A power plant operates at a 25.0% efficiency during the summer when the seawater used for cooling is at 20.0°C. The plant uses 360°C steam to drive turbines. If the plant's efficiency changes in the same proportion as the ideal efficiency, what would be the plant's efficiency in the winter, when the seawater is at 10.1°C? ______ %

A heat engine operating at steady state delivers a power output of 17 hp. The engine receives energy by heat transfer in the amount of Qh = 33 kJ during each cycle of operation from a high temperature thermal reservoir at Th = 870 K. The system is executing 50 cycles per minute.   Determine the amount of work that is delivered during each cycle in kilojoules.    Determine the actual efficiency at which the system is operating.    Assuming this engine is as efficient as possible, what would the temperature, in degrees celsius, of the colder reservoir be?

A solar collector system delivers heat to a power plant. It is well known that the thermal collection efficiency hsc of a solar collector diminishes with increasing solar collection output temperature TH , or hsc = A 2 BTH where A and B are known constants. The thermal efficiency of the power plant hth is a fixed fraction of the Carnot thermal efficiency, such that hth = F(1 2 TL/TH) where F is a known constant assumed here independent of temperatures and TL is the condenser temperature, also constant for this problem. Here, the solar collection temperature TH is also taken to be the source temperature for the power plant. (a) At what temperature TH should the solar collector be operated to obtain the maximum overall system efficiency? (b) Develop an expression for the maximum overall system efficiency.

A‭ ‬heat‭ ‬pump‭ ‬has‭ ‬a‭ ‬coefficient‭ ‬of‭ ‬performance‭ ‬3.0‭.‭ ‬How‭ ‬much‭ ‬heat‭ ‬is‭ ‬exhausted‭ ‬to‭ ‬the‭ ‬hot reservoir‭ ‬when‭ ‬300‭ ‬kJ‭ ‬of‭ ‬heat‭ ‬are‭ ‬removed‭ ‬from‭ ‬the‭ ‬cold‭ ‬reservoir?