Hydrogen is considered to be an ideal energy carrier for low carbon vehicles in the near future. It can be produced from water by using a variety of green energy sources, such as solar, wind and nuclear, and it can be converted into useful energy efficiently and without detrimental environmental effects.

 

It can also be produced from fossil fuels. So called ‘Reforming’ organic substances – Oil and natural gas contain hydrocarbons — molecules consisting of hydrogen and carbon. Using a device called a fuel processor or a reformer; you can split the hydrogen off the carbon in a hydrocarbon relatively easily and then use the hydrogen. Reformers discard the leftover carbon to the atmosphere as carbon dioxide. However, it may be a good temporary step to take during the transition to the hydrogen economy. When you hear about “fuel-cell-powered vehicles” being developed by the car companies right now, almost all of them plan to get the hydrogen for the fuel cells from gasoline using a reformer. The reason is because gasoline is an easily available source of hydrogen. Until there are “hydrogen stations” on every corner like we have fuel service stations now or so called ‘off the grid’ small domestic systems, this is the easiest way to obtain hydrogen to power a vehicle’s fuel cell. 

The only by-product is water or water vapour in fuel cell vehicles, but small amounts of NOx are produced in combustion systems.  NO_x is a generic term for the mono-nitrogen oxides NO and NO₂ (nitric oxide and nitrogen dioxide).  Hydrogen can be used in any application in which fossil fuels are being used today, especially cars, buses and trucks.  This paper considers how hydrogen as a fuel can be combined with two other technologies; 1) on-line vehicle monitoring 2) computer maps or horizon data; to give significant reduction in carbon emissions from combustion engines, especially on trucks. 

Hydrogen burns more rapidly than hydrocarbon fuels because it is smaller and enters combustion reactions at higher velocity, has lower activation energy, and incurs more molecular collisions than heavier molecules. These characteristics make it possible to use mixtures of hydrogen with conventional hydrocarbon fuels such as gasoline, diesel and propane to reduce emissions of unburned hydrocarbons. Transition from fossil fuels to renewable hydrogen by use of mixtures of hydrogen in small quantities with conventional fuels offers significant reductions in exhaust emissions. Using hydrogen as a combustion stimulant makes it possible for other fuels to meet future requirements for lower exhaust emissions in California and an increasing number of additional States an in Europe congestion and low emission zones and .

Mixing hydrogen with hydrocarbon fuels provides combustion stimulation by increasing the rate of molecular-cracking processes in which large hydrocarbons are broken into smaller fragments. Expediting production of smaller molecular fragments is beneficial in increasing the surface-to-volume ratio and consequent exposure to oxygen for completion of the combustion process. Relatively small amount of hydrogen can dramatically increase horsepower and reduce emissions of atmospheric pollutants.”

 

Hydrogen usage these day splits into 3 categories

PEM Fuel Cells

Proton exchange membrane fuel cells, also known as polymer electrolyte membrane (PEM) fuel cells (PEMFC), are a type of fuel cell being developed for transport applications as well as for stationary and portable fuel cell applications. Their distinguishing features include lower temperature/pressure ranges (50 to 100 °C) and a special polymer electrolyte membrane.

 

 

PEM Cells are by definition classified within the group known as Ranger Extenders. Essentially the electric vehicle (EV) has only a short range and the purpose of the Hydrogen fuel PEM Cell is to extend the range between battery re-charges. At this juncture it’s also worth mentioning that there are other types of Ranger Extenders. These are modern efficient petrol engines.

 

 

Dual-fuel conversion brings hydrogen fuel to existing ICE technology. 
Ref:  www.revolve.co.uk/

This project involved modifying the engine of a vehicle to operate using compressed hydrogen gas fuel – but it can also operate from its existing petrol fuelled system without any adverse effects.

The hydrogen fuel is currently designed to be stored in three tanks, under slung below the vehicle floor. This installation provides a usable storage capacity for 4.5 kilograms of hydrogen at 350bar (5000psi) and gives an estimated range between 95 miles for the urban cycle and 135 miles for open highway running. Additional capacity can be added if required. Importantly, the location and configuration of the tanks allows the retention of the volume and load height of the base vehicle – with no intrusion or interference within the load space.

