Birmingham, UK: Dearman is gearing up for Cenex’s Low Carbon Champions Awards, where it has been shortlisted for the 2014 Award for Low Carbon Innovation by an SME.
Dearman is developing an innovative liquid air engine to deliver auxiliary zero-emission power and cooling across a range of transport applications, from refrigerated trucks to buses and heavy-duty vehicles.
The engine developer, exhibiting at LCV2014 over the next two days, is also pleased to announce that it has been selected as one of only 12 companies to exhibit in the Start-Up Hub at the Conservative Party Conference, which is being held between the 28 September and 1 October in Birmingham.
Development of the technology itself is coming on rapidly. Ahead of the engine going to MIRA in the next few weeks for on-vehicle demonstration, it has now met its power, specific energy and durability targets for the mule demonstration. Despite being a first-of-a-kind, the mule vehicle will deliver a level of performance sufficient to deliver substantial operating cost savings. The Dearman team has also successfully designed and implemented an engine control unit (ECU). This means the engine can be started and will run and regulate itself without the need for intervention or manual adjustment.
Dearman has also begun working with Hubbard Products Ltd, part of the worldwide Zanotti group, and in 2015 five prototypes of the Dearman-powered Hubbard TRU will be delivered to a UK end user for commercial field trials. In addition the MTC (Manufacturing Technology Centre) has committed to production of an initial batch of the cryogen-fuelled engine for market seeding purposes – a significant step towards commercial production and availability in 2016.
Toby Peters, senior group managing director, Dearman, said: “Our shortlist for this very relevant industry award and our inclusion in the Conservative Party Conference Start-Up Hub are welcome recognition of the part liquid air has to play in establishing a cold economy. Liquid air is not a silver bullet, but it does offer a compelling solution for reducing the disproportionate impact of diesel in a variety of transport applications in the UK and globally. With our first application going into on-vehicle demonstration this year at MIRA, we look forward to seeing it operating in commercial field trials in 2015.
“We wish our fellow nominees for the Low-Carbon Innovation Award the very best of luck and look forward to meeting as many people as possible over the next two days.”
What is liquid air?
Air turns to liquid when refrigerated to -196C, and can be conveniently stored in insulated but unpressurised vessels. Exposure to heat (including ambient) causes rapid re-gasification and a 710-fold expansion in volume. This expansion creates pressure, which can be used to drive an engine piston, and also gives off cold, which can be used to provide refrigeration or air conditioning. Engines running on liquid air (or liquid nitrogen, which is already widely available) are zero emission at the point of use, and can be zero carbon depending on the source of electricity used to make it.
What is the Dearman engine?
Although liquid air cars were first built more than a century ago, the novelty of Peter Dearman’s invention lies in the use of a heat exchange fluid (water and glycol) that promotes extremely rapid rates of heat transfer inside the engine rather than in an external heat exchanger. The Dearman engine is constructed almost entirely from the components of a conventional piston engine, requires little maintenance and has a light environmental impact. The Dearman engine could be used in a number of configurations: on its own, as the ‘prime mover’ or principal engine of a zero emissions vehicle (ZEV); combined with an internal combustion engine (ICE) to form a ‘heat hybrid’; or as a power-and-refrigeration unit.
Why is Dearman engine refrigeration so efficient?
Vehicle manufacturers and industrial gas producers have begun to offer vehicle refrigeration for lorries and trailers based on the evaporation of liquid nitrogen, but these systems do not extract any power from the evaporation process. The Dearman engine is far more efficient because it extracts both cold and shaft power from the same unit of liquid air or nitrogen. First the cryogen is vaporised in a heat exchanger in the refrigeration compartment, so cooling it down; then the high pressure gas is used to drive the Dearman engine, whose shaft power can be used to drive a conventional refrigeration compressor or for auxiliary power. The Dearman system therefore delivers two bangs for one buck.
Why does vehicle refrigeration matter?
Transport refrigeration today is overwhelmingly powered by diesel. The Transport Refrigeration Unit is a compressor driven either from the vehicle’s main engine, or on larger trucks and trailers by a secondary unit known as a ‘donkey’ engine. Either way, refrigeration can consume as much as 20% of a refrigerated vehicle’s fuel, causing CO2 emissions of almost 50 tonnes per vehicle per year from refrigeration alone.
Donkey engines are currently unregulated, which means they typically emit far higher levels of nitrogen NOx and PM than a modern lorry propulsion engine (Euro 6). An analysis of regulatory standards suggests that a trailer refrigerator engine emits six times as much NOx and 29 times as much PM than a Euro 6 lorry engine. These emissions cause respiratory illnesses and 29,000 premature deaths in the UK each year.
Proposals to strengthen the regulations governing Non Road Mobile Machinery (NRMM Stage 5) are expected to be adopted by the European Commission (EC) this year, and may come into force by 2019-2021, but will make essentially no difference to the emissions of NOx and PM from transport refrigeration units.