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EP-4737704-A1 - INTERNAL COMBUSTION ENGINE

EP4737704A1EP 4737704 A1EP4737704 A1EP 4737704A1EP-4737704-A1

Abstract

Internal combustion engine (1) with at least one combustion chamber, an intake system (4) and optionally at least one prechamber for the at least one combustion chamber, wherein the intake system (4) comprises: - a liquid fuel supply (9) configured to provide a liquid fuel, - at least one air-fuel-mixing-zone (10) configured to mix air with liquid fuel from the liquid fuel supply (9) and to provide an air-fuel-mixture, - a combustion chamber intake manifold (7) leading into the at least one combustion chamber, - optionally a prechamber intake manifold (8) leading into the at least one prechamber and wherein there is provided at least one preheater (12) configured to preheat the liquid fuel prior to its evaporation.

Inventors

  • FIMML, WOLFGANG
  • URL, MICHAEL
  • SPYRA, NIKOLAUS
  • LAIMINGER, STEPHAN
  • Hillen, Friedhelm
  • LEROUX, Clement

Assignees

  • Innio Jenbacher GmbH & Co OG

Dates

Publication Date
20260506
Application Date
20241104

Claims (18)

  1. Internal combustion engine (1) with at least one combustion chamber, an intake system (4) and optionally at least one prechamber for the at least one combustion chamber, wherein the intake system (4) comprises: - a liquid fuel supply (9) configured to provide a liquid fuel, - at least one air-fuel-mixing-zone (10) configured to mix air with liquid fuel from the liquid fuel supply (9) and to provide an air-fuel-mixture, - a combustion chamber intake manifold (7) leading into the at least one combustion chamber, - optionally a prechamber intake manifold (8) leading into the at least one prechamber and wherein there is provided at least one preheater (12) configured to preheat the liquid fuel prior to its evaporation.
  2. Internal combustion engine (1) according to claim 1, wherein the at least one preheater (12) is configured to preheat the liquid fuel - prior to mixing air with the preheated liquid fuel and/or - prior to injecting the preheated liquid fuel into the at least one air-fuel-mixing-zone (10) and/or - prior to injecting the preheated liquid fuel into the combustion chamber intake manifold (7) and/or - prior to injecting the preheated liquid fuel into the prechamber intake manifold (8).
  3. Internal combustion engine (1) according to claim 1 or 2, wherein the at least one preheater (12) is located upstream of at least one component selected from the group consisting of the at least one air-fuel-mixing-zone (10), an injector, preferably a port fuel injector (21) and/or a liquid fuel injector (24), and a junction leading to at least one combustion chamber intake manifold (7) and to at least one prechamber intake manifold (8).
  4. Internal combustion engine (1), preferably according to any of the preceding claims, with at least one combustion chamber, an intake system (4) and optionally at least one prechamber for the at least one combustion chamber, wherein the intake system (4) comprises: - a liquid fuel supply (9) configured to provide a liquid fuel, - at least one air-fuel-mixing-zone (10) configured to mix air with liquid fuel from the liquid fuel supply (9) and to provide an air-fuel-mixture, - a combustion chamber intake manifold (7) leading into the at least one combustion chamber, - optionally a prechamber intake manifold (8) leading into the at least one prechamber and wherein the at least one air-fuel-mixing-zone (10) comprises or is thermally coupled to at least one heating device (11) for heating the air-fuel-mixture.
  5. Internal combustion engine (1) according to the previous claim, wherein the at least one heating device (11) is integrated in or as a separate device thermally coupled to the at least one air-fuel-mixing-zone (10) and wherein the at least one heating device (11) is configured to heat the air-fuel-mixture during and/or after mixing of air and liquid fuel.
  6. Internal combustion engine (1), preferably according to any of the preceding claims, with at least one combustion chamber, an intake system (4) and optionally at least one prechamber for the at least one combustion chamber, wherein the intake system (4) comprises: - a liquid fuel supply (9) configured to provide a liquid fuel, - at least one air-fuel-mixing-zone (10) configured to mix air with liquid fuel from the liquid fuel supply (9) and to provide an air-fuel-mixture, - a combustion chamber intake manifold (7) leading into the at least one combustion chamber, - optionally a prechamber intake manifold (8) leading into the at least one prechamber and wherein there is provided at least one intercooler configured to cool and to heat air and/or the air-fuel-mixture.
  7. Internal combustion engine (1) according to any of the preceding claims, wherein the at least one preheater (12) and/or the at least one heating device (11) and/or the at least one intercooler is located adjacent, preferably directly adjacent, to at least one component selected from the group consisting of the at least one air-fuel-mixing-zone (10), an injector, preferably a port fuel injector (21) and/or a liquid fuel injector (24), and a dosing device (13).
  8. Internal combustion engine (1) according to any of the preceding claims, wherein at least one component selected from the group consisting of the at least one preheater (12), the at least one heating device (11) and the at least one intercooler is - part of the combustion chamber intake manifold (7) and/or - part of the prechamber intake manifold (8) and/or - part of a common supply line (37).
