WO2019115858A1 - A measurement arrangement for determining cylinder-specific intake air mass flow of an internal combustion piston engine, and a gas admission valve assembly, method and an engine related thereto - Google Patents

A measurement arrangement for determining cylinder-specific intake air mass flow of an internal combustion piston engine, and a gas admission valve assembly, method and an engine related thereto Download PDF

Info

Publication number
WO2019115858A1
WO2019115858A1 PCT/FI2017/050894 FI2017050894W WO2019115858A1 WO 2019115858 A1 WO2019115858 A1 WO 2019115858A1 FI 2017050894 W FI2017050894 W FI 2017050894W WO 2019115858 A1 WO2019115858 A1 WO 2019115858A1
Authority
WO
WIPO (PCT)
Prior art keywords
cylinder
intake air
pitot tube
specific
cross
Prior art date
Application number
PCT/FI2017/050894
Other languages
French (fr)
Inventor
Mika VARJOSAARI
Original Assignee
Wärtsilä Finland Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wärtsilä Finland Oy filed Critical Wärtsilä Finland Oy
Priority to PCT/FI2017/050894 priority Critical patent/WO2019115858A1/en
Publication of WO2019115858A1 publication Critical patent/WO2019115858A1/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
    • G01F1/34—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring pressure or differential pressure
    • G01F1/36—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction
    • G01F1/40—Details of construction of the flow constriction devices
    • G01F1/46—Pitot tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B43/00—Engines characterised by operating on gaseous fuels; Plants including such engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/10—Air intakes; Induction systems
    • F02M35/10373—Sensors for intake systems
    • F02M35/10386—Sensors for intake systems for flow rate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D41/0027—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures the fuel being gaseous
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/008—Controlling each cylinder individually
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
    • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
    • F02M21/0218—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
    • F02M21/0248—Injectors
    • F02M21/0278—Port fuel injectors for single or multipoint injection into the air intake system
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F15/00—Details of, or accessories for, apparatus of groups G01F1/00 - G01F13/00 insofar as such details or appliances are not adapted to particular types of such apparatus
    • G01F15/07—Integration to give total flow, e.g. using mechanically-operated integrating mechanism
    • G01F15/075—Integration to give total flow, e.g. using mechanically-operated integrating mechanism using electrically-operated integrating means
    • G01F15/0755—Integration to give total flow, e.g. using mechanically-operated integrating mechanism using electrically-operated integrating means involving digital counting
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/30—Use of alternative fuels, e.g. biofuels

