Aquecimento de Combustível, uma forma simples de reduzir emissões veiculares

(1)

Associação Brasileira de Engenharia Automotiva

R. Salvador Correia, 80 - Aclimação CEP : 04109-070 - São Paulo - SP Tel. / Fax: 55 (11) - 5908-4043 E-mail: eventos@aea.org.br www.aea.org.br • www.aeabrazil.com

Prêmio AEA 2017 - Projetos de Meio Ambiente

Aquecimento de Combustível, uma forma simples de reduzir emissões veiculares

Roberto Gothardo Krenus Delphi Automotive Systems do Brasil

RESUMO

Heating the Fuel during the first 100 seconds on the emissions cycle results in lower emissions and lower fuel consumption and the first worldwide vehicle in production with this technology is the Hyundai GSB 1.6L MY 2017, using Delphi Heated Injectors.

Brazil has unique emissions legislation where the levels are comparable with USA but flexfuel vehicles have to pass with 3 fuels, including ethanol. The issue is the gas called NMHC (Non Methane Hydrocarbons). Ethanol fuel (E100) generates large amounts of NMHC during cold operation in the form of unburned Ethanol:

1. For Brazil actual fleet:

• Generates more than 70 Tons of unburned ethanol every year.

Passing Brazil emissions (Proconve L6) with ethanol requires the leanest possible mixture for start and warmup. Good cold drive ability requires rich mixture for start and warmup. Emissions and Drivability are in conflict.

Brazilian´s emissions legislation allows to discount the unburned ethanol from NMHC, in order to pass E100 emissions approval. It means a lot of unburned ethanol is dumped into the ambient and is not considered in emissions.

Heating the fuel is possible to pass Proconve L6 Brazil emissions with E100 without the discount of the 70 tons/year of unburned ethanol in Brazil.

(2)

Aplicabilidade

Delphi Heated Injectors can be applied to any kind of fuel from gasoline up to ethanol with the following benefits: eliminates the cold start sub-system on the flex fuel vehicles, reduce emissions on all fuel types and reduces fuel consumption when using ethanol fuel.

Delphi Heated Injectors can be applied to any engine size and cylinder number, from a small mono cylinder 125cc motorcycle up to a multi cylinder turbo vehicle.

Delphi Heated Injectors are applicable for port fuel injection engines.

Objetivo

The objectives are:

1. reduce from gasoline up to ethanol the emissions level; 2. improve ethanol fuel consumption;

3. improve cold drive ability.

Heating the Fuel during the first 100 seconds on the emissions cycle results in lower emissions and lower fuel consumption and the first worldwide vehicle in production with this technology is the Hyundai GSB 1.6L MY 2017, using Delphi Heated Injectors.

Brazil has unique emissions legislation where the levels are comparable with USA but flexfuel vehicles have to pass with 3 fuels, including ethanol. The issue is the gas called NMHC (Non Methane Hydrocarbons). Ethanol fuel (E100) generates large amounts of NMHC during cold operation in the form of unburned Ethanol:

1. For Brazil fleet:

a. 26.000.000 vehicles flex are sold in Brazil;

b. 25% of the fleet runs with E100 = 6.500.000 vehicles; c. Unburned ethanol average = 0,015g/km on cold phase; d. If every car does 2 ambient starts/day;

(3)

R. Salvador Correia, 80 - Aclimação CEP : 04109-070 - São Paulo - SP Tel. / Fax: 55 (11) - 5908-4043 E-mail: eventos@aea.org.br www.aea.org.br • www.aeabrazil.com i. 6.500.000 vehiclesx360 daysx2 startsx0,015 g/km = 70 Tons/year f. Generates more than 70 Tons of unburned ethanol every year.

Passing Brazil emissions (Proconve L6) with ethanol requires the leanest possible mixture for start and warmup. Good cold drive ability requires rich mixture for start and warmup. Emissions and Drivability are in conflict.

Brazilian´s emissions legislation allows to discount the unburned ethanol from NMHC, in order to pass E100 emissions approval. It means a lot of unburned ethanol is dumped into the ambient and is not considered in emissions.

