RU2819471C1 - Supercharging system of internal combustion engine (ice) using free piston gas generator (fpgg) - Google Patents

Abstract

FIELD: engines.

SUBSTANCE: invention can be used in internal combustion engines. Internal combustion engine (ICE) supercharging system includes supercharging unit, ICE intake receiver (14), ICE (15) and ICE exhaust receiver (16). Supercharging unit used is free-piston gas generator (FPGG) (1). FPGG (1) includes cylinder (4) with direct-flow slot blowing. Cylinder (4) has outlet and blowing inlet openings (12) and (11). In cylinder (4) two oppositely moving pistons (6), which are connected to pistons (7) of compressor, arranged in cylinders of compressor with buffer and compressor cavities (5) and (2). Receiver (3) of FPGG (1) is arranged in central part of FPGG and is connected to compressor cavities (2) through outlet valves (9) of compressor cavity. Receiver (3) of FPGG (1) is also connected to inlet receiver (14) of ICE through outlet valve (10) of receiver (3) and intercooler (13) of supercharging air. Incoming air flow enters compressor cavities (2) of cylinders (4) of FPGG (1) compressor through inlet valves (8) of the compressor cavity. Combustion products from cylinder (4) of FPGG (1) are discharged into environment through outlet openings (12) and from ICE cylinders (15) through outlet receiver (16) of ICE. Disclosed is a version of the internal combustion engine supercharging system.

EFFECT: providing high degrees of supercharging in the entire range of operating modes of the internal combustion engine at acceptable loads on the parts of the cylinder-piston group and the possibility of implementing the afterburner mode by thrust or power in any operating modes, as well as in providing stable engine starts without use of additional heating of charge at inlet.

6 cl, 6 dwg

Description

The invention relates to internal combustion engines, methods for creating highly accelerated internal combustion engines, free-piston engines, free-piston gas generators.

The intended scope of application of the invention is marine engines (mooring and steering modes), special engines that combine high liter power, afterburner mode and efficiency over the entire range of operating modes.

The problem of increasing the power of piston internal combustion engines (ICEs) is solved by two methods: increasing the working volume of the cylinders or increasing the volume of the air-fuel mixture supplied to the combustion chamber. In modern conditions of tightening environmental requirements for internal combustion engines, the method of increasing the working volume of cylinders is practically not used. A promising direction in the development of engine building is the creation of forced internal combustion engines, in which an increase in power is achieved by implementing technical solutions for a forced increase in the amount of air or air-fuel mixture supplied to the cylinders.

In known schemes of gas turbine supercharging of internal combustion engines, the amount of air-fuel mixture supplied to the cylinder is increased due to preliminary compression of air in a compressor driven by the engine crankshaft (mechanical compressor), by an electric motor (electric compressor), or by a turbine wheel on the same shaft as the compressor wheel driven , in turn, from the exhaust gases of a piston engine (gas-coupled turbochargers) [“Internal combustion engines” T. IV-14 / L.V. Grekhov, N.A. Ivashchenko, V.A. Markov and others; under general ed. A.A. Alexandrov and N.A. Ivashchenko, 2013]. The main problems of such schemes are the lack of thrust in low-load modes due to a lack of gas to spin the turbine wheel (“turbojam”), as well as a significant increase in the maximum cycle pressures in the cylinder [V.V. Makhaldiani “Internal combustion engines with variable compression ratio”].

Registered supercharging schemes are known that imply the sequential installation of at least two turbochargers with the ability to turn off one or more supercharging units [RU 194589 U1]. Such schemes provide better fuel efficiency with some deterioration in acceleration dynamics, but require the installation of high-quality turbochargers with low inertia and are characterized by high cost.

Combined internal combustion engines with a HYPERBAR supercharging system are known [N.N. Patrahaltsev, A.A. Savastenko “Boosting of internal combustion engines by supercharging”, 2007; US 2008/008 3328 A1]. In this case, in addition to the exhaust gases from the internal combustion engine, air is supplied to the gas turbine directly from the compressor. The air at the turbine inlet is heated both from the exhaust gases of the internal combustion engine and by burning part of the fuel in an additional combustion chamber installed in front of the turbine. Such a scheme is characterized by high values of boost pressure, which makes it possible to provide high average effective pressures with a significantly reduced geometric compression ratio in the internal combustion engine. Good engine response is also ensured by maintaining high boost pressures at low load conditions. The main disadvantages of the “HYPERBAR” scheme are increased fuel consumption at low loads due to the low compression ratio of the diesel engine and the need to maintain a constant fuel combustion process in the additional combustion chamber, as well as the need to heat the intake air when starting a cold engine.