Direct Injection Ice technology by Revolve  (http://www.revolve.co.uk/)

 

HHO or Oxyhydrogen 
Ref: www.thecell.com

Oxyhydrogen is sometimes referred as Brown’s Gas.

  

(Click images to enlarge)

 

HHO as a supplementary fuel

A large number of enthusiasts have added mixtures of hydrogen and oxygen produced from electrolysis, so-called HHO, to the air inlet of combustion engines, especially diesel trucks. There are claims that this addition gives lower emissions from the exhaust, improved power from the engine, and improved fuel economy. Various theories of these effects have been put forward but evidence has been difficult to confirm especially because the engine manufacturers do not generally support such modifications.  However, it is clear that there are various losses in the drive train and there are improvements that can be made, including those that stem from hydrogen addition.

A typical truck modified for hydrogen addition is shown in picture 3 above. An electrolyser system powered by the truck battery is used to generate hydrogen and oxygen (HHO) which are fed into the air inlet manifold of the engine.

A typical HHO generator system consists of a water based electrolyte reservoir, one or more electrolyser cells connected to or mounted inside the reservoir and a gas pipe from the top of the reservoir to the engine air intake. The electrodes are connected to the truck battery and alternator through a relay and current limiting electronics. However purists will argue that energy fed from the vehicles alternator is inefficient and nullifies any gains. Power taken from regenerative braking systems or KERS will add green energy to drive the electrolysis system. When the engine is running, the relay switches power to the electrodes to begin the production of hydrogen and oxygen. The negative pressure created by the engine draws in these gases which then aid the combustion of the diesel fuel in ways which have yet to be properly defined.

Results of testing on several trucks have shown several effects:-

1. Reduction in exhaust emissions
2. Less requirement for Add Blue
3. Improved engine power and torque when the HHO is injected
4. Increased fuel economy under certain engine operating conditions, with 20% being a typical enhancement.
5. Cleaner oil and less engine maintenance

 

A detailed programme of research is now under way to confirm and explain these initial observations.

On the negative side, there are some disincentives:-

• Some energy is lost in the electrolyser system because of ohmic heating etc
• Engine embrittlement if used in excessive ratios
• The engine ECU system needs to be modified using a piggy-back ECU or by using the new generation of programmable ECU
• The electrolyte chamber needs regular topping up and is alkali
• Health and Safety processes to handle the corrosive electrolyte will be needed.
• The engine warranty may be invalidated
• New vehicle insurance may be needed
• The alternator if used as source of power may not be able to supply sufficient amps and therefore limit HHO output

 

Conclusions

Vehicles, at present, use enormous amounts of fossil fuel and produce excessive emissions of carbon and other pollutants. Three potential synergistic improvements are suggested:-

1. The monitoring of truck data which allows driver training and improvement to give up to 10% less fuel usage
2. The implementation of the electronic map system ADAS which allows the computer to optimise truck performance by 20%
3. Addition of hydrogen as a supplemental or main fuel to the engine to increase combustion and drive train efficiency by an estimated 20%

The conclusion is that it should be possible to reduce vehicle fuel consumption through full adoption of these measures, while greatly improving emissions in advance of Euro6 regulations.

 

Telematics

Telematics has a roll to play when it comes to fuel savings and reductions in carbon emissions from fleets of trucks. The first is on-line monitoring of vehicle and driver performance through sensors attached to the CANbus which controls all aspects of the sub-systems’ operations including engine, acceleration, braking, fuel consumption etc. The second is ADAS, the Advanced Driver Assistance System developed by NAVTEQ. This system is a Map and Positioning Engine (MPE) which uses a computer map of the vehicle’ surroundings (horizon data) plus a global positioning system (GPS) to advise the driver on approaching hills, traffic lights, curves and other road features which influence fuel consumption. NAVTEQ along with other companies have long recognised that digital maps can play a role as a “sensor” that, when combined with other sensor inputs, can enable or support ADAS in a variety of value-adding ways.  To illustrate, road slope information from the NAVTEQ Map can inform a vehicle about upcoming hills and support adjustments to the engine throttle accordingly. This ‘Predictive Cruise Control’ application is an example of how maps can enable fuel savings within ADAS by allowing the engine to run optimally and avoid driver inefficiency. If hydrogen was also available to reduce carbon output from the truck, then three technologies could be combined to produce a substantial saving compared to current fleet operations. First we consider the CANbus monitoring system, then show how this can be combined with ADAS, and finally add in hydrogen to give further benefit.

