試題詳解

22. The smaller the temperature difference between the heat source and the heat receiver, the lower will be the condensing temperature for a given flow of cooling water and the lower will be the amount of heat energy rejected from the cycle. If the condensing temperature could be reduced to that point at which it approaches the cooling water inlet temperature, a maximum availability of heat energy for producing useful work would result. Therefore,
(A) the increase of condensing temperature improves the cycle efficiency.
(B) the increase of heat rejected to the coolant increases the work output of the cycle.
(C) the decrease of condensing temperature always requires the increased coolant entry temperature.
(D) the reduction of condensing temperature increases the thermal efficiency of cycle.