Definitions

  • the present disclosure relates to multi-cylinder internal combustion piston engines capable of using gaseous fuel as main fuel, and more particularly, a measurement arrangement for determining cylinder-specific intake air mass flow therein.
  • the present disclosure further concerns a gas admission valve assembly incorporating such a measurement arrangement, a method for determining cylinder-specific intake air mass flow using such a measurement arrangement and a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with such a measuring arrangement.
  • Intake air mass flow is an generally considered a vital parameter for controlling internal combustion piston engines capable of using gaseous fuel as main fuel, such as marine and power plant engines.
  • intake air mass flow has been determined commonly for all cylinders.
  • Intake air mass flow has typically been determined, for example, using a vane meter, a hot-wire sensor or a Karman vortex sensor.
  • measuring intake air mass flow for each cylinder provides for better control and operation of the engine.
  • problems associated with the known arrangements for measuring intake air mass flow multiplies with the number measuring arrangements used (i.e. number of cylinders) to the extent that conventional measuring arrangements have not been considered feasible for cylinder-specific measurement of intake air mass flow.
  • An object of the present disclosure is to provide a measurement arrangement for determining cylinder-specific intake air mass flow of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, without significantly increasing of flow resistance of the intake air flow and to simultaneously overcome deterioration in measuring accuracy caused contamination.
  • the disclosure is based on the idea of providing, within a cylinder specific portion of an intake duct, a pitot tube positioned upstream of gas admission valve, such that a cross- sectional flow area of the pitot tube overlaps, for the most part, with a cross-sectional flow area of a nozzle portion of said gas admission valve. That is, positioning the pitot tube such that the gas admission valve lies in the wake of the pitot tube.
  • pitot tube provides enables reliable, accurate and robust determination of the cylinder specific intake air mass flow
  • positioning of the pitot tube with respect to the gas admission valve in accordance with the present disclosure ensures minimal increase of flow resistance.
  • Fig. 1 schematically illustrates cylinders and their respective intake ducts of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with a measurement arrangement for determining cylinder-specific intake air mass flow according to an embodiment of the present disclosure
  • Fig. 2 schematically illustrates cylinders and their respective intake ducts of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with a measurement arrangement for determining cylinder-specific intake air mass flow according to another embodiment of the present disclosure
  • Fig. 3 schematically illustrates cylinders and their respective intake ducts of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with a measurement arrangement for determining cylinder-specific intake air mass flow according to a further embodiment of the present disclosure
  • Fig. 4 schematically illustrates respective cross-sectional flow areas of a measurement arrangement according an embodiment of the present disclosure within a cylinder specific portion of an intake duct, as seen upstream of the measurement arrangement towards a downstream direction.
  • Fig. 5 schematically illustrates respective cross-sectional flow areas of a measurement arrangement according another embodiment of the present disclosure within a cylinder specific portion of an intake duct, as seen upstream of the measurement arrangement towards a downstream direction.
  • a measurement arrangement for determining cylinder-specific intake air mass flow of a multi-cylinder internal combustion piston engine, capable of using gaseous fuel as main fuel, is provided.
  • the arrangement comprises a cylinder specific portion 2 of an intake duct. That is, a portion of an intake duct 2 corresponding to a single cylinder. It may be incorporated as a part of the intake duct, or for facilitating installation and maintenance, as a separate portion attached to the rest of the intake duct.
  • the arrangement further comprises a gas admission valve assembly 3.
  • the purpose of the gas admission valve assembly is to introduce gaseous fuel into the cylinder-specific portion 2 of an intake duct, at least when the respective engine is running on gaseous fuel.
  • Said gas admission valve assembly 3 comprises a base portion 3a for attaching said gas admission valve assembly to a cylinder specific portion 2 of an intake duct.
  • the gas admission valve assembly 3 further comprises a nozzle portion 3b for introducing gaseous fuel in to said cylinder specific portion 2 of an intake duct.
  • the nozzle portion 3b extends from the base portion 3a such that, when in use, the nozzle portion 3b is positioned within said cylinder specific portion 2 of the intake duct. It should be noted that the nozzle portion 3b does not need to be nozzle-shaped, as such.
  • the measurement arrangement further comprises a pitot tube 4 having at least a stagnation pressure sensor.
  • the pitot tube 4 When is use, the pitot tube 4 is positioned, within said cylinder specific portion 2 of the intake duct, upstream of the nozzle portion 3b. In other words, the nozzle portion 3b lies at least partially in the wake of the pitot tube. Moreover, the pitot tube is positioned, with respect to the nozzle portion, such that a cross-sectional flow area of the pitot tube 4 overlaps, for the most part, with a cross-sectional flow area of the nozzle portion 3b.
  • the pitot tube 4 should also be oriented, when in use, such that a measurement opening 4a of the pitot tube is facing upstream.
  • the term when in use is used to describe a situation where an entity is in operating condition of its intended use.
  • the pitot tube this means being positioned within the cylinder specific portion 2 of the intake duct, as described above.
  • cross-sectional flow area is used describe the area of an entity effectively affecting intake air flow resistance. That is, the area intersecting between a respective entity and a plane perpendicular to the intake air flow.
  • the cross-sectional flow area is the largest area intersecting between a respective entity and a plane perpendicular to the intake air flow.
  • the cross-sectional flow area is the smallest area intersecting between a respective entity and a plane perpendicular to the intake air flow.
  • upstream and downstream are used to describe the relative position of an entity in a direction opposite to that of the intake air flow with respect to another entity, and respectively, the relative position of an entity in a direction of the intake air flow with respect to another entity.
  • upstream means in a direction away from a cylinder
  • downstream means in a direction towards a cylinder.
  • the above described arrangement provides the advantage that there is minimal increase of flow resistance due to the pitot tube 4. This is because the cross-sectional flow area of the pitot tube 4, accounting for the flow resistance thereof, overlaps for the most part with the cross-sectional flow area of the nozzle portion 3b.
  • the flow resistance caused by the cross-sectional flow area of the pitot tube 4 overlapping with that of the nozzle portion 3b would simply be generated by the nozzle portion 3b itself.
  • the cross-sectional flow area of the nozzle portion 3b lying in the wake of the pitot tube 4 does not create any additional flow resistance.
  • a pitot tube 4 can be used in accordance with the present disclosure without substantially increasing flow resistance within a cylinder-specific portion 2 of an intake air duct.
  • At least 50% of the cross-sectional flow area of the pitot tube 4 overlaps with a cross-sectional flow area of the nozzle portion 3b.
  • the cross-sectional flow area of the pitot tube 4 overlaps wholly with a cross-sectional flow area of the nozzle portion 3b.
  • the lateral position of the pitot tube 4 within the cross-sectional flow area of the cylinder specific portion 2 of the intake duct is centred with respect to that of the nozzle portion 3b.
  • the additional advantage of this arrangement is that, as the pitot tube 4 and the nozzle portion 3b are respectively symmetrically positioned with regard to the intake air flow, induction of vortices is minimized, resulting in a further diminished increase of flow resistance.
  • the measurement arrangement further comprises a static pressure sensor for obtaining intake air flow static pressure measurements.
  • the static pressure sensor is integrated with the pitot tube 4.
  • the measurement arrangement further comprises a temperature sensor for obtaining intake air flow temperature measurements.
  • the pitot tube 4 is configured to be suspended within the cylinder specific portion 2 of the intake duct from the base portion 3a of the gas admission valve assembly, when in use.
  • the pitot tube 4 may comprise a stem portion and a tube portion.
  • the stem portion extends between the base portion 3a of the gas admission valve assembly 3 and the tube portion of the pitot tube 4, so as to suspend said pitot tube 4 within the cylinder specific portion 2 of the intake duct.
  • a gas admission valve assembly According to a second aspect of the present disclosure, a gas admission valve assembly
  • the gas admission valve assembly 3 comprises a base portion 3a for attaching said gas admission valve assembly to a cylinder specific portion 2 of an intake duct.
  • the gas admission valve assembly 3 further comprises a nozzle portion 3b for introducing gaseous fuel in to said cylinder specific portion 2 of an intake air duct.
  • the nozzle portion 3b extends from the base portion 3a such that, when in use, the nozzle portion 3b is positioned within said cylinder specific portion 2 of the intake duct.
  • the gas admission valve assembly 3 further comprises a pitot tube 4 having at least a stagnation pressure sensor.