The technical problem is to ensure high efficiency of the combined power plant, as well as to increase thrust at low speeds (its lack is typical for traditional piston internal combustion engines with gas turbine supercharging), with a limited increase or even a decrease in loads on the parts of the cylinder-piston group of the internal combustion engine without increasing fuel consumption at low speeds loads, as well as stable engine starts without the use of additional heating of the inlet charge.

The authors propose to solve this problem by using a free-piston gas generator as a supercharging unit.

Various designs of free-piston engines (SPD) and free-piston gas generators (SPGG) are known [RU 2800197 C1; “Free-piston gas generators for gas turbine units”, authors: Koshkin V.G., Maizel L.M., Chernomordik B.M., 1963]. In SPD and SPGG, the pistons do not have a rigid connection with the engine crankcase and move freely in the cylinders under the combined influence of gas forces in the cylinder and buffer, as well as inertia and friction forces. Classical SPD and SPGG involve performing useful work on a volumetric expansion machine, which is a turbine or a piston machine.

Of the known units of the internal combustion engine supercharging system, the closest in technical essence and in terms of the achieved result is the mechanism described in RU 2324058 C1, chosen by the authors as a prototype. The known supercharging system contains an intake duct, a turbocharger, an intake manifold, an internal combustion engine, an exhaust manifold, a connecting channel, a muffler, an exhaust duct, wherein the exhaust duct is connected to the narrowest flow part of the air diffuser. This scheme involves providing high specific power of the internal combustion engine due to additional vacuum at the turbine outlet, but its disadvantage is the lack of thrust in low load modes and a significant increase in the maximum combustion pressure when implementing a cycle with high degrees of pressure increase in the turbocharger.

The objective of the present invention is to replace a turbocharger with a modernized version of the classic one (SPGG) with compressor and buffer cavities arranged in a common housing, with the aim of using it as a supercharging unit or one of the supercharging stages of a traditional piston engine. When upgrading the classic version (SGPG), the volume of the receiver is increased and air is removed from the receiver or compressor cavities of the SGPG to the entrance to the internal combustion engine. The volume of the SGNG receiver should increase by 3-5 working volumes of the internal combustion engine, depending on the type of internal combustion engine

Similar to the mechanism described in RU 2 324 058 C1, the proposed system increases the charge air pressure at the inlet to the internal combustion engine, thereby increasing the filling of the cylinders and the efficiency of the engine operating process.

In contrast to the mechanism described in RU 2 324 058 C1, the proposed design of the supercharging unit has the advantage of providing higher degrees of pressure increase at the engine inlet and the possibility of implementing a cycle similar to an internal combustion engine with a HYPERBAR supercharging system with high average effective pressures at limited maximum cycle pressures.

In comparison with the well-known HYPERBAR supercharging system, characterized by a separate supercharging unit, a receiver at the engine inlet and a system for bypassing part of the gases from the engine inlet to the engine exhaust, as well as an additional combustion chamber, the proposed device combines all the necessary structural elements (compressor cavities , combustion chamber, large-volume receiver) in a single housing, which facilitates installation and maintenance of power plant systems. Gas transfer from the intake to the exhaust of an internal combustion engine is not required to ensure the functionality of the proposed supercharging system.

Unlike the well-known HYPERBAR supercharging system, which has problems with starting a cold engine, which are solved by heating the intake air, the proposed LPNG-based supercharging system ensures stable starts due to high temperatures at the engine inlet without additional heating of the charge. Also in the proposed invention, the main attention is paid to the joint operation of the SGNG with a classic piston internal combustion engine.

The technical result is to ensure high degrees of boost and efficiency of the piston internal combustion engine in the entire range of its operating modes with acceptable loads on the parts of the cylinder-piston group and the ability to implement afterburner mode in terms of thrust or power in any operating modes, as well as ensuring stable engine starts without the use of additional charge heating inlet.

