Chapter 6, Problem 6.45P

.11 The refrigerator (R) shown in Fig. F3.i! is a closed syster: thet oper- ates in cycles while in communication with the cold space (T;) and the building (T). The refrigeration load (QL) reaches the cold space by leak- ing from T to T across the thermal insulation system (I), which is a closed system operating steadily. If the work required by the refrigera- tor is WR, what is the net heat transferred by systems (R) and (I) to the building (Tg)? The net heat transferred by (R) and (I) to the building (QR) is removed by a heat pump (HP) that functions cyclically as a closed system. The heat pump requires the work WHp and rejects heat to the ambient of temperature T, which is warmer than the building. Together, the closed systems (R), (I), (B), and (HP) perform the function of removing the refrigeration load Q, by rejecting heat to the ambient T. T (В) Тв (HP) E WHP WR (R) (I) TL Te, Figure P3.11 38 ENTROPY GENERATION, OR EXERGY DESTRUCTION The total work requirement is WR + WHP, and…

Carnot engine absorbs 300 J of heat from a reservoir at the temperature 373.15 K and rejects heat to a reservoir at the temperature of the triple point of water ( T2 = 273.16 K )  Find the heat rejected, the work done by the engine and the thermal efficiency.

Q.4/A combination of a heat engine driving a heat pump, the heat energy supplied to the heat engine is 5040 J, and the temperature of the hot reservoir Tmin is 30 °C and the thermal efficiency of the heat engine is 41%. The work energy W12 of heat engine goes to the heat pump that the coefficient of performance COPHP=1.3. Find: a) The Tmaxmax of the heat engine, b) The Tminmin of the heat pump, c) The work done between two engines d) Qrej of the heat pump T max 150 °C Qadd = 5040 J. W 12 Н.Е. Н.Р. Qrej 30 °C T min