  • Said pitot tube 4 is suspended from the base portion 3a so as to be positioned, when in use, within said cylinder specific portion 2 of the intake duct, upstream of the nozzle portion 3b, such that a cross-sectional flow area of the pitot tube 4 overlaps, for the most part, with a cross-sectional flow area of the nozzle portion 3b.
  • the pitot tube 4 may comprise a stem portion and a tube portion.
  • the stem portion extends between the base portion 3a of the gas admission valve assembly 3 and the tube portion of the pitot tube 4, so as to suspend said pitot tube
  • the pitot tube 4 within the cylinder specific portion 2 of the intake duct.
  • the pitot tube 4 may be suspended form the base portion 3a in other suitable manners.
  • the pitot tube 4 should be oriented such that a measurement opening 4a of the pitot tube 4 is faces upstream.
  • the above described arrangement provides the advantage that there is minimal increase of flow resistance due to the pitot tube 4. This is because the cross-sectional flow area of the pitot tube 4, accounting for the flow resistance thereof, overlaps for the most part with the cross-sectional flow area of the nozzle portion 3b.
  • the flow resistance caused by the cross-sectional flow area of the pitot tube 4 overlapping with that of the nozzle portion 3b would simply be generated by the nozzle portion 3b itself.
  • the cross-sectional flow area of the nozzle portion 3b lying in the wake of the pitot tube 4 does not create any additional flow resistance.
  • at least 50% of the cross-sectional flow area of the pitot tube 4 overlaps with a cross-sectional flow area of the nozzle portion 3b.
  • the cross-sectional flow area of the pitot tube 4 overlaps wholly with a cross-sectional flow area of the nozzle portion 3b.
  • the lateral position of the pitot tube 4 with the cross-sectional flow area of the cylinder specific portion 2 of the intake duct is centred with respect to that of the nozzle portion 3b.
  • the additional advantage of this arrangement is that, as the pitot tube 4 and the nozzle portion 3b are respectively symmetrically positioned with regard to the intake air flow, induction of vortices is minimized, resulting in a further diminished increase of flow resistance.
  • the gas admission valve assembly 3 further comprising a static pressure sensor for obtaining intake air flow static pressure measurements.
  • the static pressure sensor is integrated with the pitot tube 4.
  • a method for determining cylinder- specific intake air mass flow of a multi-cylinder internal combustion piston engine 1 capable of running on gaseous fuel as main fuel, is provided.
  • the method utilizes the measurement arrangement according the first aspect of the present disclosure, including any embodiment or variants thereof.
  • the method comprises, for at least one cylinder 1 a, 1 b, 1 c, 1 d, a step of measuring, from within a cylinder specific portion 2 of an intake duct corresponding to said cylinder:
  • the method further comprises, for said at least one cylinder 1 a, 1 b, 1 c, 1 d, following steps of:
  • the method further comprises the step of determining intake air mass during a given combustion cycle of said at least one cylinder 1 a, 1 b, 1 c, 1 d by:
  • mapping determined cylinder-specific intake air mass flow values to corresponding engine crank-angle values
  • At least intake air flow static pressure and intake air flow stagnation pressure are measured with a sampling frequency of at least 10kHz.
  • intake air flow temperature is also measured with a sampling frequency of at least 10kHz.
  • a cylinder specific intake air mass flow is determined for each cylinder 1 a, 1 b, 1 c, 1 d.
  • said cylinder-specific intake air mass flow may be determined according to the following equation where
  • rh denotes cylinder-specific intake air mass flow
  • C denotes a flow correction coefficient that takes pitot probe location and pipe geometry into account, determined empirically or through computational fluid dynamics
  • A denotes flow area of said cylinder specific portion (2) of intake air duct
  • p denotes intake air density
  • said cylinder-specific intake air mass flow may be determined in accordance with the following equation
  • rh denotes cylinder-specific intake air mass flow
  • C denotes a flow correction coefficient that takes pitot probe location and pipe geometry into account, determined empirically or through computational fluid dynamics simulations;
  • A denotes flow area of said cylinder specific portion (2) of intake air duct
  • p denotes intake air static density
  • a denotes the speed of sound
  • M denotes Mach Number
  • R denotes the Specific Gas Constant
  • T t denotes the stagnation (total) temperature of the intake Air (in Kelvin)
  • T s denotes the static temperature of the intake Air (in Kelvin)
  • g denotes the ratio of specific heats of the intake air
  • p t denotes stagnation (total) pressure of the intake air
  • x denotes humidity ratio (kg water/kg air) of the intake air
  • V denotes the Velocity of gas
  • the intake air flow density for dry air may be determined, for example, as a function of static pressure and temperature in accordance with pre-existing charts or calculated for the measured data in accordance with the following formula.
  • Pdry air denotes the intake air flow density for dry air p s denotes static pressure
  • R denotes the Specific Gas Constant
  • T denotes the Temperature of the intake air (in Kelvin)
  • p denotes intake air static density
  • x denotes humidity ratio (kg water/kg air)
  • a cylinder- specific air-to-fuel -ratio is controlled based on the determined cylinder- specific intake air mass flow.
  • the minimum air-fuel ratio could be then limited cylinder-specifically in order to get the maximum possible performance.
  • Cylinder- specific air-to-fuel -ratio control allows also for a sophisticated load control, thus contributing to the improvement of reliability and repeatability mitigating problems related to knocking, for example.
  • a multi-cylinder internal combustion reciprocating piston engine 1 capable of using gaseous fuel as main fuel, is provided.
  • the engine 1 comprises a control unit, and for each cylinder, the measurement arrangement according the first aspect of this disclosure, including embodiments and variants thereof. Particularly, the sensors of the measurement arrangement are operationally coupled with the control unit.
  • control unit is configured to perform the method according to the third aspect of the present disclosure, including any embodiment and variants thereof.
  • the engine further comprises, for each cylinder 1 a, 1 b, 1c, 1d, cylinder-specific fuel delivery means operationally coupled to the control unit.
  • the control unit is further configured to operate said cylinder-specific fuel delivery means based on the determined cylinder- specific intake air mass flow so as to control a cylinder-specific air-to-fuel -ratio.
  • the minimum air-fuel ratio could be then limited cylinder-specifically in order to get the maximum possible performance.
  • Cylinder- specific air-to-fuel -ratio control allows also for a sophisticated load control, thus contributing to the improvement of reliability and repeatability mitigating problems related to knocking, for example.
  • Fig. 1 schematically illustrates cylinders 1 a, 1 b, 1c, 1 d and their respective intake ducts of a multi-cylinder internal combustion piston engine 1 capable of using gaseous fuel as main fuel.
  • Fig. 1 represents said 1 engine in a simplified manner, omitting many of its features not necessary for discussing the present disclosure.
  • the engine 1 is equipped with a measurement arrangement for determining cylinder-specific intake air mass flow, according to an embodiment of the present disclosure.
  • Each cylinder 1 a, 1 b, 1 c, 1 d has an associated intake air duct with a cylinder-specific portion 2.
  • the pitot tubes 4 resides upstream (in a direction away form a respective cylinder 1 a, 1 b, 1 c, 1 d) of the gas admission valve assembly 3.
  • the gas admission valve assembly 3 denoted by the dotted line, has a base portion 3a for attaching the valve assembly to the cylinder-specific portion 2 of the intake air duct.
  • the gas admission valve assembly 3 also has a nozzle portion 3b for introducing gaseous fuel into the cylinder-specific portion 2 of the intake air duct.
  • Other components not illustrated herein may naturally also be incorporated into the gas admission valve assembly 3.
  • Fig. 2 illustrates a similar arrangement to that of Fig. 1 with the exception of the pitot tube 4 now being included in the gas admission valve assembly 3.
  • Fig. 3 illustrates variation of the arrangements represented in Fig. 2, namely where the pitot tube 4 is supported within the cylinder-specific portion 2 of the intake air duct from the base 3a of the gas admission valve assembly 3.
  • Fig. 4 schematically illustrates respective cross-sectional flow areas of a measurement arrangement according another embodiment of the present disclosure within a cylinder specific portion 2 of an intake duct, as seen upstream of the measurement arrangement towards a downstream direction.
  • Fig. 4 illustrates the base 3a of the gas admission valve assembly 3 being attached to the cylinder-specific portion 2 of the intake air duct such that the nozzle portion 3b is suspended within said portion 2.
  • Fig. 4 clearly illustrates a cross-sectional flow area of a pitot tube 4 overlapping, for the most part, with the cross- sectional flow area of the nozzle portion 3b of the gas admission valve assembly 3.
  • Fig. 4 illustrates how the lateral positions of the nozzle portion 3b and the pitot tube 4, within the cylinder-specific portion 2 of the intake air duct, are centred with each other.
  • Fig. 5 illustrates a similar arrangement to that of Fig. 4, with the exception of a cross- sectional flow area of a pitot tube 4 overlapping wholly with the cross- sectional flow area of the nozzle portion 3b of the gas admission valve assembly 3.
  • the present disclosure has been discussed above with reference to an embodiment of a multi-cylinder internal combustion piston engine 1 having four cylinders 1 a, 1 b, 1 c, 1 d, the present disclosure may naturally be implemented with any number of cylinders, as defined by the appended Claims.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Abstract