The technical result is achieved due to the fact that the pressurization system of an internal combustion engine (ICE), including a pressurization unit, intake receiver 14 of the internal combustion engine, ICE 15 and exhaust receiver 16 of the ICE, uses a free-piston gas generator 1 (SPGG) as a pressurization unit, including cylinder 4 with direct-flow slot purge, having outlet 12 and purge inlet 11 windows located in the cylinder 4, opposingly moving two pistons 6, which are connected to the compressor pistons 7, located in the compressor cylinders with buffer 5 and compressor 2 cavities, as well as an SLNG receiver 3 located in the central part of the SPGG 1 and connected to the compressor cavities 2 through the exhaust valves 9 of the compressor cavity, and the receiver 3 of the SPGG 1 is also connected to the inlet receiver 14 of the internal combustion engine through the outlet valve 10 of the receiver and the intercooler 13 of the charge air, while the incoming air flow enters the compressor the cavities of the cylinders of the SGNG compressor 1 through the inlet valves 8 of the compressor cavity, while the combustion products from the cylinder 4 of the SGNG 1 are discharged into the environment through the exhaust windows 12 and from the cylinders of the internal combustion engine 15 through the exhaust receiver 16 of the internal combustion engine.

Additional differences of the proposed Internal Combustion Engine (ICE) Supercharging System are that:

- as the second stage of the supercharging system, a power compressor 17 is used, connected to the crankshaft of the internal combustion engine 15 through a mechanical drive, while the output of the power compressor 17 is connected to the exhaust valve 10 of the LNG receiver 1 and the inlet of the intercooler 13,

- a power turbine 18 is introduced into it, connected to the crankshaft of the internal combustion engine 15 through a mechanical drive, while the input of the power turbine 18 is connected to the exhaust windows 12 of cylinder 4 of the SGNG 1 and the output of the exhaust receiver 16 of the internal combustion engine, while combustion products are discharged into the environment from the output of the power turbines 18,

- as the second stage of the pressurization system, a compressor 17 and a turbine 18 are used on a common shaft with a gas connection with the internal combustion engine 15, while the output of the compressor 17 is connected to the outlet valve 10 of the LPGG receiver 1 and the inlet of the intercooler 13, the inlet of the turbine 18 is connected to the exhaust windows 12 cylinder 4 of the LNG 1 and the outlet of the exhaust receiver 16 of the internal combustion engine, while the combustion products are discharged into the environment from the outlet of the turbine 18.

The technical result is also achieved due to the fact that in the supercharging system of an internal combustion engine (ICE), including a supercharging unit, internal combustion engine 15, intake 14 and exhaust 16 receivers of the internal combustion engine, characterized in that a free-piston gas generator 1 (SPGG) is used as a supercharging unit , as the second stage of the pressurization system, a compressor 17 and a turbine 18 are used on a common shaft with a gas connection with the internal combustion engine 15, while the SGNG 1 includes a cylinder 4 with direct-flow slot purge, having exhaust 12 and purge inlet windows 11, located in the cylinder 4, moving in an opposite direction two pistons 6, which are connected to the compressor pistons 7, located in the compressor cylinders with buffer 5 and compressor 2 cavities, as well as a receiver 3 of the SGGG 1, located in the central part of the SGGG 1 and connected to the compressor cavities 2 through the exhaust valves 9 of the compressor cavity, and the exhaust windows 12 of the SGNG cylinder 1 are connected to the intake receiver of the internal combustion engine 14 through the bypass valve 19 and the intercooler 13 of the charge air, the incoming air flow enters the compressor cavities of 2 cylinders of the SGNG compressor and the compressor wheel 17, while the output of the compressor 17 is connected to the inlet of the intercooler 13, the input of the turbine 18 is connected to the exhaust windows 12 of the LNG cylinder 1 and the output of the exhaust receiver 16 of the internal combustion engine, while combustion products are discharged into the environment from the output of the turbine 18. An additional difference of the second embodiment of the Pressurization System is that

- the cooler inlet 13 is also connected to the outlet valve 10 of the receiver 3 of the SGNG 1.

The essence of the invention lies in the use of SGNG, the operation of which is characterized by a large percentage of oxygen in the outlet gas, as one of the boost stages with a charge air receiver. The invention makes it possible to completely solve the problems that arise during the implementation of gas turbine supercharging (lack of thrust in low load modes and a significant increase in the maximum combustion pressure when implementing a cycle with high degrees of pressure increase in the turbocharger). The presence of a receiver makes it easy to implement the afterburner mode in terms of thrust or power in any operating mode. The LPGG is a unit independent of the internal combustion engine with all the necessary structural elements (compressor cavities, combustion chamber, large-volume receiver), which facilitates the installation and maintenance of power plant systems. Stable starts of a cold engine are ensured by high air temperatures at the outlet of the SGNG; in this case, part of the gas is supposed to be supplied to the internal combustion engine cylinders by bypassing the cooler, or when the efficiency of the cooler is reduced (reduced blown area, reduced cooling air flow).

