From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
List of the advantages and disadvantages of evaporative cooling systems.
| Identifier | ExFiles\Box 178\1\ img042 | |
| Date | 15th February 1926 guessed | |
| - 26 - (iii) Advantages and disadvantages. The advantages of evaporative cooling are:- (a) Increase of 6½% in efficiency. (b) Automatic temperature control. The temperature of the system is always 100°C after the initial warming up. Shutters and thermostats are therefore superfluous. (c) Quicker warming up. The quantity of water in the system is considerably less than that in a normal system. (d) Reduction in crankcase dilution. The higher average temperature of the cylinder walls tends to reduce crankcase dilution. (e) Better distribution. Same reasons as (d). (f) Better mechanical efficiency and hence petrol consumption as (d). (g) Conservation of water when the car finally does over-heat. Normally, when the system boils, a large quantity of water is ejected with the steam. In an evaporative system steam only escapes. It will take a considerable time for as much water to be lost as steam, as is at present flung out the first time ebullition takes place. (h) Convenient method provided of heating the bodies of cars (steam heaters) and if necessary warming the crankcase and so reducing dilution. Some of the more obvious disadvantages are:- (a) Increased detonation due to increased cylinder wall temperature. (b) Difficulty of providing a quiet gear pump. (c) No means of telling when the water in the system is on the point of exhaustion. (d) Difficulty of refilling to the right level. (e) Increased temperature of driving seats. . contd. | ||