A measurement arrangement for determining cylinder-specific intake air mass flow of a multi-cylinder internal combustion piston engine (1) capable of using gaseous fuel as main fuel. The arrangement comprises a pitot tube (4) having at least a stagnation pressure sensor, said pitot tube being positioned, when in use, within a cylinder specific portion (2) of an intake duct, upstream of a nozzle portion (3b) of a gas admission valve (3), such that a cross-sectional flow area of the pitot tube (4) overlaps, for the most part, with a cross- sectional flow area of the nozzle portion (3b). Moreover, wherein said pitot tube (4) being oriented such that a measurement opening (4a) of the pitot tube is facing upstream. A gas admission valve assembly (3), a method for determining cylinder-specific intake air mass flow and a multi-cylinder internal combustion reciprocating piston engine are also concerned.

Description

A MEASUREMENT ARRANGEMENT FOR DETERMINING CYLINDER-SPECIFIC INTAKE AIR MASS FLOW OF AN INTERNAL COMBUSTION PISTON ENGINE, AND A GAS ADMISSION VALVE ASSEMBLY, METHOD AND AN ENGINE RELATED THERETO
FIELD OF THE DISCLOSURE
The present disclosure relates to multi-cylinder internal combustion piston engines capable of using gaseous fuel as main fuel, and more particularly, a measurement arrangement for determining cylinder-specific intake air mass flow therein.
The present disclosure further concerns a gas admission valve assembly incorporating such a measurement arrangement, a method for determining cylinder-specific intake air mass flow using such a measurement arrangement and a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with such a measuring arrangement.
BACKGROUND OF THE DISCLOSURE
Intake air mass flow is an generally considered a vital parameter for controlling internal combustion piston engines capable of using gaseous fuel as main fuel, such as marine and power plant engines. Conventionally, intake air mass flow has been determined commonly for all cylinders. Intake air mass flow has typically been determined, for example, using a vane meter, a hot-wire sensor or a Karman vortex sensor.
However, these arrangements have known disadvantages, such as significantly increased flow resistance and deterioration in measuring accuracy caused by contamination.
Moreover, it is known that measuring intake air mass flow for each cylinder provides for better control and operation of the engine. However, the problems associated with the known arrangements for measuring intake air mass flow multiplies with the number measuring arrangements used (i.e. number of cylinders) to the extent that conventional measuring arrangements have not been considered feasible for cylinder-specific measurement of intake air mass flow.
BRIEF DESCRIPTION OF THE DISCLOSURE
An object of the present disclosure is to provide a measurement arrangement for determining cylinder-specific intake air mass flow of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, without significantly increasing of flow resistance of the intake air flow and to simultaneously overcome deterioration in measuring accuracy caused contamination.
It is a further object to provide a gas admission valve assembly incorporating such a measurement arrangement, a method for determining cylinder-specific intake air mass flow using such a measurement arrangement and a multi-cylinder internal combustion piston engine, capable of using gaseous fuel as main fuel, equipped with such a measuring arrangement.
The objects of the disclosure are achieved by the measurement arrangement, gas admission valve assembly, method and multi-cylinder internal combustion piston engine which are characterized by what is stated in the respective independent claims. Correspondingly, the preferred embodiments of the disclosure are disclosed in the dependent claims.
The disclosure is based on the idea of providing, within a cylinder specific portion of an intake duct, a pitot tube positioned upstream of gas admission valve, such that a cross- sectional flow area of the pitot tube overlaps, for the most part, with a cross-sectional flow area of a nozzle portion of said gas admission valve. That is, positioning the pitot tube such that the gas admission valve lies in the wake of the pitot tube.
While the pitot tube provides enables reliable, accurate and robust determination of the cylinder specific intake air mass flow, positioning of the pitot tube with respect to the gas admission valve in accordance with the present disclosure ensures minimal increase of flow resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which
Fig. 1 schematically illustrates cylinders and their respective intake ducts of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with a measurement arrangement for determining cylinder-specific intake air mass flow according to an embodiment of the present disclosure;
Fig. 2 schematically illustrates cylinders and their respective intake ducts of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with a measurement arrangement for determining cylinder-specific intake air mass flow according to another embodiment of the present disclosure; Fig. 3 schematically illustrates cylinders and their respective intake ducts of a multi-cylinder internal combustion piston engine capable of using gaseous fuel as main fuel, equipped with a measurement arrangement for determining cylinder-specific intake air mass flow according to a further embodiment of the present disclosure;
Fig. 4 schematically illustrates respective cross-sectional flow areas of a measurement arrangement according an embodiment of the present disclosure within a cylinder specific portion of an intake duct, as seen upstream of the measurement arrangement towards a downstream direction.
Fig. 5 schematically illustrates respective cross-sectional flow areas of a measurement arrangement according another embodiment of the present disclosure within a cylinder specific portion of an intake duct, as seen upstream of the measurement arrangement towards a downstream direction.
It should be noted that, for the purpose of clarity, the enclosed drawings are simplified schematic illustrations and should not be interpreted in a restrictive manner.
DETAILED DESCRIPTION OF THE DISCLOSURE
According to a first aspect of the present disclosure, a measurement arrangement for determining cylinder-specific intake air mass flow of a multi-cylinder internal combustion piston engine, capable of using gaseous fuel as main fuel, is provided.
The arrangement comprises a cylinder specific portion 2 of an intake duct. That is, a portion of an intake duct 2 corresponding to a single cylinder. It may be incorporated as a part of the intake duct, or for facilitating installation and maintenance, as a separate portion attached to the rest of the intake duct.
The arrangement further comprises a gas admission valve assembly 3. The purpose of the gas admission valve assembly is to introduce gaseous fuel into the cylinder-specific portion 2 of an intake duct, at least when the respective engine is running on gaseous fuel. Said gas admission valve assembly 3 comprises a base portion 3a for attaching said gas admission valve assembly to a cylinder specific portion 2 of an intake duct. The gas admission valve assembly 3 further comprises a nozzle portion 3b for introducing gaseous fuel in to said cylinder specific portion 2 of an intake duct. The nozzle portion 3b extends from the base portion 3a such that, when in use, the nozzle portion 3b is positioned within said cylinder specific portion 2 of the intake duct. It should be noted that the nozzle portion 3b does not need to be nozzle-shaped, as such. The measurement arrangement further comprises a pitot tube 4 having at least a stagnation pressure sensor.
When is use, the pitot tube 4 is positioned, within said cylinder specific portion 2 of the intake duct, upstream of the nozzle portion 3b. In other words, the nozzle portion 3b lies at least partially in the wake of the pitot tube. Moreover, the pitot tube is positioned, with respect to the nozzle portion, such that a cross-sectional flow area of the pitot tube 4 overlaps, for the most part, with a cross-sectional flow area of the nozzle portion 3b.
Moreover, the pitot tube 4 should also be oriented, when in use, such that a measurement opening 4a of the pitot tube is facing upstream.
In the context of this disclosure, the term when in use, is used to describe a situation where an entity is in operating condition of its intended use. Particularly, regarding the gas admission valve assembly 3, this means the base portion 3a being attached to a cylinder specific portion 2 of an intake duct, while the nozzle portion 3b being positioned within said cylinder specific portion 2 of the intake duct. Regarding the pitot tube, this means being positioned within the cylinder specific portion 2 of the intake duct, as described above.
Moreover, in the context of this disclosure, the term cross-sectional flow area is used describe the area of an entity effectively affecting intake air flow resistance. That is, the area intersecting between a respective entity and a plane perpendicular to the intake air flow. For example, in the case of nozzle portion 3b and the pitot tube 4, the cross-sectional flow area is the largest area intersecting between a respective entity and a plane perpendicular to the intake air flow. On the other hand, in the case of the cylinder specific portion 2 of the intake air duct, the cross-sectional flow area is the smallest area intersecting between a respective entity and a plane perpendicular to the intake air flow.