The essence of the invention is illustrated by the following figures.

Fig. 1 - charging diagram using compressed air from receiver 3 of SGNG 1 for supply to the intake receiver 16 of the internal combustion engine through cooler 13.

Where:

1 - SPGG

2 - SGPG compressor cavity

3 - SPGG receiver

4 - SLNG cylinder

5 - buffer cavity of SPGG

6 - SPGG piston

7 - SGNG compressor piston

8 - inlet valve of the SGNG compressor cavity

9 - outlet valve of the SGNG compressor cavity

10 - outlet valve of the SGNG receiver

11 - SGNG purging windows

12 - SGNG exhaust windows

13 - cooler

14 - intake receiver ICE 15-ICE

16 - exhaust receiver of internal combustion engine

Fig. 2 - the same as in Fig. 1, but with the supply of compressed air from the LPNG receiver 3 to the intake receiver 14 of the internal combustion engine after mixing with air from the power compressor 17, driven from the crankshaft of the internal combustion engine 15, Where: 17 - power compressor

Fig. 3 - the same as in Fig. 1, but with the supply of combustion products from the cylinder 4 of the LNG and the exhaust receiver 14 of the internal combustion engine to the inlet of the power turbine connected to the crankshaft of the internal combustion engine 15 through a mechanical drive, with subsequent removal of the combustion products into the environment.

Where: 18 - power turbine

Fig. 4 - the same as in Fig. 1, but with the addition of a compressor 17 and a turbine 18 with gas connection with the internal combustion engine 15, with separation of the air flow at the inlet, with compressed air supplied through the outlet valve 10 of the receiver 3 of the LNG 1 to the intake receiver 14 of the internal combustion engine after mixing with air from the compressor 17 and cooling in the cooler 13, with the supply of combustion products from the cylinder 4 of the LNG 1 and the exhaust receiver 16 of the internal combustion engine to the inlet of the turbine wheel 18, with the subsequent removal of the combustion products into the environment.

Fig. 5 is a supercharging diagram that also includes a compressor 17 and a turbine 18 with a gas connection with the internal combustion engine 15 and a bypass valve 19. This diagram provides for the division of the air flow at the inlet between the SGNG 1 and the compressor wheel 17, while no provision is made for the removal of part of the compressed air from the receiver 3 of the SGNG 1. In this case, compressed air is supplied to the intake receiver 14 of the internal combustion engine from the compressor wheel 17 with partial mixing of combustion products from the cylinder 4 of the SGNG 1 through the bypass valve 19, then the gas, after cooling in the cooler 13, is supplied to the intake receiver of the internal combustion engine 14. The main share of combustion products from cylinder 4 of the LNG 1 and the exhaust receiver of the internal combustion engine 16 is supplied to the inlet of the turbine wheel 18, with the subsequent discharge of combustion products into the environment. Where: 19 - bypass valve

Fig. 6 - the same as in Fig. 5, but with the removal of part of the compressed air from the SGNG receiver 3, which, after mixing with compressed air from the compressor wheel 17, with partial mixing of combustion products from the SLNG cylinder 4 through the bypass valve 19, through the cooler 13 enters the intake receiver 14 of the internal combustion engine. The main share of combustion products from the cylinder 4 of the LNG 1 and the exhaust receiver 16 of the internal combustion engine is supplied to the inlet of the turbine wheel 18, with subsequent discharge into the environment.

The proposed schemes (Fig. 1-Fig. 6) of pressurization systems are used depending on the type of internal combustion engine.

The method of using SLNG as a supercharging unit is that SLNG 1 is integrated into the intake and exhaust systems of the piston internal combustion engine 15, as a supercharging unit or one of its stages. Compressor 17 can be used as the second stage of the pressurization system. Air from SGNG 1 (or a mixture of air and combustion products characterized by a large percentage of oxygen in the outlet gas) is fully or partially through the bypass valve 19, and then through the cooler 13 is supplied directly or after mixing with air from the compressor 17 of the internal combustion engine 15 into the intake receiver of the internal combustion engine 14. When starting the power plant, the SPGG 1 is first started using a pneumatic starting device that supplies air under pressure into the buffer cavities 5. Next, heated air from the SPGG receiver 3 directly or after mixing with the outlet air from the combustion chamber in the cylinder SGNG 4 is supplied to the intake receiver of the internal combustion engine 14, bypassing the cooler 13 or when the efficiency of the cooler 13 is reduced. After the start of the internal combustion engine 15, air to the intake of the internal combustion engine 15 must be supplied through the cooler 13. Combustion products from the internal combustion engine 15 through the exhaust receiver 16 is supplied to the turbine wheel 18 or discharged into the environment.