 

Controller Area Network (CANbus) Diagnostics

Background

Since 2003, vehicles have been built with an onboard communications protocol called CAN (Controller Area Network). CANbus is essentially an engineering standard for how computers and modules talk to one another via the serial data bus in a vehicle’s wiring system. It’s a high speed standard designed for powertrain control modules, antilock brakes and stability control systems.

The CANbus protocol was created back in 1984 by Robert Bosch Corp. in anticipation of future advances in onboard electronics. The first production application was in 1992 on several Mercedes-Benz models. By 2008, all new vehicles sold in the U.S were required to have a CAN-compliant onboard diagnostic system.

Like many current vehicles, information in a CAN-equipped vehicle is shared over a serial data bus. The bus is the circuit that carries all the electronic chatter between modules (nodes). The bus may have one wire or two. If it has two, the wires are usually twisted to cancel out electromagnetic interference. The speed at which the bus carries information will vary depending on the “class” rating of the bus as well as the protocol to which it conforms.

The CAN standard requires a “base frame” format for the data. What this means is that for each distinct message sent or received by a module on the network, there is a beginning bit (called the “start of frame” or “start of message” bit), followed by an “identifier” code (an 11 bit code that tells what kind of data the message contains), followed by a priority code (“remote transmission request”) that says how important the data is, followed by 0 to 8 bytes (one byte equals 8 bits) of actual data, followed by some more bits that verify the information (cyclic redundancy check), followed by some end of message bits and an “end-of-frame” bit.

LIN – developed by the LIN Consortium and a de-facto standard – was specially developed to achieve cost-effective communication for intelligent sensors and actuators in motor vehicles, and it is used wherever the bandwidth and versatility of CAN are not needed. The LIN specification includes the LIN protocol, a uniform format for the description of an entire LIN network and the interface between a LIN network and the application.

A major step forward in fuel conservation and driver training is the logging of key performance indicators (KPI’s). These are obtained from either the CAN or the LIN. Other KPI’s can be derived from the GPS and in-built accelerometers. This can include harsh braking, fast acceleration, idling time, and constant speed events but also geo-coded excess fuel consumption and harmful emissions. By monitoring a large number of performance indicators, the fuel efficiency of a vehicle can be related to each individual driver. It can be shown that the best drivers use about 20% less fuel than the poor drivers.  These KPI’s can be transmitted via GSM to form reports as illustrated below.

 

 

 

Remote Vehicle Diagnostics (RVD)

The history of RVD

There have been five distinct steps in the evolution of RVD:

1. In the beginning, each vehicle manufacturer had unique proprietary diagnostic systems, in many cases even using different systems for different models. This made access by independent systems very difficult.
2. Over time, these unique proprietary diagnostic systems were consolidated into a number of different recognised “standards”, however, each manufacturer still tended to use their own particular flavour. Access by independent systems was still difficult, but at least there was a common standard for diagnostic connectors!
3. From 2001 onwards, the situation was rationalised by the mandatory OBD requirements, which imposed a common standard on all manufacturers for emissions related applications. Access to OBD data by a “common” independent system became a practicable proposition. However, there are considerable differences between manufacturers concerning the scope of the information available via OBD: Manufacturers still retained the use of their diverse proprietary systems for internal “native” vehicle applications (e.g. fault reporting).
4. With increasing consolidation and globalisation in the motor industry, the diversity of proprietary diagnostic systems in use is reducing, as manufacturers are increasingly adopting a unified “corporate approach” across all model platforms. Access to all internal vehicle information by independent systems is now becoming a practicable proposition.
5. We are witnessing the development of garage tools that can interpret data from the OBD port and through layers or gateways into cluster data from the main ECU and OEM level data for reprogramming and adjustment and fine tuning. These are often diesels specific and common rail based. In parallel we are seeing drivers buying simple but specific OBD tools to identify faults and cancel service lights etc. With GSM and Wi-Fi it is now possible to set exception alerts and full ECU integration routines whilst the car is driven.

