EHF Fuel Formulation Test Results

SeaChange Group contracted the U.S. Department of Energy’s Oak Ridge National Laboratory in 2011 to analyze various EHF fuel formulations under a work-for-others contract sponsored by the U.S. National Science Foundation.  The goal of the project was to quantify combustion dynamics and emission reduction benefits of EHF fuels as they compare to petroleum diesel fuel.

Experimental Design

Tests were performed in the ORNL FEERC Small Engine Laboratory using a naturally-aspirated, air-cooled Hatz 517cc 2-valve single-cylinder diesel engine with mechanical fuel injection (Figure 1).  Stock engine specifications are displayed in Table 1.

Figure 1 – Hatz 1D50z engine in the ORNL FEERC Small Engine Laboratory used for fuel formulation testing.
Figure 1 – Hatz 1D50z engine in the ORNL FEERC Small Engine Laboratory.

 

Number   of cylinders

1

Mode   of operation

Air-cooled,   four-stroke, compression ignition

Combustion   method

Direct-fuel   injection

Bore/stroke

97/70   mm

Displacement

517   cm3

Table 1 – Hatz 1D50z stock engine specifications.

Engine data is acquired, processed, and stored via a system of AVL components. Table 2 describes each of these components and their function in the data acquisition system.

 Table 2 – Data acquisition system components and functions used in fuel formulation testing.
Table 2 – Data acquisition system components and functions.

For improved accuracy, the data acquisition system incorporates a series of thermocouples located in the cylinder head and wall and high-speed pressure transducers located in the cylinder, intake port, and exhaust port. This instrumentation combined with the system components outlined in Table 2 provide real-time acquisition, processing, display, and storage of low-speed (time-based), high-speed (crank angle-based), and heat release data. The low-speed data is acquired at a sampling rate of up to 100 Hz while the high-speed data is acquired at a sample increment of up to 0.1 crank angle degrees. Heat release data is calculated from the in-cylinder pressure trace and displayed in real-time.

Exhaust emissions were measured using an AVL 483 opacity smoke opacity meter and the following California Analytical Instruments (CAI) analyzers: NOx (CLD), THC (FID) and CO2/CO/O2 (NDIR).  This particular engine required mild engine intake heating to ensure fuel performance over the entire operating range of interest.

Emissions Benefits

Smoke emissions are found to reduce by as much as 25-50% based on filter smoke number (FSN) compared to ultra-low sulfur diesel fuel at equivalent power output as seen in Figure 2. NOx emissions were similarly reduced by 5-15% on a gram per kilowatt-hour rating as seen in Figure 3.  The emission reductions trend with increasing glycerol emulsion concentration.

Volatile Organic Emissions

Initial testing indicates that EHF has the same or better emissions level for volatile organics compared to the baseline fuel (ULSD).

Emissions data of Volatile Organics for EHF vs ULSD can be found here.

Fuel consumption

Use of EH fuel increases overall engine fuel consumption due to the fuel’s lower energy density as seen in Figure 4.  The increase in fuel consumption is commensurate with the concentration of glycerol in the fuel.  Despite the increased fuel consumption, engine thermal efficiency is improved and overall fuel costs to the end-user is minimized.

This data represented the initial “proof-of-concept” for EH fuel technology and was the foundation for fuel development activities sponsored by the Maine Technology Institute  and the U.S. Department of Transportation in coordination with the Maine Maritime Academy’s Marine Engine Testing and Emissions Laboratory (METEL).
Maine Technology Institute (MTI) logo                    Maine Maritime Academy (MMA) logo

 

 

Figure 2. Comparison of smoke emissions during fuel formulation testing.
Figure 2. Comparison of smoke emissions (FSN) from EH10 and EH20 fuels to ULSD. A 25-50% reduction in smoke rating is observed when using EHF fuel.
Figure 3. Comparison of NOx emissions from fuel formulation testing.
Figure 3. Comparison of NOx emissions from EH10 and EH20 fuels to ULSD. A 5-15% emissions reduction is observed.
Figure 4. Comparison of engine fuel consumption
Figure 4. Comparison of engine fuel consumption from EH10 and EH20 fuels to ULSD, increased fuel consumption is commensurate with glycerol concentration in the fuel.