Furthermore, in the context of this disclosure, the term upstream and downstream are used to describe the relative position of an entity in a direction opposite to that of the intake air flow with respect to another entity, and respectively, the relative position of an entity in a direction of the intake air flow with respect to another entity. In practise, the term upstream means in a direction away from a cylinder, and the word downstream means in a direction towards a cylinder.
The above described arrangement provides the advantage that there is minimal increase of flow resistance due to the pitot tube 4. This is because the cross-sectional flow area of the pitot tube 4, accounting for the flow resistance thereof, overlaps for the most part with the cross-sectional flow area of the nozzle portion 3b. When compared to a situation where a pitot tube is not present, the flow resistance caused by the cross-sectional flow area of the pitot tube 4 overlapping with that of the nozzle portion 3b would simply be generated by the nozzle portion 3b itself. In other words, the cross-sectional flow area of the nozzle portion 3b lying in the wake of the pitot tube 4 does not create any additional flow resistance. Hence, a pitot tube 4 can be used in accordance with the present disclosure without substantially increasing flow resistance within a cylinder-specific portion 2 of an intake air duct.
Preferably, but not necessarily, at least 50% of the cross-sectional flow area of the pitot tube 4 overlaps with a cross-sectional flow area of the nozzle portion 3b.
More preferably, but not necessarily, the cross-sectional flow area of the pitot tube 4 overlaps wholly with a cross-sectional flow area of the nozzle portion 3b.
In an embodiment according to the first aspect of the present disclosure, the lateral position of the pitot tube 4 within the cross-sectional flow area of the cylinder specific portion 2 of the intake duct is centred with respect to that of the nozzle portion 3b.
In other words, the corresponding centrelines of the nozzle portion 3b and the pitot tube 4, along which they respectively extend towards the inside of the cylinder specific portion 2 of the intake air duct, are aligned, when in use.
The additional advantage of this arrangement is that, as the pitot tube 4 and the nozzle portion 3b are respectively symmetrically positioned with regard to the intake air flow, induction of vortices is minimized, resulting in a further diminished increase of flow resistance.
In another embodiment according to the first aspect of the present disclosure, the measurement arrangement further comprises a static pressure sensor for obtaining intake air flow static pressure measurements.
Preferably, but not necessarily, the static pressure sensor is integrated with the pitot tube 4.
In still another embodiment according to the first aspect of the present disclosure, the measurement arrangement further comprises a temperature sensor for obtaining intake air flow temperature measurements.
In yet another embodiment according to the first aspect of the present disclosure the pitot tube 4 is configured to be suspended within the cylinder specific portion 2 of the intake duct from the base portion 3a of the gas admission valve assembly, when in use. For example, the pitot tube 4 may comprise a stem portion and a tube portion. In such an arrangement, the stem portion extends between the base portion 3a of the gas admission valve assembly 3 and the tube portion of the pitot tube 4, so as to suspend said pitot tube 4 within the cylinder specific portion 2 of the intake duct.
It should be noted, that the first aspect of the present disclosure encompasses the combinations of the embodiments discussed above and variations thereof.
According to a second aspect of the present disclosure, a gas admission valve assembly
3 is provided.
The gas admission valve assembly 3 comprises a base portion 3a for attaching said gas admission valve assembly to a cylinder specific portion 2 of an intake duct. In addition, the gas admission valve assembly 3 further comprises a nozzle portion 3b for introducing gaseous fuel in to said cylinder specific portion 2 of an intake air duct. The nozzle portion 3b extends from the base portion 3a such that, when in use, the nozzle portion 3b is positioned within said cylinder specific portion 2 of the intake duct.
The gas admission valve assembly 3 further comprises a pitot tube 4 having at least a stagnation pressure sensor. Said pitot tube 4 is suspended from the base portion 3a so as to be positioned, when in use, within said cylinder specific portion 2 of the intake duct, upstream of the nozzle portion 3b, such that a cross-sectional flow area of the pitot tube 4 overlaps, for the most part, with a cross-sectional flow area of the nozzle portion 3b.
For example, the pitot tube 4 may comprise a stem portion and a tube portion. In such an arrangement the stem portion extends between the base portion 3a of the gas admission valve assembly 3 and the tube portion of the pitot tube 4, so as to suspend said pitot tube
4 within the cylinder specific portion 2 of the intake duct. Naturally, the pitot tube 4 may be suspended form the base portion 3a in other suitable manners.
Moreover, the pitot tube 4 should be oriented such that a measurement opening 4a of the pitot tube 4 is faces upstream.
The above described arrangement provides the advantage that there is minimal increase of flow resistance due to the pitot tube 4. This is because the cross-sectional flow area of the pitot tube 4, accounting for the flow resistance thereof, overlaps for the most part with the cross-sectional flow area of the nozzle portion 3b. When compared to a situation where a pitot tube is not present, the flow resistance caused by the cross-sectional flow area of the pitot tube 4 overlapping with that of the nozzle portion 3b, would simply be generated by the nozzle portion 3b itself. In other words, the cross-sectional flow area of the nozzle portion 3b lying in the wake of the pitot tube 4 does not create any additional flow resistance. Preferably, but not necessarily, at least 50% of the cross-sectional flow area of the pitot tube 4 overlaps with a cross-sectional flow area of the nozzle portion 3b.
More preferably, but not necessarily, the cross-sectional flow area of the pitot tube 4 overlaps wholly with a cross-sectional flow area of the nozzle portion 3b.
In an embodiment according to the second aspect of the present disclosure, the lateral position of the pitot tube 4 with the cross-sectional flow area of the cylinder specific portion 2 of the intake duct is centred with respect to that of the nozzle portion 3b.
In other words, the corresponding centrelines of the nozzle portion 3b and the pitot tube 4, along which they respectively extend towards the inside of the cylinder specific portion 2 of the intake air duct, are aligned, when in use.
The additional advantage of this arrangement is that, as the pitot tube 4 and the nozzle portion 3b are respectively symmetrically positioned with regard to the intake air flow, induction of vortices is minimized, resulting in a further diminished increase of flow resistance.
In still another embodiment according the second aspect of the present disclosure, the gas admission valve assembly 3 further comprising a static pressure sensor for obtaining intake air flow static pressure measurements.
Preferably but not necessarily, the static pressure sensor is integrated with the pitot tube 4.
It should be noted, that the second aspect of the present disclosure encompasses the combinations of the embodiments discussed above and variations thereof.
According to a third aspect of the present disclosure, a method for determining cylinder- specific intake air mass flow of a multi-cylinder internal combustion piston engine 1 , capable of running on gaseous fuel as main fuel, is provided. Suitably, the method utilizes the measurement arrangement according the first aspect of the present disclosure, including any embodiment or variants thereof.
The method comprises, for at least one cylinder 1 a, 1 b, 1 c, 1 d, a step of measuring, from within a cylinder specific portion 2 of an intake duct corresponding to said cylinder:
- intake air flow temperature;
- intake air flow static pressure, and
- intake air flow stagnation pressure within a pitot tube 4, wherein said pitot tube being positioned on a cross-sectional flow area of said portion 2 of the intake duct, so as to reside upstream of, and, for the most part, overlapping with a nozzle portion 3b of a gas admission valve assembly 3.
The method further comprises, for said at least one cylinder 1 a, 1 b, 1 c, 1 d, following steps of:
determining cylinder specific intake air flow density based on at least the measured intake air flow temperature and the measured intake air flow static pressure;
determining cylinder specific intake air flow velocity within the portion 2 of the intake duct corresponding to said cylinder, based on at least said cylinder specific intake flow density, said intake air flow static pressure and said intake air flow stagnation pressure, and determining cylinder-specific intake air mass flow based on cylinder specific intake air flow velocity, cylinder specific intake air flow density and a cross-sectional flow area of said portion of the intake duct 2.
In an embodiment according to the third aspect of the present disclosure, the method further comprises the step of determining intake air mass during a given combustion cycle of said at least one cylinder 1 a, 1 b, 1 c, 1 d by:
mapping determined cylinder-specific intake air mass flow values to corresponding engine crank-angle values, and
