A heat engine functions between the temperature of a low temp reservoir that is

Question

A heat engine functions between the temperature of a low temp reservoir that is at the environmental temperature T_e, and a hot reservoir, T_h. An inventor suggests that the efficiency of this heat engine can be increased by using a refrigerator to lower the temperature of the cold reservoir to T_l (the hot reservoir for the fridge is effectively the environment). This refrigerator will use some but obviously not all of the work produced by the engine. Assume the theoretical maximum efficiency for both the engine and the fridge, and assume the refrigerator consumes a fraction a of the work done by the engine where 0

Explanation / Answer

Net work = work from heat engine - work input to refrigerator
= (QH-QL)-a(QH-QL) = (1-a)QH-QL
Heat extracted from hot reservoir = QH

The ratio = {(1-a)QH-QL} / QH = (1-a)(1-QL/QH) = (1-a)(1-TL/TH)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.