The efficiency of an ideal steam turbine is 60%, the heater temperature is 420 ° C.

The efficiency of an ideal steam turbine is 60%, the heater temperature is 420 ° C. What is the temperature of the refrigerator and how much of the heat from the heater goes to the refrigerator?

Let us turn to the formula for the efficiency (η) of a heat engine:

η = (T1 – T2) / T1 * 100%, where T1 is the heater temperature, T2 is the cooler temperature.

η * T1 / 100 = T1 – T2;

T2 = T1 – η * T1 / 100.

T2 = T1 * (1 – η / 100).

T2 = 420 * (1 – 30/100) = 420 * 7/10 = 294 ° C.