integrating determined cylinder-specific intake air mass flow values over engine crank-angle values during which an intake valve corresponding to said cylinder is open for said given combustion cycle.
In another embodiment according to the third aspect of the present disclosure, at least intake air flow static pressure and intake air flow stagnation pressure are measured with a sampling frequency of at least 10kHz. Preferably, intake air flow temperature is also measured with a sampling frequency of at least 10kHz.
In yet another an embodiment according to the third aspect of the present disclosure, a cylinder specific intake air mass flow is determined for each cylinder 1 a, 1 b, 1 c, 1 d.
In a further embodiment according to the third aspect of the present disclosure, said cylinder-specific intake air mass flow may be determined according to the following equation
Figure imgf000009_0001
where
rh denotes cylinder-specific intake air mass flow;
C denotes a flow correction coefficient that takes pitot probe location and pipe geometry into account, determined empirically or through computational fluid dynamics
simulations;
A denotes flow area of said cylinder specific portion (2) of intake air duct
pt denotes stagnation pressure;
ps denotes static pressure, and
p denotes intake air density.
In still a further embodiment according to the third aspect of the present disclosure, suitably when flow velocities are relatively high requiring the compressibility of gas to be taken into consideration, said cylinder-specific intake air mass flow may be determined in accordance with the following equation
rh = C * A * p * a * M,
where:
rh denotes cylinder-specific intake air mass flow;
C denotes a flow correction coefficient that takes pitot probe location and pipe geometry into account, determined empirically or through computational fluid dynamics simulations;
A denotes flow area of said cylinder specific portion (2) of intake air duct;
p denotes intake air static density;
a denotes the speed of sound, and
M denotes Mach Number;
The intake air density, the speed of sound and The Mach number, in turn, may be determined in accordance with the following formulae
Figure imgf000011_0001
pt = ps * (l + 0. 5
Figure imgf000011_0002
P s (1 + x)
Ps = RTS * (1 + 1.609 * x ) a = ^(g * R * Tt )
Figure imgf000011_0003
where:
R denotes the Specific Gas Constant
Tt denotes the stagnation (total) temperature of the intake Air (in Kelvin)
Ts denotes the static temperature of the intake Air (in Kelvin)
g denotes the ratio of specific heats of the intake air
pt denotes stagnation (total) pressure of the intake air;
ps denotes static pressure of the intake air
x denotes humidity ratio (kg water/kg air) of the intake air
For the purpose of completeness, the above has been derived from the following
Figure imgf000011_0004
and
V
M = - a
where:
a denotes the speed of sound
V denotes the Velocity of gas
M denotes Mach Number Regardless of which approach is chosen for determining intake air mass flow, the intake air flow density for dry air may be determined, for example, as a function of static pressure and temperature in accordance with pre-existing charts or calculated for the measured data in accordance with the following formula.
Figure imgf000012_0001
where:
Pdry air denotes the intake air flow density for dry air ps denotes static pressure
R denotes the Specific Gas Constant
T denotes the Temperature of the intake air (in Kelvin)
Furthermore, air humidity may be taken into consideration in accordance with the following formula
P Pdry a
Figure imgf000012_0002
where:
p denotes intake air static density;
x denotes humidity ratio (kg water/kg air)
In another embodiment according to the third aspect of the present disclosure, a cylinder- specific air-to-fuel -ratio is controlled based on the determined cylinder- specific intake air mass flow.
This enables improving balancing the air-to-fuel -ratio between individual cylinders, and hence, the whole engine, leading further to better performance with respect to emissions and efficiency.
Furthermore, for improving dynamic response, the minimum air-fuel ratio could be then limited cylinder-specifically in order to get the maximum possible performance. Cylinder- specific air-to-fuel -ratio control allows also for a sophisticated load control, thus contributing to the improvement of reliability and repeatability mitigating problems related to knocking, for example.
It should be noted, that the third aspect of the present disclosure encompasses the combinations of the embodiments discussed above and variations thereof.
According to a fourth aspect of the present disclosure, a multi-cylinder internal combustion reciprocating piston engine 1 , capable of using gaseous fuel as main fuel, is provided.
The engine 1 comprises a control unit, and for each cylinder, the measurement arrangement according the first aspect of this disclosure, including embodiments and variants thereof. Particularly, the sensors of the measurement arrangement are operationally coupled with the control unit.
In an embodiment according to the fourth aspect of the present disclosure, the control unit is configured to perform the method according to the third aspect of the present disclosure, including any embodiment and variants thereof.
In another embodiment according to the fourth aspect of the present disclosure, the engine further comprises, for each cylinder 1 a, 1 b, 1c, 1d, cylinder-specific fuel delivery means operationally coupled to the control unit. Moreover, the control unit is further configured to operate said cylinder-specific fuel delivery means based on the determined cylinder- specific intake air mass flow so as to control a cylinder-specific air-to-fuel -ratio.
This enables improving balancing the air-to-fuel -ratio between individual cylinders, and hence, the whole engine, leading further to better performance with respect to emissions and efficiency.
Furthermore, for improving dynamic response, the minimum air-fuel ratio could be then limited cylinder-specifically in order to get the maximum possible performance. Cylinder- specific air-to-fuel -ratio control allows also for a sophisticated load control, thus contributing to the improvement of reliability and repeatability mitigating problems related to knocking, for example.
It should be noted, that the fourth aspect of the present disclosure encompasses the combinations of the embodiments discussed above and variations thereof.
Fig. 1 schematically illustrates cylinders 1 a, 1 b, 1c, 1 d and their respective intake ducts of a multi-cylinder internal combustion piston engine 1 capable of using gaseous fuel as main fuel. For the purpose of clarity, Fig. 1 represents said 1 engine in a simplified manner, omitting many of its features not necessary for discussing the present disclosure. Particularly the engine 1 is equipped with a measurement arrangement for determining cylinder-specific intake air mass flow, according to an embodiment of the present disclosure.
Each cylinder 1 a, 1 b, 1 c, 1 d has an associated intake air duct with a cylinder-specific portion 2. Arranged within said cylinder specific portion 2 of the intake air ducts, are gas admission valve assemblies 3 and pitot tubes 4, one each per cylinder-specific portion 2 of the intake air duct. As can be seen, the pitot tubes 4 resides upstream (in a direction away form a respective cylinder 1 a, 1 b, 1 c, 1 d) of the gas admission valve assembly 3. Furthermore, the gas admission valve assembly 3, denoted by the dotted line, has a base portion 3a for attaching the valve assembly to the cylinder-specific portion 2 of the intake air duct. The gas admission valve assembly 3 also has a nozzle portion 3b for introducing gaseous fuel into the cylinder-specific portion 2 of the intake air duct. Other components not illustrated herein may naturally also be incorporated into the gas admission valve assembly 3.
Fig. 2 illustrates a similar arrangement to that of Fig. 1 with the exception of the pitot tube 4 now being included in the gas admission valve assembly 3.
Fig. 3 illustrates variation of the arrangements represented in Fig. 2, namely where the pitot tube 4 is supported within the cylinder-specific portion 2 of the intake air duct from the base 3a of the gas admission valve assembly 3.
Fig. 4 schematically illustrates respective cross-sectional flow areas of a measurement arrangement according another embodiment of the present disclosure within a cylinder specific portion 2 of an intake duct, as seen upstream of the measurement arrangement towards a downstream direction. Particularly, Fig. 4 illustrates the base 3a of the gas admission valve assembly 3 being attached to the cylinder-specific portion 2 of the intake air duct such that the nozzle portion 3b is suspended within said portion 2.
Moreover, Fig. 4 clearly illustrates a cross-sectional flow area of a pitot tube 4 overlapping, for the most part, with the cross- sectional flow area of the nozzle portion 3b of the gas admission valve assembly 3.
Also, Fig. 4 illustrates how the lateral positions of the nozzle portion 3b and the pitot tube 4, within the cylinder-specific portion 2 of the intake air duct, are centred with each other.
Fig. 5 illustrates a similar arrangement to that of Fig. 4, with the exception of a cross- sectional flow area of a pitot tube 4 overlapping wholly with the cross- sectional flow area of the nozzle portion 3b of the gas admission valve assembly 3. It should be noted, that although the present disclosure has been discussed above with reference to an embodiment of a multi-cylinder internal combustion piston engine 1 having four cylinders 1 a, 1 b, 1 c, 1 d, the present disclosure may naturally be implemented with any number of cylinders, as defined by the appended Claims.