  9. Internal combustion engine (1) according to any of the preceding claims, wherein the at least one air-fuel-mixing-zone (10) is integrated in or connected to at least one component selected from the group consisting of the combustion chamber intake manifold (7), the prechamber intake manifold (8), the common supply line (37) and an air-fuel-mixer (36).
  10. Internal combustion engine (1) according to any of the preceding claims, wherein the at least one air-fuel-mixing-zone (10) comprises or is connected to a liquid fuel injector (24) and/or a port fuel injector (21) configured to inject the liquid fuel into the at least one air-fuel-mixing-zone (10).
  11. Internal combustion engine (1) according to any of the preceding claims, wherein the at least one air-fuel-mixing-zone (10) is configured to evaporate the liquid fuel and/or the air-fuel-mixture at least partially, preferably completely, and/or stabilize the liquid fuel and/or the air-fuel-mixture at least partially, preferably completely, in the gas state.
  12. Internal combustion engine (1) according to any of the preceding claims, wherein the at least one preheater (12) and/or the at least one air-fuel-mixing-zone (10) is configured to maintain a pressure of 10 bar to 30 bar, and/or a temperature of at least 60 °C, preferably of 100 °C to 200 °C, preferably 125 °C to 180 °C, within the at least one preheater (12) and/or the at least one air-fuel-mixing-zone (10).
  13. Internal combustion engine (1) according to any of the preceding claims, wherein the at least one air-fuel-mixing-zone (10) and/or the at least one intercooler is configured to maintain a pressure of 4 bar to 6 bar, preferably 5 bar to 6 bar, and/or a temperature of 30 °C to 60 °C, preferably of 50 °C to 60 °C, within the at least one air-fuel-mixing-zone (10) and/or the at least one intercooler.
  14. Internal combustion engine (1) according to any of the preceding claims, wherein: - the liquid fuel is partially, preferably completely, in the liquid state at 1.013 bar and at 0 °C and/or - an evaporation enthalpy of the liquid fuel is at least 600 kJ/kg, preferably at least 800 kJ/kg, more preferably at least 1.000 kJ/kg, and/or - the liquid fuel is a pure substance or a mixture and/or - the air-fuel-mixture is at least partially, preferably completely, in the gas state at 4 bar to 6 bar, preferably 5 bar to 6 bar, and at 30 °C to 60 °C, preferably 50 °C to 60 °C, and/or - the volume fraction of the fuel in the air-fuel-mixture is between 10% v/v and 50% v/v, preferably between 20% v/v and 50% v/v.
  15. Internal combustion engine (1) according to any of the preceding claims, wherein the liquid fuel is individually or in combination selected from the group consisting of: alcohols, preferably methanol and/or ethanol, hydrocarbons, ammonia and ammoniac solutions.
  16. Internal combustion engine (1) according to any of the preceding claims, wherein a mixing device to provide a uniformly distributed air-fuel-mixture to the at least one combustion chamber (2) and/or to the at least one prechamber (3) is integrated in or connected to at least one component selected from the group consisting of the at least one air-fuel-mixing-zone (10), the combustion chamber intake manifold (7) and the prechamber intake manifold (8).
  17. Internal combustion engine (1) according to any of the preceding claims comprising at least one component selected from the group consisting of - a compressor (6) compressing air and feeding the compressed air downstream into the at least one combustion chamber (2) by the combustion chamber intake manifold (7) and/or into the at least one prechamber (3) by the prechamber intake manifold (8), - a dosing device (13), preferably a dosing valve or orifice, between the liquid fuel supply (9) and the at least one air-fuel-mixing-zone (10) for, preferably continuous or pulsed, dosing of the liquid fuel into the at least one air-fuel-mixing-zone (10), - a controlling device (14), preferably a controlling valve or orifice, downstream of the at least one air-fuel-mixing-zone (10), - a measuring device (15), preferably a mass flow sensor, upstream of the at least one air-fuel-mixing-zone (10), preferably in the prechamber intake manifold (8), - a detecting device (16), preferably a pressure sensor, within the at least one combustion chamber (2) and/or the at least one prechamber (3) and - an exhaust system (17), wherein the exhaust system (17) comprises a turbine (18), preferably wherein the turbine (18) is configured to drive the compressor (6).
  18. Internal combustion engine (1) according to any of the preceding claims, preferably to the previous claim, wherein the internal combustion engine (1) comprises a control unit (19) to control at least one property selected from the group consisting of: - the air-fuel-ratio of the air-fuel-mixture, preferably by means of the dosing device (13) and/or the compressor (6), - the amount of the air-fuel-mixture provided to the at least one prechamber (3), preferably by means of the controlling device (14), - the temperature within the at least one preheater (12) and/or the at least one air-fuel-mixing-zone (10) and/or the at least one intercooler and - the pressure within the at least one preheater (12) and/or the at least one air-fuel-mixing-zone (10) and/or the at least one intercooler.

