Selected aspects of the use of gaseous fuels blends to improve efficiency and emission of SI engine

Transcription

1 D.O.M. G Kubica Selected aspects of the use of gaseous fuels blends to improve efficiency and emission of SI engine Grzegorz Kubica, Marek Flekiewicz, Paweł Fabiś, Paweł Marzec Silesian University of Technology, Faculty of Transport Katowice, PL 2018

2 Relationships: vehicle - human - environment Sustainable development Trends in development of vehicles: Minimize adverse impacts CO 2 and pollutant reduction Energy saving improvement of efficiency, renewable fuels 2

3 Towards Hydrogen + Advantages pro-ecological fuel huge resources - Problems expensive production warehousing and distribution 3 but not immediately

4 Low-carbon fuels Solution: methane&hydrogen blends 4 World s deposits of NG in bln m 3

5 Natural gas application CNG containers: Steel or composite Compressed c.a. 33 MPa LNG containers: Cryogenic c.a C Pressure 1,6 MPa 5

6 Renewable fuels Solution: LPG&DME blends life cycle assessment (LCA) 6

7 7 DME application

8 Research object Feeding system: Petrol SPI Multec LPG gaseous injection Etagas by Tartarini CNG gaseous injection EtagasM by Tartarini Engine code X16SZR Cylinder number and layout 4 R Maximum power 55 kw@ 5200 rpm Maximum torque 128 N 2800 rpm Displacement 1598 ccm Bore x stroke 79.0 x 81.5 mm Compression ratio Fourteen of different fuels were used: Gasoline, Methane, LPG and fuel blends consisting of: - Methane with Hydrogen addition from 5%, to 50%, by volume, - LPG with DME addition from 0% to 28% DME by mass,

9 CNG enriched with Hydrogen Property Range of burning [% gas volume in air] Hydrogen H 2 Methane CH 4 Petrol ,3 15,0 1,2 6,0 Min. ignition energy [mj] ~0,02 ~0,28 ~0,25 Burning speed [m/s] ~2,90 ~0,38 ~0,37 0,43 Adiabatic flame temperature [K] ~2318 ~2190 ~2470 Selfignition temperature [K] ~858 ~813 ~ Density [kg/m 3 ]; at 293,15 K and 101,3 kpa Stoichiometric A/F ratio [kg A/kg F] Mass lower heating value [MJ/kg] Volumetric heating value of stoichiometric mixture [MJ/nm 3 ] 0,082 0, ~34 17,5 14,9 ~120 ~50 ~46 2,96 3,43 3,7 Expected results : shorter combustion period increasing of total efficiency reduction of emission CO 2 and CO 9

10 Engine performance Methane/Hydrogen blends P max [kw] at rpm Fuel T max [N m] at rpm 50, % CH 4 115, , , , , , , , % CH 4, 5% H 2 113, % CH 4, 10% H 2 117, % CH 4, 15% H 2 122, % CH 4, 20% H 2 118, % CH 4, 30% H 2 117, % CH 4, 40% H 2 117, % CH 4, 50% H 2 116,

11 Heat released during combustion 1200 HR [J] czystymetan Methane % udz.h H 2 15% udz.h H 2 30% udz.h H % udz.h H φ [degca] RoHR [J/dCA] Working conditions: WOT 100% 2500 rpm λ = 1,0 czystymetan Methane 5% 5% udz.h H 2 15% udz.h H 2 30% udz.h H 2 50% udz.h H φ [degca]

12 Combustion duration Opel Astra F X16SZR t sp [ms] 6 5,5 5 4,5 4 3,5 3 2,5 2 1, H 40 2 share[%] Increasing the share of H 2 shortens the burning time 12

13 Exhaust gas temperature T [K] 2000 Working conditions: 1600 WOT 100% 2500 rpm 1200 czysty Methane Metan 5% 5% udz.h H % udz.h H 2 30% udz.h H 2 50% udz.h H φ [degca] T [K] λ = 1, % H 2 5% H 2 Methane % H 2 50% H φ [degca]

14 Power on wheel Opel Astra F X16SZR Pw [kw] 34,0 29,0 24,0 19,0 The increase in the value of power on wheels occurs with the share of H 2 over 15% 14,0 9,0 0% 5% 10% 15% 20% 30% 40% 50% H 2 share [%]

15 Total efficiency η o [%] With the increase in the share of H 2 increases the value of total engine efficiency H 2 share [%] 15

16 Trends of emission the main components of exhaust gases 16

17 Properties of combustible mixture LPG&DME 17 Mass heating value as a function of DME mass ratio, W u - Mass heating value of stoichiometric mixture, W d - Mass heating value of fuel, L a - Stoichiometric air to fuel ratio

18 The results LPG&DME The results full loaded engine showed that a limited DME additive, in the range of approximately 7-15% by weight, increased engine performance. Too large amount of DME in the fuel causes a reduction in combustion rate and prolongs the process. 18

19 Engine performance LPG&DME P max, kw WOT, % DME, % Pw, kw WOT, % DME, % 17 The max. power and power measured on the wheels show that, with less engine load, an increase of the DME share has a beneficial effect to the performance of the vehicle. 19

20 Combustion duration LPG&DME 10%MFB, dca %MFB, dca WOT, % DME, % WOT, % DME, % 17 The graphs show the angle of the crankshaft position corresponding to the characteristic points of the combustion process, 10 and 50% of the mass fraction burned MFB. In both cases, there is a strong relationship between the share of DME in the fuel and the velocity of combustion process 20

21 Emission of CO 2 and CO LPG&DME CO2, % 11,5 11,4 11,3 CO, % 0,05 0,04 0,03 11,2 14 0,02 11, WOT, % WOT, % DME, % Emissions of carbon-containing compounds: CO 2 and CO are not subject to major changes. The influence of the type of fuel is not noticeable, because in the group of the studied fuels the total share of the C-component in the stoichiometric mixture was similar 21

22 Total efficiency LPG&DME η o, % 32 0 DME, % WOT, % ,07 26,1 25,65 22,95 20,7 19,8 7 26,28 23,76 23,94 22,05 20,61 20,7 9 23,94 24,66 24,75 22,77 20,88 19, ,31 24,39 25,47 22,5 21,87 20, ,23 24,66 26,19 24,93 22,59 20, ,33 21,96 24,3 24,93 21,69 20, Because of the general efficiency of the engine the range of partial loads is most advantageous because the highest values (LPG-like) are obtained there. This is the most common operating range of the engine 22

23 Conclusions The carried out tests give a possibility to understand fundamental combustion properties of Methane/Hydrogen and LPG/DME blends, what is important for developing advanced NG and LPG based combustion engines with necessary operating strategies. It was possible to identify the influence of hydrogen volume rate and DME mass share in the mixtures on the overall engine performance, its efficiency and on the combustion process. General aim of adding hydrogen to methane and DME to LPG is to minimize negative parts in their combustion. Because of the differences in selected properties of methane, hydrogen, DME and LPG an improvement of the conditions for the flame initiation and shortening of the charge heating period are expected. Future experimental development would foresee the optimization of the emissions of the both pollutant and CO 2 along the reduction of fuel consumption for vehicle driving cycle. It is necessary to investigate widely following set of engine variables: Spark advance, Compression ratio, A wide spectrum of values, EGR. 23

24 D.O.M. G Kubica Selected aspects of the use of gaseous fuels blends to improve efficiency and emission of SI engine Grzegorz Kubica, Marek Flekiewicz, Paweł Fabiś, Paweł Marzec Silesian University of Technology, Faculty of Transport Thank you for your attention