Claims

1 . A measurement arrangement for determining cylinder-specific intake air mass flow of a multi-cylinder internal combustion piston engine (1 ) capable of using gaseous fuel as main fuel, comprising:
a cylinder specific portion (2) of an intake duct;
a gas admission valve assembly (3), comprising
- a base portion (3a) for attaching said gas admission valve assembly (3) to a cylinder specific portion of an intake duct
- a nozzle portion (3b) for introducing gaseous fuel in to said cylinder specific portion (2) of an intake duct, the nozzle portion (3b) extending from the base portion (3a) such that, when in use, the nozzle portion (3b) is positioned within said cylinder specific portion (2) of the intake duct,
characterized by the arrangement further comprising:
a pitot tube (4) having at least a stagnation pressure sensor, said pitot tube being positioned, when in use, within said cylinder specific portion (2) of the intake duct, upstream of the nozzle portion (3b), such that a cross-sectional flow area of the pitot tube (4) overlaps, for the most part, with a cross-sectional flow area of the nozzle portion (3b),
wherein said pitot tube (4) being oriented such that a measurement opening (4a) of the pitot tube is facing upstream.
2. The measurement arrangement according to Claim 1 , characterized in that at least 50% of the cross-sectional flow area of the pitot tube (4) overlaps with a cross- sectional flow area of the nozzle portion (3b).
3. The measurement arrangement according to Claim 1 or 2, characterized in that the cross-sectional flow area of the pitot tube (4) overlaps wholly with a cross-sectional flow area of the nozzle portion (3).
4. The measurement arrangement according to any of the preceding Claims 1 -3, characterized in that, the lateral position of the pitot tube (4) within the cross-sectional flow area of the cylinder specific portion (2) of the intake duct is centred with respect to that of the nozzle portion (3b).
5. The measurement arrangement according to any of the preceding Claims 1 -4, characterized by further comprising a static pressure sensor for obtaining intake air flow static pressure measurements.
6. The measurement arrangement according to Claim 5, characterized in that the static pressure sensor is integrated with the pitot tube (4).
7. The measurement arrangement according to any of the preceding Claims 1 -6, characterized by further comprising a temperature sensor for obtaining intake air flow temperature measurements.
8. The measurement arrangement according to any of the preceding Claims 1 -7, characterized in that the said pitot tube (4) is configured to be suspended within the cylinder specific portion (2) of the intake duct from the base portion (3a) of the gas admission valve assembly (3), when in use.
9. A gas admission valve assembly (3), comprising:
- a base portion (3a) for attaching said gas admission valve assembly (3) to a cylinder specific portion (2) of an intake duct;
- a nozzle portion (3b) for introducing gaseous fuel in to said cylinder specific portion (2) of an intake duct, the nozzle portion (3b) extending from the base portion (3a) such that, when in use, the nozzle portion (3b) is positioned within said cylinder specific portion (2) of the intake duct,
characterized by the gas admission valve assembly (3) further comprising a pitot tube (4) having at least a stagnation pressure sensor, wherein:
said pitot tube (4) being suspended from the base portion (3a) so as to be positioned, when in use, within said cylinder specific portion (2) of the intake duct, upstream of the nozzle portion (3b), such that a cross-sectional flow area of the pitot tube (4) overlaps, for the most part, with a cross-sectional flow area of the nozzle portion (3b), and
said pitot tube (4) being oriented such that a measurement opening (4) of the pitot tube (4) is facing upstream.
10. The gas admission valve assembly (3) according to Claim 9, characterized in that at least 50% of the cross-sectional flow area of the pitot tube (4) overlaps with a cross- sectional flow area of the nozzle portion (3b).
1 1. The gas admission valve assembly (3) according to Claim 9 or 10, characterized in that the cross-sectional flow area of the pitot tube (4) overlaps wholly with a cross- sectional flow area of the nozzle portion (3b).
12. The gas admission valve assembly (3) according to any of the preceding Claims 9 -
11 , characterized in that, the lateral position of the pitot tube (4) within the cross- sectional flow area of the cylinder specific portion (2) of the intake duct is centred with respect to that of the nozzle portion (3b).
13. The gas admission valve assembly (3) according to any of the preceding Claims 9 -
12, characterized by further comprising a static pressure sensor for obtaining intake air flow static pressure measurements.
14. The gas admission valve assembly (3) according to any of the preceding Claims 9 -
13, characterized in that the static pressure sensor is integrated with the pitot tube (4).
15. A method for determining cylinder-specific intake air mass flow of a multi-cylinder internal combustion piston engine (1 ) capable of running on gaseous fuel as main fuel, with the measurement arrangement according to any of the preceding Claims 1 - 9, characterized by comprising, for at least one cylinder (1 a, 1 b, 1 c, 1 d), the steps of measuring, from within a cylinder specific portion (2) of an intake duct corresponding to said cylinder;
- intake air flow temperature;
- intake air flow static pressure, and
- intake air flow stagnation pressure within a pitot tube (4), said pitot tube being positioned on a cross-sectional flow area of said portion (2) of the intake duct, so as to reside upstream of, and, for the most part, overlapping with a nozzle portion (3b) of a gas admission valve assembly (3), and
determining cylinder specific intake air flow density based on at least the measured intake air flow temperature and the measured intake air flow static pressure;
determining cylinder specific intake air flow velocity within the portion (2) of the intake duct corresponding to said cylinder, based on at least said cylinder specific intake flow density, said intake air flow static pressure and said intake air flow stagnation pressure, and determining cylinder-specific intake air mass flow based on cylinder specific intake air flow velocity, cylinder specific intake air flow density and a cross-sectional flow area of said portion of the intake duct (2).
16. The method according to Claim 15, characterized by
the method further comprising determining intake air mass during a given combustion cycle of said cylinder (1 a, 1 b, 1c, 1 df) by:
- mapping determined cylinder-specific intake air mass flow values to corresponding engine crank-angle values, and
- integrating determined cylinder-specific intake air mass flow values over engine crank-angle values during which an intake valve corresponding to said cylinder is open for said given combustion cycle.
17. The method according to Claim 15 or 16, characterized in that at least intake air flow static pressure and intake air flow stagnation pressure are measured with a sampling frequency of at least 10kHz.
18. The method according to any of the preceding Claims 15 - 17, characterized in by determining a cylinder specific intake air mass flow for each cylinder (1 a, 1 b, 1c, 1d).
19. The method according to any of the preceding Claims 15 - 18, characterized in that a cylinder-specific air-to-fuel -ratio is controlled based on the determined cylinder- specific intake air mass flow.
20. A multi-cylinder internal combustion reciprocating piston engine (1 ) capable of using gaseous fuel as main fuel, comprising a control unit,
characterized by further comprising, for each cylinder, the measurement arrangement according any of the preceding Claims 1 - 9, the sensors of the measurement arrangement being operationally coupled with the control unit.
21. The multi-cylinder internal combustion reciprocating piston engine (1 ) according to Claim 20, characterized by the control unit being configured to perform the method step of any of the preceding methods 15 - 18.
22. The multi-cylinder internal combustion reciprocating piston engine (1 ) according to Claim 20 or 21 , characterized by further comprising, for each cylinder (1 a, 1 b, 1c, 1 d) cylinder-specific fuel delivery means operationally coupled to the control unit, wherein the control unit is further configured to operate said cylinder-specific fuel delivery means based on the determined cylinder- specific intake air mass flow so as to control a cylinder-specific air-to-fuel -ratio.
PCT/FI2017/050894 2017-12-14 2017-12-14 A measurement arrangement for determining cylinder-specific intake air mass flow of an internal combustion piston engine, and a gas admission valve assembly, method and an engine related thereto WO2019115858A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/FI2017/050894 WO2019115858A1 (en) 2017-12-14 2017-12-14 A measurement arrangement for determining cylinder-specific intake air mass flow of an internal combustion piston engine, and a gas admission valve assembly, method and an engine related thereto