Description

The present application claims priority under Article 88 (2) EPC and Article 88 (3) EPC to the two international applications PCT/AT/2024/060105 and PCT/AT/2024/0601056, both filed on 22 March 2024 at the Austian Patent Office, both entitled INTERNAL COMBUSTION ENGINE, the entire disclosures of which are hereby incorporated by reference. The present invention relates to an internal combustion engine with at least one combustion chamber, an intake system and optionally at least one prechamber for the at least one combustion chamber, wherein the intake system comprises: a liquid fuel supply configured to provide a liquid fuel,at least one air-fuel-mixing-zone configured to mix air with liquid fuel from the liquid fuel supply and to provide an air-fuel-mixture,a combustion chamber intake manifold leading into the at least one combustion chamber,optionally a prechamber intake manifold leading into the at least one prechamber. Internal combustion engines are driven by the combustion of an air-fuel-mixture. An important parameter for the combustion is the air-fuel-ratio which is the mass ratio of air to a solid, liquid or gaseous fuel present in the combustion process. An air-fuel-ratio of 1 describes an air-fuel-mixture with the necessary amount of air to burn all the fuel completely and in a stoichiometric manner. An air-fuel-ratio > 1 describes a lean mixture with an excess of air compared to the necessary stoichiometric amount of air needed for the complete combustion of the fuel within the air-fuel-mixture. The opposite is a rich mixture. The air-fuel-ratio may also be called lambda λ. For some applications like big bore engines a lean mixture is desired during operation which causes challenges because the engine does not always run stable and the combustion is not always sufficiently reliable. Hence, prechambers are known as ignition amplifiers for a combustion chamber of an internal combustion engine. For example, the prechamber of a gas engine can be scavenged with a gas fuel to provide a more reliable ignition amplification for the combustion chamber and improve the combustion behaviour of the engine. Despite that, due to economic and ecological reasons there is the desire to use other fuels than conventional fuels like gasoline or diesel. For example, hydrogen is a promising fuel to meet the requirements of a sustainable energy carrier. Unfortunately, hydrogen is difficult to liquefy, to handle, to transport and to store. Other alternative fuels, e.g. methanol, which are liquid at standard conditions can be handled, transported and stored in an easier manner. However, such fuels like methanol are significantly different in their chemical properties and/or their combustion behaviour in contrast to conventional liquid fuels like the fossil fuels gasoline or diesel. For example, methanol shows a significant higher evaporation enthalpy [kJ/kg] in contrast to fossil fuels. As a result, new challenges arise for internal combustion engines working on the basis of such alternative liquid fuels. These new challenges are connected to evaporation problems and condensation problems of the liquid fuel. The evaporation of the liquid fuel may be difficult due to its evaporation enthalpy. Additionally, a subsequent and undesirable condensation of the fuel after evaporation may cause problems of the internal combustion engine. Such condensation of the fuel may occur before mixing with air. During or after the mixing with air an analogue condensation of an air-fuel-mixture, i.e. condensation of at least a part of the fuel of the air-fuel-mixture, may occur, in particular in the combustion chamber intake manifold or in the prechamber intake manifold. Problems due to condensation of fuel and/or air-fuel-mixtures occur in particular at idle, at low loads or at cold start conditions of the internal combustion engine. The object of the invention is therefore to improve the combustion of an internal combustion engine in view of aforementioned problems, in particular to provide a more robust and reliable internal combustion engine running on a liquid fuel. Regarding the internal combustion engine, this object is achieved by three aspects according to claims 1, 4 and 6. Regarding the internal combustion engine, this object is achieved according to a first aspect in such a way that there is provided at least one preheater configured to preheat the liquid fuel prior to its evaporation. Due to the first aspect, the liquid fuel from the liquid fuel supply is preheated. So, the thermal energy and the temperature, respectively, of the liquid fuel is higher than without a preheater and less energy is necessary to evaporate the preheated liquid fuel. As a result, the internal combustion engine deals with less evaporation problems, condensation problems and runs more robust and reliable. An additional advantage of the first aspect can be that the liquid fuel is ideally preheated to an elevated temperature level, which enables complete an