Heating the fuel is possible to pass Proconve L6 Brazil emissions with E100 without the discount of the 70 tons/year of unburned ethanol in Brazil.

Heating the injectors during the first 100 seconds on the emissions cycle (cold phase) enables to calibrate a leaner crank and warm-up fueling without impacting drive ability, resulting in lower emissions and lower fuel consumption. There is no more need to subtract the unburned ethanol from NMHC emissions results, avoiding more than 70 Tons/year dumped into the ambient.

Delphi introduces a new powertrain component to improve emissions: Heated Fuel Injectors;

1. These injectors are able to heat the fuel to be inject on the cylinder;

2. This heating is precisely controlled to stay in a target fuel temperature during engine running.

(4)

Delphi Heated Injector Technology (Figure 1):

Heating only as much fuel as needed:

1. Thick film resistive heater heats almost Instantaneously; 2. There is no fuel contact with the heater;

3. The fuel is flow forced in contact with the heated body.

Figure 1 Heater Thick film Fuel Flow Cold Fuel Hot Fuel

(5)

Delphi Heated Injector Spray Compare Heated X Unheated (Figure 2):

Figure 2

When heating the injectors, the fuel droplet size is dramatic reduced, there is more vapor, the fuel puddle is lower and the mixture with air is easier.

Delphi Heated Injector Unburned Ethanol Compare Unheated X Heated (Figure 3):

Figure 3

To have a stoichiometric amount of ethanol vapor at the spark plug for the first fire in emissions range the accumulated unburned ethanol is 0.92g per cylinder. Using the same criteria if the fuel is heated up to 60°C the accumulated unburned ethanol is reduce down to 0.06g/cylinder (15 times less).

(6)

Delphi Heated Injector Fuel Consumption Compare Heater X Unheated (Figure 4):

Figure 4

Heating the ethanol fuel only during the first cold 100s of engine running will reduce the fuel to be inject by 21%, it means the cold fuel consumption will decrease by 21%; this will be diluted by the entire emissions cycle, resulting in 0.5% of fuel consumption

(7)

Delphi Heated Injector Overview Diagram (Figure 5):

Figure 5

The main ECU (Electronic Control Unit) control the HICM (Heated Injector Control Module) by the CAN line. The HICM is an individual Heater PWM power control who will precisely keep the fuel temperature on a target temperature.

(8)

Delphi Heated Injector Emissions results (Table 1):

Table 1

For ethanol E100, NMHC is reduced by 81% and CO by 31% when heating the system during the first 100s of the emissions cyle.

For gasoline E22, NMHC is reduced by 35% and CO by 22% when heating the system during the first 100s of the emissions cycle.

Not required yet in Brazil, but Heated Injectors also reduce up to 27% the particulate emissions.

(9)

Delphi Heated Injector Emissions Accumulated THC results (Graphic 1):

Graphic 1

Comparing the Accumulated HC over the ethanol cold phase emissions range we can observe the reduced red line (heaters ON) versus the base orange line (heaters OFF). The first 100s with Heaters ON is enough to dramatic reduce emissions and fuel consumption,

(10)

CONCLUSÃO

Heated Injectors are able to:

– Eliminate the gasoline sub tank system used for ethanol cold starts at low temperatures;

– Reduce emissions from gasoline up to ethanol;

– For ethanol E100, NMHC is reduced by 81% and CO by 31%; – For gasoline E22, NMHC is reduced by 35% and CO by 22%;. – Also reduce up to 27% particulate emissions;

– Improve ethanol fuel consumption; – Improve cold drive ability.

There is a potential to reduce more than 70 tons of unburned ethanol per year. The Heated Injectors are in production for cold starts since 2011.

The Heated Injectors are in production for emissions and fuel consumption reduction since Jan/2017 at Hyundai Creta 1.6L.

REFERÊNCIAS

[1] Star-Cd User’s Guide, V3.26, Cd-Adapco, 2005.