nansy έγραψε:Έχω την υπόνοια ότι αυτή η διαφορά έχει να κάνει κυρίως με τη φύση του ντηζελοκινητρα που λειτουργεί με συμπίεση-εκτόνωση και όχι με σπινθήρα οπότε δεν υπάρχει μεγάλη πιθανότητα έκρηξης (υποθέτω;).

In North America, gas stations offer two types of diesel fuel - according to ASTM D975[5] these are named No.1 and No.2 fuel. No.1 fuel (kerosene) has a natural CFPP of -40 °C but it is more expensive than No.2 fuel. Adding No.1 fuel will lower the CFPP of No.2 fuel - adding 10% will lower the CFPP temperature by about 5 degrees.[6]
For some diesel motors it is also possible to add even lighter fuels like gasoline to extend the CFPP characteristics. Some car makers were recommending adding up to 20% gasoline to permit operation in cold weather (at the price of higher consumption) and it had been common practice in Europe where No.1 fuel is not offered at gas stations. Since the 1990s car makers began selling only direct injection diesel engines - these will not withstand any gasoline portions in the fuel as the high pressure in the injection device will ignite the gasoline early on possibly destroying the injectors.

''if we dissolve kerosene in petrol running vehicle the petrol filter in the car will be damaged and also the pump''
''Mix gasoline in a diesel engine and you will have engine damage''

Cold Weather Characteristics
Due to the extreme weather conditions that we encounter in Western Canada, diesel fuels are blended seasonally and adjusted to provide ultimate power and performance and minimize cold weather problems which are inherent to diesel fuel. As diesel fuel is cooled it will reach the "cloud point". This is the temperature at which paraffin wax falls out of solution and starts to form wax crystals in the fuel. As the fuel is cooled further, it will eventually reach its' "pour point". This is the temperature at which fuel will no longer flow or the point at which fuel gels or turns solid.
Another key property of diesel fuel is the "Cold Filter Plug Point" (CFPP). This is the temperature where fuel can no longer flow freely through a fuel filter, approximately halfway between the cloud point and the pour point.
How critical these factors become in winter operation depends on the design of the fuel system with regard to fuel line bore, freedom from bends, size and location of filters and degree of warm fuel recirculation as well as the amount and kind of wax crystals.

Additives are being used successfully to improve fuel fluidity at low temperatures. These additives, known as wax crystal modifiers, can result in satisfactory fuel flow on average of 9°C to -27°C.

Add K-1 (kerosene) to the home heating fuel tank. This will mix with fuel oil and lower the "freeze" point, as the freeze point for K-1 is about -20F. K-1 will burn successfully in just about any home heating fuel oil furnace, but the downside is the expense (historically, K-1 can cost a 20% to 30% higher than fuel oil).

Η εξέταση του μαθήματος περιλαμβάνει δύο στάδια:

- Α΄Μέρος: Ερωτήσεις πολλαπλής επιλογής, αντιστοιχίσεις, κλπ (με κλειστά βιβλία - σημειώσεις)

- Β΄Μέρος: Υπολογιστικές ασκήσεις (με ανοιχτά βιβλία - σημειώσεις)

Κατά τη διάρκεια της εξέτασης του μαθήματος απαγορεύεται αυστηρά η χρήση κινητών τηλεφώνων, τόσο στο Α΄ μέρος (ερωτήσεις πολλαπλής επιλογής) όσο και στο Β΄ μέρος (ασκήσεις).

Για την επίλυση των ασκήσεων απαιτείται αριθμομηχανή (κομπιουτεράκι) οπότε φροντίστε να έχετε μαζί σας στην εξέταση γιατί δε θα επιτραπεί η χρήση του κινητού τηλεφώνου ούτε ως αριθμομηχανή.

As of 2010, the density of petroleum diesel is about 0.832 kg/l (6.943 lb/US gal), about 12% more than ethanol-free petrol (gasoline)