reduce the amount of light fuel entering the heavy fuel tank during the transition from one type of fuel to another (see the description of the invention to copyright certificate No. 744140, F02M 31/16 of 07/10/1980).

The disadvantage of this system is that the system does not control the fuel parameters at the engine inlet, is very complex and is not provided as automated.

There is a known system for the preparation of non-standard fuel, which has four tanks: a slop of non-standard fuel, equipped with an indicator of its level in the tank, a tank for the centrifugal cleaning unit for non-standard fuel with level control devices, an expendable tank of non-standard fuel with level control devices and a standard diesel fuel tank. The system provides multi-stage fuel filtering and heating to set temperature values from an external coolant. The control system for the fuel parameters at the outlet of the installation works out within the specified settings (see Patent RU No. 2215176, C2 F02Μ 43/00, F02D 19/18, published October 27, 2003).

The disadvantage of this system is the presence of a large number of large tanks and the lack of the ability to use them in an automated control system for fuel parameters at the engine inlet.

Closest to the proposed solution is a fuel supply system that allows the engine to work on heavy or diesel fuel. The system serves to supply fuel from the supply tank to the fuel priming pump and high pressure fuel pumps (TNVD) of the engines. In this system, fuel is supplied:

- under a certain pressure, the regulation of which is carried out at the expense of the feed pump, at the same time, the fuel pressure in the system for draining excess fuel from the injection pump from the engine must be regulated;

- at a certain temperature, moreover, temperature control is carried out in the supply tank and pipelines (heating), as well as in the fuel heater (see .ru / motoristy / 1.3-4.html website; Operation of ship propulsion systems, fuel supply system).

Adjustable fuel parameters are its pressure and temperature at the engine inlet.

The disadvantage of this system is the need to use an additional return fuel tank, the possibility of mixing regular and non-standard fuel at the time of switching the supply line from one type of fuel to another, the need for additional pressure control in the system for draining excess fuel from the injection pump from the engine, a large amount of fuel pumped through the system, inability to automate the process of regulating fuel parameters.

The objective of the proposed method of controlling fuel parameters is to optimize fuel parameters when the engine is running on fuels with a wide range of viscosity changes.

The technical result of the invention is the ability to control the parameters of the fuel by changing its pressure and temperature when the engine is running on fuels with a wide range of viscosity changes, eliminating the possibility of mixing regular and non-standard fuel at the time of switching the feed line from one type of fuel to another, reducing the amount of fuel pumped through the system by reducing the size of pipelines, filters, heaters, capacities TPN (by eliminating the need to use Nia additional heating systems), reducing the value of possible fuel leaks in case of an accident, fire hazard reduction system.

The technical result according to the first embodiment of the method for controlling the fuel parameters in the fuel supply system of a multi-fuel engine is achieved due to the fact that the engine is started up with standard fuel, then the engine is supplied with non-standard fuel by means of a discharge pump (NN), the pressure of the non-standard fuel in the make-up line of the engine is controlled by changing low speed rotation and regulate the temperature of non-standard fuel at the inlet to the fuel priming pump (TPN) located at the inlet to the high-pressure fuel pump (TNVD) of the engine by heating or cooling the excess of non-standard fuel, which is fed from the high-pressure fuel pump to the input of the fuel injection pump.

In addition, the viscosity of the non-standard fuel is measured and the required temperature of the non-standard fuel is determined from it to be fed to the WBC.

The technical result according to the second embodiment of the method of controlling the fuel parameters in the fuel supply system of a multi-fuel engine is achieved due to the fact that the engine is started up with regular fuel, then the engine is supplied with non-standard fuel by means of a charge pump (NH), and the pressure of the non-standard fuel in the engine’s feed line is controlled by changing low-speed rotation, and regulate the temperature of the abnormal fuel at the inlet to the fuel priming pump (TPN) located at the inlet into the high-pressure fuel pump (TNVD) of the engine by heating or cooling the excess of non-standard fuel, which is fed from the high-pressure fuel pump to the LV input.

In addition, the viscosity of the non-standard fuel is measured and the required temperature of the non-standard fuel is determined from it to be fed to the WBC.

The invention is illustrated by drawings, in FIG. 1 which shows a connection diagram of a dual-fuel system for implementing the first method; in FIG. 2 shows the same for the implementation of the second method.

In FIG. 1 shows a fuel supply system of a multi-fuel engine, on the example of which you can see the implementation of the method of controlling fuel parameters in the fuel supply system of a multi-fuel engine according to the first embodiment. So, the first way to control fuel parameters is as follows. The engine 3 (diesel generator) is started and stopped using standard fuel (low-viscosity fuel) supplied from the tank 13 through the non-return valve 9 using the fuel pump 10 of the engine 3. The cavity of the tank 13 is in communication with the suction cavity of the fuel pump 10. the moment of the enable signal (the moment is set either automatically according to the data from the engine speed sensors or the timer or by the operator’s command) using the control system 4, the previously closed electrical control is opened indications will faucet 8 and turns on the discharge pump 6 (electric pump unit) abnormal fuel pump (viscous oil) at a predetermined speed. The speed of the pump 6 is determined by the required capacity of the pump 6, which is necessary to create a pressure in the suction line of the fuel priming pump 10 to close the check valve 9. This ensures that the regular fuel tank 13 is disconnected from the fuel system of the engine 3 and it goes into emergency operation fuel supplied from the tank 5. Using a microprocessor control system 4, the signal from the pressure sensor 2 is used to adjust the pressure in front of the fuel pumps in high pressure (high-pressure fuel pump, not shown) engine 3. Optimum pressure is achieved by changing the capacity of the pump for transferring non-standard fuel by affecting the speed of the electric motor of the pump 6. The higher the speed of the electric motor of the pump 6, the higher the fuel pressure in front of the high-pressure fuel pump of the engine 3 and vice versa.

