Yes really intreresting!
I did some more reseach and found that some diesel cars use a simple electric coolant fluid warmer (to increase the cabinheaters performance) with heating elements that look like normal glowplugs.
This
http://www.aea.org.br/aea2009/downloads ... Araujo.pdf is also a very serious document. Should be translatet completely but did some quick translations wit google translate:
Citat:
1.2.2 Technical solutions possible
The solutions to this problem can be grouped into five categories techniques.
In Category 1, it is proposed to use a more volatile fuel, in critical conditions of operation, to enable the start of the combustion process. The current solution, until then present in all bi-fuel cars national, falls into this category. The advantages are its simplicity, low cost and availability of gasoline stations in Brazil. The disadvantages are the dependence of the User to the extent that it should remember the gas supply system, risks in situations of replenishment of the "six-pack and low reliability of the system components.
Category 2 proposes to keep warm parts of the engine, so that at the beginning of the operation, the liner is facilitated by the contact of fuel with these hot parts. This solution is adopted in the Scandinavian countries, Canada and USA. One of its forms of implementation are known "block heaters". The disadvantages of this solution are the high energy demand, which requires the connection of the vehicle to an external power source, the high cost due to the need for changes in the concept of the engine and also the dependence of the User to remember to connect your vehicle to external sources of energy.
In Category 3, heats the air, so that, in contact with the spray of cold fuel, to promote the vaporization of the same. Depending on the relationship with air-fuel should be a warm air mass proportionally higher, moreover the
process air heating is less efficient and demand large surfaces. The consequences are a high energy and°Ccupy space in the engine compartment, which complicates the lay-out.
A Category 4 is the vaporization of the fuel after injection of the same. This can be achieved by directing the spray on a heated surface, thus promoting the formation of fuel vapor, which is then inhaled along with air from the engine. This solution presents difficulties in ensuring uniform distribution of admixture between the cylinders to control the level of vaporization of fuel in different operating conditions, and affect the design of the intake manifold. There is also the risk of condensation of fuel vapor in the ducts of the intake manifold, increasing the chances of "back-fire."
A Category 5 is the heating of the fuel immediately before the injection of the same. With this approach, we can optimize energy use and improve the control of heating fuel, in different conditions of engine operation. To ensure a safe departure, the need for a minimum amount of fuel preheated to a minimum temperature requires a pre-heating, meaning the need to wait for the User until the process is complete.
1.2.3 The Flex Start
Considering that the vehicle is a closed system with limited availability of energy, we have an automotive market returned to low cost and ability to invest in upgrading the engines limited the implementation of the Flex technology Start we sought a solution within the Category 5.
Additionally, this category of solutions, enables the creation of conditions for°Ccurrence of the phenomenon known as "flash-boiling." This phenomenon°Ccurs when creating a supersaturated state in the fuel when the fuel heated undergoes a sudden change of pressure, nearly constant temperatures, after leaving a fuel injector. This, in turn, triggers this fuel, a breakdown of layers of fluid resulting in a spray droplet diameter very small, of a very highly dispersed and vaporized. The efficiency of this phenomenon depends, in addition to fuel use, fluid pressure, temperature and even pressure inside the intake manifold. The effects can be observed in Figures 9 and 10 showing a spray of ethanol injected at 20°C and 100°C, respectively.
The application of this phenomenon in gasoline had already been demonstrated by SAMENFINK et.al. [6]
Figure 11
The gallery of fuel must withstand the high temperatures reached in the process of heating, fuel pressure and continuous operation with ethanol. Its design allows the optimization of energy consumption in the heating process. It is composed of stainless steel tube, four heating elements and four fuel injectors.
The control unit individually controlled heating through high-performance FETs, each heating element, ensuring the supply of the same amount of energy and uniformity of the temperature of fuel in each injector. It performs all the functions of internal diagnostics of the heating elements and electrical heating circuit.
1.2.4 Results
The results of cold start, the improvement of handling and emissions reduction are presented below. In Figure 12, we have a game of a vehicle stocked with E100 at a temperature of -5.3°C. In this case, preheating lasted 8.7 seconds, the time control unit for heating fuel Gallery New features of the software models of temperature-and energy-Additional activities calibration-management game (optional) Control Unit of departure motor was 2.1 s. In curves can be observed, by the spindle motor, that it responds to acceleration without hesitation, showing the improvement in drivability.
In Figures 13 and 14 there is an extract of the values of HC Total Phase 1 of the cycle FTP75. The curves show the emission instant and accumulated in the same vehicle, where the Flex Start system was now on, sometimes off. Phase 1 was chosen poir represent the heating phase of the combustion engine, cycle emissions. The curves clearly show the benefits of activation of the Flex Start . The vehicle was filled with E100.
Figures 15 and 16, see the summaries of the emission testing of vehicles with 2 different engines a 1.6 L 16V engine and an engine 2.0 L 8V, respectively. The results show significant reductions in the levels of THC and NMHC. The vehicles were fueled by E100.
(my underlining)