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/FI2017/050894 WO2019115858A1 (en) 2017-12-14 2017-12-14 A measurement arrangement for determining cylinder-specific intake air mass flow of an internal combustion piston engine, and a gas admission valve assembly, method and an engine related thereto

Publications (1)

Publication Number Publication Date
WO2019115858A1 true WO2019115858A1 (en) 2019-06-20

Family

ID=60782241

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2017/050894 WO2019115858A1 (en) 2017-12-14 2017-12-14 A measurement arrangement for determining cylinder-specific intake air mass flow of an internal combustion piston engine, and a gas admission valve assembly, method and an engine related thereto

Country Status (1)

Country Link
WO (1) WO2019115858A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2094828A (en) * 1932-07-11 1937-10-05 W F Arndt Two-stroke cycle engine
US4102314A (en) * 1977-03-30 1978-07-25 Chrysler Corporation Crankcase ventilation
EP0400942A1 (en) * 1989-05-29 1990-12-05 Hitachi, Ltd. Air-fuel mixture supply apparatus for internal combustion engine
US20040260482A1 (en) * 2001-10-15 2004-12-23 Satoru Tanaka Suction air volume estimating device for internal combustion engine
US20150159578A1 (en) * 2013-12-05 2015-06-11 Ford Global Technologies, Llc Method of diagnosing injector variability in a multiple injector system
US20150276441A1 (en) * 2014-03-27 2015-10-01 Kcf Technologies, Inc. Flow sensor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2094828A (en) * 1932-07-11 1937-10-05 W F Arndt Two-stroke cycle engine
US4102314A (en) * 1977-03-30 1978-07-25 Chrysler Corporation Crankcase ventilation
EP0400942A1 (en) * 1989-05-29 1990-12-05 Hitachi, Ltd. Air-fuel mixture supply apparatus for internal combustion engine
US20040260482A1 (en) * 2001-10-15 2004-12-23 Satoru Tanaka Suction air volume estimating device for internal combustion engine
US20150159578A1 (en) * 2013-12-05 2015-06-11 Ford Global Technologies, Llc Method of diagnosing injector variability in a multiple injector system
US20150276441A1 (en) * 2014-03-27 2015-10-01 Kcf Technologies, Inc. Flow sensor

Similar Documents

Publication Publication Date Title
JP2005233047A (en) Cylinder intake air quantity calculation device for internal combustion engine
US20140208755A1 (en) Gas Turbine Air Mass Flow Measuring System and Methods for Measuring Air Mass Flow in a Gas Turbine Inlet Duct
US8095293B2 (en) Method and device for operating an internal combustion engine
US20150275782A1 (en) Control device for engine equipped with supercharger
CN115524134A (en) Air entraining amount testing structure and method for aircraft engine anti-icing system
CN111811681A (en) Air-breathing type fiber bragg grating total temperature probe and measuring system thereof
CN208534819U (en) Device for the test of fan aeroperformance
JP2006162417A (en) Total pressure/static pressure measuring venturi system flow measuring device
KR20080106972A (en) Method and device for regulating or controlling a compressor of an exhaust gas turbocharger
JP5569383B2 (en) Pulsating flow measurement method and gas flow measurement device
WO2019115858A1 (en) A measurement arrangement for determining cylinder-specific intake air mass flow of an internal combustion piston engine, and a gas admission valve assembly, method and an engine related thereto
US20110082662A1 (en) Method and device for detecting capacity changes in a fluid and turbine
CN105715395B (en) Method and device for checking a pressure-based mass flow sensor in an air supply system for an internal combustion engine
US6711491B2 (en) Mass airflow sensor for pulsating oscillating flow systems
KR20170007460A (en) Method and device for operating an internal combustion engine
Copeland The evaluation of steady and pulsating flow performance of a double-entry turbocharger turbine
US10100756B2 (en) Method for determining atmospheric pressure during the operation, in a partial load state, of a turbocharged engine
Rademakers et al. Experimental investigations on a bent engine inlet duct coupled with a turbofan engine
JP2007154841A (en) Intake air amount detection device of internal combustion engine
JP2008002833A (en) Device for correcting intake flow rate
JP2007205298A (en) Failure determination device for airflow sensor
KR20170110433A (en) The Hilly section performance testing apparatus for internal combustion engine
EP3633327A1 (en) Flow rate measurement device and flow rate measurement method
Winkler et al. Study of measured and model based generated turbine performance maps within a 1D model of a heavy-duty diesel engine operated during transient conditions
JP3000048B1 (en) Engine exhaust gas flow measurement system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17818194

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17818194

Country of ref document: EP

Kind code of ref document: A1