 

Advanced driver assistance system (ADAS)

Numerous possibilities exist for ADAS applications based on electronic map data, including:

• Electronic Stability Control
• Lane Departure Warning
• Lane Change and Lane Keeping Assistant
• Curve Warning System
• Drowsy Driver Detection
• Forward and Side Collision Warning
• Intelligent Speed Advisory
• Black Spot Warning
• Blind Spot Detection
• Overtake Assistant
• Powertrain Control / Fuel Economy
• Adaptive Front light Systems
• Stop Light and Stop Sign Warning
• Geo-coded Dual Fuel Management
• LV Air Conditioning Management

 

Image below shows a typical map segment with road sign information indicating an approaching bend. The computer informs the truck driver to slow down well ahead and this action conserves fuel.  In addition, the computer can send a message to the fleet supervisor monitoring the driver behaviour so that improvements in driver fuel economy can be implemented.

 

 

The NAVTEQ Electronic Horizon™, which is based on NAVTEQ’s patented Electronic Horizon algorithms, can thus be used to tell the vehicles of impending dangers, corners, cambers and black spots and road signs. The consequence is that a truck computer can calculate in advance the need for fuel input, or mode and even turn off the air conditioning awaiting a pending junction to save energy.

The image below shows several possibilities for improving fuel economy by the ADAS technology.  A large improvement, from 8-15%, stems from better navigation and routing. Eco-routing and eco-driving give smaller gains, from 5-15%. Predictive cruise control also gives significant benefit, from 2-5%. But the greatest possibility is to improve the efficiency of the drive-train.  One of the simplest methods proposed for generating efficient truck engine performance is addition of hydrogen/oxygen mixtures to the air inlet.

Sensors commonly used in ADAS applications help provide relevant contextual information to a vehicle, including the road conditions in front of the vehicle. When compared to the depth of road information available in a map, however, the range of these sensor inputs is confined to a relatively close proximity around the vehicle’s path. The Electronic Horizon™ can use map attributes as a type of sensor, and dramatically extend sensor range.

 

 

The concept of an Electronic Horizon provides a vehicle with road information that allows it to “see” over the hill and around the bend – in a message stream that is designed for consumption by Vehicle Control Systems. Benefits of the Electronic Horizon to ADAS include:

• Determines the most probable path and all possible paths for the vehicle
• Provisioning of those map database attributes of most interest to ADAS along the vehicle’s path.
• Delivery of optimally timed and formatted messages to enhance vehicle functionality and driver experience 
• Dramatically reduce the processing load of map information

 

 

Finally it’s clear that there has been a quiet revolution happening with improved technology combining to have an impact.  Possibly not a Paradigm shift in onboard systems yet but sufficient now on offer to help reduce fuel consumption but also assist with operational efficiencies. They include:

• AVL/MRM Tracking
• Driver behaviour
• Remote diagnostics
• Crash forensics
• KPI event reporting
• Routing / Scheduling / Optimisation (of all resources)/
• Field Service management
• Transportation and Logistics
• Job dispatching and Job Related Tracking
• Route Optimisation
• Or any application where location matters

Not forgetting that there is still a human behind the wheel and that the human-machine interface (HMI) is still a key visual element of the implementation of technology. The HMI provides appropriate feedback to the driver – for example, of the prevailing speed limit at the vehicle’s current location – as well as input configuration information.

 

Ref:

Professor Kevin Kendall University of Birmingham UK

Roy E. McAlister, P.E. is the president of the American Hydrogen Association