Claims (6)

1. A supercharging system for an internal combustion engine (ICE), including a supercharging unit, an internal combustion engine inlet receiver (14), an internal combustion engine (15) and an internal combustion engine exhaust receiver (16), characterized in that a free-piston gas generator (1) is used as a supercharging unit ( SPGG), including a cylinder (4) with direct-flow slot purge, having outlet (12) and purge inlet (11) windows located in the cylinder (4); oppositely moving two pistons (6), which are connected to the pistons (7) of the compressor, located in the compressor cylinders with buffer (5) and compressor (2) cavities, as well as a receiver (3) of the SGNG, located in the central part of the SGNG (1) and connected to the compressor cavities (2) through the exhaust valves (9) of the compressor cavity, and the receiver (3) SGNG (1) is also connected to the intake receiver (14) of the internal combustion engine through the outlet valve (10) of the receiver and the intercooler (13) of charge air, while the incoming air flow enters the compressor cavities of the cylinders of the SGNG compressor (1) through the intake valves (8) of the compressor cavity, while the combustion products from the cylinder (4) of the SGNG (1) are discharged into the environment through the exhaust windows (12) and from the internal combustion engine cylinders (15) through the exhaust receiver (16) of the internal combustion engine. 2. The internal combustion engine (ICE) supercharging system according to claim 1, characterized in that a power compressor (17) is used as the second stage of the supercharging system, connected to the ICE crankshaft (15) through a mechanical drive, with the output of the power compressor ( 17) is connected to the outlet valve (10) of the SGNG receiver (1) and the inlet of the intercooler (13). 3. The internal combustion engine (ICE) supercharging system according to claim 1, characterized in that a power turbine (18) is introduced into it, connected to the ICE crankshaft (15) through a mechanical drive, while the input of the power turbine (18) is connected to exhaust windows (12) of the cylinder (4) of the LNG gas (1) and the outlet of the exhaust receiver (16) of the internal combustion engine, while combustion products are discharged into the environment from the outlet of the power turbine (18). 4. The supercharging system of an internal combustion engine (ICE) according to claim 1, characterized in that a compressor (17) and a turbine (18) on a common shaft with a gas connection with the ICE (15) are used as the second stage of the supercharging system, while the output compressor (17) is connected to the exhaust valve (10) of the LPGG receiver (1) and the inlet of the intercooler (13), the turbine inlet (18) is connected to the exhaust windows (12) of the cylinder (4) of the LPGG (1) and the outlet of the exhaust receiver (16 ) internal combustion engine, while combustion products are discharged into the environment from the turbine outlet (18). 5. The supercharging system of an internal combustion engine (ICE), including a supercharging unit, internal combustion engine (15), intake (14) and exhaust (16) receivers of the internal combustion engine, characterized in that a free-piston gas generator (1) is used as a supercharging unit (SPGG) , as the second stage of the pressurization system, a compressor (17) and a turbine (18) are used on a common shaft with gas connection with the internal combustion engine (15), while the SGNG (1) includes a cylinder (4) with direct-flow slot blowing, having exhaust (12) and purge inlet ports (11) located in the cylinder (4); oppositely moving two pistons (6), which are connected to the compressor pistons (7), located in the compressor cylinders with buffer (5) and compressor (2) cavities, as well as a receiver (3) SGNG (1), located in the central part of the SGNG (1) and connected to the compressor cavities (2) through the exhaust valves (9) of the compressor cavity, and the outlet windows (12) of the SLNG cylinder (1) are connected to the inlet receiver (14 ) ICE through the bypass valve (19) and the intercooler (13) of the charge air, the incoming air flow enters the compressor cavities (2) of the LPNG compressor cylinders and the compressor wheel (17), while the compressor output (17) is connected to the intercooler inlet ( 13), the turbine inlet (18) is connected to the outlet windows (12) of the LNG cylinder (1) and the outlet of the exhaust receiver (16) of the internal combustion engine, while combustion products are discharged into the environment from the outlet of the turbine (18). 6. The internal combustion engine (ICE) supercharging system according to claim 5, characterized in that the cooler inlet (13) is also connected to the exhaust valve (10) of the SGNG receiver (1).