13.What ratio could be treated as the mechanical efficiency of a diesel engine?
(A)Brake mean effective pressure / Indicator mean effective pressure
(B)Indicator mean effective pressure / Brake mean effective pressure
(C)Mean effective pressure / Cycle maximum pressure
(D)Cycle maximum pressure / Cycle compression pressure
27. Which type of marine propulsive engine can offer the advantages of low weight and space
requirements?
(A) Diesel engine
(B) Steam turbine engine
(C) Gas turbine engine
(D) Steam reciprocating engine
29. The products of combustion of marine fuels include sulfur dioxide, which, when combined with
water vapor, forms acids such as the sulfurous acid and sulfuric acid. These acids cause cold-end
corrosion if allowed to condense on boiler components of flue-gas ducting. Therefore, in order to
prevent the cold-end corrosion, which action is not to be taken?
(A) To ensure the temperature of exhaust gas is always above the condensation temperature level.
(B) To install more heat exchangers in the flue-gas ducting so that the temperature of exhaust gas
is further reduced.
(C) To prevent any chemical process that formulates the acid within the boiler components of fluegas ducting.
(D) To ensure there is no water-vapor condensate formed within the flue gas by controlling the flow
temperatures in the flue-gas ducting.