The removal of excess fuel from the injection pump is directed through the check valve 12 to the input of the fuel priming pump 10 of the engine 3, which supplies fuel to the injection pump. In the case of connecting the drain pipe to the inlet of the fuel pump 10, a closed loop of the drain line is obtained. In this case, a change in the fuel pressure in the make-up line leads to an adequate change in the fuel pressure in the fuel system of the engine. The need for pressure regulation is, first of all, advisable when the engine is running on heavy and high viscosity fuel. In this case, one of the means of decreasing the viscosity of the fuel is its heating, which increases the process of vaporization with increasing temperature, and in case of reaching the saturation temperature, it boils the fuel with all the negative consequences. By increasing the fuel pressure, the saturation temperature increases and the process of vaporization decreases. The increase in fuel pressure in the case of the proposed method is limited by the threshold of structural reliability of the system.

By connecting the drain of excess fuel from the injection pump to the inlet of the fuel pump 10 through the check valve 12, it is possible to maximize the heat received by the fuel when passing through the fuel system of the engine 3. The temperature of the fuel at the inlet to the fuel pump 10 is controlled by the heat received fuel from cooling the injection pump and nozzles. The temperature control of non-standard fuel having a temperature at the outlet of the high-pressure fuel pump is higher than at the entrance to the high-pressure fuel pump is carried out in the excess fuel system (drain line) using a heat exchanger 11 for heating / cooling the fuel.

To regulate (heating / cooling) the temperature of the non-standard fuel at the inlet to the fuel priming pump 10, measure the viscosity of the non-standard fuel at the inlet to the fuel-priming pump 10 and, taking into account the permissible viscosity of the fuel, determine the required temperature of the non-standard fuel to which it should be heated or cooled to supply fuel feed pump 10.

Using an external source, for example, a heater 7 of non-standard fuel installed in the make-up line, the fuel is heated before entering the fuel priming pump 10.

The temperature of the fuel at the inlet to the high-pressure fuel pump depends on the heat balance between the excess fuel returned to the suction in a regular fuel priming pump 10 of the engine 3 and the make-up fuel supplied from the tank 5 of non-standard fuel. Temperature control is carried out in the excess fuel system by installing a heat exchanger 11 or, less preferably, in the make-up system. In the case of regulation of the excess fuel in the system, the refrigerant can use the water of the cold engine cooling circuit, and the heat agent can use the water of the hot engine cooling circuit or from an external source, as an addition to the heat supply from the high-pressure fuel pump.

The temperature control of the fuel before the injection pump is carried out by the control system 4 by the signal of the fuel temperature meter received from the temperature sensor 1.

When the engine 3 is stopped using the control system 4, the electrically operated valve 8 closes and the pump 6 for transferring non-standard fuel stops (or is switched to idle). In this case, the pressure in the suction line of the fuel pump 10 of the engine 3 (diesel generator) drops, the check valve 9 opens and the engine 3 switches to normal fuel operation from the tank 13. The engine 3 is stopped in the normal mode. The described first method is most effective when operating on non-standard fuel single diesel generators without the use of additional modules for the preparation of non-standard fuel.

In FIG. 2, you can view the implementation of the second method. The principle of operation is almost identical to the scheme in option 1. The difference from option 1 is the supply of excess fuel discharged from the engine to the suction line of the non-standard fuel transfer pump 6. The use of option 2 can be determined by the structural and technological advantages associated with the layout of the system in operation and the use of a stand-alone module for the preparation of non-standard fuel for several engines.

Claims (4)

1. The method of controlling fuel parameters in the fuel supply system of a multi-fuel engine, which consists in starting the engine with standard fuel, then supplying the engine with non-standard fuel by means of a discharge pump (NN), regulating the pressure of the non-standard fuel in the make-up line of the engine by changing the engine speed and regulate the temperature of non-standard fuel at the inlet to the fuel priming pump (TPN) located at the inlet to the high pressure fuel pump (TNVD) of the engine by heating and whether cooling the excess of abnormal fuel, which is fed from the high-pressure fuel pump to the inlet of the fuel supply station. 2. The method according to p. 1, characterized in that the viscosity of the non-standard fuel is measured and the required temperature of the non-standard fuel is determined from it to be fed to the WBC. 3. The method of controlling fuel parameters in the fuel supply system of a multi-fuel engine, which consists in starting the engine with standard fuel, then the engine is supplied with non-standard fuel by means of a discharge pump (NN), the pressure of the non-standard fuel in the make-up line of the engine is controlled by changing the engine speed and regulate the temperature of non-standard fuel at the inlet to the fuel priming pump (TPN) located at the inlet to the high pressure fuel pump (TNVD) of the engine by heating and whether cooling the excess of abnormal fuel that is fed from the high-pressure fuel pump to the inlet of the low voltage. 4. The method according to p. 3, characterized in that the viscosity of the non-standard fuel is measured and the required temperature of the non-standard fuel is determined from it to be fed to the WBC.

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